全文获取类型
收费全文 | 220篇 |
免费 | 5篇 |
专业分类
化学 | 131篇 |
晶体学 | 6篇 |
力学 | 11篇 |
数学 | 40篇 |
物理学 | 37篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 7篇 |
2015年 | 3篇 |
2014年 | 14篇 |
2013年 | 18篇 |
2012年 | 12篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1997年 | 1篇 |
1994年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1966年 | 3篇 |
排序方式: 共有225条查询结果,搜索用时 15 毫秒
21.
Sweetie R. Kanatt M. Shobita Rao S.P. Chawla Arun Sharma 《Radiation Physics and Chemistry》2010,79(12):1259-1263
A variety of ready-to-cook meat products available in Indian supermarkets (mutton mince, chicken mince, chicken chunks, and chicken legs) were studied. The samples were irradiated (2.5 kGy), or left untreated as control, and stored at 0–3 °C for up to 21 days. The effect of irradiation on the microbiological, chemical, and sensory properties was evaluated at intervals during the storage period. Irradiated samples had a longer shelf-life at 0–3 °C compared with the corresponding non-irradiated samples. Fecal coliforms were eliminated by irradiation treatment. Radiation processed samples had lower counts of Staphylococcus spp. There were no significant organoleptic changes in irradiated samples stored at chilled temperatures. 相似文献
22.
In this paper, the coupling of lateral and longitudinal vibrations due to the presence of transverse surface crack in a rotor is explored. A crack in a rotor is known to introduce coupling between lateral and longitudinal vibrations. Steady state unbalance response of a cracked rotor with a single centrally situated crack subjected to periodic axial impulses is investigated experimentally. The cracked rotor is excited axially using an electrodynamic exciter at a frequency equal to its bending natural frequency in both non-rotating and rotating conditions. The resulting time domain and frequency domain signals of the cracked rotor are studied. Spectral response of the cracked rotor with and without axial excitation is found to be distinctively different. When excited axially, it shows prominent presence of rotor bending natural frequency. However for an uncracked rotor, the response is similar with or without axial excitation. It is thus proposed that the response of the rotor to axial impulse excitation could be used for more reliable diagnosis of rotor cracks. 相似文献
23.
A tri-armed-pyrene-linked molecular receptor, 5 has been designed, synthesised and evaluated for ionic recognition. It has been observed that the synthesised molecular receptor can recognise mercury and cyanide ions through a change in colour, UV–Vis and fluorescence intensity. The binding stoichiometry of the receptor and these ionic species has been found to be 1:1 through Job’s plots, Benesi–Hildebrand plots and isothermal titration calorimetry (ITC). 相似文献
24.
The equations determining the localization of interference fringes produced by rotation of the photographic plate in ‘focused-image holography’ are derived for an arbitrary cylindrical surface. The important properties of fringe localization are discussed and are experimentally verified. 相似文献
25.
Copper doped zinc sulfide nanoparticles were prepared by chemical precipitation method. The size of the particles was varied by changing the concentration of capping agent. The XRD studies indicate that most of the samples are cubic in nature. The broadening of peaks tends to increase with increasing capping agent concentration showing decrease in particle size. The crystalline size computed using Scherrer formula is found to be in range of 3–10 nm. Absorption spectra show absorption edge in UV region. The edge was found to shift towards shorter wavelength as the capping agent concentration is increased. This indicates increased effective band gap and hence reduced particle size. The nanoparticle size has been estimated in the range 5–10 nm using effective mass approximation model. For electroluminescence (EL) study of ZnS:Cu nanocrystals, the EL cells were prepared by placing ZnS:Cu nanoparticles between SnO2 coated conducting glass plate and aluminum foil. Alternating voltage of various frequencies was applied and EL brightness (B) at different voltages (V) was measured and reported in this paper. 相似文献
26.
S. S. Chawla P. K. Srivastva 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2006,59(4):793-814
Fluid motion induced by the torsional oscillations (of angular velocity bΩcosω T) of an infinite disk in contact with an incompressible viscous rotating (with angular velocity aΩ) fluid of semi-infinite extent is analysed when the amplitude parameter α( = b/a) varies from zero to infinity. Composite solutions valid over the whole of the flow regime and specific expressions for the
shearing stress components at the disk and for the axial flow in the far region are obtained for low and high frequencies
of torsional oscillations. Using the method of matched asymptotic expansions, we find that the region of the mean flow increases
with α and reaches a maximum before settling down to the Rosenblat profile. Series expressions (for α < 1) are deduced for
physical quantities of interest when the fluid in the far field and the disk are rotating with different angular velocities
(in the same or in the opposite sense), which agree well with the known numerical results. 相似文献
27.
A convenient single step synthesis of p-thiomethylmethylcalixarenes and metal ion extraction studies
A facile synthesis of p-thiomethylmethylcalixarenes through a [2,5] sigmatropic rearrangement and extraction of soft heavy metal ions using the prepared calix[4]arene derivative is reported here. 相似文献
28.
Lanthanide induced shifts have been shown to provide reliable information on the steric disposition of protons in the vicinity of the sulfoxide group in penicillin derivatives and analogs. Because of its dipolar nature the sulfoxide bond serves as a favored site for complex formation with the lanthanide. The configuration of several penam sulfoxides and the conformation of the thiazolidine ring of one of them have been deduced. 相似文献
29.
N. C. Jayadevan K. L. Chawla K. D. Singh Mudher N. D. Dahale D. M. Chackraburtty 《Journal of Radioanalytical and Nuclear Chemistry》1984,82(1):125-134
An X-ray fluorescence binary ratio method to measure non-destructively the relative percentage of PuO2 in (U, Pu)O2 samples is described. Calibration lines for pellet and microsphere samples are established and evaluated. Independent X-ray measurement of the major component after dissolution leads to the determination of individual concentrations within ±0.5% rel. of the chemical values. 相似文献
30.