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991.
Zhang SH Ma LF Zou HH Wang YG Liang H Zeng MH 《Dalton transactions (Cambridge, England : 2003)》2011,40(43):11402-11409
Three new polynuclear complexes, [Co(7)(bm)(12)]·(ClO(4))(2)·13H(2)O (1), [Co(4)(bm)(4)Cl(4)(C(3)H(7)OH)(4)] (2), and [Co(4)(bm)(4)(μ-HCO(2))(2)(μ(2)-HCO(2))(2)(C(3)H(7)OH)(2)] (3) (Hbm = (1H-Benzimidazol)-methanol), have been synthesized and characterized by elemental analysis, IR, powder X-ray diffraction and X-ray single-crystal diffraction. Compound 1 features a centrosymmetric wheel-like heptanuclear Co(II) cluster. Compound 2 having a I4(1)/a space group exhibits a tetranuclear Co(II) cluster with a cubane topology in which the central Co(II) ion and oxygen atoms from bm occupy the alternate vertices of the cube. However, compound 3 has a tetranuclear Co(II) cluster with a C2/c space group different from that of compound 2. These results show that the geometries and sizes of the corresponding anions as well as their coordinating and hydrogen-bonding properties are essential in determining the final structures of the assemblies. Magnetic properties of 1-3 in the 2-300 K have also been discussed. The {Co(7)} (1) and {Co(4)} (2) cores display dominant ferromagnetic interactions while the {Co(4)} (3) core displays dominant anti-ferromagnetic interactions. 相似文献
992.
Numerical method of studying nonlinear interactions between long waves and multiple short waves 总被引:1,自引:0,他引:1 下载免费PDF全文
Although the nonlinear interactions between a single short gravity
wave and a long wave can be solved analytically, the solution is
less tractable in more general cases involving multiple short waves.
In this work we present a numerical method of studying nonlinear
interactions between a long wave and multiple short harmonic waves
in infinitely deep water. Specifically, this method is applied to
the calculation of the temporal and spatial evolutions of the
surface elevations in which a given long wave interacts with several
short harmonic waves. Another important application of our method is
to quantitatively analyse the nonlinear interactions between an
arbitrary short wave train and another short wave train. From
simulation results, we obtain that the mechanism for the nonlinear
interactions between one short wave train and another short wave
train (expressed as wave train 2) leads to the energy focusing of
the other short wave train (expressed as wave train 3). This
mechanism occurs on wave components with a narrow frequency
bandwidth, whose frequencies are near that of wave train 3. 相似文献
993.
本文指出全息干版薄膜在曝光后处理过程中的收缩性和折射率变化对制备全息光栅的周期、倾斜度、布喇格入射角及衍射角的影响问题,并根据实验数据对光栅设计进行修正,再结合Kogelnik衍射方程及折射率调制度和曝光量的线性关系,在实验中基本上能准确设计出指定周期、倾斜度和衍射效率的全息光栅。 相似文献
994.
Mei Luo Can Zhu Jun Yuan Liuyang Zhou M.L. Keshtov D. Yu Godovsky Yingping Zou 《中国化学快报》2019,30(12):2343-2346
Improving the performance and reducing the manufacturing costs are the main directions for the development of organic solar cells in the future. Here, the strategy that uses chemical structure modification to optimize the photoelectric properties is reported. A new narrow bandgap (1.30 eV) chlorinated non-fullerene electron acceptor (Y15), based on benzo[d][1,2,3] triazole with two 3-undecyl-thieno[2′,3′:4,5] thieno[3,2-b] pyrrole fused -7-heterocyclic ring, with absorption edge extending to the near-infrared (NIR) region, namely A-DA'D-A type structure, is designed and synthesized. Its electrochemical and optoelectronic properties are systematically investigated. Benefitting from its NIR light harvesting, the fabricated photovoltaic devices based on Y15 deliver a high power conversion efficiency (PCE) of 14.13%, when blending with a wide bandgap polymer donor PM6. Our results show that the A-DA'D-A type molecular design and application of near-infrared electron acceptors have the potential to further improve the PCE of polymer solar cells (PSCs). 相似文献
995.
用CoMFA和HQSAR两种QSAR方法研究了50个乙内酰脲类分子的定量构效关系.本研究从构象搜索所得的低能结构出发构建化合物分子的构象, 建立CoMFA模型,并进行了全空间搜索. HQSAR本质上是一种二维的QSAR方法,与CoMFA方法相比,该方法在数据处理方面,比CoMFA方法快捷,并且可重复性好.两种方法均得到了较好分析结果, CoMFA的交叉验证相关系数q2 值为0.815, HQSAR的q2值为0.893.这些方程有力地说明了该类分子在(R,R)-N-3,5-dinitrobenzoyl-1,2-diamine型手性固定相上拆分过程中的影响因素,对今后类似拆分的实验研究提供了理论支持. 相似文献
996.
对Al_2O_3颗粒增强铝复合材料与K_2Ti_5O_(13)晶须增强铝复合材料中的增强相/金属界面区域点阵位移场进行CBED研究,并对其进行电子衍射动力学理论模拟计算,结果表明:表面弛豫效应对晶须/铝界面法线方向上位移分量大小的分布影响显著,而对界面切线方向上位移分量的影响很小。这一结果对于解决CBED法测量界面应变场时遇到的表面弛豫效应问题是有意义的。 相似文献
997.
烟煤与重质油共处理的研究 总被引:4,自引:0,他引:4
煤与重质油的共处理是最有希望实现“由煤制油”的第三代煤液化新工艺之一。我国目前炼油厂每年有四、五千万吨石油渣油产出,只有一小部分用作制氢或合成气的生产原料以及生产沥青或石油焦,其余大部分用于工业燃料[1]。如将减压渣油与煤进行共处理,共同提质,提高其... 相似文献
998.
Analysis of acyclovir by high performance capillary electrophoresis with on-column amperometric detection 总被引:1,自引:0,他引:1
The separation of acyclovir (ACV) by high performance capillary electrophoresis (HPCE) with on-column amperometric detection using alpha-amino-5-mercapto-3,4-dithiazole (AMD) as internal standard is described. The calibration line was linear in the range of 0.5-20 mg/L of ACV. The detection limit was 0.15 mg/L of ACV. Its recovery ranged from 98 to 101% with relative standard deviations (RSDs) from 1.9 to 3.2% (n = 5). This method was successfully used for determining ACV in some pharmaceuticals and human urine. Comparable results with HPCE with ultraviolet (UV) detection and amperometric detection were obtained. 相似文献
999.
1000.
Lingheng Kong Xi Han Song Liu Yun Zou Yu Lan Xingwei Li 《Angewandte Chemie (International ed. in English)》2020,59(18):7188-7192
Axial‐to‐central chirality transfer is an important strategy to construct chiral centers, where the axially chiral reagents are mostly limited to atropomerically stable ones. Reported herein is a RhIII‐catalyzed enantioselective spiroannulative synthesis of nitrones. The coupling proceeds via C?H arylation to give an atropomerically metastable biaryl, followed by intramolecular dearomative trapping under oxidative conditions with high degree of chirality transfer. 相似文献