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。     

甲苯—正庚烷—庚烯-(3)三元系统的气液平衡

测定了庚烯-（3）的蒸气压。用Gillespie型平衡器测定了甲苯—庚烯-（3）、正庚烷—庚烯-（3）二元系及甲苯—正庚烷—庚烯-（3）三元系统的平衡数据,并分别用Spinner及White方法验证了这些数据,计算结果与实验结果是符合的。三元系统气液平衡的数据不论在工程中或是实验工作上都很重要,过去对三元系统气液平衡的研究虽然有一些,但对甲苯—正庚烷—庚烯-（3）三元系统气液平衡至今在文献上尚未有记载。 由于庚烯-（3）的蒸气压数据不见于文献,我们测定了它的蒸气压数据。正庚烷—甲苯二元系统前人已有许多结果发表,我们进行了一些校核,结果与文献记载符合。甲苯—庚烯-（3）二元系统文献上没有,我们倣效了并用Spinner方法及White方法整理。至于正庚烷—庚烯-（3）二元系统,因为此两组分的性质（如沸点、n_D~（20）等）极其接近,分析误差较大,我们将其当作理想溶液处理,误差当在允许误差以内。 三元系统的分析较为繁难,误差也较大,故希望从理论和实验材料找出其规律性,以校核实验数据和推算未知三元系统。本工作利用三个二元系统的数据,用Spinner以及White的方法推算三元系统的气液平衡,与实验数据相比较,是相互符合的。     

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.     

某水电站厂房洞室群围岩点荷载强度试验成果分析及利用研究

通过厂房地下洞室群围岩点荷载试验,获得了洞室不同深度位置岩石点荷载强度值,试验发现各平洞点荷载强度随洞室深度变化呈现明显的波动性变化特征。研究表明,围岩岩性、断层以及岩石微观结构等是影响岩石点荷载强度的主要因素。其中,围岩中普遍发育的矿物定向排列是导致点荷载强度波动性变化的最主要因素。最后,通过与实测单轴抗压强度比较,得出当岩石单轴抗压强度大于60 MPa时,宜采用成都理工大学推荐公式换算单轴抗压强度,当单轴抗压强度小于60 MPa时,宜采用水利水电规范推荐的转换公式计算岩石单轴抗压强度。     

基于马尔可夫链的自适应性神经网络训练算法

提出一种基于马尔可夫链的自适应性神经网络训练方法,对传统的S型激励函数进行了改进,建立了自适应性的神经网络分类器。在假设样本中噪声服从于正态分布的情况下建立最大似然估计,通过后验概率建立马尔科夫链对样本进行训练,提高了神经网络训练速度。在轴承故障诊断中的测试结果表明,该算法可以迅速稳定地训练出神经网络,有效提高诊断的分类结果。