全文获取类型
收费全文 | 13168篇 |
免费 | 1124篇 |
国内免费 | 700篇 |
专业分类
化学 | 8849篇 |
晶体学 | 116篇 |
力学 | 513篇 |
综合类 | 51篇 |
数学 | 1662篇 |
物理学 | 3801篇 |
出版年
2023年 | 152篇 |
2022年 | 163篇 |
2021年 | 247篇 |
2020年 | 330篇 |
2019年 | 354篇 |
2018年 | 261篇 |
2017年 | 275篇 |
2016年 | 421篇 |
2015年 | 435篇 |
2014年 | 517篇 |
2013年 | 756篇 |
2012年 | 960篇 |
2011年 | 1103篇 |
2010年 | 691篇 |
2009年 | 717篇 |
2008年 | 816篇 |
2007年 | 811篇 |
2006年 | 714篇 |
2005年 | 616篇 |
2004年 | 590篇 |
2003年 | 496篇 |
2002年 | 416篇 |
2001年 | 316篇 |
2000年 | 244篇 |
1999年 | 195篇 |
1998年 | 158篇 |
1997年 | 130篇 |
1996年 | 154篇 |
1995年 | 148篇 |
1994年 | 167篇 |
1993年 | 132篇 |
1992年 | 126篇 |
1991年 | 101篇 |
1990年 | 114篇 |
1989年 | 84篇 |
1988年 | 95篇 |
1987年 | 69篇 |
1986年 | 78篇 |
1985年 | 102篇 |
1984年 | 78篇 |
1983年 | 80篇 |
1982年 | 56篇 |
1981年 | 58篇 |
1980年 | 51篇 |
1979年 | 39篇 |
1977年 | 43篇 |
1976年 | 42篇 |
1975年 | 42篇 |
1974年 | 52篇 |
1973年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
61.
62.
63.
Lithium-sulfur batteries (LSBs) with high energy density and low cost have been recognized as one of the most promising next-generation energy storage systems. Although it has taken decades of development, the practical application of LSBs has been hindered by several inherent obstacles, particularly the severe shuttle effect and sluggish reaction kinetics in the sulfur cathode. Various strategies have been proposed to address these problems via rational design of electrode materials and configurations. Freestanding sulfur cathode could be a promising strategy to improve the sulfur mass loading at the cathode level and energy density of LSBs. This minireview will briefly summary the recent advances in freestanding cathodes for LSBs. The advantages and disadvantages of various freestanding cathodes are discussed and the prospects for the development of flexible cathodes are envisioned. 相似文献
64.
Yin Pengpeng Liu Chang Wang Ying Guan Lei Chen Xian Xiong Xuejia Jin Hongzhe 《Russian Journal of General Chemistry》2021,91(5):897-903
Russian Journal of General Chemistry - A dinuclear Tb complex, Tb2(H2L)3(phen)2 (1), and two similar N-donor coordination complexes, Fe(phen)3·HL (2), Fe(bipy)3·HL·5H2O (3) (Na2H2L =... 相似文献
65.
Du Yongbo Yu Pengfei Wang Junxiong Zhang Jinping Wang Chang’an Che Defu 《Journal of Thermal Analysis and Calorimetry》2021,143(1):327-334
Journal of Thermal Analysis and Calorimetry - Coal O2/CO2 combustion is a promising carbon capture and storage technology for coal-fired power plant. Char consumption rate prediction is essential... 相似文献
66.
Chang Guofeng Li Yuyang Cui Xian Ji Yunkang 《Journal of Thermal Analysis and Calorimetry》2021,145(5):2477-2485
Journal of Thermal Analysis and Calorimetry - Comprehensive performance experiments were carried out, and the thermodynamic temperature simulation model was established based on the independently... 相似文献
67.
Yaqin Wang Xibo Zhang Kuan Chang Zhiying Zhao Jiayu Huang Prof. Qin Kuang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(16):e202104514
Exploring new catalytic strategies for achieving efficient CO2 hydrogenation under mild conditions is of great significance for environmental remediation. Herein, a composite photocatalyst Zr-based MOF encapsulated plasmonic AuPt alloy nanoparticles (AuPt@UiO-66-NH2) was successfully constructed for the efficient photothermal catalysis of CO2 hydrogenation. Under light irradiation at 150 °C, AuPt@UiO-66-NH2 achieved a CO production rate of 1451 μmol gmetal−1 h−1 with 91 % selectivity, which far exceeded those obtained by Au@Pt@UiO-66-NH2 with Pt shell on Au (599 μmol gmetal−1 h−1) and Au@UiO-66-NH2 (218 μmol gmetal−1 h−1). The outstanding performances of AuPt@UiO-66-NH2 were attributed to the synergetic effect originating from the plasmonic metal Au, doped active metal Pt, and encapsulation structure of UiO-66-NH2 shell. This work provides a new way for photothermal catalysis of CO2 and a reference for the design of high-performance plasmonic catalysts. 相似文献
68.
Zheng Xinyan Hu Po Yao Ruxian cheng Jinhe Chang Yiheng Wu Haitao Mei Hongying Sun Shuxiang Chen Qingtai liu Fang Chen Shujing Wen Hua 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(5):2217-2226
Journal of Radioanalytical and Nuclear Chemistry - Enhancement of U(VI) biomineralization by Saccharomyces cerevisiae through addition of inorganic phosphorus was studied in this work. The addition... 相似文献
69.
Influence of staff number and internal constellation on surgical site infection in an operating room
Prediction of bacteria-carrying particle (BCP) dispersion and particle distribution released from staffmem- bers in an operating room (OR) is very important for creating and sustaining a safe indoor environment. Postoperative wound infections cause significant morbidity and mortality, and contribute to increased hospitalization time. Increasing the number of personnel within the OR disrupts the ventilation airflow pattern and causes enhanced contamination risk in the area of an open wound. Whether the amount of staffwithin the OR influences the BCP distribution in the surgical zone has rarely been investigated. This study was conducted to explore the influence of the number of personnel in the OR on the airflow field and the BCP distribution. This was performed by applying a numerical calculation to map the airflow field and Lagrangian particle tracking (LPT) for the BCP phase. The results are reported both for active sampling and passive monitoring approaches. Not surprisingly, a growing trend in the BCP concentration (cfu/ms) was observed as the amount of staff in the OR increased. Passive sampling shows unpredictable results due to the sedimentation rate, especially for small particles (5-10 i~m). Risk factors for surgical site infections (SSls) must be well understood to develop more effective prevention programs. 相似文献
70.
Serum pharmacochemistry combined with multiple data processing approach to screen the bioactive components and their metabolites in Mutan Cortex by ultra‐performance liquid chromatography tandem mass spectrometry 下载免费PDF全文
Jian‐hua Liu Hui Sun Ai‐hua Zhang Guang‐li Yan Ying Han Chang‐song Xue Xiao‐hang Zhou Hui Shi Xi‐jun Wang 《Biomedical chromatography : BMC》2014,28(4):500-510
Root cortex of Paeonia suffruticosa Andrews (Paeoniaceae), known as Moutan Cortex (MC), is known to have anti‐allergic and anti‐inflammatory properties. However, the constituents absorbed into blood after oral administration of MC remain unknown. A sensitive and rapid method by ultra‐high‐pressure liquid chromatography–electrospray ionization–quadrupole‐time‐of‐flight mass spectrometry (UPLC‐ESI‐Q‐TOF‐MS) technology and the MetaboLynxTM software combined with multiple data processing approach (Mdpa) was established to investigate the absorbed constituents in rats after oral administration of MC, providing unique high‐throughput capabilities for drug metabolism study. A hyphenated electrospray ionization and quadrupole‐time‐of‐flight analyzer was used for the determination of accurate mass of the fragment ion in negative mode, with excellent MS mass accuracy and enhanced data acquisition. This rapid automated analysis method was successfully applied for screening and identification of the constituents absorbed and metabolized studies of MC after oral administration to rats. A total of 46 peaks were obtained from MC, 41 of which were tentatively characterized. In the VIP‐plot of orthogonal partial least‐squares discriminant analysis, 23 interesting ions in serum samples were extracted, and 16 parent components and seven metabolites were detected in vivo. The integrative serum pharmacochemistry technique, UPLC‐ESI‐Q‐TOF‐MS, and Mdpa method were successfully applied for rapid discovery of multiple components from MC. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献