全文获取类型
收费全文 | 287598篇 |
免费 | 5091篇 |
国内免费 | 2557篇 |
专业分类
化学 | 137778篇 |
晶体学 | 4064篇 |
力学 | 15619篇 |
综合类 | 71篇 |
数学 | 43789篇 |
物理学 | 93925篇 |
出版年
2021年 | 1511篇 |
2020年 | 1729篇 |
2019年 | 1704篇 |
2018年 | 10951篇 |
2017年 | 11867篇 |
2016年 | 7344篇 |
2015年 | 3564篇 |
2014年 | 3516篇 |
2013年 | 8933篇 |
2012年 | 12167篇 |
2011年 | 22200篇 |
2010年 | 13364篇 |
2009年 | 13450篇 |
2008年 | 19272篇 |
2007年 | 22771篇 |
2006年 | 8025篇 |
2005年 | 14609篇 |
2004年 | 10057篇 |
2003年 | 8983篇 |
2002年 | 6801篇 |
2001年 | 6503篇 |
2000年 | 5156篇 |
1999年 | 3831篇 |
1998年 | 2928篇 |
1997年 | 2863篇 |
1996年 | 3005篇 |
1995年 | 2634篇 |
1994年 | 2429篇 |
1993年 | 2245篇 |
1992年 | 2553篇 |
1991年 | 2519篇 |
1990年 | 2212篇 |
1989年 | 2176篇 |
1988年 | 2190篇 |
1987年 | 2106篇 |
1986年 | 1994篇 |
1985年 | 2900篇 |
1984年 | 2879篇 |
1983年 | 2321篇 |
1982年 | 2485篇 |
1981年 | 2345篇 |
1980年 | 2294篇 |
1979年 | 2257篇 |
1978年 | 2340篇 |
1977年 | 2214篇 |
1976年 | 2183篇 |
1975年 | 2156篇 |
1974年 | 2060篇 |
1973年 | 2179篇 |
1972年 | 1221篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
11.
Nonlinear Dynamics - In this article, the authors simulate and study dark and bright soliton solutions of 1D and 2D regularized long wave (RLW) models. The RLW model occurred in various fields such... 相似文献
12.
13.
Hu Duo-Duo Gao Qian Dai Jing-Cheng Cui Ru Li Yuan-Bo Li Yuan-Ming Zhou Xiao-Guo Bian Kang-Jie Wu Bing-Bing Zhang Kai-Fan Wang Xi-Sheng Li Yan 《中国科学:化学(英文版)》2022,65(4):753-761
Science China Chemistry - A light-induced, nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is reported. This methodology exhibited mild conditions,... 相似文献
14.
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
15.
Science China Mathematics - Linear factor models are familiar tools used in many fields. Several pioneering literatures established foundational theoretical results of the quasi-maximum likelihood... 相似文献
16.
Paired single residue‐transposed Lys‐N and Lys‐C digestions for label‐free identification of N‐terminal and C‐terminal MS/MS peptide product ions: ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry and tandem mass spectrometry for peptide de novo sequencing
下载免费PDF全文
![点击此处可从《Rapid communications in mass spectrometry : RCM》网站下载免费的PDF全文](/ch/ext_images/free.gif)
17.
Hongling Yu Heyong Wang Galia Pozina Chunyang Yin Xiao-Ke Liu Feng Gao 《Chemical science》2020,11(41):11338
Metal halide perovskites have demonstrated impressive properties for achieving efficient monochromatic light-emitting diodes. However, the development of white perovskite light-emitting diodes (PeLEDs) remains a big challenge. Here, we demonstrate a single-emissive-layer all-perovskite white PeLED using a mixed halide perovskite film as the emissive layer. The perovskite film consists of separated mixed halide perovskite phases with blue and red emissions, which are beneficial for suppressing halide anion exchange and preventing charge transfer. As a result, the white PeLED shows balanced white light emission with Commission Internationale de L''Eclairage coordinates of (0.33, 0.33). In addition, we find that the achievement of white light emission from mixed halide perovskites strongly depends on effective modulation of the halide salt precursors, especially lead bromide and benzamidine hydrochloride in our case. Our work provides very useful guidelines for realizing single-emissive-layer all-perovskite white PeLEDs based on mixed halide perovskites, which will spur the development of high-performance white PeLEDs.We demonstrated a single-emissive-layer all-perovskite white light-emitting diode based on a mixed halide perovskite film. 相似文献
18.
19.
20.