Plant Cyanogenesis of <Emphasis Type="Italic">Phaseolus lunatus</Emphasis> and its Relevance for Herbivore–Plant Interaction: The Importance of Quantitative Data

Quantitative experimental results on the antiherbivorous effect of cyanogenesis are rare. In our analyses, we distinguished between the total amount of cyanide-containing compounds stored in a given tissue [cyanogenic potential (HCNp)] and the capacity for release of HCN per unit time (HCNc) from these cyanogenic precursors as a reaction to herbivory. We analyzed the impact of these cyanogenic features on herbivorous insects using different accessions of lima beans (Phaseolus lunatus L.) with different cyanogenic characteristics in their leaves and fourth instars of the generalist herbivore Schistocerca gregaria Forskål (Orthoptera, Acrididae). Young leaves exhibit a higher HCNp and HCNc than mature leaves. This ontogenetic variability of cyanogenesis was valid for all accessions studied. In no-choice bioassays, feeding of S. gregaria was reduced on high cyanogenic lima beans compared with low cyanogenic beans. A HCNp of about 15 μmol cyanide/g leaf (fresh weight) with a corresponding HCNc of about 1 μmol HCN released from leaf material within the first 10 min after complete tissue disintegration appears to be a threshold at which the first repellent effects on S. gregaria were observed. The repellent effect of cyanogenesis increased above these thresholds of HCNp and HCNc. No repellent action of cyanogenesis was observed on plants with lower HCNp and HCNc. These low cyanogenic accessions of P. lunatus were consumed extensively—with dramatic consequences for the herbivore. After consumption, locusts showed severe symptoms of intoxication. Choice assays confirmed the feeding preference of locusts for low over high cyanogenic leaf material of P. lunatus. The bioassays revealed total losses of HCN between 90 and 99% related to the estimated amount of ingested cyanide-containing compounds by the locusts. This general finding was independent of the cyanogenic status (high or low) of the leaf material.     

半钢子午胎硫化供汽系统改造

在原有供汽系统等压运行条件下，通过合理改造，加装减温减压装置，将原系统分类内胎锅炉房高压供汽系统和老锅炉房低压供汽系统，以满足半钢子午胎对高压蒸汽的需求，达到缩短硫化时间，提高生产能力的目的。     

Synthesis of highly crystalline spinel LiMn2O4 by a soft chemical route and its electrochemical performance

Highly crystalline spinel LiMn₂O₄ was successfully synthesized by annealing lithiated MnO₂ at a relative low temperature of 600 °C, in which the lithiated MnO₂ was prepared by chemical lithiation of the electrolytic manganese dioxide (EMD) and LiI. The LiI/MnO₂ ratio and the annealing temperature were optimized to obtain the pure phase LiMn₂O₄. With the LiI/MnO₂ molar ratio of 0.75, and annealing temperature of 600 °C, the resulting compounds showed a high initial discharge capacity of 127 mAh g⁻¹ at a current rate of 40 mAh g⁻¹. Moreover, it exhibited excellent cycling and high rate capability, maintaining 90% of its initial capacity after 100 charge-discharge cycles, at a discharge rate of 5 C, it kept more than 85% of the reversible capacity compared with that of 0.1 C.     

浅谈燃煤电站锅炉热风测量装置

燃煤电站锅炉的热二次风风量测量装置大多采用了传统的机翼式测量装置,其测量使用过程中暴露出了一些严重的不足——节流较大而导致风机出力加大,测量装置及引压管路积灰导致测量失准,影响了相关自动控制的投用和保护的可靠性。也因此,该不足在某种程度上产生了电能生产过程中安全、稳定、经济等方面的负面作用,需要进行深入分析和整改。     

配电变压器容量选择方法探讨

主要探讨了变压器容量选择应考虑的因素及变压器容量选择的几种方法．通过技术分析和计算,确定变压器最佳负荷系数、最小功率损耗、节能负荷系数以及经济负荷系数．在综合考虑用户负荷以及初装费用的情况下,确定合理的变压器运行方式及变压器容量,以便能够实现变压器的经济运行,减少变压器的有功功率损耗,为用户节省投资和运行成本,最大限度满足用户的需求．     

油纸电容型套管缺油的危害及判断方法

通过解析油纸电容型套管的结构,介绍了套管四大组成部分的作用和原理,并重点阐述了套管内部绝缘介质的电气性能．同时指出了套管缺油的原因及危害,并说明了如何准确地判断缺油．通过实例阐述了套管缺油的查找方法,论证了综合利用电容量C、介质损失角tanδ、油中溶解气体色谱分析及红外线成像仪对发现套管缺油的合理性及准确性．     

脉冲电子束系统沉积高温超导薄膜研究

高温超导薄膜生长是研究超导现象和超导器件的基础,一直是凝聚态物理研究的一个重要课题。各种各样的薄膜生长方法都被应用于高温超导薄膜的生长研究。采用一种崭新的薄膜沉积设备——脉冲电子束沉积系统(PED)成功制备出了NCCO、LSCO高温超导薄膜,并通过优化沉积参数,获得了具有良好表面形貌和超导转变特性的高温超导薄膜。     

紫外线对建筑膜材料拉伸性能的影响

采用2因子二次通用旋转组合设计,以紫外线照射时间和强度为两个因子,对建筑膜材料进行紫外线照射,测试材料的拉伸性能,分别建立了膜材断裂强力和断裂伸长率的数学模型。结果表明:紫外线对建筑膜材料的断裂强力和断裂伸长率有显著的影响;通过红外光谱分析,涂层化学结构发生了变化。     

型钢高强高性能混凝土梁的抗剪性能分析

为了研究型钢高强高性能混凝土梁的抗剪力学性能,对9榀不同混凝土强度等级、剪跨比和加载方式的实腹式型钢高强高性能混凝土简支梁进行了静力加载试验,分析了型钢高强高性能混凝土梁的受力过程、剪切破坏类型及抗剪承载力的影响因素.基于型钢高强高性能混凝土梁的试验研究结果,对简支梁的加载和受力过程进行了有限元模拟.有限元分析结果与试验实测相关数据的对比分析表明,采用通用有限元分析程序ANSYS对型钢混凝土构件的受力过程进行数值模拟是可行的.在此基础上,进一步分析了简支梁的抗剪机理和力学性能,同时探讨了粘结滑移对构件力学性能的影响以及型钢、钢筋和混凝土应力应变的发展分布规律.研究成果为改进型钢高强高性能混凝土梁设计计算理论和有限元分析提供了试验依据.     

碱-矿渣-锰合金渣胶凝材料的研制

锰合金渣是生产锰系合金排放的工业废弃物,近年来锰矿资源的开采和利用发展迅速,产生的大量锰渣造成了严重的环境污染。将锰合金渣与矿渣复合,制备了碱-矿渣-锰合金渣胶凝材料,测试了所制备胶结材的抗压和抗折强度,利用扫描电镜分析了其微观结构。研究结果表明,随着锰渣掺量增加,碱-矿渣-锰渣胶凝材料的强度总体呈降低趋势;提高锰渣细度,所制备的胶凝材料强度亦随之增加;碱激发下磨细锰合金渣具有一定的水化硬化活性,其活性低于磨细矿渣。