四倍体刺槐茎段遗传转化体系优化的研究

利用携带pCAMBIA2300-beta质粒的根癌农杆菌GV3101对四倍体刺槐的茎段进行遗传转化,并从As用法、菌液的活化及低温预培养3方面对四倍体刺槐转化效率的影响进行研究,发现用As溶液对外植体伤口处进行浸泡处理可明显提高抗性芽的获得率,得到的转基因株系经PCR检测为阳性。     

越冬池溶解氧含量的无线监测与控制系统初步设计

为确保鱼类安全越冬,避免因越冬池缺氧而大量死亡,设计了越冬池溶解氧含量无线监测和增氧机控制系统。该系统运行安全可靠,能够保证鱼类越冬生产的安全性,提高鱼类越冬成活率。     

Effects of dietary live or heat‐inactivated autochthonous Bacillus pumilus SE5 on growth performance,immune responses and immune gene expression in grouper Epinephelus coioides

To evaluate the possible dietary application of live and heat‐inactivated probiotic Bacillus pumilus SE5 in grouper Epinephelus coioides, juveniles (14.6 ± 0.2 g) were fed either a basal control diet (without probiotic) or the basal diet supplemented with 1.0 × 10⁸ CFU g^?1 live (T1) and heat‐inactivated B. pumilus SE5 (T2). The heat‐inactivated probiotic significantly improved the final weight, weight gain (WG) and specific growth rate (SGR) at day 60 and significantly decreased the feed conversion ratio (FCR) at day 30 and 60, while the viable probiotic significantly decreased the FCR at day 60 (P < 0.05). Phagocytic activity, serum complement C3 and IgM levels as well as SOD activity elevated significantly in fish fed the heat‐inactivated probiotic for 60 days (P < 0.05). Furthermore, the heat‐inactivated probiotic remarkably up‐regulated expression of TLR2 and pro‐inflammatory cytokines (IL‐8 and IL‐1β) in head kidney (P < 0.05), but the viable probiotic failed to do so. These results indicated that heat‐inactivated B. pumilus SE5 can effectively improve the growth performance and immune responses of E. coioides.     

南戴河海域人工鱼礁增养殖海参技术

海参是棘皮动物门海参纲动物的统称,我国有海参140种,其中以北方沿海产的刺参(Apostichopus Japonicus)品质最好,刺参具有很高的营养与药用价值,属珍贵海味,列为"八珍"之一.     

基于驾驶意图的无级变速器目标速比确定方

运用模糊数学理论提出一种基于驾驶意图的金属带式无级变速器(CVT)目标速比的确定方法,不需采用传统的经过手动方式选择动力模式或经济模式的方式,即可确定一个在动力和经济模式之间的目标速比.根据基于模糊规则的驾驶意图指数确定的目标速比进行CVT的速比控制,以达到按照驾驶意图来兼顾汽车的动力性和经济性能,从而避免了传统模式选择过程中速比突变导致传动系统的冲击、振动和发动机颤动,且能够根据驾驶员的驾驶意图进行调整,提高了驾驶操纵性.最后根据目标速比控制策略设计了控制器,并通过试验验证了目标速比确定方法的适用性.     

滚动轴承摩擦力矩的非线性特

以混沌理论为基础,通过试验研究滚动轴承摩擦力矩时间序列的非线性特征评估问题,为精确计算滚动轴承摩擦力矩的动态性能奠定基础.用关联维数标准差刻画摩擦力矩的不确定性,用关联维数均值描述摩擦力矩非线性特征的演变历程.研究表明,滚动轴承属于确定的非线性动力学系统,但其摩擦力矩呈现出明显的不确定性.随着转速的增加,滚动轴承摩擦力矩关联维数标准差与均值都呈现出非线性增大的趋势.     

Studies on fish heterosis with DNA fingerprinting

One Tilapia hybridization, Oreochromis aureus, (Steindachner) ♂ × Oreochromis niloticus, (Linnaeus) ♀, and two common carp, Cyprinus carpio, (Linnaeus) ♂, hybridizations, Russian mirror carp ♂ × Xingguo red carp ♀, and German mirror carp ♂ × Xingguo red carp ♀ were used to study the feasibility of predicting heterosis using genetic distance from DNA fingerprinting. The results indicated that highly polymorphic DNA fingerprints could be obtained with human minisatellite 33.6 as a probe on the studied varieties. The within‐population similarity indices of O. aureus, O. niloticus, Russian mirror carp, German mirror carp and Xingguo red carp were 0.785, 0.577, 0.432, 0.348 and 0.339 respectively. The similarity indices between F1 and their parents of three hybridization combinations were not significantly different (P > 0.05). There were larger genetic distances between two hybridization combinations, O. aureus♂ × O. niloticus♀ and Russian mirror carp ♂ × Xingguo red carp ♀, which showed heterosis in production and were extensively used in Chinese aquaculture. The genetic distance between O. aureus♂ and O. niloticus♀ was 0.338, and that between Russian mirror carp and Xingguo red carp was 0.344. However, the genetic distance between German mirror carp and Xingguo red carp was 0.129; this corresponded with the fact that their F1 generation did not show heterosis in the Chinese fish hybridization experiment. The study suggested that genetic distance could be used to predict fish heterosis.     

不同肥料类型对赤水河流域毛竹林生产力的影响研究

为提高赤水河流域毛竹林的生产力,采用随机区组设计,试验研究了尿素和不同氮、磷和钾配比的复合肥B、C、D对毛竹林出笋成竹、新竹质量和地上生物量的影响。结果表明:1)尿素对毛竹林成竹量和枝叶生物量的影响达显著水平,其出笋量、成竹量、新竹平均胸径、胸高断面积、秆材量和地上生物量分别为对照的120.17%、130.70%、93.49%、114.03%、111.37%、113.74%,表现出生物量上升而新竹质量降低的效果,生产上需慎用; 2)复合肥B对毛竹林的新竹胸高断面积、秆材量、枝叶量和地上生物量的影响均达显著水平,其出笋量、成竹量、新竹平均胸径、胸高断面积、秆材量和地上生物量分别为对照的112.50%、121.69%、101.76%、125.69%、126.41%、125.81%,表现为新竹质量和生物量上升,适宜于培育大径用材林; 3)复合肥C对毛竹林各项生产力指标的影响均未达显著水平,其出笋量、成竹量、新竹平均胸径、胸高断面积、秆材量和地上生物量分别为对照的101.42%、118.28%、100.10%、118.80%、119.07%、118.89%,适宜于培育笋用林和笋材兼用林; 4)生产力综合效应指数大小呈复合肥B (682.63%) > 复合肥C(476.35%) > 尿素(445.26%) > 复合肥D(261.37%) > 对照(100.00%)的变化趋势。     

20.67%万兴乳油对香蕉叶斑病的毒力测定与防治试验

香蕉尾孢菌叶斑病是危害香蕉的重要病害之一,在华南香蕉产区夏秋生长季节大量发生,严重危害香蕉叶片.2001～2003 年进行的新型复配杀菌剂20.67%万兴乳油对香蕉尾孢菌的毒力测定及对香蕉叶斑病的防治试验研究结果表明,20.67%万兴乳油对香蕉尾孢菌的抑制效果明显,对香蕉叶斑病防治效果优良,且对香蕉安全,施药3次的防治效果达81.23%～83.33%,优于对比药剂25%敌力脱乳油1 500倍的防效,是一种具保护兼治疗作用的高效杀菌剂,值得在香蕉生产上推广使用.     

输尿管镜下与开放尿道会师术治疗早期尿道球部损伤的疗效比较

目的比较输尿管镜下和开放尿道会师术治疗早期尿道球部损伤的疗效。方法 79例早期尿道球部损伤患者分别行输尿管镜下尿道会师术(40例)及开放性尿道会师术(39例)。比较两组手术时间、出血量、住院时间、治疗费用、最大尿流率、尿道狭窄率。结果输尿管镜组的手术时间、出血量、住院时间、治疗费用、尿道狭窄率明显低于开放组(P<0.01),但最大尿流率明显高于B组(P<0.01)。结论输尿管镜下尿道会师术治疗早期尿道球部损伤的疗效优于开放性尿道会师术。