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排序方式: 共有195条查询结果,搜索用时 15 毫秒
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Tiopronin (TP) is a synthetic thiol compound without chromophore. By optimizing the chromatographic conditions and sample preparation processes, an improved LC‐MS/MS analytical method without derivatization has been developed and validated to determine TP concentrations in human plasma. After reduction with 1,4‐dithiothreitol, plasma samples were deproteinized with 10% perchloric acid. The post‐treatment samples were analyzed on a C8 column interfaced with a triple quadrupole tandem mass spectrometer in negative electrospray ionization mode. Methanol–5 mmol/L ammonium acetate (20:80, v/v) was used as the isocratic mobile phase. The assay was linear over the concentration range of 40.0–5000 ng/mL. The intra‐ and inter‐day precisions were within 12.9% in terms of relative standard deviation and the accuracy within 5.6% in terms of relative error. This simple and sensitive LC‐MS/MS method with short analytical time (3.5 min each sample) was successfully applied to the pharmacokinetic study of TP in healthy Chinese male volunteers after an oral dose of 300 mg TP. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
43.
设计并合成了一种以磁性纳米粒子为核,聚合物为中间层,金属有机骨架材料为外层的三层结构磁性复合材料(Fe3O4@PAA@ZIF-8)。首先利用溶剂热法制备Fe3O4纳米粒子,然后通过蒸馏沉淀聚合法在Fe3O4纳米粒子表面包覆聚丙烯酸(PAA)层,最后通过原位沉积法在PAA外部包覆ZIF-8。在对Fe3O4@PAA@ZIF-8的组成和结构进行表征的基础上,深入研究其对孔雀石绿(MG)的吸附性能。透射电子显微镜(TEM)显示Fe3O4@PAA@ZIF-8具有明显的三层结构,Fe3O4的平均粒径为117nm,PAA层厚度约为17 nm,ZIF-8层的厚度约为14 nm。Fe3O4@PAA@ZIF-8对MG的吸附量随着p H的升高而增大,吸附过程符合准二阶动力学模型和Langmuir等温吸附模... 相似文献
44.
利用矿渣制备微晶玻璃是提高矿产资源利用率的主要形式之一。本文以白云鄂博尾矿为原料,采用微波一步法制备了CaO-MgO-Al2O3-SiO2(CMAS)系辉石相矿渣微晶玻璃。选择835 ℃作为晶化温度,研究了微波加热对微晶玻璃析晶行为和微观组织的影响。以La2O3作为研究变量探讨了La2O3添加对矿渣微晶玻璃析晶行为的作用。与传统的热处理制度相比,微波加热可以在较短的时间内达到较高的析晶效果。同时La2O3的添加促进了晶粒细化。由拉曼光谱分析,La离子添加会导致玻璃网络中桥氧的增多,促进了辉石相析晶。在La的添加量为4%(质量分数)时硬度最高,达到了829.22 MPa。 相似文献
45.
Xiong Yahong Feng Nannan Liu Shengquan Zhu Junjie Li Chunyuan Ding Weijia 《Chemistry of Natural Compounds》2022,58(3):394-397
Chemistry of Natural Compounds - A new derivative of barceloneic acid A, named phomaspether J (1), was isolated from the mangrove endophytic fungus Phoma herbarum L28. Its structure was elucidated... 相似文献
46.
Gu Hua Lin Kaiwen Liu Ximei Jian Nannan Qu Kai Xu Jingkun 《Journal of Solid State Electrochemistry》2018,22(2):599-611
Journal of Solid State Electrochemistry - A series of poly(selenophene-co-3-methylthiophene) films were synthesized by electrochemical copolymerization of selenophene and 3-methylthiophene under... 相似文献
47.
Shangtao Chen Xiaofan Zhang Hongwei Ma Zhicheng Zhang Huayi Li Zhanxia Lu Nannan Cui Youliang Hu 《Journal of organometallic chemistry》2005,690(18):4184-4191
A series of new zirconium complexes bearing bis(phenoxyketimine) ligands, bis((3,5-di-tert-butyl-C6H2-2-O)R1CN (2-R2-C6H4))ZrCl2 {R1 = Me, R2 = H (2a); R1 = Et, R2 = H (2b); R1 = Ph, R2 = H (2c); R1 = 2-Me-Ph, R2 = H (2d); R1 = 2-F-Ph, R2 = H (2e); R1 = 2-Cl-Ph, R2 = H (2f); R1 = 2-Br-Ph, R2 = H (2g); R1 = Ph, R2 = Me (2h); R1 = Ph, R2 = F (2i)}, have been prepared, characterized and tested as catalyst precursors for ethylene polymerization. Crystal structure analysis reveals that complex 2c has a six coordinate center in a distorted octahedral geometry with trans-O, cis-N, cis-Cl arrangement which possesses approximate C2 symmetry. When activated with methylaluminoxane (MAO), complexes 2a-2i exhibited high ethylene polymerization activities of 106-108 g PE (mol M h)−1. Compared with the bis(phenoxyimine) zirconium analogues bis((3,5-di-tert-butyl-C6H2-2-O)CHNC6H5)ZrCl2 (3), the introduction of substituent on the carbon atom of the imine double bond enhanced the catalytic activity and molecular weight of prepared polyethylene. Especially, when the H atom at the carbon atom of the imine double bond was replaced by 2-fluoro-phenyl with strong electronic-withdrawing property, complex 2e displayed the highest catalytic activity, and the polyethylene obtained possessed the highest molecular weight and melt point. 相似文献
48.
Shape‐Controlled Synthesis of NiCo2O4 Microstructures and Their Application in Supercapacitors 下载免费PDF全文
The shape‐controlled synthesis of NiCo2O4 microstructures through a facile hydrothermal method and subsequent calcinations was explored. By employing CoSO4, NiSO4, and urea as the starting reactants, flower‐like NiCo2O4 microstructures were obtained at 100 °C after 5 h without the assistance of any additive and subsequent calcination at 300 °C for 2 h; dumbbell‐like NiCo2O4 microstructures were prepared at 150 °C after 5 h in the presence of trisodium citrate and subsequent calcination at 300 °C for 2 h. The as‐prepared NiCo2O4 microstructures were characterized by X‐ray powder diffraction, field‐emission scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and (high‐resolution) transmission electron microscopy. Both the flower‐like and dumbbell‐like NiCo2O4 microstructures could be used as electrode materials for supercapacitors, and they exhibited excellent electrochemical performance, including high specific capacitance, good rate capability, and excellent long‐term cycle stability. Simultaneously, the shape‐dependent electrochemical properties of the product were investigated. 相似文献
49.
Worm-like mesoporous carbon synthesized from metal–organic coordination polymers for supercapacitors
Dingsheng Yuan Jingxing Chen Sanxiang Tan Nannan Xia Yingliang Liu 《Electrochemistry communications》2009,11(6):1191-1194
A green and efficient route has been employed to synthesize a worm-like mesoporous carbon with high specific surface area (2587 m2 g?1) and large pore volume (3.14 cm3 g?1). Three electrochemical methods have been used to measure its electrochemical performance. Worm-like mesoporous carbon performs the high specific capacitance (344 F g?1) at constant-current densities of 50 mA g?1. 相似文献
50.
This paper focused on a self-developed microfluidic array system with microfabricated capillary array electrophoresis (mu-CAE) chip for parallel chip electrophoresis of biomolecules. The microfluidic array layout consists of two common reservoirs coupled to four separation channels connected to sample injection channel on the soda-lime glass substrate. The excitation scheme for distributing a 20 mW laser beam to separation channels in an array is achieved. Under the control of program, the sample injection and separation in multichannel can be achieved through six high-voltage modules' output. A CCD camera was used to monitor electrophoretic separations simultaneously in four channels with LIF detection, and the electropherograms can be plotted directly without reconstruction by additional software. Parallel multichannel electrophoresis of series biomolecules including amino acids, proteins, and nucleic acids was performed on this system and the results showed fine reproducibility. 相似文献