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31.
The spring-defect model developed by us in the accompanying paper I to discuss ferroelasticity, exhibited in the BCT phase
of α-iron (BCC metals), is used to analyse anelastic relaxation across the paraelastic to ferroelastic phase transition. The
kinetics of the underlying Hamiltonian representing strain-strain interactions is treated within mean-field theory. The relaxation-response
relation of the linear response theory is employed to derive explicit expressions for the anelastic strain, the frequency-dependent
compliance and the internal friction in terms of the basic parameters of the spring-defect model. 相似文献
32.
Sangita Das Krishnendu Aich Lakshman Patra Kakali Ghoshal Saswati Gharami Maitree Bhattacharyya Tapan Kumar Mondal 《Tetrahedron letters》2018,59(12):1130-1135
Increased oxidative stress in metabolic complications like type 2 diabetes, dyslipidemia and cardiovascular disorders exerts potential health hazards in many facets. Enhanced production of reactive oxygen species (ROS) due to increased oxidative stress promotes the damage of many biologically important macromolecules. Hypochlorous acid (HOCl), a microbicidal agent is also known to be an important ROS sub-species. An enhanced generation of endogenous HOCl due to diseased condition therefore can be detrimental to health. In present work, a new quinoline-diaminomaleonitrile based probe (HQMN) has been designed for the selective detection of hypochlorite. The probe in hand shows a selective ratiometric emission change towards OCl?. The probe behaves as a highly selective and sensitive tool for the detection of OCl? over other analytes with a fast response time (within 100 s). Bioimaging study revealed that HQMN can detect endogenous OCl? in human monocytes and an increase in endogenous HOCl concentration has been witnessed in diabetic condition compared to healthy control. Thus HQMN can be used as an excellent fluorescent probe for dynamic tracking of hypochorite in living biological cells especially to identify diabetic conditions. 相似文献
33.
This paper presents a theoretical model for computing the velocity and sediment concentration profiles in a uniform sediment-laden flow carrying all fine, medium and coarse sediments. The proposed model essentially includes the effect of sediment concentration in total turbulent shear stress and eddy diffusivity in addition to the modified mixing length derived by Umeyama and Gerritsen [J. Hydr. Engng., ASCE, 118 (2) (1992) 229–245] applied to Hunt’s diffusion equation. Numerical solution of coupled differential equations for velocity and sediment concentration is carried out. The theoretical results show quite good agreement with the experimental data. 相似文献
34.
The response of giant magnetoresistance (GMR) devices depends critically on the film microstructure, with parameters such
as layer thickness and interfacial abruptness being crucial. This paper presents results obtained using high resolution electron
microscopy (HREM), chemical mapping and atom probe microanalysis. Local variations in the magnetic properties are induced
by the microstructure and also when the films are patterned to form small elements. These lead to changes in the magnetization
reversal mechanism. Some results of the studies of the magnetization reversal carried out using in situ in Lorentz transmission electron microscopy (LTEM) magnetizing experiments are also included. 相似文献
35.
Prabu Manoharan R. S. K. Vijayan Nanda Ghoshal 《Journal of computer-aided molecular design》2010,24(10):843-864
The ability to identify fragments that interact with a biological target is a key step in FBDD. To date, the concept of fragment
based drug design (FBDD) is increasingly driven by bio-physical methods. To expand the boundaries of QSAR paradigm, and to
rationalize FBDD using In silico approach, we propose a fragment based QSAR methodology referred here in as FB-QSAR. The FB-QSAR methodology was validated
on a dataset consisting of 52 Hydroxy ethylamine (HEA) inhibitors, disclosed by GlaxoSmithKline Pharmaceuticals as potential anti-Alzheimer agents. To address the issue of target selectivity, a major confounding factor
in the development of selective BACE1 inhibitors, FB-QSSR models were developed using the reported off target activity values.
A heat map constructed, based on the activity and selectivity profile of the individual R-group fragments, and was in turn
used to identify superior R-group fragments. Further, simultaneous optimization of multiple properties, an issue encountered
in real-world drug discovery scenario, and often overlooked in QSAR approaches, was addressed using a Multi Objective (MO-QSPR)
method that balances properties, based on the defined objectives. MO-QSPR was implemented using Derringer and Suich desirability
algorithm to identify the optimal level of independent variables (X) that could confer a trade-off between selectivity and activity. The results obtained from FB-QSAR were further substantiated
using MIF (Molecular Interaction Fields) studies. To exemplify the potentials of FB-QSAR and MO-QSPR in a pragmatic fashion,
the insights gleaned from the MO-QSPR study was reverse engineered using Inverse-QSAR in a combinatorial fashion to enumerate
some prospective novel, potent and selective BACE1 inhibitors. 相似文献
36.
Effects of annealing temperature on shape transformation and optical properties of germanium quantum dots 下载免费PDF全文
The influences of thermal annealing on the structural and optical features of radio frequency(rf) magnetron sputtered self-assembled Ge quantum dots(QDs) on Si(100) are investigated.Preferentially oriented structures of Ge along the(220) and(111) directions together with peak shift and reduced strain(4.9%to 2.7%) due to post-annealing at 650 ℃ are discerned from x-ray differaction(XRD) measurement.Atomic force microscopy(AFM) images for both pre-annealed and post-annealed(650 ℃) samples reveal pyramidal-shaped QDs(density ~ 0.26×10~(11) cm~(-2)) and dome-shape morphologies with relatively high density ~ 0.92×10~(11) cm~(-2),respectively.This shape transformation is attributed to the mechanism of inter-diffusion of Si in Ge interfacial intermixing and strain non-uniformity.The annealing temperature assisted QDs structural evolution is explained using the theory of nucleation and growth kinetics where free energy minimization plays a pivotal role.The observed red-shift ~ 0.05 eV in addition to the narrowing of the photoluminescence peaks results from thermal annealing,and is related to the effect of quantum confinement.Furthermore,the appearance of a blue-violet emission peak is ascribed to the recombination of the localized electrons in the Ge-QDs/SiO_2 or GeO_x and holes in the ground state of Ge dots.Raman spectra of both samples exhibit an intense Ge-Ge optical phonon mode which shifts towards higher frequency compared with those of the bulk counterpart.An experimental Raman profile is fitted to the models of phonon confinement and size distribution combined with phonon confinement to estimate the mean dot sizes.A correlation between thermal annealing and modifications of the structural and optical behavior of Ge QDs is established.Tunable growth of Ge QDs with superior properties suitable for optoelectronic applications is demonstrated. 相似文献
37.
A Triphenyl Amine‐Based Solvatofluorochromic Dye for the Selective and Ratiometric Sensing of OCl− in Human Blood Cells 下载免费PDF全文
Prof. Shyamaprosad Goswami Krishnendu Aich Sangita Das Bholanath Pakhira Kakali Ghoshal Dr. Ching Kheng Quah Dr. Maitree Bhattacharyya Prof. Hoong‐Kun Fun Prof. Sabyasachi Sarkar 《化学:亚洲杂志》2015,10(3):694-700
A new visible‐light‐excitable fluorescence ratiometric probe for OCl? has been developed based on a triphenylamine‐diamiomaleonitrile (TAM) moiety. The structure of the dye was confirmed by single‐crystal X‐ray analysis. It behaves as a highly selective and sensitive probe for OCl? over other analytes with a fast response time (~100 s). OCl? reacts with the probe leading to the formation of the corresponding aldehyde in a mixed‐aqueous system. The detection limit of the probe is in the 10?8 M range. The probe (TAM) also exhibits solvatofluorochromism. Changing the solvent from non‐polar to polar, the emission band of TAM largely red‐shifted. Moreover, the probe shows an excellent performance in real‐life application in detecting OCl? in human blood cells. The experimentally observed changes in the structure and electronic properties of the probe after reaction with OCl? were studied by DFT and TDDFT computational calculations. 相似文献
38.
We model a system of networking agents that seek to optimize their centrality in the network while keeping their cost, the number of connections they are participating in, low. Unlike other game-theory based models for network evolution, the success of the agents is related only to their position in the network. The agents use strategies based on local information to improve their chance of success. Both the evolution of strategies and network structure are investigated. We find a dramatic time evolution with cascades of strategy change accompanied by a change in network structure. On average the network self-organizes to a state close to the transition between a fragmented state and a state with a giant component. Furthermore, with increasing system size both the average degree and the level of fragmentation decreases. 相似文献
39.
Ghoshal D 《Physical review letters》2006,97(15):151601
A class of models called p-adic strings is useful in understanding the tachyonic instability of string theory. These are found to be empirically related to the ordinary strings in the p-->1 limit. We propose that these models provide discretization for the string worldsheet and argue that the limit is naturally thought of as a continuum limit in the sense of the renormalization group. 相似文献
40.
A. Ghoshal Y. K. Ho 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(3):581-589
Elastic scattering of positrons from the hydrogen atoms in weakly-coupled plasmas has
been studied using an expression for partial wave scattering amplitude that
has been derived within the framework second order distorted wave Born approximation.
The interactions among the charged particles in the plasma have been represented by Debye-Hückel potentials. A detailed study
has been made on differential and total cross sections in the energy range 20–300 eV. To the best of our knowledge such a
study on the differential and total cross sections for elastic positron-hydrogen collisions in a weakly-coupled plasma environment
is reported for the first time in the literature. 相似文献