赴陕西省出口商品展销会看西欧钼市场

经西安公司批准,由金堆城钼业公司派笔者代表西安公司有色进出口公司参加西德汉堡市举办的“陕西省出口商品展销会”。一、展销会概况“陕西省出口商品展销会”是陕西省对外经济贸易委员会1987年8月31日至9月8日组织举办的,地点在西德汉堡市的外经部西欧贸易中心大楼三楼展览厅。展销会代表团     

根据洞室开挖引起的应力变化确定原岩应力

原岩应力状态是地下工程开挖的重要设计参数,它由主应力的大小和方向确定。通常的原岩应力测试方法,如套芯法,都只能得到小范围内的测量资料,且费用很大。本文介绍了一种大范围岩体的地下洞室应力测试方法,这是一种典型的区域应力测量方法。该法要求测出洞室开挖所引起的应力变化。通过把实测应力变化同理论预测的应力变化进行比较而拟合出原岩应力场。通过在两组应力变化值之间得出一个误差函数,使误差趋于极小而求解。本文通过一个具收敛解的圆形洞室的实例来阐述这种方法及其应用。工程实例研究表明,该法具有很大的潜在优势。所得反分析值与大量套芯法实测值相当一致。与常规方法相比,这种新方法有如下优点:(1)应力资料可在工程进展中随时得到校正;(2)测得的是大范围岩体而不是某个点的应力状态;(3)最重要的是费用相对较低。     

开展经济运行 增加发电效益

黄龙滩水电站是华中电网的骨干电站之一,装机容量15万千瓦,自1974年投产以来,为湖北省工农业生产提供了大量的廉阶电能。但是,由于历史原因,黄龙滩水电站在设计施工阶段,设计方案多次变更,以致该电站调节性能差,装机容量小,汛期大量弃水,发电的潜力远没有发挥。因此,如何利     

论隔河岩水电站“三小”运行弊端—兼谈下游供水方案

本文就隔河岩水电站实际中长期存在的小出力、小流量、低水头（即“三小”）运行的弊端和原因进行了分析，以解决下游供水为主提出了避免“三小”运行的方案及办法。     

灌溉渠道正常水深显式公式

正常水深是灌溉渠道设计中的一重要参数，均匀流基本公式属于正常水深的隐式公式，不可能由公式直接求解，常藉冗繁费时的试算法方能得出答案，另外列表法和图解法虽亦能得出答案，但前者易出现双重的内插误差，后者出现读图时的判断误差。     

Continuous collection of soluble atmospheric particles with a wetted hydrophilic filter

Approximately one-third of the area (14-mm diameter of a 25-mm diameter) of a 5-microm uniform pore size polycarbonate filter is continuously wetted by a 0.25 mL/min water mist. The water forms a continuous thin film on the filter and percolates through it. The flowing water substantially reduces the effective pore size of the filter. At the operational air sampling flow rate of 1.5 standard liters per minute, such a particle collector (PC) efficiently captures particles down to very small size. As determined by fluorescein-tagged NaCl aerosol generated by a vibrating orifice aerosol generator, the capture efficiency was 97.7+% for particle aerodynamic diameters ranging from 0.28 to 3.88 microm. Further, 55.3 and 80.3% of 25- and 100-nm (NH4)2SO4 particles generated by size classification with a differential mobility analyzer were respectively collected by the device. The PC is integrally coupled with a liquid collection reservoir. The liquid effluent from the wetted filter collector, bearing the soluble components of the aerosol, can be continuously collected or periodically withdrawn. The latter strategy permits the use of a robust syringe pump for the purpose. Coupled with a PM2.5 cyclone inlet and a membrane-based parallel plate denuder at the front end and an ion chromatograph at the back end, the PC readily operated for at least 4-week periods without filter replacement or any other maintenance.     

Entropies for detection of epilepsy in EEG

The electroencephalogram (EEG) is a representative signal containing information about the condition of the brain. The shape of the wave may contain useful information about the state of the brain. However, the human observer cannot directly monitor these subtle details. Besides, since bio-signals are highly subjective, the symptoms may appear at random in the time scale. Therefore, the EEG signal parameters, extracted and analyzed using computers, are highly useful in diagnostics. The aim of this work is to compare the different entropy estimators when applied to EEG data from normal and epileptic subjects. The results obtained indicate that entropy estimators can distinguish normal and epileptic EEG data with more than 95% confidence (using t-test). The classification ability of the entropy measures is tested using ANFIS classifier. The results are promising and a classification accuracy of about 90% is achieved.     

Dynamical Monte Carlo modelling of organic solar cells: the dependence of internal quantum efficiency on morphology

We present a dynamical Monte Carlo study of the dependence of the internal quantum efficiency (IQE) of an organic bulk heterojunction solar cell on the device morphology. The IQE is found to be strongly sensitive to the scale of phase separation in the morphology, with a peak at approximately 20 nm for the PFB/F8BT system studied. An ordered, checkered morphology exhibits a peak IQE 1.5 times higher than a disordered blend.