Optimization of Vertical Distribution of Canopy Nitrogen

Summary

This article reviews the literature on the relation between vertical leaf nitrogen distribution and canopy photosynthesis, as a possible route to maximize radiation use efficiency, biomass production and yield potential in winter cereals. Main assumptions underlying the prediction of the optimum vertical leaf nitrogen allocation, i.e., the role of light climate within the canopy and total leaf nitrogen content, are revised. Dynamic aspects and possible impact of manipulation of vertical leaf N distribution on yield and quality of winter cereals are discussed and areas for future research highlighted.     

基于?ngstr?m-Prescott公式的中国太阳辐射与日照时间的关系研究

【目的】揭示中国不同地区太阳辐射与日照时间的定量关系,为缺资料地区太阳辐射的准确估算提供科学依据。【方法】基于114个地面辐射观测站和常规气象观测站1958—2016年的实测数据,在时间和空间上分别评价?ngstr?m-Prescott(?-P)公式的适用性,运用ArcGIS地统计分析工具探索?-P公式系数a、b的空间分布规律,采用空间分析工具获取了各省级行政区的系数a、b。【结果】?-P公式在时间上具有可靠的预测性能,各站点计算值与观测值的标准化均方根误差(NRMSE)和标准化平均绝对误差(NMAE)的均值分别为0.103和0.079;在空间上有良好的扩展性,各站点NRMSE和NMAE的均值分别为0.103和0.078;从全国范围来看,系数a介于0.117～0.345之间,其变化规律为由东南沿海向西北内陆逐渐增大;系数b介于0.345～0.703之间,变化规律与系数a相反。利用各省级行政区系数a、b计算的各站点月平均日太阳辐射量与实测值进行对比,NRMSE和NMAE均值分别为0.105和0.081。【结论】?-P公式能够比较准确地描述中国不同地区月平均日太阳辐射量与月平均日照时间的定量关系,可通过空间插值的方法获取缺资料地区的公式系数,采用各省级行政区系数a、b估算的月平均日太阳辐射量具有较高精度。     

中洛复线电动阀门壳体开裂的原因分析

分析了中洛复线站场电动阀门壳体开裂的原因，指出阀门阀腔内存水结冰膨胀产生轴向推力使壳体受拉，壳体材质低温脆性及壳体内外存在的温差压力是壳体开裂的主要原因。总结了事故的经验教训，并对这种阀门的质量提出了几点改进意见。     

甘蓝型油菜辐射诱变初探

以甘蓝型双低油菜品种为材料,用3个不同60co-γ射线剂量(800Gy,1000Gy,1200Gy)辐射处理材料,研究品种辐射前含油量,芥酸,硫苷和硫等成分的含量与辐射后成苗率的相关性及辐射处理对成苗率和M1,M2植株主要产量性状的影响。结果表明:(1)辐射前种子芥酸和硫的含量与成苗率呈现显著或极显著正相关,且表现为随着辐射剂量的增加,相关系数增加;含油量与成苗率则呈现显著或极显著负相关,表现为随着辐射剂量的增加相关系数的负值增加。(2)基因型不同的甘蓝型油菜品种的成苗率同一剂量辐射处理间存在显著差异。(3)辐射M1植株与其对照在SSR引物上具有条带上的多态性。(4)辐射M1植株株高、分枝部位、单株角果总数、每株角粒数和单株重量明显低于对照,千粒重与对照的差异不显著;M2植株变异株系分枝部位与对照的差异达到0．01显著水平,明显低于对照,其它性状表现出的规律不明显。(5)国内春性品种最佳辐射剂量是1000～1200Gy,国外冬性较强的品种最佳辐射剂量则为800～1000Gy。     

辐射对甘蓝型油菜诱变效应初探

本试验以甘蓝型双低油菜品种为材料，用3个不同^60Co-γ射线剂量（800，1000．1200Gy）辐射处理材料，研究辐射对出苗率、成苗率及M1．M2植株主要产量性状的影响。结果表明：①辐射M1植株与其对照在SSR引物上具有条带上的多态性。②基因型不同的甘蓝型油菜品种的成苗率同一剂量辐射处理间存在显著差异，出苗率的差异依材料不同表现不同。③辐射M1植株株高、分枝部位、单株角果总数和单株重量明显低于对照．千粒重与对照的差异不显著；M2植株变异株系分枝部位与对照的差异达到0．01显著水平，明显低于对照，其它性状表现出的规律不明显。④国内春性品种最佳辐射剂量是1000．1200Gy，国外冬性较强的品种最佳辐射剂量则为800～1000Gy。     

PROTON IRRADIATION OF FELINE NASAL PLANUM SQUAMOUS CELL CARCINOMAS USING AN ACCELERATED PROTOCOL

Fifteen cats were treated for squamous cell carcinoma of the nasal planum using proton beam radiation. The protocol used was accelerated with eight equal fractions given on four consecutive days, with a minimum of six hours between fractions. Total dose of radiation delivered was escalated with nine cats receiving 40.4 CGE (60Co Gy equivalent), and three cats each receiving 42.4 and 44.8 CGE. Complete response to the protocol was 60% (9/15), partial response was 33% (5 of 15), and no response was seen in 6.6% (1 of 15). Tumor control rate at one year was 64% and no cat had tumor recurrence after one year. Median survival was 946 days (+/- 516 days). Side effects were minimal with no severe reactions noted in the early or late period. This protocol offers an effective treatment for squamous cell carcinoma of the feline nasal planum with minimal side effects and may be adaptable to conventional radiation sources particularly when the field size is very small.     

东北输油管网泄漏事故分析

分析了东北输油管网30多年来各类泄漏事故的具体原因,提出了按泄漏事故划分泄漏类型的观点。根据泄漏事故随时间变化的走势曲线,将管道整个服役期分为初生期、前亚稳定期、稳定期、后亚稳定期和衰老期。预计今后十年东北输油管网因腐蚀与外力因素引起的泄漏事故将有较大幅度的上升。     

Nitrogen Nutrition of Potato Cultivars Differing in Maturity

In potato, dry matter (DM) production and partitioning between plant organs and N accumulation are affected by N application; however, since cultivars differ in these processes, N fertilization must be adjusted to each cultivar. This paper studies the response of potato cultivars differing in maturity to N fertilization in the south-east of the Buenos Aires Province (37°45'S, 58°18'W) in two growing seasons. Treatments combined four N doses (0–180 kg ha⁻¹) and four cultivars: Jaerla (early), Spunta (mid-early), Mailén INTA (medium late) and Huinkul MAG (late). DM and N content were measured in leaves, stems and tubers throughout the growing season and intercepted photosynthetically active radiation was regularly assessed. There was an increase in tuber yield up to intermediate N doses (60 kg ha⁻¹ in 1990 and 120 kg ha⁻¹ in 1991). Tuber yield was similar for Spunta and Huinkul MAG. There was no interaction between cultivar and N fertilization for tuber dry matter yield. DM partitioning to leaves and tubers during the growing season differed among cultivars, but N availability affected partitioning similarly for all cultivars. Jaerla had a high and Huinkul MAG had a low radiation use efficiency between plant emergence and the beginning of tuber formation. Jaerla, Spunta and Mailén INTA reached maximum N content in foliage at ≈60 days after emergence and Huinkul MAG 20 days later. Total N content at maturity varied between 120 and 250 kg ha⁻¹ and was affected by cultivar and N dose. The results will help to improve N fertilization recommendations and management practices as related to each cultivar under the environmental conditions of this region.     

油罐凹瘪原因分析

分析了油罐在运行中发生凹瘪的原因，结果表明，油罐负压超限是导致其凹瘪的主要原因，列举了引起油罐负压超限的各种因素，其中机械呼吸阀反映的问题有，安装精度未达到要求，日常维护方式不当，被空气和油蒸气腐蚀后运动阻力增大等。