Research and Development of Ceramic Cutting Tools in China

The research and development of various classes of ceramic cutting tools in China are described,because manufacturing efficiency is fundamental to the growth of China's economy.     

试谈我国IT企业的营销及其对策

与工商企业不同，ＩＴ企业具有市场需求的多样性、高风险性等营销特点。面对国内外企业的竞争，我国ＩＴ企业应根据其营销特点，制定出相应的宏观战略和微观策略。     

The plasma sheet and boundary layers under northward IMF: A multi-point and multi-instrument perspective

During conditions of northward interplanetary magnetic field (IMF), the near-tail plasma sheet is known to become denser and cooler, and is described as the cold-dense plasma sheet (CDPS). While its source is likely the solar wind, the prominent penetration mechanisms are less clear. The two main candidates are solar wind direct capture via double high-latitude reconnection on the dayside and Kelvin–Helmholtz/diffusive processes at the flank magnetopause. This paper presents a case study on the formation of the CDPS utilizing a wide variety of space- and ground-based observations, but primarily from the Double Star and Polar spacecraft on December 5th, 2004. The pertinent observations can be summarized as follows: TC-1 observes quasi-periodic (∼2 min period) cold-dense boundary layer (compared to a hot-tenuous plasma sheet) signatures interspersed with magnetosheath plasma at the dusk flank magnetopause near the dawn-dusk terminator. Analysis of this region suggests the boundary to be Kelvin–Helmholtz unstable and that plasma transport is ongoing across the boundary. At the same time, IMAGE spacecraft and ground based SuperDARN measurements provide evidence of high-latitude reconnection in both hemispheres. The Polar spacecraft, located in the southern hemisphere afternoon sector, sunward of TC-1, observes a persistent boundary layer with no obvious signature of boundary waves. The plasma is of a similar appearance to that observed by TC-1 inside the boundary layer further down the dusk flank, and by TC-2 in the near-Earth magnetotail. We present comparisons of electron phase space distributions between the spacecraft. Although the dayside boundary layer at Polar is most likely formed via double high-altitude reconnection, and is somewhat comparable to the flank boundary layer at Double Star, some differences argue in favour of additional transport that augment solar wind plasma entry into the tail regions.     

The HAL-3 radar test set

This paper presents the HAL-3 radar test set (called the set in the following) used to measure the technical specifications of the HAL-3 airborne radar and to maintain it based on tested results. Some new techniques are employed in the set, including sinusoidal pulsewidth modulation (SPWM) in the power supply, digital gyro simulator and automatic test module (ATM) with STD industrial control microprocessor series. The specially designed software implements man-machine interaction with menu in Chinese, selects parameters and operation mode, and controls testing procedures. These techniques may be extensively applied to other automatic test instruments     

鲁棒飞行控制系统的逆标架正规化设计

 本文讨论了飞行控制系统的逆标架正规化设计理论和方法,证明了正规传递函数阵具有相同特征轨迹的鲁棒稳定性定理,并用飞行控制系统的设计实例说明了这种方法的应用和优点。     

一种先进的推进剂控制阀

本文介绍一种先进的推进剂控制阀——柔性支撑双阀座电磁阀。按动力学特性对该阀门和通常使用的螺旋返回弹簧滑动导向电磁阀进行了比较,证明该阀门具有开关可靠性高、漏率低并能避免自污染等优点。文中还给出了液路系统中各串联节流孔压降公式。     

采用新型驱动器的微位移工作台设计与实验研究

介绍了一个高精度的微动工作台,该工作台以柔性铰链为弹性导轨,并采用了一种新型驱动器作为驱动元件,实现了较高的定位精度。同时对工作台的特性进行了实验和分析。     

Up-to-date observations of space energetic particles made by the Chinese satellite Fengyun-1 (B).

This paper presents the observational results of space energetic particles obtained by the Cosmic Ray Composition Monitor (CRCM) onboard the Chinese satellite, Fengyun-1(B). These results, including those of a few solar proton events, the geomagnetically trapped particles and the anomalous cosmic ray components, were obtained from 3 September 1990 to 15 February 1991. The observed elements include H, He, C, N, O and Fe of energies from 4-23 MeV/u. It was found that the proton fluxes of the inner Radiation Belt (IRB) increased obviously during the period of solar proton event (SPE). A few kinds of heavy ions (Z > or = 6) were also detected in the IRB. As to the anomalous cosmic ray component (ACRC), in addition to C, N and O, anomalous iron particles were also recorded.     

位置伺服滑态控制系统的单片机实现

本文以MCS-51(8031)为基础研究了位置伺服的滑态控制(Sliding Mode Control,简称为SMC)系统的实现。提出了SMC律的设计方法,给出了8031 SMC控制器的硬软件的设计方法与技巧,并在8031 SMC控制器上作了模数混合仿真,给出了仿真结果。     

Preliminary observing achievements of supersoft X-ray detector and γ-ray detector onboard Shenzhou2

Preliminary observing achievements by the Super Soft X-ray Detector and the γ-ray Detector in the fields of cosmic gamma-ray bursts, solar X-ray, bursts and cosmic X-ray/γ-ray background radiation are summarized. The detectors are aboard the spacecraft Shenzhou-2 that was launched on 2001 January 10. The scientific mission and general situation of the instruments are briefly described.