首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
能量自给的果园信息采集无线传感器网络节点设计   总被引:6,自引:5,他引:1  
针对果园中所存在的无线通信障碍与电池更换困难问题,该文设计了一款适合果园信息采集的无线传感器网络(wirelesssensor network,WSN)节点。节点以MSP430F149为核心,nRF905射频芯片及其外围电路作为无线通信模块,CN3058和HT6292智能充电芯片及其外围电路作为太阳能充电模块,电机驱动芯片ULN2003及水平、垂直电机作为太阳追踪模块,DHT22空气温湿度传感器和TDR-3土壤含水量传感器及其外围电路作为传感器模块,并以该硬件平台编写了通信协议、应用程序和时间同步算法。分析、测试了节点的功耗、通信距离以及太阳能充电时间,在空旷地带有效通信距离达到202m;主电路电池由3V充电至3.6V所需时间为580min,传感器电路电池由5.6V充电至7.2V所需时间为283min;在无太阳能充电且节点系统工作周期为30min情况下,主电路生命周期理论值为497d,传感器电路生命周期理论值为147d。组网试验结果表明:网络丢包率小于1.5%,能够满足果园信息采集以及能量自给的应用要求。  相似文献   

2.
柑橘园水肥一体化滴灌自动控制装置的研制   总被引:11,自引:5,他引:6  
为实现建设有独立水池和独立液肥池的柑橘园的水肥滴灌的自动控制,研制了一个干电池供电的水肥一体化滴灌定时控制装置。该装置通过2个电磁阀的开关操作分别控制2个池中的清水和液肥进入滴灌管网的顺序和时间,实现水肥一体化滴灌的自动控制。充分利用了休眠机制和电源管理技术,其静态电流小于11.2A。经连续6个月的实际应用试验表明,装置运行稳定可靠,其电池电压仅从初始值9.35V下降为8.50V。该装置操作简单,既可以进行水肥一体化滴灌,又可以进行清水滴灌,还可以将多套装置进行组合实现轮灌以控制更大的灌溉面积,具有推广应用前景。  相似文献   

3.
山地果园中低功耗无线滴灌控制装置设计与试验   总被引:1,自引:1,他引:0  
针对山地果园布线困难,而大面积滴灌需要分区控制并集中管理的需求,构建了低成本、低功耗、能满足定时分区灌溉与集中管理需求的小型无线滴灌控制装置。装置采用无线通信方式,硬件选用低功耗微控制器与双稳态电磁阀,系统软件采用基于CC1100无线唤醒机制的低功耗间同步通信算法,具有避免信道拥塞的特点。试验表明,输入电压9 V时,控制系统静态电流为400 mA、无线唤醒工作电流为19 mA、工作周期内平均电流为439 mA;1节鹏辉450 mAh的AA电池可供系统至少可工作38 d;果园内RSSI信号衰减测试表明通信距离超过60 m,最高平均丢包率为23%;有遮挡的环境中数据丢包率将大于无遮挡环境,但接收信号强度相差不大;在果园环境中尝试使用电力线载波适配器、大功率WiFi无线网桥、GPRS DTU 3种远距离通信模块建立总控制器与远程监控端的数据链路,链路试验表明,GPRS DTU与大功率WiFi网桥均能成功建立通信链路。相比之下,GPRS有强的适应性;采用无线控制系统,系统准时开启电磁阀,开启时间误差小于5 min,土壤含水率变化呈现快速上升后缓慢下降的变化,灌溉区域的土壤含水率保持13%以上,可应用于岭南绝大部分山地果园。解决了控制装置的布线工程困难,实现可远程传输滴灌信息和监测滴灌状态,并可进一步实现分区控制与轮灌控制。  相似文献   

4.
基于太阳能的微灌系统恒压供水自动控制装置研制   总被引:7,自引:6,他引:1  
微灌系统入口水压的稳定性影响着微灌的均匀性以及自动混肥装置的混肥精度。为采用自流滴灌的中小规模灌溉管网提供恒定的入口水压,采用太阳能供电驱动隔膜泵DP-60提水的方式,研制了一个恒压供水自动控制装置。该装置利用液位传感器YZ-YO-LAG1在线检测建设于高处的蓄水池的水位,根据水位信息控制DP-60提水至蓄水中,并使其水位在滴灌过程中维持于某一固定高度来实现恒压供水。蓄水池的水位检测信息及DP-60的启停通过无线通信模块CC1100进行无线传输和控制。通过光伏容量设计,确定了太阳能电池板的功率为60W、蓄电池的容量为60A·h。为最大程度利用太阳能,通过试验标定了太阳能板输出功率与太阳辐射传感器TSL230输出频率的关系,并根据太阳能板实际输出功率和蓄电池荷电状态,自动选择直接以太阳能板或蓄电池为DP-60供电。在测试DP-60性能以及无线通信可靠性的基础上,对装置进行了6个多月的实际应用试验,装置运行稳定,且在整个滴灌过程中蓄水池的水位误差小于1cm。  相似文献   

5.
基于太阳能的柑桔园自动灌溉与土壤含水率监测系统研制   总被引:6,自引:5,他引:1  
为实现柑桔园的节水节能自动灌溉与土壤含水率的监测,以太阳能为主要能源,用土壤水分传感器实时监测土壤含水率,利用CAN(controller area network)总线与GSM(global system for mobile communications)网络实现土壤含水率的远程监测。利用太阳能电池对锂电池充电,采用双锂电池结构,提高了系统供电稳定性,且将充电与放电过程完全分离,延长了锂电池寿命。土壤水分传感器每12h测量一次土壤含水率,当其低于设定的阈值时,自动打开电磁阀进行灌溉,当高于设定值时停止灌溉。在666.7m2内的土壤含水率数据利用CAN总线传输至主节点,各主节点通过短消息将数据发送至终端计算机。将桔园土壤含水率低于10%,高于20%作为系统开始自动灌溉和停止灌溉指标,且传感器距滴管外50mm时,则水分输运到柑桔根系集中区域所需滴灌时间约为6.7h。试验表明,系统运行稳定可靠,能实现柑桔园区的自动灌溉与土壤含水率的自动监测,对实现节水节能灌溉有较大的现实意义。  相似文献   

6.
太阳能供电的土壤剖面水分动态原位自动监测系统的研制   总被引:2,自引:2,他引:0  
目前,商业化的土壤水分传感器在野外观测土壤剖面含水率时仍然存在测量深度不可调节、多传感器探头之间的互换误差、野外长期监测供电困难、成本较高等问题。为此,该研究设计并研制了一种太阳能供电的可实现野外长期工作的介电管式土壤剖面水分原位自动监测系统。该系统组成包括:传感器模块、主控模块、太阳能供电模块和参数设置软件。测量时,先将PVC管垂直安装至待测土壤中,安装过程不扰动土壤结构,主控与存储模块控制土壤含水率传感器在PVC管中上下移动测量土壤含水率,并同步记录土壤深度。此外,该系统可以根据实际需求通过PC机参数设置软件进行灵活设定测量参数(传感器测量深度、测量深度间隔和测量周期)。针对该系统的性能与测量精度开展了相关测试与观测试验,功耗测试结果表明该系统待机功率为0.35 W,工作功率为1.4 W,太阳能电池板最大输出功率为5W,太阳能电池板和锂电池配合供电的情况下能实现长时间续航;土壤含水率传感器在砂土和粉壤土中的标定试验表明:该系统测量结果与实际土壤体积含水率高度吻合,标定曲线决定系数R~2均大于0.99;经过校正后,该系统探头深度定位的标准偏差在0.2 cm以内。在两种质地土壤的滴灌试验结果表明:该系统分别在6和15 mL/min两种滴水速率下均能准确获取土壤剖面含水率的动态变化过程,为观测作物生长状态和根区水分变化、制定合理的灌溉策略以及研究并检验土壤入渗水动态模型提供了可靠的技术支持和保障。  相似文献   

7.
基于物联网的桔小实蝇诱捕监测装备设计及试验   总被引:4,自引:4,他引:0  
为了实现对桔小实蝇诱捕的实时监测和快速诊断,设计了一个基于物联网的桔小实蝇诱捕监测装备。该装备包括诱捕监测装置、太阳能供电装置和监测控制装置3个主要部分,其中诱捕装置包括顶盖、透明的连通件和诱捕瓶;太阳能装置包括太阳能板、蓄电池以及太阳能板支架;控制装置包括Fit-pc控制器、3G通讯模块和自主研发的桔小实蝇监测计数系统软件。该装备结合了机器视觉技术、远程通讯技术以及太阳能供电等技术,实现了集病虫害信息采集、处理、传输与自供电为一体的桔小实蝇诱捕监测装备,可长期的、实时的、远程的监控桔小实蝇诱捕过程和精确的计算桔小实蝇数量,且可自动传输到远程服务器并保存在本地存储卡中。在实验室环境下采用该装备测试,在830 s内有138头桔小实蝇进入该装备,系统检测出的结果是131头,检测成功率为94.9%。采用该装备在杨桃公园从2013年11月到2014年12月进行了一年多测试,系统软硬件可以稳定地协同工作,仅在光照严重不足太阳能供电不力的情况下出现过系统停止运行。基于物联网的桔小实蝇诱捕监测装备能自动跟踪计算桔小实蝇数量,从而向区域监控人员提供简洁有效的监控信息,在农业上有着广泛的应用前景。  相似文献   

8.
具有最大功率点跟踪功能的户用光伏充电系统的研究   总被引:6,自引:1,他引:5  
从提高户用光伏系统蓄电池寿命和系统性能出发,设计出一个户用光伏充电系统。在这个充电系统中,提出了采用具有太阳能电池最大功率点跟踪(MPPT)功能和蓄电池充电电压温度补偿功能相结合的充电控制方法。实验和模拟仿真证明,系统实现了对太阳能电池的MPPT控制和对蓄电池充电的温度补偿。  相似文献   

9.
棉花膜下滴灌比例混合变量施肥系统的研发   总被引:1,自引:1,他引:0       下载免费PDF全文
根据膜下滴灌棉田水肥管理的要求,在建立施肥模型和施肥方案的基础上,研发适用于大田棉花膜下滴灌的比例混合变量施肥系统,该系统可通过计算机程序控制(CPC)、单板机时序控制(PLC)和遥控控制(Rc)等三种方法,实现变量控制施肥,控制部分可在24V的电压下工作,施肥器通过水流驱动无需动力,实现提高肥料利用率10%以上.  相似文献   

10.
基于太阳能的无线土壤水分传感器的研制   总被引:9,自引:6,他引:3  
为实现土壤水分的自动检测与无线传输,采用电场法检测土壤质量含水率,利用Zigbee技术构建无线传感网络实现数据传送。利用太阳能电池收集太阳能并存储于锂电池中,实现对系统供电。通过合理的充放电管理,能有效地延长锂电池寿命。试验结果表明,该传感器能够实现0~30%间的土壤质量含水率的测量,相对误差小于10%。利用Zigbee模块及MiWi(TM)协议栈构建星形网络能实现数据无线传输。当节点发射功率为1 mW时,在无阻挡条件下可靠传输距离为30 m,在有农作物遮挡时,可靠传输距离为10 m左右。在1 h采集发送  相似文献   

11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响   总被引:2,自引:2,他引:0  
【目的】以富士(Fuji)、 秦冠(Qinguan)嫁接在平邑甜茶(Malus hupehensis Rehd.)上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水(ZZ)、 低氮正常水(DZ)、 正常氮干旱(ZG)、 低氮干旱(DG)。氮素和水分均设置两个水平,分别为正常氮(6 mmol/L NO-3-N)、 低氮(0.3 mmol/LNO-3-N)、 正常供水(保持盆中砂子相对含水量为饱和含水量的80%~85%)、 干旱处理(保持盆中砂子相对含水量为饱和含水量的60%~65%)。【结果】富士和秦冠的生物量(茎和叶)、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG),并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水(ZZ)>低氮正常水(DZ)>正常氮干旱(ZG)>低氮干旱(DG); 氮、 钾元素含量在植株各部位的分布顺序依次是叶>根>茎,磷元素则是根>叶>茎;光合氮素利用效率(PNUE)和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水(DZ)处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱(DG)处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。  相似文献   

12.
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.  相似文献   

13.
正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

14.
Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.  相似文献   

15.
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.  相似文献   

16.
李聃枫  朱春梧 《土壤》2020,52(3):561-566
自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。  相似文献   

17.
Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.  相似文献   

18.
Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.  相似文献   

19.
We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.  相似文献   

20.
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号