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低频率应用1%阿托品凝胶控制低度近视眼的研究
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作者 廖爱平 刘媚 邵东平 《泰山医学院学报》 CAS 2020年第10期732-734,共3页
目的比较3种低频率应用1%阿托品眼膏对低度近视进展的控制效果及依从性观察。方法初始观察例数共90例,平均30例均分到3个组:①实验组1:连续涂3天后,每隔3周涂一次阿托品眼膏;②实验组2:每周涂一次阿托品眼膏,连续使用3月后,停药1月,之... 目的比较3种低频率应用1%阿托品眼膏对低度近视进展的控制效果及依从性观察。方法初始观察例数共90例,平均30例均分到3个组:①实验组1:连续涂3天后,每隔3周涂一次阿托品眼膏;②实验组2:每周涂一次阿托品眼膏,连续使用3月后,停药1月,之后重复;③实验组3:每周涂一次阿托品眼膏;观察时间:1年。跟踪患者使用情况、不良反应和随访丢失情况,记录用药前和用药后屈光度、眼轴、角膜曲率、眼压和集合近点等数据。结果使用频率最高的实验组3随访丢失率最高。三组实验组都有效地控制了近视的进展,而且用药物频率不一样,三组实验组眼轴增长和屈光度数变化并没有表现出明显的统计学差异。(F球镜=1.315,P球镜=0.291,F眼轴=0.369,P眼轴=0.696)。结论使用频率减低可明显减少患者的不良反应,提高使用依从性;使用高浓度阿托品后,即使减少使用频率,但眼内药物浓度保持一定的阈值,同样发挥强有力的控制近视效果,其中,阿托品药物每周涂1次,连续用3月,停1月的控制近视效果和随访依从性最高,值得普及。 展开更多
关键词 低频率应用 1%阿托品眼凝胶 近视控制
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A 1.2-to-1.4 GHz low-jitter frequency synthesizer for GPS application
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作者 胡正飞 HUANG Min-di ZHANG Li 《Journal of Chongqing University》 CAS 2013年第2期97-102,共6页
A fully integrated frequency synthesizer with low jitter and low power consumption in 0.18 μm CMOS (complementary metal-oxide semiconductor) technology is proposed in this paper.The frequency synthesizer uses a novel... A fully integrated frequency synthesizer with low jitter and low power consumption in 0.18 μm CMOS (complementary metal-oxide semiconductor) technology is proposed in this paper.The frequency synthesizer uses a novel single-end gain-boosting charge pump, a differential coupled voltage controlled oscillator (VCO) and a dynamic logic phase/frequency detecor (PFD) to acquire low output jitter.The output frequency range of the frequency synthesizer is up to 1 200 MHz to 1 400 MHz for GPS (global position system) application.The post simulation results show that the phase noise of VCO is only 127.1 dBc/Hz at a 1 MHz offset and the Vp-p jitter of the frequency synthesizer output clock is 13.65 ps.The power consumption of the frequency synthesizer not including the divider is 4.8 mW for 1.8 V supply and it occupies a 0.8 mm×0.7 mm chip area. 展开更多
关键词 frequency synthesizer phase-locked loop voltage controlled oscillator phase/frequency detector charge pump
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Increasing Production Efficiency through Casting Quality Improving by Electromagnetic Field Applying
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作者 Marija Mihailovic Aleksandra Pataric Zvonko GuliSija Miroslav Sokic 《Journal of Mechanics Engineering and Automation》 2012年第1期59-62,共4页
The increased production efficiency of heat treatable A1 alloys, as the result of applied electromagnetic field during continuous casting process was investigated. The applied frequency of the electromagnetic field (... The increased production efficiency of heat treatable A1 alloys, as the result of applied electromagnetic field during continuous casting process was investigated. The applied frequency of the electromagnetic field (EMF) during the AI alloys continuous casting was changing from 30 Hz to 50 Hz, while some castings were obtained without the EMF influence. The mechanical characterization of continuous casted AI alloys EN AW 2007 and En AW 2024 was done on testing machine Zwick/Roell Z 100. The microstructure of as-cast samples was examined, as well. When the frequency decreases (from 50 Hz to 30 Hz), the grain size decreases as well, what is noticeable through the finer microstructure and its uniformity throughout the cross-section. These results have shown that low frequency electromagnetic field significantly influenced the microstructure and therefore the mechanical properties of as cast ingots. Thus, through improved castings quality, operation time and energy savings, the production efficiency was increased. 展开更多
关键词 AI alloys electromagnetic field CASTING production efficiency.
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