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1.
Kondakov N. N. Mel´nikova T. M. Chekryzhova T. V. Mel´nikova M. V. Zinin A. I. Torgov V. I. Chizhov A. O. Kononov L. O. 《Russian Chemical Bulletin》2015,64(5):1142-1148
Russian Chemical Bulletin - Terminal disaccharide fragment of phenolic glycolipid from Mycobacterium leprae (PGL-I) was synthesized as a glycoside with 4-(2-aminoethoxy)phenyl aglycon. The obtained... 相似文献
2.
Institut des Hautes Études Scientifiques 《Publications Mathématiques de L'IHéS》2004,100(1):271-282
Sans résumé 相似文献
3.
Herve Loïc 《Integral Equations and Operator Theory》1998,32(2):199-215
LetX be a locally compact space, andT, a quasi-compact positive operator onC
0(X), with positive spectral radius,r. Then the peripheral spectrum ofT is a finite set of poles containingr, and the residue of the resolvent ofT at each peripheral pole is of finite rank. Using the concept of closed absorbing set, we develop an iterative process that gives the order,p, ofr, some special bases of the algebraic eigenspaces ker(T-r)
p
and ker(T
*-r)
p
, and finally the dimension of the algebraic eigenspace associated to each peripheral pole. 相似文献
4.
Jean Ravez Re´gnault Von Der Mu¨hll Paul Hagenmuller 《Journal of solid state chemistry》1975,14(1):20-24
Au sein d'un re´seau de type BaFeF5 des chai?nes d'octae`dres fluore´sa`sommets communs peuvent disparai?tre en donnant naissance a des canaux dont l'occupation partielle ou totale par des files de cations Sr2+ et de couples d'anions F?, conduit respectivement aux phases Sr3(FeF6)2 ou Sr5T3F19 (T = Cr, Co, Ga). Une discussion cristallochimique permet d'expliquer l'existence d'un domaine de solutions solides au sein du diagramme ternaire SrF2BaF2FeF3. 相似文献
5.
6.
The three main desialylated variants (F1, S and A) of human alpha 1-acid glycoprotein (AAG), a serum acute-phase reactant, were analysed by high-performance anion-exchange chromatography in order to determine their optimum separation conditions. The analysis consisted of three steps, as follows: (1) A desialylated commercial AAG was separated into one "fast"- and one "slow"-migrating fraction by preparative isoelectrofocusing. The "fast" and "slow" fractions were shown to contain the F1 variant and a mixture of the S and A variants, respectively. (2) The pH titration curves of these two fractions were then measured by strong anion-exchange chromatography with several buffer systems of increasing pH. From the data obtained, it was not possible to select the optimum conditions to separate the "fast" variant F1 from the "slow" variants A and S. However, the S and A variants were shown to ionize very differently. (3) The specific fractionation of the S and A variants was therefore carried out by anion-exchange chromatography under operating conditions based on the data obtained from the study of their pH titration curves. This was performed both with the "slow"-migrating fraction obtained by preparative isoelectrofocusing of commercial AAG and with an AAG (containing only variants S and A) purified from an individual serum on immobilized Cibacron Blue F3G-A. Identification of the fractionated proteins was achieved by analytical isoelectrofocusing. 相似文献
7.
8.
Thomas Andre´s Wolcan Ezequiel Fe´liz Mario R. Capparelli Alberto L. 《Transition Metal Chemistry》1997,22(6):541-544
The kinetics of the complexation of NiII by pteroylglutamic acid have been studied in the 545 ∘C range, the ionic strength
(0.6 M) being regulated with KNO3, in the 5.5–7.0pH range, using the stopped-flow method. Under the experimental conditions
two processes were observed. The faster process was detected in the millisecond range and is associated with the reaction
between NiII and the ligand. The slower is observed within a few seconds. Complementary equilibrium studies were made at 25
∘C. The results are consistent with the formation of a 1:1 complex between the reactants, and a mechanism is proposed to account
for the observed behaviour. Equilibrium constants for the NiII plus pteroylglutamic acid system, as well as activation parameters,
are reported.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
9.
The two diastereoisomeric pairs of α-phenyl α-methyl and β-phenyl β-methyl ferrocenyl cyclohexenones were prepared in optically active series from a single chiral precursor, (+) phenyl-2 methyl-2 succinic acid, the S configuration of which was established by chemical correlation. The chiral precursor and the four ketones were shown to be optically pure by isotopic dilution with tritium labelled racemates. We infer that diastereogenic cyclisation of the γ-ferrocenyl butyric acids into ketones is under pure kinetic control and leads mainly to the isomer bearing the bulkiest group in an endo position. 相似文献
10.
Liane M. Moreau Alexandre Herve Mark D. Straub Dominic R. Russo Rebecca J. Abergel Selim Alayoglu John Arnold Augustin Braun Gauthier J. P. Deblonde Yangdongling Liu Trevor D. Lohrey Daniel T. Olive Yusen Qiao Julian A. Rees David K. Shuh Simon J. Teat Corwin H. Booth Stefan G. Minasian 《Chemical science》2020,11(18):4648
We report the structural properties of ultra-small ThO2 and UO2 nanoparticles (NPs), which were synthesized without strong binding surface ligands by employing a covalent organic framework (COF-5) as an inert template. The resultant NPs were used to observe how structural properties are affected by decreasing grain size within bulk actinide oxides, which has implications for understanding the behavior of nuclear fuel materials. Through a comprehensive characterization strategy, we gain insight regarding how structure at the NP surface differs from the interior. Characterization using electron microscopy and small-angle X-ray scattering indicates that growth of the ThO2 and UO2 NPs was confined by the pores of the COF template, resulting in sub-3 nm particles. X-ray absorption fine structure spectroscopy results indicate that the NPs are best described as ThO2 and UO2 materials with unpassivated surfaces. The surface layers of these particles compensate for high surface energy by exhibiting a broader distribution of Th–O and U–O bond distances despite retaining average bond lengths that are characteristic of bulk ThO2 and UO2. The combined synthesis and physical characterization efforts provide a detailed picture of actinide oxide structure at the nanoscale, which remains highly underexplored compared to transition metal counterparts.ThO2 and UO2 nanoparticles synthesized using a COF-5 template exhibit unpassivated surfaces and provide insight into nanoscale properties of actinides. 相似文献