Archive

15 January 2009, Volume 30 Issue 1 Previous Issue    Next Issue
---
OriginalPaper


For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

OriginalPaper

Select

Chaos control of a class of delayed ecological models Fu, Jing-Chao (1); Jing, Yuan-Wei (1); Zhang, Zhong-Hua (1); Zhang, Si-Ying (1) 2009, 30 (1):  1-4+12.  DOI: - Abstract ( 427 )   HTML   PDF (467KB) ( 680 )   To a class of delayed population ecological models, the presence of chaotic phenomena in those models are validated simply and visually by numerical simulation to give the time-dependent graphs of Lyapunov exponents. Then, introducing the improved straight-line stabilization method to control the chaotic phenomena in the models, a controller is designed to stabilize the biological population in the orbits where the fixed points lie on, thus eliminating the chaotic phenomena in population to keep the population system in persistent existence. The validity of the controller is confirmed by simulation results. References | Related Articles | Metrics

Select

Feedback stabilization of nonlinear singularly perturbed systems Meng, Bo (1); Jing, Yuan-Wei (1); Liu, Xiao-Ping (1) 2009, 30 (1):  5-8.  DOI: - Abstract ( 272 )   HTML   PDF (2185KB) ( 593 )   A state feedback controller is designed for a class of singularly perturbed systems, where the fast systems are linear but the slow ones are partially input/out put linearizable. Based on the double time scale theory in singular perturbation, an original system is divided into fast and slow subsystems and the latter are in the standard form of affine nonlinear system. The relevant Lyapunov functions are deduced for the linear part and zero dynamics of slow subsystem and the boundary layer system. As a result, the sufficient conditions for asymptotical stability of the system are given through calculating the derivatives of the composite Lyapunov function along original trajectory, then the upper bound expression of Ε singular perturbation parameter is given. Simulation results show the effectiveness and feasibility of the theoretical method proposed. References | Related Articles | Metrics

Select

Design of a dynamic output variable structure controller for uncertain linear systems Yan, Min-Xiu (1); Jing, Yuan-Wei (1); Jiang, Nan (1) 2009, 30 (1):  9-12.  DOI: - Abstract ( 226 )   HTML   PDF (1161KB) ( 468 )   The design of an output feedback controller is investigated to enable a closed-loop system to be asymptotically stable for a class of uncertain systems. A controller is proposed including both nonlinear and linear parts, and the latter is stressed in design. Dynamics is introduced completely to eliminate mismatched uncertainties and, on the other hand, the nonlinear part is simplified as possible. Based on the Lyapunov theory and LMI (linear matrix inequality), the sufficient conditions for the existence of the control law of dynamic output feedback variable structure are derived and transformed into a feasibility problem in terms of LMI. The problem can thus be solved by Matlab LMI toolbox so as to build the variable structure controller for a class of uncertain linear systems. A Matlab simulation example is given to illustrate that this analysis method and its results are valid and feasible. References | Related Articles | Metrics

Select

Robust output-feedback control for a class of uncertain discrete switched fuzzy systems with time-delay Liu, Yi (1); Feng, Jia-Xin (2); Zhao, Jun (1) 2009, 30 (1):  13-16.  DOI: - Abstract ( 244 )   HTML   PDF (229KB) ( 586 )   Investigates the problems of robust output-feedback control for a class of uncertain discrete switched fuzzy systems with time-delay. A state observer is constructed when the states are immeasurable. Supposing that each and every subsystem of the switched system is fuzzy system, the multiple Lyapunov functions method is adopted for the system state with the common Lyapunov function method used for the observer error to design the switched control law. And the PDC (parallel distributed compensation) algorithm is used to design the fuzzy output-feedback controllers, thus enabling a closed-loop system to provide robustness for all admissible uncertainties in the feedback controller designed and in accordance to the switched control law designed as above. A simulation example shows the feasibility and effectiveness of the design method. References | Related Articles | Metrics

Select

Stability of singular networked control system with delay and data packet dropout Du, Zhao-Ping (1); Zhang, Qing-Ling (1); Liu, Li-Li (1) 2009, 30 (1):  17-20.  DOI: - Abstract ( 243 )   HTML   PDF (196KB) ( 660 )   The regular and impulsive-free singular NCSs (networked control systems) with networked-induced delay and data packet dropout are discussed, where the sensor node is time-driven but the controller and executor are event-driven. Assuming that the transfer delay is shorter than the sampling period and the data packets can be transferred successfully at a constant rate, the singular NCS can be modeled as an asynchronous dynamical system. With the Lyapunov function and LMI (linear matrix inequality) method, the sufficient conditions for stability is given and, by virtue of the Matlab LMI toolbox, the desired state feedback control law is given at the same time. A simulation example is given to illustrate that the proposed method is efficient. References | Related Articles | Metrics

Select

Parameter estimation based on wireless sensor network for forest fire model Wu, Cheng-Dong (1); Meng, Wei (1); Ji, Peng (1); Chen, Fei (1) 2009, 30 (1):  21-25.  DOI: - Abstract ( 261 )   HTML   PDF (336KB) ( 747 )   Since forest fire is too complicated to search, extinguish and rescue, the wireless sensor network (WSN) is applied to forest fire detection and an exact model is developed to estimate the location and intensity of fire. The approach to adaptive sampling by use of sensor nodes is discussed with a multi-peak Gaussian model proposed. Combining the expectation maximum (EM) with multiple resolution (MR) algorithm, an advanced EM-MR algorithm is proposed to estimate the parameters in the forest fire model. Based on the results of comparative simulation, this model can depict the relative real site of forest fire and provide the satisfactory estimation accuracy with computation complexity significantly reduced. References | Related Articles | Metrics

Select

Multi-model predictive control of nonlinear systems Zeng, Jing (1); Xue, Ding-Yu (1); Yuan, De-Cheng (2) 2009, 30 (1):  26-29.  DOI: - Abstract ( 308 )   HTML   PDF (313KB) ( 737 )   The multi-model predictive control strategy is presented to solve the control problem of typical nonlinear systems, i.e., the wastewater treatment process. The way to develop the multi-model is based on the local models which were systematically developed via finding out the data set from numerous accumulated system input/output database to match the current modality and taking advantage of the fitting of polynomial. Then, the multiple model were developed according to the variation in system modality. Combining the multiple models thus developed with predictive control, the multi-model predictive control strategy is proposed, thus solving the control problem of a class of unknown-structure nonlinear systems just on the basis of numerous historical database. The simulation test illustrates the validity of this approach. References | Related Articles | Metrics

Select

A new method of soft sensor modeling based on Learn+ + algorithm Tian, Hui-Xin (1); Mao, Zhi-Zhong (1) 2009, 30 (1):  30-33.  DOI: - Abstract ( 241 )   HTML   PDF (965KB) ( 548 )   A modified Learn++ algorithm adaptable to regression problems is applied to modeling soft sensors to rise above the defects in conventional method of soft sensor modeling. In the Learn+ + algorithm not only the conventional integrated algorithm can be kept up to improve the performance of single learner, but the drawbacks that the learnt information is easy to be forgotten by existing learning method of soft sensors and the waste of time/resource due to using repeatedly original training data can both be overcome. Learn+ + algorithm thus has incremental learnability. ELM algorithm is selected as a " weak learner " in modeling process because it learns faster and simpler and has higher generalizability than conventional neural network, thus getting rid of the limitation of local minimization and overfitting. The new modeling method based on Learn+ + has been used to model the soft sensors for molten steel temperature in LF, and the results revealed that its high accuracy can meet actual requirement in production. References | Related Articles | Metrics

Select

Integrated data cleaning strategy based on RFID applications Gu, Yu (1); Li, Xiao-Jing (1); Lv, Yan-Fei (1); Yu, Ge (1) 2009, 30 (1):  34-37.  DOI: - Abstract ( 417 )   HTML   PDF (403KB) ( 1153 )   Numerous unreliable, redundant and time-stamp disordered data take place in RFID applications. However, the existing techniques of RFID data cleaning are mainly for the single-type errors and not adaptable to the complicated errors. An integrated data cleaning mechanism is therefore proposed to provide the accuracy, conciseness and sequentiality for RFID data. The mechanism is composed of local filter and global filter. The local one is used to process the data received by single reader and sequence them in accordance to time-stamp with time delayed, then the false-positives are deleted through corresponding constraints according to different distributions of RFID data stream. On the other hand, the global one is used to process the data from multiple readers, where both the false negatives or positives are filled in or deleted, respectively, considering spatio-temporal correlation of tag readings with constraints set up to cancel redundant data. Experimental results showed that the cleaning mechanism proposed can correct various dirty data efficiently in accordance to different stream distributions. References | Related Articles | Metrics

Select

Analysis of IP-level topology data detected from single vantage point Zhao, Hai (1); Wang, Lin-Lin (1); Zhang, Xin (1); Yuan, Shao-Qian (1) 2009, 30 (1):  38-41.  DOI: - Abstract ( 222 )   HTML   PDF (354KB) ( 537 )   Due to the existence of cross-routing, there is a large gap between network topology detected from single point and the actual topology. The multi-point detection can make up the errors, but it's difficult to implement because of the high cost of erection and large amounts of data redundancy. The research is based on the massive data authorized by the CAIDA Skitter project and focuses on the analysis of ITM result from single vantage point in comparison with that from multiple vantage points. After calculating the difference between them on several eigenvalues, error distribution of data in each core detected from single point is analyzed based on the concept of coreness. Then, it is found that the intra-core distribution obeys the power-law and the inter-core distribution can be described by the fitted distribution formula. According to the procedure as above, the data results detected from single point can be revised to reduce errors and approach the integration data results measured from multi-points. References | Related Articles | Metrics

Select

An improved cross-realm client-to-client password-authenticated key exchange protocol Liu, Guang-Wei (1); Zhou, En-Guang (1); Yan, Hong (1); Zhou, Fu-Cai (1) 2009, 30 (1):  42-45.  DOI: - Abstract ( 269 )   HTML   PDF (182KB) ( 703 )   The client-to-client password-authenticated key exchange (C2C-PAKE) protocol enables two clients from different realms to agree on a shared common session key. Describing the C2C-PAKE protocol of Byun2007, its security is analyzed and it is found that the protocol is easy to suffer the attacks due to password-compromised impersonation and undetected on-line dictionary. An improved C2C-PAKE protocol is therefore proposed to introduce the public key mechanism into system security to resist those attacks effectively, especially only six operational steps are needed in relevant communication. As shown in security analysis, the protocol proposed is available to meet the security requirements. References | Related Articles | Metrics

Select

An improved Gabor-based fingerprint enhancement method Mao, Ke-Ming (1); Wang, Guo-Ren (1); Yu, Chang-Yong (1); Jin, Yan (1) 2009, 30 (1):  46-49.  DOI: - Abstract ( 465 )   HTML   PDF (558KB) ( 1547 )   Since most of existing fingerprint image enhancement methods using Gabor wavelet have the disadvantage that their filtering regions are fixed, an improved method is proposed. The performance of Gabor wavelet and inherent characteristics of fingerprint image are investigated in depth to determine the orientation of Gabor wavelet and relevant frequency parameters. And an area is set up as the filtering region to enhance a fingerprint image, which can be modulated automatically according to the change in local ridge orientation and frequency. Experimental results showed that the improved method can denoise the fingerprint images efficiently and that the information on ridge orientation is able to be well restored so as to improve the precision of subsequent operation for fingerprint matching. References | Related Articles | Metrics

Select

A database search algorithm based on information theory for protein identification Yu, Chang-Yong (1); Wang, Guo-Ren (1); Mao, Ke-Ming (1); Zhai, Wen-Dan (1) 2009, 30 (1):  50-53.  DOI: - Abstract ( 223 )   HTML   PDF (324KB) ( 841 )   The ITPIA (information theory based protein identification algorithm) based on information theory is proposed to search protein database by use of polypeptide tandem mass spectra for more exact protein identification. To solve efficiently the problem of low-quality and noisy spectra, the entropy theory is introduced in the ITPIA with a scoring system built to measure the similarity between the experimental spectrum and the theoretical spectrum of polypeptide in the database. The algorithm thus acquires more information on protein structure via the polypeptide tandem mass spectra. Experimental results showed that ITPIA algorithm can effectively improve the exactness of protein identification. References | Related Articles | Metrics

Select

Recognition based on multilevel SVM for different sintering states in rotary kiln Jiang, Hui-Yan (1); Zhou, Xiao-Jie (2); Chai, Tian-You (2) 2009, 30 (1):  54-57.  DOI: - Abstract ( 231 )   HTML   PDF (904KB) ( 577 )   A new design method based on multilevel SVM classifier is presented to recognizethe normal sintering, oversintering and undersintering states in rotary kiln. The ROIs (regions of interesting) were segmented from the images of sintered materials by an improved dual-fast marching method, including the zones of materials, blackbar, flame and full calcinations. Then, the characteristics of colour, shape and vein were extracted from ROIs to develop a pre-treated classifier model based on One-Versus-Another method to classify the different sintering states. The distribution of wrong sample points provided by the pre-treated classifier was studied, and the sample points that are easy to confuse with each other were classified as the same class. Based on the multilevel SVM, a new classifier model was thus redeveloped for different sintering states. The experimental results showed that the new model is fast and accurate with wide applications. References | Related Articles | Metrics

Select

Data dependencies based on Vague relational data model Zhao, Fa-Xin (1); Ma, Zong-Min (1); Wang, Hai-Long (1) 2009, 30 (1):  58-62.  DOI: - Abstract ( 244 )   HTML   PDF (2062KB) ( 582 )   Based on the vague relational data model and vague similarity measure as shown in earlier works, the vague data dependencies on database are investigated. The definitions of vague functional dependencies (VFDs) and vague multivalued functional dependencies (VMVDs) are both given, as well as the inference rules corresponding to them, which are similar to Armstrong's axioms of the VFD and VMVD in classical relational database and named the vague axioms. The effectiveness and completeness of vague axioms are proved with the idea about the satisfiability of VFDs and formula to calculate the satisfiability both given. References | Related Articles | Metrics

Select

A cluster-based security protocol in wireless sensor networks Wang, Gang (1); Wen, Tao (1); Guo, Quan (2); Ma, Xue-Bin (1) 2009, 30 (1):  63-66+82.  DOI: - Abstract ( 256 )   HTML   PDF (1712KB) ( 524 )   The CBSP (cluster-based security protocol) is proposed to enhance the original SPINS and SECOS protocols. In CBSP the security for clusterhead election and the updating mechanism of broadcast-based authentication key can efficiently improve the security of cluster and key management, thus reducing the number of nodes and consumption of network resources. The strand space model is used to make formalized analysis of the proposed protocol, and its correctness is verified. With the cluster-based intrusion detection system in CBSP, the attack from external nodes can be efficiently resisted. The updating cycles of clusterhead and key are shortened due to the response updating mechanism of IDS, and then the CBSP is further optimized. Simulation result showed that CBSP is available to adapt well the characteristics of WSN, especially when WSN suffers the selected or retransmitted attacks the CBSP will resist them effectively so as to reduce the damage to WSN resources. References | Related Articles | Metrics

Select

Research on NIRS physiological detection by Monte Carlo method Wang, Hai (1) 2009, 30 (1):  67-70.  DOI: - Abstract ( 244 )   HTML   PDF (459KB) ( 641 )   Based on NIRS physiological detection technologies, a new idea about scanning-style NIRS detection is put forward, where the NIRS imaging process will be implemented by Monte Carlo method with which the effect of scanning-style NIRS detection is first analyzed. Programmed with Visual C+ +, the detection model is developed from histology to image detection to trace a million of rays, then a comparative analysis is made for the scanned images of the channels of different lengths in combination with actual detection. A conclusion is thus drawn that the new-style detection has higher resolution than conventional one, thus verifying the distinctiveness of the new method. References | Related Articles | Metrics

Select

Implementation and verification of photon dose calculation using convolution/superposition algorithm Zhang, Tie (1); Li, Jian-Dong (1); Kang, Yan (2) 2009, 30 (1):  71-74.  DOI: - Abstract ( 392 )   HTML   PDF (1236KB) ( 824 )   Aiming at the implementation of the collapsed cone convolution/superposition dose calculation algorithm, the primary fluence or TERMA (total energy released per unit mass) is calculated using a polyenergetic spectrum which is formed with Monte Carlo code. The Hoban's algorithm is introduced into beam hardening correction, and the Ahnesjo's inverse square law is introduced to correct the kernel tilting at the dose deposition site. The accuracy of the algorithm was verified by using AAPM phantom data test packet and clinically measured data. The results revealed that the measured values conform well to the calculated results, and the accuracy of dose calculated is within 3% or 3 mm. The clinical feasibility of the collapsed cone convolution/superposition dose algorithm is therefore illustrated. References | Related Articles | Metrics

Select

Microstructure and properties of ZL116 alloy parts through semi-solid extrusion Wang, Ping (1); Liang, Tian (1); Zhao, Da-Zhi (1); Cui, Jian-Zhong (1) 2009, 30 (1):  75-78.  DOI: - Abstract ( 184 )   HTML   PDF (689KB) ( 897 )   The as-cast microstructure of ZL116 alloy castings prepared by nearby liquidus casting were studied by means of electron microscope, then the mechanical properties of the parts through thixoforming extrusion were tested on horizontal extruder and electronic tensile tester. The results showed that the ZL116 aluminum alloy castings with refined rosette grains were obtained by means of near-liquidus semi-continuous casting process, in which lots of refined Si grains are found in uniform distribution when reheating the semi-solid ingots at 575°C, and they are advantageous to semi-solid thixoforming. The brackets used in airplane can be thixoformed successfully using the horizontal 800 T extruder by which the tensile strength can be up to 320 MPa with percentage elongation 11.4% after heat-treatment. References | Related Articles | Metrics

Select

Preparation of SiC whiskers pre-added Ni-based cladding on Cu alloy surface by laser deposition Dong, Jiang (1); Liu, Fang (2); Chen, Sui-Yuan (1); Liu, Chang-Sheng (1) 2009, 30 (1):  79-82.  DOI: - Abstract ( 256 )   HTML   PDF (457KB) ( 924 )   To prepare the SiC whiskers pre-added wear-resistant Ni-based cladding on copper alloy substrate for mold making, a 5 kW continuous wave CO2 laser was used with the deposition process parameters optimized. A Ni-Cu based cladding was thus deposited, where the powdered Ni1015 was provided for the laser cladding process to form a smooth surface layer bonded metallurgically with Cu substrate, whose grain-refining microstructure is homogeneous, compact, void-free and crack-free. Tested by OM, SEM and micro Vickers, the results showed that the layer's average microhardness is 150 HV higher than no-SiC cladding, about 3.7 times as high as that of Cu substrate (85 HV). Thus, the properties of the mold made from such a Cu alloy can be greatly improved when used in continuous casting. References | Related Articles | Metrics

Select

Numerical simulation of reversible V-H multipass rolling process Wang, Xiao-Nan (1); Di, Hong-Shuang (1); Liang, Bing-Jie (1) 2009, 30 (1):  83-85+89.  DOI: - Abstract ( 245 )   HTML   PDF (303KB) ( 798 )   Based on the actual data acquired in site, the reversible V-H 5-pass rolling process was numerically simulated with explicit dynamic method and restart method. The results showed that in the rolling process the thick slabs tend to double bulging deformation, while the thin ones exhibit single bulging deformation in general. The vertical or edge rolling can correct the double bulging deformation effectively so as to avoid metal sandwiches on the edge of workpiece. Tracking the corner nodes, it is found that the slab corner metal flows to both forward and back sides of workpiece. The vertical or edge rolling can repair tiny defects to a certain extent, thus improving the edge quality of rolled strip. The approach proposed is available to analyze the reverse rolling process and will provide exact rolling parameters for each and every pass of V-H rolling. References | Related Articles | Metrics

Select

Effect of composition of powdered iron ore on sinter strength Jin, Ming-Fang (1); Zhu, Dao-Fei (2); Zheng, Zhong (2); Shen, Feng-Man (1) 2009, 30 (1):  86-89.  DOI: - Abstract ( 235 )   HTML   PDF (1215KB) ( 580 )   The structure of the bonding phases of sinter depends on the properties of melts formed during iron ore hematite sintering. A bench-scale test was therefore carried out to investigate the effect of powdered iron ore composition (SiO2, Al2O3, MgO and bacisity) on the sinter strength, of which the change was further explained by the effect of the composition on the viscosity and surface tension of the melt. The results showed that the mass ration of additive CaO to the powdered ore changes in the range from 0.08 to 0.15 and the max compression and rupture strength of sinter are obtained at the ration=0.12 and, with respect to the changing basicity during sintering, the max strengths are obtained at the basicity R=2.0. The strengths decrease gradually with the increasing MgO content in hematite, and it is unfavorable if the Al2O3 content exceeds 2.5wt%. References | Related Articles | Metrics

Select

Experimental investigation of influencing factors on carbon output from rotary calcining kilns Wang, Chun-Hua (1); Chen, Wen-Zhong (1); Chen, Hai-Geng (1); Feng, Ming-Jie (1) 2009, 30 (1):  90-93.  DOI: - Abstract ( 230 )   HTML   PDF (393KB) ( 476 )   A lab-scale experimental setup was provided to investigate the influencing factors on the carbon output from a rotary calcining kiln, such as rotating speed, kiln slope, kiln inner diameter and height of dam at kiln tail. The results indicated that the mean residence time in kiln is shortened greatly if the rotating speed is lower than 4 r/min and shortened moderately if higher than 4 r/min, and the time is shortened as well with the increasing kiln slope and height of dam. The carbon output from the kiln increases greatly if the rotating speed is lower than 3 r/min and its increment lowers if higher than 3 r/min, and the output increases greatly with the increasing height of dam. In addition, the position where the feeding pipe is mounted in also affects obviously the output from the kiln. References | Related Articles | Metrics

Select

Continuous production of Al-Li master alloys by molten salt electrolysis Li, Ji-Dong (1); Zhang, Ming-Jie (1); Zhang, Ting-An (1); Li, Dan (1) 2009, 30 (1):  94-97.  DOI: - Abstract ( 446 )   HTML   PDF (1016KB) ( 614 )   Al-Li master alloys were prepared by continuous electrolysis with either LiCl or Li2CO3 as raw material, where the graphite was used as anode and liquid aluminum as cathode in an electrolytic cell with the LiCl-LiF mixture as electrolyte. The technological parameters in electrolysis process were measured by testing device of molten salt electrolysis, including back EMF, current efficiency and alloy concentration, which were all studied in detail. The results showed that the back EMF increases with current density and decreases by 0.8 V if adding 2wt% Li2CO3. Measured by the method of electric potential control, the feeding period is 30~40 min. The current efficiency in electrolysis process for LiCl is higher than that for Li2CO3, and the highest current efficiency can be up to 66.1%. The gross output of 16kg Al-Li alloys in which the average lithium content is 6.73% were thus produced 10 times at 680°C and 300 A by continuous electrolysis for 48 h. References | Related Articles | Metrics

Select

On the BaPbO3 conductive film deposited on monocrystalline LaAlO3 substrate Gao, Feng (1); Li, Feng-Hua (1); Wang, Na (1); Fan, Zhan-Guo (1) 2009, 30 (1):  98-100+104.  DOI: - Abstract ( 273 )   HTML   PDF (873KB) ( 567 )   The flat and smooth BaPbO3 thin film with a certain crystal orientation was prepared as a conductively isolated layer for YBCO coated conductors. In the experiment, a stably homogeneous precursor solution was obtained taking the barium acetate and lead acetate as solutes with propionic acid as solvent. Then, the precursor film was deposited on the monocrystalline LaAlO3 (100) substrate by spin-coating the solution, and a BaPbO3 thin film was prepared by sintering the precursor film at 650 °C for 30 min in oxygen atmosphere. The XRD patterns showed that the film is of single-phase BaPbO3 with a slight (100) orientation, and the SEM images revealed that the film is about 650 nm thick with a compact and homogeneous surface. The thin film resistance was measured by four-probe method at room temperature and the resistivity is about 1×10-3 Ω·cm. References | Related Articles | Metrics

Select

Study on change of polysaccharide content in leaching bacteria during adsorbing refractory gold ore Yang, Hong-Ying (1); Wang, Sheng-Li (1); Fu, Yao (1); Fan, You-Jing (1) 2009, 30 (1):  101-104.  DOI: - Abstract ( 238 )   HTML   PDF (303KB) ( 568 )   The polysaccharide content in the bacterium HQ0211 lysate was determined by phenol-vitriol method, from which some optimal values were given including the lyric time 25 min, adsorption wavelength 430 nm and cooling time 10 min. In the test using the leaching bacterium HQ0211 to adsorb/oxidate the refractory As-bearing gold ore, it was found that the polysaccharide of bacterium cell changes with the potential of solution. When the potential is 480~572 mV and 638 mV, the polysaccharide contents of free bacterial cells in solution and of bacterial cells adsorbed on grains of As-bearing gold ore are 0.033~0.123 mg/mL and 5.3~8.9 mg/g, 1.155 mg/mL and 57.5 mg/g, respectively. References | Related Articles | Metrics

Select

Preparation and characterization of a new red-emitting phosphor CaxSr1-x-y-zMoO4: yEu3+, zNa+ for LED Cao, Fa-Bin (1); Tian, Yan-Wen (1); Chen, Yong-Jie (2); Xiao, Lin-Jiu (2) 2009, 30 (1):  105-109.  DOI: - Abstract ( 230 )   HTML   PDF (466KB) ( 609 )   The CaxSr1-x-y-zMoO4: yEu3+, zNa+ as a red phosphor was prepared for LED by solid-state reaction with Na+ as charge compensating agents. The effects of Na+ dose, Ca2+ content in matrix, synthesizing temperature, reaction time and the molecular fraction of Eu3+ as luminescent center on the luminescent properties and crystal structure of the phosphor were studied. The results showed that the optimum reaction conditions in molecular fraction are 6% Na+, 8% Eu3+ and 60% Ca2+ with reaction temperature 900 °C for 2 h. The luminescent spectra revealed that the red-emitting phosphor can be effectively excited at 616 nm emitting peak by 311 nm, 395 nm or 465 nm. References | Related Articles | Metrics

Select

Synthesis of chiral liquid crystal AEMBB with twist grain phases Wang, Ji-Wei (1); Wang, Jian-Hua (1); Liu, Lu-Mei (2); Zhang, Bao-Yan (1) 2009, 30 (1):  110-112.  DOI: - Abstract ( 275 )   HTML   PDF (415KB) ( 514 )   The chiral liquid crystal monomer (+)4-(2-acryloyloxy)-ethoxybenzoyloxy-[4'-(2-methyl)-butoxy] biphenyl (AEMBB) was designed and synthesized according to the theory of twist grain boundary (TGB) which can be observed in chiral materials with strong twisting power. The termination of the reaction process can be judged according to the carboxylic acid/hydroxyl peak vanished from the reactant by Fourier transform infrared spectroscopy (FTIR). The implementation of the target chemical structure of the monomer depends on the position of 1H as determined by the spectroscopy of 1H nuclear magnetic resonance (NMR). The properties and phase transition of the target monomer were studied by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC), and the results revealed that the monomer is an enantiotropic liquid crystal available to be in cholesteryl, twist grain or chiral smectic C phases. References | Related Articles | Metrics

Select

A new low-temperature synthesizing process of methanol from CO/CO2/H2 and catalysts used Li, Wen-Ze (1); Zhang, Bao-Yan (1); Xiao, Lin-Jiu (2); Yang, Rui-Qin (2) 2009, 30 (1):  113-116+124.  DOI: - Abstract ( 247 )   HTML   PDF (207KB) ( 1086 )   Methanol was synthesized with syngas (CO/CO2/H2) as starting material and Cu-Zn based catalysts at low temperature/pressure (443 K/3.0 MPa), where the 2-butanol was used as solvent. In such a reaction process the alcohol solvent was not consumed but played a catalytic role. The effects of the carriers and rare-earth additives on the activity of catalyst were investigated, and the results showed that the Cu/ZnO catalyst exhibits the highest activity in all catalysts prepared using ZnO, MgO, Al2O3, La2O3, Y2O3 as carriers in low-temperature synthesis reaction process of methanol. The activity of the Cu-Zn based catalysts increases if using rare-earth elements as additives, and the highest activity belongs to the Cu/ZnO/Y2O3 catalyst in which the Y content is 7.5 wt% or the Cu/ZnO/La2O3 catalyst in which the La content is 10 wt%, i.e., the total carbon conversion rate is 10 % or 17.5% higher than using Cu/ZnO only, respectively. The methanol output increases by 17.5% if using Cu/ZnO/Y2O3 or Cu/ZnO/La2O3 catalyst in comparison with using Cu/ZnO catalyst. References | Related Articles | Metrics

Select

Study on NURBS interpolator with Taylor expansion Liu, Yu (1); Dai, Li (1); Liu, Jie (1); Wang, Jian (1) 2009, 30 (1):  117-120.  DOI: - Abstract ( 351 )   HTML   PDF (334KB) ( 1651 )   The NURBS (non-uniform rational B-spline) interpolator was studied with the first and second order Taylor expansion to approximate NURBS parameter. Numerical example results proved that the interpolation velocity is almost the same to reference velocity. The relationships between curvature and velocity fluctuating and between chord error and interpolation period in the Taylor expansion were given. It was found that the NURBS interpolator with Taylor expansion is actually a kind of open loop method. However, it ignores the output capability of a mechanical system and, therefore, big processing error may occur when the output capability of the mechanical system is insufficient. References | Related Articles | Metrics

Select

An algorithm based on differential evolution for contour matching Gu, Yu-Ming (1); Liu, Jie (1); Yang, Ke-Shi (1); Zhang, Zhan-Yi (1) 2009, 30 (1):  121-124.  DOI: - Abstract ( 314 )   HTML   PDF (412KB) ( 755 )   Contour matching is an integral part in image processing. Analyzing the limitation of the conventional contour matching methods which take a long time to search, an improved algorithm is proposed for contour matching. In the algorithm the contours of the template image and of the image to be matched are extracted separately so as to calculate the curvature of every point on contours, and the candidate point is selected from those points on contour for satisfying the threshold. Then the eigenvectors are built at the candidate point and several points on its both sides. The comparability measurement function is built according to the Euclidean distance, and the global optimization problem is solved by differential evolution algorithm. Comparative experiment results showed that the method proposed has quick optimizing speed and high matching ability. References | Related Articles | Metrics

Select

Research on the node attribute hierarchy of structure model of complex product design Zhang, Jia-Yi (1); Wang, Cheng-En (1); Ma, Ming-Xu (1) 2009, 30 (1):  125-128.  DOI: - Abstract ( 290 )   HTML   PDF (547KB) ( 594 )   The hierarchical structure and expression method of design information are analyzed in the process of collaborative design of complex products. According to the characteristics of complex product design, such as massive data and multidisciplinary design optimization, a new two-level tree(TLT) product structure model is framed to describe the levels and construction of complex product design information. Categorizing the subjects concerned, the attribute node is extended to an attribute tree to benefit the access and management of various design information. Then, a two-level attribute tree is proposed, i.e., the subject data level and subject collaboration level. The functions of both levels and mapping relationship between them are discussed, with a uniform representation given for the data storage structure and node data in the TLT constructional model. The analysis of an example showed that the TLT model is favorable to realize the sort management of subject information and available to the effective utilization of subject information resources and improvement of complex product design efficiency. References | Related Articles | Metrics

Select

A negotiation model for customer satisfaction in collaborative design circumstances Liang, Shuang (1); Yu, Tian-Biao (1); Su, Ying-Ying (1); Wang, Wan-Shan (1) 2009, 30 (1):  129-132+152.  DOI: - Abstract ( 310 )   HTML   PDF (465KB) ( 643 )   In view of the characteristics of the product design under networked manufacturing conditions, the importance of customer satisfaction index (CSI) is analyzed in product design. The CSI is applied to the negotiation mechanism in the circumstances of collaborative design. According to the design requirements in the collaborative design circumstances, the CSI system is analyzed with a mathematical model developed. Moreover, the multi-agent technology is introduced to develop a negotiation agent model and the CSI based negotiation process is studied. Combining with the enterprise actual demand, the CSI in the negotiation process for collaboration is evaluated through training and simulation by using BP neural network to reduce artificial factors so as to improve the reliability of evaluation. At the same time, the results verified the reliability of CSI evaluation based on BP neural network. References | Related Articles | Metrics

Select

On the surface modification of basic magnesium sulfate whiskers Han, Yue-Xin (1); Li, Li-Xia (1); Yin, Wan-Zhong (1); Chen, Xu (1) 2009, 30 (1):  133-136.  DOI: - Abstract ( 433 )   HTML   PDF (453KB) ( 1315 )   The surface of basic magnesium sulfate whiskers were modified with sodium stearate as modifier, and the modification effect was evaluated by activation index, oil adsorption value and rest angle. And the whiskers were characterized beforekind after surface modification by SEM, TG-DSC and FTIR. The results showed that modification effect is so remarkable that the activation index is up to 99.21% from 0.87%, oil adsorption value loweres to 349 mL/(100 g) from 488 mL/(100 g), and the whisker surface become hydrophobic from hydrophilic. The liquidity and dispersibility of the modified whiskers are both improved significantly and no obvious effect of the surface modification process is found on the whiskers' thermal decomposition. As a conclusion, both the chemical and physical adsorption are functioning sodium stearate and the whisker surface. References | Related Articles | Metrics

Select

Preparation of polymeric silicate phosphate ferrous sulfate used to treat wastewater from high-viscosity oil petrification Xu, Xin-Yang (1); Li, Li-Jun (2); Li, Ru (1) 2009, 30 (1):  137-140.  DOI: - Abstract ( 376 )   HTML   PDF (215KB) ( 975 )   A new kind of flocculant, named polymeric silicate phosphate ferrous sulfate (PSPFS), was synthesized with ferrous sulfate as main material and silicate and phosphate as additives. The influencing factors in the synthesis process of PSPFS were experimentally investigated to determine the optimal preparation conditions as follows. The mass fractions of ferrous sulfate and sodium silicate should be 55% and 15%, respectively, and the mole ratio of ferrous sulfate to hydrogen peroxide should be 1.2:1. The oxidation temperature is 40 °C held for 4 h, and polymerization temperature is 60?°C for 2 h. Determined by homogeneous compound the optimal mole ratios of ferric ion to silicate, sulfuric acid and phosphate radical are 5.0:1, 3.2:1 and 18.0:1, respectively. The experimental results showed that the flocculant synthesized under the conditions mentioned above is able to remove 94.1% oil from high-viscosity oil petrification wastewater of Liaohe Pertrochemical Corporation. References | Related Articles | Metrics

Select

Effect of aeration quantity on separation of low-grade bauxite by cyclone-reverse flotation Gao, Shu-Ling (1); Wei, De-Zhou (1); Fang, Ping (1); Cao, Hui-Chang (2) 2009, 30 (1):  141-144.  DOI: - Abstract ( 239 )   HTML   PDF (438KB) ( 716 )   Based on the characteristics of China's bauxite and cyclone separation, the cyclone-reverse flotation technique was experimentally carried out for the separation of low-grade bauxite, of which the ω (Al2O3)/ω (SiO2), abrasive size and mass fraction are 4.39, less than 0.074 mm and 61.90%, respectively. The effect of aeration quantity on separation process/indexes was investigated. The results showed that when the aeration quantity increases in the range from 0 to 4.0 m3/h, the envelope of zero vertical velocity will shrink around the axis, and make the separation indexes poorer. But with the same aeration quantity, the increasing feed pressure will be advantageous to the process of cyclone-reverse flotation and make the separation indexes better. When the aeration quantity increases in the range from 0 to 0.8 m3/h, the envelope of zero vertical velocity shrinks slightly around the axis to weaken the classification effect on mineral particles due to size difference, but strengthen the separation effect on those particles due to the differences of density and surface properties, and at that time, the separation indexes are better than no aeration. References | Related Articles | Metrics

Select

An empirical study for industrial structure in liaoning province in the perspective of energy saving Li, Ming-Yu (1); Li, Kai (1); Yu, Pei-Li (1); Chen, Hao (1) 2009, 30 (1):  145-148.  DOI: - Abstract ( 279 )   HTML   PDF (189KB) ( 586 )   Based on the complete decomposition model, the main influencing factors on the energy consumption/saving in Liaoning Province are studied, such as energy intensity and industrial structure. The results showed that although the energy intensity plays an important role in energy saving, the industrial structure relates closer to energy saving. How the industrial restructuring steps up energy saving is therefore discussed statistically by regression analysis. It was found that there are significant relationships between the output value percentages of the industries, including industry, construction and transportation, and energy saving, and the critical proportion of output values of the three industries available to step up energy saving in Liaoning Province is given by analyzing the regression results. It was revealed that the changing trend of output value percentages of manufacture and transportation industries stepped up the energy saving. References | Related Articles | Metrics

Select

An empirical study on service personal values of consumers based on chinese cultural context Liu, Ru-Ping (1); Ma, Qin-Hai (1); Liu, Rui (2); Zhang, Yue-Xian (1) 2009, 30 (1):  149-152.  DOI: - Abstract ( 279 )   HTML   PDF (887KB) ( 581 )   The SERPVAL scale is applied to measure the mobile service for 388 consumers' service personal values in Shenyang PRC and a confirmatory factor analysis is made afterwards. The result shows that a consumer tends to assess the satisfaction of a service in view of the three dimensions of personal values, i.e., the peaceful life, social recognition and social integration. The ANOVA (analysis of variance) results reveal that there are discrepancies in respect to the satisfiable recognition due to different personal values for the mobile service provided to those customers who are different at ages and educational levels. This study will be beneficial to the service organizations to develop and design new services and marketing strategy, based on the service personal values of consumers. References | Related Articles | Metrics