全文获取类型
收费全文 | 169篇 |
免费 | 16篇 |
国内免费 | 56篇 |
专业分类
化学 | 130篇 |
晶体学 | 9篇 |
力学 | 4篇 |
综合类 | 1篇 |
数学 | 14篇 |
物理学 | 83篇 |
出版年
2023年 | 1篇 |
2022年 | 10篇 |
2021年 | 3篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 8篇 |
2016年 | 5篇 |
2014年 | 5篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 13篇 |
2010年 | 12篇 |
2009年 | 16篇 |
2008年 | 15篇 |
2007年 | 14篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 8篇 |
1986年 | 5篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有241条查询结果,搜索用时 31 毫秒
21.
22.
J. Badier M. Bardadin-Otwinowska C. Bemporad U. Berthon H. Bienvenu J. Boucrot J. Bourotte G. Burgun O. Callot Ph. Charpentier A. M. Cnops M. Cohen F. Constantini M. Crozon D. Décamp P. Delpierre J. F. Detoeuf P. Espigat B. Gandois G. R. Giannini V. Hajjar M. Hansroul Y. Karyotakis P. Lariccia P. Le D? J. Mas A. Michelini G. C. Moneti M. Moniez E. Paré G. Rahal-Callot M. Rumpf O. Runolfsson A. Tilquin S. Weisz NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1986,31(3):341-347
Direct photon production has been studied by an experiment performed with the NA3 spectrometer at CERN, using incident negative and positive beams at 200 GeV/c interacting with an isoscalar Carbon target. Two different triggers have been used; one of them requires the photon conversion. The experiment is sensitive to direct photons produced with 3.0≦P T ≦6 GeV/c and center-of-mass rapidity ?0.4≦y *≦1.2. Inclusive cross sections are given for incident π± and protons, and compared with second order QCD predictions; finally an estimation of the gluon structure function of the nucleon is given. 相似文献
23.
24.
HPLC-MS-MS法测定水体中残留的氨基甲酸酯类农药 总被引:2,自引:0,他引:2
应用高效液相色谱-串联质谱(HPLC-MS-MS)联用技术,建立了检测水体中氨基甲酸酯类农药残留的方法。水样经氨基柱固相萃取,二氯甲烷洗脱,梯度流动相洗脱,电喷雾正离子(ESI+)模式采集、选择反应性监测模式(SRM)对定性、定量离子进行MS/MS测定。5种氨基甲酸酯类农药在5~200ng/L范围内线性关系良好,回收率为80%~92%,相对标准偏差均小于10%,方法检出限分别为:异丙威和仲丁威为1.4ng/L,克百威和甲萘威为1.5ng/L,恶虫威为1.6ng/L。该方法适用于水体中氨基甲酸酯类农药残留的检测。 相似文献
25.
Arnaldi R Banicz K Castor J Chaurand B Cicalò C Colla A Cortese P Damjanovic S David A de Falco A Devaux A Ducroux L En'yo H Fargeix J Ferretti A Floris M Förster A Force P Guettet N Guichard A Gulkanian H Heuser JM Keil M Kluberg L Lourenço C Lozano J Manso F Martins P Masoni A Neves A Ohnishi H Oppedisano C Parracho P Pillot P Poghosyan T Puddu G Radermacher E Ramalhete P Rosinsky P Scomparin E Seixas J Serci S Shahoyan R Sonderegger P Specht HJ Tieulent R Usai G Veenhof R 《Physical review letters》2007,99(13):132302
The NA60 experiment studies muon pair production at the CERN Super Proton Synchrotron. In this Letter we report on a precision measurement of J/psi in In-In collisions. We have studied the J/psi centrality distribution, and we have compared it with the one expected if absorption in cold nuclear matter were the only active suppression mechanism. For collisions involving more than approximately 80 participant nucleons, we find that an extra suppression is present. This result is in qualitative agreement with previous Pb-Pb measurements by the NA50 experiment, but no theoretical explanation is presently able to coherently describe both results. 相似文献
26.
27.
28.
在水溶液条件下以六缺位的[H2P2W12O48)]12-和Eu髥为反应前躯体得到了1个新的多金属氧酸盐化合物[Eu3(H2O)17(α2-HP2W17O61)].5H2O(1),对其进行了元素分析、红外光谱、热重、荧光等表征,并用X-射线单晶衍射测定了它的晶体结构。化合物1含有双支撑的多阴离子簇[{Eu(H2O)7}2{Eu(H2O)3(α2-P2W17)}2]8-,并进一步通过Eu髥连接形成了延c轴方向的一维链。室温条件下的荧光光谱研究表明:化合物1显示了强的红光发射。 相似文献
29.
WANG Zhi-xin HOU Yi HAN Wei WANG Kai-chen GUO Bao-feng LIU Ying CHANG Xi-hua WANG Wei-hua NA Wan-li KONG Xiang-bo ZHAO Xu ZHANG Ling 《高等学校化学研究》2011,27(1):94-98
Renal cell carcinoma is the most common cancer of the kidney, and resistant to traditional therapies. The aim of this study is to investigate the effects of hydroxyapatite nanoparticles on human renal cell carcinoma 786-0 cells. Cell proliferation was assessed with an 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide(MTT) staining kit. The apoptosis assay was assessed with an FITC Annexin V Apoptosis Detection Kit. Caspase-3 and caspase-12 were detected by immunocytochemical staining and semi-qua... 相似文献
30.
HAI QING LIU LI NA ZHANG AKIRA TAKARAGI TAKEAKI MIYAMOTO 《Cellulose (London, England)》1997,4(4):321-327
The effect of substituent distribution on the water solubility of O-methylcellulose (MC) was re-examined to elucidate the
lower limit of the degree of substitution (DS) in water-soluble MC. To this end, a series of 2,3-MCs which are regioselectively
substituted at the C-2 and C-3 hydroxyl groups were prepared by homogeneous methylation. It was found that the lower limit
for the DS value of water-soluble 2,3-MC was almost the same as that for MCs having even distributions of substituents along
the cellulose chain as well as in the anhydroglucose units.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献