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排序方式: 共有321条查询结果,搜索用时 15 毫秒
71.
72.
H. F. Wiebe D. R. Harper L. Holborn F. Henning H. L. Callendar E. H. Griffiths C. W. Waidner G. K. Burgess A. L. Day R. B. Sosman L. H. Adams J. Johnston G. Moeller F. Hoffmann W. Meissner J. G. L. Stern Th. W. Richards R. C. Wells W. Meissner Th. W. Richards F. G. Jackson C. Kellner H. F. Wiebe P. Hebe P. Hebe M. Freund 《Analytical and bioanalytical chemistry》1913,52(5):304-308
73.
Xue Kui Ji Stephen B. Colbran Donald C. Craig Khaled M. Edbey Jason B. Harper Gary D. Willett 《Tetrahedron》2005,61(45):10705-10712
Two new meso-indanyl-substituted calix[4]pyrrole receptors, 2 and 3, have been synthesized. A range of calix[4]pyrrole host-neutral molecule complexes crystallise from solutions of 2 in a variety of solvents and the structures of four have been elucidated by X-ray crystallography. The F− and Cl− anion affinities of 2 have been measured in acetonitrile, and are significantly different from the corresponding affinities of the prototypical calix[4]pyrrole, the octamethyl-derivative, 1. ESI-FTICR-MS has been used to determine the relative F− and Cl− anion affinities of receptors 1 and 2 in methanol-acetonitrile solution. Deprotonation of 1 and 2 by fluoride is observed (under the conditions of the MS experiment). 相似文献
74.
James K. Harper Atta M. Arif J. Y. Li Gary Strobel David M. Grant 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e570-e571
The fungal metabolite terrein (alternative name: trans‐2,3‐dihydroxy‐4‐propenylcyclopent‐4‐enone), C8H10O3, forms monoclinic (P21) crystals. The molecules form hydrogen‐bonded chains, with O?O distances of 2.7115 (16) and 2.8155 (15) Å. 相似文献
75.
S C Brailsford T B Bolt G Bucci T M Chaussalet N A Connell P R Harper J H Klein M Pitt M Taylor 《The Journal of the Operational Research Society》2013,64(2):157-168
This paper addresses a key issue in the health OR literature, namely the apparent failure of OR modelling to become embedded and widely implemented within healthcare organisations. The research presented here is a case study to evaluate the adoption of one particular simulation modelling tool, Scenario Generator (S:G), which was developed by the SIMUL8 Corporation in a PPI partnership with the UK's National Health Service (NHS) Institute for Innovation and Improvement. The study involved semi-structured interviews with employees of 28 Primary Care Trusts who had all been engaged in some way with the initiative, with participants classified as ‘Not Started’, ‘Given Up’ and ‘Actively Using’. This paper presents a brief summary of barriers and facilitators to the successful use of the S:G software, but its main purpose is to focus more broadly on factors influencing the successful adoption of simulation tools in general within healthcare organisations. The insights gained in this study are relevant to improving the uptake of OR modelling in general within the NHS. 相似文献
76.
77.
I. T. Vieira R. C. H. Cheng P. R. Harper V. de Senna 《Annals of Operations Research》2010,178(1):173-200
It has long been recognised that the structure of social networks plays an important role in the dynamics of disease propagation.
The spread of HIV results from a complex network of social interactions and other factors related to culture, sexual behaviour,
demography, geography and disease characteristics, as well as the availability, accessibility and delivery of healthcare.
The small world phenomenon has recently been used for representing social network interactions. It states that, given some
random connections, the degrees of separation between any two individuals within a population can be very small. In this paper
we present a discrete event simulation model which uses a variant of the small world network model to represent social interactions
and the sexual transmission of HIV within a population. We use the model to demonstrate the importance of the choice of topology
and initial distribution of infection, and capture the direct and non-linear relationship between the probability of a casual
partnership (small world randomness parameter) and the spread of HIV. Finally, we illustrate the use of our model for the
evaluation of interventions such as the promotion of safer sex and introduction of a vaccine. 相似文献
78.
Lu Z Van Wagoner RM Harper MK Hooper JN Ireland CM 《Natural product communications》2010,5(10):1571-1574
Two ring-A-aromatized bile acids, 1 and 2, were isolated from the sponge Sollasella moretonensis, collected from the seabed of northern Queensland. Structures were assigned on the basis of extensive 1D and 2D NMR studies, as well as analysis by HRESIMS. Compound 2 has previously been produced synthetically, though this marks its first isolation from a natural source. 相似文献
79.
Brett Harper Mahsan Miladi Touradj Solouki 《Journal of the American Society for Mass Spectrometry》2014,25(10):1716-1729
It is shown that y-type ions, after losing C-terminal H2O or NH3, can lose an internal backbone carbonyl (CO) from different peptide positions and yield structurally different product fragment ions upon collision-induced dissociation (CID). Such CO losses from internal peptide backbones of y-fragment ions are not unique to a single peptide and were observed in four of five model peptides studied herein. Experimental details on examples of CO losses from y-type fragment ions for an isotopically labeled AAAAHAA-NH2 heptapeptide and des-acetylated-α-melanocyte-stimulating hormone (dα-MSH) (SYSMEHFRWGKPV-NH2) are reported. Results from isotope labeling, tandem mass spectrometry (MSn), and ion mobility-mass spectrometry (IM-MS) confirm that CO losses from different amino acids of m/z-isolated y-type ions yield structurally different ions. It is shown that losses of internal backbone carbonyls (as CID products of m/z-isolated y-type ions) are among intermediate steps towards formation of rearranged or permutated product fragment ions. Possible mechanisms for generation of the observed sequence-scrambled a-“like” ions, as intermediates in sequence-scrambling pathways of y-type ions, are proposed and discussed. ? 相似文献
80.
Proteins are a diverse class of molecules that can act as catalysts and structural components. Interest in their interactions with ionic solvents is on the increase due to the tuneable possibilities for non-aqueous biocatalysis, improved thermostability of biomaterials, and possible roles in medicine, such as drug delivery and use as cell-growth scaffolds. We summarise here the recent examples of these exciting new aspects of protein-ionic solvent interactions, highlighting future directions. 相似文献