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NONLINEAR STOCHASTIC HEAT EQUATION DRIVEN BY SPATIALLY COLORED NOISE: MOMENTS AND INTERMITTENCY 预览
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作者 陈乐 Kunwoo KIM 《数学物理学报:B辑英文版》 SCIE CSCD 2019年第3期645-668,共24页
In this article, we study the nonlinear stochastic heat equation in the spatial domain R^d subject to a Gaussian noise which is white in time and colored in space. The spatial correlation can be any symmetric, nonnega... In this article, we study the nonlinear stochastic heat equation in the spatial domain R^d subject to a Gaussian noise which is white in time and colored in space. The spatial correlation can be any symmetric, nonnegative and nonnegative-definite function that satisfies Dalang's condition. We establish the existence and uniqueness of a random field solution starting from measure-valued initial data. We find the upper and lower bounds for the second moment. With these moment bounds, we first establish some necessary and sufficient conditions for the phase transition of the moment Lyapunov exponents, which extends the classical results from the stochastic heat equation on Z^d to that on R^d.Then, we prove a localization result for the intermittency fronts, which extends results by Conus and Khoshnevisan [9] from one space dimension to higher space dimension. The linear case has been recently proved by Huang et al [17] using different techniques. 展开更多
关键词 Stochastic heat equation MOMENT ESTIMATES phase transition intermittency intermittency FRONT measure-valued initial data MOMENT LYAPUNOV EXPONENTS
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Molecule opacities of X^2∑+,A^2П,and B^2∑^+ states of CS^+
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作者 林晓贺 梁桂颖 +4 位作者 王建国 彭裔耕 邵彬 李瑞 吴勇 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第5期64-70,共7页
Carbon sulfide cation (CS^+) plays a dominant role in some astrophysical atmosphere environments.In this work,the rovibrational transition lines are computed for the lowest three electronic states,in which the interna... Carbon sulfide cation (CS^+) plays a dominant role in some astrophysical atmosphere environments.In this work,the rovibrational transition lines are computed for the lowest three electronic states,in which the internally contracted multireference configuration interaction approach (MRCI) with Davison size-extensivity correction (+Q) is employed to calculate the potential curves and dipole moments,and then the vibrational energies and spectroscopic constants are extracted.The Frank–Condon factors are calculated for the bands of X^2∑^+,A^2П and X^2∑^+–B^2∑^+ systems,and the band of X^2∑^+–A^2П is in good agreement with the available experimental results.Transition dipole moments and the radiative lifetimes of the low-lying three states are evaluated.The opacities of the CS+ molecule are computed at different temperatures under the pressure of 100 atms.It is found that as temperature increases,the band systems associated with different transitions for the three states become dim because of the increased population on the vibrational states and excited electronic states at high temperature. 展开更多
关键词 CS^+ DIPOLE MOMENT transition DIPOLE MOMENT OPACITY
A generalized model for estimation of aerodynamic forces and moments for irregularly shaped bodies 预览
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作者 Elvedin Kljuno Alan Catovic 《Defence Technology(防务技术)》 CAS CSCD 2019年第3期369-389,共21页
A novel method for estimation of an aerodynamic force and moment acting on an irregularly shaped body (such as HE projectile fragments) during its flight through the atmosphere is presented. The model assumes that fra... A novel method for estimation of an aerodynamic force and moment acting on an irregularly shaped body (such as HE projectile fragments) during its flight through the atmosphere is presented. The model assumes that fragments can be approximated with a tri-axial ellipsoid that has continuous surface given as a mathematical function. The model was validated with CFD data for a tri-axial ellipsoid and verified using CFD data on aerodynamic forces and moments acting on an irregularly shaped fragment. The contribution of this method is that it represents a significant step toward a modeling that does not require a cumbersome CFD simulation results for estimation of fragment dynamic and kinematic parameters. Due to this advantage, the model can predict the fragment motion consuming a negligible time when compared to the corresponding time consumed by CFD simulations. Parametric representation (generalization) of the fragment geometrical data and the conditions provides the way to analyze various correlations and how parameters influence the dynamics of the fragment flight. 展开更多
关键词 Aerodynamic FORCE Aerodynamic MOMENT FRAGMENTS
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平面双摇杆机构的优化设计 预览
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作者 宋振华 周奎 李刚 《机械》 2019年第7期30-35,共6页
初步设计了双摇杆机构并确定了4组连杆参数值,通过理论推导建立其运动方程及力学方程,得到了连杆机构中各点、各杆件的位置、速度、加速度、输出力矩的计算公式。然后使用MATLAB将公式用图形表达出来,更直观形象地分析了不同连杆长度参... 初步设计了双摇杆机构并确定了4组连杆参数值,通过理论推导建立其运动方程及力学方程,得到了连杆机构中各点、各杆件的位置、速度、加速度、输出力矩的计算公式。然后使用MATLAB将公式用图形表达出来,更直观形象地分析了不同连杆长度参数对连杆机构的影响。通过对比4组数据,从不同的侧重点进行分析并得出结论。对于双摇杆机构及其他平面四连杆机构的设计,具有很好的参考意义。 展开更多
关键词 双摇杆 速度 加速度 力矩
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新一代运载火箭箭地接口安装可靠性研究 预览
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作者 李强 张志博 +3 位作者 孙伟 申定贤 温国帅 詹家俊 《机械工程与自动化》 2019年第4期156-158,共3页
为了提高新一代运载火箭动力系统箭地接口安装的可靠性,对不同通径、不同材料的运载火箭动力系统箭地接口导管与地面工装连接力矩范围及润滑情况进行了研究。分析了箭地接口安装存在的问题,阐述了箭地接口力矩值范围的确定和最优润滑脂... 为了提高新一代运载火箭动力系统箭地接口安装的可靠性,对不同通径、不同材料的运载火箭动力系统箭地接口导管与地面工装连接力矩范围及润滑情况进行了研究。分析了箭地接口安装存在的问题,阐述了箭地接口力矩值范围的确定和最优润滑脂选择的详细技术方案,并进行了试验分析,得出了相应压力下不同通径、不同材料箭地接口安装时力矩的范围值以及最优的润滑脂选择。对箭地接口总装进一步量化,为运载火箭动力系统总装提供了数据基础,确保了箭地接口总装的质量和可靠性。 展开更多
关键词 箭地接口 力矩 润滑脂
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不同速度正向单摇双脚跳绳支撑期下肢及下肢各关节运动生物力学特征分析 预览
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作者 井兰香 段炼 《河北体育学院学报》 2019年第5期83-89,共7页
目的:测试不同速度正向单摇双脚跳绳运动支撑期动力学及运动学参数,分析下肢及下肢各关节生物力学特征变化规律。方法:选取12名男性专业跳绳运动员分别完成慢、中、快三种速度正向单摇双脚连续跳绳运动,同步采集跳绳过程地面反作用力和... 目的:测试不同速度正向单摇双脚跳绳运动支撑期动力学及运动学参数,分析下肢及下肢各关节生物力学特征变化规律。方法:选取12名男性专业跳绳运动员分别完成慢、中、快三种速度正向单摇双脚连续跳绳运动,同步采集跳绳过程地面反作用力和运动学数据,计算支撑期下肢及下肢各关节动力学参数。结果:中速跳绳峰值地面反作用力、爆发力等明显大于慢、快速跳绳(P<0.05),随着跳绳速度升高关节活动范围明显减小(P<0.05),快速跳绳时腿刚度(P<0.01)和髋、膝、踝关节刚度值最大(P<0.01),踝关节能量吸收贡献度%最大(P<0.01)。结论:慢速、中速双脚连续跳绳可锻炼髋、膝、踝关节周围肌肉的超等长收缩能力,快速跳绳主要锻炼踝关节快速超等长收缩能力及髋、膝关节稳定性;跳绳锻炼时应注意下肢尤其是踝关节拉伸热身,提高柔韧性以降低损伤风险。 展开更多
关键词 跳绳 刚度 力矩 能量吸收
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Estimating moment capacity of ferrocement members using self-evolving network
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作者 Abdussamad ISMAIL 《结构与土木工程前沿:英文版》 EI CSCD 2019年第4期926-936,共11页
In this paper, an empirical model based on self-evolving neural network is proposed for predicting the flexural behavior of ferrocement elements. The model is meant to serve as a simple but reliable tool for estimatin... In this paper, an empirical model based on self-evolving neural network is proposed for predicting the flexural behavior of ferrocement elements. The model is meant to serve as a simple but reliable tool for estimating the moment capacity of ferrocement members. The proposed model is trained and validated using experimental data obtained from the literature. The data consists of information regarding flexural tests on ferrocement specimens which include moment capacity and cross-sectional dimensions of specimens, concrete cube compressive strength, tensile strength and volume fraction of wire mesh. Comparisons of predictions of the proposed models with experimental data indicated that the models are capable of accurately estimating the moment capacity of ferrocement members. The proposed models also make better predictions compared to methods such as the plastic analysis method and the mechanism approach. Further comparisons with other data mining techniques including the back-propagation network, the adaptive spline, and the Kriging regression models indicated that the proposed models are superior in terms prediction accuracy despite being much simpler models. The performance of the proposed models was also found to be comparable to the GEP-based surrogate model. 展开更多
关键词 FERROCEMENT MOMENT capacity self-evolving neural network
Image Analysis by Two Types of Franklin-Fourier Moments 预览
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作者 Bing He Jiangtao Cui +1 位作者 Bin Xiao Xuan Wang 《自动化学报:英文版》 CSCD 2019年第4期1036-1051,共16页
In this paper,we first derive two types of transformed Franklin polynomial:substituted and weighted radial Franklin polynomials.Two radial orthogonal moments are proposed based on these two types of polynomials,namely... In this paper,we first derive two types of transformed Franklin polynomial:substituted and weighted radial Franklin polynomials.Two radial orthogonal moments are proposed based on these two types of polynomials,namely substituted Franklin-Fourier moments and weighted Franklin-Fourier moments(SFFMs and WFFMs),which are orthogonal in polar coordinates.The radial kernel functions of SFFMs and WFFMs are transformed Franklin functions and Franklin functions are composed of a class of complete orthogonal splines function system of degree one.Therefore,it provides the possibility of avoiding calculating high order polynomials,and thus the accurate values of SFFMs and WFFMs can be obtained directly with little computational cost.Theoretical and experimental results show that Franklin functions are not well suited for constructing higher-order moments of SFFMs and WFFMs,but compared with traditional orthogonal moments(e.g.,BFMs,OFMs and ZMs)in polar coordinates,the proposed two types of Franklin-Fourier Moments have better performance respectively in lower-order moments. 展开更多
关键词 FRANKLIN functions image reconstruction MOMENT INVARIANTS object recognition ORTHOGONAL MOMENTS
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SOME RECENT PROGRESS ON STOCHASTIC HEAT EQUATIONS 预览
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作者 胡耀忠 《数学物理学报:B辑英文版》 SCIE CSCD 2019年第3期874-914,共41页
This article attempts to give a short survey of recent progress on a class of elementary stochastic partial differential equations (for example, stochastic heat equations) driven by Gaussian noise of various covarianc... This article attempts to give a short survey of recent progress on a class of elementary stochastic partial differential equations (for example, stochastic heat equations) driven by Gaussian noise of various covariance structures. The focus is on the existence and uniqueness of the classical (square integrable) solution (mild solution, weak solution). It is also concerned with the Feynman-Kac formula for the solution;Feynman-Kac formula for the moments of the solution;and their applications to the asymptotic moment bounds of the solution. It also briefly touches the exact asymptotics of the moments of the solution. 展开更多
关键词 GAUSSIAN random field GAUSSIAN noise STOCHASTIC partial differential EQUATION (stochastic heat equation) Feynman-Kac FORMULA for the solution Feynman- Kac FORMULA for the moments of the solution chaos expansion hypercontractivity moment bounds HOLDER CONTINUITY joint HOLDER CONTINUITY asymptotic behaviour Trotter-Lie FORMULA Skorohod integral
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High-K isomer and the rotational properties in the odd-Z neutron-rich nucleus 163Eu
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作者 贺晓涛 陈泽龙 《中国物理C:英文版》 SCIE CAS CSCD 2019年第6期59-63,共5页
The newly observed isomer and ground-state band in the odd-Z neutron-rich rare-earth nucleus 163 Eu are investigated by using the cranked shell model(CSM), with pairing treated by the particle-number conserving(PNC)me... The newly observed isomer and ground-state band in the odd-Z neutron-rich rare-earth nucleus 163 Eu are investigated by using the cranked shell model(CSM), with pairing treated by the particle-number conserving(PNC)method. This is the first time detailed theoretical investigations are performed of the observed 964(1) keV isomer and ground-state rotational band in 163 Eu. The experimental data are reproduced very well by the theoretical results. The configuration of the 964(1) keV isomer is assigned as the three-particle state 13^-/2(v7^+/2 [633]■v1^-/2[521]■π5^+/2[413]).More low-lying multi-particle states are predicted in 163 Eu. Due to its significant effect on the nuclear mean field, the high-order ε6 deformation plays an important role in the energy and configuration assignment of the multi-particle states. Compared to its neighboring even-even nuclei 162 Sm and 164 Gd,there is a 10%15% increase of J(1) of the oneparticle ground-state band in 163 Eu. This is explained by the pairing reduction due to the blocking of the nucleon on the proton π5+/2 [413] orbital in 163 Eu. 展开更多
关键词 NEUTRON-RICH NUCLEI ISOMER high-order deformation moment of INERTIA odd-mass NUCLEI
Validity of extracting photoionization time delay from the first moment of streaking spectrogram
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作者 魏长立 赵曦 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期330-339,共10页
Photoionization time delays have been studied in many streaking experiments in which an attosecond pulse is used to ionize the atomic or solid state target in the presence of a dressing infrared laser field. Among the... Photoionization time delays have been studied in many streaking experiments in which an attosecond pulse is used to ionize the atomic or solid state target in the presence of a dressing infrared laser field. Among the methods of extracting the time delay from the streaking spectrogram, the simplest one is to calculate the first moment of the spectrogram and to measure its offset relative to the vector potential of the infrared field. The first moment method has been used in many theoretical simulations and analysis of experimental data, but the meaning of this offset needs to be investigated. We simulate the spectrograms and compare the extracted time delay from the first moment with the input Wigner delay. In this study, we show that the first moment method is valid only when the group delay dispersions corresponding to both the spectral phase of the attosecond pulse and the phase of the single-photon transition dipole matrix element of the target are small. Under such circumstance, the electron wave packet behaves like a classical particle and the extracted time delay can be related to a group delay in the photoionization process. To avoid ambiguity and confusion, we also suggest that the photoionization time delay be replaced by photoionization group delay and the Wigner time delay be replaced by Wigner group delay. 展开更多
关键词 PHOTOIONIZATION time delay strong laser field ATTOSECOND science first MOMENT
Exploring the effect of aggregation-induced emission on the excited state intramolecular proton transfer for a bis-imine derivative by quantum mechanics and our own n-layered integrated molecular orbital and molecular mechanics calculations
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作者 赵慧芳 孙朝范 +2 位作者 刘晓春 尹航 石英 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期645-649,共5页
We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonometh... We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the 'our own n-layered integrated molecular orbital and molecular mechanics'(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds. 展开更多
关键词 time-dependent density functional theory(TDDFT) METHOD excited state intramolecular proton transfer(ESIPT) our own n-layered integrated MOLECULAR orbital and MOLECULAR mechanics(ONIOM) METHOD potential energy curves atomic dipole moment corrected Hirshfeld population(ADCH) charge
不确定环境下的致命冲击模型 预览
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作者 刘颖 刘冬雪 马瑶 《天津科技大学学报》 CAS 2019年第2期75-80,共6页
针对无大量样本存在的冲击模型,运用不确定理论进行建模和分析.假设系统由 2个部件组成且环境中有 3个相互独立的冲击源,每个冲击到达均引起部件失效且失效的时间为不确定变量,在此基础上建立致命冲击的基本数学模型并进行分析,给出两... 针对无大量样本存在的冲击模型,运用不确定理论进行建模和分析.假设系统由 2个部件组成且环境中有 3个相互独立的冲击源,每个冲击到达均引起部件失效且失效的时间为不确定变量,在此基础上建立致命冲击的基本数学模型并进行分析,给出两部件寿命的联合生存不确定分布、矩的相关公式和矩母函数.最后,给出了数值算例. 展开更多
关键词 致命冲击模型 不确定变量 不确定分布
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Reading Julian Barnes’s The Sense of an Ending in Leo Tolstoy’s Anna Karenina 预览
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作者 Elena Bollinger 《文学与艺术研究:英文版》 2019年第3期275-283,共9页
This paper addresses the narrative construction of the moment of death as depicted in Tolstoy’s Anna Karenina and in Barnes’s The Sense of an Ending. Following Orr’s definition of positive influence, described as a... This paper addresses the narrative construction of the moment of death as depicted in Tolstoy’s Anna Karenina and in Barnes’s The Sense of an Ending. Following Orr’s definition of positive influence, described as a “site for cultural renewal”, it pursues the analysis of complexity and confluence of literary traditions in these texts. Though both Anna Karenina and The Sense of an Ending seem to insist on portraying a chronicle of struggle between a moment and a process of dying, it is nevertheless a physical moment of life ending which becomes an intensely condensed, and almost photographic, representation of the intimate, psychologically depicted, dying process. It is argued that the moment of death reveals, for instance, Anna’s unresolved internal conflict between psychological and physiological phenomena shaping human behaviour. Similarly, Barnes’s The Sense of an Ending builds upon a subtle dialogic tension between a process of psychological dying and a moment of physically conceived death. Specifically, this paper brings to light the repetitive occurence of the intense epiphanic moments which shape the thematic and the structural development of both Anna Karenina and The Sense of an Ending. 展开更多
关键词 comparative CRITICISM MOMENT DEATH life J. Barnes L. TOLSTOY
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陶粒混凝土叠合梁正截面开裂弯矩计算与试验研究
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作者 刘安庆 罗小满 王建民 《施工技术》 CAS 2019年第6期76-79,共4页
基于混凝土梁平截面假设和基本理论,分别用截面应力分析法、截面塑性影响系数法推导计算陶粒混凝土叠合梁开裂瞬时的受压区高度和开裂弯矩,得出开裂弯矩的计算表达式;通过设计压区为普通混凝土、拉区为陶粒混凝土的叠合梁进行试验,验证... 基于混凝土梁平截面假设和基本理论,分别用截面应力分析法、截面塑性影响系数法推导计算陶粒混凝土叠合梁开裂瞬时的受压区高度和开裂弯矩,得出开裂弯矩的计算表达式;通过设计压区为普通混凝土、拉区为陶粒混凝土的叠合梁进行试验,验证开裂弯矩计算表达式的适用性;结果表明:叠合高度在换算截面形心轴以上部分发生轻微改变时,对叠合梁开裂弯矩影响不大;而适当提高配筋率能更充分提高受拉区陶粒混凝土塑性,提高叠合梁开裂弯矩,各叠合梁拉区混凝土荷载-应变曲线变化与理论假设一致。 展开更多
关键词 混凝土 陶粒 叠合梁 弯矩 试验 研究
The Happy Moment
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作者 陆思涵 张春花(指导) +9 位作者 杨思琦 蒋景雄 钱莹(指导) 朱敬暄 茅硕敏 陆晓娟(指导) 潘越 范嘉杰 张怡宣 施金(指导) 《天天爱英语》 2019年第3期28-29,共2页
Last night,I went to see a movie with my friends.I was immersed in the story.It was my first time going out at night.Because my parents never let me do that before.Now they think I have grown up and I can protect myse... Last night,I went to see a movie with my friends.I was immersed in the story.It was my first time going out at night.Because my parents never let me do that before.Now they think I have grown up and I can protect myself,so they allowed me to go out at night.It was such a happy moment for me. 展开更多
关键词 HAPPY MOMENT MOVIE
机械式变速箱的多轴转向控制优化研究 预览
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作者 陈伟全 《智能计算机与应用》 2019年第4期230-233,236共5页
为了提高机械式变速箱的多轴转向控制的稳定性,提出基于非线性多刚体动力学分析的机械式变速箱的多轴转向控制方法,构建机械式变速箱的转向动力学模型,以输出转向力矩、换档阻力以及负载力矩等为约束参量,构建机械式变速箱的多轴转向控... 为了提高机械式变速箱的多轴转向控制的稳定性,提出基于非线性多刚体动力学分析的机械式变速箱的多轴转向控制方法,构建机械式变速箱的转向动力学模型,以输出转向力矩、换档阻力以及负载力矩等为约束参量,构建机械式变速箱的多轴转向控制的被控对象模型,采用自适应迭代学习控制方法实现多轴转向力矩的最大增益调节,采用非线性多刚体动力学分析方法进行最优控制参量估计,结合期望轨迹的模糊跟踪识别方法实现机械式变速箱的多轴转向控制律优化设计.仿真结果表明,采用该方法进行机械式变速箱的多轴转向控制的输出稳定性较好,轨迹跟踪误差较低,提高了机械式变速箱的控制品质. 展开更多
关键词 机械式变速箱 多轴转向控制 动力学模型 力矩
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Direct method for a Cauchy problem with application to a Tokamak 预览
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作者 Mohsen Tadi 《力学快报:英文版》 CAS CSCD 2019年第4期254-259,I0004共7页
This note is concerned with a new direct(non-iterative)method for the solution of an elliptic inverse problem.This method is based on the application of the Green's second identity which leads to a moment problem ... This note is concerned with a new direct(non-iterative)method for the solution of an elliptic inverse problem.This method is based on the application of the Green's second identity which leads to a moment problem for the unknown boundary condition.Tikhonov regularization is used to obtain a stable and close approximation of the missing boundary condition without any need for iterations.Four examples are used to study the applicability of the method with the presence of noise. 展开更多
关键词 CAUCHY PROBLEM MOMENT PROBLEM Non-iterative TOKAMAK
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Structure and magnetic properties of TbCu7-type melt-spun Sm–Fe–B alloys
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作者 Chuan-Jiang Zheng Yang Luo +5 位作者 Dun-Bo Yu Wen-Long Yan Hong-Wei Li Yong-Jun Mao Shuo Lu Ning-Tao Quan 《稀有金属:英文版》 SCIE EI CAS CSCD 2019年第2期151-156,共6页
The melt-spun SmFe12Bx(x = 0, 0.50, 0.75,1.00, 1.25 and 1.50) ribbons were prepared at 40 m·s-1,and their structure and magnetic properties were studied by powder X-ray diffraction(XRD), vibrating sample magnetom... The melt-spun SmFe12Bx(x = 0, 0.50, 0.75,1.00, 1.25 and 1.50) ribbons were prepared at 40 m·s-1,and their structure and magnetic properties were studied by powder X-ray diffraction(XRD), vibrating sample magnetometer(VSM) and transmission electron microscopy(TEM). XRD results indicate that SmFe12Bx alloys with 0.50 ≤ x ≤ 1.00 are composed of single-phase TbCu7-type structure. Moreover, it is found that the boron addition can inhibit the emergence of soft magnetic phase a-Fe and result in the increase in the axial ratio c/a. After annealing at 650 ℃ for 0.5 h, the metastable phase TbCu7 initially decomposes into the stable phase Sm2Fe14B(Nd2Fe14B-type) and a-Fe. The value of magnetic moment per Fe atom increases slightly from 1.75 uB for boron-free sample to 1.80 uB for the x = 0.75 sample and then decreases again.In addition, the best magnetic properties of maximum energy product [(BH)max] of 14.56 kJ·m^-3, coercivity(Hcj)of 172.6 kA·m^-1 and remanence(Br) of 0.45 T are obtained for the SmFe12B1.00 alloy. Based on transmission electron microscopy(TEM) results, the average size of grains is around 197 nm for B-free sample and decreases to 95 nm for x = 1.00 sample, indicating that the addition of boron can refine grains. 展开更多
关键词 TbCu7-type STRUCTURE Sm-Fe-B RIBBONS Phase formation MAGNETIC MOMENT Microstructure
General decay asymptotic stability of neutral stochastic differential delayed equations with Markov switching
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作者 Guangqiang LAN Fang XIA 《中国数学前沿:英文版》 SCIE CSCD 2019年第4期793-818,共26页
The p-th moment and almos t sure st ability with general decay rate of the exact solutions of neutral stochastic differential delayed equations with Markov switching are investigated under given conditions. Two exampl... The p-th moment and almos t sure st ability with general decay rate of the exact solutions of neutral stochastic differential delayed equations with Markov switching are investigated under given conditions. Two examples are provided to support the conclusions. 展开更多
关键词 NEUTRAL stochastic differential DELAYED EQUATIONS with Markov switching (NSDDEswMS) global solution general DECAY rate p-th moment stability ALMOST sure st ability
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