Crystalline and amorphous metal sulfide composite electrode materials with long cycle life:Preparation and performance of hybrid capacitors

Crystalline@amorphous NiCo_(2)S_(4)@MoS_(2)(v-NCS@MS)nanostructures were designed and constructed via an ethylene glycol-induced strategy with hydrothermal synthesis and solvothermal method,which simultaneously realized the defect regulation of crystal NiCo_(2)S_(4) in the core.Taking advantage of the flexible protection of an amor-phous shell and the high capacity of a conductive core with defects,the v-NCS@MS electrode exhibited high specif-ic capacity(1034 mAh·g^(-1) at 1 A·g^(-1))and outstanding rate capability.Moreover,a hybrid supercapacitor was assembled with v-NCS@MS as cathode and activated carbon(AC)as anode,which can achieve remarkably high specific energy of 111 Wh·kg^(-1) at a specific power of 219 W·kg^(-1) and outstanding capacity retention of 80.5%after 15000 cycling at different current densities.

Spurious Dianeutral Mixing in a Global Ocean Model Using Spherical Centroidal Voronoi Tessellations

In order to quantitatively evaluate the spurious dianeutral mixing in a global ocean model MPAS-Ocean （Model for Prediction Across Scales） using a spherical centroidal voronoi tessellations developed jointly by the National Center for Atmospheric Research and the Los Alamos National Laboratory in the United States, we choose z＊ vertical coordinate system in MPAS-Ocean, in which all physical mixing processes, such as convection adjustment and explicit diffusion parameter schemes, are omitted, using a linear equation of state. By calculating the Reference Potential Energy （RPE）, front revolution position, time rate of RPE change, probability density function distribution and dimensionless parameter 2＂, from the perspectives of resolution, viscosity, Horizontal Grid Reynolds Number （HGRN）, Rea, and momentum transmission scheme, using two ideal cases, overflow and baroclinic eddy channel, we qualitatively analyze the simulation results by comparison with the three non-isopycnal models in Ilicak et al. （2012）, i.e., MITocM, MOM, and ROMS. The results show that the spurious dianeutral mixing in the MPAS-Ocean increases over time. The spurious dianeutral transport is proportional to the HGRN directly and is reduced by increasing the lateral viscosity or using a finer resolution to control HGRN. When the HGRN is less than 10, spurious transport is reduced significantly. When using the proper viscosity closure, MPAS-Ocean performs better than MIT6c and MOM, closely to ROMS, in the 2D case without rotation, and much better than the above-mentioned three ocean models under the condition of 3D space with rotation due to the cell area difference between the hexa- gon cell and the quadrilateral cell with the same resolution. Both the Zalesak （1979） flux corrected transport scheme and Leith closure in MPAS-Ocean play an excellent role in reducing spurious dianeutral mixing. The performance of Leith scheme is preferable to the condition of three-dimensional baroclinic eddy.

制度逻辑视角下新兴市场跨国企业的组织正当性平衡战略--以万华集团跨国并购为例

本文从制度逻辑视角探讨新兴市场企业基于组织正当性平衡管理的混合逻辑战略及其过程实现机制。通过2009—2018年万华集团的跨国并购案例研究,发现新兴市场企业在东道国面临制度逻辑的国别冲突和治理竞争双向挑战,组织正当性管理焦点呈现外部到内部的动态变化;结构型混合和组合型混合战略在跨国并购不同阶段的动态切换和组合运用,有助于企业内部多重逻辑从区间隔离转向组合协作,组织正当性实现外强内弱到内外同步增强的平衡状态。相关研究为新兴市场企业如何运用混合逻辑战略实现组织正当性动态平衡提供了理论补充,同时也为中国跨国企业正当性战略选择提供实践指导。

Flexible Si/PEDOT：PSS hybrid solar cells

Si hybrid solar cells have attracted tremendous research attention in recent years because of their low production costs and high performance. However, flexible Si hybrid solar cells have rarely been reported owing to the difficulty of fabricating single-crystalline Si with good flexibility. In this study, we fabricated flexible Si/PEDOT：PSS hybrid solar cells with micro-pyramid-structured Si light absorbers using a facile approach. Compared with planar flexible hybrid solar cells with a power-conversion efficiency of 4%, solar cells with micro-pyramid-structured Si light absorbers have a higher efficiency of 6.3%. External quantum efficiency and electrochemical impedance spectroscopy measurements revealed that the solar cells with micro-pyramid-structured Si light absorbers exhibited a pronounced light-harvesting enhancement in the spectra region of 400-1,000 nm and had a smaller series resistance and larger recombination resistance compared with the planar cells, yielding a higher efficiency. Additionally, in mechanical-bending tests, the flexible solar cells with micro-pyramid-structured Si light absorbers exhibited an excellent performance stability after bending for 600 cycles. Our findings lay the foundation for the real-world applications of flexible Si/PEDOT：PSS hybrid solar cells in next-generation portable electronics.

Numerical study of soil-rock mixture:Generation of random aggregate structure

The soil-rock mixture(SRM) is highly heterogeneous. Before carrying out numerical analysis,a structure model should be generated. A reliable way to obtain such structure is by generating random aggregate structure based on random sequential addition(RSA). The classical RSA is neither efficient nor robust since valid positions to place new inclusions are formulated by trial, which involves repetitive overlapping tests. In this paper, the algorithm of Entrance block between block A and B(EAB)is synergized with background mesh to redesign RSA so that permissible positions to place new inclusions can be predicted,resulting in dramatic improvement in efficiency and robustness.

Hybrid terahertz metamaterial structure formed by assembling a split ring resonator with a metal mesh

We propose a novel metamaterial structure operating at the terahertz band. This structure is assembled by a split ring resonator (SRR) with a metal mesh within a unit cell. Our experimental studies on the composite structure indicate that the coupling of the SRR and metal mesh significantly contribute to the transparency at the terahertz range. Moreover, we experimentally demonstrated the verity of transmission peak of this structure by changing the relative positions of the SRR and the metal mesh. The simulated electric field redistributions support the dependence between position of the two components and the transmission response. This study is the first to report a hybrid metamaterial structure consisting of an SRR array and a metal mesh within a unit cell. The designed process and resonance characteristics of this composite structure make it an excellent candidate for developing tunable terahertz components via integration with the MEMS (Micro Electronic Mechanical System) technology.

Stability analysis for a size-structured model of species in a space-limited habitat

We investigate the stability of steady states of a size- and stage-structured population model, which is a hybrid system of ordinary and partial differential equations with global integral feedbacks. After the formulation of a criterion by spectrum method, we derive conditions for global stability of the trivial state and local stability of the positive equilibrium via the basic reproduction rate. Furthermore, some examples and simulations ure .presented to illustrate the obtained results.