全文获取类型
收费全文 | 39837篇 |
免费 | 1219篇 |
国内免费 | 151篇 |
专业分类
化学 | 20777篇 |
晶体学 | 205篇 |
力学 | 1091篇 |
综合类 | 7篇 |
数学 | 6662篇 |
物理学 | 12465篇 |
出版年
2023年 | 254篇 |
2021年 | 345篇 |
2020年 | 499篇 |
2019年 | 385篇 |
2018年 | 525篇 |
2017年 | 516篇 |
2016年 | 1069篇 |
2015年 | 816篇 |
2014年 | 928篇 |
2013年 | 1989篇 |
2012年 | 1782篇 |
2011年 | 1933篇 |
2010年 | 1305篇 |
2009年 | 1080篇 |
2008年 | 1802篇 |
2007年 | 1688篇 |
2006年 | 1621篇 |
2005年 | 1451篇 |
2004年 | 1262篇 |
2003年 | 1034篇 |
2002年 | 921篇 |
2001年 | 877篇 |
2000年 | 704篇 |
1999年 | 490篇 |
1998年 | 428篇 |
1997年 | 424篇 |
1996年 | 522篇 |
1995年 | 461篇 |
1994年 | 498篇 |
1993年 | 505篇 |
1992年 | 553篇 |
1991年 | 382篇 |
1990年 | 390篇 |
1989年 | 352篇 |
1988年 | 329篇 |
1987年 | 342篇 |
1986年 | 313篇 |
1985年 | 500篇 |
1984年 | 482篇 |
1983年 | 403篇 |
1982年 | 427篇 |
1981年 | 422篇 |
1980年 | 422篇 |
1979年 | 406篇 |
1978年 | 394篇 |
1977年 | 394篇 |
1976年 | 364篇 |
1975年 | 357篇 |
1974年 | 346篇 |
1973年 | 294篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Öztürk Müjdat Çalişir Oğuzhan Genç Gamze 《Journal of Thermal Analysis and Calorimetry》2021,145(3):1431-1443
Journal of Thermal Analysis and Calorimetry - In this study, the energy, exergy and economic (3E) analyses were performed for the photovoltaic/thermal collector-assisted heat pump domestic water... 相似文献
992.
Prof. Dr. Wilfred F. van Gunsteren Prof. Xavier Daura Dr. Patrick F. J. Fuchs Prof. Niels Hansen Prof. Dr. Bruno A. C. Horta Prof. Dr. Philippe H. Hünenberger Prof. Dr. Alan E. Mark Dr. Maria Pechlaner Prof. Dr. Sereina Riniker Prof. Dr. Chris Oostenbrink 《Chemphyschem》2021,22(3):264-282
Computer simulations of molecular systems enable structure-energy-function relationships of molecular processes to be described at the sub-atomic, atomic, supra-atomic or supra-molecular level and plays an increasingly important role in chemistry, biology and physics. To interpret the results of such simulations appropriately, the degree of uncertainty and potential errors affecting the calculated properties must be considered. Uncertainty and errors arise from (1) assumptions underlying the molecular model, force field and simulation algorithms, (2) approximations implicit in the interatomic interaction function (force field), or when integrating the equations of motion, (3) the chosen values of the parameters that determine the accuracy of the approximations used, and (4) the nature of the system and the property of interest. In this overview, advantages and shortcomings of assumptions and approximations commonly used when simulating bio-molecular systems are considered. What the developers of bio-molecular force fields and simulation software can do to facilitate and broaden research involving bio-molecular simulations is also discussed. 相似文献
993.
Daniel Loof Oliver Thüringer Dr. Marco Schowalter Dr. Christoph Mahr Anmona Shabnam Pranti Prof. Dr. Walter Lang Prof. Dr. Andreas Rosenauer Dr. Volkmar Zielasek Dr. Sebastian Kunz Prof. Dr. Marcus Bäumer 《ChemistryOpen》2021,10(7):697-712
Porous networks of Pt nanoparticles interlinked by bifunctional organic ligands have shown high potential as catalysts in micro-machined hydrogen gas sensors. By varying the ligand among p-phenylenediamine, benzidine, 4,4‘‘-diamino-p-terphenyl, 1,5-diaminonaphthalene, and trans-1,4-diaminocyclohexane, new variants of such networks were synthesized. Inter-particle distances within the networks, determined via transmission electron microscopy tomography, varied from 0.8 to 1.4 nm in accordance with the nominal length of the respective ligand. While stable structures with intact and coordinatively bonded diamines were formed with all ligands, aromatic diamines showed superior thermal stability. The networks exhibited mesoporous structures depending on ligand and synthesis strategy and performed well as catalysts in hydrogen gas microsensors. They demonstrate the possibility of deliberately tuning micro- and mesoporosity and thereby transport properties and steric demands by choice of the right ligand also for other applications in heterogeneous catalysis. 相似文献
994.
995.
Johan F. A. Pijnenborg Eline A. Visser Dr. Marek Noga Emiel Rossing Raisa Veizaj Prof. Dirk J. Lefeber Dr. Christian Büll Dr. Thomas J. Boltje 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(12):4022-4027
Fucosylation of glycans impacts a myriad of physiological and pathological processes. Inhibition of fucose expression emerges as a potential therapeutic avenue for example in cancer, inflammation, and infection. In this study, we found that protected 2-fluorofucose 1-phosphate efficiently inhibits cellular fucosylation with a four to seven times higher potency than known inhibitor 2FF, independently of the anomeric stereochemistry. Nucleotide sugar analysis revealed that both the α- and β-GDP-2FF anomers are formed inside the cell. In conclusion, we developed A2FF1P and B2FF1P as potent new tools for studying the role of fucosylation in health and disease and they are potential therapeutic candidates. 相似文献
996.
Dr. Kaveh Matinkhoo Antonio A. W. L. Wong Dr. Chido M. Hambira Brandon Kato Charlie Wei Dr. Christoph Müller Dr. Torsten Hechler Dr. Alexandra Braun Dr. Francesca Gallo Dr. Andreas Pahl Prof. David M. Perrin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(40):10282-10292
Alpha-amanitin, an extremely toxic bicyclic octapeptide extracted from the death-cap mushroom, Amanita phalloides, is a highly selective allosteric inhibitor of RNA polymerase II. Following on growing interest in using this toxin as a payload in antibody-drug conjugates, herein we report the synthesis and biochemical evaluation of several new derivatives of this toxin to probe the role of the trans-hydroxyproline (Hyp), which is known to be critical for toxicity. This structure activity relationship (SAR) study represents the first of its kind to use various Hyp-analogs to alter the conformational and H-bonding properties of Hyp in amanitin. 相似文献
997.
Lars Rummel Jan M. Schümann Prof. Dr. Peter R. Schreiner 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(55):13699-13702
We present a computational analysis of hexaphenylethane derivatives with heavier tetrels comprising the central bond. In stark contrast to parent hexaphenylethane, the heavier tetrel derivatives can readily be prepared. In order to determine the origin of their apparent thermodynamic stability against dissociation as compared to the carbon case, we employed local energy decomposition analysis (LED) and symmetry-adapted perturbation theory (SAPT) at the DLPNO-CCSD(T)/def2-TZVP and sSAPT0/def2-TZVP levels of theory. We identified London dispersion (LD) interactions as the decisive factor for the molecular stability of heavier tetrel derivatives. This stability is made possible owing to the longer (than C−C) central bonds that move the phenyl groups out of the heavily repulsive regime so they can optimally benefit from LD interactions. 相似文献
998.
The formation of large size clusters,and/or their relative motion as a possible excitation mode,are sugge sted to be closely related to the origin of deformation in specific cases,namely the case of two doubly-magic clusters or two clusters with nearby characterization.New lifetime data in N=Z ~(76)Sr and ~(80)Zr leading to large B(E2) values are reproduced consistently and well within this approach,along with data for a few neighboring N≈Z nuclei.These results are compared to previous studies of ~(32)S and ~(20)Ne and all of them support the ideas of the large-scale cluster approach. 相似文献
999.
Dr. George Serghiou Dr. Nicholas Odling Dr. Hans Josef Reichmann Dr. Gang Ji Prof. Dr. Monika Koch-Müller Prof. Dr. Daniel J. Frost Dr. Jonathan P. Wright Dr. Reinhard Boehler Dr. Wolfgang Morgenroth 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(57):14217-14224
Multi-anvil and laser-heated diamond anvil methods have been used to subject Ge and Si mixtures to pressures and temperatures of between 12 and 17 GPa and 1500–1800 K, respectively. Synchrotron angle dispersive X-ray diffraction, precession electron diffraction and chemical analysis using electron microscopy, reveal recovery at ambient pressure of hexagonal Ge−Si solid solutions (P63/mmc). Taken together, the multi-anvil and diamond anvil results reveal that hexagonal solid solutions can be prepared for all Ge−Si compositions. This hexagonal class of solid solutions constitutes a significant expansion of the bulk Ge−Si solid solution family, and is of interest for optoelectronic applications. 相似文献
1000.
Prof. Dr. Christian Brückner Dr. Nivedita Chaudhri Dustin E. Nevonen Dr. Sayantan Bhattacharya Arthur Graf Elizabeth Kaesmann Dr. Ruoshi Li Dr. Matthew J. Guberman-Pfeffer Prof. Dr. Tomoyasu Mani Dr. Arunpatcha Nimthong-Roldán Dr. Matthias Zeller Dr. Adrien A. P. Chauvet Prof. Dr. Victor Nemykin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(65):16189-16203