基于Workbench的单轨吊工字钢轻量化设计

以单轨吊工字钢为研究对象,利用Workbench软件进行数值模拟和有限元分析,并通过其专业优化模块Design Exploration对单轨吊工字钢横截面参数进行优化设计,仿真分析横截面参数与最大应力和最大变形之间的关系,并依据应力和变形求出工字钢轻量化最优解。优化结果表明:在保证工字钢强度以及刚度的前提下,工字钢的质量最大可降低4.45 kg,约占优化前工字钢质量的13.3%,节约了工字钢的制造成本,提高了材料利用率,为单轨吊工字钢的设计及轻量化提供了理论依据。     

缓／控释肥料的研究现状及发展趋势

介绍了缓／控释肥料的定义和类型;阐述了国内外缓／控释肥料的发展历程和研究进展;展望了缓／控释肥料的发展趋势。     

Population balance modeling for a continuous gas phase olefin polymerization reactor

Steady-state population balance models have been developed for a continuous flow gas phase olefin polymerization process with both uniform sized and log-normally size distributed high activity catalyst feeds. For the calculation of polymer properties such as molecular weight averages and weight fraction of comonomers in the copolymer, a multigrain solid core model was used with an assumption that intraparticle monomer mass transfer resistance is negligibly small. The multigrain solid core model was incorporated into the population balance model and the effects of feed catalyst particle size distribution and catalyst deactivation parameters on the polymer production rate, polymer particle size distribution, and polymer properties were investigated. It is observed for deactivating catalyst that the polymer particle size distribution tends to be narrower with a reduced amount of large polymer particles. For the catalyst with nonuniform site deactivation, polymer particles of different sizes exhibit different molecular weight and copolymer composition. © 1994 John Wiley & Sons, Inc.     

信源可信度对核电公众接受影响的研究

公众对核电的态度受各种信息的影响,信息源可信度是说服力的重要决定因素.在我国,核安全监管机构、核电企业和专家是主要的核信息发布源,研究不同信息源可信度对公众核电态度的影响对核电的可持续发展十分重要.本研究基于源可信度理论,考察了公众对不同信源的可信度认知,构建了核电公众接受回归模型并开展实证研究.研究发现,不同源的可信...     

实际应用推动辐射防护体系的不断完善

本文在简要回顾国际放射防护委员会（ＩＣＲＰ）历史的基础上，首先指出在伴随着核辐射和核能的应用不断发展的同时，由ＩＣＲＰ基本建议书推荐的辐射防护体系也在实际应用中不断完善和改进。接着简要介绍了目前倍受关心的两个实际问题及其有关初步建议。文中再次强调了ＩＣＲＰ的几个重要基本观点，以及与此相悖的“打擦边球”和“零危险”两种偏面看法。最后指出，我们应该在借鉴国际经验的同时，认真总结自己的经验，为全世界共同的辐射防护事业作出我们应有的贡献。     

甜菜专用肥配制与施肥效果的研究

简要介绍了甜菜专用复合肥的主要组成、田间小区试验结果和生产对比试验结果,从营养生理作用等方面分析了甜菜专用复合肥增产增糖的原因,并对该肥的经济效益进行了具体的核算。     

Synthesis and characterization of a new amphiphilic copolymer containing multihydroxyl segments for drug carrier

A new amphiphilic copolymer (copoly‐(MR‐BMA‐HEA‐MAA), PRBHM) containing multihydroxyl segments was designed and synthesized for application in drug carrier. PRBHM can be dissolved in water to form aggregates directly with a critical aggregate concentration (CAC) of 0.0138 mg mL^?1. The chains of PRBHM can be collapsed into hydrophobic globules when pH decreases from neutral to slightly acid condition (pH = 5.0–7.0) in water. Since the hydrophilic hydroxyl group is independent on pH, PRBHM can keep stable both in neutral and slightly acid aqueous solutions. The hydrophobic small molecules such as 5‐(4‐(4‐vinylbenzyloxy) phenyl)‐4,5‐dihydro‐1,3‐diphenyl‐1H‐pyrazole (PY) can be loaded into PRBHM aggregates via ultrasonic treatment in water, and can be internalized into BEL‐7402 cancer cells. The cytotoxicity determination also indicates the good biocompatibility of PRBHM in potential application as a drug carrier. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Intrinsically Ductile Failure in a Nanocrystalline Beta Titanium Alloy

A nanocrystalline bcc Ti_67.4Nb_24.6Zr₅Sn₃ alloy is shown to fracture in an intrinsically ductile manner with exceptionally large dimples (up to 10 µm) which are two orders of magnitude greater than the grain size (≈ 40 nm). This large plasticity length scale is attributed to a combination of low shear modulus (≈ 27 GPa), high Poisson's ratio (≈ 0.4) and ultrahigh strength (UTS ≈ 1.1 GPa), close to the ideal shear stress, which facilitates ideal shear deformation to promote transgranular shear.     

现代测量管理体系的建立与运行

对企业贯彻实施GB/T19022-2003标准,建立现代测量管理体系及运行的背景、实施内容、运行情况、结果、效益等进行了阐述和分析,以期全面清晰的把握企业在实施标准时所要做的工作。对于企业建立和运行测量管理体系工作有较好的借鉴意义。