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土壤重金属污染大生物量植物修复技术研究进展 被引量:18
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作者 周振民 朱彦云 《灌溉排水学报》 CSCD 北大核心 2009年第6期26-29,共4页
分析了土壤重金属污染修复技术的研究现状及存在的问题,研究了大生物量非超富集植物修复技术进展。对当前大生物量非超富集植物的研究进展进行了综合分析,其中包括粮食作物、油料作物、蔬菜、杂草和树木、花卉、经济作物等大生物量植物... 分析了土壤重金属污染修复技术的研究现状及存在的问题,研究了大生物量非超富集植物修复技术进展。对当前大生物量非超富集植物的研究进展进行了综合分析,其中包括粮食作物、油料作物、蔬菜、杂草和树木、花卉、经济作物等大生物量植物受重金属污染情况下的非超富集修复技术,提出了土壤重金属污染植物修复的研究方向。研究成果对土壤重金属污染修复技术的发展具有重要参考价值。 展开更多
关键词 土壤重金属污染 大生物量 植物修复技术 综合研究
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城市土壤重金属污染的大生物量植物修复技术研究进展 被引量:13
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作者 张芳芳 赵立伟 +1 位作者 苏亚勋 陈蔷 《天津农业科学》 CAS 2014年第3期47-51,共5页
分析了城市土壤重金属污染的植物修复技术研究现状及存在的问题,在此基础上进一步分析了大生物量非超富集植物修复技术的进展。概括了大生物量修复植物的优势,提出了筛选的判断标准和思路。探讨了大生物量植物应用于城市土壤重金属污染... 分析了城市土壤重金属污染的植物修复技术研究现状及存在的问题,在此基础上进一步分析了大生物量非超富集植物修复技术的进展。概括了大生物量修复植物的优势,提出了筛选的判断标准和思路。探讨了大生物量植物应用于城市土壤重金属污染修复实践的可行性。 展开更多
关键词 城市土壤 重金属污染 植物修复技术 大生物量非超富集植物 综合评估筛选法
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洱海沉水植物群落结构特征及最大生物量估算 被引量:3
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作者 杨四坤 金玲 +4 位作者 高登成 窦嘉顺 黄明雨 吕兴菊 李艳芳 《环境科学导刊》 2020年第6期11-17,共7页
以云南省洱海为研究对象,在生长季(2017年9月)对该湖泊沉水植物种类组成及生物量等群落特征进行了调查,根据频度及生物量评判物种优势度并分析沉水植物分布与水位梯度的关系。结果表明:①洱海沉水植物现有种类有13种,隶属6科8属,其中眼... 以云南省洱海为研究对象,在生长季(2017年9月)对该湖泊沉水植物种类组成及生物量等群落特征进行了调查,根据频度及生物量评判物种优势度并分析沉水植物分布与水位梯度的关系。结果表明:①洱海沉水植物现有种类有13种,隶属6科8属,其中眼子菜科5种,水鳖科3种,茨藻科2种,其余种类占沉水植物总种类数的23.1%;②洱海绝对优势物种为金鱼藻(Ceratophyllum demersum)、微齿眼子菜(Potamogeton maackianus)和苦草(Vallisneria natans),其优势度分别为37.74%、21.87%和16.70%;③不同水深梯度沉水植物种类变化:2.0~4.0m(12种)>0.0~2.0m(11种)>4.0~6.1m(8种);④沉水植物生物量最大值出现在2.0~4.0m;⑤根据优势种及组成特征,沉水植物群落主要为3个类型:金鱼藻+竹叶眼子菜+黑藻群丛、金鱼藻+微齿眼子菜群丛和金鱼藻群丛;⑥计算结果显示,洱海生物量鲜重总值约为16.09万t。本研究结果表明,洱海沉水植物种类较为丰富,生物量总量也相对较高,不同水深下优势物种组成略有区别,说明洱海沉水植物群落状况较好,但也需要加强保护。 展开更多
关键词 沉水植物 群落结构 大生物量 洱海
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两种农业种植模式对重金属土壤的修复潜力 被引量:47
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作者 杨洋 陈志鹏 +2 位作者 黎红亮 廖柏寒 曾清如 《生态学报》 CAS CSCD 北大核心 2016年第3期688-695,共8页
植物修复农田土壤重金属污染需要经历一个长期的过程,而大部分用来修复的植物都不具备利用价值,不能给当地农民带来经济收入。因此,一些农作物由于其较大的生物量和一定的经济价值,在植物修复土壤重金属污染的应用中受到广泛关注。是在... 植物修复农田土壤重金属污染需要经历一个长期的过程,而大部分用来修复的植物都不具备利用价值,不能给当地农民带来经济收入。因此,一些农作物由于其较大的生物量和一定的经济价值,在植物修复土壤重金属污染的应用中受到广泛关注。是在重金属(Cu、Zn、Pb、Cd、As、Hg)复合污染的郴州矿区废弃农田种植油菜、玉米和油葵,研究油菜-玉米和油-油葵两种种植模式对土壤重金属污染的修复潜力。实验结果表明:三种作物在复合污染土壤中对重金属都表现出一定的耐性及吸收积累能力。向日葵的根和叶中重金属Cd、Cu的含量都很高,其中Cd在向日葵的各个部位的富集系数(BCF)及Cu在向日葵的根和叶的富集系数(BCF)都大于1。两种轮作模式对作物的产量没有明显的影响,收获得到的干物质量都很高,每年每公顷分别为油菜16.6t、玉米25.29t、油葵22.5t。两种种植模式都可以对土壤中的重金属进行有效的提取,油菜-油葵种植模式下提取重金属Cu、Pb、Cd、As的量较高,分别为:Cu 2408g hm^(-2)a^(-1),Pb 2027g hm^(-2)a^(-1),Cd 658.5g hm^(-2)a^(-1),As 250g hm^(-2)a^(-1),油菜-玉米模式下Zn和Hg的提取量较高,分别为Zn 4987g hm^(-2)a^(-1)和Hg 7.92g hm^(-2)a^(-1);对于多种重金属复合污染的土壤来说,油菜-油葵的种植模式要优于油菜-玉米的种植模式。总的来说,利用3种作物两两轮作的种植模式,在不影响作物产量的前提下大大的提高了作物对重金属的提取总量。3种作物在收获以后又可以用做工业原料,这就使得当地农民充分利用矿区废弃农田修复污染的同时又能从中获得一定经济效益。 展开更多
关键词 耕地 重金属污染 农业种植模式 大生物量 植物修复
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水体扰动对多种赤潮藻生长的影响 被引量:12
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作者 李冬梅 高永利 +2 位作者 田甜 劉骏豪 殷克东 《热带海洋学报》 CAS CSCD 北大核心 2010年第6期65-70,共6页
水体扰动是海洋环境的一个重要特征。扰动通过对藻细胞周围的营养盐边界层厚度的影响,进而影响藻细胞的生长。在其他环境因子统一的条件下,通过室内实验研究扰动条件为主要影响因素对藻类生长的影响。研究结果发现扰动对中肋骨条藻、具... 水体扰动是海洋环境的一个重要特征。扰动通过对藻细胞周围的营养盐边界层厚度的影响,进而影响藻细胞的生长。在其他环境因子统一的条件下,通过室内实验研究扰动条件为主要影响因素对藻类生长的影响。研究结果发现扰动对中肋骨条藻、具齿原甲藻等10个藻种生长存在不同影响,实验数据显示,100r.min-1扰动对新月菱形藻Nitzschia closterium,中肋骨条藻Skeletonema costatum、具齿原甲藻Prorocentrum dentatum、针胞藻Fibrocapsa japonica、棕囊藻Phaeocystis spp.、定鞭金藻Prymnesium patelliferium有显著作用(P<0.05),对赤潮异弯藻Heterosigma akashiwo、亚心形扁藻Platymonas subcordiformis、青岛大扁藻Platymonas helgolandica var Tsingtaoensis、塔胞藻Pyramimonas sp.、Pyramidomonas作用不明显(P>0.05)。扰动促进了棕囊藻和定鞭金藻的生长,使之达到最大生物量,并延长了藻细胞的生长时间;同时100r.min-1扰动抑制了新月菱形藻,中肋骨条藻、具齿原甲藻、针胞藻的生长。这些不同的藻类对水体扰动有不同生长反应,结果表明水体扰动是藻类种间竞争的的选择推动力之一。 展开更多
关键词 扰动 生长率 大生物量
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铜绿微囊藻、四尾栅藻和谷皮菱形藻在低光照度下的生长研究 被引量:4
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作者 马祖友 储昭升 +4 位作者 胡小贞 金相灿 易文利 张广军 张淑英 《环境科学研究》 EI CAS CSCD 北大核心 2004年第z1期62-65,共4页
实验研究了铜绿微囊藻、四尾栅藻和谷皮菱形藻在75~1200lx光照度下的生长情况。实验结果表明:光照度为600lx以下时,3种藻都受到了光的抑制作用,生长缓慢;光照度为600~1200lx时,3种藻的生物量随光照度的增加均有不同程度的增加,其中增... 实验研究了铜绿微囊藻、四尾栅藻和谷皮菱形藻在75~1200lx光照度下的生长情况。实验结果表明:光照度为600lx以下时,3种藻都受到了光的抑制作用,生长缓慢;光照度为600~1200lx时,3种藻的生物量随光照度的增加均有不同程度的增加,其中增加最显著的是谷皮菱形藻,其次才是铜绿微囊藻和四尾栅藻。 展开更多
关键词 低光照度 光抑制 生物量 大生物量
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鲜枣采后生防菌株梅奇酵母XY201培养条件的优化
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作者 施俊凤 孙常青 +1 位作者 王潇冉 王春生 《保鲜与加工》 CAS 2014年第3期15-19,共5页
梅奇酵母(Metschnikowia zizyphicola)XY201是从冬枣表面分离筛选的新酵母菌种,对采后冬枣病原菌具有很好的抑制作用。本试验研究了该酵母菌对碳源、氮源和无机盐的利用情况,以及温度、初始pH和接种浓度三个因素对梅奇酵母生物量的影响... 梅奇酵母(Metschnikowia zizyphicola)XY201是从冬枣表面分离筛选的新酵母菌种,对采后冬枣病原菌具有很好的抑制作用。本试验研究了该酵母菌对碳源、氮源和无机盐的利用情况,以及温度、初始pH和接种浓度三个因素对梅奇酵母生物量的影响,优化其培养基配方和培养条件。结果表明,梅奇酵母最大生物量的培养基配方为:2%蔗糖+2%牛肉蛋白胨+0.05%磷酸二氢钾+0.05%硝酸钠;最优培养条件为:培养温度25℃,初始pH 6.0,接种浓度1%;在上述培养条件下进行摇瓶培养,梅奇酵母的最佳培养时间为接种后72 h。 展开更多
关键词 生防菌 梅奇酵母XY201 大生物量 培养条件
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5种微藻及其密度对铜绿微囊藻生长的影响 被引量:4
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作者 张坤 戴习林 《广东农业科学》 CAS CSCD 北大核心 2012年第10期166-169,178,共5页
以同周期单独培养的微藻生长密度为对照,采用等重复两因素完全随机试验设计开展淡水养殖池塘中5种常见微藻即淡水小球藻(C.vulgaris)、四尾栅藻-FACHB-1297(S.quadricauda)、蹄形藻(K.lunaris)、鱼腥藻-FACHB-1299(Anabaena Broy sp.)... 以同周期单独培养的微藻生长密度为对照,采用等重复两因素完全随机试验设计开展淡水养殖池塘中5种常见微藻即淡水小球藻(C.vulgaris)、四尾栅藻-FACHB-1297(S.quadricauda)、蹄形藻(K.lunaris)、鱼腥藻-FACHB-1299(Anabaena Broy sp.)、颤藻-FACHB-1120(Oscillatoria sp.)及其密度对铜绿微囊藻(M.aeruginosa)生长影响的研究。结果表明:5种微藻的初始密度对铜绿微囊藻的生长有显著影响,当铜绿微囊藻初始密度最小为4.5×105个/mL时,呈现5种微藻密度增加对铜绿微囊藻生长抑制效果越明显的规律,而当铜绿微囊藻的初始密度较高时,则5种微藻密度的增加对铜绿微囊藻生长抑制效果不明显,同时铜绿微囊藻的初始密度不同也显著影响微囊藻的生长。t检验结果也表明:铜绿微囊藻在分别与淡水小球藻、鱼腥藻、颤藻混合培养时,生长速度均显著受到抑制,而与四尾栅藻混合培养时,生长速度受到抑制不显著。因此试验用5种微藻中,淡水小球藻、鱼腥藻、颤藻均对铜绿微囊藻生长有抑制作用,且淡水小球藻对微囊藻生长抑制效果最明显,蹄形藻对微囊藻的生长促进作用明显。通过竞争参数计算几种微藻对铜绿微囊藻的竞争抑制强度从大到小依次为淡水小球藻、鱼腥藻、颤藻、四尾栅藻、蹄形藻。 展开更多
关键词 微藻 起始密度 铜绿微囊藻 竞争抑制参数 大生物量
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经济作物轮作模式下镉污染农田修复潜力 被引量:1
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作者 杨耀东 陈玉梅 +1 位作者 涂鹏飞 曾清如 《生态环境学报》 CSCD 北大核心 2023年第3期627-634,共8页
中国农田镉(Cd)污染严重且面积广大,选择适宜的经济作物对Cd污染农田进行边生产边修复至关重要。采用大田试验,在Cd轻度污染农田种植甜高粱(Sorghum dochna)、油葵(Helianthusannuus)、油菜(Brassica napus)、白芝麻(Sesamumindicum)和... 中国农田镉(Cd)污染严重且面积广大,选择适宜的经济作物对Cd污染农田进行边生产边修复至关重要。采用大田试验,在Cd轻度污染农田种植甜高粱(Sorghum dochna)、油葵(Helianthusannuus)、油菜(Brassica napus)、白芝麻(Sesamumindicum)和亚麻(Linumusitatissimum)5种高生物量经济作物,设置甜高粱-油菜、油葵-油菜和白芝麻-亚麻3种全年轮作模式,探究其对Cd污染土壤的修复潜力。结果表明,(1)3种轮作模式中作物各部位的富集系数大于1,对Cd的富集能力较强。其中,亚麻Cd富集能力最强,各部位富集系数为1.97-9.68。白芝麻、油葵茎Cd富集能力较强,甜高粱和油菜富集能力相对较弱。(2)5种经济作物均能在Cd轻度污染农田正常生长,总生物量依次为甜高粱>油葵>油菜>白芝麻>亚麻。(3)各作物均能有效提取农田中的Cd,提取总量依次为油葵>甜高粱>亚麻>白芝麻>油菜。(4)白芝麻-亚麻、油葵-油菜和甜高粱-油菜的Cd提取总量分别为32.18、30.05、28.32g·hm^(−2),对土壤的修复效率分别为3.87%、3.61%和3.40%。轮作结束后,供试土壤总Cd含量接近土壤质量标准(GB 15618—2018)。(5)在3种轮作模式中,白芝麻-亚麻轮作模式修复效率最高,预期1.62个轮作周期能将试验农田Cd降至国家标准之下。油葵-油菜、甜高粱-油菜则能在1.73和1.84个轮作周期内达成修复目标。综上所述,3种轮作模式均对Cd污染农田表现出较强修复潜力。合理利用高生物量经济作物进行轮作,能够在有效修复污染土壤的同时提升植物修复经济效益,是治理Cd污染农田可行的新思路。 展开更多
关键词 农田 镉污染 大生物量 经济作物 植物修复 轮作
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利用蝇蛆处理城市污水厂剩余污泥的研究 被引量:1
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作者 李晋 李庆新 余训民 《科技创业月刊》 2012年第5期176-178,共3页
利用蝇蛆处理污水处理厂剩余污泥,不仅能够缩减污泥体积,降低污泥含水率,达到污泥减量化的目的,还能生产蝇蛆蛋白,实现污泥的资源化利用。试验首先通过改变污泥的通透性、含水率等因素,对比获得的鲜蛆重量,得出了污泥培育蝇蛆的最适宜... 利用蝇蛆处理污水处理厂剩余污泥,不仅能够缩减污泥体积,降低污泥含水率,达到污泥减量化的目的,还能生产蝇蛆蛋白,实现污泥的资源化利用。试验首先通过改变污泥的通透性、含水率等因素,对比获得的鲜蛆重量,得出了污泥培育蝇蛆的最适宜生长条件。其次,利用添加辅料后的污泥培育蝇蛆,通过改变蛆料投入比例对单位污泥可获得的最大生物量进行了探索。结果表明,每1kg污泥在添加50g麸皮辅料后更利于蝇蛆生长,添加辅料后的污泥每1kg最多可获得127.4g鲜蛆。同时,经蝇蛆处理后的污泥物理性状也得到了改善,分散度有所提高,更利于堆肥处理。 展开更多
关键词 剩余污泥 蝇蛆处理 减量化 资源化 生长条件 大生物量
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异养条件下双酚基丙烷对小球藻生长特性的影响
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作者 闫龙 章斐 +1 位作者 陈秀荣 王璐 《净水技术》 CAS 2017年第7期45-50,共6页
在1 g/L葡萄糖和BPA共同异养培养普通小球藻的情况下,考察了BPA对小球藻生长特性影响和小球藻对BPA的去除效果。结果表明,在BPA浓度<10 mg/L时,可促进小球藻的异养生长,而BPA浓度大于10 mg/L时,则表现为抑制作用;单位量普通小球藻对... 在1 g/L葡萄糖和BPA共同异养培养普通小球藻的情况下,考察了BPA对小球藻生长特性影响和小球藻对BPA的去除效果。结果表明,在BPA浓度<10 mg/L时,可促进小球藻的异养生长,而BPA浓度大于10 mg/L时,则表现为抑制作用;单位量普通小球藻对BPA的去除速率(比去除率)与BPA浓度呈正相关关系。因此当BPA浓度为50 mg/L、培养时间为24~48 h时,BPA的最大比去除速率为3.51×10^(-7)mg/(cell·h)。普通小球藻在不同浓度BPA与1 g/L葡萄糖混合培养条件下,其生长动力学中最大比生长速率μ_(max)、最大生物量B_f值皆随BPA浓度的增加呈现先增后减的变化趋势。 展开更多
关键词 普通小球藻 双酚基丙烷 比去除率 最大比生长速率μmax 大生物量Bf
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7种常用绿化树种在修复镉污染土壤中的应用初探 被引量:3
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作者 张芳芳 赵立伟 +1 位作者 王运良 单良 《天津农业科学》 CAS 2019年第12期33-36,43,共5页
为研究大生物量树种对Cd污染土壤的修复效果,以毛白杨、馒头柳、臭椿、构树、榆树、白蜡、国槐等7种天津市常用绿化树种为材料,开展大田试验,对比各树种在Cd轻度污染土壤和未受Cd污染土壤中的生长表现(株高和茎粗生长量,成活率),分析Cd... 为研究大生物量树种对Cd污染土壤的修复效果,以毛白杨、馒头柳、臭椿、构树、榆树、白蜡、国槐等7种天津市常用绿化树种为材料,开展大田试验,对比各树种在Cd轻度污染土壤和未受Cd污染土壤中的生长表现(株高和茎粗生长量,成活率),分析Cd污染土壤中各树种不同器官对Cd的吸收和富集能力(BCF),及对土壤Cd的去除能力。结果表明:7种树种在轻度Cd污染土壤上正常生长,其株高和茎粗生长量及成活率均与未受Cd污染土壤无显著差异(P>0.05),说明各树种均对土壤重金属Cd有一定的耐性;地上部器官富集能力表现为毛白杨>馒头柳>榆树>臭椿>构树>国槐>白蜡,根部富集能力表现为毛白杨>榆树>馒头柳>构树>臭椿>白蜡>国槐,各树种根部富集能力均高于地上部;Cd去除能力表现为毛白杨>榆树>馒头柳>臭椿>构树>白蜡>国槐。综合而言,毛白杨、榆树、馒头柳、构树和臭椿每年可去除土壤中Cd大于3.71 mg·m-2,显著高于白蜡和国槐(P>0.05),在原位修复土壤Cd污染中具有广阔的应用前景。 展开更多
关键词 大生物量树种 镉污染土壤 植物修复 富集系数 去除能力
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Review on Effects of Application of Exogenous Growth Regulating Substance on Fruits Weight of Peach
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作者 马之胜 贾云云 +3 位作者 王越辉 白瑞霞 陈江玉 刘志欣 《Agricultural Science & Technology》 CAS 2015年第8期1681-1685,共5页
The effects of exogenous growth regulating substance on the fruit weight of peach were reviewed. Paclobutrazol could increase the single fruit weight in dif- ferent degree, and cytokinins could also increase the singl... The effects of exogenous growth regulating substance on the fruit weight of peach were reviewed. Paclobutrazol could increase the single fruit weight in dif- ferent degree, and cytokinins could also increase the single fruit weight. GA3 and B9 had no effect on fruit size or on reducing single fruit weight. Chlorflurenol-methy, ABT and salicylic acid had no effect on fruit size. Suggestions on the future re- search were put forward. 展开更多
关键词 PEACH Fruit size Yield Exogenous growth regulating substance
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SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK are prognosis-related in colorectal cancer 被引量:20
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作者 Shu-Jing Yu Jie-Kai Yu +3 位作者 Wei-Ting Ge Han-Guang Hu Ying Yuan Shu Zheng 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第15期2028-2036,共9页
AIM: To investigate the expression of markers that are correlated with the prognosis of colorectal cancer (CRC) patients. METHODS: One hundred and fifty-six CRC patientswere followed up for more than 3 years after rad... AIM: To investigate the expression of markers that are correlated with the prognosis of colorectal cancer (CRC) patients. METHODS: One hundred and fifty-six CRC patientswere followed up for more than 3 years after radical surgery. Immunohistochemical (IHC) analysis was performed to detect the expression of 14 pathway-related markers (p53, APC, p21ras, E-cadherin, endothelin-B receptor, Shp2, ADCY-2, SPARCL1, neuroligin1, hsp27, mmp-9, MAPK, MSH2 and rho) in specimens from these patients. Bioinformatics analysis involving a Support Vector Machine (SVM) was used to determine the best prognostic model from combinations of these markers. RESULTS: Seven markers (SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK) were significantly related to the prognosis and clinical pathological features of the CRC patients (P < 0.05). Prognostic models were established through SVM from combinations of these 7 markers and proved able to differentiate patients with dissimilar survival, especially in stage Ⅱ/Ⅲ patients. According to the best prognostic model, the p53/SPARCL1 model, patients having high p53 and low SPARCL1 expression had about 50% lower 3-year survival than others (P < 0.001). CONCLUSION: SPARCL1, Shp2, MSH2, E-cadherin, p53, ADCY-2 and MAPK are potential prognostic markers in CRC. A p53/SPARCL1 bioinformatics model may be used as a supplement to tumor-nodes-metastasis staging. 展开更多
关键词 Colorectal cancer Prognosis SPARCL1 P53 BIOINFORMATICS
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Escherichia coil Removal in Tropical Oligotrophic and Eutrophic Lakes 被引量:1
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作者 Ebenezer David Okwaning Ansa Anthonia Helga Andoh +2 位作者 Gloria Akosua Ansa Jackson Adiyiah MikeAgbesi Acheampong 《Journal of Environmental Science and Engineering(A)》 2013年第12期719-724,共6页
The mechanisms by which oligotrophic and eutrophic lakes rid itself of Escherichia coli or faecal coliforms are still not clearly understood. This study sought to review the various means by which E. coli or faecal co... The mechanisms by which oligotrophic and eutrophic lakes rid itself of Escherichia coli or faecal coliforms are still not clearly understood. This study sought to review the various means by which E. coli or faecal coliforms are inactivated or removed in lakes. The review cited temperature, solar radiation, predation, starvation, attachment and sedimentation as key factors that aid the removal of E. coli in lakes. In eutrophic lakes additional factors such as the role of algal biomass may play a role due to increased pH and dissolved oxygen levels attributed to algal presence. Algal toxins or exudates may also play a role although this is still under debate. The interactive effect of two or more of these factors on E. coli inactivation and the relative importance of these mechanisms on E. coli removal are still not known. Areas for further research include the role of algae in sedimenting E. coli or faecal coliforms and the possible role of algal exudates on E. coli inactivation. 展开更多
关键词 PREDATION SEDIMENTATION solar radiation STARVATION temperature.
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Effect Mechanism of Structure-Changed Water on Heat Stability of Lysozyme 被引量:1
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作者 赵林 谭欣 《Transactions of Tianjin University》 EI CAS 2003年第3期177-179,共3页
Based on the mechanism of the effect of hydration on the heat stability of lysozyme and the theory of water molecule clusters, the effect of structure-changed water on heat stability of lysozyme has been studied. The ... Based on the mechanism of the effect of hydration on the heat stability of lysozyme and the theory of water molecule clusters, the effect of structure-changed water on heat stability of lysozyme has been studied. The results obtained by differential scanning calorimetry (DSC) showed that the thermal denaturation temperature of lysozyme had been elevated 8.47 K through hydration of lysozyme with processed water whose structure had been changed so it was called "structured water" compared to ordinary water. The reason is that structured water changed the dipole moment of water molecules and easily formed cyclic water hexamer or cage-like water hexamer, so that the interacting force of maintaining three-dimensional conformation of lysozyme could be reinforced. 展开更多
关键词 LYSOZYME heat stability structured water water molecule clusters
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Effects of Channelization on Fish Biomass in River Ecosystems
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作者 Scott S. Knight R.F. Cullum +1 位作者 F.D. Shields Jr. P.C. Smiley 《Journal of Environmental Science and Engineering(A)》 2012年第8期980-985,共6页
Channel straightening in a naturally meandering river is a common historical trigger of channel incision which typically results in stream bank destabilization. Several of the larger river systems in the upland portio... Channel straightening in a naturally meandering river is a common historical trigger of channel incision which typically results in stream bank destabilization. Several of the larger river systems in the upland portion of the Yazoo River Basin have subjected channelization resulting in profound changes in the physical and geomorphological characteristics of these systems. Fish were sampled using electroshocking gear and hoop nets to evaluate the impact of stream bank destabilization and loss of habitat heterogeneity resulting from channelization on fish communities. While distinct differences in the fish communities were evident, only the Skuna appeared to have characteristics of a damaged system. More than 95% of the biomass was comprised of species reaching an adult length of less than 300 mm. The lotic omnivorous fishes that dominated the biomass from Skuna are often associated with smaller streams rather than rivers. Furthermore, 72% of the catch consisted of fish preferring littoral zone habitats. The shallow depth and lack of woody debris in Skuna provided a selective advantage for smaller species of fish that could use shoreline habitats as protection from the current. Based on results from the Skuna River, channel straightening that leads to channel incision, bank failure and over widening provide habitats too shallow to support a community of fishes typical of northern Mississippi riverine system. This information may be useful in making comparison of damaged riverine ecosystems and assist managers in determining impairment and success in the TMDL (Total Maximum Daily Load) process. 展开更多
关键词 Channel incision channel straightening fish biomass.
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Implementation of a Forest Biomass-Based Biofuel Industry: A Canadian Experience
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作者 Mariya Marinova Michel Perrier Jean Paris 《Journal of Energy and Power Engineering》 2014年第10期1680-1686,共7页
The forest biomass is an abundant renewable resource from which biofuels can be derived. In the Kraft process, the cellulose is extracted from the wood to form the paper pulp while the other organic components, primar... The forest biomass is an abundant renewable resource from which biofuels can be derived. In the Kraft process, the cellulose is extracted from the wood to form the paper pulp while the other organic components, primarily hemicelluloses and lignin, are burnt to produce steam. It is possible to divert part of the hemicelluloses or lignin to produce fuels on site, a mode of operation referred to as the integrated forest biorefinery. Hemicelluloses can be hydrolysed into sugars which in turn are converted into ethanol or butanol, while lignin can be extracted from a residual process stream, the black liquor, by acid precipitation, de-ionized, dried and directly used as a fuel or further processed into value added chemicals. Biorefinery processes have been proposed and analysed by simulation on Aspen Plus. Intensive integration of thermal energy, water and material systems is of paramount importance to the sustainability of the global site; the increased energy load on the utility systems could cause rising dependency of the global site on fossil fuels. To avoid this consequence, a new original energy efficiency analysis and enhancement methodology has been developed and validated on actual Canadian Kraft mills before being applied to the integrated biorefinery and, has produced remarkable results far superior to the current engineering practice. This has led to the concept of the GIFBR (green integrated forest biorefinery), i.e., an industrial site with zero fossil fuel consumption and reduced GHG (greenhouse gases) emissions vs. the Kraft process and biorefinery plant alone. The GIFBR incorporates a woody biomass gasifier producing syngas as a fuel for the integrated biorefinery and for steam production or sale. It can also include a CHP (combined heat and power) unit driven by steam made available by liberated production capacity from the installed power plant. 展开更多
关键词 Wood biomass renewable energy integrated forest biorefinery biofuels Kraft lignin extraction BIOETHANOL greenbiorefinery energy efficiency enhancement.
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Air-Sea Exchange of Volatile Organic Compounds: A New Model with Microlayer Effects
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作者 HE Cen-Lin FU Tzung-May 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第2期97-102,共6页
The authors propose a new "three-layer" conceptual model for the air-sea exchange of organic gases, which includes a dynamic surface microlayer with photochemical and biological processes. A parameterization... The authors propose a new "three-layer" conceptual model for the air-sea exchange of organic gases, which includes a dynamic surface microlayer with photochemical and biological processes. A parameterization of this three-layer model is presented, which was used to calculate the air-sea fluxes of acetone over the Pacific Ocean. The air-sea fluxes of acetone calculated by the three-layer model are in the same direction but possess half the magnitude of the fluxes calculated by the traditional two-layer model in the absence of photochemical and biological processes. However, photochemical and biological processes impacting acetone in the microlayer can greatly vary the calculated fluxes in the three-layer model, even reversing their direction under favorable conditions. Our model may help explain the discrepancies between measured and calculated acetone fluxes in previous studies. More measurements are needed to validate our conceptual model and provide constraints on the model parameters. 展开更多
关键词 air-sea transfer organic gas two-layer model microlayer surface renewal
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Investigation of Variability in Seed Size on Seedling Establishment of Buchholzia coriacea Engler
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作者 A. O. Akinyele A. O. Adegeye 《Journal of Agricultural Science and Technology(B)》 2011年第4期566-572,共7页
Investigation was carried out on the significance of seed size on morphological traits in seedlings of Buchholzia eoriaeea Engler, a medicinal plant in Southwestern Nigeria. Three size classes-large (seeds 〉 40 g),... Investigation was carried out on the significance of seed size on morphological traits in seedlings of Buchholzia eoriaeea Engler, a medicinal plant in Southwestern Nigeria. Three size classes-large (seeds 〉 40 g), medium (seeds between 25 and 40 g) and small (seed 〈 25 g) were used. Ninety uniformly growing seedlings from each size class were assessed for shoot height, number of leaves, collar diameter, leaf area and biomass production for six months. Seed size showed significant effect on height growth, collar diameter and number of leaves (P 〈 0.05). Seedlings from large seed size class had the best height and collar diameter (45.3 cm, 8.7 mm). Seeds of large and medium seed size classes had overall means of 15.6 and 15.5 leaves/seedling respectively. Leaf dry weight, stem dry weight and root biomass in seedlings from the three seed size classes were significantly different at P 〈 0.05 with the highest mean values for leaf dry weight, stem dry weight and root biomass recorded by seedlings from the large seed size class. The results showed that seed size has great influence on seedling growth when they are young. With availability of sufficient nutrient and light, effect of seed size on seedling growth and development could disappear as seedlings attain maturity. 展开更多
关键词 Buchholzia coriacea medicinal plant morphological traits seed size.
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