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111.
Yan Dai~a Bin Dong Li~a Heng Dao Quan~b Chun Xu Lü~ a School of Chemical Engineering Nanjing University of Science Technology Nanjing China b National Institute of Advanced Industrial Science Technology Ibaraki Japan 《中国化学快报》2010,21(6):678-681
<正>[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation.The catalyst was recycled more than 10 times without any apparent loss of catalytic activity. 相似文献
112.
Lia Va 《Journal of Pure and Applied Algebra》2007,210(3):847-853
We prove that every perfect torsion theory for a ring R is differential (in the sense of [P.E. Bland, Differential torsion theory, Journal of Pure and Applied Algebra 204 (2006) 1–8]). In this case, we construct the extension of a derivation of a right R-module M to a derivation of the module of quotients of M. Then, we prove that the Lambek and Goldie torsion theories for any R are differential. 相似文献
113.
114.
采用在周期性氧化电压信号中插入恒压波形的方法成功制备了具有缺陷模的一维氧化铝光子晶体. 这种晶体的透射光谱研究表明,缺陷的厚度对缺陷模的透过率具有显著影响,当缺陷厚度在180 nm时,光子禁带内部出现透过率为55%、半峰宽约为18 nm的缺陷模. 该缺陷模能够对进入到氧化铝孔道内部的液体物质做出响应,其位置与液体的折射率线性相关. 相似文献
115.
Synthesis and biological evaluation of new pyrrolopyrazinone compounds as potential antitumor agents
Ying Meng Guan Wang Yue Li Kuan Hou Yue Yuan Li-Juan Zhang Hong-Rui Song Wei Shi 《中国化学快报》2013,24(7):619-621
A series of pyrrolo[1,2-a]pyrazinone compounds(5a-9f) were synthesized,and their cytotoxic activity against SKOV-3,A549.HeLa cells in vitro were evaluated by the MTT method.Some of the compounds showed potential antitumor activity against three tumor cell lines.Among them,compounds 9c and 9d showed the most potent cytotoxic activity.The preliminary mechanism of action was discussed. 相似文献
116.
Fan-Yun Meng Ying-Qin Wei Heng Lu Xiao-Teng Zhou Jin-Xin Liu Geng Li Jing-Yi Hou 《中国化学快报》2013,24(6):506-508
A new method for the analysis of copper and its speciation in Rhizoma coptidis was proposed using chelatometric dispersive liquid-liquid microextraction(cDLLME) followed by capillary electrophoresis. Dithizone was used as a chelating agent for extraction and carbon tetrachloride and ethanol were used as extraction and dispersive solvent,respectively.The calibration curve was linear in the range of 0.5- 20.0μg/mL with a correlation coefficient of 0.9990(n = 6) and the average recovery was in the range of 88.26%-94.44%.The method was successfully used to determine the total and water soluble copper in Rhizoma coptidis herbal medicine.The results suggested that it would be reasonable to setting the criterion of heavy metals in an herbal medicine according to the dosage forms. 相似文献
117.
A fundamental study on C-C coupling, that is the crucial step in the Fischer-Tropsch synthesis (FTS) process to obtain multi-carbon products, is of great importance to tailor catalysts and then guide a more promising pathway. It has been demonstrated that the coupling of CO with the metal carbide can represent the early stage in the FTS process, while the related mechanism is elusive. Herein, the reactions of the CuC\begin{document}$ _3 $\end{document} H\begin{document}$ ^- $\end{document} and CuC\begin{document}$ _3 $\end{document} \begin{document}$ ^- $\end{document} cluster anions with CO have been studied by using mass spectrometry and theoretical calculations. The experimental results showed that the coupling of CO with the C\begin{document}$ _3 $\end{document} H\begin{document}$ ^- $\end{document} moiety of CuC\begin{document}$ _3 $\end{document} H\begin{document}$ ^- $\end{document} can generate the exclusive ion product COC\begin{document}$ _3 $\end{document} H\begin{document}$ ^- $\end{document} . The reactivity and selectivity of this reaction of CuC\begin{document}$ _3 $\end{document} H\begin{document}$ ^- $\end{document} with CO are greatly higher than that of the reaction of CuC\begin{document}$ _3 $\end{document} \begin{document}$ ^- $\end{document} with CO, and this H-assisted C-C coupling process was rationalized by theoretical calculations. 相似文献
118.
Marcus Herbig Lia Gevorgyan Moritz Pflug Dr. Jörg Wagler Dr. Sandra Schwarzer Prof. Edwin Kroke 《ChemistryOpen》2020,9(9):894-902
Amine treatment is commonly used to capture CO2 from exhaust gases and from ambient air. The Si−N bond in aminosilanes is capable of reacting with CO2 more readily than amines. In the current study we have synthesized trimethylsilylated ethanolamines, diethanolamines and piperazines and investigated their reaction toward CO2. All products were characterized by 1H, 13C, and 29Si NMR, RAMAN spectroscopy as well as mass spectrometry. The product of a twofold CO2-insertion into bis-trimethylsilylated piperazine was analysed by single-crystal X-ray diffraction. Furthermore, quantum chemical calculations (DFT) were used to supplement the experimental results. Geometry optimizations and NBO calculations for each starting material were carried out at the B3LYP level with different basis sets. DFT calculations at the B3LYP, WB97XD and M062x level were conducted for geometry optimization and frequency calculations to examine the thermochemical data. The calculations were carried out both for the gas phase and in solvent environment. The calculated reaction enthalpies varied between −37 and −107 kJ mol−1, while experimental values around −100 kJ mol−1 were determined. 相似文献
119.
Recent papers in the physics literature have introduced spin-coupled (or spinor) Ginzburg–Landau models for complex vector-valued order parameters in order to account for ferromagnetic or antiferromagnetic effects in high-temperature superconductors and in optically confined Bose–Einstein condensates. In this Note we observe that such models can lead to new types of vortices, with fractional degree and non-trivial core structure. To cite this article: S. Alama, L. Bronsard, C. R. Acad. Sci. Paris, Ser. I 337 (2003). 相似文献
120.
Ziblat R Leiserowitz L Addadi L 《Angewandte Chemie (International ed. in English)》2011,50(16):3620-3629
Biological membranes comprise thousands of different lipids, differing in their alkyl chains, headgroups, and degree of saturation. It is estimated that 5% of the genes in the human genome are responsible for regulating the lipid composition of cell membranes. Conceivably, the functional explanation for this diversity is found, at least in part, in the propensity of lipids to segregate into distinct domains, which are important for cell function. X-ray diffraction has been used increasingly to characterize the packing and phase behavior of lipids in membranes. Crystalline domains have been studied in synthetic membranes using wide- and small-angle X-ray scattering, and grazing incidence X-ray diffraction. Herein we summarize recent results obtained using the various X-ray methods, discuss the correlation between crystalline domains and liquid ordered domains studied with other techniques, and the relevance of crystalline domains to functional lipid domains in biological membranes. 相似文献