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自聚焦玻璃材料的分布常数与波长和半径的经验公式 被引量:1
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作者 郑书信 《西北建筑工程学院学报(自然科学版)》 1994年第4期60-65,共6页
自聚焦玻璃材料的分布常数A随波长λ和玻璃材料的半径R的变化而变化,是一个非线性关系。利用非线性曲线化为线性曲线的方法,建立了A与λ和A与R的经验公式。利用这些关系式,可以计算对任意的λ和R的A值.
关键词 自聚焦玻璃材料 分布常数 波长 线性曲线
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焦距法测试自聚焦透镜折射率分布常数 被引量:1
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作者 井传发 《光学技术》 CAS CSCD 1995年第2期33-35,共3页
本文介绍了一种测量自聚焦透镜折射率分布常数的方法─—焦距法,并进行了原理公式推导,和精度分析,其测量不确定度为±1×10 ̄(-3);其次,简要地介绍了实验方法。实验结果证明了焦距法是测量自聚焦透镜折射率分布常... 本文介绍了一种测量自聚焦透镜折射率分布常数的方法─—焦距法,并进行了原理公式推导,和精度分析,其测量不确定度为±1×10 ̄(-3);其次,简要地介绍了实验方法。实验结果证明了焦距法是测量自聚焦透镜折射率分布常数的简单实用的方法,它具有装置简单、数据处理也不复杂的特点,是一种非破坏性的测试方法。 展开更多
关键词 自聚焦透镜 折射率分布常数 焦距法测试
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基于迭代算法的功能梯度绝缘子介电常数分布优化 被引量:13
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作者 梁虎成 杜伯学 +3 位作者 陈允 郝留成 田浩 李进 《电工技术学报》 EI CSCD 北大核心 2020年第17期3758-3764,共7页
为了改善气体绝缘输电管道绝缘子沿面电场分布,提出一种基于迭代算法的功能梯度绝缘子介电常数分布优化方法,该方法具有策略简单、迭代次数少、效率高等优点。通过对圆台绝缘子和盆式绝缘子的介电常数分布进行优化,得到主要结论如下:圆... 为了改善气体绝缘输电管道绝缘子沿面电场分布,提出一种基于迭代算法的功能梯度绝缘子介电常数分布优化方法,该方法具有策略简单、迭代次数少、效率高等优点。通过对圆台绝缘子和盆式绝缘子的介电常数分布进行优化,得到主要结论如下:圆台绝缘子的沿面电场分布呈现出由高压电极三结合点向地电极递减的趋势。优化后,圆台绝缘子沿面电场强度最大值由2.3 kV/mm降至1.1 kV/mm,下降幅度超过50%。对盆式绝缘子的介电常数分布进行优化时,需要兼顾绝缘子凹面和凸面的沿面电场分布。经过优化的盆式绝缘子的相对介电常数分布在径向坐标上呈现出“中间低,两侧高”的趋势,绝缘子的凹面电场强度最大值下降幅度超过60%。考虑到实际应用中构造连续梯度非常困难,该文提出“等厚梯度”和“等差梯度”两种离散化方案,对最优的连续介电常数分布进行离散化处理。 展开更多
关键词 气体绝缘输电管道 电场畸变 功能梯度绝缘子 介电常数分布优化 离散化
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利用自聚焦透镜工作特性单点精确测量聚焦常数
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作者 苏宏武 苏秀琴 +1 位作者 李哲 张广华 《科学技术与工程》 2006年第19期3032-3037,共6页
介绍了一种测量自聚焦透镜的折射率分布常数的方法——自准直反射法,用几何传像原理对光路计算,并用来分析光路原理,同时利用理论公式推导出经验公式,且对经验公式进行了精度分析。其测量不确定度为±1×10-3;其次,简要地介绍... 介绍了一种测量自聚焦透镜的折射率分布常数的方法——自准直反射法,用几何传像原理对光路计算,并用来分析光路原理,同时利用理论公式推导出经验公式,且对经验公式进行了精度分析。其测量不确定度为±1×10-3;其次,简要地介绍了试验方法。试验结果证明了自准直反射法是测量自聚焦透镜的折射率分布常数的简单实用方法,它具有装置简单、数据处理也不复杂的特点。是一种非破坏性的测试方法。 展开更多
关键词 信息光学 反射法测量 折射率分布常数 自聚焦透镜
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一种新的常数度数的P2P覆盖网络 被引量:16
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作者 陈贵海 须成忠 +2 位作者 沈海英 叶懋 刘之育 《计算机学报》 EI CSCD 北大核心 2005年第7期1084-1095,共12页
许多结构式P2P系统使用DHT技术将数据映射到相应的节点,以便在数据的存放与查找方面有很好的扩展性.但是,在节点数为n的网络中,大多数结构式P2P系统的每一次查询(lookup)都需要O(logn)步,而且每个节点都要维护O(logn)个邻居.该文提出了... 许多结构式P2P系统使用DHT技术将数据映射到相应的节点,以便在数据的存放与查找方面有很好的扩展性.但是,在节点数为n的网络中,大多数结构式P2P系统的每一次查询(lookup)都需要O(logn)步,而且每个节点都要维护O(logn)个邻居.该文提出了一种新的常数度数的P2P系统,它模仿立方体互连圈(CubeConnectedCycle)的拓扑结构,命名为Cycloid.在节点数为n=d×2d的Cycloid系统中,每次查询只要Ο(d)步,并且每个节点只需要维护Ο(1)个邻居.模拟实验表明,在网络规模较大和节点出入频繁的动态P2P网络中,Cycloid比其它常数度数的P2P系统(如Viceroy和Koorde)具有更好的性能,尤其是Cycloid具有更高的搜索效率、更均匀的数据分配、更平衡的节点负载. 展开更多
关键词 对等计算 覆盖网络 CYCLOID Viceroy Koorde 分布式哈希表 常数度数的分布式哈希表
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立磨制备煤粉的粒度分布表征 被引量:1
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作者 陈丹丹 刘江 +2 位作者 康利华 马青华 李东 《陕西煤炭》 2017年第4期24-26,49,共4页
将陕西煤业化工新型能源有限公司神木分公司送来的煤粉取样做工业筛分以检测煤粉粒度。测试结果显示立磨机制备煤粉的粒径(x)与其对应的质量分数(y)呈幂函数y=axb。粒度分布比例常数值和粒度分布幂值不是互相独立的,而是存在着内在的依... 将陕西煤业化工新型能源有限公司神木分公司送来的煤粉取样做工业筛分以检测煤粉粒度。测试结果显示立磨机制备煤粉的粒径(x)与其对应的质量分数(y)呈幂函数y=axb。粒度分布比例常数值和粒度分布幂值不是互相独立的,而是存在着内在的依存关系。粒度特性方程可以用于检验煤粉的粒度质量指标和波动。 展开更多
关键词 粒度特性方程 幂函数 粒度分布比例常数 粒度分布
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基于Yan Meng风场模型的台风风场模拟及参数敏感性分析 被引量:4
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作者 孔莉莎 张秀芝 《船舶工程》 CSCD 北大核心 2020年第S01期581-585,589,共6页
采用Yan Meng等研发的台风风场模型,利用13个台风过程中13个浮标站、16个岛屿站的实测风速对YanMeng风场模型进行验证,并对模型中压力分布常数B、最大风速半径Rmax和等效粗糙高度z0三个参数进行敏感性试验。试验结果表明,模型中的这3个... 采用Yan Meng等研发的台风风场模型,利用13个台风过程中13个浮标站、16个岛屿站的实测风速对YanMeng风场模型进行验证,并对模型中压力分布常数B、最大风速半径Rmax和等效粗糙高度z0三个参数进行敏感性试验。试验结果表明,模型中的这3个关键参数对风场模拟有显著影响。同时,以1808号超强台风"玛莉亚"为例,得到不同时刻的台风风场模拟结果,分析了利用Yan Meng风场模型模拟我国近海台风风场的可行性。 展开更多
关键词 台风风场模拟 Yan Meng风场模型 最大风速半径 压力分布常数 等效粗糙高度
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光学元件测试及设备
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《中国光学》 EI CAS 1996年第1期81-82,共2页
TB92 96010572微机形成的非球面干涉图=Generating asphericsurfaces interferograms by mierocomputer[刊,中]/曹天宁,岑兆丰(浙江大学现代光学仪器国家重点实验室。浙江,杭州(310027))∥光学仪器。—1995,17(2)。
关键词 光学非球面 干涉图 现代光学仪器 折射率分布常数 自聚焦透镜 浙江大学 检测方法 精度分析 国家重点实验室 非球面面形
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Effects of homogeneous-heterogeneous reactions in flow of Powell-Eyring fluid 被引量:1
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作者 T.Hayat M.Imtiaz A.Alsaedi 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第8期3211-3216,共6页
The steady two-dimensional flow of Powell-Eyring fluid is investigated. The flow is caused by a stretching surface with homogeneous-heterogeneous reactions. The governing nonlinear differential equations are reduced t... The steady two-dimensional flow of Powell-Eyring fluid is investigated. The flow is caused by a stretching surface with homogeneous-heterogeneous reactions. The governing nonlinear differential equations are reduced to the ordinary differential equations by similarity transformations. The analytic solutions are presented in series forms by homotopy analysis method(HAM). Convergence of the obtained series solutions is explicitly discussed. The physical significance of different parameters on the velocity and concentration profiles is discussed through graphical illustrations. It is noticed that the boundary layer thickness increases by increasing the Powell-Eyring fluid material parameter(ε) whereas it decreases by increasing the fluid material parameter(δ). Further, the concentration profile increases when Powell-Eyring fluid material parameters increase. The concentration is also an increasing function of Schmidt number and decreasing function of strength of homogeneous reaction. Also mass transfer rate increases for larger rate of heterogeneous reaction. 展开更多
关键词 Powell-Eyring fluid boundary layer flow stretching sheet homogeneous-heterogeneous reactions
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Radiative Decays of (0^+,1^+) Strange-Bottom Mesons 被引量:2
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作者 WANG Zhi-Gang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第7期91-98,共8页
In this article, we assume that the (0^+,1^+) strange-bottom mesons are the conventional bs mesons, and calculate the electromagnetic coupling constants d, g1, g2, and g3 using the light-cone QGD sum rules. Then w... In this article, we assume that the (0^+,1^+) strange-bottom mesons are the conventional bs mesons, and calculate the electromagnetic coupling constants d, g1, g2, and g3 using the light-cone QGD sum rules. Then we study the radiative decays Bs0→Bs^*γ, Bs1→Bsγ, Bs1→Bs^*γ, and Bs1→Bs0γ, and observe that the widths are rather narrow. We can search for the (0^+, 1^+) strange-bottom mesons in the invariant Bsπ^0 and Bs^*π^0 mass distributions in the strong decays or in the invariant Bs^*γ, and Bsγ mass distributions in the radiative decays. 展开更多
关键词 strange-bottom mesons light-cone QCD sum rules
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Analysis on the Observation Data of Three Profiles across the Qilian Mountain-Haiyuan Fault Zone
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作者 Hu Yaxuan Wang Xiong Cui Duxin Zhu Yiqing 《Earthquake Research in China》 2011年第4期486-497,共12页
By analyzing GPS, leveling and gravity observation data from the Minle, Huazangsi and Shagouhe profiles across the Qilian Mountain-Haiyuan fault during 2005 - 2009, the changes of these data and activity characteristi... By analyzing GPS, leveling and gravity observation data from the Minle, Huazangsi and Shagouhe profiles across the Qilian Mountain-Haiyuan fault during 2005 - 2009, the changes of these data and activity characteristics of the main faults in different time are obtained. The results show that the Changma-Erbo, Maomaoshan, Zhunglanghe and Haiyuan faults have been active in recent years. The relationship between the vertical displacement and mobile gravity data is analyzed, and the results reveal the gravity changes are mainly due to mass transfer. The results of GPS observation show that the direction of the horizontal movement velocity was almost along the fault strike in 2006 - 2007, while the horizontal velocity deviated from the fault direction in 2007 - 2008, characterized by increased eastward displacement. Further analysis upon removal of the linear trend on the time series of the N and E coordinate values of the continuous observation stations of the Crustal Movement Observation Network of China near the three profiles reveals that the Wenchuan earthquake had an effect on the observations in 2007 - 2008. Comparing the gravitational changes in 2008 - 2009 with the Bouguer gravity anomaly background, we find that the area near Minle profile is in the stage of adjustment and recovery, while the anomaly is not completely recovered around Huazangsi and Shagouhe profiles. 展开更多
关键词 Qilian Mountain-Haiyuan fault zone Comprehensive observation profiles Horizontal movement rate Vertical displacement Gravity change
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Study on the Cause of Complex Spatial Distribution of the Tangshan Earthquake Sequence
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作者 Liu Puxiong Xiaojian 《Earthquake Research in China》 2012年第1期1-19,共19页
By analyzing higher-accuracy location data of the Tangshan earthquake sequence,a clear distribution pattern of three aftershock belts in the NE,NWW,and NW directions of has been obtained.The analysis reveals three rup... By analyzing higher-accuracy location data of the Tangshan earthquake sequence,a clear distribution pattern of three aftershock belts in the NE,NWW,and NW directions of has been obtained.The analysis reveals three rupture planes of strong events of MS7.8,MS7.1 and MS6.9 in the sequence.It indicates that the complex pattern is closely related to the earthquake source,and the NE-,NWW-and NW-trending regional fault zones,which have been revealed by the research of the pre-seismicity anomaly.In summary,the source is located in the junction of the three fault zones,and the rupture planes of the three strong events located in the source can be regarded as the locked segments on the three fault zones.On these grounds,the paper explains the complexity of the source and epicentral distribution of aftershocks. 展开更多
关键词 Tangshan earthquake Earthquake sequence Precursory seismic activity Earthquake source fault Fault zone
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Some Properties of Two-mode Displaced Excited Squeezed Vacuum States
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作者 MENG Xiang-Guo WANG Ji-Suo LIANG Bao-Long 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第9期493-499,共7页
In this paper,two-mode displaced excited squeezed vacuum states (TDESVS) are constructed and theirnormalization and completeness are investigated.Using the entangled state representation and Weyl ordering formof the W... In this paper,two-mode displaced excited squeezed vacuum states (TDESVS) are constructed and theirnormalization and completeness are investigated.Using the entangled state representation and Weyl ordering formof the Wigner operator,the Wigner functions of TDESVS are obtained and the variations of Wigner functions withthe parameters m,n and r are investigated.Besides,two marginal distributions of Wigner functions of TDESVS areobtained,which exhibit some entangled properties of the two-particle's system in TDESVS. 展开更多
关键词 two-mode displaced excited squeezed vacuum state Weyl ordering Wigner function marginal distribution entangled state representation
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电路总论
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《电子科技文摘》 2001年第4期43-43,共1页
N2001-06976 0105882电子情报通信学会技术研究报告:电路与系统 CAS99-101~104(信学技报,Vol.99,No.550)[汇,日]/日本电子情报通信学会.—2000.01.—30P.(L)本文集收录4篇论文。内容主要涉及:单电子倒相电路的设计与多值特性的应用,折... N2001-06976 0105882电子情报通信学会技术研究报告:电路与系统 CAS99-101~104(信学技报,Vol.99,No.550)[汇,日]/日本电子情报通信学会.—2000.01.—30P.(L)本文集收录4篇论文。内容主要涉及:单电子倒相电路的设计与多值特性的应用,折叠式分布常数滤波器。 展开更多
关键词 情报通信 电路与系统 非线性滤波器 研究报告 单电子 倒相电路 分布常数 驱动放大器 电路分析 容量负荷
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Extremals in some classes of Carnot groups 被引量:3
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作者 HUANG TiRen YANG XiaoPing 《Science China Mathematics》 SCIE 2012年第3期633-646,共14页
Let G be a Carnot group and D={e 1,e 2 } be a bracket generating left invariant distribution on G.In this paper,we obtain two main results.We first prove that there only exist normal minimizers in G if the type of D i... Let G be a Carnot group and D={e 1,e 2 } be a bracket generating left invariant distribution on G.In this paper,we obtain two main results.We first prove that there only exist normal minimizers in G if the type of D is (2,1,...,1) or (2,1,...,1,2).This immediately leads to the fact that there are only normal minimizers in the Goursat manifolds.As one corollary,we also obtain that there are only normal minimizers when dim G 5.We construct a class of Carnot groups such as that of type (2,1,...,1,2,n 0,...,n a) with n 0 1,n i 0,i=1,...,a,in which there exist strictly abnormal extremals.This implies that,for any given manifold of dimension n 6,we can find a class of n-dimensional Carnot groups having strictly abnormal minimizers.We conclude that the dimension n=5 is the border line for the existence and nonexistence of strictly abnormal extremals.Our main technique is based on the equations for the normal and abnormal extremals. 展开更多
关键词 Carnot group EXTREMAL MINIMIZER
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Multiple Image Method for the Two Conductor Spheres in a Uniform Electrostatic Field 被引量:5
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作者 高欣 胡林 孙刚 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第6期1066-1070,共5页
A method using multiple mirror images of point charges is put forward to analyze the polarization of two identical conductor spheres in a uniform electrostatic field.By use of the method,the electric field distributio... A method using multiple mirror images of point charges is put forward to analyze the polarization of two identical conductor spheres in a uniform electrostatic field.By use of the method,the electric field distribution and the interaction force between two spheres can be calculated accurately even for very small gap between two spheres.Our results show that the magnitude of the product of the gap between two spheres and the local electric field in the center of the gap is approximately in the same order and the interaction between two spheres increases very fast as the two spheres are close to each other.We also show that the interaction force between two conductor spheres is almost same with that between two dielectric spheres with high permittivity. 展开更多
关键词 electric field polariztion mirror image method
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The distribution of normalized zero-sets of random meromorphic functions
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作者 YAO WeiHong 《Science China Mathematics》 SCIE 2011年第6期1119-1128,共10页
This paper is concerned with the distribution of normalized zero-sets of random meromorphic functions.The normalization of the zero-set plays the same role as the counting function for a meromorphic function in Nevanl... This paper is concerned with the distribution of normalized zero-sets of random meromorphic functions.The normalization of the zero-set plays the same role as the counting function for a meromorphic function in Nevanlinna theory.The results generalize the theory of Shiffman and Zelditch on the distribution of the zeroes of random holomorphic sections of powers of positive Hermitian holomorphic line bundles.As in a very special case,our paper resembles a form of First Main Theorem in classical Nevanlinna Theory. 展开更多
关键词 random meromorphic functions Poincar'e-Lelong formula DISTRIBUTION currents dirac delta function normalized counting divisors
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Laser-Plasma Interaction in Presence of an Obliquely External Magnetic Field:Application to Laser Fusion without Radioactivity
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作者 M.Mobaraki S.Jafari 《Communications in Theoretical Physics》 SCIE CAS CSCD 2016年第8期237-243,共7页
In this paper, the nonlinear interaction of ultra-high power laser beam with fusion plasma at relativistic regime in the presence of obliquely external magnetic field has been studied. Imposing an external magnetic fi... In this paper, the nonlinear interaction of ultra-high power laser beam with fusion plasma at relativistic regime in the presence of obliquely external magnetic field has been studied. Imposing an external magnetic field on plasma can modify the density profile of the plasma so that the thermal conductivity of electrons reduces which is considered to be the decrease of the threshold energy for ignition. To achieve the fusion of Hydrogen–Boron(HB) fuel,the block acceleration model of plasma is employed. Energy production by HB isotopes can be of interest, since its reaction does not generate radioactive tritium. By using the inhibit factor in the block model acceleration of plasma and Maxwell's as well as the momentum transfer equations, the electron density distribution and dielectric permittivity of the plasma medium are obtained. Numerical results indicate that with increasing the intensity of the external magnetic field, the oscillation of the laser magnetic field decreases, while the dielectric permittivity increases. Moreover, the amplitude of the electron density becomes highly peaked and the plasma electrons are strongly bunched with increasing the intensity of external magnetic field. Therefore, the magnetized plasma can act as a positive focusing lens to enhance the fusion process. Besides, we find that with increasing θ-angle(from oblique external magnetic field) between 0 and 90°, the dielectric permittivity increases, while for θ between 90° and 180°, the dielectric permittivity decreases with increasing θ. 展开更多
关键词 laser-plasma interaction external magnetic field laser fusion HB fuel
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