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81.
82.
We introduce a version of weighted anisotropic Morrey spaces and anisotropic Hardy operators. We find conditions for boundedness of these operators in such spaces. We also reveal the role of these operators in solving some classes of degenerate hyperbolic partial differential equations. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
83.
A Signal‐Passing DNA‐Strand‐Exchange Mechanism for Active Self‐Assembly of DNA Nanostructures 下载免费PDF全文
Dr. Jennifer E. Padilla Dr. Ruojie Sha Dr. Martin Kristiansen Prof. Junghuei Chen Prof. Natasha Jonoska Prof. Nadrian C. Seeman 《Angewandte Chemie (International ed. in English)》2015,54(20):5939-5942
DNA nanostructured tiles play an active role in their own self‐assembly in the system described herein whereby they initiate a binding event that produces a cascading assembly process. We present DNA tiles that have a simple but powerful property: they respond to a binding event at one end of the tile by passing a signal across the tile to activate a binding site at the other end. This action allows sequential, virtually irreversible self‐assembly of tiles and enables local communication during the self‐assembly process. This localized signal‐passing mechanism provides a new element of control for autonomous self‐assembly of DNA nanostructures. 相似文献
84.
Dr. Claire M. Young Alex Elmi Dr. Dominic J. Pascoe Rylie K. Morris Calum McLaughlin Andrew M. Woods Dr. Aileen B. Frost Dr. Alix de la Houpliere Dr. Kenneth B. Ling Prof. Terry K. Smith Prof. Alexandra M. Z. Slawin Prof. Patrick H. Willoughby Prof. Scott L. Cockroft Prof. Andrew D. Smith 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(9):3734-3739
The importance of 1,5-O⋅⋅⋅chalcogen (Ch) interactions in isochalcogenourea catalysis (Ch=O, S, Se) is investigated. Conformational analyses of N-acyl isochalcogenouronium species and comparison with kinetic data demonstrate the significance of 1,5-O⋅⋅⋅Ch interactions in enantioselective catalysis. Importantly, the selenium analogue demonstrates enhanced rate and selectivity profiles across a range of reaction processes including nitronate conjugate addition and formal [4+2] cycloadditions. A gram-scale synthesis of the most active selenium analogue was developed using a previously unreported seleno-Hugerschoff reaction, allowing the challenging kinetic resolutions of tertiary alcohols to be performed at 500 ppm catalyst loading. Density functional theory (DFT) and natural bond orbital (NBO) calculations support the role of orbital delocalization (occurring by intramolecular chalcogen bonding) in determining the conformation, equilibrium population, and reactivity of N-acylated intermediates. 相似文献
85.
Davis C Gordon N Murphy S Singh I Kavanagh K Carberry S Doyle S 《Analytical and bioanalytical chemistry》2011,401(8):2519-2529
Gliotoxin is produced by non-ribosomal peptide synthesis and secreted from certain fungi, including Aspergillus fumigatus. It is an epipolythiodioxopiperazine that contains an intact disulphide bridge and is the focus of intense research as a
consequence of its negative immunomodulatory properties. Gliotoxin detection is generally enabled by reversed-phase–high-performance
liquid chromatography (RP-HPLC), with absorbance detection (220–280 nm), or liquid chromatography-mass spectrometry, yet detection
is not readily achievable by matrix-assisted laser desorption ionisation–time-of-flight mass spectrometry (MALDI-ToF MS).
We have developed a single-pot derivatisation strategy which uses sodium borohydride-mediated reduction of gliotoxin followed
by immediate alkylation of exposed thiols by 5′-iodoacetamidofluorescein to yield a stable product, diacetamidofluorescein-gliotoxin
(GT-(AF)2), of molecular mass 1103.931 Da ((M + H)+). This product is readily detectable by RP-HPLC and exhibits a 6.8-fold increase
in molar absorptivity compared with gliotoxin, which results in a higher sensitivity of detection (40 ng; 125 pmoL). GT-(AF)2 also fluoresces (excitation/emission, 492:518 nm). Unlike free gliotoxin, the product (>800 fmol) is detectable by MALDI-ToF
MS. Sporidesmin A can also be detected by RP-HPLC and MALDI-ToF MS (>530 fmol) using this strategy. We also demonstrate that
the strategy facilitates detection of gliotoxin (mean ± SD = 3.55 ± 0.07 μg 100 μL−1; n = 2) produced by A. fumigatus, without the requirement for organic extraction of culture supernatants and associated solvent removal. GT-(AF)2 is also detectable (150 ng; 460 pmol) by thin-layer chromatography. 相似文献
86.
Rhys NH Wang MC Jowitt TA Helliwell JR Grossmann JG Baldock C 《Journal of synchrotron radiation》2011,18(1):79-83
The low-resolution structure of α-crustacyanin has been determined to 30 ? resolution using negative-stain electron microscopy (EM) with single-particle averaging. The protein, which is an assembly of eight β-crustacyanin dimers, appears asymmetrical and rather open in layout. A model was built to the EM map using the X-ray crystallographic structure of β-crustacyanin guided by PISA interface analyses. The model has a theoretical sedimentation coefficient that matches well with the experimentally derived value from sedimentation velocity analytical ultracentrifugation. Additionally, the EM model has similarities to models calculated independently by rigid-body modelling to small-angle X-ray scattering (SAXS) data and extracted in silico from the β-crustacyanin crystal lattice. Theoretical X-ray scattering from each of these models is in reasonable agreement with the experimental SAXS data and together suggest an overall design for the α-crustacyanin assembly. 相似文献
87.
Li F Clegg JK D'Alessandro DM Goux-Capes L Sciortino NF Keene TD Kepert CJ 《Dalton transactions (Cambridge, England : 2003)》2011,40(45):12388-12393
Three high-spin tetranuclear cobalt(II) complexes have been prepared with the bridging ligand 4,7-phenanthrolino-5,6:5',6'-pyrazine (ppz) through metal-ion directed self-assembly. The complexes differ by the incorporation of three different coordinating anions: chloride, thiocyanide and selenocyanide. The physical properties of these complexes have been investigated in detail. 相似文献
88.
N Thorne M Shen WA Lea A Simeonov S Lovell DS Auld J Inglese 《Chemistry & biology》2012,19(8):1060-1072
Highlights? A representative small molecule library contains 12% firefly luciferase inhibitors ? Competitive, noncompetitive, uncompetitive, and MAI inhibitors were identified ? For FLuc-RGAs 65% of FLuc inhibitors with known MOIs increased the luminescence signal ? Methods to identify FLuc inhibitors that interfere with assay results are described 相似文献
89.
90.
Graczyk A Murphy FA Nolan D Fernández-Moreira V Lundin NJ Fitchett CM Draper SM 《Dalton transactions (Cambridge, England : 2003)》2012,41(25):7746-7754
A series of novel fused 4'-substituted 2,2'?:?6',2'-terpyridine ligands and their ruthenium(II) complexes were prepared. The unusual 4'-substituents comprised 2,3,4,5-pentaphenylbenzene and its tert-butyl derivative (1 and 2) and the products from oxidative cyclodehydrogenation, i.e. polyaromatic fragments consisting of ten or thirteen fused benzene rings (3 and 4). The syntheses of all the ligands are discussed in terms of the demands and limitations of the Scholl reaction. The optical properties of the ligands, along with the single-crystal X-ray structures of 1 and 2, are presented. The latter show that the pentaphenylbenzene and terpyridine appendages of 1 and 2 are perpendicular in the solid state. Despite the inclusion of the large organic chromophore the absorption and emission properties of the Ru(II) bis-terpy complexes (of ligands 1, 2 and 3) were found to be comparable to those of [Ru(terpy)(2)](2+). They are non-emissive at room temperature but emit at 77 K with excited state lifetimes of 11-12 μs. 相似文献