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反电动势对无扰载荷航天器精确定向的影响
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作者 孔宪仁 武晨 +1 位作者 李海勤 杨震国 《国防科技大学学报》 EI CAS CSCD 北大核心 2019年第2期75-81,共7页
无扰载荷航天器中非接触式作动器反电动势会引起有效载荷模块与支持模块之间的耦合,影响有效载荷模块的精确定向性能。通过建立无扰载荷航天器的耦合动力学模型,分析非接触式作动器反电动势对有效载荷模块精确定向性能的影响。考虑六支... 无扰载荷航天器中非接触式作动器反电动势会引起有效载荷模块与支持模块之间的耦合,影响有效载荷模块的精确定向性能。通过建立无扰载荷航天器的耦合动力学模型,分析非接触式作动器反电动势对有效载荷模块精确定向性能的影响。考虑六支杆立方构型无扰载荷接口,结合拉格朗日方程和牛顿欧拉方法建立有效载荷模块平台动力学模型。推导非接触式作动器的输出力模型,并引入有效载荷模块平台动力学模型,给出考虑非接触式作动器反电动势的耦合动力学模型。将支持模块上飞轮动静不平衡引起的谐振作为干扰力矩,建立了无扰载荷航天器在轨定向状态的Simulink仿真模型。仿真结果表明,反电动势系数越大,干扰力矩对有效载荷模块的影响越大,有效载荷模块精确定向精度越低。 展开更多
关键词 无扰载荷航天器 反电动势 有效载荷精确定向 耦合动力学模型
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New Exact Solutions for a Class of Nonlinear Coupled Differential Equations
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作者 ZHAOHong GUOJun +1 位作者 BAICheng-Lin HANJi-Guang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第5期781-786,共6页
More new exact solutions for a class of nonlinear coupled differential equations are obtained by using a direct and efficient hyperbola function transform method based on the idea of the extended homogeneous balance m... More new exact solutions for a class of nonlinear coupled differential equations are obtained by using a direct and efficient hyperbola function transform method based on the idea of the extended homogeneous balance method. 展开更多
关键词 nonlinear couple differential equations new exact solutions hyperbola function transform method
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Exact Solutions to Three-Dimensional Schrodinger Equation with anExponentially Position-Dependent Mass
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作者 CAIChang-Ying RENZhong-Zhou JUGuo-Xing 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第6期1019-1022,共4页
For an exponentially position-dependent mass, we obtain the exact solutionsof the three-dimensional Schrodinger equation by using coordinate transformation method for thereference problems with Coulomb potential, Krat... For an exponentially position-dependent mass, we obtain the exact solutionsof the three-dimensional Schrodinger equation by using coordinate transformation method for thereference problems with Coulomb potential, Kratzer potential, and spherically square potential wellof infinite depth, respectively. The explicit expressions for the energy eigenvalues and thecorresponding eigenfunctions of the three systems are presented. 展开更多
关键词 schrodinger equation exact solutions coordinate transformation effectivemass
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Maximum Effective Hole Mathematical Modei and Exact Solution for Commingled Reservoir 被引量:2
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作者 孙贺东 刘磊 +1 位作者 周芳德 高承泰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2003年第5期550-554,共5页
The maximum effective hole-diameter mathematical modei describing the flow of slightly compressible fluid through a commingled reservoir was solved rigorously with consideration of wellbore storage and different skin ... The maximum effective hole-diameter mathematical modei describing the flow of slightly compressible fluid through a commingled reservoir was solved rigorously with consideration of wellbore storage and different skin factors. The exact solutions for wellbore pressure and the production rate obtained from layer j for a well production at a constant rate from a radial drainage area with infinite and constant pressure and no flow outer boundary condition were expressed in terms of ordinary Bessel functions. These solutions were computed numerically by the Crump's numerical inversion method and the behavior of systems was studied as a function of various reservoir parameters. The modei was compared with the real wellbore radii modei. The new modei is numerically stable when the skin factor is positive and negative, but the real wellbore radii modei is numerically stable only when the skin factor is positive. 展开更多
关键词 well-testing mathematical model effective hole diameter layered reservoir
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问题化教学设计中进行有效性提问初探
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作者 宁鹏 《人生十六七》 2017年第8Z期59-59,共1页
教师提问的艺术与学生质疑的能力是提高课堂内在活力的基本点,是实现有效教学的教学手段,提问的好坏直接影响到课堂教学的质量。老师提问不只是为了得到一个符合要求的结论,而是为了让学生通过积极思考,运用已有知识培养思维能力、归纳... 教师提问的艺术与学生质疑的能力是提高课堂内在活力的基本点,是实现有效教学的教学手段,提问的好坏直接影响到课堂教学的质量。老师提问不只是为了得到一个符合要求的结论,而是为了让学生通过积极思考,运用已有知识培养思维能力、归纳能力和语言表达能力。课堂提问是师生合作进行教与学活动的重要纽带,也是开启学生智慧之门的钥匙,是真正体现学生主体地位的有效教学手段,是师生互动、生生互动基点,更是高效课堂的重要途径。首先,问题预设要精确有效,是历史教师提高课堂提问有效性前提;其次,老师提出问题要适时,这是历史教师提高课堂提问有效性的基础。还有,在教学问题的设计上,'求解'并非其唯一目的,更重要的目的是激发学生积极主动地思考,点燃学生的思维火花,因此教学问题应能激发学生的思考与探究,有启发性。 展开更多
关键词 历史课堂 问题预设与提问 有效 精确有效 提出问题要适时
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High precision nuclear mass predictions towards a hundred kilo-electron-volt accuracy 被引量:2
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作者 Zhongming Niu Haozhao Liang +3 位作者 Baohua Sun Yifei Niu Jianyou Guo Jie Meng 《Science Bulletin》 SCIE EI CSCD 2018年第12期759-764,共6页
Mass is a fundamental property and an important fingerprint of atomic nucleus.It provides an extremely useful test ground for nuclear models and is crucial to understand energy generation in stars as well as the heavy... Mass is a fundamental property and an important fingerprint of atomic nucleus.It provides an extremely useful test ground for nuclear models and is crucial to understand energy generation in stars as well as the heavy elements synthesized in stellar explosions.Nuclear physicists have been attempting at developing a precise,reliable,and predictive nuclear model that is suitable for the whole nuclear chart,while this still remains a great challenge even in recent days.Here we employ the Fourier spectral analysis to examine the deviations of nuclear mass predictions to the experimental data and to present a novel way for accurate nuclear mass predictions.In this analysis,we map the mass deviations from the space of nucleon number to its conjugate space of frequency,and are able to pin down the main contributions to the model deficiencies.By using the radial basis function approach we can further isolate and quantify the sources.Taking a pedagogical mass model as an example,we examine explicitly the correlation between nuclear effective interactions and the distributions of mass deviations in the frequency domain.The method presented in this work,therefore,opens up a new way for improving the nuclear mass predictions towards a hundred kilo-electron-volt accuracy,which is argued to be the chaos-related limit for the nuclear mass predictions. 展开更多
关键词 Nuclear masses Nuclear effective interactions Fourier analysis Radial basis function approach
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