Study on the Grain-filling Characteristic of the Succession of Wheat Cultivars in the Gully Areas of the Loess Plateau

为了解黄土高原沟壑区小麦品种演替过程中的籽粒灌浆特性,以此地区20世纪50年代至今的主栽小麦品种为供试材料,研究了不同小麦品种演替过程中籽粒干物质积累量及灌浆速率的变化。结果表明,黄土高原沟壑区小麦演替过程中,小麦籽粒千粒重呈现逐渐增加的趋势。平均灌浆速率逐渐增加,小麦籽粒的干物质积累随之增加,长旱58的W0最大,达50.53 g。灌浆三阶段中,各阶段的灌浆速率表现为,V2>V1>V3。从灌浆持续时间看,T1和T2持续的时间较长且变异系数较大,而T3和T相对稳定。从灌浆速率来看,V1、V2、V3、Vm、Va变异系数较大,灌浆速率易受环境因素影响而波动

小麦小偃22及其亲本灌浆特性研究

以小偃22及其亲本小偃6号和小偃107为试验材料,研究小偃22的灌浆特性与其亲本的异同。试验结果表明,籽粒干重随花后天数变化均可用Logistic方程拟合其灌浆曲线,拟合效果良好;小偃22的平均灌浆速率大于亲本,超亲优势达16.94%;小偃22缓增期灌浆速率和持续天数变异系

干旱胁迫对紫花苜蓿幼苗形态和生理特征的影响

为研究干旱胁迫对不同紫花苜蓿品种幼苗生长的影响,选取我国北方育成的5个耐寒苜蓿品种,采用盆栽实验的方式,模拟不同干旱胁迫水平(对照、轻度干旱、中度干旱和重度干旱)。通过测量紫花苜蓿幼苗农艺指标、形态和生理特征,并利用隶属函数综合评估各品种的耐旱性。研究结果表明,干旱胁迫程度显著影响苜蓿的形态和生理特征,随干旱胁迫程度的升高,各品种苜蓿形态性状中的地上生物量、基茎粗、株高、根长、叶片数和根瘤数下降,而根长、叶绿素含量和可溶性蛋白质含量表现为先升高后下降的趋势。经综合评价,5个品种抗旱性能力由强到弱依次为:敖汉苜蓿>公农1号>甘农3号>龙牧803>东苜1号。综上所述,敖汉苜蓿适合在重度干旱条件下种植,甘农3号适合在轻度和中度干旱条件下种植,公农1号在各干旱条件下种植表现均优。以上结果为紫花苜蓿的耐旱研究、抗旱选育及在干旱、半干旱地区的栽培种植提供了重要信息

Soil Water Variation of Alfalfa Grassland under Different Planting Patterns in the Loess Plateau of China

在长期定位试验的基础上,通过田间实地测定0~400 cm土壤含水量,分析和比较了不同种植方式下苜蓿草地土壤水分的变化。结果表明,连作苜蓿地、轮作苜蓿地的400 cm土层平均土壤含水量分别为10.6%和11.4%,均低于土壤稳定湿度,其干燥化指数为24.6%和37.2%,分别属强烈干燥化和严重干燥化,而小麦连作的干燥化指数为86.4%,属轻度干燥化。连作苜蓿地土壤干层最厚,400 cm处仍十分干燥,而轮作苜蓿地和连作小麦地到240 cm以下时,土壤水分开始有所恢复。连作苜蓿地和轮作苜蓿地通过降雨可恢复部分土壤水分,可恢复的土壤深度为40 cm和60 cm,而连作小麦地可达100 cm。不同施肥措施下连作苜蓿地土壤干燥化程度都很严重,施肥措施不是造成土壤干燥化的主要原因。轮作系统中不同轮作年限苜蓿地的土壤水分状况有一定的差异,但是均没有形成深厚的土壤干层。与连作苜蓿相比,轮作苜蓿不会大量消耗土壤深层水分而形成深厚的土壤干层,有利于土壤水分的可持续利用

Microstructural Evolution of Shear Localization in High-Speed Cutting of CoCrFeMnNi High-Entropy Alloy

Shear localization is one of the most important failure mechanisms subjected to high-strain-rate deformation and has significant effects on the process, plastic deformation, and catastrophic failure of a material. Shear localization was observed in serrated chips produced during the high-speed cutting of the CoCrFeMnNi high-entropy alloy. Electron backscatter diffraction was performed to systematically investigate microstructural evolution during shear banding. The elongation and subdivision of the narrow grains were observed in the areas adjacent to the shear band. The microstructure inside the shear band was found to be composed of equiaxed ultrafine grains. The results reveal that grain subdivision and dynamic recrystallization might have significant roles in the microstructural evolution of shear bands. These results offer key insights into our understanding of shear localization and high-speed machining behavior for high entropy alloys

The Effects of Irradiation on the Allergenicity of Crab Tropomyosins

食物过敏是当前食品安全领域较为突出的问题,辐照作为食物过敏原的加工处理方法之一,引起了学者的重视.作者对中华绒鳌蟹和三疣梭子蟹的主要过敏原(原肌球蛋白)进行了辐照处理,并分析了辐照处理对原肌球蛋白性质的影响.十二烷基磺酸钠-聚丙烯酰胺凝胶电泳结果显示,部分纯化的蟹类原肌球蛋白经7 kgy辐照处理后出现明显降解,10 kgy辐照处理后完全降解;蟹类过敏者血清的免疫印迹分析结果显示,部分纯化原肌球蛋白经3--7 kgy辐照处理后的过敏原性无明显变化,而10 kgy辐照处理后的过敏原性降低;兔抗锯缘青蟹原肌球蛋白抗体的免疫胶体金层析检测结果证实部分纯化原肌球蛋白经10 kgy辐照处理后的抗原性为阴性.但是,3--10 kgy辐照处理对整蟹原肌球蛋白及其过敏原性无明显影响,模拟胃液消化反应结果也表明3--10 kgy辐照处理对整蟹原肌球蛋白的酶解消化特性无明显影响.Food allergy is a prominent issue in the field of food safety.Irradiation treatment of food allergens has aroused extensive attention in the world.This study focused on the effects on the characteristic of the allergen(tropomyosins) from Chinese mitten crab and Swimming crab through irradiation.Analysis of SDS-PAGE showed that partially purified tropomyosins obviously degraded after treated with 7 kGy dose while almost degraded after 10 kGy treatment.Analysis of Western-Blotting with crab allergenic patients' sera indicated that the allergenicity of partially purified tropomyosins that treated by 10 kGy irradiation have an obvious decrease while that of partially purified tropomyosins treated by 3--7 kGy irradiation have slight differences.The results of the gold immunochromatography assay with animal antibody indicated that the antigenicity of partially purified tropomyosins was negative after treatment with 10 kGy irradiation.On the other hand,there was little effect on the allergenicity of tropomyosins from the entire Chinese mitten crab and the entire Swimming crab through irradiation.The simulating digestion experiment of gastric fluid also showed that there was little effect on the digestive stability of the tropomyosins from the entire crab through irradiation.国家自然科学基金(30571450;30871947);福建省科技计划重点项目(2006I0023;2006F5064)资

A comparative study of functional magnetic resonance imaging between successful aging and mild cognitive impairment aging

目的探讨成功老龄与轻度认知功能损害老年人执行认知任务时的脑功能差异。方法对10例成功老龄(成功老龄组)和9例轻度认知功能损害(MCI,MCI组)患者进行词汇流畅性作业(VFTs)的功能磁共振成像检查,比较两组的VFTs和脑激活结果。结果(1)成功老龄组平均激活强度(F=10.16)大于MCI组(F=7.86),差异有统计学意义(P<0.01)。两组间各脑区激活体积差异均有统计学意义(P<0.01)。(2)成功老龄组的脑激活呈一致优势侧偏[偏侧化指数(LIs)=0.46],左顶叶、前额叶(包括背外侧皮质)、扣带前回及双侧枕叶的激活明显。(3)MCI组的脑激活总体上无偏侧性(LIs=-0.12),除右前额叶外,脑激活普遍低下,枕叶无明显激活。结论成功老龄的脑功能明显优于MCI,左前额叶尤其是背外侧皮质可能是与此差异相关的主要脑区