全文获取类型
收费全文 | 50篇 |
免费 | 1篇 |
专业分类
化学 | 29篇 |
力学 | 1篇 |
数学 | 11篇 |
物理学 | 10篇 |
出版年
2018年 | 1篇 |
2013年 | 5篇 |
2012年 | 4篇 |
2011年 | 3篇 |
2010年 | 1篇 |
2008年 | 5篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 3篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有51条查询结果,搜索用时 15 毫秒
11.
12.
Differentially protected glycosyl phosphates prepared by a straightforward synthesis from glycal precursors are used as powerful glycosyl donors. Activation of beta-glycosyl phosphates by TMSOTf at -78 degrees C achieves the selective formation of beta-glycosidic linkages in excellent yields with complete stereoselectivity. Reaction with thiols results in the conversion of glycosyl phosphates into thioglycosides in nearly quantitative yield. An orthogonal coupling strategy using glycosyl phosphate donors and thioethyl glycoside acceptors allows for the rapid synthesis of a trisaccharide. 相似文献
13.
Kihong Lee Bonnie Choi Dr. Ilan Jen‐La Plante Maria V. Paley Xinjue Zhong Prof. Andrew C. Crowther Prof. Jonathan S. Owen Prof. Xiaoyang Zhu Prof. Xavier Roy 《Angewandte Chemie (International ed. in English)》2018,57(21):6125-6129
Two‐dimensional (2D) materials are commonly prepared by exfoliating bulk layered van der Waals crystals. The creation of synthetic 2D materials from bottom‐up methods is an important challenge as their structural flexibility will enable chemists to tune the materials properties. A 2D material was assembled using C60 as a polymerizable monomer. The C60 building blocks are first assembled into a layered solid using a molecular cluster as structure director. The resulting hierarchical crystal is used as a template to polymerize its C60 monolayers, which can be exfoliated down to 2D crystalline nanosheets. Derived from the parent template, the 2D structure is composed of a layer of inorganic cluster, sandwiched between two monolayers of polymerized C60. The nanosheets can be transferred onto solid substrates and depolymerized by heating. Electronic absorption spectroscopy reveals an optical gap of 0.25 eV, narrower than that of the bulk parent crystalline solid. 相似文献
14.
15.
[formula: see text] A beta-(1-->4)-linked trisaccharide was prepared in 53% yield on a polymer support using glycosyl phosphates and released by cross-metathesis of a novel linker to reveal the anomeric n-pentenyl glycoside. Heptasaccharide 33 was prepared in 9% yield in 14 steps. 相似文献
16.
[reaction: see text] Glycosyl phosphates were examined for their utility in the synthesis of challenging glycosidic linkages. beta-Glucosamine glycosides were formed preferentially and in good yield. beta-Mannosides were constructed in high overall yield with modest anomeric selectivity. Interesting solvent and conformational influences on the stereochemical outcome of the coupling reactions were observed. 相似文献
17.
Gérard Demazeau Patrick Maestro Théophile Plante Michel Pouchard Paul Hagenmuller 《Journal of Physics and Chemistry of Solids》1980,41(10):1139-1145
A new solid solution Cr1?x,RhxO2 (0?x?1) has been prepared using oxidizing acids or ammonium perchlorate under pressure. The magnetic study suggests that chromium (IV) and rhodium (IV) are present in the structure at x ? 0.2 and chromium (V) and rhodium (III) at 0.2 < x ? 0.5. Forx > 0.5 increasing rhodium (IV) content gives rise to properties similar to those of RhO2. 相似文献
18.
19.
Abstract High oxygen pressures have been developed these last twenty years using three main methods: compressed gas, oxidizing solution or in solid state thermal decomposition of KClO3. Using these different techniques and adjusting the local structural and chemical bonding characterizing the local surrounding of a transition element, unusual oxidation states [Fe(IV), Fe(V),Co(III),Co(IV),Ni(III),Cu(III)] have been stabilized in oxygen lattices derived from the (3D) perovskite or (2D)K2NiF4 structures. 相似文献
20.
Angle J Aprile E Arneodo F Baudis L Bernstein A Bolozdynya A Coelho LC Dahl CE DeViveiros L Ferella AD Fernandes LM Fiorucci S Gaitskell RJ Giboni KL Gomez R Hasty R Kastens L Kwong J Lopes JA Madden N Manalaysay A Manzur A McKinsey DN Monzani ME Ni K Oberlack U Orboeck J Plante G Santorelli R dos Santos JM Shagin P Shutt T Sorensen P Schulte S Winant C Yamashita M;XENON Collaboration 《Physical review letters》2008,101(9):091301
XENON10 is an experiment to directly detect weakly interacting massive particles (WIMPs), which may comprise the bulk of the nonbaryonic dark matter in our Universe. We report new results for spin-dependent WIMP-nucleon interactions with 129Xe and 131Xe from 58.6 live days of operation at the Laboratori Nazionali del Gran Sasso. Based on the nonobservation of a WIMP signal in 5.4 kg of fiducial liquid xenon mass, we exclude previously unexplored regions in the theoretically allowed parameter space for neutralinos. We also exclude a heavy Majorana neutrino with a mass in the range of approximately 10 GeV/c2-2 TeV/c2 as a dark matter candidate under standard assumptions for its density and distribution in the galactic halo. 相似文献