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Electronic Structure and Transport Coefficients of the Thermoelectric Materials Bi_2Te_3 from First-principles Calculations 被引量:1
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作者 颜欣心 ZHENG Wenwen +1 位作者 LIU Fengming 杨述华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第1期11-15,共5页
The electronic structures of bulk Bi_2Te_3 crystals were investigated by the first-principles calculations.The transport coefficients including Seeback coefficient and power factor were then calculated by the Boltzman... The electronic structures of bulk Bi_2Te_3 crystals were investigated by the first-principles calculations.The transport coefficients including Seeback coefficient and power factor were then calculated by the Boltzmann theory,and further evaluated as a function of chemical potential assuming a rigid band picture.The results suggest that p-type doping in the Bi_2Te_3 compound may be more favorable than n-type doping.From this analysis results,doping effects on a material will exhibit high ZT.Furthermore,we can also find the right doping concentration to produce more efficient materials,and present the "advantage filling element map" in detail. 展开更多
关键词 thermoelectric BI2TE3 first-principles calculations electronic structure transport coefficients
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Activity coefficient calculation model for NaAl(OH)_4-NaOH-H_2O system 被引量:4
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作者 李小斌 吕卫君 +4 位作者 刘桂华 彭志宏 周秋生 孟芸 任万能 《中国有色金属学会会刊:英文版》 EI CSCD 2005年第4期908-912,共5页
Resorting to Debye-Hückel equation, the conception of the apparent dielectric constant ε′ of sodium aluminate solution is introduced. By supposing that all the influences are attributed to it, ε′ is successfu... Resorting to Debye-Hückel equation, the conception of the apparent dielectric constant ε′ of sodium aluminate solution is introduced. By supposing that all the influences are attributed to it, ε′ is successfully related to caustic ratio αK, concentration mNaOH, T and temperature T. Then an activity coefficient calculation model for NaAl(OH)4-NaOH-H2O system from 25℃ to 100℃ is established, which can be used in much wider αK and mNaOH, T ranges than those covered by the equilibrium solubility data. 展开更多
关键词 NaAl(OH)4-NaOH-H2O 计算模型 活动系数 平衡性 绝缘体 冶炼工艺
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A General Calculating Method of Rotor’s Torsional Stiffness Based on Stiffness Influence Coefficient 被引量:1
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作者 Danmei Xie Wangfan Li +3 位作者 Ling Yang Yong Qian Xianbo Zhao Zhigang Gao 《Engineering(科研)》 2010年第9期698-704,共7页
In order to develop a general calculating rotor’s torsional stiffness based on stiffness influence coefficient for different rotor assembling, the calculation method of the torsional stiffness influence coefficient o... In order to develop a general calculating rotor’s torsional stiffness based on stiffness influence coefficient for different rotor assembling, the calculation method of the torsional stiffness influence coefficient of equal thickness disc is researched in this paper at first. Then the torsional stiffness influence coefficient λ of equal thickness disc is fit to a binary curved face and a calculation equation is obtained based on a large quantity of calculating data, which lays the foundation for research on a general calculating method of rotor torsional stiffness. Thirdly a simplified calculation method for equivalent stiffness diameter of stepped equal thickness disc and cone disc in the steam turbine generators is suggested. Finally a general calculating program for calculating rotor’s torsional vibration features is developed, and the torsional vibration features of a verity of steam turbine rotors are calculated for verification. The calculating results show that stiffness influence coefficient λ of equal-thickness disc depends on parameters of B and H, as well as the stiffness influence coefficient λ;and discs with complex structure can be simplified to equal-thickness discs with little error by using the method suggested in this paper;error can be controlled within 1% when equivalent diameter of stiffness is calculated by this method. 展开更多
关键词 ROTOR DISC GENERAL calculATING Method Torsional STIFFNESS STIFFNESS Influence coefficient
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An Iterative Calculating Method for Inbreeding and Relationship Coefficient
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作者 HANDan-dan SONGRen-xue 《Journal of Northeast Agricultural University(English Edition)》 CAS 2001年第1期19-22,共4页
The iterative formulas of inbreeding and relationship coefficients were put forward by using numerator elationship. It is suitable for any none - generation - overlap pedigree. The inbreeding and relationship coeffi- ... The iterative formulas of inbreeding and relationship coefficients were put forward by using numerator elationship. It is suitable for any none - generation - overlap pedigree. The inbreeding and relationship coeffi- ient of offsprings can be calculated by those of parents. The deducing process of numerator relationship is simple and clear comparing with path analysis. An example shows the usage of these formulas. 展开更多
关键词 Inbreeding coefficient relationship coefficient numerator relationship iterative calculating
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Simplified Calculation Methods for All-Vertical-Piled Wharf in Offshore Deep Water 被引量:3
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作者 WANG Yuan-zhan HE Lin-lin 《China Ocean Engineering》 SCIE EI CSCD 2017年第2期182-191,共10页
All-vertical-piled wharf is a kind of high-piled wharf, but it is extremely different from the traditional ones in some aspects, such as the structural property, bearing characteristics, failure mechanism, and static ... All-vertical-piled wharf is a kind of high-piled wharf, but it is extremely different from the traditional ones in some aspects, such as the structural property, bearing characteristics, failure mechanism, and static or dynamic calculation methods. In this paper, the finite element method (FEM) and theoretical analysis method are combined to analyze the structural property, bearing behavior and failure mode of the all-vertical-piled wharf in offshore deep water, and to establish simplified calculation methods determining the horizontal static ultimate bearing capacity and the dynamic response for the all-vertical-piled wharf. Firstly, the bearing capability and failure mechanism for all-vertical-piled wharf are studied by use of FEM, and the failure criterion is put forward for all-vertical-piled wharf based on the 'plastic hinge'. According to the failure criterion and P-Y curve method, the simplified calculation method of the horizontal static ultimate bearing capacity for all-vertical-piled wharf is proposed, and it is verified that the simplified method is reasonable by comparison with the FEM. Secondly, the displacement dynamic magnification factor for the all-vertical-piled wharf under wave cyclic loads and ship impact loads is calculated by the FEM and the theory formula based on the single degree of freedom (SDOF) system. The results obtained by the two methods are in good agreement with each other, and the simplified calculation method of the displacement dynamic magnification factor for all-vertical-piled wharf under dynamic loads is proposed. Then the simplified calculation method determining the dynamic response for the all-vertical-piled wharf is proposed in combination with P-Y curve method. That is, the dynamic response of the structure can be obtained through the static calculation results of P-Y curve method multiplied by the displacement dynamic magnification factor. The feasibility of the simplified dynamic response method is verified by comparison with the FEM under different conditions. 展开更多
关键词 all-vertical-piled wharf failure criterion plastic hinge dynamic amplification coefficient simplified calculation methods
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Rules for confidence intervals of permeability coefficients for water flow in over-broken rock mass 被引量:7
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作者 Liu Weiqun Fei Xiaodong Fang Jingnian 《International Journal of Mining Science and Technology》 2012年第1期29-33,共5页
Based on the steady-state seepage method, we used the Mechanical Testing and Simulation 815.02 System and a self-designed seepage instrument for over-broken stone to measure seepage properties of water flows in three ... Based on the steady-state seepage method, we used the Mechanical Testing and Simulation 815.02 System and a self-designed seepage instrument for over-broken stone to measure seepage properties of water flows in three types of crushed rock samples. Three methods of confidence interval in describing permeability coefficients are presented: the secure interval, the calculated interval and the systemic interval. The lower bound of the secure interval can be applied to water-inrush and the upper bound can solve the problem of connectivity. For the calculated interval, as the axial pressure increases, the length of confidence interval is shortened and the upper and lower bounds are reduced. For the systemic interval, the length of its confidence interval, as well as the upper and lower bounds, clearly vary under low axial pressure but are fairly similar under high axial pressure. These three methods provide useful information and references for analyzing the permeability coefficient of over-broken rock. 展开更多
关键词 Over-broken rock mass Permeability coefficient Secure interval calculated interval Systemic interval
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First-principles calculations on elastic, magnetoelastic, and phonon properties of Ni_2FeGa magnetic shape memory alloys 被引量:1
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作者 贺王强 黄厚兵 +1 位作者 柳祝红 马星桥 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第1期438-443,共6页
The elastic, magnetoelastic, and phonon properties of Ni2FeGa were investigated through first-principles calculations. The obtained elastic and phonon dispersion curves for the austenite and martensite phases agree we... The elastic, magnetoelastic, and phonon properties of Ni2FeGa were investigated through first-principles calculations. The obtained elastic and phonon dispersion curves for the austenite and martensite phases agree well with available the- oretical and experimental results. The isotropic elastic moduli are also predicted along with the polycrystalline aggregate properties including the bulk modulus, shear modulus, Young's modulus, and Poisson's ratio. The Pugh ratio indicates that Ni2FeGa shows ductility, especially the austenite phase, which is consistent with the experimental results. The Debye tem- peratures of the Ni2FeGa in the austenite and martensite phases are 344 K and 392 K, respectively. It is predicted that the magnetoelastic coefficient is -5.3 x 10^6 J/m3 and magnetostriction coefficient is between 135 and 55 ppm in the Ni2FeGa austenite phase. 展开更多
关键词 Ni2FeGa elastic constants first-principles calculations magnetoelastic coefficients
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Boron diffusion in bcc-Fe studied by first-principles calculations
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作者 李向龙 吴平 +4 位作者 杨锐杰 闫丹 陈森 张师平 陈宁 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第3期307-313,共7页
The diffusion mechanism of boron in bcc-Fe has been studied by first-principles calculations. The diffusion coefficients of the interstitial mechanism, the B-monovacancy complex mechanism, and the B-divacancy complex ... The diffusion mechanism of boron in bcc-Fe has been studied by first-principles calculations. The diffusion coefficients of the interstitial mechanism, the B-monovacancy complex mechanism, and the B-divacancy complex mechanism have been calculated. The calculated diffusion coefficient of the interstitial mechanism is DO = 1.05 x l0-7 exp (-0.75 eV/kT) m2. s-1, while the diffusion coefficients of the B-monovacancy and the B-divacancy complex mechanisms are D1 =1.22 x 10-6fl exp (-2.27 eV/kT) mE. s-1 and D2 - 8.36 x 10-6 exp (-4.81 eV/kT) m2. s-l, re- spectively. The results indicate that the dominant diffusion mechanism in bcc-Fe is the interstitial mechanism through an octahedral interstitial site instead of the complex mechanism. The calculated diffusion coefficient is in accordance with the reported experiment results measured in Fe-3%Si-B alloy (bcc structure). Since the non-equilibrium segregation of boron is based on the diffusion of the complexes as suggested by the theory, our calculation reasonably explains why the non-equilibrium segregation of boron is not observed in bcc-Fe in experiments. 展开更多
关键词 BORON diffusion coefficient DIVACANCY first-principles calculation
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Adhesion coefficient of automobile tire and road surface
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作者 刘长生 《Journal of Central South University》 SCIE EI CAS 2008年第S1期210-214,共5页
The adhesion coefficient of automobile tire and road surface was analyzed and the formula about it was derived.Some suggestions about highway construction,driving safety of the drivers and the judgment of the traffic ... The adhesion coefficient of automobile tire and road surface was analyzed and the formula about it was derived.Some suggestions about highway construction,driving safety of the drivers and the judgment of the traffic accidents were presented.The results show that the adhesion coefficient is a function with the extreme value.If there is atmospheric pressure in the tire,the load of the vehicle and the degree of the coarse on the road surface is not selected properly,it will reach the least and affect the safety of the running automobile. 展开更多
关键词 CONSTITUTIVE model microstructure MECHANICS element connecting type ADHESION coefficient PAVEMENT profile TRIBOLOGY analysis calculation COMPREHENSION evaluation
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Determination Method of Thermal Expansion Coefficient of Cordierite
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作者 YANG Daoyuan ZHU Kai WU Juan 《China's Refractories》 CAS 2013年第4期14-17,共4页
Cordierite ceramics were prepared by using talc, bauxite and kaolin clay as starting materials. According to the detected resuh of XRD step-scanning from 25° to 35° by a high temperature X-ray diffractometer... Cordierite ceramics were prepared by using talc, bauxite and kaolin clay as starting materials. According to the detected resuh of XRD step-scanning from 25° to 35° by a high temperature X-ray diffractometer, 20 and d values of five peaks of cordierite crystal were ascer- rained. Then the least squares technique was used to cal- culate the crystal parameters : at 25 ℃ , a = b = O. 981 8 nm, c =0. 927 4 nm, V=O. 774 3 nm3 ; at 600 ℃ , a =b =O. 982 0 nm, c=0.9252 nm, V=O. 773 5 nm3. The crystal volumetric coefficient of thermal expansion (CTE) and linear CTE along a and c axes were calcu- lated, αv = 2. 33 × 10-6℃-1, αa = αb, = 3. 27 × 10-6℃ -1 , αc = -4.19 ×10-6℃ -1. The average CTE of cordierite crystal is as low as O. 78 × 10-6℃ -1 展开更多
关键词 CORDIERITE thermal expansion coefficient calculation method high temperature XRD
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Calculation of Solidification Process of Continuous Cast Bar
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作者 A I Golodnov R K Mysik +2 位作者 A V Sulitsin S V Brusnitsyn I A Gruzdeva 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第5期112-118,共7页
In this paper,it presents the results of calculation of solidification process of copper continuous cast bar by cross section size 120 mm × 70 mm with application of Pro Cast 2010 software. The estimation of moul... In this paper,it presents the results of calculation of solidification process of copper continuous cast bar by cross section size 120 mm × 70 mm with application of Pro Cast 2010 software. The estimation of mould design effect on solidification process of continuos copper cast bar is completed at various speeds of casting.Profiles of liquid metal cavities and temperature allocations in the cast bar at various casting speeds are defined.The analysis of received liquid metal cavity profiles shows that a new mold construction allows significantly decrease of the length of the liquid metal cavity during continuous copper casting at HAZELETTcasting machine and the increase of maximum casting speed from 10 to 11 m / min. Adequacy of the results of copper continuous cast bar solidification process calculation is confirmed by the experimental data. 展开更多
关键词 continuous casting copper cast bar water cooling mold liquid metal cavity heat emission coefficient calculation of solidification process
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Calculation of terminal velocity in transitional flow for spherical particle
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作者 Zhang Lei Honaker Ricky +2 位作者 Liu Wenli Men Dongpo Chen Jinxiang 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第2期311-317,共7页
The terminal velocity has been widely used in extensive fields, but the complexity of drag coefficient expression leads to the calculation of terminal velocity in transitional flow (1 〈 Re ≤ 1000) with much more d... The terminal velocity has been widely used in extensive fields, but the complexity of drag coefficient expression leads to the calculation of terminal velocity in transitional flow (1 〈 Re ≤ 1000) with much more difficulty than those in laminar flow (Re ≤ 1) and turbulent flow (Re ≥ 1000). This paper summarized and compared 24 drag coefficient correlations, and developed an expression for calculating the terminal velocity in transitional flow, and also analyzed the effects of particle density and size, fluid density and viscosity on terminal velocity. The results show that 19 of 24 previously published correlations for drag coefficient have good prediction performance and can be used for calculating the terminal velocity in the entire transitional flow with higher accuracy. Adapting two dimensionless parameters (w*, d*), a proposed explicit correlation, w*=-25.68654 × exp (-d*/77.02069)+ 24.89826, is attained in transitional flow with good performance, which is helpful in calculating the terminal velocity. 展开更多
关键词 Transitional flow Drag coefficient Terminal velocity Spherical particle calculation
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基于温度--应力试验的混凝土温度应力仿真
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作者 赵志方 王哲 +3 位作者 朱敏敏 赵志刚 施韬 刘艳明 《浙江工业大学学报》 CAS 北大核心 2024年第5期487-491,共5页
为分析早龄期混凝土的温度变形和温度应力,使用ABAQUS有限元分析软件,考虑混凝土的热膨胀系数和弹性模量随等效龄期的变化规律,通过现有的堆石坝面板混凝土温度—应力试验测试数据建立温度—应力试验试件有限元分析模型,开展混凝土温度... 为分析早龄期混凝土的温度变形和温度应力,使用ABAQUS有限元分析软件,考虑混凝土的热膨胀系数和弹性模量随等效龄期的变化规律,通过现有的堆石坝面板混凝土温度—应力试验测试数据建立温度—应力试验试件有限元分析模型,开展混凝土温度变形对应的温度场和应力场的数值仿真研究。研究结果表明:使用等效龄期,考虑早龄期混凝土热膨胀系数、弹性模量的时变性,可以提高温度应力场仿真模拟的精度,为实际工程提供更安全的设计依据。 展开更多
关键词 温度—应力试验 等效龄期 热膨胀系数 仿真计算
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基于系数匹配与参数整合的P波旅行时计算方程
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作者 魏建 孙祥娥 《吉林大学学报(地球科学版)》 CAS CSCD 北大核心 2024年第1期337-344,共8页
基于泰勒展开的旅行时公式是计算P波旅行时的一种常用方法。泰勒展开的结果仅在计算点附近准确,而地层中具有垂直对称轴的横向各向同性(transverse isotropy with vertical symmetry axis,VTI)介质进一步放大了旅行时计算的不准确性。... 基于泰勒展开的旅行时公式是计算P波旅行时的一种常用方法。泰勒展开的结果仅在计算点附近准确,而地层中具有垂直对称轴的横向各向同性(transverse isotropy with vertical symmetry axis,VTI)介质进一步放大了旅行时计算的不准确性。本文提出了一种改进的P波旅行时计算方法。该方法以基于泰勒展开的偏移距八阶旅行时方程为基础,利用系数匹配方法分别处理偏移距八阶项与六阶项的系数、偏移距六阶项与四阶项的系数,用整合处理优化得到的参数结构,形成了基于系数匹配与参数整合的偏移距四阶P波旅行时计算方法。水平层状VTI介质模型测试结果表明,该方法能够得到更小的计算误差,保证其在远偏移距处具有较好的表现。三维垂直地震剖面数据实验结果表明,该方法经参数调整后能够进行数据分析,在中偏移距处的表现相对稳定,在远偏移距处具有一定优势。 展开更多
关键词 旅行时计算 系数匹配 参数整合 VTI介质
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基坑中软土的水平抗力系数几种确定方法探讨 被引量:1
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作者 陈富强 杨光华 廖汉阳 《广东水利水电》 2024年第6期7-11,23,共6页
该文围绕基坑中软土的的水平抗力系数的确定方法开展了探讨,分析了基坑规程中土的水平反力系数的比例系数m值的来源,分析了水平抗力系数确定的理论,罗列了现行规范中软土的水平抗力系数的经验值,最后通过案例分析,将3种土的水平抗力系... 该文围绕基坑中软土的的水平抗力系数的确定方法开展了探讨,分析了基坑规程中土的水平反力系数的比例系数m值的来源,分析了水平抗力系数确定的理论,罗列了现行规范中软土的水平抗力系数的经验值,最后通过案例分析,将3种土的水平抗力系数的计算方法(m值、k值和c值)的计算结果与实测进行了比较,发现按目前基坑规程公式计算的软土的水平反力系数的比例系数m值偏小的现象。 展开更多
关键词 基坑工程 软土 土的水平抗力 土的水平反力系数的比例系数 计算方法
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围缘扁钢加强的开圆孔无限平板应力解析算法
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作者 王小明 王红旭 《船舶力学》 EI CSCD 北大核心 2024年第5期748-759,共12页
为了研究围缘扁钢加强的开圆孔无限平板应力解析计算方法,近似认为围缘扁钢区域的平均应力处于广义平面应力状态。运用复变函数论的方法,将应力函数表示为两个待定的解析函数;列出围缘扁钢的边界条件、围缘扁钢与平板之间的应力连接条... 为了研究围缘扁钢加强的开圆孔无限平板应力解析计算方法,近似认为围缘扁钢区域的平均应力处于广义平面应力状态。运用复变函数论的方法,将应力函数表示为两个待定的解析函数;列出围缘扁钢的边界条件、围缘扁钢与平板之间的应力连接条件和位移连接条件,求出应力函数,根据求出的应力函数便可求出应力。为了描述围缘扁钢减缓孔口应力集中的效果,提出围缘扁钢加强系数的定义。算例计算表明:本文提出的解析算法计算结果与有限元法计算结果吻合良好,围缘扁钢加强的开圆孔无限平板应力普遍小于开圆孔无限平板应力,围缘扁钢加强效果明显;相同体积的加强构件,围缘扁钢的加强效果优于环形加厚板。 展开更多
关键词 应力集中 开孔加强板 复变函数论方法 应力解析算法 加强系数
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考虑参数空间差异的复合式滑坡推力计算分析
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作者 赵健 姚嘉昊 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第8期3189-3199,共11页
由于复合式滑坡不同滑区同一岩土计算参数数值存在差异性,导致滑坡推力大小判别难度加大。根据复合式滑坡破坏模式,概化构建滑坡地质模型,在此基础上建立滑坡物理力学模型,并对各区参数进行理论分析。根据滑坡失稳特征以及前人对复合式... 由于复合式滑坡不同滑区同一岩土计算参数数值存在差异性,导致滑坡推力大小判别难度加大。根据复合式滑坡破坏模式,概化构建滑坡地质模型,在此基础上建立滑坡物理力学模型,并对各区参数进行理论分析。根据滑坡失稳特征以及前人对复合式滑坡演化阶段划分的研究,将滑坡演化过程划分为前后裂隙开裂、前后滑带局部软化、前后滑带扩展、中部滑带软化、边坡整体失稳5个阶段,基于传递系数法和静力平衡条件构建不同演化阶段下的滑坡推力计算式。以汉巴南铁路某复合式滑坡为例,揭示了滑坡推力随水平距离增加的变化规律,并将计算结果与不考虑不同滑区同一岩土计算参数数值差异得出的计算结果进行对比分析。研究结果表明:1)在计算复合式滑坡推力时,考虑不同滑区同一岩土计算参数数值差异性的影响,其计算结果更加准确,规避因单一取值而导致计算推力不合理等问题。2)根据复合式滑坡不同演化阶段下的推力变化规律,在滑坡初期应以推移区和牵引区加固为主,当中部锁固区开始滑动,应以中部锁固区加固为主,同时也要加强推移区和牵引区的加固。3)在识别复合式滑坡演化阶段的基础上,根据此阶段构建的滑坡推力计算式得出推力空间变化规律,从而可提出较为合理的防治措施。 展开更多
关键词 复合式滑坡 演化过程 参数差异 传递系数法 推力计算
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Fe-3%Si大尺寸合金单晶的制备及磁感系数的计算
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作者 游清雷 蒋奇武 +2 位作者 庞树芳 贾志伟 张海利 《鞍钢技术》 CAS 2024年第3期26-31,共6页
以取向Fe-3%Si合金热轧板为原材料,采用二次再结晶法制备了尺寸大于200 mm的合金单晶。随机选取3个单晶样品剪切成7个与轧向成不同角度、尺寸为50 mm×50 mm的样品,分别对所选样品进行单晶定向,并对每个样品的横、纵向磁性能进行了... 以取向Fe-3%Si合金热轧板为原材料,采用二次再结晶法制备了尺寸大于200 mm的合金单晶。随机选取3个单晶样品剪切成7个与轧向成不同角度、尺寸为50 mm×50 mm的样品,分别对所选样品进行单晶定向,并对每个样品的横、纵向磁性能进行了测量。以单晶定向结果为依据,计算每个单晶在晶体学坐标架下的极角和辐角,提出了一种单晶磁感系数的计算方法,并基于该方法以单晶磁性能实测值及其在晶体学坐标架下的极角和辐角为输入条件,测算了Fe-3%Si合金单晶磁感应强度系数并验证了其可靠性。采用该方法对{110}晶面平行于板面的任意方向单晶的磁感应强度进行了计算,为开展多晶材料磁性能计算提供了理论依据。 展开更多
关键词 Fe-3%Si合金 大尺寸单晶 磁感系数 定量计算
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基于桥梁响应的高速铁路简支梁离心力折减方法
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作者 李奇 揭崇清 +1 位作者 石龙 李克冰 《铁道建筑》 北大核心 2024年第1期65-70,共6页
为分析规范离心力计算公式中竖向活载折减系数的理论来源,建立列车-曲线桥-墩系统的空间模型进行车桥耦合振动仿真计算。提出以桥梁动力响应与设计离心力产生的静力响应之比作为竖向活载折减系数的方法,结合反向传播神经网络分析列车车... 为分析规范离心力计算公式中竖向活载折减系数的理论来源,建立列车-曲线桥-墩系统的空间模型进行车桥耦合振动仿真计算。提出以桥梁动力响应与设计离心力产生的静力响应之比作为竖向活载折减系数的方法,结合反向传播神经网络分析列车车速、桥梁墩高、跨度、曲线半径等因素对折减系数的影响程度。结果表明:车速对折减系数的影响最大,其次为桥梁跨度;竖向活载折减系数反映了列车荷载图式中设计活载与运营列车轴重的差异,折减系数应与列车荷载图式、实际运营列车相匹配;现行规范中竖向活载折减系数公式对中国高速铁路ZK荷载具有良好的适配性,能满足高速铁路简支梁离心力设计的要求。 展开更多
关键词 铁路桥梁 离心力 数值计算 折减系数 简支梁 车桥耦合 桥梁响应
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酸碱滴定教学中的动态演示探讨
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作者 余晓 《广州化工》 CAS 2024年第12期154-156,共3页
酸碱滴定是《分析化学》课程中的重点内容,因其涉及分布系数、酸碱平衡的计算、指示剂的变色原理等难点,知识点及相关公式较多,计算复杂,概念也比较抽象,笔者研发了基于C#编程语言的酸碱滴定曲线虚拟动态演示系统,包括酸碱组分分布系数... 酸碱滴定是《分析化学》课程中的重点内容,因其涉及分布系数、酸碱平衡的计算、指示剂的变色原理等难点,知识点及相关公式较多,计算复杂,概念也比较抽象,笔者研发了基于C#编程语言的酸碱滴定曲线虚拟动态演示系统,包括酸碱组分分布系数、酸碱滴定曲线及酸碱指示剂三个动态演示模块、将晦涩难懂的理论知识转变为具有动态可视化和趣味性的虚拟平台,以提高学生的计算及创新应用能力。 展开更多
关键词 酸碱滴定 滴定曲线计算 酸碱指示剂 分布系数 动态演示
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