共查询到20条相似文献，搜索用时 177 毫秒
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介绍了一种采用单片机控制的禽孵化器翻蛋器. 详细阐述了其硬件结构,工作原理,此翻蛋器可以预置不同的孵化工艺,从而实现智能孵化. 相似文献
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周殿凤 《唐山师范学院学报》2013,(5):44-45
运用可编程逻辑器件CPLD设计了一款并网光伏发电控制器。该控制器由CPLD开发平台、温度传感器、接口电路组成,充电采用PWM方式控制。该控制器具有自动运行、双向切换的功能,可杜绝孤岛效应,并可对蓄电池的充放电进行保护。 相似文献
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针对高校创新教育教学和技能竞赛的需要,设计一种基于嵌入式技术的四轮驱动智能教育机器人.介绍了机器人的总体设计方案、硬件组成和软件编程.该系统采用嵌入式控制技术,以ARM9系列S3C2440A处理器为主控制器,AVR单片机ATmegal6L作为驱动电路控制器,采用Linux操作系统和基于PID算法的C语言编程.该教育机器入实现了自动寻迹、图像采集、无线通信、温度探测等功能,在全国机器人技能竞赛中取得了优异的成绩. 相似文献
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张小青 《咸阳师范专科学校学报》2013,(6):21-24
电流滞环跟踪PWM控制技术能较好地得到三相对称正弦波电流,以电流滞环跟踪PWM控制器为内环,转速外环调节器选用PI调节器,建立异步电动机双闭环调速系统.建立系统主电路及控制电路进行仿真模型,主电路由异步电动机模块、电动机测量单元模块、逆变器模块、直流电源、负载模块等组成,控制电路由转速给定信号、转速调节器、电流给定信号及电流滞环跟踪控制器等组成.仿真得到电流、转速及电磁转矩曲线,验证了方法的有效性. 相似文献
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指纹密码锁的设计采用的是以单片机AT89C52为主要的控制器,主要由液晶显示电路、指示(LED)电路、报警(蜂鸣器)电路,开锁电路等组成.指纹处理采用DSP芯片,通过proteus软件进行仿真,绘制PCB板,基于C51编写程序来实现指纹密码锁的功能.指纹密码锁可实现6位密码输入和指纹采集,密码或指纹正确则锁打开;修改密码和指纹需要二次确认,以防止误操作;解锁错误次数超过3次,蜂鸣器报警.设计此系统的密码锁具有较高的安全性和科学性. 相似文献
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周佐琳 《九江职业技术学院学报》2009,(1)
"光控定时装置"由光敏电阻、晶体三极管、晶体二极管、与非门集成电路CD4011、555定时器、集成运算放大器LM324、继电器、定时琴键选择开关及工作指示发光二极管等元件组成.集成电路CD4011的四个门均接成"与"输入,以检测环境输入端的亮、暗状态.555定时器接成单稳态触发电路形式,运放集成块LM324接成电压跟随器与电压比较器的电路形式. 相似文献
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光耦合器件的原理演示,常是教师教学中的一个难点,笔者根据演示的直观性、可操作性,改用音频信号做光耦器件的光电信号转换传输实验,效果直观、学生便于理解,易掌握光耦器件原理,加深印象.电路组成:此实验电路由NE555和红外发光二极管组成的音频发射电路和以CD4069构成的音频信 相似文献
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为实现城市供热系统用户热量表数据的远程采集和集中管理,设计了一种基于仪表总线M-Bus和GPRS通信技术的新型热量表数据采集控制器.该数据采集控制器利用M-Bus技术读取热量表数据,并将数据进行本地存储,然后利用GPRS技术将数据传送到远程服务器.主要对数据采集控制器的总体结构、硬件电路设计进行了分析,给出了M-Bus发送电路、M-Bus接收电路、电源电路、短路保护电路、GPRS通信电路的设计方案.通过实际测试表明,该数据采集控制器能够对数据进行准确地发送和接收,具有较高的应用价值. 相似文献
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[目的]探讨腹膜、腹膜后间质瘤的临床病理特点.[方法]对大连大学附属医院近3a收治11例腹膜、腹膜后间质瘤患者的临床病理特点及用免疫组织化学方法检测CD117、CD34、SMA、S100蛋白表达的情况进行回顾性分析.[结果]11例患者中发生于结肠(横结肠)上区3例,结肠(横结肠)下区8例.肿瘤未能完整切除者4例.肿瘤大小≤2cm者2例,>2～5cm者1例,>5～10cm者3例,>10cm者5例.细胞形态以梭形细胞为主9例,以上皮样细胞为主2例.11例患者CD117全部阳性,CD34阳性7例,SMA阳性5例,S100全阴性.[结论]结果提示腹膜、腹膜后间质瘤作为GIST的一种特殊类型,有着其自身的临床病理特点. 相似文献
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城市与乡村的教育资源配置上存在明显的差距,表现为优质教师资源配置和教育信息资源的非均衡发展＂。农远工程模式一＂投入少、设备操作简单的特点适合于农村中小学教学点,但其缺乏人机交互和信息反馈的缺点也十分明显。树立正确观念,立足自身,正确运用＂农远工程模式一＂的光盘教学资源,探寻不同层次的光盘教学模式,缩小城乡教师资源差距,促进乡村教师专业化发展。 相似文献
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André Wagstaff 《Educational Media International》2013,50(3):114-117
Abstract Education and CD‐ROM may seem as natural a pairing as the accounting profession and spreadsheets ‐‐ but ensuring a smooth take up of new technologies is never straightforward. This article is an account of the unfolding of a deliberate central strategy for deploying CD‐ROM in British schools over the last three years. 相似文献
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王瑞阳 《温州职业技术学院学报》2003,3(2):54-55,62
本文针对晶闸管移相触发的一些弱点，提出了过零触发的观点。应用CD4098单稳态触发器组成了三相过零触发电路，达到了较为理想的调功效果。该触发器电路简单．调试方便，具有一定的实用价值。 相似文献
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MMP-9和CD15s与胃癌血管生成的相关性研究及其临床意义 总被引：2，自引：0，他引：2
目的:探讨基质金属蛋白酶9(MMP-9)和唾液酸化Lewis X(CD15s)抗原与胃癌侵袭转移的相关性。方法:采用CD105,MMP-9,CD15s进行免疫组化S-P法染色,对47例胃癌根治性切除手术标本病理组织切片进行标记,检测CD105的微血管密度(MVD),并对MVD与MMP-9、CD15s的关系进行统计分析。结果:MMP-9、CD15s表达都呈阳性的胃癌组织微血管密度高于MMP-9和CD15s单阳性及二者均阴性的胃癌组织。结论:MMP-9高表达有利于癌组织局部浸润,CD15s高表达有利于癌细胞血行转移,MMP-9及CD15s检测对临床诊治胃癌及判断预后具有一定意义。 相似文献
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Liu Y Chen L Peng SY Chen ZX Hoang-Vu C 《Journal of Zhejiang University. Science. B》2005,6(9):913-918
Objectives: To explore the mechanism of development and aggressiveness in gastric carcinomas by investigating the expression and role of CD97 and its cellular ligand CD55 in gastric carcinomas. Methods: Tumor and corresponding normal mucosal tissue, collected from 39 gastric carcinoma patients, were examined by immunohistochemistry and RT-PCR for the expression of CD97 and CD55. Results: CD97stalk was strongly stained on scattered tumor cells or small tumor cell clusters at the invasion front of gastric carcinomas. The expression of CD97stalk was frequently observed in tumors of stage Ⅰ and T1 gastric carcinoma patients. The expression of CD97stalk between Stage Ⅰ and Stage Ⅱ, Ⅲ, Ⅳ specimens showed significant difference (P＜0.05), between T1 and T2, T3, T4 specimens also showed significant difference (P＜0.05). Specimens with tumor invasion depth limited in mucosa of T 1 specimens showed higher positive CD55 expression than specimens with the same tumor invasion depth in T2, T3, T4 specimens, the expression of CD55 between T1 and T2, T3, T4 specimens was significantly different (P＜0.05).There was strong correlation between the distribution patterns of CD97stalk and CD55 on tumor tissues (r=0.73, P＜0.05). Signet ring cell carcinomas frequently contained strong CD97stalk and CD55-staining. Conclusions: Our results suggest that CD97stalk is probably involved in the growth, invasion and aggressiveness of gastric carcinomas by binding its cellular ligand CD55. CD97stalk and CD55 could be useful as molecular markers for prognosis and therapy of gastric carcinoma patients. 相似文献
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Sun Jian 《上海大学学报(英文版)》1998,2(2):164-169
１ＩｎｔｒｏｄｕｃｔｉｏｎＨｙｐｅｒ－ＩｇＭｓｙｎｄｒｏｍｅ（ＨＩＭ）ｉｓａｒａｒｅｉｍｍｕｎｏｄｅｆｉｃｉｅｎｃｙｃｈａｒａｃｔｅｒｉｚｅｄｂｙａｎｉｎｃｒｅａｓｅｄｓｕｓｃｅｐｔｉｂｉｌｉｔｙｔｏｒｅｃｕｒｒｅｎｔｉｎｆｅｃｔｉｏｎｓａｎｄｍａｒ... 相似文献
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Objectives: To explore the mechanism of development and aggressiveness in gastric carcinomas by investigating the expression
and role of CD97 and its cellular ligand CD55 in gastric carcinomas. Methods: Tumor and corresponding normal mucosal tissue,
collected from 39 gastric carcinoma patients, were examined by immunohistochemistry and RT-PCR for the expression of CD97
and CD55. Results: CD97stalk was strongly stained on scattered tumor cells or small tumor cell clusters at the invasion front of gastric carcinomas. The
expression of CD97stalk was frequently observed in tumors of stage I and T1 gastric carcinoma patients. The expression of CD97stalk between Stage I and Stage II, III, IV specimens showed significant difference (P<0.05), between T1 and T2, T3, T4 specimens also showed significant difference (P<0.05). Specimens with tumor invasion depth limited in mucosa of T1 specimens showed higher positive CD55 expression than
specimens with the same tumor invasion depth in T2, T3, T4 specimens, the expression of CD55 between T1 and T2 T3, T4 specimens
was significantly different (P<0.05). There was strong correlation between the distribution patterns of CD97stalk and CD55 on tumor tissues (r=0.73,P<0.05). Signet ring cell carcinomas frequently contained strong CD97stalk and CD55-staining. Conclusions: Our results suggest that CD97stalk is probably involved in the growth, invasion and aggressiveness of gastric carcinomas by binding its cellular ligand CD55.
CD97stalk and CD55 could be useful as molecular markers for prognosis and therapy of gastric carcinoma patients.
Project (No. 2004C34010) supported by the Science and Technology Bureau of Zhejiang Province, China 相似文献
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采用改进的BP网络分类器对CD4细胞图像进行识别.首先对图像进行了预处理,分析了图像的特征,然后通过增L减R法选择,介绍了BP网络分类器和LM算法的原理,构建了基于LM算法的BP网络分类器,较好地实现了CD4细胞的识别. 相似文献