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排序方式: 共有807条查询结果,搜索用时 15 毫秒
71.
Taris Thierry Begueret Jean-Baptiste Lapuyade Hervé Deval Yann 《Microelectronics Journal》2006,37(11):1251-1260
After a theoretical and analytical study of the body effect in MOS transistors, this paper offers two useful models of this parasitic phenomenon. Thanks to these models, a design methodology, which takes advantage of the bulk terminal, allows to turn this well-known body-effect drawback into an analog advantage, giving thus an efficient alternative to overcome the design constraints of the CMOS VLSI wireless mass market. To illustrate the approach, four RF building blocks are presented. First, a 0.9 V 10 dB gain LNA, covering a frequency range 1.8-2.4 GHz, thanks to a body-effect common mode feedback, is detailed. Secondly, a body-effect linearity controlled pre-power amplifier is presented exhibiting a 5 dB m input compression point (ICP1) variation under 1.8 V power supply for half the current consumption. Lastly, two mixers based on body-effect mixing are presented, which achieve a 10 dB conversion gain under 1.4 V for a −52 dB LO-to-RF isolation. Well suited for low-power/low-voltage applications, these circuits implemented in a 0.18 μm CMOS VLSI technology are dedicated to multi-standard architectures and system-on-chip implementations. 相似文献
72.
八周有氧锻炼的效果评价--体育锻炼对女大学生身体自我和生活满意度的影响 总被引:5,自引:0,他引:5
朱大梅 《徐州工程学院学报》2006,21(4):105-107
身体自我是指个体对自己身体的认知和评价,是对自己身体范围内各方面要素的能力感觉。通过体育锻炼,身体自我概念的某几个方面会产生较大的变化,但并不是所有变量都发生变化的。体育锻炼对女大学生身体自我会产生一定的影响,对于改善她们的生活满意度有积极的作用。 相似文献
73.
刘尚喜 《数字社区&智能家居》2006,(3):146-147
综合布线系统作为建筑智能化不可缺少的基础设施,其接地系统的好坏将直接影响到综合布线系统的运行质量,故而显得尤为重要。本文介绍了综合布线系统接地的结构及设计要求,并提出在接地设计中应注意的几个问题. 相似文献
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76.
Sudhanshu K. Semwal J. Karl Armstrong Douglas E. Dow Fumio E. Maehara 《The Visual computer》1994,10(7):388-406
Most parts of the human body are cylindrical in shape. Generalized cylinders, with two cross-sectional openings, are a logical choice to represent these cylindrical shapes. However, a variety of human body regions can be visualized as surfaces with multiple openings or multimouth (MM) surfaces. Some examples of such surfaces are the pelvis, the chest, and the palms of the hands. We investigated the suitability of non-uniform rational B-spline (NURBS) formulation for creating multimouth surfaces. Two techniques, the surface wrapping model and the garland model, are presented. 相似文献
77.
Double-blind cross-over trials in which trained assessors evaluated axillary malodour on a 0 to 10 scale showed that ethanol at 60% and 99% w/w significantly reduced odour for up to 24 h. Reduction in odour was increased by the addition of non-volatile antimicrobial ingredients such as chlorhexidine, Irgasan DP 300 (Triclosan, Ciba Geigy) or aluminium chlorhydrate.
Volunteer panellists were able to identify statistically significant deodorant effects when they rated their own axillary odour on a 0 to 10 scale.
An odour absorber, zinc ricinoleate (Grillocin, Grillo-Werke, A. G.) was used to treat existing malodour and gave reduced perception of that malodour for up to 24 h.
A close correlation was found between panel odour scores and the bacterial status of the axilla as assessed by the replipad technique when biocidal systems were studied. Irgasan DP 300, a bacteriostat, did not perform so well in skin flora sampling procedures, but was nevertheless effective as a deodorant ingredient. Thus in vivo microbiological techniques, although often useful as predictors of deodorancy, do not replace the carefully controlled clinical trial with direct assessment of odour.
L'evaluation de l'odeur des aisselles 相似文献
Volunteer panellists were able to identify statistically significant deodorant effects when they rated their own axillary odour on a 0 to 10 scale.
An odour absorber, zinc ricinoleate (Grillocin, Grillo-Werke, A. G.) was used to treat existing malodour and gave reduced perception of that malodour for up to 24 h.
A close correlation was found between panel odour scores and the bacterial status of the axilla as assessed by the replipad technique when biocidal systems were studied. Irgasan DP 300, a bacteriostat, did not perform so well in skin flora sampling procedures, but was nevertheless effective as a deodorant ingredient. Thus in vivo microbiological techniques, although often useful as predictors of deodorancy, do not replace the carefully controlled clinical trial with direct assessment of odour.
L'evaluation de l'odeur des aisselles 相似文献
78.
本文简介了邯钢7#高炉热风炉的工艺状况,重点描述了基于Quantum PLC的热风炉本体仪控系统、基于西门子S7-400PLC(软件配置按PCS7系统模式)的热风炉热油预热控制系统和基于西门子S7与S5系列PLC混合配置的热风炉换炉电控系统的构成、软硬件配置、工作原理、主要控制功能和应用效果。 相似文献
79.
80.
The interaction between process and machine tool behaviour can lead to process instabilities in terms of self‐excited vibrations where the energy of the machine tool oscillation is generated by process excitation. The regenerative chatter effects lead to wavy surfaces on the work‐piece. This effect has been simulated for turning processes with an integrated simulation approach, which couples a time domain simulation model for the machine tool and the workpiece with an analytical turning model. In this paper a procedure is illustrated for coupling an FEA‐based 3‐dimensional turning model with the time domain model for the machine tool under consideration of the resulting workpiece surface. In comparison to an analytical approach for calculating the mechanical tool load, the 3D‐FEA‐model has the potential to determine the resulting cutting forces for even complex‐shaped tool geometries, e.g. a complicated chip breaker or a varying cutting edge radius on the main or minor cutting edge. As a matter of the huge model size the calculation time in particular for 3‐dimensional problems is comparatively long to analytical cutting force models. Therefore, in this paper an approach to reduce the calculation time by using characteristic diagrams for the calculated process forces in the FEA‐model is presented. The research has also been focused on the current major problem in the FEA‐based modelling that the thrust and feed forces are generally underestimated in the simulation. 相似文献