Active Vibration Isolation System for Sub-microultra-precision Turning Machine

Now vibration isolation of ultra-precision machine tool is usually achieved through air-springs systems. As far as HCM-I sub-micro turning machine developed by HIT, an active vibration isolation system that consists of air-springs and electro-magnetic actuators was presented. The primary function of air-springs is to support the turning machine and to isolate the high-frequency vibration. The electro-magnetic actuators controlled by fuzzy-neural networks isolate the low-frequency vibration. The experiment indicates that active vibration isolation system isolates base-vibration effectively in all the frequency range. So the vibration of the machine bed is controlled under 10-6g and the surface roughness is improved.     

Living fluids

One of the major emerging fields of research of the beginning of this century concerns living fluids. By “living fluids”, we mean two major categories of complex fluids: (i) fluids which are essential to life, like blood, and (ii) active fluids made of particles that are able to propel themselves in the suspending fluid by converting a form of their energy into mechanical motion. Studies on active fluids have known a considerable interest since the last decade. Blood might be viewed as an old topic, but the progresses in experimental techniques, analytical concepts and numerics, have contributed nowadays to a dramatic renewal of the interest in this field, with a great potential towards understanding physical and mechanical factors in cardiovascular diseases. These fields have considerably strengthened interdisciplinary research. The series of reviews of this dossier focus on the tremendous recent progress achieved in research on living fluids both from the experimental and theoretical points of views. These reviews present also the major open issues, making of this dossier a unique guide for future research in these fields. This project grew up thanks to the international summer school that we organized on the topic “living fluids” at the IES (Institut dʼétudes scientifiques) of Cargèse (Corsica) in 2012.     

活性炭吸附下TiO2光催化降解苯酚的研究

探索了不同C/TiO2质量比例下,影响苯酚去除率的一些因素.通过实验得到:在单一影响因素下C/TiO2质量的比例为1∶1时效果最佳,降解速度最快;苯酚的起始浓度升高,其降解速度增大,但去除率降低;在pH5～10范围内,pH7时1h去除率最大;TiO2的最佳用量为10g/L.在此条件下,50mg/L苯酚溶液光解2h,去除率达99%以上.     

Ytterbium triflate hydrate catalyzed Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds

Catalyzed by ytterbium（III） triflate hydrate [Yb（OTf）3.xH20], the Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.     

Hydrogenase enzymes: Recent structural studies and active site models

Recent developments in active site structure determination of the three types of hydrogenase enzymes are described. Aspects of recent studies using model complexes relevant to the structure and function of the enzymes are reviewed.     

Seasonal variation of radon-222 concentrations in specific locations in Jordan

Previously calibrated passive detectors (CR-39) and an active radon device (Radon Monitor RM3) were used to study seasonal variation of radon-222 concentration levels inside and outside specific locations in Jordan. The study sites were located in an area that used to be an old phosphate mine. We found that the maximum value of radon concentration in air inside the dwellings, as measured by the passive dosimeters, was 1532.9 Bq/m³ during the winter season, and the minimum one was 46.3 Bq/m³ during fall season. While the highest and lowest readings of the active monitor were 892 and 4 Bq/m³ during fall and summer seasons, respectively. The radon concentration in soil ranges from 0.2 kBq/m³ in spring to 37.8 kBq/m³ in fall.     

计算机主动视觉理论研究

在David Marr提出视觉计算理论之后，计算机视觉的研究取得了很大进步，但Marr理论也遇到了很多困难．本文介绍了主动视觉的基本思想和已经研制成功的主动视觉系统，分析了当前主动视觉研究领域面临的问题，针对这些问题，作者提出了一些建议．     

Multilayer hydrous oxide growth on copper in base and its correlation with previously reported electrocatalytic data for this electrode system

A repetitive potential cycling procedure was used to produce a specific multilayer hydrous oxide film on copper in base at 60 °C. Such a deposit undergoes reduction in a quasi-reversible manner at ca. −0.1 V (RHE), i.e. at a potential that is unrelated to Pourbaix data for copper but, as demonstrated previously, is of major significance with regard to the electrocatalytic behaviour of this electrode system. In accordance with the incipient hydrous oxide/adatom mediator model of electrocatalysis, an active surface state of the metal (Cu*) is assumed to be involved both in electrocatalysis and as a primary product in the hydrous oxide reduction reaction. While the latter process occurs very rapidly at −0.1 V, it is not usually reversible as it is accompanied by subsequent rapid loss of the active state of the metal. The same general approach was used previously to explain the hydrous oxide and electrocatalytic behaviour of a range of noble metals. Received: 28 August 1999 / Accepted: 11 November 1999     

An Algorithm Based on Active Sets and Smoothing for Discretized Semi-Infinite Minimax Problems

We present a new active-set strategy which can be used in conjunction with exponential (entropic) smoothing for solving large-scale minimax problems arising from the discretization of semi-infinite minimax problems. The main effect of the active-set strategy is to dramatically reduce the number of gradient calculations needed in the optimization. Discretization of multidimensional domains gives rise to minimax problems with thousands of component functions. We present an application to minimizing the sum of squares of the Lagrange polynomials to find good points for polynomial interpolation on the unit sphere in ℝ³. Our numerical results show that the active-set strategy results in a modified Armijo gradient or Gauss-Newton like methods requiring less than a quarter of the gradients, as compared to the use of these methods without our active-set strategy. Finally, we show how this strategy can be incorporated in an algorithm for solving semi-infinite minimax problems.     

Ytterbium triflate hydrate catalyzed Michael addition and cyclocondensation of α,β-unsaturated ketones with active methylene compounds

Catalyzed by ytterbium(Ⅲ) triflate hydrate [Yb(OTf)3.xH2O], the Michael addition and cycloeondensation of α,β-unsaturated ketones with active methylene compounds to afford the 1,4-adducts and benzo[b]pyran derivatives, respectively were studied.