全文获取类型
收费全文 | 18933篇 |
免费 | 3181篇 |
国内免费 | 2103篇 |
专业分类
化学 | 13511篇 |
晶体学 | 189篇 |
力学 | 1065篇 |
综合类 | 103篇 |
数学 | 1952篇 |
物理学 | 7397篇 |
出版年
2024年 | 78篇 |
2023年 | 421篇 |
2022年 | 666篇 |
2021年 | 768篇 |
2020年 | 762篇 |
2019年 | 780篇 |
2018年 | 682篇 |
2017年 | 605篇 |
2016年 | 928篇 |
2015年 | 913篇 |
2014年 | 1075篇 |
2013年 | 1369篇 |
2012年 | 1692篇 |
2011年 | 1574篇 |
2010年 | 1090篇 |
2009年 | 1018篇 |
2008年 | 1148篇 |
2007年 | 1075篇 |
2006年 | 984篇 |
2005年 | 883篇 |
2004年 | 646篇 |
2003年 | 552篇 |
2002年 | 537篇 |
2001年 | 406篇 |
2000年 | 360篇 |
1999年 | 438篇 |
1998年 | 352篇 |
1997年 | 347篇 |
1996年 | 328篇 |
1995年 | 281篇 |
1994年 | 228篇 |
1993年 | 200篇 |
1992年 | 157篇 |
1991年 | 139篇 |
1990年 | 157篇 |
1989年 | 114篇 |
1988年 | 78篇 |
1987年 | 56篇 |
1986年 | 60篇 |
1985年 | 63篇 |
1984年 | 35篇 |
1983年 | 34篇 |
1982年 | 37篇 |
1981年 | 21篇 |
1980年 | 13篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1973年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 12 毫秒
71.
Jing Li Huayi Shi Runzhi Chen Xiaofeng Wu Jiayi Cheng Fenglin Dong Houyu Wang Yao He 《Chemical science》2021,12(3):896
Synthesis of programmable atom-like nanoparticles (PANs) with high valences and high yields remains a grand challenge. Here, a novel synthetic strategy of microfluidic galvanic displacement (μ-GD) coupled with microfluidic DNA nanoassembly is advanced for synthesis of single-stranded DNA encoder (SSE)-encoded PANs for reliable surface-enhanced Raman scattering (SERS) sensing. Notably, PANs with high valences (e.g., n-valence, n = 12) are synthesized with high yields (e.g., >80%) owing to the effective control of interfacial reactions sequentially occurring in the microfluidic system. On the basis of this, we present the first demonstration of a PAN-based automatic analytical platform, in which sensor construction, sample loading and on-line monitoring are carried out in the microfluidic system, thus guaranteeing reliable quantitative measurement. In the proof-of-concept demonstration, accurate determination of tetracycline (TET) in serum and milk samples with a high recovery close to 100% and a low relative standard deviation (RSD) less than 5.0% is achieved by using this integrated analytical platform.A novel synthetic strategy is presented for microfluidic preparation of programmable atom-like nanoparticles with high valences and high yields. 相似文献
72.
Reliability bounds in DFRA class with known mean and variance 总被引:1,自引:0,他引:1
RELIABILITYBOUNDSINDFRACLASSWITHKNOWNMEAN AND VARIANCECHENGKAN(程侃)(InstituteofAppliedMathematics,theChineseAcademyofScience,B... 相似文献
73.
Artuso M Gao M Goldberg M He D Horwitz N Moneti GC Mountain R Muheim F Mukhin Y Playfer S Rozen Y Stone S Xing X Zhu G Bartelt J Csorna SE Egyed Z Jain V Gibaut D Kinoshita K Pomianowski P Barish B Chadha M Chan S Cowen DF Eigen G Miller JS O'Grady C Urheim J Weinstein AJ Würthwein F Asner DM Athanas M Bliss DW Brower WS Masek G Paar HP Gronberg J Korte CM Kutschke R Menary S Morrison RJ Nakanishi S Nelson HN Nelson TK Qiao C Richman JD Roberts D Ryd A Tajima H Witherell MS Balest R Cho K 《Physical review letters》1995,75(5):785-789
74.
75.
76.
Bai JZ Bardon O Blum I Breakstone A Burnett T Chen GP Chen HF Chen J Chen SJ Chen SM Chen Y Chen YB Chen YQ Cheng BS Cowan RF Cui HC Cui XZ Ding HL Du ZZ Dunwoodie W Fan XL Fang J Fero M Gao CS Gao ML Gao SQ Gao WX Gratton P Gu JH Gu SD Gu WX Gu YF Guo YN Han SW Han Y Harris FA Hatanaka M He J He KR He M Hitlin DG Hu GY Hu HB Hu T Hu XQ Huang DQ Huang YZ Izen JM Jia QP Jiang CH Jin Y Jones L Kang SH Kelsey MH Kim BK Lai YF Lan HB Lang PF Lankford A Li F Li J Li PQ Li Q Li RB 《Physical review D: Particles and fields》1995,52(7):3781-3784
77.
Summary Let be a circle domain in the Riemann sphere whose boundary has -finite linear measure. We show that is rigid in the sense that any conformal homeomorphism of onto any other circle domain is equal to the restriction of a Möbius transformation. Previously, Kaufman and Bishop have independently found examples of non-rigid circle, domains whose boundary is a Cantor set of (Hausdorff) dimension one.Oblatum 19-VI-1992 & 2-IV-1993Supported by NSF and Sloan Foundation 相似文献
78.
Integrable systems of NLS type in 2+1 dimensions are studied in three ways: their special solutions by Lie point symmetries, breaking-solutions by the ISM, as well as the non-isospectral problems.Department of Mathematics, Statistics and Computing Science, University of New England, Armidale N.S.W. 2351, Australia. E-mail: zhuhan@neumann.une.edu.au, xhe@metz.une.edu.au Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 99, No. 3, pp. 382–389, June, 1994. 相似文献
79.
Battle M Ernst J Kwon Y Roberts S Thorndike EH Wang CH Dominick J Lambrecht M Sanghera S Shelkov V Skwarnicki T Stroynowski R Volobouev I Wei G Zadorozhny P Artuso M Goldberg M He D Horwitz N Kennett R Mountain R Moneti GC Muheim F Mukhin Y Playfer S Rozen Y Stone S Thulasidas M Vasseur G Zhu G Bartelt J Csorna SE Egyed Z Jain V Kinoshita K Edwards KW Ogg M Britton DI Hyatt ER MacFarlane DB Patel PM Akerib DS Barish B Chadha M Chan S Cowen DF Eigen G Miller JS O'Grady C Urheim J Weinstein AJ 《Physical review letters》1994,73(8):1079-1083
80.
Martin Norgren Sailing He 《International Journal of Infrared and Millimeter Waves》1994,15(9):1537-1554
A time-harmonic electromagnetic plane wave obliquely incident on a half-space or a slab consisting of a so-called medium is considered. The up- and down-going eigenmodes in the medium are derived and used to calculate the reflection and transmission coefficients for TE and TM modes. The Brewster angles for an half-space are computed. Numerical results for the co- and cross-polarized reflection and transmission coefficients for an slab are presented. 相似文献