基准相态为气相的液态烃物理(火用)计算

指出了在石化企业中掌握在不同状态下轻烃类物理焓、熵及 计算方法的重要意义.从5个方面重点对基准相态为气相的液态烃焓、熵及 的计算方法进行了详细的分析探讨:(1)在气相轻烃单体从基准状态被等温压缩至其饱和蒸气压而开始液化前的焓、熵及(火用);(2)在可逆相变过程中的焓为该物质的蒸发潜热,在该相变过程中的焓、熵及(火用);(3)把液相变压过程中的液相性质看成与压力无关;(4)在液相变温过程中轻烃单体的焓、熵及(火用);(5)轻烃类混合物的焓、熵及 .最后,以炼油过程中轻烃单体及其混合物物理 的计算作为实例来说明这些计算策略的应用.     

无分流换热网络的弹性设计(Ⅰ)基于温度波动情形

提出了基于温度波动的无分流换热网络的超结构模型和同步优化的弹性设计方法。对于起始温度在一定范围内波动的物流进行预处理即分段处理,并提出了分段原则;提出了基于规则的网络超结构模型并建立了弹性换热网络同步优化的数学模型;采用遗传算法求解了所提出的优化数学模型;提出了分段物流的合并及能量松弛的原则,对分段物流进行合并,并通过能量松弛方法得到优化的弹性换热网络结构。通过几个换热网络的弹性设计,说明了本方法的有效性和应用前景。     

采用双(多)壳程换热器来促进换热网络的进一步优化

文中从过程工业换热流程优化的角度论述了采用双（多）壳程换热器的重要性和必要性,并从单个匹配和整个换热网络两方面进行了理论分析,指出采用双（多）壳程换热器具有降低换热器投资,提高换热网络热回收率和过程系统的能量综合优化化水平等多重效果。     

一种非线性控制的正弦波逆变器的研究

提出了一种基于ｏｎｅ－ｃｙｃｌｅ非线性控制的ＤＣ４８Ｖ／ＡＣ２２０Ｖ正弦波逆变器,详细阐明了控制原理,进行了谐波分析,仿真结果证明主出版社为器具有优良的抗线扰动性和限随性能。     

9274份肉及肉制品食源性致病菌监测结果分析

目的 了解吉林省9274份肉及肉制品食源性致病菌污染情况,为防控食源性疾病提供科学依据。方法从吉林省9个地市级行政区采集市售6类肉及肉制品样品共9274份,包括生畜肉、生禽肉、熟肉制品、调理肉制品、冷冻肉糜制品和动物血液及制品。按照国家标准方法检测10种食源性致病菌。结果 全部9274份样本食源性致病菌总阳性检出率为3.9%(366/9274)。检出率最高为调理肉制品 (13.0%,63/483),其次是生禽肉(5.6%,107/1900)和生畜肉(5.0%,71/1428)。检出的主要致病菌为单核细胞增生李斯特菌、金黄色葡萄球菌和沙门菌。生禽肉中弯曲菌检出率(7.5%,31/411)和产气荚膜梭菌检出率(3.9%,7/180)均高于沙门菌检出率(3.5%,8/231)。生禽肉、生畜肉中未检出小肠结肠炎耶尔森菌。动物血液及制品未检出单细胞增生李斯特菌、弯曲菌和小肠结肠炎耶尔森菌。冷冻肉糜制品未检出沙门菌。熟肉制品未检出大肠埃希氏菌O157、志贺菌和蜡样芽胞杆菌。熟肉制品各年度检出率范围为1.3%-4.4%。结论 吉林省市售的肉及肉制品较长时间受到不同程度的食源性致病菌污染,存在食源性疾病发生的风险。     

稳定型悬索桥与普通悬索桥固有振动对比研究

用含索组合有限元模型模拟稳定型悬索桥和普通悬索桥,考虑结构几何非线性特征,导出了系统广义特征方程,计算了两桥型前十阶特征对,对比分析了稳定型悬索桥及普通悬索桥垂直—扭转耦合固有振动。结果表明．稳定型悬索桥具有良好时自振特性。     

煤矿瓦斯灾害风险隐患大数据监测预警云平台与应用

瓦斯灾害仍然是我国深部煤矿开采的主要灾害,随着采深及开采强度的加大,危险性日趋严重.瓦斯灾害影响因素及耦合关系非常复杂,灾害事故时有发生.基于安全监测大数据进行瓦斯灾害和风险隐患一体化分析预警已成为煤矿安全管理、监管和监察的迫切需求.分析了瓦斯灾害与风险隐患的大数据特征,提出了基于安全监测大数据的瓦斯灾害风险隐患识别与...     

不同岩性整形机制砂混凝土的力学性能研究

整形机制砂具有优异的力学性能,因而在传统建材中能够替代河砂而得到广泛地应用。为了研究整形后不同岩性及大掺量整形机制砂混凝土的力学性能,利用塌落度筒和混凝土流变仪测试混凝土工作性能和流变性能,同时进行抗压强度的力学性能试验。结果表明;整形机制砂混凝土的塌落度随着机制砂掺量的增加而降低,同时其塑性粘度和抗压强度随着整形机制砂掺量的增加呈现先升高后降低的趋势;整形鹅卵石和整形花岗岩混凝土的屈服强度均随掺量的增加而降低,整形山砂混凝土的屈服强度与塑性粘度的变化相一致;整形鹅卵石、整形花岗岩及整形山砂在机制砂混凝土中的最优替代率分别为30%、40%和50%,而整形山砂在工作性能、流变性能和力学性能上方面均优于整形鹅卵石和整形花岗岩。     

A process performance index and its application to optimization of the rtm process

Resin transfer molding (RTM) is a promising manufacturing process for hig formance composite materials. However, the fact that RTM process design has traditionally been an expensive, time‐consuming trial‐and‐error procedure has p ited its wide application base. This paper proposes a solution to that problem—a simulation‐based optimum process design scheme for RTM. This scheme ei engineers to determine the optimum locations of injection gates and vents so both process efficiency and high part quality can be ensured. Essential to this mum process design scheme is a process performance index, which is defined respect to the major factors influencing RTM process efficiency and part quality This index is then used as the objective function for the RTM process design optimization model. Gate and vent locations are the process design parameters optimized. All data is obtained by running an RTM simulation program, and th netic algorithm (GA) is employed to carry out the optimization procedure for design parameters. It is found that constant pressure optimization will yi process with a short flow path, whereas constant flow optimization will yield process with smooth and vent‐oriented flow pattern. Although there is no dry factor in the objective function, it is interesting to note that both constant pres and constant flow optimization procedures result in process designs with a mil mum probability of dry spot formation. This study finds that, in general, cons flow optimization should be employed if injection pressure is not a major cone otherwise, constant pressure optimization should be used. Two case studies presented to illustrate the efficacy of this approach.     

Evaluation of corrosion behaviour of a new class of Pb‐free solder materials (Sn‐In‐Zn)

In view of the need for a lead‐free drop in replacement for the widely used 40Pb‐60Sn near eutectic solder, new Sn‐In‐Zn based alloys with substantially the same melting point have been developed. The corrosion resistance and the influence of zinc content on electrochemical behaviour of some special alloys Sn‐In‐Zn in 3% NaCl solution has been investigated using electrochemical techniques. The good resistance of this ternary system is confirmed. In decreasing dissolution rate, they are ranked as follows: 40Pb‐60Sn, Sn‐10.6In‐27Zn, Sn‐11In‐23Zn and Sn‐13In‐12Zn. The increase of zinc content induces a decrease of corrosion resistance of ternary Sn‐In‐Zn alloys. So, the Sn‐In‐Zn system with low indium and zinc concentrations might be a good candidate for solder materials and present a good corrosion resistance.