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排序方式: 共有216条查询结果,搜索用时 437 毫秒
81.
Andrew E. Howery Shelley Elvington Sherwin J. Abraham Kee-Hyun Choi Sierra Dworschak-Simpson Sabrina Phillips Christopher M. Ryan R. Lea Sanford Jonas Almqvist Kevin Tran Thomas A. Chew Ulrich Zachariae Olaf S. Andersen Julian Whitelegge Kimberly Matulef Justin Du Bois Merritt C. Maduke 《Chemistry & biology》2012,19(11):1460-1470
Highlights? OADS is a known small-molecule inhibitor of a CLC antiporter ? OADS specifically inhibits the ClC-ec1 antiporter but not the ClC-1 channel ? Photoaffinity labeling and mass spectrometry have localized OADS binding to two discrete sites ? The unique binding mode and lipid dependence of OADS suggest potential mechanisms of action 相似文献
82.
Wee Chew 《Journal of Raman spectroscopy : JRS》2011,42(1):36-47
A methodology of multivariate chemometric techniques based on the information‐theoretic approach was applied for elucidating chemical reaction information from a Raman data array R m×ν that arises from in situ reaction monitoring. This reaction‐induced dynamic dataset R m×ν can be contaminated by random cosmic ray spikes found in the midst of characteristic spectral variations associated with the disappearance or emergence of Raman active reactants, intermediates and products. Such spurious cosmic spikes were identified and removed using a novel and fast numerical approach based on maximum and minimum spectral entropy principles while preserving the genuine reaction‐induced spectral variations. Subsequently, the band‐target entropy minimization (BTEM) algorithm, a minimum spectral entropy based self‐modeling curve resolution technique, was applied to recover the pure component spectra of Raman active chemical species. Information gain through the chemometric analyses was calculated using information entropies with base 2 logarithm. This sequence of information‐theoretic chemometric analyses (or transinformations) was successfully tested on the reaction spectral data obtained from alcoholysis of acetic anhydride, which contains four Raman active chemical species. It is envisioned that this series of multivariate statistical analyses will be useful in chemical reaction studies and process analytical technology (PAT) applications that utilize in situ Raman spectroscopy to monitor transient dynamic changes in chemical concentrations, and also in Raman microscopy/imaging data containing spatial variations. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
83.
84.
The potential of electrospun pullulan/dextran (P/D) nanofibers (average diameter = 323 nm) for vascular tissue engineering applications is explored. The mechanical properties of the nanofibers are of the same order of magnitude as that of human arteries (Young's modulus ≈0.88 MPa; tensile strength ≈0.35 MPa). It is demonstrated that the nanofiber topography enables cell adhesion and that the endothelial phenotype is maintained on the nanofibers. Moreover, P/D nanofibers support a stable confluent monolayer of endothelial cells over 14 d. SMCs seeded on nanofibers display similar levels of alpha smooth muscle actin and a lower proliferation rate than cells on 2D cultures. The observations suggest that nanofibers promote a shift to a quiescent contractile phenotype in SMCs.
85.
By introducing an additional hydrogen bond to hydrogen bond interaction in the force field of the CSAW (Conditioned Self-Avoiding
Walk) model, we investigate into the mechanism of antiparallel β-sheet formation based on the folding of a short polyalanine in gas phase. Through our numerical simulation, we detect the
possible presence of a transient helix during β-sheet formation, whose presence is shown to have slowed the formation of β-sheets by an order of magnitude. While we observe the mechanisms of nucleation, zipping and induction that drives the formation
of a β-sheet, we uncover a new mechanism that involves transient β-turns and short β-sheets during the formation of long β-sheets. Our results have enabled us to provide an overview on the mechanisms of β-sheet formation via two main folding pathways: slow folding through the intermediate state of transient helix, and fast folding
from the nucleation of β-turn. 相似文献
86.
Three numerical approaches for solving the incompressible Navier–Stokes equations in primitive variable form are proposed and compared in this work. All these approaches are based on the SIMPLE strategy with GDQ discretization on a non-staggered grid. It was found that the satisfying of the continuity equation on the boundary is critical to obtain an accurate numerical solution. The proposed three approaches are to make sure that the continuity equation is satisfied on the boundary, and in the meantime, recommend the boundary condition for pressure correction equation. Through a test problem of two-dimensional driven cavity flow, the performance of three approaches is comparatively studied in terms of the efficiency and accuracy. For all three approaches, accurate numerical results can be obtained by using just a few grid points. 相似文献
87.
88.
Pd‐Catalyzed Enantiodivergent and Regiospecific phospha‐Michael Addition of Diphenylphosphine to 4‐oxo‐Enamides: Efficient Access to Chiral Phosphinocarboxamides and Their Analogues 下载免费PDF全文
Renta Jonathan Chew Xi‐Rui Li Dr. Yongxin Li Dr. Sumod A. Pullarkat Prof. Dr. Pak‐Hing Leung 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(12):4800-4804
The palladacycle‐catalyzed asymmetric P?H addition of 4‐oxo‐enamides has been developed, which provides efficient access to phosphinocarboxamides and their analogues. Solvent‐mediated reversal of stereoselectivity (ee from +96 % to ?92 %) was observed, and the underlying mechanism that allows facile access to both enantiomers of the product by judicious choice of solvents is revealed. 相似文献
89.
The development of an interactive simulation program generator which is available on micro and mainframe computers is outlined. The generator forms part of a simulation environment being researched into and constructed by a group of researchers at the London School of Economics. The generated programs are written in Pascal, using a suite of routines which assume a three-phase structure for simulation programs. Experiences of modelling using such a simulation modelling environment are outlined, as well as details of related research and future research plans. 相似文献
90.
L. M. Gan K. C. Lee C. H. Chew E. S. Tok S. C. Ng 《Journal of polymer science. Part A, Polymer chemistry》1995,33(7):1161-1168
Polymerization of methyl methacrylate (MMA) has been studied in ternary microemulsions which were stabilized by tetradecyltrimethylammonium bromide (TTAB) or stearyltrimethylammonium chloride (STAC). The sizes of MMA-swollen polymer particles (Rh) increased continuously during polymerization. This is in contrast to that of the styrene system, where Rh increased very rapidly to a maximum and then decreased continuously towards a constant value. The continuous growth of PMMA particles at 60°C are discussed. The stability of PMMA latexes increased with increasing the hydrophobic chain length of the cationic surfactant used. Traces of the coagulations of PMMA particles in the TTAB system can be seen from TEM. © 1995 John Wiley & Sons, Inc. 相似文献