温度对土壤水分张力计的内压影响及校正方法(英文)

在土壤水分张力计系统内嵌入一电子式温度传感器,对管内温度进行实时监测,对照管内压力发现:以密封塞取代陶土头时,管内温度上升26.9℃内压力变化了14.6Kpa。当实验盆钵内的土壤含水量相对不变时,负压计中的压力值仍然随着温度变化出现有规律的周期变动,温度上升22.2℃管内压力变化了7.4 Kpa。通过对采集管内张力数据进行补偿运算,对张力计系统的升温和降温阶段进行温度补偿,可有效对由温度变化引起的张力计系统误差进行校正。当测定间隔为4h、温差为18.1℃时,两点的张力相差仅0.278Kpa,未做补偿的两点压力差达6.5 Kpa。说明在在土壤水分张力计系统内嵌入一电子式温度传感器能够有效校正温度变化引起的张力计系统误差,达到全天候实时对目标地区实现水分管理的目的。     

Integrating Remote Sensing and Proximal Sensors for the Detection of Soil Moisture and Salinity Variability in Coastal Areas

Soil moisture and salinity are two crucial coastal saline soil variables, which influence the soil quality and agricultural productivity in the reclaimed coastal region. Accurately characterizing the spatial variability of these soil parameters is critical for the rational development and utilization of tideland resources. In the present study, the spatial variability of soil moisture and salinity in the reclaimed area of Hangzhou gulf, Shangyu City, Zhejiang Province, China, was detected using the data acquired from radar image and the proximal sensor EM38. Soil moisture closely correlates radar scattering coefficient, and a simplified inversion model was built based on a backscattering coefficient extracted from multi-polarization data of ALOS/PALSAR and in situ soil moisture measured by a time domain reflectometer to detect soil moisture variations. The result indicated a higher accuracy of soil moisture inversion by the HH polarization mode than those by the HV mode. Soil salinity is reflected by soil apparent electrical conductivity (ECa). Further, ECa can be rapidly detected by EM38 equipment in situ linked with GPS for characterizing the spatial variability of soil salinity. Based on the strong spatial variability and interactions of soil moisture and salinity, a cokriging interpolation method with auxiliary variable of backscattering coefficient was adopted to map the spatial variability of ECa. When compared with a map of ECa interpolated by the ordinary kriging method, detail was revealed and the accuracy was increased by 15.3%. The results conclude that the integrating active remote sensing and proximal sensors EM38 are effective and acceptable approaches for rapidly and accurately detecting soil moisture and salinity variability in coastal areas, especially in the subtropical coastal zones of China with frequent heavy cloud cover.     

基于无线图像传感器的太阳能系统设计和实现

【目的】电源决定着无线传感器节点的生命周期,本研究通过软硬件一体化设计最大限度地延长节点寿命。【方法】针对自主研发的无线图像传感器节点,根据公式估算节点总功耗,计算铅酸蓄电池容量,根据电池容量设计太阳能电池板,最后根据太阳能电池板和电池参数,设计太阳能充放电智能控制器。【结果】节点选用阀控式密封高能铅酸蓄电池的容量为10 Ah,额定电压为12 V;选用功率为10 W、输出电压17 V、输出电流0.5 A、尺寸为540mm×350 mm的单晶硅太阳能电池板。【结论】太阳能供电系统运行在该无线图像传感器节点中,能够稳定、可靠、长期工作。     

基于无线传感器网络的农业信息采集系统设计

设计了一种基于无线传感器网络和智能网关的农业信息采集系统。系统采用PIC18F87K90微控制器作为采集控制中心,结合温湿度、照度、二氧化碳等环境信息采集模块及无线数据收发模块组成整套系统,实现了对农业信息的采集、存储、显示及监测等功能,适用于农田、冷链车和冷库等典型环境。     

土壤环境监测中传感器网络覆盖算法的研究

为了解决土壤环境监测中的无线传感器网络节能覆盖问题。通过将感兴趣区域用r/2正方形网格划分,建立坐标系,根据传感器在网格中的位置及其覆盖度确定其是否激活,通过节点的覆盖度及邻节点的状态休眠重复覆盖的传感器,最终使激活的传感器节点能够最大限度的覆盖感兴趣的区域。结果表明:该方法能够很好的覆盖感兴趣的区域,且能够节省能量,延长网络的工作时间。     

基于nRF905的水产养殖环境参数自动监控系统

根据现代化水产养殖的低耗高效的发展要求,设计了基于nRF905的水产养殖环境参数自动监控系统.该系统把监控中心PC机作为上位机,通过VB 6.0构建上位机监控软件,同时以单片机MSP430作为下位机,并通过nRFg05构建无线传感网络,从而实现自动监控系统的各项功能.经过试验,该自动监控系统能够对DO、pH进行实时的数据采集、显示和存储,并与增氧机结合对DO进行自动控制以及超限报警.养殖现场试验结果表明,该系统工作稳定、实时性好、能耗低,控制电路设计简单、成本低,有一定的应用推广价值和实际意义.     

变应传感器在甜菜根茎测定中的应用

将变应传感器应用在甜菜根茎生长测定中,测定地表下5cm处甜菜块根直径以期观测甜菜根部生长状态。试验结果表明,2点法测量的误差小于1点法,年度间差异变化不大,并且没有在甜菜表面造成损伤和形成生育障碍,说明2点法可以在生产中应用。     

用于测定黑茶中铅的荧光增强化学传感器

铅(Ⅱ)对固定在增塑的聚氯乙烯(PVC)敏感膜中的红霉素A有可逆荧光增强作用,据此研制了测定铅(Ⅱ)的荧光化学传感器。该传感膜的组成为:50.0 mg PVC、100.0 mg邻苯二甲酸二异辛酯和2.94 mg红霉素A。该传感器在pH 8.0的Tris-HCl缓冲溶液中,测定铅(Ⅱ)的动力学范围为4.00~6.00 mmol·L~(-1),检出限为0.10μmol·L~(-1),响应时间小于50 s。该传感器具有良好的重现性、可逆性和选择性,除Cr_2O_7~(2-)和MnO_4~-外,常见阴离子和阳离子不干扰测定。该传感器应用于黑茶水样中铅(Ⅱ)含量的测定,结果与GB 5009.12—2010法一致。     

基于加速仪运动传感器的牲畜行为监测研究进展

加速仪运动传感器被大量用于牲畜行为监测,是当前开展精准养殖研究的重要方向。综述了加速仪运动传感器在牲畜行为分类方面的研究,介绍了加速仪运动传感器在牲畜身上的可佩戴位置,并对比了其在腿部和颈部的佩戴差异,详细论述了基于加速仪运动传感器的牲畜行为分类流程,具体包括采样时间窗口确定、特征向量抽取、分类算法构建等。行为自动分类是对牲畜进行自动化监测、精准化管理的前期和基础,未来应进一步突破分类模型构建、多元传感器融合、实时数据处理等关键技术研究。     

Predictive modelling of illegal fishing in no‐take marine protected areas

Illegal fishing is an acknowledged problem within no‐take areas (NTAs), which are frequently used as a marine conservation management tool. While gathering data on illegal fishing is difficult, it is necessary, as these data enable increased efficiency of compliance patrols, where resources are inherently limited. In particular, information about short‐term temporal variations in illegal fishing in NTAs is needed to guide management and compliance efforts. To address this knowledge gap, daily variations in illegal fishing effort were examined using surveillance cameras at two sites in New South Wales, Australia. Generalised linear modelling (GLM) identified that illegal fishing was significantly greater on non‐working days and during periods with no rain, light winds and slight seas. The GLM developed provided useful predictions of illegal activity in both the NTA used to build the model and in a second nearby NTA. The study demonstrated that illegal fishing was principally concentrated on days with good boating conditions and was greater at the study site closer to boat launching facilities. These insights will assist with future targeting of enforcement, community outreach and management efforts, which should focus on days and sites with an increased likelihood of illegal fishing.