湖南洋泉水库调度的最优气候决策方法探讨

充分利用气候资源作好水库水位（量）调度、提高水库在抗旱和发电中的经济效益,是当今水库调度决策亟待解决的一个重要课题.本文根据气象经济学原理,运用连续函数求极值方法,利用洋泉水库有关经济参数,建立水库气候最优调度决策,在水库的实际调度中应用,可取得明显的社会经济效益.     

水头可调薄壁堰式渠道流量智能测控系统优化试验研究

采用巴赞堰流公式计算流量的水头可调薄壁堰式渠道流量智能测控系统通过渠道流量量测与控制试验,验证了其精准的测流功能和智能控制技术的可行性。为进一步提高该测控系统运行的效率和稳定性,减少运行能耗,对矩形薄壁堰堰流公式进行水力试验研究,通过分析堰上水头和流量关系,拟合出矩形薄壁堰流量计算公式。通过向该拟合公式引入修正系数λ=0.848,将测控系统测得的堰上水头数据值代入该拟合公式求得的流量值与电磁流量计测得流量值的差值的平均值为-0.004L/s,标准差为0.119,线性相关系数R2=0.989 1。该拟合公式相对于巴赞堰流公式形式简单、参数较少、运算简便,同时也满足节水灌溉对精准测流的要求,更适用于水头可调薄壁堰式渠道流量智能测控系统,对于在灌区推广和使用该测控系统具有重要的意义。     

迷迭香的药效及在兽医临床的应用

迷迭香为唇形科植物,喜温,原产地中海沿岸,广泛用于医药、油炸食品及各类油脂的保鲜。研究表明,迷迭香具有抗炎、抗氧化、抗菌、抗癌、护肝等药效作用,在兽医临床可能有广泛的应用前景。通过查阅国内外有关文献资料,综述了迷迭香药效和兽医临床应用的进展,为迷迭香的进一步研究提供参考。     

微肥Zn和Mn在苜蓿生产中的应用试验

针对河南省气候土壤特点,Zn、Mn肥的生理功能以及牧草生产利用中存在的问题,对Zn、Mn微肥在优质牧草紫花苜蓿Medicago sativa生产中的配施技术进行了研究.结果表明:Zn肥对紫花苜蓿的有效范围为400～500 mg/kg,最佳浓度为430 mg/kg.430 mg/kg的Zn肥与380 mg/kg的Mn 肥结合使用,效果更好,可使牧草产量提高10.7%,种子产量提高13.7%.     

两个地理种群蠋蝽的生物学特性差异比较

蠋蝽Arma chinensis Fallou是一种优良的捕食性天敌昆虫, 在多种农林害虫的生物防治中发挥着重要作用?为明确不同地理来源的蠋蝽种群的生物学特征, 指导蠋蝽的扩繁及在不同地区的释放应用, 本研究测定并比较了河北廊坊和贵州六盘水两个地区蠋蝽种群的表观形态?发育历期?成虫寿命和繁殖能力等生物学指标?结果表明, 贵州六盘水蠋蝽种群的体型显著大于河北廊坊种群; 河北廊坊蠋蝽种群的若虫期虽长于贵州六盘水种群, 但二者无显著差异; 河北廊坊种群配对饲养的雄虫和单雌饲养的雌虫其寿命显著长于贵州六盘水种群, 配对饲养的雌虫寿命两种群间无显著差异; 两个种群蠋蝽雌虫均在羽化后5~8 d进入产卵高峰期, 贵州六盘水种群的产卵前期较短, 且配对饲养条件下其单雌产卵量显著高于河北廊坊种群?     

氮肥深施对旱作覆膜农田土壤养分含量及春玉米产量的影响

以春玉米为供试作物,于2021—2022年在甘肃省定西市进行不同深度施肥田间试验,以双垄沟覆膜种植为基础,设置3个氮肥施用深度：5 cm(D5)、15 cm(D15)和25 cm(D25),以不施氮(N0)处理为对照,共4个处理,分析不同氮肥施用深度对农田土壤养分含量、干物质积累、水分利用及玉米产量的影响,为优化施肥模式和进一步提升其节水增产效能提供理论依据。结果表明,随施肥深度的增加,农田0～40 cm土层土壤养分含量逐渐增大,D25处理较D15和D5处理的土壤有机碳、全氮、速效磷和速效钾含量分别平均提高8.67%、2.23%、22.11%和15.18%;氮肥深施可提高生育后期养分供给能力,玉米干物质积累量显著提高,D25处理播后105 d～收获期干物质积累量分别较D15和D5提高6.53%和25.30%;2个试验年份农田耗水量和水分利用效率均随着施肥深度的增加逐渐增大,D25处理分别较D15和D5平均提高10.09%和10.08%;D25处理玉米生物产量和经济产量较D5处理分别平均提高27.20%和34.93%。在西北旱作区,氮肥25 cm深施模式能为玉米提供更好的养分供给,是提高...     

Assessment of microbial biocontrol agent (BCA) viability to mechanical and thermal stress by simulating spray application conditions

Background

In order to improve the biological control agent (BCA) efficacy, stress factors threatening the viability of microorganisms during spray application need to be determined. The effect of spray mixture temperature and exposure time on Trichoderma harzianum T 22 and Bacillus amyloliquefaciens QST713 viability were tested. Concurrently the combined effect of mechanical and thermal stress effect on BCA viability were tested at two initial spray mixture temperatures (14 and 25 °C) by simulating a spray application using airblast sprayers featured by different tank capacity and a spray liquid circuit (without and with hydraulic agitation system). To assess the BCA microorganism viability, spray mixture samples were collected at time intervals along trials and plated to count the colony forming units (CFU).

Results

The critical temperature threshold that inhibited BCA viability was 35 °C with 30 min of exposure. The sprayer type, the initial temperature of the spray mixture and the temperature increment during the trials significantly decreased the number of CFU recovered. When simulating a spray application, the spray mixture temperature increase rate was determined mainly by the residual amount of spray mixture in the tank. Even if the tank capacity does not substantially affect the final temperature reached by the spray mixture, the higher residual spray mixture in bigger tanks can expose the BCAs for a longer time to critical temperatures.

Conclusions

Experimental trials allowed us to identify the effect of factors affecting the viability of tested BCAs, providing information about the actual chance to guarantee the biological efficacy of BCA treatments. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Challenges and opportunities of unmanned aerial vehicles as a new tool for crop pest control

The application of pesticides is not simply delivering chemicals to the target area. It also involves considering the negative aspects and developing strategies to deal with them during the application process, to ensure the maximization of pesticides use efficiency and the maintenance of the ecosystem. Unmanned aerial vehicle (UAV) sprayers demonstrate unique advantages compared to traditional ground sprayers, particularly in terms of maneuverability and labor intensity reduction, showed great potential for chemical application in pest control. It is undeniable that there exist challenges in the practice of UAV spraying, such as higher potential risks of pesticide drift or pathogen transmission, uncertainty canopy deposition for different crops, and unexpected leaf breakage induced by downwash flow. Maximizing the utilization of downwash flow while avoiding lateral air movement outside the intended target crop area is a major issue for chemical application with UAV sprayers, particularly in light of the increasingly apparent consensus on the need for enhanced environmental protection during the chemical application process. It must be considered that the operation strategy in different scenarios and for different crop targets is not the same, unique requirements should be given on nozzle atomization, flight parameters, adjuvants and aircraft types in specific working situations. In future, the implementation of spray drift prediction, technical procedures development, and other solutions aimed at reducing pesticide drift and improving deposition quality, is expected to promote the adoption of UAV sprayers by more farmers. © 2023 Society of Chemical Industry.     

FLUENT软件及其在植保机械方面的应用

FLUENT软件是流体力学中通用性较强的商业软件之一，由于FLUENT软件的应用，节省了大量的人力和物力。对实际应用有重大的指导作用。为此，通过简述FLUENT在植保机械方面的应用实例，提出了FLUENT在植保机械方面的发展前景。