3种改良剂对不同土壤-水稻系统中Cd行为的影响

通过水稻盆栽试验,研究了钙镁磷肥、石灰和硅肥作为土壤改良剂对几种中度污染水稻土中Cd的赋存形态以及对水稻生长的影响和改善糙米品质安全性的作用。结果表明,由于各种改良剂的性质和改良机理上存在差异,改良效果各不相同,其中硅肥的改良效果最好,其次是钙镁磷肥,然后是石灰。虽然3种改良剂均能降低土壤中有效态Cd以及糙米和秸秆中Cd的含量,使稻米质量符合国家食品卫生安全标准,但土壤性质的不同会影响改良剂的效果。同一改良剂施用在红壤上的效果最为明显,其次是黄泥土,而呈碱性的潮黄土由于土壤有效态Cd的含量明显低于前两种土壤,施用改良剂后糙米和秸秆中的Cd含量虽有所降低,但改善效果不太明显。     

诱变结合小孢子培养的氮高效大麦DH株系评价

为了筛选大麦氮高效种质资源,以花30和8份不同诱变来源的DH株系为研究对象,采用田间试验方法,设置高氮(160 kg·hm-2)和低氮(45 kg·hm-2)两个氮肥水平,研究不同DH株系对两个氮肥水平的响应,同时对不同氮效率类型DH株系的干物质和氮素积累、转运以及氮素吸收利用特性进行分析.结果表明,在两个氮肥水平下,...     

喷口形状对喷水推进器性能的影响

为探究不同喷口形状的喷水推进器推进性能,以一台轴流式喷水推进器为研究对象,应用计算流体力学的方法针对3种不同形状(平面形、凸面形和凹面形)喷口的喷水推进器进行定常数值模拟,对比分析额定转速与高转速时其不同形状喷口内部流动特征和喷水推进器推力性能,从而寻找最优推力性能的喷口形状.计算结果表明：叶轮转速在不断变化时,平面形喷口的推力性能始终大于另外2种形状喷口的喷水推进器性能;在高于额定转速时,空化发生会影响叶轮做功能力,从而降低喷水推进器推力性能;在额定转速时,平面形和凹面形喷口推力性能较好,但平面形喷口最高轴向速度分布较多;高转速时,平面形喷口受空化影响最小,能够持续提供稳定的动力.研究结果揭示了不同喷口形状对不同转速下喷水推进器的适用性以及喷水推进效能,可为喷水推进器性能优化及设计提供一定的理论依据.     

不同保鲜膜对草莓果实贮藏品质的影响

以草莓"红颜"为试材,以PVC(聚氯乙烯)膜为对照,研究了PE(聚乙烯)膜、PHM(多层PE系)膜、纳米银膜、PVDC(聚偏二氯乙烯)膜等5种保鲜处理在(4.0±0.6)℃贮藏条件下对草莓果实失重率、硬度和可溶性固形物、维生素C、可溶性糖含量及感官品质的影响。结果表明:相较于PVC保鲜膜,PVDC膜与PHM膜能够较好的保持草莓果实的贮藏品质。其中PVDC膜包装可以有效地减少果实水分散失,保持草莓的硬度以及果实可溶性固形物含量;PHM膜包装可以较好的保持草莓果实可溶性固形物、维生素C、可溶性糖含量,维持果实的营养成分。     

麦田蚜茧蜂的初步研究

武昌麦田蚜茧蜂共有5种,以燕麦蚜茧峰、烟蚜茧蜂为优势种;重寄生蜂有三种,以黄足分盾细蜂为优势种。蚜茧蜂4月中、下旬进入麦田,5月中旬种群数量达到高峰:蚜茧蜂种群数量主要受寄主—蚜虫密度和4～5月的雨量,相对湿度的影响。麦田蚜茧蜂对麦蚜有一定的控制作用,寄生率最高可达40％以上。解决好重寄生和跟随现象的问题,可提高好苗蜂对麦蚜的控制效果。     

用喷雾器喷施线虫对其存活和侵染力的影响

试验表明,应用高压机动喷雾机喷施线虫,防治桃小食心虫,在每平方厘米10～20公斤压力下,对线虫的存活、侵染力和寄生强度,均无明显影响。     

转变畜牧业生产方式是草原生态保护建设的有效途径

以宁夏的做法和经验为例,论述了大力提高草原生产力、完善配套政策措施、转变畜牧业生产方式是草原生态保护建设的有效途径。     

Effect of L-lysine Added in Diluent on the Fresh Semen Quality of Dorper Sheep

In order to explore the effect of different L-lysine levels added in semen dilution on the fresh Dorper sheep quality stored at liquid state,3 health Dorper ram were used to collect semen which were equal-packaged and added to solution containing different levels (0,0.1,0.2,0.3,0.4 and 0.5 g) L-lysine in 120 mL diluent and at 0,6,24,30,48,54,72 and 78 h,the sperm motility,membrane integrity and acrosome integrity were detected.The results showed that the sperm motility in groups added 0,0.1 and 0.2 g L-lysine were higher than other groups,and that in 0.4 and 0.5 g L-lysine groups decreased faster than other groups;The sperm motility in 0.5 g L-lysine group reduced to 0 at 30 h,and it reduced to 0 at 48 h in the group added 0.4 g L-lysine;The effective survival time and survival index in the group added 0.1 g L-lysine was higher than other groups (P< 0.05);The membrane integrity of 0.1 g group was the highest,that had no significant difference with control group from 0 to 54 h (P >0.05),while after 72 h the two groups had significant differences (P< 0.05).The membrane integrity in 0.4 and 0.5 g groups were the worst,and that was significant different with other groups (P< 0.05);The acrosome integrity of 0.1 g group was the highest which had no significant difference with control group (P >0.05),0.4 and 0.5 g groups were the worst,the difference between them was not significant (P >0.05),while was extremely significant difference with other groups except for 0 and 6 h (P< 0.01).The results suggested that dilution added a high concentration of L-lysine could inhibit sperm quality,when the count of L-lysine was more than 0.2 g,sperm quality was significantly decreased,adding 0.1 g L-lysine could improve Dorper sheep fresh sperm quality stored at liquid state.     

钼蓝比色法测定笃斯越橘成熟果实中还原型抗坏血酸含量及体系优化

以笃斯越橘(Vaccinium uliginosum)成熟果实为试材,以钼蓝比色法测定笃斯越橘果实还原型抗坏血酸(Reduced ascorbic acid,As A)含量进行条件优化。结果表明,3%偏磷酸-乙酸用量为100μL、5%硫酸和5%钼酸铵用量均为200μL、以去离子水补充至1 500μL,30℃干热恒温浴显色40 min,取出室温下放置1 h后,在700 nm下测定,所得数据稳定,准确性适合用于笃斯越橘果实As A含量的测定;测得含量为(40.20±6.23)mg/100 g FW。     

苹果果实表皮总蛋白提取及双向电泳方法的优化

以苹果果实表皮为试材,采用3种方法提取果实表皮总蛋白,并对双向电泳(2-DE)操作体系进行优化。结果表明:改良酚提法适于苹果果实表皮总蛋白的提取,优化后的2-DE分离体系为预制IPG胶条18cm pH 4~7,上样量600μg,改进后的等电聚焦程序,浓度16%的分离胶,适于苹果果实表皮总蛋白的2-DE分离。