Preparation and electrochemical performance of nanosized Co3O4 via hydrothermal method

The hydrotalcite-type cobalt compounds were prepared through oxidation of Co（OH）2 gel using NH4OH as precipitating agent and H2O2 as oxidant. These hydrotalcite-type cobalt compounds were transformed into Co3O4 through hydrothermal decomposition with nanostructural deformation. The precursor and product were characterized by Fourier-transform infrared（FT-IR） spectrum, X-ray diffractometry（XRD） and transmission electron microscopy（TEM）. The electrochemical performances of as-prepared nanosized Co3O4 as anode materials in lithium-ion batteries were tested by charge-discharge test in the voltage range of 0-3.0 V. The influence of morphology of Co3O4 particle on the capacity and cycling performance was studied. The results show that the shape and size of the final product can be controlled by altering cobalt sources. The irregular cubic Co3O4 with the average particle size of about 10 nm shows the best electrochemical performance. After 10 charge-discharge cycles, the specific charge capacity retains 555 mA.h/g.     

Synthesis of Ti3SiC2 by spark plasma sintering(SPS)of elemental powders

Ti3SiC2 materials have been fabricated by spark plasma sintering of the elemental powders with the addition of Al.At the heating rate of 80℃/min and under the pressure of 30MPa,the ideal synthesis temperature of Ti3SiC2 is in the range of 1150-1250℃.The addition of Al is in favor of the formation of Ti3SiC2.The synthesized compound has the molecular of Ti3Si0.8Al0.2C2 and lattice parameters of α=0.3069nm,c=1.7670nm.Its grain is plane-shape with a size of about 50μm in the elongated dimension.The prepared material has Vickers hardness of 3.5-5.5GPa(at 1N and 15s) and is as readily machinable as graphite‘s.     

汽车覆盖件冲模的消失模铸造技术

消失模铸造生产冲模毛坯具有许多的优点，其工艺设计、涂料的性能等不同于普通砂型铸造。冲模铸件材料可依据模具的工作环境选择不同铸铁。结合生产实际介绍了消失模铸造的一些技术要点，并分析了常见的铸件缺陷。     

Microstructure and mechanical properties of high strength as—cast Ti—15—3 alloy

The effects of heat treatment and solidification cooling rate on the microstructure and mechanical properties of as-cast Ti-15-3 alloy prepared by induction skull melting method were investigated.Results show that the microstructure of as-cast Ti-15-3 alloy changes from the features of simplified and larger size of beta grains to finer grain size with increasing solidification cooling rate.After solution treatment and different ageing treatment,alpha phase precipitates in grains interior as well as in grain boundaries.Due to the modification of the precipitate phase,the tensile stength and elongation of the alloy are improved simultaneously.A good combination of the values of 1.406GPa of σb and 4.5% of δ was obtained,which will be satisfied the use of this kind of alloy in critical areas.     

反求工程的产品几何建模技术研究

分析了目前在反求工程产品几何建模中广泛应用的曲面模型的局限性，指出反求工程为实现创新功能必须采用产品特征模型，提出了基于实体造型的特征建模方法。这种方法可以避免曲面模型的缺陷，拓宽反求工程的应用范围，是实现三维重构的新方法。探讨了有关的理论和关键技术。     

离心成型法制备Al2O3/Ni功能梯度材料及性能表征

用离心成型法制备了Al2O3/Ni功能梯度材料,并研究了料浆调制工艺、制备参数和梯度材料的力学性能.结果表明,良好的料浆的最佳流动性配比为粘结剂(聚乙二醇)含量为2 mass%、固相含量为63 vol.%、球磨时间为36 h.经离心成型-真空烧结(1400℃,2 h)可获得致密、组元宏观连续过渡的Al2O3/Ni梯度材料.该复合材料孔隙率低,力学性能好,抗弯强度可达321 MPa.     

燃烧合成Ni_3Al组织结构转变动力学过程分析

采用端部淬火熄火方法分析了自蔓延合成Ｎｉ－２５ａｔ．－％Ａｌ合金中的组织结构转变过程．研究表明：合金中的合成反应是从铝熔化后形成富铝合金溶液及富铝化合物处开始，然后再通过一系列中间过渡反应逐渐向γ′Ｎｉ_３Ａｌ产物相转化，其中液态反应物形成及其流动铺展，是形成快速放热反应及其自发扩展燃烧波的主要机制．     

气-电纺PHB引导组织再生膜的仿生矿化研究

实验将PHB通过气流-高压静电纺丝制成无纺膜，利用扫描电镜（SEM）、X射线衍射（XRD）对其形态和结构进行表征。在体外研究中，分别将无纺膜样本浸入37℃1．5倍仿生体液（SBF）中3、7、14、28d后对其表面形态和结构进行表征。结果表明，气电纺PHB无纺膜由超细纤维交织而成，纤维之间有多孔形成；通过气流一静电纺丝之后，PHB的结晶度及晶体的有序度降低；PHB膜在SBF中浸泡3天之后就有矿化结晶在纤维的表面形成，随着浸泡时间的增长，矿化结晶的数目增加，结晶度也随之增高，XRD及FTIR表明形成的结晶为含有碳酸根的磷灰石晶体。     

Fe3Al氢脆机理的研究

用余氏理论计算了氢对Ｆｅ３Ａｌ金属间化合物键结构、键能和电子分布的影响，分析发现，Ｆｅ３Ａｌ的氢脆是由于氢原子溶入扣引起Ｆｅ，Ａｌ原子状态变化。使晶体内晶格电子数大大减少，导致晶体局域金属性减弱，并构成具有严重各向异性的键络的结果。同时得出，氢在Ｆｅ３Ａｌ中占据间隙位置。     

Ni3Al中B和Mg的非平衡晶界共偏聚

在1023－1373K的初始温度和0.05-268.91K/s的冷速范围内，用Auger剖层分析确定含B和Mg的Ni3Al合金中B和Mg的非平衡晶界共偏聚行为，按照溶质－空位复合体迁移机制所导出的描述非平衡晶界偏聚的扩散速率方程解析表达式，很好地模拟了本实验结果，并确定了Ni3Al-B-Mg合金中B及B－空位复合体，Mg及Mg-空位复合体的扩散系数及复合体激活能。