全文获取类型
收费全文 | 217篇 |
免费 | 13篇 |
国内免费 | 3篇 |
专业分类
化学 | 108篇 |
晶体学 | 2篇 |
力学 | 24篇 |
数学 | 55篇 |
物理学 | 44篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 3篇 |
2016年 | 11篇 |
2015年 | 12篇 |
2014年 | 9篇 |
2013年 | 21篇 |
2012年 | 12篇 |
2011年 | 13篇 |
2010年 | 11篇 |
2009年 | 20篇 |
2008年 | 9篇 |
2007年 | 9篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 2篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1997年 | 5篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有233条查询结果,搜索用时 31 毫秒
11.
12.
Experimental determination of interfacial energies for Ag2Al solid solution in the CuAl2--Ag2Al system
下载免费PDF全文
![点击此处可从《中国物理 B》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The equilibrated grain boundary groove shapes of solid solution Ag2Al in equilibrium with an Al-Cu-Ag liquid were observed from a quenched sample with a radial heat flow apparatus.The Gibbs-Thomson coefficient,solid-liquid interfacial energy and grain boundary energy of the solid solution Ag2Al have been determined from the observed grain boundary groove shapes.The thermal conductivity of the solid phase and the thermal conductivity ratio of the liquid phase to solid phase for Ag2Al-28.3 at the %CuAl2 alloy at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus,separately. 相似文献
13.
14.
Yavuz Surme Ibrahim Narin Mustafa Soylak Huseyin Yuruk Mehmet Dogan 《Mikrochimica acta》2007,157(3-4):193-199
The conditions for cloud point extraction of lead(II) from aqueous solutions were investigated and optimized. The procedure
is based on the separation of Pb(II) – brillant cresyl blue (BCB) complexes into the micellar media by adding the surfactant
Triton X-114. After phase separation, the surfactant-rich phase was dissolved with 1 mol L−1 HNO3 in ethanol and diluted with 1 mol L−1 HNO3 solution before lead was determined by flame atomic absorption spectrometry. Optimization of the pH, ligand and surfactant
quantities, incubation time, temperature, viscosity, sample volume, and interfering ions was performed. The effects of the
matrix ions were also examined. The detection limits for three times the standard deviations of the blank for lead were 7.5 μg L−1 for water samples and 0.33 μg g−1 for sediment samples. The validity of cloud point extraction was checked by employing certified reference samples of Lake
Sediment IAEA-SL-1 and Sewage Sludge BCR-CRM 144R. The procedure was applied to natural waters and sediment samples with satisfactory
results (recoveries >95%, relative standard deviations <6.4%). 相似文献
15.
The post-divergence behaviour of non-gradient systems is studied through a perturbation approach, attention being restricted to equilibrium paths in the neighbourhood of a critical point. Simple and coincident critical points are treated separately. Various characteristic phenomena are explored in general terms by identifying certain distinct properties of the Jacobian matrix in a state-space formulation. It is demonstrated that the well-known asymmetric and symmetric points of bifurcation can also arise in non-gradient systems and the conditions giving rise to each of these phenomena are discussed. An illustrative example is presented. 相似文献
16.
Selman Akbulut 《Inventiones Mathematicae》1978,49(3-4):193-198
17.
Nurcan Kurtoglu Mehmet Aslantaş Huseyin Zengin Ertan Şahin Mukerrem Kurtoglu 《Chemical Papers》2010,64(5):645-651
This study focuses on the preparation, single crystal X-ray diffraction, characterization, and optical properties of some
anthraquinone-based dyes. The anthraquinone-based antimicrobial dye N-{2-[(9,10-dioxo-9,10-dihydroanthracen-1-yl)amino]-2-oxoethyl}-N,N-dimethylbutan-1-aminium chloride monohydrate (III) was obtained from 1-aminoanthraquinone (I) via 2-chloro-N-(9,10-dioxo-9,10-dihydroanthracen-1-yl)acetamide (II) using known preparation and characterization methods. Single crystal X-ray diffraction analysis of III revealed a monoclinic system, space group P21/n, Z = 4. Photoluminescence properties of anthraquinone dyes I–III were also investigated. These dyes gave an intense emission (λmax = 341 nm) upon the irradiation by UV light and showed photoluminescence quantum yields of 73 %, 66 %, and 61 % with long
excited-state lifetimes of 6.87 ns, 6.14 ns, and 5.69 ns, respectively. These anthraquinone dyes are of interest as an organic
light emitting material for electroluminescent devices. 相似文献
18.
Integration of paper-based microfluidic devices with commercial electrochemical readers 总被引:2,自引:0,他引:2
The combination of simple Electrochemical Micro-Paper-based Analytical Devices (EμPADs) with commercially available glucometers allows rapid, quantitative electrochemical analysis of a number of compounds relevant to human health (e.g., glucose, cholesterol, lactate, and alcohol) in blood or urine. 相似文献
19.
Cengiz Toker Bulent Uzun Huseyin Canci F. Oncu Ceylan 《Radiation Physics and Chemistry》2005,73(6):365-367
The effects of radiation on the shoot and root lengths of germinated seedling of irradiated seeds of Cicer species, i.e. three kabuli types and four desi types of cultivated chickpea (Cicer arietinum Ladiz.) and 2 annual wild types (C. reticulatum Ladiz. and C. bijugum K.H. Rech.) were investigated. The seeds were irradiated with a 60Co gamma source using 0, 200, 300 and 400 Gy doses at 1.66 kGy h−1. At 200 Gy minor effects could be observed, but at 400 Gy an obvious depression of shoot length was observed. The kabuli types were more affected than the desi ones. The critical dose that prevented the shoot and root elongation varied among species and also ranged from genotypes to genotype within species. 相似文献
20.
A perturbation method of analysis for the estimation of the stability boundary of symmetric conservative structural systems, whose loss of stability is associated with pre-buckling large deflections, is presented in completely general terms. 相似文献