共查询到20条相似文献,搜索用时 772 毫秒
1.
2.
3.
4.
综述了超声波法制备高吸水树脂研究进展,包括超声波法制备合成聚合物系列高吸水树脂、超声波法制备天然多糖交联型高吸水树脂、超声波法制备接枝天然多糖型高吸水树脂等。最后指出了超声波法制备高吸水树脂研究需要加强的几个方向:即加强超声波法制备各种类型高吸水树脂的实验研究;加强超声辐射产生设备的革新研究;降低成本,扩大应用领域。 相似文献
5.
探讨了梯度材料的合成与制备方法的研究进展,提出在非自然环境中制备PMMA梯度折射率材料的制备方法和模型研究。研究表明,增加反应物中两相物质分子或颗粒的作用力差是制备具有应用前景的梯度高聚物材料的关键。并就非自然环境中制备高聚物梯度材料的实验方法、数学模型及利用该方法制备出的高聚物梯度材料的性能表征进行了研究。 相似文献
6.
7.
8.
9.
10.
11.
Albert Erkip 《Polymer》2004,45(2):641-648
The fluctuations of residues of proteins about their equilibrium configurations are analyzed by the Langevin equation. Residue pairs that are covalently bonded and those that are within a given cutoff distance of each other are assumed to be connected by linear springs. The actions of the solvent and intramolecular interactions on each residue are treated as random noise. The correlations of fluctuations resulting from the solution of the Langevin equation are observed to be identical to those obtained by the Gaussian Network Model based on equilibrium statistical mechanics. The time-delayed correlations of fluctuations, and the response of the protein to a given frequency and to a window of frequencies are determined. The fluctuations of the residues resulting from a given fixed externally applied frequency are evaluated for different modes of the system. Synchronous and asynchronous components of correlations for different modes are formulated. The findings of the present paper are applied to the 241 residue protein S. marcescens endonuclease (1QL0). 相似文献
12.
膨胀石墨与活性炭对工业油吸附性的对比研究 总被引:4,自引:0,他引:4
选用膨胀体积为150、250、350 mL/g的膨胀石墨和活性炭为吸附剂,以汽油、煤油、柴油、真空泵油和汽机油为吸附质,采用重量法测定了吸附剂对吸附质的吸附性能,实验结果表明:膨胀体积为350 mL/g的膨胀石墨对吸附质的吸附量分别为40、47、52、64、70 g,活性炭的吸附量分别为3.02、3.04、3.08、3.1、3.4 g;膨胀石墨的滞留吸附量分别减少至8、10、17、24、30 g,活性炭的滞留吸附量变化不大.对比了不同膨胀体积的膨胀石墨和活性炭对吸附质的吸附性能,膨胀体积越大,吸附量越大.用SEM和TEM对膨胀石墨的形貌进行了表征,探讨了吸附和滞留吸附的机理. 相似文献
13.
14.
分光光度法测定天然多酚类化合物含量的研究进展 总被引:1,自引:0,他引:1
介绍了近年来分光光度法在测定天然多酚类化合物方面的研究进展。综述了测定天然多酚类化合物方法的应用范围,对测定方法按化学反应进行分类,如络合反应、氧化还原反应、亲核加成反应和重氮化-偶合反应等,并探讨了测定方法的反应原理及测定方法中存在的问题,对今后的研究方向作了展望。 相似文献
15.
引 言甲基乙烯基二氯硅烷是重要的有机硅单体和硅烷偶联剂 ,在硅橡胶、涂料、印染、化妆品等领域有着广泛的应用 .在合成甲基乙烯基二氯硅烷的过程中 ,甲苯作为均相催化剂的载体以及反应的媒介体循环使用 ,甲基三氯硅烷是副产物 ,在分离过程的设计中需要有关甲基三氯硅烷、甲基乙烯基二氯硅烷、甲苯体系的汽液平衡数据 ,此前文献尚未见报道 .为了满足过程开发与工程设计的需要 ,本研究测定了甲基三氯硅烷、甲基乙烯基二氯硅烷和甲苯三元体系及其 3个二元体系的相平衡数据 ,并进行了热力学关联 .1 实验部分1 1 试 剂甲基三氯硅烷 :江西蓝… 相似文献
16.
详细阐述了金属腐蚀的危害机理,分析了影响数控机床腐蚀的因素,介绍了防腐涂料及防腐技术在数控机床上的应用现状,提出了数控机床整机防腐的对策及防锈措施。 相似文献
17.
A freeze-drying procedure is developed for manufacturing silver nanopowder with regular shape and uniform diameter. The procedure includes four steps: preparing the precursor solution, freezing the solution, drying the congelation, and calcining the drying product. The starting substances are silver nitrate and caustic soda and the precursor is diammine silver solution. Three freezing styles including direct freezing, vacuum evaporation freezing, and spray freezing are adopted to freeze the precursor solution. In the drying stage, two heating styles for the frozen solution are compared. X-ray diffraction (XRD) and energy disperse spectroscopy (EDS) spectrograms show that the products of freeze drying are pure amorphous silver nanopowder without hard agglomerations. Silver cubic nanocrystals are subsequently obtained by calcination. The chemical fundamentals and the drying curves of freeze drying are given. The processes of preparing silver nanopowder are described in detail. The effect of freezing and heating on characteristics of the powder are discussed. The mechanism of grain forming and growing up is analyzed according to the observation results. The characteristics of powder freeze drying and its feasibility for volume production are presented. 相似文献
18.
19.
以平顶山煤和徐州煤为原料,利用回收NMP与CS_2混合溶剂和反萃取剂将两种煤全组分分离成萃余煤组分、沥青质组分、精煤组分和轻质组分四大族组分,主要对比原煤及各族组分的真密度、工业分析与元素分析。结果表明,萃余煤组分真密度最大,分别为1.59和1.45,精煤组分与沥青质组分真密度低于原煤。轻质组分具有较多非共价键成键点,易与水分子形成氢键,水分含量最高,分别为6.09%和5.77%,而萃余煤组分水分含量最低,分别为0.96%和0.63%。沥青质组分接近无灰。挥发分含量以轻质组分沥青质组分精煤组分原煤萃余煤组分顺序降低。C元素含量以精煤组分与沥青质组分相对较高,萃余煤组分C元素含量较两者偏低,分别为80.91%和80.65%。轻质组分中N、O和S元素含量较高,C元素含量最低。 相似文献
20.
介绍了世界洗涤剂醇的生产能力和供需情况,对洗涤剂醇的市场状况及消费现状进行了分析。指出国内洗涤剂醇的一些应用领域,对今后洗涤剂醇的发展提出了建设性的建议,并对洗涤剂醇的未来趋势进行了预测。 相似文献