碳布负载高致密Sn/SnBi合金的电催化CO2还原性能

通过分步电沉积法制备碳布(CC)负载高致密Sn/SnBi合金催化剂：首先在CC上电沉积致密Sn颗粒,而后利用酸性电解液部分溶解Sn为Sn²⁺离子,实现在Sn颗粒表面共沉积SnBi合金枝晶,随后经过原位化学氧化及电化学还原步骤将SnBi合金枝晶转变为SnBi合金纳米颗粒(SnBi NPs)。得益于Sn提供形核位点,SnBi枝晶在碳织物表面垂直致密生长,并通过后续氧化还原转化实现了直径约20nm的SnBi合金颗粒在CC上致密均匀生长。CC/Sn/SnBiNPs三维电极在-1.08V(vsRHE)下显示出较高的电催化还原CO₂活性,电流密度高达36mA·cm^-2且甲酸盐产物选择性为94.9%。同时,在连续12h恒电压测试中性能未发生衰减,表明电极具有良好的稳定性。     

JOINT MODEL AND CRITERION OPTIMAL EXPERIMENT DESIGN

In this paper,a new optimal design criterion--joint model and criterion optimal de-sign criterioon is put forward. The design that is subject to this criterion satisfies many kinds of lin-ear optimal criterion and D-optimal criterion on several experiment models at the same time. Theequivalent condition of this optimal design is given. Its iterative algorithm and the algorithm cover-genee are stated.     

广义分散控制系统的结构脉冲固定模

一、引言广义分散控制系统日益受到人们的重视.从80年代后期开始,Chang、王朝珠等人各自提出并讨论了这类系统的脉冲固定模;文[3—7]和[10]从不同的角度讨论了脉冲固定模的特征.本文将从系统结构上讨论脉冲固定模及其结构特征.     

Longitudinal-Random-Field Mixed Ising Model with Arbitrary Spins

The longitudinal-random-fieM mixed Ising model consisting of arbitrary spin values has been studied by the use of an effective field theory with correlations （EFT）. The phase diagrams of systems with mixed spins： σ = 1/2, S = 1; σ = 1/2, S = 3/2 are plotted. Not only the discontinuity at T = 0 K, is found when both longitudinal fields are trimodal distributed, but also the trieritical behavior is observed in these phase diagrams between the bimodal and trimodal distributions of longitudinal fields, which is different from the single-spin one. The appearance of tricritical point is independent of the coordination number and spin values.     

Magnetic properties of a mixed spin- 1/2 and spin- 3/2 transverse Ising model in a longitudinal magnetic field

The mixed spin- 1/2 and spin- 3/2 transverse Ising model in a longitudinal magnetic field is studied within the framework of the effective-field theory with correlations. In this approach the effective-field equations are derived by using a probability distribution method based on the generalized but approximated van der Waerden identities. The total longitudinal and transverse magnetizations, the transverse susceptibility and longitudinal susceptibility and the critical temperatures are obtained. We find a number of interesting phenomena in these quantities, due to the applied transverse field and the longitudinal field.     

大倾角煤层回采巷道矿压显现规律研究

大倾角煤层回采巷道因处于显著的各向异性环境中而难以维护。本文用离散元法分析了回采巷道的变形破坏机理和形式, 结合现场巷道的围岩松动范围实测, 证实巷道的上帮普遍破坏严重, 是整个巷道破坏的突破点, 应重点防范并采用综合支护进行治理。     

岩石失稳破裂的变形突跳研究

针对在非刚性加载条件下岩石失稳破裂过程中变形突跳的特性, 根据时间的不可逆性, 研究了岩石试样在普通试验机下的变形规律及突跳特性, 得到了与尖点突变模式相似的突变机构。再利用突变理论中尖点突变模型研究由试验机和岩石试样组成的力学系统的失稳机制, 结果表明：两者得到的岩石变形突变量非常相似, 且具有同一变化趋势。     

Mode I crack tips propagating at different speeds under differential surface tractions

By application of the theory of complex functions, mode I crack tips propagating at different speeds under differential surface tractions were researched. Analytical solutions are attained by the approaches of self-similar functions. The problems considered can be facilely transformed into Riemann–Hilbert problems and their closed solutions are obtained rather straightforward by this method.     

稀土气态配合物的热力学性质

稀土气态配合物的热力学性质王林山,王之昌（东北大学化学系,沈阳,１１０００６）关键词稀土气态配合物,热力学性质,钆断目前,对稀土液相和固相配合物已有了较为全面的研究,并总结出其热力学性质与原子序数或离子基态之间有钆断、四分组、斜Ｗ等实验规律或效应［１...     

垂直上升圆管内等温泡状流的数值模拟

介绍了描述等温状态下垂直气泡流流动的总体平衡方法(population balanceapproach). 将平均气泡数密度控制方程引入到双流体模型中实现总体平衡. 介绍了描述气泡聚并与破裂机制的Yao和Morel理论模型以及Hibiki等人的实验方法. 利用商业计算流体力学软件ANSYSCFX10, 对圆管特定位置上的5个基本变量:气含率、气泡平均直径、相间表面积浓度以及气体和液体速度沿半径分布进行了模拟计算. 预测结果与实验数据的比较表明,预测结果和实测数据之间有很好的一致性.