Phosphorene: a Potential 2D Material for Highly Efficient Polysulfide Trapping and Conversion

Effectively trapping lithium polysulfide species and accelerating the reaction conversion kinetics are the main strategies to improve the performance of lithium-sulfur(Li-S) batteries. Since the researchers found in 2014 that two-dimensional(2D) phosphorene nanosheets could be exfoliated from the bulk black phosphorus, numerous researches have been devoted to exploring the phosphorene with unique properties for the application in Li-S batteries. In this review, we summarize the recent theoretical and experimental progress of phosphorene for Li-S batteries. Besides, we also introduce the relationship between the interfacial interaction on phosphorene and the performance enhancement of Li-S batteries. Furthermore, future challenges and remaining opportunities for phosphorene in Li-S batteries are finally discussed.     

噪声对小白鼠条件反射建立的影响

以小白鼠为实验对象，就噪声对其条件反射建立的影响进行了研究。结果表明：噪声可影响条件反射的建立，对成年鼠的影响不具永久性，对幼年鼠的影响可保持到成年期。     

Two-dimensional vermiculite separator for lithium sulfur batteries

A lamellar vermiculite separator assembled with exfoliation vermiculites is developed for lithium sulfur batteries. The vermiculite separator can simultaneously suppress the parasitic reactions induced by polysulfide intermediate shuttle, and prevent the short circuit by potential lithium dendrite penetration with the ultrahigh Young's modulus.     

A nanoscale field effect data storage of bipolar endo-fullerenes shuttle device

We investigated the internal dynamics of an electro-fluid shuttle memory element, consisting of K⁺@C₆₀ and F⁻@C₆₀ encapsulated in a C₆₄₀ nanocapsule. Energetics and operating responses of bipolar endo-fullerenes shuttle memory device, (K⁺@C₆₀–F⁻@C₆₀)@C₆₄₀, were examined by classical molecular dynamics simulations under the external force fields.     

In-situ polymerized cross-linked binder for cathode in lithium-sulfur batteries

Volume expansion and polysulfide shuttle effect are the main barriers for the commercialization of lithium-sulfur(Li-S) battery.In this work,we in-situ polymerized a cross-linked binder in sulfur cathode to solve the aforementioned problems using a facile method under mild conditions.Polycarbonate diol(PCDL),triethanolamine(TEA) and hexamethylene diisocyanate(HDI) were chosen as precursors to prepare the cross-linked binder.The in-situ polymerized binder(PTH) builds a strong network in sulfur cathode,which could restrain the volume expansion of sulfu r.Moreover,by adopting functional groups of oxygen atoms and nitrogen atoms,the binder could effectively facilitate transportation of Li-ion and adsorb polysulfide chemically.The Li-S battery with bare sulfur and carbon/sulfur composite cathodes and cross-linked PTH binder displays much better electrochemical performance than that of the battery with PVDF.The PTH-bare S cathode with a mass loading of 5.97 mg/cm^2 could deliver a capacity of 733.3 mAh/g at 0.2 C,and remained 585.5 mAh/g after 100 cycles.This in-situ polymerized binder is proved to be quite effective on restraining the volume expansion and suppressing polysulfide shuttle effect,then improving the electrochemical performance of Li-S battery.     

Nonlinear-map model for bus schedule in capacity-controlled transportation

We study the schedule of shuttle buses in the transportation system controlled by capacity. The bus schedule is closely related to the dynamic motion of buses. We present the nonlinear-map model for the dynamics of shuttle buses. The motion of shuttle buses depends on the inflow rate. The dependence of the fixed points on the inflow is derived. The dynamic transitions occur with increasing the value of inflow rate. At the dynamic transition point, the motion of buses changes from a stable state to an unstable state and vice versa. The shuttle buses display periodic, quasi-periodic, and chaotic motions in the unstable state. In the unstable state, the number of riding passengers fluctuates complexly with varying trips. The bus schedule is governed by the complex motion of buses.     

Solid Interhalogen Compounds with Effective Br0 Fixing for Stable High-energy Zinc Batteries

Though massive efforts have been devoted to exploring Br-based batteries, the highly soluble Br₂/Br₃⁻ species causing rigorous “shuttle effect”, leads to severe self-discharge and low Coulombic efficiency. Conventionally, quaternary ammonium salts such as methyl ethyl morpholinium bromide (MEMBr) and tetrapropylammonium bromide (TPABr) are used to fix Br₂ and Br₃⁻, but they occupy the mass and volume of battery without capacity contribution. Here, we report an all-active solid interhalogen compound, IBr, as a cathode to address the above challenges, in which the oxidized Br⁰ is fixed by iodine (I), thoroughly eliminating cross-diffusing Br₂/Br₃⁻ species during the whole charging and discharging process. The Zn||IBr battery delivers remarkably high energy density of 385.8 Wh kg⁻¹, which is higher than those of I₂, MEMBr₃, and TPABr₃ cathodes. Our work provides new approaches to achieve active solid interhalogen chemistry for high-energy electrochemical energy storage devices.     

A simple greedy algorithm for a class of shuttle transportation problems

Greedy algorithms for combinatorial optimization problems are typically direct and efficient, but hard to prove optimality. The paper presents a special class of transportation problems where a supplier sends goods to a set of customers, returning to the source after each delivery. We show that these problems with different objective functions share a common structural property, and therefore a simple but powerful generic greedy algorithm yields optimal solutions for all of them.     

基于PCS7与PROFIBUS的水泥窑头生产线控制系统

以水泥窑头生产线为研究对象,根据实际工艺流程和控制要求,设计了基于PCS7与PRO-FIBUS的集散控制的水泥窑头生产线过程控制系统。该系统分为:操作管理层、过程控制层及现场设备层3个层次,构建了控制系统网络(工业以太网)和现场总线网络(PROFIBUS-DP)组成的管控一体化网络。通过现场运行证明,该系统运行稳定可靠,具有很好的应用和推广价值。