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181.
182.
Aggregation‐Induced‐Emission‐Active Macrocycle Exhibiting Analogous Triply and Singly Twisted Möbius Topologies
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Engui Zhao Luming Meng Christian Schütt Jacky W. Y. Lam Herman H. Y. Sung Prof. Dr. Ian D. Williams Prof. Xuhui Huang Prof. Rainer Herges Prof. Ben Zhong Tang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(33):11707-11711
Molecules with Möbius topology have drawn increasing attention from scientists in a variety of fields, such as organic chemistry, inorganic chemistry, and material science. However, synthetic difficulties and the lack of functionality impede their fundamental understanding and practical applications. Here, we report the facile synthesis of an aggregation‐induced‐emission (AIE)‐active macrocycle (TPE‐ET) and investigate its analogous triply and singly twisted Möbius topologies. Because of the twisted and flexible nature of the tetraphenylethene units, the macrocycle adjusts its conformations so as to accommodate different guest molecules in its crystals. Moreover, theoretical studies including topological and electronic calculations reveal the energetically favorable interconversion process between triply and singly twisted topologies. 相似文献
183.
Ying Yu Hao Xing Zhicong Zhou Junkai Liu Herman H-YSung Ian D.Williams Jonathan E.Halpert Zheng Zhao Ben Zhong Tang 《中国科学:化学(英文版)》2022,65(1):135-144
Molecular interactions are crucial in diverse fields of protein folding,material science,nanotechnology,and life origins.Although mounting experimental research controls luminescent behavior by adjusting molecular interactions in light-emitting materials,it remains elusive to correlate microscopic molecular interactions with macroscopic luminescent behavior directly.Here,we synthesized three red luminogens with subtle structural variation and investigated the influence of molecular interactions on their luminescent behavior in solution and aggregate states.Our results indicate that strongπ-πand D-A interactions in both dilute solution(between luminogen and solvent molecules)and aggregate(between luminogens)states cause the redshift in emission,while weak interactions(e.g.,Van der Waals,C–H…π,and C–H…F interactions)enhance the quantum yield.This work provides a thoughtful investigation into the complicated influence of various molecular interactions on luminescent behavior. 相似文献
184.
Bob Boyd Gareth Brenton Eddie Clayton Jonathan Curtis R. M. Elliott G. A. Errock B. N. Green R. H. Bateman Simon J. Gaskell Iwan Griffiths Zdenek Herman Philip Jonathan Rich Kondrat Mila Laušević Chris Lock Deepak Mathur John F. J. Todd Károly Vékey 《Rapid communications in mass spectrometry : RCM》2016,30(11):1253-1264
185.
Controlling Proton and Electron Transfer Rates to Enhance the Activity of an Oxygen Reduction Electrocatalyst
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Rajendra P. Gautam Yi Teng Lee Gabriel L. Herman Cynthia M. Moreno Prof. Dr. Edmund C. M. Tse Prof. Dr. Christopher J. Barile 《Angewandte Chemie (International ed. in English)》2018,57(41):13480-13483
An electrochemical approach is developed that allows for the control of both proton and electron transfer rates in the O2 reduction reaction (ORR). A dinuclear Cu ORR catalyst was prepared that can be covalently attached to thiol‐based self‐assembled monolayers (SAMs) on Au electrodes using azide–alkyne click chemistry. Using this architecture, the electron transfer rate to the catalyst is modulated by changing the length of the SAM, and the proton transfer rate to the catalyst is controlled with an appended lipid membrane modified with proton carriers. By tuning the relative rates of proton and electron transfer, the current density of the lipid‐covered catalyst is enhanced without altering its core molecular structure. This electrochemical platform will help identify optimal thermodynamic and kinetic parameters for ORR catalysts and catalysts of other reactions that involve the transfer of both protons and electrons. 相似文献
186.
A General Approach Towards Triazole‐Linked Adenosine Diphosphate Ribosylated Peptides and Proteins
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Qiang Liu Dr. Hans A. V. Kistemaker Dr. Sagar Bhogaraju Prof. Dr. Ivan Dikic Prof. Dr. Herman S. Overkleeft Prof. Dr. Gijsbert A. van der Marel Prof. Dr. Huib Ovaa Dr. Gerbrand J. van der Heden van Noort Dr. Dmitri V. Filippov 《Angewandte Chemie (International ed. in English)》2018,57(6):1659-1662
Current methods to prepare adenosine diphosphate ribosylated (ADPr) peptides are not generally applicable due to the labile nature of this post‐translational modification and its incompatibility with strong acidic conditions used in standard solid‐phase peptide synthesis. A general strategy is presented to prepare ADPr peptide analogues based on a copper‐catalyzed click reaction between an azide‐modified peptide and an alkyne‐modified ADPr counterpart. The scope of this approach was expanded to proteins by preparing two ubiquitin ADPr analogues carrying the biological relevant α‐glycosidic linkage. Biochemical validation using Legionella effector enzyme SdeA shows that clicked ubiquitin ADPr is well‐tolerated and highlights the potential of this strategy to prepare ADPr proteins. 相似文献
187.
Herman O. Desseyn Antonio C. Fabretti Wanda Malavasi 《Journal of chemical crystallography》1990,20(4):355-362
The title compound (C6H10CdN12S2) was prepared and characterized by means of X-ray, Raman, and IR measurements. The crystals are orthorhombic:Pbcn, (No. 60),a=9.558(2),b=9.491(2),c=15.898(2) Å,Z=4. The structure was solved by the heavy-atom method, and least-squares refinement of structural parameters led toR=0.021 (R
w
=0.020) for 863 independent reflections. The compound exhibits two-dimensional Cd(II) networks, with the 1,2,4-triazole molecule acting as a bidentate bridging ligand. The structure consists of centrosymmetric units, in which the cadmium atoms are coordinated in distorted octahedral geometries by six nitrogen atoms. Each cadmium atom is linked by four 1,2,4-triazole molecules, and two thiocyanate ions complete the octahedral coordination around the metal. Each 1,2,4-triazole molecule bridges two cadmium atoms. The NH and NH2 groups of the guanazole unit are involved in intermolecular hydrogen bonds. Infrared and Raman bands are diagnostic of the coordination environments around the metal atoms. 相似文献
188.
van der Heden van Noort GJ Verhagen CP van der Horst MG Overkleeft HS van der Marel GA Filippov DV 《Organic letters》2008,10(20):4461-4464
A one-pot procedure for the preparation of phosphoramidates, phosphorothioates, pyrophosphates, phosphodiesters, and phosphofluoridates has been devised using di(p-methoxybenzyl)-N,N-diisopropylphosphoramidite as the common phosphitylating reagent. 相似文献
189.
Jongejan A Lim HD Smits RA de Esch IJ Haaksma E Leurs R 《Journal of chemical information and modeling》2008,48(7):1455-1463
A three-dimensional homology model of the human histamine H 4 receptor was developed to investigate the binding mode of a series of structurally diverse H 4-agonists, i.e. histamine, clozapine, and the recently described selective, nonimidazole agonist VUF 8430. Mutagenesis studies and docking of these ligands in a rhodopsin-based homology model revealed two essential points of interactions in the binding pocket, i.e. Asp3.32 and Glu5.46 (Ballesteros-Weinstein numbering system). It is postulated that Asp3.32 interacts in its anionic state, whereas Glu5.46 interacts in its neutral form. The hypothesis was tested with the point mutations D3.32N and E5.46Q. For the D3.32N no binding affinity toward any of the ligands could be detected. This is in sharp contrast to the E5.46Q mutant, which discriminates between various ligands. The affinity of histamine-like ligands was decreased approximately a 1000-fold, whereas the affinity of all other ligands remained virtually unchanged. The proposed model for agonist binding as well as ab initio calculations for histamine and VUF 8430 explain the observed differences in binding to the H 4R mutants. These studies provide a molecular understanding for the action of a variety of H 4 receptor-ligands. The resulting H 4 receptor model will be the basis for the development of new H 4 receptor-ligands. 相似文献
190.