香菇液体菌种固化技术研究

食用菌液体菌种由于具有不耐贮藏和不便于运输等缺点,极大地限制了液体菌种的推广应用。研究报道了一种食用菌液体菌种固化技术,可有效解决液体菌种的上述缺点。在优选的蔗糖、豆饼粉液体培养基中摇瓶培养香菇856,将得到的菌丝球与优选的主要成分是棉籽壳的固化载体基质按1∶6的比例混合,制成固化菌种,室温保藏30d,与保藏0d的固化菌种相比,呼吸强度低,纤维素酶活力明显升高,萌发力强,菌丝生长快。     

不同碳源、氮源对香魏菇菌丝体生长的影响测定

以菌丝体生物量为指标,对香魏菇液体培养基中碳氮营养源进行了优化。结果表明香魏菇菌株能利用多种碳源、氮源,其中碳源以葡萄糖较好;有机氮源优于无机氮源,牛肉膏为较佳氮源。     

奶牛抗热应激中草药添加剂对小鼠热耐力的影响

试验研究奶牛抗热应激中草药添加剂对热应激小鼠机体耐力的影响。试验分A、B、C、D4个处理,每个处理20只小鼠,分别喂以不同添加剂浓度的饲料21d[A组:0.5g/(10g体重)、B组:0.25g/(10g体重)、C组:0.13g/(10g体重)、D组0g/(10g体重)],每日光暗节律各12h,自由摄食与饮水。试验结果表明,A、B组体重增加显著高于C、D组(P<0.01),A、B、C组小鼠死亡数显著少于D组(P<0.05),受热90min后,A、B、C组小鼠肛温比D组分别低0.3℃、0.3℃、0.5℃(P<0.05),说明该添加剂具有一定的提高小鼠热耐力作用。     

Seed yield and water use efficiency of canola (Brassica napus L.) as affected by high temperature stress and supplemental irrigation

The effects of high temperature stress and supplemental irrigation on seed yield and water use efficiency (WUE) of canola (Brassica napus L.) were studied in a field experiment conducted for 2 years. The experiment was a randomized complete block design arranged in split plot, conducted at Agricultural Research Station of Gonbad, Iran. It was arranged in two conditions, i.e. supplemental irrigation and rainfed. Two cultivars of canola (Hyola401 and RGS003) as subplots were grown at five sowing dates as main plots. The sowing dates were 9 November, 6 December, 5 January, 4 February and 6 March in 2005-2006 and 6 November, 6 December, 5 January, 4 February and 6 March in 2006-2007, to have a wide range of environmental conditions around flowering and seed filling periods, and to coincide reproductive stages of the crop with high temperature stress. Seed yield was improved due to field management practices, such as supplemental irrigation and optimum sowing date. Supplemental irrigation was an efficient practice to mitigate water stress, and to increase aboveground dry matter and seed yield. There was a strongly negative relationship between seed yield and air temperature during reproductive stages. Delay in sowing led to more rapid developmental of canola, decreased aboveground dry matter, leaf area index (LAI), harvest index (HI), WUE, and seed yield. Achieving a high aboveground dry matter was an essential prerequisite for high reproductive growth and a high seed yield. Greater seed yield and WUE at first sowing date were associated with greater LAI and aboveground dry matter, and lower temperatures during reproductive stages. The results support the view that WUE can be used as an indirect selection criterion for seed yield in genotypic selection.     

气吸振动式排种器种盘内种群运动的离散元分

根据离散元法的基本思想,采用线性弹簧-阻尼-滑动接触力学模型,编写Matlab模拟程序,分析了气吸振动式精密排种器振动种盘内种群的三维运动规律.为了描述籽粒离散分布程度,给出了体积膨胀系数的计算公式.结果表明,种盘作小幅高频振动,种群可以产生向上抛掷运动而有效分离;膨胀系数随着振动强度的增加而增大,随种层厚度的增加而减小.分析了摩擦因数和碰撞恢复系数对不同层厚种子膨胀系数的影响.在初始层厚参数hs≈3.8、振动强度kv=5.65时,种子具有理想的运动状态,通过性能试验得到排种器的吸种率达98%.     

针板电极荷电液体射流不稳定性分析

基于荷电液体射流的模型和广义坐标下的Lagrange方程,建立了静电场作用下无粘性液体射流的色散方程,并对该方程进行了数值求解,分析了若干因素对荷电液体射流的轴对称模型和非轴对称模型的影响.研究结果表明:随着电场强度的增大,荷电液体射流的最大扰动增长率增大.低电压时静电场对轴对称射流的不稳定性有显著作用,电压逐渐升高时非轴对称模型逐渐占据主导地位,最终导致液滴的破碎;随着射流半径的减小,荷电液体射流的不稳定性增加,轴对称模型下射流半径的改变对射流不稳定性的影响比非轴对称模型小;不同的液体介质对荷电液体射流不稳定性的影响在非轴对称模型下表现得更为显著.     

2BYS—6型水田中耕除草机设计与试验

简述了2BYS-6型水田中耕除草机的结构、工作原理及关键部件的设计,对该机旋转除草和摆动除草两种工作部件运动作了理论分析.田间试验结果表明:该机用于机插秧水稻田除草行间杂草平均除净率(相对除净率)78.1%,中耕深度4.39 cm,作物损伤率不大于6.89%.     

加压条件下气力轮式精密排种器性能分

针对研制的气力轮式精密排种器,采用均匀设计法设计试验,运用均匀设计软件UST 1.0建立了大豆排种性能指标数学模型,分析气力条件下排种器设计参数对排种性能的影响规律.分析表明:气力条件下,排种性能指标主要受气压和作业速度影响,气压范围为1.4～1.8 kPa时粒距合格率达到85%以上,满足8 km/h速度以上大豆精密播种;充种角和清种角变化对排种性能影响不显著,充种角和清种角优化区域与常压条件下排种试验优化结果一致:充种角为46.35°、清种角为55°;气流方向对排种性能没有显著影响.     

不同大气压下直喷式柴油机的性能研究

在大气模拟试验台架上对运行在不同大气压下的直喷式柴油机的经济性、动力性、烟度及噪声特性进行对比试验研究与分析。试验结果表明:随着大气压力的减少,柴油机有效燃油消耗率、小时燃油消耗量、排气温度、烟度及噪声声功率增加,动力性下降。     

农业综合开发与高效农业结合的思考

落实科学发展观,提高农业综合生产能力,促进农民增收,农业增效,是农业综合开发工作的出发点和落脚点。以泗阳县为例,就如何做好农业综合开发与高效农业的结合。提出了农业综合开发工作更好地服务、支持现代高效农业的发展思路和措施。