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基于AT89C2051单片机的频率计设计 被引量:5
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作者 杜刚 高军 童宁宁 《微计算机应用》 2004年第4期498-502,共5页
本频率计设计以AT89C2 0 5 1为核心 ,应用单片机的算术运算和控制功能并采用串口液晶显示块实时地将所测频率显示出来。使用串口的液晶显示模块 ,节省了单片机的口线和外围器件 ,简化了显示部分的编程控制。使用高效的快速转换算法和用... 本频率计设计以AT89C2 0 5 1为核心 ,应用单片机的算术运算和控制功能并采用串口液晶显示块实时地将所测频率显示出来。使用串口的液晶显示模块 ,节省了单片机的口线和外围器件 ,简化了显示部分的编程控制。使用高效的快速转换算法和用来测量信号多倍周期的分频电路计算信号频率 ,既保证了系统的测频精度 ,又使系统具有较好的实时性。在本设计中实现了频率信号的实时高精度地测量与显示。 展开更多
关键词 频率计 设计 AT89C2051单片机 串口液晶显示块
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基于51单片机的RFID门禁密码锁设计 被引量:6
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作者 赵永涛 《自动化应用》 2022年第12期185-187,191,共4页
伴随现代社会信息化水平不断提高,现代建筑楼宇向智能化方向不断发展。门禁系统作为安全防范系统中的一个重要分支因其独特的优越性得到了飞速的发展和较广泛的应用。为满足现代信息时代各种用户在不同场景下的各种需求,智能门禁系统开... 伴随现代社会信息化水平不断提高,现代建筑楼宇向智能化方向不断发展。门禁系统作为安全防范系统中的一个重要分支因其独特的优越性得到了飞速的发展和较广泛的应用。为满足现代信息时代各种用户在不同场景下的各种需求,智能门禁系统开始出现。智能门禁以更加现代化的方式实现各种门禁自动化管理,可以广泛应用于楼宇管理区、出入口、仓库、设备控制中心和电梯口等重要通道门,可实现自动识别人员身份,对出入口实现管理控制。该系统结合了微电子技术、嵌入式设计、计算机软件、电气控制及通信技术及射频识别等相关技术,通过门禁锁对IC卡片或者密码进行识别,用卡片或者密码替代了传统钥匙功能,不但给管理者提供了更安全、更方便、更智能化的管理方式,而且也给使用者带来了极大的方便。 展开更多
关键词 STC89C52RC单片机 主控单片机 液晶显示块
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The Use of Life Cycle Management Principles in Biosystems Engineering: A Pragmatic Approach to Solving Agri-industrial Sustainability Problems 被引量:1
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作者 Israel S Dunmade 《Journal of Agricultural Science and Technology(A)》 2012年第3期357-362,共6页
LCM (life cycle management) is a systematic approach, mindset and culture that considers economic, social, and environmental factors among other factors in the decision making process throughout various business or ... LCM (life cycle management) is a systematic approach, mindset and culture that considers economic, social, and environmental factors among other factors in the decision making process throughout various business or organizational decisions that affect both inputs and outputs of a product or service life cycle. It is a product, process, or activity management system aimed at minimizing environmental and socio-economic burdens associated with an organization's product or process during its entire life cycle and value chain. LCM's application is gaining wider acceptance both in the corporate and governmental organizations as an approach to reduce ecological footprints and to improve the sustainability of human activities. But where and how can it be used in agricultural engineering applications? This study highlights the potential areas of LCM application in agricultural and allied sectors and how it can be utilized. The study revealed that LCM tools such as design for environment and life cycle analysis can be used to evaluate the environmental impacts of-and to improve the products, equipment, and structures produced by biosystems engineers as well as the processes used to generate them. 展开更多
关键词 Life cycle management biosystems engineering life cycle assessment design for environment social life cycleassessment life cycle costing enabling supply and infrastructure assessment.
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Laser capture microdissection and genetic analysis of carbon-labeled Kupffer cells
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作者 Stephan Gehring Edmond Sabo +3 位作者 Maryann E San Martin Elizabeth M Dickson Chao-Wen Cheng Stephen H Gregory 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第14期1708-1718,共11页
AIM: To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection (LCM). METHODS: Tissues are complex structures compri... AIM: To develop a method of labeling and microdissecting mouse Kupffer cells within an extraordinarily short period of time using laser capture microdissection (LCM). METHODS: Tissues are complex structures comprised of a heterogeneous population of interconnected cells. LCM offers a method of isolating a single cell type from specific regions of a tissue section. LCM is an essential approach used in conjunction with molecular analysis to study the functional interaction of cells in their native tissue environment. The process of labeling and acquiring cells by LCM prior to mRNA isolation can be elaborate, thereby subjecting the RNA to considerable degradation. Kupffer cell labeling is achieved by injecting India ink intravenously, thus circumventing the need for in vitro staining. The significance of this novel approach was validated using a cholestatic liver injury model. RESULTS: mRNA extracted from the microdissected cell population displayed marked increases in colonystimulating factor-1 receptor and Kupffer cell receptor message expression, which demonstrated Kupffer cell enrichment. Gene expression by Kupffer ceils derived from bile-duct-ligated, versus sham-operated, mice was compared. Microarray analysis revealed a significant (2.5-fold, q value 〈 10) change in 493 genes. Based on this fold-change and a standardized PubMed search, 10 genes were identified that were relevant to the ability of Kupffer cells to suppress liver injury. CONCLUSION; The methodology outlined herein provides an approach to isolating high quality RNA from Kupffer cells, without altering the tissue integrity. 展开更多
关键词 Kupffer cells India ink Laser capturemicrodissection Bile duct ligation DNA microarray
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