全文获取类型
收费全文 | 120篇 |
免费 | 2篇 |
专业分类
化学 | 59篇 |
晶体学 | 1篇 |
力学 | 11篇 |
数学 | 4篇 |
物理学 | 47篇 |
出版年
2023年 | 5篇 |
2022年 | 1篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2001年 | 2篇 |
1998年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有122条查询结果,搜索用时 15 毫秒
61.
Fluorescence probes NA1 and NA2 derived from 1-naphthylamine (NA) as fluorophore have been synthesized and characterized by different spectroscopic studies. Identification behaviour of these probes towards various metal ions has been investigated. Both the fluorescent probes are selective as well as sensitive towards Fe(III) ion. Novel fluorescence probe NA2 afforded turn-on fluorescence behaviour for Fe(III) ion over other metal ions such as Ca(II), Mg(II), Mn(II), Fe(II), Co(II), Fe(III), Ni(II), Cu(II), Zn(II) and Hg(II). 相似文献
62.
C. S. Prajapati Ajay Kushwaha P. P. Sahay 《Applied Physics A: Materials Science & Processing》2013,113(3):651-662
Sn-doped ZnO thin films were deposited on clean glass substrates using the chemical spray pyrolysis technique. XRD analyses confirm stable ZnO hexagonal wurtzite structure of the films with crystallite size in the range of 20–28 nm. The surface roughness of the films increases on Sn doping, which favors to higher adsorption of oxygen species on the film surface, resulting in higher gas response. Optical studies reveal that the band gap decreases on Sn doping. All the films show near band edge emission, and on Sn doping the luminescence peak intensity has been found to increase. Photocurrent in the 1.5 at.% doped film enhances about three times to that observed in the undoped ZnO film. Among all the films examined, the 1.5 at.% Sn-doped film exhibits the maximum response (~94.5 %) at the operating temperature of 275?°C for 100 ppm concentration of formaldehyde, which is much higher than the response (~35 %) in the undoped film. The gas response of the film is attributed to the chemisorption of oxygen on the film surface and the subsequent reaction between the adsorbed oxygen species and the formaldehyde molecules. 相似文献
63.
Kushwaha Reena Srivastava Pankaj Bahadur Lal 《Journal of Solid State Electrochemistry》2017,21(6):1533-1543
Journal of Solid State Electrochemistry - We are presenting herein the effect of using three different cell electrolytes namely: (a) propylene carbonate containing 0.2 M LiI and... 相似文献
64.
Magnetic field induced first order antiferromagnetic (AFM) to ferrimagnetic (FRI) transition in polycrystalline Mn1.85Co0.15Sb has been studied using magnetic force microscopy (MFM) at 60 K and up to 8 T magnetic fields. Our MFM studies provide real space visualization of AFM to FRI transition. It shows growth (decay) of FRI phase with increasing (decreasing) magnetic field. The hysteretic behavior and co-existing FRI and AFM phases across the critical field required for FRI-AFM transition in Mn1.85Co0.15Sb are highlighted. This study demonstrates the potential of MFM for studying phase co-existence at high field and low temperatures. 相似文献
65.
Using a two parameter model pseudopotential, in conjunction with the recent improved self-consistent dielectric function of Vashishta and Singwi, we have studied the phonon dispersion relations of cadmium which crystallizes in hcp structure with maximum anisotropy (). 相似文献
66.
The metallic interaction is split into (i) closed-shell part and (ii) ion- electron-ion part. The former is evaluated using non-central forces upto the third neighbour and the latter is obtained from the concept of bulk modulus of the electron gas. Phonon dispersion relations of h.c.p. scandium have been calculated and compared with the experimental results. 相似文献
67.
Photoacoustic spectroscopy (PAS) is one of the important branches of spectroscopy, which enables one to detect light-induced
heat production following the absorption of pulsed radiation by the sample. As2S3, As2Se3 and GeSe2 exhibit a wide variety of photo-induced phenomena that enable them to be used as optical imaging or storage medium and various
electronic devices, including electro-optic information storage devices and optical mass memories. Therefore, accurate measurement
of thermal properties of semiconducting films is necessary to study the memory density. The thermal conductivity of thin films
of As2S3 (thickness 100 μm and 80 μm), As2Se3 (thickness 100 μm and 80 μm) and GeSe2 (thickness 120 μm and 100 μm) has been measured using PAS technique. Our result shows that the thermal conductivity of thicker films is larger than the
thinner films. This can be explained by the thermal resistance effect between the film and the surface of the substrate.
相似文献
68.
R. A. Ganeev P. A. Naik H. Singhal U. Chakravarty V. Arora J. A. Chakera M. Raghuramaiah R. A. Khan S. R. Kumbhare R. P. Kushwaha P. D. Gupta 《Optics and Spectroscopy》2007,102(6):949-959
A significant increase, as well as a decrease, in the intensity of single higher harmonics of femtosecond radiation of a Ti:sapphire laser that are generated in a weakly excited laser plasma on the surface of GaAs, Cr, InSb, In, and stainless steel is demonstrated. The intensities of some higher harmonics in different regions of their plateaulike distribution varied from a 23-fold excess over the intensity of the neighboring harmonics to the complete absence in the extreme ultraviolet spectrum. The specific features of a 200-fold increase in the intensity of the 13th harmonic generated in indium plasma are analyzed. These variations in the intensity distribution of harmonics in the plateau region are obtained by varying the chirp of laser pulses. 相似文献
69.
Acoustic band structure of periodic elastic composites 总被引:9,自引:0,他引:9
70.
Dwivedi A Mujtaba SF Kushwaha HN Ali D Yadav N Singh SK Ray RS 《Photochemistry and photobiology》2012,88(2):344-355
Levofloxacin (LVFX) is a broad spectrum third generation fluoroquinolone antibiotic, used in the treatment of severe or life-threatening bacterial infections. Photosensitizing mechanism of LVFX was investigated under the ambient environmental intensities of UV-A, UV-B and sunlight exposure. Phototoxic effects of LVFX were assessed on NIH-3T3 and HaCaT cell lines. Results identified first time three photoproducts of LVFX at ambient levels of UV-R by LC-MS/MS. The generation of reactive oxygen species (ROS) was investigated photochemically as well as intracellularly in HaCaT cell line. ROS were significantly quenched by specific quenchers like DABCO, NaN(3), D-mannitol and NAC. Photosensitized LVFX caused lipid peroxidation at different concentrations. Quenching study with superoxide dismutase confirms the LVFX-induced lipid photoperoxidation. Further, photocytotoxicity of LVFX showed significant reduction in cell viability by MTT and neutral red uptake assays. LVFX caused cell arrest in G2/M phases as well as induced apoptosis through ROS-dependent pathway. In addition, photosensitized LVFX also induced upregulation of p21 and Bax/Bcl-2 genes ratio. India is a tropical country and most of the human activities such as agriculture, commerce, sports, etc. take place in bright sunlight; therefore, photosensitive LVFX may lead to skin/ocular disorders and immune suppression. Information is needed regarding the phototoxicity of LVFX for human safety. 相似文献