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1.
郑寿荣  颜其洁 《分子催化》1995,9(2):139-144
应用X射线衍射(XRD)、酸碱滴定,激光拉曼(LRS)和紫外漫反射(UV-DRS)等方法对磷钨酸(PW12)与γ-Al2O3的相互作用及其在γ-Al2O3上的铺展状态进行了研究。结果表明:在单层铺展时,磷钨酸与γ-Al2O3存在不可逆的强相互作用,但其Keggin结构仍保持稳定,随负载量的增加,PW12在γ-Al2O3表面上依次以单层,一级结构,二级结构形式铺展。  相似文献   

2.
应用X射线衍射(XRD)、酸碱滴定,激光拉曼(LRS)和紫外漫反射(UV-DRS)等方法对磷钨酸(PW_(12))与γ-Al_2O_3的相互作用及其在γ-Al_2O_3上的铺展状态进行了研究。结果表明:在单层铺展时,磷钨酸与γ-Al_2O_3存在不可逆的强相互作用,但其Keggin结构仍保持稳定,随负载量的增加,PW_(12)在γ-Al_2O_3表面上依次以单层,一级结构,二级结构形式铺展。  相似文献   

3.
测定了三元体系La(ClO4)3-OCBAAP-H2O在30℃时的溶解度.结果表明,该体系有一个新固相(不一致溶解化合物)La(OCBAAP)4(ClO4)3·6H2O形成.参考该体系溶度图确定合成条件,合成了系列化合物Ln(OCBAAP)4(ClO4)3·nH2O(Ln=La,n=6;Ln=Pr,Nd,Sm,Gd,Yb,n=2).通过化学分析、元素分析、TG-DTG、IR和密度对化合物进行了表征,计算了La(OCBAAP)4(ClO4)3热分解过程各阶段的表观活化能.  相似文献   

4.
采用半微量相平衡方法研究了Gd(ClO_4)_3·3H_2O-18C6-CH_3CN三元体系在25℃时的溶解度,测定了饱和溶液的折光率。结果表明,该体系在25℃时形成两种化学计量的配合物,其组成分别为:Gd(ClO_4)_3·18C6·3H_2O·2CH_3CN和Gd(ClO_4)_3·2(18C6)·3H_2O·2CH_3CN,制备了固态配合物,用化学分析及元素分析、IR、DTG、TG及DSC等研究了配合物的组成与性质。  相似文献   

5.
提出用溶胶粒子表面修饰方法,结合溶胶-凝胶技术制备无机催化膜,该方法的基本原理是利用合适的金属配合物在胶粒表面吸附作用,经溶胶-凝胶过程,将活性组分结合到无机膜中,实验测定结果表明:(NiEDTA)^2-,VO^-3,MoO^2-4,(Pd(NH3)4^2+,PdCl^2-4,PtCl^2-6和RhCl^3-6可用来修饰AlOOH溶胶,以Pd/γ-Al2O3催化膜的制备为例,经三次溶胶-凝胶过程,  相似文献   

6.
提出用溶胶粒子表面修饰方法,结合溶胶凝胶技术制备无机催化膜.该方法的基本原理是利用合适的金属配合物在胶粒表面的吸附作用,经溶胶凝胶过程,将活性组分结合到无机膜中.实验测定结果表明:(NiEDTA)2-,VO-3,MoO2-4,(Pd(NH3)4)2+,PdCl2-4,PtCl2-6和RhCl3-6可用来修饰AlOOH溶胶.以Pd/γAl2O3催化膜的制备为例,经三次溶胶凝胶过程,可制得无裂缺的厚度为9μm的Pd/γAl2O3催化膜,膜材料的平均孔直径为6nm,Pd被均匀地分布在膜的顶层,其平均粒径为23nm.  相似文献   

7.
用XRD、TG、热重氨吸附法等手段,测定了Al_2(SO_4)_3/γ-Al_2O_3中单层分散相与Al_2(SO_4)_3担载量之间的关系,测定了表面单层最大分散量一阈值。其与用密置单层模型计算所得值接近,这为Al_2(SO_4)_3在γ-Al_2O_3上单层分散行为提供了证据,且将该催化剂的表面行为与其对丁烯齐聚反应活性进行了关联。  相似文献   

8.
以TiCl和Ti(OC4H9)4为源物质采用热化学气相淀只(CVD)法及射频PCVD法在多孔α-Al2O3陶瓷衬底上淀积生长TiO2薄膜,观测TiO2膜的生长方式、生长速率以及结构和表面形貌等,讨论其生长机制,评价CVD改性生长的顶怪TiO2陶瓷膜的气体渗透性。  相似文献   

9.
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   

10.
合成了三个稀土-二笨甲酰甲烷-三辛基氧化膦三元配合物Ln(DBM)_3·TOPO(Ln=Y、Eu、Er)。用红外光谱、紫外光谱及差热—热重谱对其进行了表征,同时还研究了Eu(DBM)_3·H_2O(A)和Eu(DBM)_3·TOPO(B)在固态下及CHCl_3溶液中的荧光光谱和荧光寿命,结果表明在CHCl_3溶液中,B的荧光强度为A的48倍,其荧光寿命分别为(149±10)μs和(86±10)μs。另外对这些化合物在空气/水界面的单分子膜行为也进行了研究。  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.

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.

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13.
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   

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.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

16.
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   

17.
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   

18.
袁丽秋 《化学教育》2006,27(5):8-10
面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。  相似文献   

19.
20.
黄酮化合物的合成研究进展   总被引:2,自引:0,他引:2  
黄酮化合物是一类具有多种生物活性的天然产物,其经典的合成方法主要为查耳酮路线和β-丙二酮路线.近年来出现了许多新技术、新方法.本文介绍了2'-羟基查尔酮的氧化关环法、黄烷酮氧化法、改进的Baker-Venkataraman法及其他合成黄酮化合物的方法.  相似文献   

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