甲基红褪色光度法测定数量溴酸根离子

研究了盐酸介质中 ,在氯化纳的催化作用下 ,溴酸根离子氧化甲基红褪色的最佳条件 .吸收波长为 5 18nm .表观摩尔吸光系数为 7.2×10 4 L· m ol- 1 · cm- 1 ,溴酸根离子在 3.0～ 18μg/2 5 m L范围内符合比尔定律 .方法用于化学试剂中微量溴酸根的测定 ,结果令人满意 .     

播量和行距对紫羊茅种子产量的影响

本研究是在呼和浩特市的自然条件下，对紫羊茅种子产量在不同播种量和不同行距情况下进行了试验。结果表明，紫羊茅的最适播量７．５０ｋｇ／ｈｍ２，行距为３０ｃｍ，在此播种体系中种子产量平均可达６６２．５ｋｇ／ｈｍ２。     

金银花和红银花挥发性成分的顶空固相微萃取#br# 气质联用检测与比较

 采用顶空固相微萃取气质联用（SPME–GC–MS）的方法检测红银花与金银花新鲜花蕾和 干花蕾的挥发性成分。4 种花蕾样品共鉴定出67 种挥发性物质,其中新鲜红银花与金银花分别检测出48 种和46 种,经烘干处理的干红银花与金银花分别检测出34 种和37 种。[3.2.1.0（1,5）]三环辛烷、β– 芳樟醇、5–甲基–2–己醇和以及十六烷是4 种样品共有的成分。其中红银花挥发性成分主要以烃类、 醇酮类为主,β–芳樟醇含量显著高于金银花;样品在由新鲜到烘干这一过程中,烃类和酯类挥发性物质 含量降低,醛类和醇酮类挥发性物质显著增加。     

棉花高光谱及其红边特征(I)

通过大田和室内试验,测定了2个品种的棉花冠层、完全展开倒1、3叶在不同时期的高光谱反射率及对应叶片的叶绿素、类胡萝卜素含量。结果表明:随发育期推移,棉花冠层光谱反射率在可见光范围降低,在近红外区域增高;叶片背面光谱反射率略高于正面,透射率小于反射率;叶面积指数、鲜叶重和干叶重与冠层反射光谱变量ρ800 ρ550、ρ800 ρ680、ρ680 ρ570之间存在显著相关;叶片叶绿素和类胡萝卜素浓度与其反射光谱变量ρ680 ρ570、ρ673 ρ640、ρ680 ρ550、PSSRa、PSNDa、RCh之间也呈显著相关。     

微氧处理对干红葡萄酒酚类物质的影响

研究了微氧处理对葡萄酒酚类物质的影响,分析了单宁、花色素苷、盐酸指数、明胶指数和 PVP指数的变化。结果表明:适宜的微氧处理可以促进游离态花色素苷向结合态转化,促进单宁聚合 等;相关分析表明单宁、盐酸指数、明胶指数间两两相关,游离花色素苷与其他指标呈负相关。     

Introgression of low temperature tolerance and red rot resistance from Erianthus in sugarcane

Eighteen clones involving Erianthus, as one of the parents, were evaluated in a randomised block design under sub-tropical conditions of Karnal (Haryana, India). Fifteen characters, which contribute towards stalk yield and juice-quality, were studied. The growth of these clones was monitored during peak winter months of December and January. Significant variability existed among the clones for all the traits studied, except for pol % in juice at 10-month crop age, indicating potentiality of the clones to select desirable types. Nine clones showed significant increase in stalk length during winter months over the better standard Co 1148. Whereas 6 clones developed more number of leaves than Co 1148. Both these characters showed high genetic variability, high heritability and hence, high expected genetic gain. Path analysis revealed that these traits contributed about 16%, 5% and 4% to the total genetic variability in juice quality traits (pol % and CCS %), stalk yield and CCS yield, respectively. Growth in winter months has resulted in an increase in stalk yield and CCS yield. This may help in reducing the yield gap between tropical and sub-tropical regions. Majority of clones showed resistance to red rot disease (major disease of sugarcane in sub-tropical region). Hence, hybridization of Erianthus with sugarcane has resulted in introgression of genes for cold tolerance and red rot resistance. As Erianthus is known for its hardiness, resistance, of these clones, to other abiotic and biotic stresses is to be ascertained. This revised version was published online in August 2006 with corrections to the Cover Date.     

Identification of pathogenic races ofPhytophthora fragariae Hickman in Germany

Summary The fungusPhytophthora fragariae Hickman is the causal agent of red stele disease in strawberry (Fragaria × ananassa), this being a major disease in many areas with cool and moist conditions. Success of resistance breeding can be nullified by the appearence of specific races of the fungus capable of overcoming the introduced resistance. In some countries (USA, UK, Japan and Canada) races were identified by using a differential set of strawberry cultivars. The absence of an international standard differential set and the use of different test methods make a comparison of the identified races difficult or even lead to contradictory results for one variety/race combination. The aim of this study was to obtain information about the spectrum of pathogenic races in Germany as a basic contribution to research on resistance breeding against the fungus. The susceptibility of different strawberry cultivars to German isolates ofP. fragariae was evaluated. The inoculation was done by modifying a method described by Milholland et al. (1989). Rootedin vitro plants, four weeks after transferring them to the soil, were used for the investigation. Inoculation was done with a zoospore suspension of defined concentration. Up to now three German isolates, G-1, G-2, and G-3, can be separated by their ability to infect and produce oospores in the roots of the strawberry cultivars ‘Senga Sengana’, either ‘Saladin’, ‘Redgauntlet’ or ‘Climax’ andFragaria chiloensis clone ‘YaquinaB’. These results confirm the existence of pathogenic races ofP. fragariae in Germany and should be taken into consideration for resistance breeding against the fungus.     

Influence of Neutral Principal Stress on the Elastic-Plastic Solution of Expansion of Cylinder Cavities

In the elastic-plastic solution of expansion of cylinder cavities based on Tresca strength criterion and Mohr-Coulomb strength criterion, the influence of neutral principal stress is not considered. In this paper the influence of neutral principal stress on elastic-plastic solution of expansion of cylinder cavities is considered. The calculation shows that the radius and displacement of plastic zone will reduce when the neutral principal stress is considered. The conclusions are of practical significance for geotechnical engineering.     

杂种野猪宰后肌肉品质特性的研究

猪的品种是影响猪肉食用品质的最主要因素,而猪肉的化学组成成分和宰后生理生化变化则是肌肉品质形成的基础。针对杂种野猪和本地白猪两种不同的品种猪在相同条件下饲养和屠宰,研究了宰后肌肉的色泽红度a值、pH值、嫩度(剪切力)和蒸煮损失的变化情况。试验表明,杂种野猪肉红度较深且保持时间长,pH值高,嫩度差,蒸煮损失少。