Recursive Operability Analysis as a decision support tool for Risk-Based Maintenance

This work was developed with the support of MEMC, one of the most important producers of ultra-pure silicon wafers for electronic applications throughout the world. The availability of ultra-pure water is of prime importance in the silicon production process. In order to maximize the availability of UP water, MEMC has developed a preventive maintenance program and a detailed record of each maintenance intervention is recorded. This has allowed a complete failure rate data bank to be developed. In order to optimize the maintenance intervention, a Recursive Operability Analysis (ROA) has been used as a decision support tool. The results of the ROA, coupled with the failure rates, have made it possible to calculate the expected number of events (ENE) of various top events (TEs). The magnitude of each TE has been estimated on the basis of the monetary losses provoked by each event. The risk then has been calculated and the events ranked on this basis. Maintenance policies have been optimized with the aim of reducing the risk of the top ranked events.     

飞行数据可视化技术研究

针对航空器事故调查和不安全事件分析的结果及改进的需要,研究基于FDR/QAR/DAR/CVR的数据可视化技术。提出基于飞行仪表布局语言(FILL)的仪表模型构建与驱动的技术方案,解决FDR/QAR/DAR记录数据的导入与修正处理、不同分辨率三维地形的生成与显示以及飞行数据与驾驶舱话音同步播放等问题。实践证明,利用数据可视化技术所构建的包括飞机、航迹、仪表、地形、跑道、航图等元素的三维图形飞行环境集成再现了飞行过程,为事故调查和事件分析提供了科学有效的辅助分析工具。     

Using SWAT to Model Streamflow in Two River Basins With Ground and Satellite Precipitation Data1

Abstract: Both ground rain gauge and remotely sensed precipitation (Next Generation Weather Radar – NEXRAD Stage III) data have been used to support spatially distributed hydrological modeling. This study is unique in that it utilizes and compares the performance of National Weather Service (NWS) rain gauge, NEXRAD Stage III, and Tropical Rainfall Measurement Mission (TRMM) 3B42 (Version 6) data for the hydrological modeling of the Middle Nueces River Watershed in South Texas and Middle Rio Grande Watershed in South Texas and northern Mexico. The hydrologic model chosen for this study is the Soil and Water Assessment Tool (SWAT), which is a comprehensive, physical‐based tool that models watershed hydrology and water quality within stream reaches. Minor adjustments to selected model parameters were applied to make parameter values more realistic based on results from previous studies. In both watersheds, NEXRAD Stage III data yields results with low mass balance error between simulated and actual streamflow (±13%) and high monthly Nash‐Sutcliffe efficiency coefficients (NS > 0.60) for both calibration (July 1, 2003 to December 31, 2006) and validation (2007) periods. In the Middle Rio Grande Watershed NEXRAD Stage III data also yield robust daily results (time averaged over a three‐day period) with NS values of (0.60‐0.88). TRMM 3B42 data generate simulations for the Middle Rio Grande Watershed of variable qualtiy (MBE = +13 to ?16%; NS = 0.38‐0.94; RMSE = 0.07‐0.65), but greatly overestimates streamflow during the calibration period in the Middle Nueces Watershed. During the calibration period use of NWS rain gauge data does not generate acceptable simulations in both watersheds. Significantly, our study is the first to successfully demonstrate the utility of satellite‐estimated precipitation (TRMM 3B42) in supporting hydrologic modeling with SWAT; thereby, potentially extending the realm (between 50°N and 50°S) where remotely sensed precipitation data can support hydrologic modeling outside of regions that have modern, ground‐based radar networks (i.e., much of the third world).     

硫酸锰渣污染土壤中重金属的形态分布及生物活性

测定了硫酸锰渣污染土壤中Cu,Zn,Cd,Pb,Mn的总量和各形态含量.结果表明重金属总量远超过环境背景值和土壤环境二级标准.重金属各形态分布特征:Cu,有机态>残渣态>铁锰氧化态>碳酸盐态>可交换态;Zn,残渣态>铁锰氧化态>有机态>碳酸盐态>可交换态;Cd,铁锰氧化态>可交换态>碳酸盐态>残渣态>有机态;Pb,铁锰氧化态>残渣态>有机态>碳酸盐态>可交换态;Mn,铁锰氧化态>残渣态>可交换态>有机态>碳酸盐态.重金属的生物可利用性系数和迁移系数均为Cd>Mn>Pb>Cu>Zn.     

我国信息系统数据结构标准对比研究

数据结构是信息系统的核心,建立数据结构标准是建立高效、统一、高度共享的信息系统的重要保障。本文介绍了我国信息系统数据结构标准的研究进展,并对信息系统数据结构标准从建立的时间、分布的行业和内部的数据元属性三个不同的角度进行了对比研究,总结发现了目前我国信息系统存在的主要问题、以及数据结构标准在信息系统建设和促进数据共享中所起的重要作用以及存在的主要矛盾,并提出了针对作业场所职业危害监管信息系统基础数据结构标准化过程中可能存在的主要问题以及拟采用的解决方法。     

作业场所职业危害基础数据标准设计

作业场所职业危害基础信息数据标准是避免信息孤岛现象,促进数据共享和作业场所职业危害相关信息系统建设的重要基础。本文介绍了数据元的主要分类方法,并采用面分类方法和线分类方法相结合的方法对作业场所职业危害基础信息数据进行分类,通过面分类方法设计了合理的作业场所职业危害基础信息数据元对象类,通过线分类方法将作业场所职业危害基础信息数据元划分到不同的对象类下,并阐述了作业场所职业危害基础信息数据标准设计的内容和方法。     

TiO_2/PTh/Fe_3O_4催化剂制备及光催化与磁回收性能

以聚噻吩磁性微珠PTh/Fe3O4(PF)为载体,采用低温水热法(170℃,pH=7±0.2)在其表面负载TiO2,制备了壳/壳/核结构的磁载光催化剂TiO2/PTh/Fe3O4(TPTF)。用透射电子显微镜(TEM)、X射线衍射仪(XRD)、傅里叶红外分光光度计(FT-IR)、振动样品磁强计(VSM)对催化剂的形貌、物相组成、表面性质、磁学性质进行了表征。以苯酚为模拟污染物,评价其光催化活性;通过自制的磁回收装置,考察其磁回收特性。结果表明,TiO2晶粒大小在4~6 nm之间,具有混晶结构(锐钛矿型占93.6%,金红石型占6.4%);当nTiO2∶n噻吩单体∶nFe3O4=75∶2.5∶1时,TPTF的催化活性最佳;P25、纯TiO2、TPTF(nTiO2∶n噻吩单体:nFe3O4=75∶2.5∶1)和TiO2/Fe3O4(TF)光催化降解苯酚的速率常数分别是0.0371、0.0302、0.0253和0.0106 min-1;TPTF循环使用5次,其反应速率常数、饱和磁化强度以及磁回收率为0.0205 min-1、1.59emu/g和89.3%,比第1次的0.0253 min-1、1.85 emu/g和94.7%略有降低。     

吸附剂浓度对Zn(Ⅱ)和Cd(Ⅱ)在高岭土上吸附的影响

研究了吸附剂浓度(Cs)对Zn(Ⅱ)和Cd(Ⅱ)在高岭土上吸附的影响。结果表明,随Cs增大,吸附等温线下降,呈现出明显的吸附剂浓度效应(Cs-effect)。采用经典Langmuir和Freundlich吸附等温式对吸附数据进行拟合表明,在给定Cs下,Zn(Ⅱ)和Cd(Ⅱ)的吸附等温线分别符合Langmuir和Freundlich等温式;但这2个等温式不能描述或预测Cseffect,模型参数与Cs有关,与模型理论预测相悖。为解释和描述固/液界面吸附中的Cs-effect,我们近期提出了表面组分活度(SCA)模型,并推导出了Langmuir-SCA和Freundlich-SCA等温式。采用SCA模型等温式对吸附数据进行拟合表明,Langmuir-SCA和Freundlich-SCA等温式可分别准确地描述Zn(Ⅱ)和Cd(Ⅱ)在高岭土上吸附的Cs-effect结果,证明SCA模型是合理的。     

城市垃圾焚烧渗沥液中Ca2＋对厌氧EGSB处理效果的影响

研究了城市生活垃圾焚烧厂渗沥液中Ca2＋对厌氧颗粒污泥膨胀床反应器（EGSB）处理效果的影响,并采用静态实验方法考察了Ca2＋对厌氧颗粒污泥产甲烷活性的影响。实验结果表明,进水COD为17000mg／L的条件下,当Ca2＋浓度低于6000mg／L时,EGSB对COD去除率达93％以上;当Ca2＋浓度高于6000mg／L时,COD去除率随运行时间明显下降,并在污泥中形成大量沉淀。静态实验结果表明,废水中低浓度Ca2＋促进了厌氧颗粒污泥的产甲烷活性,但高浓度Ca2＋明显抑制了其产甲烷活性,这是导致高Ca2＋浓度条件下EGSB对COD去除率降低的主要原因。研究表明,颗粒污泥产甲烷活性恢复程度随Ca2＋浓度增加而减弱。     

磺胺和四环素类抗生素对活性污泥性能的影响

废水处理工艺中抗生素类污染物的存在可能会对生物处理过程产生长期而深远的影响,为探明此类污染物对废水生物处理主体活性污泥性能等方面的影响,采用间歇培养法研究了活性污泥法处理污水时,抗生素类污染物的存在对活性污泥性能如胞外聚合物（EPS）、污染物处理能力、脱氢酶活性和群落结构的影响。结果表明,抗生素的存在会导致活性污泥的胞外聚合物总量及其主要组分蛋白质和多糖增加,以产生保护屏障;且由于污泥絮体解体,细胞破裂导致EPS中DNA和色氨酸含量增加。同时,由于蛋白质大量增加引起的表面负电荷的增加,使污泥疏水性增强,絮凝性能恶化;污泥絮体解体导致污泥颗粒变小,SVI也随之下降;在活性污泥脱氢酶活性急剧下降的同时,出水TOC迅速升高。此外,抗生素类污染物在抑制活性污泥中大部分细菌的同时,对部分菌群也有刺激生长作用,最终导致活性污泥生物群落结构的改变。四环素类抗生素对活性污泥的EPS和絮凝沉降性能的影响大于磺胺类,而对污水处理能力和群落结构的影响则不如磺胺类。抗生素类污染物的长期存在会对活性污泥沉降性能、絮凝性能、脱氢酶活性以及活性污泥群落结构等产生一系列负面影响,进而影响污染物去除效果,导致出水水质恶化。