For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can b...For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can be completely absorbed or dissipated for the aim of safety. Two composite structures(circumscribed circle structure and inscribed circle structure) were constructed. In addition, comparison and optimization of the crashworthy characteristic of the two structures were carried out based on the method of explicit finite element analysis(FEA) and Kriging surrogate model. According to the result of Kriging surrogate model, conclusions can be safely drawn that the specific energy absorption(SEA) and ratio of specific energy absorption to initial peak force(REAF) of circumscribed circle structure are lager than those of inscribed circle structure under the same design parameters. In other words, circumscribed circle structure has better performances with higher energy-absorbing ability and lower initial peak force. Besides, error analysis was adopted and the result of which indicates that the Kriging surrogate model has high nonlinear fitting precision. What is more, the SEA and REAF optimum values of the two structures have been obtained through analysis, and the crushing results have been illustrated when the two structures reach optimum SEA and REAF.展开更多
The performance-based passive control analysis of the Maxwell dampers between one 10-story and one 6-story adjacent RC frames is conducted in this work.Not only the optimal parameters but also the optimal arrangements...The performance-based passive control analysis of the Maxwell dampers between one 10-story and one 6-story adjacent RC frames is conducted in this work.Not only the optimal parameters but also the optimal arrangements of the Maxwell dampers are proposed based on the optimal target of making the total exceeding probability of the adjacent structures to be minimal.The applicability of the analytical expressions of the Maxwell damper damping parameters under different seismic performance targets are firstly examined and then the preferable damping parameters of the Maxwell dampers are proposed through the extensive parametric studies.Furthermore,the optimal arranging positions and optimal arranging numbers of the Maxwell dampers between the adjacent buildings are derived based on a large number of seismic fragility analyses,as well.The general arranging laws of the Maxwell dampers between the adjacent buildings are generated based on the discussion of the theoretical method through the simplified plane model.The optimal parameters and optimal arrangement of the Maxwell dampers presented make both the adjacent structures have preferable controlled effects under each seismic performance target which can satisfy the requirements of multi-performance seismic resistance of the modern seismic codes.展开更多
Front bumper, crash box and side rail are key body structural parts in front crash. Deformation space is affected by compartment packaging. The improvement suggestions are proposed to solve the problems existed in the...Front bumper, crash box and side rail are key body structural parts in front crash. Deformation space is affected by compartment packaging. The improvement suggestions are proposed to solve the problems existed in the current vehicle struc- ture and compartment packaging based on the areas that influence performance of automobile offset deformable barrier impact, such as the side rail, mounting, storage battery packaging,etc. It is proved that dO % offset crash simulation result of one certain car is well-correlated with the physical test. Optimization cases meet the crash performance requirements. The objec- tive of the analysis is to guide structural design and improves a car＇ s crash safety performance.展开更多
During the 100%front impact,all the parts of front car will participate in the course;the crash stiffness of bodywork will also reach the peak.During the crash,rational structure of bodywork can resist the distortion,...During the 100%front impact,all the parts of front car will participate in the course;the crash stiffness of bodywork will also reach the peak.During the crash,rational structure of bodywork can resist the distortion,absorb more energy and get better mode of distortion and low deceleration rate,so as to meet the performance of crash safety.The paper mainly makes optimization analysis based on the problems of front side rails,subframe,firewall,and optimization cases are confirmed which can decrease the intrusion and deceleration rate of the whole car.The structure of bodywork after optimization can meet the performance of crash safety.展开更多
Increasing size of wind turbine and deep water deployment have raised the issue of appropriate selection of the most suitable support structure to make offshore wind energy cost competitive.The paper presents an optim...Increasing size of wind turbine and deep water deployment have raised the issue of appropriate selection of the most suitable support structure to make offshore wind energy cost competitive.The paper presents an optimization methodology for decision making process of bottom mounted supports of offshore wind turbines （OWTs） through reasonable engineering attributes derivation.Mathematic models of support structures are reduced by the generalized single-degree-of-freedom theory with relatively fewer structural parameters.Soft-stiff design optimization based on dynamic properties of OWTs is performed for monopile and lattice supports with different wind turbines,water depth and hub height.Attributes of support structures,wind turbines and environment conditions are applied in the multi-criteria decision making method——TOPSIS for benchmarking of those options.The results illustrate the effectiveness of the proposed optimazation methodology combined with economical and environmental attributes together.展开更多
In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A B...In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A Bidirectional Clone Node Chord model (BCNChord) based on CNP protocol is designed and realized.In BCNChord,Anticlockwise Searching Algorithm,Difference Push Synchronize Algorithm and Optimal Maintenance Algorithm are put forward to increase the performances.In experiments,according to the frequency of nodes,the maintenance cost of BCNChord can be 3.5%～32.5% lower than that of Chord.In the network of 212 nodes,the logic path hop is steady at 6,which is much more prior to 12 of Chord and 10 of CNChord.Theoretical analysis and experimental results show that BCNChord can effectively reduce the maintenance cost of its structure and simultaneously improve the query efficiency up to (1/4)O(logN).BCNChord is more suitable for highly dynamic environment and higher real-time system.展开更多
This paper introduces the performances of compound gear pump. Based on the target of having the smallest mass per unit volume, the paper established a mathematical model of optimization, and obtained the results of op...This paper introduces the performances of compound gear pump. Based on the target of having the smallest mass per unit volume, the paper established a mathematical model of optimization, and obtained the results of optimization of the pump.展开更多
From the view of system theory, modern agriculture in a region embodies elements conformity, structure optimization, multi-functionality and sustainable development. This paper first expounds on the relationship among...From the view of system theory, modern agriculture in a region embodies elements conformity, structure optimization, multi-functionality and sustainable development. This paper first expounds on the relationship among agricultural elements, structure, function and development theoretically, compartmentalizes agriculture types based on human-land elements matching, and depicts the development path of agricultural multi-functionality. it shows that the matching of human-land elements is a key to agricultural types, and the multi-functionality is an indication of agricultural development stages. At last, as a case study of Suzhou in eastern coastal area, the paper analyzes the evolvement situation and developing mechanism and some typical models of modern agriculture which suit to agriculture system evolvement. The results .show that in Suzhou the agriculture productivity, has improved greatly; And along with the agriculture structure optimizing, agriculture function has translated from ＂production ＂ to ＂non- production and production ＂. With simulation of agricultural trend in Suzhou, it is .found that Suzhou has a LP- dependence （labor productivity） on agricultural element, so Suzhou will has much more potential in land productivity. Based on the above analysis on agricultural system, some typical patterns on modern agriculture in Suzhou are brought up, such as export-oriented agriculture, enterprises-leading agriculture, science and technology, parks agriculture, stereoseopic agriculture, and tourism and sightseeing agriculture.展开更多
Both of planar and mesoporous architectures prevail for perovskite solar cells(PSCs).However,it is still an open question how the architecture affects the performance of PSCs.The inconsistent results in the references...Both of planar and mesoporous architectures prevail for perovskite solar cells(PSCs).However,it is still an open question how the architecture affects the performance of PSCs.The inconsistent results in the references often create confusion.In particular,the specific roles of mesoporous frameworks are yet to be well elaborated and require further clarification.In this study,we carefully compared the properties of perovskite films and the device performances for both architectures to unravel the roles of mesoporous TiO2 framworks in CH3NH3PbI3 PSCs.The detailed characterizations of structural,microscopic,optical and electrical properties revealed that the presence of mesoporous TiO2 framework contributed to enlarged perovskite crystal sizes,enhanced light harvesting,efficient electron extration and suppressed charge recombination.As a result,compared with the planar device,the mesoporous device yielded an improved power conversion efficiency of 18.18%,coupled with a reduced hystersis.This study reveals the benefits of mesoporous TiO2 framework in PSCs and provides the guidance for the design and optimization of architectures for high-performance devices.展开更多
基金Projects(51405516,U1334208)supported by the National Natural Science Foundation of ChinaProject(2013GK2001)supported by the Science and Technology Program for Hunan Provincial Science and Technology Department,ChinaProject(2013zzts040)supported by the Graduate Degree Thesis Innovation Foundation of Central South University,China
文摘For the safety protection of passengers when train crashes occur, special structures are crucially needed as a kind of indispensable energy absorbing device. With the help of the structures, crash kinetic-energy can be completely absorbed or dissipated for the aim of safety. Two composite structures(circumscribed circle structure and inscribed circle structure) were constructed. In addition, comparison and optimization of the crashworthy characteristic of the two structures were carried out based on the method of explicit finite element analysis(FEA) and Kriging surrogate model. According to the result of Kriging surrogate model, conclusions can be safely drawn that the specific energy absorption(SEA) and ratio of specific energy absorption to initial peak force(REAF) of circumscribed circle structure are lager than those of inscribed circle structure under the same design parameters. In other words, circumscribed circle structure has better performances with higher energy-absorbing ability and lower initial peak force. Besides, error analysis was adopted and the result of which indicates that the Kriging surrogate model has high nonlinear fitting precision. What is more, the SEA and REAF optimum values of the two structures have been obtained through analysis, and the crushing results have been illustrated when the two structures reach optimum SEA and REAF.
基金Projects(51408443,51178203)supported by the National Natural Science Foundation of ChinaProject(K201511)supported by the Science Foundation of Wuhan Institute of Technology,China
文摘The performance-based passive control analysis of the Maxwell dampers between one 10-story and one 6-story adjacent RC frames is conducted in this work.Not only the optimal parameters but also the optimal arrangements of the Maxwell dampers are proposed based on the optimal target of making the total exceeding probability of the adjacent structures to be minimal.The applicability of the analytical expressions of the Maxwell damper damping parameters under different seismic performance targets are firstly examined and then the preferable damping parameters of the Maxwell dampers are proposed through the extensive parametric studies.Furthermore,the optimal arranging positions and optimal arranging numbers of the Maxwell dampers between the adjacent buildings are derived based on a large number of seismic fragility analyses,as well.The general arranging laws of the Maxwell dampers between the adjacent buildings are generated based on the discussion of the theoretical method through the simplified plane model.The optimal parameters and optimal arrangement of the Maxwell dampers presented make both the adjacent structures have preferable controlled effects under each seismic performance target which can satisfy the requirements of multi-performance seismic resistance of the modern seismic codes.
基金"Twelfth Five-year Plan"for Sci & Tech Research of China(No.2011BAG03B02No.2011BAG03B06)
文摘Front bumper, crash box and side rail are key body structural parts in front crash. Deformation space is affected by compartment packaging. The improvement suggestions are proposed to solve the problems existed in the current vehicle struc- ture and compartment packaging based on the areas that influence performance of automobile offset deformable barrier impact, such as the side rail, mounting, storage battery packaging,etc. It is proved that dO % offset crash simulation result of one certain car is well-correlated with the physical test. Optimization cases meet the crash performance requirements. The objec- tive of the analysis is to guide structural design and improves a car＇ s crash safety performance.
基金"Twelfth Five-year Plan"for Sci & Tech Research of China(No.2011BAG03B02No.2011BAG03B06)
文摘During the 100%front impact,all the parts of front car will participate in the course;the crash stiffness of bodywork will also reach the peak.During the crash,rational structure of bodywork can resist the distortion,absorb more energy and get better mode of distortion and low deceleration rate,so as to meet the performance of crash safety.The paper mainly makes optimization analysis based on the problems of front side rails,subframe,firewall,and optimization cases are confirmed which can decrease the intrusion and deceleration rate of the whole car.The structure of bodywork after optimization can meet the performance of crash safety.
基金Supported by the National Natural Science Foundation of China （No.51309209,51279186） and the National Basic Research Program of China （No.2011CB013704）.
文摘Increasing size of wind turbine and deep water deployment have raised the issue of appropriate selection of the most suitable support structure to make offshore wind energy cost competitive.The paper presents an optimization methodology for decision making process of bottom mounted supports of offshore wind turbines （OWTs） through reasonable engineering attributes derivation.Mathematic models of support structures are reduced by the generalized single-degree-of-freedom theory with relatively fewer structural parameters.Soft-stiff design optimization based on dynamic properties of OWTs is performed for monopile and lattice supports with different wind turbines,water depth and hub height.Attributes of support structures,wind turbines and environment conditions are applied in the multi-criteria decision making method——TOPSIS for benchmarking of those options.The results illustrate the effectiveness of the proposed optimazation methodology combined with economical and environmental attributes together.
基金supported by the National Natural Science Foundation of China under Grant No.61100205Science and Technology Project of Beijing Municipal Education Commission under Grant No.KM201110016006Doctor Start-up Foundation of BUCEA under Grant No.101002508
文摘In order to reduce the maintenance cost of structured Peer-to-Peer (P2P),Clone Node Protocol (CNP) based on user behavior is proposed.CNP considers the regularity of user behavior and uses the method of clone node.A Bidirectional Clone Node Chord model (BCNChord) based on CNP protocol is designed and realized.In BCNChord,Anticlockwise Searching Algorithm,Difference Push Synchronize Algorithm and Optimal Maintenance Algorithm are put forward to increase the performances.In experiments,according to the frequency of nodes,the maintenance cost of BCNChord can be 3.5%～32.5% lower than that of Chord.In the network of 212 nodes,the logic path hop is steady at 6,which is much more prior to 12 of Chord and 10 of CNChord.Theoretical analysis and experimental results show that BCNChord can effectively reduce the maintenance cost of its structure and simultaneously improve the query efficiency up to (1/4)O(logN).BCNChord is more suitable for highly dynamic environment and higher real-time system.
文摘This paper introduces the performances of compound gear pump. Based on the target of having the smallest mass per unit volume, the paper established a mathematical model of optimization, and obtained the results of optimization of the pump.
基金supported by Major Program of the National Natural Science Foundation of China (Grant No.40771014)
文摘From the view of system theory, modern agriculture in a region embodies elements conformity, structure optimization, multi-functionality and sustainable development. This paper first expounds on the relationship among agricultural elements, structure, function and development theoretically, compartmentalizes agriculture types based on human-land elements matching, and depicts the development path of agricultural multi-functionality. it shows that the matching of human-land elements is a key to agricultural types, and the multi-functionality is an indication of agricultural development stages. At last, as a case study of Suzhou in eastern coastal area, the paper analyzes the evolvement situation and developing mechanism and some typical models of modern agriculture which suit to agriculture system evolvement. The results .show that in Suzhou the agriculture productivity, has improved greatly; And along with the agriculture structure optimizing, agriculture function has translated from ＂production ＂ to ＂non- production and production ＂. With simulation of agricultural trend in Suzhou, it is .found that Suzhou has a LP- dependence （labor productivity） on agricultural element, so Suzhou will has much more potential in land productivity. Based on the above analysis on agricultural system, some typical patterns on modern agriculture in Suzhou are brought up, such as export-oriented agriculture, enterprises-leading agriculture, science and technology, parks agriculture, stereoseopic agriculture, and tourism and sightseeing agriculture.
基金financially supported by the National Natural Science Foundation of China(51602088)the Open Fund of the Key Laboratory of Photovoltaic and Energy Conservation Materials,Chinese Academy of Sciences(PECL2019KF007)and China Postdoctoral Science Foundation(2017T100313)。
文摘Both of planar and mesoporous architectures prevail for perovskite solar cells(PSCs).However,it is still an open question how the architecture affects the performance of PSCs.The inconsistent results in the references often create confusion.In particular,the specific roles of mesoporous frameworks are yet to be well elaborated and require further clarification.In this study,we carefully compared the properties of perovskite films and the device performances for both architectures to unravel the roles of mesoporous TiO2 framworks in CH3NH3PbI3 PSCs.The detailed characterizations of structural,microscopic,optical and electrical properties revealed that the presence of mesoporous TiO2 framework contributed to enlarged perovskite crystal sizes,enhanced light harvesting,efficient electron extration and suppressed charge recombination.As a result,compared with the planar device,the mesoporous device yielded an improved power conversion efficiency of 18.18%,coupled with a reduced hystersis.This study reveals the benefits of mesoporous TiO2 framework in PSCs and provides the guidance for the design and optimization of architectures for high-performance devices.
