全文获取类型
收费全文 | 142篇 |
免费 | 0篇 |
专业分类
化学 | 79篇 |
晶体学 | 1篇 |
数学 | 4篇 |
物理学 | 58篇 |
出版年
2022年 | 6篇 |
2019年 | 6篇 |
2016年 | 6篇 |
2013年 | 4篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1940年 | 1篇 |
1934年 | 1篇 |
1932年 | 2篇 |
1931年 | 3篇 |
1927年 | 5篇 |
1926年 | 1篇 |
1924年 | 1篇 |
1888年 | 1篇 |
1887年 | 2篇 |
1886年 | 1篇 |
1885年 | 1篇 |
1884年 | 2篇 |
1883年 | 2篇 |
排序方式: 共有142条查询结果,搜索用时 9 毫秒
1.
2.
3.
The effect of the bifunctional crosslinking reagent glutaraldehyde on the activity of the restriction enzymes Bam HI,Hind III, EcoRI, and Tthlll I was investigated. The four enzymes exhibited differential sensitivity to inactivation. Tthlll I
was the most sensitive, with activity losses occurring at levels of 0.0025% and above.Hind III was the most stable of the four and remained fully active at concentrations as high as 0.075%. Addition of BSA to incubation
mixtures generally had a stabilizing effect. Implications of these results for the design of glutaraldehyde-based methods
for the immobilization of restriction endonucleases are discussed. 相似文献
4.
Paulina Mech-Warda Artur Giedo Anna Kawiak Natalia Maciejewska Mateusz Olszewski Mariusz Makowski Agnieszka Chylewska 《Molecules (Basel, Switzerland)》2022,27(12)
Pyrazine and its derivatives are a large group of compounds that exhibit broad biological activity, the changes of which can be easily detected by a substituent effect or a change in the functional group. The present studies combined theoretical research with the density functional theory (DFT) approach (B3LYP/6-311+G**) and experimental (potentiometric and spectrophotometric) analysis for a thorough understanding of the structure of chlorohydrazinopyrazine, its physicochemical and cytotoxic properties, and the site and nature of interaction with DNA. The obtained results indicated that 2-chloro-3-hydrazinopyrazine (2Cl3HP) displayed the highest affinity to DNA. Cytotoxicity studies revealed that the compound did not exhibit toxicity toward human dermal keratinocytes, which supported the potential application of 2Cl3HP in clinical use. The study also attempted to establish the possible equilibria occurring in the aqueous solution and, using both theoretical and experimental methods, clearly showed the hydrophilic nature of the compound. The experimental and theoretical results of the study confirmed the quality of the compound, as well as the appropriateness of the selected set of methods for similar research. 相似文献
5.
6.
Bogdan Boduszek Tomasz Olszewski Waldemar Goldeman Magdalena Konieczna 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):787-795
The synthesis of a series of new pyridine aminomethylphosphinic acids is described. These compounds were obtained in the reaction of the corresponding pyridine aldehydes with primary amines and with ethyl phenylphosphinate, or methylphosphinate, in the presence of bromotrimethylsilane. In aqueous, strong acid solutions, pyridine aminophosphinic acids were split, forming the phenyl-, or methylphosphonic, acid and the corresponding secondary pyridyl-alkylamines. The kinetics of some observed cleavages were measured, and a mechanism of the cleavage has been proposed. 相似文献
7.
M.?Paczwa A.?A.?Sapiga M.?Olszewski N.?A.?SergeevEmail author A.?V.?Sapiga 《Applied magnetic resonance》2015,46(5):583-592
The temperature dependences of nuclear magnetic resonance and magic angle spinning nuclear magnetic resonance spectra of 27Al nuclei in natrolite (Na2Al2Si3O10· 2H2O) have been studied. The influence of water molecules and sodium ions mobility on the shape of the 27Al NMR spectrum and framework dynamics have been discussed The temperature dependences of the spin–lattice relaxation times T1 of 27Al nuclei in natrolite have also been studied. It has been shown that the spin–lattice relaxation of the 27Al is governed by the electric quadrupole interaction with the crystal electric field gradients modulated by translational motion of H2O molecules in the natrolite pores. The dipolar interactions with paramagnetic impurities become significant as a relaxation mechanism of the 27Al nuclei only at low temperatures (<270 K). 相似文献
8.
The non-Bloch LCAO wave functions for cubic crystals are discussed and applied to the calculation of the matrix elements for electron transitions in an external electric field. The sum of transitions between non-Bloch electron states is compared with the matrix element for a conventional nearly free electron transition. © 1996 John Wiley & Sons, Inc. 相似文献
9.
S. Olszewski 《International journal of quantum chemistry》1996,57(1):35-41
Electron orbits having a definite angular momentum in a static magnetic field are calculated with the aid of the Bohr–Sommerfeld quantization rules. The quantization gives that orbits are arranged along a straight line but the distance between the centers of two neighboring orbits decreases with increase of the absolute value of the angular momentum. With the energy correction equal to the zero-point energy of the harmonic oscillator, the distribution of orbits becomes identical to that obtained recently with the aid of a mixed semiclassical and quantum mechanical theory. © 1996 John Wiley & Sons, Inc. 相似文献
10.