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171.
172.
Christopher Barner‐Kowollik Sébastien Perrier 《Journal of polymer science. Part A, Polymer chemistry》2008,46(17):5715-5723
We examine the reversible addition fragmentation chain transfer (RAFT) process with regard to its potential and limits in future industrial applications (including those conducted on a larger scale) as well as materials science. The outlook for the RAFT process is bright: Its unrivaled inherent process simplicity coupled with a wide tolerance to monomer classes and functionalities makes it a prime candidate for the use in large reactors. At the same time, it allows for ready access to complex macromolecular architectures of variable shape and size. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5715–5723, 2008 相似文献
173.
Three samples of pelletized zeolite Na-13X from different industrial suppliers were hydrothermally treated in an open system
for up to 3500 adsorption/desorption cycles. Before and after this aging procedure, the samples have been characterized by
water uptake measurements, X-ray powder diffraction (XRD), Hg-porosimetry, N2- and CO2-adsorption and small-angle X-ray scattering (SAXS). Large differences in the degree of degradation were found between the
different materials: The adsorbent with the best performance maintains 79% of its original water uptake capacity after 3500
cycles, whereas this value is reduced to 65% after only 1600 cycles in case of the most unstable sample. For all materials,
the residual water adsorption capacity was found to be higher than it was to expect from XRD data. In addition to structural
changes of the zeolite cages, Hg-porosimetry and SAXS reveal a modification of the sample morphology in the meso- and macropore
range. CO2 adsorption experiments evidence that as a result of the aging process mass transfer kinetics are slowed down significantly.
These findings indicate that the influence of hydrothermal treatment on the water adsorption performance not only depends
on the crystal structure of the actual adsorbent, but is indeed a result of a complex interplay with the system of larger
pores. The crucial role of the binder material is underlined by the fact that the most stable sample was produced by a so-called
binder-free method. 相似文献
174.
Krueger A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(5):1382-1390
Nanoscale diamond particles have become an interesting material. Due to their inertness, small size and surface structure, they are well-suited for biological applications, such as labelling and drug delivery. Here we discuss the surface structure and functionalisation of diamond nanoparticles. Non-covalent as well as covalent grafting of bioactive moieties is possible, and first applications of fluorescent diamond nanoparticles are described. 相似文献
175.
Lidija Fras Zemljič Per Stenius Janne Laine Karin Stana-Kleinschek 《Cellulose (London, England)》2008,15(2):315-321
Adsorption of carboxymethyl cellulose (CMC) as a method to introduce charged (ionizable) groups onto cellulose cotton fibre
surfaces was investigated. The method was based on application of a previously published method used for wood fibres. The
amount of adsorbed ionizable groups was determined indirectly by analysis of CMC in solution by the phenol–sulphuric acid
method and directly by conductometric titration of the fibres. Results from the two methods correlated well. The molecular
weight and purity of the CMC had an influence on its adsorption onto cotton; high molecular weight CMC was preferentially
adsorbed. The adsorbed charge correlated linearly with the amount of CMC adsorbed. The total charge of the cotton fibres could
be increased by more than 50% by adsorption of CMC. It is expected that this modification procedure can be used in a wide
spectrum of practical applications.
Lidija Fras Zemljič and Karin Stana-Kleinschek are the members of the European Polysaccharide Network of Excellence (EPNOE). 相似文献
176.
This review reports the reactivity of indolizines. The reactions section covers, in general, electrophilic, oxidation, reduction, addition, cycloaddition, condensation, and Mannich and multicomponent reactions. The synthesis of bis-indolizines and cyclazines are reported. The reaction mechanisms are discussed. 相似文献
177.
The chemistry of 1,2,5-triazepines and related compounds is reported. The investigated heterocycles are monocyclic and fused 1,2,5-triazepines. The different sections cover the synthesis and reactions of monocyclic and fused heterocycles incorporating 1,2,5-triazepine ring systems. This review also covers modifications of the 1,2,5-triazepines into many useful ring systems using a host of reagents and other multistep transformations. The biological evaluation of the target compounds is described, as well as the synthetic applications. The reaction mechanisms are discussed. 相似文献
178.
Rafael Luís 《Journal of Difference Equations and Applications》2016,22(10):1389-1403
This paper is an extension of an earlier paper that dealt with global dynamics in autonomous triangular maps. In the current paper, we extend the results on global dynamics of autonomous triangular maps to periodic non-autonomous triangular maps. We show that, under certain conditions, the orbit of every point in a periodic non-autonomous triangular map converges to a fixed point (respectively, periodic orbit of period p) if and only if there is no periodic orbit of prime period two (respectively, periodic orbits of prime period greater than p). 相似文献
179.
Electrospinning is a versatile technique providing highly tunable nanofibrous nonwovens. Many biomedical applications have been developed for nanofibers, among which the production of antimicrobial mats stands out. The production of scaffolds for tissue engineering, fibers for controlled drug release, or active wound dressings are active fields of research exploiting the possibilities offered by electrospun materials. The fabrication of materials for active food packaging or membranes for environmental applications is also reviewed. We attempted to give an overview of the most recent literature related with applications in which nanofibers get in contact with living cells and develop a nano-bio interface. 相似文献
180.
Nancy Sarahy Gaytn-Barrientos David Morales-Morales Dea Herrera-Ruiz Reyna Reyes-Martínez Jesús Rivera-Islas 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(4):280-284
Dapsone, formerly used to treat leprosy, now has wider therapeutic applications. As is the case for many therapeutic agents, low aqueous solubility and high toxicity are the main problems associated with its use. Derivatization of its amino groups has been widely explored but shows no significant therapeutic improvements. Cocrystals have been prepared to understand not only its structural properties, but also its solubility and dissolution rate. Few salts of dapsone have been described. The title salts, C12H13N2O2S+·C6H5O3S−·H2O and C12H13N2O2S+·CH3SO3−·H2O, crystallize as hydrates and both compounds exhibit the same space group (monoclinic, P21/n). The asymmetric unit of each salt consists of a 4‐[(4‐aminophenyl)sulfonyl]anilinium monocation, the corresponding sulfonate anion and a water molecule. The cation, anion and water molecule form hydrogen‐bonded networks through N—H…O=S, N—H…Owater and Owater—H…O=S hydrogen bonds. For both salts, the water molecules interact with one sulfonate anion and two anilinium cations. The benzenesulfonate salt forms a two‐dimensional network, while the hydrogen bonding within the methanesulfonate salt results in a three‐dimensional network. 相似文献