苦楝果提取物对桑天牛产卵量及卵孵化率的影响

以用一定浓度的苦楝果提取物处理的构树枝条作为天牛的食物 ,研究了其对桑天牛产卵及卵孵化的影响。在室温下用苦楝果提取物 5 0 0mg/kg处理枝条 ,处理组天牛 ( 7对 )在1 5天试验中 ,7对天牛日平均产卵量为 8.5 3± 2 .35个 ,而对照组 7对天牛日平均产卵量为1 5 .80± 0 .98个。经T检验处理组与对照组之间差异极显著。用 2 5 0、1 0 0 0、2 0 0 0mg/kg的苦楝果提取物处理枝条 ,在 1 5天试验中 ,7对天牛日平均产卵量分别为 8.0 6± 2 .90、6.73± 3.82、5 .2 0± 1 .74个 ,而对照组 7对天牛的日平均产卵量为 1 3.73± 2 .90个。经T检验它们与对照之间差异极显著。取食含苦楝果提取物 2 5 0、1 0 0 0、2 0 0 0mg/kg处理枝条后 ,天牛产的卵分别需经 1 2、1 5、1 9d达到其最终孵化率 94.2 1 %、87.1 2 %、43.5 8% ;而对照组 1 1d达到最终孵化率 99.5 0 %。并据上述结果提出并讨论了应用苦楝果提取物防治桑天牛的前景     

梳冬夜蛾和白边切夜蛾卵抗寒性研究

对梳冬夜蛾和白边切夜蛾卵的过冷却点、结冰点和不同低温强度及持续时间等指标的冷冻处理测定结果:梳冬夜蛾卵过冷却点为-18.76±4.09℃,结冰点为-17.7±5.02℃;白边切夜蛾卵的相应指标分别为-8.13±3.17℃和-7.15±3.09℃。两种蛾卵在一定的低温条件下,处理时间愈长,卵孵化率愈低;随着低温强度加大,卵孵化率明显降低。     

ND-EDS二联油乳疫苗免疫对比及田间免疫试验

以自制 ND- EDS二联油苗为主进行免疫试验 ,并以同种二联油苗、ND和 EDS单油苗作对照 ,测定各种疫苗免疫后 ND、EDSHI抗体消涨规律 ,并进行强毒攻击试验。在此基础上 ,用自制二联苗实地免疫产前蛋鸡 2 6 830只 ,进行田间免疫试验。结果表明 :自制二联苗免疫效果良好 ,免疫期为 36 0 d左右 ,免疫期内对 ND和 EDS强毒攻击的保护率分别为 10 0 %和 95.8%     

三种益生菌对罗曼粉壳蛋鸡蛋品质的影响

为探究三种草科鸡源益生菌(枯草芽孢杆菌、植物乳杆菌和戊糖片球菌)对鸡蛋蛋品质的影响.选用1日龄480羽罗曼粉壳蛋鸡,随机分为4组,每组3个重复,每个重复40只鸡,对照组(CP)饲喂基础饲粮,试验组在基础饲粮的基础上分别添加枯草芽孢杆菌(Bacillus subtilis,BS)、植物乳杆菌(Lactobacillus plantarum,LP)和戊糖片球菌(Pediococcu spentosaceus,PP),活菌数大于10~7CFU/g.220日龄测定600枚鸡蛋的蛋品质:与对照组相比,饲料中添加植物乳杆菌(LP)能加深蛋黄颜色2.91%(P0.05).戊糖片球菌(PP)与对照组相比,蛋黄颜色加深了1.68%(P0.05).BS组与对照组相比,平均蛋黄重增加了4.09%(P0.05);蛋壳平均厚度增加了9.64%(P0.05);蛋重增加了3.22%(P0.05).在改善蛋品质整体效果上,枯草芽孢杆菌优于植物乳杆菌,植物乳杆菌优于戊糖片球菌,而益生菌对蛋黄胆固醇的影响并不稳定.本试验为微生态制剂在蛋鸡生产上的应用与推广提供了科学依据.     

真刺唇角水蚤产卵率的饵料效应和自然种群繁殖特征

在1986年4月至1987年8月间研究了厦门港真刺唇角水蚤(Labidcceracuchaeta Giesbrecht)的生殖率。结果表明,恒温(20℃)时,相对产卵率(Fe,％C■/d)与饵料密度(P,μgC/ml)成正相关,Fe=0.1732(P-0.0179)/P,总产卵效率(以C计)约为62％,与饵料密度和摄食率无关,产卵雌体百分数终年处于较高水平,平均69％,且与现场产卵率一样呈季节变化,真刺唇均水蚤在厦门港终年持续繁殖,夏季当繁殖盛季,冬季为淡季,根据种群平均产卵率高峰数■断一年有10个■代。     

用核磁共振测定受精过程卵子中水质子的纵向弛豫时间T_1

使用核磁共振波谱技术测定并比较受精前后卵子中水质子的T_1值,初步探讨了造成其变化规律的原因.受精后卵子中水质子的纵向弛豫时间明显比受精前增加,而且在一定的时间范围内,随卵子与精子混合时间延长,T_1值有随之增大的趋势.从受精后卵子中总氮量减小推测细胞内水分子与含氮的极性生物大分子之间的作用减弱,这是T_1值增大的主要原因之一.     

A troublesome sibling species complex of scuttle flies (Diptera: Phoridae) revisited

The complex of species resembling Megaselia pulicaria (Fallén) has proved to be one of the most troublesome challenges to attempts to resolve the recognition of species within the huge genus Megaselia Rondani. The new data presented allow more confident recognition of species and reveal that most published records represent misidentifications. The penis complex is discussed and its use in species identification demonstrated. All specimens currently assigned to M. pulicaria, other than the lectotype, are consequently reassigned to other species. These include the reinstatement of M. angusta (Wood) and its newly designated subspecies M. angusta angustina Schmitz, M. eupygis Schmitz, M. longifurca (Lundbeck) and M. monochaeta (Strobl) as valid species, and the recognition of M. buchsi sp. nov. from Germany, M. iberiensis sp. nov. from Spain, M. martensi sp. nov. from Nepal, M. nectergata sp. nov. from Britain, M. oviaraneae sp. nov. from Britain, and M. rotundapicis sp. nov. from Scotland. Five synonyms are proposed. The hitherto unknown male of M. petraea Schmitz is described. It and M. longifurca are reported from Britain and the latter from the Nearctic Region also. Natural history information is summarized for each species. In particular, it is reported that the species whose larvae prey upon spider eggs are M. angusta, M. longifurca and M. oviaraneae.     

A simulation experiment on phosphatized spherical microfossils

The identification and characterization of the phosphate preservation of the spherical microfossils in the Ediacaran Doushantuo time and the Early Cambrian has long been controversial.Modern artificial simulation experiments of phosphate animal eggs can provide scientific evidence to settle the aforementioned disputes.This experiment simulated environmental changes to observe the early morphological changes of the Bluntnose black bream eggs(Megalobrama amblycephala).It was found that the eggs can show a different morphology in the phosphate environment and that these eggs exhibited considerable morphological variations under different conditions.Thus,those eggs cannot be ascribed to the same species based only on the features.The experimental results are expected to provide a useful reference for the identification of phosphatized microfossils and provide a more empirical basis for their genesis.     

废弃蛋壳微波合成羟基磷灰石

以废弃蛋壳为主要原料,通过微波法合成了羟基磷灰石。对产品进行了红外光谱表征。探讨了加热温度、反应时间、物料状态、前期处理对合成产物的影响。     

余维数为2的中心仿射微分几何的积分公式

高余维子流形是偏向微分几何中难于处理的问题,鉴此,主要研究在余维数为２个情况下,中心仿射微分几何的积分公式。