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51.
Chi-Fung Yeung Sik-Him Tang Zhe Yang Tsun-Yin Li Ka-Kit Li Yuen-Man Chan Hau-Lam Shek Kai-Wa Io King-Ting Tam Shek-Man Yiu Man-Kit Tse Chun-Yuen Wong 《Molecules (Basel, Switzerland)》2022,27(5)
Mononuclear and dinuclear Ru(II) complexes cis-[Ru(κ2-dppm)(bpy)Cl2] (1), cis-[Ru(κ2-dppe)(bpy)Cl2] (2) and [Ru2(bpy)2(μ-dpam)2(μ-Cl)2](Cl)2 ([3](Cl)2) were prepared from the reactions between cis(Cl), cis(S)-[Ru(bpy)(dmso-S)2Cl2] and diphosphine/diarsine ligands (bpy = 2,2′-bipyridine; dppm = 1,1-bis(diphenylphosphino)methane; dppe = 1,2-bis(diphenylphosphino)ethane; dpam = 1,1-bis(diphenylarsino)methane). While methoxy-substituted ruthenafuran [Ru(bpy)(κ2-dppe)(C^O)]+ ([7]+; C^O = anionic bidentate [C(OMe)CHC(Ph)O]− chelate) was obtained as the only product in the reaction between 2 and phenyl ynone HC≡C(C=O)Ph in MeOH, replacing 2 with 1 led to the formation of both methoxy-substituted ruthenafuran [Ru(bpy)(κ2-dppm)(C^O)]+ ([4]+) and phosphonium-ring-fused bicyclic ruthenafuran [Ru(bpy)(P^C^O)Cl]+ ([5]+; P^C^O = neutral tridentate [(Ph)2PCH2P(Ph)2CCHC(Ph)O] chelate). All of these aforementioned metallafuran complexes were derived from Ru(II)–vinylidene intermediates. The potential applications of these metallafuran complexes as anticancer agents were evaluated by in vitro cytotoxicity studies against cervical carcinoma (HeLa) cancer cell line. All the ruthenafuran complexes were found to be one order of magnitude more cytotoxic than cisplatin, which is one of the metal-based anticancer agents being widely used currently. 相似文献
52.
53.
Xin Li Guangcun Shan Ruguang Ma Chan-Hung Shek Hongbin Zhao Seeram Ramakrishna 《Frontiers of Physics》2022,17(6):63501
MXene-based hydrogels have drawn considerable attention as flexible and wearable sensors. However, the application of MXene-based hydrogels after sensing failure has rarely been investigated, which is of great significance for expanding their engineering application. In this work, multifunctional mineral MXene hydrogels (MMHs) were synthesized via a simple method inspired by biomineralization. The prepared MMHs were stretchable, self-healable and conductive, and can be used to fabricate wearable tensile strain sensors showing a super-wide sensing range with excellent sensitivity. MMHs-based strain sensors were designed to be directly attached to the skin surface to detect tiny and large human motions. In addition, with the advantages of a large specific area, excellent hydrophilicity and abundant active adsorption sites for MXene nanosheets and hydrogels, dehydrated MMHs were used as highly efficient adsorbents for the removal of strontium ions from aqueous solutions. This work shows the great potential of MXene in promoting the development of next-generation functional materials. 相似文献
54.
Chen Z Li Q Wang J Pan D Jiao Z Wu M Shek CH Wu CM Lai JK 《Inorganic chemistry》2011,50(14):6756-6761
Metal/semiconductor thin films are a class of unique materials that have widespread technological applications, particularly in the field of microelectronic devices. New strategies of fractal assessment for Pd/Ge bilayer films formed at various annealing temperatures are of fundamental importance in the development of micro/nanodevices. Herein, Pd/Ge bilayer films with interesting fractal nanoclusters were successfully prepared by evaporation techniques. Temperature-dependent properties of resistance and fractal dimensions in Pd/Ge bilayer films with self-similar Ge fractal nanoclusters were investigated in detail. Experimental results indicated that the fractal crystallization behavior and film resistance in Pd/Ge bilayer films are influenced significantly by annealing temperatures and fractal dimensions. The measurements of film resistance confirmed that there is an evident relationship between the film resistance and the fractal dimension. These phenomena were reasonably explained by the random tunneling junction network mechanism. 相似文献
55.
N. A. Sobolev D. V. Denisov A. M. Emel’yanov E. I. Shek B. Ya. Ber A. P. Kovarskii V. I. Sakharov I. T. Serenkov V. M. Ustinov G. E. Cirlin T. V. Kotereva 《Physics of the Solid State》2005,47(1):113-116
The technology and properties of light-emitting structures based on silicon layers doped by erbium during epitaxial MBE growth are studied. The epitaxial layer forming on substrates prepared from Czochralski-grown silicon becomes doped by oxygen and carbon impurities in the process. This permits simplification of the Si: Er layer doping by luminescence-activating impurities, thus eliminating the need to make a special capillary for introducing them into the growth chamber from the vapor phase. The photoluminescence spectra of all the structures studied at 78 K are dominated by an Er-containing center whose emission line peaks at 1.542 μm. The intensity of this line measured as a function of the substrate and erbium dopant source temperatures over the ranges 400–700°C and 740–800°C, respectively, exhibits maxima. The edge luminescence and the P line observed in the PL spectra are excited predominantly in the substrate. The erbium atom concentration in the epitaxial layers grown at a substrate temperature of 600°C was studied by Rutherford proton backscattering and exhibits an exponential dependence on the erbium source temperature with an activation energy of ~2.2 eV. 相似文献
56.
C.H. Shek T.S. Gu G.M. Lin J.K.L. Lai 《Applied Physics A: Materials Science & Processing》1998,66(4):413-418
2 O3 and nanocrystalline Al2O3 specimens. The short-lifetime (170±20 ps), intermediate-lifetime (410±20 ps) and long-lifetime components correspond to three
different kinds of defects: monovacancy-like free volumes, microvoids, and larger voids. The appearance of lifetimes in the
range 1–5 ns indicates the formation of positronium. The influence of thermal annealing from 873 K to 1373 K on positron lifetime
parameters was also analyzed. The components with lifetimes τ1=170 ps and τ2=410 ps persisted even after the grains had grown to 100 nm in size, while the long-lifetime component declined significantly
when grain sizes exceeded 10 nm. The interface characteristics of polycrystalline nano-Al2O3 prepared by the two methods were compared by analyzing the variations of the positron-lifetime parameters with grain growth.
Received: 1 April 1997/Accepted: 13 August 1997 相似文献
57.
The forward-current dependence of defect-related electroluminescence (EL) in silicon structures produced by erbium and oxygen implantation into silicon single crystals with subsequent annealing in a chlorine-containing ambient at 1100°C has been studied. At 80 K, an increase in the current was observed to cause the photon energies corresponding to the maxima of two defect-related EL peaks to increase from 0.807 and 0.87 eV to 0.85 and 0.92 eV, respectively. The increase in the current was also accompanied by an increase in the half-width and intensity of the EL peaks. To explain the observed effects, a model that was proposed earlier for the defect-related EL in plastically deformed silicon is developed further; this model assumes the possible generation of inverse population involving four energy levels. 相似文献
58.
Ekiel-Jezewska ML; Wajnryb E 《The Quarterly Journal of Mechanics and Applied Mathematics》2006,59(4):563-585
An example system is studied to discuss precision of the multipoleexpansion, applied to determine forces exerted on particlesby a viscous low-Reynolds-number fluid flow. A single spherein an ambient flow (pure shear, quadratic, and modulated shear)parallel to a close plane wall is considered. Forces and torquesexerted by the ambient flow on a motionless sphere are evaluated.Their precision is determined and related to a multipole orderof the truncation. Similar analysis is performed for a movingsphere with no ambient flow and for a freely moving sphere.Relative motion of the sphere with respect to the wall givesrise to strong lubrication interactions. It is analysed howthese interactions affect accuracy of the pure multipole expansion,and what are the smallest distances where it becomes insufficient.An alternative precise method is applied, in which lubricationexpressions are subtracted from the hydrodynamic forces andtorques, and the residue is evaluated as a fast-convergent seriesof inverse powers of the distance between the sphere centreand the wall. The accuracy of this procedure is carefully analysed. 相似文献
59.
Yanbin Jiang Guoyi Tang Chanhung Shek Yaohua Zhu 《Applied Physics A: Materials Science & Processing》2009,97(3):607-615
The effect of electropulsing treatment (EPT) on the microstructure, mechanical properties, and tensile fracture behavior of
aged Mg–9Al–1Zn alloy strip at room temperature was investigated. The results indicated that EPT accelerated the spheroidizing
and dissolution of β phase tremendously in the aged Mg–9Al–1Zn alloy strip. The EPT-induced microstructural change resulted in remarkably increasing
elongation to failure, remained tensile strength unchanged. A mechanism for rapid spheroidizing and dissolution process of
β phase during EPT was proposed based on the reduction of nucleation thermodynamic barrier and enhancement of atomic diffusion.
Fracture analysis showed that with increase in frequency of EPT transgranular dimple fracture becomes predominant instead
of the quasicleavage fracture. 相似文献
60.