全文获取类型
收费全文 | 2511篇 |
免费 | 87篇 |
国内免费 | 5篇 |
专业分类
化学 | 1901篇 |
晶体学 | 42篇 |
力学 | 22篇 |
数学 | 120篇 |
物理学 | 518篇 |
出版年
2023年 | 12篇 |
2021年 | 32篇 |
2020年 | 24篇 |
2019年 | 34篇 |
2018年 | 28篇 |
2017年 | 22篇 |
2016年 | 47篇 |
2015年 | 42篇 |
2014年 | 57篇 |
2013年 | 130篇 |
2012年 | 121篇 |
2011年 | 136篇 |
2010年 | 75篇 |
2009年 | 75篇 |
2008年 | 165篇 |
2007年 | 179篇 |
2006年 | 147篇 |
2005年 | 193篇 |
2004年 | 165篇 |
2003年 | 108篇 |
2002年 | 109篇 |
2001年 | 56篇 |
2000年 | 58篇 |
1999年 | 32篇 |
1998年 | 36篇 |
1997年 | 24篇 |
1996年 | 34篇 |
1995年 | 25篇 |
1994年 | 26篇 |
1993年 | 18篇 |
1992年 | 21篇 |
1991年 | 18篇 |
1990年 | 15篇 |
1989年 | 16篇 |
1988年 | 20篇 |
1987年 | 11篇 |
1986年 | 18篇 |
1985年 | 30篇 |
1984年 | 33篇 |
1983年 | 12篇 |
1982年 | 26篇 |
1981年 | 17篇 |
1980年 | 25篇 |
1979年 | 19篇 |
1978年 | 16篇 |
1977年 | 18篇 |
1976年 | 9篇 |
1975年 | 15篇 |
1974年 | 13篇 |
1972年 | 9篇 |
排序方式: 共有2603条查询结果,搜索用时 31 毫秒
991.
Yamasaki A Imada S Higashimichi H Fujiwara H Saita T Miyamachi T Sekiyama A Sugawara H Kikuchi D Sato H Higashiya A Yabashi M Tamasaku K Miwa D Ishikawa T Suga S 《Physical review letters》2007,98(15):156402
Sm-based heavy-fermion compound SmOs4Sb12 has been investigated by soft x-ray (hnu=1070-1600 eV) and hard x-ray (HX; hnu=7932 eV) spectroscopy. The HX photoemission spectroscopy clearly demonstrates that the strongly mixed-valence state and the heavy-fermion state coexist in the bulk. It is found that the Sm valence decreases below 100 K, indicating that the Kondo coherence develops with approaching the proposed Kondo temperature. Our theoretical analyses suggest that the origin of the coexistence in SmOs4Sb12 is the coincidence of two conditions, namely, (i) the energy difference between Sm divalent and trivalent states is very small and (ii) the hybridization between Sm 4f and conduction electrons is weak. 相似文献
992.
Yano M Sekiyama A Fujiwara H Saita T Imada S Muro T Onuki Y Suga S 《Physical review letters》2007,98(3):036405
By virtue of the soft x-ray angle-resolved photoelectron spectroscopy, the three-dimensional bulk fermiology has been successfully performed for a strongly correlated Ce compound, ferromagnet CeRu2Ge2 in the paramagnetic phase. A clear difference of the Fermi surface topology from either band calculation or de Haas-van Alphen results in the ferromagnetic phase is observed and interpreted by considering the difference of the 4f contribution to the Fermi surfaces in the paramagnetic phase. 相似文献
993.
Tokurakawa M Shirakawa A Ueda K Yagi H Yanagitani T Kaminskii AA 《Optics letters》2007,32(23):3382-3384
Diode-pumped Kerr-lens mode-locked laser operations of Yb3+:Sc2O3 ceramics have been achieved. 92 fs pulses with the average power of 850 mW under 3.89 W incident pump power were obtained at a center wavelength of 1042 nm. The optical-to-optical efficiency was 21.9%. 90 fs pulses with the average power of 160 mW were also obtained at a center wavelength of 1092 nm. To our knowledge, this is the first demonstration of a Kerr-lens mode-locked Yb3+:Sc2O3 laser. 相似文献
994.
Andresen G Bertsche W Boston A Bowe PD Cesar CL Chapman S Charlton M Chartier M Deutsch A Fajans J Fujiwara MC Funakoshi R Gill DR Gomberoff K Hangst JS Hayano RS Hydomako R Jenkins MJ Jørgensen LV Kurchaninov L Madsen N Nolan P Olchanski K Olin A Povilus A Robicheaux F Sarid E Silveira DM Storey JW Telle HH Thompson RI van der Werf DP Wurtele JS Yamazaki Y;ALPHA Collaboration 《Physical review letters》2007,98(2):023402
We have demonstrated storage of plasmas of the charged constituents of the antihydrogen atom, antiprotons and positrons, in a Penning trap surrounded by a minimum-B magnetic trap designed for holding neutral antiatoms. The neutral trap comprises a superconducting octupole and two superconducting, solenoidal mirror coils. We have measured the storage lifetimes of antiproton and positron plasmas in the combined Penning-neutral trap, and compared these to lifetimes without the neutral trap fields. The magnetic well depth was 0.6 T, deep enough to trap ground state antihydrogen atoms of up to about 0.4 K in temperature. We have demonstrated that both particle species can be stored for times long enough to permit antihydrogen production and trapping studies. 相似文献
995.
Saito N Akagawa K Ito M Takazawa A Hayano Y Saito Y Ito M Takami H Iye M Wada S 《Optics letters》2007,32(14):1965-1967
We report on a sodium D(2) resonance coherent light source achieved in single-pass sum-frequency generation in periodically poled MgO-doped stoichiometric lithium tantalate with actively mode-locked Nd:YAG lasers. Mode-locked pulses at 1064 and 1319 nm are synchronized with a time resolution of 37 ps with the phase adjustment of the radio frequencies fed to acousto-optic mode lockers. An output power of 4.6 W at 589.1586 nm is obtained, and beam quality near the diffraction limit is also achieved in a simple design. 相似文献
996.
[reaction: see text] Arylmagnesiation of unfunctionalized alkynes in the presence of catalytic amounts of chromium(II) chloride and pivalic acid proceeds with high stereoselectivity. The alkenylmagnesium intermediate reacts with various electrophiles to afford the corresponding tetrasubstituted olefins in good yields. 相似文献
997.
Zhang X Kono H Liu Z Nishimoto S Tryk DA Murakami T Sakai H Abe M Fujishima A 《Chemical communications (Cambridge, England)》2007,(46):4949-4951
A transparent superhydrophobic TiO2 film, prepared by spin-coating a TiO2 slurry on a glass substrate and modifying the resultant TiO2 film with fluoroalkylsilane molecules, was patterned by illumination with ultraviolet light through a photomask, producing a superhydrophobic/superhydrophilic surface micropattern with very small superhydrophilic areas, which we were able to selectively fill with alginate hydrogel. 相似文献
998.
999.
1000.
Negative thermal expansibility change for dissociation of lysozyme variant amyloid protofibril 下载免费PDF全文
Ryo Ishiguro Hiroshi Matsuo Keiichi Kameyama Hideki Tachibana Tetsuro Fujisawa 《Electrophoresis》2015,36(6):893-901
A disulfide‐deficient variant of hen lysozyme, 0SS, is known to form an amyloid protofibril spontaneously, and to dissociate into monomers at high hydrostatic pressure. We carried out native PAGE at various temperatures (20–35°C) and pressures (0.1–200 MPa), to characterize the dissociation equilibrium of disulfide‐deficient variant of hen lysozyme amyloid protofibril. Based on the density profiles, the partial molar volume and thermal expansibility changes for dissociation, ΔvD and ΔeD, were obtained to be ?74 cm3/mol at 25°C and ?2.3 cm3 mol?1 K?1, respectively. The dissociation of amyloid fibril destroys the cross β‐structure, and such conformational destruction in native protein fold rarely accompanies negative thermal expansibility change. We discussed the negative thermal expansibility change in terms of hydration and structural packing of the amyloid protofibril. 相似文献