用于磁场测量的高精度500A/30V零压开关直流稳流电源

研制了一种带有无源辅助网络的全桥移相脉宽调制零压开关(FB PSPWMZVS)高精度磁铁稳流电源,并在电磁铁磁场测量中得到应用,其电流稳定度在8h内优于±1×10-4。     

软管充填封口机

<正> 人们都想了解如何使用软管充填机械,以及这些机械的优点使用范围和功能,想知道怎么选择最合适的机器用于现行和规划中的软管,以满足产品生产的要求。软管的材料,如塑料、金属或复合材料,影响着对机器的选择。然而,大多数的机器都设计成     

首钢内部网络防病毒体系的设计与应用

介绍了网络防病毒技术和首钢企业网防病毒的规划、体系结构、系统设置和实施，提出了首钢企业网从桌面到服务器全方位、完整的可通过控制中心控制的解决方案.     

综合水平井地质资料进行储层描述：北海南部Lancelot地区赤底统砂岩实例

Ｌａｎｃｅｌｏｔ和Ｅｘｃａｌｉｂｕｒ气田主要由水平钻探开发的Ｒｏｔｌｉｅｇｅｎｄｅ（赤底统）群气田。对这些气田水平井的地质资料进行了解释，并与垂直井资料相结合评价了目的层，改善了储层描述。     

气井分层测压工艺技术与应用

概述了一种气井分层测压工艺新技术，该工艺可实现气井的分层测试、井下气嘴大小的任意调整。应用该技术，可准确地测得各个层段的分层流压和分层静压，并通过对所测得的测试资料的分析和对井下气嘴大小的调控，可充分发挥气井不同储层的潜能，减少层间干扰，提高气井的产气量。     

Development and validation of a Monte Carlo simulation of photon transport in an Anger camera

The geometric component of the point spread function (PSF) of a gamma camera collimator can be determined analytically, and the penetration component can be calculated readily by numerical ray-tracing. A Monte Carlo simulation of photon transport which includes collimator scatter is developed. The simulation was implemented with an array processor which propagates up to 1024 photons in parallel, allowing accurate estimates of the total radial PSF in less than a day. The simulation was tested by imaging monoenergetic point sources of Tc-99m, Cr-51, and Sr-85 (140, 320, and 514 keV, respectively) on a General Electric Star Cam with low-energy, general-purpose, and medium-energy collimators. Comparisons of measured and simulated PSFs demonstrate the validity of the model and the significance of collimator scatter in the degradation of image quality.     

Bias-free identification of a linear model-predictive steering controller from measured driver steering behavior

Recent developments in modeling driver steering control with preview are reviewed. While some validation with experimental data has been presented, the rigorous application of formal system identification methods has not yet been attempted. This paper describes a steering controller based on linear model-predictive control. An indirect identification method that minimizes steering angle prediction error is developed. Special attention is given to filtering the prediction error so as to avoid identification bias that arises from the closed-loop operation of the driver-vehicle system. The identification procedure is applied to data collected from 14 test drivers performing double lane change maneuvers in an instrumented vehicle. It is found that the identification procedure successfully finds parameter values for the model that give small prediction errors. The procedure is also able to distinguish between the different steering strategies adopted by the test drivers.     

Post-mortem glycolysis in rabbit Longissimus dorsi muscles following electrical stimulation

The effects of both high voltage and low voltage electrical stimulation were studied in rabbit Longissimus dorsi muscles. The rate of fall of pH as well as the activities of phosphorylase a, phosphorylase kinase, and phosphorylase phosphatase were measured. The effects on the yield, ATPase activities, and calcium permeability of the sarcoplasmic reticulum (SR) were also measured. Although only high voltage stimulation increased the post-stimulation rate of pH fall, both types of electrical stimulation increased the phosphorylase a activity, apparently by increasing the activity of phosphorylase kinase and destroying a large part of the phosphorylase phosphatase activity. Electrical stimulation reduced the yield of SR and increased its basal ATPase activity. It also increased the ability of the SR to retain accumulated calcium. We conclude that the different rates of pH fall observed following the two types of stimulation are due to the differential effects of these treatments on one of the ATPase activities, probably the myofibrillar ATPase.