N-TuF50高强钢球罐裂纹焊接修复

分析N-TuF50钢球罐裂纹的原因。提出焊接修复裂纹的方案,确定补焊用焊接材料的原则,进行焊接模拟试验。     

带修复操作整型编码遗传算法求解大规模机组组合问题

针对发电机组组合调度问题,提出了一种带修复操作的整型编码遗传算法(r-ICGA)。算法采用整数串的编码方式,有效减小了染色体的长度。同时引入一组新的修复操作来处理约束,将进化过程中产生的新个体修复成为可行个体。与罚函数约束处理方法相比,所提算法不引入惩罚项,避免了针对不可行解的经济负载分配子问题求解,节省了大量计算时间。将所提方法应用于六种不同规模的机组组合问题,仿真结果表明算法的搜索效率更高,求得的调度结果更好。随机组规模增大,算法所需执行时间近似线性地平缓增长,表明r-ICGA算法比其他方法更适合于求解大规模机组组合调度问题。     

袋式除尘器滤饼固定化研究

为研究滤饼微观结构,对滤饼固定化方法进行了研究。首先介绍了传统的树脂包埋法,分析了该方法的优缺点。提出了一种新型的滤饼固定化方法——羧甲基纤维素钠(CMC)黏合法。经检测证明,CMC黏合法固定过程耗时短,方法简单,可真实反映滤饼结构。     

Method for quantitative evaluation of kinetic constants in olefin polymerizations. I. Kinetic study of a conventional Ziegler–Natta catalyst used for propylene polymerizations

A method for quantitative evaluation of kinetic constants in Ziegler–Natta and metallocene olefin polymerizations is presented. The method comprises some fundamental steps, which include the initial design of a statistical experimental plan, the execution of the designed experiments, the development of simple mathematical models to describe the polymerization, and the estimation of kinetic parameters from available rate, gel permeation chromatography, and NMR data. The method is applied to the slurry propylene polymerization, using a conventional first generation Ziegler–Natta catalyst, in a lab‐scale polymerization reactor. It is shown that the proposed method allows the successful interpretation of experimental olefin polymerization data and the quantitative evaluation of kinetic constants, which can be inserted into a process simulator to provide an accurate picture of actual industrial plant behavior. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2076–2108, 2001     

Rapid isolation of microsomes for studies of lipid peroxidation

Conventional isolation of microsomes by high-speed centrifugation from isotonic sucrose requires exposure to air for several hours, leading to the formation of low levels of lipid peroxidation products. Sucrose interferes in protein and malondialdehyde assays and provides no protection against lipid peroxidation during workup. A new procedure for the purification of microsomes from rat liver substitutes mannitol (a hydroxyl radical scavenger) for sucrose and takes advantage of the properties of morpholinopropane sulfonic acid (MOPS) buffer and triethylenetetramine to provide protection against lipid peroxidation during the rapid (less than one hour) workup and subsequent low-temperature storage. The microsomal fractions prepared by the proposed method are free of detectable mitochondrial contamination and at least as pure overall as those prepared by the conventional method, but they have higher glucose-6-phosphatase and laurate hydroxylase activities and significantly less malondialdehyde than conventional microsomes at the time isolation is complete. Laurate hydroxylase activity is more stable during frozen storage in mannitol medium. The kinetics of lipid peroxidation in vitro are quite different for microsomes prepared by the two methods.     

球形/球柱形微胶囊自修复水泥基复合材料修复效率数值模拟

水泥基复合材料因其固有的脆性和较低的抗拉强度,在工程结构中不可避免会发生开裂。胶囊法自修复系统为水泥基材料基体开裂的修复和延缓潜在危害提供了一种可行的方法。借助扩展有限元方法,模拟了微胶囊自修复水泥基模型材料内微裂缝的产生、扩展、断裂过程及胶囊破裂行为,验证了裂缝迫使胶囊发生破裂的概率;应用复合材料理论,计算出了不同掺量下球形/球柱形微胶囊修复前后水泥基复合材料的有效弹性模量,表征了该复合材料的修复效率。     

Solving mixed-integer nonlinear programming problems using improved genetic algorithms

This paper proposes a method for solving mixed-integer nonlinear programming problems to achieve or approach the optimal solution by using modified genetic algorithms. The representation scheme covers both integer and real variables for solving mixed-integer nonlinear programming, nonlinear programming, and nonlinear integer programming. The repairing strategy, a secant method incorporated with a bisection method, plays an important role in converting infeasible chromosomes to feasible chromosomes at the constraint boundary. To prevent premature convergence, the appropriate diversity of the structures in the population must be controlled. A cross-generational probabilistic survival selection method (CPSS) is modified for real number representation corresponding to the representation scheme. The efficiency of the proposed method was validated with several numerical test problems and showed good agreement.     

基于流程模拟的常减压装置过程操作与生产计划集成优化

传统的炼油企业生产计划优化与过程操作优化往往是分离的, 从而造成生产计划优化系统制定出的生产方案可能在实际的生产装置操作上无法实现的情况。为了确保石化企业生产计划制定的方案可行的同时实现过程装置操作优化, 基于流程模拟软件建立了常减压蒸馏装置生产计划与过程操作的集成优化策略, 并提出了该优化策略的有效寻优方法。该方法通过流程模拟软件验证生产计划的可达性, 不断修正生产计划关键变量的优化区间, 在求得生产计划最优解的同时确定装置的工艺操作条件。以某炼油厂常减压蒸馏装置炼油为例验证提出的集成优化方法, 案例证明该集成策略不仅确保生产计划在实际生产的可操作性, 还得到了生产计划与过程装置操作的同步优化。     

尿素合成塔衬里修复浅谈

介绍了采用盖板贴补修复尿素合成塔内衬里焊缝腐蚀缺陷的方法及效果。探索尿素合成塔衬里修复的新方式。     

Study of the properties of ceramic surfacing material used for restoring coking chamber linings

Properties are given for original raw components and a production scheme is provided for preparing ceramic surfacing for repairing the dinas lining of coking furnaces. Data are presented for x-ray phase and petrographic analyses of ceramic surfacing. Adeformation - temperature diagram is provided. Recommendations are given for use of the proposed compositions for repairing heating units.     

A gas flow method for determination of in‐plane permeability of fiber preforms

Resin flow plays a crucial role in many composite manufacturing processes. The most important parameters used in modeling and designing mold filling are the permeability of the fibrous preform, which is a kind of flow conductance and a property of the reinforcement, and the viscosity of the resin. The extent reaction, or degree of cure, is also important and causes change of chemical during mold filling. To determine the permeability of fiber preform searchers have been using liquid flow analysis. In this study, a new scheme for determining permeability using gas flow is proposed. In conventional liquid flow methods, radial propagation of the polymer into a porous medium is measured and used to determine permeability, whereas in the gas flow method, the several different preform geometries is measured and used. The effectiveness of the gas flow method was verified by comparing it with conventional methods.     

基于仿真的炼油厂罐区操作再调度策略

针对炼油厂操作过程中所存在的大量操作不确定性,提出了一种基于两层仿真系统的再调度方法保证了调度指令的稳定性。在下层模型中引入罐区操作的不确定干扰,并对初始优化方案进行仿真。上层仿真系统采用启发式寻优的方法,当下层干扰发生后得到保证组分和物料双重平衡的安全方案。基于此安全方案,通过固定混合整数线性优化模型中的二元变量并对方案的偏离进行惩罚从而缩小可行域快速得到局部优化解。以某炼厂罐区操作为例,验证了这一再调度策略的有效性。     

Designing of multiple deferred state sampling plan for generalized inverted exponential distribution

In this article, we propose a sampling plan called a multiple deferred state sampling plan for sentencing a lot based on the information of current and successive lot samples. Based on this sampling plan, the median life of the product is assured based on a time-truncated life test where the lifetime of the product follows the generalized inverted exponential distribution. The quality of the product is measured by its median life. The optimal parameters of the proposed plan are obtained by using the approach of two points on the operating characteristic curve. Tables are also constructed for determining the optimal parameters with various shape parameters. The implementation of the proposed plan is illustrated with examples. The performance of the proposed plan is compared with the performance of existing sampling plans under the generalized inverted exponential distribution.     

脱吸塔底再沸器管箱故障分析与排除

本文对脱吸塔底再沸器管箱衬环法兰检漏孔渗漏原因进行分析,提出改进管箱结构型式及制造工艺的返修方案,经生产实践验证效果良好,并总结了衬环法兰等不锈钢衬里设备的设计、制造应注意的问题.     

密炼机转子铜瓦椭圆的修复方法

简要介绍了一种XHM253/20密闭式炼胶机转子铜瓦椭圆的修复方法.该方法简便易行,修复工期短,修复质量高,在实际工作中具有一定参考价值.     

Determination of multiple dependent state repetitive group sampling plan based on the process capability index

Abstract

In this article, we propose a sampling plan called a multiple dependent state repetitive group sampling plan for variable inspection based on the process capability index C_pk. The proposed sampling plan is applicable for the inspection of normally distributed quality characteristics when both mean and variance are assumed to be unknown. This new plan under variable inspection will be very useful particularly in compliance testing. Tables are also constructed for the determination of optimal parameters for easy selection and implementation of the plan. The optimal parameters can be determined by using the approach of two points on the operating characteristic curve. Symmetric and asymmetric cases based on the fraction nonconforming by the lower and the upper specification limits are also considered. Advantages of the proposed plan are also discussed. It is also shown that the proposed plan outperforms other existing sampling plans under variable inspection.     

一种新的生产计划与催化裂化装置过程操作集成的闭环策略

Production planning models generated by common modeling systems do not involve constraints for process operations, and a solution optimized by these models is called a quasi-optimal plan. The quasi-optimal plan cannot be executed in practice some time for no corresponding operating conditions. In order to determine a practi- cally feasible optimal plan and corresponding operating conditions of fluidized catalytic cracking unit （FCCU）, a novel close-loop integrated strategy, including determination of a quasi-optimal plan, search of operating conditions of FCCU and revision of the production planning model, was proposed in this article. In the strategy, a generalized genetic algorithm （GA） coupled with a sequential process simulator of FCCU was applied to search operating conditions implementing the quasi-optimal plan of FCCU and output the optimal individual in the GA search as a final genetic individual. When no corresponding operating conditions were found, the final genetic individual based correction （FGIC） method was presented to revise the production planning model, and then a new quasi-optimal production plan was determined. The above steps were repeated until a practically feasible optimal plan and corresponding operating conditions of FCCU were obtained. The close-loop integrated strategy was validated by two cases, and it was indicated that the strategy was efficient in determining a practically executed optimal plan and corresponding operating conditions of FCCU.     

硫化热粘法在0#皮带抢修中的应用实例及冷粘法应用的前景分析

在详述硫化热粘法具体操作过程的基础上,指出该方法因为工艺复杂、粘接时间长等原因并不适合用于0#皮带抢修这一特殊环境。考虑到冷粘法所具有的无可比拟的优势,阐明了该方法在0#皮带抢修中具有良好的应用前景。     

Method for quantitative evaluation of kinetic constants in olefin polymerizations. II. Kinetic study of a high‐activity Ziegler–Natta catalyst used for bulk propylene polymerizations

A method for quantitative evaluation of kinetic constants in Ziegler–Natta and metallocene olefin polymerizations presented previously (Matos, V.; Mattos Neto, A. G.; Pinto, J. C. J Appl Polym Sci 2001, 79, 2076) is adapted to allow the estimation of kinetic constants for bulk propylene polymerizations by using a conventional fourth‐generation high‐activity Ziegler–Natta catalyst (HAC). In this particular case, reaction rate profiles are not available, so that estimation of kinetic data must rely on average polymer yields. The method comprises some fundamental steps, including the initial design of a statistical experimental plan, the execution of the designed experiments, the development of simple mathematical models to describe the polymerization, and the estimation of kinetic parameters from available yields, gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR) data. It is shown that the proposed method allows the successful interpretation of experimental olefin polymerization data and the quantitative evaluation of kinetic parameters, which can be inserted into a process simulator to provide an accurate picture of actual industrial plant behavior. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3226–3245, 2002     

热板对上横梁结构设计的影响

将四立柱式平板硫化机上横梁及热板的力学模型模拟为叠板，通过受力分析得出结论：由于热板的存在，通常上横梁的最危险点是在上横梁矩形板长边的中点，并通过实验予以验证。指出上横梁结构宜设计为空腹、立筋式，清沙口宜为下置式。