聚乙烯

Michael addition reaction between poly and propyl vinyl sulfoxide was studied in sodium hydroxide aqueous solution.

本文研究聚乙烯醇与丙基乙烯基亚砜经Michael 加成反应合成含亚砜基的改性聚乙烯醇功能高分子。

Hereinto, Tyr-Fal was prepared from L-tyrosine and formaldehyde under alkaline conditions.Firstly, a new multi-functional film with well-defined layered structure was fabricated from Tyr-Fal and PEI via LbL method. Experiment revealed that this Tyr-Fal/PEI multilayer film emit yellow fluorescence under UV radiation. The ability of the Tyr-Fal/PEI multilayer film for adsorbing rosaniline improved after UV-exposed, which can be used in preparing micropattern.

然后以Tyr-Fal为结构单元，通过静电力自组装构筑了两种功能性的酪氨酸基多层膜：(1)利用Tyr-Fal与聚乙烯亚胺间的静电力构筑了结构稳定、有序、能在紫外光照射下发出耀眼黄色荧光的聚乙烯亚胺/酪氨酸缩甲醛超薄膜。

The self-centering mechanism design of bipolar endoprosthesis has advocated the use of offset centers of rotation between the inner and outer joint bearing surfaces to generate a self-centering moment on loading to prevent impingement of polyethylene rim and stem neck or cup fixed at wrong place. The design was used popularly, but the function of self-centering mechanism was discussed in very few papers. Three bipolar endoprosthesis were evaluated: UNIQHIP system, UHR system, and AML system.

双极式半人工髋关节的离心复位机构，是利用髋臼外帽的球心与股小球的球心两者在不同点，来防止发生髋臼外帽固定於髋臼中某角度卡住不动，而使股骨柄颈部固定磨损超高分子聚乙烯内衬之一边缘，进而加速超高分子聚乙烯内衬之磨耗，造成骨溶蚀与人工髋关节的松脱。

Mainly using protein - film voltammetric technique, we have achieved direct electrochemical response of lots of proteins such as hemoglobin, myoglobin, cytocrome c, cytocrome b5, horseradish peroxiase, GOD ,Vitreoscillia sp. haemoglobin, etc., at a series of protein membrane modified electrodes, for instance, protein/kieselgubr, protein/polyethylene glycol, protein/polyethyleneimine, protein/phosphatidylcholine, protein/DNA, protein/montmorillonite/polyvinyl alcohol, protein/silver nanoparticle/ cysteamine membrane modified electrode, etc., which are prepared by casting, incorperating or layer by layer self-assembly methods. Electrochemical behavior of these proteins in the films have been studied, and their structural and conformational changes have also been examined with spectrometric techniques.

三年来，在基金委的支持下，我们以蛋白膜伏安法这一新技术作为主要的研究手段，并结合其他生物、化学技术，研究了血红蛋白、肌红蛋白、细胞色素C、细胞色素b5、辣根过氧化物酶、葡萄糖氧化酶以及好氧革兰式阴性菌透明颤菌中的血红素类蛋白等多种蛋白质在以涂布和自组装方法制成的蛋白质/硅藻土膜、蛋白质/聚乙二醇膜、蛋白质/卵磷脂膜、蛋白质/聚乙烯亚胺膜、蛋白质/蒙托石/聚乙烯醇自组装膜以及蛋白质/银胶/半胱胺自组装膜等修饰电极上的直接电化学行为，结合各种光谱技术，对蛋白质在膜中的构象进行表征，探索其电子传递机理。

The main products of the plant are as follows:liquid alkali,hydrochloric,chlorinated polyethylene,High purity chlorinated polyethylene,furfuralcohol,layred crystal sodium metasilicate,hight purity dimethyl carbonate,propanedilo.

主要产品有：烧碱、液氯、盐酸、氯化聚乙烯、高氯化聚乙烯、糠醇、层层状结晶硅酸钠、高纯碳酸二甲酯和丙二醇。

The results showed that the size of spherule formed with 5% of SA and 11% of PVA was appropriate and elastic, furthermore, 5% SA could keep the enzymatic activity better, it is higher by 16% than 11% PVA, therefore, it is the optimum immobilization conditions.

研究结果表明，5%的海藻酸钠、11%的聚乙烯醇形成的固定化菌球大小合适，有弹性，但5%的海藻酸钠能更好的保持酶活性，比11%聚乙烯醇高16%，其为最佳的固定化条件。

The experimental results showed that the trinary of additive flame - retardant was needed to be used together to produce ideal self-extinguishing high expansion PE products while the performances of high expansion PE were unchanged.

研究结果表明：只有对添加型阻燃剂三元并用，方能不降低高发泡聚乙烯的物性，制得较为理想的高发泡聚乙烯自熄型制品。

The authors compare the behaviors of space charge in dried and undried low density polyethylene and which doped with 0.5% Al_2O_3 powder via infrared spectrum method, thermogravimetry and the Pressure Wave Propagationmethod, and the water content is quantitatively measured.

作者通过红外吸收光谱法、热重分析法和压力波法，分别对低密度聚乙烯以及以0.5%Al2O3粉末掺杂的低密度聚乙烯在干燥前后的有关空间电荷行为进行了比较，定量给出水份含量和对应的空间电荷特性。

The above method can be used as a general method of determining molecular weight distribution of polymers.4.Solid-state ~1H wide-line NMR and ~(31)p magic angle spinningNMR were applied to a series of PEI/DNA complex samples with different PEI molecular weights and nitrogen/phosphatemolar ratios,in order to disclose the influence of various structural factors on the interactions and morphology.The results of ~1H NMR spectra showed that the linewidth of the PEI signal was greatly broadened with increasing the N/P ratio.Meanwhile,in the ~(31)p M_AS experiment,the signal was found to shift upfield with the increase of the N/P ratio.Both ~1H and ~(31)P NMR experiments demonstrated that the interaction between two constituents and subsequently the morphology of the complexes vary with the N/P ratio.

首次将固体核磁共振应用到聚合物/DNA复合物体系，观察复合物体系中不同N/P比对其相互作用和相结构的影响，研究表明N/P比的变化对聚乙烯亚胺/DNA基因递送体系分子水平上相互作用有着很大的影响；另外，还发现不同分子量的聚乙烯亚胺聚合物载体在N/P比为3的情况下对复合物中DNA的微观尺度没有明显影响；通过氢的自旋扩散实验，首次测得在PEI/DNA复合物体系中DNA相尺寸的大小，并发现在体系中N/P比达到3以上的复合物中DNA和PEI达到了分子水平上的相容。

The kinetics of thermal oxidation of rosin and abietic acid absorbed on the polyethylene film were respectively studied.

设计了松香和枞酸在聚乙烯膜上的氧化反应器，建立了枞酸在聚乙烯膜上的紫外分光光度分析方法，跟踪测定了松香和枞酸氧化反应的过程。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。