基于WSN的油菜生长环境数据采集系统     

李建辉  廖桂平  王访 《湖南农业大学学报(自然科学版)》2013,39(6):675-682

针对传统作物生长环境数据获取手段实时性差、劳动强度大以及部署微型自动气象站和商用Zigbee产品成本高、开放性较差等问题，设计并实现了一种基于WSN的油菜生长环境数据采集系统。提出了轻量级的能量感知路由协议CLFP，并给出了软硬件的相关设计方法。仿真和大田试验结果表明，系统温度采集精度最高可达0.01 ℃，测湿精度达±5%，光强采集范围为1~65 535 lx，可并发的数据传输达到36路，可满足农业现场环境数据的较高测量要求。在标称电源供电情况下，系统实际有效生存周期超过142 d，由于采用AT89C51和nRF2401作为基础硬件平台，成本低廉，有助于大规模部署和应用。  相似文献   

Preventive effects of CIDR-based protocols on premature ovulation before timed-AI in Ovsynch in cycling beef cows     

Sakase M  Kawate N  Nakagawa C  Fukushima M  Noda M  Takeda K  Ueno S  Inaba T  Kida K  Tamada H  Sawada T 《Veterinary journal (London, England : 1997)》2007,173(3):691-693

Ovsynch is a program developed to synchronize ovulation for timed breeding. In this paper, the authors investigate whether controlled internal drug release (CIDR)-based protocols prevent premature ovulation before timed-artificial insemination (AI) when Ovsynch is started a few days before luteolysis in cycling beef cows. Nine beef cows at 16 days after oestrus were treated with (1) Ovsynch, i.e. gonadotropin releasing hormone (GnRH) analogue on day 0, prostaglandin (PG) F(2alpha) analogue on day 7 and GnRH analogue on day 9 with timed-AI on day 10, (n=3); (2) Ovsynch+CIDR (Ovsynch protocol plus a CIDR for 7 days from day 0, n=3), or (3) oestradiol benzoate (OB)+CIDR+GnRH (OB on day 0 in lieu of the first GnRH treatment, followed by the Ovsynch+CIDR protocol, n=3). In the Ovsynch group (1) plasma progesterone concentrations fell below 0.5 ng/mL earlier (day 5) than in both CIDR-treated groups (2) and (3), where this occurred on day 8. Plasma oestradiol-17beta concentrations peaked on day 8 in the Ovsynch group and on day 9 in both CIDR-treated groups. The dominant follicle ovulated on day 10 in the Ovsynch group and on day 11 in both CIDR-treated groups. Thus, both CIDR-based protocols prevented premature ovulation before timed-AI in Ovsynch when the protocol was started a few days before luteolysis. This reflects the fact that progesterone levels remained high until the beef cattle were treated with PGF(2alpha).  相似文献   

Rapid brain MRI protocols result in comparable differential diagnoses versus a full brain protocol in most canine and feline cases     

Kelsey A. Johnson  James Sutherland-Smith  Trisha J. Oura  Amy F. Sato  Bruce Barton 《Veterinary radiology & ultrasound》2023,64(1):86-94

Evaluation of brain disease in veterinary patients uses a wide variety of MRI sequences. A shortened protocol that maintains consistency of interpretation would reduce radiologist reporting time, patient anesthetic time, and client cost. The aims of this retrospective, methods comparison, observer agreement study were to evaluate whether abbreviated MRI protocols alter differential diagnoses and recommendations compared to our institution's standard protocol; evaluate interobserver agreement on standard brain MRIs; and assess whether differential diagnoses change after postcontrast images. Normal and pathologic canine and feline brain MRIs were retrieved from hospital archives. Three protocols were created from each: a 5-sequence noncontrast enhanced Fast Brain Protocol 1 (FBP1); a 6-sequence contrast-enhanced Fast Brain Protocol 2 (FBP2); and an 11-sequence standard brain protocol (SBP). Three blinded veterinary radiologists interpreted FBP images for 98 cases (1 reader/case) and SBP images for 20 cases (3 readers/case). A fourth observer compared these interpretations to the original MRI reports (OMR). Overall agreement between FBPs and OMR was good (k = 0.75) and comparable to interobserver agreement for multiple reviews of SBP cases. Postcontrast images substantially altered conclusions in 17/97 cases (17.5%), as well as improved interobserver agreement compared to noncontrast studies. The conclusions reached with shortened brain protocols were comparable to those of a full brain study. The findings supported the use of a 6-sequence brain MRI protocol (sagittal T2-weighted [T2w] TSE; transverse T2w turbo spin echo fluid-attenuated inversion recovery, T2*-weighted gradient recalled echo, T1-weighted spin echo, and diffusion weighted imaging/apparent diffusion coefficient; and postcontrast transverse T1-weighted spin echo) for dogs and cats with suspected intracranial disease.  相似文献   

INTERCONNERCTION BETWEEN SUPER-MINICOMPUTER ETHERNT E     

Li Hua Wu Zhongfu Chen Dazhi 《保鲜与加工》1989,(2):35-42

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THE DESIGN AND CONTROL OF A CLASS OF INTERCONNECTION NETWORKS FOR NEW MULTICOMPUTER SYSTEMS     

Feng Feiling 《保鲜与加工》1992,(2):77-81

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Clustering Routing for Wireless Sensor Networks     

HE Li-yuan  LI Yong-ming  WANG Quan-di 《保鲜与加工》2007,(1):50-53

In wireless sensor networks that consist of a large number of low-power sensors.Because the sensor's energy is limited,one of the main design is to obtain long system lifetime.The authors firstly analyse LEACH and LEACH-C clustering routing for wireless sensor networks.Aimming at their shortcoming,they present a new routing LEACH-NEW.This routing uses multi ho Pinstead of one hop.At last,they use NS2 to simulate them.Simulation show results that new routing exhibits noticeably longer system lifetime than rouing LEACH and LEACH-C.  相似文献   

分布式异构数字资源整合概述     

孟凡静  李国朋 《农业环境科学学报》2007,(5)

 

对分布式异构数字资源的整合检索模式、整合协议、资源连接方式、编码等几个方面

进行了概括介绍。

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基于Modbus协议的电力监控系统设计     

翁自勇  燕善俊 《金陵科技学院学报》2012,28(1):14-17

针对ACR系列网络多功能电力仪表的特性完成了上位机监控系统的设计,该系统使用VB语言编写,通过RS232接口,利用MODBUS协议与20个仪表进行通信,将分析得到的电压数据在系统界面上显示。经测试,该设计可满足实际需要。  相似文献   

基于Packet Tracer的VoIP网络仿真     

窦如林  施卫娟  王少平 《金陵科技学院学报》2012,28(1):18-22

介绍VoIP工作原理,通过Packet Tracer仿真软件构建VoIP通信网络,对网络中的设备进行配置,实现VoIP通信过程,并对数据传输进行协议分析,为VoIP实验教学提供一种廉价、高效的解决方案。  相似文献   

Improved protocol for Agrobacterium mediated transformation of tomato and production of transgenic plants containing carotenoid biosynthetic gene CsZCD     

Dongliang Qiu  Gianfranco Diretto  Raffaela Tavarza  Giovanni Giuliano 《Scientia Horticulturae》2007

Improved protocol for Agrobacterium mediated transformation of tomato (Lycopersicon esculentum) Micro-Tom was developed to use in corporation of the carotenoid biosynthetic genes CsZCD (Crocus zeaxanthin 7,8-cleavage dioxygenase). From these experiment, a transformation methodology using explants from cotyledons cultured for 1 day on the medium with zeatin 2 mg/L, IAA 0.1 mg/L, carefully submerged in the Agrobacterium inoculum for 20 min, then concultured with the agrobacterium for 3 days on the same medium, followed by a transfer to the same medium with 500 mg/L cefotaxin for 3 days and then by a transfer to the same medium with 100 mg/L kanamycin and 500 mg/L carabenillin for 6–8 weeks and resulted in a greater than 20% transformation efficiency in the concentration of Agrobacterium OD600 = 0.2 tested. In this transformation method, no feeder layers were used and the subculture media was minimal. Among the Agrobacterium concentrations of OD600 = 0.2, 0.5 and 1.0, the best transformation efficiency, 20.87%, was obtained by using OD600 = 0.2, which was significantly higher than that of OD600 = 1.0. The presence of the inserted target genes was checked using a rapid and efficient PCR test. The protocol was successfully employed in the production of transgenic Micro-Tom tomato containing the carotenoid biosynthesis CsZCD under constructive promoter. This procedure represents a simple, efficient and general means of transforming tomato.  相似文献