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15 November 2005, Volume 26 Issue 11 Previous Issue    Next Issue
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Hybrid guaranteed cost control with quadratic stability for a class of uncertain discrete systems Sun, Wen-An (1); Feng, Jia-Xin (2); Fu, Jun (1); Zhao, Jun (1) 2005, 26 (11):  4-7.  DOI: - Abstract ( 232 )   HTML   PDF (1528KB) ( 522 )   Discusses hybrid state feedback guaranteed cost control with quadratic stability for a class of uncertain discrete systems of which the state matrix contains time-varying uncertainties. Assuming that there is a limited number of candidate controllers with known gain matrices and using the common Lyapunov function, a sufficient condition is derived to hybrid guaranteed cost control with quadratic stability under arbitrary switching laws. Then, based on the single Lyapunov function method, relevant sufficient conditions and conceptual design of switching rule are both given. A simulation demonstrated the effectiveness of the proposed method. References | Related Articles | Metrics

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Soft sensing modeling based on support vector machines for fermentation process Chang, Yu-Qing (1); Wang, Fu-Li (2); Wang, Xiao-Gang (2); Lu, Zhe (2) 2005, 26 (11):  8-11.  DOI: - Abstract ( 275 )   HTML   PDF (1249KB) ( 647 )   A regression method is proposed to improve the LS-SVM (least square-support vector machine) model. The sparseness of LS-SVM is thus obtained from the regression model to increase greatly the computation speed by way of removing most of the sample points in accordance to the Euclidian distances between input variables and sample points. The proposed method has been applied to the fermentation process to develop a soft sensing model so as to estimate the product's concentration on-line in penicillin fermentation process. Simulation results showed that the proposed method can provide a new useful approach to the real-time monitoring of quality variables which are hard to measure on-line in fermentation processes. References | Related Articles | Metrics

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BPR-based business operation procedure in electronic brokering Zhang, Zhen-Hua (1); Wang, Ding-Wei (1) 2005, 26 (11):  12-15.  DOI: - Abstract ( 265 )   HTML   PDF (166KB) ( 560 )   Guided by the principles of BPR, a typical business operation procedure is designed for electronic brokers. It is characterized by modularized design consisting of 5 modules, such as information checking, registering/request submitting, brokers matching, negotiation and delivery/payment. The idea customer faced is considered to simplify the business operation procedure so as to make transactions convenient and ensure their validity with dependable information provided. During the delivery and payment, the participation of broker can improve the mutual trust between both parties with direct bargaining available, thus improving the efficiency. Some ways are proposed to improve the automation in broker matching and stabilize the matching between both parties, such as the search done by intelligent agent in attribute tree, CBR-based modification for recommendation list and the Gale-Shapley matching algorithm. References | Related Articles | Metrics

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LMP calculation on PJM power market and its trial in China Zhang, Rui-You (1); Han, Shui (2); Zhang, Jin-Zhu (3); Wang, Ding-Wei (1) 2005, 26 (11):  16-18.  DOI: - Abstract ( 1655 )   HTML   PDF (153KB) ( 5974 )   For the pricing of power transmission/distribution in China, the PJM power market is introduced as a reference and studied, in which the locational marginal price (LMP) with no transmission loss taken into account is calculated according to the security constrained economic dispatch (SCED) based on de-power flow. To adapt the actual need, the constraints on the sum of transmitted power of multiple branches are added to the original PJM model, and the power transmission distributed factor (PTDF) matrix is proposed for branch sets. To test the efficiency of the proposed approach, a calculation trial has been done using a mathematical model of a 500 kV network. The results showed that the approach can provide correct signals to all parties on power market and manage well the costs due to congestion with the fixed transmission right (FTR) used together. References | Related Articles | Metrics

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Partner selection model with maximum completion probability Huang, Min (1); Wang, Xing-Wei (1); Wang, Ding-Wei (1) 2005, 26 (11):  19-22.  DOI: - Abstract ( 233 )   HTML   PDF (155KB) ( 424 )   To control the competition risk of a project of virtual enterprise in dynamic alliance, of which the time to complete its subprojects is stochastic, the problem of partner selection is studied to maximize the completion probability of the project that is constrained by investment and the precedence of its subprojects, which is described on the basis of program evaluation and review technique (PERT). Then, a nonlinear integer-programming model is developed and a PERT-embedded genetic algorithm is designed to solve the problem. A case study is carried out to compare the proposed algorithm with enumeration algorithm. The results suggest that the proposed method is effective in both running time and performance, as a useful management instrument to select partner for a virtual enterprise in dynamic alliance under random conditions. References | Related Articles | Metrics

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Production/sales decision model for price control of seasonal goods on tight market Liu, Bao-Zheng (1); Liu, De-Bao (1); Gao, Li-Qun (1) 2005, 26 (11):  23-26.  DOI: - Abstract ( 360 )   HTML   PDF (109KB) ( 1167 )   Discusses the production/sales decision model for the price control of the seasonal goods on tight market, such as perishable vegetables and fruits. Based on people's daily economic activities and their natural demand for such goods with relevant sales volume on market in a yearly period, some conditions are assumed as actual as possible to develop a model. By way of mathematic analysis and extremum method, and the curves expressing the functions of sales price curve and the sales volume are determined reasonably. A theoretical reference is thus provided for goods supply pricing, which will serve a directive function to agriculture production and relevant business operation. References | Related Articles | Metrics

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Algorithm to mine and analyze intrusion alert patterns Dong, Xiao-Mei (1); Yu, Ge (1) 2005, 26 (11):  27-30.  DOI: - Abstract ( 274 )   HTML   PDF (159KB) ( 434 )   To reduce effectively the frequency of alerts and extract useful information from them, an algorithm was proposed to mine and analyze the patterns of intrusion alert streams on the basis of CLOSET algorithm. In a distributed intrusion detection system, the algorithm can help the response component mine and analyze the alerts especially their frequently closed patterns from its detection components so as to response in reference to the patterns. To find latent intrusion, the intrusion detection message exchange format (IDMEF) was extended with a concept of suspicion level proposed. To study further those alerts which are highly suspicious but less frequent, the algorithm as above was improved by adding a parameter of lowest suspicion level to it. Experimental results showed that both algorithms are effective in reducing the frequency of alerts but the improved one is better at mining useful information. References | Related Articles | Metrics

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Sharing strategy supporting multi-aggregate queries in sliding window over data streams Yu, Ya-Xin (1); Zhu, Xin-Hua (2); Yu, Ge (1) 2005, 26 (11):  31-34.  DOI: - Abstract ( 292 )   HTML   PDF (245KB) ( 541 )   How to improve the efficiency of multi-aggregate queries is a key problem, to which a novel linked-tree sharing strategy is proposed to support multi-aggregate queries in sliding window over data streams. In this way, each and every sliding window will divide the linked-tree logically into several sub-trees where the aggregate values of different root nodes are just the answers corresponding to their aggregate queries. This kind of logical division makes several queries run in a tree simultaneously, thus avoiding the repeated construction of different linked-trees. Taking advantage of the characteristic of the linked-tree available to reduce the number of fruitlessly repeated comparisons, the aggregate value of each query can be given with few updates/comparisons to do when many queries are required for answers from the same linked-tree. Extensive experiments showed that sharing the same linked-tree can cause lots of queries to share the resources with memory content decreased accordingly. As a result, the query processing efficiency, throughputs of real time tasks and system's performance are all improved dramatically. References | Related Articles | Metrics

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Call access control based on soft-handoff/double queue for multi-class traffic in 3G systems Guan, Shao-Ying (1); Gao, Ke-Ning (1); Xia, Li (1); Wang, Guang-Xing (1) 2005, 26 (11):  35-37.  DOI: - Abstract ( 159 )   HTML   PDF (140KB) ( 421 )   An approach to call access control based on soft handoff/double queue for multi-class traffic in 3G systems is proposed to give different priorities in accordance to different traffic. The different calls are controlled to enter into the networks according to different network conditions. And, especially, a soft-handoff/double queue model is used to ensure that the useful false soft-handoff requests not to be lost, so as to decrease the soft-handoff failure probabilities. Experimental results showed that the control model can allocate bandwidth dynamically and utilized network resource effectively and be realized easily on hardware to ensure effectively the QoS of different soft-handoff traffic. It has advantages of low soft-handoff call drop ratio and shorter time for waiting. References | Related Articles | Metrics

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Scheduling algorithms for replica location request You, Xin-Dong (1); Chang, Gui-Ran (2); Chen, Xue-Yao (1); Zeng, Wan-Dan (1) 2005, 26 (11):  38-40.  DOI: - Abstract ( 268 )   HTML   PDF (131KB) ( 473 )   According to the heterogeneous characteristics of the data grid nodes, a scheduling algorithm based on FCFS and the idea able person should do more work is proposed. The simulation experiments using Java program showed that when employing this scheduling algorithm the simulation system performs better than employing the scheduling algorithm based only on FCFS in the M/M/N queuing model if the rate generating of the replica location requests and the total local abilities of the home nodes in the former are both the same to those in the later and, local abilities among all home nodes are in geometrical series. The algorithm proposed will therefore improve several performance parameters in the simulated system, such as the average response time of replica location requests. References | Related Articles | Metrics

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Dynamic routing management algorithm based on AODV protocol Wang, Cui-Rong (1); Chen, Shu-Yi (1); Yang, Xiao-Zong (2) 2005, 26 (11):  41-44.  DOI: - Abstract ( 315 )   HTML   PDF (115KB) ( 966 )   A dynamic routing management algorithm based on AODV protocol was proposed, to which the required different protocol parameters could dynamically be allocated so as to adapt it to the changing network contexts and improve its routing performance. Taking advantage of fuzzy logic, the MANET network contexts were classified in the algorithm and the different AODV routing parameters to be selected according to different network contexts for improving the routing performance. The algorithm was applied to AODV protocol and simulated by NS2 to compare its performance with standard AODV protocol. The simulation results showed that the algorithm can improve significantly the routing performance and that the application of fuzzy logic is available to optimizing the routing performance of MANET. References | Related Articles | Metrics

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Target detection method based on a new multi-scale fractal feature Wei, Ying (1); Tong, Guo-Feng (1); Shi, Ze-Lin (2); Yu, Hai-Bin (2) 2005, 26 (11):  45-48.  DOI: - Abstract ( 379 )   HTML   PDF (401KB) ( 1294 )   The detection of small single-frame image is investigated in complicated natural background. A new multi-scale fractal feature is proposed according to the fact that the fractal feature of man-made objects changes shaper than the natural background. The new feature causes the man-made objects to stand out much better from natural background than what can be done by the standard fractal dimensions, thus inhibiting well three kinds of images from different background clutters. Local gray histogram statistics is applied to object detection in the images with multi-scale fractal feature. Experimental results showed that the algorithm to detect the objects with such a feature is quite stable and generally acceptable to IR and TV images in complicated ground or sea background and, especially, it can localize small objects in a single-frame image with an accuracy up to over 95%. References | Related Articles | Metrics

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Effect of heating temperature on structure and properties of IF steel during hot rolling Zhang, Jin-Gang (1); Jiang, Qi-Wu (1); Liu, Yan-Dong (1); Zuo, Liang (1) 2005, 26 (11):  49-52.  DOI: - Abstract ( 257 )   HTML   PDF (402KB) ( 963 )   The heating temperature was taken as an influencing factor on controlling the properties of Ti-Nb-IF steel during hot rolling. To study the relationship among the heating temperature, steel structure and properties, the microstructure, second-phase particles and texture of Ti-Nb-IF samples hot-rolled at 1140°C and 1214°C were analyzed separately. The results showed that the lower heating temperature (1140°C) is more beneficial to improving mechanical properties than rolled at 1214°C, i.e., the yield strength decreases by 30 MPa with plastic strain ratio increases by 0.16 at 1140°C. The main reasons are elucidated by experimental results as follows: When Ti-Nb-IF steel sheets are hot-rolled at 1140°C, bigger second-phase particles and finer ferrite grains are available to provide homogeneous appearance and strong γ recrystallization texture in such subsequent processes, as cold rolling and annealing. References | Related Articles | Metrics

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Phase constituents of some kinds of 6000-series aluminium alloys for automotive body sheets Liu, Hong (1); Zhao, Gang (1); Liu, Chun-Ming (1); Zuo, Liang (1) 2005, 26 (11):  53-56.  DOI: - Abstract ( 255 )   HTML   PDF (428KB) ( 861 )   By means of SEM/energy spectrum, XRD and metallographic analysis, the effects of different alloying compositions on the constituents of some 6000-series aluminium alloys for automotive body sheets were investigated. The results indicated that the phases formed in as-cast state include Al19CuMg4.1Si3.3, Al8(FeMnCr)2Si, Al5(FeMnCr)Si, Al4(MnFeCr)3Si2, Al5(MnFeCr)12Si7 and Mg2Si. And the quantities of such phases as Al(FeMnCr)Si, Al(MnFeCr)Si and Mg2Si increase with the mass ratios Mg/Si and Mg/Cu and Mn content. When homogenizing the Al alloys, the types of their phases remain unchanged except the Al5(FeMn)Si which is transformed into Al8(FeMn)2Si phase. Then, after rolling and final heat treatment, all the phases no longer change. References | Related Articles | Metrics

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Microstructure investigation on in-situ synthesis of (Ti,W)C reinforced iron-based composite Pan, Wei-Dong (1); Ren, Ying-Lei (2); Cai, Qing-Kui (3); Qiu, Ke-Qiang (2) 2005, 26 (11):  57-60.  DOI: - Abstract ( 526 )   HTML   PDF (1088KB) ( 709 )   The in-situ synthesis of 10 vol% (TiW)C-Fe composite was investigated by melting the Fe-W, Fe-Ti and Fe-C alloys with melting temperature and time controlled. The microstructure and phase composition were checked by employing SEM and XRD with Cu Kα radiation. The results showed that (Ti,W)C particles, as the only ones, can form reinforcement when the alloy is melted at higher temperature and/or longer time by properly controlling solidification rate. (Ti,W)C particles are evenly distributed in the matrix due to the lower mismatched densities between (Ti,W)C particles and liquid metal. References | Related Articles | Metrics

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Effect of rare earth on mechanical properties of high-carbon steel with different cleanliness Liu, Cheng-Jun (1); Jiang, Mao-Fa (1); Li, Chun-Long (1); Chen, Jian-Jun (1) 2005, 26 (11):  61-64.  DOI: - Abstract ( 238 )   HTML   PDF (241KB) ( 886 )   How the state and content of RE vary in high-carbon steel and affect its mechanical properties were studied experimentally and theoretically. It was found that adding RE properly to the steel can improve significantly and stably steel's mechanical properties even if the cleanliness of steel has greatly been enhanced and that the adding amount of RE can properly be reduced along with the increasing cleanliness. Experimental results showed that the plasticity and impact toughness can be improved greatly when the optimum adding amounts of RE are 0.02 and 0.01 wt% to low and high cleanliness steels, respectively. However, adding a large amount of RE can't increase solid RE solution content in low cleanliness steel, which will be kept below 0.0012 wt%. References | Related Articles | Metrics

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Effect of RE oxides on the physicochemical properties of mold flux for continuous casting Wang, De-Yong (1); Jiang, Mao-Fa (1); Liu, Cheng-Jun (1); Shi, Pei-Yang (1) 2005, 26 (11):  65-68.  DOI: - Abstract ( 233 )   HTML   PDF (169KB) ( 514 )   In the process of feeding RE wires in a mold, an amount of RE oxides enter into the molten slag, thus affecting and restricting the mold flux to serve metallurgical functions. Effect of RE oxides on the melting temperature, viscosity and crystallization temperature of mold flux was measured systemically. It was found that the melting temperature, viscosity and crystallization temperature of mold flux increase remarkably with increasing RE oxides as addition. If adding B2O3 and Li2O as new fluxes to the mold flux, the effect of RE oxides on the physicochemical properties of mold flux may be weakened remarkably. A theoretical basis is therefore available to develop further a new type of mold flux for RE steel, of which both the composition and physicochemical properties will be more reasonable. References | Related Articles | Metrics

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Thermodynamic analysis of PbO-PbCl2 oxychlorides formed during urban refuse incineration/melting Wang, Nan (1); Zou, Zong-Shu (1); Yamaguchi, Shu (2) 2005, 26 (11):  69-72.  DOI: - Abstract ( 215 )   HTML   PDF (333KB) ( 568 )   Investigates thermodynamically the Pb-oxychlorides formed during urban refuse incineration/melting by way of high-temperature XRD and activity determination of such solid oxychlorides, including the binary phase diagram of PbO-PbCl2, the relative chemical potential of PbO and standard free energy of formation or Gibbs free energy of activation of intermediate compounds. A thermodynamical basis is thus provided for the formation and precipitation reaction of Pb-oxychlorides during melting. Furthermore, the stability function and ideal associated solution model are employed to discuss the effect of stability of liquid PbO-PbCl2 on the formation of complex ionic species. The results show that the stable intermediate compounds are PbCl2 · PbO, PbCl2 · 2PbO and PbCl2 · 4PbO. References | Related Articles | Metrics

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Bubble stability of foam aluminum in foaming process Wei, Li (1); Li, Zhen-Jiang (2); Yao, Guang-Chun (1) 2005, 26 (11):  73-75.  DOI: - Abstract ( 440 )   HTML   PDF (744KB) ( 888 )   The influence of foaming effect on bubble stability of foam aluminum prepared by powder metallurgy was studied, with relevant influencing factors analysed. The results showed that the melt viscosity and decomposition of TiH2 are the two predominant factors on which the bubble stability depends. The melt viscosity is improved by adding calcium in Al-Si alloy powder so as to control the surface tension of the melt. The hydrogen emitted from the decomposition of controlled by TiH2 addition. The foaming process is controlled in a period of bubble stability by controlling the foaming time. Keeping the balance between gas pressure inside bubbles and their surface tension will get the foam Al with even porosity and appropriate density. References | Related Articles | Metrics

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Study on digestion of Chinese middle/low grade bauxite in lime Bayer process Fu, Gao-Feng (1); Tian, Fu-Quan (1); Quan, Kun (2) 2005, 26 (11):  76-78.  DOI: - Abstract ( 297 )   HTML   PDF (96KB) ( 1476 )   Lime is used widely in the Bayer process, which plays an important role in various applications. In particular, it can minimize soda loss in red mud. The conventional and lime Bayer processes using diasporic bauxite (w(Al2O3/w(SiO2):5.36) were contrastively investigated. The effects of lime addition and pre-desilication on the composition of red mud were mainly studied. The results showed that the x(Al2O3/x(SiO2) in red mud increases linearly but the x(Na2O)/x(SiO2) decreases obviously with lime charge and that the main constituent of red mud in lime Bayer and conventional processes are 3CaO · Al2O3 · xSiO2 · nH2O and Na2O · Al2O3 · xSiO2 · nH2O by which a big amount of soda will be lost, respectively. After pre-desilicating for 4 h, the x(Al2O3)/x(SiO2) and x(Na2O)/x(SiO2) in red mud decrease from 1.53 to 1.43 and 0.28 to 0.24, respectively. References | Related Articles | Metrics

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Hydrothermal synthesis and characterization of ZnO rod-like crystal Zhang, Yan-Hui (1); Tian, Yan-Wen (1); Shao, Zhong-Cai (2); Qian, Jian-Hua (3) 2005, 26 (11):  79-81.  DOI: - Abstract ( 237 )   HTML   PDF (284KB) ( 1109 )   Zn(Ac)2 · 2H2O and NaOH were used as experimental material to synthesize ZnO microcrystal powder with long-chain PEG and cyclohexane as additives. XRD, SEM and TEM were used to characterize the powder. The experimental results showed that not only the special shape of ZnO was produced under the action of long-chain PEG, but also the one-dimension of rod-like ZnO with big aspect ratio can also be produced under the action of cyclohexane. References | Related Articles | Metrics

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Electrochemical properties of Zn/Zn-Al alloys as hot-dip galvanized coating protecting steel in hot seawater Li, Xin (1); Du, Hong-Yan (2); Wei, Xu-Jun (1); Li, Yan (3) 2005, 26 (11):  82-85.  DOI: - Abstract ( 291 )   HTML   PDF (408KB) ( 1035 )   To compare quantitatively the cathodic protection effects of Zn and several Zn-Al alloys as hot-dip galvanized coating materials on steel in 50°C seawater, their electrochemical properties were tested with constant current, according to the China national standard GB/T 17848-1999. Their current efficiencies were then calculated with surface's corrosive peeling and homogeneity observed. Thus, their effects of anti-corrosion protection were evaluated. The results showed that the electrochemical properties of such zinc-aluminum alloys as Zn-5Al-0.1RE, Zn-5Al-0.5Mg, Zn-6Al-3Mg, Zn-11Al-0.2Si-3Mg, Zn-25Al-0.2Si-0.2Mg and Zn-25Al-0.2Si-0.2RE are medium, while Zn is the best and Zn-55Al-1.6Si alloy the poorest one. References | Related Articles | Metrics

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Study on adsorption of Au(III) by CCCS and ECCS resin Dang, Ming-Yan (1); Zhang, Ting-An (1); Wang, Ping (2); Jiang, Xiao-Li (1) 2005, 26 (11):  86-89.  DOI: - Abstract ( 196 )   HTML   PDF (163KB) ( 574 )   Chloromethylthiirane and epichlorohydrin were used separately as crosslinking agents to crosslink with chitosan so as to synthesize them into two different resins of which the static adsorbilities to Au(III) were determined. The effects of each and main influencing factor of chloromethylthiirane crosslinked chitosan (CCCS) resin and epichlorohydrin crosslinked chitosan (ECCS) resin on their adsorbilities to Au(III) were also investigated by orthogonal tests. The results indicated that CCCS can be used wider in respect to its temperature, pH value and initial Au(III) concentrations especially its adsorbilities than ECCS under the same conditions. The adsorbility capacities of CCCS is up to 296.67 μg/mg with an adsorption rate 98.1%. References | Related Articles | Metrics

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Effect of biosorption of Cd2+ by suspended saccharomycete biomass Su, Xiu-Juan (1); Zhu, Yi-Min (1); Shen, Yan-Bai (1); Wei, De-Zhou (1) 2005, 26 (11):  90-93.  DOI: - Abstract ( 238 )   HTML   PDF (259KB) ( 838 )   The biosorption of Cd2+ by suspended saccharomycete was investigated with various influencing factors on the process discussed. The results showed that 10 minutes after starting the process, the adsorption equilibrium comes about. The pH value has a great effect on the biosorption, and when it is 5.41, the biosobent shows a best adsorbing effect. The initial mass concentration of adsorbate is also an important influencing fact on the biosorption, and the adsorbing rate can be up to 99% if the concentration of adsorbate is 228.4 mg/L and that of adsorbent is 14 g/L. The results of IR spectrum showed that the adsorbing positions of the suspended saccharomycete biomass to Cd2+ are mainly the -OH, C=O, P=O, -NH2, and S=O. References | Related Articles | Metrics

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Self-stability analysis and the geological characteristics of long-span and shallowly-buried tunnel Wang, Shu-Hong (1) 2005, 26 (11):  94-97.  DOI: - Abstract ( 238 )   HTML   PDF (363KB) ( 1267 )   The shallowly-buried long-span Hanjialing tunnel is an integral part of the expansion project of Shenyang-Dalian expressway in Northeast China. Based on the field survey of geological conditions, the geological characteristics of key positions of the tunnel were investigated, especially how the new Austrian tunneling method (NATM) construction process will affect its stability. Some measures are proposed to take so as to play fully the role of host rock in construction process. The practice showed that the geological/engineering conditions of the long-span tunnel are very complex, and it is of importance to monitor rocks structural plane and deformation and to readjust timely the construction schedule and relevant technologies. It is stressed that the self-stability mechanism of key positions should be monitored and controlled carefully so as to play fully the role of self-stability of hast rock. What the measures proposed to take and relevant experience will benefit the construction of the other similar projects. References | Related Articles | Metrics

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- - 2005, 26 (11):  98-101.  DOI: - Abstract ( 192 )   HTML   PDF (181KB) ( 647 )   - References | Related Articles | Metrics

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- - 2005, 26 (11):  102-105.  DOI: - Abstract ( 221 )   HTML   PDF (187KB) ( 986 )   - References | Related Articles | Metrics