全文获取类型
收费全文 | 302篇 |
免费 | 5篇 |
国内免费 | 10篇 |
专业分类
化学 | 234篇 |
数学 | 9篇 |
物理学 | 74篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2014年 | 5篇 |
2012年 | 83篇 |
2011年 | 106篇 |
2010年 | 16篇 |
2009年 | 1篇 |
2008年 | 4篇 |
2007年 | 18篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1990年 | 2篇 |
排序方式: 共有317条查询结果,搜索用时 12 毫秒
91.
92.
We consider the nonstationary quantum relaxation of the Ising spin chain in a transverse field of strength h. Starting from a homogeneously magnetized initial state the system approaches a stationary state by a process possessing quasi-long-range correlations in time and space, independent of the value of h. In particular, the system exhibits aging (or lack of time-translational invariance on intermediate time scales) although no indications of coarsening are present. 相似文献
93.
为筛选更好的乙酰胆碱酯酶抑制剂, 应用1H NMR的方法研究了石杉碱甲的一个类似物——石杉碱戊与乙酰胆碱酯酶的结合性质, 获得了加乙酰胆碱酯酶([配体]∶[蛋白]=1∶0.005)和不加酶时石杉碱戊部分质子的非选择性、单选择性和双选择性的自旋晶格弛豫速率. 加酶后质子的选择性弛豫速率变化较大, 在T=298 K时石杉碱戊的H-1a/H-1b质子对的分子运动相关时间τ1a,1b由不加酶时的27.7 ps变化到结合酶后的11.7 ns, H-2/H-3质子对的分子运动相关时间τ2,3由35.2 ps变化到9.46 ns, 由此得出石杉碱戊与乙酰胆碱酯酶有较强的结合作用. 相似文献
94.
Dongyang Li Yulan Huang Zhiwei Ren Abbas Amini Aleksandra B.Djuri?i? Chun Cheng Gang Li 《Journal of Energy Chemistry》2023,(4):168-191
In recent years, inverted perovskite solar cells(IPSCs) have attracted significant attention due to their low-temperature and cost-effective fabrication processes, hysteresis-free properties, excellent stability,and wide application. The efficiency gap between IPSCs and regular structures has shrunk to less than 1%. Over the past few years, IPSC research has mainly focused on optimizing power conversion efficiency to accelerate the development of IPSCs. This review provides an overview of recent... 相似文献
95.
A. Turan Gürkanl 《数学物理学报(B辑英文版)》2007,27(1):107-116
Let G be a locally compact abelian group. The main purpose of this article is to find the space of multipliers from the Lorentz space L(p1, q1)(G) to L(p21,q21)(G). For this reason, the authors define the space Ap1,q1p2,q2(G), discuss its properties and prove that the space of multipliers from L(p1,q1)(G) to L(p21,q21)(G) is isometrically isomorphic to the dual of Ap1,q1p2q2(G). 相似文献
96.
Athanasios Zavras Antonija Mravak Margarita Bu?an?i? Jonathan M. White Vlasta Bona?i?-Koutecky Richard A. J. O''Hair 《化学物理学报》2019,32(2):182-186
本文合成一种新的双膦连接Ag60纳米团簇[{Cl@Ag12}@Ag48(dppm)12],并通过X射线晶体学进行表征. 二十面体的银处于核心位置,里面是中心氯化物组成,外面有48 个银原子/离子的包裹,顶端是12个双(二苯基膦基)甲烷(dppm)配体. 同时利用密度泛函理论对阳离子[{Cl@Ag12}@Ag48(dppm)12]+进行计算,以确定该结构是否对应于核心数n=58的超原子. DFT计算的优化结构与X射线一致,但是HOMO-LUMO的能差并不能保证其超级稳定性. 相似文献
97.
Abelev B Abrahantes Quintana A Adamová D Adare AM Aggarwal MM Aglieri Rinella G Agocs AG Agostinelli A Aguilar Salazar S Ahammed Z Ahmad N Ahmad Masoodi A Ahn SU Akindinov A Aleksandrov D Alessandro B AlfaroMolina R Alici A Alkin A Almaráz Aviña E Alt T Altini V Altinpinar S Altsybeev I Andrei C Andronic A Anguelov V Anson C Antičić T Antinori F Antonioli P Aphecetche L Appelshäuser H Arbor N Arcelli S Arend A Armesto N Arnaldi R Aronsson T Arsene IC Arslandok M Asryan A Augustinus A Averbeck R 《Physical review letters》2012,108(8):082001
The ALICE Collaboration has studied J/ψ production in pp collisions at √s=7 TeV at the LHC through its muon pair decay. The polar and azimuthal angle distributions of the decay muons were measured, and results on the J/ψ polarization parameters λ(θ) and λ(φ) were obtained. The study was performed in the kinematic region 2.5相似文献
98.
本文报道了氯化氢-水二聚体的两种同位素,HCl-H2O和DCl-H2O(DH)的J=1分子内和分子间振转态的全维和完全耦合量子束缚态计算. 本研究补充了我们最近对于这两类体系J=0九维(9D)振动水平结构的理论研究,并采用相同的精确9D置换不变多项式-神经网络势能面. 该计算得到了所有这些分子间和分子内低能的振转态的基本量,将结果与相同二聚体的9D J=0计算的结果进行了比较. K=1和K=0本征态之间的能量差异表现出与分子间振转态的明显变化,为此本文提供了定性的解释. 相似文献
99.
This paper deals with a non-local parabolic equation of Lotka-Volterra type that describes the evolution of phenotypically structured populations.Nonlinearities appear in these systems to model interactions and competition phenomena leading to selection.In this paper,the equation on the structured population is coupled with a differential equation on the nutrient concentration that changes as the total population varies.Different methods aimed at showing the convergence of the solutions to a moving Dirac mass are reviewed.Using either weak or strong regularity assumptions,the authors study the concentration of the solution.To this end,BV estimates in time on appropriate quantities are stated,and a constrained Hamilton-Jacobi equation to identify where the solutions concentrates as Dirac masses is derived. 相似文献
100.
In this article, an integrated approach for prediction and optimization in ion chromatography (IC) was presented. The approach provides a fast and reliable insight in the elution behavior of an IC system. The predictions are based on a mathematical model that predicts ion retentions (for both isocratic and gradient modes) by using an empirical isocratic model. Other chromatographic values significant for the optimal elution conditions (resolution, peak asymmetry) are calculated quickly and easily from the predicted retention values of characteristic points of a chromatographic peak. Every day, IC users might find this approach a suitable tool for finding optimal IC elution conditions in a given system. 相似文献