钢丝帘线泊松比的实验研究

本文对钢丝帘线／橡胶复合材料中的钢丝帘线泊松比的定义提出了新的见解，建议用钢丝帘线横截面变化率代替其横向应变，并提出了利用扫描电子显微镜测定截面变化率的实验方法     

爆轰波与金属的斜相互作用

应用二种截然不同的炸药PBX 95 0 1和T2 ,计算了爆轰波在不同入射角下与金属平板的斜相互作用。在正规反射区 ,计算结果与激波极线理论基本一致 ;应用燃烧模型 ,分别计算了Fe球壳装药JB90 0 3(HE)及JB90 14 (IHE)散心爆轰波的绕射传播 ,计算结果与实验很好地符合。在非正规反射区 ,二维拉氏程序计算结果明显地不同于经典理论结果 ,计算中没有出现Mach反射。计算结果显示 ,毗邻介质影响节点附近的爆轰波阵面形状及爆轰波速度 ;不同的反应率函数计算的节点图像不同。     

一种不锈轴承钢离子束增强沉积表面的微观分析和摩擦学性能研究

利用离子束增强沉积技术，在将Ｔｉ用Ａｒ＾＋束溅沉积到淬火态９Ｃｒ１８Ｍｏ不锈轴承钢表面的同时，分别用Ａｒ＾＋，Ｎ＾＋和Ｃ＾＋轰击试样表面，制取了增强沉积的表面改性层     

任意激励关系下非保守耦合振子能量分布与功率流的一般特征

传统的统计能量分析(SEA)理论不能解决非保守耦合系统和保守或非保守耦合系统在相关输入时的能量分析问题。作为任意输入关系下非保守耦合系统统计能量分析的基础,本文研究了耦合振子在非保守耦合及任意输入条件下能量分布与功率流的一般特征,推导了功率平衡方程式及各有关功率项的计算式,讨论了振子间功率流的构成及各向功率流之间的关系。研究结果表明,耦合阻尼和输入形式对耦合振子能量平衡和功率总体特征有着显著的影响。     

Guest-dependent complexation of triptycene-derived macrotricyclic host containing one anthracene moiety with paraquat derivatives: construction of [2]rotaxanes

Complexation between the triptycene-derived macrotricyclic polyether containing an anthracene unit and paraquat derivatives in both solution and solid state was investigated. It was found that the macrotricyclic host with multi-cavity structure could form a series of [2]pseudorotaxanes with different terminal functionalised paraquat derivatives in different threading modes, which subsequently resulted in the construction of two novel [2]rotaxanes.     

Synthesis and crystal structures of Ag and Hg complexes of bis(N-heterocyclic carbenes) on p-tert-butylcalix[4]arene platform

A series of p-tert-butylcalix[4]arene 1,3-diimidazolium salts were successfully prepared by the alkylation of p-tert-butylcalix[4]arene with dibromoalkanes, and sequential substitution reaction with 1-alkylimidazole. Furthermore, coordination reactions of p-tert-butylcalix[4]arene 1,3-diimidazolium salts with silver oxide and mercury acetate gave novel Ag and Hg complexes of bis(N-heterocyclic carbenes) on p-tert-butylcalix[4]arene platform. The single-crystal structures of four p-tert-butylcalix[4]arene 1,3-diimidazolium salts and three metal complexes were successfully determined by X-ray diffraction. An Ag–Ag argentophilic interaction (Ag–Ag bond length is 3.1599(6) Å) is formed between the two Ag–NHC complexes and a dimetallic coordination mode exists in Hg–NHC complexes.     

Fast quantification of endogenous carbohydrates in plasma using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry

Endogenous carbohydrates in biosamples are frequently highlighted as the most differential metabolites in many metabolomics studies. A simple, fast, simultaneous quantitative method for 16 endogenous carbohydrates in plasma has been developed using hydrophilic interaction liquid chromatography coupled with tandem mass spectrometry. In order to quantify 16 endogenous carbohydrates in plasma, various conditions, including columns, chromatographic conditions, mass spectrometry conditions, and plasma preparation methods, were investigated. Different conditions in this quantified analysis were performed and optimized. The reproducibility, precision, recovery, matrix effect, and stability of the method were verified. The results indicated that a methanol/acetonitrile (50:50, v/v) mixture could effectively and reproducibly precipitate rat plasma proteins. Cold organic solvents coupled with vortex for 1 min and incubated at –20°C for 20 min were the most optimal conditions for protein precipitation and extraction. The results, according to the linearity, recovery, precision, matrix effect, and stability, showed that the method was satisfactory in the quantification of endogenous carbohydrates in rat plasma. The quantified analysis of endogenous carbohydrates in rat plasma performed excellently in terms of sensitivity, high throughput, and simple sample preparation, which met the requirement of quantification in specific expanded metabolomic studies after the global metabolic profiling research.     

Separation of isorhamnetin 3‐sulphate and astragalin from Flaveria bidentis (L.) Kuntze using macroporous resin and followed by high‐speed countercurrent chromatography

D4020 resin offered the best dynamic adsorption and desorption capacity for total flavonoids based on the research results from ten kinds of macroporous resin. A column packed with D4020 resin was used to optimize the separation of total flavonoids from Flaveria bidentis (L.) Kuntze extracts. The content of flavonoids in the product was increased from 4.3 to 30.1% with a recovery yield of 90%. After the treatment with gradient elution on D4020 resin, the contents of isorhamnetin 3‐sulfate and astragalin were increased from 0.49 to 8.70% with a recovery yield of 74.1% and 1.16 to 30.8%, with a recovery yield of 92.2%, respectively. Further purification was carried out by one‐run high‐speed countercurrent chromatography yielding 4.5 mg of isorhamnetin 3‐sulfate at a high purity of 96.48% and yielding 24.4 mg of astragalin at a high purity of over 98.46%.     

Vortex‐assisted liquid–liquid microextraction using a low‐toxicity solvent for the determination of five organophosphorus pesticides in water samples by high‐performance liquid chromatography

Vortex‐assisted liquid–liquid microextraction followed by high‐performance liquid chromatography with UV detection was applied to determine Isocarbophos, Parathion‐methyl, Triazophos, Phoxim and Chlorpyrifos‐methyl in water samples. 1‐Bromobutane was used as the extraction solvent, which has a higher density than water and low toxicity. Centrifugation and disperser solvent were not required in this microextraction procedure. The optimum extraction conditions for 15 mL water sample were: pH of the sample solution, 5; volume of the extraction solvent, 80 μL; vortex time, 2 min; salt addition, 0.5 g. Under the optimum conditions, enrichment factors ranging from 196 to 237 and limits of detection below 0.38 μg/L were obtained for the determination of target pesticides in water. Good linearities (r > 0.9992) were obtained within the range of 1–500 μg/L for all the compounds. The relative standard deviations were in the range of 1.62–2.86% and the recoveries of spiked samples ranged from 89.80 to 104.20%. The whole proposed methodology is simple, rapid, sensitive and environmentally friendly for determining traces of organophosphorus pesticides in the water samples.