几种新型热作模具钢的性能对比研究

利用洛氏硬度计和冲击试验机对SDCM1、SDCM2、SDCM3、SDCM4等4种热作模具钢作硬度和冲击试验,得到了这4种钢的最佳热处理工艺参数。利用BAHR DIL805A相变仪、SDT CM600热重/DSC联用热分析仪、LFA 457激光导热系数测量仪等设备测量了这4种材料的膨胀系数、比热和热扩散系数。结果表明:SDCM3具有最佳的综合力学性能,SDCM4在这4种材料中具有最好的热作模具性能。     

Comparative Analysis of Three Methods for Stochastic Lumber Drying Simulation

Abstract:

This article describes a novel stochastic model designed to simulate systems that cannot be analyzed as a unit, but as a collection of a large number of similar components. In order to state advantages and disadvantages, the proposed method is compared with two other published models. The first is a symbolic mathematical relationship designed to predict average moisture content and standard deviation after conventional drying of lumber. Since this model is exact, it was used as reference to evaluate the accuracy of the other approximate numerical methods. The second model is entirely random, and it emulates a real system behavior in which the parameters and conditions randomly change from one component to the other. The proposed method is based on numerical integration of the parameter's frequency distribution curves, which always produce the same and most probable result for the same parameters and conditions. The three methods were applied for simulation of conventional lumber drying, and the results were compared both qualitatively and numerically.     

羧甲基淀粉作印花糊料的应用研究

本文介绍了以淀粉为原料制备羧甲基淀粉的合成方法及用作印花糊料的性能特点，并将之与海藻酸钠进行比较，证明羧甲基淀粉不仅价格低廉，而且性能较好，能代替海藻酸钠，是一种新型的印花糊料。     

Solid Fat Content Estimation by Differential Scanning Calorimetry: Prior Treatment and Proposed Correction

The objective of this work was to develop a corrected method for solid fat content estimation by differential scanning calorimetry (DSC), as important differences are usually observed between the results given by DSC and pulsed nuclear magnetic resonance (NMR). Cold storage after full melting of fats was necessary to avoid the appearance of exothermic peaks in the modulated temperature DSC thermograms, in order to make an appropriate estimation of melting energy. Different fats were analyzed by NMR and DSC, obtaining considerably higher solid fat content values with the latter, uncorrected method. These differences were attributed to the fact that consumed energy per unit of melted mass tends to increase with the increase of the melting temperature of each fraction of the fats. A linear correlation between melting enthalpy and melting point of different triglycerides was used to estimate the energy per unit of mass consumed at each temperature. From these data, an estimated transformation of melting energy into melted mass was performed and new solid fat content values were calculated. The results obtained from this correction were much closer to the measurements made by NMR, in comparison to the uncorrected DSC method.     

世界典型国家可再生能源政策比较分析及对我国的启示

本文回顾了美国、加拿大、德国、英国、丹麦、日本、巴西、印度和中国等典型国家的可再生能源发展历程,系统地介绍了这些国家的可再生能源激励政策,比较分析了各国政策的实施经验,以期为我国可再生能源政策的进一步完善提供决策参考。     

国内外矿业权流转制度比较研究

矿业权流转是矿业权市场管理的主要职责之一,为了实现资源的资产化管理,充分发挥市场优化配置资源的作用,促进矿业经济的可持续发展,对各国矿业权流转制度进行了比较,以期对改善我国矿业权制度起到借鉴作用.     

国内外矿业城市转型政策的比较与借鉴

从矿业城市经济结构、环境、就业和社会保障等方面分析了我国矿业城市面临的转型困境,介绍了国外矿业城市,如美国的休斯敦、德国比鲁尔区的转型经验,就制订投融资、财税、人才、环境等方面的政策提出了有益的建议。     

中直径ERW机组单卷和连续生产工艺的优缺点分析比较（下）

对中直径ERW机组是采用单卷生产工艺还是连续生产工艺,在国内焊管界存在较大的意见分歧。从产品规格、技术先进性、年生产能力、金属收得率、产品质量、能源消耗、投资等多个方面对单卷生产工艺和连续生产工艺进行分析比较,认为中直径ERW机组采用单卷生产工艺比连续生产工艺更具有优势,建议在建设中直径ERW机组时多采用单卷生产工艺。     

SY/T4109-2005与JB/T4730—2005射线检测标准对比分析

论述了执行新颁布SY/T 4109—2005标准在新建长输管道对接焊缝射线检测工艺和底片评定方面的实际应用。通过与JB/T 4730—2005标准的比较,突出了SY/T 4109—2005标准在长输管道射线检测应用中的实用性。     

GB3323—1987标准与ASME规范的比较和分析

对GB3323－1987标准和ASME规范的相关内容进行了比较和分析,提出了有关标准制订和应用方面的一些观点。