全文获取类型
收费全文 | 520篇 |
免费 | 38篇 |
国内免费 | 1篇 |
专业分类
化学 | 416篇 |
晶体学 | 15篇 |
力学 | 3篇 |
数学 | 32篇 |
物理学 | 93篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 7篇 |
2021年 | 17篇 |
2020年 | 20篇 |
2019年 | 20篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 19篇 |
2015年 | 18篇 |
2014年 | 21篇 |
2013年 | 37篇 |
2012年 | 57篇 |
2011年 | 58篇 |
2010年 | 30篇 |
2009年 | 26篇 |
2008年 | 32篇 |
2007年 | 30篇 |
2006年 | 26篇 |
2005年 | 20篇 |
2004年 | 19篇 |
2003年 | 4篇 |
2002年 | 4篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 6篇 |
1972年 | 7篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有559条查询结果,搜索用时 672 毫秒
31.
Dr. Yinhua Huang Guo Hao Chan Prof. Shunsuke Chiba 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(23):6644-6647
A new protocol for amide-directed ortho and lateral C−H sodiation is enabled by sodium hydride (NaH) in the presence of either sodium iodide (NaI) or lithium iodide (LiI). The transient organosodium intermediates could be transformed into functionalized aromatic compounds. 相似文献
32.
Back Cover: Understanding the Origins of Nucleophilic Hydride Reactivity of a Sodium Hydride–Iodide Composite (Chem. Eur. J. 21/2016)
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
33.
We demonstrate the efficiency of the optical poling process that depends on the CE phase-controlled quantum interference. For the experiment we employed our noncollinear optical parametric amplifier system for the self-stabilization of the CE phase, with the f-to-2f spectral interferometry system to control the CE phase. 相似文献
34.
35.
Vladimir F. Petrov Sofia I. Torgova Ludmila A. Karamysheva Shunsuke Takenaka 《Liquid crystals》1999,26(8):1141-1162
In this review the effect on physico-chemical and electro-optical properties of the introduction of the trans-1,4-cyclohexylene fragment into the molecular core of liquid crystals is discussed, rationalized in terms of existent theories, and compared with the effect of other well-known molecular fragments. 相似文献
36.
Yoshito Hirata Shunsuke Horai Kazuyuki Aihara 《The European physical journal. Special topics》2008,164(1):13-22
We propose a method to reproduce distance matrices and original time series
from recurrence plots. The procedure is to (i)convert a recurrence plot
to a weighted graph and (ii)calculate a distance between each pair
of nodes on this weighted graph.
We demonstrate this method by reproducing the topological shape of
original time series.
We also propose two applications.
The first application is to obtain the maximal Lyapunov exponent
from a recurrence plot without reproducing the shapes
of original time series.
The second application is to reconstruct a common deterministic driving
force from observations of forced systems.
Thus, the method opens new fields in data analysis. 相似文献
37.
This article presents a full account of intramolecular vinylic substitution reactions of bromoalkenes having an acetylthio moiety, which give sulfur-containing heterocycles such as dihydrothiophene, tetrahydrothiopyran, and 2-alkylidenethietane derivatives. The reaction pathways of the substitution reactions were investigated by theoretical and experimental studies. 相似文献
38.
Koji Nagahama Kanae Fujiura Shunsuke Enami Tatsuro Ouchi Yuichi Ohya 《Journal of polymer science. Part A, Polymer chemistry》2008,46(18):6317-6332
Starburst triblock copolymers consisting of 8‐arm poly(ethylene glycol) (8‐arm PEG) and biodegradable poly(L ‐lactide) (PLLA) or its enantiomer poly(D ‐lactide) (PDLA), 8‐arm PEG‐b‐PLLA‐b‐PEG ( Stri‐L ), and 8‐arm PEG‐b‐PDLA‐b‐PEG ( Stri‐D ) were synthesized. An aqueous solution of a 1:1 mixture ( Stri‐Mix ) of Stri‐L and Stri‐D assumed a sol state at room temperature, but instantaneously formed a physically crosslinked hydrogel in response to increasing temperature. The resulting hydrogel exhibited a high‐storage modulus (9.8 kPa) at 37 °C. Interestingly, once formed at the transition temperature, the hydrogel was stable even after cooling below the transition temperature. The hydrogel formation process was irreversible because of the formation of stable stereocomplexes. In aqueous solution, gradual hydrolytic erosion was observed because of degradation of the hydrogel. The combination of rapid temperature‐triggered irreversible hydrogel formation, high‐mechanical strength, and degradation behavior render this polymer mixture system suitable for use in injectable biomedical materials, for example, as a drug delivery system for bioactive reagents or a biodegradable scaffold for tissue engineering. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6317–6332, 2008 相似文献
39.
Oxidative Degradation of Aqueous Cresols Induced by Gaseous Plasma with Contact Glow Discharge Electrolysis 总被引:2,自引:0,他引:2
The oxidative degradation of cresols smoothly proceeded toward inorganic end products when a gaseous plasma generated by means
of dc glow discharge was sustained in contact with the surface of aqueous solution containing organic compounds. In order
to get mechanistic insight, the monohydroxylation products from each isomeric cresol were closely examined as primary intermediates
to reveal that the aromatic hydroxylation preferentially occurred at the position para to the hydroxyl group of each starting
material. It was also established that the degradation of cresols strictly followed the first-order rate law. On the basis
of the orientational analysis and the kinetical consideration including the effects of Fe ions added on the reaction rate,
it was concluded that hydroxyl radical, which might result from the homolytic cleavage of water molecules by the action of
plasma, was the most likely reagent responsible for the mineralization of cresols. 相似文献
40.
ArS(ArSSAr)+ (arylbis(arylthio)sulfonium ions), which were generated and accumulated by the electrochemical oxidation of diaryl disulfides (ArSSAr) in CH2Cl2 at −78 °C, reacted with alkenes to give the corresponding diarylthio-substituted compounds in a stereospecific manner in good yields, when the reaction was quenched with a soft nucleophile, such as allylsilanes, ketene silyl acetals, and triethylamine. A mechanism involving the initial formation of an episulfonium ion followed by ring-opening by the attack of ArSSAr has been suggested. The reactions of ArS(ArSSAr)+ with alkynes also took place to give 1,2-diorganothio-substitued alkenes stereoselectively under similar conditions. 相似文献