首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1241篇
  免费   24篇
  国内免费   3篇
化学   621篇
晶体学   18篇
力学   61篇
数学   108篇
物理学   460篇
  2022年   13篇
  2021年   10篇
  2020年   20篇
  2019年   27篇
  2018年   16篇
  2017年   24篇
  2016年   43篇
  2015年   19篇
  2014年   36篇
  2013年   62篇
  2012年   74篇
  2011年   78篇
  2010年   62篇
  2009年   40篇
  2008年   73篇
  2007年   73篇
  2006年   61篇
  2005年   50篇
  2004年   36篇
  2003年   39篇
  2002年   34篇
  2001年   21篇
  2000年   23篇
  1999年   11篇
  1998年   17篇
  1997年   15篇
  1996年   17篇
  1995年   15篇
  1994年   13篇
  1993年   19篇
  1992年   11篇
  1991年   5篇
  1990年   11篇
  1989年   18篇
  1988年   6篇
  1987年   19篇
  1986年   7篇
  1985年   14篇
  1984年   13篇
  1983年   14篇
  1982年   13篇
  1981年   10篇
  1980年   11篇
  1979年   7篇
  1978年   7篇
  1977年   5篇
  1975年   4篇
  1972年   4篇
  1960年   4篇
  1954年   5篇
排序方式: 共有1268条查询结果,搜索用时 31 毫秒
101.
102.
In recent decades it has become increasingly clear that induction of autophagy plays an important role in the development of treatment resistance and dormancy in many cancer types. Unfortunately, chloroquine (CQ) and hydroxychloroquine (HCQ), two autophagy inhibitors in clinical trials, suffer from poor pharmacokinetics and high toxicity at therapeutic dosages. This has prompted intense interest in the development of targeted autophagy inhibitors to re-sensitize disease to treatment with minimal impact on normal tissue. We utilized Scanning Unnatural Protease Resistant (SUPR) mRNA display to develop macrocyclic peptides targeting the autophagy protein LC3. The resulting peptides bound LC3A and LC3B—two essential components of the autophagosome maturation machinery—with mid-nanomolar affinities and disrupted protein–protein interactions (PPIs) between LC3 and its binding partners in vitro. The most promising LC3-binding SUPR peptide accessed the cytosol at low micromolar concentrations as measured by chloroalkane penetration assay (CAPA) and inhibited starvation-mediated GFP-LC3 puncta formation in a concentration-dependent manner. LC3-binding SUPR peptides re-sensitized platinum-resistant ovarian cancer cells to cisplatin treatment and triggered accumulation of the adapter protein p62 suggesting decreased autophagic flux through successful disruption of LC3 PPIs in cell culture. In mouse models of metastatic ovarian cancer, treatment with LC3-binding SUPR peptides and carboplatin resulted in almost complete inhibition of tumor growth after four weeks of treatment. These results indicate that SUPR peptide mRNA display can be used to develop cell-penetrating macrocyclic peptides that target and disrupt the autophagic machinery in vitro and in vivo.

SUPR peptide mRNA display was used to evolve a cell-permeable, macrocyclic peptide for autophagy inhibition.  相似文献   
103.
Summary In this work we present an elementary proof of the Faber-Krahn inequality for the first eigenvalue of the p-Laplacian on bounded domains in ℝn. Let λ1 be the first eigenvalue and λ 1 * be the first eigenvalue for the ball of the same volume. Then we show that λ11 * iff the domain is a ball. Our proof makes considerable use of the corresponding Talenti's inequality and some well known properties of the first eigenfunction. Entrata in Redazione il 20 aprile 1998.  相似文献   
104.
Summary Cosmic-ray air shower structure functions for the distance dependence of electron density in cosmic-ray air showers in the size range 104⋎108 have been computed for their intercomparison and comparison with Monte Carlo simulation results and measurements from recent experiments. The analysis has yielded the present status of theoretical structure functionsvis à vis experimental results and Monte Carlo simulation distributions. The effect of core location error on the lateral distribution of electrons is also discussed from the point of view of different theoretical and experimental results. The energy flow in the soft component of air showers of size ∼4·105 has been evaluated within a ring of radius 10m about the axis of the showers.  相似文献   
105.
The temperature dependent (30-300 K) Doppler broadening of the positron annihilated γ-radiation measurement has been investigated on single crystalline Bi2Sr2CaCu2O8+δ (Bi-2212) high Tc superconducting samples along two different crystallographic orientations. It has been observed that throughout the temperature range the electron momentum distribution has a larger value along the crystallographic c-axis than in the a-b plane. The temperature dependent Doppler broadened positron annihilation γ-radiation lineshape analysis shows a step like increase of S-parameter at the temperature region 92-116 K.  相似文献   
106.
We have set up the algebraic Bethe ansatz equation for an open Heisenberg spin chain having an impurity of a different type of spin. The chain is considered to be open and hence the QISM approach as modified by Sklyanin is used to set up the equations for the Bethe ansatz.  相似文献   
107.
Using the pseudopotential method, theoretical investigation has been made on the firstorder Korteweg-deVries ion-acoustic solitons in a multicomponent plasma consisting of warm positive ions, negative ions and isothermal electrons. The effects of electron-inertia and drift motion of the ions on the amplitudes and widths of the solitons have been studied in a plasma having (H+, Cl), (H+, O), (He+, H) and (He+, O) ions. Ion-acoustic double-layers have also been investigated for such plasmas. It has been found that drift velocity and electron-inertia have significant contribution on the formation of double-layers in multicomponent plasma  相似文献   
108.
The 132 MeV 16O + 58Ni reaction has been experimentally investigated by using coincident charged particle techniques. A closed-form theoretical approach, describing in a simple picture the non-equilibrium component and the evaporative one of the angular correlation between light particles and reaction residues emitted in a peripheral heavy-ion collision, is applied — in the hypotesis of a sequential process — to the (C,N,O)-α and (C,N,O)-p differential multiplicities for the 16O + 58Ni at 8.25 MeV/A deep inelastic collision. From this analysis some reaction mechanism information is deduced.  相似文献   
109.
A spin-polarized vertical-cavity surface-emitting laser is demonstrated with electrical spin injection from an Fe/Al0.1Ga0.9As Schottky tunnel barrier. Laser operation with a spin-polarized current results in a maximum threshold current reduction of 11% and degree of circular polarization of 23% at 50 K. A cavity spin polarization of 16.8% is estimated from spin-dependent rate equation analysis of the observed threshold reduction.  相似文献   
110.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号