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941.
This paper is concerned with the problem of deciding whether a semialgebraic set S of an algebraic variety X over R is basic. Furthermore, in such a case, we decide what is the sharp number of inequalities defining S. For that, it suffices to desingularize X, as well as the boundary of S, and then ask the same question for the trace of S on its boundary. In this way, after a finite number of blowing-ups, we lower the dimension of the data and by induction we get a finite decision procedure to solve this problem. Decidability of other known criteria is also analyzed. 相似文献
942.
经典分形集测度上估的计算机搜索Ⅰ──对典型例子Sierpinski垫片编码技术的剖析 总被引:2,自引:1,他引:1
分形集的Hausdorff测度是一个非线性科学的理论课题,至今结果甚少,即使对于一些生成很有规则的经典分形集亦是如此间.SISrpinski垫片就是这样一个经典分形集,但因其预分形的图形尚未被研究者解析地认识,所以对其Hausdorff测度的研究进展很慢.文献问猜测1十年之后,这个猜测才被文献问以估值否定.接着,文献同又得到更好的估值出由于采取了对Sierpinski垫片发生规则的编码技术,从而方便地得到H”(S)的一个上方估值函数o(x).上面提到的一系列猜测值或上方估值,依次由0(1/2),o(l/4),以司对给出,而则给出TH”(S)… 相似文献
943.
Robert Samuel Simon 《International Journal of Game Theory》1999,28(3):367-384
Common knowledge can be defined in at least two ways: syntactically as the common knowledge of a set of formulas or semantically,
as the meet of the knowledge partitions of the agents. In the multi-agent S5 logic with either finitely or countably many
agents and primitive propositions, the semantic definition is the finer one. For every subset of formulas that can be held
in common knowledge, there is either only one member or uncountably many members of the meet partition with this subset of
formulas held in common knowledge. If there are at least two agents, there are uncountably many members of the meet partition
where only the tautologies of the multi-agent S5 logic are held in common knowledge. Whether or not a member of the meet partition
is the only one corresponding to a set of formulas held in common knowledge has radical implications for its topological and
combinatorial structure. 相似文献
944.
Homicidal Chauffeur Game with Target Set in the Shape of a Circular Angular Sector: Conditions for Existence of a Closed Barrier 总被引:3,自引:0,他引:3
V. Y. Glizer 《Journal of Optimization Theory and Applications》1999,101(3):581-598
A planar constant-speed pursuit-evasion problem with dynamic model similar to the one of the homicidal chauffeur game and with prescribed angular constraints in the capture criterion is analyzed as a differential game of kind. Because of the angular constraints, the target set of the game has the shape of a circular angular sector. Conditions for the existence of the game barrier (closed) are obtained. Using these conditions, a necessary and sufficient condition for capture of a slower evader from any initial state of the game is established. This condition is represented by an expression for the minimal nondimensional capture radius, normalized by the pursuer minimal turning radius, which guarantees capture of all slower evaders. This minimal capture radius depends on the angular constraints. Capture from any initial state implies that the barrier of the game does not exist and vice versa. In this game, two types of barrier are derived, with termination at either points of smoothness or points of nonsmoothness (corner points) of the boundary of the target set. The results are illustrated by numerical examples. 相似文献
945.
In this paper, we develop second-order necessary and sufficient optimality conditions for multiobjective optimization problems with both equality and inequality constraints. First, we generalize the Lin fundamental theorem (Ref. 1) to second-order tangent sets; then, based on the above generalized theorem, we derive second-order necessary and sufficient conditions for efficiency. 相似文献
946.
Toshikatsu Koga Hiroshi Tatewaki Hisashi Matsuyama Yasuharu Satoh 《Theoretical chemistry accounts》1999,102(1-6):105-111
Six minimal basis sets of contracted Gaussian-type functions (GTFs) are developed for the third-row atoms K through Kr. The
smallest and largest sets for transition metal atoms are (3333/33/3) and (8433/84/8), respectively, where a slash distinguishes
the s, p, and d symmetries and single-digit figures in the parentheses denote the numbers of primitive GTFs. The two largest sets, (7433/74/7)
and (8433/84/8), surpass the (62111111/33111/311) set of Schaefer et al. in the associated total energies. Our (8433/84/8)
set is also superior to their (842111/631/411) set. The quality of the present basis sets is tested by self-consistent field
(SCF) and configuration interaction (CI) calculations on the Cu2 molecule. As the accuracy of the basis set increases, SCF calculations show a decrease in the dissociation energy and an
increase in the equilibrium internuclear distance. The same tendencies are found in the results of CI calculations with and
without a Davidson correction. All the present basis sets are freely available at the internet address: http://202.35.198.41/∼htatewak/.
Received: 17 June 1998 / Accepted: 4 August 1998 / Published online: 23 November 1998 相似文献
947.
Anthony Carbery Michael Christ James Wright 《Journal of the American Mathematical Society》1999,12(4):981-1015
Van der Corput's lemma gives an upper bound for one-dimensional oscillatory integrals that depends only on a lower bound for some derivative of the phase, not on any upper bound of any sort. We establish generalizations to higher dimensions, in which the only hypothesis is that a partial derivative of the phase is assumed bounded below by a positive constant. Analogous upper bounds for measures of sublevel sets are also obtained. The analysis, particularly for the sublevel set estimates, has a more combinatorial flavour than in the one-dimensional case.
948.
赋范线性空间中的最佳共逼近的一点注记 总被引:2,自引:1,他引:1
本文用例子表明最佳共逼近与最佳逼近间有着区别.指出强共逼近的元未必是唯一的;凸集未必是共太阳集和强共Kolmogorov集;而在最佳逼近论中它们的相应回答均是肯定的. 相似文献
949.
V. A. Makara N. S. Bolotovets O. V. Vakulenko A. I. Datsenko S. N. Naumenko T. V. Ostapchuk O. V. Rudenko 《Journal of Applied Spectroscopy》1999,66(3):458-463
The effect of chemical treatment of porous silicon samples by HF on its photoluminescence and its evolution with time in sample
aging in air is investigated. It is shown that the effect of HF on the luminescence parameters depends on the duration of
the treatment and the initial photoluminescence intensity of the sample. It is found that chemical etching in HF accelerates
the growth of the total luminescence intensity in aging of the sample in air. The evolution of the photoluminescence spectrum
in aging of the sample in air after chemical etching can be explained within the framework of the quantum-size model of the
luminescence of porous silicon.
Presented at the Fall Meeting of the Material Research Society, December 1–5, 1997, Boston, USA
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 3, pp. 423–427, May–June, 1999. 相似文献
950.