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991.
隙控式全射流喷头性能特点及与摇臂式喷头的比较研究 总被引:7,自引:3,他引:7
研制了一种新型旋转式喷头——隙控式全射流喷头,介绍了其结构形式及工作原理。首次对二种PX10型号的全射流喷头及一种PY210摇臂式喷头的水力性能进行了对比试验及分析。研究表明:隙控式全射流喷头的流量大于试验用PY2摇臂式喷头8%左右,射程比摇臂式喷头的射程明显加大,最大增幅达到31%。全射流喷头水量分布均匀性与摇臂式喷头相当,但末端雨滴直径小于摇臂式喷头。由于其独特的射流元件及反向机构,全射流喷头结构简单,性能优良,价格低廉,具有显著的节能效果及良好的市场前景。 相似文献
992.
Shuiyang Yu Hai Long Hong Yang Jie Zhang Guangbing Deng Zhifen Pan Erliang Zhang Maoqun Yu 《Euphytica》2012,186(1):247-255
Powdery mildew (Pm), caused by Blumeria graminis f. sp. tritici (Bgt), is one of the most serious diseases for common wheat in many regions around the world. Seeking for new resistance source is urgently required to meet the challenge of the rapid loss of resistance due to the co-evolution of the pathogen’s virulence. Wheat line 07jian126 (Triticum aestivum L.) is highly resistant to the Pm disease prevailing in Sichuan province of China. Previous study showed that a SSR marker Xbarc183 was linked to the Pm resistance in 07jian126, which might be controlled by a single dominant gene, designated as Pm07J126. In this study, two additional F2 populations were used to confirm the linkage between Pm07J126 and Xbarc183. Furthermore, rye chromatin was detected in 07jian126 by molecular analysis of a rye-specific SCAR marker O5 which co-segregated with Pm07J126. This result indicated that Pm07J126 might originate from rye. The reaction patterns to 21 Bgt isolates and molecular marker analysis implied that Pm07J126 might be different from the known rye-derived Pm genes Pm7, Pm8, Pm17 and PmJZHM2RL. Chromosome observation, molecular marker, and A-PAGE analysis suggested that 07jian126 might be a rye introgression line and neither contain 1RS translocation nor secalins gene. Consequently, 07jian126 could be considered as a valuable resource for Pm resistance development of wheat. Besides, the molecular markers Xbarc183 and O5 are useful in marker-assisted selection of Pm07J126 in wheat breeding programs. 相似文献
993.
四川黑茶品质化学成分的研究 总被引:12,自引:2,他引:12
采用氨基酸自动分析法、高效液相色谱法分析了四川黑茶原料、渥堆叶、康砖成品茶的氨基酸、儿茶素组成含量及咖啡碱、茶多酚、水浸出物的含量。四川黑茶原料氨基酸含量为1424.00βmg/100g,必需氨基酸含量为547.00βmg/100g,茶氨酸含量为87.15βmg/100g,儿茶素含量为27.63βmg/g,咖啡碱、茶多酚、水浸出物含量分别为1.30%、8.18%、26.94%;渥堆叶氨基酸含量为1590.00βmg/100g,必需氨基酸含量为668.00βmg/100g,茶氨酸含量为67.62βmg/100g,儿茶素含量为27.52βmg/g,咖啡碱、茶多酚、水浸出物含量分别为1.24%、7.90%、24.53%;康砖成品茶氨基酸含量为1420.00βmg/100g,必需氨基酸含量为529.00βmg/100g,茶氨酸含量为66.88βmg/100g,儿茶素含量为13.65βmg/g,咖啡碱、茶多酚、水浸出物含量分别为1.27%、5.99%、23.92%。 相似文献
994.
Soil fauna can sensitively respond to alterations in soil environment induced by land-use changes.However,little is known about the impact of urban land-use changes on earthworm communities.In this study,three land-use types(i.e.,forest,nursery and abandoned lands)were chosen to identify differences in diversity,abundance and biomass of earthworm community in Kunming City.Urban land-use had a pronounced difference in species composition,evenness and diversity of earthworm communities.Forest land had the highest density,biomass and diversity of the earthworm communities.Total abundance was dominated by endogeic species in nursery land(70%)and abandoned land(80%),whereas in the forest land,the earthworm community comprised epigeic,endogeic and anecic species.Temporal changes in earthworm density and biomass were also significantly affected by land-use change.Total density and biomass of earthworms in the forest and nursery lands were highest in September,but highest in the abandoned land in October.The influence of soil physicochemical properties on the earthworm density and biomass also varied with land-use types.Soil temperature significantly affected earthworm density and biomass in the three land-use types.Soil pH was positively correlated with earthworm biomass in the forest land,but negatively associated with earthworm density in the abandoned land.Soil organic matter was positively correlated only with density and biomass of earthworms in the nursery and abandoned lands.Our results suggest that the species composition,abundance and biomass of earthworm communities can be determined by the modification of soil properties associated with urban land-use type. 相似文献
995.
植物根系生长的三维可视化模拟 总被引:16,自引:0,他引:16
利用模拟植物形态结构的L系统理论结合计算机图形学方法建立了模拟植物根系生长的三维可视化模拟系统。并利用随机参数L系统方法对豆科作物根系的生长过程进行了模拟。 相似文献
996.
不同日粮营养水平对种鸽繁殖性能的影响 总被引:4,自引:0,他引:4
试验一设计了4种不同蛋白质、能量水平的颗粒料配方 ,通过试验筛选出基础日粮的ME和CP分别为11.86MJ/kg和16 %。在试验一的基础上 ,试验二设计了3种不同Ca含量颗粒料配方 ,,以鸽场饲喂的饲料作对照 (ME为13.31MJ/kg,CP为11.79 % ),进行饲养试验。结果表明 :ME为11.86MJ/kg、CP为16.16 %、Ca含量为1.09 %的颗粒料效果较好 ,种鸽的繁殖指标较高 相似文献
997.
本文通过免疫药理作用的实验研究证明,低胆红素培植牛黄(胆红素含量为8.7%),按1g/kgpo给药对小鼠溶菌酶活力,单核巨噬细胞系统的吞噬功能,DNCB所致的迟发型过敏反应以及B淋巴细胞功能均有显著的抑制作用。 相似文献
998.
999.
1000.
基施磷肥对石灰性土壤上番茄产量的影响 总被引:4,自引:0,他引:4
A lysimeter experiment with undisturbed soil profiles was carried out to study nitrogen cycling and losses in a paddy soll with applications of coated urea and urea under a rice-wheat rotation system in the Taihu Lake region from 2001 to 2003. Treatments for rice and wheat included urea at conventional, 300 (rice) and 250 (wheat) kg N ha^-1, and reduced levels, 150 (rice) and 125 (wheat) kg N ha^-1, coated urea at two levels, 100 (rice) and 75 (wheat) kg N ha^-1, and 150 (rice) and 125 (wheat) kg N ha^-1, and a control with no nitrogen arranged in a completely randomized design. The results under two rice-wheat rotations showed that N losses through both NH3 volatilization and runoff in the coated urea treatments were much lower than those in the urea treatments. In the urea treatments N runoff losses were significantly (P 〈 0.001) positively correlated (r = 0.851) with applied N. N concentration in surface water increased rapidly to maximum two days after urea application and then decreased quickly. However, if there was no heavy rain within five days of fertilizer application, the likelihood of N loss by runoff was not high. As the treatments showed little difference in N loss via percolation, nitrate N in the groundwater of the paddy fields was not directly related to N leaching. The total yield of the two rice-wheat rotations in the treatment of coated urea at 50% conventional level was higher than that in the treatment of urea at the conventional level. Thus, coated urea was more favorable to rice production and environmental protection than urea. 相似文献