Au-Ag-Si新型中温共晶钎料的研究

根据合金相图的基本原理,分析了Au-Ag-Si系相图,研制出熔化温度在400℃～500℃的共晶钎料合金.通过钎料合金与Ni板的润湿性测试和润湿后界面的微观组织分析.结果表明:Au-Ag-Si系钎料对于纯Ni具有良好的漫流性和润湿性,在450℃～500℃范围内,可以对Ni板进行钎焊.     

N3-Kethoxal-Based Bioorthogonal Intracellular RNA Labeling

There is growing interest in developing intracellular RNA tools. Herein, we describe a strategy for N₃-kethoxal (N₃K)-based bioorthogonal intracellular RNA functionalization. With N₃K labeling followed by an in vivo click reaction with DBCO derivatives, RNA can be modified with fluorescent or phenol groups. This strategy provides a new way of labeling RNA inside cells.     

准贝氏体铸钢正火热处理工艺的研究

研究了准贝氏体铸钢不同奥氏体温度正火对其组织与力学性能的影响 ,结果表明 ,随奥氏体化温度的提高 ,准贝氏体铸钢的强韧性改善 ,在 10 4 0℃正火 ,准贝氏体铸钢具有最佳强韧性配合。分析了高温奥氏体化正火强韧性提高的原因。     

Effect of laser fluences on the structure of carbon nitride films deposited by direct current plasma assisted pulsed laser ablation

Carbon nitride films were deposited by direct current plasma assisted pulsed laser ablation of a graphite target under a nitrogen atmosphere at room temperature. The surface morphology, composition and bonding structure of the deposited films were characterized by atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, Raman, and X-ray photoelectron spectroscopy (XPS). The effect of laser fluences in the range 0.5–3 J/cm² on the surface morphology, composition and bonding structure of the carbon nitride films were systematically studied. As laser fluence is increased, AFM results show a great decrease in the surface roughness of carbon nitride films. FTIR and XPS results indicate an increase in the N/C ratio and the content of N atoms bonded to sp³ C, as well as a decrease in the content of H atoms and the content of N atoms boned to sp² C in the deposited films, and Raman spectra indicate an increase in the content of disordered sp² C atoms and the sp² cluster size. The increase in the film density and the decrease in the particle fraction contribute to the decrease of surface roughness with increasing laser fluence.     

逆向工程技术在复杂铸造模具制造中的应用

首先介绍了逆向工程技术与传统制造技术的区别,然后着重讨论利用逆向工程技术快速制造复杂铸造模具的过程及工艺路线,同时给出一些具体应用实例。最后得出与传统制造方法相比具有效率高、成本低、操作简单等优点的结论。     

聚铝溶液pH值及盐基度的相关性研究

为聚铝溶液进行了ＰＨ值和盐基度的分析和估算,给出了聚铝溶液的极限ＰＨ值和极限盐基度与总溶解铝浓度的关系曲线,最终计算结果表明：在平衡条件下,聚铝溶液的ＰＨ值和盐基度具有相关性,即当基中一个参数发生变化时。另一个参数必然要发生相应的改变。     

红河州磷肥厂6万t／a半水－二水法磷酸装置试生产情况

主要介绍了红河州磷肥厂引进的６万ｔ／ａ半水一二水法磷酸生产技术及三年来该装置的试生产情况，着重介绍了针对试生产中存在问题进行的技术改造。现该套装置运行正常，生产指标已接近设计值。     

MOLECULAR PRINCIPLE OF CORRESPONDING STATES FOR VISCOSITY AND THERMAL CONDUCTIVITY OF FLUID MIXTURES

Conformal solution theory is developed for the viscosity and thermal conductivity of fluid mixtures. The procedure involves expanding the transport coefficient for the mixture about the value for an ideal solution, using groupings of the potential parameters and molecular mass as expansion coefficients. The parameters for the ideal solution are chosen so as to annul the first-order term in this expansion, thus encouraging rapid convergence. This yields mixing rules (similar to those of the van der Waals 1 theory for thermodynamic properties) for the potential parameters and molecular mass of the reference fluid. Reference fluid properties are obtained from pure fluid corresponding states correlations

By making calculations for dilute gas mixtures and comparing with Chapman-Enskog theory, it is found that the first-order theory works well for mixtures of quite widely different energy parameters (ε) and molecular masses; it is more sensitive to the size difference of the molecular components, however. For cryogenic liquid mixtures composed of simple liquids good results are obtained using two-parameter corresponding states for the reference fluid. For polyatomic fluids it is necessary to use a three-parameter corresponding states approach for the pure fluids. A method of introducing a third parameter, while retaining the simplicity of having only two independent variables, is used for such fluids. Good results are obtained for a variety of binary mixtures. The method is of particular value for multicomponent fluids. Thus, without fitting any parameters from ternary data the theory predicts viscosities for the system carbon tetrachloride/n-hexane/benzene over the full composition range with a standard deviation of only 1.69%.     

Ag/CeO2-ZnO催化剂上甲醇部分氧化制氢气研究

研究了用于甲醇部分氧化制氢气反应的Ag/CeO2-ZnO催化剂的制备条件以及反应条件对催化剂性能的影响.Ag/CeO2-ZnO催化剂中银含量、焙烧温度、反应温度以及反应气的比例等对催化剂性能具有很大的影响.Ag/CeO2-ZnO催化剂的制备条件以及反应条件控制在一定范围内时,Ag/CeO2-ZnO催化剂对甲醇部分氧化制氢气具有很高的催化活性与选择性.