柔性可穿戴传感技术在智慧渔业中的应用进展

随着智慧渔业的发展,现代渔业中运用的先进传感设备越来越多。近年来,柔性传感技术凭借出色的可拉伸性和生物相容性,既良好地实现了刚性和植入型传感器的传感功能,又弥补了传统传感器体积重量大、生物不相容的缺陷,拓宽了传感器在渔业应用的范围,显示出巨大的应用潜力。该文系统地阐述了柔性传感装置使用的柔性材料、制造工艺、供能和通信系统,总结并分析了柔性可穿戴传感技术在鱼类运动监测、水环境监测、水产品质量检测3个方面的应用及其优缺点。最后,讨论了可穿戴设备在渔业应用中的机遇和挑战,认为其在低成本制备、多功能集成、新材料开发、应用场景的挖掘等方面具有较大的发展潜力,有广阔的应用前景,同时指出提高复杂条件下可穿戴设备传感的稳定性和可靠性、设计多参数一体化检测的微型传感系统、开发可靠的可穿戴设备自供电模块和拓展应用场景是柔性可穿戴技术在智慧渔业领域的重要发展方向。     

适用于农业气象的热敏电阻测温方法

农业气象中较高精度测量温度要素,不仅要限制传感元件本身的误差,还要考虑传感元件在进行信号转换测量方法的误差.本文介绍了热敏电阻的测温特性;对热敏电阻测温的特性作了精确的回归模拟.采用稳定的恒流源式电桥将热敏电阻变化量提取,经数据放大器放大信号进行温度转换测量.最后比较了测温结果;简述了常用热敏电阻测温方法和本文所述方法的特点.     

面向智慧农业的无芯片射频跨域感知研究进展

随着传统农业逐渐向智慧农业转型，室温条件下具有低成本、长寿命、低功耗、小型化的检测手段对于农业环境及动植物本体指标检测至关重要，尤其对于无法进行电路有线连接的农业场景。随着器件传感和无线通信的整合，无芯片射频识别（chipless radio frequency identification, CRFID）因为具有轻量、价格合理、普适性等优势被广泛应用，CRFID标签具有理论上的“无限”寿命，代替了集成电路，成为标识传感信息融合的重要媒介，适用于农业环境、动植物生长监测、物流运输、食品品质检测等。该研究首先介绍了CRFID系统构成，以及其基本原理，指出天线是CRFID实现跨域感知的关键要素之一，随着农业场景中气体、环境温湿度、pH值等变化，天线负载敏感材料的电导率、磁导率、介电常数变化，引起CRFID标签的反向散射信号变化；其次，基于时频域标签，介绍了CRFID用于湿度、温度、气体（二氧化碳、氨气、乙烯）、pH和食品（猪肉、牛肉、鱼肉、果蔬、牛奶）检测的国内外最新研究进展，对比了相关传感器的关键性能指标；最后，针对CRFID技术的成功案例，指出了该类型传感器面临的主要研究挑战、未来研究...     

四端法土壤电导率原位快速检测传感器设计与试验

实现土壤电导率的快速获取可为农业生产精准管理提供有效的数据支撑。目前,田间电导率采集在农业生产前进行,需要专门的电导率检测设备对种植田块开展大范围数据采集并生成电导率空间分布图,该方式操作繁琐、费时费力,同时检测的电导率值由于时间滞后原因,难以准确反映农业生产各环节(如播种)实施过程中的真实电导率情况。针对上述问题,基于交流"电流-电压"四端法原理,该研究设计了一种土壤电导率原位快速检测传感器,用于搭载在不同的农业生产机具上,实现土壤电导率的实时检测与作业参数的在线调整。该传感器以STM32处理器为核心,配合电源电路、交流信号源电路、有效值检测电路及其他外围电路搭建了硬件及软件架构,同时集成了信息的实时检测与显示、定时存储与无线传输等功能,实现了土壤电导率的原位高精度获取。传感器标定试验及工作稳定性试验结果表明,传感器输出值与DDB-303A电导率仪测得的电导率值呈明显线性关系,线性拟合R2为0.995,且在不同电导率水平下,连续测量的标准偏差均小于0.76μS/cm,具有较高的准确性及工作稳定性。与JXBS-3001传感器在实验室条件下(温度25℃),对配置的不同电导率浓度土样(含水率15%)检测的对比试验结果表明,所设计的电导率传感器的测量误差及响应时间更低,绝对误差为-5.9～19.4μS/cm,相对误差为-1.05%～2.39%,响应时间小于2.01s。利用电导率传感器在现场(温度20.6℃)对地块不同位置测量的绝对误差为-11.36～25.30μS/cm,相对误差为-7.91%～7.88%。综合而言,该研究所设计的土壤电导率传感器能快速准确的检测土壤电导率信息,可为无人农场的土壤信息采集提供一种高精度的检测工具。     

下限温度对北京樱花盛花始期模拟效果的影响

利用实际物候观测资料,通过人为设定不同生长发育下限温度值,比较不同指标对应发育阶段所需积温的稳定性和物候模拟准确率,是鉴定植物生长发育下限温度指标的常用统计方法。利用1998-2014年北京市海淀区玉渊潭公园樱花盛花始期观测资料,在设定下限温度0.0～5.0℃范围内,以0.1℃为步长,分别统计历年1月1日-樱花盛花始期的阶段活动积温和有效积温,对比分析不同温度指标对两种模型阶段积温稳定性和发育期模拟准确率的影响。结果表明：（1）阶段积温随设定下限温度指标而变化,且阶段活动积温值及其年际变化值均大于有效积温;（2）两种积温的标准差以活动积温的标准差较大,表明采用有效积温测算樱花盛花始期的误差小于活动积温测算结果;阶段有效积温在设定下限温度0.0～2.9℃范围内变异系数较小,3.0℃及其以上时活动积温的变异系数小于有效积温,活动积温离散程度更小;（3）不同设定下限温度值的始花期预测结果,均以2～3℃的准确率较高。对应设定下限温度0.0～3.2℃范围,有效积温模拟始花期基本准确率（误差小于3d）和准确率（误差2d以内）均大于活动积温模拟结果,但设定下限温度＞3.8℃时结果相反。设定下限温度处于3.3～3.8℃时,有效积温模拟误差的基本准确率大于活动积温,误差小于2d准确率则低于活动积温。综上所述,无论活动积温还是有效积温,均以设定下限温度2.0～3.5℃的计算结果标准差和变异系数最小,准确率较高,在未进行生理测定的条件下,可将其作为樱花盛花始期的下限温度指标。     

植物柔性传感器研究进展与展望

智慧农业的快速发展对农业传感器的精确性和生物安全性提出了更高的要求。不同于传统的刚性传感器,近年来新兴的植物柔性传感器因具有出色的力学特性和良好的生物相容性,在农业领域引起了广泛关注。该综述首先概述了制备植物柔性传感器所需的材料及制备工艺,重点阐述了植物柔性传感器在作物生长中的监测应用,如对植物电信号、挥发性化学物质、水分含量、生长速率的监测,以及对植物表面温度、湿度、照度等小气候的监测。同时介绍了柔性电子自供电的发展现状。最后,对植物柔性电子在智慧农业领域中的应用进行了总结和展望,以期为基于植物柔性传感器及相应传感网络的智慧农业管理系统提供参考。     

基于GNSS姿态与电机编码器的农机转向角度测量系统研制

典型的农业机械自动驾驶系统需要在车辆转向轮上安装角度传感器测量转向角度,存在安装不便与可靠性差问题。该研究提出一种基于GNSS模块和电机编码器组合的转向轮转向角度测量系统。该系统通过组合利用GNSS姿态测量值与运动模型得到转向轮期望角度,利用电机转向速度和全液压转向阀的传递模型推算转向角度变化值,经卡尔曼滤波融合解算得到车辆转向轮的实时转向角度。与霍尔式绝对角度传感器对比的动态测试结果表明,该系统在直线行驶时的测量标准方差小于0.91°,在转向轮-10°～+10°区间,测量标准方差小于1.0°;直线自动驾驶作业时的导航误差小于2.5 cm,曲线作业自动驾驶的导航误差小于9.0 cm,满足农机自动调头等场景应用。     

基于同心轴圆筒式电容传感器的花生仁水分无损检测技术

为了实现花生仁含水率的快速准确检测,设计了以MSP430单片机为控制芯片的花生仁含水率检测仪,利用圆筒式电容传感器、温度传感器和称质量传感器分别检测花生仁的电容、温度和容积密度,通过信号检测调理电路进行测量信号电容到频率的转换,单片机进行数据处理后计算出花生仁含水率,在液晶屏上显示检测结果,并将检测数据存储到内存卡中。进一步研究了含水率、温度和容积密度对频率的影响规律,建立了描述含水率与差频、温度的数学模型,并验证了基于电容法检测花生含水率的可行性和模型的可靠性。试验表明,在含水率6.4%~18.2%、温度10~40℃范围内,该检测仪的测量相对误差绝对值小于0.5%。该研究为快速无损检测花生仁含水率提供了参考。     

改进AOA模式的大田农机无人驾驶导航参数检测系统设计

卫星导航、视觉导航和雷达导航的成本昂贵、系统构成复杂和适用作业场景有限,在生产特征呈现区域化、适度小规模和分布零散的国内南方水田难以实现便捷跨区域作业和无法适用多农业场景。针对上述问题,该研究以大田环境下无人驾驶农机的牛耕式往复作业路径模式为背景,提出了改进AOA(信号到达角度,Angle-of-Arrival)模式的农业机械无人驾驶导航参数检测系统。该系统采用UWB(超宽带通信,Ultra Wide Band)基站-标签作为检测传感器,设计了TBZ(田边双基站-车身纵向双标签)和TBH(田边双基站-车身横向双标签)2种传感器布置方式,实现农业机械无人驾驶过程中导航参数的快速精准检测。静态试验结果表明:对于2种传感器布置方式,在固定的基站间距和标签间距下,随着标签间距或基站间距的增大导航参数检测精度均有所提高,横向偏差检测误差≤8 cm,航向偏差趋近于0,但不大于1°,并通过正交组合试验方差分析明确了2种传感器布置方式的关键参数对横向偏差和航向偏差检测精度影响的显著性,确定了主次因素和较优参数组合。动态试验结果表明:随着车速增大,横向偏差和航向偏差的检测精度有所降低,横向偏差误差均不超过10 cm,航向偏差的检测误差均小于3°,变异系数均小于10%,说明动态环境下自主导航参数检测系统仍具有较高的检测精度,可满足农机大田自主导航作业需求。研究结果可为研制低成本、高精度和便捷的无人驾驶系统提供参考。     

GU-PCM2型控温式相变蓄冷冷藏车设计与空载性能试验

现有蓄冷冷藏车蓄冷装置多位于车厢顶部,存在重心偏高、不可控温等问题,基于此,该文设计了一款集相变蓄冷单元、车载制冷系统、隔热车厢、送风系统等于一体的GU-PCM2型蓄冷冷藏车。该蓄冷车将蓄冷装置独立设置于车厢前端并保温,系统利用夜间低谷电进行充冷,可在-25～10℃之间根据需要调控车厢温度。对蓄冷冷藏车厢设定温度为0和-18℃的2种工况进行空载温度场仿真与测试。结果表明,车厢内各测温点的模拟温度与实测温度均方根误差分别为0.7和0.8℃,最大绝对误差分别为1.1和1.2℃。冷藏车可有效控温10 h以上,车厢平均温度分别在1.1～2.9℃和-14.8～-16.9℃之间,波动范围为1.8和2.1℃,温度不均匀度系数在1.0以内。控温式蓄冷冷藏车与传统蓄冷车的对比试验结果表明,其平均温度波动值降低48.7%,温度绝对不均匀度系数降低50%以上,车厢质心较顶置式蓄冷车下降25.9%。研究结果可为蓄冷冷藏车的进一步优化设计与应用提供参考。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【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。     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

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.     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

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.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

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.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

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,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

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,     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

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,     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

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.