全文获取类型
收费全文 | 58869篇 |
免费 | 990篇 |
国内免费 | 367篇 |
专业分类
化学 | 27438篇 |
晶体学 | 749篇 |
力学 | 3300篇 |
综合类 | 19篇 |
数学 | 4747篇 |
物理学 | 23973篇 |
出版年
2022年 | 458篇 |
2021年 | 448篇 |
2020年 | 511篇 |
2019年 | 477篇 |
2018年 | 591篇 |
2017年 | 523篇 |
2016年 | 929篇 |
2015年 | 664篇 |
2014年 | 1038篇 |
2013年 | 2558篇 |
2012年 | 2427篇 |
2011年 | 3090篇 |
2010年 | 2182篇 |
2009年 | 2227篇 |
2008年 | 2813篇 |
2007年 | 2614篇 |
2006年 | 2513篇 |
2005年 | 2205篇 |
2004年 | 1998篇 |
2003年 | 1766篇 |
2002年 | 1581篇 |
2001年 | 2974篇 |
2000年 | 2077篇 |
1999年 | 1485篇 |
1998年 | 1039篇 |
1997年 | 1001篇 |
1996年 | 817篇 |
1995年 | 770篇 |
1994年 | 701篇 |
1993年 | 614篇 |
1992年 | 949篇 |
1991年 | 930篇 |
1990年 | 843篇 |
1989年 | 742篇 |
1988年 | 728篇 |
1987年 | 793篇 |
1986年 | 653篇 |
1985年 | 880篇 |
1984年 | 824篇 |
1983年 | 566篇 |
1982年 | 560篇 |
1981年 | 534篇 |
1980年 | 494篇 |
1979年 | 619篇 |
1978年 | 644篇 |
1977年 | 658篇 |
1976年 | 573篇 |
1975年 | 481篇 |
1974年 | 521篇 |
1973年 | 448篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Stozhkov Y. I. Filippov M. V. Logachev V. I. Makhmutov V. S. 《Physics of Atomic Nuclei》2021,84(6):1007-1010
Physics of Atomic Nuclei - In the last two decades the new experimental data on cosmic rays concerning energy spectra in a wide energy range up to 10 $${}^{14}$$ eV, isotropy, ratio of positron... 相似文献
2.
M.Y. Pustylnik A.A. Pikalev A.V. Zobnin I.L. Semenov H.M. Thomas O.F. Petrov 《等离子体物理论文集》2021,61(10):e202100126
Low-pressure gas discharge plasmas are known to be strongly affected by the presence of small dust particles. This issue plays a role in the investigations of dust particle-forming plasmas, where the dust-induced instabilities may affect the properties of synthesized dust particles. Also, gas discharges with large amounts of microparticles are used in microgravity experiments, where strongly coupled subsystems of charged microparticles represent particle-resolved models of liquids and solids. In this field, deep understanding of dust–plasma interactions is required to construct the discharge configurations which would be able to model the desired generic condensed matter physics as well as, in the interpretation of experiments, to distinguish the plasma phenomena from the generic condensed matter physics phenomena. In this review, we address only physical aspects of dust–plasma interactions, that is, we always imply constant chemical composition of the plasma as well as constant size of the dust particles. We also restrict the review to two discharge types: dc discharge and capacitively coupled rf discharge. We describe the experimental methods used in the investigations of dust–plasma interactions and show the approaches to numerical modelling of the gas discharge plasmas with large amounts of dust. Starting from the basic physical principles governing the dust–plasma interactions, we discuss the state-of-the-art understanding of such complicated, discharge-type-specific phenomena as dust-induced stratification and transverse instability in a dc discharge or void formation and heartbeat instability in an rf discharge. 相似文献
3.
Kobayashi M. Zhang Y. Ishikawa H. Sun J. Oddershede J. Juul Jensen D. Miura H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such... 相似文献
4.
Physics of Atomic Nuclei - We have investigated the robustness of the spin-navigator based method for manipulating the beam polarization to bend magnet installation errors. Toward that end,... 相似文献
5.
Lebedev D. V. Egorov V. V. Shvetsov A. V. Zabrodskaya Y. A. Isaev-Ivanov V. V. Konevega A. L. 《Crystallography Reports》2021,66(2):242-253
Crystallography Reports - The review describes the application of small-angle scattering (SAS) of neutrons and complementary methods to study the structures of biomacromolecules. Here we cover SAS... 相似文献
6.
Russian Physics Journal - Connection of Pauli’s principle with the nontrivial structure of the fermion supertime is shown. When supersymmetry is localized as supergravitation, fields of... 相似文献
7.
8.
9.
Antibiotics, once being released into the environment, become recalcitrant organic pollutants, which pose a potential risk to ecological balance and human health. In this study, a Z-scheme heterojunction of bismuth oxyiodide (BiOI)/exfoliated g-C3N4 (BiOI/ECN hereafter) was synthesized by the combination of thermal exfoliation of g-C3N4 and chemical precipitation of BiOI for efficient photocatalytic degradation of tetracycline in aqueous solutions under visible light irradiation. The optimized BiOI/ECN delivered an outstanding degradation rate at circa 0.0705 min?1, which was 10 times higher than that of the bulk g-C3N4. The photocatalytic degradation efficiency of tetracycline remained almost unchanged in a pH range of 3–11, and the BiOI/ECN displayed an excellent photostability upon recycled usage. The photocatalytic mechanism of tetracycline was ascribed to the main reactive oxidation species of photogenerated holes and superoxide radicals. In addition, the possible degradation pathways of tetracycline were investigated by HPLC-MS to identify intermediates. The toxicity of photocatalytic-generated intermediates of tetracycline was found significantly alleviated according to the calculation of quantitative structure–activity relationship prediction. This work not only provides an attractive photocatalyst for the removal of tetracycline but also opens a new avenue for rational design of Z-scheme heterojunction composites for tetracycline degradation. 相似文献
10.
Yuan Wang Xuemei Liu Quyun Chen Tian C. Zhang Like Ouyang Shaojun Yuan 《Materials Today Chemistry》2022
Addressing arsenite pollution in groundwater has drawn great attention. It is attractive to pre-oxidize highly mobile As(III) to relatively low-toxic As(V) with a subsequent adsorption separation process. Herein, BiOI anchoring on γ-Fe2O3 is performed to synthesize BiOI/γ-Fe2O3 core–shell nanoparticles for efficient removal of As(III) via a simultaneous photocatalytic oxidization–adsorption process. The physical and chemical structures of BiOI/γ-Fe2O3 are investigated by transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction measurements. The photoluminescence and electron spin resonance (ESR) characterization were employed to ascertain the possible reaction mechanism of visible-light-driven photocatalytic oxidation of As(III). Such BiOI/γ-Fe2O3 delivers a superior As(III) removal capability under visible light irradiation with an arsenic removal efficiency of 99.8% within 180 min, higher than those of BiOCl/γ-Fe2O3 (81.7%) and BiOBr/γ-Fe2O3 (98.9%). The optimal BiOI/γ-Fe2O3 (molar ratio of 2:1) is obtained by rationally adjusting the molar ratio of BiOI to γ-Fe2O3. The as-synthesized BiOI/γ-Fe2O3 performs well in a wide pH range of 2–8. Only coexisting PO43? anions have a significant effect on the As(III) removal. The free radical trapping experiment and ESR results demonstrate that the ?O2? and h+ are the main active substances for the photocatalytic oxidation of As(III) on BiOI/γ-Fe2O3. This work not only gives a novel magnetic core–shell nanoparticle photocatalyst for efficient photocatalytic oxidation and adsorption of As(III) but also offers a new strategy to rationally design BiOX for its related practical applications. 相似文献