全文获取类型
收费全文 | 1646篇 |
免费 | 34篇 |
国内免费 | 17篇 |
专业分类
化学 | 1124篇 |
晶体学 | 11篇 |
力学 | 23篇 |
数学 | 310篇 |
物理学 | 229篇 |
出版年
2023年 | 5篇 |
2022年 | 21篇 |
2021年 | 37篇 |
2020年 | 26篇 |
2019年 | 31篇 |
2018年 | 27篇 |
2017年 | 23篇 |
2016年 | 62篇 |
2015年 | 35篇 |
2014年 | 52篇 |
2013年 | 110篇 |
2012年 | 91篇 |
2011年 | 103篇 |
2010年 | 74篇 |
2009年 | 89篇 |
2008年 | 101篇 |
2007年 | 94篇 |
2006年 | 99篇 |
2005年 | 73篇 |
2004年 | 76篇 |
2003年 | 44篇 |
2002年 | 58篇 |
2001年 | 21篇 |
2000年 | 29篇 |
1999年 | 17篇 |
1998年 | 19篇 |
1997年 | 18篇 |
1996年 | 20篇 |
1995年 | 18篇 |
1994年 | 10篇 |
1993年 | 18篇 |
1992年 | 13篇 |
1991年 | 7篇 |
1990年 | 18篇 |
1989年 | 11篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 15篇 |
1984年 | 17篇 |
1983年 | 14篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1980年 | 11篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 4篇 |
1973年 | 7篇 |
排序方式: 共有1697条查询结果,搜索用时 15 毫秒
61.
62.
63.
Dr. Anaïs Depaix Agnieszka Mlynarska-Cieslak Dr. Marcin Warminski Dr. Pawel J. Sikorski Prof. Dr. Jacek Jemielity Dr. Joanna Kowalska 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(47):12190-12197
Labeled RNAs are invaluable probes for investigation of RNA function and localization. However, mRNA labeling remains challenging. Here, we developed an improved method for 3′-end labeling of in vitro transcribed RNAs. We synthesized novel adenosine 3′,5′-bisphosphate analogues modified at the N6 or C2 position of adenosine with an azide-containing linker, fluorescent label, or biotin and assessed these constructs as substrates for RNA labeling directly by T4 ligase or via postenzymatic strain-promoted alkyne-azide cycloaddition (SPAAC). All analogues were substrates for T4 RNA ligase. Analogues containing bulky fluorescent labels or biotin showed better overall labeling yields than postenzymatic SPAAC. We successfully labeled uncapped RNAs, NAD-capped RNAs, and 5′-fluorescently labeled m7Gp3Am-capped mRNAs. The obtained highly homogenous dually labeled mRNA was translationally active and enabled fluorescence-based monitoring of decapping. This method will facilitate the use of various functionalized mRNA-based probes. 相似文献
64.
65.
66.
Pawel Uznanski Agnieszka Walkiewicz-Pietrzykowska Krzysztof Jankowski Joanna Zakrzewska Aleksander M. Wrobel Jacek Balcerzak Jacek Tyczkowski 《应用有机金属化学》2020,34(8):e5674
Amorphous silicon oxycarbide (a-SiOC:H) films produced by remote plasma RPCVD from diethoxymethylsilane (DEMS) were characterized in terms of their basic properties related to the coatings deposited using conventional plasma enhanced PECVD method. The effect of substrate temperature (TS) on the growth rate, chemical composition, structure, and properties of resulting a-SiOC:H films is reported. Film growth is an adsorption-controlled process, wherein two mechanisms can be distinguished with a transition at about TS=70°C. Depending on the temperature, films of different nature can be obtained, from polymer-like to highly crosslinked material with C-Si-O network. The chemical structure of a-SiOC:H films was characterized by FTIR, 13C and 29Si solid-state NMR, and X-ray photoelectron spectroscopes. The a-SiOC:H films were also characterized in terms of their density, refractive index, surface morphology, conformality of coverage, hardness, adhesion to a substrate, and friction coefficient. The films were found to be morphologically homogeneous materials exhibiting good conformality of coverage and small surface roughness. Their refractive index exhibits anomalous effect revealing a minimum value at TS=125°C. Due to their exceptional physical properties a-SiOC:H films produced by RPCVD from DEMS precursor seems to be useful as potential dielectric materials or coatings for various encapsulation applications. 相似文献
67.
68.
69.
70.
Estefanía Moreno-Gordaliza Sven J. van der Lee Ayşe Demirkan Cornelia M. van Duijn Johan Kuiper Petrus W. Lindenburg Thomas Hankemeier 《Analytica chimica acta》2016
A new capillary isotachophoresis (cITP) method for lipoprotein profiling with superior lipoprotein coverage compared to previous methods has been developed, resolving twice as many lipoprotein species (18 peaks/fractions) in serum or plasma in less than 9.5 min. For this, a novel mixture of 24 spacers, including amino acids, dipeptides and sulfonic acids, was developed and fine-tuned, using predictive software (PeakMaster) and testing of spiked serum samples. Lipoprotein peaks were identified by serum-spiking with reference lipoproteins. Compatibility with common lipophilic stains for selective lipoprotein detection with either UV/Vis or laser-induced fluorescence was demonstrated. A special new capillary with a neutral coating (combining water-compatible OV1701-OH deactivation and methylation) was used for the first time for electrodriven separations, allowing very stable separations in a pH 8.8–9.4 gradient system, being functional for more than 100 injections. Excellent reproducibility was achieved, with coefficients of variation lower than 2.6% for absolute migration times. Comparison was performed with human plasma samples analyzed by NMR, leading to similar results with cITP after multivariate statistics, regarding group-clustering and lipoprotein species correlation. The new cITP method was applied to the analysis of serum samples from a LDL receptor knock-out mice model fed either a normal diet or a western-type diet. Differences in the lipoprotein levels and in the sublipoprotein types were detected, showing a shift to more atherogenic particles due to the high cholesterol diet. In summary, this novel method will allow more detailed and informative profiling of lipoprotein particle subtypes for cardiovascular disease research. 相似文献