径向基函数网络(Radial Basis Function Network,RBFN)是二十世纪八十年代末提出的一种神经网络.当网络的输入维数较大时,RBFN的系统复杂性大大提高,从而使RBFN的行为受到影响,因此降低RBFN输入维数已成为RBFN的研究热点.本文提出一类基...径向基函数网络(Radial Basis Function Network,RBFN)是二十世纪八十年代末提出的一种神经网络.当网络的输入维数较大时,RBFN的系统复杂性大大提高,从而使RBFN的行为受到影响,因此降低RBFN输入维数已成为RBFN的研究热点.本文提出一类基于RBFN的分工协作系统及其学习算法(A Divide-and-Cooperate Hybrid System Based RBFN,DCRBFN).DCRBFN是一种由多个子RBFN组成的混合结构,每个子RBFN具有自己的输入空间.由于DCRBFN把高维模型分解为低维模型,所以DCRBFN不仅明显降低了RBFN的复杂性而且网络的收敛速度更快.实验表明,DCRBFN在处理高维模型的行为明显优于RBFN.展开更多
From the protection of Chinese white dolphin and living environment,and considering the industrial development in coastal areas,we put forward adjustment program for Jiangmen Chinese White Dolphin Provincial Nature Re...From the protection of Chinese white dolphin and living environment,and considering the industrial development in coastal areas,we put forward adjustment program for Jiangmen Chinese White Dolphin Provincial Nature Reserve. Meanwhile we analyzed the feasibility of this program by systematically focusing the effect of adjusted functional regions on Chinese white dolphin.展开更多
Aim To propose a modelling method for flexible manipulators. Methods The improved algorithm and structure of the ANN (artificial neural networks) were used. All of the data used in the process of modelling came from e...Aim To propose a modelling method for flexible manipulators. Methods The improved algorithm and structure of the ANN (artificial neural networks) were used. All of the data used in the process of modelling came from experiments based on a very flexible link which was fixed on a FANUC Robot S-Model 300 in our lab.Results and Conclusion The theoretical analysis and experiment results showed that this modelling scheme is more suitable for flexible systems with characteristics of fast changing dynamics, and also it can be more accurate than others and is more convenient for real-time use.展开更多
Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, ...Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, if a distributed parameter system is described by ordinary differential equations (ODE) during the analysis and the design of distributed parameter system, the reliability of the system description will be reduced, and the systemic errors will be introduced. Studies on working condition real-time monitoring can improve the security because the rechargeable LIBs are widely used in many electronic systems and electromechanical equipment. Single particle model (SPM) is the simplification of LIB under some approximations, and can estimate the working parameters of a LIB at the faster simulation speed. A LIB modelling algorithm based on PDEs and SPM is proposed to monitor the working condition of LIBs in real time. Although the lithium ion concentration is an unmeasurable distributed parameter in the anode of LIB, the working condition monitoring model can track the real time lithium ion concentration in the anode of LIB, and calculate the residual which is the difference between the ideal data and the measured data. A fault alarm can be triggered when the residual is beyond the preset threshold. A simulation example verifies that the effectiveness and the accuracy of the working condition real-time monitoring model of LIB based on PDEs and SPM.展开更多
An integrated approach for new vehicle program launching and associated manufacturing systems deployment,is presented in this paper.To overcome weaknesses and difficulties in the traditional production distribution (P...An integrated approach for new vehicle program launching and associated manufacturing systems deployment,is presented in this paper.To overcome weaknesses and difficulties in the traditional production distribution (PD) network models,the case based reasoning is first applied to generate an initial network configuration based on the collected localization case base.Secondly,and economic model of performance evaluation of existing manufacturing facilities is developed to identify the advantages in location sensitive production factors for various components in order to take full advantages of local and global production factors.Finally,a modified PD model is developed to optimize the overall network deployment.Various deployment scenarios,such as minimizing manufacturing cost,maximizing profitability or promotion of early market entry,can be analyzed and testified.A typical case study of launching a new vehicle program in China is also presented to demonstrate the effectiveness and feasibility of the proposed approach.展开更多
Allylpolyethoxy carboxylate macromonomers possessing polyethylene oxygen long chains were synthesized by advanced technology of the polyether cap.A novel double-hydrophilic block copolymer was prepared through free ra...Allylpolyethoxy carboxylate macromonomers possessing polyethylene oxygen long chains were synthesized by advanced technology of the polyether cap.A novel double-hydrophilic block copolymer was prepared through free radical polymeric reactions in aqueous solution and its performance on CaCO3 inhibition and dispersancy activity towards Fe2 O3 was evaluated in recirculating cooling water systems.The study shows that acrylic acid-allylpolyethoxy carboxylate has a significant ability to inhibit the precipitation of calcium carbonate and an excellent dispersing capability to stabilize iron Ⅲ in industrial cooling systems. X-ray diffraction shows that there is a number of vaterite crystals in the presence of the phosphorous free and non-nitrogen copolymer. The change in crystal forms is also confirmed by the Fourier-transform infrared spectra the scanning electron microscopy and the transmission electron microscopy. The inhibition mechanism is proposed and it shows that the interactions between calcium and polyethylene glycol PEG are the fundamental impetus for restraining the formation of the scale in cooling water systems.展开更多
Qingdao waters,including both the semi-enclosed Jiaozhou Bay(JB) and the adjacent water out of JB(OJB),have been the areas that are most frequently affected by harmful algal blooms(HABs) in the western Yellow Sea(west...Qingdao waters,including both the semi-enclosed Jiaozhou Bay(JB) and the adjacent water out of JB(OJB),have been the areas that are most frequently affected by harmful algal blooms(HABs) in the western Yellow Sea(west of 124°E).In this research,HAB occurrences in Qingdao waters from 1990 to 2009 were investigated using spatial tools in geographic information system(GIS) and are discussed in terms of their connection to temporal variation.Additionally,the effects of each HAB occurrence were further evaluated using a simple model.The calculated results were then visualized using a GIS software to indicate the effects of HABs in Qingdao waters during the entire period.As a result,the OJB was proven to be responsible for the frequent HAB occurrences in Qingdao waters after 2000,although JB was traditionally believed to be the principle source of HAB occurrences in Qingdao waters.In addition,increasing nitrogen and N/P structure imbalance were essential for increasing HAB occurrences in Qingdao waters throughout the entire period,especially for the recent HAB occurrences in the OJB.The results of this research would improve the current understanding on HAB occurrences in Qingdao waters,which would benefit HAB monitoring and the implementation of a control strategy in China as well.展开更多
Underground Electro Magnetic Interference (EMI) has become so serious that there were false alarms in monitoring system,which induced troubles of coal mine safety in production.In order to overcome difficulties caused...Underground Electro Magnetic Interference (EMI) has become so serious that there were false alarms in monitoring system,which induced troubles of coal mine safety in production.In order to overcome difficulties caused by the explosion-proof enclosure of the equipments and the limitation of multiple startup and stop in transient process during EMI measurement,a novel technique was proposed to measure underground EMI distri- bution indirectly and enhance Electromagnetic Campatibility(EMC) of the monitoring sys- tem.The wavelet time-frequency analysis was introduced to underground monitoring sys- tem.Therefore,the sources,the startup time,duration and waveform of EMI could be as- certained correctly based on running records of underground electric equipments.The electrical fast transient/burst (EFT/B) was studied to verify the validity of wavelet analysis. EMI filter was improved in accordance of the EMI distribution gotten from wavelet analysis. Power port immunity was developed obviously.In addition,the method of setting wavelet thresholds was amended based upon conventional thresholds in the wavelet filter design. Therefore the EFT/B of data port was restrained markedly with the wavelet filtering.Coor- dinative effect of EMI power and wavelet filter makes false alarms of monitoring system reduce evidently.It is concluded that wavelet analysis and the improved EMI filter have enhanced the EMC of monitoring system obviously.展开更多
An extended algorithm of flexibility analysis with a local adjusting method for flexibility region of chemical processes, which is based on the active constraint strategy, is proposed, which fully exploits the flexibi...An extended algorithm of flexibility analysis with a local adjusting method for flexibility region of chemical processes, which is based on the active constraint strategy, is proposed, which fully exploits the flexibility region of the process system operation. The hyperrectangular flexibility region determined by the extended algorithm is larger than that calculated by the previous algorithms. The limitation of the proposed algorithm due to imperfect convexity and its corresponding verification measure are also discussed. Both numerical and actual chemical process examples are presented to demonstrate the effectiveness of the new algorithm.展开更多
The applicability of the density rule of Pathwardhan and Kumer and the rule based on the linear isopiestic relation is studied by comparison with experimental density data in the literature. Predicted and measured val...The applicability of the density rule of Pathwardhan and Kumer and the rule based on the linear isopiestic relation is studied by comparison with experimental density data in the literature. Predicted and measured values for 18 electrolyte mixtures are compared. The two rules are good for mixtures with and without common ions, including those containing associating ions. The deviations of the rule based on the linear isopiestic relation are slightly higher for the mixtures involving very strong ion complexes, but the predictions are still quite satisfactory.The density rule of Pathwardhan and Kumer is more accurate for these mixtures. However, it is not applicable for mixtures containing non-electrolytes. The rule based on the linear isopiestic relation is extended to mixtures involving non-electrolytes. The predictions for the mixtures containing both electrolytes and non-electrolytes and the non-electrolyte mixtures are accurate. All these results indicate that this rule is a widely applicable approach.展开更多
An ADS (automated dispensing system) was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI (r...An ADS (automated dispensing system) was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI (return on investment), after seven years of use. ROI was calculated annually (from 2008 to 2015), by deducting the cost of investment (ADS buying and implementation, maintenance, repairs and ADS upgrade) from the cost saving (drugs stock reduction and decrease of pharmacy staff dedicated to global dispensing). In 2015, total costs saving (+$1,141,987) were divided between decreasing drug stock value and reduction of pharmacy staff. Total costs of investment (-$978,656) were acquisition, maintenance, repairs and an unplanned upgrade costs. Finally, the real ROI was +$163,331 after seven years of use. In 2008, projected ROI was +$410,786. The real payback period has been increased by approximately two years (six years of use, instead of four years as expected). Despite their cost, ADSs are a worthwhile investment, leading to a ROI within a few years. These economic considerations should be put into perspective with optimization of drugs stock management, greater efficiency of the global dispensing process, securitization of medication process and redeployment of pharmacy staff.展开更多
We have developed a process model to simulate the behavior of an industrial-scale pressurized Lurgi fixed-bed coal gasifier using Aspen Plus and General Algebraic Modeling System(GAMS). Reaction characteristics in the...We have developed a process model to simulate the behavior of an industrial-scale pressurized Lurgi fixed-bed coal gasifier using Aspen Plus and General Algebraic Modeling System(GAMS). Reaction characteristics in the fixed-bed gasifier comprising four sequential reaction zones—drying, pyrolysis, combustion and gasification are respectively modeled. A non-linear programming(NLP) model is developed for the pyrolysis zone to estimate the products composition which includes char, coal gases and distillable liquids. A four-stage model with restricted equilibrium temperature is used to study the thermodynamic equilibrium characteristics and calculate the composition of syngas in the combustion and gasification zones. The thermodynamic analysis shows that the exergetic efficiency of the fixed-bed gasifier is mainly determined by the oxygen/coal ratio. The exergetic efficiency of the process will reach an optimum value of 78.3% when the oxygen/coal and steam/coal mass ratios are 0.14 and 0.80, respectively.展开更多
Both distillation performance and hydrodynamic study for backmixing by tracer technique were carried out in a high-pressure packed column with 0.15 m inner diameter over a wide range of operating conditions. Isobutane...Both distillation performance and hydrodynamic study for backmixing by tracer technique were carried out in a high-pressure packed column with 0.15 m inner diameter over a wide range of operating conditions. Isobutane and n-pentane are employed as test mixture in the distillation experiment and air/water is used for the hydrodynamic study. The column is installed with Mellapak 350Y structured packing and the total packing height is 2.0 m. With the increasing operating pressure, the separation efficiency increases slightly while the F-factor corresponding to the maximum efficiency at each pressure is descending. It is noted that, at all operating pressures, with the increase of F-factor, the packing efficiency is slightly higher up to the flooding point. The application of SRP model to high-pressure distillation gives much lower values of HTUOG than those obtained experimentally. An additional term, the height of mixing unit, is introduced to correct the SRP model and improve its accuracy at high pressure. From the tracer experiments, the height of mixing unit for gas phase was found to be larger than that for the liquid phase. From this viewpoint, it is believed that the gas phase backmixing gives more unfavorable influence on the separation efficiency in comparison with liquid phase.展开更多
TDD(Time Division Duplex) is one of the two duplex modes.TD-SCDMA(Time division Synchronous CDMA) is the first TDD-based cellular mobile system which is commercialized in wide area and large scale and TD-SCDMA is also...TDD(Time Division Duplex) is one of the two duplex modes.TD-SCDMA(Time division Synchronous CDMA) is the first TDD-based cellular mobile system which is commercialized in wide area and large scale and TD-SCDMA is also the first cellular mobile system which adopted smart antenna technology,also called as beamforming.As the long term evolution of TD-SCDMA,TDLTE(A)(Time Division-Lone Term Evolution,and TD-LTE Advanced) introduced OFDM(Orthogonal Frequency Division Multiplexing)and enhanced smart antenna technology together with MIMO(Multiple Input Multiple Output),which are adopted by LTE FDD(Frequency Division Duplex) either.It is indicated that TD-SCDMA and TD-LTE(A)have opened a sustainable utilization era of TDD and smart antenna Technologies in the wireless mobile communication.This paper aims to present a systematic introduction to TDD-based mobile communications from TD-SCDMA to TD-LTE and beyond and its comparisons to FDD,with particular focuses on TDD key technologies,principles of TDD cellular mobile systems,TDD evolution path,and future TDD 5G directions.We hope that this paper will provide a comprehensive overview of TDD technology upgrade and its standard evolution,and serve as a valuable reference for research on 5G mobile communication systems.It is believed that TDD will play more important role in 5G.展开更多
The synthetic index K s for evaluating flip-flow screens is proposed and systematically optimized in view of the whole system. A series of optimized values of relevant parameters are found and then compared with those...The synthetic index K s for evaluating flip-flow screens is proposed and systematically optimized in view of the whole system. A series of optimized values of relevant parameters are found and then compared with those of the current industrial specifications. The results show that the optimized value K s approaches the one of those famous flip-flow screens in the world. Some new findings on geometric and kinematics parameters are useful for improving the flip-flow screens with a low K s value, which is helpful in developing clean coal technology.展开更多
文摘径向基函数网络(Radial Basis Function Network,RBFN)是二十世纪八十年代末提出的一种神经网络.当网络的输入维数较大时,RBFN的系统复杂性大大提高,从而使RBFN的行为受到影响,因此降低RBFN输入维数已成为RBFN的研究热点.本文提出一类基于RBFN的分工协作系统及其学习算法(A Divide-and-Cooperate Hybrid System Based RBFN,DCRBFN).DCRBFN是一种由多个子RBFN组成的混合结构,每个子RBFN具有自己的输入空间.由于DCRBFN把高维模型分解为低维模型,所以DCRBFN不仅明显降低了RBFN的复杂性而且网络的收敛速度更快.实验表明,DCRBFN在处理高维模型的行为明显优于RBFN.
基金Support by Key Project in Marine Science and Technology of Guangdong (No.A20099E01)Guangdong Provincial 908 Project ( No.GD908-02-05)~~
文摘From the protection of Chinese white dolphin and living environment,and considering the industrial development in coastal areas,we put forward adjustment program for Jiangmen Chinese White Dolphin Provincial Nature Reserve. Meanwhile we analyzed the feasibility of this program by systematically focusing the effect of adjusted functional regions on Chinese white dolphin.
文摘Aim To propose a modelling method for flexible manipulators. Methods The improved algorithm and structure of the ANN (artificial neural networks) were used. All of the data used in the process of modelling came from experiments based on a very flexible link which was fixed on a FANUC Robot S-Model 300 in our lab.Results and Conclusion The theoretical analysis and experiment results showed that this modelling scheme is more suitable for flexible systems with characteristics of fast changing dynamics, and also it can be more accurate than others and is more convenient for real-time use.
文摘Lithium ion batteries are complicated distributed parameter systems that can be described preferably by partial differential equations and a field theory. To reduce the solution difficulty and the calculation amount, if a distributed parameter system is described by ordinary differential equations (ODE) during the analysis and the design of distributed parameter system, the reliability of the system description will be reduced, and the systemic errors will be introduced. Studies on working condition real-time monitoring can improve the security because the rechargeable LIBs are widely used in many electronic systems and electromechanical equipment. Single particle model (SPM) is the simplification of LIB under some approximations, and can estimate the working parameters of a LIB at the faster simulation speed. A LIB modelling algorithm based on PDEs and SPM is proposed to monitor the working condition of LIBs in real time. Although the lithium ion concentration is an unmeasurable distributed parameter in the anode of LIB, the working condition monitoring model can track the real time lithium ion concentration in the anode of LIB, and calculate the residual which is the difference between the ideal data and the measured data. A fault alarm can be triggered when the residual is beyond the preset threshold. A simulation example verifies that the effectiveness and the accuracy of the working condition real-time monitoring model of LIB based on PDEs and SPM.
基金Supported by Ford- China Research and Development Foundation(971 551 1 )
文摘An integrated approach for new vehicle program launching and associated manufacturing systems deployment,is presented in this paper.To overcome weaknesses and difficulties in the traditional production distribution (PD) network models,the case based reasoning is first applied to generate an initial network configuration based on the collected localization case base.Secondly,and economic model of performance evaluation of existing manufacturing facilities is developed to identify the advantages in location sensitive production factors for various components in order to take full advantages of local and global production factors.Finally,a modified PD model is developed to optimize the overall network deployment.Various deployment scenarios,such as minimizing manufacturing cost,maximizing profitability or promotion of early market entry,can be analyzed and testified.A typical case study of launching a new vehicle program in China is also presented to demonstrate the effectiveness and feasibility of the proposed approach.
基金The National Natural Science Foundation of China(No.51077013)China Postdoctoral Science Foundation(No.2014M560381)+3 种基金Jiangsu Planned Projects for Postdoctoral Research Funds(No.1401033B)Transformation Program of Science and Technology Achievements of Jiangsu Province(No.BA2011086)the 333High-Level Talents Training Project of Jiangsu Province(No.BRA2010033)the Project of Young Scientist Foundation of Nanjing Xiaozhuang University(No.2013NXY89)
文摘Allylpolyethoxy carboxylate macromonomers possessing polyethylene oxygen long chains were synthesized by advanced technology of the polyether cap.A novel double-hydrophilic block copolymer was prepared through free radical polymeric reactions in aqueous solution and its performance on CaCO3 inhibition and dispersancy activity towards Fe2 O3 was evaluated in recirculating cooling water systems.The study shows that acrylic acid-allylpolyethoxy carboxylate has a significant ability to inhibit the precipitation of calcium carbonate and an excellent dispersing capability to stabilize iron Ⅲ in industrial cooling systems. X-ray diffraction shows that there is a number of vaterite crystals in the presence of the phosphorous free and non-nitrogen copolymer. The change in crystal forms is also confirmed by the Fourier-transform infrared spectra the scanning electron microscopy and the transmission electron microscopy. The inhibition mechanism is proposed and it shows that the interactions between calcium and polyethylene glycol PEG are the fundamental impetus for restraining the formation of the scale in cooling water systems.
基金Supported by the National Natural Science Foundation of China(NSFC)-Shandong Joint Fund for Marine Science Research Centers(No.U1406403)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA11020302)+1 种基金the National Natural Science Foundation of China for Young Scholars(No.41506135)the National Nature Science Foundation of China for Creative Group Research(No.41121064)
文摘Qingdao waters,including both the semi-enclosed Jiaozhou Bay(JB) and the adjacent water out of JB(OJB),have been the areas that are most frequently affected by harmful algal blooms(HABs) in the western Yellow Sea(west of 124°E).In this research,HAB occurrences in Qingdao waters from 1990 to 2009 were investigated using spatial tools in geographic information system(GIS) and are discussed in terms of their connection to temporal variation.Additionally,the effects of each HAB occurrence were further evaluated using a simple model.The calculated results were then visualized using a GIS software to indicate the effects of HABs in Qingdao waters during the entire period.As a result,the OJB was proven to be responsible for the frequent HAB occurrences in Qingdao waters after 2000,although JB was traditionally believed to be the principle source of HAB occurrences in Qingdao waters.In addition,increasing nitrogen and N/P structure imbalance were essential for increasing HAB occurrences in Qingdao waters throughout the entire period,especially for the recent HAB occurrences in the OJB.The results of this research would improve the current understanding on HAB occurrences in Qingdao waters,which would benefit HAB monitoring and the implementation of a control strategy in China as well.
基金the National Natural Science Foundation of China(50674093)
文摘Underground Electro Magnetic Interference (EMI) has become so serious that there were false alarms in monitoring system,which induced troubles of coal mine safety in production.In order to overcome difficulties caused by the explosion-proof enclosure of the equipments and the limitation of multiple startup and stop in transient process during EMI measurement,a novel technique was proposed to measure underground EMI distri- bution indirectly and enhance Electromagnetic Campatibility(EMC) of the monitoring sys- tem.The wavelet time-frequency analysis was introduced to underground monitoring sys- tem.Therefore,the sources,the startup time,duration and waveform of EMI could be as- certained correctly based on running records of underground electric equipments.The electrical fast transient/burst (EFT/B) was studied to verify the validity of wavelet analysis. EMI filter was improved in accordance of the EMI distribution gotten from wavelet analysis. Power port immunity was developed obviously.In addition,the method of setting wavelet thresholds was amended based upon conventional thresholds in the wavelet filter design. Therefore the EFT/B of data port was restrained markedly with the wavelet filtering.Coor- dinative effect of EMI power and wavelet filter makes false alarms of monitoring system reduce evidently.It is concluded that wavelet analysis and the improved EMI filter have enhanced the EMC of monitoring system obviously.
文摘An extended algorithm of flexibility analysis with a local adjusting method for flexibility region of chemical processes, which is based on the active constraint strategy, is proposed, which fully exploits the flexibility region of the process system operation. The hyperrectangular flexibility region determined by the extended algorithm is larger than that calculated by the previous algorithms. The limitation of the proposed algorithm due to imperfect convexity and its corresponding verification measure are also discussed. Both numerical and actual chemical process examples are presented to demonstrate the effectiveness of the new algorithm.
基金Supported by the Science Foundation of University of Petroleum (No. ZX9903), the Open Science Foundation of the State Key Laboratory of Heavy Oil Processing (No. 200005), and the National Natural Science Foundation of China (No. 20006010).
文摘The applicability of the density rule of Pathwardhan and Kumer and the rule based on the linear isopiestic relation is studied by comparison with experimental density data in the literature. Predicted and measured values for 18 electrolyte mixtures are compared. The two rules are good for mixtures with and without common ions, including those containing associating ions. The deviations of the rule based on the linear isopiestic relation are slightly higher for the mixtures involving very strong ion complexes, but the predictions are still quite satisfactory.The density rule of Pathwardhan and Kumer is more accurate for these mixtures. However, it is not applicable for mixtures containing non-electrolytes. The rule based on the linear isopiestic relation is extended to mixtures involving non-electrolytes. The predictions for the mixtures containing both electrolytes and non-electrolytes and the non-electrolyte mixtures are accurate. All these results indicate that this rule is a widely applicable approach.
文摘An ADS (automated dispensing system) was implemented in our hospital pharmacy in 2008 to optimize and secure the medication process. The main objective of this study was to compare the projected and the real ROI (return on investment), after seven years of use. ROI was calculated annually (from 2008 to 2015), by deducting the cost of investment (ADS buying and implementation, maintenance, repairs and ADS upgrade) from the cost saving (drugs stock reduction and decrease of pharmacy staff dedicated to global dispensing). In 2015, total costs saving (+$1,141,987) were divided between decreasing drug stock value and reduction of pharmacy staff. Total costs of investment (-$978,656) were acquisition, maintenance, repairs and an unplanned upgrade costs. Finally, the real ROI was +$163,331 after seven years of use. In 2008, projected ROI was +$410,786. The real payback period has been increased by approximately two years (six years of use, instead of four years as expected). Despite their cost, ADSs are a worthwhile investment, leading to a ROI within a few years. These economic considerations should be put into perspective with optimization of drugs stock management, greater efficiency of the global dispensing process, securitization of medication process and redeployment of pharmacy staff.
基金Supported by the National Basic Research Program of China(2012CB720500)the National Natural Science Foundation of China(U1162121)
文摘We have developed a process model to simulate the behavior of an industrial-scale pressurized Lurgi fixed-bed coal gasifier using Aspen Plus and General Algebraic Modeling System(GAMS). Reaction characteristics in the fixed-bed gasifier comprising four sequential reaction zones—drying, pyrolysis, combustion and gasification are respectively modeled. A non-linear programming(NLP) model is developed for the pyrolysis zone to estimate the products composition which includes char, coal gases and distillable liquids. A four-stage model with restricted equilibrium temperature is used to study the thermodynamic equilibrium characteristics and calculate the composition of syngas in the combustion and gasification zones. The thermodynamic analysis shows that the exergetic efficiency of the fixed-bed gasifier is mainly determined by the oxygen/coal ratio. The exergetic efficiency of the process will reach an optimum value of 78.3% when the oxygen/coal and steam/coal mass ratios are 0.14 and 0.80, respectively.
基金the National Natural Science Foundation of China (No. 20136010).
文摘Both distillation performance and hydrodynamic study for backmixing by tracer technique were carried out in a high-pressure packed column with 0.15 m inner diameter over a wide range of operating conditions. Isobutane and n-pentane are employed as test mixture in the distillation experiment and air/water is used for the hydrodynamic study. The column is installed with Mellapak 350Y structured packing and the total packing height is 2.0 m. With the increasing operating pressure, the separation efficiency increases slightly while the F-factor corresponding to the maximum efficiency at each pressure is descending. It is noted that, at all operating pressures, with the increase of F-factor, the packing efficiency is slightly higher up to the flooding point. The application of SRP model to high-pressure distillation gives much lower values of HTUOG than those obtained experimentally. An additional term, the height of mixing unit, is introduced to correct the SRP model and improve its accuracy at high pressure. From the tracer experiments, the height of mixing unit for gas phase was found to be larger than that for the liquid phase. From this viewpoint, it is believed that the gas phase backmixing gives more unfavorable influence on the separation efficiency in comparison with liquid phase.
基金supported in part by the National Natural Science Foundation of China for Distinguished Young Scholar,Grant Number:61425012
文摘TDD(Time Division Duplex) is one of the two duplex modes.TD-SCDMA(Time division Synchronous CDMA) is the first TDD-based cellular mobile system which is commercialized in wide area and large scale and TD-SCDMA is also the first cellular mobile system which adopted smart antenna technology,also called as beamforming.As the long term evolution of TD-SCDMA,TDLTE(A)(Time Division-Lone Term Evolution,and TD-LTE Advanced) introduced OFDM(Orthogonal Frequency Division Multiplexing)and enhanced smart antenna technology together with MIMO(Multiple Input Multiple Output),which are adopted by LTE FDD(Frequency Division Duplex) either.It is indicated that TD-SCDMA and TD-LTE(A)have opened a sustainable utilization era of TDD and smart antenna Technologies in the wireless mobile communication.This paper aims to present a systematic introduction to TDD-based mobile communications from TD-SCDMA to TD-LTE and beyond and its comparisons to FDD,with particular focuses on TDD key technologies,principles of TDD cellular mobile systems,TDD evolution path,and future TDD 5G directions.We hope that this paper will provide a comprehensive overview of TDD technology upgrade and its standard evolution,and serve as a valuable reference for research on 5G mobile communication systems.It is believed that TDD will play more important role in 5G.
文摘The synthetic index K s for evaluating flip-flow screens is proposed and systematically optimized in view of the whole system. A series of optimized values of relevant parameters are found and then compared with those of the current industrial specifications. The results show that the optimized value K s approaches the one of those famous flip-flow screens in the world. Some new findings on geometric and kinematics parameters are useful for improving the flip-flow screens with a low K s value, which is helpful in developing clean coal technology.