农田鼠类数量统计方法的研究

目前统计大仓鼠Cricetulus triton、黑线仓鼠C.barabensis和黑线姬鼠Apodemus agrarius等地面活动的农田鼠类广泛采用夹捕法和查洞法,夹捕法又要求连续布夹三夜。本文对用一夜、连续二夜和三夜夹捕的统计结果作了对比研究,结果表明,三种夹捕方法的统计结果一致,呈极显著正相关。作者认为只用一夜捕鼠减少了工作量和样方去除效应,可在农田鼠情常规测报中代替连续三夜捕鼠法。查洞法的统计结果不能反映农田鼠类数量的季节变化,不宜在鼠情测报中使用。     

Spatial regression approach to estimate synthetic unit hydrograph by geomorphic characteristics of watersheds in arid regions

Rainfall-runoff relationship in arid regions is unique and challenging to study. Studies for bridging the hydro-meteorological knowledge gap for planning, designing and managing water resources is therefore vitally important. The objective of this study is to develop a method for estimating unit hydrograph at reasonably finer time resolutions (10-min and 1-h) which can be easily adaptable by practitioners at sub-catchment levels, especially when the focus area is ungauged. Observed wadi-flow at 5-min interval and tipping bucket rainfall measurements at 1-min interval were obtained to cover 10 major watersheds in Oman. The deconvolution method was applied to derive the unit hydrographs (UHs) from wadi-flow and excess rainfall. Key catchment characteristics such as the watershed area, length of the main wadi and the length to the centroid of the catchment area were derived from digital elevation model (DEM) data. The whole study area was then divided into 515 sub-catchments with various shapes and sizes. A strong relationship was found between the wadi length and the length to the centroid of the catchment area (R²>0.89). This relationship was then adopted to simplify the classical Snyder method to determine UHs. Moreover, several parameters of the Snyder method were calibrated to the arid environment by matching the peak-flow, lag-time and three time-widths (75%, 50% and 30% of the peak-flow) of 10-min and 1-h UHs with physical characteristics of the watersheds. All developed relationships were validated with independent rainfall and wadi-flow events. Results indicate that the calibrated parameters in these arid watersheds are quite distinct from those suggested for other regions of the world. A marked difference was found between the 10-min UHs estimated by the S-hydrograph method and the deconvolution method. Therefore, it is concluded that a method depends on natural hydro-meteorological conditions would be more practical in arid region. The proposed methodology can be used for water resources management in arid regions having similar climate and geographical settings.     

Detection of beet yellows virus in sugarbeet plants by enzyme-linked immunosorbent assay (ELISA)

Beet yellows virus can be detected in leaf extracts of infected sugarbeet plants by ELISA. The use of discs was studied and proved to be a valuable and qualitatively reliable method. Leaf material could be stored at 4^o or 22°C for at least six days without affecting the detection of this virus by ELISA. A dramatic decrease in ELISA values was found when leaf extracts were frozen.In an analysis of the distribution of virus over the plant it was found that young leaves present at the moment of infection and those which had still to develop after infection will contain virus. Symptoms produced by systemic virus invasion occur on the oldest leaves containing virus.Samenvatting Het bietevergelingsvirus kan op betrouwbare wijze met de ELISA methode in geïnfecteerde bieteplanten worden aangetoond. Een aanzienlijke vereenvoudiging van de procedure kan worden bereikt met de zogenaamde disc-method, waarbij intacte ponsstukjes in de putjes van de ELISA-plaat worden geïncubeerd. Hierbij komt voldoende virus uit de ponsstukjes voor ELISA vrij. Bladmateriaal kon op verschillende wijzen bewaard worden zonder dat de mogelijkheid om het virus aan te tonen achteruitging. Met bladextracten die ingevroren waren, werden echter slechte resultaten verkregen.In een analyse naar de verdeling van het virus over het loof bleek het virus voor te komen in de geïnoculeerde bladeren, in die bladeren die op het tijdstip van inoculatie minder dan de helft van hun uiteindelijke lengte bereikt hadden en in de bladeren die nog moesten verschijnen. De symptomen ontwikkelden zich op de oudste systemisch geïnfecteerde bladeren.     

浅淡单点校正法和标准曲线法及其在农药分析中的应用

本文从单点校正法和标准曲线法的适用前提条件出发，运用数学方法，探讨了单点校正法代替标准曲线法的条件，并为在农药分析中选择单点校正法和标准曲线法提供依据，从而简化正常农药分析步骤，避免一些分析误差。     

10%溴虫氟苯双酰胺SC对草地贪夜蛾的控制效果

为探索新型杀虫剂溴虫氟苯双酰胺对草地贪夜蛾的防治效果,采用喷雾法和浸叶法在室内研究了10%溴虫氟苯双酰胺悬浮剂(SC)对草地贪夜蛾的杀虫性,并用喷雾法进行了田间控制效果研究。室内试验结果表明,10%溴虫氟苯双酰胺SC喷雾处理对草地贪夜蛾卵的孵化率无明显影响,但能显著提高初孵幼虫的死亡率(P<0.05),各处理校正死亡率均高于78.26%。同时,10%溴虫氟苯双酰胺SC对3龄和5龄幼虫均有较强的活性,处理72 h后的校正死亡率均高于90%,并且随着浓度的增加,死亡率升高。田间药效试验表明,不同浓度的10%溴虫氟苯双酰胺SC处理后1 d和7 d防效均可达96.33%以上,显著高于对照药剂5.7%甲维盐微乳剂(ME)和200 g/L氯虫苯甲酰胺SC;药后14 d各处理防效为41.71%～66.32%,其中10 mL/667m~2处理与对照药剂5.7%甲维盐ME防效相当。研究表明,10%溴虫氟苯双酰胺SC可以有效控制草地贪夜蛾,且速效性和持效性较好,建议每667 m~2使用制剂10～15 mL,防治适期为草地贪夜蛾卵孵化盛期及低龄幼虫期。     

药剂对小麦叶锈菌生物活性试验方法的研究

应用人工接菌方法,小麦叶锈菌能在含有６－苄基氨基嘌呤洋菜培养基中的感病离体小麦叶段上产生夏孢子堆。它在药剂生物活性测定中反应较为灵敏,与室内活体生物测定有较高的相关性,但也存在一定差异。如果两者结合使用,则可取长补短,避免漏筛。     

吐伦球坚蚧在杏树上的分布及抽样方法研究

为确定吐伦球坚蚧在杏树上的分布格局及其田间虫口数量估计的最佳抽样方法,以最近邻体法分别对吐伦球坚蚧越冬若虫、成虫和越夏若虫在杏树上的分布进行研究,并比较五点法、棋盘式、双对角线、Z字形、平行线5种抽样方法与总体平均数的差异显著性及各抽样方法的误差率。结果表明：吐伦球坚蚧越冬若虫、成虫和越夏若虫在杏树上的分布均为聚集型。Z字形抽样方法对田间吐伦球坚蚧越冬若虫和成虫进行抽样最可靠;越夏若虫以平行线抽样法最具代表性且最为可靠。     

A general multi-objective programming model for minimum ecological flow or water level of inland water bodies

Assessment of ecological flow or water level for water bodies is important for the protection of degraded or degrading ecosystems caused by water shortage in arid regions, and it has become a key issue in water resources planning. In the past several decades, many methods have been proposed to assess ecological flow for rivers and ecological water level for lakes or wetlands. To balance water uses by human and ecosystems, we proposed a general multi-objective programming model to determine minimum ecological flow or water level for inland water bodies, where two objectives are water index for human and habitat index for ecosystems, respectively. Using the weighted sum method for multi-objective optimization, minimum ecological flow or water level can be determined from the breakpoint in the water index–habitat index curve, which is similar to the slope method to determine minimum ecological flow from wetted perimeter–discharge curve. However, the general multi-objective programming model is superior to the slope method in its physical meaning and calculation method. This model provides a general analysis method for ecological water uses of different inland water bodies, and can be used to define minimum ecological flow or water level by choosing appropriate water and habitat indices. Several commonly used flow or water level assessment methods were found to be special cases of the general model, including the wetted perimeter method and the multi-objective physical habitat simulation method for ecological river flow, the inundated forest width method for regeneration flow of floodplain forest and the lake surface area method for ecological lake level. These methods were applied to determine minimum ecological flow or water level for two representative rivers and a lake in northern Xinjiang of China, including minimum ecological flow for the Ertix River, minimum regeneration flow for floodplain forest along the midstream of Kaxgar River, and minimum ecological lake level for the Ebinur Lake. The results illustrated the versatility of the general model, and can provide references for water resources planning and ecosystem protection for these rivers and lake.     

Dynamics of ecosystem carbon stocks during vegetation restoration on the Loess Plateau of China

In the last few decades, the Loess Plateau had experienced an extensive vegetation restoration to reduce soil erosion and to improve the degraded ecosystems. However, the dynamics of ecosystem carbon stocks with vegetation restoration in this region are poorly understood. This study examined the changes of carbon stocks in mineral soil(0–100 cm), plant biomass and the ecosystem(plant and soil) following vegetation restoration with different models and ages. Our results indicated that cultivated land returned to native vegetation(natural restoration) or artificial forest increased ecosystem carbon sequestration. Tree plantation sequestered more carbon than natural vegetation succession over decades scale due to the rapid increase in biomass carbon pool. Restoration ages had different effects on the dynamics of biomass and soil carbon stocks. Biomass carbon stocks increased with vegetation restoration age, while the dynamics of soil carbon stocks were affected by sampling depth. Ecosystem carbon stocks consistently increased after tree plantation regardless of the soil depth; but an initial decrease and then increase trend was observed in natural restoration chronosequences with the soil sampling depth of 0–100 cm. Moreover, there was a time lag of about 15–30 years between biomass production and soil carbon sequestration in 0–100 cm, which indicated a long-term effect of vegetation restoration on deeper soil carbon sequestration.     

几种化学和物理方法处理对狼毒种子发芽率的影响

几种不同方法对狼毒种子进行处理结果表明：浓度为1．25g／L的甲基托布津溶液漫种0．5h,置于浓度为2．5mg／L的赤霉素(GA3)溶液润湿的培养皿中,发芽率最高(61．7％),其次是98％浓度H2SO4稀释50倍液漫种0．5h,置于浓度为2．5mg／L的赤霉素(GAa)溶液润湿的培养皿中发芽效果较好(48．3％)。变温和紫外线照射对狼毒种子的发芽都有一定的效果。超声波处理和NaOH浸种有抑制作用。     

10%硫虫酰胺SC对草地贪夜蛾的控制效果

为了筛选对草地贪夜蛾防效优良的新型药剂,采用浸卵法和浸叶法在室内研究了10%硫虫酰胺SC对草地贪夜蛾的毒力,并用喷雾法进行了田间控制作用研究。结果表明,硫虫酰胺浸卵处理对草地贪夜蛾的卵孵化率无明显影响,但能显著提高初孵幼虫的死亡率,其中66.7、133.3、266.7 mg/L等3个浓度处理初孵幼虫校正死亡率均高于92.77%;硫虫酰胺对草地贪夜蛾3龄幼虫有较强的毒杀作用,各处理72 h后的校正死亡率为65.55%～100%,但对5龄幼虫防效差。田间药效试验表明,药后1 d各处理防效为61.56%～76.75%,速效性差于对照药剂5.7%甲氨基阿维菌素苯甲酸盐(甲维盐)ME;药后7 d各处理防效为84.84%～95.82%,持效性优于5.7%甲维盐ME和200 g/L氯虫苯甲酰胺SC。研究表明,10%硫虫酰胺SC可以有效控制草地贪夜蛾,且持效性较好,建议每667 m~2制剂用量30 mL左右,防治适期为草地贪夜蛾卵孵盛期及3龄幼虫前。     

科尔沁沙丘-草甸田间持水量的综合测定与影响

以科尔沁沙丘-草甸相间地区表层土壤为对象,选用4种不同测试方法,对不同地貌与植被类型组合区土壤的田间持水量进行综合测定,并对其影响因素和影响过程进行系统分析。结果表明:1在不同地貌类型区4种试验方法得到的田间持水量变化的规律大体一致,但数值差异很大。威尔科克斯法结果比围框淹灌法和天然降水法测定结果大。2草甸地受地下水位埋深的影响很大,围框淹灌法及天然降水法测定结果不可用;沙丘区地下水位埋深大,围框淹灌法与天然降水法获得的田间持水量对实践更具指导意义,天然降水法在地下水位深埋大的沙丘区表层40 cm以内基本可以获得较准确的田间持水量,取样时间可以在降雨后12~24 h。3科尔沁沙地实施田间持水量测量时建议选用天然降水法,对漫灌型农田土壤小面积也可选择围框淹灌法,大面积测量宜选择威尔科克斯法,但应建立威尔科克斯法与天然降水法和围框淹灌法之间的转换关系,利用威尔科克斯法测量田间持水量时,沙性土壤的测量时间可选择36~40 h、草甸区壤沙土与沙壤土可选择44~48 h。     

用点滴法和浸叶法监测棉铃虫抗药性的比较

本文分别采用点滴法和浸叶法，监测了山东省阳谷县、河南省新乡县、河北省邯郸市和安徽省萧县第２代棉铃虫对氯氰菊酯、灭多威及久效磷的抗性，并对这两种方法的监测结果进行了比较。从同一种药剂对４个地区棉铃虫毒力大小顺序来看，两种方法的测定结果基本一致。而从抗性倍数来看，点滴法与浸叶法的结果具有差异：点滴法测得的氯氰菊酯的抗性倍数（２０．８～３４．８倍）高于浸叶法测得的抗性倍数（２．０～１８．７倍），对灭多威测得的抗性倍数（５．４～１６．４倍）也高于浸叶法测得的抗性倍数（１．４～６．５倍）；而浸叶法测得的对久效磷的抗性倍数（１１．３～７０．１倍）却明显高于点滴法测得的抗性倍数（２．８～９．３倍）。本文并对产生这种差异的原因进行了分析和讨论，建议对有机磷杀虫剂采用浸叶法作抗性监测比较确。     

基于条件植被温度指数的冬小麦主要生育时期干旱监测效果评价——I.因子权重排序法和熵值法组合赋权

选取关中平原冬小麦越冬后2002—2009年每年3—5月共9旬的条件植被温度指数（VTCI）遥感干旱监测结果,将冬小麦越冬后分为四个主要生育时期,分别运用因子权重排序法、熵值法及组合赋权法确定各生育时期干旱对产量的影 响权重,计算关中平原各市冬小麦每年的加权VTCI,并建立加权VTCI与冬小麦单产间的一元线性回归模型。结果表明,关中平原大部分地区的加权VTCI与小麦单产密切相关。其中,熵值法确定的加权VTCI与小麦单产的线性相关性不显著,渭南、咸阳及铜川的决定系数R²值均低于0.5;因子权重排序法和组合赋权法确定的加权VTCI与小麦单产的线性相关性显著,咸阳、宝鸡及西安的R²值接近或高于0.6,渭南接近 0.5,铜川较差。且组合赋权法的结果中宝鸡和西安的R²值接近0.7,优于因子权重排序法和熵值法的结果。     

杀细菌剂毒力测定方法的研究

用抑菌圈法和平板菌落计数法分别测定农用链霉素、氧氯化铜对柑桔溃疡病菌与白菜软腐病菌的毒力，以比较两种毒力测定方法。结果表明，与抑菌圈法相比，平板菌落计数法具有快速、简便、重复性好等优点。认为平板菌落计数法可用于室内杀细菌剂的毒力测定。     

大豆食心虫新测报方法的研究

传统的豆田惊蛾 ,目测虫量的大豆食心虫测报办法因预报期短 ( 3～ 5d) ,且受天气、人为误差及中期预报无直接观测依据等因素影响 ,限制了测报乃至整体防治水平的提高。为此 ,1 990年起开展了以人工采集虫源 ,利用羽化箱接虫 ,用冬后 ( 6月份 )及化蛹羽化期存活率做为观测指标的新测报方法研究 ,并建立了分区预报模型 ,使预报期提前至 2 0～ 4 0d ,从而达到了较为准确的中期预报     

农药淡水水生生物水质基准研究进展

水环境质量基准(简称水质基准)是环境保护部门制定水质标准、进行水质管理的基础,其中,水生生物水质基准是保护水生生物物种多样性及充分发挥水生生物群落生态功能的保证,是制定水环境管理目标及措施的重要依据。目前用于推导淡水水生生物水质基准的方法主要有评价因子法、物种敏感度分布曲线法及毒性百分数排序法,综述了3种方法的推导过程、适用范围以及优缺点,并对我国农药淡水水生生物水质基准研究的现状及发展趋势进行了探讨。     

复合菌剂AR99防治辣椒青枯病

 从本实验室生防细菌库中选择5个功能互补性的菌株复配,制成防治辣椒青枯病的生防制剂AR99。温室实验中,AR99复合菌剂和5个单一菌株防病效果分别达到91.1%(AR99)、88.9%(R1)、57.0%(A6)、66.7%(R9)、80.5%(J3)、80.5%(A9),复合菌剂AR99的防治效果最为显著。2000、2001年在淮阴分别用拌菌堆肥法、灌根法进行生防实验。70 d后用AR99复合菌剂平均防效为94.0%(拌菌堆肥法)、77.0%(灌根法),平均增产效果分别为367.0%、57.8%。     

陕西关中地区杀虫剂清园措施对桃树桃蚜种群的影响

在田间条件下研究了陕西关中地区5种杀虫剂在不同时间进行清园处理对桃树桃蚜种群的影响。结果表明,两次施药对桃蚜种群的增长均有较好的控制效果,尤以第1次施药后45d内和第2次施药后30d内,即5月6日前控制效果明显。但5月6日以后,各药剂处理的控制效果均明显下降,至第1次施药后的第60天和第2次施药后第45天,有的药剂处理已经完全失去了控制效果。早春清园对桃蚜种群的早期增长有较好的防治效果,但此时桃蚜种群数量总体偏低,直接危害并不严重,从减少用药次数和用药量的角度,早春清园预防桃蚜有无必要值得进一步试验研究。     

50年来靖远县气候变化趋势分析

根据靖远县气象站1951-2004年气温、降水观测资料,运用累积滤波器法和Kendall秩次相关法,对不同时间尺度的气温和降水量变化趋势进行分析.结果表明:靖远县年平均气温呈现显著升高趋势,降水量有微弱增加,但增加趋势很不明显;春季、秋季和冬季气温均呈增加趋势,冬季增温趋势显著,夏季气温有降低趋势;各个季节降水量变化趋势较为复杂,春季和夏季降水量呈微弱增加趋势,而秋季和冬季变化趋势相反;各时段气温和降水量也反映了同样的变化规律.