Synthesis, Structure and Conductivity of the New Charge-transfer Salt (ET)_2(CH_2=CH-CH_2-SO_3)·H_2O

ET is one of the most famous electron-donor molecules, which forms charge-transfer complexes (abbr. CT-complexes) with various types of counterions. These complexes have received intense attention because a wide range of physical properties such as conductivity and superconductivity1, ferromagnetism2-4 and nonlinear optical properties5 was found in these materials. Although the majority of the ET-based CT-complexes were prepared by combining with inorganic counterions, CT-complexes with o…     

Synthesis and mesomorphic properties of n-butyl-4- [4-((4-n-alkoxyl-tetrafluorophenyl)ethynyl)benzyloxy]benzoates

A homologous series of n-butyl-4-[4-((4-n-alkoxyl-tetrafluorophenyl)ethynyl)benzyloxy]benzoates have been synthesized.Their phase transition temperatures have also measured by polarizing textural observation and confirmed by DSC.     

用遗传算法构造光正交码

提出了一种利用遗传算法构造任意码长、码重、自相关限、互相关限光正交码(GA-OOC)的方法,设计了新的码字矩阵;分析了基于GA-OOC的光CDMA系统的误码率性能。仿真结果表明:该算法具有构造算法简单、易于编程实现的特点;与基于PC,EPC,QC和BIBD-OOC的光码分多址系统相比,GA-OOC的光码分多址系统具有更好的误码率性能。GA-OOC有望用于构造二维光地址码。     

基于流量测点的热网变动阻力系数优化辨识

随着供热计量系统的普及,系统可以根据负荷的变化进行调整,管网的阻力系数随即发生变化.对变动阻力系数进行优化辨识是了解供热管网实时运行状况的有效手段.提出一种基于流量监测数据的供热管网变动阻力系数优化辨识方法,并利用遗传算法进行求解.对洛阳市某小区供暖季管网实际运行数据进行验证,辨识结果的相对误差在5％以内.结果表明:该...     

振动噪声等高图的电驱动桥噪声预测及优化*

在项目开发前期通过优化电驱动桥扭矩特性的设计,可以规避噪声大问题。根据电驱动桥台架在对应扭矩下的振动噪声特性,提出了一套稳定高效的测试流程和分析方法。首先设计了一套完整的试验流程,制定了精准的数据分析方法。然后绘制出能够全面反映电驱动桥振动噪声特性的等高图。最后利用电驱动桥台架的振动噪声等高图,准确评估电驱动桥加速工况下振动噪声风险,为主机厂和电驱动桥零部件企业提供电驱动桥扭矩特性设计前期指导。利用该方法成功识别到某电驱动桥匀速及加速工况下电机及齿轮的啸叫问题。通过优化电驱动桥扭矩特性设计,电机48阶噪声峰值降低了8.5dB(A),确认该方法准确可靠,具备推广应用价值。     

考虑油膜力作用的船舶主推进系统冲击研究

舰船推进轴系是舰船动力装置的重要组成部分,它的稳定性是舰船生命力的基本保证.本文以舰船主推进轴系为研究对象,考虑了非线性油膜力的作用,在推进轴的非线性油膜力模型中,考虑了油膜涡动效应和挤压效应以及多个轴承油膜力的耦合影响,并考虑了轴承结构本身的刚度.文中采用弹性体动力学方法对推进轴建模,考虑了在外冲击作用下转速和轴承油膜力对于转轴冲击响应的影响,考虑横向运动与转动耦合作用,导出以非线性偏微分方程描述的舰船主推进轴的动力学方程,并用经典理论对其进行离散,最后采用龙格-库塔法进行数值仿真.实例分析指出转速对于转轴冲击响应的影响不可忽略.     

Hepatoprotective Effects of Ixeris chinensis on Nonalcoholic Fatty Liver Disease Induced by High-Fat Diet in Mice: An Integrated Gut Microbiota and Metabolomic Analysis

Ixeris chinensis (Thunb.) Nakai (IC) is a folk medicinal herb used in Mongolian medical clinics for the treatment of hepatitis and fatty liver diseases even though its pharmacological mechanism has not been well characterized. This study investigated the hepatoprotective mechanism of IC on mice with nonalcoholic fatty liver disease (NAFLD) by integrating gut microbiota and metabolomic analysis. A high-fat diet (HFD) was used to develop nonalcoholic fatty liver disease, after which the mice were treated with oral IC (0.5, 1.5 and 3.0 g/kg) for 10 weeks. HFD induced NAFLD and the therapeutic effects were characterized by pathological and histological evaluations, and the serum indicators were analyzed by ELISA. The gut microbial and metabolite profiles were studied by 16S rRNA sequencing and untargeted metabolomic analysis, respectively. The results showed that the administration of IC resulted in significant decreases in body weight; liver index; serum biomarkers such as ALT, TG, and LDL-C; and the liver inflammatory factors IL-1β, IL-6, and TNF-α. The 16S rRNA sequencing results showed that administration of IC extract altered both the composition and abundance of the gut microbiota. Untargeted metabolomic analysis of liver samples detected a total of 212 metabolites, of which 128 were differentially expressed between the HFD and IC group. IC was found to significantly alter the levels of metabolites such as L-glutamic acid, pyridoxal, ornithine, L-aspartic acid, D-proline, and N4-acetylaminobutanal, which are involved in the regulation of glutamine and glutamate, Vitamin B6 metabolism, and arginine and proline metabolic pathways. Correlation analysis indicated that the effects of the IC extract on metabolites were associated with alterations in the abundance of Akkermansiaceae, Lachnospiraceae, and Muribaculaceae. Our study revealed that IC has a potential hepatoprotective effect in NAFLD and that its function might be linked to improvements in the composition of gut microbiota and their metabolites.     

Three-dimensional architectures based on carbon nanotube bridged Ti2C MXene nanosheets for Li-S batteries

Lithium-sulfur(Li-S)batteries are promising candidates for high density electrochemical energy storage systems.However,the poor conductivity of S and the shuttl...     

旋转物体温度的非接触检测原理

本文讨论了利用交流电桥作感温部件及旋转变压器原理实验对旋转体温度的非接触检测。     

涡轮叶栅前缘槽缝气膜冷却的数值模拟

应用FINE/TURBO软件包,求解三维雷诺平均N-S方程,对叶片前缘有两列冷却槽缝的气膜冷却流场进行了数值模拟,获得了不同吹风比下叶片表面静压分布与极限流线.在计算结果与实验数据良好符合的基础上,详细分析了槽缝冷却三维定常流场结构与槽缝附近的流动细节.研究结果表明,槽缝冷却对前缘压力分布影响较大,且在压力面引起较大的分离流动,不利于冷却.