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虚拟装配环境中的一种碰撞干涉检测方法
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作者 李跃海 胡志勇 《重型机械》 2006年第3期17-19,22,共4页
提出了在虚拟装配过程中零件与装配体碰撞干涉检测的一种方法。用投影轴算法检测出装配对象的碰撞,用坐标跟踪检测方法确定干涉余量值,并用连续包围盒对复杂和不规则的模型进行分割,通过这三种方法的配合使用,虚拟装配系统对干涉体进行... 提出了在虚拟装配过程中零件与装配体碰撞干涉检测的一种方法。用投影轴算法检测出装配对象的碰撞,用坐标跟踪检测方法确定干涉余量值,并用连续包围盒对复杂和不规则的模型进行分割,通过这三种方法的配合使用,虚拟装配系统对干涉体进行了有效的、实时的、精确的检测。 展开更多
关键词 分离轴 干涉余量值 干涉体 连续包围盒
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基于Pro/E干涉检测功能的采煤机齿轮修形研究 被引量:3
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作者 王彪 赵利平 梁义维 《煤矿机械》 北大核心 2013年第9期48-50,共3页
为了使鼓形齿可以有效解决采煤机摇臂齿轮因安装误差引起的啮合冲击的问题,采用Pro/E装配体干涉检测功能确定鼓形修形量,联合ANSYS进行有限元仿真,仿真结果显示,运用Pro/E干涉检测功能进行修形后的齿轮,对安装误差具有一定的适应性,很... 为了使鼓形齿可以有效解决采煤机摇臂齿轮因安装误差引起的啮合冲击的问题,采用Pro/E装配体干涉检测功能确定鼓形修形量,联合ANSYS进行有限元仿真,仿真结果显示,运用Pro/E干涉检测功能进行修形后的齿轮,对安装误差具有一定的适应性,很好地解决了由安装误差引起的采煤机摇臂齿轮啮合误差,对采煤机齿轮的制造具有一定的指导意义。 展开更多
关键词 PRO E装配干涉检测 安装误差 鼓形齿 有限元
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基于UG的发射箱自动化虚拟装配系统开发 被引量:2
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作者 王冠千 李蓓智 +1 位作者 黄顺舟 杨建国 《制造技术与机床》 北大核心 2019年第10期17-20,共4页
目前实际生产中发射箱与纵筋的虚拟装配是依靠人机交互的方式进行。为了提高装配效率,对自动化虚拟装配技术进行了研究。通过对UG装配模块进行二次开发,建立了组件位置数据库、干涉报告数据库,提出了一种新的干涉计算方法,并将全部的工... 目前实际生产中发射箱与纵筋的虚拟装配是依靠人机交互的方式进行。为了提高装配效率,对自动化虚拟装配技术进行了研究。通过对UG装配模块进行二次开发,建立了组件位置数据库、干涉报告数据库,提出了一种新的干涉计算方法,并将全部的工艺参数、组件信息、数据库调用命令嵌入至API操作函数编制的程序中,省略了干涉检测复杂的交互设置,开发了一套实现自动化装配与干涉检测的系统。以发射箱与纵筋装配为例,进行了装配实验。结果表明该系统大大减少了人机交互步骤,提高了虚拟装配的效率。 展开更多
关键词 UG二次开发 发射箱 虚拟装配 干涉体算法 自动化
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Cloning of Cotton Delta-12 Oleate Desaturase Gene FAD2-1 and Construction of Its ihpRNA and amiRNA Interference Vectors 被引量:1
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作者 赵立群 李红岺 +3 位作者 李仁 李蔚 华金平 郭仰东 《Agricultural Science & Technology》 CAS 2012年第11期2281-2283,2286,共4页
Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cott... Delta-12 oleate desaturase gene (FAD2-1) which converts oleic acid into linoleic acid, is the key enzyme determining the fatty acid composition of cottonseed oil. By employing RT-PCR method, full length cDNA of cotton delta-12 oleate desat- urase gene GhFAD2-1 containing an open reading frame of 1 158 bp was cloned for constructing RNAi vector. A 515 bp long specific fragment of this gene was se- lected for constructing ihpRNA vector under the control of a seed-specific promoter NAPIN, named pFGC1008-NAPIN-FAD2-1; meanwhile miRNA gene-silencing vector pCAMBIA1302-amiRNA-FAD2-1 targeting GhFAD2-1 was also constructed. 展开更多
关键词 Cotton delta-12 oleate desaturase gene GhFAD2-1 ihpRNA interferencevector amiRNA interference vector High oleic acid contents
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Tapered Multimode Interference Combiners for Coherent Receivers 被引量:1
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作者 武志刚 张伟刚 +5 位作者 王志 开桂云 袁树中 董孝义 宇高胜之 和田恭雄 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第2期328-335,共8页
A new tapered multimode interference (MMl)-based coherent lightwave combiner is reported. A comprehensive theoretical analysis of mode behaviors in the tapered MMI waveguide is presented, and the output characterist... A new tapered multimode interference (MMl)-based coherent lightwave combiner is reported. A comprehensive theoretical analysis of mode behaviors in the tapered MMI waveguide is presented, and the output characteristics of the tapered MMI combiners with various structures are demonstrated. The combiner is fabricated on a silicon-on-insulator (SO1) substrate. Due to its advantages of having no end-facet reflection,easy extension to a multi-port configuration, high tolerance for fabrication errors, and compact size, the tapered MMI is a good candidate for a coherent lightwave combiner to be used in large-scale photonic integrated circuits. 展开更多
关键词 integrated optics multimode interference COMBINER SILICON-ON-INSULATOR
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AN ALGORITHM OF DISTANCE CALCULATION BETWEEN A BOUNDING SPHERE AND A BOUNDING CSG PRIMITIVE 被引量:1
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作者 屠立忠 季平 +1 位作者 左敦稳 王珉 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1999年第2期165-169,共5页
A simple method for calculating distance between a solid sphere and a constructive solid geometry (CSG) so lid primitive (including block, cone, cylinder, sphere, wedge and torus) is derived to support the collision ... A simple method for calculating distance between a solid sphere and a constructive solid geometry (CSG) so lid primitive (including block, cone, cylinder, sphere, wedge and torus) is derived to support the collision detection algorithm. By decomposing the whole space into relative positions and geometric features of the sphere and the primitive considered, closed form distance formula are got. These calculations are very useful in the real time collision detection in which primitives are used as bounding volumes of complex objects. 展开更多
关键词 distance calculation collision detection real time constructive solid geometry (CSG) virtual reality
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金属硬密封蝶阀密封参数选择分析
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作者 朱翠娟 《河北工业科技》 CAS 2009年第4期240-242,共3页
运用AutoCAD绘图软件对三偏心金属硬密封蝶阀密封挤压带创建干涉体,并对其进行定性分析和定量分析,为修正、验证和确定蝶阀的三偏心参数提供设计依据。
关键词 三偏心蝶阀 挤压带 干涉体 密封
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基于符号零压缩二叉决策图的装配可行性判定方法 被引量:1
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作者 彭瑞 李凤英 +1 位作者 常亮 孟瑜 《计算机科学》 CSCD 北大核心 2016年第6期28-31,49,共5页
为了扩大装配序列规划的求解规模并提高求解效率,提升装配自动化水平,给出了装配体联接矩阵和干涉矩阵的零压缩二叉决策图描述,建立了基于符号零压缩二叉决策图的装配操作可行性判定方法。基于该方法,可以高效地求解出一个装配体的可行... 为了扩大装配序列规划的求解规模并提高求解效率,提升装配自动化水平,给出了装配体联接矩阵和干涉矩阵的零压缩二叉决策图描述,建立了基于符号零压缩二叉决策图的装配操作可行性判定方法。基于该方法,可以高效地求解出一个装配体的可行装配操作。结合实例验证了基于符号零压缩二叉决策图的装配体模型和可行装配操作判定方法的正确性和可行性。 展开更多
关键词 装配可行性 装配联接矩阵 装配干涉矩阵 零压缩二叉决策图
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Measurement of Optic Axis Direction Based on Interference Fringe Method 被引量:1
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作者 LI Wei-tao SHEN Wei-min WANG Yu-hong 《Semiconductor Photonics and Technology》 CAS 2006年第3期188-193,共6页
In order to conquer the defect in low precision and small range for measuring optic axial angle based on conoscopic interference method, interference fringe method is proposed. It is not the distance deviating from me... In order to conquer the defect in low precision and small range for measuring optic axial angle based on conoscopic interference method, interference fringe method is proposed. It is not the distance deviating from melatope but fringe numbers to decide optic axial angle. Fringe numbers are divided into integer portion and decimal fraction portion, the decimal fraction portion is calculated by non-linear interpolation method and integer portion is determined by the relative placement of interference fringes in the principal section. Extremum arithmetic of digit image is proposed and can be used to determine the interference fringes conveniently and precisely. After different niobate crystals were measured, the result shows that measurement range of optic axial angle is increased efficiently and measurement error is reduced to 0.1°. 展开更多
关键词 Crystal optics Conoscopic interference pattern Uniaxial crystal CCD camera Optic axis
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超冷原子系综的非高斯纠缠态与精密测量 被引量:3
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作者 鹿博 韩成银 +3 位作者 庄敏 柯勇贯 黄嘉豪 李朝红 《物理学报》 SCIE EI CAS CSCD 北大核心 2019年第4期66-75,共10页
量子精密测量是基于量子力学的基本原理对特定物理量实施测量,并利用量子效应提高测量精度的交叉科学.随着超冷原子实验技术的发展,超冷原子为量子精密测量提供了一个优异的研究平台.利用发展成熟的量子调控技术,人们可以基于超冷原子... 量子精密测量是基于量子力学的基本原理对特定物理量实施测量,并利用量子效应提高测量精度的交叉科学.随着超冷原子实验技术的发展,超冷原子为量子精密测量提供了一个优异的研究平台.利用发展成熟的量子调控技术,人们可以基于超冷原子系综制备一些新奇的非高斯多粒子纠缠态.基于多体量子干涉,利用这些非高斯纠缠态作为输入,可以实现超越标准量子极限的高精度测量.本文简要综述这一研究领域的进展. 展开更多
关键词 量子精密测量 非高斯纠缠态 超冷原子系综 量子干涉
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One-Step Realization of SWAP Gate with Superconducting Quantum-Interference Devices and Atoms in Cavity QED 被引量:1
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作者 ZHAN Zhi-Ming 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第6期1603-1606,共4页
We put forward a simple scheme for one-step realization of a two-qubit SWAP gate with SQUIDs (superconducting quantum-interference devices) in cavity QED via Raman transition. In this scheme, the cavity field is onl... We put forward a simple scheme for one-step realization of a two-qubit SWAP gate with SQUIDs (superconducting quantum-interference devices) in cavity QED via Raman transition. In this scheme, the cavity field is only virtually excited and thus the cavity decay is suppressed. The SWAP gate is realized by using only two lower fiux states of the SQUID system and the excited state would not be excited. Therefore, the effect of decoherence caused from the levels of the SQUID system is possibly minimized. The scheme can also be used to implement the SWAP gate with atoms. 展开更多
关键词 SWAP gate SUPERCONDUCTING Raman transition
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Generation of Entangled States of Multiple Superconducting Quantum Interference Devices in Cavity
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作者 ZHAN Zhi-Ming LI Jia-Hua LI Wei-Bin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第4期709-711,共3页
We propose a scheme for generating the maximally entangled states of many superconducting quantum interference devices (SQUIDs) by using a quantized cavity field and classical microwave pulses in cavity. In the sche... We propose a scheme for generating the maximally entangled states of many superconducting quantum interference devices (SQUIDs) by using a quantized cavity field and classical microwave pulses in cavity. In the scheme, the maximally entangled states can be generated without requiring the measurement and individual addressing of the SQUIDs. 展开更多
关键词 ENTANGLEMENT SUPERCONDUCTING CAVITY
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Unconventional Geometric Phase-Shift Gates Based on Superconducting Quantum Interference Devices Coupled to a Single-Mode Cavity
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作者 SONG Ke-Hui ZHOU Zheng-Wei GUO Guang-Can 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第4X期631-634,共4页
We present a scheme to realize geometric phase-shift gate for two superconducting quantum interference device (SQUID) qubits coupled to a single-mode microwave field. The geometric phase-shift gate operation is perf... We present a scheme to realize geometric phase-shift gate for two superconducting quantum interference device (SQUID) qubits coupled to a single-mode microwave field. The geometric phase-shift gate operation is performed in two lower flux states, and the excited state [2〉 would not participate in the procedure. The SQUIDs undergo no transitions during the gate operation. Thus, the docoherence due to energy spontaneous emission based on the levels of SQUIDs are suppressed. The gate is insensitive to the cavity decay throughout the operation since the cavity mode is displaced along a circle in the phase space, acquiring a phase conditional upon the two lower flux states of the SQUID qubits, and the cavity mode is still in the original vacuum state. Based on the SQUID qubits interacting with the cavity mode, our proposed approach may open promising prospects for quantum iogic in SQUID-system. 展开更多
关键词 geometric phase-shift gate superconducting quantum interference device CAVITY-QED
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Measuring the Object Deformation by Real Time Holographic Interferometry with Automatically Calculating Hologram
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作者 WANGWensheng XUBin 《Semiconductor Photonics and Technology》 CAS 1997年第2期105-108,114,共5页
Used Ar + laser as a light source,BSO(Bi 12 SiO 20 ) crystal as a hologram recording material,CCD camera as a detector,and a holographic setup controlled by a computer,we have realized real time holographic i... Used Ar + laser as a light source,BSO(Bi 12 SiO 20 ) crystal as a hologram recording material,CCD camera as a detector,and a holographic setup controlled by a computer,we have realized real time holographic interferometry in terms of 3-interfe-rogram method.The deformation of a plate is measured under a pressure. 展开更多
关键词 BSO Crystal Holographic Interferometry HOLOGRAPHY
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Review of AIDS Health Education and Behavioral Interventions in China
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作者 蔡于茂 曾序春 董时富 《Chinese Journal of Sexually Transmitted Infections》 2002年第3期54-57,共4页
Acquired Immune Deficiency Syndrome (AIDS) is an infectious disease caused by HIV It has been epidemic formore than 20 years, but there is no cure of it. Health educationand behavioral interventions are some of the mo... Acquired Immune Deficiency Syndrome (AIDS) is an infectious disease caused by HIV It has been epidemic formore than 20 years, but there is no cure of it. Health educationand behavioral interventions are some of the most effectiveapproaches in the control and prevention of AIDS. China isone of the countries with the fastest growing HIVseroprevalence rate, and is facing a widespread epidemic ofAIDS. Currently, high-risk populations such as individualswith multiple sexual partners and intravenous drug users arethe main foci of health education and behavioral interventionsin China. Encouraging results have been observed in manyforms of health education and behavioral intervention. Theapplication of health education and behavioral interventionsmust emerge from scientific evidence, follow a series ofstrategies, be carried out from various perspectives, andrequire the participation of all societal communities. 展开更多
关键词 AIDS health education behavioral intervention
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Strain measurement using frequency modulation fiber optic interferometer
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作者 LIChangchun LUOFei 《Semiconductor Photonics and Technology》 CAS 1995年第1期31-34,共4页
The method for measuring the strain of an object using an optical fiber and a frequency modulation(FM) coupled cavity semiconductor laser is proposed.This method uses the coherent FM heterodyne principle of the Michel... The method for measuring the strain of an object using an optical fiber and a frequency modulation(FM) coupled cavity semiconductor laser is proposed.This method uses the coherent FM heterodyne principle of the Michelson interferometer and can avoid the π/2 nonreciprocal phase bias and phase shifting problem existing in general fiber optic interferential sensors, the maximum detection range is limited by the coherent length of the semiconductor laser and its relative factor. 展开更多
关键词 Frequency Modulation Fiber Optic Sensors Semiconductor Lasers Michelson Interferometer
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Electron Transport Through Double-Dot Aharonov-Bohm Interferometer in theKondo Regime
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作者 DINGGuo-Hui YUANQing-Xin XUBo-Wei 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第1期123-126,共4页
By applying the slave boson technique, we have studied the electron transport through double-dotAharonov-Bohm interferometer in the Kondo regime. For the system with symmetric quantum dots, the linear con-ductance is ... By applying the slave boson technique, we have studied the electron transport through double-dotAharonov-Bohm interferometer in the Kondo regime. For the system with symmetric quantum dots, the linear con-ductance is shown to be enhanced by Kondo effect, but it is suppressed in the deep dot level regime in the presence ofnonzero magnetic flux. The Aharonov Bohm oscillations of the conductance are also investigated. 展开更多
关键词 quantum dot Aharonov-Bohm interferometer Kondo effect
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Multi-dimensional wave steering with higher-order topological phononic crystal 被引量:2
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作者 Changqing Xu Ze-Guo Chen +2 位作者 Guanqing Zhang Guancong Ma Ying Wu 《Science Bulletin》 SCIE EI CSCD 2021年第17期1740-1745,M0003,共7页
The recent discovery and realizations of higher-order topological insulators enrich the fundamental studies on topological phases.Here,we report three-dimensional(3D)wave-steering capabilities enabled by topological b... The recent discovery and realizations of higher-order topological insulators enrich the fundamental studies on topological phases.Here,we report three-dimensional(3D)wave-steering capabilities enabled by topological boundary states at three different orders in a 3D phononic crystal with nontrivial bulk topology originated from the synergy of mirror symmetry of the unit cell and a non-symmorphic glide symmetry of the lattice.The multitude of topological states brings diverse possibilities of wave manipulations.Through judicious engineering of the boundary modes,we experimentally demonstrate two functionalities at different dimensions:2D negative refraction of sound wave enabled by a firstorder topological surface state with negative dispersion,and a 3D acoustic interferometer leveraging on second-order topological hinge states.Our work showcases that topological modes at different orders promise diverse wave steering applications across different dimensions. 展开更多
关键词 Higher-order topological insulator Topological states Negative refraction 3D acoustic interferometer
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Terahertz polarization beam splitter based on photonic crystal and multimode interference 被引量:1
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作者 刘汉 李九生 《Optoelectronics Letters》 EI 2014年第5期325-328,共4页
We design a compact terahertz(THz) polarization beam splitter. Both plane wave expansion method and finite-difference time-domain method are used to calculate and analyze the characteristics of the proposed device. Th... We design a compact terahertz(THz) polarization beam splitter. Both plane wave expansion method and finite-difference time-domain method are used to calculate and analyze the characteristics of the proposed device. The designed polarization beam splitter can split TE-polarized and TM-polarized THz waves into different propagation directions. The simulation results show that the extinction ratios are larger than 18.36 dB for TE polarization and 13.35 dB for TM polarization in the frequency range from 1.86 THz to 1.91 THz, respectively. The designed polarization beam splitter has the advantages of small size and compact structure with a total size of 4.825 mm×0.400 mm. 展开更多
关键词 Finite difference time domain method Optical instruments Photonic crystals PRISMS Time domain analysis
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Temperature Measurement of Small Objects by Mach-Zehnder Interferometer
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作者 Y.T.Wong W.K.Chin 《Journal of Thermal Science》 SCIE EI CAS CSCD 1993年第4期270-274,共5页
A Mach-Zehnder Interferometer incorporated with image processing has been set up to study the temperature field of small objects.Small objects with width to height ratios ranging from 0.33 to 1.0 subjected to natural ... A Mach-Zehnder Interferometer incorporated with image processing has been set up to study the temperature field of small objects.Small objects with width to height ratios ranging from 0.33 to 1.0 subjected to natural convection are used to simulate the condition at which the end effects are significant. Interferogram representing the temperature gradient is captured,digitized,and image processed with the aid of an image processing unit.A simple correction model is proposed to treat the stored interferometric data.The interference data are found to compare well with those provided by the thermocouples. 展开更多
关键词 temperature measurement small objects mach-zehnder interferometer
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