黑光灯和白僵菌无纺布对青杨脊虎天牛的防治效果

为探索青杨脊虎天牛的无公害控制技术,采用不同波长(320~560 nm)黑光灯对其成虫进行诱捕。结果,青杨脊虎天牛成虫对低波长区间(320~368 nm)具有趋光性,对368 nm(黄)较360 nm(绿)更为敏感,处理时间18:00—24:00中,最佳诱捕时间为20:00—22:00,晴天的诱捕效果要比晴转阴和阴天要好,黑光灯可作为监测和控制青杨脊虎天牛的监测辅助工具。测定7种白僵菌菌株制作的无纺布菌条对青杨脊虎天牛的毒力,各菌株在处理后30 d内孢子含量逐渐下降,对青杨脊虎天牛防治效果最佳的菌株为球孢白僵菌Bb01和布氏白僵菌Bb CF327。     

土壤的石灰反应强度估测CaCO_3含量和pH研究——以山西省黄土性母质土壤为例

pH和CaCO_3含量是土壤常规分析的两个测定指标,但其室内测定均需借助相应的仪器设备完成,耗时费力。以山西省土系调查采集的110个典型土壤剖面的426个发生层土样的野外测定的石灰反应强度和实验室测定的土壤pH、CaCO_3含量、交换性钠饱和度(Exchangeable Sodium Percentage,ESP)数据为基础,尝试建立石灰反应强度与pH、CaCO_3含量之间的定量关系模型。结果表明:北方黄土性母质土壤,当pH9.0时,CaCO_3含量是影响土壤pH的重要因素,二者的回归拟合最优关系符合幂函数曲线;当pH9.0时,CaCO_3与pH之间无明显关系。石灰反应强度在一定程度上可以半定量地反映pH或CaCO_3含量,但其确定的pH或CaCO_3含量尚是一个范围,并非精确值。同时,从发生学意义角度,土壤中CaCO_3含量高低对形态学研究具有重要意义,在这种情况下,如果需要用pH或CaCO_3含量来确定准确的土壤系统分类类型(如确定土体是否为酸性、具有钙积层/钙积现象等),为慎重起见建议还是以实验室的准确测定数据为准;对于非碱化(pH9.0)、野外有泡沫反应的北方黄土性母质土壤,无论泡沫反应强弱和CaCO_3含量高低,土壤pH基本稳定在8.51±0.49,这一pH范围对作物生长基本没有制约,如果仅从pH或CaCO_3含量是否影响作物生长角度考虑,无需实验室测定pH或CaCO_3含量。     

2007～2008年大连地区闪电时空分布特征分析

采用大连地区不同地理位置的4个雷击探测仪组成的闪电监测定位系统获取的2007-2008年云地闪电资料,从闪电的极性分布、日变化、强度、闪电密度等方面,研究了大连周边地区云地闪电时空分布特点。结果表明,云地闪中负闪电占闪电总数的93.9%,平均闪电强度为27.99 kA;正闪电占闪电总数的6.1%,平均闪电强度为35.56 kA;闪电频次的日变化呈明显的双峰双谷结构,17：00-18：00和04：00-05：00为2个峰值,2个谷值分别出现在09：00-10：00和00：00-01：00;5-9月闪电次数占全年闪电总数的91.5%,其中6-8月闪电次数最多;正、负闪电的强度主要集中在15-35 kA,80%以上闪电强度小于40 kA,100 kA以下的闪电次数约占闪电总数的99.3%;大连周边地区闪电空间分布呈明显的地域性差异,辽东湾和大连东部沿海地区是对流发生的主要发生地,远离海区的内地区域闪电发生的频率要低的多,沿海地区是大连周边地区雷电灾害防御工作重点。     

银中杨苗木光需求的图像分析法

近年来,在一些国际农林业学术会议上出现了智能林业的概念(Hirafuji et al.,2008a;2008b),智能林业的主体是林业机器人,与人类信息的70%以上来自视觉一样,机器人的主要信息源也是     

光照长度、强度及温度对试管薯诱导的影响

通过一步法进行试管薯的诱导,不更换培养基,不添加任何外源激素,研究试管苗培养阶段光照周期、光照强度及温度对Favorita、Atlantic和克新1号3个马铃薯品种试管薯诱导的影响。结果表明:短光周期培养有利于试管薯的诱导,但产生的试管薯较小,适当的延长光照时间有利于诱导较大的试管薯;不同品种需要不同的适宜试管薯诱导的光照强度;变温处理最适于试管薯的诱导。不同品种需要做培养环境的筛选和品种结薯性评价,以筛选出最佳的诱导条件。     

发达国家和发展中国家生态补偿机制比较分析

生态补偿是处理环境保护和经济发展之间的矛盾、保障环境保护领域的社会公平的重要手段。通过比较研究发现,发达国家的生态补偿机制基于完善公共财政体系,直接以降低保护区的经济活动强度为导向;发展中国家的生态补偿机制则更倾向于通过自然资源的可持续开发来补偿保护地的发展机会损失。这两类生态补偿机制在实际应用中都存在一定的局限性。研究认为,我国应当在借鉴发达国家和发展中国家经验的基础上,以降低保护地经济活动强度为导向,结合我国的城市化进程,建立适合我国国情的生态补偿机制。     

Effects of Acetylsalicylic Acid and Calcium Chloride on Photosynthetic Apparatus and Reactive Oxygen-Scavenging Enzymes in Chrysanthemum Under Low Temperature Stress with Low Light

The effects of acetylsalicylic acid （ASA）, CaCl2, and ASA ＋ CaCl2 on the photosynthetic apparatus and antioxidant enzyme activities were investigated in chrysanthemum Jinba （a cut flower cultivar） under low temperature stress with low light （TL stress） （16/12℃, day/night, PFD 100 μmol m^-2 s-1）. The results showed that under TL stress, the net photosynthesis rate （Pn）, carboxylation efficiency （CE）, apparent quantum yield （AQY）, maximal photochemical efficiency （Fv/Fm） of PSII, quantum yield of PSII electron transport （ФPSII）, and photochemical quenching （qP） of the chrysanthemum leaves in all treatments were significantly decreased, but the decreases were alleviated by ASA, CaCl2, and ASA ＋ CaCl2 treatments compared with the controls. The alleviating effect of ASA ＋ CaCI2 was better than either ASA or CaCl2 single treatment. Moreover, the ASA ＋ CaCl2 treatment highly improved the chlorophyll content, relatively improved the number and size of chloroplast and starch grain in the leaves of chrysanthemum plants compared with ASA and CaCl2 treatments. It was indicated that ASA and/or CaCI2 could regulate the photosynthetic functions in the leaves of chrysanthemum plants to enhance the resistance against TL stress. On the other hand, reduction in relative conductance rate implied that ASA and/ or CaCl2 could protect from membrane injury in leaves of chrysanthemum plants. The activities of SOD, POD, and CAT in the treated leaves of chrysanthemum were increased as compared with the controls. It was suggested that ASA and/or CaCl2 had positive regulation effects on the defence enzyme activities in chrysanthemum leaves which could protect the photosynthetic apparatus to a certain degree under the TL stress. In brief, the treatment of ASA together with CaCl2 was better for chrysanthemum plants to adapt TL stress than single ASA or CaCl2 treatments.     

陇东黄土高原典型草原滩羊践踏强度与放牧强度关系的研究

通过在环县典型草原不同放牧强度下轮牧试验的跟群观测,发现放牧强度增加3倍,其践踏强度却增加5倍多,说明践踏作用对放牧的敏感性高于以家畜采食作用为基础的适宜载畜量和放牧强度,获得了家畜践踏强度随放牧强度幂函数式增大的定量结论,说明调控放牧家畜的践踏效应应是放牧管理的一项重要的指标。     

Application of epifluorescence light microscopy (EFLM) to study the microstructure of wheat dough: a comparison with confocal scanning laser microscopy (CSLM) technique

To study dough microstructure, epifluorescence light microscopy (EFLM) combined with digital image processing software was used, which enabled an improved image quality. A comparison was made between EFLM and confocal scanning laser microscopy (CSLM) methods. Both techniques were satisfactorily able to demonstrate changes in the dough microstructure upon different stages of z-blade mixing. Dough mixed for a shorter time (under-mixed) showed a heterogeneous structure with coarse protein domains and clusters of starch due to local segregation or de-mixing effect. Increasing mixing time (optimal mixing) led to development of interconnected gluten network covering starch granules throughout the dough, representing optimal development. Over-mixing led to formation of a homogeneous dough microstructure in which the gluten phase showed a fine distribution throughout the dough. Using a double staining method in the preparation of samples for both microscopic techniques it was possible to observe gluten network structures together with starch granules. Moreover, special features of image processing software described in this study enabled us to improve EFLM images and to obtain comparable images with CSLM. This could favour a low cost and a convenient microscopic observation of biomaterials.     

不同经济发展水平地区耕地利用变化对比研究

基于中国农产品成本收益资料与中国农村统计年鉴等基础数据,选择浙江、河南和四川3个处于不同经济区位和发展水平下的典型省份,系统分析了3个地区1980—2007年的耕地利用方式、集约度及其内部结构以及耕地产出的变化情况。结果显示:在种植结构上,近年来粮食播种面积占总播种面积的比例降幅次序为浙江>河南>四川,浙江蔬菜瓜果占地比例增加,而其他2省粮食作物仍占主导地位;劳动集约度持续下降,下降幅度浙江>河南>四川,到2007年形成劳动集约度水平与三地经济发展水平呈反比的关系;机械投入表现为与经济发展水平的正比关系;但经济发达省份在种子、化肥和农药等增产性投入方面未表现出显著优势,其增加幅度次序为河南>浙江>四川;从耕地产出变化情况看,近年来耕地生产率的增长幅度显著低于劳动生产率,劳动生产率的快速提高在经济发达的浙江更为显著,说明经济发展水平越高地区的农户,在耕地利用中越重视追求劳动生产率最大化的目标。