全文获取类型
收费全文 | 244篇 |
免费 | 16篇 |
国内免费 | 1篇 |
专业分类
化学 | 235篇 |
晶体学 | 8篇 |
数学 | 8篇 |
物理学 | 10篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 6篇 |
2015年 | 11篇 |
2014年 | 13篇 |
2013年 | 11篇 |
2012年 | 24篇 |
2011年 | 42篇 |
2010年 | 16篇 |
2009年 | 17篇 |
2008年 | 27篇 |
2007年 | 15篇 |
2006年 | 11篇 |
2005年 | 11篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1992年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有261条查询结果,搜索用时 15 毫秒
31.
32.
Amanda L. Martin Jennifer L. Hickey Amber L. Ablack John D. Lewis Leonard G. Luyt Elizabeth R. Gillies 《Journal of nanoparticle research》2010,12(5):1599-1608
The imaging of molecular markers associated with disease offers the possibility for earlier detection and improved treatment
monitoring. Receptors for gastrin-releasing peptide are overexpressed on prostate cancer cells offering a promising imaging
target, and analogs of bombesin, an amphibian tetradecapeptide have been previously demonstrated to target these receptors.
Therefore, the pan-bombesin analog [β-Ala11, Phe13, Nle14]bombesin-(7–14) was conjugated through a linker to dye-functionalized
superparamagnetic iron oxide nanoparticles for the development of a new potential magnetic resonance imaging probe. The peptide
was conjugated via click chemistry, demonstrating a complementary alternative methodology to conventional peptide-nanoparticle
conjugation strategies. The peptide-functionalized nanoparticles were then demonstrated to be selectively taken up by PC-3
prostate cancer cells relative to unfunctionalized nanoparticles and this uptake was inhibited by the presence of free peptide,
confirming the specificity of the interaction. This study suggests that these nanoparticles have the potential to serve as
magnetic resonance imaging probes for the detection of prostate cancer. 相似文献
33.
Senanayake K Thompson AL Howard JA Botta M Parker D 《Dalton transactions (Cambridge, England : 2003)》2006,(45):5423-5428
The macrocyclic ligand 1,4,7,10-tetraazacyclododecane-1,4,7-triyl(methylenebenzyl-phosphinic acid) H3L3, has been prepared and its complexes with Eu, Gd and Tb(III) studied by NMR, relaxometry, luminescence and single crystal X-ray crystallography. In solution and in the crystal, the complexes have eight-coordinate metal centres with bridging phosphinate groups linking the two twisted square antiprismatic coordination polyhedra. A single stereoisomer crystallises from solution with an RRR and SSS configuration at the P centres in each sub-unit. The relaxivity of [GdL3]2 is low (1.9 mM-1 s-1, 298 K, 20 MHz), consistent with the absence of any proximate water molecules. The terbium dimer possesses a relatively long excited state lifetime (2.47 ms, 298 K). 相似文献
34.
Pickard FC Shepherd RL Gillis AE Dunn ME Feldgus S Kirschner KN Shields GC Manoharan M Alabugin IV 《The journal of physical chemistry. A》2006,110(7):2517-2526
We present a detailed theoretical study of geometries, electronic structure, and energies of transition states and intermediates completing the full Bergman cycloaromatization pathway of ortho-substituted enediynes with a focus on polar and steric contributions to the kinetics and thermodynamics of hydrogen abstraction. This study provides a rare unambiguous example of remote substitution that affects reactivity of a neutral reactive intermediate through an sigma framework. 相似文献
35.
36.
Sidra Amin Aneela Tahira Amber R. Solangi Raffaello Mazzaro Zafar Hussain Ibupoto Almas Fatima Alberto Vomiero 《Electroanalysis》2020,32(5):1052-1059
Nickel oxide (NiO) nanostructures are employed in the basic medium for the oxidation of ethanol. A variety of NiO nanostructures are synthesized by wet chemical growth method, using different hydroxide (OH?) ion sources, particularly from ammonia, hexamethylenetetramine, urea and sodium hydroxide. The use of urea as (OH?) ion source results in flower‐like NiO structures composed by extremely thin nanowalls (thickness lower than 10 nm,), which demonstrated to be the most active for ethanol oxidation. All the samples exhibit NiO cubic phase, and no other impurity was detected. The cyclic voltammetry (CV) curves of NiO nanostructures were found linear over the concentration range 0.1–3.5 mM (R2=0.99) of ethanol, with the limit of detection estimated to be 0.013 mM for ethanol. The NiO nanostructures exhibit a selective signal towards ethanol oxidation in the presence of different members of alcohol family. The proposed NiO nanostructures showed a significant practicality for the reproducible and sensitive determination of ethanol from brandy, whisky, mixture of brandy and rum, and vodka samples. The nanomaterial was used as a surface modifying agent for the glassy carbon electrode and it showed a stable electro‐oxidation activity for the ethanol for 16 days. These findings indicate that the presented NiO nanomaterial can be applied in place of noble metals for ethanol sensing and other environmental applications (like fuel cells). 相似文献
37.
38.
Romain Bénéteau Anne Boussonnière Jean‐Christophe Rouaud Prof. Dr. Jacques Lebreton Dr. Jérôme Graton Prof. Dr. Denis Jacquemin Dr. Muriel Sebban Prof. Dr. Hassan Oulyadi Ghanem Hamdoun Dr. Amber N. Hancock Prof. Dr. Carl H. Schiesser Dr. Fabrice Dénès 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4809-4824
α‐Bromo aluminium acetals are suitable substrates for Ueno–Stork‐like radical cyclisations affording γ‐lactols and acid‐sensitive methylene‐γ‐lactols in high yields. The mechanistic study herein sets the scope and limitation of this reaction. The influence of the halide (or chalcogenide) atom X (X=Cl, Br, I, SPh, SePh) in the precursors α‐haloesters, as well as influence of the solvent and temperature was studied. The structure of the aluminium acetal intermediates resulting from the reduction of the corresponding α‐haloesters has been investigated by low‐temperature 13C‐INEPT diffusion‐ordered NMR spectroscopy (DOSY) experiments and quantum calculations, providing new insights into the structures of these thermally labile intermediates. Oxygen‐bridged dimeric structures with a planar Al2O2 ring are proposed for the least hindered aluminium acetals, while monomeric structures seem to prevail for the most hindered species. A comparison against the radical cyclisation of aluminium acetals derived from allyl and propargyl alcohols with the parent Ueno–Stork has been made at the BHandHLYP/6‐311++G(d,p) level of theory, highlighting mechanistic similarities and differences. 相似文献
39.
Amber M. Kelley Eni Minerali Jennifer E. Wilent Nicholas J. Chambers Kyla J. Stingley G. Tyler Wilson Kimberly S. Petersen 《Tetrahedron letters》2019,60(18):1262-1264
A straightforward method for the asymmetric preparation of novel lactone and lactam spirocycles is described. An initial desymmetrization via a chiral Brønsted acid yields enantioenriched lactones which readily undergo a second cyclization to give the desired spirocycle. 相似文献
40.
Mass spectral studies on 1‐n‐pentyl‐3‐(1‐naphthoyl)indole (JWH‐018), three deuterium‐labeled analogues and the inverse isomer 1‐naphthoyl‐3‐n‐pentylindole
下载免费PDF全文
![点击此处可从《Rapid communications in mass spectrometry : RCM》网站下载免费的PDF全文](/ch/ext_images/free.gif)