芦山地震水库震害考察及灾区大坝总风险评估(研究生论坛稿件）

为全面了解四川芦山7.0级强烈地震对灾区水库的震害影响,本文对地震重灾区宝兴县及天全县9座水库进行了实地震害考察,并给出了水库震害程度初步评价。调查及分析显示,水库典型震害现象为大坝附属结构变形和破坏,坝体渗漏增加以及库区滑坡崩塌等地质灾害引发的间接损害,大坝主体保持完好或基本完好。整体来看,除个别小型水库震损严重甚至损毁外,大多数水坝经受了强地震的考验。同时,为进一步分析大坝在地震中存在的潜在风险,本文引入了Bureau大坝地震总风险分析方法,并结合地区大坝建设及经济人口情况对坝高和下游损失风险因子进行了适当调整,应用于芦山地震灾区19座不同类型大坝进行地震总风险评级。结果显示,大坝整体处于中等风险级别,符合考察实情及决策经验,可进一步为大坝震害评估和水库的除险加固决策等提供参考。     

磁处理改善低碳钢焊接接头的耐腐蚀性能

研究了磁处理对低碳钢焊接接头耐腐蚀性能的影响.低碳钢平板焊接试样的全浸泡腐蚀试验结果表明,磁处理后,试样的腐蚀速率有一定量的下降,下降的相对平均值为2.58%.对低碳钢平板试样的TIG焊接过程进行了有限元数值模拟,分析了平板试样内的残余应力分布.并在此基础上,对试样在磁处理前后的腐蚀速率差异值进行了统计意义上的显著性检验.分析结果表明,磁处理引起试样的腐蚀速率下降值在显著性为5%的试验误差范围以外,由此可见,磁处理可在显著性水平为5%的意义上改善低碳钢焊接接头的耐腐蚀性能.     

低压异电制三相异步电动机电气性能检测及数据分析

主要讲述了三相异步电动机出厂检测时50Hz与60Hz电源的换算关系,阐明了异电制三相异步电动机空载电流的基本规律,推导出异电制电机在不同电压下的空载电流计算公式;从而使人们对不同电制的电机在线检测时有所参考,使用时有所依据。     

勘探工程造价面临的问题和解决思路

勘探工程定额落后于勘探工程技术的发展、定额管理体制不顺是目前勘探工程造价管理面临的主要问题。要解决这个问题,就要走出把定额当成“定价”和把定额作为投资控制的惟一因素误区,恢复定额的“中性”性质,按定额的本质要求编制定额,加强定额的基础;超出“利益”之争,把定额纳入消耗标准制定轨道,以总量控制、效益指标制约进行投资控制。     

从建筑电气设计角度浅析火灾的防范

近年来 ,由于电气线路故障引起的火灾事故增多 ,如何杜绝火灾隐患 ,本文从导线截面选择、线路敷设、电缆选型等几个方面作了介绍。     

An evaluation of the Hunt94 color appearance model under different light sources at low photopic to low mesopic light levels

Color appearance models allow for the quantification of color appearance under a variety of viewing conditions. Such models may ultimately provide a measure for accurate assessments of the color‐rendering properties of light sources. This article evaluates the Hunt94 color appearance model using a new set of color‐naming and magnitude‐rating data. At one photopic level (10 cd/m²), the evaluations showed that for a xenon lamp and an enhanced metal halide lamp that have chromaticities and spectra close to an equal energy spectrum, the Hunt94 model provided good predictions of the primary and secondary color names and hue magnitudes for a wide range of color chips under the two illuminants. However, for other light sources the Hunt94 model predictions deviated considerably from the evaluations. Three modifications were applied to the Hunt94 color appearance model to predict color‐naming and magnitude‐rating data better for all light sources. The modified Hunt94 model gave good predictions (correlation coefficients r ～ 0.95) of the secondary hue magnitude of the color chips used in the experiment at photopic light levels (10 cd/m² and 1 cd/m² background luminances) under “white” light sources. However, the modified model was still unable to predict color appearances at low mesopic light levels (0.1 cd/m² and 0.01 cd/m²). © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 107–117, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20088     

我国工程造价管理存在的若干问题及其对策

主要分析了我国工程造价管理的现状和缺陷，并在此基础上提出了工程造价管理的对策建议和改革思路。     

加氢联合装置火灾爆炸危险分析及控制

本文运用美国道化学公司火灾道氏指数评价(第七版)对克石化厂加氢联合装置各单元的火灾爆炸危险性进行分析、分级,并就影响因素进行探讨,提出一些控制措施。     

浅谈建筑业劳动定额与劳动力市场价格

分析了建筑劳动力市场和建筑市场,研究了建筑业劳动定额与劳动力市场价格的发展,强调了研究劳动力市场价格的重要性,提出了对劳动力市场加强宏观调控与管理的对策,以促进建筑企业的发展。     

Crystalline silicon cell performance at low light intensities

Measured and modelled JV characteristics of crystalline silicon cells below one sun intensity have been investigated. First, the JV characteristics were measured between 3 and 1000 W/m² at 6 light levels for 41 industrially produced mono- and multi-crystalline cells from 8 manufacturers, and at 29 intensity levels for a single multi-crystalline silicon between 0.01 and 1000 W/m². Based on this experimental data, the accuracy of the following four modelling approaches was evaluated: (1) empirical fill factor expressions, (2) a purely empirical function, (3) the one-diode model and (4) the two-diode model. Results show that the fill factor expressions and the empirical function fail at low light intensities, but a new empirical equation that gives accurate fits could be derived. The accuracy of both diode models are very high. However, the accuracy depends considerably on the used diode model parameter sets. While comparing different methods to determine diode model parameter sets, the two-diode model is found to be preferred in principle: particularly its capability in accurately modelling V_OC and efficiency with one and the same parameter set makes the two-diode model superior. The simulated energy yields of the 41 commercial cells as a function of irradiance intensity suggest unbiased shunt resistances larger than about 10 kΩ cm² may help to avoid low energy yields of cells used under predominantly low light intensities. Such cells with diode currents not larger than about 10⁻⁹ A/cm² are excellent candidates for Product Integrated PV (PIPV) appliances.