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121.
Das A Hübner A Weber M Bolte M Lerner HW Wagner M 《Chemical communications (Cambridge, England)》2011,47(40):11339-11341
The dimethyl sulfide adduct 2(DMS) is a crystalline storage form of the unstable hydroboration reagent 9-H-9-borafluorene (2); 2(DMS) is available by the addition of DMS to either in situ generated [2](2) or 1,2-(2,2'-biphenylylene)diborane(6) (7). 相似文献
122.
A new anthracenyl-imino-glucosyl conjugate (L) selectively senses Hg(2+) by turn-on fluorescence with a 13 ± 1 fold enhancement by forming a 2?:?1 complex in pH 5 to 10 even in the presence of several biologically and ecologically relevant metal ions, with a 25 ± 2% fluorescence enhancement at the EPA limit of 2 ppb. L is equally sensitive towards Hg(2+) in the presence of albumin proteins and in blood serum and milk. 相似文献
123.
Tapas Mitra G. Sailakshmi A. Gnanamani A. B. Mandal 《Journal of Thermal Analysis and Calorimetry》2011,105(1):325-330
This study emphasizes, cross-linking potential of a simple di-carboxylic acid, namely, oxalic acid with type I collagen for
the preparation of collagen based biomaterial for clinical applications. Further the study discusses the characteristics features
of the cross-linked material in comparison with the standard cross-linker. In addition, the study also demonstrates the role
of ionic interactions in providing the thermal stability and tensile strength to the cross-linked biopolymer material. Type
I collagen from rat tail tendon treated with oxalic acid at optimized concentrations provided a biopolymer material without
changing the triple helical pattern of collagen (CD spectrum) and also with 6–7 fold increase in tensile strength than native
collagen. FTIR spectral details demonstrate the ionic interactions between collagen and oxalic acid. Thermal stability analyses
of oxalic acid cross-linked biopolymer revealed, high thermal stability compared to materials of glutaraldehyde cross-linked.
The results of the study suggest oxalic acid as a suitable cross-linker for collagen and it cross-link with collagen through
ionic interactions. 相似文献
124.
Gholamali Atefi Mohammad Reza Talaee 《Archive of Applied Mechanics (Ingenieur Archiv)》2011,81(5):569-583
Analytical solution of the non-Fourier Axisymmetric temperature field within a finite hollow cylinder is investigated considering
the Cattaneo-Vernotte constitutive heat flux relation. The solution is found for the most general linear time-independent
boundary conditions. The material is assumed to be homogeneous and isotropic with temperature-independent thermal properties.
The standard method of separation of variables is used. The present solution can be reduced to special problems of interest
by choosing appropriate boundary condition parameters. The solution is applied for two special cases including constant heat
flux and the Gaussian distribution heating of a cylinder, and their respective non-Fourier thermal behavior is studied. 相似文献
125.
From numerical and experimental investigations it has been recently established that convective heat transfer can be dramatically enhanced by the generation of longitudinal vortices in the flow. The phenomenological similarity between heat and mass transfer suggests that longitudinal vortices should increase also mass transfer. The mixing between two parallel streams of two components in a rectangular channel with and without a pair of rectangular winglets as vortex generators has been numerically investigated. The results show that one pair of vortex generators can increase the global mixing by more than 50 for laminar flow. This global mixing has been defined as the sum of the square of the differences of concentrations. 相似文献
126.
Indranil Chakraborty Debolina Mitra Satya P. Moulik 《Journal of nanoparticle research》2005,7(2):227-236
CdS is a large band gap material compared to HgS. Both are interesting from academic and technological points of view. The nanodispersions (colloids) of CdS and HgS as well their core-shell products and composites (co-colloids) were prepared by varied modes of precursor addition in micellar solution of cationic surfactant cetyltrimethylammonium bromide (CTAB). The prepared dispersions were studied by spectroscopic and electron microscopic techniques. 相似文献
127.
Konstantin Volosov Gautam Mitra Fabio Spagnolo Cormac Lucas 《Computational Optimization and Applications》2005,32(1-2):179-207
In this paper we formulate a model for foreign exchange exposure management and (international) cash management taking into consideration random fluctuations of exchange rates. A vector error correction model (VECM) is used to predict the random behaviour of the forward as well as spot rates connecting dollar and sterling. A two-stage stochastic programming (TWOSP) decision model is formulated using these random parameter values. This model computes currency hedging strategies, which provide rolling decisions of how much forward contracts should be bought and how much should be liquidated.The model decisions are investigated through ex post simulation and backtesting in which value at risk (VaR) for alternative decisions are computed. The investigation (a) shows that there is a considerable improvement to “spot only” strategy, (b) provides insight into how these decisions are made and (c) also validates the performance of this model. 相似文献
128.
A complex harmonic-oscillator basis is employed for the three-body problem obeying S
3-symmetry. Unlike a real basis it generates an additional quantum number (N
a
), in addition to the standard principal quantum number (N), and thus facilitates a more quantitative S
3-classification of the various states than is usually possible. It is shown that certain bilinear forms with definite S
3-symmetry properties, which can be constructed out of the linear harmonic-oscillator operators (a, a
†) satisfy several uncoupled sets of SO(2, 1) algebras with spectra bounded from below. It is also briefly indicated how this S
3-formalism can be adapted to the core structure of a more general relativistic three-particle system with unequal-mass kinematics
through an appropriate choice of internal variables.
Received May 11, 1994; revised November 3, 1994; accepted for publication November 23, 1994 相似文献
129.
130.
The deduction of the so well-renowned and established Laws of Kirchhoff relating to the currents flowing in a network, which are considered to be almost axiomatic in electrical engineering sciences, seems to be preposterous and non-sensical at first sight. However, on a closer examination it will appear that these laws are based on two principles, viz, the steady-state condition under which accumulation of free electrical charge is precluded, and, the experimentalOhm's Law, which propounds a linear relation between the difference of potential across a conductor and the total current flowing through the same. But, there are two things, which are normally overlooked. The conductors inKirchhoff's Laws are “wires”, which are one-dimensional lines, and theOhm's Law is the macroscopicOhm's Law for total currents applied to these lumped resistors. Strictly speaking, the “Laws” are to be deduced from the more fundamental electromagnetic equations for continuous media and the microscopicOhm's Law. It is to be noted that theKirchhoff Nodal Law is but a consequence of the steady state condition derivable from these basic equations, viz, the current-density is divergence-free. For a continuous medium, what the form of theKirchhoff's Laws will be, is difficult to guess unless deduced from the basic equations. Once these are established from the basic equations of electromagnetism for a continuous medium, the usual form ofKirchhoff's Laws will follow as corollary of the general case, as has been shown here. 相似文献