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941.
942.
Vasily Lavrentiev Jiri Vacik Hiroshi Naramoto 《Applied Physics A: Materials Science & Processing》2008,92(3):673-680
Glassy carbon (GC) was implanted by 150 keV Co+ ions to the doses of 1×1016 (low dose) and 1×1017 ions/cm2 (high dose). The low dose implantation results in GC structure disordering with formation of amorphous carbon (a-C). Analysis
of Rutherford backscattering (RBS) and Raman spectra has revealed 15 at.% of sp3-bonded C atoms in the a-C structure. The in-pane size of sp2 clusters was estimated to be 1.1 nm. On the contrary, the high dose ion implantation results in ordering of the a-C structure.
Content of the sp3 atoms in a-C was reduced to about 5% and, respectively, the in-plane sp2 cluster size was increased up to 2.8 nm. Together with the a-C structure ordering the Raman spectra identifies formation
of transpolyacetylene (TPA)-like chains after the high-dose Co+ implantation. In parallel, RBS suggests an enhanced diffusion of the implanted cobalt within the modified carbon layer. Correlation
of the RBS and Raman results argues a driving role of cobalt diffusion in the TPA-like chains formation and a-C ordering.
Great surface roughening observed after the high dose Co+ implantation suggests also the pronounced cobalt clustering causing large flux of “free volume” to the surface. 相似文献
943.
944.
Kai Yang Xiuling Zhang Dr. Mohanapriya Venkataraman Prof. Dr. Jakub Wiener Xiaodong Tan Prof. Dr. Guocheng Zhu Prof. Dr. Juming Yao Prof. Dr. Jiri Militky 《Chemphyschem》2023,24(19):e202300234
Phase change materials (PCMs) textiles have been developed for personal thermal management (PTM) while limited loading amount of PCMs in textiles reduced thermal buffering effect. In this work, we proposed a sandwich fibrous encapsulation to store polyethylene glycol (PEG) with PEG loading amount of 45 wt %, which consisted of polyester (PET) fabrics with hydrophobic coating as protection layers, polyurethane (PU) nanofibrous membranes as barrier layers and PEG-loaded viscose fabric as a PCM-loaded layer. The leakage was totally avoided by controlling weak interfacial adhesion between protection layer and melting PEG. The sandwich fibrous PEG encapsulations had an overall melting enthalpy value ranging from 50 J/g to 78 J/g and melting points ranging from 20 °C to 63 °C by using different PEGs. Besides, introduction of Fe microparticles in PCM-loaded layer enhanced thermal energy storage efficiency. We believe that the sandwich fibrous PEG encapsulation has a great potential in various fields. 相似文献
945.
A residual existence theorem for linear equations 总被引:1,自引:0,他引:1
Jiri Rohn 《Optimization Letters》2010,4(2):287-292
A residual existence theorem for linear equations is proved: if ${A \in \mathbb{R}^{m\times n}}$ , ${b \in \mathbb{R}^{m}}$ and if X is a finite subset of ${\mathbb{R}^{n}}$ satisfying ${{\rm max}_{x \in X}p^T(Ax-b) \geq 0}$ for each ${p \in \mathbb{R}^{m}}$ , then the system of linear equations Ax = b has a solution in the convex hull of X. An application of this result to unique solvability of the absolute value equation Ax + B|x| = b is given. 相似文献
946.
M. Novak I. Kokanović M. Baćani D. Babić 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,83(1):57-61
The static magnetic susceptibility (χ) of own-made HCl-doped polyaniline pellets is investigated experimentally over the full range of the protonation level Y and in the temperature (T) range 10–300 K.The obtained results suggest that χ and the electrical conductivity σ – which is known from previous work – are interrelated.Namely, there is a weakly Y dependent crossover temperature T * where both χ and σ undergo notable changes.In χ, this refers to a simultaneous enhancement (reduction) of the Pauli-type susceptibility χ P and reduction (enhancement) of the Curie constant C at T = T * when T increases (decreases).Below T < T *, where thermal effects are weak to moderate, a steep increase of χ P(Y) around Y = 0.3 occurs together with a drop of C(Y).The above findings are consistent with a picture in which, at T *, spins that disappear from C reappear in χ P, and vice versa.This model is used to address the longitudinal and transversal electron localisation lengths as functions of Y, the former being estimated to take values in the range 7–8 Åand the latter in the range 1–2 Å. 相似文献
947.
Multiwall carbon nanotubes and conducting polyaniline, doped with dodecylbenzenesulfonic acid, are blended by employing the solubility of both materials in chloroform. Pellets are made by pressing the dried powder of the obtained composite, and films by sedimentary deposition onto a plastic substrate. In these composites, the advantageous properties of carbon nanotubes can be utilized in fully conducting bulk and planar structures while the strong decrease of the conductivity of doped polyaniline at low temperatures is simultaneously suppressed. The nanotube content in pellets can be as high as 40% by weight, and this wide range leads to a control over the shape and magnitude of the conductivity versus temperature curves. As the nanotube content grows, the temperature dependence of the conductivity becomes less steep, which is similar to the effect of annealing temperature on the conductivity of certain polycrystalline graphene films. In our case, this change is most likely caused by the increase of the density of highly conducting channels and not by homogeneous delocalization effects. 相似文献
948.
Jiri Rohn 《Mathematical Programming》1990,46(1-3):255-256
We give a short proof of the finiteness of Murty's principal pivoting algorithm for solving the linear complementarity problemy = Mz + q, y
T
z = 0,y 0,z 0 withP-matrixM. 相似文献
949.
High dimensional polynomial interpolation on sparse grids 总被引:2,自引:0,他引:2
Barthelmann Volker Novak Erich Ritter Klaus 《Advances in Computational Mathematics》2000,12(4):273-288
We study polynomial interpolation on a d-dimensional cube, where d is large. We suggest to use the least solution at sparse grids with the extrema of the Chebyshev polynomials. The polynomial
exactness of this method is almost optimal. Our error bounds show that the method is universal, i.e., almost optimal for many
different function spaces. We report on numerical experiments for d = 10 using up to 652 065 interpolation points.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
950.