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动物组织含约45种矿物元素,依其在动物体内含量多寡,分为常量及微量矿物元素,其中含量多于0.01%的矿物元素称常量元素,包括钙,磷,镁,硫,钠,钾,氯,含量少于0.01%者称微量元素,与动物营养有关的主要有铁,铜,锰,锌,硒,碘,钴,钼 ,氟,锡,镍,硅,砷,铬,钒(吴成坤,1991年,韩友文,1996)。本文仅对我国猪矿物元素营养研究进展予以综述,主要涵盖矿物元素需要量,来源及生物学效价等内容。 相似文献
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这是本单元第一课时,单词新授课。本节课主要任务是学习常见动物单词:elephant, panda, lion,giraffe, monkey,以及拓展一些动物及其所喜爱食物的单词: tiger,bear, frog, rabbit, cat, dog, duck, pig, cow, sheep, bamboo, leaves, meat, grass. 相似文献
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《网络安全技术与应用》2003,(11)
The content of the article includes:Firewall and their roles,service packs,account considerations,antivirus,dial in accessor remote network access,intrusion detection,strong password practices,serVices installed,file system,bios,booting drivers,installing IIS on separate network segments,segment the network,branch offices,backups,etc. 相似文献
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《数字社区&智能家居》2003,(24)
《X-Man》游戏秘技选关指令:在游戏过程中,于主选单中顺序输入-三角,圆圈,三角,正方,三角,圆圈.L1+R1.解放所有服装:在游戏开始前,于主选单中顺序输入-三角,圆圈,三角,正方,正方,正方,L1+L2.解放CEREBRO FILES:在游戏开始前,于主选单中顺序输入-三角,圆圈,三角,正方,正方,正方,R1+R2.(假若成功,选择Bonus后再选Cerebro就可看CEREBRO FILES)解放CHEAT MENU功能:在游戏开始前,于主选单中顺序输入-三角,三角,圆圈,圆圈,正方,正方,圆圈,圆圈,L1+R1,L2+R2.(成功后,在游戏中进入PAUSE MENU,就发现CHEAT MENU的新指令)《… 相似文献
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《软件世界》1997,(10)
Formanyyears,computersciencehasbeenstrainingattheboundsofthecomputer,hopingforalanguage,atechnique,asysternthatwouldtranscendtherigidboundsofthepurelyprocedural.Allofthoseattemptshavefailed,toagreaterorlesserdegree.Yetnow,withoutintendingit,weperhapsfindourselvesimperceptiblyoverthatedge.Thereisnosinglewatershedevent,butwehaveneverthelesscrossedfromonecomputingeraintoanother.TwoMicrosoftonlineencyclopedias,EncartaandCinemania,standoneithersideofacontinentaldivideinelectronicpublishing.Bothma… 相似文献
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题记:滔滔江水,奔涌向前,悲喜,沉浮,生死都牵发于江湖,如一叶浮萍,生于晨,而亡于暮,委于风或覆于水,身负血海深仇,胸怀磅礴大志,浪流千里,饮风而长,沐雨而壮。忍辱、沉默、等待,人在江湖,身不由己,苦海无边,回首是岸。——前言 相似文献
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根据变频器工作原理和主回路拓扑,详细的分析了变频器输出侧长导线对地短路产生直流母线过压故障的原因。 相似文献
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为了有效检测疲劳金属构件发射的外逸电子数目,基于双栅极空气计数管的智能传感器系统的工作原理,通过研究双栅极空气计数管的工作过程,得出双栅极空气计数管的工作时序,提出双栅极猝熄电压和抑制电压幅度和宽度算法,并在此基础上设计出以猝熄电路和抑制电路为主的控制电路;通过实验方案设计与实施,结果表明,双栅极空气计数管及其控制电路能较好地控制放电量和二次电子发射,有效实现计数功能,电路完全能够满足系统设计要求。 相似文献
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介绍了一种用于改善中低压配电网电压质量的新型静止无功发生器(DSTATCOM),其主电路采用基于VSI-SPWM结构的电压型逆变器,指令电流的运算和补偿电流的控制均采用同步旋转参考坐标系。重点论述了DSTATCOM用于抑制电压跌落和电压闪变两种常见的电压质量问题。根据无功指令电流形成的不同方法,DSTATCOM有恒功率因数和恒电压两种运行模式。在两种运行模式下对DSTATCOM抑制电压跌落和电压闪变进行了仿真研究,仿真结果表明,恒功率因数模式适合于抑制电压闪变,而恒电压模式适合于抑制电压跌落。 相似文献
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Seong Min Lee Cheol Jang Kwan Hyun Cho Kyung Cheol Choi 《Journal of the Society for Information Display》2009,17(11):883-890
Abstract— The driving characteristics and wall‐charge model of an ac plasma‐display panel (ACPDP) with an auxiliary electrode were investigated by using voltage‐transfer closed‐surface modeling. To understand the wall‐charge behavior of an ACPDP with an auxiliary electrode qualitatively, voltage‐transfer closed‐surface analysis was applied to a test panel under the full driving waveform. The voltage‐transfer closed surfaces were obtained after the sustain, reset, and address periods, when the full‐stage driving waveform was employed with the test panel. As a result, it was proven that the wall‐charge model predicted in the previous work corresponded with the wall‐charge behavior of an ACPDP with an auxiliary electrode. Also, based on the resultant form after the address period, the wall‐charge model after the address period was recently added and the entire wall‐charge model was completed in this work. In addition, by investigating the trajectory of the cell‐state movement during the reset period, it was confirmed that the priming effect affected the reduced discharge time lag of an ACPDP with an auxiliary electrode under the newly proposed driving waveform for reducing address time lag. 相似文献
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