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81.
82.
为探究团簇Ni4P催化析氢最强的结构,基于密度泛函理论,在B3LYP/Lan12dz水平下,对团簇Ni4P的初始构型进行计算和优化,得到5种优化构型。从热力学稳定性、前线轨道图和前线轨道能级差对团簇Ni4P的析氢性能分析发现,构型1(4)和1(2)的热力学稳定性较强;团簇Ni4P各优化构型均易吸附水中的氢原子,Ni原子为团簇Ni4P催化活性位点,且构型1(4)、1(2)和2(4)催化析氢的活性更强。(1(2))-H、(2(2))-H在电化学脱附法和化学重组法中均具有较强的催化活性。以上说明构型1(2)是团簇Ni4P催化析氢最强的结构。 相似文献
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Data on the reactions of triazole, tetrazole, dioxazole, oxadiazole, and thiadiazole aldoximes, ketoximes, and amidoximes,
their synthesis, and the reactions of their derivatives are reviewed. The synthesis of new heterocycles based on the oximes
of five-membered heterocyclic compounds with three and four heteroatoms is examined separately. The principal results from
investigation of the biological activity of ethers of these oximes are also presented.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 963–990, July, 2008. 相似文献
87.
Technology of preparing anode films and the effect of co-sensitization in dye-sensitized solar cells 总被引:2,自引:0,他引:2
Jingchang Zhang Zhenhai Fu qian lv Xiuying Yang Weiliang Cao 《Journal of Sol-Gel Science and Technology》2012,63(3):554-562
Nanocrystalline N–Zn/TiO2 anode films were prepared by doping element N and Zn. These element-doped films have a better performance in dye-sensitized solar cell than the non-doped film. The test shows that the best thickness of N–Zn/TiO2 anode film is 13.5 μm. UV–Visible measurements show that there is a complementarity in ultraviolet–visible absorbance range between P3OT and N719, both are used as dyes in this study, the former is prepared and the latter is commercially available. SEM shows a significant mass increase of anode film after treated with TiCl4. Solar cells based on N–Zn/TiO2 anode film with TiCl4 treatment was firstly co-sensitized by N719/P3OT. A solar-to-electric energy conversion efficiency of 3.54 % was obtained. Compared with the traditional dye-sensitized solar cell, the photoelectric conversion efficiency, V oc and J sc have been increased. 相似文献
88.
Kevin Buchin Ji?í Matou?ek Robin A. Moser D?m?t?r Pálv?lgyi 《Mathematical Programming》2012,135(1-2):323-335
For an integer d ≥ 1, let τ(d) be the smallest integer with the following property: if v 1, v 2, . . . , v t is a sequence of t ≥ 2 vectors in [?1, 1] d with ${{\bf v}_1+{\bf v}_2+\cdots+{\bf v}_t \in [-1,1]^d}$ , then there is a set ${S\subseteq \{1,2,\ldots,t\}}$ of indices, 2 ≤ |S| ≤ τ(d), such that ${\sum_{i \in S}{\bf v}_i \in [-1,1]^d}$ . The quantity τ(d) was introduced by Dash, Fukasawa, and Günlük, who showed that τ(2)?=?2, τ(3)?=?4, and τ(d)?=?Ω(2 d ), and asked whether τ(d) is finite for all d. Using the Steinitz lemma, in a quantitative version due to Grinberg and Sevastyanov, we prove an upper bound of τ(d) ≤ d d+o(d), and based on a construction of Alon and V?, whose main idea goes back to H?stad, we obtain a lower bound of τ(d) ≥ d d/2-o(d). These results contribute to understanding the master equality polyhedron with multiple rows defined by Dash et?al. which is a “universal” polyhedron encoding valid cutting planes for integer programs (this line of research was started by Gomory in the late 1960s). In particular, the upper bound on τ(d) implies a pseudo-polynomial running time for an algorithm of Dash et?al. for integer programming with a fixed number of constraints. The algorithm consists in solving a linear program, and it provides an alternative to a 1981 dynamic programming algorithm of Papadimitriou. 相似文献
89.
Glycerol monooleate-blood interactions 总被引:1,自引:0,他引:1
Ericsson EM Faxälv L Weissenrieder A Askendal A Lindahl TL Tengvall P 《Colloids and surfaces. B, Biointerfaces》2009,68(1):20-26
In the present study the initial blood compatibility of glycerol monooleate (GMO)-coated surfaces was evaluated after deposition to surfaces and in bulk. The model surface was silica onto which multiple layers of fibrinogen or human serum albumin (HSA) was immobilized. The protein-coated surfaces were subsequently dip-coated in GMO in ethanol and used for blood plasma and whole blood experiments. The characterization methods included null ellipsometry, scanning electron microscopy, imaging of coagulation, hemolysis test and whole blood coagulation time by free oscillation rheometry. The results showed a GMO film thickness of approximately 350 A (approximately 4 microg/cm(2)) upon dip-coating in ethanolic solution. A major part of the deposited layer detached in aqueous solutions, especially during shear conditions. The coagulation time on GMO was significantly prolonged compared to that on HSA coated silica. Whole blood tests showed that GMO is a very weak hemolytic agent. Deposited GMO detached easily from surfaces upon rinsing or shearing, although a stable layer with undefined phase structure and a thickness of 50-70 A remained on HSA and fibrinogen precoated surfaces. This indicates that GMO has stronger adhesive forces to its substrate compared to the cohesive forces acting within the bulk GMO. The ability of GMO to detach from itself and tentatively form micelles or lipid bilayers when subjected to flowing blood may be of use in extravascular applications. It is concluded that GMO results in weak blood activation, and the material may in spite of this be suitable in selected biomaterial applications, especially as a biosealant and in colloidal dispersions. 相似文献
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