全文获取类型
收费全文 | 243篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
化学 | 114篇 |
力学 | 5篇 |
数学 | 30篇 |
物理学 | 99篇 |
出版年
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 14篇 |
2011年 | 20篇 |
2010年 | 10篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 3篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 2篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1997年 | 2篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1976年 | 5篇 |
1974年 | 3篇 |
1969年 | 2篇 |
1967年 | 1篇 |
1965年 | 1篇 |
1963年 | 1篇 |
1960年 | 1篇 |
1959年 | 1篇 |
1956年 | 1篇 |
1945年 | 2篇 |
1944年 | 2篇 |
1943年 | 1篇 |
1898年 | 1篇 |
排序方式: 共有248条查询结果,搜索用时 15 毫秒
31.
M. Corti V. DeGiorgio C. E. Swenberg S. L. Shapiro F. Wang H. Pant B. R. Jennings P. J. Ridler M. D. Duncan J. Reintjes T. J. Manuccia V. S. Letokhov A. Andreoni R. Cubeddu S. De Silvestri P. Laborta F. Docchio R. Ramponi C. A. Sacchi G. Bottiroli I. Freitas V. S. Antonov A. N. Shibanov 《Applied physics. B, Lasers and optics》1982,28(2-3):240-245
32.
33.
Photophysical properties of cinchonine dication (C++) have been studied in protic and aprotic polymers by monitoring steady state and time resolved measurements. It is found to be sensitive towards the microenvironment of polymers. Edge excitation red shifted emission (EERS) is observed in all polymeric matrices. However, the magnitude of EERS is relatively high in protic as compared to aprotic polymer. Isobestic point in excitation spectra and three decay components in time resolved measurements indicate more than two trapped chemical species in the heterogeneous environment of the polymer. Solute-polymer interactions are found to produce the third decay channel, unlike in solution phase and may be useful to understand the polymer microenvironment. 相似文献
34.
35.
36.
Eric D. Robertson Kapil Pant Matthew J. Grismer José A. Camberos 《International Journal of Computational Fluid Dynamics》2013,27(6-7):261-277
ABSTRACTA framework based on incremental proper orthogonal decomposition (iPOD) and data mining to perform large-scale computational data analysis is presented. It includes iPOD to incrementally reduce data dimensions and decouple dynamic flow structures in massive CFD data; data mining to classify and identify candidate global regions of interest (ROIs) for focused analysis; feature detection to capture key flow features and ultimate ROIs (UROIs); and targeted data storage and visualisation. Quantitative results show that iPOD is able to process large datasets that overwhelm the batch-POD, leading to 4–16× data reduction in the temporal domain. Data mining and feature detection algorithms, respectively, identify 50–70% of the spatial domain with high probability of flow feature occurrence and only 2–30% containing key flow features. The UROI and associated data can be selectively stored and visualised. In contrast to batch-POD, iPOD reduces memory usage by more than 10× and time by up to 75%. 相似文献
37.
Electrochemical synthesis of multi-armed CuO nanoparticles and their remarkable bactericidal potential against waterborne bacteria 总被引:1,自引:0,他引:1
Pratibha Pandey S. Merwyn G. S. Agarwal B. K. Tripathi S. C. Pant 《Journal of nanoparticle research》2012,14(1):709-13
Copper (II) oxide multi-armed nanoparticles composed of 500–1000 nm long radiating nanospicules with 100–200 nm width near
the base and 50–100 nm width at the tapered ends and ~25 nm thickness were synthesized by electrochemical deposition in the
presence of an oxidant followed by calcination at 150 °C. The nanoparticles were characterized using SEM/EDX for morphology
and composition, Raman spectroscopy for compound identification, and broth culture method for antibacterial efficacy. The
CuO nanoparticles have shown remarkable bactericidal efficacy against Gram-positive and -negative waterborne disease causing
bacteria like Escherichia coli, Salmonella typhi, staphylococcus aureus and Bacillus subtilis. E. coli has been chosen as representative species for waterborne disease causing bacteria. In antibacterial tests 500 μg/mL nano
CuO killed 3 × 108 CFU/mL E. coli bacteria within 4 h of exposure. Moreover, 8.3 × 106 CFU/mL E. coli were killed by 100 and 10 μg/mL nano CuO within 15 min and 4 h of exposure, respectively. Antibacterial activity of nano
CuO has been found many-fold compared with commercial bulk CuO. The fate of nanoparticles after antibacterial test has also
been studied. The synthesized CuO nanoparticles are expected to have potential antibacterial applications in water purification
and in paints and coatings used on frequently touched surfaces and fabrics in hospital settings. 相似文献
38.
JPC – Journal of Planar Chromatography – Modern TLC - An inexpensive, simple, and reproducible SPE-TLC method has been developed and validated for analysis of haloperidol and its three... 相似文献
39.
40.
The predominant circulating folate coenzyme in plasma/serum, 5‐methyltetrahydrofolate (5‐MTHF) was determined in human blood, serum and urine using a method based on the hyphenation of capillary ITP and zone electrophoresis. Measurements were done with a commercially available instrument for capillary isotachophoresis equipped with a column‐switching system. The choice of electrolytes was limited by the instability of 5‐MTHF and volatility of electrolytes for the potential coupling of the instrumentation with MS detector. To get an insight into the separability of individual sample components in an isotachophoretic analysis, we constructed zone existence diagrams for isotachophoretic electrolyte systems having a leading electrolyte composed of acetate and ammonium of pH 4.5 and 7.0, hydrocarbonate and ammonium, pH 7.8, chloride and ammonium, pH 5.6, and chloride and creatinine, pH 5.0, with hydroxide ion as the terminator. For isotachophoretic preseparation, the non‐volatile leading electrolyte with good buffering capacity composed of 1×10−2 M HCl and 2.5×10−2 M creatinine, pH 5.0, and terminating electrolyte composed of 1×10−2 M MES was selected as the most suitable. The optimum BGE for CZE analysis from the standpoint of analyte stability, separability and volatility for MS coupling was 1×10−2 M acetate with 3.5×10−2 M ammonium, pH 4.5. Using this combination of electrolytes, LODs reached with optical detection at 220 nm were 1.6×10−7 M in human blood, 1.1×10−7 M in human serum and 4.7×10−6 M in human urine. Estimated content of 5‐MTHF in blood and serum samples of women following oral daily administration of 0.8 mg of folic acid was 1.2×10−5 and 5.8×10−6 M, respectively. 相似文献