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101.
Nikolay Evdokimenko Zhanna Yermekova Sergey Roslyakov Olga Tkachenko Gennady Kapustin Denis Bindiug Alexander Kustov Alexander S. Mukasyan 《Materials》2022,15(15)
Active and stable catalysts are essential for effective hydrogenation of gaseous CO2 into valuable chemicals. This work focuses on the structural and catalytic features of single metals, i.e., Co and Ni, as well as bimetallic CoNi alloy catalysts synthesized via combustion of reactive sol-gels. Different characterization methods were used for studying the relationships between the structure, composition, and catalytic activity of the fabricated materials. All catalysts exhibited highly porous sponge-like microstructure. The outermost surfaces of the CoNi alloys were more saturated with Co, while a stoichiometric Co/Ni ratio was observed for the particle’s bulk. Catalytic properties of the as-synthesized powders were studied in the CO2 hydrogenation reaction at 300 °C for over 80 h of time on stream. All the catalysts demonstrated exceptional selectivity with respect to CH4 formation. However, the combination of elemental Co and Ni in a single phase resulted in a synergistic effect in bulk alloy catalysts, with activity twofold to threefold that of single-metal catalysts. The activity and stability of the CoNi3 catalyst were higher than those previously reported for Ni-based catalysts. The reasons for this behavior are discussed. 相似文献
102.
Micha Zieliski Monika Kot Mariusz Pietrowski Robert Wojcieszak Jolanta Kowalska-Ku Ewa Janiszewska 《Materials》2021,14(16)
This paper investigates the catalytic properties of the iridium catalysts supported on modified silicalite-1. Post-synthesis modification of silicalite-1, with solutions of ammonium compounds (NH4F and NH4OH), appeared to be an efficient method to generate the acidic sites in starting support. The modification of support led not only to changes in its acidity but also its porosity—formation of additional micro- and mesopores. The novel materials were used as supports for iridium. The iridium catalysts (1 wt.% Ir) were characterized by N2 adsorption/desorption measurements, temperature-programmed reduction with hydrogen (TPR-H2), H2 chemisorption, transmission electron microscopy (TEM), temperature-programmed desorption of ammonia (TPD-NH3), X-ray photoelectron spectroscopy (XPS) and tested in the hydrogenation of toluene reaction. The catalytic activity of iridium supported on silicalite-1 treated with NH4OH (higher porosity of support, better dispersion of active phase) was much higher than that of Ir supported on unmodified and modified with NH4F silicalite-1. 相似文献
103.
Steve Arns Anne Moreau Robert N. Young 《Journal of labelled compounds & radiopharmaceuticals》2010,53(4):205-207
The first general method for asymmetric tritiation using ruthenium catalyzed transfer hydrogenation and its application to the radiosynthesis of an exemplary prostaglandin EP4 receptor‐selective Prostaglandin E2 analog is described. The methodology should be of general utility for the enantioselective preparation of α‐tritiated chiral secondary alcohols. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
104.
目的 制备用于新型多肽类药物全合成研究的非必需氨基酸N-叔丁氧羰基-DL-(±)-高酪氨酸(1).方法 以L-天冬氨酸(2)为原料,经N-甲氧羰基保护、分子内脱水酸酐化、与邻氯苯甲醚的Friedel-Crafts反应、10%钯碳催化氢化、48%氢溴酸脱N-甲氧羰基和酚甲醚保护、N-叔丁氧羰基保护6步反应合成了目标化合物.结果 以总收率49.7%成功地合成了目标化合物1,其结构经电喷雾质谱(ESI-MS)、氢谱(1H NMR)和碳谱(13C NMR)确认.结论 该合成路线具有原料价廉易得、操作简便、总收率高等优点. 相似文献
105.
以邻硝基甲苯为起始原料 ,经缩合、加氢还原、磷酸成盐得 2 ,2′-二氨基联苄二磷酸盐 ,再经环合制得 10 ,11-二氢 - 5 H -二苯并 [b,f]氮杂。总收率 6 3.5 %。 相似文献
106.
在对混合丁醛加氢制丁醇的反应体系进行热力学与动力学分析的基础上。采用一维拟均相数学模型对丁醛加氢制丁醇管壳式固定床反应器进行数学模拟设计。预测了反应温度、冷却介质温度、反应压力和反应空速对加氢反应结果的影响。结果表明:丁醛加氢制丁醇的数学模拟结果与生产数据吻合良好。 相似文献
107.
硫酸沙丁胺醇的合成研究Ⅰ 总被引:3,自引:0,他引:3
以水杨醛与叔丁胺为起始原料,经缩合、酯化、Fries重排三步一锅反应制成2-氯-1-{[(1,1-二甲基乙基)亚胺基甲基]-4-羟基苯基}-乙基酮(4).再经缩合、水解、成盐三步一锅反应转化成5-{[(1,1-二甲基乙基)胺基]乙酰基}-2-羟基苯甲醛盐酸盐(5),再经甲醇钠中和、催化转移氢化还原、成盐即得硫酸沙丁胺醇(1),总收率约50%。 相似文献
108.
109.
应用溶剂化金属原子浸渍法制血了四中不同比表面积树脂固载的Co-Ag双金属催化剂。射线衍射(XRD)和磁测定结果表明,随着树脂比表面积的增大,具有相同金属含量的催化剂Co和Ag的颗粒减小,分散度增大,因而催化剂在二丙酮醇加氢以及燃料电池电极上氧还原的催化活性增大。 相似文献
110.