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1.
硼掺杂多晶金刚石薄膜电极的电化学特性   总被引:1,自引:0,他引:1  
朱建中  许春芳 《分析化学》1995,23(7):824-827
用循环伏安法和恒电位法研究了硼掺杂多晶金刚石薄膜电极(DFE)的若干电化学特性。电极面积4×4mm^2。在0.1mol/L KCl,NaNO3,NaOH和KH2PO4+Na2HPO4(pH=6.86)电解质溶液中电势窗口均为-500 ̄+800mV;而在0.1mol/L HCl和H2SO4溶液中电势窗口为-200 ̄+1100mV.K3Fe(CN)6的氧化峰电位为+500mV,与Pt电极测量相同;校正  相似文献   

2.
三取代钨硅杂多配合物的导电性和磁性   总被引:5,自引:0,他引:5  
合成了α-NamHn[SiW9M3(H2O)3O37]·16H2O(M=Co(Ⅱ),Ni(Ⅱ),V(Ⅴ)杂多配合物),通过ICP,IR,UV,TG-DTA,XPS,EPR,极谱等手段进行了表征.配合物在室温下的电导率σ值达1×10-3S·cm-1,343K时可达1×10-2S·cm-1,是有实用化前景的新型固体电解质.变温磁化率结果表明α-Na10[SiW9Co3(H2O)3O37]·16H2O和α-Na10[SiW9Ni3(H2O)3O37]·16H2O具有反铁磁性.  相似文献   

3.
考察甲基丙烯酸甲酯在室温Na2SO3水溶液的聚合能力,发现在该溶液添加聚丙烯酰胺(PAAm)-氯化铜(CuCl2)配合物膜以组成PAAm-CuCl2膜/Na2SO3催化引发体系是必不可少的.采用ESR、IR、XPS和电导率等手段研究该体系催化剂的表面结构.结果表明,膜的单位面积平均含铜量在一定范围内和配位体种类等对催化活性有显著影响,即催化性能与催化剂的表面结构紧密相关.  相似文献   

4.
郭忠先 《分析化学》1996,24(4):459-462
研究了在乳化剂OP存在下,2-羟基-3-羧基-5-磺酸基苯重氮氨基偶氮苯(HCSDAA)-汞(Ⅱ)显色体系流动注射分光光度法。用PH10.0-10.5的Na2B4O7-NaOH缓冲溶液作载流,汞(Ⅱ)与HCSDAA和乳化剂OP的混合试剂反应形成红色络合物。用于测定汞时,方法的线性范围是0.05-1.0mg/L,检测限为0.016mg/L,进样频率为100样/h。直接应用于头发、自来水和废水中微量汞  相似文献   

5.
考察甲基丙烯酸甲酯在室温Na2SO3水溶液的聚合能力,发现在该溶液添加聚丙烯酰胺(PAAm)-氯化铜(CuCl2)配合物膜以组成PAAm-CuCl2膜/Na2SO3催化引发系是必不可少的,采用ESR、IR、XPS和电导率等手段研究该体系催化剂的表面结构,结果表明,膜的单位面积平均含铜量在一定范围内和配位体种类等对催化活性有显著影响,即催化性能与催化剂的表面结构紧密相关。  相似文献   

6.
2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚(5-Br-PADAP)在极谱和伏安分析中的应用已有一些报道。陈林林等曾经研究过Ti(Ⅳ)-5-Br-PADAP络合物在稀H2SO4-H2C2O4溶液中的极谱行为,但灵敏度不高(1.0×10-7mol/L)。我们发现,在pH4.1左右的HAc-NaAc底液中,Ti(Ⅳ)-5-Br-PADAP-NaClO3体系产生一灵敏的极谱吸附催化波,二次导数峰电位在-0.86V(vs.SCE)左右,波形良好,波高稳定,检测限可达4×10-10mol/L。1 实验部…  相似文献   

7.
以白炭黑和硅溶胶为硅源,在(TPA)2O-Na2O-SiO2-H2O体系60℃下合成了高结晶度纯相硅沸石,由SEM没得其晶粒尺寸为0.2μm和0.45μm用XRD线宽法是的为0.02μm,一180℃时合成的硅沸石样品相比,低温合成的细晶粒硅沸石已上备内米级的若干特性,其正己烷吸附量反常增大;XRD、FTIR、^29SiMAS NMR和TG/DTG/DTA的研究证明,其结构破坏温度和单斜/正交对称性  相似文献   

8.
二氧化碳加氢合成甲醇铜基催化剂表面组成的研究   总被引:5,自引:0,他引:5  
本文分别采用XRD、ESR、XPS和XAES等技术对于二氧化碳加氢低压合成甲醇用CuO,CuO-ZnO,CuO-ZnO-Al_2O_3,CuO-ZnO-ZrO_2催化剂在不同条件下表面Cu、Zn、Al、Zr的存在价态进行了深入分析。实验发现催化剂在还原前Cu以Cu ̄2+存在,在还原后和反应状态下以Cu ̄0存在;Zn在还原后和反应状态下有部分被还原为Zn ̄(2-δ)(0<δ<2),Zr和Al仍保持其还原前价态。催化剂的表面化学组成为:Cu ̄0/Zn(2-δ) ̄+/Zr ̄4+/Al ̄3+/O ̄2-。  相似文献   

9.
反相离子对色谱法测定硫代硫酸根和碘离子的研究   总被引:4,自引:0,他引:4  
张晓彤  云自厚 《色谱》1997,15(1):57-59
首次利用S2O2-3和I-与Hg-EDTA二元络合物通过柱前衍生形成EDTA-Hg-S2O3和EDTA-Hg-I两种三元络合物的方法,实现了对S2O2-3和I-的间接反相离子对色谱分离和紫外检测。在ZorbaxODS柱上,用甲醇∶水=23∶77作流动相,内含对离子TBA+3.0mmol/L,EDTA1.0mmol/L,NaNO32.0mmol/L和缓冲剂KH2PO4-Na2HPO4(pH7.0),紫外254nm检测。S2O2-3和I-的最小检出限分别为61.1ng和37.6ng。方法简便,选择性好。  相似文献   

10.
SO_4~(2-)/ZrO_2超强酸制备方法的改进   总被引:1,自引:0,他引:1  
用BET、XRD、流动指示剂法、化学分析、低温正丁烷异构化反应等手段研究了制备条件对ZrO2前驱体和SO/ZrO2超强酸性能的影响.实验结果表明,采用不同的制备条件,ZrO2前驱体的比表面可相差1.8倍,SO/ZrO2的酸强度相差约1000倍.SO/ZrO2的正丁烷异构化反应活性相差约300倍.ZrO2最高比表面可达245m2/g,SO/ZrO2酸强度为H0≤-1.60,20℃时SO/ZrO2正丁烷异构化反应速率常数为15.5×10-3h-1。  相似文献   

11.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

12.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

13.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

  相似文献   

14.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

15.
In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.  相似文献   

16.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

17.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

18.
The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.  相似文献   

19.
20.
设计了铁的锈蚀实验,说明了铁钉的处理方法,增加了温度、酸、碱的影响条件,实现了铁跟蒸馏水及空气中氧气快速反应而生锈,使实验在5 min左右就能够得到准确的结果。  相似文献   

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