922 resultados para 2003-08-BS
Resumo:
By employing a procedure that combines ELISA and photoacoustic spectroscopy, we have examined the content of 5-methylcytosine (m(5)C) in DNA of individuals who differed from one another in the number of X chromosomes in their genomes. The results show that the human inactive X chromosome (Xi) contains very high amounts of this modified nucleotide. We estimate that in the 46,XX female there is more m(5)C in Xi (similar to3.6 x 10(7)) than in all the remaining chromosomes put together (similar to2.1 x 10(7)). Our results also suggest that nearly one-fifth of all cytosines in Xi are methylated and that, in addition to CpG methylation, there is extensive non-CpG methylation as well.
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We briefly review the growth and structural properties of View the MathML source bulk single crystals and View the MathML source epitaxial films grown on semi-insulating GaAs substrates. Temperature-dependent transport measurements on these samples are then correlated with the information obtained from structural (XRD, TEM, SEM) and optical (FTIR absorption) investigations. The temperature dependence of mobility and the Hall coefficient are theoretically modelled by exactly solving the linearized Boltzmann transport equation by inversion of the collision matrix and the relative role of various scattering mechanisms in limiting the low temperature and View the MathML source mobility is estimated. Finally, the first observation of Shubnikov oscillations in InAsSb is discussed.
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We describe the nanofabrication study of self-aligned electrodes on suspended multiwalled carbon nanotube structures. When metal is deposited on a suspended multiwalled carbon nanotube structure, the nanotube acts as an evaporation mask, resulting in the formation of discontinuous electrodes. The metal deposits on the nanotubes are removed with lift-off. Using Al sacrificial layers, it was possible to fabricate self-aligned contact electrodes and control electrodes nanometers from the suspended carbon nanotubes with a single lithography step. It was also shown that the fabrication technique may also be used to form nano-gapped contact electrodes. The technique should prove useful for the fabrication of nano-electromechanical systems.
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Reflete sobre a viabilidade de Projeto de Lei que disponha sobre a extinção dos serviços sociais e de aprendizagem que integram o sistema "S" e, ao mesmo tempo, crie o Instituto Brasileiro do Trabalho - IBRAT.
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Consultoria Legislativa - Área XVI - Saúde Pública, Sanitarismo.
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Consultoria Legislativa - Área XI - Meio Ambiente e Direito Ambiental, Organização Territorial, Desenvolvimento Urbano e Regional.
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根据流体力学差压原理 ,采用硅微机械加工手段设计制作了微挡板结构的压阻式流量传感器。测试结果表明 ,该传感器具有测量 0 .1~ 10L/min的气体流量的能力
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对油气田在役管道实行定期检测及时发现问题,采取措施延长寿命,提高安全可靠性,已成为我国油气田降低石油和天然气生产成本的关键所在。本文介绍漏磁检测、超声波检测和涡流检测三种管道内腐蚀检测方法的检测原理、检测方法以及应用情况,国外管道内检测装置的发展水平以及我国管道腐蚀检测技术的发展趋势。
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The main aim of this paper is to measure the extent to which part-time work enhances fertility for married or cohabiting women of fertile age. The study covers eleven European countries. The data used are a pool sample of five waves of the European Community Household Panel. Given that we believe that the decisions concerning fertility and labor market status are taken jointly, we carry out a simultaneous estimation approach. Results suggest that policy makers wishing to implement adequate part-time schedules so as to enhance fertility should look at the part-time schedules available in Belgium, Ireland and The Netherlands, which enhance fertility for women who take advantage of this flexibility measure so as to reconcile family and work.
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综述了农业工程中所存在的主要力学问题或现象,如:应力与植物的生长、种子损伤与激活、土壤粒子(泥沙)在雨水和江河中的流动、农作物体内水分、矿质元素和光合产物的运输、农作物种植、农产品运输和土壤耕作过程中所存在的力学问题或现象,并在概述了相关研究现状的同时,着重探讨了今后农业生物力学研究的主要方向,强调了加强生物力学研究的重要性.
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对中心装药爆炸后冲击波的产生、传播和壳体动态响应全过程进行了数值研究。认为RDX瞬时爆炸,爆炸近场采用自相似解;冲击波传播和波系演化采用PPM(the Piecewise Parabolic Method)格式求解Euler方程;壳体响应采用有限元方法求解拉氏坐标系下由虚功原理得到的动力学方程。壳体内壁面边界条件分别采用强耦合和弱耦合方法处理。结果表明:(1)当装药量相同时,薄壁壳体振型比厚壁宙体复杂得多,振幅也大;(2)当装药量不同,壳体厚度相同时,爆炸场冲击波的演化过程不同;(3)对少量装药,产生的冲击波强度低,壳体变形小,是否考虑内边界运动,对计算结果的影响不大;(4)在本文条件下,爆炸容器封头顶点所受的载荷最大,是取易发生破坏的地方,侧壁与爆点所在横截面的交线,也易破坏。