全文获取类型
收费全文 | 253篇 |
免费 | 15篇 |
专业分类
化学 | 206篇 |
力学 | 1篇 |
数学 | 11篇 |
物理学 | 50篇 |
出版年
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 19篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 13篇 |
2012年 | 21篇 |
2011年 | 19篇 |
2010年 | 7篇 |
2009年 | 15篇 |
2008年 | 21篇 |
2007年 | 26篇 |
2006年 | 19篇 |
2005年 | 15篇 |
2004年 | 10篇 |
2003年 | 7篇 |
2002年 | 16篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1993年 | 1篇 |
1989年 | 1篇 |
1979年 | 1篇 |
1932年 | 1篇 |
1931年 | 1篇 |
1928年 | 3篇 |
1924年 | 1篇 |
1923年 | 1篇 |
排序方式: 共有268条查询结果,搜索用时 15 毫秒
11.
Dr. Roman S. Erdmann Dr. Hideo Takakura Alexander D. Thompson Felix Rivera‐Molina Dr. Edward S. Allgeyer Prof. Dr. Joerg Bewersdorf Prof. Dr. Derek Toomre Prof. Dr. Alanna Schepartz 《Angewandte Chemie (International ed. in English)》2014,53(38):10242-10246
We report a lipid‐based strategy to visualize Golgi structure and dynamics at super‐resolution in live cells. The method is based on two novel reagents: a trans‐cyclooctene‐containing ceramide lipid (Cer‐TCO) and a highly reactive, tetrazine‐tagged near‐IR dye (SiR‐Tz). These reagents assemble via an extremely rapid “tetrazine‐click” reaction into Cer‐SiR, a highly photostable “vital dye” that enables prolonged live‐cell imaging of the Golgi apparatus by 3D confocal and STED microscopy. Cer‐SiR is nontoxic at concentrations as high as 2 μM and does not perturb the mobility of Golgi‐resident enzymes or the traffic of cargo from the endoplasmic reticulum through the Golgi and to the plasma membrane. 相似文献
12.
13.
H.?IshikawaEmail author J.?M.?ThuswaldnerEmail author 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》2004,74(1):11-32
Matsuoka showed an asymptotic formula for the coefficients of the Laurent expansion of ζ (s) at s = 1. In the present paper we extend this result to a large class of Dirichlet series which was first studied by Chandrasekharan
and Narasimhan. Our proofs are based on a saddle point argument and use the fact that the Dirichlet series under consideration
admit a functional equation.
The second author was supported by the FWF project S381O. 相似文献
14.
Doyle AW Fick J Himmelhaus M Eck W Graziani I Prudovsky I Grunze M Maciag T Neivandt DJ 《Langmuir : the ACS journal of surfaces and colloids》2004,20(21):8961-8965
Structural deformations of lipid hybrid bilayer membranes induced by signal peptideless (SPL) proteins have been studied for the first time using the inherently surface specific nonlinear optical technique of sum frequency generation vibrational spectroscopy. Specifically, deformations of 1,2-distearoylphosphatidylglycerol(DSPG) membranes induced by interaction with FGF-1, a SPL protein which is released asa function of cellular stress through a nonclassical pathway, have been investigated. FGF-1 was found to induce lipid alkyl chain deformations in previously highly ordered DSPG membranes at the extremely low concentration of 1 nM at 60 degrees C. The deformation process was shown to exhibit a degree of reversibility upon removal of the protein by rinsing with buffer solution. 相似文献
15.
Yu-Ming Lin Joerg Appenzeller Zhihong Chen Phaedon Avouris 《Physica E: Low-dimensional Systems and Nanostructures》2007,37(1-2):72
We investigate electrical transport and noise in semiconducting carbon nanotubes. By studying carbon nanotube devices with various diameters and contact metals, we show that the ON-currents of CNFETs are governed by the heights of the Schottky barriers at the metal/nanotube interfaces. The current fluctuations are dominated by 1/f noise at low-frequencies and correlate with the number of transport carriers in the device regardless of contact metal. 相似文献
16.
Joerg Hippler Markus Hollmann Heinrich Juerling Alfred V. Hirner 《Chemical Papers》2009,63(6):742-744
After the synthesis and isolation of methylated bismuth cysteine, its initial identification by IR-spectroscopy was performed,
whereas for definitive identification, high resolution mass spectrometry (ESI-TOF-MS and LTQ Orbitrap) was carried out. 相似文献
17.
18.
Richard Nader Elie Moussaed Michel Kazan Joerg Pezoldt Pierre Masri 《Superlattices and Microstructures》2008,44(2):191-196
Structural and optical measurements were performed on silicon carbide (SiC) samples containing several polytypes. The SiC samples investigated were grown on (111) Si substrates by solid source molecular beam epitaxy (SSMBE). Several quantities of Ge were predeposited before the growth procedure. The influence of Ge on the SiC polytypes formation was studied by X-Ray, FTIR and μ-Raman characterizations methods. The spectra of the samples with less than one Ge monolayer exhibit a mixture of 2H, 15R and 3C–SiC polytypes. This mixture is due to the mismatch between the heterostructure layers. We propose that the Ge predeposition in the heterostructure can be used to stabilize and unify the polytypes formation. 相似文献
19.
Edi?Bralatei Karolina?Nekrosiute Jenny?Ronan Andrea?Raab Evin?McGovern Dagmar?B.?Stengel Eva?M.?Krupp Joerg?FeldmannEmail authorView authors OrcID profile 《Mikrochimica acta》2017,184(6):1701-1709
Inorganic arsenic (iAs) in 13 store-bought edible seaweed samples and 34 dried kelp (Laminaria digitata) samples was determined by a newly developed, field-deployable method (FDM) with the aid of a field test kit for arsenic in water. Results from the FDM were compared to results from speciation analysis achieved by using high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The FDM consisted of a simple extraction method using diluted HNO3 to quantitatively extract iAs without decomposing the organoarsenicals to iAs followed by the selective volatilisation of iAs as arsine (AsH3) and subsequent chemo-trapping on a filter paper soaked in mercury bromide (HgBr2) solution. Method optimization with a sub-set of samples showed 80–94% iAs recovery with the FDM with no matrix effect from organo-arsenic species in the form of dimethylarsinic acid (DMA) on the iAs concentration. The method displayed good reproducibility with an average error of ±19% and validation by HPLC-ICP-MS showed that the results from the FDM were comparable (slope = 1.03, R2 = 0.70) to those from speciation analysis with no bias. The FDM can be conducted within an hour and the observed limit of quantification was around 0.05 mg kg?1 (dry weight). This method is well suited for on-site monitoring of iAs in seaweed before it is harvested and can thus be recommended for use as a screening method for iAs in seaweed. 相似文献
20.
Calmano T Siebenmorgen J Reichert F Fechner M Paschke AG Hansen NO Petermann K Huber G 《Optics letters》2011,36(23):4620-4622
We fabricated waveguides in Pr:SrAl(12)O(19) crystals by direct femtosecond laser writing. The propagation losses were calculated to be as low as 0.16 dB/cm at a wavelength of 633 nm. Laser oscillation in a diode-pumped waveguide at a wavelength of 643.5 nm was realized. The output power of the waveguide laser was 28.1 mW at a slope efficiency of 8%. 相似文献