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991.
Qi‐jing Lin Shu‐ming Yang Chen‐ying Wang Jian‐jun Ding Zhuang‐de Jiang 《Surface and interface analysis : SIA》2013,45(8):1223-1227
Two bilayer thin films with different stacking sequences, Cu/Ti/Si and Ti/Cu/Si, were deposited by DC magnetron sputtering technique. X‐ray diffraction technique was used to measure the crystallization structures, and scanning electron microscopy and atomic force microscopy were used to measured surface morphology. The multifractal spectra f(α)‐α was used to characterize the surface morphology. The result of |q|max ≤ 53 is obtained by multifractal analysis. The shape of the multifractal spectra f(α) ? α is hook‐like for Cu/Ti/Si and bell jar‐like for Ti/Cu/Si. The spectrum width Δα = αmax ? αmin and Δf(=f(αmin) ? f(αmax)) of the multifractal spectra is able to quantitatively analyze the growth and surface roughness of the Cu/Ti bilayer thin films. The surface of Ti/Cu/Si thin film is more uniform and smoother than the film of Cu/Ti/Si. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
992.
有机硅化合物是半导体工业中产生硅元件的基本原料和有机合成中的重要试剂,是多年来大家研究较多的分子体系之一.本文报导了用同步辐射加速器产生的真空紫外光,电离St(CH3hCI。分子.在50-120n-m波长范围内,测量了各种离子产物与真空紫外光波长的关系,推算得它的绝热电离电势和离子中几个化学键的键能.1实验装置和方法本工作在国家同步辐射实验室光化学实验站进行.进行分子真空紫外光电离研究的实验系统已在文献山中详细描述.同步辐射加速器产生的真空紫外光波长用Ne气的电离势标定,其误差<士0-Inln.单色仪的分辨率为河凸… 相似文献
993.
Rong-Bin Huang Chun-Ru Wang Zhao-Yang Liu Lan-Sun Zheng Fei Qi Liu-Si Sheng Shu-Qin Yu Yun-Wu Zhang 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1995,33(1):49-52
A series of cluster anions C n X? are produced from laser ablation of appropriate samples, where X is selected as a group-VB element. The recorded mass spectra of these cluster anions display a drastic even/odd alternation on ion intensities: For C n N?, only anions with oddn can be observed; For C n P? and C n As?, cluster anions with evenn are produced but with lower signal intensities; For C n Sb?, the signal intensity of clusters does not show even/odd alternation; Finally, for C n Bi?, the intensities of cluster anions with evenn are higher than those with oddn. This parity effect can be attributed to the linear structure of the cluster anions, and the parity reversal of C n X? from C n N? to C n Bi? can be explained from the electronegativity decreasing of the heteroatom X as it descends in the group. The Hückel model was applied to account the structural feature of these clusters. 相似文献
994.
Huaqian Chen Tao Lu Minglong Qiao Jiawen Hu Chunmei Li Chenze Qi Furen Zhang 《Journal of heterocyclic chemistry》2021,58(11):2132-2139
A series of 1,5-dihydro-4H-pyrrolo[3,2-c]pyridin-4-one derivatives with 3-(4-hydroxy-2-oxo-2H-pyran-3-yl) groups were synthesized via a one-pot three-component reaction of 4-aminopyridin-2(1H)-ones, 2,2-dihydroxy-1-arylethan-1-ones, and 4-hydroxy-2H-pyran-2-ones in water. This strategy not only provides a valuable tool in the design and synthesis of new hydrogenated pyrrolo[3,2-c]pyridines but also has the advantages of inexpensive starting materials, atom and step economy, environmental friendliness, good to excellent yields, and operational simplicity. A total of 14 examples were examined to show a broad substrate scope and high yields. 相似文献
995.
Haiquan Chen Fengna Dai Mengxia Wang Chunhai Chen Guangtao Qian Youhai Yu 《Journal of polymer science. Part A, Polymer chemistry》2021,59(10):833-842
A pair of isomer diamines containing both benzimidazole and benzoxazole and derived homopolyimides were synthesized for the first time. Due to rich rigid and linear benzoazole units, as well as the strong intermolecular interactions from the hydrogen bonding and the charge transfer complexation (CTC), the obtained polyimides (PIs) exhibited outstanding thermal properties, including high thermal weight loss temperature (Td5% = 540–561°C), high glass transition temperature (Tg = 392–421°C), and low coefficient of thermal expansion (CTE = 1.3–20.9 ppm/°C). In addition, the obtained PIs also showed ideal mechanical properties (TS = 189–240 MPa, TM = 4.1–5.0 GPa and EB = 2.9%–4.7%). These potential novel PI films with high Tg and low CTE were expected to be applied to next generation of flexible display substrate material. 相似文献
996.
997.
XinZHANG DeHuaHE QiJiangZHANG BoQingXU QiMingZHU 《中国化学快报》2003,14(10):1066-1069
Comparatively high CH3OH selectivity (60.0%) and yield (6.7%) were obtained on MoOx/(LaCoO3 Co3O4) catalysts in selective oxidation of methane to methanol using molecular oxygen as oxidant. The interaction between MoOx and La-Co-oxide modified the molecular structure of molybdenum oxide and the ratio of O^-/O^2- on the catalyst surface, which controlled the catalytic performance of MoOx/(LaCoO3 Co3O4) catalysts. 相似文献
998.
Qi FANG* Hong LEI Wen XU State Key Laboratory of Crystal Materials Shandong University Jinan School of Information Science Engineering Shandong University Jinan 《中国化学快报》2003,(11)
It was commonly thought that a molecular conductor or semiconductor should be composed of at least two components to make the conducting component in partially charged state. However, this idea became questionable by the recent report of the single-component molecular conductor [Ni(tmdt)2]1 as well as several reports about single-component molecular semiconductors such as [Ni(ptdt)2]2 and [Ni(C10H10S8)2]3. In fact, as early as 1985, [Ni(dmit)2] as a by-product in synthesizing TTF[Ni(dmit… 相似文献
999.
The keto-enol tautomerization of p-hydroxyphenylpyruvic acid (pHPP) in aqueous solutions and the complexation reaction between enolic pHPP and boric acid have been studied by electrochemical techniques including linear sweep voltammetry (LSV), pulse voltammetry, and cyclic voltammetry (CV), combining with UV spectrometry. Electrochemical techniques reveal that in aqueous solution, there are two tautomers of pHPP: enolic form and ketonic form; the former exists mainly in freshly prepared pHPP solution, and the latter exists mainly in equilibrium solution. Both enolic and ketonic pHPP are electroactive. The electrochemical oxidation of enolic pHPP gives rise to two anodic waves, I(a) and II(a), while the electrochemical oxidation of ketonic pHPP only results in the observation of the second wave II(a). The oxidation process I(a) is revealed to be associated with the quasi-reversible, two-electron two-proton oxidation of "C=C"group at the side chain of enolic pHPP, and the oxidation process II(a) is proposed to result from the irreversible oxidation of phenolic hydroxyl group. It is observed that in aqueous solution, enolic pHPP can quickly complex with boric acid to yield enol-borate complex that can also oxidize at a glassy carbon electrode to yield an anodic wave. 相似文献
1000.