基于多元统计学的青稞HPLC指纹图谱研究

为了筛选品质良好的青稞,选择不同产地的10批青稞样品,建立了青稞的高效液相指纹图谱,并进行了聚类分析和主成分分析,测定了儿茶素、表儿茶素和芦丁3种指标成分的含量.首先采用高效液相色谱法测得了10批青稞的色谱图,建立其共有模式,确定了11个共有峰,蓝青稞指标成分含量均高于白青稞.对共有峰数据进行聚类分析和主成分分析,10...     

辐照处理对油菜籽光谱特性影响的研究

针对油菜籽经过核辐照处理后其光谱反射特性会发生改变的特点,提出了应用可见／近红外光谱技术进行油菜籽的快速无损鉴别。利用偏最小二乘法和BP神经网络建立鉴别模型,并比较了不同光谱预处理方法、主成分数据变换方式及隐含层节点数对模型预测结果的影响。实验采用五种剂量辐照(50, 100, 150, 200Gy和不经核辐照处理)的油菜籽共135个样本进行建模,49个进行预测。结果显示,最优模型是原始光谱数据先经过中值滤波平滑法、附加散射校正及一阶求导法预处理。经PLS方法提取6个主成分经自然对数变换后,选取神经网络隐含层结点数为4个或9个。最优模型对是否经过核辐照处理的样本识别率达100%,对核辐照剂量预测精度为85.71%, 说明提出的方法可以用于评估核辐照处理对油菜籽光谱特性产生的明显影响。     

青花菜抗坏血酸过氧化物酶基因BoAPX的克隆与表达分析

根据NCBI基因数据库提供的抗坏血酸过氧化物酶(Ascorbate Peroxidase,APX)基因序列设计简并引物,以青花菜(Brassica oleracea var.italica)叶片cDNA和DNA为材料进行PCR扩增,基因定名为BoAPX(Gen-Bank登录号:HQ871864).BoAPX的基因组全长为1 394bp,具7个内含子,编码区全长为753bp,编码250个氨基酸残基.序列分析结果表明,BoAPX的N端中没有信号肽序列,为胞质型APX,BoAPX与已知APX具有较高的同源性.RT-PCR结果表明,BoAPX的表达受霜霉菌(Hyaloperonospora parasitica)诱导,在96h时达最大值,说明BoAPX与霜霉菌抗性相关.以pBI121为植物表达载体,BoAPX为目的基因,成功构建了重组表达载体pBI121-BoAPX.     

吴茱萸碱、吴茱萸次碱和去氢吴茱萸碱的碳氢NMR信号全指定

应用1DNMR和梯度2DNMR反相技术(gCOSY,gNOESY,gHMQC,gHMBC)研究了从疏毛吴茱萸中分离得到的三个生物碱:吴茱萸碱、吴茱萸次碱和去氢吴茱萸碱的结构,并对其碳氢NMR信号进行了全归属.     

芜菁拮抗交通性污染物致小鼠遗传毒性效应的初步研究

以清洁级ICR小白鼠为实验动物,选择温州市鹿城区十里亭、火车站、南站交通岗亭为处理现场,采用小鼠骨髓嗜多染红细胞(PCE)的微核试验、小鼠精子畸形试验以及分光光度法测定小鼠肝脏过氧化氢酶(CAT)活性等实验方法,研究温州市区交通污染物对小鼠的遗传毒性及芜菁块根汁对它的拮抗效应.结果表明:经交通污染物处理的小鼠,其PCE的微核率、精子畸形率以及肝脏过氧化氢酶活性均明显高于阴性对照组;灌芜菁块根汁均可使小鼠PCE微核率、精子畸形率以及CAT活性明显下降,微核抑制率分别为62.96%、80.18%、87.36%,精子畸形抑制率分别为21.88%、45.89%、40.65%,CAT活性抑制率分别为17.27%、31.36%、37.76%.结论是交通性污染物对小鼠具有明显的遗传毒性效应;芜菁块根汁对交通性污染物引起小鼠遗传毒性效应具有显著的拮抗效应.     

Constituents of Helichrysum stoechas variety olonnense

The isolation of 18 phenolic compounds (-pyrones, phloroglucinols, phenolic acids, flavonoids, and coumarin) from the aerial parts of Helichrysum stoechas var. olonnense is reported.     

Secoiridoids Glycosides from Some Selected Jasminum SPP

Secoiridoid glycosides of three oleaceaous plants are described. Fractionation of the ethanolic extracts of Jasminum nitidum Skan, J. giraldii Diels and J. sambac (L.) Ait. var. trifoliatum Hort. (Oleaceace) resulted in the isolation of syringalactones A ( 1 ) and B ( 2 ), oleoside 7,11‐dimethyl ester ( 3 ), jasminoside (7), jaslanceosides B ( 8 ), sambacoside A ( 9 ) and molihuaside D ( 10 ). The structures of these secoiridoid glycosides were elucidated on the basis of spectral methods. Chemotaxonomy for plants of Jasminum is also discussed.     

Temporary Biological N Cońservation by Winter Oilseed Turnip (Brassica Rapa L.) and its Influence on Following Crops and N-Percolation

Abstract

As shown in field plot trials with application of ¹⁵N on loamy sand (albic luvisol), winter oilseed turnip (Brassica rapa L.; ssp. oleifera (Dc.) METZG.) incorporated considerable N amounts during the winter period. By this a reduction of N percolation into deeper soil layers was achieved. After mulching, about 30% of the catch crop N was taken up by the following crop, maize (Zea mays L., cv. ‘BEKENOVA’). Maize covered 11% of its total N demand deriving from the catch crop.     

基于SOGI-FLL算法的油田电网动态无功补偿对策研究

为了解决油田无功补偿装置爆电容现象,本课题在现有无功补偿装置存在问题的基础上,提出了采用晶闸管投切电容器与静止无功发生器相结合的补偿方案。将SOGI－FLL算法应用于电压精准锁相和无功功率的准确计算中,其结果分别用于确定matlab仿真模型中晶闸管投切电容器的投入时刻和提供静止无功发生器的控制参考信号,从而实现谐波和无功电流的有效控制。仿真结果表明,该方案不仅实现了无功功率的有效补偿,而且进一步降低了油田配电网无功损耗,提高了功率因数。     

Neomerane-type sesquiterpenoids from Valeriana officinalis var. latifolia

Valeneomerins A–D, two new neomerane-type sesquiterpenoids and two new nor-sesquiterpenoids, were isolated from the roots of Valeriana officinalis var. latifolia. Among them, valeneomerin A (1) was identified as a sesquiterpenoid with an unprecedented 15,3-lactone loop while valeneomerin C (3) and valeneomerin D (4) were determined to be nor-sesquiterpenoids with a new 15-reductive neomerane-type carbon skeleton. Their structures were elucidated by detailed spectroscopic analysis and Cu Kα X-ray crystallography. Compounds 1, 2, and 4 exhibited significant neuroprotective effects against H₂O₂ induced oxidative stress in SH-SY5Y cells with viability of 49.8, 40.9, and 44.6% each at 50 μM, respectively, in contrast to positive control (catechin, 50 μM) with viability of 32.6%.