钇提高YT14硬质合金耐磨性的机制

研究了不同Ｙ添加量对ＹＴ１４硬质合金显微组织、结构和耐磨性的影响。结果表明，在ＹＴ１４硬质合金中添加微量Ｙ，可显著提高合金的耐磨性。Ｙ的主要作用是均匀细化碳化物相和Ｃｏ相；提高Ｃｏ粘结相中Ｗ、Ｔｉ元素的固溶量及αＣｏ相所占的体积分数，从而提高Ｃｏ粘结相的强韧性；Ｙ在合金中形成Ｙ２ＷＯ６，表明Ｙ还可还原和清除碳化钨表面氧化膜，增强Ｃｏ粘结相与硬质相之间的结合强度     

SOLUBILITIES OF POLYCYCLIC AROMATIC HYDROCARBONS AND DI-REGION THEORY

By using the relationship equation of Partition coefficients with water solubilities for polycyclic aromatic hydrocarbons (PAHs), we have estimated the solubilities of PAHs. In addition the high-performance liquid chromatograph (HPLC) method has been used for the indirect determination of solubilities of PAHs. t3ased on the di-region theory, We have studied the relationship of the solubilities of PAHs with carcinogenicity and introduced the solubility parameter into the di-region theory equation. The calculated carcinogenicity of PAHs from the obtained equation shows little difference from that calculated from Dai Qianhuan's equation.     

高分散直接甲醇燃料电池Pt／C阴极电催化剂的制备过程机理与表征

 通过调变的多元醇法制备了40％Pt／C直接甲醇燃料电池阴极电催化剂，应用透射电镜（TEM）及X射线衍射（XRD）方法表征催化剂．结果表明，由该制备方法可得到高分散，金属粒子粒径分布窄的高载量贵金属催化剂．TEM统计结果表明，调变多元醇法制备的40％Pt／C催化剂的金属粒子平均粒径约为2．9nm．直接甲醇燃料电池单池性能测试表明，该方法制得的40％Pt／C的电催化氧还原能力比同型商品催化剂更好．另外，利用UV－Vis光谱研究了催化剂的制备过程．结果表明，在调变的多元醇法中，Pt4＋的还原是一步完成的．     

制备纳米氧化锌的新方法

以草酸和醋酸锌为原料，用室温固相化学反应首先制备前驱物二水合草酸锌，后者在微波场辐射分解得到产物纳米氧化锌。用XRD，TEM和IR等技术对产物的组成，大小及形貌进行了表征。结果表明：产物纳米氧化锌为粒度分布均匀的球形六角晶系结构，平均粒径约为8nm。     

NUCLEAR PORE COMPLEX IN SPERMATOGENESIS OF BEIJING DOMESTIC DUCK——ELECTRON MICROSCOPE OBSERVATION OF FREEZE-ETCHING

The nuclear pore complex in spermatogenesis of Beijing domestic duck has been studiedby means of electron microscopic observation of freeze-etching. The structure of the poreobserved proves to be in accord with the model of the nuclear pore complex proposed respec-tively by Franke (1970) and Roberts et al. (1970). But its central granule may be present(1--3 granules) or absent. The granules are considered to be material in transit. The sizeand frequency of the pore vary with different types of reproductive cells, which is believedto be related to the cells' function. The pores concentrate on the side of nucleus near Golgizone in primary spermatocyte and near the proacrosome of spermatid, and this shows thefunctional variety of parts in the nucleus.     

PtRu/C电催化剂上甲醇吸附氧化过程的电化学原位红外光谱

采用调变的多元醇法制备了高分散的Pt/C, PtRu/C和Ru/C电催化剂. XRD计算结果表明, PtRu/C电催化剂的平均粒径和合金度分别为2.2 nm和71%. 采用电化学方法和原位傅里叶变换红外反射光谱方法(in situ FTIRS)研究了甲醇在3种电催化剂上的吸附氧化过程, 发现PtRu/C对甲醇的催化活性明显高于Pt/C, Ru的加入一方面影响了甲醇在Pt上的解离吸附性能, 另一方面提供了Ru-OH物种, 从而抑制了低电位下电催化剂中毒. 红外光谱研究结果表明, 线性吸附态CO(COL)是主要毒化物种, 反应产物主要是CO2, 还有少量的甲酸甲酯. 根据实验结果讨论了甲醇在PtRu/C电催化剂上的氧化机理.     

HCN(HNC)与NH3, H2O和HF分子间相互作用的理论研究

在MP2/aug-cc-pVTZ水平上, 对HCN(HNC)与NH3, H2O和HF分子间可能存在的氢键型复合物进行了全自由度能量梯度优化, 通过在相同水平上的频率验证分析发现了稳定的分子间相互作用形式是HCN(HNC)作为质子供体或作为质子受体形成的复合物. 基组重叠误差对总相互作用能的影响均小于3.34 kJ/mol. 通过自然键轨道(NBO)分析, 研究了单体和复合物中的原子电荷和电荷转移对分子间相互作用的影响. 对称性匹配微扰理论(SAPT, Symmetry Adapted Perturbation Theory)能量分解结果表明, 在分子间相互作用中, 静电作用与诱导作用占主导地位, 而诱导作用与复合物的电荷转移之间具有良好的正相关性.     

Directional Analysis of the Chaotic Superlattice around the Equilibrium Point in the Phase Space

The recently proposed method of our research group named as directional Lyapunov exponents(DLEs) is presented. Then, DLEs are used to analyze the eigenstructure of the output phase space around the equilibrium points. Finally, the impacts of the superlattice parameter changes on the characteristics of the output chaotic signal are analyzed. The experimental results show that parameter changes of the superlattice will affect the eigenstructure around the equilibrium points in the output phase space, and DLEs are sensitive to these changes.     

Analysis of total nitrogen and total phosphorus in soil using laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy(LIBS) is used to determine the total nitrogen(TN) and total phosphorus(TP) in soil.Quantitative determinations are conducted using the line intensity of the analyte element and element concentration.Calibration models are obtained using ten samples for TN and seven samples for TP.The rest samples are used to validate the results.Strong linear correlations are obtained from the determined TN and TP concentrations.LIBS is a powerful tool for analyzing soil samples to determine nutrient elements by selecting calibration and validation samples with similar matrix composition.     

一维正方准晶中裂纹和刚性线夹杂的封闭形式解（英文）

通过引入广义复变函数方法,研究含裂纹和刚性体夹杂物的反平面模型的一维正方准晶问题.对于一维正方准晶,考虑周期平面为(x_1, x_2),含有宏观裂纹或刚性线夹杂,具有准周期x_3方向的原子结构存在相位位移,本文重点研究相位位移对相关物理量的影响.利用广义复变函数方法,将这两个模型简化为Riemann-Hilbert问题,得到反平面的声子场与相位场的封闭解.同时求得声子场和相位场的应力强度因子的显式解,这在断裂力学和工程领域具有广泛的应用价值.结果表明,反平面情形下,含裂纹和刚性体夹杂物的声子和相位的应力强度因子,与声子场和相位场的耦合无关.