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81.
使用一维机械模板的高分辨阿达玛变换显微图像探测技术研究 总被引:2,自引:1,他引:1
阿达玛变换(HT)是一种类似于傅里叶变换(FT)的光谱调制技术,具有多通道同时检测和多通道成像能力等优点,但两者的数学模型、对光信号的调制方法和调制手段都不一样。由于HT仅涉及四则运算,而FT涉及较为复杂的三角函数和复数运算,所以HT的解码速度快于FT。在成像技术方面,HT具有直接成像的能力,而FT只能对通过其它方式获取的图像进行加工处理。 相似文献
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Guan‐E Wang Gang Xu Ning‐Ning Zhang Ming‐Shui Yao Ming‐Sheng Wang Guo‐Cong Guo 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(9):2718-2721
Superlattice materials offer new opportunities to modify optical and electrical properties of recently emerging 2D materials. The insertion of tetraethylbenzidine (EtDAB) into interlamination of the established 2D PbI2 semiconductor through a mild solution method yielded the first lead iodide superlattice, EtDAB?4PbI2 (EtDAB=tetraethylbenzidine), with radical and non‐radical forms. The non‐radical form has a non‐ionic structure that differs from the common ionic structures for inorganic–organic hybrid lead halides. The radical form shows five orders of magnitude greater conductance and broader photoconductive response range (UV/Vis → UV/Vis‐IR), than pure PbI2 and the non‐radical form of the superlattice. 相似文献
84.
Dr. Guan‐E Wang Prof. Dr. Gang Xu Bin‐Wen Liu Ming‐Sheng Wang Ming‐Shui Yao Guo‐Cong Guo 《Angewandte Chemie (International ed. in English)》2016,55(2):514-518
Crystalline nanotube array would create great opportunity for novel electrical application. Herein we report the first example of a metal halide based crystalline nanotube array which is constructed from an unprecedented giant [PbII18I54(I2)9] wheel cluster, as determined by synchrotron X‐ray diffraction. The electrical properties of the single crystal were studied and the present compound shows typical semiconductivity and highly anisotropic conductivity. 相似文献
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Kun Hu Kang Zheng Xingyou Tian Lin Chen Lili Sun Xiangyu Shui 《Journal of Macromolecular Science: Physics》2013,52(5):846-859
Attapulgite (AT) was modified by grafting with butyl acrylate (BA) via polymerizations initiated by Gamma radiation. Polypropylene (PP)/AT nanocomposites were synthesized via melt extrusion in a twin-screw extruder. Fourier transform infrared (FTIR) spectroscopy and thermogravimetry (TG) were used to assess the structure of the hybrid materials and the dispersion of AT was verified by transmission electron microscopy (TEM). The crystallization kinetics of PP/AT nanocomposites were investigated by differential scanning calorimetry (DSC) and analyzed by using the Avrami method. The isothermal crystallization kinetics showed that the addition of AT increased both the crystallization rate and the isothermal Avrami exponent of PP. Step-scan differential scanning calorimetry (SDSC) was used to study the influence of AT on the crystallization and subsequent melting behavior. The results revealed that PP and PP/AT nanocomposites experienced multiple melting and secondary crystallization processes during heating. The melting behaviors of PP and PP/AT nanocomposites varied with the variation of crystallization temperature and AT content. 相似文献
88.
Catalysis and deactivation of SO42−/ZrO2 solid acid on the alkylation of benzene and 1-dodecene were studied by the characterization of XRD, BET, IR, TG/DTA, and
NH3-TPD techniques and the determination of the 1-dodecene conversion, the yield of dodecylbenzene and the selectivity of linear
alkylbenzene respectively. In addition, some treatment methods, such as the extraction with benzene or THF as solvent, and
the calcinations with or without the dipping of H2SO4 in air, were respectively used to recover the activity of deactivated catalyst. The results indicate that SO42−/ZrO2 solid acid shows higher catalytic activity for the alkylation of benzene and 1-dodecene with nearly 100% of 1-dodecene conversion
and more than 80% of dodecylbenzene yield, and higher selectivity of 2-LAB. The activity of catalyst for the alkylation of
benzene is in proportion to the content and the strength of medium acid site. However, the distinct deactivation of catalyst
was also obversed in the alkylation. According to the characterization of deactivated catalyst, the accumulation of hydrocarbon
fragment and the removal of are mainly reasons of SO42−/ZrO2 deactivation. The SO42−/ZrO2 calcinated at higher temperature is apt to deactivate. The treatment by extraction with solvent or calcinations can recover
the catalytic activity of spent catalyst at a certain extent, especially calcination with the dipping of H2SO4.
Published in Russian in Kinetika i Kataliz, 2009, Vol. 50, No. 3, pp. 455–463.
The article is published in the original. 相似文献
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重金属离子对猪胰α-淀粉酶活性影响的作用机理研究 总被引:17,自引:0,他引:17
通过在α-淀粉酶介质中加入Ce^3 ,Cd^2 和Pb^2 ,研究其对α-淀粉酶活性影响的作用机理。结果表明,低浓度重金属离子对酶活性有激活作用,高浓度则严重抑制酶活性。在高浓度下,Ce^3 ,Cd^2 和Pb^2 能完全竞争出α-淀粉酶中的Ca^2 。荧光滴定结果表明,Ce^3 ,Cd^2 和Pb^2 不仅可能完全占据Ca^2 的结合位点,而且还可能在Ca^2 的结合位点以外的氨基酸残基上结合,从而导致酶的构象改变。 相似文献