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排序方式: 共有266条查询结果,搜索用时 140 毫秒
111.
International Journal of Theoretical Physics - In this paper, we discuss partial steerability and nonlocality of multipartite quantum states. For a state ρ of an n-partite system... 相似文献
112.
Mohamed Aklalouch José Manuel Amarilla Rosa M. Rojas Ismael Saadoune José María Rojo 《Electrochemistry communications》2010,12(4):548-552
Single phase LiCr0.2Ni0.4Mn1.4O4 spinel has been synthesized by a simple sucrose assisted combustion method that yields highly crystalline homogeneous sub-micrometric samples (650 nm). The LiCr0.2Ni0.4Mn1.4O4, with capacity retention of 92% at 60 C discharge rate, shows the highest rate capability among LiNi0.5Mn1.5O4-type cathodes. It delivers very high-power (34.8 kW kg?1 at 60 C). Studies developed at 55 °C demonstrate that LiCr0.2Ni0.4Mn1.4O4 retains huge rate capability and large cycleability at high temperature. 相似文献
113.
Juan Daniel Rivaldi Boutros Fouad Sarrouh Ricardo de Freitas Branco Ismael Maciel de Mancilha Silvio Silvério da Silva 《Applied biochemistry and biotechnology》2012,167(7):2054-2067
Ten yeast strains were evaluated concerning their capabilities to assimilate biodiesel-derived glycerol in batch cultivation. The influence of glycerol concentration, temperature, pH and yeast extract concentration on biomass production was studied for the yeast selected. Further, the effect of agitation on glycerol utilization by the yeast Hansenula anomala was also studied. The yeast H. anomala CCT 2648 showed the highest biomass yield (0.30?g?g?1) and productivity (0.19?g?L?1?h?1). Citric acid, succinic acid, acetic acid and ethanol were found as the main metabolites produced. The increase of yeast extract concentration from 1 to 3?g?L?1 resulted in high biomass production. The highest biomass concentration (21?g?L?1), yield (0.45?g?g?1) and productivity (0.31?g?L?1?h?1), as well as ribonucleotide production (13.13?mg?g?1), were observed at 700?rpm and 0.5?vvm. These results demonstrated that glycerol from biodiesel production process showed to be a feasible substrate for producing biomass and ribonucleotides by yeast species. 相似文献
114.
The aim of this paper is to study the variety of distributive nearlattices with greatest element. We will define the class of N-spaces as sober-like topological spaces with a basis of open, compact, and dually compact subsets satisfying an additional condition. We will show that the category of distributive nearlattices with greatest element whose morphisms are semi-homomorphisms is dually equivalent to the category of N-spaces with certain relations, called N-relations. In particular, we give a duality for the category of distributive nearlattices with homomorphisms. Finally, we apply these results to characterize topologically the one-to-one and onto homomorphisms, the subalgebras, and the lattice of the congruences of a distributive nearlattice. 相似文献
115.
A set S of vertices of a graph is a defensive k-alliance if every vertex ${v\in S}$ has at least k more neighbors in S than it has outside of S. Analogously, a set S is an offensive k-alliance if every vertex in the neighborhood of S has at least k more neighbors in S than it has outside of S. Also, a powerful k-alliance is a set S of vertices of the graph, which is both defensive k-alliance and offensive (k?+?2)-alliance. A powerful k-alliance is called global if it is a dominating set. In this paper we show that for k?≥ 0, no graph is partitionable into global powerful k-alliances and, for k?≤ ?1, we obtain upper bounds on the maximum number of sets belonging to a partition of a graph into global powerful k-alliances. In addition, we study the close relationships that exist between partitions of a Cartesian product graph, Γ1?× Γ2, into (global) powerful (k 1?+?k 2)-alliances and partitions of Γ i into (global) powerful k i -alliances, ${i\in \{1,2\}}$ . 相似文献
116.
The domination number γ(G) of a connected graph G of order n is bounded below by(n+2-e(G))/ 3 , where (G) denotes the maximum number of leaves in any spanning tree of G. We show that (n+2-e(G))/ 3 = γ(G) if and only if there exists a tree T ∈ T ( G) ∩ R such that n1(T ) = e(G), where n1(T ) denotes the number of leaves of T1, R denotes the family of all trees in which the distance between any two distinct leaves is congruent to 2 modulo 3, and T (G) denotes the set composed by the spanning trees of G. As a consequence of the study, we show that if (n+2-e(G))/ 3 = γ(G), then there exists a minimum dominating set in G whose induced subgraph is an independent set. Finally, we characterize all unicyclic graphs G for which equality (n+2-e(G))/ 3= γ(G) holds and we show that the length of the unique cycle of any unicyclic graph G with (n+2-e(G))/ 3= γ(G) belongs to {4} ∪ {3 , 6, 9, . . . }. 相似文献
117.
Accurate localization of brain activity using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) has been challenged because of the large BOLD signal within distal veins. Arterial spin labeling (ASL) techniques offer greater sensitivity to the microvasculature but possess low temporal resolution and limited brain coverage. In this study, we show that the physiological origins of BOLD and ASL depend on whether percent change or statistical significance is being considered. For BOLD and ASL fMRI data collected during a simple unilateral hand movement task, we found that in the area of the contralateral motor cortex the centre of gravity (CoG) of the intersubject coefficient of variation (CV) of BOLD fMRI was near the brain surface for percent change in signal, whereas the CoG of the intersubject CV for Z-score was in close proximity of sites of brain activity for both BOLD and ASL. These findings suggest that intersubject variability of BOLD percent change is vascular in origin, whereas the origin of inter-subject variability of Z-score is neuronal for both BOLD and ASL. For longer duration tasks (12 s or greater), however, there was a significant correlation between BOLD and ASL percent change, which was not evident for short duration tasks (6 s). These findings suggest that analyses directly comparing percent change in BOLD signal between pre-defined regions of interest using short duration stimuli, as for example in event-related designs, may be heavily weighted by large-vessel responses rather than neuronal responses. 相似文献
118.
Gómez-Segura J Díez-Pérez I Ishikawa N Nakano M Veciana J Ruiz-Molina D 《Chemical communications (Cambridge, England)》2006,(27):2866-2868
The presence of alkoxyl chains on the single-molecule magnet [(Pc')2Tb(III)] and its planar character favour its 2-D self-assembly on HOPG with the molecular plane parallel to the graphite surface, enabling us to control and/or predict the orientation of the preferential magnetization axis on the surface. 相似文献
119.
120.
Tejero I Garcia-Viloca M Gonzalez-Lafont A Lluch JM York DM 《The journal of physical chemistry. B》2006,110(48):24708-24719
A fully microscopical simulation of the rate-limiting hydrogen abstraction catalyzed by soybean lipoxygenase-1 (SLO-1) has been carried out. This enzyme exhibits the largest, and weakly temperature dependent, experimental H/D kinetic isotope effect (KIE) reported for a biological system. The theoretical model used here includes the complete enzyme with a solvation shell of water molecules, the Fe(III)-OH- cofactor, and the linoleic acid substrate. We have used a hybrid QM(PM3/d-SRP)/MM method to describe the potential energy surface of the whole system, and the ensemble-averaged variational transition-state theory with multidimensional tunneling (EA-VTST/MT) to calculate the rate constant and the primary KIE. The computational results show that the compression of the wild-type active site enzyme results in the huge contribution of tunneling (99%) to the rate of the hydrogen abstraction. Importantly, the active site becomes more flexible in the Ile553Ala mutant reactant complex simulation (for which a markedly temperature dependent KIE has been experimentally determined), thus justifying the proposed key role of the gating promoting mode in the reaction catalyzed by SLO-1. Finally, the results indicate that the calculated KIE for the wild-type enzyme has an important dependence on the barrier width. 相似文献