基于演化博弈的大运河文化带城市间合作发展策略研究

目前我国正向纵深推进大运河文化带建设,合作发展是推进其建设的重要手段。文章引入经济环境、城市间资源互补性、收益分配比例、机会主义收益、惩罚成本等影响因子,运用演化博弈研究大运河文化带沿线城市间合作的形成机制。结果表明良好的宏观经济环境或城市间资源互补性强时,带来高合作超额收益,从而提高城市间向合作演化的可能性;机会收益与惩罚成本之间的差额越小,越能提高合作可能性;相反,合作成本限制了双方的合作;此外,超额收益在城市间的配比影响合作,且影响方向取决于双方投入成本与收益分配比例。因此,当前亟需政府采取各种政策鼓励城市间,特别是资源互补性强的城市间利用良好的经济建设环境加强合作,同时提高监查力度。合作城市在合作中要重视诸如利益分配、违约惩罚机制等管理机制的设计。     

噻吩分子及其与异辛烷二元混合物在MCM-22分子筛中吸附的蒙特卡罗模拟

应用巨正则蒙特卡罗模拟方法研究了噻吩分子以及噻吩与异辛烷混合物在MCM-22分子筛中的吸附和分布. 通过模拟获得了噻吩分子在MCM-22分子筛中不同温度(298、363 和393 K)下的吸附等温线和等量吸附热, 以及298 K时噻吩和异辛烷分子二元混合物在MCM-22分子筛中的吸附及分布情况. 结果表明, 吸附温度和吸附压力对噻吩分子在MCM-22分子筛吸附都有影响, 但等量吸附热受温度和吸附量影响较小. 对于二元混合物的吸附, 噻吩和异辛烷在分子筛中存在竞争吸附过程, 噻吩能够大量吸附在MCM-22分子的十元环和超笼中, 而异辛烷主要吸附在MCM-22分子筛的超笼系统, 从而可以将噻吩分子与异辛烷分子分离开来.     

甲烷在AFS型分子筛中的吸附模拟

采用巨正则系综蒙特卡罗(GCMC)方法模拟了甲烷分子在AFS型分子筛中的吸附量, 并和Dvren等人(Langmuir, 2004, 20: 2683)设计的金属有机骨架中的甲烷吸附量进行比较, 发现AFS型沸石分子筛对甲烷分子有很好的吸附性能, AFS型分子筛是中低压吸附储存天然气系统中的一种比较理想的吸附剂. 采用Dubinin Asakhov(DA)微孔分析方法, 分析了沸石结构对甲烷储量大小的影响, 总结了影响甲烷储量大小的物理因素.     

Baryon number violating nuclear decay

The expressions for baryon number violating nuclear partial decay widths are derived from the interactions as predicted by grand unified theories. Theory predicts that the baryon number violating proton decay inside the nucleus is hindered relative to the free proton decay rate. In the case of closed shell nuclei, the meson spin-isospin dependence of the partial width is the same as that for the nucleon decay. The branching ratios of decay amplitudes depend on the nuclear binding energies. Nuclear structure introduces lepton energy spread of ±49.5 MeV for light closed shell nuclei, while it does not affect the back to back emission of lepton-meson pair.     

Theoretical Investigation of the Topology of Spiroborate-Linked Ionic Covalent Organic Frameworks (ICOFs)

A novel type of ionic covalent organic framework (ICOF) with a spiroborate linkage has been recently designed and synthesized by Zhang and co-workers (Ionic Covalent Organic Frameworks with Spiroborate Linkage, Angew. Chem. Int. Ed. 2016 , 55, 1737–1741). The spiroborate-linked ICOFs exhibit high Brunauer–Emmett–Teller (BET) surface areas and significant amounts of H₂ and CH₄ uptakes, combined with excellent thermal and chemical stabilities. Inspired by the novel properties of ICOFs, with the aim of gaining better understanding of the structure of such spiroborate-linked ICOFs, a series of potential 3D network configurations of ICOFs connected with tetrahedral [BO₄]⁻ nodes were proposed, assuming the [BO₄]⁻ node in spiroborate segments takes a tetrahedral configuration. These ICOFs, in terms of 2D and 3D topology through torsional energy of the [BO₄]⁻ fragment, pore-size distribution, total energy of the framework, and gas adsorption properties were compared and systematically investigated by density functional theory calculations, molecular mechanics, and well-established Grand canonical Monte Carlo simulations. The results indicate that spiroborate-linked ICOFs are likely a mixture of various topologies. Among these architectures, the five-fold interpenetrating model shows the lowest energy and reasonable gas uptakes, therefore, it is considered to be the most possible structure. More importantly, the five-fold interpenetrating model, showing high CH₄ uptakes compared with several classic porous materials, represents a promising CH₄ storage material.     

A six-dimensional gauge-Higgs unification model based on E6 gauge symmetry

We construct a six-dimensional gauge-Higgs unification model with the enlarged gauge group of E₆ on S²/Z₂$S^2/Z_2$ orbifold compactification. The standard model particle contents and gauge symmetry are obtained by utilizing a monopole background field and imposing appropriate parity conditions on the orbifold. In particular, a realistic Higgs potential suitable for breaking the electroweak gauge symmetry is obtained without introducing extra matter or assuming an additional symmetry relation between the SU(2) isometry transformation on the S²$S^2$ and the gauge symmetry. The Higgs boson is a KK mode associated with the extra-dimensional components of gauge field. We also compute the KK masses of all fields at tree level.     

Diffusion and Adsorption of Benzene and Propylene in MFI,MWW and BEA Zeolites:Molecular Dynamics and Grand Canonical Monte Carlo Simulations

The diffusion and adsorption behaviors of benzene and propylene in zeolites MFI, MWW and BEA have been studied by molecular dynamics(MD) and grand canonical Monte Carlo(GCMC) simulations. The diffusion coefficients of benzene and propylene in MFI, MWW and BEA zeolites were calculated by simulating the mean-square displacements(MSD) at 298 and 600 K. Benzene and propylene showed the different adsorption rules in the channels of the three zeolites. For propylene, the molecular loadings decreased in the order:...     

Grand Bochner–Lebesgue space and its associate space

Our aim is to introduce the grand Bochner–Lebesgue space in the spirit of Iwaniec–Sbordone spaces, also known as grand Lebesgue spaces, and prove some of its properties. We will also deal with the associate space for grand Bochner–Lebesgue spaces.     

Proton hexality in local grand unification

Proton hexality is a discrete symmetry that avoids the problem of too fast proton decay in the supersymmetric extension of the standard model. Unfortunately it is inconsistent with conventional grand unification. We show that proton hexality can be incorporated in the scheme of “Local Grand Unification” discussed in the framework of model building in (heterotic) string theory.