全文获取类型
收费全文 | 262篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 55篇 |
晶体学 | 13篇 |
力学 | 2篇 |
数学 | 3篇 |
物理学 | 192篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2016年 | 3篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 12篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 17篇 |
2007年 | 11篇 |
2006年 | 19篇 |
2005年 | 7篇 |
2004年 | 18篇 |
2003年 | 12篇 |
2002年 | 14篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 11篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有265条查询结果,搜索用时 15 毫秒
11.
12.
13.
The adsorption of 2,4-dinitrotoluene (DNT) on the tetrahedral and octahedral surfaces of dickite (a clay mineral of the kaolinite group with a 1:1 dioctahedral structure characterized by the common chemical formula Al2Si2O5(OH)4) was studied using small representative mineral models. The calculations have been performed at the HF/3-21G level of theory. The orientation of DNT on the tetrahedral surface of dickite was found to be coplanar with the surface plane. In the case of the adsorption on the octahedral surface the DNT molecule is placed with an inclination about 30∘ to the surface plane. This type of adsorption results in an electron density redistribution of DNT on the surface of the mineral that is more significant in the case of the adsorption on the tetrahedral surface. The interaction energies of DNT with the octahedral and tetrahedral surfaces corrected by the BSSE energy were found. The adsorption energy of a DNT-tetrahedral fragment amounts to −6.5 kcal/mol, and the interaction energy of the DNT-octahedral fragment system is −17.7 kcal/mol. 相似文献
14.
Schumm BA Koetke DS Adolphsen CE Alexander JP Averill D Barish BC Barklow T Barnett BA Blockus D Boyarski A Brabson B Breakstone A Bulos F Burchat PR Burke DL Cence RJ Chapman J Chmeissani M Cords D Coupal DP Dauncey P DeStaebler HC Dorfan JM Drell PS Drewer DC Durrett D Elia R Feldman GJ Field RC Ford WT Fordham C Frey R Fujino D Gan KK Gero E Gidal G Glanzman T Goldhaber G Gomez Cadenas JJ Gratta G Hanson G Harr R Harral B Harris FA Hayes K Hearty C Heusch CA Hildreth MD Himel T Hinshaw DA 《Physical review D: Particles and fields》1992,46(1):453-456
15.
Nitrite reduction by a copper complex featuring a proton-responsive tripodal ligand is demonstrated. Gaseous nitric oxide was confirmed as the sole NOX by-product in quantitative yield. DFT calculations predict that nitrite reduction occurs via a proton and electron transfer process mediated by the ligand. The reported mechanism parallels nitrite reduction by copper nitrite reductase. 相似文献
16.
Tomasz Tuzimski Anna Petruczynik Barbara Kapro Anna Makuch-Kocka Magorzata Szultka-Myska Justyna Misiurek Grayna Szymczak Bogusaw Buszewski 《Molecules (Basel, Switzerland)》2021,26(4)
Melanoma is a serious form of skin cancer that begins in cells known as melanocytes. While it is less common than the other forms of skin cancer, melanoma is more dangerous because of its ability to spread to other organs more rapidly if it is not treated at an early stage. The number of people diagnosed with melanoma has increased over the last few decades. The most widely used treatments include surgery, chemotherapy, and radiation therapy. The search for new drugs to treat various cancers is one of the most important challenges of modern scientific research. Some isoquinoline alkaloids found in different plant species have strong cytotoxic effects on various cancer cells. We tested the effect of isoquinoline alkaloids and extracts obtained from various parts of Mahonia aquifolium collected in various vegetation seasons on human melanoma cancer cells and our data indicated that investigated extract induced significant reduction in cell viability of Human malignant melanoma cells (A375), human Caucasian malignant melanoma cell line (G361), and human malignant melanoma cell line (SKMEL3 cancer cell lines in a dose- and time-dependent manner. Differences in cytotoxic activity were observed for extracts obtained from various parts of Mahonia aquifolium. Significant differences were also obtained in the alkaloids content and cytotoxic activity of the extracts depending on the season of collection of plant material. Our investigations exhibit that these plant extracts can be recommended for further in vivo experiments in order to confirm the possibility of their use in the treatment of human melanomas. 相似文献
17.
Background
Growth hormone (GH) plays an incompletely understood role in the development of the central nervous system (CNS). In this study, we use transgenic mice expressing a growth hormone antagonist (GHA) to explore the role of GH in regulating postnatal brain, spinal cord and body growth into adulthood. The GHA transgene encodes a protein that inhibits the binding of GH to its receptor, specifically antagonizing the trophic effects of endogenous GH. 相似文献18.
An "arrested" chloride abstraction occurs in the reaction of trans-RuCl(2)(DMeOPrPE)(2) with TlPF(6); the product is a 1-D coordination polymer in which the Tl(I) centers have an unusual octahedral coordination geometry with a stereochemically active 6s(2) lone pair. 相似文献
19.
Gomez L Slutzky C Ferron J de La Figuera J Camarero J Vazquez De Parga AL de Miguel JJ Miranda R 《Physical review letters》2000,84(19):4397-4400
Generic computer simulations using empiric interatomic potentials suggest a new, collective mechanism that could be responsible for mixing at heteroepitaxial interfaces. Even if single adsorbate atoms diffuse by hopping on the substrate surface and do not mix at the terraces, two-dimensional islands formed by nucleation may become unstable above a certain critical size and explode upwards forming clusters of several atomic layers. This process is accompanied by strong distortions of the underlying atomic layers, and on soft materials it can result in surface etching and incorporation of substrate atoms into the islands. 相似文献
20.
L. V. Udod G. A. Petrakovskiĭ A. M. Vorotynov O. A. Bayukov D. A. Velikanov A. V. Kartashev A. F. Bovina Yu. G. Shvedenkov M. Baran R. Szymczak 《Physics of the Solid State》2007,49(3):500-504
This paper reports on the first study of the temperature and field dependences of the magnetization, heat capacity, and electrical properties of synthesized polycrystalline samples of aerugite Co10Ge3O16, as well as on x-ray diffraction analysis of this compound. It is shown that the cobalt ions in this compound occupy three nonequivalent positions. The results of the experimental and theoretical studies suggest that aerugite is a ferrimagnet with two uncompensated magnetic moments of the cobalt atom per formula unit. 相似文献