全文获取类型
收费全文 | 175篇 |
免费 | 4篇 |
国内免费 | 5篇 |
专业分类
化学 | 114篇 |
晶体学 | 3篇 |
数学 | 10篇 |
物理学 | 57篇 |
出版年
2023年 | 2篇 |
2022年 | 14篇 |
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 18篇 |
2012年 | 10篇 |
2011年 | 7篇 |
2010年 | 9篇 |
2009年 | 14篇 |
2008年 | 10篇 |
2007年 | 9篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有184条查询结果,搜索用时 15 毫秒
51.
New series of triorganotin(IV) complexes with 4′‐nitrobenzanilide semicarbazone (L1H) and 4′‐nitrobenzanilide thiosemicarbazone (L2H) of the type [R3Sn(L)] (R = ‐CH3, ‐C6H5 and n‐C4H9) were synthesized under microwave irradiation. All the complexes were characterized by elemental analysis, conductance measurements, molecular weight determinations and spectral data, viz., IR, UV–vis, 1H, 13C and 119Sn NMR. The central tin atoms of these complexes are all five‐coordinated with trigonal bipyramidal geometry. In order to assess their growth inhibitory potency semicarbazone, thiosemicarbazone and their triorganotin(IV) complexes were tested in vitro against some pathogenic fungi and bacteria. Also the ligands and their organotin(IV) complexes were studied to assess the effects of long‐term ingestion of these compounds on fertility, body and reproductive organ weights. The biochemical analyses were also performed on blood samples and reproductive organs of male rats. The findings have been presented in this paper. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
52.
Kirubakaran Ramachandran Sharma Pratibha Manisekaran Ahilan Bijwe Jayashree Nebhani Leena 《Journal of Thermal Analysis and Calorimetry》2020,142(3):1233-1242
Journal of Thermal Analysis and Calorimetry - The present work demonstrates the synthesis of new bio-based benzoxazine monomers via Mannich-like condensation of naturally occurring raw materials,... 相似文献
53.
Epoxidations of indene, styrene, 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 4-bromostyrene, and naphthalene using Musa paradisiaca plant juice chloroperoxidase in the presence of H2O2 and t-butyl peroxide as oxidants have been studied. The steady-state kinetic parameters, Km and kcat of the enzyme for the above substrates have been determined. The temperature and pH optima of the epoxidation are 25°C and 6.2, respectively. The yield of styrene oxide in the presence of H2O2 was 44%. The results show that M. paradisiaca plant juice chloroperoxidase is a potential biocatalyst for organic epoxidation reactions. 相似文献
54.
An environment friendly method for the synthesis of 2-oxo/thioxooctahydroquinazolin-5-one derivatives has been devised using Ceric ammonium nitrate (CAN) as catalyst and polyethylene glycol (PEG) as solvent. The cytotoxic effect of these compounds was studied on U87 human glioma cells, compounds 4c, 4d and 4e are found to exhibit excellent activity at a concentration as low as 0.06 μg/ml. 相似文献
55.
T. Punniyamurthy Pratibha Asthana Swinder Jeet Singh Kalra Javed Iqbal 《Journal of Chemical Sciences》1995,107(4):335-342
2-Methylpropanal promotes the formation of cobalt(III)-dioxygen species from catalysts1 or2 and dioxygen. The cobalt(III)-dioxygen complexes efficiently catalyse the oxidation of various alcohols to carbonyl compounds
in the presence of dioxygen and 2-methylpropanal. Similarly substituted alkenes are smoothly transformed to the corresponding
monoepoxides under these reaction conditions. EPR study of these reactions indicates that different activated dioxygen species
are formed in the presence of catalysts1 and2. 相似文献
56.
D. P. Bhattacharyya S. Chakrabarty R. Rakshit B. Basu Pratibha Pal S. Biswas 《Il Nuovo Cimento C》1993,16(3):249-254
Summary A stack consisting of CR-39(DOP) detector with 2.6 cm Al target was exposed to a238U beam of energy 0.927 GeV/n from LBL BEVALAC to study the large-fragmentation phenomena during U+Al interaction. The diameter
distribution of the etch pits formed in the plastic detectors for the first three projectile fragments of chargeZ
F≥89 yields the partial cross-section data which is comparable to the data obtained from the cone length distribution. The
present result on the partial cross-section is significantly higher than those expected from the abrasion-ablation model of
Wilson, Townsed and Badavi (1987).
The authors of this paper have agreed not to receive the proofs for correction. 相似文献
57.
Summary The energy spectra of sea-level muons at different zenith angles have been estimated from the latest JACEE primary spectrum
using ISR results modified for p-nucleus interactions. The theoretical results have been compared with the experimental results.
Using the recent modified range-energy relation after Kobayakawa along with the fluctuation correction procedure after Kiraly,
Kiraly and Osborne, the muon range spectra in deep underground at different polar angles have been calculated. The derived
results are well in agreement with the latest Mont Blanc data after Bergamascoet al., Battistoniet al. and Utah experiments after Bergessonet al.
Riassunto Si stimano gli spettri d'energia muonica a livello del mare a differenti angoll zenitali dal piú recente spettro delle primarie JACEE usando risultati ISR modificati per interzioni p-nucleo. I risultati teorici sono stati confrontati con i risultati sperimentali. Usando la recente relazione modificata intervallo-energia di Kobayakawa oltre alla procedura di correzione delle fluttuazioni di Kiraly, Kiraly e Osborne sono stati calcolati gli spettri dell'intervallo muonico in profondità per differenti angolia polari. I risultati derivati sono in buon accordo con i dati piú recenti del Monte Bianco di Bergamascoet al., Battistoniet al. e gli esperimenti Utah di Bergessonet al.
Резюме Оцениваются энергетические спектры мюонов на уровне моря длл различных зенутных углов, исходя из последнего JACEE первичного спектра с использованием ISR-результатов, модифицированных для протон-ядерных взаим действий. Теоретические результаты сравниваются с экспериментальными данным Используя недавнее модифицированное соотношение между пробегом и энергиек Кобайакавы и методику Кирали, Кирали и Осборна для флуктуационных поправок вычисляются спектры пробегов мюонов под землей для различных полярных углов. Полученные резулятаты хорошо согласуются с последними данными под Мон-Бланом и с результатами Юта-экспериментов.相似文献
58.
59.
Raman and infrared intensity analysis of CHCl3 is attempted to determine the bond polarisability derivatives and bond dipole moments and their derivatives respectively,
on lines expained in our earlier papers. 相似文献
60.
In the infrared spectra of molecules with more than one C-H bond the symmetric and antisymmetric stretching bonds often overlap,
causing uncertainty in the intensity analysis. For CH2Cl2 and CD2Cl2 in the vapour state, the two bands overlap to such an extent that Straley who takes it as one band attributes it to antisymmetric
stretching while Saekiet al assign it to the symmetric stretching. Following the method of analysis initiated in this laboratory, we have solved this
problem by ultimately obtaining intensities separately forA
1 andB
2 species. The band is mostly due to the symmetric stretching, 0.06 out of the total of 0.31 contributing toB
2. Thus, this gives a method of separating the intensities of bands which are highly overlapping.
Presented at the Symposium on Crystallography and Crystal Physics, Osmania University, Hyderabad held on 5–7, December 1977. 相似文献