甘蓝型油菜脂肪酸链延长酶基因FAE1的克隆与原核表达

脂肪酸延长酶1(FAE1)是广泛存在于植物中并定位于内质网上的一种能催化脂肪酸碳链延长的酮脂酰CoA合成酶.根据Genbank上已知的植物FAE1基因设计引物,以从甘蓝型油菜叶片中提取的总DNA为模板,进行PCR扩增,获得了1380bp的片段.回收该片段,并连接到pMD18-T载体测序.序列比对结果说明了该片段与植物中已知的FAE1序列有极高的相似性,并且不存在内含子序列.将该片段通过高保真酶扩增,EcoRⅠ酶切消化后定向克隆到pGEX-2T表达载体中,在IPTG诱导下于28℃表达出Mr76×103的蛋白质条带.用兔抗GST多克隆抗体做第一抗体进行Western-blot检测,并获得阳性检测结果.这为甘蓝型油菜脂肪酸链延长酶基因FAE1功能的进一步研究奠定了基础.图4表1参14     

国外松人工促进天然更新初步研究

国外松飞子成林能力较强，在人工促进措施下进行天然更新，幼树的地径和树高生长速度达到人工造林水平，而每亩可节约造林成本34．95元，经济效益显著。值得大力推广。     

高CO_2浓度下水稻高产品种特三矮2号的生长、产量与米质的研究(英)

于1996年晚季，从移栽到收割水稻高产品种特三矮2号种植于高CO2浓度（xco2=600X10-6）与目前大气CO2浓度（xco2=350X10-6）的塑料大棚内.xco2浓度由自动监控系统调节控制在整个生育期内，地上部生物学产量在高xco2下显著增加抽穗前，绿叶面积在高CO2浓度下显著增加；但抽穗后，绿叶面积在高CO2浓度下下降更快高CO2浓度下，谷产量、结实率和千粒重增加，而穗数和每穗谷粒数下降蒸煮品质（包括直链淀粉含量，胶稠度和碱消值）不受CO2浓度影响；而营养品质（蛋白质与氨基酸含量）在高CO2浓度下显著下降.我们认为，为了获得水稻的最大生产力和保持米的营养品质，施氮的数量与时间在高CO2浓度下应该有所调整.     

CFD simulations of dust dispersion in the 20 L vessel: Effect of nominal dust concentration

Measurements of flammability and explosion parameters for dust/air mixtures require uniform dispersion of the dust cloud inside the test vessel. In a previous work, we showed that, in the standard 20 L sphere, the dust injection system does not allow generation of a uniform cloud, but rather high gradients of dust concentration are established. In this work, we used a previously validated three-dimensional CFD model to simulate the dust dispersion inside the 20 L sphere at different dust nominal concentrations (and fixed dust diameter). Results of numerical simulations have shown that, as the dust nominal concentration is increased, sedimentation prevails and, thus, when ignition is provided, the dust is mainly concentrated at the vessel walls.     

Do lower electricity storage costs reduce greenhouse gas emissions?

In the electricity sector, innovation in large-scale storage is anticipated to reduce costs and improve performance. The effect on greenhouse gas emissions of lower storage costs depends on the interactions between storage and the entire grid. The literature has disagreed on the role of storage in reducing emissions. In this paper we present a stylized model, which suggests that the effect of storage costs on emissions depends on the supply responsiveness of both fossil and renewable generators. Under common conditions in the United States, lower storage costs are more likely to reduce emissions when wind investment responds to equilibrium electricity prices and when solar investment does not. Simulations of a computational model of grid investment and operation confirm these intuitions. Moreover, because of its effect on coal and natural gas–fired supply responsiveness, introducing a carbon dioxide emissions price may increase the likelihood that lower storage costs reduce emissions.     

Induction of glutathione reductase enzyme activity by β‐aminobutyric acid in plant leaves

Abstract

Treatment of pea and tobacco leaf discs with the resistance inducer DL‐β‐amino‐n‐butyric acid (BABA) led to a substantial induction of glutathione reductase (GR, E.C. 1.6.4.2.) enzyme activity. After exposure to 1 mM BABA for 96 hrs, the GR activities were 3.2‐fold and 2.9‐fold higher in pea and tobacco leaf discs, respectively, than GR activities in untreated controls. Elevated GR levels may contribute to the antioxidative protection of plants during pathogen attack.     

非织造布的防辐射性能对比研究

本文比较了80g／m^2复合法（SMS）非织造布经涂层与未经涂层两种试样对90Sr放射源的防护性能，结果显示经涂层非织造布的屏蔽率提高很大。分析表明，涂层剂对提高屏蔽率的作用要显著高于单纯增加厚度和克重来提高屏蔽率。     

Biodegradation of fatty acylamino acids by fusarium culmorum

Abstract

Biodegradation of the fatty acylamino acids by Fusarium culmorum, measured in terms of the release of radioactive aspartate and lysine, occurred maximally at pH 6.5 and pH 7.0, respectively in 10 day cultures. Thirty‐six percent and twenty‐four percent of the total radioactivity recovered were in released aspartate and lysine, respectivley at 30°C. Twenty degrees (C) was the minimum temperature for biodegradation of these compounds by F. culmorum. Greater degradation was observed at 15°C and 30°C. The data suggest the activity of hydrolytic isoenzymes, with optima at different pH's and temperatures, operating in the biodegradation process.     

镉在日本无刺楤木叶片的积累与对其抗氧化系统的影响

为考察镉对日本无刺楤木(Aralia elata var. inermis)生长及品质安全性的影响,采用生物盆栽法研究镉处理对不同生长期楤木叶片抗氧化系统影响及与镉含量关系。结果表明:展叶末期楤木叶片镉含量较少,镉对楤木叶片抗氧化能力有促进作用,随着处理量增加,叶片过氧化物酶(POD)活性、叶绿素含量先增大后减小,镉对过氧化氢酶(CAT)活性影响较强,可使其降至对照的30%,丙二醛(MDA)含量呈一定的先下降后上升的变化。生长中期POD活性达整个生长期最低;随着镉处理量增加,CAT活性先增强后减弱,但明显高于对照;叶绿素含量降幅各生长期最大,最低为对照69.1%;MDA含量则有显著增加。落叶初期叶片镉含量达到同处理最大;随着镉处理量的增加,POD活性持续减弱,CAT活性先增强后减弱,所受影响小于生长中期;叶绿素含量持续下降;落叶初期MDA含量在低量镉处理中降低,高量镉处理下继续升高。     

不同螯合剂对花生富集污染土壤中Co的影响

采用模拟Co污染土壤的方法,分别投加2.5 mmol/kg、5.0mmol/kg、7.5 mmol/kg的EDDS、NTA、CA和OA,研究了其对花生生长与吸收土壤重金属Co,以及对土壤中Co的活化能力的影响.结果表明:整合剂处理使花生的生物量降低,在高浓度整合剂处理时,降幅最大;EDDS的添加比NTA、CA和OA更显著地增加了土壤Co的有效态质量比,同时明显提高了花生的富集系数和转运能力;在螯合剂处理下,花生的转运系数最高达到0.916,具备了修复土壤重金属污染的能力;根系和地上部富集Co能力最强时分别达到58.64 mg/kg和46.33mg/kg,是对照组的1.29和3.63倍;各处理花生根系中的Co质量比要高于茎叶中的质量比,花生植株Co质量比与土壤有效态Co质量比呈显著(p＜0.05)或极显著相关(p＜0.01);综合来看,螯合剂的投加能有效活化土壤溶液中的Co,促进植物吸收、转运重金属.