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971.
Tobias Schröder Satya Narayan Sahu Dario Anselmetti Jochen Mattay 《Israel journal of chemistry》2011,51(7):725-742
Self-assembly by H-bonding and by metal-coordination of functionalized calix[4]arenes and cavitands to large supramolecular capsules is described. In addition, a new method of analyzing supramolecular recognition processes at the single molecule level is discussed. By measuring interaction forces in a hydrogen-bonded assembly using single-molecule force spectroscopy (SMFS), the dynamics of the self-assembly process can be evaluated. In the future, consequent application of this new technique will influence supramolecular design principles and the use of non-covalent interactions as construction elements in the field of nanotechnology. 相似文献
972.
The field of dynamic covalent nanocapsule synthesis is very young, and most contributions to the development of reliable approaches for the assembly of dynamic covalent capsules have been made during the past five years. In 1991, Quan and Cram published the first Schiff base molecular container compound. Over the past six years, a large number of multi-component polyimine hemicarcerand and polyhedron syntheses have been developed. This review will focus primarily on recent achievements in the area of pure Schiff base nanocapsules and highlight different synthetic approaches and design strategies, as well as first applications of these capsules in molecular recognition, gas storage, and gas separation. 相似文献
973.
The halogenated boron-doped diamond (BDD) surfaces were reacted with sodium azide through a nucleophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the "click" reaction. Because of the attractive electrochemical properties of ferrocene-containing molecules, such as fast electron transfer rates, reversible redox activities, and favorable redox potentials, we show that ferrocene derivatives can be grafted onto non-oxidized diamond surfaces by click"chemistry". These redox-active ferrocene-containing layers on a BDD surface, because of their ability to store and release charges reversibly, have the potential to be used as hybrid molecular/semiconductor memory devices. 相似文献
974.
975.
BaPt5Si12 has been synthesized by argon arc melting the elements. The structure was solved by direct methods from Kappa CCD intensity data. The novel silicide crystallizes in a unique monoclinic structure type: space group C2/m; a = 0.61327(2) nm, b = 3.23481(8) nm, c = 0.61180(1) nm, β = 90.130(2)°. The structure of BaPt5Si12 is characterized by Pt atoms, which are all arranged in planes parallel x–z resulting in tetrahedral coordination for Si1, Si2, Si3 and Si4 atoms and more complex distorted polyhedra around Si5 and Si6 atoms. Three voids were encountered in the structure at the centres of an Achimedian antiprism and two cube-octahedra. These voids do not show any residual electron densities. BaPt5Si12 turns out to be metallic; no phase transitions are found within the temperature range from 300 mK to 300 K. The overall resistivity is rather large, presumably a consequence of the voids in the crystal structure. Additionally, the quite complex crystal structure gives rise to intricate phonon modes. 相似文献
976.
综合研究实验不仅激发了学生的学习兴趣、创新意识,而且使学生初步掌握科学研究的思维方式和解决问题的方法,使学生的综合素质得以提高。开设综合实验既是贯彻党和国家的教育方针,也是培养新型人才的需要。文章就目前综合性化学实验的设计和开设做一综述。 相似文献
977.
Steve H. Lu Iris C. Yang Hai Mei Shih-Pin Tu Teh-Fu Yen 《Petroleum Science and Technology》2013,31(5-6):657-670
ABSTRACT Two types of filter are developed. One is for the removal of sulfur compounds in petroleum and its derived products. The other is for upgrading, which is to lower the amount of asphaltene. Although research in selectivity and life cycle estimation of intermetallic media is still continuing, the mechanisms behind this technology are based upon the concept of nanotechnology and the principle of membrane mimetic chemistry. 相似文献
978.
Julie Le Grandois Eric Marchioni Saïd Ennahar Francesca Giuffrida Françoise Bindler 《Food chemistry》2010
Heat-induced oxidative modifications of two phosphatidylcholine molecular species as potential functional food components were evaluated. 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) and 1-stearoyl-2-linoleoyl-sn-glycero-3-phosphocholine (SLPC) were chosen as models. The optimal temperature for hydroperoxide formation was determined by MS for each standard: 125 °C for SLPC and 150 °C for SOPC. Oxidation was performed at these temperatures and degradation products were identified using LC–ESI-MS combined to an acid treatment. Kinetics of formation of oxidation products from SOPC and SLPC were monitored over 120 min and curves were drawn for each identified structure. Results showed that native phospholipids rapidly decreased with heat and that oxidation products showed functions, such as hydroxyl, oxo or epoxy groups. Kinetics pointed out that some of these quite stable oxidation products are likely to be found in sizable amounts in processed foods containing phospholipids. 相似文献
979.
980.
浅论心理引导对化学专业英语教学效果的提升作用 总被引:2,自引:0,他引:2
专业英语是大学专业教育的重要内容,但大量的专业词汇和严谨繁复的表达方式也很容易让学生感觉枯燥,进而失去兴趣和注意力。本文着重探讨了对学生进行心理引导的作用以及使教学生动有趣的方法。 相似文献