五年来我国有色金属工业结构调整状况及对策建议

本文总结了近5年来我国有色金属工业结构调整和产业升级的基本情况,即中国有色金属工业集约化程度、技装备水平提高,生产成本下降,行业整体实力增强。而这些成绩的取得都有赖于国家积极的财政政策及“债转股”政策的推动,有赖于深化企业改革及发挥市场资源配置的作用等等。同时,针对对当前及今后有色金属工业结构调整和产业结构升级所面临的问题,提出了有关对策建议     

Composite group vector space method for estimating melting and boiling point of pure organic compound

Composition Group Vector Space (CGVS) method for estimating melting and boiling point T _m , T _b of organic compound has been proposed, and the principle of this method has been elucidated. The models for estimating T _m , T _b have been established and the numerical values of relative parameters have been presented. The average percentage deviations of T _m , T _b estimation are 7.53 and 1.58, respectively, which show that the present method demonstrates significant improvement in applicability to predict the above properties, compared to conventional group methods.     

CpTi(dbm)Cl_2催化烯烃聚合及其聚合物性质

开发了一种新型非茂聚烯烃催化剂———CpTi(dbm)Cl2,考察了催化剂在均相及负载条件下对乙烯及乙烯-1-己烯共聚的催化行为。催化剂在均相条件下对乙烯聚合的催化活性较低,但用MgCl2和MgCl2/SiO2复合双载体对催化剂进行负载后,催化乙烯聚合具有非常好的催化活性。催化剂还具有良好的共聚能力及良好的氢调敏感性。     

The long string as a field probe

We show how a long string can be used to probe the incident field across the target zone of a radar cross section (RCS) test range. The string may be stretched horizontally from wall to wall, or vertically from floor to ceiling. One end of the string is fixed and the other end is moved by an actuator mounted in the wall or ceiling. The resulting motion changes the angle of the string with respect to the incident-field direction, during which time the coherent radar echo is recorded as a function of the string angle. The coherent signal-as-a-function-of-angle data are then transformed to the cross-range domain using the fast Fourier transform (FFT), whence we obtain a chart of the incident field amplitude as a function of cross-range distance. Numerical examples are presented that show how variations in the incident field influence the string echo. A sample of experimental data shows that the processed data are readily interpreted.     

A high-resolution burst-mode laser transmitter with fast and accurate level monitoring for 1.25 Gb/s upstream GPONs

An innovative burst-mode laser transmitter (BM-TX) is presented for gigabit-capable passive optical network (GPON) upstream transmission at 1.25 Gb/s. The laser bias and modulation current each can reach 80 mA with a resolution of 0.1 mA providing a total drive current up to 160 mA. Both currents are generated by 10-bit current steering digital-to-analog converters (DACs), the architecture of which is specially adapted to yield a monotonic current setting at settling times below 12.8 ns. Tests show that fast automatic power control (APC) can stabilize and track the launched optical power with a tolerance of less than 1 dB over a wide temperature range for outdoor operation. The APC only requires a straightforward calibration of the "0" and the "1" level at room temperature. Optical level monitoring on strings of four consecutive "0" bytes and two consecutive "1" bytes at 1.25 Gb/s is demonstrated. APC based on such short strings of data has not been shown before. The circuits have been designed in a 0.35 /spl mu/m SiGe BiCMOS process. Experimental results show that this dc-coupled BM-TX meets the specifications of the recently approved ITU-T Recommendation G.984.2 supporting an intelligent power leveling mechanism (PLM).     

添加VC的TiB2基硬质材料研究

对添加VC的TiB2基硬质材料进行了研究。通过实验测定了硬度、横向断裂强度、高温强度以及耐磨性等性能，通过观察SEM照片研究了VC对TiB2基硬质材料组织结构的影响。综合各种指标，我们确定在TiB2-Fe—Mo硬质材料中VC的最佳添加量为0．5％。     

成都市火车南站斜拉桥斜拉索安装工艺

采用倒链葫芦、卷扬机或软牵引装置对斜拉索进行牵引安装 ,使牵引力达到 5 0 0余kN ,解决了斜拉索安装拉力大这一施工难题。     

电液比例控制技术在工程船舶中的应用

以长江及沿海航道铺排工程船(长雁1号)液压系统的工程项目为背景,采用电液比例控制技术设计了一种新型的电液比例控制系统,通过对移船马达速度的控制实现了移船的移位和准确定位,同时液压系统的能耗也大大降低.