挥发性冲压油的研制

以异构烷烃为基础油研制的挥发性冲压油具有优异的挥发性能、润滑性能和防腐蚀性能,可用于铝翅片和铜管的加工.     

Physicochemical Characterization of a Heat Treated Calcium Alginate Dry Film Prepared with Chicken Stock

Solid sodium alginate was dissolved into chicken stock in order to give a final alginate concentration of 0.9 percent (w/v). Calcium ions present in chicken stock were enough to induce ionic gelation. After drying, Fourier transform infrared spectroscopy, thickness and mechanical properties of films obtained were determined. Calcium alginate‐chicken stock films were heated at 130 °C for different times between 0 and 15 min. Mechanical and optical studies, differential scanning calorimetry, visual aspect and scanning electron microscopy were carried out to describe physicochemical properties of heat treated films. Heating developed a maroon ochre color and increased the brittleness (crispness) of the films related to the intensity of the treatment. Differential scanning thermometry and study on appearance of the films suggested that Maillard reactions may be responsible for the observed changes. Maillard reactions mainly occurred between reducing sugar monomers and free amino groups of gelatin peptides present in the chicken stock, and between alginate and gelatin peptides to a lesser extent. In addition, the plasticizing effect of fat added with chicken stock was also studied. These studies suggest a potential use of heat treated chicken stock films as a substitute of roasted chicken skin.     

再生水行业最优资本结构的实证研究

确定最优资本结构对再生水项目的融资和行业发展具有重要的意义,本文采用基于公司股票价值最大化的最优资本结构研究模型,结合上市公司数据对再生水行业的最优资本结构进行实证分析,旨在为再生水行业的项目融资安排提供参考。     

基于离散数据的汽轮机叶片荒加工的研究

汽轮机叶片毛坯在铸造过程中变形严重,导致粗加工时余量分布极不均匀,提出了一种新的毛坯荒加工算法.该算法能直接从测量数据中生成荒加工刀位轨迹.首先将待加工曲面按照参数线进行网格划分成曲面片,然后采用投影的方法确定每个网格内的曲面片是否为可加工,并将这些可加工网格内的曲面片连接,从而获得荒加工区域.本算法剔除一般粗加工中无用的走刀路径,大大提高了复杂曲面类毛坯数控加工的效率.此算法避免了根据测量的离散数据点进行自由曲面造型,并通过曲面求交来获得荒加工区域.该算法已经应用于某汽轮机叶片的荒加工仿真,结果表明,该算法不仅效率高,而且结果非常理想.     

库存周转率在涂料企业库存管理中的应用

介绍了库存周转率的理论基础,结合企业的实际运用情况,论述了库存周转率在涂料产品库存管理中的重要作用及其在涂料企业库存管理中的具体应用:运用库存周转率,建立涂料产品库存管理分析模型,提高库存管理水平,并取得了较好的经济效益,涂料产品的库存金额大幅度减少。     

Computational modelling of industrial pulp stock chests

Agitated pulp stock chests are the most widely used mixers in pulp and paper manufacture. Stock chests are used for a number of purposes, including attenuation of high‐frequency disturbances in pulp properties (such as mixture composition, fibre mass concentration, and suspension freeness) and are designed using semi‐empirical rules based largely on previous experience. Tests made on both laboratory and industrial‐scale pulp chests indicate that they are subject to non‐ideal flows, including channelling and creation of dead zones. In the present work, a commercial computational fluid dynamic (CFD) software (Fluent) is used to model two industrial pulp stock chests. The first chest is rectangular, agitated using a single side‐entering impeller, and feeds a mixture of chemical pulps at 3.5% mass concentration (C_m) to a papermachine. The second chest has rectangular geometry, with a mid‐feather wall used to direct suspension flow through a U‐shaped trajectory past four side‐entering impellers. This chest is used to remove latency from a C_m = 3.5% thermomechanical pulp suspension ahead of stock screening. For CFD computations, pulp rheology was described using a modified Hershel–Buckley model. Steady‐state simulations were made corresponding to process conditions during mill tests. The calculated steady‐state flows were then used to determine the dynamic response of the virtual chests and then compared with experimental measurements and found to agree reasonably well. The computed flow fields provided insight into mixing processes occurring within the chests, showing cavern formation around the impellers (which reduced the agitated volume available for mixing). Mass‐less particle tracking, using the steady‐state flow field, gave insight into the stagnant regions and bypassing zones created in the vessels. This paper discusses difficulties encountered in characterising the mixing (both experimentally and computationally) and the limitations of the industrial data.     

1060铝合金铸轧板坯裂边的控制

倾斜式铸轧机浇注系统边部耳子是用硅酸铝纤维制成的。在生产1060铝合金板坯时,板坯裂边在8.5 mm左右。通过采用流线型成型耳子,控制铸轧速度、铸轧区长度、w(Fe)/w(Si)比值等,板坯裂边可以控制在3 mm左右。     

中外矿业资本证券市场对比分析及对我国的启示

全球主要证券交易所是矿业公司融资的重要场所。本文介绍了全球及我国主要矿业资本市场交易现状,并对全球主要矿业资本市场的特点和我国矿业资本市场所存在的问题进行了分析,从而对完善我国矿业资本市场提出了一些建议,我国矿业公司应以谋求在国外主要证券交易所上市为首选融资渠道,加快推进国有地勘单位企业化改革,建立多层次的矿业资本市场,修订我国矿产资源储量报告标准,同时完善我国矿业资本市场配套制度与中介服务体系。     

浅议存货监盘

存货监盘是一项核心的审计程序.文章就存货监盘的重要性,监盘计划的制订、监盘和抽查程序的实施,期间应注意的问题以及存货监盘结果的评估等进行了论述.