全文获取类型
收费全文 | 793篇 |
免费 | 38篇 |
国内免费 | 40篇 |
专业分类
化学 | 288篇 |
晶体学 | 7篇 |
力学 | 12篇 |
综合类 | 12篇 |
数学 | 73篇 |
物理学 | 479篇 |
出版年
2021年 | 4篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 10篇 |
2017年 | 13篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 21篇 |
2012年 | 25篇 |
2011年 | 53篇 |
2010年 | 26篇 |
2009年 | 22篇 |
2008年 | 43篇 |
2007年 | 47篇 |
2006年 | 50篇 |
2005年 | 34篇 |
2004年 | 29篇 |
2003年 | 18篇 |
2002年 | 23篇 |
2001年 | 19篇 |
2000年 | 29篇 |
1999年 | 10篇 |
1997年 | 4篇 |
1996年 | 33篇 |
1995年 | 32篇 |
1994年 | 22篇 |
1993年 | 30篇 |
1992年 | 26篇 |
1991年 | 17篇 |
1990年 | 20篇 |
1989年 | 10篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 12篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 11篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1974年 | 6篇 |
1973年 | 9篇 |
1972年 | 6篇 |
1967年 | 3篇 |
排序方式: 共有871条查询结果,搜索用时 15 毫秒
11.
Abulencia A Acosta D Adelman J Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arguin JF Arisawa T Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Azzurri P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Bartsch V Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Haim EB Benjamin D Beretvas A Beringer J Berry T Bhatti A Binkley M Bisello D Blair RE 《Physical review letters》2006,96(23):231801
We report the first observation of B(0)(s)-->Psi(2S)Phi decay in p(p_) collisions at square root of 8=1.96 TeV using 360 pb(-1) of data collected by the CDF II detector at the Fermilab Tevatron. We observe 20.2 +/- 5.0 and 12.3 +/- 4.1 B(0)(s)-->Psi(2S)Phi candidates, in Psi(2S)-->mu(+)mu(-) and Phi(2S)-->J/Phipi(+)pi(-) decay modes, respectively. We present a measurement of the relative branching fraction Beta(B(0)(s)-->Psi(2S)Phi)/Beta(B(0)(s)-->J/PsiPhi)=0.52 +/- 0.13(stat) +/- 0.04(syst) +/- 0.06(BR) using the Psi(2S)-->mu(+)mu(-) decay mode. 相似文献
12.
Abulencia A Acosta D Adelman J Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arguin JF Arisawa T Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Azzurri P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Bartsch V Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Haim EB Benjamin D Beretvas A Beringer J Berry T Bhatti A Binkley M Bisello D Blair RE 《Physical review letters》2006,96(21):211802
We describe a general search for resonances decaying to a neutral emu final state in pp collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing 344 pb(-1) of integrated luminosity recorded by the Collider Detector at Fermilab II experiment, we compare standard model predictions with the number of observed events for invariant masses between 50 and 800 GeV/c2. Finding no significant excess (5 events observed vs 7.7 +/- 0.8 expected for M(emu) > 100 GeV/c2 ), we set limits on sneutrino and Z' masses as functions of lepton family number violating couplings. 相似文献
13.
Acosta D Adelman J Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arisawa T Arguin JF Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barker GJ Barnes VE Barnett BA Baroiant S Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Ben-Haim E Benjamin D Beretvas A Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B 《Physical review letters》2005,95(7):071801
We present a search for long-lived doubly charged Higgs bosons (H(+/- +/-)), with signatures of high ionization energy loss and muonlike penetration. We use 292 pb(-1) of data collected in pp collisions at sqrt[s] = 1.96 TeV by the CDF II detector at the Fermilab Tevatron. Observing no evidence of long-lived doubly charged particle production, we exclude H(+/- +/-)(L) and H(+/- +/-)(R) bosons with masses below 133 GeV/c(2) and 109 GeV/c(2), respectively. In the degenerate case we exclude H(+/- +/-) mass below 146 GeV/c(2). All limits are quoted at the 95% confidence level. 相似文献
14.
Acosta D Affolder T Albrow MG Ambrose D Amidei D Anikeev K Antos J Apollinari G Arisawa T Artikov A Ashmanskas W Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Barone M Bauer G Bedeschi F Behari S Belforte S Bell WH Bellettini G Bellinger J Benjamin D Beretvas A Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K Blumenfeld B Bocci A Bodek A Bolla G Bolshov A Bortoletto D Boudreau J Bromberg C Brubaker E Budagov J 《Physical review letters》2005,94(17):171802
We report the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, Nq and Ng, produced at the Fermilab Tevatron in pp collisions with a center-of-mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The measurements are made for jets with average energies of 41 and 53 GeV by counting charged particle tracks in cones with opening angles of theta(c) = 0.28, 0.36, and 0.47 rad around the jet axis. The corresponding jet hardness Q = Ejet theta c varies in the range from 12 to 25 GeV. At Q = 19.2 GeV, the ratio of multiplicities r = Ng/Nq is found to be 1.64+/-0.17, where statistical and systematic uncertainties are added in quadrature. The results are in agreement with resummed perturbative QCD calculations. 相似文献
15.
The as-deposited and annealed Ge-Au film and Ge-Au/Au bilayer films have been observed by transmission electron microscopy. The bilayer with a composition of Ge-5at%Au film is amorphous, while the Ge-22at%Au film is polycrystalline. Higher concentration of Au raises the structural heterogeneity and instability. Fractals can be observed in the Ge-5at%Au/Au bilayer samples annealed at 60-100℃. The difference of the fractal patterns generated from Ge-Au/An and a-Ge/Au films call be attributed to the higher heterogeneity and instability in Ge-Au/An bilayers. 相似文献
16.
Abe F Akimoto H Akopian A Albrow MG Amendolia SR Amidei D Antos J Anway-Wiese C Aota S Apollinari G Asakawa T Ashmanskas W Atac M Azfar F Azzi-Bacchetta P Bacchetta N Badgett W Bagdasarov S Bailey MW Bao J de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Barzi E Bauer G Baumann T Bedeschi F Behrends S Belforte S Bellettini G Bellinger J Benjamin D Benlloch J Bensinger J Benton D Beretvas A Berge JP Berryhill J Bertolucci S Bevensee B Bhatti A Biery K Binkley M Bisello D Blair RE Blocker C 《Physical review letters》1996,77(25):5005-5010
17.
Abe F Akimoto H Akopian A Albrow MG Amendolia SR Amidei D Antos J Anway-Wiese C Aota S Apollinari G Asakawa T Ashmanskas W Atac M Azfar F Azzi-Bacchetta P Bacchetta N Badgett W Bagdasarov S Bailey MW Bao J de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Barzi E Bauer G Baumann T Bedeschi F Behrends S Belforte S Bellettini G Bellinger J Benjamin D Benlloch J Bensinger J Benton D Beretvas A Berge JP Berryhill J Bertolucci S Bhatti A Biery K Binkley M Bisello D Blair RE Blocker C Bodek A 《Physical review letters》1996,77(10):1945-1949
18.
Abe F Akimoto H Akopian A Albrow MG Amendolia SR Amidei D Antos J Anway-Wiese C Aota S Apollinari G Asakawa T Ashmanskas W Atac M Auchincloss P Azfar F Azzi-Bacchetta P Bacchetta N Badgett W Bagdasarov S Bailey MW Bao J de Barbaro P Barbaro-Galtieri A Barnes VE Barnett BA Barzi E Bauer G Baumann T Bedeschi F Behrends S Belforte S Bellettini G Bellinger J Benjamin D Benlloch J Bensinger J Benton D Beretvas A Berge JP Berryhill J Bertolucci S Bhatti A Biery K Binkley M Bisello D Blair RE 《Physical review letters》1996,76(23):4307-4311
19.
Aaltonen T Alvarez González B Amerio S Amidei D Anastassov A Annovi A Antos J Apollinari G Appel JA Apresyan A Arisawa T Artikov A Asaadi J Ashmanskas W Auerbach B Aurisano A Azfar F Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Barria P Bartos P Bauce M Bauer G Bedeschi F Beecher D Behari S Bellettini G Bellinger J Benjamin D Beretvas A Bhatti A Binkley M Bisello D Bizjak I Bland KR Blumenfeld B Bocci A Bodek A Bortoletto D Boudreau J Boveia A Brigliadori L Brisuda A Bromberg C Brucken E 《Physical review letters》2012,108(1):011801
A search for a narrow Higgs boson resonance in the diphoton mass spectrum is presented based on data corresponding to 7.0 fb{-1} of integrated luminosity from pp collisions at sqrt[s]=1.96 TeV collected by the CDF experiment. No evidence of such a resonance is observed, and upper limits are set on the cross section times branching ratio of the resonant state as a function of Higgs boson mass. The limits are interpreted in the context of the standard model and one fermiophobic benchmark model where the data exclude fermiophobic Higgs bosons with masses below 114 GeV/c{2} at a 95% Bayesian credibility level. 相似文献
20.