全文获取类型
收费全文 | 118篇 |
免费 | 2篇 |
专业分类
化学 | 85篇 |
晶体学 | 2篇 |
力学 | 1篇 |
数学 | 9篇 |
物理学 | 23篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 9篇 |
2012年 | 8篇 |
2011年 | 6篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 6篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 8篇 |
2004年 | 4篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1995年 | 2篇 |
1977年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有120条查询结果,搜索用时 296 毫秒
71.
Dr. Pritam Shankhari Nika G. Bakshi Prof. Dr. Yuemei Zhang Dr. Dejan Stekovic Prof. Dr. Mikhail E. Itkis Prof. Dr. Boniface P. T. Fokwa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(9):1979-1988
Metal-rich borides with the Ti3Co5B2-type structure represent an ideal playground for tuning magnetic interactions through chemical substitutions. In this work, density functional theory (DFT) and experimental studies of Ru-rich quaternary borides with the general composition A2MRu5B2 (A=Zr, Hf, M=Fe, Mn) are presented. Total energy calculations show that the phases Zr2FeRu5B2 and Hf2FeRu5B2 prefer ground states with strong antiferromagnetic (AFM) interactions between ferromagnetic (FM) M-chains. Manganese substitution for iron lowers these antiferromagnetic interchain interactions dramatically and creates a strong competition between FM and AFM states with a slight preference for AFM in Zr2MnRu5B2 and for FM in Hf2MnRu5B2. Magnetic property measurements show a field dependence of the AFM transition (TN): TN is found at 0.1 T for all phases with predicted AFM states whereas for the predicted FM phase it is found at a much lower magnetic field (0.005 T). Furthermore, TN is lowest for a Hf-based phase (20 K) and highest for a Zr-based one (28 K), in accordance with DFT predictions of weaker AFM interactions in the Hf-based phases. Interestingly, the AFM transitions vanish in all compounds at higher fields (>1 T) in favor of FM transitions, indicating metamagnetic behaviors for these Ru-rich phases. 相似文献
72.
Paul M Gorman Sanguk Kim Meng Guo Roman A Melnyk Joanne McLaurin Paul E Fraser James U Bowie Avijit Chakrabartty 《BMC neuroscience》2008,9(1):17
Background
Amyloid precursor protein (APP) is enzymatically cleaved by γ-secretase to form two peptide products, either Aβ40 or the more neurotoxic Aβ42. The Aβ42/40 ratio is increased in many cases of familial Alzheimer's disease (FAD). The transmembrane domain (TM) of APP contains the known dimerization motif GXXXA. We have investigated the dimerization of both wild type and FAD mutant APP transmembrane domains. 相似文献73.
Bonnet D Grandjean C Rousselot-Pailley P Joly P Bourel-Bonnet L Santraine V Gras-Masse H Melnyk O 《The Journal of organic chemistry》2003,68(18):7033-7040
A novel procedure for the preparation of alpha-hydrazinoacetyl peptides is reported on the basis of the solid-phase coupling of partially or fully Boc-protected hydrazino acetic acid derivatives. The degree of unwanted polymerization of the activated ester during both activation and coupling was found to be significant for the monoprotected derivative BocNHNHCH(2)CO(2)H but could be minimized with the diprotected derivative BocNHNH(Boc)CH(2)CO(2)H and suppressed with the fully protected acid. Despite the instability of the imidocarbonate group toward acids and bases, a low-cost and effective route was sought for the preparation of the tris(Boc)-protected derivative. The N,N,N'-tris(Boc)hydrazinoacetic acid could be introduced on the solid phase after or before peptide elongation using Fmoc/tert-butyl chemistry. In this latter case, HR MAS NMR analysis of model solid supports demonstrated the partial loss of one Boc group during the repetitive piperidine treatments. Despite this slight instability, N,N,N'-tris(Boc)hydrazinoacetic acid was found to be a highly convenient reagent for the robust and easily scalable preparation of hydrazinopeptides in good yield and high purity. 相似文献
74.
Zazhigalov V. A. Sachuk E. V. Diyuk E. A. Bacherikova I. V. Shcherban N. D. Kurmach M. M. Melnyk A. K. 《Theoretical and Experimental Chemistry》2019,55(3):215-221
Theoretical and Experimental Chemistry - It was shown that mechanochemical treatment of 1 : 1 MoO3–CeO2 oxide mixture leads to the formation of nanosized particles with core–shell type... 相似文献
75.
Ervin Győri Abhishek Methuku Nika Salia Casey Tompkins Máté Vizer 《Discrete Mathematics》2018,341(9):2602-2605
In this note we asymptotically determine the maximum number of hyperedges possible in an -uniform, connected -vertex hypergraph without a Berge path of length , as and tend to infinity. We show that, unlike in the graph case, the multiplicative constant is smaller with the assumption of connectivity. 相似文献
76.
Properties of phonons-quanta of the crystal lattice vibrations-in graphene have recently attracted significant attention from the physics and engineering communities. Acoustic phonons are the main heat carriers in graphene near room temperature, while optical phonons are used for counting the number of atomic planes in Raman experiments with few-layer graphene. It was shown both theoretically and experimentally that transport properties of phonons, i.e. energy dispersion and scattering rates, are substantially different in a quasi-two-dimensional system such as graphene compared to the basal planes in graphite or three-dimensional bulk crystals. The unique nature of two-dimensional phonon transport translates into unusual heat conduction in graphene and related materials. In this review, we outline different theoretical approaches developed for phonon transport in graphene, discuss contributions of the in-plane and cross-plane phonon modes, and provide comparison with available experimental thermal conductivity data. Particular attention is given to analysis of recent results for the phonon thermal conductivity of single-layer graphene and few-layer graphene, and the effects of the strain, defects, and isotopes on phonon transport in these systems. 相似文献
77.
Olivier C Perzyna A Coffinier Y Grandidier B Stiévenard D Melnyk O Durand JO 《Langmuir : the ACS journal of surfaces and colloids》2006,22(16):7059-7065
While fluorescent-based methods are generally used to detect the immobilization and the interactions of biomolecules to solid supports, recent studies have shown their limitations in the case of silicon surfaces. As an alternative, we investigated the synthesis of peptides labeled with a metal transition complex and their subsequent immobilization to the silicon surfaces. The feasibility of using such probes has been explored by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). By starting with hydrogen-terminated or oxidized silicon surfaces, we functionalized those surfaces with semicarbazide groups and showed the site-specific linkage of glyoxylyl peptides labeled with a Co2(CO)6 moiety. 相似文献
78.
Taras O. Banakh Fedor A. Bogomolov Andrij I. Gatalevych Ihor J. Guran Yurij B. Ishchuk Mykola Ya. Komarnytskyi Igor S. Kuz Ivanna O. Melnyk Vasyl M. Petrychkovych Yaroslav G. Prytula Oleh M. Romaniv Oleh B. Skaskiv Ludmyla L. Stakhiv Georgiy T. Sullym Bohdan V. Zabavskyi Volodymir P. Zelisko Mykhajlo M. Zarichnyi 《Central European Journal of Mathematics》2013,11(9):1547-1551
79.
80.
Fabrice Melnyk 《Comptes Rendus Mathematique》2002,335(7):643-648
We consider the gravitational collapse of the charged star leading to a black-hole. We prove that a fixed observer in Schwarzschild variables observes, at the last moments of the collapse in his own proper time, an outgoing thermal flux of spin 1/2 particles containing preferentially the particles with the same charge that the black-hole. This is the Hawking effect. To cite this article: F. Melnyk, C. R. Acad. Sci. Paris, Ser. I 335 (2002) 643–648. 相似文献