带箱形转换层高层建筑结构的抗震性能研究

进行了带箱形转换层高层建筑结构模型的地震模拟振动台试验.采用微粒混凝土制作1/10比例的结构模型,得到结构在地震作用下的动力特性以及加速度、位移等地震响应,研究了模型结构的受力机理和破坏模式.在试验研究的基础上,采用有限元分析程序对原型结构进行抗震分析,理论分析与试验结果吻合较好.研究表明,该结构体系总体抗震性能良好,大震作用下仍具有较好的工作性能,能满足我国抗震设计规范的要求.     

橡胶人字弹簧的研制

介绍了铁路工程车辆悬挂系统用橡胶人字弹簧的胶料配方设计和生产工艺要点,并进行了胶料物理机械性能、成品规格尺寸、外观质量、静态刚度、超载残余变形、疲劳试验和选配试验等.结果表明,产品各项性能均能达到指标要求.     

基于Taguchi和UDE试验设计的注塑工艺参数优化

基于Taguchi试验设计和均匀试验设计(UDE)方法,应用Moldflow对注塑过程进行模拟,对模拟结果分析处理,优化注塑工艺参数,并分析比较了Taguchi试验设计和UDE方法应用于注塑工艺优化的特点.结果表明,Taguchi试验设计和UDE均能满足注塑工艺优化的要求,但对多因素多水平试验,UDE方法试验次数较少,效率较高,优化结果较理想.     

风电聚氨酯齿型同步带性能试验设计及应用

针对风电聚氨酯齿型同步带进行性能试验。设计了同步带破断力、齿体剪切力和屈挠疲劳试验新方案,并对同步带的窄带破断力和齿体剪切力进行了测试。结果表明：试验设计新方案的装置结构合理、操作方便、满足试验要求,能准确地测试同步带的性能,可为同步带类产品性能试验以及同步带用骨架材料的研发和试验提供参考。     

乘用车尾门密封条的压缩仿真分析

先对乘用车尾门密封条三元乙丙橡胶密实胶和海绵胶进行力学性能试验,确定2种材料的本构模型,然后采用Abaqus有限元分析软件对尾门密封条的压缩过程进行仿真分析。结果表明:尾门密封条的海绵胶泡管应力、应变和应变能均较大,海绵胶与密实胶接触部位有较大的应变和应变能;尾门密封条的仿真与试验压缩力-压缩量曲线拟合良好,试验压缩力平均误差不超过10%,仿真与试验结果一致性好。     

炸药模拟环境温湿度试验技术研究

介绍了炸药模拟环境试验的装置、温度和湿度范围、循环程序、周期及失效判据的选择，对十几种炸药进行了环境适应性试验，取得大量数据，对炸药的环境适应能力进行评估，在此基础上研究建立了炸药模拟环境试验技术。该技术不但能判断炸药药柱是否合格，而且能发现药柱相互间差异，排出优劣顺序，为炸药性能的评价提供了一个较好的试验方法     

常压塔器试验压力取值探讨

对JB/T4710—2005规定的"常压塔器设计压力取值不小于0.1 MPa"及"卧置试压时,试验压力应计入试验介质的液柱静压力"合理性进行探讨。从压力试验的目的和原则出发,分析了塔器强度被不同载荷控制时的应力特点,提出了两个观点:常压塔器设计压力取值不低于工作压力;液压试验时须计入工作状态时的液柱静压力,希望能与同行交流、探讨。     

用正交试验研究影响环氧摩擦学性能的因素

利用正交试验研究了影响环氧树脂摩擦磨损性能的因素,通过直观分析法对试验结果进行了分析,结果显示对摩擦系数和磨损率而言,载荷和表面粗糙度都是显著的影响因素。用电镜对不同粗糙度下的磨损面形貌进行了观察,结果表明随粗糙度增加材料的磨损机理由疲劳磨损变为磨粒磨损。     

航标硬质塑料压缩性能试验方法编制研究

阐述了航空行业标准"硬质塑料压缩性能试验方法"标准编制过程中的几个主要问题,包括编制原则、标准的适用范围、试样的形状和尺寸、结果的计算方法等,并结合相关材料试验对标准进行了试验验证。     

火力发电厂海水冷却塔循环冷却水处理方法的研究

针对某滨海电厂一期现场取水口海水水质,采用静态腐蚀挂片试验对钛、双相不锈钢、塑料等材质进行了抗腐蚀性能对照试验分析;通过动态模拟试验,投加氧化性杀生剂液氯,在浓缩倍数为2.0、2.5以及在海水阻垢分散剂XD01浓度为20mg/L的条件下,对几种管材的抗腐蚀性能分别进行了研究与评价。试验结果表明钛管和双向不锈钢对海水的耐蚀性能良好。     

纤维-聚合物复合防弹材料的能量耗散机制及其调控技术研究进展

能量耗散是纤维-聚合物复合材料防弹机制的最本质特征,也是纤维-聚合物复合防弹材料多功能化的重要设计依据。介绍了纤维-聚合物复合防弹材料的能量耗散机制,并综述了纤维复合材料能量耗散调控技术的研究进展。     

Liquid/solid mass transfer in an air-lift loop reactor with a dispersed solid phase

In processes with immobilized cells mass transfer across the boundary layer surrounding the support often plays an important role. Relatively little is known about external mass transfer as a function of the superficial gas velocity in bioreactors such as air-lift loop reactors. In this work ion-exchange resins were used as a solid phase to determine the mass-transfer coefficient in such a reactor. Relations between the Sherwood number and the superficial gas velocity were derived and compared with relations from the literature. Relations in which the Sherwood number is a function of the energy-dissipation rate and relations in which the relative particle velocity is calculated from the rate of free fall of the particle were compared. It was shown that the Sherwood numbers that were functions of the energy-dissipation rates were higher than could be calculated on the basis of the rate of free fall. The Sherwood number obtained was used to calculate the k_l,s of carrageenan gel beads as a solid phase in an air-lift loop reactor. © 1998 SCI.     

钢筋混凝土无洞叠合剪力墙低周反复荷载试验

研究钢筋混凝土无洞叠合剪力墙的抗震性能。对4片钢筋混凝土无洞叠合剪力墙和2片钢筋混凝土普通剪力墙分别进行了低周反复荷载试验,对比研究试件的受力全过程、开裂部位、裂缝发展情况以及破坏形态,分析试件的承载能力、滞回曲线、骨架曲线、刚度退化曲线、延性性能等抗震性能。研究表明:钢筋混凝土叠合剪力墙的受力性能与钢筋混凝土普通剪力墙类似,具有较好的抗震性能,剪式支架能使钢筋混凝土叠合剪力墙的预制部分与现浇混凝土形成整体,共同工作,承受外部荷载。     

Toughening of polylactide with epoxy-functionalized methyl methacrylate–butyl acrylate copolymer

Glycidyl methacrylate-functionalized methyl methacrylate–butyl acrylate (GACR) core–shell structure copolymers were synthesized to toughen polylactide (PLA). With an increase in GACR content, the PLA/GACR blends showed decreased tensile strength and modulus; however, the elongation at break and the impact strength were significantly increased compared with that of PLA. The brittle fracture of neat PLA was gradually transformed into ductile fracture by the addiction of GACR. From dynamic mechanical analysis, the rigidity of the PLA/GACR blends was decreased with the increase of GACR content. The addition of GACR decreased the degree of crystallinity of PLA. The GACR was found to aggregate to form clusters with size increasing with increasing GACR content by transmission electron microscope analysis. The clusters dispersed in PLA matrix uniformly. It was found that PLA demonstrated large area, plastic deformation (shear yielding) and cavities in the blend upon being subjected the tensile and impact tests, which was an important energy-dissipation process and led to a toughened and transparent blend.     

Passage of a Bubble-Detonation Wave into a Liquid

The passage of a detonation wave from a chemically active bubble media into a chemically inert medium (liquid) is studied experimentally. The structure of the transmitted wave and the wave reflected from the butt-end of a shock tube (post-detonation waves) is investigated, and the pressures of these waves for different liquids are measured. The evolution of the post-detonation waves is traced, their velocities are measured, and the attenuation constants of these waves are determined. The energy-dissipation mechanisms for post-detonation waves in liquids are analyzed qualitatively.     

A CFD-PBM coupled model under entire turbulent spectrum for simulating a bubble column with highly viscous media

To account for the effect of liquid viscosity, the bubble breakup model considering turbulent eddy collision based on the inertial subrange turbulent spectrum was extended to the entire turbulent spectrum that included the energy-containing, inertial, and energy-dissipation subranges. The computational fluid dynamics-population balance model coupled model was modified to include this extended bubble breakup model for simulations of a bubble column. The effect of turbulent energy spectrum on the bubble breakup and hydrodynamic behaviors was studied in a bubble column under different liquid viscosities. The results showed that when the liquid viscosity was <80 mPa s, the bubble breakup and hydrodynamics were almost independent on the turbulent spectrum. At liquid viscosity >80 mPa s, the bubble breakup rate and gas holdup were significantly under-predicted when the inertial turbulent spectrum was used, and when using the entire turbulent spectrum the predictions were more consistent with experimental data.     

Effective oxygen-consumption rates in fermentation broths with filamentous organisms

The concept of coupling molecular diffusion and reaction has been applied in the past to various biological systems with clearly defined geometrical properties like pellets and immobilised enzymes/microorganisms. This paper investigates the use of the same principle to characterise the diffusional limitation in suspensions of filamentous microorganisms. Experimental results of oxygen-uptake measurements from Aspergillus niger fermentations in a 50 dm³ turbine-agitated fermentor are presented with theoretical predictions of coupled diffusion and oxygen kinetics. Results are discussed on the basis of turbulence theory so that the mycelial broth can be structured in hypothetical spherical elements. Consideration of local energy-dissipation rates in the impeller region provides reasonable explanation of the strong influence of the impeller/tank diameter ratio on the effective oxygen-uptake rate at a given power input.     

Surprising shape-memory effect of polylactide resulted from toughening by polyamide elastomer

Melt blending of polylactide (PLA) and biodegradable polyamide elastomer (PAE) has been performed in an effort to toughen the PLA. DMA tests showed good compatibility between PAE and PLA blends, and the PAE were dispersed in PLA matrix uniformly shown in SEM photos. Mechanical properties of blends with different PAE concentrations were observed. With the PAE contents increasing, the elongation at break of blends increased and the brittle break became ductile break. When the PAE content is 10%, the tensile strength of blend is similar to neat PLA, and the elongation increased to 194.6% significantly. Remarkably, the blends showed wonderful shape-memory effect. PAE domains act as stress concentrators in system with the stress release locally and lead to energy-dissipation process. These will prevent PLA matrix from breaking under high deformation, and lead to the PLA molecular orientation. Consequently, the blends occurred to deformation upon tensile load, and heating up the material will reform the shape back to the original shape.     

Reflection of a bubble-detonation wave from a rigid obstacle

The process of detonation-wave reflection from a rigid obstacle in mono- and polydisperse bubble media is studied experimentally. The evolution of the reflected wave formed upon interaction of the detonation wave with the butt-end of a shock tube is traced. The structure of the detonation and reflected waves is studied and the wave pressures are measured at various parameters of the bubble media. The damping constants of the reflected waves are determined. In addition, the velocities of the detonation and reflected waves are measured. The effect of the gas-bubble size on the characteristics of these waves is investigated. The energy-dissipation mechanisms in the detonation and reflected waves in the bubble media are analyzed qualitatively. Translated fromFizika Goreniya i Vzryva, Vol. 36, No. 3, pp. 107–113, May–June, 2000. This work was supported by the Russian Foundation for Fundamental Research (Grant No. 98-03-32325).     

分相式多孔壁微通道流动冷凝传热强化与减阻

微通道换热器应用广泛,强化传热和减阻是新型换热器设计的重要目标。为了同时实现这两相目标,本文提出了一种分相式多孔壁微通道冷凝器,利用微针肋阵列组成的多孔壁在冷凝传热过程中实现了汽液两相分离。采用实验研究方法对比了分相式多孔壁微通道与普通实心壁微通道的流动和传热特性,结果证明分相式微通道在冷凝传热中同时具备强化传热和减阻的作用。深入研究了通道内两相流动摩擦耗散原理并提出了相分离减阻理论,指出汽液两相流内部摩擦耗散的减小是分相流减阻的关键。另一方面,分相过程使针肋换热面侧壁直接与高温蒸汽接触,极大消减了蒸汽与换热壁面之间的传热液膜厚度。沿流动方向不断扩展的液通道截面与不断减缩的汽通道截面积适应了流动冷凝过程延工质流动方向"水渐多,汽渐少"的规律,保证沿程传热效果不会恶化。