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1.
2.
Nonlocal vertex algebras generated by formal vertex operators 总被引:2,自引:0,他引:2
Haisheng Li 《Selecta Mathematica, New Series》2005,11(3-4):349-397
This is the first paper in a series to study vertex algebra-like objects arising from infinite-dimensional quantum groups
(quantum affine algebras and Yangians). In this paper we lay the foundations for this study. For any vector space W, we study what we call quasi compatible subsets of Hom (W,W((x))) and we prove that any maximal quasi compatible subspace has a natural nonlocal (namely noncommutative) vertex algebra
structure with W as a natural faithful quasi module in a certain sense, and that any quasi compatible subset generates a nonlocal vertex algebra
with W as a quasi module. In particular, taking W to be a highest weight module for a quantum affine algebra we obtain a nonlocal vertex algebra with W as a quasi module. We also formulate and study a notion of quantum vertex algebra and we give general constructions of nonlocal
vertex algebras, quantum vertex algebras and their modules. 相似文献
3.
从江浙蝮蛇毒腺中抽提总RNA,RT-PCR进行体外扩增,获得江浙蝮蛇蛇毒蛋白C激活因子基因,克隆至pGEX-5X-3载体中,对3个重组克隆分别作DNA全序列分析,通过遗传密码推导出相应的氨基酸序列,与其它已知的丝氨酸复白酶蛇毒蛋白的氨基酸作比较,其中许多上氨基酸有很强的同源性,该基因的成功克隆,不仅推导出江浙蝮蛇蛇毒蛋白C激活因子的蛋白质序列,也为进一步开展江浙蝮蛇蛇毒蛋白C激活因子蛋白质工程的研究工作打下良好的基础。 相似文献
4.
Denis V. Osin 《Archiv der Mathematik》2007,88(5):403-412
The aim of this paper is to show that free Burnside groups of sufficiently large odd exponent are non-amenable in a certain
strong sense. More precisely their left regular representations are isolated from the trivial representation uniformly on
finite generating sets. It follows that free Burnside groups are of uniform exponential growth. This answers a question of
de la Harpe.
This work has been partially supported by the NSF grant DMS-0605093 and by the RFBR Grant # 05-01-00892.
Received: 25 April 2006 相似文献
5.
ZverovichIE ZverovichOI 《高校应用数学学报(英文版)》2004,19(2):125-132
Two new hereditary classes of P5-free graphs where the stability number can be found in polynomial time are proposed. They generalize several known results. 相似文献
6.
7.
On the 2-rainbow domination in graphs 总被引:2,自引:0,他引:2
The concept of 2-rainbow domination of a graph G coincides with the ordinary domination of the prism G□K2. In this paper, we show that the problem of deciding if a graph has a 2-rainbow dominating function of a given weight is NP-complete even when restricted to bipartite graphs or chordal graphs. Exact values of 2-rainbow domination numbers of several classes of graphs are found, and it is shown that for the generalized Petersen graphs GP(n,k) this number is between ⌈4n/5⌉ and n with both bounds being sharp. 相似文献
8.
K. Kosmidou F. Pasiouras M. Doumpos C. Zopounidis 《Central European Journal of Operations Research》2006,14(1):25-44
Further consolidation takes place not only among UK banks but also across borders, since some banks see size as a key factor
in remaining competitive in international markets. Therefore, it is interesting to investigate the effectiveness and performance
of UK banks. Based on their assets, banks are distinguished into small and large ones and a classification of UK banks in
a multivariate environment for the period 1998–2002 takes place. The PAIRCLAS multicriteria methodology is employed to investigate
the performance of UK small and large banks over multiple criteria, such as asset quality, capital adequacy, liquidity and
efficiency/profitability. A comparison with discriminant analysis (DA) and logistic regression (LR) facilitates the investigation
of the relative performance of PAIRCLAS against them. The results of the study determine the key factors that specify the
classification of a bank as small or large and provide us with the responsible banking decision makers for future readjustments. 相似文献
9.
Cytosine deaminase gene ofEscherichia coli strain H-30 was cloned, and its initiation codon of ‘GTG’ was mutated to ‘ATG’ by PCR. Prokaryotic recombinant expression
vector pBV220-CD was constructed. Clone with high enzyme activity were selected by detecting their specific activity of cytosine
deaminase. 5-FC(5-FC, 5-fluorocytosine) could induce the lethal toxicity to cells containing active CD gene. DNA sequence
analysis indicated that there were 16 altered bases and 5 of them resulted in the alteration of amino acids in predicted peptide
by comparing DNA sequence of the clone H-30-CD-11 with high enzyme activity with CD gene reported in Gene Bank. 相似文献
10.
John J. Fenske Andrew Hashimoto Michael H. Penner 《Applied biochemistry and biotechnology》1998,73(2-3):145-157
The relative toxicity of the combined nonxylose components in prehydrolysates derived from three different lignocellulosic
biomass feedstocks was determined. One woody (poplar) and two herbaceous (corn stover and switchgrass) feedstocks were dilute-acid
pretreated under temperature and acid conditions chosen to optimize xylose recovery in the liquid prehydrolysate; xylose yields
averaged 96,89,and 87% of theoretical for switchgrass,corn stover,and poplar,respectively. Prehydrolysates from each feedstock
were neutralized,adjusted to equivalent xylose concentrations,and bioassayed for toxicity,using a standardized fermentation
protocol withPichia stipitis NRRL 11545. Full time-courses for ethanol production (30-60 h) clearly illustrate the distinct inhibitory effects of prehydrolysates
from different feedstocks. The relative toxicity of the prehydrolysates,ranked in order of decreasing toxicity,is poplar-derived
prehydrolysates > switchgrass-derived prehydrolysates > corn stover-derived prehydrolysates. The inhibition of ethanol production
appeared to be the result of a general slowdown of yeast metabolism,rather than the result of the production of alternative,
nonethanol end products. Ethanol yields averaged 74,83,and 88% of control values for poplar,switchgrass,and corn stover prehydrolysates,
respectively. Volumetric ethanol productivities (g ethanol L/h) averaged 32,70,and 102% of control values for poplar,switchgrass,and
corn stover prehydrolysates,respectively. Ethanol productivities correlated closely with acetate concentrations in the prehydrolysates;
however, regression lines correlating acetate concentrations and ethanol productivities were found to be feedstock-dependent.
Oregon State University Agricultural Experiment Station Technical Publication Number 11114 相似文献