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61.
Peggy Cénac Brigitte Chauvin Frédéric Paccaut Nicolas Pouyanne 《Random Structures and Algorithms》2015,46(1):117-141
Common assumptions on the source producing the words inserted in a suffix trie with n leaves lead to a height and saturation level. We provide an example of a suffix trie whose height increases faster than a power of n and another one whose saturation level is negligible with respect to . Both are built from VLMC (Variable Length Markov Chain) probabilistic sources and are easily extended to families of tries having the same properties. The first example corresponds to a “logarithmic infinite comb” and enjoys a non uniform polynomial mixing. The second one corresponds to a “factorial infinite comb” for which mixing is uniform and exponential. © 2013 Wiley Periodicals, Inc. Random Struct. Alg., 46, 117–141, 2015 相似文献
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64.
Dr. Andrea Hornemann Dr. Diane M. Eichert Arne Hoehl Dr. Brigitte Tiersch Prof. Gerhard Ulm Prof. Maxim G. Ryadnov Dr. Burkhard Beckhoff 《Chemphyschem》2022,23(4):e202100815
Synchrotron radiation-based Fourier transform infrared spectroscopy enables access to vibrational information from mid over far infrared to even terahertz domains. This information may prove critical for the elucidation of fundamental bio-molecular phenomena including folding-mediated innate host defence mechanisms. Antimicrobial peptides (AMPs) represent one of such phenomena. These are major effector molecules of the innate immune system, which favour attack on microbial membranes. AMPs recognise and bind to the membranes whereupon they assemble into pores or channels destabilising the membranes leading to cell death. However, specific molecular interactions responsible for antimicrobial activities have yet to be fully understood. Herein we probe such interactions by assessing molecular specific variations in the near-THz 400–40 cm−1 range for defined helical AMP templates in reconstituted phospholipid membranes. In particular, we show that a temperature-dependent spectroscopic analysis, supported by 2D correlative tools, provides direct evidence for the membrane-induced and folding-mediated activity of AMPs. The far-FTIR study offers a direct and information-rich probe of membrane-related antimicrobial interactions. 相似文献
65.
Kamel Arraki Perle Totoson Alain Decendit Andy Zedet Justine Maroilley Alain Badoc Cline Demougeot Corine Girard 《Molecules (Basel, Switzerland)》2021,26(6)
Polyphenolic enriched extracts from two species of Cyperus, Cyperus glomeratus and Cyperus thunbergii, possess mammalian arginase inhibitory capacities, with the percentage inhibition ranging from 80% to 95% at 100 µg/mL and 40% to 64% at 10 µg/mL. Phytochemical investigation of these species led to the isolation and identification of two new natural stilbene oligomers named thunbergin A-B (1–2), together with three other stilbenes, trans-resveratrol (3), trans-scirpusin A (4), trans-cyperusphenol A (6), and two flavonoids, aureusidin (5) and luteolin (7), which were isolated for the first time from C. thunbergii and C. glomeratus. Structures were established on the basis of the spectroscopic data from MS and NMR experiments. The arginase inhibitory activity of compounds 1–7 was evaluated through an in vitro arginase inhibitory assay using purified liver bovine arginase. As a result, five compounds (1, 4–7) showed significant inhibition of arginase, with IC50 values between 17.6 and 60.6 µM, in the range of those of the natural arginase inhibitor piceatannol (12.6 µM). In addition, methanolic extract from Cyperus thunbergii exhibited an endothelium and NO-dependent vasorelaxant effect on thoracic aortic rings from rats and improved endothelial dysfunction in an adjuvant-induced arthritis rat model. 相似文献
66.
A. Akindinov A. Alici P. Antonioli S. Arcelli M. Basile G. Cara Romeo M. Chumakov L. Cifarelli F. Cindolo A. De Caro D. De Gruttola S. De Pasquale M. Fusco Girard C. Guarnaccia D. Hatzifotiadou H.T. Jung W.W. Jung D.W. Kim H.N. Kim J.S. Kim S. Kiselev G. Laurenti K. Lee S.C. Lee E. Lioublev M.L. Luvisetto A. Margotti A. Martemiyanov R. Nania F. Noferini P. Pagano A. Pesci R. Preghenella G. Russo E. Scapparone G. Scioli R. Silvestri Y. Sun I. Vetlitskiy K. Voloshin L. Vorobiev M.C.S. Williams B. Zagreev C. Zampolli A. Zichichi 《The European Physical Journal C - Particles and Fields》2007,50(2):341-352
In this work we explore the possibility to perform “effective energy” studies in very high energy collisions at the CERN large
hadron collider (LHC). In particular, we focus on the possibility to measure in pp collisions the average charged multiplicity
as a function of the effective energy with the ALICE experiment, using its capability to measure the energy of the leading
baryons with the zero degree calorimeters. Analyses of this kind have been done at lower centre-of-mass energies and have
shown that, once the appropriate kinematic variables are chosen, particle production is characterized by universal properties:
no matter the nature of the interacting particles, the final states have identical features. Assuming that this universality
picture can be extended to ion–ion collisions, as suggested by recent results from RHIC experiments, a novel approach based on the scaling hypothesis for limiting
fragmentation has been used to derive the expected charged event multiplicity in AA interactions at LHC. This leads to scenarios
where the multiplicity is significantly lower compared to most of the predictions from the models currently used to describe
high energy AA collisions. A mean charged multiplicity of about 1000–2000 per rapidity unit (at η∼0) is expected for the most
central Pb–Pb collisions at .
In memory of A. Smirnitskiy 相似文献
67.
α‐Halogenoacetanilides as Hydrogen‐Bonding Organocatalysts that Activate Carbonyl Bonds: Fluorine versus Chlorine and Bromine
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Dr. Sylvain Koeller Dr. Coralie Thomas Dr. Fréderic Peruch Dr. Alain Deffieux Dr. Stéphane Massip Prof. Dr. Jean‐Michel Léger Dr. Jean‐Pierre Desvergne Prof. Dr. Anne Milet Dr. Brigitte Bibal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(10):2849-2859
α‐Halogenoacetanilides (X=F, Cl, Br) were examined as H‐bonding organocatalysts designed for the double activation of C?O bonds through NH and CH donor groups. Depending on the halide substituents, the double H‐bond involved a nonconventional C?H???O interaction with either a H?CXn (n=1–2, X=Cl, Br) or a H?CAr bond (X=F), as shown in the solid‐state crystal structures and by molecular modeling. In addition, the catalytic properties of α‐halogenoacetanilides were evaluated in the ring‐opening polymerization of lactide, in the presence of a tertiary amine as cocatalyst. The α‐dichloro‐ and α‐dibromoacetanilides containing electron‐deficient aromatic groups afforded the most attractive double H‐bonding properties towards C?O bonds, with a N?H???O???H?CX2 interaction. 相似文献
68.
Marcileia Zanatta Dr. Anne‐Lise Girard Nathalia M. Simon Prof. Gunter Ebeling Prof. Hubert K. Stassen Prof. Paolo R. Livotto Prof. Francisco P. dos Santos Prof. Jairton Dupont 《Angewandte Chemie (International ed. in English)》2014,53(47):12817-12821
1‐n‐Butyl‐2,3‐dimethylimidazolium (BMMI) ionic liquids (ILs) associated with different anions undergo H/D exchange preferentially at 2‐Me group of the imidazolium in deuterated solvents. This process is mainly related to the existence of ion pairs rather than the anion basicity. The H/D exchange occurs in solvents (CDCl3 and MeCN for instance) in which intimate contact ion pairs are present and the anion possesses a labile H in its structure, such as hydrogen carbonate and prolinate. In D2O, separated ion pairs are formed and the H/D exchange does not occur. A plausible catalytic cycle is that the IL behaves as a neutral base in the course of all H/D exchange processes. NMR experiments, density functional calculations, and molecular dynamics simulations corroborate these hypotheses. 相似文献
69.
Jochen Schölhammer Brigitte Baretzky Wolfgang Gust Eric Mittemeijer Boris Straumal 《Interface Science》2001,9(1-2):43-53
The atomic force microscopy (AFM) was used to study the grain boundary (GB) groove profiles far away from the melting temperature T
m. It is shown that AFM allows one to measure the temperature dependence of the GB energy in a rather broad temperature interval (from 0.85 T
m to T
m). The GB energy and GB segregation of Bi were measured at 1123 K in the interval of the Bi bulk concentration x
v
Bi from 5 to 140 ppm Bi. The transition from monolayer to multilayer adsorption is observed for the 19a GB at 1123 K and x
v
Bi = 60 at. ppm Bi. At the same point (1123 K and x
v
Bi = 60 at. ppm Bi) a discontinuity of the first derivative of the GB energy is observed. These features were explained using the model of GB prewetting phase transformation developed previously. 相似文献
70.
Dautrey Sébastien Bodiguel Jacques Arrault Axelle Jamart-Grégoire Brigitte 《Tetrahedron》2012,68(23):4362-4367
1H NMR and FTIR experiments performed on the 1:1[α:α-N-amino]mers series let us to point out a rare NH–π interaction between the carbamidic NH of the i residue and the phenyl group of a phenylalanine residue located at i+2. 相似文献