全文获取类型
收费全文 | 36050篇 |
免费 | 5639篇 |
国内免费 | 3254篇 |
专业分类
化学 | 13101篇 |
晶体学 | 209篇 |
力学 | 1658篇 |
综合类 | 602篇 |
数学 | 9527篇 |
物理学 | 19846篇 |
出版年
2024年 | 96篇 |
2023年 | 424篇 |
2022年 | 1152篇 |
2021年 | 1158篇 |
2020年 | 1064篇 |
2019年 | 995篇 |
2018年 | 914篇 |
2017年 | 1024篇 |
2016年 | 1244篇 |
2015年 | 1083篇 |
2014年 | 1633篇 |
2013年 | 2446篇 |
2012年 | 1788篇 |
2011年 | 2081篇 |
2010年 | 1852篇 |
2009年 | 2288篇 |
2008年 | 2507篇 |
2007年 | 2534篇 |
2006年 | 2341篇 |
2005年 | 1814篇 |
2004年 | 1610篇 |
2003年 | 1498篇 |
2002年 | 1465篇 |
2001年 | 1217篇 |
2000年 | 1146篇 |
1999年 | 952篇 |
1998年 | 898篇 |
1997年 | 639篇 |
1996年 | 508篇 |
1995年 | 438篇 |
1994年 | 364篇 |
1993年 | 345篇 |
1992年 | 433篇 |
1991年 | 257篇 |
1990年 | 223篇 |
1989年 | 208篇 |
1988年 | 168篇 |
1987年 | 159篇 |
1986年 | 125篇 |
1985年 | 136篇 |
1984年 | 135篇 |
1983年 | 77篇 |
1982年 | 151篇 |
1981年 | 211篇 |
1980年 | 211篇 |
1979年 | 228篇 |
1978年 | 202篇 |
1977年 | 131篇 |
1976年 | 129篇 |
1973年 | 94篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
M. Brando N. Büttgen V. Fritsch J. Hemberger H. Kaps H.-A. Krug von Nidda M. Nicklas K. Pucher W. Trinkl A. Loidl E.W. Scheidt M. Klemm S. Horn 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,25(3):289-298
We present susceptibility, microwave resistivity, NMR and heat-capacity results for Li1-xZnx(V1-yTiy)2O4 with 0 ?
x
? 0.3 and 0 ?
y
? 0.3. For all doping levels the susceptibility curves can be fitted with a Curie-Weiss law. The paramagnetic Curie-Weiss temperatures
remain negative with an average value close to that of the pure compound Θ≈ - 36 K. Spin-glass anomalies are observed in the susceptibility, heat-capacity and NMR measurements for both type of dopants.
From the temperature dependence of the spin-lattice relaxation rate we found critical-dynamic behavior in the Zn doped compounds
at the freezing temperatures. For the Ti-doped samples two successive freezing transitions into disordered low-temperature
states can be detected. The temperature dependence of the heat capacity for Zn-doped compounds does not resemble that of canonical
spin glasses and only a small fraction of the total vanadium entropy is frozen at the spin-glass transitions. For pure LiV2O4 the spin-glass transition is completely suppressed. The temperature dependence of the heat capacity for LiV2O4 can be described using a nuclear Schottky contribution and the non-Fermi liquid model, appropriate for a system close to
a spin-glass quantum critical point. Finally an (
x
/
y
,
T
)-phase diagram for the low-doping regime is presented.
Received 16 March 2001 and Received in final form 30 October 2001 相似文献
72.
73.
74.
Mingxin Wang 《Journal of Mathematical Analysis and Applications》2002,274(1):424-436
This paper deals with positive solutions of degenerate and quasilinear parabolic systems not in divergence form: ut=up(Δu+av), vt=vq(Δv+bu), with null Dirichlet boundary conditions and positive initial conditions, where p, q, a and b are all positive constants. The local existence and uniqueness of classical solution are proved. Moreover, it will be proved that all solutions exist globally if and only if ab?λ12, where λ1 is the first eigenvalue of −Δ in Ω with homogeneous Dirichlet boundary condition. 相似文献
75.
76.
Examples are worked out using a new equation proposed in the previous paper to show that it has new physical predictions for mesoscopic systems. 相似文献
77.
78.
X-ray diffraction patterns of nanocrystalline Fe-Cu-Nb-Si-B (FINEMET) alloys reveal that bcc α-Fe/α-FeSi crystallites with
the average grain size of 20(5) nm are dispersed in amorphous matrix. Enhanced electron—electron interaction (EEI) and quantum
interference (QI) effects as well as electron-magnon (and/or electron-spin fluctuation) scattering turn out to be the main
mechanisms that govern the temperature dependence of resistivity. Of all the inelastic scattering processes, inelastic electron-phonon
scattering is the most effective mechanism to destroy phase coherence of electron wave functions. The diffusion constant,
density of states at the Fermi level and the inelastic scattering time have been estimated, for the first time, for the alloys
in question
Article presented at the International Symposium on Advances in Superconductivity and Magnetism: Materials, Mechanisms and
Devices, ASMM2D-2001, 25–28 September 2001, Mangalore, India. 相似文献
79.
Fillmore在[1]中得到一个定理:设A,T是Banach空间X上的线性变换,A有界,若Lat(A) Lat(T)且AT=TA,则T是A的多项式.在本文里,以此作为引理,讨论了Banach空间上可逆线性变换A在什么情况下,A-1可表示为A的多项式.本文最主要的结论是定理3.4:设X是Banach空间,A是X上的有界线性变换,且可逆,则A-1是A的多项式当且仅当A-1是A的局部多项式. 相似文献
80.
A. Khrennikov 《Annalen der Physik》2003,12(10):575-585
We study the probabilistic consequences of the choice of the basic number field in the quantum formalism. We demonstrate that by choosing a number field for a linear space representation of quantum model it is possible to describe various interference phenomena. We analyse interference of probabilistic alternatives induced by real, complex, hyperbolic (Clifford) and p‐adic representations. 相似文献