全文获取类型
收费全文 | 135篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
化学 | 47篇 |
力学 | 1篇 |
数学 | 3篇 |
物理学 | 89篇 |
出版年
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 5篇 |
2012年 | 1篇 |
2011年 | 6篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 5篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 4篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1996年 | 5篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1967年 | 3篇 |
1966年 | 1篇 |
1939年 | 1篇 |
1937年 | 1篇 |
1936年 | 3篇 |
1933年 | 2篇 |
1928年 | 2篇 |
1926年 | 2篇 |
1914年 | 1篇 |
排序方式: 共有140条查询结果,搜索用时 15 毫秒
51.
We discuss the analysis of data from πN elastic scattering and single pion photo- and electroproduction. The main focus is a study of low-lying non-strange baryon resonances. Here we concentrate on some difficulties associated with resonance identification, in particular the Roper and higher P11 states. 相似文献
52.
Chen S Avakian H Burkert VD Eugenio P Adams G Amarian M Ambrozewicz P Anghinolfi M Asryan G Bagdasaryan H Baillie N Ball JP Baltzell NA Barrow S Batourine V Battaglieri M Beard K Bedlinskiy I Bektasoglu M Bellis M Benmouna N Berman BL Biselli AS Bonner BE Bouchigny S Boiarinov S Bosted P Bradford R Branford D Briscoe WJ Brooks WK Bültmann S Butuceanu C Calarco JR Careccia SL Carman DS Carnahan B Cazes A Cole PL Collins P Coltharp P Cords D Corvisiero P Crabb D Crannell H Crede V Cummings JP 《Physical review letters》2006,97(7):072002
The longitudinal target-spin asymmetry AUL for the exclusive electroproduction of high-energy photons was measured for the first time in ep-->e;'pgamma. The data have been accumulated at JLab with the CLAS spectrometer using 5.7 GeV electrons and a longitudinally polarized NH3 target. A significant azimuthal angular dependence was observed, resulting from the interference of the deeply virtual Compton scattering and Bethe-Heitler processes. The amplitude of the sinvarphi moment is 0.252+/-0.042stat+/-0.020sys. Theoretical calculations are in good agreement with the magnitude and the kinematic dependence of the target-spin asymmetry, which is sensitive to the generalized parton distributions H and H. 相似文献
53.
54.
55.
56.
This paper reviews the status of the gas-to-liquids(TGL) industry-including current commercial plants,announced projects and the technologies that are are likely to be implemented in these future projects.Today,only 35,000 B/D of GTL products (0.1% of market) are manufactured from commercial gas-based plants,Advances in technology have lowered the cost of plants to the point where GTL phants can be profitable at crude oil prices of $16/B ,The advanced stage of development of several proposed GTL projects and attractive integrated economicws,for both the gas field and plant ,show that GTL can be a significant alternative for monetizing natural gas in the 21st centruy,GTL technologies includes more than Fischer-Tropsch technology and extends to other liquid fuels,especially in the oxygenate family (methanol,dimethyl ether ,etc.). 相似文献
57.
Titmuss S Briscoe WH Dunlop IE Sakellariou G Hadjichristidis N Klein J 《The Journal of chemical physics》2004,121(22):11408-11419
Using surface force balance measurements we have established that polystyrene chains bearing three zwitterionic groups have a higher end-group sticking energy than equivalent chains bearing a single zwitterionic group. In a good solvent, polystyrene chains end-functionalized with three zwitterionic groups form brushes of a higher surface coverage than those bearing a single zwitterion. The increase in surface coverage is slow compared with the initial formation of the brush. Measurements of the refractive index allow us to directly quantify the variation of surface coverage, permitting comparison with models for the kinetics of brush formation based on scaling theory and an analytical self-consistent field. We find qualitative support for associating the kinetic barrier with the energy required for an incoming chain to stretch as it penetrates the existing brush. 相似文献
58.
Hartman Kok PJ Kazarian SG Briscoe BJ Lawrence CJ 《Journal of colloid and interface science》2004,280(2):511-517
In this work we investigate the change in particle concentration near a solid boundary for colloidal dispersions in pressure driven flow, commonly referred to as wall depletion. In particular we determine the effect of Peclet number on the strength and spatial extent of the depleted layer. The change in concentration near the solid boundary is measured with attenuated total reflection infrared (ATR-IR) spectroscopy described previously (P.J.A. Hartman Kok et al., J. Rheol. 46 (2002) 481). The method is capable of measuring the concentration of particles at distances ranging from 0.2 to 1.0 mum from the boundary. The suspensions investigated consisted of mono-dispersed polystyrene particles in water. Particles of four different sizes were used, with radius, a, of 30, 54, 105, and 197 nm. (The ratio H/a was in the range 2500-17,000 with H being the height of the flow cell.) This enabled us to measure the wall depletion effect over a wide range of Peclet numbers, ranging from 0.01 to 45. We found that wall depletion was not significant for Peclet numbers smaller than unity. Estimates of the wall slip layer thickness obtained from rheological experiments were consistent with the results obtained by ATR-IR spectroscopy. 相似文献
59.
This paper reports on an experimental study of the adhesive contact of a single microscopic (about 300 μm) elastomer sphere compressed between two smooth parallel glass platens at small imposed deformations. An experimental arrangement that allows the simultaneous measurement of the compressive displacements and the reaction forces is described. A number of interesting phenomena, including the pull-off separation and the “jump” contact phenomena of the microsphere and the moving platen supported by a cantilever, are shown in the experimental force-displacement curve of a loading and unloading cycle. The pull-off forces are demonstrated to not depend upon the applied dimensionless approach (compressive displacement/initial particle diameter), while they increase with the increasing rate at which the interfaces are separated. The predictions of an established contact mechanical adhesive theory, Johnson–Kendall–Roberts (JKR) theory, in which the influence of the surface energy on the contact has been taken into account, are in good agreement with these experimental results. An application of the JKR analysis to the pull-off force provides a reasonable estimate of the interfacial free energy of the contact. 相似文献
60.