连续定态传热过程平均温差的统一推导

采用统一的方法对定态传热逆流和并流的平均温差进行了推导。推导过程无需假定冷热流体的特定流向,并利于得到对数平均温差“同侧相减”的规律。     

基于“人才安全屋”视角我国人才逆流研究

本文构建了一个以政策体制为落脚点,经济发展为出发点,人文环境为支撑点,发展潜力为着眼点四维度的“人才安全屋”理论模型,设计了一个“人才安全屋”指标体系,通过R语言编程对全国31个省市自治区的数据进行了人才区域逆向流动的实证分析和对比。分析结果表明：虽然我国东部、中部、西部地区人才逆流指数存在明显梯度差异,但随着国家“长江经济带”、“一带一路”等经济战略的稳步推进,在东部地区人才逆流指数稍有下滑趋势的同时,中部、西部地区展现出了上升的态势,这样有益于缩小我国区域贫富差距,增强区域发展协调性,促进经济结构转型升级。     

影响pH区带逆流色谱分离效果的主要因素

pH区带逆流色谱是在高速逆流色谱基础上发展起来的一种新型制备型分离技术,利用物质解离常数和疏水性的不同进行分离,具有分离量大、分离效果好等优点,并且应用领域十分广泛,在中草药等天然产物的有效成分分离纯化方面也得到了越来越多的应用.文中着重探讨了影响pH区带逆流色谱分离效果的流动相流速、逆流色谱转速、溶剂组成、样品量和酸碱度等主要影响因素.     

利用高速逆流色谱分离大黄活性成分

利用高速逆流色谱,采用加入酸碱的方法对传统中药大黄中的蒽醌类活性成分进行了分离研究.采用三氟乙酸做为保留酸,氨水作为洗脱碱,溶剂系统为正己烷/乙酸乙酯/甲醇/水(体积比为9∶1∶5∶5).对于分离产物做高效液相色谱分析,证明得到了大黄蒽醌的五种纯物质.     

还珠楼主《蜀山剑侠传》的成败得失

还珠楼主的《蜀山剑侠传》，集剑仙神魔化武侠小说之大成，其想象力丰富、怪谲，令人叹为观止；笔佳妙；写打斗则层次井然，高潮迭起；写风光历历在目，如诗如画。但也表现出了逃避现实、恶性发展剑仙神魔小说、为嫌取稿费不惜胡编乱造的创作倾向，同时亦充满了恐怖血腥、黄色下流的描写。     

A novel long-chain acyl-derivative of epigallocatechin-3-O-gallate prepared and purified from green tea polyphenols

Lipophilic tea polyphenols (LTP) were prepared by catalytic esterification of green tea polyphenols (GTP) with hexadecanoyl chloride. A novel long-chain acyl-derivative of epigallocatechin-3-o-gallate (EGCG) was first isolated from purification of LTP by high-speed countercurrent chromatography (HSCCC) using a solvent system composed of n-hexane-ethyl acetate-methanol-water (1∶1∶1∶1, v/v). The molecular structure of the acyl-derivative, Epigallocatechin-3-O-gallate-4′-O-hexadecanate, was elucidated by means of elemental analysis, IR,¹H-NMR and MS spectra. Project (No. 200010) supported by Zhejiang Provincial Natural Science Foundation, China     

初探文学翻译的创造性叛逆

文学翻译中的创造性叛逆是文学作品跨越地理、超越时空进行传播与接受的基本规律。在翻译实践中应该遵循这个规律,提高翻译质量。     

CFD Simulation of Film Flow and Gas/Liquid Countercurrent Flow on Structured Packing

A mathematic model of two-phase flow and a physical model of two-dimensional (2D) vertical section for the plate-type structured packing Mellapak 250.Y were set up and verified. The models were used to study the influence of packing’s surface microstructure on the continuity of liquid film and the amount of liquid holdup. Simulation results show that the round corner shape and micro wavy structure are favorable in remaining the continuity of liquid film and increasing the amount of liquid holdup. The appropriate liquid flow rate was determined by investigating different liquid loadings to obtain an unbroken liquid film on the packing surface. The pressure difference between inlet and outlet for gas phase allowed gas and liquid to flow countercurrently in a 2D computational domain. The direction change of gas flow occurred near the phase interface area.     

A novel long-chain acyl-derivative of epigallocatechin-3-O -gallate prepared and purified from green tea polyphenols

Lipophilic tea polyphenols (LTP) were prepared by catalytic esterifica tion of green tea polyphenols (GTP) with hexadecanoyl chloride. A novel long-ch a in acyl-derivative of epigallocatechin-3-o-gallate (EGCG) was first isol ated fro m purification of LTP by high-speed countercurrent chromatography (HSCCC) using a solvent system composed of n-hexane-ethyl acetate-methanol-water (1:1:1:1, v/v ). The molecular structure of the acyl-derivative, Epigallocatechin-3-O- gall ate-4′-O-hexadecanate , was elucidated by means of elemental analysis, I R, 1H-NMR and MS spectra.     

多聚半乳糖醛酸酶抑制蛋白抗血清的制备及鉴定

用电泳纯的小麦多聚半乳糖醛酸酶抑制蛋白免疫新西兰雄兔,获得了特异性强,效价较高的小麦.多聚半乳糖醛酸酶抑制蛋白抗血清.用此抗血清采用Dot—immunobinding assay,对流免疫电泳二种方法测定PGIP的检出限量,由此建立了多聚半糖醛酸酶抑制蛋白的Dot—immunobinding检测方法,并对制备该抗血清的意义予以讨论.