运用"6 σ管理法"的思想改善安全管理

尝试将“6σ管理法”的思想引入安全管理活动中,把安全管理活动设计成一定的管理流程,通过分析流程中每个过程的偏差或缺陷,从而找出消除偏差或缺陷的方法并加以实施,追求安全管理的精细和完美,最终实现安全生产。     

基于优化组合赋权的煤层气开发风险评价研究

煤层气开发项目的高风险制约着我国煤层气产业的发展,为此,通过对煤层气开发风险因素的分析,基于煤层气开发特征构建由7个一级指标和34个二级指标构成的风险评价体系。运用离差平方和优化组合熵值法和三角模糊数法所得权重确定指标最佳权重,建立煤层气开发风险评价模型。最后,以沁水盆地南部柿庄南区块煤层气井为例进行实证评价,结果显示地质资源因素对该地区煤层气开发影响最大,其中渗透率的影响最为显著。研究表明:模型能优化主观评价和客观评价的赋权比重,最大化的减少主观因素对评价结果的影响,能客观合理的表达多指标间的对比差异,对煤层气开发风险进行可靠的定量化评价。为煤层气开发风险的控制和规避提供科学的理论依据。     

ESTIMATING PARAMETERS OF EV1 DISTRIBUTION FOR FLOOD FREQUENCY ANALYSIS1

ABSTRACT: The parameters of the extreme value type 1 distribution were estimated for 55 annual flood data sets by seven methods. These are the methods of (1) moments, (2) probability weighted moments, (3) mixed moments, (4) maximum likelihood estimation, (5) incomplete means, (6) principle of maximum entropy, and (7) least squares. The method of maximum likelihood estimation was found to be the best and the method of incomplete means the worst. The differences between the methods of principle of maximum entropy, probability weighted moments, moments, and least squares were only minor. The difference between these methods and the method of maximum likelihood was not pronounced.     

HAZOP技术实施程序

介绍了危险与可操作性分析(HAZards and Operability,HAZOP)技术的实施步骤,详细说明了每一步的工作内容及需要把握的关键.目标在于提供操作性强的实施程序,指导安全人员准确理解技术的内涵,科学、有效的应用该技术进行危害辩识,提高安全工作的水平.     

HAZOP分析核心技术

介绍了危险与可操作性(HAZOP0分析的核心内容,即如何划分分析节点,如何确定有意义的偏差,及分析偏差的原因、后果、安全保护措施时,应遵从哪些原则,从哪些方面去考虑.以进一步了解HAZOP分析的技术内涵,掌握HAZOP分析的技巧,更好的为安全生产服务.     

Modeling soil and plant phosphorus within DSSAT

The crop models in the Decision Support System for Agrotechnology Transfer (DSSAT) have served worldwide as a research tool for improving predictions of relationships between soil and plant nitrogen (N) and crop yield. However, without a phosphorus (P) simulation option, the applicability of the DSSAT crop models in P-deficient environments is limited. In this study, a soil-plant P model integrated to DSSAT was described, and results showing the ability of the model to mimic wide differences in maize responses to P in Ghana are presented as preliminary attempts to testing the model on highly weathered soils. The model simulates P transformations between soil inorganic labile, active and stable pools and soil organic microbial and stable pools. Plant growth is limited by P between two concentration thresholds that are species-specific optimum and minimum concentrations of P defined at different stages of plant growth. Phosphorus stress factors are computed to reduce photosynthesis, dry matter accumulation and dry matter partitioning. Testing on two highly weathered soils from Ghana over a wide range of N and P fertilizer application rates indicated that the P model achieved good predictability skill at one site (Kpeve) with a final grain yield root mean squared error (RMSE) of 535 kg ha⁻¹and a final biomass RMSE of 507 kg ha⁻¹. At the other site (Wa), the RMSE was 474 kg ha⁻¹ for final grain yield and 1675 kg ha⁻¹ for final biomass. A local sensitivity analysis indicated that under P-limiting conditions and no P fertilizer application, crop biomass, grain yield, and P uptake could be increased by over 0.10% due to organic P mineralization resulting from a 1% increase in organic carbon. It was also shown that the modeling philosophy that makes P in a root-free zone unavailable to plants resulted in a better agreement of simulated crop biomass and grain yield with field measurements. Because the complex soil P chemistry makes the availability of P to plants extremely variable, testing under a wider range of agro-ecological conditions is needed to complement the initial evaluation presented here, and extend the use of the DSSAT-P model to other P-deficient environments.     

基于IIAHP-Entropy-ssd的采空区遗煤自燃危险性评价模型及应用

为了能够对煤矿采空区遗煤自燃危险性进行准确判定,提出基于IIAHP-Entropy-ssd最优综合赋权模糊评价模型。首先,结合影响采空区遗煤的自燃性及环境影响因素,建立危险性评价指标体系,并确定各评价指标的分级准则;其次,利用区间数代替数值评价打分,并运用可能度互补矩阵进行修正的改进区间数层次分析法（IIAHP）,结合熵权法（Entropy）,根据现场实测数据,得出各评价指标的主、客观权重,并运用离差平方和（ssd）的最大化思想进行最优综合赋权,克服评价过程中主、客观因素对评价结果的影响,运用属性数学理论,建立各评价指标的隶属函数;最后,运用该模型对忻州窑矿8914综放工作面采空区遗煤自燃危险性进行评价,并与现场实际情况进行对比,结果表明:该模型的评价结果与实际情况基本一致,验证了该评价模型的准确性,为采空区遗煤自燃危险性评价提供参考和借鉴思路。