全文获取类型
收费全文 | 229篇 |
免费 | 12篇 |
国内免费 | 2篇 |
专业分类
化学 | 169篇 |
晶体学 | 5篇 |
力学 | 9篇 |
综合类 | 2篇 |
数学 | 23篇 |
物理学 | 35篇 |
出版年
2023年 | 5篇 |
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 11篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 11篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 11篇 |
2011年 | 25篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 18篇 |
2007年 | 12篇 |
2006年 | 10篇 |
2005年 | 16篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有243条查询结果,搜索用时 0 毫秒
71.
Jais Abdul Azim Ali S. A. Muhammed Anwar Mustafa Somalu Mahendra Rao Muchtar Andanastuti Isahak Wan Nor Roslam Wan Baharudin Nurul Akidah Lim Kean Long Brandon Nigel P. 《Journal of Solid State Electrochemistry》2020,24(3):711-722
Journal of Solid State Electrochemistry - Nickel/scandia-ceria-stabilized-zirconia (Ni/10Sc1CeSZ) cermet is a potential anode for solid oxide fuel cells. The anode powder is prepared through a... 相似文献
72.
Muhammed Talat Sariaydin Talat Krpinar 《Mathematical Methods in the Applied Sciences》2019,42(16):5154-5158
In this paper, we study the Bäcklund transformations for the adjoint curve in the Euclidean 3‐space. Firstly, it is obtained some essential equations of the Bäcklund transformation. After this, we give a new theorem, the Bäcklund transformations for the adjoint curve in Euclidean 3‐space. 相似文献
73.
74.
Dash C Kroll P Yousufuddin M Dias HV 《Chemical communications (Cambridge, England)》2011,47(15):4478-4480
Cationic gold carbonyl complexes supported by N-heterocyclic carbene ligands, SIDipp and IDipp, have been synthesized. [(SIDipp)Au(CO)][SbF(6)] has a linear, two-coordinate gold center. [(SIDipp)Au(CO)][SbF(6)] and [(IDipp)Au(CO)][SbF(6)] display ?ν(CO) values at 2197 and 2193 cm(-1), respectively. Computational studies on [(SIMe)Au(CO)](+) indicate the presence of a strong Au(I)-CO bond. 相似文献
75.
The total synthesis of an analogue of the marine alkaloid kealiiquinone has been completed through application of an intramolecular Diels-Alder reaction of an imidazole-containing enyne. Oxidative aromatization of the lactone adduct and N-methylation facilitates C2-oxidation via the imidazolium salt. Conversion of the lactone to the phthalaldehyde derivative and then to the dihydroxybenzoquinone was achieved via a reaction with glyoxal in the presence of KCN. Esterification of the vinylogous diacid and deprotection provided 7'-desmethylkealiiquinone. 相似文献
76.
Muhammed een Jong Min Oh Zeynep
zdemir Saliha Ebru Büyüktuncel Mehtap Uysal Mohamed A. Abdelgawad Arafa Musa Nicola Gambacorta Orazio Nicolotti Bijo Mathew Hoon Kim 《Molecules (Basel, Switzerland)》2020,25(22)
Twelve pyridazinones (T1–T12) containing the (2-fluorophenyl) piperazine moiety were designed, synthesized, and evaluated for monoamine oxidase (MAO) -A and -B inhibitory activities. T6 was found to be the most potent MAO-B inhibitor with an IC50 value of 0.013 µM, followed by T3 (IC50 = 0.039 µM). Inhibitory potency for MAO-B was more enhanced by meta bromo substitution (T6) than by para bromo substitution (T7). For para substitution, inhibitory potencies for MAO-B were as follows: -Cl (T3) > -N(CH3)2 (T12) > -OCH3 (T9) > Br (T7) > F (T5) > -CH3 (T11) > -H (T1). T6 and T3 efficiently inhibited MAO-A with IC50 values of 1.57 and 4.19 µM and had the highest selectivity indices (SIs) for MAO-B (120.8 and 107.4, respectively). T3 and T6 were found to be reversible and competitive inhibitors of MAO-B with Ki values of 0.014 and 0.0071, respectively. Moreover, T6 was less toxic to healthy fibroblast cells (L929) than T3. Molecular docking simulations with MAO binding sites returned higher docking scores for T6 and T3 with MAO-B than with MAO-A. These results suggest that T3 and T6 are selective, reversible, and competitive inhibitors of MAO-B and should be considered lead candidates for the treatment of neurodegenerative disorders like Alzheimer’s disease. 相似文献
77.
78.
Investigating the impurity structure for Fe3+ ions doped into rutile titanium dioxide single crystal
Muhammed Açıkgöz 《辐射效应与固体损伤》2013,168(4):300-312
The local environment around Fe3+ centers in rutile TiO2 crystals is studied by employing fourth-order perturbation theory formula based on the dominant spin–orbit coupling mechanism. The zero-field splitting parameters (ZFSPs) D and E and crystal field parameters are modeled for the Fe3+ ions not only at the substitution Ti4+ site, but also at the interstitial site with local symmetry D2h. In order to acquire the best agreement between the calculated ZFSPs and those measured by electron magnetic resonance, the model parameters are adjusted on the basis of several approaches. This enables us to determine the feasible values of the structural distortions resulting from dopant Fe3+ ions. Consequently, it is confirmed that Fe3+ ions substitute for Ti4+ sites in rutile TiO2 crystals. 相似文献
79.
Muhammed Ali Alan 《Potential Analysis》2013,38(2):457-470
We analyze the supports of weighted equilibrium measures in ? n . We give explicit examples of families of compact sets which arise as the support of a weighted equilibrium measure for some admissible weight w. These examples also give new constructions of plurisubharmonic functions in the Lelong class. We also include a list of open problems on the support of extremal measures which are related to solutions of Monge–Ampère equations. 相似文献
80.
AKHTER Kulsoom AHMED Muhammed Naeem GHOUS Tahseen RASHEED Basharat TAHIR Muhammad Nawaz ARSHAD Ifzan 《结构化学》2019,38(9)
The structure of 1-hydroxy-3,5-dimethoxy-9 H-xanthen-9-one isolated from chloroform extract of Ajuga bracteosa root was analyzed by single-crystal X-ray diffraction. DPPH(1,1-diphenyl-2-picryl hydrazyl), ABTS(2,2?-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities(RSA) and Fe2+ chelating activities were carried out to determine the antioxidant potential of the compound. RSA values for the compound were 96%, 96% and 96% for all the three activities respectively at maximum concentration of the compound(100 μ gmL-1) with the IC50 values of 3.40, 4.86 and 0.10(μ gmL-1). Antidiabetic activities including antiglycation and α-glucosidase inhibition were also performed where the antiglycation activity was performed using two techniques including spectrofluorometric as well as spectrophotometric technique. Spectrofluorometric technique provided 97% antiglycation potential while 92% antiglycation potential was observed by spectrophotometric technique for the isolated compound. The compound at a concentration of 10 μ gmL-1 exhibited 31% α-glucosidase inhibitory potential with IC50 of 15.56 μ gmL-1. Antimicrobial activity data showed that the compound was active against all the studied pathogenic bacteria. 相似文献