Detection of a periodic structure hidden in random background: the role of signal amplitude in the matched filter detection method

The matched filter method for detecting a periodic structure on a surface hidden behind randomness is known to detect up to (r(0)/Lambda) gt;= 0.11, where r(0) is the coherence length of light on scattering from the rough part and 3 is the wavelength of the periodic part of the surface-the above limit being much lower than what is allowed by conventional detection methods. The primary goal of this technique is the detection and characterization of the periodic structure hidden behind randomness without the use of any complicated experimental or computational procedures. This paper examines this detection procedure for various values of the amplitude a of the periodic part beginning from a = 0 to small finite values of a. We thus address the importance of the following quantities: `(a)lambda) `, which scales the amplitude of the periodic part with the wavelength of light, and (r(0))Lambda),in determining the detectability of the intensity peaks.

Effect of magnetic field on the binding energy of a hydrogenic donor in a vertical bar z vertical bar(2/3) quantum well

We have calculated the binding energy of a hydrogenic donor in a quantum well with potential shape proportional to \z\(2/3) as a function of the width of the quantum well and the barrier height under an applied uniform magnetic field along the a axis. As the well width decreases, the binding energy increases initially up to a critical well width (which is nearly the same for all magnetic fields) at which there is a turnover. The results are qualitatively similar to those of a hydrogenic donor in a rectangular well. We have also calculated [rho(2)](1/2) and [z(2)](1/2) for the donor electron. [rho(2)](1/2) is found to be strongly dependent on the magnetic field for a given well width and weakly dependent on the well width and the barrier height, for a given value of magnetic field [z(2)](1/2) is weakly dependent on the applied magnetic field. The probability of finding the donor electron inside the well shows a rapid decrease as the well width is reduced at nearly the well width at which the binding energy shows a maximum.

Synchrotron Study of the Dynamical Effects in the LVV Auger Transitions in the First-Row Transition Elements

The intensity ratio between L2-M45M45 and L3-M45M45 spectral features for both Fe and Co indicates significant tranfer of intensity from L2- to L3-M45M45 region due to Coster-Kronig L2-M45M45 transition. The L2-L3M45 transition can be suppressed by turning the photon energy between the L2 and L3 thresholds; however, the L3-M45M45 spectral shapes for Fe and Co do not change very significantly even at these photom energies unlike the cases of Ni, Cu and Zn, thus establishing that the M45-hole decays predominantly before the L3-hole Auger decay in the early transition elements in contrast to the late ones.

Multiple beam interference of light in an absorbing wedge

Multiple beam interference of light in a wedge is considered when the wedge is filled with an absorbing medium. The aim is to examine a method that may give values of both the real and the imaginary parts of the refractive index of the absorbing medium. We propose here a method to determine these quantities from simple techniques like fringe counting and interferometry, by using as the incident wave either a single Gaussian beam or two parallel Gaussian beams.

Numerical simulation of g-jitter effects on half floating zone convection under microgravity environment

The g-jitter effects on the thermocapillary convection in liquid bridge of floating half zone were studied by numerical simulation for unsteady and axi-symmetric model in the cylindrical coordinate system. The g-jitter field was given by a steady microgravity field in addition to an oscillatory low-gravity field, and the effects on the flow field, temperature distribution and free surface deformation were analyzed numerically.

Observations on the distribution, daytime migrations and daily food intake rates of Chaoborus flavicans (Meigen) in the Goggausee [Translation from: Carinthia II 165(85), 184-190, 1975]

The Goggausee, in spite of its modest depth (Zmax = 12 metres), shows meromictic properties: autumn and spring circulation extend only to a depth of 8 metres. The water layers below about 10 metres are constantly oxygen-free, the critical zone with at least intermittent oxygen loss lies at a depth of between 6 and 10 metres. A limnological excursion in May 1974 offered an opportunity to investigate the daily vertical migration of the species Chaoborus flavicans with reference to its food supply of zooplankton as well as the chance to carry out some preliminary experiments on its rate of food intake. Among the studied features were the planktonic depth distribution of Chaoborus flavicans and the food intake of Chaoborus larvae under experimental conditions.

Entre a lei e a luta: o movimento pela saúde do trabalhador docente

Esse trabalho tem como perspectiva colocar em análise o modo pelo qual os movimentos sociais vêm abordando as questões da saúde do trabalhador docente em suas lutas, não apenas como ausência de doença, mas como um estado em que a saúde rompe com os limites do previsível. Estabelecemos como foco de análise a atuação dos movimentos sociais em educação, em especial o Fórum Nacional em Defesa da Escola Pública na LDB, como um espaço/tempo de proposição e articulação do movimento que busca, para o trabalho docente, a saúde. Trazemos como questão a tensão entre o modelo de gestão presente na atualidade e a proposta de gestão apresentada pelos movimentos que vinculavam a emergência dos conselhos de participação social como uma forma de intensificar a implementação de um Estado democrático. Retomar o processo de aprovação da LDB é retomar um processo de lutas e de golpe na vida dos educadores, por isso nosso interesse em buscar saídas, espaços de tensão onde os movimentos estão presentes, onde a saúde prevalece.

鱼腥藻HB1017株化能异养生长的研究

以葡萄糖和蔗糖为碳源，检测了六株（种）鱼腥藻的化能异养生产能力。其中鱼腥藻ＨＢ１０１７株化能异养生长较快，鱼腥藻ＨＢ０株化能异养生长缓慢，其余四种鱼腥藻不能进行化能异养生长。鱼腥藻ＨＢ１０１７株能利用果糖、葡萄糖、蔗糖为底物进行化能异养生长，但生长速率依次递减，差别显著。８磅湿热灭菌的果糖和蔗糖，与过滤灭菌的相比，只能维持低得多的化能异养生长速率。然而，８磅湿热灭菌的葡萄糖能维持比过滤法灭菌的高得多的化能异养生长速率，与过滤灭菌的果糖效果类似。添加外源精氨酸使异养生长速率明显提高。氮源以硝酸钠较好。２５℃

氮化镓基蓝、绿光LED中游工艺技术产业化研究

氮化镓基蓝、绿光LED在光显示及未来的白光照明领域具有广阔的应用前景，中国科学院半导体研究所和深圳市方大国科光电技术公司利用双方各自的技术优势和资金管理优势，实现了氮化镓基蓝、绿光LED中游工艺技术产业化，目前产品已经批量上市销售。

El currículo escolar mexicano de las ciencias en el nivel medio

En este trabajo se reportan los resultados obtenidos en un estudio de tendencias realizado sobre el currículo escolar mexicano de ciencias naturales y exactas en el nivel educativo medio. Para la realización de este estudio se utilizó una metodología documental acompañado de entrevistas estructuradas a expertos en materia curricular. El propósito fue caracterizar los diferentes momentos por los que ha transitado el currículo en las últimas cuatro décadas y establecer posibles directrices.

Outposts of Empire: Scientific Discovery and Colonial Displacement in Gaskell's Wives and Daughters

This article offers a fresh consideration of Elizabeth Gaskell's unfinished Wives and Daughters (1864–6), in terms of what this metropolitan novelist knew about contemporary scientific debates and imperial exploration of Africa, and how her familiarity with these discourses was incorporated into her imaginative work. Her focus for these two related themes is the naturalist Roger Hamley, whose character and exploits are meant to parallel those of the young Charles Darwin. Roger's direct involvement in the historical Geoffroy–Cuvier debate allows Gaskell to offer a sophisticated examination of how discussions about evolutionary biology (about which she learned from personal acquaintances and printed sources) contributed to political and social change in the era of the first Reform Bill. Roger's subsequent journey to Abyssinia to gather specimens allows Gaskell to form a link between science and imperial exploration, which demonstrates how, when carried to its conclusion, the development of classificatory knowledge systems was never innocent; rather, it facilitated colonial exploitation and intervention, which allowed for the ‘opening up of Africa’. Gaskell's pronouncements about science in the novel are far more explicit than her brief references to empire; the article ponders why this should be so, and offers some suggestions about how her reliance on imaginative and discursive constructs concerning the ‘Dark Continent’ may be interpreted as tacit complicity with the imperial project, or at least an interest in its more imaginative aspects.