内孔键槽偏转度的快速测量原理及其专用检测装置

内孔键槽偏转度的快速测量原理及其专用检测装置朱正德（上海大众汽车有限公司，２０１８０５）１问题的提出键在多数动力机械中，只起着传递扭矩的作用，此时健槽在圆周上的位置可以是任意的。但对一些由齿轮、齿形同步带传动的机械，由于轴与轮子的相对位置直接关系到产...

内孔键槽偏转度的快速测量原理及其专用检测装置

本文介绍内孔键槽偏转度的快速测量原理，检测装置的结构及使用方法，分析了引起测量误差的因素。该装置解决了难以在工序现场测量内孔键槽偏转度的问题。

液体扩散时的折射率分布和扩散系数的测定

本实验提供一种测量透明度或半透明度液体的折射率和扩散系数的方法。此方法可用于食品工业、日用化学工业、石油工业及制药工业部门。

同坡屋面交线的一种图解新法

同坡屋面是房屋建筑中常用的屋顶形式之一,但在建筑工程制图学习中,补全同坡屋面投影却是令人感到困扰的一个问题。针对同坡屋面中的墙角为直角、檐口线平行的形式,结合这种屋面形式的投影规律,本文提出一种求解该屋面交线的新方法,即45度偏转法。本文还对这种方法进行了理论分析和实例验证,结果证明,在提高作图效率方面效果明显。

Application of Dynamic Track Drawing Algorithm in Ship Monitoring System

The function of dynamic track drawing realized in the ship monitoring system. Based on the function, we could draw the sailing tracks dynamically according to the ship＇s orientation. Two kernel algorithms are involved during the system developing process, i.e. the algorithms of angular deflection and distance interval value. The practice of system development shows that the proper application of these two algorithms has good effect＇in the visualization of sailing track.

利用线性回归偏离角评价地下水质量

介绍了线性回归偏离角的基本概念及其在地下水质量评价中的应用,并与内梅罗指数法、模糊综合评判法、物元可拓法及BP神经网络模型法评价结果对比,证明利用线性回归偏离角评价法判定地下水质量等级结果客观、准确、合理。

Influence of deflection angles on flow behaviours in openchannel bends

The deflection angle of a river bend plays an important role on behaviours of the flow within it, and a clear understanding of the angle's influence is significant in both theoretical study and engineering application. This paper presents a systematic numerical investigation on effects of deflection angles(30°, 60°, 90°, 120°, 150°, and 180°) on flow phenomena and their evolution in open-channel bends using a Re-Normalization Group(RNG) κ-ε model and a volume of fluid(VOF) method. The numerical results indicate that the deflection angle is a key factor for flows in bends. It is shown that the maximum transverse slope of water surface occurs at the middle cross section of a bend, and it increases with the deflection angle. Besides a major vortex, or, the primary circulation cell near the channel bottom, a secondary vortex, or, an outer bank cell, may also appear above the former and near the outer bank when the deflection angle is sufficiently large, and it will gradually migrate towards the inner bank and evolve into an inner bank cell. The strength of the secondary circulations increases with the deflection angle. The simulation demonstrates that there is alow-stress zone on the bed near the outer bank and a high-stress zone on the bed near the inner bank, and both of them increase in size with the deflection angle. The maximum of shear stress on the inner bank increases nonlinearly with the angle, and its maximums on the outer bank and on the bed take place when the deflection angle becomes 120°.

Prestack migration velocity analysis based on simplified two-parameter moveout equation

Stacking velocity V_（C2）,vertical velocity ratio γ_0,effective velocity ratio γ_（eff）,and anisotropic parameter x_（eff） are correlated in the PS-converted-wave（PS-wave） anisotropic prestack Kirchhoff time migration（PKTM） velocity model and are thus difficult to independently determine.We extended the simplified two-parameter（stacking velocity V_（C2） and anisotropic parameter k_（eff）） moveout equation from stacking velocity analysis to PKTM velocity model updating and formed a new four-parameter（stacking velocity V_（C2）,vertical velocity ratio γ_0,effective velocity ratio γ_（eff）,and anisotropic parameter k_（eff）） PS-wave anisotropic PKTM velocity model updating and process flow based on the simplified twoparameter moveout equation.In the proposed method,first,the PS-wave two-parameter stacking velocity is analyzed to obtain the anisotropic PKTM initial velocity and anisotropic parameters;then,the velocity and anisotropic parameters are corrected by analyzing the residual moveout on common imaging point gathers after prestack time migration.The vertical velocity ratio γ_0 of the prestack time migration velocity model is obtained with an appropriate method utilizing the P- and PS-wave stacked sections after level calibration.The initial effective velocity ratio γ_（eff） is calculated using the Thomsen（1999） equation in combination with the P-wave velocity analysis;ultimately,the final velocity model of the effective velocity ratio γ_（eff） is obtained by percentage scanning migration.This method simplifies the PS-wave parameter estimation in high-quality imaging,reduces the uncertainty of multiparameter estimations,and obtains good imaging results in practice.

Research on suppress vibration of rotor misalignment with shear viscous damper

A new type of shear viscous damper for rotating machinery is designed. The new damper with good stability and reliability can inhibit all kinds of frequency multiplication vibration caused by misalignment in the condition of nonstop machine. It analyzes and discusses the use of the shear viscous damper for misalignment vibration response inhibition with a finite element method, and experi ments are extensively carried out with a laboratory test rig. Both the simulation and experimental re suits basically agree well in that, the damper can effectively control the misalignment vibration of the rotor system and improves the stability of the plitude of one time running speed component bration has been basically eliminated. entire rotor system. Experimental results show the am decreases by 30% , and the two time running speed vibration has been basically eliminated.

Stability analysis of quasicrystal torsion micromirror actuator based.on the strain gradient theory

Electrostatic torsional micromirrors are widely applied in the fields·of micro-optical switches,optical attenuators,optical scanners,and optical displays.In previous lectures,most of the micromirrors were twisted along the urtiaxial or biaxial direction,which limited the range of light reflection.In this·paper,a quasicrystal torsional micromirror that can be deflected in any direction is designed and the dynamic model of the electrostatically driven micromirror is established.The static and dynamic phenomena and pull-in characteristics are analyzed through the numerical solution of the strain gradient theory.The results of three kinds of mirror deflection directions are compared and analyzed.The results show the significant differences in the torsion models with different deflection axis directions.When the deflection angle along the oblique axis reaches 45°,the instability voltage is the smallest.The pull-in instability voltage increases with the increment ofphonon-phason coupling elastic modulus and phason elastic modulus.The perrriittivity of quasicrystal,the strain gradient parameter,and the air damping influence the torsion of the micromirror dynaniic system.A larger pull-in instability voltage generates with the decrease of surface distributed forces.

Criteria of limiting temperature and parametric analysis of the large deflection behavior for fully restrained steel beams in fire

This paper mainly involve 3 parts:1) To apply the minimum principle of acceleration in dynamics of elastic-plastic continua at finite deformation to the statics problems,a computing model is presented for the restrained steel beams exposed to the fire.In this model,both effects of large deflection and thermal expansion deformation are taken into account,and the constitutive equations with the temperature effects are used.Then a dynamic finite difference(DFD) method is presented by using the dis-crete technique,which can be used in simulating the response of the steel beams at elevated temperature,and the large deflec-tion behavior and catenary action effects of the beams can be adequately expressed.The primary numerical results show that the method is valid and credible.Compared with other methods,this technique is very simple,and it can also be further devel-oped to simulate the behavior of steel beams subjected to the coupling loading of explosion and fire when both effects of strain rate and inertia are considered.2) By using this DFD method,detailed parametric analysis are presented so as to check the consistency of response results for several different formulas of thermal expansion deformation and retention factors of steel at elevated temperature,the influence of these parameters on the critical temperature is examined.3) Based on the analysis for the curves of temperature-generalized yield function comprised by the axial force and bending moment,both criteria to determine the limiting temperature(or failure temperature) of large deflection steel beams are presented more explicitly,that is,both lim-iting temperatures can be determined by if the catenary force begins to appear or arrives at the maximum value,respectively.It is shown by numerical results that both limiting temperatures are close to the both critical temperatures which are correspond-ing to the maximum deflections equal to span/20 and span/10,respectively.This conclusion may be helpful to make rational fire resisting design for the steel beams.

A burst segmentation-deflection routing contention resolution mechanism in OBS networks

One of the key problems to hinder the realization of optical burst switching(OBS) technology in the core networks is the losses due to the contention among the bursts at the core nodes.Burst segmentation is an effective contention resolution technique used to reduce the number of packets lost due to the burst losses.In our work,a burst segmentation-deflection routing contention resolution mechanism in OBS networks is proposed.When the contention occurs,the bursts are segmented according to the lowest packet loss probability of networks firstly,and then the segmented burst is deflected on the optimum routing.An analytical model is proposed to evaluate the contention resolution mechanism.Simulation results show that high-priority bursts have significantly lower packet loss probability and transmission delay than the low-priority.And the performance of the burst lengths,in which the number of segments per burst distributes geometrically,is more effective than that of the deterministically distributed burst lengths.

Polarized upconversion luminescence from a single LiLuF_(4):Yb^(3+)/Er^(3+) microcrystal for orientation tracking

Polarized upconversion luminescence(UCL)of lanthanide-doped micro/nano-crystals has shown great promise in single-particle tracking and super-resolution bioimaging.However,because of the spectral line broadening and multiple sites of lanthanide in upconversion particles(UCPs),the crystal-field(CF)polarization components of UCL are usually undistinguishable.Herein,we report the linearly polarized UCL in LiLuF_(4):Yb^(3+)/Er^(3+) single microcrystals with resolvable CF transition lines and a polarization degree up to 0.82.The CF levels and CF transition lines of Er^(3+),as well as their emission polarization anisotropy,are unraveled for the first time through low-temperature and high-resolution photoluminescence(PL)and UCL spectroscopies.By taking advantage of the well-resolved and highly-polarized CF transition lines of Er^(3+),we demonstrate the application of LiLuF_(4):Yb^(3+)/Er^(3+) single microcrystals as anisotropic UCL probes for orientation tracking.These findings provide fundamental insights into the polarization anisotropy of UCL in lanthanide-doped single particles,thus laying a foundation for the future design of anisotropic luminescent probes towards versatile applications.

Microstructure and mechanical properties of liquid phase sintered silicon carbide composites

Silicon carbide (SiC) composites were prepared by hot-press sintering from α-SiC starting powders with BaAl2Si2O8 (BAS). The effects of additives on densification, microstructure, flexural strength, and fracture behavior of the liquid phase sintered (LPS) SiC composites were investigated. The results show that the served BAS effectively promotes the densification of SiC composites. The flexural strength and fracture toughness of the SiC composites can reach a maximum value of 454 MPa and 5.1 MPa·m1/2, respectively, for 40% (w/w) BAS/SiC composites. SiC grain pullout, crack deflection, and crack bridging were main toughening mechanisms for the sintered composites.

Wavelength conversion based on nonlinear polarization rotation in gain transparent SOA

We describe an all-optical wavelength conversion scheme for 1310 nm to 1550 nm based on nonlinear polarization rotation in a gain-transparent semiconductor optical amplifier （GT-SOA） which brings in the assistant light to improve the property of the converted light. From the SOA carder density equations, the 1310 nm-to-1550 nm wavelength conversion scheme is analyzed by the Jones matrix. The phase shift between TE and TM modes and the converted light are simulated at bit rate of 30 Gbit/s. We also analyze the influence of the input signal power, the injected current and the assistant light power on the extinction ratio of the converted li~,ht.