Metal–organic supramolecular compounds self-assembled from [Mg(H2O)6]2+ clusters and ferrocene-containing carboxylic acids to inverse lipid-like layered structures with good pH response

Two metal–organic supramolecular compounds, [Mg(H₂O)₆]·2FcCO₂·2H₂O (1) and [Mg(H₂O)₆]·2FcCOC₆H₄CO₂·2H₂O (2), were prepared by solvothermal synthesis. The solids exhibit non-covalent self-assembly and layered structures with unprecedented inverse lipid-like bilayer arrangements. Further investigations revealed that the layered structures were sensitive to pH changes. The proposed synthesis method in this report would allow development of new types of pH-responsive materials.     

Structural Tunability and Diversity of Two-Dimensional Lead Halide Benzenethiolate

Two-dimensional (2D) organic-inorganic hybrid materials are currently of great interest for applications in electronics and optoelectronics. Here, the synthesis and optical properties of a new type of halide-organothiolate-mixed 2D hybrid material, Pb₂X(S-C₆H₅)₃, are reported, in which X is a halide (I, Br, or Cl). Different from conventional lead-based 2D layered materials, these compounds feature unusual five-coordinated lead centers with a stereochemically active electron lone pair on the lead atoms and four-coordinated iodine atoms. The Pb₂X(S-C₆H₅)₃ materials feature an indirect bandgap, strongly emissive long-lived self-trap states, and an extremely large Stokes shift. Interestingly, the optical bandgap of the materials can be tuned through variation of the halides; however, the photoluminescence is less sensitive to the composition and is more likely dominated by lead-sulfur lattice interactions or the lead lone-pair electrons. Our results support that a halide–organothiolate mixed anion hybrid structure offers a unique platform for discovering new exciting 2D electronic materials.     

Outsourcing and capacity planning in an uncertain global environment

Firms employing offshore outsourcing strategies may face both exchange rate and demand uncertainties. In this paper, we show that the firms may benefit from operational option to switch production by keeping capacities with both domestic and foreign suppliers. The value of the operational option increases as the exchange rate uncertainty or demand uncertainty increases. In addition, when the firms become risk-averse, they may use domestic capacity to hedge against offshore capacity. As a result, the firms may choose to hold local capacity even if it exhibits negative marginal contribution to the profit. Furthermore, risk-averse firms may keep more total capacity than risk-neutral firms.     

单脉冲加载的Hopkinson扭杆装置

分析了反复加载现象及其对变形微结构的影响，介绍了对现有标准Ｈｏｐｋｉｎｓｏｎ扭杆的改进。改进后的新型Ｈｏｐｋｉｎｓｏｎ扭杆是具有特殊设计的加载头和传动器的四杆系统，它完全消除了应力波的反复加载效应，实现了过程的单脉冲加载。改进前后的实验波形和变形局部化微结构形态的比较证实了改进的有效性。     

酚醛玻璃钢动态本构关系的实验研究

本文叙述了在轻气炮上作高速撞击实验,使用碳膜压阻传感器,一次记录多个应力历史波形,用Lagrange分析和路径线方法,求材料动态本构关系的方法。给出了应力在2 GPa、应变率4105S-1以下酚醛玻璃钢的数值形式本构关系。探讨了强应力脉冲在酚醛玻璃钢中传播衰减的物理原因。     

一种光学成像垂轴几何畸变校正方法

光学成像系统非线性几何畸变的校正仍是一个未能很好解决的课题，一些方法还不能很好地实用。本文对成像系统主要因镜头的失常导致的非线性几何畸变，分析了成像过程。提出一种以径向几何畸变为主的非线性几何畸变模型。依据此模型，提出一种通用的校正方法，应用计算机处理，可对实际的非线性几何畸变图像进行校正。文中用所提出的方法对实际成像的畸变进行了校正，给出了校正实验结果，校正效果良好，有一定的实验价值。     

Switchable and Highly Robust Ultralong Room-Temperature Phosphorescence from Polymer-Based Transparent Films with Three-Dimensional Covalent Networks for Erasable Light Printing

In this work, an efficient polymer-based organic afterglow system, which shows reversible photochromism, switchable ultralong organic phosphorescence (UOP), and prominent water and chemical resistance simultaneously, has been developed for the first time. By doping phenoxazine (PXZ) and 10-ethyl-10H-phenoxazine (PXZEt) into epoxy polymers, the resulting PXZ@EP-0.25 % and PXZEt@EP-0.25 % films show unique photoactivated UOP properties, with phosphorescence quantum yields and lifetimes up to 10.8 % and 845 ms, respectively. It is found that the steady-state luminescence and UOP of PXZ@EP-0.25 % are switchable by light irradiation and thermal annealing. Moreover, the doped films can still produce conspicuous UOP after soaking in water, strong acid and base, and organic solvents for more than two weeks, exhibiting outstanding water and chemical resistance. Inspired by these exciting results, the PXZ@EP-0.25 % has been successfully exploited as an erasable transparent film for light printing.     

Synthesis of water and oil dual-absorption materials by bicontinuous microemulsion polymerization

Water and oil dual-absorption materials for application in oil well cement for self-healing micro creaks has been synthesized through bicontinuous microemulsion polymerization. Bicontinuous structure of microemulsion was used to implement the performance of absorbing both water and oil. Phase behavior of the microemulsion system was analyzed by “ε–β fish-shape phase diagram” from which middle phase line was obtained to provide the formula of polymerization. The product was characterized using scanning electron microscope (SEM), pore size distribution (BET), water/oil absorption rate test and water/oil absorption speed test. SEM analysis showed that neither water absorption component nor oil absorption component formed separated particles, while they formed continuous component respectively. Due to the bicontinuous structure and pores, the materials have fast water and oil absorption rate.     

Diversity synthesis of complex pyridines yields a probe of a neurotrophic signaling pathway

Recognizing the value of including complex pyridines in small-molecule screening collections, we developed a previously unexplored [2 + 2 + 2]-cycloaddition of silyl-tethered diynes with nitriles. The tether provides high regioselectivity, while the solvent THF allows catalytic CpCo(CO)(2) to be used without exogenous irradiation. One of the resulting bicyclic and monocyclic (desilylated) pyridines was identified as an inhibitor of neuregulin-induced neurite outgrowth (EC(50) = 0.30 microM) in a screen that probes a pathway likely to be involved in breast cancers and schizophrenia.     

Influences of direction and magnitude of Mg2+ doping concentration gradient on the performance of full concentration gradient cathode material

Journal of Solid State Electrochemistry - Achieving a highly stable structure is the key to successfully enhancing the cycling stability and safety performance of LiNi0.8Co0.1Mn0.1O2 (NCM811)...