3D Studio MAX 5.0是3DS系列软件中的最新版本,其现代化的工作流程设计、条理清晰、定制简便的用户界面,为用户提供了轨迹条、层级视图、可浮动和嵌入的工具栏、右键菜单、命令面板卷动条等,使整个操作更为流畅(图1)。快速和效果极佳的...3D Studio MAX 5.0是3DS系列软件中的最新版本,其现代化的工作流程设计、条理清晰、定制简便的用户界面,为用户提供了轨迹条、层级视图、可浮动和嵌入的工具栏、右键菜单、命令面板卷动条等,使整个操作更为流畅(图1)。快速和效果极佳的渲染;流畅的NURBS建模,基于样条曲线的面片建模;完整的人物动画工具,如蒙皮、二级运动以及变形;线形编辑界面,精确的UVW贴图操纵器;功能强劲的非线性动画编辑;效果卓越,使众多的三维创作者对之爱不释手。展开更多
The hot compression tests of 7Mo super austenitic stainless(SASS)were conducted to obtain flow curves at the temperature of 1000-1200℃and strain rate of 0.001 s^(-1)to 1 s^(-1).To predict the non-linear hot deformati...The hot compression tests of 7Mo super austenitic stainless(SASS)were conducted to obtain flow curves at the temperature of 1000-1200℃and strain rate of 0.001 s^(-1)to 1 s^(-1).To predict the non-linear hot deformation behaviors of the steel,back propagation-artificial neural network(BP-ANN)with 16×8×8 hidden layer neurons was proposed.The predictability of the ANN model is evaluated according to the distribution of mean absolute error(MAE)and relative error.The relative error of 85%data for the BP-ANN model is among±5%while only 42.5%data predicted by the Arrhenius constitutive equation is in this range.Especially,at high strain rate and low temperature,the MAE of the ANN model is 2.49%,which has decreases for 18.78%,compared with conventional Arrhenius constitutive equation.展开更多
The effects of pre-deformation following solution treatment on the microstructure and mechanical properties of aged high purity Al-Cu-Mg alloy were studied by tensile test, micro-hardness measurements, transmission el...The effects of pre-deformation following solution treatment on the microstructure and mechanical properties of aged high purity Al-Cu-Mg alloy were studied by tensile test, micro-hardness measurements, transmission electron microscopy and scanning electron microscopy. The micro-hardness measurements indicate that compared with un-deformed samples, the peak hardness is increased and the time to reach peak hardness is reduced with increasing pre-strain. Additionally, a double-peak hardness evolution behavior of cold-rolled (CR) samples was observed during aging. The results of TEM observation show that the number density of S′(Al2CuMg) phase is increased and the size is decreased in CR alloy with increase of pre-strain. The peak hardness and peak strength of the CR alloy are increased because of quantity increasing and refinement of S′ phase and high density dislocation.展开更多
The deformation behaviors of a new quaternary Mg-6Zn-1.5Cu-0.5Zr alloy at temperatures of 523-673 K and strain rates of 0.001-1 s-1 were studied by compressive tests using a Gleeble 3800 thermal-simulator.The results ...The deformation behaviors of a new quaternary Mg-6Zn-1.5Cu-0.5Zr alloy at temperatures of 523-673 K and strain rates of 0.001-1 s-1 were studied by compressive tests using a Gleeble 3800 thermal-simulator.The results show that the flow stress increases as the deformation temperature decreases or as the strain rate increases.A strain-dependent constitutive equation and a feed-forward back-propagation artificial neural network were used to predict flow stress,which showed good agreement with experimental data.The processing map suggests that the domains of 643-673 K and 0.001-0.01 s-1 are corresponded to optimum conditions for hot working of the T4-treated Mg-6Zn-1.5Cu-0.5Zr alloy.展开更多
AIM:Many defense factors of the mother's colostrum or milk protect infants from intestinal, respiratory and systemic infections. In the present study, we investigated the effect of colostrum and mature human milk ...AIM:Many defense factors of the mother's colostrum or milk protect infants from intestinal, respiratory and systemic infections. In the present study, we investigated the effect of colostrum and mature human milk on E. histolytica parasites in vitro.METHODS:Samples of human milk were collected from 5 healthy lactating mothers.The medium with human milk at concentrations of 2%, 5% and 10% was obtained.RESULTS:The lethal effect of E. histolytica on the medium supplemented with different concentrations of both colostrum and mature human milk was significant during the first 30min. We also detected that the results of colostrum and mature human milk were similar. No statistically significant differences were found between same concentrations of colostrum and mature human milk at the same times.CONCLUSION:Colostrum and mature human milk have significant lethal effect on E. histolytica and protect against its infection in breast fed children.展开更多
The hot deformation behavior of Al?6.2Zn?0.70Mg?0.30Mn?0.17Zr alloy was investigated by isothermal compressiontest on a Gleeble?3500machine in the deformation temperature range between623and773K and the strain rate ra...The hot deformation behavior of Al?6.2Zn?0.70Mg?0.30Mn?0.17Zr alloy was investigated by isothermal compressiontest on a Gleeble?3500machine in the deformation temperature range between623and773K and the strain rate range between0.01and20s?1.The results show that the flow stress decreases with decreasing strain rate and increasing deformation temperature.Basedon the experimental results,Arrhenius constitutive equations and artificial neural network(ANN)model were established toinvestigate the flow behavior of the alloy.The calculated results show that the influence of strain on material constants can berepresented by a6th-order polynomial function.The ANN model with16neurons in hidden layer possesses perfect performanceprediction of the flow stress.The predictabilities of the two established models are different.The errors of results calculated by ANNmodel were more centralized and the mean absolute error corresponding to Arrhenius constitutive equations and ANN model are3.49%and1.03%,respectively.In predicting the flow stress of experimental aluminum alloy,the ANN model has a betterpredictability and greater efficiency than Arrhenius constitutive equations.展开更多
The effect of pre-deformation followed by or together with artificial aging on the mechanical properties as strength and ductility of an AA6060 aluminium alloy was studied. AA6060 was initially cast, homogenized and e...The effect of pre-deformation followed by or together with artificial aging on the mechanical properties as strength and ductility of an AA6060 aluminium alloy was studied. AA6060 was initially cast, homogenized and extruded according to standard industrial practice. The extruded material was then subjected to a solution heat treatment and subsequently artificial aging after (sequential mode) and during (simultaneous mode) various combinations of deformation (0-10%) and heat treatments. The aging behaviour and mechanical properties were characterized in terms of Vickers hardness and tensile testing. It is found that precipitation kinetics and associated mechanical response, in terms of hardness and tensile properties are strongly affected by pre-deformations. In terms of aging behaviour, kinetics is accelerated and the peak strength generally increases. Comparing sequential mode and simultaneous mode, the latter seems to give overall better mechanical properties and after considerably shorter aging times. The results of the two modes of pre-deformation are compared and discussed in view of differences in processing conditions and microstructure characteristics.展开更多
For a self-reconfigurable robot, how to metamorphose to adapt itself to environment is a difficult problem. To solve this problem, a new relative orientation model which describes modules and their surrounding grids w...For a self-reconfigurable robot, how to metamorphose to adapt itself to environment is a difficult problem. To solve this problem, a new relative orientation model which describes modules and their surrounding grids was given, a module motion rules database which enables the robot to avoid obstacles was established, and finally a three-layer planner based on dynamic meta-modules was developed. The firstlayer planner designates the category of each module in robot by evaluation functions and picks out the modules in dynamic meta-modules. The second-layer planner plans the dynamic meta-module path according to output parameters of the first-layer planner. The third-layer planner plans the motion of the modules in dynamic meta-module using topology variation oriented methods. To validate the efficiency of the three-layer planner, two simulations were given. One is the simulation of a single dynamic meta-module, the other is the simulation of planning with an initial configuration composed of 8 modules in complicated environment. Results show that the methods can make robot with any initial configuration move through metamorphosis in complicated environment efficiently.展开更多
Village landscapes, which integrate small-scMe agriculture with housing, forestry, and a host of other land use practices, cover more than 2 million square kilometers across China. Village lands tend to be managed at ...Village landscapes, which integrate small-scMe agriculture with housing, forestry, and a host of other land use practices, cover more than 2 million square kilometers across China. Village lands tend to be managed at very fine spatial scales (≤ 30 m), with managers both adapting their practices to existing variation in soils and terrain (e.g., fertile plains vs. infertile slopes) and also altering soil fertility and even terrain by terracing, irrigation, fertilizing, and other land use practices. Relationships between fine-scale land management patterns and soil organic carbon (SOC) in the top 30 cm of village soils were studied by sampling soils within fine-scale landscape features using a regionally weighted landscape sampling design across five environmentally distinct sites in China. SOC stocks across China's village regions (5 Pg C in the top 30 cm of 2 ×10^6 km^2) represent roughly 4% of the total SOC stocks in global croplands. Although macroclimate varied from temperate to tropical in this study, SOC density did not vary significantly with climate, though it was negatively correlated with regional mean elevation. The highest SOC densities within landscapes were found in agricultural lands, especially paddy, the lowest SOC densities were found in nonproductive lands, and forest lands tended toward moderate SOC densities. Bue to the high SOC densities of agricultural lands and their predominance in village landscapes, most village SOC was found in agricultural land, except in the tropical hilly region, where forestry accounted for about 45% of the SOC stocks. A surprisingly large portion of village SOC was associated with built structures and with the disturbed lands surrounding these structures, ranging from 〉 18% in the North China Plain to about 9% in the tropical hilly region. These results confirmed that local land use practices, combined with local and regional variation in terrain, were associated with most of the SOC variation within and across China's village landscapes and may be an important cause of regional variation in SOC.展开更多
AIM To explore the association between Helicobacter pylori (H. pylori) infection status, intestinal metaplasia (IM), and colorectal adenomas. METHODS We retrospectively reviewed 1641 individuals aged >= 40 years wh...AIM To explore the association between Helicobacter pylori (H. pylori) infection status, intestinal metaplasia (IM), and colorectal adenomas. METHODS We retrospectively reviewed 1641 individuals aged >= 40 years who underwent physical examination, laboratory testing, C-13-urea breath testing, gastroscopy, colonoscopy, and an interview to ascertain baseline characteristics and general state of health. Histopathological results were obtained by gastric and colorectal biopsies. RESULTS The prevalence of H. pylori infection and adenomas was 51.5% (845/1641) and 18.1% (297/1641), respectively. H. pylori infection was significantly correlated with an increased risk of colorectal adenomas (crude OR = 1.535, 95% CI: 1.044-1.753, P = 0.022; adjusted OR = 1.359, 95% CI: 1.035-1.785, P = 0.028). Individuals with IM had an elevated risk of colorectal adenomas (crude OR = 1.664, 95% CI: 1.216-2.277, P = 0.001; adjusted OR = 1.381, 95% CI: 0.998-1.929, P = 0.059). Stratification based on H. pylori infection stage and IM revealed that IM accompanied by H. pylori infection was significantly associated with an increased risk of adenomas (crude OR = 2.109, 95% CI: 1.383-3.216, P = 0.001; adjusted OR = 1.765, 95% CI: 1.130-2.757, P = 0.012). CONCLUSION H. pylori-related IM is associated with a high risk of colorectal adenomas in Chinese individuals.展开更多
A self-reconfigurable robot is a non-linear complex system composed of a large number of modules. The complexity caused by non-linearity makes it difficult to solve the problem of module motion planning and shape-chan...A self-reconfigurable robot is a non-linear complex system composed of a large number of modules. The complexity caused by non-linearity makes it difficult to solve the problem of module motion planning and shape-changing control with the traditional algorithm. In this paper, a full-discrete metamorphic algorithm is proposed. The modules concurrently process the local sensing information, update their eigenvector, and act by the same predetermined logical rules. Then a reasonable motion sequence for modules and the global metamorphosis can be obtained. Therefore, the complexity of metamorphic algorithm is reduced, the metamorphic procedure is simplified, and the self-organizing metamorphosis can be obtained. The algorithm cases of several typical systems are studied and evaluated through simulation program of 2-D planar homogeneous modular systems.展开更多
Many researchers in China are actively engaged in the development of new types of wrought magnesium alloys with low cost or with high-performances and novel plastic processing technologies.The research activities are ...Many researchers in China are actively engaged in the development of new types of wrought magnesium alloys with low cost or with high-performances and novel plastic processing technologies.The research activities are funded primarily through four government-supported programs:the Key Technologies R&D Program of China,the National Basic Research Program of China,the National High-tech R&D Program of China,and the National Natural Science Foundation of China.The key R&D activities for the development of new wrought magnesium alloys in China are reviewed,and typical properties of some new alloys are summarized. More attentions are paid to high-strength wrought magnesium alloys and high-plasticity wrought magnesium alloys.Some novel plastic processing technologies,emerging in recent years,which aim to control deformation texture and to improve plasticity and formability especially at room temperature,are also introduced.展开更多
文摘3D Studio MAX 5.0是3DS系列软件中的最新版本,其现代化的工作流程设计、条理清晰、定制简便的用户界面,为用户提供了轨迹条、层级视图、可浮动和嵌入的工具栏、右键菜单、命令面板卷动条等,使整个操作更为流畅(图1)。快速和效果极佳的渲染;流畅的NURBS建模,基于样条曲线的面片建模;完整的人物动画工具,如蒙皮、二级运动以及变形;线形编辑界面,精确的UVW贴图操纵器;功能强劲的非线性动画编辑;效果卓越,使众多的三维创作者对之爱不释手。
文摘The hot compression tests of 7Mo super austenitic stainless(SASS)were conducted to obtain flow curves at the temperature of 1000-1200℃and strain rate of 0.001 s^(-1)to 1 s^(-1).To predict the non-linear hot deformation behaviors of the steel,back propagation-artificial neural network(BP-ANN)with 16×8×8 hidden layer neurons was proposed.The predictability of the ANN model is evaluated according to the distribution of mean absolute error(MAE)and relative error.The relative error of 85%data for the BP-ANN model is among±5%while only 42.5%data predicted by the Arrhenius constitutive equation is in this range.Especially,at high strain rate and low temperature,the MAE of the ANN model is 2.49%,which has decreases for 18.78%,compared with conventional Arrhenius constitutive equation.
基金Project(51301209)supported by the National Natural Science Foundation of China
文摘The effects of pre-deformation following solution treatment on the microstructure and mechanical properties of aged high purity Al-Cu-Mg alloy were studied by tensile test, micro-hardness measurements, transmission electron microscopy and scanning electron microscopy. The micro-hardness measurements indicate that compared with un-deformed samples, the peak hardness is increased and the time to reach peak hardness is reduced with increasing pre-strain. Additionally, a double-peak hardness evolution behavior of cold-rolled (CR) samples was observed during aging. The results of TEM observation show that the number density of S′(Al2CuMg) phase is increased and the size is decreased in CR alloy with increase of pre-strain. The peak hardness and peak strength of the CR alloy are increased because of quantity increasing and refinement of S′ phase and high density dislocation.
基金supported by the R&D Program of Korea Institute of Materials Sciencethe World Premier Materials Program funded by The Ministry of Knowledge Economy,Koreasupport from China Scholarship Council(CSC)
文摘The deformation behaviors of a new quaternary Mg-6Zn-1.5Cu-0.5Zr alloy at temperatures of 523-673 K and strain rates of 0.001-1 s-1 were studied by compressive tests using a Gleeble 3800 thermal-simulator.The results show that the flow stress increases as the deformation temperature decreases or as the strain rate increases.A strain-dependent constitutive equation and a feed-forward back-propagation artificial neural network were used to predict flow stress,which showed good agreement with experimental data.The processing map suggests that the domains of 643-673 K and 0.001-0.01 s-1 are corresponded to optimum conditions for hot working of the T4-treated Mg-6Zn-1.5Cu-0.5Zr alloy.
文摘AIM:Many defense factors of the mother's colostrum or milk protect infants from intestinal, respiratory and systemic infections. In the present study, we investigated the effect of colostrum and mature human milk on E. histolytica parasites in vitro.METHODS:Samples of human milk were collected from 5 healthy lactating mothers.The medium with human milk at concentrations of 2%, 5% and 10% was obtained.RESULTS:The lethal effect of E. histolytica on the medium supplemented with different concentrations of both colostrum and mature human milk was significant during the first 30min. We also detected that the results of colostrum and mature human milk were similar. No statistically significant differences were found between same concentrations of colostrum and mature human milk at the same times.CONCLUSION:Colostrum and mature human milk have significant lethal effect on E. histolytica and protect against its infection in breast fed children.
基金Project(2016GK1004) supported by the Science and Technology Major Project of Hunan Province,China
文摘The hot deformation behavior of Al?6.2Zn?0.70Mg?0.30Mn?0.17Zr alloy was investigated by isothermal compressiontest on a Gleeble?3500machine in the deformation temperature range between623and773K and the strain rate range between0.01and20s?1.The results show that the flow stress decreases with decreasing strain rate and increasing deformation temperature.Basedon the experimental results,Arrhenius constitutive equations and artificial neural network(ANN)model were established toinvestigate the flow behavior of the alloy.The calculated results show that the influence of strain on material constants can berepresented by a6th-order polynomial function.The ANN model with16neurons in hidden layer possesses perfect performanceprediction of the flow stress.The predictabilities of the two established models are different.The errors of results calculated by ANNmodel were more centralized and the mean absolute error corresponding to Arrhenius constitutive equations and ANN model are3.49%and1.03%,respectively.In predicting the flow stress of experimental aluminum alloy,the ANN model has a betterpredictability and greater efficiency than Arrhenius constitutive equations.
基金Project (176816/I40) supported by the Research Council of Norway
文摘The effect of pre-deformation followed by or together with artificial aging on the mechanical properties as strength and ductility of an AA6060 aluminium alloy was studied. AA6060 was initially cast, homogenized and extruded according to standard industrial practice. The extruded material was then subjected to a solution heat treatment and subsequently artificial aging after (sequential mode) and during (simultaneous mode) various combinations of deformation (0-10%) and heat treatments. The aging behaviour and mechanical properties were characterized in terms of Vickers hardness and tensile testing. It is found that precipitation kinetics and associated mechanical response, in terms of hardness and tensile properties are strongly affected by pre-deformations. In terms of aging behaviour, kinetics is accelerated and the peak strength generally increases. Comparing sequential mode and simultaneous mode, the latter seems to give overall better mechanical properties and after considerably shorter aging times. The results of the two modes of pre-deformation are compared and discussed in view of differences in processing conditions and microstructure characteristics.
基金the National High Technology Research and Development Program of China(No.2006AA04Z220)the National Nature Science Foundation of China(No.60705027)+1 种基金Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT)(No.IRT0423)Heilongjiang Postdoctoral Foundation of China(No.LRB-KY 02029)
文摘For a self-reconfigurable robot, how to metamorphose to adapt itself to environment is a difficult problem. To solve this problem, a new relative orientation model which describes modules and their surrounding grids was given, a module motion rules database which enables the robot to avoid obstacles was established, and finally a three-layer planner based on dynamic meta-modules was developed. The firstlayer planner designates the category of each module in robot by evaluation functions and picks out the modules in dynamic meta-modules. The second-layer planner plans the dynamic meta-module path according to output parameters of the first-layer planner. The third-layer planner plans the motion of the modules in dynamic meta-module using topology variation oriented methods. To validate the efficiency of the three-layer planner, two simulations were given. One is the simulation of a single dynamic meta-module, the other is the simulation of planning with an initial configuration composed of 8 modules in complicated environment. Results show that the methods can make robot with any initial configuration move through metamorphosis in complicated environment efficiently.
基金Project supported by the US National Science Foundation (No. DEB-0075617)
文摘Village landscapes, which integrate small-scMe agriculture with housing, forestry, and a host of other land use practices, cover more than 2 million square kilometers across China. Village lands tend to be managed at very fine spatial scales (≤ 30 m), with managers both adapting their practices to existing variation in soils and terrain (e.g., fertile plains vs. infertile slopes) and also altering soil fertility and even terrain by terracing, irrigation, fertilizing, and other land use practices. Relationships between fine-scale land management patterns and soil organic carbon (SOC) in the top 30 cm of village soils were studied by sampling soils within fine-scale landscape features using a regionally weighted landscape sampling design across five environmentally distinct sites in China. SOC stocks across China's village regions (5 Pg C in the top 30 cm of 2 ×10^6 km^2) represent roughly 4% of the total SOC stocks in global croplands. Although macroclimate varied from temperate to tropical in this study, SOC density did not vary significantly with climate, though it was negatively correlated with regional mean elevation. The highest SOC densities within landscapes were found in agricultural lands, especially paddy, the lowest SOC densities were found in nonproductive lands, and forest lands tended toward moderate SOC densities. Bue to the high SOC densities of agricultural lands and their predominance in village landscapes, most village SOC was found in agricultural land, except in the tropical hilly region, where forestry accounted for about 45% of the SOC stocks. A surprisingly large portion of village SOC was associated with built structures and with the disturbed lands surrounding these structures, ranging from 〉 18% in the North China Plain to about 9% in the tropical hilly region. These results confirmed that local land use practices, combined with local and regional variation in terrain, were associated with most of the SOC variation within and across China's village landscapes and may be an important cause of regional variation in SOC.
文摘AIM To explore the association between Helicobacter pylori (H. pylori) infection status, intestinal metaplasia (IM), and colorectal adenomas. METHODS We retrospectively reviewed 1641 individuals aged >= 40 years who underwent physical examination, laboratory testing, C-13-urea breath testing, gastroscopy, colonoscopy, and an interview to ascertain baseline characteristics and general state of health. Histopathological results were obtained by gastric and colorectal biopsies. RESULTS The prevalence of H. pylori infection and adenomas was 51.5% (845/1641) and 18.1% (297/1641), respectively. H. pylori infection was significantly correlated with an increased risk of colorectal adenomas (crude OR = 1.535, 95% CI: 1.044-1.753, P = 0.022; adjusted OR = 1.359, 95% CI: 1.035-1.785, P = 0.028). Individuals with IM had an elevated risk of colorectal adenomas (crude OR = 1.664, 95% CI: 1.216-2.277, P = 0.001; adjusted OR = 1.381, 95% CI: 0.998-1.929, P = 0.059). Stratification based on H. pylori infection stage and IM revealed that IM accompanied by H. pylori infection was significantly associated with an increased risk of adenomas (crude OR = 2.109, 95% CI: 1.383-3.216, P = 0.001; adjusted OR = 1.765, 95% CI: 1.130-2.757, P = 0.012). CONCLUSION H. pylori-related IM is associated with a high risk of colorectal adenomas in Chinese individuals.
文摘A self-reconfigurable robot is a non-linear complex system composed of a large number of modules. The complexity caused by non-linearity makes it difficult to solve the problem of module motion planning and shape-changing control with the traditional algorithm. In this paper, a full-discrete metamorphic algorithm is proposed. The modules concurrently process the local sensing information, update their eigenvector, and act by the same predetermined logical rules. Then a reasonable motion sequence for modules and the global metamorphosis can be obtained. Therefore, the complexity of metamorphic algorithm is reduced, the metamorphic procedure is simplified, and the self-organizing metamorphosis can be obtained. The algorithm cases of several typical systems are studied and evaluated through simulation program of 2-D planar homogeneous modular systems.
基金Project(50725413)supported by the National Natural Science Foundation of ChinaProject(2007CB613704)supported by the National Basic Research Program of ChinaProject(2008DFR50040)supported by the International Cooperation Program of Ministry of Science and Technology of China
文摘Many researchers in China are actively engaged in the development of new types of wrought magnesium alloys with low cost or with high-performances and novel plastic processing technologies.The research activities are funded primarily through four government-supported programs:the Key Technologies R&D Program of China,the National Basic Research Program of China,the National High-tech R&D Program of China,and the National Natural Science Foundation of China.The key R&D activities for the development of new wrought magnesium alloys in China are reviewed,and typical properties of some new alloys are summarized. More attentions are paid to high-strength wrought magnesium alloys and high-plasticity wrought magnesium alloys.Some novel plastic processing technologies,emerging in recent years,which aim to control deformation texture and to improve plasticity and formability especially at room temperature,are also introduced.