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轨道炮发射过程中轨道的受力与变形问题研究 被引量:2
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作者 崔孟阳 王学智 +2 位作者 丁日显 童思远 陈青荣 《弹箭与制导学报》 北大核心 2019年第4期114-117,122,共5页
为了实现轨道炮的安全连续发射,对轨道炮的发射过程进行仿真分析,获得轨道与电枢的受力情况和变形机理。利用有限元分析软件建立电磁-应力多物理场耦合模型,通过仿真得到轨道和电枢的电流与磁场分布情况、体积力密度与应力分布情况。分... 为了实现轨道炮的安全连续发射,对轨道炮的发射过程进行仿真分析,获得轨道与电枢的受力情况和变形机理。利用有限元分析软件建立电磁-应力多物理场耦合模型,通过仿真得到轨道和电枢的电流与磁场分布情况、体积力密度与应力分布情况。分析结果表明:在电磁力作用下电枢尾翼张角变大、产生形变挤压轨道,电枢所在位置的轨道应力和形变较大。通过分析轨道的受力与变形情况,可以为轨道炮的设计与维护提供参考。 展开更多
关键词 轨道炮 体积力密度 多物理场耦合 分布
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Effect of additives on properties of aluminium titanate ceramics 被引量:7
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作者 姜澜 陈晓燕 +1 位作者 韩国明 孟宇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第7期1574-1579,共6页
The influence of some additives on bulk density,phase composition,mechanical strength and thermal shock resistance of aluminium titanate (AT) ceramics was investigated.AT ceramics with different additives of MgO,SiO... The influence of some additives on bulk density,phase composition,mechanical strength and thermal shock resistance of aluminium titanate (AT) ceramics was investigated.AT ceramics with different additives of MgO,SiO2 and Fe2O3 were prepared by reaction sintering.Properties of AT ceramics were tested by using Archimedes,three-point bending and thermal cycling tests.It was found that additives of MgO,SiO2 and Fe2O3 or their compound additives are favorable to reduce the porosities of AT,enhance mechanical strength and thermal shock resistance.The role of additives can be rationalized in terms of promotion of sintering process,formation of new phases and influence on lattice constant c of AT ceramics. 展开更多
关键词 aluminium titanate ceramics ADDITIVE bulk density mechanical properties
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SDBD等离子体中正、负离子的动量传递效率 被引量:7
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作者 车学科 聂万胜 +3 位作者 田希晖 侯志勇 程钰锋 周鹏辉 《高电压技术》 EI CAS CSCD 北大核心 2014年第4期1222-1228,共7页
为研究表面介质阻挡放电(SDBD)等离子体体积力密度的产生机理,采用粒子图像测速技术测量了SDBD激励器的诱导射流。发现采用正极性纳秒脉冲激励时诱导射流从植入电极指向暴露电极,与一般交流激励SDBD诱导射流方向相反,说明负离子对体积... 为研究表面介质阻挡放电(SDBD)等离子体体积力密度的产生机理,采用粒子图像测速技术测量了SDBD激励器的诱导射流。发现采用正极性纳秒脉冲激励时诱导射流从植入电极指向暴露电极,与一般交流激励SDBD诱导射流方向相反,说明负离子对体积力密度的产生具有重要影响。同时,数值模拟了正极性纳秒脉冲激励下SDBD放电过程,得到了正离子、负离子和电子浓度分布随时间的演化情况;计算了正离子、负离子产生的时均体积力密度,发现整个脉冲放电周期内负离子数密度一直低于正离子,其产生的体积力密度绝对值远小于正离子情况,与实验结果进行对比表明负离子动量传递效率要远高于正离子,正离子的动量传递效率应低于37.9%。电流计算结果表明,放电过程中出现了2个连续正向放电和1个反向放电。 展开更多
关键词 纳秒脉冲 表面介质阻挡放电 数值模拟 离子 体积力密度 动量传递效率
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Density Functional Approach Based on Numerically Obtained Bridge Functional
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作者 ZHOUShi-Qi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第3期355-360,共6页
The Ornstein-Zernike equation is solved with the Rogers-Young approximation for bull, hard sphere fluid and Lennard-Jones fluid for several state points. Then the resulted bulk fluid radial distribution function combi... The Ornstein-Zernike equation is solved with the Rogers-Young approximation for bull, hard sphere fluid and Lennard-Jones fluid for several state points. Then the resulted bulk fluid radial distribution function combined with the test particle method is employed to determine numerically the function relationship of bridge functional as a function of indirect correlation function. It is found that all of the calculated points from different phase space state points for a same type of fluid collapse onto a same smooth curve. Then the numerically obtained curve is used to substitute the analytic expression of the bridge functional as a function of indirect correlation function required in the methodology [J. Chem. Phys. 112 (2000) 8079] to determine the density distribution of non-uniform hard sphere fluid and Lennard-Jones fluid. The good agreement of theoretical predictions with the computer simulation data is obtained. The present numerical procedure incorporates the knowledge of bulk fluid radial distribution function into the constructing of the density functional approximation and makes the original methodology more accurate and more flexible for various interaction potential fluid. 展开更多
关键词 density functional theory bridge functional integral equation theory
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Density and Excess Molar Volume of Binary Mixtures ofp-Xylene+Acetic Acid and o-Xylene+Acetic Acid at Different Temperatures and Pressures
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作者 杨天宇 夏淑倩 +1 位作者 邸志国 马沛生 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第2期247-255,共9页
A new apparatus was designed with a thick-walled glass capillary, electric heater tube with red copper and heat preservation. The thick-walled glass capillary was used for its advantages of resistance to acid corrosio... A new apparatus was designed with a thick-walled glass capillary, electric heater tube with red copper and heat preservation. The thick-walled glass capillary was used for its advantages of resistance to acid corrosion and pressure, and ease of observation. The experimental densities over the entire range of mole fraction for the binary mixture of p-xylene+acetic acid and o-xylene+acetic acid were measured using the new apparatus at temperatures ranging from 313.15K to 473.15K and pressure ranging from 0.20 to 2,0 MPa. The density values were used in the determination of excess molar volumes, W. The Redlich-Kister equation was used to fit the excess molar volume values, and the coefficients and estimate ot the standard error values were presented. The experimental resuits prove that the density measurement apparatus is successful. 展开更多
关键词 DENSITY excess molar volume P-XYLENE O-XYLENE acetic acid
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First Principles Study of AI-Li Intermetallic Compounds 被引量:1
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作者 Hai-li Yu Xiao-hui Duan +1 位作者 Yong-jun Ma Min Zeng 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2012年第6期659-665,I0003,共8页
The structural properties, heats of formation, elastic properties, and electronic structures of four compositions of binary A1-Li intermetallics, A13Li, A1Li, A12Li3, and A14Li9, are ana- lyzed in detail by using dens... The structural properties, heats of formation, elastic properties, and electronic structures of four compositions of binary A1-Li intermetallics, A13Li, A1Li, A12Li3, and A14Li9, are ana- lyzed in detail by using density functional theory. The calculated formation heats indicate a strong chemical interaction between A1 and Li for all the A1-Li intermetallics. In partic- ular, in the Li-rich A1-Li compounds, the thermodynamic stability of intermetallics linearly decreases with increasing concentration of.Li. According to the computational single crystal elastic constants, all the four A1-Li intermetallic compounds considered here are mechani- cally stable. The polycrystalline elastic modulus and Poisson's ratio have been deduced by using Voigt, Reuss, and Hill approximations, and the calculated ratios of bulk modulus to shear modulus indicate that the four compositions of binary A1-Li intermetallics are brittle materials. With the increase of Li concentration, the bulk modulus of A1-Li intermetallics decreases in a linear manner. 展开更多
关键词 First principles A1-Li intermetallic compound Mechanical property Forma-tion heat Elastic properties
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