机构精度分配的价值分析法

本文利用价值分析的理论和观点,论述和提出了机构精度分配的价值分析法,并导出了相应机构精度分配公式和算法的具体步骤。     

三相逆变电源新型解耦控制策略研究

针对基于燃烧法的燃气热值计量标准的尾气收集装置的缸体容积精确测量问题,应用现代仪器精度与误差理论,对该尾气收集装置的各项误差源进行分析,得到各分量的传递系数表达式,并按工程实际情况对精度指标进行了分配与调整。对分配的精度指标进行了合成计算,结果表明所设计的燃气热值计量尾气收集装置的最大允许误差为0.24％,完全满足尾气体积的测量精度要求。论文研究对建立我国新一代天然气热值计量标准有很好的指导意义和工程实用前景。     

燃气热值计量标准的尾气收集装置精度设计

针对基于燃烧法的燃气热值计量标准的尾气收集装置的缸体容积精确测量问题,应用现代仪器精度与误差理论,对该尾气收集装置的各项误差源进行分析,得到各分量的传递系数表达式,并按工程实际情况对精度指标进行了分配与调整;对分配的精度指标进行了合成计算,结果表明所设计的燃气热值计量尾气收集装置的最大允许误差为0.24％,完全满足尾气体积的测量精度要求;论文研究对建立我国新一代天然气热值计量标准有很好的指导意义和工程实用前景。     

T型架光电经纬仪动态精度检测方法的研究与应用

根据动态精度靶标的机械结构和由a,b,θ角计算出来的光电经纬仪回转中心的空间位置,结合T型架光电经纬仪的机构特点,采用偏心的方法对其进行动态精度的检测。通过对某型号光电经纬仪的实际检测,验证了该方法的正确性。     

软X射线谱学显微光束线单色器结构设计及精度测试

针对上海光源谱学显微光束线站的性能要求,对其核心部件单色器进行结构设计。阐述了单色器的扫描运动原理,论述了波长扫描机构的设计方案,具体分析平面镜和光栅的转角重复精度影响因素;描述光栅切换机构,着重分析其水平偏差、垂直偏差、滚角、摆角和投角的精度问题;采用六杆并联机构的方案完成镜箱调节机构的设计,分析其支杆的调节范围和分辨力情况。给出了单色器的结构,并且对其精度进行了测试。测试结果表明,平面镜和光栅的转角重复精度分别为0.166″和0.149″;光栅切换机构的滚角、摆角和投角的重复精度分别为0.08″、0.12″和0.05″。这说明了单色器的结构设计方案和机械精度满足技术要求。     

一种消象旋传动机构的设计与精度分析

本文提出了一种消象旋机构的结构形式.并对齿轮传动的结构方式做了重点介绍.通过对齿轮传动进行精度分析,可以得出传动过程中齿轮精度及传动误差对棱镜消旋系统正象精度的影响.     

离轴三反测绘相机调焦机构的设计

针对测绘相机对相机成像质量和内方位元素稳定性的要求,在分析3种调焦方式特点的基础上,确定了符合离轴三反测绘相机需要的调焦方式。设计了滚珠丝杠驱动的直线导轨式调焦机构,计算得到调焦机构的灵敏度为0.2μm。对该调焦机构进行了精度检测和试验验证,结果显示其指向精度〈2″,定位精度〈3μm。得到的结果表明：该空间调焦机构具有结构紧凑、刚度高、位移精度好等特点,能够满足离轴三反测绘相机的调焦要求。     

双光栅光谱仪波长扫描机构精度分析

光栅光谱仪作为研究太阳辐射的重要设备之一,其波长扫描机构的精度很大程度上决定了最终测量结果的准确性。从光机系统的光栅参量误差和机械结构误差两方面入手,对丝杠摆杆波长扫描机构展开综合精度分析,依据凹面光栅色散原理,推导出波长λ与摆杆末端沿丝杠方向位移x,摆杆长度l,光栅常数g和入射光线与出射光线夹角半值δ之间的关系。再对等式求导,依据误差叠加原理,计算出在红外工作波段650 nm~2 400 nm范围内,其波长定标误差应不超过±1.227 nm。在实验样机上进行验证,以汞灯为光源拟合出误差与波长的关系曲线,并以氦氖激光器为光源加以验证。实验结果证明了理论计算的正确性,该分析方法为双光栅光谱仪零部件精度指标的确定提供了依据。     

阵列化空间滤波器关键结构技术

针对大型空间滤波器从功能和技术上的不断发展，在大口径、阵列化光束超长程传输，光路控制，结构支撑稳定性，以及所有耦合镜的匹配特性和调节精度、镜座的稳定性、离轴调节、大型机械加工精度以及高真空的获得等关键技术问题，都必须通过深入的理论分析和实验验证，为阵列化空间滤波器的定型设计提供可靠的理论、实验依据。     

有限精度函数理论与Einstein-Maxwell方程的光子解

提出了有限精度函数理论,并基于该理论求出了有限精度的Einstein-Maxwell方程的光子解,揭示了经典光子的电磁、引力与时空几何的重要性质. 关键词： 有限精度函数理论 Einstein-Maxwell方程 光子解     

Spin-Spin Interactions in Gauge Theory of Gravity, Violation of Weak Equivalence Principle and New Classical Test of General Relativity

For a long time, it has been generally believed that spin-spin interactions can only exist in a theory where Lorentz symmetry is gauged, and a theory with spin-spin interactions is not perturbatively renormalizable. But this is not true. By studying the motion of a spinning particle in gravitational field, it is found that there exist spin-spin interactions in gauge theory of gravity. Its mechanism is that a spinning particle will generate gravitomagnetic field in space-time, and this gravitomagnetic field will interact with the spin of another particle, which will cause spin-spin interactions. So, spin-spin interactions are transmitted by gravitational field. The form of spin-spin interactions in post Newtonian approximations is deduced. This result can also be deduced from the Papapetrou equation. This kind of interaction will not affect the renormalizability of the theory. The spin-spin interactions will violate the weak equivalence principle, and the violation effects are detectable. An experiment is proposed to detect the effects of the violation of the weak equivalence principle.     

由爱因斯坦狭义相对论的基本原理导出洛仑兹变换的一种方法

本文从教学角度讨论了由狭义相对论的两条基本假设严格导出洛仑兹变换的问题，同时指出了某些流行的教材中处理这一内容时的不妥之处，并给出了解决方案．     

The Principle of Covariance and the Hamiltonian Formulation of General Relativity

The implications of the general covariance principle for the establishment of a Hamiltonian variational formulation of classical General Relativity are addressed. The analysis is performed in the framework of the Einstein-Hilbert variational theory. Preliminarily, customary Lagrangian variational principles are reviewed, pointing out the existence of a novel variational formulation in which the class of variations remains unconstrained. As a second step, the conditions of validity of the non-manifestly covariant ADM variational theory are questioned. The main result concerns the proof of its intrinsic non-Hamiltonian character and the failure of this approach in providing a symplectic structure of space-time. In contrast, it is demonstrated that a solution reconciling the physical requirements of covariance and manifest covariance of variational theory with the existence of a classical Hamiltonian structure for the gravitational field can be reached in the framework of synchronous variational principles. Both path-integral and volume-integral realizations of the Hamilton variational principle are explicitly determined and the corresponding physical interpretations are pointed out.     

Some basic principles in dynamic theory of viscoelastic materials with voids

According to the basic idea of classical yin-yang complementarity and modern dual-complementarity, in a simple and unified way proposed by Luo, some basic principles in the dynamic theory of viscoelastic materials with voids can be estab- lished systematically. In this paper, an important integral relation in terms of con- volutions is given, which can be considered as the generalized principle of virtual work in mechanics. Based on this relation, it is possible not only to obtain the principle of virtual work and the reciprocal theorem, but also to derive systemati- cally the complementary functionals for the eight-field, six-field, four-field simpli- fied Gurtin-type variational principles and the potential energy-functional for the two-field one in the dynamic theory of viscoelastic materials with voids by the generalized Legendre transformations given in this paper. Furthermore, with this approach, the intrinsic relationship among various principles can be explained clearly.     

A New Way for the Extension of Quantum Theory: Non-Bohmian Quantum Potentials

Quantum Mechanics is a good example of a successful theory. Most of atomic phenomena are described well by quantum mechanics and cases such as Lamb Shift that are not described by quantum mechanics, are described by quantum electrodynamics. Of course, at the nuclear level, because of some complications, it is not clear that we can claim the same confidence. One way of taking these complications and corrections into account seems to be a modification of the standard quantum theory. In this paper and its follow ups we consider a straightforward way of extending quantum theory. Our method is based on a Bohmian approach. We show that this approach has the essential ability for extending quantum theory, and we do this by introducing “non-Bohmian” forms for the quantum potential.     

Cu、Zn掺杂对AlSb电子结构和光学性质影响

运用密度泛函平面波赝势方法和广义梯度近似,对替代式掺杂Cu和Zn的闪锌矿AlSb的超晶胞晶体结构、电子结构和光学性质进行了计算。分析了其电子态分布和结构的关系,给出了掺杂前后AlSb体系的复介电常数和复折射函数。结果表明,掺有Cu和Zn的AlSb晶体空穴密度增大,会明显提高材料的电导率;两种掺杂体系光学带隙均变窄;通过分析掺杂前后AlSb晶体的复介电常数和复折射函数,解释了体系的发光机制。     

Information and Self-Organization II: Steady State and Phase Transition

This paper starts from Schrödinger’s famous question “what is life” and elucidates answers that invoke, in particular, Friston’s free energy principle and its relation to the method of Bayesian inference and to Synergetics 2nd foundation that utilizes Jaynes’ maximum entropy principle. Our presentation reflects the shift from the emphasis on physical principles to principles of information theory and Synergetics. In view of the expected general audience of this issue, we have chosen a somewhat tutorial style that does not require special knowledge on physics but familiarizes the reader with concepts rooted in information theory and Synergetics.     

Deposition pattern of drying droplets

The drying of liquid droplets is a common daily life phenomenon that has long held a special interest in scientific research. When the droplet includes nonvolatile solutes, the evaporation of the solvent induces rich deposition patterns of solutes on the substrate. Understanding the formation mechanism of these patterns has important ramifications for technical applications,ranging from coating to inkjet printing to disease detection. This topical review addresses the development of physical understanding of tailoring the specific ring-like deposition patterns of drying droplets. We start with a brief introduction of the experimental techniques that are developed to control these patterns of sessile droplets. We then summarize the development of the corresponding theory. Particular attention herein is focused on advances and issues related to applying the Onsager variational principle (OVP) theory to the study of the deposition patterns of drying droplets. The main obstacle to conventional theory is the requirement of complex numerical solutions, but fortunately there has been recent groundbreaking progress due to the OVP theory. The advantage of the OVP theory is that it can be used as an approximation tool to reduce the high-order conventional hydrodynamic equations to first-order evolution equations,facilitating the analysis of soft matter dynamic problems. As such, OVP theory is now well poised to become a theory of choice for predicting deposition patterns of drying droplets.