Identification of volatile allelochemicals fromAmaranthus palmeri S. Wats

Allelopathic volatiles associated with the weed Palmer amaranth (Amaranthus palmeri S. Wats.; AMAPA) were trapped on Tenax GC, thermally desorbed, and identified by gas chromatography-mass spectroscopy. Methyl ketones and alcohols (C₄–C₁₁) were the principal components of the volatiles mixture. Seedheads, stems, or roots were placed in a glass container and incubated at 31 °C (10 hr)/21 °C (14 hr) for three days prior to trapping the volatiles. Seedheads were rich in 2-heptanone which was consistently found, together with 2-heptanol, in all AMAPA tissues. Vapors of authentic 2-heptanone and (±)-2-heptanol at concentrations of 1 ppm or higher strongly inhibited the germination of onion and carrot and almost completely suppressed the germination of tomato and AMAPA seeds.Names of companies or commercial products are given solely for the purpose of providing specific information; their mention does not imply recommendation or endorsement by the U.S. Department of Agriculture over others not mentioned.     

菜籽除芒装置的试验

本文根据物料间相互揉搓除芒原理研制的菜籽除芒装置，避免了机械元件直接作用于种子造成的损伤，并能很好地脱去小粒菜籽种皮上的种毛，为进一步提纯和处理种子提供光滑的种粒．通过一次回归正交试验找出除芒装置转速、出口活门开启压力和螺距对除芒效果影响的主次作用和最佳参数组合，为进一步完善除芒装置提供了依据。经辽宁省种子公司生产试验表明，研制的除芒装置具有结构简单、工作可靠、生产率和除芒率高等特点。     

Influence de la réfrigération et de la congélation sur la qualité et l'aptitude à la germination des grainesInfluence of chilling and freezing on seed quality and germination ability

The high dehydration level of seeds provides them with an exceptional survival period, nevertheless seeds are living organs which can die. Refrigeration can prevent the germination of seeds which are destined for human or animal consumption or, on the contrary, produce germination in a required time. The article first describes some of the biological particularities of seeds which can be considered as survival or reproductive organs. As a survival organ, refrigeration can be used to preserve seeds to: Prevent germination: the storage of seeds of tropical and sub-tropical origin at +5°C: the maintenance of a cold and dry atmosphere for the bulk storage of seeds in silos. Prevent parasitic attack: a low temperature and low relative humidity to protect against bacterial or fungal growth: it is more difficult to combat insect invation. Protect product viability: the drier the seed and the lower the temperature, the longer the seed life. Refrigeration can also be used to facilitate germination by eliminating dormancy. It is already well known that humid cold promotes germination by eliminating embryonic dormancy (in general, from one to a few months at a temperature of about +5°C). Furthermore, good germination of ‘hard seeds’ (with teguments impermeable to water) can be obtained by immersing them in liquid nitrogen and repeating the operation if necessary.

Résumé

Les graines sont des organes très particuliers en ce sens qu'elles prérentent le plus souvent un état de déshydration très poussé. Les problèmes de stockage qui en résultent sont de ce fait très différents de ceux que l'on recontre généralement avec les autres produits végétaux. Les basses températures empêchent leur germination pendant la conservation, limitent les altérations dues aux parasites et prolongent leur durée de vie. La réfrigération et la congélation des graines ont permis la mise au point d'applications originales. Quelques graines ne peuvent germer qu'après un séjour au froid en milieu humide. Des graines imperméables à l'eau deviennent capables de germer facilement aprés traitement à très basse température (azote liquide).     

词源研究与术语规范--X射线词族的词源研究

词源研究的重要内容是针对词语个体的产生和发展进行深入细致的研究,词源研究尤其是近现代及当代产生的词语的词源研究对术语规范工作有重要的参考价值,词语的发展尤其是术语的发展与术语规范方面的工作有密切关系。本以X射线词族的发展过程为例说明二之间的密切关系。     

A note on repeated measures in the study of short-term memory.

Keppel's (1965) objection to averaging over repeated measures is discussed. Several possibilities for minimizing proactive interference are suggested, including increasing time between tests. Consideration is given to acceptance of a constant amount of proactive interference over conditions in which other variables are studied. The advantages of using repeated measures in regard to efficiency as well as interpretation are noted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于特征性脂肪酸和甘油三酯指标的油茶籽油掺伪定性鉴别模型对比分析

为解决油茶籽油掺伪其他植物油的定性鉴别问题,在油茶籽油中分别掺入大豆油、花生油、葵花籽油、棉籽油、葡萄籽油、菜籽油、棕榈油和米糠油,设置高和低两种不同掺伪梯度,基于14个特征性脂肪酸和甘油三酯指标,运用Python语言构建并对比分析了二分类决策树模型、多分类决策树模型和多层感知机人工神经网络(MLP-ANN)模型用于油茶籽油掺伪定性鉴别的效果。结果表明：高和低掺伪梯度下,二分类决策树模型对油茶籽油掺伪其他植物油的定性鉴别的准确率均达到0.95以上;多分类决策树模型的精确率和准确率在高掺伪梯度下均达到了0.95,但在低掺伪梯度下仅为0.90;在高和低掺伪梯度下,MLP-ANN模型对油茶籽油掺伪定性鉴别的平均精确率均达到0.98,准确率分别达到0.97和0.98。相比于决策树模型,MLP-ANN模型能很好地实现油茶籽油掺伪定性鉴别。     

The effect of grape seed extract or Cistus ladanifer L. on muscle volatile compounds of lambs fed dehydrated lucerne supplemented with oil

Thirty-six Merino Branco lambs were assigned to six dietary treatments: control diet (C) consisting of 90% dehydrated lucerne and 10% wheat bran; control diet with 6% of oil blend (CO); control with 2.5% of grape seed extract (GS); control with 2.5% of grape seed extract and 6% of oil blend (GSO); control with 25% of Cistus ladanifer (an aromatic bush widespread in Portugal; CL); control with 25% of C. ladanifer and 6% of oil blend (CLO). The muscle longissimus dorsi was then subjected to the analysis of volatile compounds (SPME–GC/MS). The CLO diet increased the concentration of heptanal, 3-hydroxy-2-butanone and 2-ethyl-phenol in muscle compared to the CL diet. When lambs received the CL diet, their meat contained lower amounts of 4-heptenal compared to the other treatments. The meat of the GS and GSO lambs contained similar amounts of volatile compounds deriving from lipid oxidation (such as heptanal, 2-nonenal, 4-heptenal and 3-hydroxy-2-butanone). These results indicate that in the presence of grape seed extract, oil supplementation did not enhance the production of lipid-derived volatile compounds. Verbenone and 2,2,6-trimethyl-cyclohexanone were detected only in the meat of the Cistus-fed lambs, suggesting that these compounds could be markers of feeding Cistus-containing diets. Meat volatile compounds profile allowed to discriminate between the lambs receiving C. ladanifer and those not receiving this bush in the diet.     

Variation of sesamin,sesamolin and tocopherols in sesame (Sesamum indicum L.) seeds and oil products in Thailand

Sesame (Sesamum indicum L.) seed and oil contain abundant lignans, including sesamin, sesamolin and lignan glycosides. The aim of the present study was to determine sesamin, sesamolin and tocopherol contents in sesame seed and oil available in Thailand. The results showed that there was a large variation of sesamin and sesamolin contents in products. The distribution plot of sesamin and sesamolin contents in seeds showed that the mean values of sesamin and sesamolin were 1.55 mg/g (SD = 1.63; range n.d.–7.23 mg/g) and 0.62 mg/g (SD = 0.48; range n.d.–2.25 mg/g), respectively. The range of total tocopherols of these sesame lines was 50.9–211 μg/g seed. In commercial sesame oils, the ranges of sesamin and sesamolin were 0.93–2.89 mg/g oil and 0.30–0.74 mg/g oil, respectively, and tocopherol contents were 304–647 μg/g oil. The study reveals the extensive variability in sesamin, sesamolin and tocopherol contents among sesame products.     

不同方法提取丝瓜籽油的工艺研究

以丝瓜籽为原料,对丝瓜籽油的不同提取工艺和提取效果进行了比较.通过正交试验得到溶剂法最佳提取条件为:提取溶剂选用石油醚(b.p.60～90℃),提取时间为3 h,料液比为1:8(g:mL),提取温度为60℃,提取次数为2次,提取率为17.93%.超声波辅助法最佳提取条件为提取溶剂选用石油醚.超声时间为40min,超声功率为120 W,料液比为1:12(g:mL),超声温度为50℃,提取次数为2次,提取率为18.76%.结果表明,超声波辅助法提取的丝瓜籽油提取率高于溶剂提取法的提取率,并且比溶剂法提取的温度低、时间短,是一种短时高效的提取方法.     

Preparation of Nano‐Structured Polyaniline Composite Film via “Carbon Nanotubes Seeding” Approach and its Gas‐Response Studies

Summary: Polyaniline composite film with nano‐structure was prepared through a chemical oxidation method by adding carbon nanotubes (CNTs) as nano‐fiber seeds. Spin‐coating or casting method was employed on the interdigital electrodes of carbon and the composite film was formed with an in‐situ polymerization approach. The gas‐response to trimethylamine was also examined at room temperature. It was found that the difference was not only in the morphology, but also in the value of gas‐sensitivity. Comparing with films without the CNTs, the value of gas‐sensitivity decreased dramatically, while the baseline current of the sensor increased remarkably. This method can be an effective way to adjust the gas‐sensitivity of sensors made from polyaniline composite film by adding a small amount of carbon nanotube. XRD data showed that the degree of orientation of polyaniline was increased greatly with the addition of CNTs.

Morphology and reproducibility (inset) of polyaniline composite film containing carbon nanotubes.