苹果管道气力输送装置参数优化与试验

针对苹果在管道输送过程中的撞击损伤问题,对管道气力输送装置的参数组合进行研究。以输送管道内径、管型和进风口风速为影响因素,以苹果迎风面风速为响应值,通过单因素仿真试验确定各因素对响应值的影响规律;基于单因素仿真结果利用多因素仿真试验获得最优输送参数组合,通过验证试验检验最优组合的可靠性。单因素仿真试验结果表明:当管道内径分别为88、96、104、112和120 mm时,随着输送管道内径的增大,苹果迎风面风速呈先增大后减小的趋势;管型对苹果迎风面风速大小影响的排序为,下圆弧管>螺旋管>S型管>上圆弧管>反S型管;当进风风速分别为14.07、15.83、17.59、19.35和21.11 m/s时,随着进风风速的增大,苹果迎风面风速呈先增大后减小的趋势。多因素仿真试验结果表明:最优输送参数组合为,管道内径112 mm、下圆弧型管型、进风风速19.35 m/s,此时苹果迎风面风速为18.46 m/s。验证试验结果表明,基于最优输送参数组合的管道气力输送装置输送苹果时苹果损伤率为14%,苹果损伤面积0~14.82 mm²,损伤体积0~23.84 mm³,86%的苹果为一等及以上果,14%的苹果为二等果。管道气力输送装置可有效降低苹果采摘后落入果筐时的损伤。     

棉花烂铃及炭疽病的研究

长江流域棉区常见的烂铃病菌有:炭疽病菌(Glomerella gossppii)、角斑病菌(Xanthomonas malvacearum)、花腐病菌(Choanephora cucurbitarum)、黑果病菌(Diplodia gossypina)、印度炭疽病菌(Colletotrichum indicum)、面包霉菌(Rhizopus nigricans)、红粉病菌(Cephalothecium roseum)、红腐病菌(Fusarium spp.)、疫菌(Phytophthora sp.)、轮纹斑病菌(Alternaria spp.)、褐斑病菌(Phyllosticta spp.)、青霉菌(Penicillium spp.)、黑子菌(Nigrospora sp.)、斑纹病菌(Pestalozzia sp.)、(?)腐病菌(Aspergillus spp.)、蠕子菌(Helminthos-porium cuverlaria)、黑斑病菌(Ceratostoma sp.)、汚叶病菌(Cladosporium sp.)等18种,某些年分以炭疽、角斑、红腐等为最主要。1950—51年田间观察结果表明,棉花生长期8、9二个月久雨多湿是引起炭疽病及其他烂铃发生的重要因子。田间接种试验证明:气温平均在25—30℃以及长期保湿,炭疽病菌能直接侵害棉铃。机械损伤、虫孔、角斑病等都是病菌侵害的有利条件。以生长10天的幼铃抗力最强。接近吐絮时的自然裂口,在高湿多雨时,也可成为各种菌类侵害的重要途径。适当密植,合理施用氮肥,进行整枝摘叶,使株行间通风透光,减低湿度,对减轻烂铃损失有一定的作用。     

三门湾春秋季鱼类群落特征及其与环境因子的关系

根据2014年11月(秋季)和2015年5月(春季)在三门湾进行渔业资源调查以及同步调查的6个主要环境因子数据(水温、盐度、悬浮物、p H、溶解氧及化学需氧量等),对三门湾鱼类群落结构及其与6个主要环境因子的关系进行了研究。结果显示,共捕获鱼类33种,其中以季节性洄游种类和暖水性种类为主。春、秋季优势种各有5种,其中棘头梅童鱼、龙头鱼和孔虾虎鱼为共同优势种。应用非度量多维测度分析(NMDS)和单因子相似性分析(ANOSIM)可得,春、秋鱼类群落均可划分为2组,其中1组主要分布在湾内,而另1组主要分布在湾口,在不同站位组间均存在极显著差异。长度谱分析结果显示,鱼类群落长度谱的斜率和截距有明显的季节性差异。RDA分析结果表明,鱼类群落主要受温度、溶解氧、悬浮物和p H等环境因子影响。     

Pinnisterols A–C,New 9,11-Secosterols from a Gorgonian Pinnigorgia sp.

Three new 9,11-secosterols, pinnisterols A–C (1–3), were isolated from a gorgonian coral Pinnigorgia sp., collected off the waters of Taiwan. The structures of these compounds were elucidated on the basis of spectroscopic methods. The new sterols 1 and 3 displayed significant inhibitory effects on the generation of superoxide anions and the release of elastase by human neutrophils, and sterol 1 was found to show moderate cytotoxicity in hepatic stellate cells (HSCs).     

Multiplex PCR genotyping for five bacterial blight resistance genes applied to marker‐assisted selection in rice (Oryza sativa)

Bacterial blight (BB) is the most economically damaging disease of rice in Asia and other parts of the world. In this study, a multiplex PCR genotyping method was developed to simultaneously identify genotypes of five BB resistance genes, Xa4, xa5, Xa7, xa13 and Xa21. The resistance R alleles were amplified using five functional markers (FMs) to generate amplicons of 217, 103, 179, 381 and 595 bp in IRBB66. Amplicons of 198, 107, 87, 391 and 467 bp corresponded to susceptible alleles in Taiwanese japonica rice cultivars. In backcross breeding programmes, the multiplex PCR assay was integrated into selection from a population using BB resistance donor IRBB66 crossed to rice cultivar ‘Tainung82’. Two plants with homozygosity for Xa4, xa5, Xa7, xa13 and Xa21 were selected from 1100 BC₂F₂ plants. In addition, the five BB resistance genes were also accurately identified in F₂ populations. This multiplex PCR method provides a rapid and efficient method for detecting various BB resistance genes, which will assist in pyramiding genes to improve durability of BB resistance in Taiwanese elite rice cultivars.     

番茄斑萎病毒对云南莴苣类蔬菜的侵染为害

莴苣类蔬菜是常见的食用蔬菜。近年在云南发现生菜、莴笋、油麦菜有症状表现为叶片黄化、褪绿、坏死斑的病害流行危害,为确定其病原,通过电子显微镜观察、回接试验、ELISA检测、病毒基因分析,在典型症状病样组织粗汁液和超薄切片中均观察到有类似番茄斑萎病毒属病毒的粒体,该病毒粒体为球形,直径80～85 nm; ELISA检测和病毒基因分析显示,侵染莴苣类蔬菜的病毒为番茄斑萎病毒。     

Effects of Silver on the Photocatalytic Degradation of Gaseous Isopropanol

Water, Air, & Soil Pollution - The decomposition of gaseous isopropanol (IPA) by UV/TiO2 process in an annular photoreactor was studied under various conditions such as UV light intensity and...     

Impact of biodiversity-climate futures on primary production and metabolism in a model benthic estuarine system

Background  

Understanding the effects of anthropogenically-driven changes in global temperature, atmospheric carbon dioxide and biodiversity on the functionality of marine ecosystems is crucial for predicting and managing the associated impacts. Coastal ecosystems are important sources of carbon (primary production) to shelf waters and play a vital role in global nutrient cycling. These systems are especially vulnerable to the effects of human activities and will be the first areas impacted by rising sea levels. Within these coastal ecosystems, microalgal assemblages (microphytobenthos: MPB) are vital for autochthonous carbon fixation. The level of in situ production by MPB mediates the net carbon cycling of transitional ecosystems between net heterotrophic or autotrophic metabolism. In this study, we examine the interactive effects of elevated atmospheric CO₂ concentrations (370, 600, and 1000 ppmv), temperature (6°C, 12°C, and 18°C) and invertebrate biodiversity on MPB biomass in experimental systems. We assembled communities of three common grazing invertebrates (Hydrobia ulvae, Corophium volutator and Hediste diversicolor) in monoculture and in all possible multispecies combinations. This experimental design specifically addresses interactions between the selected climate change variables and any ecological consequences caused by changes in species composition or richness.     

Briarenolides F and G, new briarane diterpenoids from a Briareum sp. octocoral

Two new briarane diterpenoids, briarenolides, F (1) and G (2), were isolated from an octocoral identified as Briareum sp. The structures of briaranes 1 and 2 were established by spectroscopic methods and by comparison of the spectroscopic data with those of known briarane analogues. Briarenolide F was proven to be the first 6-hydroperoxybriarane derivative and this compound displayed a significant inhibitory effect on the generation of superoxide anion by human neutrophils.