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981.
982.
983.
A continuous–discontinuous second‐order transition in the satisfiability of random Horn‐SAT formulas
Cristopher Moore Gabriel Istrate Demetrios Demopoulos Moshe Y. Vardi 《Random Structures and Algorithms》2007,31(2):173-185
We compute the probability of satisfiability of a class of random Horn‐SAT formulae, motivated by a connection with the nonemptiness problem of finite tree automata. In particular, when the maximum clause length is three, this model displays a curve in its parameter space, along which the probability of satisfiability is discontinuous, ending in a second‐order phase transition where it is continuous but its derivative diverges. This is the first case in which a phase transition of this type has been rigorously established for a random constraint satisfaction problem. © 2007 Wiley Periodicals, Inc. Random Struct. Alg., 2007 相似文献
984.
本文提出了Pr_6O_(11)样品ICP摄谱分析时干扰系数法校正光谱干扰的方法和相应的计算机软件系统。建立了Pr基体对14种稀土杂质元素24条灵敏分析线的干扰系数表(KCT),利用所提出的方法分析了Pr_6O_(11)合成样品,由91个实验点所得回收结果可知,回收率在90~110%之间的占93.4%。可见校正是相当有效和十分必要的。 相似文献
985.
986.
Summary The Korteweg-de Vries equation for ion acoustic waves in the presence of weakly relativistic ion streaming velocity is derived
in a magnetic plasma. It is found that relativistic effects are important in the solitary wave propagation for both fast and
slow modes. Earlier results are reconfirmed.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
987.
N. Jachowicz G. C. McLaughlin 《The European Physical Journal A - Hadrons and Nuclei》2006,29(1):43-47
We argue that isotropization and, consequently, thermalization of the system of gluons and quarks produced in an ultrarelativistic
heavy-ion collision does not follow from Feynman diagram analysis to any order in the coupling constant. We conclude that
the apparent thermalization of quarks and gluons, leading to success of perfect fluid hydrodynamics in describing heavy-ion
collisions at RHIC, can only be attributed to the non-perturbative QCD effects not captured by Feynman diagrams. We proceed
by modeling these non-pertrubative thermalization effects using viscous hydrodynamics. We point out that matching Color Glass
Condensate inital conditions with viscous hydrodynamics leads to a continuous evolution of all the components of the energy-momentum
tensor and, unlike the case of ideal hydrodynamics, does not give rise to a discontinuity in the longitudinal pressure. An
important consequence of such a matching is a relationship between the thermalization time and shear viscosity: we observe
that small viscosity leads to short thermalization time. 相似文献
988.
J. Hafiz R. Mukherjee X. Wang M. Cullinan J.V.R. Heberlein P.H. McMurry S.L. Girshick 《Journal of nanoparticle research》2006,8(6):995-1002
The synthesis of silicon nanowires that are densely coated with silicon nanoparticles is reported. These structures were produced in a two-step process, using a method known as hypersonic plasma particle deposition. In the first step, a Ti–Si nanoparticle film was deposited. In the second step the Ti-source was switched off, and nanoparticle-coated nanowires grew under the simultaneous action of Si vapor deposition and bombardment by Si nanoparticles. Total process time, including both steps, equaled 5 min, and resulted in formation of a dense network of randomly oriented nanowires covering1.5 cm2 of substrate area. The nanowires are composed of single-crystal Si. The diameters of the nanowires vary over the range
100–800 nm. Each nanowire has a crystalline TiSi2 catalyst particle, believed to have been solid during nanowire growth, at its tip. 相似文献
989.
N. K. Dutta N. D. Tran N. R. Choudhury 《Journal of Polymer Science.Polymer Physics》2005,43(11):1392-1400
Scanning thermal microscopy (SThM) has been used for the visualization and characterization of an ultrathin plasma polymer film of perfluoro(methylcyclohexane) at a submicrometer level. The morphology, molecular dynamics, and lateral homogeneity of the ultrathin film have all been examined precisely with SThM. The growth of the plasma polymer film on a silicon wafer (Si‐wafer) has also been precisely determined using a new burning‐hole technique. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1392–1400, 2005 相似文献
990.
Benjamin Bederson 《Physics in Perspective (PIP)》2005,7(4):453-472
I discuss the family background and early life of the German theoretical physicist Fritz Reiche (1883–1969) in Berlin; his
higher education at the University of Berlin under Max Planck (1858–1947); his subsequent work at the University of Breslau
with Otto Lummer (1860–1925); his return to Berlin in 1911, where he completed his Habilitation thesis in 1913, married Bertha
Ochs the following year, became a friend of Albert Einstein (1879–1955), and worked during and immediately after the Great
War. In 1921 he was appointed as ordentlicher Professor of Theoretical Physics at the University of Breslau and worked there until he was dismissed in 1933. He spent the academic
year 1934–1935 as a visiting professor at the German University in Prague and then returned to Berlin, where he remained until,
with the crucial help of his friend Rudolf Ladenburg (1882–1952) and vital assistance of the Emergency Committee in Aid of
Displaced Foreign Scholars, he, his wife Bertha, and their daughter Eve were able to emigrate to the United States in 1941
(their son Hans had already emigrated to England in 1939).From 1941–1946 he held appointments at the New School for Social
Research in New York, the City College of New York, and Union College in Schenectady, New York, and then was appointed as
an Adjunct Professor of Physics at New York University, where his contract was renewed year-by-year until his retirement in
1958. 相似文献