全文获取类型
收费全文 | 91篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
化学 | 77篇 |
力学 | 3篇 |
数学 | 4篇 |
物理学 | 14篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 6篇 |
2013年 | 5篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 1篇 |
2008年 | 8篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1982年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有98条查询结果,搜索用时 4 毫秒
31.
Xian Li Lijun Wu Yaeko Konda Mieko Iguchi Hiroshi Takahasi Yoshihiro Harigaya Masayuki Onda 《Journal of heterocyclic chemistry》1989,26(2):493-501
The absolute stereochemistry of bruceines D, E and H has been confirmed to be 1S, 5S, 7R, 8R, 9R, 10S, 11R, 12S, 13R, 14R, 15R and additionally 2S for bruceine E by a combination of 2D nmr [1H-1H and 1H-13C (one-bond and long-range) COSY] nOe and cd spectroscopic analyses. 相似文献
32.
A Soibel SS Banerjee Y Myasoedov ML Rapparort E Zeldov S Ooi T Tamegai 《Pramana》2002,58(5-6):893-898
Using a novel differential magneto-optical imaging technique we investigate the phenomenon of vortex lattice melting in crystals
of Bi2Sr2CaCu2O8 (BSCCO). The images of melting reveal complex patterns in the formation and evolution of the vortex solid-liquid interface
with varying field (H)/temperature (T). We believe that the complex melting patterns are due to a random distribution of material disorder/inhomogeneities across
the sample, which create fluctuations in the local melting temperature or field value. To study the fluctuations in the local
melting temperature/field, we have constructed maps of the melting landscape T
m(H, r), viz., the melting temperature (T
m) at a given location (r) in the sample at a given field (H). A study of these melting landscapes reveals an unexpected feature: the melting landscape is not fixed, but changes rather
dramatically with varying field and temperature along the melting line. It is concluded that the changes in both the scale
and shape of the landscape result from the competing contributions of different types of quenched disorder which have opposite
effects on the local melting transition. 相似文献
33.
34.
Shiva Konda Kiran M. S. R. N. Ramamurty U. Asokan S. Bhattacharyya Aninda J. 《Journal of Solid State Electrochemistry》2012,16(11):3643-3649
Journal of Solid State Electrochemistry - We demonstrate here that mesoporous tin dioxide (abbreviated M-SnO2) with a broad pore size distribution can be a prospective anode in lithium-ion... 相似文献
35.
36.
Venkatapuram Padmavathi Guda Dinneswara Reddy Gali Sudhakar Reddy Konda Mahesh Adivireddy Padmaja 《Journal of heterocyclic chemistry》2011,48(4):973-976
The reactivity of barbituric/thiobarbituric ketene dithiolates with bromoacetic ester and phenacyl bromide is studied. J. Heterocyclic Chem., (2011). 相似文献
37.
Xian Li Lijun Wu Zhizong Ji Yoshihiro Harigaya Yaeko Konda Mieko Iguchi Hiroshi Takahashi Masayuki Onda 《Journal of heterocyclic chemistry》1988,25(5):1403-1406
The absolute stereochemistry of curcumol ( 1 ) is confirmed on the basis of the spectroscopic data. The existence of two conformations in curdione ( 4 ) is revealed by nOe experiments at ambient temperature. One-step conversion of 4 into 1 stereospecifically proceeds via the ene-reaction without epimerization at any asymmetric center in 4 . 相似文献
38.
Konda Ashok Prashant V. Kamat Manapurathu V. George 《Research on Chemical Intermediates》1990,13(3):203-220
The results of our studies on potassium-induced transformations of several bridgehead-substituted dibenzobarrelenes are presented.
The dibenzobarrelenes 1b,c,e,f having methyl, hydroxymethyl, methoxy and phenyl groups, respectively, at the bridgehead position and the bridgehead-dimethyl
derivative 1g give, on treatment with potassium in THF, the corresponding anthracenes 8b,c,e-g, dihydrodibenzobarreneses 6b,c,e-g and benzoic acid (5). The dibenzobarrelenes 1b,g give, in addition to 8b,g, 6b,g and 5, the corresponding mono-debenzoylated products 7b,g, whereas the methoxy derivative 1e gives both anthraquinone (9) and an enol derivaiive 11, besides 8e, 6e and 5. In contrast, the reaction of the hydroxy derivative 1d with potassium in THF gives a mixture of 5, anthracene (8a), the anthrone 10 and the anthrol 12. To assess the role of oxygen in these reactions, if any, the reactions of some representative substrates such as 1b,d,e with potassium in THF, saturated with oxygen and with potassium superoxide have been studied. Cyclic voltammetric studies
have been carried out to measuee the reduction potentials for both one electron and two electron processes, leading to the
generation of the corresponding radical anions and dianion intermediates. The radical anions of 1b-g have also been generated pulse radiolytically in methanol and their spectra show absorption maxima in the regions 310-390
and 400-450 nm. 相似文献
39.
T 1 andT m for nitridochromium(V) tetratolylporphyrin and nitridochromium(V) octaethylporphyrin were measured by saturation recovery and electron spin echo EPR, respectively, between 10 and 130 K. The temperature dependence of 1/T 1 was similar to that observed previously for chromium(V) complexes of hydroxycarboxylic acids. The spin lattice relaxation rate was faster in the perpendicular plane (the porphyrin plane) than normal to this plane. 1/T m was orientation dependent with the fastest rates observed for orientations intermediate between the principal axes. The orientation dependence of 1/T m increased with increasing temperature and decreasing rigidity of the matrix, and is attributed to molecular motion. 相似文献
40.
Padmavathi V Nagendra Mohan AV Mahesh K Padmaja A 《Chemical & pharmaceutical bulletin》2008,56(6):815-820
Novel sulfone linked bis heterocycles containing two different heterocyclic rings viz., pyrazoline in combination with thiadiazole, oxadiazole and triazole were synthesized and studied their antimicrobial activity. 相似文献