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Search Results: 1 - 10 of 55785 matches for " 郭咏雪 "
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基于磁流变阻尼器的双跨轴系PID振动控制研究
咏雪,何立东,王锎
- , 2018, DOI: 10.13543/j.bhxbzr.2018.03.010
Abstract: 为了解决双轴串联的旋转机械在临界转速处产生共振问题,搭建了双跨转子实验台,在不改变原有支撑形式的条件下将磁流变阻尼器分别安装在串联的轴1、轴2上,并建立双跨轴系振动的半主动控制系统,采用比例-积分-微分(PID)控制方法,以振幅为反馈参数实时调节阻尼器电流,在线抑制双跨轴系的振动,并在此基础上通过整定PID控制的比例系数K研究其值对振动控制效果的影响。实验结果表明:基于磁流变阻尼器的PID控制系统可以有效控制两个串联轴在临界转速附近的振动;对临界振幅过大的转子宜采用较大K值,而对临界振幅较小的转子可适当减小K值。
Abstract:In order to study the vibration problems of rotating machinery consisting of a two-span shaft around its critical speeds, a two-span rotor test rig was built, and two magneto-rheological dampers were installed on the two coupled rotors without changing the original support. Subsequently, by incorporating a proportion-integration-differentiation (PID) control method, a semi-active control system for the two-span rotor system vibration was established. Using vibration amplitude as the feedback parameter, the system controlled the electric currents of the magneto-rheological at any time allowing the rotor system vibration to be controlled online. In addition, in order to study how the proportionality coefficient influences the control effect, the value of K was varied. The experimental results indicated that the PID control system based on magneto-rheological dampers can successfully suppress the vibration of the two coupled rotors at their critical speeds. For higher values of K, the control effect is better, but very large values of K make the control effect worse. Therefore K should be large in the case of a rotor with a large critical vibration and smaller in the case of a rotor with a smaller critical vibration.
Analysis on the Editorial Consciousness in the Publishing of Popular Science Journals
浅析科普期刊出版中的编辑意识

咏雪
中国科技期刊研究 , 2010,
Abstract: 从编辑意识的内涵和具体内容分别论述了对科普期刊编辑的要求以及提升期刊市场竞争力的重要性,同时结合编辑实务中的具体运用,阐述了将人文精神引入科普创作,科学应与艺术相结合等观点,为创新科普期刊的主题策划与栏目设置提供借鉴。
浅析科普期刊出版中的编辑意识
咏雪
中国科技期刊研究 , 2010,
Abstract: 从编辑意识的内涵和具体内容分别论述了对科普期刊编辑的要求以及提升期刊市场竞争力的重要性,同时结合编辑实务中的具体运用,阐述了将人文精神引入科普创作,科学应与艺术相结合等观点,为创新科普期刊的主题策划与栏目设置提供借鉴。
吞咽说话瓣膜在气管切开合并吞咽障碍患者中的应用及研究进展
谭茗丹,咏雪,温红梅
- , 2017,
Abstract:
增城市健康人群麻疹抗体水平调查
廖永东, 邓耀方, 温仕妹,咏雪
中国公共卫生 , 1999,
Abstract: ?为了分析本市健康人群的免疫状况,不断完善免疫程序,我们于1997年10月对本市健康人群抽样进行麻疹抗体水平的检测。结果报告如下。
NaClO与KMnO4氧化对针杆藻灭活特性研究
Inactivation efficiencies of synedra sp. by NaClO and KMnO4 oxidation

张梦然,姚娟娟,杨峰,范培震,张智,咏雪,陈龙甫,郎海
- , 2015, DOI: 10.11835/j.issn.1674-4764.2015.03.019
Abstract: 以针杆藻(Synedra sp.)为研究对象,考察了NaClO与KMnO4在不同投量和不同pH条件下对针杆藻的灭活特点以及对光合活性的影响。结果表明,在0~5 mg/L投加范围内,NaClO对针杆藻的灭活效果随剂量的增大而提高,投加量为3 mg/L是抑制藻活性的最佳投量,并且在酸性条件下NaClO能更好的发挥其氧化降解的作用;KMnO4对针杆藻的降解效果不明显,说明投加KMnO4(≤5 mg/L)对针杆藻没有很好的灭活效果。氯化对针杆藻灭活效果好,但是会造成细胞解体,引起藻内有机物的释放,危及饮用水安全。
The inactivation efficiencies of Synedra sp. by NaClO and KMnO4 oxidation were investigated. The results indicated that in the range of 0~5 mg/L in the neutral condition, the inactivation efficiencies increased with the increase of NaClO dosage and the optimun dosage was 3 mg/L. Meanwhile NaClO showed a better degradation ability in acidic condition. The degradation ability of KMnO4 was not significant, indicating that KMnO4 had no effect on inactivation. Chlorination was effective for Synedra sp. inactivation, and however led to cell disintegration and organic matter release, thus endangering the safety of drinking water.
强化企业内部控制 提高企业管理效率
Reinforce the Internal Control of Enterprise and Improve the Efficiency of Enterprise Management
 [PDF]


Modern Management (MM) , 2011, DOI: 10.12677/mm.2011.13040
Abstract: 财务造假、偷税漏税、侵吞公司财产等违法犯罪案件的屡屡发生,一个重要的原因是内部控制失灵。由此人们越来越清楚地认识到企业内部控制的重要性,逐渐把企业内部控制作为现代企业管理的重要组成部分。因而研究企业内部控制的问题显得尤为重要。本文从控制环境、控制活动、信息与沟通、风险意识和监督机制等方面对中外企业内部控制失效的原因进行了分析,并提出了完善内部控制环境、改善控制活动、加强协调与沟通、完善风险评估和监督机制等强化企业内部控制的对策建议。
The failure of enterprise internal control system has become one of the most important reasons for the frequently occurring of enterprise criminal cases like financial fraudulence, tax evasion and etc, Therefore, study of enterprise internal control system has get more and more focus and has gradually become one of the most important component part of the modern enterprise management. So it is of great significance to study the internal control system of enterprises. The article analyzes the invalidation reasons of inner controlling of Chinese and foreign enterprises through controlling environment, controlling activities, information and communication, risk consciousness, supervisory mechanism and other aspects and provides advices on improving inner controlling environment, controlling activities, coordination and communication, risk assessment and supervisory mechanism and on strengthening inner controlling of the enterprises.
对中国乳业现状的几点思考
发表于《中国乳品工业》2014年04期,引自
http://www.cqvip.com/QK/91276X/201404/49399864.html  [PDF]

明若
QianRen Biology (QRB) , 2014, DOI: 10.12677/QRB.2014.11002
Abstract:
乳及乳制品已成为我国消费者的主要食物之一,中国乳制品的生产和消费规模与层次已取得明显的进步。但我国乳业还存在许多问题,其中乳制品安全就是我们应当首先应对的挑战。本文通过介绍美国乳业的现状和安全管理举措,结合我国乳业现状和存在问题,提出高度重视原料奶生产、细化产品包装标注、加强基础研究和进一步优化产品结构的切实可行的解决方案,以保证我国乳品工业健康可续发展。
Milk and milk products have become a major part of their diet for Chinese people. The production and consumption of dairy foods have increased significantly during the last decade. But many problems still exist in China’s dairy industry and the safety of dairy products remains a challenge. This article describes the situation, management, regulations of the American dairy industry. The possible solutions were suggested to resolve the problems, including enhancing the raw milk production, refining the product packaging labels, strengthening basic research and further opti-mizing product structure, which will ensure healthy development of the dairy industry of China.
遗传平衡定律和遗传漂变理论之关联性分析
Association Analysis of Hardy-Weinberg Law and Genetic Drift Theory
 [PDF]

向东
Hans Journal of Biomedicine (HJBM) , 2014, DOI: 10.12677/HJBM.2014.44005
Abstract:
在一个群体中,突变率,选择,遗传漂变这些因素共同决定了基因频率,基因型频率。因为选择只是对一部分性状起作用,所以基因频率,基因型频率,突变率,遗传漂变这四个因素的整体关系,对群体遗传的变化就尤为重要。遗传漂变理论认为随机因素是影响基因频率的一个重要因素,遗传平衡定律认为,在一个群体中,突变率和选择才是决定基因频率和基因型频率的关键因素。特别是对于选择不起作用的性状,突变率才是决定基因频率的决定因素。即一个群体中,基因频率的高低不是取决于原始群体的基因频率,而是由基因的突变率决定。
In a population, the factors determining gene frequency and genetype frequency are the mutation rate, selection and genetic drift. Because the selection only works on the part of characters, so the overall relation among the gene frequency, genotype frequency, mutation rate and genetic drift is very important to the genetic variation of population. According to the theory of genetic drift, random factors influence gene frequency. But according to the theory of genetic equilibrium, in a population, the key factors determining gene frequency and gene frequency are the mutation rate and selection. Especially for the traits of nonfunctional selection, the mutation rate is the deter-mining factor of gene frequency. As a group, the gene frequency is not dependent on the original group, but decided by gene mutation rate.
蓝莓的营养保健功效及其在食品加工中的应用
The Nutrition Health Care Efficacy and the Application of Blueberry in Food Processing
 [PDF]

佳佳
Hans Journal of Food and Nutrition Science (HJFNS) , 2015, DOI: 10.12677/HJFNS.2015.43010
Abstract:
作为一种绿色健康的果品,蓝莓的营养保健功效日益被人们重视。本文重点分析了蓝莓果实中的维生素、微量元素以及花青苷、SOD、蓝莓多糖等生物活性物质的营养成分,阐述了蓝莓具有抗氧化、缓解眼睛疲劳、降低胆固醇、预防心脏病、预防癌症等多种保健功效,介绍了蓝莓果品在食品加工中的应用,以期为蓝莓的进一步批量生产和产品开发提供参考。
As a kind of green and healthy fruit, the blueberry nutrition health care efficacy is attracting more and more people’s attention. This paper analyzes the nutrition of vitamins, microelement, antho-cyanin, SOD and polysaccharides in the blueberry, expounds that the blueberry can antioxidant, protect eyesight, lower cholesterol, and prevent heart disease and cancer. In order to provide ref-erence for the further production and development of blueberry, this paper also introduces the application of blueberry in food processing.
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