Low-threshold lasing and broad-band multiphoton-excited light emission from Ag aggregate-adsorbate complexes in microcavity

A novel class of composites for optics, microcavities doped with metal fractal aggregates, is studied. Lasing and broad-band Stokes and anti-Stokes emission from (Ag colloidal aggregates)/(adsorbed molecules)/(micro-cavity) composite at low-intensity cw and pulse laser excitation has been found. At 633 nm cw excitation wavelength the emission spectrum contains many peaks, spanning a range from wavelength 200 nm to 800 nm. Experiments with pulse excitation of Ag/dye/microcavity composite show that the duration of the observed broad-band anti-Stokes emission significantly exceeds the pump pulse duration, dye molecule fluorescence time, and relaxation times in silver particles. It may be interpreted as a luminescence governed by long-living triplet states of dye molecules. These observations were made possible by use of a fractal-microcavity composite, where coupling the localized plasmon modes in fractal aggregates with microcavity resonances is provided. The important role of multiphoton resonant transitions between discrete states of a finite-size metal particle in enhanced local fields is shown. Analysis, based on the model of a spherical potential well, shows that the observed spectra contain fingerprints of the quantum size effect.     

Partial exponential stability of semi-state systems

The general class of non-linear non-autonomous semi-state systems is considered from the viewpoint of stability of system motions. A theorem is proved giving necessary and sufficient conditions for partial exponential stability of arbitrary motion of these systems over finite or infinite time intervals.

The results are illustrated by the analysis of a non-linear electrical circuit.     

LIQUID TWO-PHASE WATER—PROTEIN—POLYSACCHARIDE SYSTEMS AND THEIR PROCESSING INTO TEXTURED PROTEIN PRODUCTS

Conditions for the formation of liquid two-phase water—protein—polysaccharide systems containing the main classes of proteins, as defined by Osborne, and various acid and neutral polysaccharides have been determined. Phase diagrams of some of these systems have been obtained. It is shown that, proceeding from liquid two-phase water—protein—polysaccharide systems, one can obtain different protein products without using spinnerets.     

面向难变形材料精密成形的板式楔横轧机研究

为满足楔横轧工艺研究的需要,推动板式楔横轧机在我国的应用与发展,中国科学院金属研究所与白俄罗斯科学院物理技术研究所共同开展了高精度板式楔横轧机(IM500)的研制工作.IM500轧机采用卧式水平结构和液压驱动的单板可动设计方案,由主体机械结构、液压站、电控柜三部分组成.在主体机械结构方案设计过程中,采用有限元模拟方法进...     

Stable and Metastable Phase Relations in the System ZrO2-CaO

The chemical equilibrium for the system ZrO₂-CaO was rede termined for temperatures above ∼1000°C by heating reactive powders for extended periods of time. The eutectoid decom position of the cubic solid solution was found to occur at 1140°±40°C and 17.0±0.5 mol% CaO. Decomposition reac tions in sintered cubic solid solutions were studied using elec tron diffraction and transmission techniques. Decomposition follows metastable extensions of the boundary lines which sena rate two-phase regions from the adjacent cubic solid solution region. The appearance of the diffuse diffraction features in the electron diffraction patterns of cubic solid solutions Seems to be associated with short-range ordering of oxygen vacancies.'Duo ordered phases, CaZr₄O₉ and Ca₆Zr₁₉O₄₄, were syn thesized and their upper limits of stability were determined to be 1235°±15° and 1355°±15°C, respectively.     

NUMERICAL ALGORITHM FOR ARCING FAULTS DETECTION AND FAULT DISTANCE CALCULATION ON OVERHEAD LINES

ABSTRACT

In this paper a new numerical algorithm for arcing faults detection and fault distance calculation will be presented. It provides the solution for both the symmetrical and the unsymmetrical faults. The algorithm is based on the line terminal voltages and currents processing. A simple square wave are voltage model is assumed to model the long are in free air in computer simulation and algorithm development. The frequency dependence of line parameters is taken into account. A series of computer simulated and laboratory tests have shown that the new algorithm can be utilized in transmission system practice.     

电力系统频率动态行为衍变与分析方法需求综述

低惯量可再生能源发展导致电力系统运行形态发生变化, 频率动态行为愈加复杂, 频率安全稳定面临新的挑战。阐述频率动态响应过程, 综述频率动态行为量化特征和分析方法, 强调基于人工智能分析方法的优势和前景。从可再生能源发电强波动、电源非同步并网低惯量及大功率缺额与连锁故障高风险三个角度, 分析电力系统运行形态变化, 探讨对频率分析与控制的新要求。剖析可再生能源快速发展背景下电力系统等效惯量的内涵, 综述可再生能源虚拟惯量控制方法, 强调多类型虚拟惯量协调控制的优势和前景。总结频率分析与控制领域中亟待研究的重点内容, 给出后续研究建议。     

Fracture of Brittle Solids in the Presence of Thermoelastic Stresses

A micromechanical model for strength behavior as a function of grain size in two-phase materials with thermal expansion mismatch and in single-phase materials with thermal expansion anisotropy is presented. The strength vs grain-size plot is interpreted in terms of internal stresses and the ratio of grain to flaw size. The strength of thermally isotropic material is predicted to exhibit a weak grain-size dependence with a negative grain-size exponent normally different from 0.5. In thermally anisotropic poly crystalline solids, before the critical grain size for spontaneous cracking is reached, there will be a region of decreasing strength with increasing grain size due to an increase in the grain-to-flaw size ratio. When a critical grain size is reached, the ratio of grain to flaw size will decrease instantaneously and the strength will decrease in the same fashion. Very good agreement was obtained between predicted and experimentally observed strength behavior for TiO₂ and MgO ceramics.     

阿拉伯半乳聚糖对2型糖尿病大鼠肠道碱性磷酸酶、细菌内毒素和肠道中细胞因子的影响

本实验以低剂量腹腔注射链脲佐菌素（30 mg/kg）建立糖尿病大鼠模型，建模成功后，连续给予大鼠灌胃阿拉伯半乳聚糖（Arabinogalactan, AG）水溶液（100 mg/kg、500 mg/kg），测定大鼠体质量及血糖变化、粪便中肠道碱性磷酸酶（IAP）的活力及细菌内毒素中脂多糖（LPS）的浓度变化，并通过MSD多因子方法检测肠道中细胞因子浓度的变化。结果表明，与模型组大鼠相比，AG剂量组空腹血糖浓度显著降低（P<0.05），IAP活力显著增加（P<0.05），LPS浓度显著降低（P<0.05），且肠道中促炎因子白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、γ干扰素（IFN-γ）、白细胞介素-1（IL-1β）、生长调节致癌基因α（KC/GRO）的浓度显著减少（P<0.05），而抗炎因子白介素-4（IL-4）、白介素-5（IL-5）、白介素-10（IL-10）、白介素-13（IL-13）的浓度显著增加（P<0.05）。因此，可以证明AG能够提高IAP活力，降低LPS浓度，调控大鼠细胞因子，进而对2型糖尿病大鼠模型在免疫方面具有一定改善作用。     

Biosorption of Rare Earth Elements

Abstract

By using X-ray microanalysis, the mechanism of sorption of rare earth elements (REE) and their localization in cells of Candida utilis were found to depend on the metal ion speciation in solution, the permeability of the cytoplasmic membrane (CPM), and elemental composition of cells. Sorption capacity of the yeast cells increased with the increase in the pH of solution, which is connected with the extent of metal hydrolysis. Cells with native permeability of CPM did not sorb either scandium at pH values below 4.5 or lanthanum and samarium at pH values below 5.0. Such cells accumulate rare earth elements on surface structures. Only the cells with impaired CPM could sorb REE from the acid solutions. In this case, REE were accumulated inside the cells due to the interaction with phosphorus-containing compounds; the amount of sorbed REE depended on the content of phosphorus in the yeast cells. The yeast cells were shown to have extremely high affinity to scandium which thus can be selectively sorbed from solutions containing other REE, iron, and aluminum.