结构地震多因素模糊破坏评估

本文考虑结构破坏模糊性,把它作为模糊破坏集合概念来处理,同时也考虑到结构地震破坏是多因素造成的综合结果,采用模糊数学中的综合评判方法,提出了结构在地震动作用下的多因素模糊破坏评估方法.     

Statistical evaluation of a liquid desiccant dehumidification system using RSM and theoretical study based on the effectiveness NTU model

In the present study the performance of an air dehumidifier using lithium bromide (LiBr) as a desiccant was investigated. Response surface methodology (RSM) was used to assess individual and interactive effects of the six main factors (velocity, temperature and humidity of air, flow rate, temperature and concentration of desiccant) on dehumidification mass rate. A reduced quadratic statistical model was derived to predict dehumidification mass rate. The maximum dehumidification mass rate was obtained 0.154 g/s under the optimal conditions of an air velocity of 4.1 m/s, desiccant flow rate of 0.035 kg/s, air humidity ratio of 0.0185 kg/kg, desiccant concentration of 0.48 kg/kg, air temperature of 29.5 °C, and desiccant temperature of 21.8 °C. The effectiveness number of transfer unit (NTU) model was employed to describe the coupled heat and mass transfer. The results of the model and the experimental data show good agreement. Dimensionless mass and heat transfer coefficients correlations are proposed; the average absolute differences between the predicted values and the experimental findings for Sh and Nu numbers were calculated as 2.14% and 5.27%, with the discrepancies mainly within ±9% and ±13%, respectively.     

煤层气储层的测井评价方法研究综述

煤层气储层的测井评价方法研究,一直以来都是研究人员关注的一个重点。总结了煤层气测井技术发展现状、煤储层的特点以及相关的测井响应、储层参数的测井评价方法,指出存在的问题及下一步工作要点。     

Elastoplastic Finite Element Analysis and Strength Evaluation of Adhesive Butt Joints of Similar and Dissimilar Hollow Shafts Subjected to External Bending Moments

Stress distributions and deformation of adhesive butt joints are analyzed by an elastoplastic finite element method when the joints of similar and dissimilar shafts are subjected to external bending moments. The effects of the ratio of Young's modulus for the adherends to that for an adhesive and the effects of the adhesive thickness on the interface stress distribution are investigated. Joint strength is predicted by using the elastoplastic interface stress distributions. It is found that the singular stress at the edge of the interfaces increases with an increase of the ratio of Young's modulus. Measurement of strains in joints and experiments on joint strength were conducted. The numerical results are in fairly good agreement with the experimental results. It is observed that the joint strength for dissimilar shafts are smaller than those for similar shafts. A fracture of dissimilar adhesive up-bonded shafts occurred from the interface of the adherend with smaller Young's modulus. It is seen that joint strength increases as the adhesive thickness increases.     

Analysis of seed oil from ricinus communis and dimorphoteca pluvialis by gas and supercritical fluid chromatography

The seed oils from Dimorphoteca pluvialis and Ricinus communis contain hydroxy fatty acids. Dimorphoteca pluvialis contains Δ-9-hydroxy-10t, 12t-octadecadienoic acid (dimorphecolic acid) and R. communis contains Δ-12-hydroxy-9c-octadecenoic acid (ricinoleic acid). The oils were derivatized and analyzed to determine the content of hydroxy fatty acids. The trimethylsilyl fatty acid methyl ester (TMS-FAME) derivatives were analyzed by capillary gas chromatography (GC), and the free fatty acid (FFA) derivatives and the oils were analyzed by capillary supercritical fluid chromatography (SFC). Further, mass spectroscopy of the TMS-FAME derivatives was performed to check the purity of the derivatives. The results from the GC analyses of TMS-FAME corresponded to the results found by SFC analysis of the FFA. The content of ricinoleic acid in the glycerolipids of R. communis was 87.7 wt%, and the content of dimorphecolic acid in D. pluvialis was 54.0 wt%. The methods were evaluated with respect to the cost, ease, and time needed for sample preparation and analysis.     

论我国环保资金项目绩效评价指标体系的构建

环保专项资金项目的绩效评价工作在我国尚处于探索阶段,为科学、定量评价环保专项资金项目实施绩效,采用目标预定与实施效果比较法,在将现行环保专项资金支持项目分成六大类的基础上,构建了适用于当前我国环保专项资金项目特点的绩效评价指标体系,以期为我国环保专项资金项目绩效评价提供可借鉴的依据。     

西南地区煤炭矿区规划环境影响评价指标体系探析

以矿区规划环评导则以及相关法律法规的要求为基准,按照西南地区煤炭矿产资源分布现状及矿区规划特点,针对西南地区自然环境背景、矿区开采特点及已经存在的矿区环境问题,结合国内外研究成果提出了西南地区煤炭矿区规划环境影响评价指标体系及指标值。     

一种咪唑啉缓蚀剂的合成及评价

以硬脂酸、羟乙基乙二胺为原料,制备了咪唑啉类缓蚀剂ZW-1,利用失重法和极化曲线法评价了缓蚀剂ZW-1在不同浓度下的缓蚀性能,通过环境扫描电子显微镜扫描腐蚀钢片表面形貌,对其所形成缓蚀膜进行了表征。结果表明,当以饱和CO2及3.0%氯化钠为腐蚀介质,缓蚀剂质量浓度为400 mg/L时,缓蚀率可达到98%。同时极化曲线表明,缓蚀剂ZW-1是一种混合型缓蚀剂。     

模糊综合评判法在洗手液感官评价中的应用

构建了洗手液的模糊综合评判模型,综合考察了洗手液感官品质的气味、分散性等因素,采用权重分配方案和乘法算子,获得了洗手液感官评价各评定项目的权重、相应的隶属函数和评价标准,由此建立了洗手液使用品质的感官评价体系和方法。利用该评价体系,对3种不同配方洗手液样品进行感官评价。结果表明,评判结果与实际情况完全吻合。     

黑龙江省典型蔬菜大棚土壤重金属污染评价

为探索黑龙江省典型大棚土壤中重金属Cu、Zn、Cd的污染状况,采用单因子与限值比较、综合因子指数法和相关系数法对污染情况进行综合评价。结果表明:除肇东2a、肇东6a棚龄无污染外,其他大棚均有不同程度的污染;五常8a、肇东11a棚龄属轻度污染,其他棚龄均达中污染程度,而且五常大棚综合污染程度较肇东严重。Cu、Zn、Cd与棚龄之间的相关系数显示,各元素与棚龄之间存在着相关关系。五常大棚Cu、Zn、Cd与棚龄呈显著相关(P<0.05),相关程度Cu>Cd>Zn;肇东大棚Cu、Zn、Cd与棚龄之间达极显著相关(P<0.01)。