浸提时间对污泥中重金属浸出的影响

[目的]探讨污泥中重金属的释放动力学特性。[方法]采集了我国南京某污水厂的剩余污泥,应用固体废物浸出毒性的浸出方法,研究了浸提时间对污泥中重金属浸出的影响。[结果]污泥中重金属在水溶液中的浸出存在明显的吸附-解吸(释放)的动态平衡过程。污泥中重金属种类的最大浸出浓度因重金属种类的不同而存在较大差异,其中,Cr、Cu、Fe、Ni和Zn的最大浸出浓度均出现在第8小时,Mn的则出现在第18小时左右,而Mo虽然在第8小时后的浸出浓度变化渐趋缓慢,直到第24小时时仍未达到其最高浸出浓度。[结论]浸提时间对污泥中重金属的浸出影响显著,污泥具有较高含量的有机质、氮和磷等营养元素,其潜在的农业利用价值较高。     

播种时间和覆土厚度对硫华菊种子萌发和幼苗生长的影响

在实验室内观测了不同品种硫华菊种子的发芽率和发芽势,在试验田内研究了播种时间(4~8月)和覆土厚度(0.3、0.8、1.6、2.4、3.0 cm)对硫华菊种子出苗率、幼苗株高和幼苗死亡率的影响。结果表明:不同品种间硫华菊种子的发芽率和发芽势差异较大,其中黄色品种的发芽率和发芽势分别为88.33%和81.67%,橙色品种的发芽率和发芽势分别为80.67%和68.67%,红色品种的发芽率和发芽势分别为66.67%和47.33%。覆土厚度大于0.3 cm时,随着覆土厚度的增加,出苗率明显降低;覆土厚度大于0.8 cm时,随着覆土厚度的增加,幼苗死亡率显著上升;覆土厚度小于2.4 cm时,苗高差异不明显;覆土厚度为3.0 cm时,不能出苗。8月播种的幼苗死亡率最高,7月播种有部分死苗,4~6月播种没有死苗。综上所述,硫华菊单位面积播种量较少的是黄色品种,适宜播种时间为4~6月,适宜覆土厚度为0.3~0.8 cm。     

射流自吸喷灌泵喷嘴系数的理论推导与试验

为了研究射流式自吸喷灌泵射流喷嘴的内特性,利用流体力学基本原理,对射流喷嘴阻力系数、流量系数进行了理论推导.设计了4种不同尺寸的射流喷嘴,对4种喷嘴的阻力系数、流量系数进行了理论计算,得到了不同出口直径下各系数的变化规律.对分别安装4种射流喷嘴的喷灌泵进行了自吸性能的试验.结合试验结果和各系数的变化规律,分析了射流喷嘴阻力系数和流量系数对射流式自吸喷灌泵自吸性能的影响.结果表明,随着喷嘴出口直径的增大,阻力系数减小,流量系数增大,自吸时间缩短,但达到一定程度后,卷吸作用减弱,自吸性能变差.     

二甲基甲酰胺对猪精液冷冻保存效果的影响

用二甲基甲酰胺(DMF)完全替代甘油,比较不同平衡时间和不同DMF添加量对猪精液冷冻保护效果的影响。结果表明,DMF能完全替代甘油,获得较好的冷冻保护效果。最佳平衡时间为90 min,解冻后精子活力为(44.57±0.72)%,显著高于对照组和其他组(P0.05)。当DMF添加量为5%时,冻后精子活力、活率、线粒体活性、顶体完整率和质膜完整率分别为(49.91±0.39)%(、46.51±0.26)%、(47.51±0.52)%(、49.84±0.56)%、(46.30±1.61)%,均显著高于2%、3%、6%DMF添加组(P0.05),但与4%DMF添加组相比,冻后精子活力、活率和质膜完整率差异不显著(P0.05)。本试验结果表明,DMF最适添加量为5%。     

水稻持久抗瘟性研究

以病区时空动态效应强度检验为核心,以纬度病圃、抗谱测定和抗性信息流的追踪考证作为持久抗瘟性鉴定评价方法的基础。经综合评价,认为特特勃(Tetep)、小粒野生稻Oryzaminuta J.S.Presl ex C.B.Presl、湘资3150、天津野生稻、谷梅二号、魔王谷等具有持久抗瘟性,可作抗源用,其中小粒野生稻兼具持久抗褐飞虱Nilaparvata lugens St(?)l性能;提出了持久抗瘟性鉴定的原则和方法。对持久抗瘟性的时空动态特性、广谱抗性与持久抗性的关系等进行了讨论。     

库木库里沙漠形成时代的初步探讨

本文依据小沙子湖湖积剖面的年代学、沉积学、地球化学与矿物学分析,探讨了湖积剖面的建造与库木库里沙漠发育的关系,认为,在该湖积剖面建造中,沙漠尚未出现,库木库里沙漠的形成在距今6000年前以后。     

Components of resistance to late blight (Phytophthora infestans) in eight South AmericanSolanum species

Four components of partial resistance toPhytophthora infestans were measured after inoculation in the greenhouse and in the field ofSolanum arnezii x hondelmannii, S. berthaultii, S. circaeifolium, S. leptophyes, S. microdontum, S. sparsipilum, S. sucrense andS. vernei, and four hybrid progenies ofS. microdontum withS. tuberosum. The four components were infection efficiency, lesion growth rate, generation time and sporulation capacity. The results were compared with resistance ratings derived from field experiments, and with observations made on the potato cultivars Bintje, Bildstar, Libertas and Pimpernel. Genetic variation for all components was found, while the relative importance of the components of partial resistance appeared to vary between the species. InS. microdontum, generation time, infection efficiency and lesion growth rate, and inS. tuberosum infection efficiency, lesion growth rate and sporulation capacity appeared positively associated, but in other species no such association was found. A strong hypersensitive reaction, the expression of which appeared to depend on environmental conditions, was found inS. microdontum. ForS. berthaultii, infection efficiency appeared to be the main resistance component.Abbreviations ADPC area under the disease progress curve - IE infection efficiency - LGR lesion growth rate - GT generation time - SC sporulation capacity     

兔病毒性出血症首免时间的研究

针对生产上出现的从断奶育成这一年龄段多发兔病毒性出血症的实际情况，采用快速、敏感的Dot-ELISA方法，通过测定不同免疫状态下的母兔所产兔的母源抗体动态变化规律，并进一步测定不同抗体效价的成年兔攻毒后是否得到保护的结果，再结合生产实际，得出兔病毒性出血症首免时间为30日龄，且剂量加倍。     

Evaluation of turnip-rooted parsley (Petroselinum crispum ssp. tuberosum) for root and foliage production under a warm,Mediterranean climate

Two experiments were undertaken in southern Greece during 2000–2002 in which turnip-rooted parsley was tested for its suitability for cultivation in comparison with locally grown curly-leafed and plain-leafed forms. Plants were harvested when the foliage was acceptable for marketing, rather than on completion of the vegetative cycle, hence root size was relatively small. In year 1, the foliage development of plain-leafed parsley was significantly higher than that of the other two forms, irrespective of sowing date. In year 2, both plain-leafed and curly-leafed parsley produced more foliage than turnip-rooted parsley in the early sowing (November), but not in subsequent sowings (December and February). During both years, root development was higher in turnip-rooted parsley than in curly-leafed parsley, although in the November and February sowings of year 1 the root weight of both plain-leafed and turnip-rooted forms were similar. In all three types of parsley, foliage yield fell off significantly in the spring sowing (February), and in year 1 there was a considerable decrease in root production as well. In most cultivars, foliage weight was higher when plants were grown from transplanted seedlings rather than by direct sowing, whereas the effect of sowing method on root weight was sowing date dependent. Cultivar differences in the foliage weight of direct sown and transplanted plants were reflected by differences in plant height and, in some cases, by leaf number. It is concluded that although overall turnip-rooted parsley produced rather less foliage than that plain-leafed parsley, this was compensated for by the satisfactory production of roots and therefore turnip-rooted cultivars may constitute a suitable crop for introduction to the Mediterranean region.     

饲用小叶锦鸡儿在山西的最佳采收时期

本研究连续3年对小叶锦鸡儿的生长规律及物候期进行观察,并采集1~8a不同年龄枝条及3a不同物候期枝条(带叶、花、果)测定并比较其营养成分(粗蛋白、粗脂肪、粗纤维、粗灰分、无氮浸出物、钙、磷等)的含量;采用层次分析法(AHP),计算各枝龄、物候期与参考向量的灰色关联度,确定最佳饲用采收期,以期评价小叶锦鸡儿(Caragana microphylla)不同年龄枝条和年生长周期的不同物候期营养成分变化规律,确定其饲用最佳采收期,为科学经营和合理利用资源提供理论依据。结果表明,1)按枝条不同生长年龄营养价值等权关联度排序为3a2a4a5a1a6a7a8a;加权关联度排序为3a1a5a2a4a6a7a8a。2)按不同物候期等权关联度排序为结果中期果熟期果后生长期花期展叶期萌芽期落叶期休眠期;加权关联度排序为结果中期果后生长期果熟期花期展叶期落叶期萌芽期休眠期。3a枝条结果中期作为加工饲料的最佳采收期,也是最佳平茬更新时期。