音响驯化技术在红鳍东方鲀养殖中的应用试验

网箱养鱼对水域所造成的污染,主要表现在两个方面:一是鱼的排泄物污染,二是剩余饵料造成的污染。通过对红鳍东方进行音响驯化,研究了解决剩余饵料对水域污染问题的方法,并求得了鱼类生长(体长与体重)与摄食量之间的关系曲线,从而达到减少剩余饵料沉积量,科学制定投饵量,指导网箱养殖红鳍东方快速、持续发展的目的。     

旅华欧洲游客旅游决策行为模式研究——以西安入境欧洲游客为例

研究以国家自然科学基金项目支持的入境旅游市场调查数据为基础,以入境游客旅游决策行为为切入点,通过对西安入境欧洲游客的问卷调查,对其旅游决策行为及其影响因素进行分析研究,对西安欧洲旅游客源市场的拓展提出针对性的建议和对策。     

藏山羊若干行为观察研究

对全放牧藏山羊若干行为进行了昼夜连续24小时跟踪观测研究。结果表明,藏山羊昼夜采食时间为541.37±93.65分。反刍为280.21±67.59分,睡眠为173.30±45.92分,游走为136.15±62.79分,站立为133.35±34.88分,其他行为占175.62±53.18分。采食、游走、站立及其他行为多发生在白天,反刍和睡眠多在夜间。反刍与采食的时间比例为0.52:1。藏山羊母性较强,好喜戏和觅群,少争斗。此外,藏山羊还有搔痒、打喷嚏、啃食异物等异常行为。研究结果,可供藏山羊的培育和饲养管理作为参改。     

Chromosomal location of genes controlling grain size in a large grained selection of wheat (Triticum aestivum L.)

Summary Grain size in wheat is the most stable yield component and has a favorable effect on flour yield. To identify the chromosomes associated with the large grains of line G603-86, (grain weight over 60 mg and grain length of about 9 mm), F₃ lines, extracted from F₂ populations obtained from F₁ monosomics of crosses between G603-86 (P₁) and the monosomic set of Favorit (P₂) were tested in the field. ANOVA showed significant differences among parents for grain weight and grain length, but not for grain width or the factor expressing the difference in grain form and density. Homoeologous groups had significant effects on grain weight and on all components of grain weight, while genomes were not significantly different for any of these characters. Grain weight was significantly increased by chromosomes 6D and 4A of G603-86. Grain length was significantly increased by chromosomes 4A, 4B, 2B, 3A and 1B, grain width by chromosomes 1A and 1B, and the factor form-density by chromosomes 6D and 6A. The high grain size in G603-86 results from the effects of genes located on many chromosomes which affect grain dimensions, form and density.     

基于刚度退化的框架结构受力性能研究

根据模型试验数据确定各变形阶段框架的实际抗侧刚度,采用框架抗推刚度退化系数对框架各楼层抗推刚度进行修正,再引入周期、剪力与侧移修正系数对弹性阶段的结构受力性能予以修正,提出一种考虑刚度退化时框架结构的计算方法,并给出具体计算步骤.以8层框架为例,探讨了抗侧刚度退化对结构受力性能的影响.结果表明:考虑结构的刚度退化,结构自振周期增大,楼层剪力减少,侧移增加,符合工程实际,且概念清晰,简单适用,能为现行规范的补充与完善提供参考.     

联吡啶类除草剂的作用机制及环境行为

介绍了以敌草快、百草枯为代表的联吡啶类除草剂的主要作用机制和选择机理,对该类农药在环境中的行为进行了归纳和探讨,指出该类除草剂对气候条件的影响并不特别敏感,挥发性亦不强,而与土壤的结合能力较强。展望了对其作用机制和环境行为的研究将进一步深入的前景。     

中年ICR小鼠和昆明小鼠种属型行为改变及其性别差异

探讨中年ICR小鼠和昆明小鼠种属行为的改变及其性别差异。结果表明,两品系中年小鼠的储藏行为没有改变。ICR小鼠的挖掘行为下降,且主要归因于雌鼠。两品系中年小鼠的作窝能力下降;ICR小鼠主要归因于雌性,昆明小鼠雌雄性均下降。这些结果提示在ICR和昆明小鼠,作窝能力的下降出现较早,可较好地反映衰老效应。挖掘和储藏行为对衰老效应的判定意义不大。     

利用核素示踪技术研究磷酸根在杭州西湖沉积物环境中的行为

运用32P同位素示踪技术,在实验室条件下研究了西湖沉积物中磷酸根的吸附和释放.结果表明:当磷酸根达最大释放量时,沉积物中的无机磷约有5%可以通过扩散等途径进入上覆水.而水层中95%的磷可以通过沉积物表面的吸附、交换等途径进入沉积物;E值测定表明:西湖沉积物含有78～184 μg/g可交换的P磷酸根的形态转化实验表明:磷酸根在15 d内大部分转化为不溶性的无机磷酸盐类,只有1.90%的标记磷以溶解态和吸附态存在.     

He-Ne激光对蚕豆(Vicia faba)根尖细胞的诱变效应

用不同剂量的 He-Ne 激光照射蚕豆干种子、湿种子、去皮湿种子和发芽种子,引起细胞发生变异。变异类型既有小核细胞和染色体断片,也有落后染色体及染色体数目变异。小核细胞的百分数从对照为0.47%增至3.09%,染色体总畸变率(断片+落后染色体+数目变异)从对照为1.24%增至8.88%。He-Ne 激光的剂量是17、34,68、102(J/cm~2)。在剂量为17—102(J/cm~2)的范围内,小核细胞的百分数和总畸变率都随剂量的增加而提高。     

Advances in Localization and Molecular Markers of Wheat Leaf Rust Resistance Genes

Genetic resistance is the most economical method of reducing yield losses caused by wheat leaf rust. To identify the leaf rust resistance genes in commonly used parental germplasm and released cultivars become very important for utilizing the genetic resistance tc wheat leaf rust fully. Up to date, about 90 leaf rust resistance genes have been found,of which 51 genes have been located and mapped to special chromosomes, and 56 genes have been designated officially according to the standards set forth in the Catalogue of Gene Symbols for wheat. Twenty-four wheat leaf rust resistance genes have been developed for their molecular markers. It is very important to isolate, characterize, and map leaf rust resistance genes due to the resistance losses of the genes caused by the pathogen continuously.