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Poly‐p‐phenyleneterephthalamide (PPTA) is widely used in national defense, military industry, and aerospace. However, with weak compression resistance and twist resistance, development of PPTA is greatly impeded. In this work, a novel rigid rod polymer was synthesized by polycondensation of 2,6‐dihydroxyterephthalic acid with 2,3,5,6‐tetraminopyridine which have a large quantity of hydrogen bonds between these polymer chains which provide excellent thermal properties named poly [N‐(2,5‐diamino‐6‐[imino]‐3‐pyridyl)‐4‐formyl‐2,6‐dihydroxybenzamide] (PPDA). The structure of the polymers was characterized by X‐ray diffraction and Fourier transform infrared spectroscopy. The resulting showed that PPDA has good thermal stability and crystallinity, the maximum thermal decomposition temperature close to 900°C under the nitrogen atmosphere. At the same time, PPDA was insoluble in most organic solvents and exhibited good chemical stability. This indicated a superior performance over that of the poly(2,6‐diimidazo(4,5‐b:4′5′‐e)pyridinylene‐1,4(2,5‐dihydroxy)phenylene). In addition, we can foresee that PPDA will play an important role in prospective surgery and aramid areas. [ABSTRACT FROM AUTHOR]

Research has been conducted on the fulleride anions. The preparation of these anions by means of deprotonation of fullerene C-H bonds and the alkylation of fullerene ions prepared electrochemically are described.

This article used four types rock powder, including granite, gneiss, basalt and limestone, to replace 20% cement to prepare concrete with a water -to -binder of 0.47 or 0.32, and tested their workability and 3 ~1080 d strength, such as cube compressive strength and splitting tensile strength, when the fly ash concrete was selected as the reference sample. The testing results show that the rock powder will affect the concrete workability in different level, and the development model of concrete strength exhibit two-stage feature which contained the rapid development period at 3~180 d and the slow development period at 180 d to 1080 d. Compound exponential function can be used to accurately predict the strength development model of rock powder concrete. The compressive strength ratio of rock powder concrete and fly ash concrete was 0.7~0.9 while the splitting tensile strength ratio was 0.8~1.0. The relationship of compressive strength and splitting tensile strength of rock powder strength can be described by powder function. The 28~90d strength of rock powder concrete was 0.7~0.9 of long-age (1080 d) strength. [ABSTRACT FROM AUTHOR]

Photocatalysis with universality and feasibility has been widely applied to degrade pollutants that mainly exist in gas and liquid systems. However, the photocatalytic degradation of contaminants on solid surfaces is rarely reported. The investigation of the photocatalytic degradation mechanism of pesticide on a solid surface will provide a vital reference for removing pesticide residues on fruit surfaces. Here, we discovered that in situ photocatalytic degradation on solid surface (PDSS) is a moisture dependent process regulated by the interaction between TiO2 and H2O. The interaction mechanism between TiO2 and moisture was revealed by X-ray photoelectron spectroscopy and in situ FT-IR. Meanwhile, we investigated a water layer formed between TiO2 and water on the surface by density functional theory. The photocatalytic degradation process of imidacloprid on the solid surface is proposed. This work explores the H2O impact on photocatalysis in solid surfaces and provides a significant reference for removing pesticide residues in realistic environmental conditions. [ABSTRACT FROM AUTHOR]

Byline: Junpeng Shao, Guihua Han, Zhongwen Wang, Wang Dong In order to improve the rigidity performance of the hydrostatic thrust bearing, an electro-hydraulic pressure servo system is proposed to adjust oil film pressure in real-time. A rapid prototyping method is adopted to identify the model of the pressure servo system. A non-linear hybrid controller is applied, which is composed of a classical PID controller and a fuzzy controller based on self-adjusting modifying factor and a fuzzy switching mode is employed to reject undesirable disturbances caused by the switchover between the two control methods. The identification model of the practical system and the feasibility of the control scheme are validated by hardware-in-the-loop simulation experiments. The experiments results show that the hybrid PID controller exhibits high bearing rigidity (the maximum overshoot is 0.07, while PID is 0.2), improves stability and rapidity when load changes. Further, the control performance can be enhanced through matching the load rigidity and mass reasonably; and it is feasible to apply electro-hydraulic pressure servo system to hydrostatic thrust bearing.

Research has been conducted on C (sub)60. The authors describe solution-phase electron-transfer reaction of C (sub)60 with alpha-bromoacetonitrile, zinc, alpha-bromo ketones, allyl bromide and benzyl bromide in DMF carried out in order to prepare C (sub)60 monoalkylated derivatives.

The nicotinic acetylcholine receptor (nAChR) is one of the targets for developing drugs for the treatment of central nervous system (CNS) disorders and for control of agricultural pests. Pyrido[3,4‐b] homotropane (PHT) was originally designed and synthesized by Kanne and co‐workers and showed strong affinity binding to nAChR. PHT has a novel aza‐[4.2.1]nonane skeleton. Owing to its excellent biological activities and novel chemical structure, synthetic and medicinal chemists have been attracted by this molecule. Some PHT analogues with bridged aza‐[n.2.1] skeletons were also designed and synthesized via different strategies. Herein, we summarize the syntheses of PHT and its analogues. Their biological activity study is also briefly discussed. [ABSTRACT FROM AUTHOR]