全文获取类型
收费全文 | 91篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学 | 20篇 |
晶体学 | 1篇 |
数学 | 16篇 |
物理学 | 55篇 |
出版年
2022年 | 2篇 |
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2016年 | 3篇 |
2014年 | 4篇 |
2013年 | 10篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2000年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1975年 | 1篇 |
排序方式: 共有92条查询结果,搜索用时 0 毫秒
51.
We report the observation of a propounced peak in surface resistance at microwave frequencies of 4.88 GHz and 9.55 GHz and
its disappearance after irradiation with swift ions in laser ablated DyBa2Cu3O7-δ (DBCO) thin films. The measurements were carried out in zero field as well as in the presence of magnetic fields (up to 0.8
T). The films were irradiated using 90 MeV oxygen ions at Nuclear Science Centre, New Delhi at a fluence of 3×1013 ions/cm2. Introduction of point defects and extended defects after irradiation suppresses the peak at 9.55 GHz whereas no suppression
is observed at 4.88 GHz. These results and the vortex dynamics in the films at microwave frequencies before and after irradiation
are discussed. 相似文献
52.
Shiv P. Patel J.C. Pivin M.K Patel Jonghan Won Ramesh Chandra D. Kanjilal Lokendra Kumar 《Journal of magnetism and magnetic materials》2012
The effect of swift heavy ions (SHI) on magnetic ordering in ZnS thin films with Co ions substituted on Zn sites is investigated. The materials have been synthesized by pulsed laser deposition on substrates held at 600 °C for obtaining films with wurtzite crystal structure and it showed ferromagnetic ordering up to room temperature with a paramagnetic component. 120 MeV Ag ions have been used at different fluences of 1×1011 ions/cm2 and 1×1012 ions/cm2 for SHI induced modifications. The long range correlation between paramagnetic spins on Co ions was destroyed by irradiation and the material became purely paramagnetic. The effect is ascribed to the formation of cylindrical ion tracks due to the thermal spikes resulting from electron–phonon coupling. 相似文献
53.
Madhavi Thakurdesai T. Mohanty D. Kanjilal Varsha Bhattacharyya 《Applied Surface Science》2009,255(21):8935-8940
Nanocrystalline TiO2 structures are formed by irradiation of 100 MeV Au8+ ion beam on amorphous thin films of TiO2. Surface morphology of the nanocrystals is studied by Atomic Force Microscopy (AFM). Amorphous to nanocrystalline phase transformation is identified by Glancing Angle X-ray Diffraction (GAXRD) and Raman spectroscopic studies. Optical characterization is carried out by UV-VIS spectroscopy technique. Blue shift observed in absorption band edge indicates the formation of nanophase TiO2 after irradiation. The impinging swift heavy ion (100 MeV Au8+) induces nucleation of nanoparticles along the ion trajectory through inelastic collisions of the projectile with electrons of the material. It is observed that the shape and size of nanoparticles formed is dependant on the irradiation fluence. 相似文献
54.
R. Vishnoi R. Singhal K. Asokan D. Kanjilal D. Kaur 《Applied Physics A: Materials Science & Processing》2012,107(4):925-934
The effects of 200 MeV Au ions irradiation on the structural and magnetic properties of Ni–Mn–Sn ferromagnetic shape memory alloy (FSMA) thin films have been systematically investigated. In order to understand the role of initial microstructure and phase of the film with respect to high energy irradiation, the two types of Ni–Mn–Sn FSMA films having different phases at room temperature were irradiated, one in martensite phase (Ni58.9Mn28.0Sn13.1) and other in austenite phase (Ni50Mn35.6Sn14.4). Transmission electron microscope (TEM) and scanning electron microscope (SEM) images along with the diffraction patterns of X-rays and electrons confirm that martensite phase transforms to austenite phase at a fluence of 6×1012 ions/cm2 and a complete amorphization occurs at a fluence of 3×1013 ions/cm2, whereas ion irradiation has a minimal effect on the austenitic structure (Ni50Mn35.6Sn14.4). Thermo-magnetic measurements also support the above mentioned behaviour of Ni–Mn–Sn FSMA films with increasing fluence of 200 MeV Au ions. The results are explained on the basis of thermal spike model considering the core and halo regions of ion tracks in FSMA materials. 相似文献
55.
S. Chandramohan R. Sathyamoorthy P. Sudhagar D. Kanjilal D. Kabiraj K. Asokan V. Ganesan T. Shripathi U. P. Deshpande 《Applied Physics A: Materials Science & Processing》2009,94(3):703-714
The effect of high electronic energy deposition on the structure, surface topography, optical properties, and electronic structure
of cadmium sulfide (CdS) thin films have been investigated by irradiating the films with 100 MeV Ag+7 ions at different ion fluences in the range of 1012–1013 ions/cm2. The CdS films were deposited on glass substrate by thermal evaporation, and the films studied in the present work are polycrystalline
with crystallites preferentially oriented along (002)-H direction. It is shown that swift heavy ion (SHI) irradiation leads
to grain agglomeration and hence an increase in the grain size at low ion fluences. The observed lattice compaction was related
to irradiation induced polygonization. The optical band gap energy decreased after irradiation, possibly due to the combined
effect of change in the grain size and in the creation of intermediate energy levels. Enhanced nonradiative recombination
via additional deep levels, introduced by SHI irradiation was noticed from photoluminescence (PL) analysis. A shift in the
core levels associated with the change in Fermi level position was realized from XPS analysis. The chemistry of CdS film surface
was studied which showed profound chemisorption of oxygen on the surface of CdS. 相似文献
56.
Thermoluminescence properties of barium strontium mixed sulfate have been studied by irradiation with Argon ions. The sample was recrystallized by chemical co-precipitation techniques using H2SO4. The X-ray diffraction study of prepared sample suggests the orthorhombic structure with average grain size of 60 nm. The samples were irradiated with 1.2 MeV Argon ions at fluences varying between 1011 and 1015 ions/cm2. The argon ions penetrate to the depth of 1.89 μm and lose their energy mainly via electronic stopping. Due to ion irradiation, a large number of defects in the sample are formed. Thermally stimulated luminescence (TSL) glow curves of ion irradiated Ba0.12Sr0.88SO4 phosphor exhibit broad peak with maximum intensity at 495 K composed of four overlapping peaks. This indicates that different sets of traps are being activated within the particular temperature range each with its own value of activation energy (E) and frequency factor (s). Thermoluminescence (TL) glow curves were recorded for each of the ion fluences. A linear increase in intensity of TL glow peaks was found with the increase in ion dose from 59 kGy to 5.9 MGy. The kinetic parameters associated with the prominent glow peaks were calculated using glow curve deconvolution (GCD), different glow curve shape and sample heating rate methods. 相似文献
57.
K. ElayarajaM.I. Ahymah Joshy R.V. SuganthiS. Narayana Kalkura M. PalanichamyM. Ashok V.V. SivakumarP.K. Kulriya I. SulaniaD. Kanjilal K. Asokan 《Applied Surface Science》2011,257(6):2134-2141
Titanium substrate was coated with hydroxyapatite by radiofrequency magnetron sputtering (rf-magnetron sputtering) technique and subjected to swift heavy ion (SHI) irradiation of 125 MeV with Si9+ at fluences of 1 × 1010, 1 × 1011 and 1 × 1012 ions/cm2. The glancing incidence X-ray diffraction (GIXRD) analysis confirmed the HAp phase of the irradiated film. There was a considerable decrease in crystallinity and particle size after irradiation. In addition, DRS-UV reflectance spectra revealed a decrease in optical band gap (Eg) from 5.2 to 4.6 eV. Wettability of biocompatible materials plays an important role in biological cells proliferation for tissue engineering, drug delivery, gene transfer and bone growth. HAp thin films irradiated with 1 × 1011 ions/cm2 fluence showed significant increase in wettability. While the SHI irradiated samples exhibited enhanced bioactivity, there was no significant variation in cell viability. Surface roughness, pores and average particle size were analyzed by atomic force microscopy (AFM). 相似文献
58.
Ahmed SU Singh SK Pandey A Kanjilal S Prasad RB 《Applied biochemistry and biotechnology》2009,152(1):108-116
To study the effect of agitation speed (rpm) and dissolved oxygen concentration (DO) on the production of gamma linolenic
acid by Mucor sp. RRL001, a central composite design experiment was performed in a 5-L stirred tank bioreactor. The design consisted of
a total of 10 runs consisting of runs at five levels for each factor and was divided in two blocks. The ANOVA analysis and
Pareto chart of effects suggested agitation speed (p = 0.0142) linear effect and DO concentration (p = 0.0342) quadratic effects were significant factors with significant contribution to the response. The validation run based
on the optimum production zone in response surface plot resulted in the maximum 350.3 mg l−1 GLA yield as compared with model predicted value of 340.7 mg l−1. The study suggests that agitation rate is having more pronounced effect on GLA yield than dissolved oxygen concentration
by ensuring enhanced mass transfer and by preventing wall growth at elevated agitation speed. Also, it shows that higher GLA
yields can be obtained in a simple medium at moderate oxygen saturation and that the Mucor sp. RRL001 is resistant to high agitation linked shear stress and suitable for GLA production at higher scale. 相似文献
59.
Mirkovi?–Vilonen (MV) polytopes have proven to be a useful tool in understanding and unifying many constructions of crystals for finite-type Kac-Moody algebras. These polytopes arise naturally in many places, including the affine Grassmannian, pre-projective algebras, PBW bases, and KLR algebras. There has recently been progress in extending this theory to the affine Kac-Moody algebras. A definition of MV polytopes in symmetric affine cases has been proposed using pre-projective algebras. In the rank-2 affine cases, a combinatorial definition has also been proposed. Additionally, the theory of PBW bases has been extended to affine cases, and, at least in rank-2, we show that this can also be used to define MV polytopes. The main result of this paper is that these three notions of MV polytope all agree in the relevant rank-2 cases. Our main tool is a new characterization of rank-2 affine MV polytopes. 相似文献
60.