全文获取类型
收费全文 | 240734篇 |
免费 | 6903篇 |
国内免费 | 3637篇 |
专业分类
化学 | 137020篇 |
晶体学 | 2899篇 |
力学 | 10268篇 |
综合类 | 169篇 |
数学 | 27078篇 |
物理学 | 73840篇 |
出版年
2021年 | 2145篇 |
2020年 | 2736篇 |
2019年 | 2853篇 |
2018年 | 3250篇 |
2017年 | 3219篇 |
2016年 | 4783篇 |
2015年 | 3502篇 |
2014年 | 4799篇 |
2013年 | 10569篇 |
2012年 | 9926篇 |
2011年 | 11687篇 |
2010年 | 8136篇 |
2009年 | 7880篇 |
2008年 | 10318篇 |
2007年 | 10312篇 |
2006年 | 9653篇 |
2005年 | 8805篇 |
2004年 | 7666篇 |
2003年 | 6654篇 |
2002年 | 6189篇 |
2001年 | 6863篇 |
2000年 | 5162篇 |
1999年 | 3860篇 |
1998年 | 3192篇 |
1997年 | 3213篇 |
1996年 | 3212篇 |
1995年 | 2908篇 |
1994年 | 2954篇 |
1993年 | 2748篇 |
1992年 | 2983篇 |
1991年 | 3036篇 |
1990年 | 2798篇 |
1989年 | 2682篇 |
1988年 | 2608篇 |
1987年 | 2556篇 |
1986年 | 2551篇 |
1985年 | 3333篇 |
1984年 | 3356篇 |
1983年 | 2803篇 |
1982年 | 3040篇 |
1981年 | 2783篇 |
1980年 | 2586篇 |
1979年 | 2759篇 |
1978年 | 2976篇 |
1977年 | 3012篇 |
1976年 | 3035篇 |
1975年 | 2786篇 |
1974年 | 2889篇 |
1973年 | 2941篇 |
1972年 | 2305篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
Reutova O. V. Belokoneva E. L. Dimitrova O. V. Volkov A. S. 《Crystallography Reports》2022,67(7):1122-1126
Crystallography Reports - Fluoride crystals K2(Ta0.9I0.1)F7 (sp. gr. Р21/c) complementary to the K2TaF7 and K2NbF7 fluoride family have been obtained by hydrothermal synthesis. Their... 相似文献
2.
Rui Feng Zi-Ying Li Zhao-Quan Yao Zi-Ang Guo Yi-Nan Zhang Hao-Xiang Sun Wei Li Xian-He Bu 《中国科学:化学(英文版)》2022,65(1):128-134
The rational designability and chemical tunability of metal-organic frameworks(MOFs)are enabling tributes to efficaciously enhance their room temperature phosphorescence(RTP)performance.A family of stable anionic MOFs,[Zn2(4,5-ImDC)2]M2(NKU-132,M=(CH3)2NH2or(CH2CH3)2NH2),featuring significant RTP have been synthesized.By rational cation selection and in-situ replacement from dimethylammonium to diethylammonium,the phosphorescence lifetime is increased from 30.88 to126.3 ms,along with less sensitivity to air.This work provides an anti-quenching and lifetime tuning example for RTP-MOFmaterials via facile host-guest chemistry. 相似文献
3.
Zlámalová M. Pitňa Lásková B. Vinarčíková M. Zukalová M. Kavan L. 《Journal of Solid State Electrochemistry》2022,26(3):639-647
Journal of Solid State Electrochemistry - The addition of nanocrystalline titanium dioxide (P90) to a cathode of Li/S cell enhances its voltammetric charge capacity by 19%, from which only a small... 相似文献
4.
Potekaev A. I. Klopotov A. A. Trishkina L. I. Cherkasova T. V. Kulagina V. V. Tazin I. D. 《Russian Physics Journal》2022,65(1):114-122
Russian Physics Journal - The results of a study of the dislocation structure evolution in polycrystals of homogeneous solid solutions in low-stability states in Cu-Mn-based alloys with FCC crystal... 相似文献
5.
Russian Physics Journal - Aiming at problems of low probability of interception and poor anti-jamming performance of the multi-output radar, the numerical simulation based on a chaos optimization... 相似文献
6.
Ribeiro Sabrina Dias Meneguin Andria Bagliotti Barud Hernane da Silva Silva Jhonatan Miguel Oliveira Rafael L. Asuno Rosana Maria Nascimento de Tormin Thiago Faria Muoz Rodrigo Alejandro Abarza Filho Guimes Rodrigues Ribeiro Clovis Augusto 《Journal of Thermal Analysis and Calorimetry》2022,147(13):7265-7275
Journal of Thermal Analysis and Calorimetry - Cellophane film production generates cellulosic residues from scraps, edges, and low-quality films. In this work, cellophane was used as a raw material... 相似文献
7.
Science China Chemistry - Human health is always under global spotlight, but now it suffers from severe environmental issue and various diseases. Developing highly selective and effective... 相似文献
8.
JETP Letters - The mechanical characteristics of diamond-like films, such as Dn21.8, Dn27.8, and Dn29.4 moiré diamanes, formed by the hydrogenation of graphene layers twisted at an angle of... 相似文献
9.
Yin Qingqing Xu Fen Sun Lixian Li Yaying Liao Lumin Wang Tao Guan Yanxun Xia Yongpeng Zhang Chenchen Wei Sheng Zhang Huanzhi Li Bin 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6583-6592
Journal of Thermal Analysis and Calorimetry - Polyethylene glycol (PEG) is widely used as phase change materials (PCMs). However, the leakage and low thermal conductivity issues restrict its... 相似文献
10.
Zhi Sun Mengfan Zhao Lihua Zuo Shengnan Zhou Feng Fan Qingquan Jia Lianping Xue Hanbing Li Jian Kang Xiaojian Zhang 《Journal of separation science》2022,45(2):518-528
Juglandis Mandshuricae Cortex is the bark of Juglans mandshurica Maxim., which has been used as a folk medicine plant in China and India. In this study, an ultra-high performance liquid chromatography–quadrupole/orbitrap high-resolution mass spectrometry method was developed to clarify and quantify the chemical profiling of Juglandis Mandshuricae Cortex rapidly. A total of 113 compounds were characterized. Among them, seven flavonoids were simultaneously quantified in 15 min, including myricetin, myricetrin, taxifolin, kaempferol, quercetin, quercitrin, and naringenin. The method was validated for accuracy, precision, and the limits of detection and quantification. All calibration curves showed a good linear relationship (r > 0.9990) within test ranges. The intra- and inter-day relative standard deviations were less than 2.16%. Accuracy validation showed that the recovery was between 95.6 and 101.3% with relative standard deviation values below 2.85%. The validated method was successfully applied to determine the contents of seven flavones in Juglandis Mandshuricae Cortex from seven sources and the contents of these places were calculated respectively. This method provides a theoretical basis for further developing the medicinal value of Juglandis Mandshuricae Cortex. 相似文献