全文获取类型
收费全文 | 1514篇 |
免费 | 53篇 |
国内免费 | 5篇 |
专业分类
化学 | 1100篇 |
晶体学 | 36篇 |
力学 | 9篇 |
综合类 | 1篇 |
数学 | 98篇 |
物理学 | 328篇 |
出版年
2022年 | 8篇 |
2021年 | 17篇 |
2020年 | 19篇 |
2019年 | 20篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 32篇 |
2015年 | 24篇 |
2014年 | 38篇 |
2013年 | 85篇 |
2012年 | 63篇 |
2011年 | 62篇 |
2010年 | 39篇 |
2009年 | 38篇 |
2008年 | 55篇 |
2007年 | 74篇 |
2006年 | 75篇 |
2005年 | 71篇 |
2004年 | 57篇 |
2003年 | 56篇 |
2002年 | 52篇 |
2001年 | 47篇 |
2000年 | 53篇 |
1999年 | 35篇 |
1998年 | 16篇 |
1997年 | 17篇 |
1996年 | 38篇 |
1995年 | 25篇 |
1994年 | 16篇 |
1993年 | 16篇 |
1992年 | 34篇 |
1991年 | 24篇 |
1990年 | 24篇 |
1989年 | 22篇 |
1988年 | 36篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 25篇 |
1984年 | 15篇 |
1983年 | 19篇 |
1982年 | 17篇 |
1981年 | 22篇 |
1980年 | 14篇 |
1979年 | 27篇 |
1978年 | 13篇 |
1976年 | 6篇 |
1975年 | 9篇 |
1974年 | 10篇 |
1973年 | 18篇 |
1972年 | 10篇 |
排序方式: 共有1572条查询结果,搜索用时 46 毫秒
101.
Back Cover: Motion Capture and Manipulation of a Single Synthetic Molecular Rotor by Optical Microscopy (Angew. Chem. Int. Ed. 38/2014)
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
102.
103.
Frontispiece: Picket‐Fence Polythiophene and its Diblock Copolymers that Afford Microphase Separations Comprising a Stacked and an Isolated Polythiophene Ensemble
下载免费PDF全文
![点击此处可从《Angewandte Chemie (International ed. in English)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
104.
Munetaka Iwamura Airi Fukui Koichi Nozaki Hikaru Kuramochi Satoshi Takeuchi Tahei Tahara 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(51):23354-23361
Femtosecond time-resolved absorption and picosecond time-resolved emission measurements were carried out for highly concentrated aqueous solutions of K2[Pt(CN)4] to investigate excited-state dynamics of the [Pt(CN)42−] oligomers formed with metallophilic interactions. Time-resolved absorption spectra exhibit complicated dynamics that are represented with five time constants. Among them, the 90-ps and 400-ps dynamics were assigned to the S1 → T1 intersystem crossing of the trimer and tetramer coexisting in the solution by comparison with the fluorescence decays. Clear oscillations of transient absorption were observed in the first few picoseconds, and the frequency-detected-wavelength 2D analysis revealed that the 135-cm−1 and 65-cm−1 oscillations arise from the Pt–Pt stretch motions of the S1 trimer and S1 tetramer, respectively. The obtained time-resolved spectroscopic data provide a clear view of the excited-state dynamics of the [Pt(CN)42−] oligomers in the femto-/picosecond time region. 相似文献
105.
Ryota Kudo Masahiro Sonobe Yoshiaki Chino Yu Kitazawa Mutsumi Kimura 《Molecules (Basel, Switzerland)》2020,25(23)
The synthesis and characterization of two phthalocyanine (Pc) structural isomers, 1 and 2, in which four 2,6-di(hexyloxy)phenyl units were attached directly to the 1,8,15,22- or 1,4,15,18-positions of the Pc rings, are described. Both Pcs 1 and 2 exhibited low melting points, i.e., 120 and 130 °C respectively, due to the reduction in intermolecular π-π interaction among the Pc rings caused by the steric hindrance of 2,6-dihexyloxybenzene units. The thermal behaviors were investigated with temperature-controlled polarizing optical microscopy, differential scanning calorimetry, powder X-ray diffraction, and absorption spectral analyses. Pc 1, having C4h molecular symmetry, organized into a lamellar structure containing lateral assemblies of Pc rings. In contrast, the other Pc 2 revealed the formation of metastable crystalline phases, including disordered stacks of Pcs due to rapid cooling from a melted liquid. 相似文献
106.
Sudhir Kumar Keshri Atsuro Takai Tomoya Ishizuka Takahiko Kojima Masayuki Takeuchi 《Angewandte Chemie (International ed. in English)》2020,59(13):5254-5258
The design and synthesis of an enantiomeric pair of 1,8‐diethynylanthracene‐bridged naphthalenediimide (NDI)‐based cyclophanes ( Cyclo‐NDI s) are reported. Each enantiomer of Cyclo‐NDI exhibits a circularly polarized luminescence signal with a relatively large luminescence dissymmetry factor (glum=±8×10?3). We have further investigated the modulation of through‐space electronic communication between co‐facially oriented NDIs in a discrete Cyclo‐NDI with changes in the temperature. Tuning of the electronic communication results from the conformational transformation of monomer‐ versus dimer‐like features of Cyclo‐NDI , as confirmed by UV/Vis, fluorescence, circular dichroic, and NMR spectroscopic analysis. The temperature‐dependent optical response in the Cyclo‐NDI through the conformational transformation could be utilized as a highly sensitive and reversible optical thermometer in a wide temperature range (100 to ?80 °C). 相似文献
107.
108.
Miyauchi Suguru Yamada Shuji Takeuchi Shintaro Tazaki Asahi Kajishima Takeo 《Transport in Porous Media》2022,141(1):185-199
Transport in Porous Media - A concise and accurate prediction method is required for membrane permeability in chemical engineering and biological fields. As a preliminary study on this topic, we... 相似文献
109.
110.
By attaching condenser plates directly to the tensile specimen, creep rates of β-CuZn single crystals have been measured by the capacitance change in the strain-rate range of 10−7 to 10−5 s−1 and at temperatures between 0.7 and 17 K using a 3He cryostat. Slope of the temperature variation of the stress to give a constant strain-rate decreases below 5 K and seems to level off at 0 K. The strain-rate sensitivity becomes almost constant below 2 K. The conventional activation analysis showed that an ARRHENIUS type strain-rate equation breaks down drastically below 5 K. For an effective temperature T* which gives 2 K at 0 K and asympototically coincides with the testing temperature at 5 K, the experimental results can be fitted to the ARRHENIUS strain-rate equation with an activation enthalpy ΔH(τ) for the PEIERLS mechanism. The above result is interpreted in terms of the quantum-mechanical oscillation of the dislocations. 相似文献