全文获取类型
收费全文 | 5572篇 |
免费 | 599篇 |
国内免费 | 573篇 |
专业分类
化学 | 1379篇 |
晶体学 | 8篇 |
力学 | 432篇 |
综合类 | 182篇 |
数学 | 3099篇 |
物理学 | 1644篇 |
出版年
2024年 | 12篇 |
2023年 | 55篇 |
2022年 | 112篇 |
2021年 | 159篇 |
2020年 | 130篇 |
2019年 | 150篇 |
2018年 | 130篇 |
2017年 | 191篇 |
2016年 | 247篇 |
2015年 | 189篇 |
2014年 | 315篇 |
2013年 | 387篇 |
2012年 | 344篇 |
2011年 | 320篇 |
2010年 | 254篇 |
2009年 | 375篇 |
2008年 | 389篇 |
2007年 | 364篇 |
2006年 | 362篇 |
2005年 | 306篇 |
2004年 | 240篇 |
2003年 | 226篇 |
2002年 | 210篇 |
2001年 | 172篇 |
2000年 | 182篇 |
1999年 | 134篇 |
1998年 | 131篇 |
1997年 | 120篇 |
1996年 | 92篇 |
1995年 | 57篇 |
1994年 | 79篇 |
1993年 | 37篇 |
1992年 | 32篇 |
1991年 | 30篇 |
1990年 | 24篇 |
1989年 | 27篇 |
1988年 | 21篇 |
1987年 | 12篇 |
1986年 | 13篇 |
1985年 | 26篇 |
1984年 | 15篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 15篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1975年 | 3篇 |
排序方式: 共有6744条查询结果,搜索用时 15 毫秒
161.
《Optimization》2012,61(9):1075-1086
In this article, we establish some relationships between a solution of generalized vector variational-like inequalities and an efficient solution or a weakly efficient solution to the nonsmooth vector optimization problem under the assumptions of pseudoinvexity or invariant pseudomonotonicity. Our results extend and improve the corresponding results in the literature. 相似文献
162.
《Optimization》2012,61(3):435-448
We give a definition of gamma-convergence (epi-convergence) for the case of vector valued sequences of functions and prove some related properties analogous to the scalar case. We obtain one of the main variational theorems about convergence of ?-minimizers. In the convex case, we consider also variable domains and obtain stability of efficient points and minimal values. 相似文献
163.
We formulate a sufficient condition for the existence of a consistent price system (CPS), which is weaker than the conditional full support condition (CFS). We use the new condition to show the existence of CPSs for certain processes that fail to have the CFS property. In particular this condition gives sufficient conditions, under which a continuous function of a process with CFS admits a CPS, while the CFS property might be lost. 相似文献
164.
In the present paper, we give an answer to a question which is closely related to doubly warped product of Finsler metrics: ‘‘For each n, is there an n-dimensional Finsler manifold , admitting a non-constant smooth function f on M such that ?”. We relate the preceding mentioned condition to different concepts appeared and studied in Finsler geometry. We introduce and investigate the notion of a semi concurrent vector field on a Finsler manifold. We show that some special Finsler manifolds admitting such vector fields turn out to be Riemannian. We prove that Tachibana's characterization of Finsler manifolds admitting a concurrent vector field leads to Riemannian metrics. Various examples for conic Finsler spaces that admit semi-concurrent vector field are presented. 相似文献
165.
Fang Lu 《Applicable analysis》2013,92(8):1567-1586
In the context of Euclidean spaces, we present an extension of the Newton-like method for solving vector optimization problems, with respect to the partial orders induced by a pointed, closed and convex cone with a nonempty interior. We study both exact and inexact versions of the Newton-like method. Under reasonable hypotheses, we prove stationarity of accumulation points of the sequences produced by Newton-like methods. Moreover, assuming strict cone-convexity of the objective map to the vector optimization problem, we establish convergence of the sequences to an efficient point whenever the initial point is in a compact level set. 相似文献
166.
We study the well‐posedness of the fractional differential equations with infinite delay on Lebesgue–Bochner spaces and Besov spaces , where A and B are closed linear operators on a Banach space X satisfying , and . Under suitable assumptions on the kernels a and b, we completely characterize the well‐posedness of in the above vector‐valued function spaces on by using known operator‐valued Fourier multiplier theorems. We also give concrete examples where our abstract results may be applied. 相似文献
167.
168.
Guillaume Erbland Dr. Seifallah Abid Yohan Gisbert Nathalie Saffon-Merceron Yuichiro Hashimoto Leonardo Andreoni Théo Guérin Dr. Claire Kammerer Prof. Dr. Gwénaël Rapenne 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(71):16328-16339
The design and synthesis of two families of molecular-gear prototypes is reported, with the aim of assembling them into trains of gears on a surface and ultimately achieving controlled intermolecular gearing motion. These piano-stool ruthenium complexes incorporate a hydrotris(indazolyl)borate moiety as tripodal rotation axle and a pentaarylcyclopentadienyl ligand as star-shaped cogwheel, equipped with five teeth ranging from pseudo-1D aryl groups to large planar 2D paddles. A divergent synthetic approach was followed, starting from a pentakis(p-bromophenyl)cyclopentadienyl ruthenium(II) complex as key precursor or from its iodinated counterpart, obtained by copper-catalyzed aromatic Br/I exchange. Subsequent fivefold cross-coupling reactions with various partners allowed high structural diversity to be reached and yielded molecular-gear prototypes with aryl-, carbazole-, BODIPY- and porphyrin-derived teeth of increasing size and length. 相似文献
169.
《Mendeleev Communications》2020,30(4):462-464
- Download : Download high-res image (138KB)
- Download : Download full-size image
170.
In this paper, we present examples of codes all of whose weight classes support 1‐designs, with duals whose classes include two that support 2‐designs. We can find these examples in the triply even binary codes of length 48, which have been classified by Betsumiya and Munemasa. 相似文献