岩溶富水区地下工程施工期地下水位变化规律分析

由于当前的计算水平有限和工程实用中存在的问题,在一个工程的渗流分析中同时采用几种不同的模型有些困难。为此,提出采用改进的等效连续介质渗流模型,即在实体建模过程中对岩溶发育区采用挖孔管道的形式按照自由出流进行模拟,裂隙发育区首先采用等效连续介质模型得到该区域的渗透张量然后在实际分析模型中仍采用均质连续模型,对工程区流场开展计算分析。结合我国西南某工程施工期地下水变化开展研究,得到了施工全过程地下水的动态变化情况,为工程设计和建设提供了依据。     

Autodesk Inventor R11 SP2对Inventor资源中心的改进

Autodesk Inventor 11 SP2在SPl的基础上对Inventor功能和性能作了改进.本文将参考Autodesk Inventor 11SP2 Release Notes(Readme),详田介绍Autodesk Inventor 11 SP2对Inventor资源中心CC(Content Center)的功能改进及性能改善.     

三菱控制器在转杯纺纱中的应用

利用三菱伺服系统实现电子防叠导纱功能,为416锭国内最长转杯纺纱机提供解决方案,从而为客户创造更大的价值。     

Optical Diagnostics of Multi-Gap Gas Switches for Linear Transformer Drivers

The trigger characteristics of a multi-gap gas switch with double insulating layers,a square-groove electrode supporter and a UV pre-ionizing structure are investigated aided by a high sensitivity fiber-bundle array detector, a UV fiber detector, and a framing camera, in addition to standard electrical diagnostics. The fiber-bundle-array detector is used to track the turn-on sequence of each electrode gap at a timing precision of 0.6 ns. Each fiber bundle, including five fibers with different azimuth angles, aims at the whole emitting area of each electrode gap and is fed to a photomultiplier tube. The UV fiber detector with a spectrum response of 260-320 nm,including a fused-quartz fiber of 200 μm in diameter and a solar-blinded photomultiplier tube, is adopted to study the effect of UV pre-ionizing on trigger characteristics. The framing camera,with a capacity of 4 frames per shot and an exposure time of 5 ns, is employed to capture the evolution of channel arcs. Based on the turn-on light signal of each electrode gap, the breakdown delay is divided into statistical delay and formative delay. A decrease in both of them, a smaller switch jitter and more channel arcs are observed with lower gas pressure. An increase in trigger voltage can reduce the statistical delay and its jitter, while higher trigger voltage has a relatively small influence on the formative delay and the number of channel arcs. With the UV pre-ionizing structure at 0.24 MPa gas pressure and 60 kV trigger voltage, the statistical delay and its jitter can be reduced by 1.8 ns and 0.67 ns, while the formative delay and its jitter can only be reduced by 0.5 ns and 0.25 ns.     

三倍体毛白杨枝桠材NaOH-AQ法制浆特性

为了探索三倍体毛白杨枝桠材的利用途径，以5年生三倍体毛白杨枝桠材和同年生的黑杨枝桠材为原料，对其化学成分、制浆条件、纸张性能进行了探讨。实验得出三倍体毛白杨NaOH—AQ法制浆最佳工艺：用碱量（以NaOH计）21％，AQ0．05％，液比1：4，最高温度165℃，保温时间3h。浆料抄片后经检测得出三倍体毛白杨枝桠材是优于黑杨枝桠材的一种造纸原料。     

GaAs光阴极像增强器的选通特性

针对GaAs光阴极像增强器在ns级选通成像中的时空特性，通过引入传输线阻抗完善了光阴极径向RLC传输模型，更准确地描述了选通过程中光快门的变化趋势，实验证实去除防离子反馈膜有利于改善光快门，使得光快门与电快门更为一致，在驱动电脉冲宽度为17.7 ns时，光快门宽度与电快门宽度的差异仅为1.1 ns；基于蒙特卡罗模拟方法，建立了光电子在分段线性快门脉冲电压驱动下经过第一近贴后的空间弥散模型，模拟结果表明：GaAs光阴极相较于S20光阴极在选通成像中的空间分辨下降更小。在20 lp/mm时，GaAs的动态空间分辨是静态空间分辨的80%，而S20光阴极不足70%，理论模拟与实验结果相一致，所建立的模型可用来分析和优化像增强器结构参数，为优化选通成像性能提供理论依据。