Boosting photocatalytic Suzuki coupling reaction over Pd nanoparticles by regulating Pd/MOF interfacial electron transfer

Palladium-catalyzed C-C coupling reactions are of significant importance, but they often require harsh conditions. Herein, we report an interface-regulated photocatalytic Suzuki coupling reaction over Pd nanoparticles supported on a metal-organic framework (MOF), ZIF-8. Two Pd/MOFs were synthesized, Pd_PVP/ZIF-8 and Pd/ZIF-8, which have similar Pd sizes and loading amounts, except that the former contains poly(vinylpyrrolidone) (PVP) as a surfactant. The diffuse-reflectance infrared Fourier transform of CO adsorption (CO-DRIFT) indicates that Pd/ZIF-8 represents a more negative electronic state of Pd than Pd_PVP/ZIF-8. In the photocatalytic Suzuki coupling reaction between iodobenzene and phenylboronic acid, Pd/ZIF-8 exhibits excellent performance (99.1% yield), much better than that of Pd_PVP/ZIF-8 (57.9% yield). Moreover, Pd/ZIF-8 is highly stable and shows broad substrate scope for this reaction. The superior activity of Pd/ZIF-8 can be attributed to sufficient electron transfer between the MOFs and Pd nanoparticles in the absence of an interfacial surfactant. This work provides new insights into a Pd-catalyzed C-C coupling reaction involving photocatalysis and interfacial electron transfer.     

基于响应面和NSGA-II的AGV系统多目标优化配置

AGV（automated guided vehicle）系统对于制造系统的生产柔性和生产效率具有重要作用,由于AGV系统具有许多的变量且有动态性、随机性特点,其优化配置比较复杂。提出了一种将系统仿真、数学解析和多目标优化相结合的方法,对AGV系统进行了优化配置;运用离散事件仿真模拟AGV系统运行,利用敏感性分析分离设计变量,采用析因试验和响应面方法拟合多目标优化数学模型,基于非支配解排序多目标遗传算法求解多目标优化解。通过AGV系统实例,证明了该方法的有效性,可为制造系统和物流仓储领域中AGV系统的优化配置提供一种有效的系统性分析方法。     

Long-Time Behavior and Density Function of a Stochastic Chemostat Model with Degenerate Diffusion

This paper considers a stochastic chemostat model with degenerate diffusion. Firstly, the Markov semigroup theory is used to establish sufficient criteria for the existence of a unique stable stationary distribution. The authors show that the densities of the distributions of the solutions can converge in L¹ to an invariant density. Then, conditions are obtained to guarantee the washout of the microorganism. Furthermore, through solving the corresponding Fokker-Planck equation, the authors give the exact expression of density function around the positive equilibrium of deterministic system. Finally, numerical simulations are performed to illustrate the theoretical results.

     

武器装备体系组合规划的高维多目标优化决策

针对武器装备体系组合规划问题中存在多类相互冲突的高维多目标问题(目标数 ≥ 5),提出了一种三阶段的集成优化决策方法. 首先运用目的规划技术将高维多目标问题转换为一般多目标优化模型(目标数 ≤ 3); 然后提出一种多目标差分进化算法,用于搜索属于决策者关心区间的非劣解集; 最后提出基于预测优化的理想点算法,可生成精确满足决策者偏好的最佳折衷解. 通过某侦察装备体系组合规划示例,证明了各算法模块的优势和该方法的整体有效性,可为武器装备发展和顶层规划提供决策支持.     

Discovering non-terminating inputs for multi-path polynomial programs

This paper investigates the termination problems of multi-path polynomial programs （MPPs） with equational loop guards. To establish sufficient conditions for termination and nontermination simultaneously, the authors propose the notion of strong/weak non-termination which under/over- approximates non-termination. Based on polynomial ideal theory, the authors show that the set of all strong non-terminating inputs （SNTI） and weak non-terminating inputs （WNTI） both correspond to tile real varieties of certain polynomial ideals. Furthermore, the authors prove that the variety of SNTI is computable, and under some sufficient conditions the variety of WNTI is also computable. Then by checking the computed SNTI and WNTI varieties in parallel, termination properties of a consid- ered MPP can be asserted. As a consequence, the authors establish a new framework for termination analysis of MPPs.     

SHL6.5t／h锅炉掺烧无烟煤及扩容技术改造

论述了ＳＨＬ６．５ｔ／ｈ锅炉改造后掺烧６０％－７０％无烟煤的方法，并使锅炉的产汽量增加到８ｔ／ｈ，改造中采用了人字拱，热管式换热器等我技术，取得了显著的经济效益。     

刺槐抗旱造林试验研究

采用农膜、根宝、生根粉、保水剂在干旱地区对刺槐造林成活率进行了田间对比试验。结果表明：农膜、根宝对提高造林成活率的影响显著高于常规造林方法，分别提高43．63％，36．36％，而生根粉和保水剂与常规造林法比较差异不显著。4种产品中根宝的经济适用性优于其它产品。     

为语言学中的某些术语正名

本文主要对现代语言学中一些不尽合理的术语加以分析,并提出了应该采用的科学合理的术语;同时对一些尚未引起注意的文字间的关系,进行了分析说明。     

《汇编语言》课程设计的改革与实践

本通过对《汇编语言》课程设计各环节的深刻讨论，在总结以往工作经验的基础上，为读推荐了一种较实用的《汇编语言》课程设计的改革方案，经实践检验具有一定的推广价值。     

计算机多机通讯及其在变电站中的应用

变电站是供电过程中的重要组成部分，怎样对变电站中的各种参数进行实时监控，尤其是边远无人地区的变电站，以免除人工记录带来的种种不便及错误，成为本文所讨论的问题。该系统解决了对变电站数据的自动实时检测。