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71.
以三聚氯氰(TCT)为中间桥梁,将聚六亚甲基双胍(PHMB)接枝到N-(2-羟丙基-3-甲基氯化铵)壳聚糖(HTCC)上,制备胍基壳聚糖季铵盐(HCP).研究制备HCP的最佳反应条件,采用元素分析、傅里叶变换红外光谱(FTIR)和核磁共振氢谱(1H NMR)对产物的结构进行表征,并测试其抗菌性能.得到HCP的最佳反应条件为HTCC和TCT的摩尔比1.0∶2.5,HTCC和PHMB的质量比1.0∶1.2,缚酸剂为三乙胺,TCT一取代的反应时间8 h,二取代的反应时间14 h,反应温度40℃.结果表明:制得的HCP对大肠杆菌(E.coli)和金黄色葡萄球菌(S.aureus)的最低抑菌质量浓度分别为0.020,0.005 mg·mL-1;质量浓度为1.0 mg·mL-1的HCP对E.coli和S.aureus的抑菌率分别为89.8%和100.0%,高于相同质量浓度下HTCC对E.coli和S.aureus的抑菌率18.2%和18.7%. 相似文献
72.
《自然科学进展(英文版)》2023,33(2):211-224
Mg-based materials are currently a hot research topic as hydrogen storage materials due to their considerable theoretical hydrogen storage capacity. However, the kinetic performance of hydrogen absorption and desorption of Mg is too slow and requires high temperature, which seriously hinders the application of this material. MXene is a new type of two-dimensional material with significant role in improving thermodynamics and kinetics. In this experiment, a two-dimensional layered MXene containing Cl functional group was prepared by molten salt etching using the Ti-containing MAX phase as the raw material. Then different ratios of Ti3C2Clx were uniformly dispersed onto the surface of Mg by high energy ball milling. The samples were characterized by hydrogen absorption and desorption kinetics, SEM, XRD, XPS, and DSC to investigate the effect of Ti3C2Clx on the hydrogen absorption and desorption performance of Mg. The onset hydrogen absorption temperature can be reduced to room temperature and the hydrogen release temperature is reduced by 200 °C by doping Ti3C2Clx. And there is also 5.4 wt% hydrogen storage in the isothermal hydrogen absorption test at 400 °C. The results of DSC demonstrate that the Ea of Mg+15 wt% Ti3C2Clx was reduced by 12.6% compared to pristine Mg. The ΔH is almost invariable. The results of XPS show that the presence of multivalent Ti promotes electron transfer and thus improves the conversion between Mg2+/Mg and H−/H. This study provides a guideline for further improving the hydrogen absorption and desorption performance of Mg-based hydrogen storage materials. 相似文献
73.
V. R. Kartashov T. N. Sokolova O. A. Leksina A. B. Radbil N. V. Malisova Yu. K. Grishin 《Russian Chemical Bulletin》1995,44(3):527-531
The reaction of Hg(OAc)2 with bornylene in THF-H2O and CH3CN-H2O mixed solvents (75 25, v/v) was studied. The effects of the addition of NaOAc on the reaction rate and the composition of products were investigated. In the CH3CN-H2O mixture, the addition of NaOAc decreases the amount of the rearranged product, fundamentally changes the ratio between the regioisomeric solvoadducts, and promotes the formation of products of Hg(OAc)2 addition. The reaction proceedsvia an ion pair and free mercurinium ion; the cation of the ion pair and the free mercurinium ion have dissimilar structures.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 544–548, March, 1995. 相似文献
74.
The characteristics, pattern, hydrodynamic and hydrochemical features, and the movement pattern of the salt waterfresh water
interface of the sea water intrusion and the salt water intrusion, which occur in the coastal area of Laizhou Bay in Shandong
Province, are analysed. The characteristics of the two kinds of intrusion are compared as well. A three-dimensional sea water
intrusion model to describe the sea water intrusion with a transitional zone 1.5–6.0 km wide in the phreatic aquifer and a
solute transport model describing the behavior of cations exchange in the process of sea water intrusion are established. 相似文献
75.
盐胁迫下Na^+,K^+,Cl^—对碱蓬和玉米离子的吸收效应 总被引:9,自引:1,他引:8
用NaCl、KCl、NaNO3和KNO3处理碱蓬(Suaedasalsa)和玉米(Zeamays)幼苗,发现NaCl胁迫引起K+、Ca2+、Mg2+、Fe2+、Zn2+、NO-3等必需元素的含量降低.认为KCl和KNO3处理引起碱蓬幼苗幼叶黄化的主要原因是Na+的缺乏;KCl处理引起玉米和碱蓬幼苗的干枯死亡主要是由于植物体内高浓度Cl-引起的;Na+是引起盐生植物碱蓬叶片肉质化的重要因子;Cl-是刺激碱蓬生长的重要因子 相似文献
76.
盐胁迫下灰绿藜叶片光合特性与叶绿体离子调节的研究 总被引:5,自引:0,他引:5
冯立田 《曲阜师范大学学报》1998,24(3):57-61
NaCl处理后,灰绿藜整个叶片内N^+a和Cl&-积累,但叶绿体内仅少量增加。叶绿体与叶片的K^+浓度都降低。 相似文献
77.
用五种Schif碱型双(苯并_15_冠_5)为离子载体,在水_1,2_二氯乙烷体系中研究了其对碱金属苦味酸盐的萃取性能,测定了分配比D和萃取平衡常数Ke.结果表明,这些双冠醚与苦味酸钠以1∶1(冠醚单元∶金属离子)形式络合,而与苦味酸钾和苦味酸铷则以2∶1形式络合. 相似文献
78.
对已筛选出的小麦耐盐细胞系的耐盐稳定性进行有关生理、生化分析。结果表明:耐盐细胞系脯氨酸含量不仅稳定,而且高于对照;SOD活性在耐盐系增加,耐盐系对一定的盐浓度损伤DNA修复能力大于对照系,耐盐系RNA和蛋白质合成量分别是对照的5.4和4.5倍,并对小麦耐盐性的有关问题进行了讨论。 相似文献
79.
电荷转移多金属氧酸盐的研究进展 总被引:3,自引:0,他引:3
概述了多金属氧酸盐与TTF类π电子有机给体形成的电荷转移盐研究的简短历史和新近进展,着重评述了它们的合成、结构、性质以及研究方法. 相似文献
80.
V. R. Kartashov T. N. Sokolova I. V. Timofeev E. V. Skorobogatova N. S. Zefirov 《Russian Chemical Bulletin》1994,43(5):760-768
The kinetics of mercuration of bornylene and cyclohexene in different solvents in the presence of NaOAc and LiClO4 has been investigated. Addition of NaOAc sharply decreases the rate of addition reactions of mercuric acetate to bornylene and cyclohexene in alcohols; the main direction of the mercuration of bornylene is the formation of acetoxy-adducts, and the yield of solvo-adducts decreases from 76 % in the absence of NaOAc, to 19 % in the presence of the salt (4·10–3 mol L–1). A reaction scheme involving the participation of intermediate ion pairs and a solvated mercurinium ion is suggested and confirmed by a steady-state concentration method. The influence of NaOAc on the rate of the reaction and on product formation is realized through the common ion effect.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 819–826, May, 1994. 相似文献