日光温室分段智能屋脊通风效果研究

针对现有日光温室人工通风方式劳动强度大、室内气温分布不均匀等问题,在温室内安装2台或3台智能型屋脊通风设备对温室进行2段或3段智能通风,并在北京地区冬季日光温室与人工通风控制进行了对比。结果表明:在保温被揭开期间,当采用3段智能通风时,温室内空气温度最大值与最小值之差为(1.1±0.5)℃;而2段智能控制和人工控制分别为(2.3±1.1)℃和(3.8±1.3)℃。此外,应用该智能屋脊通风技术,还能将667m2均效益提高0.97万元。因此,智能型屋脊通风设备可显著改善温室内温度分布的均匀性,提高种植的经济收益。     

我国果树玻璃化试管苗特征、成因、机理及控制研究进展

该研究统计了我国已报道的出现玻璃化试管苗的果树种类多达50种,并基于近年果树工作者的相关研究,总结并系统论述了玻璃化试管苗的生理生化特性、形态解剖学特征、DNA的MSAP分析、成因、发生机理及控制措施,对系统研究果树试管苗玻璃化现象、增加转基因植株的遗传稳定性、保存和恢复珍贵材料无性系、提高次生代谢物产量和消除毒性及工厂化育苗都具有十分重要的意义。     

地熊蜂为重庆地区设施番茄授粉的效果研究

为评价地熊蜂在重庆地区设施番茄的授粉效果,在重庆市荣昌区龙舌嘴村开展授粉效果比较试验,分析地熊蜂授粉对设施番茄产量、果实品质及畸形果率的影响。试验结果显示,经地熊蜂授粉的设施番茄平均产量为2 206.44 kg/667 m2,与未授粉组相比显著提高了104.95%,授粉组的单果质量、果纵径、果最大横径、可溶性固形物含量、VC含量及总糖含量显著高于未授粉组。由此,认为地熊蜂适宜为重庆地区设施番茄授粉,且能够显著提高重庆地区设施番茄的产量与品质。     

沈从文湘西世界中的狂欢化倾向

现代文学研究中以"牧歌"来概括沈从文创作风格。但是,沈从文笔下的湘西世界充满着动荡、躁动和不安,形成了有别于传统"牧歌"审美价值的"狂欢"世界。呈现了节庆、婚嫁和丰收等富有民族特色的嬉闹杂耍的狂欢场面;建构了以生死和肉体为核心的狂欢化意象;通过回环的叙事模式、双重的叙事空间及诙谐语言和咒骂语言构筑了鲜明的狂欢式话语系统。沈从文笔下的湘西世界应和了巴赫金的"狂欢"理论,指认着获得民族和文化认同的乡土"类狂欢"形态。     

外源ACC通过激活乙烯合成及信号转导诱导小豆抗锈性

大量研究表明, 乙烯可激发植物对死体营养型真菌的抗性, 但我们前期研究发现, 乙烯合成前体ACC可提高小豆对活体营养型真菌——锈菌的抗性, 为初步明确其机制, 本研究分析了ACC处理对小豆乙烯合成及信号转导的影响, 结果表明, ACC处理显著提高了乙烯合成基因VaACS1及信号通路关键基因VaEIN2?VaEIN3?VaERF5的表达水平?此外, ACC处理后再接种锈菌, 小豆锈病的发病程度显著降低?对接种锈菌后不同时间VaPR2和VaPR4的表达分析表明, 相比ACC处理后不接种对照, ACC处理后再接种锈菌的处理, 接种后1~5 d这两个基因表达量显著升高; 与水处理不接种锈菌相比, 水处理接种锈菌5~8 d后VaPR2和VaPR4的表达量虽显著上调, 但应答时间较ACC处理滞后, 且总体表达水平低, 表明ACC激活乙烯通路进而诱导防卫反应基因上调表达是其诱导小豆抗锈性的关键?     

水氮调控对苜蓿与无芒雀麦混播草地生长和辐射利用的影响

针对我国内陆干旱区人工草地生产管理粗放及气候资源利用不充分等问题,探究合理的牧草种植与水氮供应模式,以充分挖掘区域牧草的生产潜力。采用3 a生(2018年播种)紫花苜蓿(简称‘苜蓿’)和无芒雀麦,分析种植模式(苜蓿与无芒雀麦混播,D1;无芒雀麦单播,D2)、施氮量(低氮量N1:60 kg·hm^-2;高氮量N2:120 kg·hm^-2)和灌水量(以灌水下限占田间持水量θ_f的百分比计,分枝期均充分灌水(75%～85%θ_f),现蕾和初花期轻度亏水W1:65%～75%θ_f、中度亏水W2:55%～65%θ_f、重度亏水W3:45%～55%θ_f,灌水上限均为85%θ_f)对牧草叶面积指数(LAI)、干物质累积量、累积截获光合有效辐射量(CIPAR)、辐射利用效率(RUE)、产量(Y)、耗水量(ET_a)、水分利用效率(WUE)和氮肥偏生产力(PFP_N)的影响。结果表明：(1)牧草LAI和...     

Physiological but not morphological adjustments along latitudinal gradients in a human commensal species,the Eurasian tree sparrow

Human commensal species take advantage of anthropogenic conditions that are less likely to be challenged by the selective pressures of natural environments. Their morphological and physiological phenotypes can therefore dissociate from habitat characteristics. Understanding how these species adjust their morphological and physiological traits across latitudinal gradients is fundamental to uncovering the eco-physiological strategies underlying coping mechanisms. Here, we studied morphological traits in breeding Eurasian tree sparrows (ETSs; Passer montanus) among low-latitude (Yunnan and Hunan) and middle-latitude (Hebei) localities in China. We then compared body mass; lengths of bill, tarsometatarsus, wing, total body, and tail feather; and baseline and capture stress-induced levels of plasma corticosterone (CORT) and the metabolites including glucose (Glu), total triglyceride (TG), free fatty acid (FFA), total protein, and uric acid (UA). None of the measured morphological parameters varied with latitude except in the Hunan population, which demonstrated longer bills than those in other populations. Stress-induced CORT levels significantly exceeded baseline levels and decreased with increasing latitude, but total integrated CORT levels did not vary with latitude. Capture stress-induced significantly increased Glu levels and decreased TG levels, independent of site. However, the Hunan population had significantly higher baseline CORT, baseline and stress-induced FFA levels, but lower UA levels, which differed from other populations. Our results suggest that rather than morphological adjustments, physiological adjustments are mainly involved in coping mechanisms for middle-latitude adaptation in ETSs. It is worth investigating whether other avian species also exhibit such dissociation from external morphological designs while depending on physiological adjustments.     

野生老芒麦种质资源鉴定与基部叶鞘绒毛变异分析

为更好地利用老芒麦(Elymus sibiricus L.)野生资源,本研究从我国青藏高原、西北、华北、东北地区以及国外部分地区共采集了1 723份野生披碱草属种质资源,通过表型特征观测和流式细胞仪检测,共鉴定出了990份野生老芒麦种质,246份垂穗披碱草种质,并测得老芒麦的DNA含量在5.86～7.30 Gb之间,平均DNA含量为6.66 Gb;垂穗披碱草材料的DNA含量在9.50～10.36 Gb之间,平均DNA含量为9.97 Gb。研究结果显示,在西北、华北以及东北地区的部分野生老芒麦材料在苗期基部叶鞘出现了绒毛,分析发现该表型出现的概率与经度和纬度呈极显著正相关关系(P<0.01),与海拔、年年均气温以及年平均降雨量呈极显著负相关关系(P<0.01)。表明老芒麦苗期基部叶鞘绒毛的有无与环境因子之间存在着必然的联系,可能是老芒麦种质应对不同环境类型的适应性机制之一。本研究为老芒麦的形态鉴定提供了新的依据,为老芒麦种质资源挖掘和育种应用提供了材料基础。     

FLUENT软件及其在植保机械方面的应用

FLUENT软件是流体力学中通用性较强的商业软件之一，由于FLUENT软件的应用，节省了大量的人力和物力。对实际应用有重大的指导作用。为此，通过简述FLUENT在植保机械方面的应用实例，提出了FLUENT在植保机械方面的发展前景。     

Biodegradation of Linear Alkyl Benzene Sulphonate

The paper researches on the degradation of LAS (Linear Alkyl benzene Sulphonate) by combining AS1.860 immobilized with low intensity ultrasonic irradiation. The paper also discusses the influence of pH, rotary velocity, LAS concentration and the condition of low intensity ultrasonic irradiation on the degradation of LAS, the degradation rate of LAS is the main index of our experiment, the results of orthogonal test shows that low ultrasonic irradiation can increase the metabolizing of microorganism cells and facilitate the biodegradation of immobilized cells to LAS, here we research the degradation condition of 50mg/L LAS simulation wastewater with low ultrasonic irradiation, and the results show that the influence is obvious, the optimization degradation rate is about 83%, nine point five percent higher than that of the immobilized cells without ultrasonic irradiation.