Anthropogenic aluminum cycle in China was analyzed by the aluminum flow diagram based on the life cycle of aluminum products. The whole anthropogenic aluminum cycle consists of four stages: alumina and aluminum produ...Anthropogenic aluminum cycle in China was analyzed by the aluminum flow diagram based on the life cycle of aluminum products. The whole anthropogenic aluminum cycle consists of four stages: alumina and aluminum production, fabrication and manufacture, use and reclamation. Based on the investigation on the 2003-2007 aluminum cycles in China, a number of changes can be found. For instance, resources self-support ratio (RSR) in alumina production dropped from 95.42%to 55.50%, while RSR in the aluminum production increased from 52.45%to 79.25%. However, RSR in the Chinese aluminum industry leveled off at 50%in the period of 2003-2007. The respective use ratios of domestic and imported aluminum scrap in the aluminum industry of 2007 were 5.38% and 9.40%. In contrast, both the net imported Al-containing resources and the lost quantity of Al-containing materials in aluminum cycle increased during the same period, as well as the net increased quantity of Al-containing materials in social stock and recycled Al-scrap. Proposals for promoting aluminum cycle were put forward. The import/export policy and reducing the loss of Al-containing materials for the aluminum industry in China in the future were discussed.展开更多
By introducing the analytic hierarchy process (AHP), a model is constructed to compare the logistics development level of cold chain for agricultural products between China and other developed countries such as Unit...By introducing the analytic hierarchy process (AHP), a model is constructed to compare the logistics development level of cold chain for agricultural products between China and other developed countries such as United States, Japan and Euro- pean. The paper makes a comparative study on the development levels of agricultural cold chain logistics in China and developed countries from the aspects of the level of cold chain logistics facilities and equipments, the degree of cold chain logistics market-oriented and the capacity of cold chain logistics, then determines the problems of cold chain logistics in China. With the experiences learning from developed countries, some countermeasures are proposed to resolve those problems of cold chain logistics for agricultural products development combining with the national conditions in China.展开更多
Gassmann's equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction r...Gassmann's equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction reliability.In this paper,combining the Russell fluid factor with the Gassman-Biot-Geertsma equation and introducing the dry-rock Poisson's ratio,we propose an effective matrix mineral bulk modulus extraction method.This method can adaptively invert the equivalent matrix mineral bulk modulus to apply the Gassmann equation to fluid substitution of complex carbonate reservoirs and increase the fluid prediction reliability.The verification of the actual material fluid substitution also shows that this method is reliable,efficient,and adaptable.展开更多
Aimed at the uncertain characteristics of discrete logistics network design,an interval hierarchical triangular uncertain OD demand model based on interval demand and network flow is presented.Under consideration of t...Aimed at the uncertain characteristics of discrete logistics network design,an interval hierarchical triangular uncertain OD demand model based on interval demand and network flow is presented.Under consideration of the system profit,the uncertain demand of logistics network is measured by interval variables and interval parameters,and an interval planning model of discrete logistics network is established.The risk coefficient and maximum constrained deviation are defined to realize the certain transformation of the model.By integrating interval algorithm and genetic algorithm,an interval hierarchical optimal genetic algorithm is proposed to solve the model.It is shown by a tested example that in the same scenario condition an interval solution[3275.3,3 603.7]can be obtained by the model and algorithm which is obviously better than the single precise optimal solution by stochastic or fuzzy algorithm,so it can be reflected that the model and algorithm have more stronger operability and the solution result has superiority to scenario decision.展开更多
[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus(AIV).[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid(MPA) to be m...[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus(AIV).[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid(MPA) to be monolayer on the silver-coated electrode of quartz crystal and coupling the monoclonal antibody to H9 subtype AIV with N-ethy-N'-(3-dimethyl aminopropyl)carbodiimide hydrochloride(EDC) and N-hydroxysuccinimide(NHS).The immunosensor to detect H9 subtype AIV was established.[Result] The results showed that the immunosensor displayed better specificity to H9 AIV and had no response to H5AIV and NDV when it was used for detection.The sensitivity test indicated the detection sensitivity for the H9 subtype AIV could reach 20-100 EID50.[Conclusion] The research provided a foundation for further research on the immunosensor for detecting AIV and it could be a new approach to detect other related viruses.展开更多
Single-phase Ag2Al intermetallic nanoparticles, and Ag and Al metallic nanoparticles were synthesized by the flow-levitation (FL) method. Measurements of d-spacings from X-ray diffraction and electron diffraction co...Single-phase Ag2Al intermetallic nanoparticles, and Ag and Al metallic nanoparticles were synthesized by the flow-levitation (FL) method. Measurements of d-spacings from X-ray diffraction and electron diffraction confirmed that the intermetallic nanoparticles had the hexagonal Ag2Al structure. The morphology, crystal structure and chemical composition of Ag2Al nanoparticles were investigated by transmission electron microscopy, X-ray diffraction and induction-coupled plasma spectroscopy. A thin amorphous coating was formed around the particles when exposed to air. Based on the XPS measurements, the surface coating of the Ag2Al nanoparticles could most likely be aluminum oxide or silver aluminum oxide. Therefore, the single-phase nanocrystalline Ag2Al intermetallic compound particles can be produced by adjusting some experimental parameters in FL method.展开更多
To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each ...To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each stage, the Pruefer number is used. With theimproved decoding procedure, any Pruefer number produced stochastically can be decoded to a feasiblelogistic pattern, which can match with the capacities of the nodes of the logistic system. Withthese two innovations, a new modeling method based on parameterized interface distribution and thePriifer number coding is put forward. The corresponding genetic algorithm, named as PIP-GA, can findbetter solutions and require less computational time than st-GA. Although requiring a little moreconsumption of memory, PIP-GA is still an efficient and robust method in the modeling andoptimization of unbalanced multi-stage logistic systems.展开更多
This paper presents a new method for robust and accurate optical flow estimation.The sig- nificance of this work is twofold.Firstly,the idea of bi-directional scheme is adopted to reduce the model error of optical flo...This paper presents a new method for robust and accurate optical flow estimation.The sig- nificance of this work is twofold.Firstly,the idea of bi-directional scheme is adopted to reduce the model error of optical flow equation,which allows the second order Taylor's expansion of optical flow equation for accurate solution without much extra computational burden;Secondly,this paper establishs a new optical flow equation based on LSCM (Local Structure Constancy Model) instead of BCM (Brightness Constancy Model),namely the optical flow equation does not act on scalar but on tensor-valued (ma- trix-valued) field,due to the two reason:(1) structure tensor-value contains local spatial structure information,which provides us more useable cues for computation than scalar;(2) local image structure is less sensitive to illumination variation than intensity,which weakens the disturbance of non-uniform illumination in real sequences.Qualitative and quantitative results for synthetic and real-world scenes show that the new method can produce an accurate and robust results.展开更多
A new wastewater treatment equipment, the bi-external recycling biological fluidized bed (BRBFB), which is an effective equipment, was investigated. Anaerobic digestion, aerobic aeration and settlement processes with ...A new wastewater treatment equipment, the bi-external recycling biological fluidized bed (BRBFB), which is an effective equipment, was investigated. Anaerobic digestion, aerobic aeration and settlement processes with a fixed sequential procedure were compacted into this reactor. By five different treatment courses, the optimization of the combined operation procedure in the system was determined to be a 12-hour cycle including an inflow process, a 4 h anaerobic digestion process, a 4 h aerobic aeration process, a 2 h settlement process and a 2 h recess process including effluent discharge process. By utilizing BRBFB to treat a synthetic dyeing wastewater, 90% of COD_ Cr is removed for a higher-concentration water (COD_ Cr 1 000-1 200 mg/L), and 82% of COD_ Cr is removed for a lower-concentration water (COD_ Cr 400-600 mg/L). Near 100% color is removal and discharging standards for industry wastewater are achieved.展开更多
This paper introduced an integrated allocation model for distribution centers (DCs). The facility cost, inventory cost, transportation cost and service quality were considered in the model. An improved genetic algorit...This paper introduced an integrated allocation model for distribution centers (DCs). The facility cost, inventory cost, transportation cost and service quality were considered in the model. An improved genetic algorithm (IGA) was proposed to solve the problem. The improvement of IGA is based on the idea of adjusting crossover probability and mutation probability. The IGA is supplied by heuristic rules too. The simulation results show that the IGA is better than the standard GA(SGA) in search efficiency and equality.展开更多
In the present study, the effect of electroacupuncture (EA) of acupoints of Ren, Spleen and Stomach Meridians on artificial abortion induced side effects was observed in 100 artificial abortion women. In comparison wi...In the present study, the effect of electroacupuncture (EA) of acupoints of Ren, Spleen and Stomach Meridians on artificial abortion induced side effects was observed in 100 artificial abortion women. In comparison with 45 artificial abortion women in the control group (who had not accepted EA treatment), EA possessed significant effects in relieving abdominal pain, reducing vaginal bleeding duration, lowering infection rate and infertility rate after artificial abortion operation.展开更多
The Nanfei River (Anhui Province, China) is a severely polluted urban river that flows into Chaohu Lake. In the present study, sediments were collected from the river and analyzed for their heavy metal contents. Mul...The Nanfei River (Anhui Province, China) is a severely polluted urban river that flows into Chaohu Lake. In the present study, sediments were collected from the river and analyzed for their heavy metal contents. Multivariate statistics and the fuzzy comprehensive assessment method were used to determine the sources of pollution, the current pollution status, and spatial and temporal variations in heavy metal pollution in sediments. The concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) in sediments ranged from 5.67-113, 0.08-40.2, 41.6-524, 15.5-460, 0.03-4.84, 13.5-180, 18.8-250, and 47.9-1 996 mg/kg, and the average concentrations of each metal were 1.7, 38.7, 1.8, 5.5, l 8.8, 1.3, 2.5, and 11.1 times greater than the background values, respectively. Multivariate statistical analysis demonstrated that Hg, Cu, Cr, Cd, and Ni may have originated from industrial activities, whereas As and Pb came from agricultural activities. The fuzzy comprehensive assessment method, based on the fuzzy mathematics theory, was used to obtain a detailed assessment of the sediment quality in the Nanfei River watershed. The results indicated that the pollution was moderate in the downstream tributaries of the Nianbu and Dianbu Rivers, but was severe in the main channel of the Nanfei River and in the upstream tributaries of the Sill and Banqiao Rivers. Therefore, sediments in the Nanfei River watershed are heavily polluted and urgent measures should be taken to remedy the status.展开更多
Partition of unity based numerical manifold method can solve continuous and discontinuous problems in a unified framework with a two-cover system,i.e.,the mathematical cover and physical cover.However,renewal of the t...Partition of unity based numerical manifold method can solve continuous and discontinuous problems in a unified framework with a two-cover system,i.e.,the mathematical cover and physical cover.However,renewal of the topology of the two-cover system poses a challenge for multiple crack propagation problems and there are few references.In this study,a robust and efficient strategy is proposed to update the cover system of the numerical manifold method in simulation of multiple crack propagation problems.The proposed algorithm updates the cover system with a bottom-up process:1)identification of fractured manifold elements according to the previous and latest crack tip position;and 2)local topological update of the manifold elements,physical patches,block boundary loops,and non-persistent joint loops according to the scenario classification of the propagating crack.The proposed crack tracking strategy and classification of the renewal cases promote a robust and efficient cover renewal algorithm for multiple crack propagation analysis.Three crack propagation examples show that the proposed algorithm performs well in updating the cover system.This cover renewal methodology can be extended for numerical manifold method with polygonal mathematical covers.展开更多
A real-time sensing of the molecular distillation process temperature by a FLUKE brand thermograph Ti50 IR FlexCam and thermography technique was realized. After completion of the molecular distillation, three propert...A real-time sensing of the molecular distillation process temperature by a FLUKE brand thermograph Ti50 IR FlexCam and thermography technique was realized. After completion of the molecular distillation, three properties of heat transport chain cuts and residues obtained in the process were estimated by Differential Scanning Calorimetry (DSC) (specific heat, enthalpy, thermal conductivity). These properties are of great importance for improving oil characterization and for future modeling and simulation of the molecular distillation process. The results show that through the method of Differential Scanning Calorimetry, profiles have been obtained from the variation of specific heat, enthalpy and thermal condutivity as a function of temperature for samples of cuts from the distillation (ASTM D-2892) and fractions of distillate and residue from the process of molecular distillation.展开更多
The critical properties of five compounds, including propanal,butanal, 1-pentanal, 2-methel butanal and trimer of ethanal, weredetermined for the first time by a new capillary quick-flow method.The apparatus was impro...The critical properties of five compounds, including propanal,butanal, 1-pentanal, 2-methel butanal and trimer of ethanal, weredetermined for the first time by a new capillary quick-flow method.The apparatus was improved with a capillary tube and checked withhexane and 10heptene as standard reagents. The experimental resultsproved that the determination of critical properties by quick-flowmethod with a capillary tube apparatus was successful.展开更多
Pulsed signal experiment was carried out to determine the hydrodynamic behaviours of lateral flow biological aerated filter(LBAF). With the analysis of experimental results, LBAF is viewed as an approximate plug flow ...Pulsed signal experiment was carried out to determine the hydrodynamic behaviours of lateral flow biological aerated filter(LBAF). With the analysis of experimental results, LBAF is viewed as an approximate plug flow reactor, and hydraulic retention time distribution function was derived based on LBAF. The results show that flow rate and aeration strength are two critical factors which influence flow patterns in LBAF reactor. The hydrodynamic behaviour analysis of LBAF is the theoretical basis of future research on improving capacity factor and developing kinetic model for the reactor.展开更多
Three simple analytic expressions satisfying the limitation condition at low densities for the radial distribution function of hard spheres are developed in terms of a polynomial expansion of nonlinear base functions ...Three simple analytic expressions satisfying the limitation condition at low densities for the radial distribution function of hard spheres are developed in terms of a polynomial expansion of nonlinear base functions and the Carnahan-Starling equation of state. The simplicity and precision for these expressions are superior to the well-known Percus Yevick expression. The coefficients contained in these expressions have been determined by fitting the Monte Carlo data for the first coordination shell, and by fitting both the Monte Carlo data and the numerical results of PercusYevick expression for the second coordination shell. One of the expressions has been applied to develop an analytic equation of state for the square-well fluid, and the numerical results are in good agreement with the computer simulation data.展开更多
This paper deals with the problem of robust reliable H∞ control for a class of uncertain nonlinear systems with time-varying delays and actuator failures. The uncertainties in the system are norm-bounded and time-var...This paper deals with the problem of robust reliable H∞ control for a class of uncertain nonlinear systems with time-varying delays and actuator failures. The uncertainties in the system are norm-bounded and time-varying. Based on Lyapunov methods, a sufficient condition on quadratic stabilization independent of delay is obtained. With the help of LMIs (linear matrix inequalities) approaches, a linear state feedback controller is designed to quadratically stabilize the given systems with a H∞ performance constraint of disturbance attenuation for all admissible uncertainties and all actuator failures occurred within the prespecified subset. A numerical example is given to demonstrate the effect of the proposed design approach.展开更多
基金Projects (71003018,71373003) supported by the National Natural Science Foundation of ChinaProjects (N110402003,N120302004) supported by the Fundamental Research Funds for the Central Universities,ChinaProject (13YJCZH172) supported by the Ministry of Education of China of Humanities and Social Sciences
文摘Anthropogenic aluminum cycle in China was analyzed by the aluminum flow diagram based on the life cycle of aluminum products. The whole anthropogenic aluminum cycle consists of four stages: alumina and aluminum production, fabrication and manufacture, use and reclamation. Based on the investigation on the 2003-2007 aluminum cycles in China, a number of changes can be found. For instance, resources self-support ratio (RSR) in alumina production dropped from 95.42%to 55.50%, while RSR in the aluminum production increased from 52.45%to 79.25%. However, RSR in the Chinese aluminum industry leveled off at 50%in the period of 2003-2007. The respective use ratios of domestic and imported aluminum scrap in the aluminum industry of 2007 were 5.38% and 9.40%. In contrast, both the net imported Al-containing resources and the lost quantity of Al-containing materials in aluminum cycle increased during the same period, as well as the net increased quantity of Al-containing materials in social stock and recycled Al-scrap. Proposals for promoting aluminum cycle were put forward. The import/export policy and reducing the loss of Al-containing materials for the aluminum industry in China in the future were discussed.
基金Supported by the Research Project of the Research Center of Hubei Logistics Development,China (2011A03)the Humanities and Social Sciences Project of Hubei Provincial Department of Education Project,China (2011jyty027)~~
文摘By introducing the analytic hierarchy process (AHP), a model is constructed to compare the logistics development level of cold chain for agricultural products between China and other developed countries such as United States, Japan and Euro- pean. The paper makes a comparative study on the development levels of agricultural cold chain logistics in China and developed countries from the aspects of the level of cold chain logistics facilities and equipments, the degree of cold chain logistics market-oriented and the capacity of cold chain logistics, then determines the problems of cold chain logistics in China. With the experiences learning from developed countries, some countermeasures are proposed to resolve those problems of cold chain logistics for agricultural products development combining with the national conditions in China.
基金sponsored by National Natural Science Foundation of China(Grant No.40904035)
文摘Gassmann's equations are commonly used for predicting seismic wave velocity in rock physics research.However the input matrix mineral bulk modulus parameters are not accurate,which greatly influences the prediction reliability.In this paper,combining the Russell fluid factor with the Gassman-Biot-Geertsma equation and introducing the dry-rock Poisson's ratio,we propose an effective matrix mineral bulk modulus extraction method.This method can adaptively invert the equivalent matrix mineral bulk modulus to apply the Gassmann equation to fluid substitution of complex carbonate reservoirs and increase the fluid prediction reliability.The verification of the actual material fluid substitution also shows that this method is reliable,efficient,and adaptable.
基金Project(51178061)supported by the National Natural Science Foundation of ChinaProject(2010FJ6016)supported by Hunan Provincial Science and Technology,China+1 种基金Project(12C0015)supported by Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(13JJ3072)supported by Hunan Provincial Natural Science Foundation of China
文摘Aimed at the uncertain characteristics of discrete logistics network design,an interval hierarchical triangular uncertain OD demand model based on interval demand and network flow is presented.Under consideration of the system profit,the uncertain demand of logistics network is measured by interval variables and interval parameters,and an interval planning model of discrete logistics network is established.The risk coefficient and maximum constrained deviation are defined to realize the certain transformation of the model.By integrating interval algorithm and genetic algorithm,an interval hierarchical optimal genetic algorithm is proposed to solve the model.It is shown by a tested example that in the same scenario condition an interval solution[3275.3,3 603.7]can be obtained by the model and algorithm which is obviously better than the single precise optimal solution by stochastic or fuzzy algorithm,so it can be reflected that the model and algorithm have more stronger operability and the solution result has superiority to scenario decision.
基金Supported by the Supporting Program of the"Eleventh Five-year Plan"for Sci&Tech Research of China(2006BAK20A29)Strategical Project for Science and Technology of Guangdong Province(2004A2090102)~~
文摘[Objective] The aim is to develop the piezoelectric immunosensor to detect H9-subtype avian influenza virus(AIV).[Method] The immunosensor chip was constructed by self-assembling mercaptopmpionic acid(MPA) to be monolayer on the silver-coated electrode of quartz crystal and coupling the monoclonal antibody to H9 subtype AIV with N-ethy-N'-(3-dimethyl aminopropyl)carbodiimide hydrochloride(EDC) and N-hydroxysuccinimide(NHS).The immunosensor to detect H9 subtype AIV was established.[Result] The results showed that the immunosensor displayed better specificity to H9 AIV and had no response to H5AIV and NDV when it was used for detection.The sensitivity test indicated the detection sensitivity for the H9 subtype AIV could reach 20-100 EID50.[Conclusion] The research provided a foundation for further research on the immunosensor for detecting AIV and it could be a new approach to detect other related viruses.
基金Project (10804101) supported by the National Natural Science Foundation of China
文摘Single-phase Ag2Al intermetallic nanoparticles, and Ag and Al metallic nanoparticles were synthesized by the flow-levitation (FL) method. Measurements of d-spacings from X-ray diffraction and electron diffraction confirmed that the intermetallic nanoparticles had the hexagonal Ag2Al structure. The morphology, crystal structure and chemical composition of Ag2Al nanoparticles were investigated by transmission electron microscopy, X-ray diffraction and induction-coupled plasma spectroscopy. A thin amorphous coating was formed around the particles when exposed to air. Based on the XPS measurements, the surface coating of the Ag2Al nanoparticles could most likely be aluminum oxide or silver aluminum oxide. Therefore, the single-phase nanocrystalline Ag2Al intermetallic compound particles can be produced by adjusting some experimental parameters in FL method.
文摘To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each stage, the Pruefer number is used. With theimproved decoding procedure, any Pruefer number produced stochastically can be decoded to a feasiblelogistic pattern, which can match with the capacities of the nodes of the logistic system. Withthese two innovations, a new modeling method based on parameterized interface distribution and thePriifer number coding is put forward. The corresponding genetic algorithm, named as PIP-GA, can findbetter solutions and require less computational time than st-GA. Although requiring a little moreconsumption of memory, PIP-GA is still an efficient and robust method in the modeling andoptimization of unbalanced multi-stage logistic systems.
基金Supported by the National Natural Science Foundation of China(No.60672153)the Shenzhen Science & Technology Project (No.200424).
文摘This paper presents a new method for robust and accurate optical flow estimation.The sig- nificance of this work is twofold.Firstly,the idea of bi-directional scheme is adopted to reduce the model error of optical flow equation,which allows the second order Taylor's expansion of optical flow equation for accurate solution without much extra computational burden;Secondly,this paper establishs a new optical flow equation based on LSCM (Local Structure Constancy Model) instead of BCM (Brightness Constancy Model),namely the optical flow equation does not act on scalar but on tensor-valued (ma- trix-valued) field,due to the two reason:(1) structure tensor-value contains local spatial structure information,which provides us more useable cues for computation than scalar;(2) local image structure is less sensitive to illumination variation than intensity,which weakens the disturbance of non-uniform illumination in real sequences.Qualitative and quantitative results for synthetic and real-world scenes show that the new method can produce an accurate and robust results.
文摘A new wastewater treatment equipment, the bi-external recycling biological fluidized bed (BRBFB), which is an effective equipment, was investigated. Anaerobic digestion, aerobic aeration and settlement processes with a fixed sequential procedure were compacted into this reactor. By five different treatment courses, the optimization of the combined operation procedure in the system was determined to be a 12-hour cycle including an inflow process, a 4 h anaerobic digestion process, a 4 h aerobic aeration process, a 2 h settlement process and a 2 h recess process including effluent discharge process. By utilizing BRBFB to treat a synthetic dyeing wastewater, 90% of COD_ Cr is removed for a higher-concentration water (COD_ Cr 1 000-1 200 mg/L), and 82% of COD_ Cr is removed for a lower-concentration water (COD_ Cr 400-600 mg/L). Near 100% color is removal and discharging standards for industry wastewater are achieved.
文摘This paper introduced an integrated allocation model for distribution centers (DCs). The facility cost, inventory cost, transportation cost and service quality were considered in the model. An improved genetic algorithm (IGA) was proposed to solve the problem. The improvement of IGA is based on the idea of adjusting crossover probability and mutation probability. The IGA is supplied by heuristic rules too. The simulation results show that the IGA is better than the standard GA(SGA) in search efficiency and equality.
文摘In the present study, the effect of electroacupuncture (EA) of acupoints of Ren, Spleen and Stomach Meridians on artificial abortion induced side effects was observed in 100 artificial abortion women. In comparison with 45 artificial abortion women in the control group (who had not accepted EA treatment), EA possessed significant effects in relieving abdominal pain, reducing vaginal bleeding duration, lowering infection rate and infertility rate after artificial abortion operation.
基金Supported by the Major Science and Technology Program for Water Pollution Control and Treatment(No.2012ZX07103-005)
文摘The Nanfei River (Anhui Province, China) is a severely polluted urban river that flows into Chaohu Lake. In the present study, sediments were collected from the river and analyzed for their heavy metal contents. Multivariate statistics and the fuzzy comprehensive assessment method were used to determine the sources of pollution, the current pollution status, and spatial and temporal variations in heavy metal pollution in sediments. The concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) in sediments ranged from 5.67-113, 0.08-40.2, 41.6-524, 15.5-460, 0.03-4.84, 13.5-180, 18.8-250, and 47.9-1 996 mg/kg, and the average concentrations of each metal were 1.7, 38.7, 1.8, 5.5, l 8.8, 1.3, 2.5, and 11.1 times greater than the background values, respectively. Multivariate statistical analysis demonstrated that Hg, Cu, Cr, Cd, and Ni may have originated from industrial activities, whereas As and Pb came from agricultural activities. The fuzzy comprehensive assessment method, based on the fuzzy mathematics theory, was used to obtain a detailed assessment of the sediment quality in the Nanfei River watershed. The results indicated that the pollution was moderate in the downstream tributaries of the Nianbu and Dianbu Rivers, but was severe in the main channel of the Nanfei River and in the upstream tributaries of the Sill and Banqiao Rivers. Therefore, sediments in the Nanfei River watershed are heavily polluted and urgent measures should be taken to remedy the status.
基金Project(51321065,51479191,11672360)supported by the National Natural Science Foundation of China。
文摘Partition of unity based numerical manifold method can solve continuous and discontinuous problems in a unified framework with a two-cover system,i.e.,the mathematical cover and physical cover.However,renewal of the topology of the two-cover system poses a challenge for multiple crack propagation problems and there are few references.In this study,a robust and efficient strategy is proposed to update the cover system of the numerical manifold method in simulation of multiple crack propagation problems.The proposed algorithm updates the cover system with a bottom-up process:1)identification of fractured manifold elements according to the previous and latest crack tip position;and 2)local topological update of the manifold elements,physical patches,block boundary loops,and non-persistent joint loops according to the scenario classification of the propagating crack.The proposed crack tracking strategy and classification of the renewal cases promote a robust and efficient cover renewal algorithm for multiple crack propagation analysis.Three crack propagation examples show that the proposed algorithm performs well in updating the cover system.This cover renewal methodology can be extended for numerical manifold method with polygonal mathematical covers.
文摘A real-time sensing of the molecular distillation process temperature by a FLUKE brand thermograph Ti50 IR FlexCam and thermography technique was realized. After completion of the molecular distillation, three properties of heat transport chain cuts and residues obtained in the process were estimated by Differential Scanning Calorimetry (DSC) (specific heat, enthalpy, thermal conductivity). These properties are of great importance for improving oil characterization and for future modeling and simulation of the molecular distillation process. The results show that through the method of Differential Scanning Calorimetry, profiles have been obtained from the variation of specific heat, enthalpy and thermal condutivity as a function of temperature for samples of cuts from the distillation (ASTM D-2892) and fractions of distillate and residue from the process of molecular distillation.
基金Supported by the Natural Science Foundation of Tianjin (No. 973602911).
文摘The critical properties of five compounds, including propanal,butanal, 1-pentanal, 2-methel butanal and trimer of ethanal, weredetermined for the first time by a new capillary quick-flow method.The apparatus was improved with a capillary tube and checked withhexane and 10heptene as standard reagents. The experimental resultsproved that the determination of critical properties by quick-flowmethod with a capillary tube apparatus was successful.
基金Project(2001BA604A01) supported by the Key Project of National"Tenth Five Year"Science & Technology of China
文摘Pulsed signal experiment was carried out to determine the hydrodynamic behaviours of lateral flow biological aerated filter(LBAF). With the analysis of experimental results, LBAF is viewed as an approximate plug flow reactor, and hydraulic retention time distribution function was derived based on LBAF. The results show that flow rate and aeration strength are two critical factors which influence flow patterns in LBAF reactor. The hydrodynamic behaviour analysis of LBAF is the theoretical basis of future research on improving capacity factor and developing kinetic model for the reactor.
基金The project supported by National Natural Science Foundation of China under Grant Nos.19904002 and 10299040by the Science and Technology Foundation for the Youth of the University of Electronic Science and Technology of China under Grant No.YF020703
文摘Three simple analytic expressions satisfying the limitation condition at low densities for the radial distribution function of hard spheres are developed in terms of a polynomial expansion of nonlinear base functions and the Carnahan-Starling equation of state. The simplicity and precision for these expressions are superior to the well-known Percus Yevick expression. The coefficients contained in these expressions have been determined by fitting the Monte Carlo data for the first coordination shell, and by fitting both the Monte Carlo data and the numerical results of PercusYevick expression for the second coordination shell. One of the expressions has been applied to develop an analytic equation of state for the square-well fluid, and the numerical results are in good agreement with the computer simulation data.
基金Sponsored by the Scientific Research Foundation of Harbin Institute of Technology (Grant No.HIT.2003.02)
文摘This paper deals with the problem of robust reliable H∞ control for a class of uncertain nonlinear systems with time-varying delays and actuator failures. The uncertainties in the system are norm-bounded and time-varying. Based on Lyapunov methods, a sufficient condition on quadratic stabilization independent of delay is obtained. With the help of LMIs (linear matrix inequalities) approaches, a linear state feedback controller is designed to quadratically stabilize the given systems with a H∞ performance constraint of disturbance attenuation for all admissible uncertainties and all actuator failures occurred within the prespecified subset. A numerical example is given to demonstrate the effect of the proposed design approach.