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构造地质图中若干问题的浅析 被引量:2
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作者 钱德玲 宋传中 《安徽地质》 1994年第4期70-75,共6页
构造地质研究中,以下4个方面值得编图时注意。①构造形态的分析从“二维”转向“三维”,也就是说从平面形迹转向立体位态。当今,平面图上描绘出来的构造形迹,只是地质构造在地表出露的痕迹,是二维图象,它不能准确、全面地反映该... 构造地质研究中,以下4个方面值得编图时注意。①构造形态的分析从“二维”转向“三维”,也就是说从平面形迹转向立体位态。当今,平面图上描绘出来的构造形迹,只是地质构造在地表出露的痕迹,是二维图象,它不能准确、全面地反映该构造的立体形状、位态和性质。而三维空间表示各构造的形态及相互关系,并能正确查明构造性状。②从“定性”描述进入“定量”分析。常规地质图上的有限资料分析构造,是一种概略性的定性描述,常常有偏面性或以偏概全之虞。大量专门性构造测量工作,才能更客观地反映构造特征,因此,构造图上应该突出专门性的构造工作成果。③从构造的“形态研究”深入到“形成机制”的研究。构造形成时的应力、应变状况,应适当的表示在地质图上。④对构造的变形研究从“一次性概括”深化到“多期性筛分”。构造图上应将不同时代的构造群层次分明地表达出来;将先后不同构造的叠加现象有条不紊地反映清楚。 展开更多
关键词 构造图 应变系 构造层 构造形态
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Effect of flow stress—strain relation on forming limit of 5754O aluminum alloy 被引量:3
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作者 王海波 万敏 阎昱 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第10期2370-2378,共9页
A modified Swift type flow stress—strain relation was presented in order to describe the uniaxial tension test curve reasonably. The FLD-strain (forming limit diagram made up of limit strain) of 5754O aluminum allo... A modified Swift type flow stress—strain relation was presented in order to describe the uniaxial tension test curve reasonably. The FLD-strain (forming limit diagram made up of limit strain) of 5754O aluminum alloy sheet was calculated based on the two flow stress—strain relations using Yld2000-2d yield function. By comparing the theoretical and experimental results, it is found that the calculated FLD-strain based on the modified Swift flow stress—strain relation can reasonably describe the experimental results. However, though the common Voce flow stress—strain relation can describe the deformation behavior during homogenous deformation phase accurately, the FLD-strain calculated based on it is obviously lower than the experimental result. It is concluded that the higher the hardening rate of sheet metal is, the higher the forming limit is. A method for determining the reasonable flow stress—strain relation is recommended for describing the material behavior during inhomogenous phase and the forming limit of sheet metal. 展开更多
关键词 aluminum alloy forming limit sheet metal flow stress—strain relation inhomogenous deformation
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Research on 1-3 Orthogonal Anisotropic Piezoelectric Composite Material Sensors- 被引量:1
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作者 熊克 张为公 骆英 《Journal of Southeast University(English Edition)》 EI CAS 2002年第2期136-140,共5页
Piezoelectric composite material (PCM) is an important branch of modernsensor and actuator materials with wide applications in smart structures. In this paper, based onpiezoelectric ceramic, composite and experimental... Piezoelectric composite material (PCM) is an important branch of modernsensor and actuator materials with wide applications in smart structures. In this paper, based onpiezoelectric ceramic, composite and experimental mechanics theories, a kind of 1-3 orthogonalanisotropic PCM (OAPCM) sensor is developed, and the sensing principle is analyzed to describesensor behaviors. In order to determine strain and stress on isotropic or orthogonal anisotropiccomponent surface, the relationships between strain and stress are established. The experimentalresearch on 1-3 OAPCM sensor is carried out in uniaxial and biaxial stress states. The results showthat 1-3 OAPCM sensors offer orthotropic properties of piezoelectricity, and sensing equations canbe used for strain or stress measurement with good accuracy. 展开更多
关键词 1-3 PCM orthogonal anisotropic SENSOR strain-stress relationship
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Impact analysis of supplier relationship on supply chain resilience using biological cellular resilience theory 被引量:2
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作者 王新平 赵林度 《Journal of Southeast University(English Edition)》 EI CAS 2015年第2期282-287,共6页
A supply chain resilience model is established based on the biological cellular resilience theory to analyze the impact of the supplier relationship on supply chain resilience. A scenario where the market demand is ch... A supply chain resilience model is established based on the biological cellular resilience theory to analyze the impact of the supplier relationship on supply chain resilience. A scenario where the market demand is changed suddenly by some undesired events is considered. The results reveal that enhancing collaboration with a more resilient supplier can significantly improve supply chain resilience and reduce supply chain losses. It is also found that enhancing the supplier relationship can significantly benefit supply chain resilience if the collaborative intensity is relatively low, and it has less effect if supply chain members have already collaborated closely. Thus, enhancing the supplier relationship to a limited intensity is a relatively effective and economic method to strengthen supply chain resilience. 展开更多
关键词 supply chain risk supply chain resilience biological cellular resilience demand shocks supplier rela-tionship
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Sea level change and forecast in the future — climate of the past,today and the future 被引量:1
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作者 岳军 DONG yue +3 位作者 陈满春 韩芳 段焕春 王国明 《Marine Science Bulletin》 CAS 2011年第2期33-50,共18页
The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change... The sea-level change is resulted from superposition of sun, moon and other planeries, and earth itself, biological process, atmosphere and oceanography, as well as artificial actions. As a result, the sea level change is really a sensitive integral variation value of many variations, or a combined function of coupling effects of various big systems. Therefore the above mentioned superposed action of different systems and the coupling effect of sun earth and biological aspects may be called as sun earth biological coupling effect system. Based on this hypothesis, the corresponding sun dynamic, air dynamic, water dynamic and earth dynamic conceptional models are established in order to research the multiple coupling effects and feedback machsnism between these big systems. In order to determine the relations, effectness and coherent relation of different variations, the quantity, analysis is conducted through collective variation and stage division. The quantity analysis indicates that the earths spindle rotation speed is the dynamic mechanism controlling the sea level change of fluctuation. The change rate of sea level in the world is +1.32 + 0.22 mm/a, while the sea level change rate in China is only+1.39 + 0.26 mm/a in average. If take the CO2 content as the climate marker, eight cold stages (periods) are grouped out since two hundreds years AC. The extreme cold of the eighth cold stage started approximately at 1850 years AC. and if the stage from the extreme cold to extreme warm is determined as long as 200 years, the present ongoing warm stage will end at about 2050 years, there after the temperature will begin to tower. If the stage between cold and warm extremes lasts for 250 years, then the temperature will become lower at about 2100 year. Until to that time, the sea-level is estimated to raise +7 - +11 + 3.5 cm again, and there after, the sea level will begin the new lowering trend. In the same time, the climate will enter into next new cold stage subsequently. 展开更多
关键词 Sun earth biological coupling effect system sea-level change mechanism change rate of the sea-level climate cold stage forecast of the sea-level changes in the future
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Effect of jet milling on micro-strain behavior and rupture behavior of agglomerates of ultrafine WC powders 被引量:7
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作者 Ya-li SUN Qing-cai LIU +3 位作者 Xin HUANG Fa-xing ZHANG Jian YANG Hua MEI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第10期2128-2140,共13页
The Williamson-Hall and uniaxial compression methods were used to study the variations of the micro-strain and stress-strain relations in WC powders after jet milling and ball milling, respectively. The rupture behavi... The Williamson-Hall and uniaxial compression methods were used to study the variations of the micro-strain and stress-strain relations in WC powders after jet milling and ball milling, respectively. The rupture behavior of agglomerates in WC powders was investigated. Meanwhile, the as-obtained WC powders treated by different milling methods were used to fabricate WC-10%Co cemented carbides, followed by the performance assessment of cemented carbides. The results show that the micro-strain of the jet-milled WC powders decreases significantly compared with that of the ball-milled WC powders, and that the cemented carbides prepared by jet-milled WC powders exhibit excellent properties with a transverse-rupture strength of 4260 MPa, due to the elimination of agglomerates and the reduction of lattice strain. 展开更多
关键词 ultrafine WC powder micro-strain stress-strain relation jet milling agglomerate rupture mechanism
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Crack evolution behavior of rocks under confining pressures and its propagation model before peak stress 被引量:10
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作者 ZUO Jian-ping CHEN Yan LIU Xiao-li 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第11期3045-3056,共12页
The understanding of crack propagation characteristics and law of rocks during the loading process is of great significance for the exploitation and support of rock engineering.In this study,the crack propagation beha... The understanding of crack propagation characteristics and law of rocks during the loading process is of great significance for the exploitation and support of rock engineering.In this study,the crack propagation behavior of rocks in triaxial compression tests was investigated in detail.The main conclusions were as follows:1)According to the evolution characteristics of crack axial strain,the differential stress?strain curve of rocks under triaxial compressive condition can be divided into three phases which are linear elastic phase,crack propagation phase,post peak phase,respectively;2)The proposed models are applied to comparison with the test data of rocks under triaxial compressive condition and different temperatures.The theoretical data calculated by the models are in good agreement with the laboratory data,indicating that the proposed model can be applied to describing the crack propagation behavior and the nonlinear properties of rocks under triaxial compressive condition;3)The inelastic compliance and crack initiation strain in the proposed model have a decrease trend with the increase of confining pressure and temperature.Peak crack axial strain increases nonlinearly with the inelastic compliance and the increase rate increases gradually.Crack initiation strain has a linear relation with peak crack axial strain. 展开更多
关键词 crack strain crack propagation behavior crack propagation model stress strain relationship
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Behaviour of large post-liquefaction deformation in saturated sand-gravel composites 被引量:2
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作者 潘华 陈国兴 +1 位作者 孙田 刘汉龙 《Journal of Central South University》 SCIE EI CAS 2012年第2期547-552,共6页
The laboratory tests on the post-liquefaction deformation of saturated sand-gravel composites were performed to investigate the characteristics of stress-strain relation and the dissipation of pore water pressure by t... The laboratory tests on the post-liquefaction deformation of saturated sand-gravel composites were performed to investigate the characteristics of stress-strain relation and the dissipation of pore water pressure by the hollow cylinder apparatus. It is found that the stress-strain response and the dissipation process of pore water pressure are composed of three stages, including the low intensive strength stage, the superlinear strength recovery stage and the sublinear strength recovery stage, and the demarcation points of the curve of pore water pressure are lag behind those of the stress-strain response. The comparison results of the behaviour of large post-liquefaction deformation between saturated sand-gravel composites and Nanjing fine sand show that the low intensive strength stage and the superlinear strength recovery stage of saturated sand-gravel composites are shorter while the sublinear strength recovery stage is longer. A stress-strain model and a dissipation model of excess pore water pressure of liquefied sand-gravel composites are established, in which the initial confining pressure and the relative density can be considered synthetically. And it is found that the predicted results by the two models are in good agreement with experimental data. 展开更多
关键词 saturated sand-gravel composites post-liquefaction deformation stress-strain relation dissipation model: pore water pressure
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Effects of curing age on compressive and tensile stress-strain behaviors of ecological high ductility cementitious composites 被引量:1
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作者 Chai Lijuan Guo Liping +1 位作者 Chen Bo Cao Yuanzhang 《Journal of Southeast University(English Edition)》 EI CAS 2020年第1期73-80,共8页
To obtain the design parameters of the structure made by ecological high ductility cementitious composites(Eco-HDCC),the effects of curing age on the compressive and tensile stress-strain relationships were studied.Th... To obtain the design parameters of the structure made by ecological high ductility cementitious composites(Eco-HDCC),the effects of curing age on the compressive and tensile stress-strain relationships were studied.The reaction degree of fly ash,non-evaporable water content and the pH value in pore solution were calculated to reveal the mechanical property.The results indicate that as the curing age increases,the peak compressive strength,peak compressive strain and ultimate tensile strength of Eco-HDCC increase.However,the ultimate compressive strain and ultimate tensile strain of Eco-HDCC decrease with the increase in curing age.Besides,as the curing age increases,the reaction degree of fly ash and non-evaporable water content in Eco-HDCC increase,while the pH value in the pore solution of Eco-HDCC decreases.Finally,the simplified compressive and tensile stress-strain constitutive relationship models of Eco-HDCC with a curing age of 28 d were suggested for the structure design safety. 展开更多
关键词 ecological high ductility cementitious composites(Eco-HDCC) compressive stress-strain behavior tensile stress-strain behavior curing age reaction degree non-evaporable water content pH value in pore solution
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Unsaturated Creep Behaviors of Weak Intercalated Soils in Soft Rock of Badong Formation 被引量:4
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作者 ZHU Yan-Bo YU Hong-Ming 《Journal of Mountain Science》 SCIE CSCD 2015年第6期1460-1470,共11页
The cutting slopes in soft rock of redbed appeared in Yichang-Badong highway often suffer from the instability along weak intercalations, so the creep behaviors of weak intercalated soils are crucially important for t... The cutting slopes in soft rock of redbed appeared in Yichang-Badong highway often suffer from the instability along weak intercalations, so the creep behaviors of weak intercalated soils are crucially important for the stability of cutting slopes. Because the deformation of weak intercalated soils is significantly affected by water content due to the strong water sensitivity, it is necessary to study the influence of matric suction on the creep behaviors of weak intercalated soils. In order to find out the unsaturated creep characters of weak intercalated soils, a GDS unsaturated triaxial apparatus was used. Then the triaxial creep experiments on weak intercalated soil samples under varying matric suction were conducted to obtain the unsaturated creep curves. The results show that the weak intercalated soils have obvious creep behaviors, and the creep strain is in nonlinear relationship with stress and time. When the matric suction is constant, a larger deviator stress will lead to a larger creep strain; When the deviator stress is constant, a smaller matric suction will lead to a larger creep strain. Based on the Mesri creep model, an improved creep model for weak intercalated soils under varying matric suction was established, in which the relationship of stress-strain was expressed with a hyperbolic function, and the relationship of strain-time was expressed with power functions in stages. Then an unsaturated creep model including stress-matric suction-strain-time for weak intercalated soils was established based on the power function relationship between matric suction and Ed(a parameter of the improved creep model). The comparison of the calculated values of creep model and the experimental values shows that the creep behaviors of weak intercalated soils can be predicted by the unsaturated creep model by and large. 展开更多
关键词 Badong formation Weak intercalated soils Unsaturated creep behaviors Soil triaxial apparatus Creep model
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Stress-strain relationship of unsaturated cohesive soil 被引量:2
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作者 梅国雄 陈启明 姜朋明 《Journal of Central South University》 SCIE EI CAS 2010年第3期653-657,共5页
A moisture-content based constitutive model was proposed based on the hyperbolic model as an attempt to move towards the implementation of unsaturated soil mechanics into routine geotechnical engineering practice. The... A moisture-content based constitutive model was proposed based on the hyperbolic model as an attempt to move towards the implementation of unsaturated soil mechanics into routine geotechnical engineering practice. The stress-strain behavior of in-situ soil at a depth of 5 m was investigated by conducting undrained triaxial compression tests using the remolded soil samples. The test results show that the stress-strain relationship of unsaturated cohesive soil is still hyperbolic. The values of parameters a and b given in the model decrease with increasing the confining pressure for soil samples with the same moisture content and increase with increasing the moisture content for soil samples under the same confining pressure. The relationships between parameters a, b and moisture content were studied for confining pressures of 100, 150, 200 and 250 kPa. The comparison between the measured and predicted stress-strain curves for an additional group of soil samples, having a moisture content of 25.4%, shows that the proposed moisture content-dependent hyperbolic model provides a good prediction of stress-strain behavior of unsaturated cohesive soil. 展开更多
关键词 unsaturated cohesive soil moisture content triaxial compression test stress-strain relationship
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Adaptive predictive functional control based on Takagi-Sugeno model and its application to pH process 被引量:5
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作者 苏成利 李平 《Journal of Central South University》 SCIE EI CAS 2010年第2期363-371,共9页
In order to obtain accurate prediction model and compensate for the influence of model mismatch on the control performance of the system and avoid solving nonlinear programming problem,an adaptive fuzzy predictive fun... In order to obtain accurate prediction model and compensate for the influence of model mismatch on the control performance of the system and avoid solving nonlinear programming problem,an adaptive fuzzy predictive functional control(AFPFC) scheme for multivariable nonlinear systems was proposed.Firstly,multivariable nonlinear systems were described based on Takagi-Sugeno(T-S) fuzzy models;assuming that the antecedent parameters of T-S models were kept,the consequent parameters were identified on-line by using the weighted recursive least square(WRLS) method.Secondly,the identified T-S models were linearized to be time-varying state space model at each sampling instant.Finally,by using linear predictive control technique the analysis solution of the optimal control law of AFPFC was established.The application results for pH neutralization process show that the absolute error between the identified T-S model output and the process output is smaller than 0.015;the tracking ability of the proposed AFPFC is superior to that of non-AFPFC(NAFPFC) for pH process without disturbances,the overshoot of the effluent pH value of AFPFC with disturbances is decreased by 50% compared with that of NAFPFC;when the process parameters of AFPFC vary with time the integrated absolute error(IAE) performance index still retains to be less than 200 compared with that of NAFPFC. 展开更多
关键词 Takagi-Sugeno (T-S) model adaptive fuzzy predictive functional control (AFPFC) weighted recursive least square (WRLS) pH process
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Analysis of strain variation in cross shear zone of plate during snake hot rolling 被引量:1
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作者 张涛 吴运新 +2 位作者 龚海 石文泽 蒋方敏 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第2期296-302,共7页
In order to study the distribution of equivalent and shear strain of aluminum alloy plate during snake hot rolling, several coupled thermo-mechanical finite element models(FEM) are established. Effects of speed ratio ... In order to study the distribution of equivalent and shear strain of aluminum alloy plate during snake hot rolling, several coupled thermo-mechanical finite element models(FEM) are established. Effects of speed ratio and offset distance on strain distribution of the plate are analyzed. The length of cross shear zone is defined to have a better understanding of the deformation characteristic in cross shear zone, which is the essential difference from symmetrical rolling in deformation zone. The results show that the equivalent strain and shear strain of lower part both increase with the increase of speed ratio, while the upper part decreases; the equivalent strain through the whole thickness decreases with ascending offset distance, while the shear strain of lower part increases. The length of cross shear zone quickly increases with ascending speed ratio and slightly decreases with ascending offset distance. The "positive" and "negative" cross shear zones are formed with the increase of speed ratio and offset distance, respectively. The value of the sensitivity coefficient of speed ratio is an order of magnitude bigger than the offset distance. However, the shear strain at center point increases with the ascending speed ratio and offset distance for different mechanism. As speed ratio increases, the asymmetry of the distribution of equivalent is becoming larger and the shear strain is generated in the same direction in cross shear zone. The FEM results agree well with experimental results. 展开更多
关键词 aluminum alloy plate snake hot rolling speed ratio offset distance cross shear zone
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Modeling Seasonal Variations of Subsurface Chlorophyll Maximum in South China Sea 被引量:4
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作者 GONG Xiang SHI Jie GAO Huiwang 《Journal of Ocean University of China》 SCIE CAS 2014年第4期561-571,共11页
In the South China Sea(SCS), the subsurface chlorophyll maximum(SCM) is frequently observed while the mechanisms of SCM occurrence have not been well understood. In this study, a 1-D physical-biochemical coupled model... In the South China Sea(SCS), the subsurface chlorophyll maximum(SCM) is frequently observed while the mechanisms of SCM occurrence have not been well understood. In this study, a 1-D physical-biochemical coupled model was used to study the seasonal variations of vertical profiles of chlorophyll-a(Chl-a) in the SCS. Three parameters(i.e., SCM layer(SCML) depth, thickness, and intensity) were defined to characterize the vertical distribution of Chl-a in SCML and were obtained by fitting the vertical profile of Chl-a in the subsurface layer using a Gaussian function. The seasonal variations of SCMs are reproduced reasonably well compared to the observations. The annual averages of SCML depth, thickness, and intensity are 75 ± 10 m, 31 ± 6.7 m, and 0.37 ± 0.11 mg m-3, respectively. A thick, close to surface SCML together with a higher intensity occurs during the northeastern monsoon. Both the SCML thickness and intensity are sensitive to the changes of surface wind speed in winter and summer, but the surface wind speed exerts a minor influence on the SCML depth; for example, double strengthening of the southwestern monsoon in summer can lead to the thickening of SCML by 46%, the intensity decreasing by 30%, and the shoaling by 6%. This is because part of nutrients are pumped from the upper nutricline to the surface mixed layer by strong vertical mixing. Increasing initial nutrient concentrations by two times will increase the intensity of SCML by over 80% in winter and spring. The sensitivity analysis indicates that light attenuation is critical to the three parameters of SCM. Decreasing background light attenuation by 20% extends the euphotic zone, makes SCML deeper(~20%) and thicker(12% – 41%), and increases the intensity by over 16%. Overall, the depth of SCML is mainly controlled by light attenuation, and the SCML thickness and intensity are closely associated with wind and initial nitrate concentration in the SCS. 展开更多
关键词 South China Sea subsurface chlorophyll maximum seasonal variation numerical modeling
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Significance of induced magnetic field and variable thermal conductivity on stagnation point flow of second grade fluid 被引量:2
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作者 A.A.KHAN S.ILYAS +1 位作者 T.ABBAS R.ELLAHI 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第11期3381-3390,共10页
In this study,the stagnation point transport of second grade fluid with linear stretching under the effects of variable thermal conductivity is considered.Induced magnetic field impact is also incorporated.The nonline... In this study,the stagnation point transport of second grade fluid with linear stretching under the effects of variable thermal conductivity is considered.Induced magnetic field impact is also incorporated.The nonlinear set of particle differential equations is converted into set of ordinary differential equations through appropriate transformation.The resulting equations are then resolved by optimal homotopy analysis method.The effect of pertinent parameters of interest on skin friction coefficient,temperature,induced magnetic field,velocity and local Nusselt number is inspected by generating appropriate plots.For numerical results,the built-in bvp4 c technique in computational software MATLAB is used for the convergence and residual errors of obtained series solution.It is perceived that the induced magnetic field is intensified by increasing β.It can also be observed that skin friction coefficient enhances with increasing value of magnetic parameter depending on the stretching ratio a/c.For the validness of the obtained results,a comparison has been made and an excellent agreement of current study with existing literature is found. 展开更多
关键词 stagnation point variable thermal conductivity induced magnetic field second grade fluid
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Construction and Identification of the Helper Plasmids for Reverse Genetic System of Rabies Virus Street Strain
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作者 Ping-gang MING Ying HUANG +4 位作者 Qing TANG Jia-liang DU Xiao-yan TAO Jia-xin YAN Rong-liang HU 《Virologica Sinica》 SCIE CAS CSCD 2009年第6期559-565,共7页
To obtain the helper plasmids for a reverse genetics system of rabies virus, the cDNAs of the complete open reading frames of the N, P, G, and L genes of rabies street virus stain HN10 were each cloned into expression... To obtain the helper plasmids for a reverse genetics system of rabies virus, the cDNAs of the complete open reading frames of the N, P, G, and L genes of rabies street virus stain HN10 were each cloned into expression vector pVAX1, These four plasmids were identified by restriction enzyme digestion and gene sequencing. The plasmid encoding the N protein was selected to determine the expression effect of these plasmids in NA cells. The results showed that the helper plasmids for a reverse genetics system of rabies street virus strain HN10 had been successfully constructed. 展开更多
关键词 Rabies virus Helper plasmids Reverse genetic system
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Finite element analysis of rolling process for variable cross-section blade 被引量:2
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作者 孔祥伟 李佳 礼宾 《Journal of Central South University》 SCIE EI CAS 2013年第12期3431-3436,共6页
Due to the variation of the blade cross-section, the deformation stress and strain of the workpiece keep changing during the rolling process and the conventional rolling theory is no longer valid. The complexity and d... Due to the variation of the blade cross-section, the deformation stress and strain of the workpiece keep changing during the rolling process and the conventional rolling theory is no longer valid. The complexity and diversity of the blade cross-section determine it impossible to establish an universal theoretical model for the rolling process. Finite element analysis(FEA) provides a perspective solution to the prediction. The FEA software DEFORM was applied to discovering the deformation, stress, strain and velocity field of the variable cross-section workpiece, and the effects of friction coefficient and rolling speed during the rolling process. which indicates that the average rolling force at friction coefficient of 0.4 is 6.5% higher than that at 0.12, and the rolling velocity has less effect on the equivalent stress and strain distribution, which would confer instructive significance on the theoretical study as well as the engineering practice. 展开更多
关键词 variable section rolling finite element analysis forming law BLADE
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Macroscopic Frost Heave Model Based on Segregation Potential Theory
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作者 吉植强 徐学燕 于琳琳 《Transactions of Tianjin University》 EI CAS 2010年第4期304-308,共5页
A macroscopic frost heave model with more clear parameters was established. Based on a porosity rate frost heave model and segregation potential theory, a porosity rate function was deduced and introduced into the str... A macroscopic frost heave model with more clear parameters was established. Based on a porosity rate frost heave model and segregation potential theory, a porosity rate function was deduced and introduced into the stress-strain relationship. Numerical simulation was conducted and verified by frost heave tests. Results show that the porosity rate within the frozen fringe is proportional to the square of temperature gradient and current porosity, and is also proportional to the exponential function of applied pressure. The relative errors between the calculated and measured results of frost depth and frost heave are within 3% and 15% respectively, demonstrating that the temperature gradient, applied pressure and current porosity are the main influencing factors, while temperature is just the constraint of frozen fringe. The improved model have meaningful and accessible parameters, which can be used in engineering with good accuracy. 展开更多
关键词 frost heave model porosity rate segregation potential frost heave test temperature gradient
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Alkalibacillus halophilus subsp. hitensis subsp. nov.:A new subspecies of moderately halophilic bacterium isolated from a chemical plant in China
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作者 李维国 马放 +2 位作者 魏利 李丽萍 苏俊峰 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第3期297-302,共6页
In order to develop halophilic microorganism resources to improve environment, a Gram-positive, strictly aerobic and moderately halophilic bacterial strain JSA1 was obtained from the waste water sample collected from ... In order to develop halophilic microorganism resources to improve environment, a Gram-positive, strictly aerobic and moderately halophilic bacterial strain JSA1 was obtained from the waste water sample collected from Jinhong Chemical Plant at Weihai city, by the methods of quick isolation and screening of halophilie bacteria. Systematic studies on it were carried out. Results show that the strain JSA1 is bacillus. The temperature range most suitable for its growth is 29 - 35 ℃ and the most suitable pH is 6. 5 - 9. 0. It can grow well at the salt mass concentration of 30 - 150 g/L. The C + G mole fraction of its DNA is 37.5%. The analytical result of 16S rRNA gene sequence reveals that this strain has the closest relationship with Alkalibacillus halophilus (DQ359731) of Alkalibacillts. Their similarities are as high as 99%. However, they have obvious differences in aspects of whole-cell main fatty acid components, cell size, cell morphology, motility, oxidase, gelatine liquefication, NaCl tolerance range, pH tolerance range, G + C mole fraction, sole carbon source, sole nitrogen source, antibiotic sensitivity and strain source. Comparing with other species of the same genus, differences of this strain are even more obvious. In view of muhiple identification results, we believe this strain is a new subspecies ofAlkalibacillus halophilus and name it Alkalibacillus halophilus subsp, hitensis subsp, nov. 展开更多
关键词 moderately halophilic bacterium polyphasic taxonomy new subspecies Alkalibacillus halophilus subsp hitensis subsp nov.
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EFFECTS OF ROCK BEHAVIOR AND STRESS CONDITION ON FIELD STRESS DETERMINATION 被引量:1
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作者 D. H. (Steve) Zou (Department of Mining and Metallurgical Engineering,Technical University of Nova Scotia, Canada) 《Journal of China University of Mining and Technology》 1995年第1期23-33,共11页
Non-consistency of stress results is of ten observed during field measurements. In some cases, even the rneasurernents are made at the same location in a massive rockrnass, the results can vary widely. In order to sol... Non-consistency of stress results is of ten observed during field measurements. In some cases, even the rneasurernents are made at the same location in a massive rockrnass, the results can vary widely. In order to solve the problem, extensive research has been carried out to study the major factors wh1ch rnay affect stress deterrnlnation. They include the rock behaviour and the stress state. For rocks showing non-isotropic behaviour, the values of Young’s modulus and Poisson ratio vary with the orientation of loading and measurement. Stress condition in the rock affects the rock behaviour. Furtherrnore, the loading condition on rock samples durlng laboratory tests is different from in the field and therefore the determined e1astic constants may not represent the field condi tion. In general , the Young’s modulus may depend on the orientation, the loading path, the stress magnitude and the stress ratio. This paper examines in detail the effects of those factors, especially for rocks showing transversely isotropic behaviour. It is found that the discrepancy of stress results from field measurernents in this type of rock is mainly due to over simplification of the rock behavior and inadequate use of elastic constants of the rock during stress calculation. A case study is given,which indicates the significance of these factors and demonstrates the proper procedure for stress calculation from measurements. 展开更多
关键词 in-situ stress overcoring transverse isotropy microfractures Young 's modulus stress state
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