全文获取类型
收费全文 | 269篇 |
免费 | 64篇 |
国内免费 | 53篇 |
专业分类
化学 | 317篇 |
晶体学 | 6篇 |
物理学 | 63篇 |
出版年
2024年 | 2篇 |
2023年 | 3篇 |
2022年 | 12篇 |
2021年 | 16篇 |
2020年 | 14篇 |
2019年 | 10篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 19篇 |
2015年 | 13篇 |
2014年 | 17篇 |
2013年 | 24篇 |
2012年 | 19篇 |
2011年 | 11篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 16篇 |
2007年 | 11篇 |
2006年 | 23篇 |
2005年 | 12篇 |
2004年 | 16篇 |
2003年 | 19篇 |
2002年 | 19篇 |
2001年 | 10篇 |
2000年 | 13篇 |
1999年 | 4篇 |
1998年 | 15篇 |
1997年 | 6篇 |
1996年 | 7篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1989年 | 1篇 |
排序方式: 共有386条查询结果,搜索用时 15 毫秒
31.
32.
Glenn J. Scerri Melchior Caruana Nicola Agius Godfrey Agius Thomas J. Farrugia Jake C. Spiteri Alex D. Johnson David C. Magri 《Molecules (Basel, Switzerland)》2022,27(18)
Polyacrylamide hydrogels formed by free radical polymerisation were formed by entrapping anthracene and 4-amino-1,8-naphthalimide fluorescent logic gates based on photoinduced electron transfer (PET) and/or internal charge transfer (ICT). The non-covalent immobilisation of the molecules in the hydrogels resulted in semi-solid YES, NOT, and AND logic gates. Two molecular AND gates, examples of Pourbaix sensors, were tested in acidic aqueous methanol with ammonium persulfate, a strong oxidant, and displayed greater fluorescence quantum yields than previously reported. The logic hydrogels were exposed to aqueous solutions with chemical inputs, and the fluorescence output response was viewed under 365 nm UV light. All of the molecular logic gates diffuse out of the hydrogels to some extent when placed in solution, particularly those with secondary basic amines. The study exemplifies an effort of taking molecular logic gates from homogeneous solutions into the realm of solid-solution environments. We demonstrate the use of Pourbaix sensors as pE-pH indicators for monitoring oxidative and acidic conditions, notably for excess ammonium persulfate, a reagent used in the polymerisation of SDS-polyacrylamide gels. 相似文献
33.
D. P. Krut'ko M. V. Borzov A. V. Churakov D. A. Lemenovśkii O. A. Reutov 《Russian Chemical Bulletin》1998,47(11):2280-2285
ansa{·5,·5′-[1,1′-(1-silacyclopent-3-ene-1,1-diyl)bis(indenyl)]} dichlorozirconium (1a,b) was synthesized. The crystal structure ofmeso-[(1,4-CH2CH=CHCH2)Si(C9H6)2ZrCl2] (1b) was established by X-ray diffraction analysis. Photoinduced interconversion of the racemic (1a) andmeso forms was studied under various conditions. The photostationary state (rac: meso=55∶45) was established rapidly when solutions ofansa-zirconocene were irradiated with visible light.
Deceased
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2351–2356, November, 1998. 相似文献
34.
S. P. Gromov E. N. Ushakov A. I. Vedernikov L. G. Kuz’mina M. V. Alfimov 《Theoretical and Experimental Chemistry》2009,45(1):3-11
A universal approach to the molecular design of light-sensitive nanodimensional systems with specific characteristics was
developed on the basis of unsaturated and macrocyclic compounds. It was possible to construct various nanodimensional systems
within the scope of a single class of compound using a limited number of components. The use of photostructural transformations
to control complex formation and mechanical movements in molecular devices and machines is discussed.
Translated from Teoreticheskaya i éksperimental’naya Khimiya, Vol. 45, No. 1, pp. 1–7, January-February, 2009. 相似文献
35.
36.
荧光分子开关是超分子化学领域的研究热点之一,本文根据开关动作完成的方式对近年来研究的各类荧光分子开关进行了简要的归类总结,并介绍了一些具有特殊功能的荧光分子开关器件. 相似文献
37.
3,5-二氰基-2,4,6-三甲基吡啶在新型光电功能材料的合成中有重要的应用价值.本文在CCl4中光照1,4-二氢-3,5-二氰基-2,4,6-三甲基吡啶,高产率地合成了3,5-二氰基-2,4,6-三甲基吡啶. 相似文献
38.
K. Chen M. S. Zhang W. C. Chen Q. Chen 《Progress in Crystal Growth and Characterization of Materials》2000,40(1-4):43-50
Raman scattering and photoinduced light scattering in Co-, Cr- and Fe-doped lithium niobate were examined. The A1(TO) modes appear in E symmetry spectrum of the doped lithium niobate. Their intensities vary with different dopings. In the spectrum of z(yy)x geometry, the properties of the lowest-frequency E(TO) mode of the Cr-doped lithium niobate are different from those of pure, Co- and Fe-doped lithium niobate. The intensity of the A1(TO) mode at 637cm-1 I is decreased in doped lithium niobate compared with the pure crystal. We attribute these properties to both the photorefractive effect which is enhanced by dopants and to the different occupation of the doping ions. A light climbing effect was observed in Co- and Cr-doped lithium niobate for the first time. A higher photodamage threshold and quicker light climbing speed were found in Co- and Cr-doped lithium niobate in comparison with the light climbing effect in the Fe-doped lithium niobate. The results from the photoinduced light scattering experiments were compared with those from a Raman spectroscopic study. 相似文献
39.
本文合成了8个 四羧酸多联体化合物;测定了这些化合物的吸收光谱、荧光光谱。研究了由供电子分子键连的多联体分子的光谱特性及其分子体系内稳态荧光猝灭机理。首次从吸收光谱和荧光光谱上分析和考察了四羧酸多联体化合物分子体系内的光致电子转移反应。 相似文献
40.
本文合成了降冰片二烯和咔唑为侧基的甲基丙烯酸酯共聚物,并与仅带有降冰片二烯侧基的聚甲基丙烯酸酯进行了光异构化反应的对比研究。实验结果表明,当入射光波长小于350nm时,两种降冰片二烯聚合物均发生了光异构化反应;当入射光波长大于350nm时,只有共聚物的降冰片二烯侧基能够异构化为相应的四环烷。利用荧光猝灭实验及化学诱导动态核极化(CIDNP)等研究了咔唑的敏化机理,利用三氟乙酸作催化剂实现了四环烷的反向异构化。 相似文献