杜梨对盐碱胁迫的生理响应及耐盐碱性评价

为探究不同杜梨资源对盐碱胁迫的生理响应及筛选耐盐碱资源,以甘肃、山西、辽宁等地收集的17份杜梨资源3000余株幼苗为试验材料,采用中性盐和碱性盐混合胁迫处理,测定盐碱抗性相关的生理指标,基于主成分分析法、热图及聚类分析法和抗逆系数法进行抗性评价。研究发现,抗性强的资源抗氧化酶活性和脯氨酸含量在受到胁迫后显著上升,300 mmol/L盐碱胁迫下超氧化物歧化酶活性显著上升的资源为河底杜梨3和平陆杜梨1,分别上升了75.04%、70.04%;过氧化物酶活性上升显著的资源为甘肃杜梨1和河底杜梨1,分别上升了1136.11%、742.86%;过氧化氢酶活性显著上升的资源为甘肃杜梨15、甘肃杜梨4,分别上升了344.58%、343.42%,脯氨酸含量显著上升的资源为平陆杜梨2、河底杜梨1、河底杜梨3,丙二醛含量上升较多的资源为甘肃杜梨16、甘肃杜梨13、甘肃杜梨1。除甘肃杜梨13在低浓度(100 mmol/L)盐碱胁迫即出现明显盐害现象外,其他杜梨资源均在300 mmol/L浓度处理下才开始出现不同程度的盐害;利用不同方法进行耐盐碱性分析结果存在一定的差异,其中基于主成分分析法发现河底杜梨1、河底杜梨3、平陆杜梨1、甘肃杜梨15、山西杜梨1耐盐碱性强;基于热图和聚类分析发现甘肃杜梨4、甘肃杜梨15、平陆杜梨1、河底杜梨1和河底杜梨3具有较强的耐盐碱性;而利用抗逆系数法分析耐盐碱性较强的资源为甘肃杜梨1、河底杜梨1、甘肃杜梨16、甘肃杜梨4、甘肃杜梨15。综合3种方法的分析结果,河底杜梨1和甘肃杜梨15属于高抗盐碱类型,而甘肃杜梨13则为盐碱敏感型资源。

氯离子扩散系数测定仪标准与计量技术

氯离子扩散系数测定仪是用于测量混凝土抗氯离子侵蚀强度的检测设备,被广泛应用于水运工程领域混凝土耐久性检测试验,其工作性能和计量性能直接关系着测量结果的准确性,测量结果不准确将为水工建筑物的安全使用带来隐患。本文对影响检测结果的产品规格与性能提出具体要求;选取数字多用表和精密电阻等标准器搭建串并联基本电路,采用电学测量法对氯离子扩散系数测定仪的电压和电流进行检定试验并给出检定方法,选取标准铂电阻和恒温水槽等标准器对氯离子扩散系数测定仪的温度参数进行检定试验并给出检定方法。研究成果用于水运工程氯离子扩散系数测定仪行业标准和计量检定规程的制定。

销轴连接中3种不同形式耳板分析

销轴的连接已广泛应用于各个领域,在销轴连接中,一般采用加厚耳板中间部位的方式来分散耳板内孔壁所承受的应力。本文通过符合《钢结构设计标准》中满足销轴连接构造及强度要求的算例,运用有限元分析软件对不同形式的中部加厚耳板进行分析,为工程应用提供参考。

光电式含沙量测量仪器的校准方法及结果评定

为了维护航道港池泊位水深,每年需要投入大量的经费用于航道疏浚,准确测量水体中含沙量量值,可为港口及航道区域泥沙淤积量的计算、预报和后报提供准确的含沙量测量数据,这对于港口航道维护运营具有重要意义。为了解决水体中含沙量测量的准确性问题,研究了0.1~30 kg/m^(3)范围的含沙量标准场的配制及测试技术,采用烘干称重的方法对该含沙量标准场进行含沙量标准值测试,测试结果显示含沙量标准场均匀度均小于2.88%。提出含沙量测量仪器的校准方法,得到含沙量测量仪器的测量结果相对误差均小于7%。以实例分析了该校准测量结果的不确定度评定方法,实现对含沙量测量仪器的校准能力。

An assessment of the genetic diversity of pear(Pyrus L.)germplasm resources based on the fruit phenotypic traits

Germplasm resources are an important basis for genetic breeding and analysis of complex traits,and research on genetic diversity is conducive to the exploration and creation of new types of germplasm.In this study,the distribution frequency,coefficient of variation,Shannon-Wiener index,and variance and cluster analyses were used to analyze the diversity and trait differences of 39 fruit phenotypic traits from 570 pear accessions,which included 456 pear accessions from 11 species and 114 interspecific hybrid cultivars that had been stored in the National Germplasm Repository of Apple and Pear(Xingcheng,China).The comprehensive evaluation indices were screened by correlation,principal component and regression analyses.A total of 132 variant types were detected in 28 categorical traits of pear germplasm fruit,which indicate a rich diversity.The diversity indices in decreasing order were:fruit shape(1.949),attitude of calyx(1.908),flesh texture type(1.700),persistency of calyx(1.681),russet location(1.658),relief of area around eye basin(1.644),flavor(1.610)and ground color(1.592).The coefficient of variation of titratable acidity in the 11 numerical traits of pear germplasm fruit was as high as 128.43%,which could more effectively reflect the differences between pear accessions.The phenotypic differentiation coefficient V_(st)(66.4%)among the five cultivated pear species,including Pyrus bretschneideri(White Pear),P.pyrifolia(Sand Pear),P.ussuriensis(Ussurian Pear),P.sinkiangensis(Xinjiang Pear),and P.communis(European Pear),was higher than the within population phenotypic differentiation coefficient V_(st)(33.6%).The variation among populations was the main source of variation in pear fruit traits.A hierarchical cluster analysis divided the 389 accessions of six cultivated pear species,including P.pashia(Himalayan Pear),into six categories.There were certain characteristics within the populations,and the differences between populations were not completely clustered by region.For example,Sand Pear cultivars from Japan and the Korean Peninsula clustered together with those from China.Most of the White Pear cultivars clustered with the Sand Pear,and a few clustered with the Ussurian Pear cultivars.The Ussurian Pear and European Pear cultivars clustered separately.The Xinjiang Pear and Himalayan Pear did not cluster together,and neither did the cultivars.Seventeen traits,three describing fruit weight and edible rate(fruit diameter,fruit length and fruit core size),five describing outer quality and morphological characteristics(over color,amount of russeting,dot obviousness,fruit shape,and stalk length),and nine describing inner quality(flesh color,juiciness of flesh,aroma,flavor,flesh texture,flesh texture type,soluble solid contents,titratable acidity,and eating quality)were selected from the 39 traits by principal component and stepwise regression analyses.These 17 traits could reflect 99.3%of the total variation and can be used as a comprehensive evaluation index for pear germplasm resources.

混凝土搅拌楼强制式改自落式技术实现

在水利水电工程中,由于混凝土配比、施工工艺的不同,选用的混凝土设备也有所不同,本文介绍了一种把强制式混凝土搅拌楼改造为自落式混凝土搅拌楼的技术,成功把HL320-2S4500L强制式混凝土搅拌楼改造成HL400-4F5000L自落式混凝土搅拌楼,并在新疆JH水电站工程中应用。