仙客来播种育苗试验

将仙客来种子用高锰酸钾质量分数1000×10 6液浸泡26h左右,进行种皮软化和消毒处理,然后播种在泥炭基质内,深度为(0 6±0 1)cm。在无光条件下保持温度(20±5)℃,湿度90%左右,在50～60d后即可发芽。发芽后应注意增加光照和施肥,也可以用稀释的肥料代替喷水,成苗率达89 9%。     

圆齿野鸦椿芽继代增殖的影响因素研究

[目的]研究不同激素配比、蔗糖、活性炭等附加物质及光照对圆齿野鸦椿丛生芽增殖的影响,寻求最适圆齿野鸦椿试管苗增殖的培养基配方及培养条件,为圆齿野鸦椿组培快繁提供一些有益的参考。[方法]以圆齿野鸦椿初代培养的丛生芽为外植体,基础培养基为1／2MS,在不同激素配比、蔗糖、活性炭等附加物质的培养基中进行继代增殖培养,观察不同培养基及光照对圆齿野鸦椿试管苗芽增殖数量和玻璃化的影响。[结果]当培养基的激素配比为IBA0．1mg／L＋6-BA2．0mg／L＋NAA0．1mg／L＋琼脂7昏／L＋蔗糖30g/L,丛生芽增殖系数最高可达3．9倍,激素对芽增殖系数的影响为：NAA〉6-BA〉IBA;活性炭有抑制圆齿野鸦椿芽增殖、促进芽体高生长和降低玻璃化的作用;糖是增殖培养阶段不可缺少的成分;自然光照较日光灯照和暗培养效果好。[结论]激素的合理配比、蔗糖以及自然光照有利于圆齿野鸦椿芽继代增殖培养,活性炭有抑制圆齿野鸦椿芽继代增殖的作用。     

不同光照条件下玉米碳酸酐酶活性差异比较与分析

[目的]比较不同光照条件下不同玉米品种碳酸酐酶（CA）活性的变化情况。[方法]以毕单系列玉米品种（毕单10、13、15、17、18号）为试材,待幼苗长至34叶时在不同光照条件（＂弱光＂、＂中光＂、＂强光＂）下培养,培养3 d后开始取样测定CA活性,研究不同处理玉米品种CA活性的变化规律。[结果]在＂弱光＂至＂中光＂段,随着光照强度的升高,各品种的CA活性逐渐升高,但在＂中光＂至＂强光＂段,各品种的CA活性普遍下降,其中毕单15号CA活性降幅最大,毕单18号CA活性降幅最小。＂弱光＂和＂中光＂处理各品种的CA活性差别较小,而＂强光＂处理各品种的CA活性差别较大。[结论]在一定范围内,供试玉米品种的CA活性随光照强度的增加而升高。     

不同青贮玉米品种与紫花苜蓿的间作效应

不同青贮玉米品种与紫花苜蓿的间作表明,间作青贮玉米边际效应显著,并因品种和生育时期的不同而异。大喇叭口期,间作青贮玉米光照强度和透光率比单作的提高,在基部为15.3%～88.1%和15.1%～89.0%,在中部为52.1%～74.1%和51.2%～73.0%。全生育期内,间作青贮玉米平均透光率比单作的提高,在基部为49.5%～62.1%,中部为40.7%～56.6%。5～30 cm土层地温从上到下呈递减趋势,同一土层温度均为间作高于单作;5 cm土层生育期内的平均地温间作比单作提高了1.0%～1.8%。收获期,间作青贮玉米株高、茎粗和叶面积指数比相同种植面积的单作玉米分别提高了2.3%～20.9%、0.4%～7.6%和2.2%～19.6%。间作复合群体的粗脂肪和粗蛋白含量比单作玉米分别提高了30.8%～59.1%和99.4%～137.5%,而鲜草和干草产量比单作玉米分别降低了22.7%～32.3%和17.6%～28.2%,比单作紫花苜蓿分别提高了156.7%～202.4%和176.5%～197.5%。间作紫花苜蓿初花期鲜草和干草产量及粗脂肪和粗蛋白含量表现出边行劣势,但差异不显著。综合分析表明,间作复合群体可充分利用田间光照和地温条件,并且紫花苜蓿是多年生豆科牧草,具有覆盖地面、防风固沙、培肥地力的作用,第2年5～6月份即可收获第一茬,不仅可以解决内蒙古因缺草而影响养殖业发展的问题,而且为间作青贮玉米提供了较大的生长空间。     

Comparison of illuminations to identify wheat classes using monochrome images

Wheat class identification using machine vision is an objective method which can be used for online testing to automate handling, binning and shipping operations in grain industry. The efficiencies of a monochrome camera-based vision system with three different illuminations (incandescent light (IL), fluorescent ring light (FRL), fluorescent tube light (FTL)) were determined to identify eight western Canadian wheat classes at four moisture levels (11%, 14%, 17% and 20%). The monochrome images of the bulk wheat samples were acquired at each moisture level (3 illuminations × 8 classes × 4 moisture contents × 100 replications = 9600 images). A linear discriminant function was used for the classification of wheat samples using 32 gray level textural features extracted from the monochrome images. The mean gray values of the wheat classes were in the ranges of 75–103, 73–115, and 107–143 for IL, FRL and FTL, respectively. The mean gray values of wheat classes were significantly different within each illumination and between different illuminations (α = 0.05). Mean gray value was the highest for FTL and the lowest for IL illumination. The moisture content of the wheat samples had significant effect on the mean gray values. The overall classification accuracies were 90%, 81% and 96% for IL, FRL and FTL, respectively, when all the wheat classes were at the same moisture levels. It was 66%, 53% and 85% for IL, FRL and FTL, respectively, when the wheat classes were at different moisture levels. The classification accuracies of a 2-stage classification system for the classes with different moisture levels were 68%, 56% and 90% for IL, FRL and FTL, respectively.     

《画法几何》、《工程制图》课程中的启发式教学法的研讨

本文介绍画法几何、工程制图时采用审题后将难题分解成相关与本题解题有关的小题,并采用提问及启发方法,将思路归纳到本题,随后解题.解题后可以根据本题意给予展开成相应的题目再深入讨论.     

环境因素对淡水浮丝藻生长及产生嗅味的影响

浮丝藻(Planktothrix) 是一种在我国水域中普遍存在, 可以引起蓝藻水华的水华藻之一,其代谢生成的二-甲基异莰醇 (2-methylisoborneol, 2-MIB) 可导致水体产生令人厌恶的嗅和味,从而使饮用水感官质量下降。本文探讨了温度 (15-30℃),BG11营养盐浓度 (20-100% (w/v))和光照强度 (1000-4000 Lux)对分离于巢湖的浮丝藻(Planktothrix sp.) FACHB-1372生长密度,总2-MIB生成量及胞外2-MIB分泌量的影响。研究结果表明在所述实验条件范围内,温度对浮丝藻生长密度,总2-MIB生成量及胞外2-MIB分泌量影响最显著。25 ℃是浮丝藻最适宜的生长温度,最高细胞密度可达6.04×10_⁵ cell?ml_^-1,30 ℃是其最适宜的产2-MIB温度,总2-MIB生成量和胞外2-MIB分泌量最高分别可达3.64×10_³ ng?L_^-1和2.78×10_³ ng?L_^-1；其次为营养盐浓度,增大BG-11营养盐浓度,浮丝藻生长密度和总2-MIB生成量会随之增加,但实验发现低浓度营养盐时,胞外2-MIB分泌量所占比例较高,表明低浓度营养盐更有利于浮丝藻进行胞外2-MIB分泌；光照对浮丝藻生长及产嗅味物质影响较小,强光照可促进2-MIB胞外释放,4000 Lux时其胞外2-MIB分泌量达最高。最后,依据实验结果为控制和预警浮丝藻过渡繁殖和嗅味物质释放提出了应对方法。     

半导体发光二极管(LED)的应用及发展前途

半导体二极管(LED)是应用最为广泛的电子元件之一,本文介绍了半导体二极管(LED)的发光原理、特性、分类、检测、应用及发展前景。     

Influences of indigenous phototrophs on methane emissions from a straw-amended paddy soil

A pot experiment was conducted to investigate the influences of indigenous phototrophs on methane (CH₄) emissions from a paddy soil where rice straw was incorporated or was surface-applied. During the cultivation, half of the pots were covered with aluminum foil, except for the minimum space for rice plants, to prevent ambient light reaching the floodwater or the soil surface. Growth of oxygen-producing phototrophs was hardly observed in the unilluminated plots, whereas intensive growth of algae, duckweed and hydrophytes was found in the illuminated ones. Plant growth was not affected by the different treatments. Seasonal changes in CH₄ emission determined by a closed chamber method indicated that illumination had no or only minor effects on CH₄ emissions when rice straw was incorporated or was not applied, but significantly reduced CH₄ emissions when rice straw was surface-applied. Methanogenesis occurring in the soil-floodwater interface was further investigated in two lab-scale model experiments measuring methanogenic activity. As a result, more activated methanogenesis was found in the surface-applied rice straw and the soil around the straw compared with the soil incubated without rice straw. The magnitude of the methanogenic activity in the rice straw incubated under illuminated conditions was significantly lower than that incubated in the dark. Consequently, this study demonstrates that methanogenesis in paddy soil occurs even in the soil-floodwater interface if plant residues like rice straw exist, and such methanogenesis is likely to be suppressed by growth of indigenous phototrophs under illumination.     

日光温室内反光膜补光的实践与理论探析

试验结果表明 ,温室后墙悬挂反光膜进行补光后 ,对温室内测定点处最大光照度值无影响 ,但平均提高测定点处水平光照度值 15 4 8% ;温室内凌晨时气温、地温、墙温和被反光膜遮掩处墙温分别比对照温室低 1 1℃、1 5℃、0 9℃和 1 8℃ ,但正午时分别比对照温室高 1 6℃、1 4℃、0 3℃和低 11 4℃。温室经济产量增加 7 4 % ,当期经济效益增加 2 1元 /m2 。