Influence of Cold Rolling Reduction on Microstructure and Mechanical Properties of TWIP Steel

The influence of cold rolling reduction on microstructure and mechanical properties of the TWIP (ttwinning induced plasticity) steel was investigated. The results indicated that the steel had better comprehensive mechanical properties when cold rolling reduction was about 65.0% and the annealing temperature was 1000℃. The tensile strength of the steel is about 640MPa and the yield strength is higher than 255MPa, while the elongation is above 82%. The microstructure is composed of austenitic matrix and annealing twins at room temperature, at the same time, a significant amount of annealing twins and stacking faults are observed by transmission electron microscopy (TEM). Mechanical twins play a dominant role during deformation, and result in excellent mechanical properties.     

卷绕铅酸电池泡沫铅负极电化学行为的研究

以泡沫铅作为负极集流体制备了卷绕VRLA电池.采用计时电流法、循环伏安曲线、电化学阻抗谱和充放电实验研究了泡沫铅负极的电化学行为,结果表明泡沫铅负极的真实表面积比铅箔负极的大,因此泡沫铅负极具有较低的过电势,并且不论是在怎样的放电状态下,泡沫铅负极的电化学反应电阻较小;与铅箔负极相比,在10、5和2小时率放电状态下,泡沫铅负极的质量比容量分别增加25.9%,30.0%和48.2%.此外,SEM观察显示,泡沫铅负极表面活性物质为更加细小的晶体颗粒和具有更高的孔率.     

Gas barrier properties and periodically fractured surface of thin DLC films coated on flexible polymer substrates

Thin DLC films coated on polymer surfaces are attracting considerable attention due to their wide applications and their interesting surface properties. When DLC films were coated on polymers, the resulting DLC-polymer composites are highly functionalized materials, some of which presenting dramatically improved gas barrier properties.In this paper, we will introduce several commonly used polymers including polyethylene terephthalate (PET), polyethylene (PE) and polypropylene (PP) for semi-crystalline polymers, and polymethyl methacyrlate (PMMA) for an amorphous polymer. The polymers were coated with thin DLC films and the gas barrier properties of the resulting DLC-polymer composites were investigated. Some of the DLC-polymer composites dramatically improved their gas barrier properties while they presented horizontal crack lines and vertical micro-buckling lines on the DLC surface when stretched to a certain strain. The gas barrier properties of the DLC-polymer composites with fractured DLC surface were also studied. It was found that the gas barrier property of the polymer substrates with lower residual strains was less damaged, when the substrates were mechanically deformed, than that of the polymer substrates with higher residual strains. When the number of the cracks increases, the strain imposed on each crack decreases, since the overall deformation is almost equally distributed to each crack while the crack spacing of each crack becomes shorter. Thus, it was found that the degradation of the gas barrier property after mechanical deformation is dependent on the residual strain of the polymers and the number of cracks on DLC films.     

Tuning performance of Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst for methane combustion by optimizing calcination temperature of support

A series of 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2 catalysts were prepared by impregnation method based on the presynthesis of Sn_(0.9)Ce_(0.1)O_2 support prepared by co-precipitation method, and then characterized by Brunauer–Emmett–Teller(BET), X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), Raman, CO chemical adsorption and hydrogen temperature-programmed reduction(H_2-TPR) techniques. The effect of calcination temperature of the composite oxide support on the catalytic performances of the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst for the CH_4 total oxidation was studied. It is found that the catalytic activity of the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst increases with the increase in calcination temperature of the Pd/Sn_(0.9)Ce_(0.1)O_2 support. The 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2/1100 catalyst(the Pd/Sn_(0.9)Ce_(0.1)O_2 support was calcined at 1100 ℃) exhibits the best reactive activity(T_(10)= 255 ℃). The excellent activity of the 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2/1100 catalyst should be attributed to the high reducibility of PdO, the excellent oxygen mobility of the support and the high content of active Pd~(2+) species on the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst.     

利用PDZ合成锆英石基陶瓷颜料

利用PDZ原料成功地合成出了锆钒蓝、锆镨黄、锆铁红陶瓷颜料,讨论了各工艺参数对颜料合成的影响,优化出了PDZ合成锆英石颜料的最佳工艺制度。     

Torque Transmission Capabilities of Bonded Polygonal Lap Joints for Carbon Fiber Epoxy Composites

Although carbon fiber epoxy composite materials have excellent properties for structures, the joint in composite materials often reduces the efficiency of the composite structure because the joint is often the weakest area in the composite structure.

In this paper, the effects of the adhesive thickness and the adherend surface roughness on the static and fatigue strengths of adhesively-bonded tubular polygonal lap joints have been investigated by experimental methods. The dependencies of the static and fatigue strengths on the stacking sequences of the composite adherends were observed.

From the experimental investigations, it was found that the fatigue strength of the circular adhesively-bounded joints was quite dependent on the surface roughness of the adherends and that polygonal adhesively-bonded joints had better fatigue strength characteristics than circular adhesively-bonded joints.     

BaPbO3／BaTiO3系复合陶瓷的研究

报道了导电陶瓷ＢａＰｂＯ３与铁电陶瓷ＢａＴｉＯ３进行复合的结果，研究了该复合功能陶瓷的物相、导电性和低温电阻温度特性。结果表明：采用合理的合成工艺，可得到呈现混和分布的两相复合功能陶瓷材料，该复合材料的电导特征符合三维渗流导电行为。     

反应注射充模特性及模具浇口结构设计的研究

本文对反应注射充模过程中的铺展流、射流、绕流和气泡的特性进行了分析研究，并讨论了模具浇口结构及位置对充模的影响，给出了制品的设计方法。     

煤热解过程中酚类化合物生成机理及数学模型

在深入研究前人工作的基础上，结合煤分子结构研究的最新进展，提出并定义了“酚类形成”，“酚类分解”，“中间酚类”，“酚类生成”和“键寿命”等概念，建立了酚类形成与分解相互竞争的Ｆ－Ｄ－Ｃ酚类生成机理模型，并以此为基础建立了描述酚类总产率ｆ（ｔ）与热解温度ｔ关系的数学模型。用正态分布函数模拟酚类形成，用威布尔分布函数模拟了酚类分解，二者结合构成了ＭＲＦ酚类生成的数学模型。采用无约束非线性单纯形搜索法进     

煤气甲烷化新技术：——生物甲烷化技术

本文重点介绍国外煤气生物甲烷化技术的原理、甲烷化微生物、生物甲烷化反应器动力学研究及生物甲烷化技术经济评价。