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   82篇
  免费   2篇
化学   31篇
数学   9篇
物理学   44篇
  2021年   4篇
  2020年   4篇
  2018年   1篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   2篇
  2013年   2篇
  2012年   5篇
  2011年   7篇
  2010年   7篇
  2009年   5篇
  2008年   3篇
  2007年   2篇
  2006年   3篇
  2005年   2篇
  2004年   1篇
  2003年   5篇
  2002年   4篇
  2001年   2篇
  2000年   7篇
  1999年   3篇
  1998年   3篇
  1996年   2篇
  1993年   3篇
  1991年   1篇
  1984年   1篇
  1966年   1篇
排序方式: 共有84条查询结果,搜索用时 15 毫秒
1.
Partial critical dependences of the form current-magnetic field in a two-layered symmetric Josephson junction are modeled. A numerical experiment shows that, for the zero interaction coefficient between the layers of the junction, jumps of the critical currents corresponding to different distributions of the magnetic fluxes in the layers may appear on the critical curves. This fact allows a mathematical interpretation of the results of some recent experimental results for two-layered junctions as a consequence of discontinuities of partial critical curves.  相似文献   
2.
A new ordinary differential inequality without global solutions is proposed. Comparison with similar differential inequalities in the well‐known concavity method is performed. As an application, finite time blow up of the solutions to nonlinear Klein–Gordon equation and generalized Boussinesq equation is proven. The initial energy is arbitrary high positive. The structural conditions on the initial data generalize the assumptions used in the literature for the time being. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
3.
The galvanic behavior of a hollow cathode discharge versus an external weak magnetic field is investigated. The application of this field leads to disordering of the self-aligned states, which is detected as a resonance in the discharge current, named the magneto-galvanic signal. A correlation magneto-galvanic signal–operating voltage-current point is established and attributed to Penning ionization. The contribution of the metastable Ne I 1 s5 to the magneto-galvanic resonance is also verified.  相似文献   
4.
In situ, reversible coacervate formation within lipid vesicles represents a key step in the development of responsive synthetic cellular models. Herein, we exploit the pH responsiveness of a polycation above and below its pKa, to drive liquid–liquid phase separation, to form single coacervate droplets within lipid vesicles. The process is completely reversible as coacervate droplets can be disassembled by increasing the pH above the pKa. We further show that pH-triggered coacervation in the presence of low concentrations of enzymes activates dormant enzyme reactions by increasing the local concentration within the coacervate droplets and changing the local environment around the enzyme. In conclusion, this work establishes a tunable, pH responsive, enzymatically active multi-compartment synthetic cell. The system is readily transferred into microfluidics, making it a robust model for addressing general questions in biology, such as the role of phase separation and its effect on enzymatic reactions using a bottom-up synthetic biology approach.  相似文献   
5.
The process e + e ? → η′γ, η′ → η π0π0, η → γγ is investigated by an SND detector in experiment on a VEPP-2M equipment with colliding electron-positron beams. The analysis of experimental data yields a value of B(? → η′γ)=(6.7 ?4.2 +5.0 ±1.5)×10?5 for the decay probability. Taking into account a previous measurement of this quantity by an SND detector in the decay channel η′ → π+π?η, one finally obtains B(?→η ′γ)=(6.7 ?2.4 +2.8 ±0.8)×10?5.  相似文献   
6.
A post-column infusion system was developed in order to analyze suppression of electrospray ionization (ESI) tandem mass spectrometry response in the presence of endogenous plasma interferences. By enabling direct detection of these interfering components, this experimental system was used to analyze the ability of several common extraction procedures to remove endogenous plasma components that cause changes in the ESI response of model drug substances. Methyl-t-butyl ether (MTBE) liquid-liquid, Oasis and Empore solid-phase, and acetonitrile (ACN) protein precipitation sample preparation methods were tested using the post-column infusion system. In all cases, ACN protein precipitation samples showed the greatest amount of ESI response suppression while liquid-liquid extracts demonstrated the least. In addition, the three test compounds, phenacetin, caffeine, and a representative Merck compound, demonstrated that ESI response suppression is compound dependent. Suppression was greatest with caffeine, the most polar analyte, and the smallest for the Merck compound, the least polar analyte. Copyright 1999 John Wiley & Sons, Ltd.  相似文献   
7.
Physics of Atomic Nuclei - The process $$e^{+}e^{-}\to\eta\pi^{0}\gamma$$ is studied in the range of center-of-mass (c.m.) collision energies between 1.05 and 2.00 GeV on the basis of data...  相似文献   
8.
Physics of Atomic Nuclei - In an experiment with the SND detector at the VEPP-2000 $$e^{+}e^{-}$$ collider, the cross sections for the processes $$e^{+}e^{-}\to K^{+}K^{-}\pi^{0}$$ and...  相似文献   
9.
We study the interaction of alkali metal chlorides with lipid vesicles made of palmitoyloleoylphosphatidylcholine (POPC). An elaborate set of techniques is used to investigate the binding process at physiological conditions. The alkali cation binding to POPC is characterized thermodynamically using isothermal titration calorimetry. The isotherms show that for all ions in the alkali group the binding process is endothermic, counterintuitively to what is expected for Coulomb interactions between the slightly negatively charged POPC liposomes and the cations. The process is entropy driven and presumably related to the liberation of water molecules from the hydration shells of the ions and the lipid headgroups. The measured molar enthalpies of the binding of the ions follows the Hofmeister series. The binding constants were also estimated, whereby lithium shows the strongest affinity to POPC membranes, followed by the rest of the ions according to the Hofmeister series. Cation adsorption increases the net surface potential of the vesicles as observed from electrophoretic mobility and zeta potential measurements. While lithium adsorption leads to slightly positive zeta potentials above a concentration of 100 mM, the adsorption of the rest of the ions mainly causes neutralization of the membrane. This is the first study characterizing the binding equilibrium of alkali metal chlorides to phosphatidylcholine membranes at physiological salt concentrations.  相似文献   
10.
A mechanism of the laser action of 5d 8 6s 2 –5d 9 6p HgIII transitions is proposed. The explanation is based on atomic constants of the transitions and the predominant role of direct electron excitation of the upper laser level. The kinetic models of electron beam and hollow cathode discharge sources are calculated. The theoretical estimations are compared with experimental data and possible laser transitions are also proposed. The role of electron impact excitation in the formation of inverse population for two-electron transitions in CuII and AgII obtained in hollow cathode discharges is discussed.  相似文献   
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