基于现代信息技术的蔬菜安全预警与追溯平台建设

【目的】借助现代信息技术,实现蔬菜从生产到销售整个环节质量安全的预警与追溯。【方法】以蔬菜为研究对象,以国家蔬菜生产基地--寿光市为示范区,围绕寿光市蔬菜质量安全监管和溯源管理的信息化需求,采用WebGIS、物联网、条码识别、数据库等多种现代信息技术,研究蔬菜物流数据的采集和存储形式,并探索蔬菜质量安全预警与追溯平台的建设。【结果】结合物联网数据采集技术,采用SQLServer2008作为前台建立了一套属性数据库,包括产地蔬菜数据、蔬菜加工环节数据、蔬菜运输环节数据、蔬菜销售环节数据等。利用GIS功能制作了一套蔬菜质量安全相关空间数据,包括山东省道路图、寿光市采样点图、寿光市土壤养分图等。在此基础上,建立了一套切实有效的蔬菜质量安全预警与追溯平台。平台设计结合各种信息技术及寿光市蔬菜安全生产业务的需要,同时充分考虑数据的保密性和用户的需求,将平台划分为四大模块：数据查询、蔬菜质量安全预警、蔬菜质量安全追溯、辅助工具。实现的功能主要包括：蔬菜信息录入编辑,蔬菜产品信息及运送信息查询、地理坐标查询,实时预警,蔬菜质量安全追溯,蔬菜空间立体信息展示,蔬菜物流运输路径优化,蔬菜产地土壤养分统计,蔬菜产地土壤养分插值,网络视频监控等。其中实时预警功能利用物联网实时获取数据的特点,将采集的坐标、温度、湿度、时间等信息传送到平台服务器,该平台对蔬菜的温度、湿度、保质期等进行实时监测、预警,确保蔬菜的质量安全;蔬菜质量安全追溯功能根据蔬菜条形码和记载的物流坐标,在地图上对物流配送路径进行追溯;路径分析功能可以根据蔬菜运输的出发地和目的地进行路径的最优设计;蔬菜空间立体信息展示功能可以实现从土壤到地面再到大气的整个垂直面的立体化展示,是空间、时间不同节点信息数据的立体化集成。【结论】本研究充分利用GIS技术更形象地展示了蔬菜从开始种植到最后销售所有环节的信息,对蔬菜质量安全管理的提升有很大的帮助,一定程度上对政府相关部门监管蔬菜安全起到了很好的辅助决策功能。     

Spatial and interspecific variability in phenological responses to warming temperatures

A comprehensive understanding of species phenological responses to global warming will require observations that are both long-term and spatially extensive. Here we present an analysis of the spring phenological response to climate variation of twelve taxa: six plants, three birds, a frog, and two insects. Phenology was monitored using standardized protocols at 176 meteorological stations in Japan and South Korea from 1953 to 2005, and in some cases even longer. We developed a hierarchical Bayesian model to examine the complex interactions of temperature, site effects, and latitude on phenology. Results show species-specific variation in the magnitude and even in the direction of their responses to increasing temperature, which also differ from site-to-site. At most sites the differences in phenology among species are forecast to become greater with warmer temperatures. Our results challenge the assertion that trends in one geographic region can be extrapolated to others, and emphasize the idiosyncratic nature of the species response to global warming. Field studies are needed to determine how these patterns of variation in species response to climate change affect species interactions and the ability to persist in a changing climate.     

BP神经网络在旅游安全预警信息系统中的应用研究

利用BP神经网络对旅游安全预警信息系统的应用进行了研究,并通过BP神经网络模型的构建和仿真试验结果证明了该模型的适用性和可行性。     

近60年贵州省清镇市耕地变化研究

采用地方统计资料分析黔中清镇市1949~2006年耕地的数量变化、1992~2002年耕地变化的空间差异和耕地坡度分布变化,计算最小人均耕地面积和压力指数,建立初步的粮食安全预警机制。研究表明,1949~2006年清镇市耕地变化的总体趋势是不断减少;1992~2002年相对变化率由靠近市区和贵阳的东南部向西北部递减;耕地分布的坡度有向2°~15°集中的趋势;1973年之后,耕地压力指数保持在大于1的水平,处于粮食安全警戒状态;4种情景模拟的结果表明,未来清镇市耕地压力也难以得到缓解。     

次生盐渍化对膜下滴灌棉花生长发育的影响及其预警研究

以7块次生盐渍化程度不同的膜下滴灌棉田为研究对象,探明次生盐渍化对新疆棉花生长发育的影响,并以此为基础探讨其状态预警问题.研究结果表明:在各生育期,土壤盐度和棉花株高、干物质重、叶面积指数均呈极显著的负相关关系.生育期不同,影响棉花生长的关键盐度也有所差别.各棉田的警度随着生育期的进行有逐渐减轻的趋势.0.6 dS/m以下的土壤盐度在各生育期都不会对棉花生长造成较大危害,2.8 dS/m以上的土壤盐度在前期更易对棉花生长造成严重影响,到吐絮期2.8 dS/m左右的盐度已不能对棉田造成较大危害.     

Effect of vegetation on soil water retention and storage in a semi-arid alpine forest catchment

The runoff generated from mountainous regions is recognized as the main water source for inland river basins in arid environments. Thus, the mechanisms by which catchments retain water in soils are to be understood. The water storage capacity of soil depends on its depth and capacity to retain water under gravitational drainage and evapotranspiration. The latter can be studied through soil water retention curve (SWRC), which is closely related to soil properties such as texture, bulk density, porosity, soil organic carbon content, and so on. The present study represented SWRCs using HYDRUS-1D. In the present study, we measured physical and hydraulic properties of soil samples collected from Sabina przewalskii forest (south-facing slope with highest solar radiation), shrubs (west-facing slope with medium radiation), and Picea crassifolia forest (north-facing slope with lowest radiation), and analyzed the differences in soil water storage capacity of these soil samples. Soil water content of those three vegetation covers were also measured to validate the soil water storage capacity and to analyze the relationship between soil organic matter content and soil water content. Statistical analysis showed that different vegetation covers could lead to different soil bulk densities and differences in soil water retention on the three slope aspects. Sand content, porosity, and organic carbon content of the P. crassifolia forest were relatively greater compared with those of the S. przewalskii forest and shrubs. However, silt content and soil bulk density were relatively smaller than those in the S. przewalskii forest and shrubs. In addition, there was a significant linear positive relationship between averaged soil water content and soil organic matter content (P<0.0001). However, this relationship is not significant in the P. crassifolia forest. As depicted in the SWRCs, the water storage capacity of the soil was 39.14% and 37.38% higher in the P. crassifolia forest than in the S. przewalskii forest and shrubs, respectively, at a similar soil depth.     

一次致害雷暴电荷轨迹分布特征研究

雷暴是一种能引起严重灾害的自然现象。2007年7月9日,秦皇岛市发生多起雷击事故,局部地点还出现了冰雹。利用＂GDS-2型高精度闪电探测仪＂监测到的雷暴天气和此次雷暴灾害天气过程资料,对出现雷暴、强雷暴灾害的电荷结构、闪电出现频率、闪电放电轨迹分布特征进行了分析。结果表明,7月9日雷暴、冰雹发生时,地面电场电荷以正电荷为主,地面电场闪电放电轨迹具有离散性、集中性和线性特征。揭示了闪电频次〉10次/min出现雷暴灾害、冰雹可能性大;闪电发生的集中地点极有可能出现雷暴、冰雹天气,应当及时预警预报,并建议采取有效措施对该地区进行防护。     

我国农业上市公司亏损的财务预警分析——以香梨股份有限公司为例

运用香梨股份有限公司的财务信息,从一般财务分析的角度对它进行研究,通过对财务预警系统在农业上市公司的运用进行分析,说明财务预警对我国农业上市公司的有效程度,以便为我国农业上市公司财务预警提供借鉴与参考。     

基于指标阈值法的森林火险气象等级预报研究

利用河北省承德市近7年的温、湿、风、降水和199次森林火灾火警资料,分析各气象要素与森林火灾火警的相关性;通过对预报因子的预处理,利用指标阈值法建立了适合承德市地理气候条件的森林火险等级预报方程与落区预报方程;结合气象数值预报产品建立预报预警平台,从而实现了森林火险等级实况、预报、落区的全自动运行,提高了森林火险等级预报的精度。     

Improving preventive locust management: insights from a multi‐agent model

BACKGROUND

Preventive management of locust plagues works in some cases but still fails frequently. The role of funding institution awareness was suggested as a potential facilitating factor for cyclic locust plagues. We designed a multi‐agent system to represent the events of locust plague development and a management system with three levels: funding institution, national control unit and field teams. A sensitivity analysis identified the limits and improvements of the management system.

RESULTS

The model generated cyclic locust plagues through a decrease in funding institution awareness. The funding institution could improve its impact by increasing its support by just a few percent. The control unit should avoid hiring too many field teams when plagues bring in money, in order to ensure that surveys can be maintained in times of recession. The more information the teams can acquire about the natural system, the more efficient they will be.

CONCLUSION

We argue that anti‐locust management should be considered as a complex adaptive system. This not only would allow managers to prove to funders the random aspect of their needs, but would also enable funders and decision‐makers to understand and integrate their own decisions into the locust dynamics that still regularly affect human populations. © 2017 Society of Chemical Industry