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1.
论述了四类抗结核药物的应用,着重讨论了利福平、氧氟沙星、力排肺疾等的应用。  相似文献   

2.
我国稀土生物无机化学研究进展   总被引:22,自引:3,他引:22  
我国稀土生物无机化学研究的特点是紧密结合稀土在农用及药物中应用所提出急需回答的问题, 经过长期的工作, 已在稀土的跨细胞膜运转, 稀土进入动物体内后的物种分布, 稀土与细胞膜的作用, 稀土对血红蛋白结构与载氧功能的作用, 稀土对骨细胞及骨结构的影响以及稀土在大鼠肝脏中的积累等方面取得了满意的结果. 从而可以为今后开展稀土元素在农用及药用中危险性评价的基础数据, 同时亦将促进稀土细胞化学的发展.  相似文献   

3.
寡聚脱氧核苷酸吸附状态随电位的变化   总被引:2,自引:0,他引:2  
利用原位电化学及表面增强拉曼散射(SERS)光谱方法对寡聚脱氧核苷酸(26-mers ODN和13-mers ODN)在银电极表面上的吸附状态进行了研究. 实验表明, 单链寡聚脱氧核苷酸在银电极上有很好的SERS光谱,单链寡聚脱氧核苷酸在银表面上主要以碱基腺嘌呤(A)为吸附点,吸附状态随电位变化而变化, 链长较短的寡聚脱氧核苷酸在银电极表面的吸附态对电位变化较敏感.  相似文献   

4.
《Analytical letters》2012,45(8):1653-1673
ABSTRACT

Principal component analysis and classification techniques were used to investigate the effect on the properties of wine of different fungicide treatments performed on the grapes. 55 variables were determined, 17 on the grape just-collected and the others on the wines. 27 samples of grape and wine were considered, produced in 1992, 1993" acceptdate="and 1994. The wines were classified as a function of the production year but no important correlation was found between fungicide treatment and the wine features. The classification was performed by a SIMCA method.

Clustering analysis, on the other hand, allowed a separation of the wine samples in three clusters, relative to three main kinds of grape treatments, i.e. based on i) copper sulfate, ii) copper hydroxide and iii) Mancozeb (the only one that does not contain Cu). The treatments based on copper oxychloride and the blank, that are the less active or characterized treatments, gave mixed results within the three clusters.  相似文献   

5.
The molecular statistical method for evaluating the distribution of active sites of various adsorbents relative to their energies has been improved. This method is used not only for the treatment of experimental data on the adsorption of hydrocarbons on various adsorbents, which is the usual procedure, but also data on the adsorption of polar water and methanol molecules on the active sites of adsorbent surfaces. Two types of active sites differing in energy have been shown to exist on the surface of graphitized carbon black, the complex shungite carbon/mineral adsorbent, and modified Silochrom. Chromatographic, calorimetric, and structural adsorption data were used to establish the relationship between the observed maxima of the energy distribution function of the adsorption sites with concrete adsorption sites or pores of the surface, on which the molecules are adsorbed. Translated from Teoreticheskaya i éksperimental'naya Khimiya, Vol. 44, No. 5, pp. 315–320, September–October, 2008.  相似文献   

6.
小环化合物中饱和碳质子化学位移的计算   总被引:3,自引:0,他引:3  
小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:  相似文献   

7.
In this work the thermal properties of chitins of different origin were compared using a thermogravimetric technique. The αsr method, which makes possible a comparison of the thermal resistances of materials with similar thermostability, was used. The basic range of thermal conversion was determined. In this range, the thermal resistance depends on the chitin origin. The value of activation energy was calculated. No influence on the average molecular mass, crystallinity and the degree of acetylation on the thermal resistance was observed. On the other hand, it was found that the thermal stability depends on the size and perfection of crystallites as well as on the crystalline form of the chitin.  相似文献   

8.
咪唑啉酰胺在电偶电极表面的吸附行为   总被引:1,自引:0,他引:1  
采用原子力显微镜技术研究了有机阳离子缓蚀剂(咪唑啉酰胺)在电偶电极表面的吸附行为, 并探讨了其腐蚀抑制机理. 结果表明, 金属表面的过剩电荷较大地影响缓蚀剂分子的吸附行为. 在1%的NaCl溶液中, 碳钢电极表面带有过剩的负电荷;不锈钢电极表面带有过剩的正电荷;碳钢电极和不锈钢电极耦合后, 其表面分别带有过剩的正电荷和负电荷. 在耦合前阳离子缓蚀剂分子仅吸附在碳钢表面, 耦合后缓蚀剂分子在偶对的阴极(不锈钢)和阳极(碳钢)表面均有吸附, 但缓蚀剂分子在碳钢表面的吸附强度和覆盖度较之耦合前降低, 缓蚀剂的腐蚀抑制能力减弱.  相似文献   

9.
NMR technologies such as relaxation, self-diffusion coefficient and other NMR methods were reviewed. The results of NMR measurements, especially, on 1H, 13C, 19F-NMR spectra and quadrupolar echo of 2H-NMR spectra on self-assembled properties and structures have been obtained. The investigations on the self-assembly of amphiphiles and the transition of self assembled structures were introduced and the determination of NMR measurements on micelles, vesicles and microemulsions was summed.  相似文献   

10.
综述了过去十年中微乳液高效液相色谱法的发展与应用,主要涉及溶质的迁移行为及其影响因素和微乳液高效液相色谱在药物分析中的应用(引用文献33篇)。  相似文献   

11.
The adsorption pattern of gold nanoparticles (AuNPs) on functionalized self-assembled monolayers (SAMs) produced on a Au(111) surface was characterized. The Au(111) was modified with 11-amino-1-undecanethiol hydrochloride (AUT), 11-mercapto-1-undecanol (MUT), or 11-mercaptoundecanoic acid (MUA) at an elevated temperature and pressure. The AuNPs aggregated on the AUT-SAM surface, whereas they were well dispersed on the MUT-SAM surface and localized on the MUA-SAM surface. The results suggest that interactions between AuNPs differ according to the degree of peeling of citrate-layer-capped AuNPs. The degree of peeling, which is related to both the surface randomness of the SAMs and the functional characteristics of the terminal group of each SAM, was discussed on the basis of scanning tunneling microscopy observations, X-ray photoelectron spectroscopic analyses, and contact angle measurements. Our study shows that AuNP patterns can be controlled by changing the terminal group of the alkyl thiol SAM on a Au(111) surface.  相似文献   

12.
环取代基对金属化聚苯胺衍生物膜修饰电极性能的影响   总被引:1,自引:0,他引:1  
通过比较聚2,5-二甲氧基苯胺(PDMAn)、聚邻甲基苯胺(POT)和聚间氯苯胺(PmClAn)膜修饰电极的氧化还原电位、沉积在这3种聚合物上的铂微粒的表面形态与晶面取向以及异丙醇在分散Pt微粒的聚苯胺膜修饰电极上的氧化行为,从电子效应和立体效应探讨了聚合物电化学性质与环取代基的关系以及不同聚合基质对Pt沉积机理和有催化性能的影响,结果表明,在硫酸溶液中PDMAn膜修饰电极的氧化还原电位最负、POT次之、PmClAn最正,Pt在PDMAn和POT膜上的电沉积机理与在PmClAn膜上的不同,聚合物膜上沉积的Pt微粒呈现(200)晶面择优取向,其中POT膜上择优取向度最大,PDMAn次之,Pm-ClAn最小,异丙醇在金属化聚合物膜电极上的氧化电位取决于聚苯胺的本质,在POT膜修饰电极上异丙醇的电氧化主要发生在POT的活性电位区,而在PDMAn与PmClAn膜上的电氧化则主要发生在Pt上的氧化电位区,说明聚合物膜不仅作为Pt微粒的分散介质,而且本身有产生催化作用。  相似文献   

13.
The different functions of polymer binders on the processing of the electrode, the electrical (electronic and ionic) and mechanical properties of the electrode, and as a consequence on the electrochemical performance are discussed. The role of the polymer binder on the solid–electrolyte interface (SEI) layer and the cyclability of the graphite- and silicon-based negative electrodes is also addressed. All these properties critically depend on the very thin layer formed by the polymer at the surface of the active and conductive particles. That is where research efforts have to focus on, now, for further optimization of electrodes through tailoring of the binder combination.  相似文献   

14.
水性纸品上光涂料是用于印刷品的精加工及包装材料的表面整饬的一种涂料,具有成本低、无污染、无毒无害、性能优良,运输方便等优点,是当前印刷上光涂料的主要发展方向。目前,国内的水性纸品上光涂料生产技术多样化,质量参差不齐,且成本高,耐水、耐磨、光泽度性能都达不到高档印刷品的上光要求,70%的高档水性纸品上光涂料需要依靠进口。本文系统地介绍了目前国内外水性纸品上光涂料的研究进展,总结了水性纸品上光涂料的各自特点与应用,并提出一种水性纸品上光涂料制备的新方法。  相似文献   

15.
16.
It is shown that calorimetric experiments on the dilution process of polyelectrolytes, i.e. on the excess enthalpy of electrostatic origin, can give information on the conformational state of the polymer. Analytical expression are obtained relating the enthalpy of dilution to the charge density on the polymer, from Manning's theory. The experimental data reported on some ionic biopolymers are interpreted on the basis of the theoretical prediction of the electrostatic contribution to the enthalpy of dilution in water of a polyelecrolytic salt and of a weak polyacid. The procedure outlined provides a means of calculating the actual charge/per unit length and of disclosing possible non-electrostatic effects arising from conformational transitions.  相似文献   

17.
季铵阳离子对木质素减水剂性能的影响   总被引:3,自引:0,他引:3  
以木质素磺酸钙为原料 ,通过离子交换法制备了五种季铵阳离子木质素磺酸盐 ,系统的研究了它们对水泥各项性能的影响。研究结果表明 :不同季铵阳离子所对应的木质素磺酸盐在应用性能上存在明显差异 ,有些木质素磺酸季铵盐显示出新的应用潜力。  相似文献   

18.
Ru上有氧条件下氨分解的动力学研究   总被引:3,自引:0,他引:3  
IthasbeenshownthatRuisvalidforthesyn thesisanddecompositionofammonia[1,2 ] .FurtherstudyofammoniaadsorptionanditsdecompositionproductsdesorptiononRuwillbeimportant .Previ ousstudiesofammoniaadsorptiononRumainlyfo cusedontheammoniasynthesisandhydrogenpro ductionintheabsenceofoxygen[3] ,onlyafewinves tigationsonammoniadecompositioninthepresenceofoxygenhavebeenreported[4 ,5] ,andtheeffectofad sorbedoxygenontheratesofammoniadecompositionandproductformationonRuarestillnotwellunder stood .Inthispa…  相似文献   

19.
The effect of thiourea (TU) on the nickel deposition process was analyzed by means of linear-sweep voltammetry. Raman spectroscopy and infrared reflectance spectroscopy were used to investigate the adsorption of TU and the formation of nickel-TU complexes on copper surface. The experimental results indicate that the nucleation and the preceding conversion step are involved in the deposition of nickel on copper electrodes. TU makes the onset nucleation potential negative due to the formation of nickel-TU complexes. which can accelerate the nickel deposition. Moreover, the S atom in the TU molecule adsorbed on copper surface facilitates the coordination of TU to Ni^2 . Meanwhile, TU might be adsorbed at a flatter orientation if no Ni^2 is on the surface, while at a perpendicular orientation when Ni^2 is coadsorbed.  相似文献   

20.
碳化钨在对硝基苯酚电还原过程中的电催化行为   总被引:4,自引:0,他引:4  
以碳化钨(WC)粉末为电催化材料制成了碳化钨粉末微电极(WC-PME). 采用循环伏安和线性扫描等方法研究了酸性溶液中对硝基苯酚(PNP)在WC-PME上的电还原行为. 研究表明, 在相同测试条件下, PNP在WC-PME上电还原的电位比Cu-Hg微电极正得多;WC-PME对氢具有较强的吸附能力, 有利于有机物的电还原反应. PNP在WC-PME上和Pt微电极上的还原电位相近, 但在WC-PME上的峰电流比在Pt微电极上高5倍多, 这主要与WC粉末的结构形貌有关.  相似文献   

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