Construction of the nano-carbon connections among the carbon-coated LiFe0.8Mn0.2PO4 grains by sol-gel technique

Nano-carbon connections among carbon-coated LiFe_0.8Mn_0.2PO₄ grains are successfully constructed using polyacrylic acid and sucrose as carbon sources by sol-gel method, which can improve the electrochemical performance of LiFe_0.8Mn_0.2PO₄. Samples were characterised by X-ray diffraction, scanning electron microscopy and electrochemical tests. The electrochemical tests show LiFe_0.8Mn_0.2PO₄ grains connected by nano-carbon networks obtain the discharge specific capacity of 165 mA h g^?1 at 0.1 C rate and excellent rate capability. Its specific capacity reaches 122 mA h g^?1 at 5 C rate. Its capacity retention at 5 C rate attains 97% cycled 100 cycles. Therefore the construction of nano-carbon networks offers an effective and convenient technique to improve the specific capacities and rate capabilities of electrode materials of low electronic conductivity.     

17.1%-Efficiency organic photovoltaic cell enabled with two higher-LUMO-level acceptor guests as the quaternary strategy

Quaternary blended organic solar cells utilize four blended material components(one donor plus three acceptors, two donors and two acceptors, or three donors plus one acceptor) as the active layer materials. The use of four material components allows us to have more material selections and more mechanism choices to improve the photon-to-electron conversion efficiency. In this contribution, we present a new case of quaternary material system, that shows 17.1% efficiency obtained by adding IDIC and PC_(71)BM as the guest acceptors of the host binary of PM6:Y6. The lowest unoccupied molecular orbital(LUMO) levels of IDIC and PC_(71)BM are both higher than that of Y6, which is one reason to obtain increased open-circuit voltage(V_(oc)) in the quaternary device. Upon introduction of IDIC and PC_(71)BM as the acceptor guests, the hole and electron mobilities are both increased, which contributes to the increased short-circuit current-density(J_(sc)). Effects of the weight ratios of the three acceptor components are investigated, which demonstrates that the increased hole and electron mobilities, the accelerated hole-transfer, and the reduced monomolecular recombination are the factors contributing to the increased J_(sc)and fill-factor. This case of quaternary device demonstrates the applicability of the quaternary strategy in increasing the device functions and hence the efficiencies in the field of organic photovoltaic cells.     

Chaotic resonance in Izhikevich neural network motifs under electromagnetic induction

Nonlinear Dynamics - Chaotic resonance (CR) is the response of a nonlinear system to weak signals enhanced by internal or external chaotic activity (such as the signal derived from Lorenz system)....     

独立学院大学生创业观的塑造

针对独立学院创业教育的现状、优势和存在的问题,提出在大学生创业观上必须正确处理好自身条件与社会需求、个人就业观与家庭期望、学校创业教育与个人专业学习三大关系。     

竖向地震加速度对堤坝抗震性能影响分析

将堤坝地震动力响应的有限元效值分析方法与坝坡地震滑移量的Newmark估算方法相结合,通过效值计算探讨了水平与竖向加速度组合作用下堤坝的抗震稳定性．首先以堤坝地震动力响应的二维平面应变有限元分析为基础,按照Makdisi与Seed所建议的计算方法估算堤坝安全系效的变化过程,依此对地震过程中堤坝的瞬态稳定性进行评价．对瞬时安全系效小于1的时段,采用Newmark方法估算滑坡体的可能滑移量,进而由此评判堤坝的抗震安全性．最后,针对一座高度为100m的堤坝,分别采用正弦波和实际El-Centro地震加速度记录作为激励,通过具体效值计算讨论了竖向地震加速度对堤坝抗震稳定性的影响．研究表明竖向加速度对堤坝瞬态稳定性及地震滑移量均具有显著影响,在堤坝抗震设计中应合理地予以考虑．     

Twiston vs. random fluctuation as the source of the rapid motion of polyethylene in the inclusion complex with perhydrotriphenylene

Recently molecular dynamics simulations were performed for polyethylene in the inclusion complex with perhydrotriphenylene. The system contained ninety molecules of perhydrotriphenylene, arranged in six stacks of fifteen molecules each, and one molecule of n-tetracontane, C₄₀H₈₂. The internal CH₂-CH₂ bonds in n-tetracontane have a very strong preference for the trans state. Nevertheless, the chain exhibits a high degree of internal flexibility. This motion produces a characteristic pattern in δ|ψ N + i ψi| vs. N, where ψ_i describes the instantaneous angle of a C-H bond vector at carbon atom i about the axis defined by the channel, and δ denotes the fluctuation. The pattern expected for δ|ψ N + i ψi| vs. N is derived for the case where the rapid internal motion is produced by a twiston. It is compared with the results from the simulation and from the expectation for the case where the rapid motion arises from uncorrelated internal fluctuations within the trans state at each CH₂-CH₂ bond.     

Newly Emerging Strategies in Antiviral Drug Discovery: Dedicated to Prof. Dr. Erik De Clercq on Occasion of His 80th Anniversary

Viral infections pose a persistent threat to human health. The relentless epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health problem, with millions of infections and fatalities so far. Traditional approaches such as random screening and optimization of lead compounds by organic synthesis have become extremely resource- and time-consuming. Various modern innovative methods or integrated paradigms are now being applied to drug discovery for significant resistance in order to simplify the drug process. This review provides an overview of newly emerging antiviral strategies, including proteolysis targeting chimera (PROTAC), ribonuclease targeting chimera (RIBOTAC), targeted covalent inhibitors, topology-matching design and antiviral drug delivery system. This article is dedicated to Prof. Dr. Erik De Clercq, an internationally renowned expert in the antiviral drug research field, on the occasion of his 80th anniversary.     

Upper Bound of the Number of Zeros for Abelian Integrals in a Kind of Quadratic Reversible Centers of Genus One

By using the methods of Picard-Fuchs equation and Riccati equation, we study the upper bound of the number of zeros for Abelian integrals in a kind of quadratic reversible centers of genus one under polynomial perturbations of degree $n$. We obtain that the upper bound is $7[(n-3)/2]+5$ when $n\ge 5$, $8$ when $n=4$, $5$ when $n=3$, $4$ when $n=2$, and $0$ when $n=1$ or $n=0$, which linearly depends on $n$.     

VISA存储网络系统元数据管理的研究

为了提高虚拟接口存储结构(VISA)存储网络系统的性能,设计实现了基于块级的元数据管理子系统.该系统的元数据管理子系统实现了物理设备和逻辑设备的块地址空间之间的映射,支持动态地址映射、动态块重分配和热块冗余技术,可以对I/O请求的路径和数据传输的路径完全控制,从而有效地改善了VISA存储网络系统的I/O性能,使数据布局更加合理,提高了存储管理的灵活性,初步实现了负载均衡,并且使VISA存储网络系统具备了容错能力和节点的动态增加能力.测试结果表明:在加入了基于块级的元数据管理功能带来相应开销的情况下,VISA存储网络系统原型与传统存储网络系统iSCSI Linux MD相比,传输延迟减少了8.2%～21.0%,传输吞吐率提高了8.7%～11.9%.