温度及低温贮存天数对丽蚜小蜂成虫羽化率的影响

[目的]探究温度及低温贮存天数对丽蚜小蜂(Encarsia formosa Gahan)成虫羽化率的影响,为贮存和指导田间适期释放丽蚜小蜂提供理论依据。[方法]研究不同温度[(10.0±0.5)、(15.0±0.5)、(25.0±0.5)、(30.0±0.5)℃]对被丽蚜小蜂寄生的烟粉虱(Bemisiatabaci Gennadius)褐蛹成虫羽化率的影响;测定丽蚜小蜂褐蛹在(10.0±0.5)℃下低温贮存10、15、20、25、30 d后分别放入(25.0±0.5)、(30.0±0.5)℃恒温培养箱后的成虫羽化率。[结果]在设定的温度范围内,随着温度的升高,羽化率和羽化速率相应提高,在(10.0±0.5)℃下10 d羽化率仅为15.3%,而在(30.0±0.5)℃下7 d羽化率即达92.5%;低温贮存20 d后,在(25.0±0.5)℃和(30.0±0.5)℃下羽化率可分别达92.9%(11 d)和90.9%(7 d),而贮存25 d后羽化率只有31.2%和41.8%(11 d)。[结论]温室温度应在20℃以上时放蜂,且放蜂时应增加10%放蜂量;丽蚜小蜂褐蛹低温贮存时间最长为20 d。     

有机肥中氨基酸废料添加量的安全阈值研究

氨基酸废料因其价格低廉、富含氨基酸与养分资源等特征,是有机肥的优质添加剂,评估氨基酸废料添加量的安全阈值是研制生物有机肥的重要依据。将氨基酸废料溶解于水,从0到15%共设置7个添加量,喷至有机肥成品,分析不同添加量下有机肥酸碱度、电导率、氯离子含量和种子发芽指数的变化特征。研究结果表明,氨基酸废料添加量在3%范围内,pH呈现较为平稳的趋势,当添加量进一步增加,pH则逐渐降低。电导率随着氨基酸废料添加量的升高呈现同步增加的趋势,有机肥中盐分含量逐渐增加,Cl ^-含量同样是稳步上升,当添加量在10%范围内,Cl ^-含量均低于3%。当氨基酸废料添加量≤1%时,种子发芽指数可达到75%以上,但添加量增至3%时,种子发芽指数骤降,出现明显的毒害现象。因此,氨基酸废料添加量需控制在3%以内,本研究推荐1%为研制生物有机肥的安全阈值。     

Determination of visual detection thresholds of selected iron fortificants and formulation of iron-fortified pocket-type flat bread

Wheaten pocket-type flat breads were baked from refined flours fortified to contain iron from ferrous sulphate (FeSO₄), hydrogen-reduced elemental iron (Fe) or sodium iron ethylenediaminetetraacetic acid (NaFeEDTA). Individual and group visual detection thresholds were determined by the 3-alternative forced choice (3-AFC) test according to the American Society of Testing and Materials (ASTM) method E-1432. The group visual detection thresholds of FeSO₄, NaFeEDTA and Fe in bread were established in samples baked from the corresponding wheat flours fortified with 69.46, 236.82 and 304.97 mg iron/kg flour, respectively. Sensory testing showed that iron-fortified pocket-type flat breads were similar (P < 0.01) to regular bread when baked from flours formulated to contain iron at levels lower by 25% than the group visual detection thresholds of Fe and FeSO₄ and two 25% increments lower than the threshold of NaFeEDTA. These findings indicate that iron-fortified pocket-type flat breads, which are sensorially similar to regular bread, baked from flours that contained 52.1, 133.22 and 228.73 mg iron/kg flour as FeSO₄, NaFeEDTA and Fe, would provide the segment of the population at the highest risk of iron-deficiency anaemia, specifically women of childbearing age, with 91%, 207% and 346% of their recommended daily intakes for iron, respectively.     

上海地区桔小实蝇生物学特性初步研究

上海地区桔小实蝇以蛹越冬,成虫发生高峰期为9～10月份。研究表明：桔小实蝇幼虫、蛹的发育起点温度和有效积温分别为11．30&#177;2．83℃、11．96&#177;0．84℃和102．38&#177;21．26日度、153．57&#177;9．75日度。9月中旬～翌年1月,室温下成虫饲养结果表明,成虫产卵较少或几乎不产卵。     

基于Landsat8影像的不同水质类型的水体提取

以2015年Landsat8多光谱遥感影像作为基本信息源,在各地物光谱特征差异分析的基础上,采用谱间关系法与阈值法,构建不同水质水体提取模型,并结合实地水质监测数据及污染源数据,对提取结果进行精度评价与分析。结果表明,基于该方法能将一般水体、富营养化水体与其他地物区别开来,可以准确有效地获取不同水质的水体信息。     

Bird responses to broad-leaved forest patch area in a plantation landscape across seasons

Although plantation forests have widely replaced native forests worldwide, few studies have examined the effects of plantation forestry on organisms at the landscape level. In this study, we examined the effects of broad-leaved forest patch area (1.4–312 ha) on bird assemblages in a conifer plantation-dominated landscape during wintering and breeding seasons. We also surveyed birds in the plantation matrix and treated the patch area of the matrix as 0. We examined whether the detection rates of species changed suddenly across patch area (threshold) using segmented regression. We found that species richness increased with patch area in both seasons. Responses of detection rates to patch area varied and were categorized as follows: insensitive, linear increase and decrease, quadratic increase and decrease, concave and convex. Thresholds indicating that the detection rate suddenly increased above a certain patch area were found for two species only in the winter. Species responses varied more in the winter than in the breeding season. Certain ecological traits of species were consistently associated with the responses to patch area across seasons (migratory strategy, nesting substrate and foraging trait), while body weight was only associated in the winter. Because species richness and detection rates of many species were high in large patches, large broad-leaved forests (especially >40 ha) should be retained and restored with high priority. Additionally, bird responses to patch area in the winter should not be ignored because many species required large patches during the winter season.     

青岛市城阳区强降水极端气候阈值研究

根据青岛市城阳区2008—2015年汛期(6—9月)日降水量资料,采用简单插值法、经验插值法、Z指数变换法、平方根变换法和立方根变换法等5种计算阈值的方法,比较分析得到适用于城阳区的阈值确定方法,并计算分析了精细化的城阳区极端降水阈值。结果表明,5种方法中,Z指数变换法更适于城阳区实际情况;城阳区极端降水阈值的分布大致呈南部阈值偏大、中部阈值偏小、北部的棘洪滩阈值也偏大。     

粗糙元覆盖对土壤风蚀的控制作用

应用湍流边界层中粗糙壁面的阻力分解规律研究土壤风蚀中的临界侵蚀风速、输沙率和风蚀率,建立了一个揭示地表粗糙元对土壤风蚀控制作用的理论模型。该模型给出了临界侵蚀风速与盖度之间的指数关系,临界侵蚀风速与农田茬高之间的指数关系,以及反映输沙率(或风蚀率)与盖度(或茬高)、风速之间依赖关系的理论公式。然后应用天然地表风蚀和农田风蚀的多家实验数据,对这些理论公式进行了广泛地检验和评价,发现具有很好的普适性。     

不同类型农田地表粉尘起动摩阻风速的野外观测

[目的]为北方城市空气污染控制提供依据。[方法]选择不同地表类型,观测起尘差异,分析表土微团粒粒度,计算起动摩阻风速。[结果]沙化农田的光滑地表空气动力学粗糙度（Z0s）为0．0012cm,小麦地为0．0021cm,果树苗地的为0．0025cm。有植被覆盖的地表粉尘起动摩阻风速明显高于裸露地表,且随着植被高度增加而增大。延安果树苗地地表起动摩阻风速达到了139：15cm／s。裸露小麦地和果树苗地地表粉尘起动摩阻风速大于裸露沙化农田（7．39cm／s）。小麦返青期、成熟期、收割后地表粉尘起动摩阻风速分别为46．85、98．93、29．05cm／s,裸露地表和幼苗期果树苗地地表粉尘起动摩阻风速分别为26．01和139．15cm／s。[结论]植被高度和土壤结构性质是影响地表粉尘起动摩阻风速的重要因素。     

MICROCOMPUTER PROCESSING THE PHOTOGRAPH OF TIMBER WITH HOLE KNOTS

THRESHoLDWhenthetimberswiththeho1eknotsarepassedthesystemofX-raynon-de-structiveinvestigation,thesimulatednu-meralsfigureoftheholeknotsappearinthemonitor.Thesimulatednumeralsfigureisshownintablel.Meanwhilethehistogramofthisfigurearedoublepeakcertainly.Inordertoidentifytheedgeoftheholeknotswithnakedeyeandcarryoutautomatictreatment,Wetakethebinaryva1uetreatmentforthefigure'Thechoos-ingthresholdisaveryimportantpartinthebinaryvaluetreatment.Howtochooseasuitablethreshold?Weshouldpaymuchattenti…