全文获取类型
收费全文 | 43094篇 |
免费 | 7236篇 |
国内免费 | 5229篇 |
专业分类
化学 | 31400篇 |
晶体学 | 484篇 |
力学 | 2419篇 |
综合类 | 287篇 |
数学 | 4852篇 |
物理学 | 16117篇 |
出版年
2024年 | 93篇 |
2023年 | 883篇 |
2022年 | 1598篇 |
2021年 | 1557篇 |
2020年 | 1747篇 |
2019年 | 1744篇 |
2018年 | 1582篇 |
2017年 | 1406篇 |
2016年 | 2151篇 |
2015年 | 2032篇 |
2014年 | 2484篇 |
2013年 | 3283篇 |
2012年 | 3731篇 |
2011年 | 3998篇 |
2010年 | 2801篇 |
2009年 | 2539篇 |
2008年 | 2873篇 |
2007年 | 2517篇 |
2006年 | 2316篇 |
2005年 | 1980篇 |
2004年 | 1521篇 |
2003年 | 1205篇 |
2002年 | 1249篇 |
2001年 | 940篇 |
2000年 | 842篇 |
1999年 | 860篇 |
1998年 | 671篇 |
1997年 | 609篇 |
1996年 | 602篇 |
1995年 | 493篇 |
1994年 | 517篇 |
1993年 | 433篇 |
1992年 | 335篇 |
1991年 | 343篇 |
1990年 | 302篇 |
1989年 | 224篇 |
1988年 | 165篇 |
1987年 | 129篇 |
1986年 | 132篇 |
1985年 | 116篇 |
1984年 | 92篇 |
1983年 | 58篇 |
1982年 | 55篇 |
1981年 | 37篇 |
1980年 | 46篇 |
1976年 | 26篇 |
1975年 | 22篇 |
1974年 | 20篇 |
1973年 | 22篇 |
1968年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Chen Zi-Han Li Yue-Hua Qi Ming-Yu Tang Zi-Rong Xu Yi-Jun 《Research on Chemical Intermediates》2022,48(1):1-12
Research on Chemical Intermediates - Owing to the simultaneous utilization of photogenerated electrons and holes, coupling light-driven hydrogen (H2) evolution reaction (HER) and biomass-derived... 相似文献
2.
Song Zhang Luke A. Galuska Xiaodan Gu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(7):1108-1129
Thin films with a nanometer-scale thickness are of great interest to both scientific and industrial communities due to their numerous applications and unique behaviors different from the bulk. However, the understanding of thin-film mechanics is still greatly hampered due to their intrinsic fragility and the lack of commercially available experimental instruments. In this review, we first discuss the progression of thin-film mechanical testing methods based on the supporting substrate: film-on-solid substrate method, film-on-water tensile tests, and water-assisted free-standing tensile tests. By comparing past studies on a model polymer, polystyrene, the effect of different substrates and confinement effect on the thin-film mechanics is evaluated. These techniques have generated fruitful scientific knowledge in the field of organic semiconductors for the understanding of structure–mechanical property relationships. We end this review by providing our perspective for their bright prospects in much broader applications and materials of interest. 相似文献
3.
Yujie Gao Zhiye Qiu Lei Liu Mengmeng Li Bingjie Xu Dan Yu Dongming Qi Jindan Wu 《Journal of polymer science. Part A, Polymer chemistry》2022,60(15):2191-2212
Refractory wounds have always been an important issue to healthcare systems, whose healing process is always delayed by multiple factors, including bacterial infections, chronic inflammation, and excessive exudates, etc. Employing multifunctional wound dressings is recognized as an effective strategy to deal with refractory wounds, which has yielded promising outcomes in recent years. Among these advanced wound dressings, fibrous dressings have gained growing attention due to their unique merits. Such wound dressings have demonstrated great potential in delivering theranostic agents, such as antibacterial agents, anti-inflammatory drugs, growth factors, and diagnostic probes, etc., for the purposes of accelerating wound healing. This paper reviews the development of multifunctional fibrous dressings and their applications in treating refractory wounds. The construction approaches of novel fibrous dressing with capabilities of antibacterial, anti-inflammation, exudate management and diagnosis were also introduced. Furthermore, the existing problems and challenges are also discussed briefly. 相似文献
4.
5.
6.
7.
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
8.
Hongjin Wang Tengfei Long Hao Zhang Meng Li Qi Sun Xin Zhai Lixin Sun 《Biomedical chromatography : BMC》2022,36(4):e5301
3,4-Difluorobenzyl(1-ethyl-5-(4-((4-hydroxypiperidin-1-yl)-methyl)thiazol-2-yl)-1H-indol-3-yl)carbamate (NAI59), a small molecule with outstanding therapeutic effectiveness to anti-pulmonary fibrosis, was developed as an autotaxin inhibitor candidate compound. To evaluate the pharmacokinetics and plasma protein binding of NAI59, a UPLC–MS/MS method was developed to quantify NAI59 in plasma and phosphate-buffered saline. The calibration curve linearity ranged from 9.95 to 1990.00 ng/mL in plasma. The accuracy was −6.8 to 5.9%, and the intra- and inter-day precision was within 15%. The matrix effect and recovery, as well as dilution integrity, were within the criteria. The chromatographic and mass spectrometric conditions were also feasible to determine phosphate-buffered saline samples, and it has been proved that this method exhibits good precision and accuracy in the range of 9.95–497.50 ng/mL in phosphate-buffered saline. This study is the first to determine the pharmacokinetics, absolute bioavailability, and plasma protein binding of NAI59 in rats using this established method. Therefore, the pharmacokinetic profiles of NAI59 showed a dose-dependent relationship after oral administration, and the absolute bioavailability in rats was 6.3%. In addition, the results of protein binding showed that the combining capacity of NAI59 with plasma protein attained 90% and increased with the increase in drug concentration. 相似文献
9.
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
10.