银川都市圈城乡西线供水工程建设的必要性分析

推进银川都市圈建设是自治区第十二次党代会确定的重大战略任务,但银川都市圈内现有城市供水工程水源均为地下水,无论从水量和水质方面,均不能满足推进银川都市圈建设的需要。文章详细介绍了银川都市圈供水现状及存在的问题,对银川都市圈城乡西线供水工程建设的必要性进行了分析,认为工程建设十分必要和紧迫。     

安捷伦4396B阻抗分析仪在测试吸波材料复相对介电常数上的应用

依据平行板电容器物理模型的基本原理、安捷伦4396B阻抗分析仪以及安捷伦16453A介质材料测试夹具,建立了1 MHz～1 GHz频率范围内复相对介电常数的测试系统.将测试结果与已知材料进行比对,结果表明,该系统的测试数据真实可靠.此测试系统可应用于新型吸波材料的仿真设计.     

Experimental and numerical studies on the receiving gain enhancement modulated by a sub-wavelength plasma layer

A novel technique based on sub-wavelength plasma structure effects on enhancement of RF communication signals on a receiving antenna is carried out in this paper in laboratory experiments and analyzed by corresponding numerical simulations. Considerable intensification on receiving signal gain up to～10 dB in comparison with that without the plasma modulation is observed experimentally in～1 GHz RF band, with an effective enhancement bandwidth of～340 MHz and the fractional bandwidth of～34％. Then, the optimal modulation parameters of plasma are further studied by a numerical simulation. It is shown that the number density, the layer thickness, and the collision frequency of the plasma, as well as the relative distance between the plasma layer and antenna synergistically affect the modulation. Compared to the metallic antenna with the same overall dimension, the modulated antenna covered by the subwavelength plasma structure features higher receiving efficiency and lower radar cross section in the studied RF band. The mechanism of the reception enhancement is further revealed by analyzing characteristics of electromagnetic scattering and electric field distribution in the subwavelength plasma layer. The results then exhibit scientific significance and application potential of sub-wavelength plasma modulation on compact receiving antennas with higher performance and better feature of radar stealth.     

五粮液淡季涨价传闻疑是炒作

继白酒业"老大"茅台价格一路蹿高后,稳居中国高档白酒第二把交椅的五粮液再次传出跟风涨价消息,一些城市甚至出现供货紧张的局面. 而记者在采访中发现,沈阳各酒类专卖店五粮液并未出现涨价苗头,且货源充足.专家表示,在白酒销售淡季出现涨价传闻,有可能是一种炒作.     

添加细焦粉配煤炼焦的实验室研究

通过坩埚炼焦试验分析,得出配煤中添加3%焦粉,可以充分利用煤料的粘结能力,改善焦炭块度和机械强度。并通过焦炭光学组织的分析看出在此研究中添加3%焦粉,焦炭质量是最好的。     

从炼焦生产过程分析焦炭平均粒度的变化趋势

对马钢不同炉型、不同熄焦。方式生产的焦炭在生产过程中的平均粒度变化情况作一调研，对现场实验数据进行统计和分析，对存在的问题进行改进和完善，使得焦炭平均粒度在原有的基础上有所提高。     

高强TRIP钢焊接工艺及冲击韧性

通过对TRIP980钢进行二氧化碳激光焊接实验制定出适于TRIP980钢的焊接工艺参数,并对焊缝区域进行了冲击试验,通过SEM观察了焊缝区断口形貌。研究表明：TRIP980钢母材冲击断口形貌表现为韧性断裂,焊缝冲击断口形貌表现为脆性断裂,与原始材料相比,激光焊接后焊缝冲击韧性下降,主要原因是焊缝熔融区存在大量马氏体组织。     

矿区总机修厂设计趋势浅议

本文以华亭矿区总机修厂设计为例,在广泛调研的基础上,对矿区总机修厂提出了几种设计构想     

Simulation of Magnetically Dispersed Arc Plasma

Magnetically dispersed arc plasma [1] exhibits typically dispersed uniform arc column as well as diffusive cathode root [1,2] and diffusive anode root.In this paper magnetically dispersed arc plasma coupled with solid cathode is numerically simulated by the simplified cathode sheath model of LOWKE [3].The numerical simulation results in argon show that the maximum value of arc root current density on the cathode surface is 3.5×10 7 A/m 2,and the maximum value of energy flux on the cathode surface is 3×10 7 J/m 2,both values are less than the average values of a contracted arc,respectively.     

浅谈企业物料需求计划MRP

物料需求计划（MRP）主要用于非独立性需求（相关性需求）性质的库存控制,在企业中的应用是非常广泛的,物料需求计划是为适应多品种中小批量生产的要求而发展起来的,经过不断的发展创新以及与计算机辅助管理的结合,目前已形成为一种新的生产计划与控制的理论,并且其应用领域和范围不断扩大。