CuO-Bi2O3/SiO2-MgO催化剂的制备及炔化性能

采用浸渍法、沉积-沉淀法、共沉淀法制备了CuO-Bi2O3/SiO2-MgO催化剂,利用低温N2物理吸-脱附、透射电镜(TEM)、X射线衍射(XRD)、H2程序升温还原(H2-TPR)、傅里叶红外(FT-IR)等技术对其进行了表征,并考察了催化剂在甲醛乙炔化合成1,4-丁炔二醇反应中的催化性能.结果表明,制备方法对催化剂中活性组分分散度及还原性能有较大影响,进而在甲醛乙炔化合成1,4-丁炔二醇反应中表现出不同的催化活性.采用共沉淀法制备的催化剂中活性物种CuO具有高的分散度与较好的还原能力,经活化后可生成数量较多的炔铜配合物活性中心,表现出最佳的炔化反应活性与丁炔二醇选择性.     

糠醛气相加氢制备糠醇Cu/SiO2催化剂的失活机理研究

采用共沉淀法制备了Cu/SiO₂催化剂，在固定床反应器上评价其糠醛气相催化加氢制备糠醇的反应性能，并采用XRD、H2-TPR、ICP-OES、XPS、TG、Raman、TEM等手段对使用后的Cu/SiO₂催化剂进行表征，研究其在反应中的失活机理。在常压、反应温度140℃、质量空速2.4 h^-1、氢醛比9.7的条件下，反应5 h内糠醛转化率均高于97%；反应6-21 h，糠醛转化率从96%快速下降到32%，说明Cu/SiO₂催化剂在糠醛加氢反应中快速失活，失活的主要原因是活性组分铜的团聚烧结和催化剂表面上积炭覆盖了反应活性位。     

不同沉淀剂制备CuO-ZnO催化剂甲醛乙炔化反应性能

分别以NaOH、Na₂CO₃、NaHCO₃为沉淀剂,采用共沉淀法制备了Cu：Zn摩尔比为2：1的CuO-ZnO催化剂,利用氢气程序升温还原（H₂-TPR）、热重（TG）、X射线衍射（XRD）及拉曼光谱（Raman）等技术对催化剂进行了表征,结合甲醛乙炔化活性评价,研究了沉淀剂对催化剂结构及催化性能的影响.结果表明,不同沉淀剂对催化剂中活性组分分散度有较大影响,进而在甲醛乙炔化合成1,4-丁炔二醇反应中表现出不同的催化活性.以Na₂CO₃为沉淀剂制备的催化剂中形成CuO-ZnO固溶体,提高了CuO的分散度及Cu⁺在还原性气氛下的稳定性,经活化后可生成较多的活性物种炔化亚铜,表现出最佳的炔化反应活性与1,4-丁炔二醇选择性.     

在仲丁醇脱氢反应中负载型铜催化剂的研究

采用浸渍法制备Cu/SiO₂和Cu-ZnO/SiO₂催化剂.研究了活性物种Cu和助剂ZnO的担载量对催化剂的结构和性能的影响,同时考察该催化剂对仲丁醇脱氢活性和选择性的影响.借助XRD和TPR对催化剂进行了表征,结果表明,高分散的Cu⁰为反应的活性中心,ZnO起到分散和稳定铜物种的作用.铜-锌之间的某种相互作用导致了缩合产物增加.     

焙烧温度对K-Cu/Zn/La/ZrO2催化剂上异丁醇合成的影响

采用共沉淀法制备了Cu/Zn/La/ZrO₂催化剂,并浸渍K对其进行改性.以合成气合成异丁醇为探针反应,考察了焙烧温度对K-Cu/Zn/La/ZrO₂催化剂合成反应的影响.采用XRD、TG、BET、NH₃-TPD、H₂-TPR、Raman及XPS等手段表征了催化剂的结构和表面性质.结果表明,催化剂体相结构、比表面积与其催化活性没有直接关系;催化剂表面强酸中心的存在不利于异丁醇的生成;Cu-Zn-Zr活性组分间协同作用对催化剂活性影响很大,450 ℃焙烧温度下,Cu-Zn-Zr活性组分间协同作用最强,CuO最容易还原,催化活性最高,此时CO的转化率(物质的量)达到69.47%,醇中异丁醇的选择性(质量分数)为19.09%,甲醇+异丁醇的选择性(质量分数)为95.02%.     

负载型金属催化剂上合成气制甲醇反应体系的耐硫性能

研究了共沉淀法制备的系列金属负载型催化剂合成气制甲醇反应性能,重点考察了催化剂上合成甲醇反应体系的耐硫性能。结果表明,Cu/ZnO催化剂显示了较好的甲醇合成反应性能,但该反应在含硫气氛下迅速失活;Pd/CeO₂催化剂体现了良好的甲醇合成反应性能和该反应体系的高耐硫性能。结合多种物理化学表征手段分析得出, Cu/ZnO催化剂在含硫气氛下因活性组分形成金属硫化物而失活;Pd/CeO₂催化剂中的载体CeO₂可优先与硫作用而保护金属活性组分,进而保持了Pd/CeO₂反应体系的高抗硫性能。     

CeO2修饰SiO2担载Cu-Ir双金属催化剂的研究

制备了CeO₂修饰SiO₂担载型铜铱基双金属催化剂,添加CeO₂使Cu-Ir/SiO₂催化剂在甲醇裂解模型反应中的初始活性和稳定性明显提高,反应10h后甲醇的转化率保持在96%以上,而Cu-Ir/SiO₂催化剂反应10h后活性下降至39.1%.采用XPS,H₂-TPR,XRD和TEM等手段对催化剂进行了结构分析,结果表明,铜和铱发生强相互作用,加入助剂CeO₂可减少催化剂颗粒团聚.     

等离子体还原催化剂在CO2甲烷化反应中的活性

采用浸渍法和原位生长水滑石法制备了Ni-Ce/γ-Al₂O₃和Ni-Ce-LDHs/γ-Al₂O₃ 2种不同类型的催化剂前驱体, 考察了2种前驱体分别经氩-氢等离子体和常规氢热方法还原所得催化剂在CO₂甲烷化反应中的活性. 结果表明, 等离子体还原催化剂的低温活性明显高于常规氢热还原催化剂, 主要表现为前者反应启动的临界温度点比后者低20~30 ℃. 采用X射线衍射(XRD)分析、 透射电子显微镜(TEM)、 CO₂程序升温脱附(CO₂-TPD)以及X射线光电子能谱(XPS)对所得催化剂的形貌和结构进行了表征. 结果表明, 等离子体还原催化剂具有较小的活性组分粒径、 较高的活性组分分散度以及较高的表面碱性, 这些特性有利于催化剂活性位对CO₂的化学吸附, 使其在甲烷化反应中表现出较好的低温活性.     

草酸二甲酯气相催化加氢合成乙二醇的研究

采用共沉淀法制备了一系列 CuO/SiO₂ 催化剂,进行草酸二甲酯气相加氢活性评价,分别考察了不同沉淀剂（Na₂CO₃、NH₃·H₂O、NaOH）、催化剂组成以及反应工艺条件对加氢性能的影响。采用N₂ 吸附脱附、N₂O吸附、XRD、TG热重分析、H₂-TPR等手段对催化剂进行表征。结果表明,草酸二甲酯加氢反应活性与Cu⁰有关,提高铜比表面积有利于提高加氢活性。采用以NaOH沉淀剂制备的CuO质量分数为50%的CuO/SiO₂催化剂,在200℃、2MPa、0.07h^-1和氢酯摩尔比为100时,草酸二甲酯转化率可达 98%,乙二醇选择性87%,且催化剂表现出较好的稳定性。     

共沉淀法和浸渍法制备的HoCeMn/TiO2催化剂的脱硝性能

采用浸渍法和共沉淀法制备了Ho Ce Mn/Ti O₂脱硝催化剂并对其结构和性能进行了表征。结果表明共沉淀法增强了活性组分和载体的相互作用,从而增加了Ho Ce Mn Ti-C催化剂表面Ce³⁺、Mn⁴⁺以及吸附氧的含量,使其表现出优异的低温氧化还原性能。此外,共沉淀法制备的HoCeMnTi-C具有更多的表面酸性位点及更强的表面酸性。催化剂表面酸性和氧化还原性能的提高有助于氨的吸附和活化,从而显著提高其活性。表面酸性位点的增多还抑制了H₂O和SO₂在催化剂表面的吸附,提升了催化剂的抗水抗硫性能。催化剂上的选择性催化还原(SCR)反应遵循Eley-Rideal(E-R)机制,催化剂硫中毒是源于形成的硫酸盐覆盖或破坏了催化剂活性位。     

Furyl- and thienyl-silatranes and germatranes

We review our research on the synthesis and study of the physical and biological properties of furyl- and thienylgermatranes and -silatranes.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 725–732, June, 1992.     

Review and patents and literature

The use of the insect cell/baculovirus expression system for producing recombinant proteins of bacterial, plant, insect, and mammalian origin has become widespread. The popularity of this eukaryotic expression system is due to many factors, including (1) potentially high protein expression levels, (2) ease and speed of genetic engineering, (3) ability to accommodate large DNA inserts, (4) protein processing similar to higher eukaryotic cells (e.g., mammalian cells), and (5) ease of insect cell growth (e.g., suspension growth). The following review of the literature discusses two engineering aspects of recombinant protein synthesis by insect cell cultures: bioreactor scale-up and insect cell line selection. Following this review patent abstracts and additional literature pertaining to expression of recombinant proteins in insect cell culture are listed.     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Preparation and photolysis of poly-p-ethylacrylophenone and poly-p-chloroacrylophenone and their copolymers with styrene and methyl methacrylate

Poly-p-ethylacrylophenone (PPEtAP) and poly-p-chloroacrylophenone (PPClAP) and their copolymers with styrene (PEtAP/S) and (PClAP/S) and with methyl methacrylate (PEtAP/MMA) and (PClAP/MMA) were prepared. Quantum yields of main-chain scissions at 366 nm at room temperature in benzene solution are of the same order as those of the unsubstituted polyacrylophenone and its copolymers. Substitution with chlorine and ethyl group in the para position compared to the unsubstituted polyacrylophenone and its copolymers leads to an increase of the lifetime for the n–π^* excited triplet state, as is evident from the measured quenching constants of photolysis. The low-temperature emission spectra of the copolymers are similar to the spectra of the model compounds in a polymer film. For the homopolymer, however, the character of the emission spectrum changes considerably.     

Concentrations and distributions of trace and minor elements in Chinese and Canadian coals and ashes

A total of 35 trace and minor elements including some of environmental significance were determined in each of a selection of 15 Chinese and 6 Canadian thermal coals and their ashes by using the SLOWPOKE-2 nuclear reactor facility of the University of Toronto. The concentrations and distributions of these constituents among the coals and their combustion products (viz. ash and volatile matter) are presented together with an interpretation of their significance in relation to the large scale combustion of these coals as thermal fuels in industrialized countries such as China and Canada. The detailed results showed wide variations in trace impurity concentrations (up to a factor of 100 and more) among the coals studied with few large differences between those of Chinese and Canadian origin except that the rare earths, Sc, Th, U, I, and Se were much higher in the former, other halogens, As and Na were lower. Values for elemental enrichment factors (EF) relative to normal crustal abundances indicated that only As(EF=13), Br(5.7), I(16), S(230), Sb(11) and Se(320) were appreciably enriched in coal. During static ashing at 750°C most of the halogens, S and Se were volatilized whereas most other inorganic constituents were highly retained and concentrated in the ash by factors of 6 to 11.