全文获取类型
收费全文 | 81544篇 |
免费 | 10202篇 |
国内免费 | 6652篇 |
专业分类
化学 | 50733篇 |
晶体学 | 938篇 |
力学 | 5431篇 |
综合类 | 518篇 |
数学 | 9758篇 |
物理学 | 31020篇 |
出版年
2023年 | 1411篇 |
2022年 | 1522篇 |
2021年 | 2244篇 |
2020年 | 2566篇 |
2019年 | 2474篇 |
2018年 | 2298篇 |
2017年 | 2033篇 |
2016年 | 3132篇 |
2015年 | 3113篇 |
2014年 | 3799篇 |
2013年 | 5319篇 |
2012年 | 6510篇 |
2011年 | 6965篇 |
2010年 | 4760篇 |
2009年 | 4694篇 |
2008年 | 4949篇 |
2007年 | 4567篇 |
2006年 | 4380篇 |
2005年 | 3744篇 |
2004年 | 3037篇 |
2003年 | 2341篇 |
2002年 | 2103篇 |
2001年 | 2320篇 |
2000年 | 1949篇 |
1999年 | 1994篇 |
1998年 | 1608篇 |
1997年 | 1452篇 |
1996年 | 1395篇 |
1995年 | 1249篇 |
1994年 | 1185篇 |
1993年 | 1004篇 |
1992年 | 909篇 |
1991年 | 796篇 |
1990年 | 683篇 |
1989年 | 586篇 |
1988年 | 455篇 |
1987年 | 426篇 |
1986年 | 363篇 |
1985年 | 374篇 |
1984年 | 256篇 |
1983年 | 210篇 |
1982年 | 171篇 |
1981年 | 140篇 |
1980年 | 98篇 |
1978年 | 72篇 |
1977年 | 70篇 |
1976年 | 75篇 |
1975年 | 84篇 |
1974年 | 69篇 |
1973年 | 76篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
21.
Li Y. Shi W. H. Dong L. M. Xu S. X. Huang H. J. Yin J. R. 《Journal of Applied Spectroscopy》2022,89(3):534-541
Journal of Applied Spectroscopy - Sr3B2O6:Dy3+, Eu3+ single-matrix white-light-emitting materials are prepared using the high-temperature solid-state method. The microstructure, emission spectrum,... 相似文献
22.
Meihua Shen Dr. Xinpeng Zhao Dr. Lu Han Nanxi Jin Prof. Song Liu Prof. Tao Jia Prof. Zhijun Chen Prof. Xiuhua Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(20):e202104137
Solar-driven interfacial vaporization by localizing solar-thermal energy conversion to the air−water interface has attracted tremendous attention. In the process of converting solar energy into heat energy, photothermal materials play an essential role. Herein, a flexible solar-thermal material di-cyan substituted 5,12-dibutylquinacridone (DCN−4CQA)@Paper was developed by coating photothermal quinacridone derivatives on the cellulose paper. The DCN−4CQA@Paper combines desired chemical and physical properties, broadband light-absorbing, and shape-conforming abilities that render efficient photothermic vaporization. Notably, synergetic coupling of solar-steam and solar-electricity technologies by integrating DCN−4CQA@Paper and the thermoelectric devices is realized without trade-offs, highlighting the practical consideration toward more impactful solar heat exploitation. Such solar distillation and low-grade heat-to-electricity generation functions can provide potential opportunities for fresh water and electricity supply in off-grid or remote areas. 相似文献
23.
Yi-Tong Xu Tian-Yang Zhang Zheng Li Xiang-Nan Liu Yuan-Cheng Zhu Wei-Wei Zhao Hong-Yuan Chen Jing-Juan Xu 《Electroanalysis》2022,34(6):947-955
Photoelectrochemical (PEC) cytosensors, a combination of the PEC process and the living-cell assay, have emerged as a powerful tool in the analytical and biological science. This mini review provides a brief introduction of this arena and summaries the key steps about the development of PEC cytosensors with representative examples, followed by future prospects based on our own opinions. 相似文献
24.
25.
Nonlinear Dynamics - This paper proposes an optimal parameter design of control scheme for mechanical systems by adopting the Stackelberg game theory. The goal of the control is to drive the... 相似文献
26.
Restricted testing conditions were considered recently. For the maximal operator, Hytönen, Li and Sawyer [8] first obtained parental testing condition. Later, they [9] showed that it suffices to restrict testing to doubling cubes. Chen and Lacey [3] gave a similar restricted testing condition. In our paper, we discuss a version of the latter in the multilinear setting.
相似文献27.
Mathematical Programming - Convergence analysis of accelerated first-order methods for convex optimization problems are developed from the point of view of ordinary differential equation solvers. A... 相似文献
28.
Donglei Wei Huili Li Chuanqing Yang Jianmin Fu Hou Chen Liangjiu Bai Wenxiang Wang Huawei Yang Lixia Yang Ying Liang 《Journal of polymer science. Part A, Polymer chemistry》2022,60(10):1588-1594
Acridone as a new kind of visible light photocatalyst has been developed to catalyze metal free atom transfer radical polymerization (ATRP). The photocatalyst possess low excited state potential as can undergo an oxidative quenching pathway to initiate ATRP of vinyl monomers. Kinetic study and light on/off reaction demonstrate the “living”/controlled nature of the polymerization by light. Block copolymers can be achieved by using PMMA as macroinitiator to reinitiate polymerization of other vinyl monomers, which shows highly preserved Br chain-end functionality in the synthesized polymers. Moreover, the polymerization can be conducted under air atmosphere as most photocatalysts need anaerobic condition, which may give inspiration of further application of this kind of photocatalyst. 相似文献
29.
Atopic dermatitis is characterized by leukocyte migration into the skin dermis and typically driven by excessive chemokine production at the site of inflammation. Conventional topical formulations such as gels, creams, and ointments are insufficient for this treatment because of low penetration of drug molecules into the targeted skin tissues. Herein, using a simple, green, sustainable strategy, we have developed novel primary zein nanoparticles embedded in curcumin (Cur) and coated with silk sericin (ZHSCs) for the topical delivery of Cur to penetrate into the dermis and exercise anti-dermatitis effects on the lesion with minimal side-effects. Transdermal delivery experiments and porcine skin fluorescence imaging indicated that ZHSCs facilitate the penetration of Cur across the epidermis layer of skin to reach deep-seated sites. Notably, ZHSCs = 1:0.25 (zein-to-silk sericin mass ratios of 1:0.25) markedly elevated the skin permeability and cumulative turnover of Cur transferred, which were provided a greater than a 3.8-fold increase relative to free Cur. The special nanoparticles of ZHS = 1:0.25 possessed the deepest localization depth and experience a transition of the particle structure and core-shell separation after penetrating into the dermis of skin. In a cell model of dermatitis induced by tumor necrosis factor α/interferon γ co-stimulation, compared with free Cur, Cur-loaded ZHS nanoparticles down-regulated the generation of inflammatory cytokines and chemokines in keratinocytes through suppression of the nuclear translocation of NF-κBp65 and hence exerted an anti-dermatitis effect. This strategy may provide new avenues and direction for the demanding issues of valid topical delivery systems. 相似文献
30.