The Leaching Behaviour and Balances of Nitrogen and Other Elements under Spring Wheat in Lysimeter Experiment 1985–92

Abstract

In a lysimeter study it was found that moderate rates of ammonium nitrate increased utilization percentages in spring wheat, and the leaching was 10% or less of added N. Over-optimal rates reduced utilization percentages and increased leaching to almost 50% of the highest doses. Late split application of calcium nitrate increased the percentage of N in grain. Furthermore, leaching of N was not reduced, but occurred somewhat later in the fall and winter seasons. Leaching of Cl^? was more rapid and that of SO₄ ^2- was delayed relative to the leaching of NO₃ ^?. Rather large negative N balances were obtained, also after over-optimal application rates, and total N content of the soil was reduced. Compared with the N₀ treatment, differences in soil N residues amounted to 15–25% of added N in seven years. Gaseous losses had apparently taken place both from the added N and from soil N according to the total-N analysis.     

联合收割机割刀驱动行星轮系多目标优化设计

针对联合收割机割刀机构的工作特点,采用2K-H型行星齿轮机构,分析了割刀机构工作原理。通过建立2K-H型行星轮系的优化设计模型,应用NSGA-2算法对2K-H型行星齿轮机构进行多目标优化设计。以最小体积和最大承载力为优化设计目标,通过编制MATLAB程序得到Pareto前沿,进而得到最优解,与以往多目标优化设计比较,设计得到了很好的改善。     

A possible mechanism of mineral responses to elevated atmospheric CO2 in rice grains

Increasing attentions have been paid to mineral concentration decrease in milled rice grains caused by CO2 enrichment, but the mechanisms still remain unclear. Therefore, mineral(Ca, Mg, Fe, Zn and Mn) translocation in plant-soil system with a FACE(Free-air CO2 enrichment) experiment were investigated in Eastern China after 4-yr operation. Results mainly showed that:(1) elevated CO2 significantly increased the biomass of stem and panicle by 21.9 and 24.0%, respectively, but did not affect the leaf biomass.(2) Elevated CO2 significantly increased the contents of Ca, Mg, Fe, Zn, and Mn in panicle by 61.2, 28.9, 87.0, 36.7, and 66.0%, respectively, and in stem by 13.2, 21.3, 47.2, 91.8, and 25.2%, respectively, but did not affect them in leaf.(3) Elevated CO2 had positive effects on the weight ratio of mineral/biomass in stem and panicle. Our results suggest that elevated CO2 can favor the translocation of Ca, Mg, Fe, Zn, and Mn from soil to stem and panicle. The CO2-led mineral decline in milled rice grains may mainly attribute to the CO2-led unbalanced stimulations on the translocations of minerals and carbohydrates from vegetative parts(e.g., leaf, stem, branch and husk) to the grains.     

转基因油菜TOPAS 19/2质粒分子多家协同实验及不确定度评定

质粒分子是转基因产品核酸定量检测的一类新型标准物质,具有易制备、周期短、成本低等特点。采用实时荧光定量PCR技术,并协同7家实验室对转基因油菜TOPAS 19/2质粒分子进行了基因组的可替代性研究、协同实验研究及不确定度评定。T检验表明,质粒和基因组所产生的内源和外源基因标准曲线的斜率和线性相关系数没有显著性差异。对多家定值的数据进行了统计分析得出,TOPAS19/2质粒分子的量值结果0.910,扩展标准不确定度（K=2）为0.013。     

早熟晚粳机插秧700kg/667m~2精确定量栽培技术规程

通过对早熟晚粳稻品种武运粳19号及武2645新品种的引种试验和示范,将"机插育壮秧、控行缩株适苗、麦草全量还田、精确定量施肥"等技术进行集成,制订了早熟晚粳机插精确定量栽培技术规程,以期为大面积机插秧实现高产提供技术支撑。     

W/O微乳液体系中SA和MS清除·O_2~-的研究

以水溶液体系作为对照,利用分光光度法研究了W/O型微乳液体系中水杨酸（SA）和水杨酸甲酯（MS）清除超氧阴离子自由基（·O2-）的性能.结果发现,在水浴时间为20min、pH值为8.20和邻苯三酚加入量适宜的情况下,W/O微乳液体系中SA、MS对·O2-的清除率分别可达72.92%、81.47%.微小的pH值变化会引起邻苯三酚自氧化速率的显著变化,电解质溶液对其也有明显的影响,但对SA、MS清除·O2-的能力影响不大.     

不同添加剂对柱花草青贮品质的影响

以热研2号柱花草为原料， 通过直接青贮（CK）、 添加山梨酸（0.2％）、 蔗糖（2％）、 青贮宝（0.1％）等处理， 30 d后测定了柱花草青贮饲料pH值、 乳酸、 乙酸、 丙酸、丁酸等含量并分析其主要营养成分含量。结果表明： 柱花草直接青贮品质较差， 添加山梨酸、 蔗糖、 青贮宝等处理能降低pH值和提高乳酸含量， 添加2％蔗糖能极显著降低pH值(p<0.01)、 提高乳酸含量(p<0.05)， 改善青贮品质， 提高营养价值。     

农业航空喷雾雾滴漂移及其数学分析

通过田间试验研究,探索了装配GP—81喷头的运五型飞机喷洒2,4—D丁酯乳油稀释液的雾滴漂移状况,建立了有关数学模型。研究表明,较低蒸发度的水雾滴漂移距离为340m,较高挥发度的2,4—D丁酯漂移距离达700m;雾滴密度和沉降量随下风距离增加而减小较快,雾滴直径减小较慢;气象因子和喷液配方对雾滴漂移有重要影响;三次多项式方程Y=b_0 b_1X b_2X~2 b_3X~3能很好地描述雾滴漂移与下风距离的关系,模型中的参数具有明确的实际意义,提出了喷洒2,4—D丁酯时的有效隔离带宽度。     

Tolerance to the Nephrotoxic Component of Narthecium ossifragum in Sheep: The Effects of Repeated Oral Doses of Plant Extracts

Young adult sheep were dosed with extracts of Narthecium ossifragum plants by the oral or parenteral routes and the resulting nephrotoxicity was assessed from the increases in the concentrations of creatinine and urea in the serum. Following single intraruminal or intraperitoneal doses of extracts derived from 30 g N. ossifragum (wet weight) per kg live weight (kg lw), serum creatinine concentrations increased from about 100 mol/L to between 260 and 510 mol/L. The serum urea concentrations increased from about 5–8 mmol/L to between 11 and 66 mmol/L in individual sheep. Daily intraruminal administration of 5–30 g/kg lw to three sheep over a 10- or 15-day period increased creatinine concentrations from 100 mol/L to 300–760 mol/L, and urea concentrations from 5–8 mmol/L to 35 mmol/L. A single intraperitoneal challenge dose of 30 g/kg lw, delivered 7 or 12 days after the final intraruminal dose, did not lead to increased serum creatinine or urea concentrations, indicating that oral treatment had apparently resulted in an increased tolerance to the nephrotoxic principle(s) in N. ossifragum.