全文获取类型
收费全文 | 118篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学 | 43篇 |
力学 | 5篇 |
数学 | 34篇 |
物理学 | 39篇 |
出版年
2019年 | 1篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2013年 | 7篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 6篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1956年 | 1篇 |
1940年 | 2篇 |
排序方式: 共有121条查询结果,搜索用时 15 毫秒
11.
12.
Song ZJ Tellers DM Journet M Kuethe JT Lieberman D Humphrey G Zhang F Peng Z Waters MS Zewge D Nolting A Zhao D Reamer RA Dormer PG Belyk KM Davies IW Devine PN Tschaen DM 《The Journal of organic chemistry》2011,76(19):7804-7815
Development of a practical synthesis of MK-7009, a 20-membered [corrected] macrocycle, is described. A variety of ring-closing strategies were evaluated, including ring-closing metathesis, intermolecular palladium-catalyzed cross-couplings, and macrolactamization. Ring closure via macrolactamization was found to give the highest yields under relatively high reaction concentrations. Optimization of the ring formation step and the synthesis of key intermediates en route to MK-7009 are reported. 相似文献
13.
Gary M. Lieberman 《Annali di Matematica Pura ed Applicata》1993,164(1):103-120
Summary Gradient bounds are proved for solutions to a class of second order elliptic systems in divergence form. The main condition on this class is a generalization of the assumption that the system be the Euler-Lagrange system of equations for a functional depending only on the modulus of the gradient of the solution. 相似文献
14.
15.
16.
17.
Lieberman M.A. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1988,16(6):638-644
A self-consistent solution for the dynamics of a high voltage, capacitive radio frequency (RF) sheath driven by a sinusoidal current source is obtained under the assumptions of time-independent, collisionless ion motion and inertialess electrons. Expressions are obtained for the time-average ion and electron densities, electric field and potential within the sheath. The nonlinear oscillation motion of the electron sheath boundary and the nonlinear oscillating sheath voltage are also obtained. The effective sheath capacitance and conductance are also determined. It was found that: (1) the ion-sheath thickness S m is √50/27 larger than a Child's law sheath for the DC voltage and ion current density; (2) the sheath capacitance per unit area for the fundamental voltage harmonic is 2.452 ϵ0 /Sm, where ϵ0 is the free space permittivity; (3) the ratio of the DC to peak value of the oscillating voltage is 54/125; (4) the second and third voltage harmonics are, respectively, 12.3 and 4.2% of the fundamental; and (5) the conductance per unit area for stochastic heating by the oscillating sheath is 2.98 (λD/S m)2/3 (e 2n 0/mu e), where n 0 is the ion density, λD is the Debye length at the plasma-sheath edge, and u e is the mean electron speed 相似文献
18.
Wood B.P. Lieberman M.A. Lichtenberg A.J. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1991,19(4):619-627
The sheath motion in a capacitively coupled RF discharge is highly nonlinear. The voltage waveform on a cylindrical probe placed in the sheath region is measured as a function of position and time. A circuit model of the probe-discharge system relates the observed probe voltage to the sheath motion. The equations derived from this circuit model are solved numerically with varying nonlinear sheath motions; the resulting waveforms are compared with the experimental observations to determine the actual sheath motion. The time-varying plasma potential is also determined, indirectly, from the comparison. The authors also report observation of oscillations related to the plasma frequency, whose peak harmonic component can be calculated from a single plasma model. These oscillations can be a useful plasma diagnostic for determining plasma density. The presence of these high-frequency oscillations may significantly enhance the rate of stochastic heating of electrons 相似文献
19.
20.