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101.
C Vasilakis C Pagel S Gallivan D Richards A Weaver M Utley 《The Journal of the Operational Research Society》2013,64(7):1049-1059
We describe a modelling toolkit that was developed with the aim of assisting those responsible for introducing stepped care systems to local mental health services in the UK. The toolkit was pre-populated with real patient flow data collected from four sites that piloted the stepped care system design. Two analytical models were developed and coded as part of the toolkit to provide insights concerning workload, patient throughput, and changes in waiting times and waiting list size. An interface was built to allow users to specify their own stepped care system and input their own estimates or data of service demands and capacities at different steps. Despite the challenges and limitations, the use of modelling to inform the design of new service configurations is an important step in the right direction and we would recommend this as a reasonable way forward. 相似文献
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104.
J. Matzerath Niels Jörgen Traberg Arthur Wilhelmi G. Wempe Gasmotorenfabrik Deutz F. D. Harger Greiner Friedrichs Hammermann E. J. Goegg H. C. Deming E. Mauguin Otto Johannsen H. N. Gilbert G. A. Burrell E. R. Weaver J. D. Edwards R. Henr Forrières A. H. Elliot G. H. Oberfell G. Frerichs E. Mannheim F. W. Richardson A. Jaffée H. Kaesbohrer H. Droop Richmond E. Hembrough Harold Heath Gray G. Schuhmacher Jens O. Neuberg A. Jacquerod Tourpaïan Contzen G. T. Baxter H. W. Storkweather Société Roubaisienne d'Eclairage 《Analytical and bioanalytical chemistry》1919,58(2):70-78
105.
106.
The new ferrocenyl substituted ditertiary phosphine {FcCH2N(CH2PPh2)CH2}2 [Fc = (η5-C5H4)Fe(η5-C5H5)] (1) was prepared, in 72% yield, by Mannich based condensation of the known bis secondary amine {FcCH2N(H)CH2}2 with 2 equiv. of Ph2PCH2OH in CH3OH. Phosphine 1 readily coordinates to various transition-metal centres including Mo0, RuII, RhI, PdII, PtII and AuI to afford the heterometallic complexes {RuCl2(p-cym)}2(1) (2), (AuCl)2(1) (3), cis-PtCl2(1) (4), cis-PdCl2(1) (5), cis-Mo(CO)4(1) (6), trans,trans-{Pd(CH3)Cl(1)}2 (7) and trans,trans-{Rh(CO)Cl(1)}2 (8). In complexes 2, 3, 7 and 8 ligand 1 displays a P,P′-bridging mode whilst for 4-6 a P,P′-chelating mode is observed. All new compounds have been fully characterised by spectroscopic and analytical methods. Furthermore the structures of 1, 2 · 2CH2Cl2, 3 · CH2Cl2, 4 · CH2Cl2, 6 · 0.5CHCl3 and 8 have been elucidated by single crystal X-ray crystallography. Electrochemical measurements have been undertaken, and their redox chemistry discussed, on both noncomplexed ligand 1 and representative compounds containing this new ditertiary phosphine. 相似文献
107.
Heymann JJ Weaver KD Mietzner TA Crumbliss AL 《Journal of the American Chemical Society》2007,129(31):9704-9712
The ferric binding protein, FbpA, has been demonstrated to facilitate the transport of naked Fe3+ across the periplasmic space of several Gram-negative bacteria. The sequestration of iron by FbpA is facilitated by the presence of a synergistic anion, such as phosphate or sulfate. Here we report the sequestration of Fe3+ by FbpA in the presence of sulfate, at an assumed periplasmic pH of 6.5 to form FeFbpA-SO4 with K'(eff) = 1.7 x 10(16) M(-1) (at 20 degrees C, 50 mM MES, 200 mM KCl). The iron affinity of the FeFbpA-SO4 protein assembly is 2 orders of magnitude lower than when bound with phosphate and is the lowest of any of the FeFbpA-X assemblies yet reported. Iron reduction at the cytosolic membrane receptor may be an essential aspect of the periplasmic iron-transport process, and with an E(1/2) of -158 mV (NHE), FeFbpA-SO4 is the most easily reduced of all FeFbpA-X assemblies yet studied. The variation of FeFbpA-X assembly stability (K'(eff)) and ease of reduction (E(1/2)) with differing synergistic anions X(n-) are correlated over a range of 14 kJ, suggesting that the variations in redox potentials are due to stabilization of Fe3+ in FeFbpA-X by X(n-). Anion promiscuity of FbpA in the diverse composition of the periplasmic space is illustrated by the ex vivo exchange kinetics of FeFbpA-SO4 with phosphate and arsenate, where first-order kinetics with respect to FeFbpA-SO4 (k = 30 s(-1)) are observed at pH 6.5, independent of entering anion concentration and identity. Anion lability and influence on the iron affinity and reduction potential for FeFbpA-X support the hypothesis that synergistic anion exchange may be an important regulator in iron delivery to the cytosol. This structural and thermodynamic analysis of anion binding in FeFbpA-X provides additional insight into anion promiscuity and importance. 相似文献
108.
Gayathri S Lakshminarayanan R Weaver JC Morse DE Kini RM Valiyaveettil S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(11):3262-3268
The mechanisms of formation of biogenic magnesium-rich calcite remain an enigma. Here we present ultrastructural and compositional details of ossicles from the seastar Pisaster giganteus (Echinodermata, Asteroidea). Powder X-ray diffraction, infrared spectroscopy and elemental analyses confirm that the ossicles are composed of magnesium-rich calcite, whilst also containing about 0.01 % (w/w) of soluble organic matrix (SOM) as an intracrystalline component. Amino acid analysis and N-terminal sequencing revealed that this mixture of intracrystalline macromolecules consists predominantly of glycine-rich polypeptides. In vitro calcium carbonate precipitation experiments indicate that the SOM accelerates the conversion of amorphous calcium carbonate (ACC) into its final crystalline product. From this observation and from the discovery of ACC in other closely related taxa, it is suggested that substitution of magnesium into the calcite lattice through a transient precursor phase may be a universal phenomenon prevalent across the phylum echinodermata. 相似文献
109.
Bruce E. Dale Justin Weaver F. Michael Byers 《Applied biochemistry and biotechnology》1999,77(1-3):35-45
The ammonia fiber explosion (AFEX) process, previously run only in a batch reactor, has been adapted to run on a twin-screw
extruder. The sugar yield of AFEX material after enzymatic hydrolysis has been increased up to 3.5 times over that of completely
untreated material. The ruminant digestibility of corn fodder has been increased up to 32% (from 54–71%) over completely untreated
material, and 23% (from 63–77%) over material extruded with no ammonia. Extrusion-treated material proved more digestible
by the ruminant at 48 h than material treated in the batch reactor. 相似文献
110.
Guilin Duan Vedene H. Smith Donald F. Weaver 《International journal of quantum chemistry》2000,80(1):44-60
Interactions between aromatic groups and backbone amide groups in protein environments are characterized both through data mining analyses of X‐ray protein structures and through ab initio molecular orbital calculations on a model complex. The data mining analyses of 1029 X‐ray protein structures elucidate the configurational characteristics of the interaction as well as the positions of the interacting moieties involved. On a statistical average, more than seven such interactions occur in a typical protein structure. The configurations of these interactions are restricted with the face‐to‐face orientation as the preferred arrangement. The interaction occurs mainly within a single peptide chain. Both α‐helix and β‐strand secondary structures provide an almost equal number of backbone amides to participate within this interaction. The interaction energy was evaluated with the supermolecular ab initio method at the MP2 level. It is shown that aromatic–amide(backbone) interactions identified in proteins can achieve a stabilization energy of 3.3 kcal/mol. The interaction involves the entirety of the backbone amide rather than only its amine portion. This study concludes that the interaction between aromatic and backbone amide groups is of general significance to protein structure due to its strength and common occurrence. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 80: 44–60, 2000 相似文献