全文获取类型
收费全文 | 406篇 |
免费 | 17篇 |
专业分类
化学 | 301篇 |
晶体学 | 1篇 |
力学 | 9篇 |
数学 | 67篇 |
物理学 | 45篇 |
出版年
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 17篇 |
2020年 | 13篇 |
2019年 | 17篇 |
2018年 | 14篇 |
2017年 | 13篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 14篇 |
2013年 | 26篇 |
2012年 | 27篇 |
2011年 | 32篇 |
2010年 | 18篇 |
2009年 | 10篇 |
2008年 | 30篇 |
2007年 | 19篇 |
2006年 | 24篇 |
2005年 | 32篇 |
2004年 | 17篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有423条查询结果,搜索用时 218 毫秒
1.
Komarov Pavel D. Nifant’ev Ilya E. Roitershtein Dmitrii M. Minyaev Mikhail E. 《Journal of chemical crystallography》2021,51(3):352-362
Journal of Chemical Crystallography - The crystal structure of decakis(μ-chloro)-tetrakis(1,2,4-triphenylcyclopentadienyl)-hexakis(tetrahydrofuran)-di-potassium-tetra-neodymium(III)... 相似文献
2.
Obydennov Dmitrii L. Simbirtseva Alena E. Sosnovskikh Vyacheslav Y. 《Research on Chemical Intermediates》2022,48(5):2155-2179
Research on Chemical Intermediates - Synthesis of 2-cyano-6-styryl-4-pyrones has been developed on the basis of 6-metylcomanic acid via modifications of the methyl and carboxyl groups. Reactions of... 相似文献
3.
Dmitrii O. Kharchenko Olga M. Shchokotova Vasyl O. Kharchenko Viktor V. Kupriienko S.V. Kokhan Xiaoyong Wu 《辐射效应与固体损伤》2020,175(7-8):602-626
ABSTRACT We study microstructure transformation in Zr–Nb system under neutron irradiation and its mechanical properties change under mechanical loads in a form of shear deformation by using phase field methodology. The developed phase field approach takes into account defects dynamics based on reaction rate theory and elastic contribution to study mechanical properties change. A numerical modeling is provided in three stages: sample preparation, irradiation of the prepared sample and mechanical loading of the irradiated sample. A precipitation of β-Niobium particles of the size of several nanometers is discussed. Results of phase field modeling indicate that β-Niobium particles grow slowly during irradiation due to point defects rearrangement. Statistical analysis of dynamics of radiation-induced microstructure transformations is provided. Simulation results of shear deformation of pre-irradiated and post-irradiated alloys are discussed. Maps of local distribution of strain and stress and strain–stress curves are obtained. Results are verified with experimental data. 相似文献
4.
Ilya Kolesnikov Daria Mamonova Dmitrii Pankin Gulia Bikbaeva Anastasia Khokhlova Anna Pilip Anastasia Egorova Vladislav Zigel Alina Manshina 《Photochemistry and photobiology》2023,99(3):929-935
Modern progress in photopharmocology calls for new generation of compounds joining bioactivity, photoswitchable properties and high selectivity of response to light wavelength. Introduced here, phosphonate–fullerene hybrids are the first representatives of such compounds. Phosphonate–fullerene hybrids were synthesized on a base of fullerene C60 and organophosphates with the function of photoswitchable cholinesterase activity—phosphorylated thiazolotriazole and aminomalonate compounds and studied with FTIR, UV–VIS spectroscopy and IPC-micro neurotoxin amperometric analysis. As a result of spectroscopic and bioactivity characterization, it was not only demonstrated butyrylcholinesterase (BuChE) inhibition increase in phosphonate–fullerene hybrids compared with pure phosphonates but also pronounced response of inhibition degree to laser irradiation of hybrids. It was found opposite behavior of hybrids as a result of laser irradiation—BuChE inhibition drop-off for thiazolotriazole–fullerene and pronounced growth for aminomalonate–fullerene. The other remarkable peculiarity of presented phosphonate–fullerene hybrids is high selectivity of inhibition change degree to laser wavelength (266 or 325 nm). 相似文献
5.
6.
Mikhail E. Minyaev Dmitrii M. Roitershtein Ilya E. Nifant'ev Ivan V. Ananyev Tatyana V. Minyaeva Timofey A. Mikhaylyev 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(6):491-498
(1RS,2SR,3RS,4SR,5RS)‐2,4‐Dibenzoyl‐1,3,5‐triphenylcyclohexan‐1‐ol or (4‐hydroxy‐2,4,6‐triphenylcyclohexane‐1,3‐diyl)bis(phenylmethanone), C38H32O3, (1), is formed as a by‐product in the NaOH‐catalyzed synthesis of 1,3,5‐triphenylpentane‐1,5‐dione from acetophenone and benzaldehyde. Single crystals of the chloroform hemisolvate, C38H32O3·0.5CHCl3, were grown from chloroform. The structure has triclinic (P) symmetry. One diastereomer [as a pair of (1RS,2SR,3RS,4SR,5RS)‐enantiomers] of (1) has been found in the crystal structure and confirmed by NMR studies. The dichoromethane hemisolvate has been reported previously [Zhang et al. (2007). Acta Cryst. E 63 , o4652]. (1RS,2SR,3RS,4SR,5RS)‐2,4‐Dibenzoyl‐3,5‐bis(2‐methoxyphenyl)‐1‐phenylcyclohexan‐1‐ol or [4‐hydroxy‐2,6‐bis(2‐methoxyphenyl)‐4‐phenylcyclohexane‐1,3‐diyl]bis(phenylmethanone), C40H36O5, (2), is also formed as a by‐product, under the same conditions, from acetophenone and 2‐methoxybenzaldehyde. Crystals of (2) have been grown from chloroform. The structure has orthorhombic (Pca21) symmetry. A diastereomer of (2) possesses the same configuration as (1). In both structures, the cyclohexane ring adopts a chair conformation with all bulky groups (benzoyl, phenyl and 2‐methoxyphenyl) in equatorial positions. The molecules of (1) and (2) both display one intramolecular O—H...O hydrogen bond. 相似文献
7.
Sophie Ketter Aathira Gopinath Olga Rogozhnikova Dmitrii Trukhin Dr. Victor M. Tormyshev Prof. Dr. Elena G. Bagryanskaya Dr. Benesh Joseph 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(7):2299-2304
In situ investigation of membrane proteins is a challenging task. Previously we demonstrated that nitroxide labels combined with pulsed ESR spectroscopy is a promising tool for this purpose. However, the nitroxide labels suffer from poor stability, high background labeling, and low sensitivity. Here we show that Finland (FTAM) and OX063 based labels enable labeling of the cobalamin transporter BtuB and BamA, the central component of the β-barrel assembly machinery (BAM) complex, in E coli. Compared to the methanethiosulfonate spin label (MTSL), trityl labels eliminated the background signals and enabled specific in situ labeling of the proteins with high efficiency. The OX063 labels show a long phase memory time (TM) of ≈5 μs. All the trityls enabled distance measurements between BtuB and an orthogonally labeled substrate with high selectivity and sensitivity down to a few μm concentration. Our data corroborate the BtuB and BamA conformations in the cellular environment of E. coli. 相似文献
8.
Gladis G. Zakirova Dmitrii Yu. Mladentsev Nataliya E. Borisova 《Tetrahedron letters》2017,58(35):3415-3417
Bis(diphenylphosphine oxides) and bis(tert-butyl(phenyl)phosphine oxides) of 1,10-phenanthroline, 2,2′-bipyridine and pyridine were synthesised in good yields via the Pd(OAc)2/dppf mediated cross-coupling reactions between 6,6′-dichloro-2,2′-bipyridine, 2,9-dichloro-1,10-phenanthroline, or 2,6-dichloropyridine and the corresponding secondary phosphine oxides. These compounds represent potential tetradentate chelating ligands for ions of f-block elements. 相似文献
9.
A cyber-physical system (CPS) is a coupled system integrating computing, networking, and physical processes. Through actuation, cyber-physical systems control the physical processes, usually with feedback loops, where the physical processes affect computing and networking processes, and vice versa. In civil engineering, the most common fields of CPS applications are structural health monitoring (SHM) and structural control. A typical CPS task is the assessment of a structure based on (i) collected measurement data and (ii) a corresponding model. However, for an accurate and precise assessment of a structure, the CPS itself must be modeled and evaluated. In this paper, a conceptual modeling and evaluation approach is proposed, in which each part of a CPS is evaluated individually. In this study, the conceptual approach is presented for modeling and evaluation of CPS in civil engineering. The evaluation is based on an abstract approach allowing a discussion of a principle (i.e. general) model structure of a CPS, identifying critical issues to be studied in more detail in future research. (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
10.