地貌发育阶段判识方法研究——以泥河沟流域和枣子沟流域为例

为更加准确判识小流域地貌发育阶段，以黄土高原综合治理小流域——陕西省淳化县泥河沟流域和乾县枣子沟流域为例，分别应用盒分维方法和Horton分维方法进行水系分维值的计算，并利用面积高程积分和地貌信息熵进行验证。结果表明，泥河沟和枣子沟流域水系盒分维值分别为1.886和1.827。根据Strahler曲线积分值和地貌信息熵方法验证结果表明，盒分维方法计算的水系分维值对流域地貌发育阶段的判识更加准确、可靠；这2个流域地貌处于侵蚀发育阶段的壮龄期，其生态敏感性整体上处于较低水平，生态环境抗干扰能力增强并趋于更加稳定的状态。     

基于主成分分析和Copula函数的灌溉水利用系数影响因素研究

以新疆生产建设兵团第十二师中型灌区为研究对象，采用首尾法测算2018年和2019年4个样点灌区的灌溉水利用系数，在采用主成分分析法对指标体系降维处理的基础上，用Copula函数构建PCA-Copula评价分析方法，对灌溉水利用系数各影响因素的影响程度和影响规律进行计算分析。结果表明：两年测算数据表明，4个样点灌区灌溉水利用系数都在0.63以上，且最大值达到0.668，分别高于同期全疆、全国平均水平5.05%、10.15%；主成分分析得出，渠道衬砌率（0.944）、滴灌灌溉面积比（0.746）、作物需水量（0.635）、实际灌溉面积（0.734）等都具有超过60%的正贡献率，而葡萄种植比（-0.586）和灌区毛灌溉用水量（-0.645）等具有超过58%的负贡献率。利用PCA-Copula分析评估方法得出，作物种植比例和节水灌溉工程状况对十二师中型灌区灌溉水有效利用系数影响显著（P<0.05），其中葡萄净灌溉定额和灌区毛灌溉用水量对灌溉水有效利用系数的影响极其显著（P<0.01），相关系数分别为0.875、0.742，同时利用Spearman等级相关系数检验法和线型回归来检验PCA-Copula评价法与熵值法的密切程度，检验结果其相关系数分别为 0.87（P＜0.05）和0. 52（P＜0.001），表明PCA-Copula评价方法适用于研究灌溉水利用系数影响因素。     

基于YOLO v3与图结构模型的群养猪只头尾辨别方法

在利用视频监控技术对群养猪只进行自动行为监测时,对猪只准确定位并辨别其头尾位置对提高监测水平至关重要,基于此提出一种基于YOLO v3(You only look once v3)模型与图结构模型(Pictorial structure models)的猪只头尾辨别方法。首先,利用基于深度卷积神经网络的YOLO v3目标检测模型,训练猪只整体及其头部和尾部3类目标的检测器,从而在输入图像中获得猪只整体及头尾部所有的检测结果;然后,引入图结构模型,描述猪只的头尾结构特征,对每个猪只整体检测矩形框内的头尾部位组合计算匹配得分,选择最优的部位组合方式;对部分部位漏检的情况,采取阈值分割与前景椭圆拟合的方法,根据椭圆长轴推理出缺失部位。在实际猪场环境下,通过俯拍获得猪舍监控视频,建立了图像数据集,并进行了检测实验。实验结果表明,与直接利用YOLO v3模型相比,本文方法对头尾定位的精确率和召回率均有一定提高。本文方法对猪只头尾辨别精确率达到96.22%,与其他方法相比具有明显优势。     

宁南山区经济林降雨集流机理试验研究

[目的]探究宁夏回族自治区固原市原州区彭堡镇红梅杏经济林降雨集流渗灌系统的雨水收集能力,明确当地红梅杏经济林降雨分配特征,为降雨集流的定量研究和该地区集雨农业的发展提供科学依据。[方法]以当地红梅杏为研究对象,采用对比观测的方法,以天然降雨和人工模拟降雨相结合的方式,对红梅杏降雨集流过程进行观测与模拟。[结果] 2019年7—9月在彭堡红梅杏基地观测到的总计19场降雨数据,天然降雨中5 mm以下的降雨次数占到天然降雨总次数的83.3%,天然降雨与人工模拟降雨的相似系数为0.91,总体的集流率为61.29%,渗灌系统截留率为27.12%,林冠截留率为11.95%。[结论]试验地小降雨频率大,两种降雨方式具有较高相似性,降雨集流渗灌系统集流效率高,渗灌系统的集流量与降雨量成线性关系(R~2=0.995 5),集流率与降雨量成对数关系(R~2=0.693 9)。     

两种油脂对小鼠皮肤创伤修复作用研究

本研究旨在观察阿勒泰大尾羊尾脂油脂对损伤皮肤是否具有修复作用，并与牛油脂、市售商品做比较。研究选择40 只体重在31 ± 1 g 之间的昆明小鼠，雌雄各半，通过构建小鼠皮肤损伤模型，将小鼠分为4 组（羊尾油组、牛油组、市售商品组和空白组）进行试验观察。小鼠皮肤伤口愈合良好，雌鼠的创面愈合能力强于雄鼠，雌鼠伤口愈合速度：羊尾油组＞牛油组＞市售商品组＞空白对照组。雄鼠伤口愈合速度：羊尾油组＞市售商品组＞牛油组＞空白对照组。皮肤组织病理学结果显示，涂抹羊尾脂、牛油脂、市售商品与空白对照处皮肤相比，创伤修复组织中脂肪细胞、胶原纤维以及其他细胞的数量、排列分布均有差异。羊尾油和牛油均有修复皮肤创伤的作用，且羊尾油修复作用更强，羊尾油可通过促进胶原纤维的生成加速皮肤修复。     

How to characterize ‘good’ and ‘greening’ in the EU Common Agricultural Policy (CAP): the case of clay soils in the Netherlands

The change in the Common Agricultural Policy (CAP) of the European Union from product to producer support, including requirements for ‘good agricultural and environmental conditions’ and ‘greening’, is excellent. However, these requirements are now defined in rather general terms. Questions can be raised about suitable indicators, and there is a recognized need for effective management recommendations to support farmers in achieving the required ‘good’ conditions. These recommendations are bound to be quite different for different soils in different countries. A study of Dutch clay soils was based on a storyline describing current problems and management options for improvement, which were quantified using a soil–water–crop simulation model. Indicators were defined for agricultural conditions and suggestions made for the use of the model in a predictive mode to help farmers improve their soil management. Environmental conditions were judged by current environmental guidelines for water and air. When modelling, implicit assumptions that soils are homogeneous were shown to be unrealistic for these clay soils, requiring development of innovative methods and procedures, presenting a challenge for soil research.     

青土湖水面形成区土壤颗粒组成与化学特性变化

青土湖输水作为石羊河流域治理的一项关键措施,对保护湖区水资源和生态环境具有重要意义。在距青土湖水面边缘东南方向0-450 m的10个样点中分3层取0-60 cm土样,测定土壤粒径的质量百分比与全氮、全磷、全钾和电导率,分析青土湖水面形成后土壤颗粒组成与化学特性变化。结果表明,随着离水面边缘距离的增加,土壤颗粒与化学特性呈有规律的增减变化,土壤粘粉粒组成与其全磷、全钾之间存在正线性相关。青土湖水面形成加剧了距水面边缘0-150 m处的土壤理化性质变化;土壤细粒及养分出现富集,分别在距水面边缘100-150 m和300 m处达到最大值。因此,土壤养分与土壤细物质的良好相关性表明,土壤粘粉粒变化可作为反映该区域土壤性状变化和评价衡量水面形成后土壤恢复程度的定量指标之一。     

Effect of water temperature on the feeding activity and the resultant mercury levels in the muscle of cultured bluefin tuna Thunnus orientalis (Temminck and Schlegel)

Tuna muscle often contains high levels of mercury, and fish samples with mercury concentrations ten times higher than the specified safety standards have been reported. Here, we report on the relationship between water temperature and the concentration of mercury in the tail muscle tissue of cultured bluefin tuna Thunnus orientalis. The fish used in this study were cultured at Fisheries Laboratory of Kinki University (Amami Experimental Station, Kagoshima, Japan). One hundred fish weighing 26.2–89.4 kg were selected for analysis between February 2007 and January 2008. Water temperature during rearing ranged from 21 to 29 °C. The total mercury levels were measured using the reduction vaporizing atomic absorption method after acid digestion. Body weight increased approximately 1.5 times that observed in a previous study, despite feeding activity either being the same or less than that observed previously. The average mercury concentration in white muscle was 0.353 mg kg^?1, remaining almost constant and independent of body growth. Unlike previous studies, seasonality was not observed in this study. Based on these findings, water temperatures within a certain range were considered to stabilize feeding activity and increase feeding efficiency. Consequently, water temperature is considered to have a moderating effect on seasonal fluctuations in muscle mercury concentrations in cultured bluefin tuna.     

几种杀菌剂对猕猴桃主要真菌性叶斑病菌的室内毒力测定

猕猴桃假尾孢Psedocercospora actinidiae Deighton和叶点霉菌Phyllosticta sp．是引起猕猴桃生长期的两种主要真菌病害。为了能筛选到对猕猴桃假尾孢和叶点霉菌具有高效抑制作用的杀菌剂，本文采用茵丝生长速率法测定了几种杀菌剂的毒力，结果表明，除腈菌唑外其余几种杀菌剂均可作为猕猴桃主要叶斑病的田间药效试验的首选药剂。     

TOPMODEL在水阳江流域的应用及模型对DEM昀敏感性检验

将TOPMODEL模型应用到安徽水阳江流域，检验其在湿润地区的径流模拟能力，得到了较好的模拟结果。同时，利用安徽水阳江流域不同分辨率的DEM数据，进行了DEM分辨率对TOPMODEL模型的模拟结果的敏感性实验分析，结果袁明，随着流域DEM数据分辨率的降低，模型的确定性系数也随之降低，模型对流域的DEM数据是敏感的。