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15 October 2007, Volume 28 Issue 10 Previous Issue    Next Issue
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High-temperature deformation behavior of Nb/V/Ti-bearing and Ti-bearing HSLA rolled steels Yi, Hai-Long (1); Du, Lin-Xiu (1); Wang, Guo-Dong (1); Liu, Xiang-Hua (1) 2007, 28 (10):  1369-1373.  DOI: - Abstract ( 243 )   HTML   PDF (1514KB) ( 636 )   The high-temperature deformation behavior of both Nb/V/Ti-bearing and Ti-bearing HSLA rolled steels was investigated, with the single-pass reduction conducted on the Gleeble 2000 thermomechanical simulator and multi-pass quenching on a D450 experimental rolling stand. The results showed that the softening is restricted by the carbonitrides of microalloying elements Nb, V and Ti in the HSLA steel and, after 6-pass reduction, the austenite grain size is down to 8 μm through grain refining, i.e., the controlled rolling process is not implemented in the recrystallization zone. However, the recrystallization effect by single Ti element is weaker in the HSLA-Ti steel where the austenite grain size is down to about 11 μm after 6-pass reduction, i.e., the controlled rolling process is in the recrystallization zone. References | Related Articles | Metrics

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On the static softening behavior of sheet billet during continuous casting-rolling process Zhou, Xiao-Guang (1); Liu, Zhen-Yu (1); Wu, Di (1); Wang, Guo-Dong (1) 2007, 28 (10):  1374-1377.  DOI: - Abstract ( 282 )   HTML   PDF (981KB) ( 600 )   The static softening behavior of the austenite in the sheet billet during continuous casting-rolling was investigated on the Gleeble-2000 thermomechanical simulator in Bensteel. The results revealed some facts as follows by comparison. The Nb-bearing steel inhibits the static recrystallization of austenite more obviously than the steel contains no Nb, with relevant curves showing flat portion. And in the steel, the Nb precipitate inhibits the static recrystallization greater than the solid Nb solution. Moreover, the activation of static recrystallization at intervals between two pass reductions for low-carbon steel during continuous casting-rolling is more obviously than that during conventional rolling, i.e., the static softening behavior is less possible. References | Related Articles | Metrics

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Roll wear model for 1700 hot strip mill Guo, Zhong-Feng (1); Xu, Jian-Zhong (1); Liu, Xiang-Hua (1) 2007, 28 (10):  1378-1380.  DOI: - Abstract ( 334 )   HTML   PDF (421KB) ( 1333 )   The roll wear model for 1700 hot strip mill(HSM) was studied and the influencing factors on roll wear were analyzed. Programming the off-line simulation process and computing the working roll wear in a certain rolling period as scheduled. The results showed that the roll wear presents a box-like shape and is affected mainly by strip width. The strip length is also one of the important factors affecting roll wear. The wear on the middle of the top roll F7 is about 302 μm after a rolling period. The roll wear curve obtained by programmed computation is compared with that plotted according to the actual measurement on a high-precision grinder, and both are well in conformity. The model is therefore proved highly accurate. References | Related Articles | Metrics

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Process control system for tandem cold mill in Tangsteel Zhang, Hao (1); Jiao, Zhi-Jie (1); Liu, Cui-Hong (2); Zhang, Dian-Hua (1) 2007, 28 (10):  1381-1384.  DOI: - Abstract ( 376 )   HTML   PDF (956KB) ( 712 )   With the purpose of upgrading automation control level, a process control system has been developed for the new five-stand tandem cold mill in Tangsteel, using the PC server and Windows 2000 operation system as the system platform. Database, human-machine interface (HMI) and core control system are all included in the design of the process control system, where the Oracle database is used to store all the data needed to save or exchange and the HMI is developed with VB language to implement the man-machine interaction. Based on the VAIronment software development environment, the core control system is developed with C++ language to implement such auxiliary functions as system management, data communication, running message management, tag message management and process tracking, with the core set values computed through computation module. The application result in site shows that the system can provide accurate setting values. References | Related Articles | Metrics

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Preparation of stainless steel clad guardrails for superhighway by brazing/hot-rolling process Zu, Guo-Yin (1); He, Jia-Li (1); Yu, Jiu-Ming (1); Wen, Jing-Lin (1) 2007, 28 (10):  1385-1388.  DOI: - Abstract ( 293 )   HTML   PDF (457KB) ( 636 )   Aiming at the main problems of the hot-dip galvanized guardrails for superhighway, the carbon steel plate with stainless steel cladding was recommended as a new guardrail material. The preparation of stainless steel cladding guardrail by brazing/hot-rolling process was proposed, the stainless steel sheet and carbon steel plate are bonded together first by brazing in furnace, then the bonding strength is improved by hot-rolling. The results showed that an effective braze welding can be obtained by using a silver-base soldering flux developed, in which the Ag content is 15wt.%. The following parameters are regarded as ideal: the brazing temperature is 720-730°C, at which the time needed is 3-4 min. The soldering flux layer shows good plasticity in hot-rolling process. When the percent reduction is less than 30%, no cracks and lamination are found in the soldering flux layer after hot-rolling, with the shear strength of stainless steel clad guardrails up to 338.4 MPa. References | Related Articles | Metrics

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Preparation of ultra-fine grain alloy A2017 by combining semisolid casting with accumulative roll-bonding process Guan, Ren-Guo (1); Kang, Li-Wen (1); Wang, Chao (1); Xing, Zhen-Huan (1) 2007, 28 (10):  1389-1392.  DOI: - Abstract ( 284 )   HTML   PDF (1040KB) ( 558 )   The ultra-fine grain alloy A2017 was prepared the way the molten alloy A2017 was poured onto tilting corrugated board and then became two semisolid cast slabs for accumulative roll-bonding process to make them composite under the condition the equivalent strain was 4.0, of which the mean grain size was 0.5 p. During the accumulative roll-bonding process the Vichers hardness of workpieces increases then decreases and increases slowly once again along with the increasing number of passes. A2017's microstructure was transformed into stable state from metastable at a certain annealing temperature, i.e., the grain growth is slow at 200°C for 1 hour, while the grains grow obviously if the annealing temperature is higher than 200°C. The microstructure reveals static recovery/recrystallization process with increasing annealing temperature, and the effect of work hardening disappears gradually with Vichers hardness decreased. References | Related Articles | Metrics

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On high-temperature mechanical properties of 12Cr1MoV steel during continuous casting Kang, Li (1); Wang, Yang (2); Wang, En-Gang (1); He, Ji-Cheng (1) 2007, 28 (10):  1393-1396.  DOI: - Abstract ( 375 )   HTML   PDF (566KB) ( 1089 )   The high-temperature mechanical properties of the low-alloy steel 12Cr1MoV during continuous casting were tested on a Gleeble-1500 thermal simulator within the temperature range from mold to outlet rollers. As a result, the plastic flow and strength and thermal plasticity curves at different strain rates from 600°C to peak temperature were given, with fracture morphology of specimens observed at different temperature. The test results showed that the ZST and ZDT of the steel are 1425°C and 1400°C, respectively. The percentage reduction of area of the tested steel is greater than 60% within the range from 1100°C to 1300°C, thus showing that the steel has higher resistance to high-temperature cracking. Its brittle temperature range is 1350°C to melting point and below 900°C. References | Related Articles | Metrics

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Numerical investigations of magnetic flux density distributions in soft-contacting EMCC round billet mold. Part II: Influences of structural and operating parameters Li, Ben-Wen (1); Sun, Yang (1); Deng, An-Yuan (1); He, Ji-Cheng (1) 2007, 28 (10):  1397-1400+1405.  DOI: - Abstract ( 237 )   HTML   PDF (1150KB) ( 649 )   Continuously from part I, three dimensional distributions of magnetic field in soft-contacting electromagnetic continuous casting (EMCC) mold are systematically investigated numerically. Influences of structural parameters such as slit length/width, number of slit and wall thickness of mold, and the operating parameters such as free surface heights of liquid steel, electrical current densities, on magnetic flux density in mold were investigated separately. The max magnetic induction increases from 0.056T to 0.071T when slit length goes up to 220 mm from 130 mm; and increases from 0.058T to 0.089T when slit width goes up to 1.1 mm from 0.3 mm. The magnetic induction increases remarkably when the number of slit increases from 8 to 32, and the increase trend becomes smooth after 32. The max magnetic induction decreases about 50% when the mold wall thickness increases from 10 mm to 19 mm. The free surface of liquid steel should locate at the center position of inductor coil to obtain the largest magnetic induction. The max magnetic induction increases linearly against electrical density. References | Related Articles | Metrics

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Numerical simulation of preheating core of composite roll for continuous casting Feng, Ming-Jie (1); Wang, En-Gang (1); Wang, Jun-Gang (1); He, Ji-Cheng (1) 2007, 28 (10):  1401-1405.  DOI: - Abstract ( 302 )   HTML   PDF (449KB) ( 477 )   Some mathematical models were developed for preheating the core of composite roll for continuous casting, then the effects of the casting speed and ceramic heat-insulation tube on the distribution of preheating temperature were investigated by numerical simulation. The results indicated that the maximum temperature difference between roll core's surface and center appears when the core is drawn up to equivalent to the bottom of coil, and the center temperature is higher than surface's when it goes off to distance from the position because of the heat radiation of core's surface. The high casting speed is disadvantageous to roll core reheating. The ceramic heat-insulation tube will benefit the heat preservation of core's surface when the casting speed is low but it is not so obvious at high casting speed. References | Related Articles | Metrics

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Effect of low-frequency electromagnetic field on microstructure of hypereutectic Al-Si alloys Qin, Ke (1); Cui, Jian-Zhong (1); Hiromi, Nagaumi (2); Zhang, Hai-Tao (1) 2007, 28 (10):  1406-1409.  DOI: - Abstract ( 286 )   HTML   PDF (671KB) ( 621 )   The influence of low-frequency electromagnetic field on microstructure and morphology of primary Si particles of Al-19.2%Si alloy ingot specimens prepared by semicontinuous casting process was investigated with electronic optical microscopy, where the specimens were taken from different parts of the cast to which different electromagnetic fields are applied. The results showed that when applying the low-frequency electromagnetic field to the casting process the microstructure can be improved obviously with the sump in melt decreased due to more uniform temperature distribution in comparison with DC casting, especially efficient refinement of primary Si particles along with the increasing magnetic field intensity is shown. However, the increasing frequency of electromagnetic field will result in bigger primary Si particle size. In this experiment, the finest size of primary Si particles is found at 15 Hz under 12000 At. References | Related Articles | Metrics

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Model analysis of behavior of cerium in molten steel for heavy rail Liu, Cheng-Jun (1); Fang, Lei (1); Wang, Yun-Sheng (1); Jiang, Mao-Fa (1) 2007, 28 (10):  1410-1413.  DOI: - Abstract ( 258 )   HTML   PDF (624KB) ( 945 )   A thermodynamic model was developed quantitatively to analyze the behavior of the RE element cerium in the molten steel for heavy rail, in which the existence state of Ce and constituents of inclusions can be forecasted under different cleanliness. The results showed that in the molten steel the increasing mass fractions of initial oxygen and sulfur benefit the precipitation of Ce oxide/Ce oxysulfide and that of Ce sulfide/Ce oxysulfide, respectively. The necessary conditions for Ce2O3 and Ce2S3 precipitations at 1783 K are that the activity ratio of oxygen to sulfur is greater than or equal to 0.19 and less than or equal to 0.39, respectively. The necessary condition for transforming CeS into Ce2O2S is that the activity ratio of oxygen to sulfur is 0.53-0.96. With the cleanliness improved, the mass fraction of Ce solute increases gradually. References | Related Articles | Metrics

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Melting properties of vanadium-titanium BF slag with high Al2O3 content Zhang, Zhen-Feng (1); Lu, Qing (2); Li, Fu-Min (2) 2007, 28 (10):  1414-1416+1420.  DOI: - Abstract ( 301 )   HTML   PDF (490KB) ( 596 )   The high contents of Al2O3 and TiO2 in slag bring the BF melting process to facing lots of difficulties. An experimental investigation was therefore performed on the melting properties of vanadium-titanium BF slag with high Al2O3 content in Chengsteel. The results show that the temperature of BF slag should be controlled above 1400°C, in accordance to the actuality, with the binary basicity controlled about 1.02 and MgO content about 13.95%. The Al2O3 content should be controlled in the range of 12%-14% with TiO2 content lower than 12.57%. References | Related Articles | Metrics

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Choking phenomenon used as an approach to measure sonic velocity of air-powder two-phase flow Li, Qiang (1); Feng, Ming-Xia (1); Zou, Zong-Shu (1); Shen, Feng-Man (1) 2007, 28 (10):  1417-1420.  DOI: - Abstract ( 302 )   HTML   PDF (984KB) ( 659 )   Experiments were carried out to investigate the sonic velocity of air-powder two-phase flow in a horizontal constant cross section duct. Based on the forming principle of choking phenomenon, an approach is proposed to measure the sonic velocity of air-powder two-phase flow. The relationship between the mass flow rates of such an air-powder two-phase flow and inlet stagnant pressure is obtained with different solid-to-air ratios, thus determining the pressure under which the choking phenomenon takes place and, further, giving the relationship of the ratio of back pressure to critical pressure and the solid-to-air ratio. Taking the continuity equation of air-powder flow into consideration, the apparent sonic velocity of two-phase flow can be given. Furthermore, the apparent sonic velocity is compared with theoretical sonic velocity calculated on the theory of two-phase equilibrium flow. References | Related Articles | Metrics

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Contrast investigation on coking processes from wet coal and from dried coal Lei, Yong (1); Cai, Jiu-Ju (1); Liao, Hong-Qiang (2); Yu, Guang-Wei (2) 2007, 28 (10):  1421-1424.  DOI: - Abstract ( 465 )   HTML   PDF (291KB) ( 872 )   Using a 2 kg experimental coke oven, the coking processes from wet coal and from dried coal were investigated contrastively including the characteristics of the products, coke quality and composition of tar and gas, where the moisture of wet coal is 10%. The results showed the higher stack density of dried coal and the following characteristics of the coke with dried coal as raw material. The output and the receivable basic yields increased with water content decreased, but, in view of the drying-based yield, the coke and tar increased while the gas decreased. The pore volume of coke decreases with its strength index improved obviously, and the aryl organic compound in tar increased with alkene decreased. And in the gas H2 increased with CH4 decreased. References | Related Articles | Metrics

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Corrosion behavior of hot-dip 55% Al-Zn alloy coated sheet steel exposed to different seawater zones in Qingdao Li, Xin (1); Li, Yan (2); Wei, Xu-Jun (1) 2007, 28 (10):  1425-1429.  DOI: - Abstract ( 262 )   HTML   PDF (594KB) ( 595 )   Commercial hot-dip 55% Al-Zn alloy coated sheet steel was investigated for its seawater corrosion behavior in Qingdao through electrochemical measurements, weight loss tests and SEM, where the coating was exposed to different seawater zones. The results indicated that the 55% Al-Zn coating is superior to conventionally galvanized coating and 5% Al-Zn coating in anticorrosivity when its specimens were immersed in seawater because of its low corrosion current density and protective corrosion products. Since the protective zinc corrosion products are mechanically retained in the Al-rich interdendritic network to retard further corrosive attack and the well-aerated condition promotes the passivity of the Al-rich phase so as to inhibit greatly the mass transfer process of corrosion, the 55% Al-Zn coating shows better anticorrosivity in tidal and splash zones than in immersion zone, i.e., 2-3 times as high as in immersion zone. What is worthy to notice is that serious pitting corrosion was found when the 55% Al-Zn coating specimens were in immersion zone. References | Related Articles | Metrics

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On settling performance of digested red mud pulp during sweetening process Wang, Yi-Yong (1); Zhang, Ting-An (1); Chen, Xia (1); Bao, Li (1) 2007, 28 (10):  1430-1433.  DOI: - Abstract ( 310 )   HTML   PDF (263KB) ( 546 )   The settling performance of digested red mud pulp during sweetening process was investigated with Weipa ore from Australia and Al(OH)3 as additions. Blanked experiments without flocculant and with starch and A-1000 as flocculants were conducted comparatively to clarify the effect of flocculant on the settling performance of red mud pulp, as well as the settling performance of sweetened red mud pulp in comparison with that unsweetened. The results showed that applying the sweetening process to treating ore can obviously improve the settling performance of digested pulp, and the digested pulp with Weipa ore as the addition during the sweetening process has better settling performance than without addition or using other flocculants. References | Related Articles | Metrics

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Cadmium-resistance of ore bioleaching bacteria Tong, Lin-Lin (1); Jiang, Mao-Fa (1); Yang, Hong-Ying (1); Yin, Shu-Yan (1) 2007, 28 (10):  1434-1437.  DOI: - Abstract ( 231 )   HTML   PDF (546KB) ( 438 )   Cadmium ions were added into the culture medium to make certain the cadmium-resistance of ore bioleaching bacteria and the influence of cadmium ions on their growth. The results showed that different concentrations of cadmium ions affect differently the growth and activity of the bacteria. If the concentration in the liquid medium is lower than 0.1 mmol/L, it is nutrient to the strain we selected and expedites its growth, whereas the further increasing concentration will inhibit its growth. Ore bioleaching bacteria have a good ability to resist cadmium and they remain growing with high activity kept on even if the concentration of cadmium ions is up to 8 mmol/L. However, if the concentration is 10 mmol/L, the growth of ore bioleaching bacteria will be inhibited. References | Related Articles | Metrics

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Stability of aqueous suspension containing carbon nanotubes Hao, Su-Ju (1); Zhang, Yu-Zhu (1); Jiang, Wu-Feng (2); Pang, Zhen-Li (2) 2007, 28 (10):  1438-1441.  DOI: - Abstract ( 289 )   HTML   PDF (489KB) ( 1265 )   A suspension of carbon nanotubes as a nanofluids was prepared by dispersing carbon nanotubes into deionized water. The effects of several typical kinds of surfactants such as sodium dodecyl benzene sulfonate (SDBS), hexadecyl trimethyl ammonium bromide (HTAB) and emulsifying agent OP on the stability of the nanofluid were studied by stationary and centrifugal tests with sample morphologies characterized by SEM and TEM. The results showed that the carbon nanotubes can not be dispersed homogeneously in water without surfactant, but the stability of the nanofluid in which a surfactant has been added is enhanced significantly and then it can be kept up for several months. There is a best concentration of surfactant to make the stability optimal, and a best stability is available if using OP as surfactant. References | Related Articles | Metrics

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System design and application of a miniature climbing robot Xiao, Jun (1); Jia, Ning-Yu (1); Wang, Hong-Guang (2); Xi, Ning (3) 2007, 28 (10):  1442-1445.  DOI: - Abstract ( 468 )   HTML   PDF (385KB) ( 1547 )   A control system based on DSP2812 was designed for a new miniature bipedal climbing robot, adopting the bipedal suction feet and an under-actuated mechanism with three motors to drive five joints. The suction feet make the robot available to climb on a smooth plane or ceiling and transit the passage between two inclined surfaces. The under-actuated mechanism can reduce the number of motors required hence the robot size/weight and power consumption. However, it imposes challenges on robot control and motion planning. The motion mode, joint control, communication module and suction cup foot control have all been designed, and the experimental results have verified the validity of the design scheme proposed. References | Related Articles | Metrics

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QoS multicast routing based on chaotic genetic algorithm Yue, Cheng-Jun (1); Zheng, Xiu-Ping (1); Jing, Yuan-Wei (1) 2007, 28 (10):  1446-1449.  DOI: - Abstract ( 219 )   HTML   PDF (268KB) ( 758 )   To overcome the drawback that the premature convergence is liable to take place in the process of optimal multicast tree searching by genetic algorithm, a chaotic genetic algorithm is proposed to inhibit the premature. Introducing the intrinsic stochastic property and ergodicity of chaos, the algorithm proposed employs the chaotic perturbation in GA to operate the population with a mutation-like chaotic perturbation when judging that the premature happens. Thus, the population becomes more diverse and the premature convergence can be overcome effectively with GA's ability in global search kept and algorithm performance greatly improved. Simulation results showed that the proposed algorithm can also build an optimal multicast tree efficiently and quickly to meet the requirement of QoS restriction. References | Related Articles | Metrics

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Short-term load forecasting based on process neural network Guan, Shou-Ping (1); Lu, Xin (1); Zhang, Yan-Rui (1) 2007, 28 (10):  1450-1453.  DOI: - Abstract ( 298 )   HTML   PDF (247KB) ( 575 )   Conventionally the electric load forecasting can hardly attain a result whose accuracy meets what's required. A short-term load forecasting model is therefore developed to solve the problem, based on the process neural network of which the input is the function of time and the high forecasting accuracy is available. Describes the structure of the model, discrete data fitting method by the expansion of function orthogonal basis and learning algorithm. According to the daily load data of a certain power network in Northeast China, the model training and the accuracy of load forecasting were investigated. The simulation results showed that the load forecasting model based on process neural network is better than on BP neural network. References | Related Articles | Metrics

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Lossless compression of medical images by combining integer wavelet transform with DPCM Zhao, Li-Hong (1); Tian, Ya-Nan (1); Sha, Yong-Gang (1); Li, Jing-Hua (1) 2007, 28 (10):  1454-1457.  DOI: - Abstract ( 277 )   HTML   PDF (361KB) ( 961 )   A new method is presented to improve the efficiency of lossless compression of medical images instead of the low-efficiency method conventionally used. Its operating principle and the implementation of relevant algorithm are described and discussed in detail. Base approach of medical image lossless compression is described briefly. After analyzing and implementing the effect of differential pulse code modulation (DPCM) on lossless compression, a new method combining integer wavelet transform (IWT) with DPCM is proposed and tested to compress medical images. Comparing the different methods and analyzing the test results, the method proposed shows simpler and more useful with high compression ratio and practicability in lossless compression of medical images. References | Related Articles | Metrics

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Energy-efficient MAC protocol based on traffic of nodes for wireless sensor networks Liao, Xian-Lin (1); Geng, Na (1); Zhao, Lin-Liang (1); Wang, Guang-Xing (1) 2007, 28 (10):  1458-1461.  DOI: - Abstract ( 364 )   HTML   PDF (408KB) ( 636 )   According to that the lifetime of sensor nodes depends on their energy consumption, an energy-efficient MAC (medium access control) protocol was designed to prepare the TBEE-MAC, i.e., the traffic based energy-efficient MAC protocol for wireless sensor networks, where the traffic refers to the nodes in network. In the TBEE-MAC protocol the sensor nodes sleep periodically to save energy, and a listening time framework with relevant synchronous scheduling based on traffic of nodes are suggested, which can readjust the periods of the synchronous scheduling within the range the time error is permitted to reduce energy consumption. Simulation results showed that TBEE-MAC obviously outperforms S-MAC in energy efficiency with shorter time-delay available. References | Related Articles | Metrics

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Imprecise temporal relationship modeling based on fuzzy sets Deng, Li-Guo (1); Ma, Zong-Min (1); Zhang, Gang (1) 2007, 28 (10):  1462-1464+1476.  DOI: - Abstract ( 282 )   HTML   PDF (192KB) ( 608 )   Based on the theory of fuzzy sets, an expansion of Allen's fuzzy temporal interval model for tempoal interval is derived, and the fuzzy relation between temporal intervals is discussed in view of classical tense relations. Then, a concept of time point in fuzzy temporal sequence is proposed with a fuzzy definition given to the tense relation attributes. In addition, the boundary relations of fuzzy temporal intervals are defined with fuzzy temporal sequence. Combining the sequence with the measure formula of temporal sequence, an accurate expression is given qualitatively to 13 fuzzy tenses, which can express both the precise and imprecise relationship of fuzzy events, and provide a theoretical basis for fuzzy reasoning. References | Related Articles | Metrics

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Modeling process of fuzzy information during quality function deployment Song, Nai-Hui (1); Ren, Zhao-Hui (1); Wen, Bang-Chun (1); Chen, Yi-Zeng (1) 2007, 28 (10):  1465-1468.  DOI: - Abstract ( 279 )   HTML   PDF (211KB) ( 754 )   In the process of product design, most input information necessary for quality function deployment (QFD) usually possesses the fuzzy and linguistic characteristics. So, various input information of house of quality (HOQ) are regarded as linguistic variable to compile a glossary of fuzzy terms for various linguistic variables and form the fuzzy numbers corresponding to them, with the conventional HOQ theory extended to fuzzy domain on the principle of fuzzy expansion. Elaborates the modeling process of fuzzy information by such theories as four arithmetic operations, fuzzy decision and fuzzy reasoning, which is of theoretical significance to the decisionmaking of products' design in fuzzy circumstances. References | Related Articles | Metrics

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Kinematic analysis based on multi-body dynamics for placer jib of concrete pump truck Dai, Li (1); Liu, Jie (1); Liu, Yu (1); Zhao, Li-Juan (2) 2007, 28 (10):  1469-1472.  DOI: - Abstract ( 269 )   HTML   PDF (402KB) ( 843 )   Based on the multi-body dynamics and Lagrange equation, the differential equation of rigid motion of the four-bar placer jib of a concrete pump truck is deduced. With the numerical solution to the equation, the rotation angles between every two bars and the jib end track are analyzed. A dynamical simulation software is used to develop the rigid motion model for the jib, in which the same kinematic parameters are selected to those in numerical solution, thus comparing the track as the result of simulation with that numerically solved. It is shown that the two results are basically in conformity with each other. The multi-body dynamics is therefore proved useful to express the movement equation of the placer jib of concrete pump truck with each and all dynamic behavior expressed exactly. References | Related Articles | Metrics

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Kinematic/dynamic simulation based on ADAMS for 3-TPS hybrid machine tool Zhu, Li-Da (1); Shi, Jia-Shun (1); Cai, Guang-Qi (1); Wang, Wan-Shan (1) 2007, 28 (10):  1473-1476.  DOI: - Abstract ( 282 )   HTML   PDF (414KB) ( 1042 )   Aiming at the problems of selection of motor parameters and mechanism design of the 3-TPS hybrid machine tool, a three-dimensional model of the machine tool is developed by SolidWorks software, then the assembly model is introduced into ADAMS/View to form a virtual prototype simulation model based on multi-body dynamics. The velocity and driving force curves of all driving links are got by simulation to analyze kinematically and dynamically the hybrid machine tool, and the maximum velocity and driving force of all driving links are found by space search. The kinematic/dynamic properties of 3-TPS hybrid machine tool are thus obtained, which provides an important reference to the motor selection and designs for mechanism framework and control system. References | Related Articles | Metrics

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Product quality design based on CSCW Jiang, Xing-Yu (1); Zhao, Hai-Feng (1); Wang, Gui-He (1); Wang, Wan-Shan (1) 2007, 28 (10):  1477-1480.  DOI: - Abstract ( 267 )   HTML   PDF (699KB) ( 738 )   In view of the characters of the quality design in advanced manufacturing circumstances, and what are required by modern manufacturers, a new design mode of product quality is proposed, and a collaborative product quality design system is developed on CSCW basis to adapt to not only a manufacturer but several collaborative ones. Each and every part, especially the support technologies for implementing collaboration are analyzed and studied. Applying Java, JSP and JavaServlet to the system with the open WWW platforms used to enhance the communication function, improve working efficiency and shorten the development cycle so as to respond to the fluctuation of market demands as quick as possible. The QFD analysis of some automobile is introduced as an example to verify that the system developed will meet efficiently the requirements of networked manufacturers. References | Related Articles | Metrics

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Dynamic simulation of a biglide parallel NC grinder for helical drill point machining Zou, Ping (1); Qiu, Huan-Ren (1) 2007, 28 (10):  1481-1484.  DOI: - Abstract ( 310 )   HTML   PDF (582KB) ( 557 )   A new biglide parallel NC grinder for helical drill point machining was developed. The mathematical model for the grinder is simple and makes it easy to accomplish the real-time control. The structure and characteristics of the grinder were introduced. Otherwise, the dynamic model that the biglide parallel NC grinder is machining the helical drill points was developed by Lagrange approach. Moreover, the dynamic simulations based on the dynamic model were done for the grinder with Matlab/Simulink software. The simulated curves can reflect the driving forces of the linear motors and kinematics parameters of the mobile platform of the grinder when it is grinding. The results showed that the simulations are reliable, and the dynamic characteristic of the grinder is satisfied. Therefore, the biglide parallel NC grinder for helical drill point machining has great value in application. References | Related Articles | Metrics

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Application of ecological footprint in Chinese cities' development Li, Guang-Jun (1); Wang, Qing (1); Gu, Xiao-Wei (1); Chu, Dao-Zhong (1) 2007, 28 (10):  1485-1488.  DOI: - Abstract ( 315 )   HTML   PDF (671KB) ( 639 )   The principles and mathematical model of ecological footprint are introduced in the case studies of Chinese cities in 2004 and applied to their sustainable development. The results show that the ecological footprint in Hong Kong was the biggest: 4.8676 hm2/cap, where the ecological capacity was just 0.039 hm2/cap, the former was 122 times higher than the latter. Shanghai was the next one in respect to ecological footprint, with Beijing, Tianjin, Qingdao, Shenyang, Shenzhen and Chongqing following it in sequence. As to the ecological efficiency in 2004, Hong Kong is tiptop: 39299 yuan/hm2, with Shenzhen, Shanghai, Shenyang, Qingdao, Beijing, Tianjin and Chongqing following it in sequence. It's revealed that there were big gaps of ecological efficiency between the cities in Chinese Mainland and Hong Kong. References | Related Articles | Metrics

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Dye removal by fungal biosorption in aqueous solution Zhang, Li-Fang (1); Wei, De-Zhou (1) 2007, 28 (10):  1489-1492.  DOI: - Abstract ( 478 )   HTML   PDF (1069KB) ( 1214 )   A strain of iungus (Penicilium sp.) capable of high uptake for dyes was isolated from air to remove the cationic dye malachite green from aqueous solution and the effect of fungal biosorption on dye removal was investigated experimentally, including dye structures, pretreatment methods and initial pH values of the solution. The results showed that the adsorption quantity of untreated and NaHCO3-treated fungal mycelia as biosorbent are 29.3 and 35.3 mg/g if the concentration of the dye malachite green is 50 mg/L, respectively, and the latter has best effect. In the biosorption process the pH value plays an important role, and the maximum adsorbability can be obtained at pH value 5. The Langmuir and Freundlich models are able to describe the biosorption equilibrium of malachite green with the NaHCO3-treated fungal mycelia. The maximum uptake is 555.6 mg/g dry biomass. The dye biosorption process by fungal mycelia follows the pseudo second-order kinetics equation. References | Related Articles | Metrics

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Bacteria screening to biodegrade diesel and their characteristics Zhang, Hui (1); Hu, Xiao-Min (1); Li, Pei-Jun (2); Verkhozina, V.A. (3) 2007, 28 (10):  1493-1496.  DOI: - Abstract ( 272 )   HTML   PDF (410KB) ( 527 )   The commercial 0# diesel was used as the only source of carbon to screen out bacteria for diesel biodegradation and two strains were identified, i.e., Y1 Bacillus and Y2 Flavobacterium. Both were selected according to their morphological, physiological and biochemical characters. Then, their growing curves were plotted through tests to offer certain evidences for the immobilization of microorganism species and further study on the characters of biodegradation of the two bacteria strains in diesel. The results showed that when the initial oil concentration is 150 mg/L, and the strain Y1 or Y2 after batch culturing for 48 h has been inoculated into the diesel in a ratio of 1/10, the oil removal rate of Y1 and Y2 is 79.5% and 77.23%, respectively, and the effects of oil biodegradation of both Y1 and Y2 decrease with increasing initial oil concentration. It was also observed that the pH value affects greatly the physiological characteristics of Y1 and Y2. References | Related Articles | Metrics

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Approximate algorithm based on Neumann expansion for rotational response identification Kang, Yu-Mei (1); Chen, Geng-Ye (1); Li, Zhou (2) 2007, 28 (10):  1497-1500.  DOI: - Abstract ( 286 )   HTML   PDF (1665KB) ( 497 )   Aiming at the problem that the rotational response is difficult to measure in structural identification, an approximate algorithm based on Neumann expansion theory is developed for rotational response identification. The rotational response cannot be calculated according to structural displacement response based on the static condensation algorithm in FEM analysis since the stiffness parameters are unknown in structural identification. When the difference among structural parameters are not big, the inverse matrix is available by introducing Neumann expansion to get the information on rotational response. Theoretic analysis and numerical examples are given to illustrate that the approximate algorithm based Neumann expansion is applicable when structural parameters differ not widely from each other, and an accurate solution can be obtained if the structural parameters are all the same. The norm errors of the approximate algorithm is generally small, while the smaller the absolute value is, the greater the component errors will be. References | Related Articles | Metrics

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Experimental investigation on utilizing recycled asphalt mixture for high-speed way blacktop Ouyang, Wei (1); Wang, Lian-Guang (1) 2007, 28 (10):  1501-1504.  DOI: - Abstract ( 263 )   HTML   PDF (248KB) ( 676 )   Investigates experimentally the blacktop performance of high-speed way utilizing recycled asphalt mixture, as well as the cause of damage to blacktop and its aging mechanism. Discusses and analyzes in detail the sieving result of outspent asphalt mixture, properties of aggregate and especially the properties of the asphalt mixture in which the reclaiming agent has been added in the outspent one. The results show that the blacktop performance can be improved efficiently up to existing technical standard if adding properly the reclaiming agent in the outspent asphalt mixture. Some key points are suggested for designing recycled asphalt mixture as blacktop, which may be referable to the design and construction of utilizing recycled asphalt mixture. References | Related Articles | Metrics

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Fuzzy dynamic study on vehicle routing schedule combining out and back hauls Guo, Fu (1); Long, Ying (2); Zhao, Xi-Nan (1) 2007, 28 (10):  1505-1508.  DOI: - Abstract ( 255 )   HTML   PDF (158KB) ( 539 )   A coefficient spare space is introduced in cargo transport schedule for out and backhaul to prevent from empty vehicle running and rearrangement during vehicle routing process, where the fuzzy parameters and random backhaul are taken into account dynamically. The solution to the routing problem is given as such that all the nodes, vehicles and routes between adjacent nodes are labeled with initial route chosen. Then, the label interpolation method is used to solve the fuzzy dynamic problem. If the given schedule fails, an alternative scheme is provided in time. A simulative example is given to verify the validity of the method proposed. References | Related Articles | Metrics

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On consistency of expert group's judgments based on decision matrices in form of interval numbers Chen, Xia (1); Fan, Zhi-Ping (1); Chen, Yan (1) 2007, 28 (10):  1509-1513.  DOI: - Abstract ( 297 )   HTML   PDF (1220KB) ( 658 )   With respect to the consistency problem of expert group's judgments based on the preference information on the decision matrices in form of interval numbers, an analytic method is proposed. The concept of interval number and the method to normalize the decision matrix are introduced. Then, defining the distance between two interval numbers and decision function of consistency, an analytic method is given to the consistency of expert group's judgment including each and all elements, alternatives and indices. Meanwhile, a discrimination approach is proposed for the consistency of expert group's judgment based on the preference information on decision matrices in form of interval numbers, with a readjusting way provided if there is no consensus on the judgment. A numerical example is given to illustrate the validity of the analysis method proposed. References | Related Articles | Metrics

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Existence of positive solution to a class of problems of singular elliptic boundary value with asymptotical linearity Song, Shu-Ni (1); Liu, Xia (1) 2007, 28 (10):  1514-1516+1520.  DOI: - Abstract ( 264 )   HTML   PDF (463KB) ( 573 )   According to the critical point theory, a class of problems of elliptic boundary value with an asymptotically linear term and singular term is studied. It is proved that the functional J corresponding to the elliptic boundary value satisfies PS condition on the convex closed set ΓΕ = {u ∈ C01 (Ω¯)|u > Εφ1} by the property of elliptic operator eigenvalue in combination with the asymptotical linearity of the function f(u). Then it is also proved that J is retractable to a ∈ R+ on ΓΕ by the ordinary differential equation theory in Banach space. Furthermore, ΓΕ is proved an invariant set of decent flow of J by Schauder condition, and J(u) is proved lower bounded for u ∈ΓΕ. A conclusion is therefore reasoned out that there is a positive solution at least to the problems of singular elliptic boundary value. References | Related Articles | Metrics

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Formation thermodynamics of the vapour complexes in the TaCl5-NaCl binary system Li, Jun-Li (1); Yang, Dong-Mei (1); Zhang, Qin (1); Wang, Zhi-Chang (1) 2007, 28 (10):  1517-1520.  DOI: - Abstract ( 305 )   HTML   PDF (269KB) ( 682 )   Taking advantage of the theory of chemical vapour transfer reaction, the formation thermodynamics of vapour complex NauTavClu+5v was experimentally investigated in closed Pyrex ampoules as reactors at 588-663 K under 0.06-0.12 MPa for about 6 h by way of high-temperature phase equilibrium quenching. The results showed that the ln(PNaTaCl6)/P⊖ vs. ln(PTaCl5)/P⊖ plot and lnKp vs. 1/T plot are both in linear relation and the vapour complex NaTaCl6 is the sole reaction product from tantalum chloride and sodium chloride. The thermodynamic equilibrium constants of the reaction are all determined from experimental result. Based on the stability constant obtained at different temperatures from experiments, the changes in enthalpy and entropy in reaction are given by least square method, i.e., ΔHm⊖ = (-25.2 ± 1.5) kJ·mol-1 and ΔSm⊖ (-58.4 ± 2.0) J·mol-1·K-1, respectively. References | Related Articles | Metrics