益蝽对草地贪夜蛾高龄幼虫的捕食能力评价和捕食行为观察

为了探究天敌昆虫益蝽对草地贪夜蛾的捕食潜力,本试验在室内条件下评价了益蝽5龄若虫对草地贪夜蛾6龄幼虫的捕食能力,结合田间观察总结了益蝽的捕食行为特点。结果表明：益蝽5龄若虫对草地贪夜蛾6龄幼虫的捕食功能反应符合HollingⅡ模型,对草地贪夜蛾6龄幼虫的日最大捕食量、瞬时攻击率和处理时间分别为4.671头、1.512和0.215 d;益蝽偏食活猎物,对草地贪夜蛾幼虫致死量大,当草地贪夜蛾幼虫密度大时,益蝽将一头猎物刺吸致死后并不持续吸取,而是快速攻击其他猎物,这一特点对于控制草地贪夜蛾种群数量十分有利。     

黄粉虫粪不同用量对制种黄瓜幼苗质量的影响

研究了营养土中不同黄粉虫粪搀入量对马坊营旱黄瓜幼苗生长的影响，结果表明：用黄粉虫粪与营养土按1：(160-320)(体积比)混配的基质进行黄瓜育苗，能促进幼苗生长，显著提高幼苗简单指标、相对指标和复合指标的值。     

杭州市茶馆消费情况调查分析

通过问卷调查与统计分析相结合的方式对杭州市民喜爱的茶馆类型、茶馆吸引消费者的因素、消费茶类结构、消费目的、消费者满意度等方面进行了分析和总结。结果显示,目前市区、农家、风景区三种茶馆类型,各自占有一定的市场份额,自助茶馆相对于清茶馆更受欢迎。消费者对茶馆环境的要求很高。绿茶在消费中仍然占据主导地位。消费者的消费目的以自我放松和亲友聚会为主。认为茶馆价格不合理的消费者比例约为20%,认为物有所值的接近50%。大多数人对杭州茶馆的现状表示满意和基本满意。     

游离甲醛和人造板释放甲醛

甲醛是室内空气污染源，它常与甲醛系统粘接连在一起，本文根据国内外资料评述人造板甲醛释放量，分析了脲醛树脂的水解和人造板释放甲醛的机理，还介绍了甲醛的毒害，各国政府的有关法规以各种降低甲醛释放量的方法。     

骨髓间充质干细胞移植治疗脑缺血的动物实验研究

    探讨骨髓间充质干细胞(MSCs)移植对大鼠脑缺血的修复和治疗.体外分离培养大鼠MSCs,以Hoeschst33342标记,移植到大脑中动脉梗塞(MCAO)模型的大鼠体内,分别设立缺血1 d和缺血7 dMSCs移植组与缺血对照组,对各组大鼠进行神经功能损害严重程度评分(NSS)及大脑组织切片观察比较.结果发现,缺血1 d MSCs移植组大鼠NSS评分低于另外两组,差异显著(P＜0.05),大脑组织结构清晰、完整,胶质瘢痕少;缺血7 d MSCs移植组与对照组无明显差异(P＞0.05).故缺血早期进行MSCs移植,大鼠神经功能恢复情况明显.MSCs在损伤后的脑组织内能够存活并且分化为神经元、胶质细胞等,对动物神经损伤后组织重建及功能恢复有一定的治疗作用.     

浙江白术挥发油化学成分研究

目的：以药材气味为指标,准确区分不同产地、不同炮制品种白术样品;研究浙江白术挥发油的化学成分。方法：采用电子感官Alpha M．O．S传感器矩阵系统,对不同产地及不同炮制品种白术样品的复杂气味基质进行定性;常规硅胶柱层析分离纯化白术挥发油的化学成分,用核磁共振和X-射线衍射法鉴定其结构。结果：不同产地及不同炮制品种的白术样品其气味间存在显著差异,相对比而言,炮制工艺对样品气味特征的影响远比产地差异的作用大。白术内酯I的晶体属正交晶系,空间群为P212121。晶胞参数：a=8．756（1）,b=12．012（2）,C=12．555（1）h,V=1320．5（2）A^3,Z=4。Dx=1．169g／cm^3。最终可靠因子R1=0、041,wR2=0．1219。独立衍射点为1391个,可观察点（IFl^2≥2σlFl^2）为1328个。结果表明白术内酯I由2个反式联接的椅式六元环和1个五元内酯环组成。晶态下不存在分子内和分子间氢键联系,分子间以范德华力维系其在空间的稳定排列。结论：气味指纹分析技术对不同白术样品具有很高的灵敏度,能够有效的区分具有细小差异的样品;白术内酯I首次从浙江白术中分离得到,白术内酯I单晶首次从白术中制备得到。     

Nitrous oxide emission as affected by changes in soil water content and nitrogen fertilization

Nitrous oxide emission was measured in laboratory incubations of an alluvial soil (58% clay, pH 7.4). The soil was amended with 40 mg N kg⁻¹ as NaNO₃ or NH₄Cl, or with NaCl as a control. Each fertilization treatment was adjusted to three different water contents: constant 60% WHC (water-holding capacity), constant 120% WHC, and water content alternating between 60 and 120% WHC. During an 8-day incubation period N₂O emission rates and inorganic nitrogen concentrations in soil (NH₄⁺, NO₂⁻, NO₃⁻) were determined at regular intervals. In the control and after nitrate application small N₂O emission rates occurred with only minor variations over time, and no differences between the water treatments. In contrast, with ammonium application N₂O emission rates were much higher during the first two days of incubation, with peaks in the constant 60% WHC and 120% WHC at day 1 and in the changing-water treatment at day 2, when the first wet period (120% WHC) was completed. This N₂O peak in the changing-water treatment was 4 to 9 times higher than with constant WHC and occurred when both, NH₄⁺ and NO₂⁻ concentrations declined sharply. Thus, this N₂O emission flush can be attributed to nitrifier denitrification. After the second rewetting of the NH₄⁺-amended soil no further N₂O emission peak was observed, being in accordance with small NH₄⁺ and NO₂⁻ concentrations in soil at that time. The unexpectedly small N₂O fluxes in the constant 120% WHC treatment after nitrate application were probably caused by the reduction of N₂O to N₂ under the prevailing conditions. It can be concluded that continuous wetting or flooding of a soil is an effective measure to reduce N₂O emissions immediately after the application of NH₄⁺ fertilizers.     

我国棉田残膜污染危害与治理措施研究进展

地膜覆盖技术的应用为我国棉花产量提升做出重大贡献.但随着聚乙烯地膜的长期使用,土壤残膜污染问题日益突出,影响棉田土壤环境和棉花可持续发展.综述了我国棉田地膜残留现状、分布特征及其对棉花生长的危害,从土壤结构变化、水分迁移状况、有害物质释放、土壤物质代谢、微生物种群结构等方面系统总结了棉田残膜污染的危害机制,归纳了现阶段...     

茶园土壤动物群落特征及其与土壤理化特性的关系

为了解荒地植茶后土壤质量变化趋势及科学评价其生态效益,以四川省名山县生态茶园为例,采用手捡法和干、湿漏斗法,并以相邻人工林地为对照,研究茶园土壤动物群落结构特征及其与土壤理化性质的关系.结果表明:研究区共获取土壤动物11 720只,隶属于5门15纲32目36类;蜱螨目、线虫纲和弹尾目为2种土地利用方式下土壤动物共有的优势类群;茶园土壤动物群落类群数、Shannon-Wiener指数、均匀度、密度-类群指数和群落复杂性指数均小于人工林,而群落个体数和优势度大于人工林;茶园土壤动物群落的季节波动大于人工林;土壤动物密度、类群数、群落多样性及均匀性在土层中分布均呈现一定的表聚性;茶园土壤动物群落仅类群数和Shannon-Wiener指数表现出层次间的显著差异,而人工林群落的类群数、密度、多样性和均匀度均表现出层次间的显著或极显著差异;茶园土壤有机质、自然含水量、速效氮和全氮与土壤动物群落特征呈显著(P0.05)或极显著(P0.01)偏相关关系,而土壤容重、田间持水量、pH、阳离子交换量、速效钾和速效磷与群落特征无显著偏相关性(P0.05).