粮食粉爆事故分析与安全评估方法

通过对近20年来我国部分省市发生的重大粮食粉尘爆炸事故的分析，提出了防止粉尘爆炸的安全评价方法。     

A STUDY ON FRACTURE MECHANICS OF BRITTLE MATERIAL WITH PER-CRACKS

In this paper the fracture process of specimen,with single crack, double cracks and triple cracks is observed and analysed. The experimental results show that the fracture process of specimen is different because of the differention of the number, the distance and the type of array of cracks. And the fracture propagation of specimen with triple cracks and double cracks is foundmentally the same.     

A CATASTROPHE ANALYSIS OF THREE -POINT BEND ROUND BEAM SPECIMENS OF ROCK

The snap-back instability (also known as catastrophe behavior) .which may happen during the process of fracture testing with three-point bend round beam of rock .concrete and ceramic materials is analysed,an instability criterion for this kind of specimen is propoesd.it is different from that of the three-point bend rectangular beam.     

STABILITY FACTORS OF THREE-POINT BEND ROUND BEAM SPECIMENS FOR FRACTURE TESTING

Crack growth stability is very important for fracture toughness testing of brittle materials. The width of crack for a three-point bend round beam specimen changes continuously during the process of crack extension, so that the analysis of crack growth stability becomes complicated for this kind of specimen. This paper presents a method for calculating its stability factors, and the results of the calculation are compared with those of other specimens.     

STUDY ON MIXED MODE FRACTURE AND STRENGTH PROPERTIES IN ROCK UNDER COMPRESSION

Mixed mode fracture in rock subjected to compressive loading has many differ-ent features in fracture hehaviour from those subjected to tensile loading,especially when the aper-ture is partly or fully closed.The traditional theory of elastic fracttire mechanics can not be used tosolove compressive-shear fracture problem. Based on fracture characteristics of rock under compres-sion,the formulas to calculate stress intensity factor are updated so that the new strength criterion isevolved to evaluate the crack initiation streilgth.The stress distribution and the relative displacementof crack surface in central slit is confirmed by FEM analysis.     

A STUDY OF PHOTO-ELASTIC EXPERIMENT TO FRACTURE PROCESS OF LIMESTONE SPECIMEN WITH PRE-CRACKS

In this paper, the fracture process of specimen with pre-cracks is studied by using photo-elastic expe' merit.The analysis results of cracks stress field show that because the inter-effection appears between the the two cracks and the tensile fracture occured when the tensile stress concentration reaches to a certain degree, and cracks link up with each other, macroscopic failure will gradually result. Positions of cracks will have different effections to speciment's fracture.     

粮食干燥技术评价指标体系的构建

通过运用模糊综合评价法、层次分析法对粮食干燥技术构建评价指标体系,提出运用多级模糊综合评价方法以及全面的定量化和定性化的层次结构评价模式,通过300t/d玉米真空低温连续干燥实际案例进行综合评价,建立了塔型连续真空干燥设计方案的模糊综合评价、粮食干燥企业工艺优选模糊综合评价、粮食干燥品质质量AHP综合评价、粮食干燥整体效益AHP综合评价,结果表明四种综合评判体系的构建是可行的。     

A SKETCH DISCUSSION ON SCIENTIFIC DICISION OF STRATGIC IMPORTANCE IN SAFBTY INVESTMBNT OF FIRE PROTECTION

This paper presents a problem of scientific decision of strategic importance insafety in vestment of fire protection and discusses the scientific con notation,far-sightnese,two-wayability,sychronism and effectiveness of the problem.On the basis of similar action principle of deter-minable multifactors,the main point,strentth and the suggestions of scientific manage system insatfety investiment of fire protection are advanced.     

A MATHEMATICAL MODEL OF FUZZY EVALUATION METHOD FOR ENVIRONMENTAL POLLUTION

The problem of fuzzy evaluation of environmental pollution is importantboth in environment science and in environmental protection.Usual evaluationmethods have their own characteristics.This paper puts forward a mathematicalmodel of fuzzy evaluation method in grades by means of systematic analysisfor environmental pollution.At the same time,it assigns weighted values byordering based on paired comparison.     

A COMPARATIVE STUDY ON QUANTITATIVE EVALUATION METHODS FOR DIRECT INVESTMENT ENVIRONMENT

ABSTRACT This paper discusses the most representative and practical quantitative evaluation methods of direct investment environment at home and abroad, analyses them deeply and comprehensively in the form of comparative study, and points out some further studying perspectives of the quantitative methods of direct investment environment.     

模糊综合评价分析两种生物农药对玉米储藏品质的影响

应用模糊综合评价研究了蛇床子素和多杀菌素两种生物农药拌粮防治储粮害虫的同时对玉米储藏品质的影响。在玉米储藏4个月、8个月和10个月时,分别构建稻谷储藏品质变化的模糊综合评价模型的指标矩阵,先用极差变换及线性比例变换对指标矩阵进行无量纲化处理,再用夹角余弦法确定权重向量,最后得到模糊综合评价值,并用拉依达检验法检验,确定了该评价模型的可行性。结果显示:综合评分值H和F均小于2s(2s相当于显著水平α=0.05),由此可以看出,各样品不显著,即拌以0.5 mg/kg、0.75 mg/kg、1.0mg/kg的1%蛇床子素粉剂和0.5mg/kg、1.0mg/kg、1.5mg/kg的0.5%多杀菌素粉剂的两种生物农药对玉米的储藏品质在10个月内没有显著影响,并且为粮食品质储藏研究工作提供了一个重要的认识工具。     

A FRACTURE MECHANICS ANALYSIS OF FRACTURE PLANE CONTROL IN FRACTURE CONTROL BLASTING

A procedure of fracture control blasting for achieving directional breaking of rocks by blasting is presented. The criterion for initiating of radial cracks in borehole wall under dynamic load and the method for determining the permissible rang of initial gas pressure (p0) in the charge cavity are developed .and the branching of radial cracks and the effeets of the pressure (p0) and blasthole geometry (R0.a.L3) on final dimensions of directed cracks are studied .with Fracture Mechanics analysis in all three aspects of fracture process including crack initiation .crack propagation and crack arrest.     

A FUZZY COMPREHENSIVE EVALUATION METHOD BASED ON STANDARD INDEXES

A method of fuzzy comprehensive evaluation based on standard indexes is presented. This method regards all sorts of standard indexes of evaluation objects as basic evaluation standards. Its main setps are: (1 )obtain evaluation parameters(all kinds of parameters which decide main performances of evaluation objects)and set up evaluation parameter matrix; (2) determine satisfaction degrees of various parameters and set up satisfaction degree matrix; (3) determine the weight of various prarmeters and set up the weight set; (4) make comprehensive evaluation and obtain evaluation result. Its common program is worked out and the typical example is presented.     

THE PERFORMANCE EVALUATION OF RELATIONAL DATABASE ON B~+ TREE INDEX

An approach for evaluating the performance of relational database is introduced, the stroage cost, responding time and maintenance ccst oi a relational database based on B+ tree index are theoretically analyzed, and the evaluation model is proposed     

粮油品质分析质量保证机制的探讨

根据粮油质量分析的特点,提出了粮油品质分析质量保证的管理系统设计,概括了保证分析质量的分析方法评价和分析质量评价的主要方法。     

ON THE UTILITY SUM OF ACCUMULATED PRESENT VALUE FOR THE ECONOMIC EVALUATION OF INVESTMENT PROJECT

To counteract the weakness of Net Present Value, a new index, the utility sum of accumulated net-cash-flow present value, is put forward in this paper.     

应用灰色关联分析法综合评估小麦高分子量麦谷蛋白亚基的研究

本文利用在河南种植的72个小麦品种面包烘烤品质指标的试验资料,借助于灰色关联分析法,对11种高分子量麦谷蛋白亚基进行了综合评估.结果表明:等权关联度与加权关联度分析结果基本吻合;Glu-1D5+10亚基对小麦烘烤品质的贡献最大;各亚基的关联度排序与其实际烘焙功能相一致.同时认为,采用多个品质指标的综合评估结果制定HMW麦谷蛋白亚基的评分系统,可能比用单一指标制定的评分方法更可靠.     

A DISCUSSION ON THE RATIONAL FORMULA OF DOSING LIME AMOUNT

This paper analyses the change of raw water quality by the addition of coagulant and the existing form of Fe and H_2 SiO3 in the water and their effects on lime dosage. On the basis of this analysis, the existing formulas of lime dosage is revised, and rational formula derived, which agrees with practice     

对十种林木病原真菌拉丁学名的讨论

本文对十种林木病原真菌的拉丁学名进行了讨论.这些学名,有的为裸名,有的为同物异名,有的值得再商榷,但这些名称目前在国内使用很普遍,故提出来加以讨论和订正,以期引起注意,避免混乱.例如文中对我国的白杨锈病病原菌学名改用Melampsoraaecidioides plowr以取代M.magnusiana Wagn和M.rostrupiiwagn的建议,希望得到指正.