如何对叉车检测中方向盘自由转向量进行不确定度评定

本文通过对叉车检测中WZX─I型转向参数测试仪的测量不确定度进行分析和评估,并根据叉车检验规程中检测项目及其仪器技术指标,建立其测量不确定度的数学模型及计算公式,同时提供一评估和计算实例,为叉车检验检测工作提供了不确定度应用方面的参考。

复数与坐标轴的旋转

本文利用复数乘法的几何意义,推导出曲线绕原点旋转所得到的曲线方程及其旋转公式,进一步推广为曲线绕任意一点旋转所得到的曲线方程及其坐标变换公式,以及在实际问题中的运用。

基于ITCC与PLC的自动化控制系统优化设计与实践应用

自动化控制结构内存在多组伺服电机组,在优化设计处理时,调和伺服电机的转向量过小,导致自动化控制量小、控制效果不佳的问题,研究基于ITCC与PLC的自动化控制系统优化设计与实践应用。控制接触器与电磁体串联,重组PLC逻辑控制装置,变换脉冲的处理顺序,调和伺服电机的转向量,形成ITCC伺服执行结构。联合流量变送器的测量值,设定ITCC喘振极限运行参数,采用纳维-斯托克斯方程确定触发响应的压缩边界量,设置控制关联机理,最终完成对自动化控制系统的优化。在实践应用过程中搭建系统测试环境,配置系统结构运行组态后,准备基于DCS的自动化控制系统、基于DNN的自动化控制系统以及所优化的自动化设计系统参与实践应用测试,结果表明:优化后的自动化控制系统可控制量最多,实际控制效果最佳。

Direct computing methods for turn flows in traffic assignment

Two methods based on a slight modification of the regular traffic assignmentalgorithms are proposed to directly compute turn flows instead of estimating them from link flows orobtaining them by expanding the networks. The first one is designed on the path-turn incidencerelationship, and it is similar to the computational procedure of link flows. It applies to thetraffic assignment algorithms that can provide detailed path structures. The second utilizes thelink-turn incidence relationship and the conservation of flow on links, a law deriving from thisrelationship. It is actually an improved version of Dial's logit assignment algorithm. The proposedapproaches can avoid the shortcomings both of the estimation methods, e. g. Furness's model andFrator's model, and of the network-expanding method in precision, stability and computation scale.Finally, they are validated by numerical examples.

Uncertainty analysis of ship model vertical center of gravity and transverse moment of inertia test

The usability of test results of ship model vertical center of gravity and transverse moment of inertia is generally depends on its uncertainty. Referring to the guidelines for uncertainty analysis in examination of liquid dynamic recommended by International Towing Tank Conference （ ITTC）, the results were analyzed, bias limits and precision limits were calculated and total uncertainty was estimated. The total uncertainty of six tests on ship model vertical center of gravity is is 0. 16% of the mean value, and the total uncertainty of six tests on ship model transverse moment of inertia is 5.66% of the mean value. The test results show that the total uncertainty of both the multiple tests and the single test is from the precision limits of ship model vertical center of gravity and transverse moment of inertia tests. Thus, the improved measurement system stability can enormously decrease the total uncertainty of multiple tests and the single test.

One-Way Quantum Authenticated Secure Communication Using Rotation Operation

This study proposes a theoretical quantum authenticated secure communication(QASC) protocol using Einstein-Podolsky-Rosen(EPR) entangle state,which enables a sender to send a secure as well as authenticated message to a receiver within only one step quantum transmission without having the classical channels and the certification authority.

Three-dimensional transformation of magnetization direction and magnetic field component at low latitudes based on vertical relationship

The transformation of the magnetization direction and the magnetic fi eld component is one of the important methods in magnetic data processing and transformation,which can be conducted in both wavenumber and spatial domains.The transformation method in the wavenumber domain has simpler processing expression and higher processing effi ciency than in the spatial domain;however,they are unstable at low latitude.In this paper,the conclusion that the sum is 0 of two vertical magnetic fi eld components(magnetization inclinations are also perpendicular)in 2D is used for the 3D transformation of the magnetization direction and the magnetic field component.In addition,the transformation method at low latitudes based on vertical relationship(VMT)is proposed,which is an iterative algorithm that converts the transformation of the magnetization direction and the magnetic field component at the low latitude into the high latitude.This method restrains the instability of transformation of constant and variable magnetization direction and magnetic fi eld components in low latitudes.The accuracy,stability,and practicality are verifi ed from synthetic models and real data.

Energy Shift Caused by Non-isotropy of 2-Dimensional Anisotropic Quantum Dot in Presence of Uniform Magnetic Field

Based on the squeezing mechanism in quantum dots in the presence of uniform magnetic field, we derive the energy shift caused by the non-isotropy of 2-dimensional anisotropic quantum dot. We also study sudden squeezing of the size of the quantum dot. The whole discussion is proceeded smoothly by virtue of the entangled state representation.

Metric of Rotating Charged Spherical Mass in Vacuum for Vector Graviton Metric Theory of Gravitation

Based on the vector graviton metric theory of gravitation (VGM) suggested by one of the authors of this article, using the method of null tetrad and analytic continuation, this paper gives the metric of the rotating charged spherical mass in VGM. The result shows once again that a replacement of G by G* = G(1 - G M /2r) in general relativity will yield the corresponding result in VGM for the metric in vacuum.

Relative Molecular Orientations in Organic Optoelectronic Films Probed via Polarization-Selected UV/IR Mixed Frequency Ultrafast Spectroscopy

Molecular packing patterns are crucial factors determining electron/energy transfer processes that are critical for the optoelectronic properties of organic thin film devices.Herein,the polarization-selective ultraviolet/infrared(UV/IR)mixed frequency ultrafast spectroscopy is applied to investigate the relative molecular orientations in two organic thin films of 7-(diethylamino)coumarin-3-carboxylic acid(DEAC)and perylene.The signal anisotropy changes caused by intermolecular energy/electron transfers are utilized to calculate the cross angles between the electronic transition dipole moment of the donor and the vibrational transition dipole moments of the acceptor,yielding the relative orientation between two adjacent molecules.Using this method,the relative orientation angle in DEAC film is determined to be 53.4°,close to 60°of its single crystalline structure,and that of the perylene film is determined to be 6.2°,also close to-0.2°of its single crystalline structure.Besides experimental uncertainties,the small difference between the angles determined by this method and those of single crystals also results from the fact that the thin film samples are polycrystalline where some of the molecules are amorphous.

Application of Coordinate-Momentum Intermediate Representation in Solving Eigenstate Problem of a Coupled Oscillator System

We study the eigenstate problem of a kind of coupled oscillators in the new quantum mechanical representation ｜q,μ,υ〉, which is defined as the eigenvector of the operator （μQ ＋ υP）, whereμ and υ are two real parameters. We also use the U operator transformation method to deal with the same problem. We obtain the normally ordered product expressions of U operator and eigenvector. It is shown that the ground state of system Hamiltonian is a squeezed state.

Distinct intensity of 10-30-day intraseasonal waves over the North Pacific between early and late summers

The authors’previous study identified the wave trains of intraseasonal oscillations,which are mainly in the band of 10–30 days,over the North Pacific during summer.The wave trains are zonally oriented and trapped along the upper-tropospheric westerly jet,and accordingly gain energy mainly through baroclinic energy conversion.In this study,the authors investigate the distinct features of the wave trains between early summer(1 June to 7 July)and late summer(8 July to 31 August),considering that the westerly jet experiences a remarkable subseasonal variation over the North Pacific during summer—that is,the jet is much stronger in early summer than late summer.The results indicate that the wave trains are stronger in early summer compared with late summer.Further analysis suggests that,in early summer,the wave trains can obtain energy more efficiently from the basic flow;or more exactly,stronger westerlies through baroclinic energy conversion.

Forced Axial and Torsional Vibrations of a Shaft Line Using the Transfer Matrix Method Related to Solution Coefficients

This present paper deals with a mathematical description of linear axial and torsional vibrations. The normal and tangential stress tensor components produced by axial-torsional deformations and vibrations in the propeller and intermediate shafts, under the influence of propeller-induced static and variable hydrodynamic excitations are also studied. The transfer matrix method related to the constant coefficients of differential equation solutions is used. The advantage of the latter as compared with a well-known method of transfer matrix associated with state vector is the possibility of reducing the number of multiplied matrices when adjacent shaft segments have the same material properties and diameters. The results show that there is no risk of buckling and confirm that the strength of the shaft line depends on the value of the static tangential stresses which is the most important component of the stress tensor.

Integration optimization of novel electric power steering system based on quality engineering theory

The dynamic model of a novel electric power steering （EPS） system integrated with active front steering function （the novel EPS system） is built. The concepts and quantitative expressions of the steering road feel, steering sensibility, and steering operation stability are introduced. Based on quality engineering theory, the optimization algorithm is proposed by integrating the Monte Carlo descriptive sampling, elitist non-dominated sorting genetic algorithm （NSGA-II） and 6-sigma design method. With the steering road feel and the steering portability as optimization targets, the system parameters are optimized by the proposed optimization algorithm. The simulation results show that the system optimized based on quality engineering theory can improve the steering road feel, guarantee steering stability and steering portability and thus provide a theoretical basis for the design and optimization of the novel electric power steering system.

Fatigue damage evaluation by metal magnetic memory testing

Tension-compression fatigue test was performed on 0.45% C steel specimens.Normal and tangential components of magnetic memory testing signals,Hp(y) and Hp(x) signals,with their characteristics,K of Hp(y) and Hp(x)M of Hp(x),throughout the fatigue process were presented and analyzed.Abnormal peaks of Hp(y) and peak of Hp(x) reversed after loading; Hp(y) curves rotated clockwise and Hp(x) curves elevated significantly with the increase of fatigue cycle number at the first a few fatigue cycles,both Hp(y) and Hp(x) curves were stable after that,the amplitude of abnormal peaks of Hp(y) and peak value of Hp(x) increased more quickly after fatigue crack initiation.Abnormal peaks of Hp(y) and peak of Hp(x) at the notch reversed again after failure.The characteristics were found to exhibit consistent tendency in the whole fatigue life and behave differently in different stages of fatigue.In initial and crack developing stages,the characteristics increased significantly due to dislocations increase and crack propagation,respectively.In stable stage,the characteristics remained constant as a result of dislocation blocking,K value ranged from 20 to 30 A/(m·mm)-1,and Hp(x)M ranged from 270 to 300 A/m under the test parameters in this work.After failure,both abnormal peaks of Hp(y) and peak of Hp(x) reversed,K value was 133 A/(m·mm)-1 and Hp(x)M was-640 A/m.The results indicate that the characteristics of Hp(y) and Hp(x) signals were related to the accumulation of fatigue,so it is feasible and applicable to monitor fatigue damage of ferromagnetic components using metal magnetic memory testing(MMMT).

A Note on Classification of Spatially Homogeneous Rotating Space-Times According to Their Teleparallel Killing Vector Fields in Teleparallel Theory of Gravitation

In this paper we classify spatially homogeneous rotating space-times according to their teleparallel Killing vector fields using direct integration technique.It turns out that the dimension of the teleparallel Killing vector fields is 5 or 10.In the case of 10 teleparallel Killing vector fields the space-time becomes Minkowski and all the torsion components are zero.Teleparallel Killing vector fields in this case are exactly the same as in general relativity.In the cases of 5 teleparallel Killing vector fields we get two more conservation laws in the teleparallel theory of gravitation.Here we also discuss some well-known examples of spatially homogeneous rotating space-times according to their teleparallel Killing vector fields.

Optimal estimation of zonal velocity and transport through Luzon Strait using variational data assimilation technique

A P-vector method was optimized using variational data assimilation technique, with which the vertical structures and seasonal variations of zonal velocities and transports were investigated. The results showed that westward and eastward flowes occur in the Luzon Strait in the same period in a year. However the net volume transport is westward. In the upper level (0m -500m),the westward flow exits in the middle and south of the Luzon Strait, and the eastward flow exits in the north. There are two centers of westward flow and one center of eastward flow. In the middle of the Luzon Strait, westward and eastward flowes appear alternately in vertical direction. The westward flow strengthens in winter and weakens in summer. The net volume transport is strong in winter (5.53 Sv) but weak in summer (0.29 Sv). Except in summer, the volume transport in the upper level accounts for more than half of the total volume transport (0m bottom). In summer, the net volume transport in the upper level is eastward (1.01 Sv), but westward underneath.

Absolute geostrophic currents in global tropical oceans

A set of absolute geostrophic current(AGC) data for the period January 2004 to December 2012 are calculated using the P-vector method based on monthly gridded Argo profi les in the world tropical oceans. The AGCs agree well with altimeter geostrophic currents, Ocean Surface Current Analysis-Real time currents, and moored current-meter measurements at 10-m depth, based on which the classical Sverdrup circulation theory is evaluated. Calculations have shown that errors of wind stress calculation, AGC transport, and depth ranges of vertical integration cannot explain non-Sverdrup transport, which is mainly in the subtropical western ocean basins and equatorial currents near the Equator in each ocean basin(except the North Indian Ocean, where the circulation is dominated by monsoons). The identifi ed nonSverdrup transport is thereby robust and attributed to the joint effect of baroclinicity and relief of the bottom(JEBAR) and mesoscale eddy nonlinearity.

Heat and salt transport throughout the North Pacific Ocean

Absolute geostrophic currents in the North Pacific Ocean are calculated using the P-vector method and gridded Argo profiling data from January 2004 to December 2012. Three-dimensional structures and seasonal variability of meridional heat transport(MHT) and meridional salt transport(MST) are analyzed. The results show that geostrophic and Ekman components are generally opposite in sign, with the southward geostrophic component dominating in the subtropics and the northward Ekman component dominating in the tropics. In combination with the net surface heat flux and the MST through the Bering Strait, the MHT and MST of the western boundary currents(WBCs) are estimated for the fi rst time. The results suggest that the WBCs are of great importance in maintaining the heat and salt balance of the North Pacifi c. The total interior MHT and MST in the tropics show nearly the same seasonal variability as that of the Ekman components, consistent with the variability of zonal wind stress. The geostrophic MHT in the tropics is mainly concentrated in the upper layers, while MST with large amplitude and annual variation can extend much deeper. This suggests that shallow processes dominate MHT in the North Pacific, while MST can be affected by deep ocean circulation. In the extratropical ocean, both MHT and MST are weak. However, there is relatively large and irregular seasonal variability of geostrophic MST, suggesting the importance of the geostrophic circulation in the MST of that area.