期刊文献+
共找到1,242篇文章
< 1 2 63 >
每页显示 20 50 100
颜色对枸杞木虱成虫引诱作用的研究 被引量:12
1
作者 王平 佟德艳 +1 位作者 王艳 李文英 《内蒙古农业大学学报(自然科学版)》 CAS 2006年第4期102-104,共3页
枸杞木虱Paratrioza sinicaYang&L i.是枸杞主要害虫之一,刺吸危害枸杞叶片、花果,造成落叶、落果。目前,主要采用的化学农药防治方法,既污染环境,又影响了枸杞果作为营养保健品的价值。为了探索无污染的防治方法,本文在室外自然条... 枸杞木虱Paratrioza sinicaYang&L i.是枸杞主要害虫之一,刺吸危害枸杞叶片、花果,造成落叶、落果。目前,主要采用的化学农药防治方法,既污染环境,又影响了枸杞果作为营养保健品的价值。为了探索无污染的防治方法,本文在室外自然条件下,选用土黄、黄、橘黄、红、粉、天蓝、深蓝、褐、绿9种颜色作为引诱色,寻找对枸杞木虱成虫最具引诱能力的颜色。实验结果表明:土黄色、红色、黄色对枸杞木虱成虫的引诱作用显著。其他颜色(p=0.01),特别是土黄的诱虫效果最明显,可以选土黄色作为引诱色诱杀枸杞木虱。而且,还可用色板监测枸杞木虱成虫的种群数量动态。 展开更多
关键词 枸杞木虱(Paratrioza sinica Yang&Li) 色板 引诱作用
下载PDF
Three Stilbene Tetramers from the Roots of Caragana sinica 被引量:6
2
作者 马大友 骆宏丰 胡昌奇 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2004年第2期207-211,共5页
Three stilbene tetramers, carasinols AC (13), along with three known substances, leachianol C, cararosinol A and stenophyllol B, were isolated from the roots of Caragana sinica. Their structures were elucidated by spe... Three stilbene tetramers, carasinols AC (13), along with three known substances, leachianol C, cararosinol A and stenophyllol B, were isolated from the roots of Caragana sinica. Their structures were elucidated by spec-troscopy. It was found that compounds isolated except for stenophyllol B stimulated the proliferation of cultured osteoblasts. 展开更多
关键词 Caragana sinica FABACEAE RESVERATROL carasinols AC
原文传递
三种结缕草试管繁殖研究 被引量:4
3
作者 柴明良 郭达初 +2 位作者 钮友民 胡叔良 董令善 《科技通报》 1993年第6期411-415,共5页
以结缕草属的马尼拉草、结缕草和中华结缕草进行了试管繁殖的研究.以马尼拉草匍匐茎为外植体,通过芽直接增殖和愈伤组织分化途径形成了2个试管无性系;从结缕草和中华结缕草的实生苗中也筛选出了若干个试管无性系.嫩极丛在1/2MS培养基添... 以结缕草属的马尼拉草、结缕草和中华结缕草进行了试管繁殖的研究.以马尼拉草匍匐茎为外植体,通过芽直接增殖和愈伤组织分化途径形成了2个试管无性系;从结缕草和中华结缕草的实生苗中也筛选出了若干个试管无性系.嫩极丛在1/2MS培养基添加IBA或 NAA0.5 mg/L、IBA0.25mg/L+NAAO.25mg/L上生根,经38 d培养,马尼拉草生根率为100%,结缕草为88%~90%.移栽成活率马尼拉草在95%以上,结缕草高于90%.试管草移栽后生长旺盛。 展开更多
关键词 马尼拉草 中华结缕草 结缕草属
下载PDF
Comment on"A new discovery of the Early Cretaceous supercritical hyperpycnal flow deposits on Lingshan Island,East China"by Yang Tian et al.in Acta Geologica Sinica(English Edition),2017,91(2):749-750 被引量:9
4
作者 TAN Mingxuan ZHU Xiaomin LIU Wei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第5期1944-1945,共2页
Yang Tian et al.(2017)recognize bed-load-dominated and suspended-load-dominated hyperpycnites in the Beilaishi section,but we maintain that only Fig.1b is well consistent with their descriptions.The interface existi... Yang Tian et al.(2017)recognize bed-load-dominated and suspended-load-dominated hyperpycnites in the Beilaishi section,but we maintain that only Fig.1b is well consistent with their descriptions.The interface existing in the lower part separates it into two thin-bedded grading deposits then with climbing ripples in Fig. 展开更多
关键词 in Acta Geologica sinica English Edition
下载PDF
Relationship between rooting ability and endogenous phytohormone changes in successive continuous generation cuttings of Buxus sinica var. parvifolia, an endangered woody species in China 被引量:7
5
作者 Huang Yan Ji Kong-shu Zhai Jin-ru 《Forestry Studies in China》 CAS 2007年第3期189-197,共9页
The objectives of this study were to investigate the effects of successive continuous generation (SCG) cuttings of Buxus sinica var. parvifolia on the rejuvenation of ortets at the hormone level, detect levels of in... The objectives of this study were to investigate the effects of successive continuous generation (SCG) cuttings of Buxus sinica var. parvifolia on the rejuvenation of ortets at the hormone level, detect levels of indoleacetic acid (IAA), abscisic acid (ABA), isopentenyladenosine (iPA), zeatin riboside (ZR) and gibberellin4 (GA4) during the rooting process of different generations by means of enzyme-linked immunosorbent assay (ELISA) technology and statistically analyze the rooting characteristics of cuttings. The results show that, the root systems of subsequent generations (generation 1998, 2000) developed satisfactorily, only a few initial generation (generation 1990, 1994) cuttings rooted and the root growth was inhibited. Around the period of callus formation and root projection through the epidermis, there was a marked, regular variation in the levels of IAA, ABA and GA4 between the initial generations and subsequent generations. 展开更多
关键词 Buxus sinica var. parvifolia PHYTOHORMONES successive continuous generation cutting REJUVENATION
下载PDF
基于子句抽取的文本摘要自动提取算法
6
作者 朱兵兵 罗飞 +2 位作者 罗勇军 丁炜超 黄浩 《华东理工大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期114-120,共7页
TextRank算法及SWTextRank等改进算法在抽取式摘要生成中得到了广泛的应用,但它们都没有有效地解决抽取式摘要所存在的冗余性问题。为此,提出一种基于子句抽取的文本摘要自动提取算法(PTextRank)。首先,使用Sinica Treebank(STB)对每个... TextRank算法及SWTextRank等改进算法在抽取式摘要生成中得到了广泛的应用,但它们都没有有效地解决抽取式摘要所存在的冗余性问题。为此,提出一种基于子句抽取的文本摘要自动提取算法(PTextRank)。首先,使用Sinica Treebank(STB)对每个句子进行语法标记,进而基于子句设置抽取单元;接着,使用BERT(Bidirectional Encoder Representation from Transformers)构建标题和每个子句的特征向量,并计算子句特征向量间的相似性,将其存放在相似度矩阵中;最后结合子句位置、子句与标题的相似度等调整子句相似度矩阵,迭代计算直至收敛,进而选取得分最高的子句作为最终摘要。实验分析表明,PTextRank算法有效地避免了多个句子中存在的冗余信息,且相比于TextRank和SWTextRank,PTextRank生成摘要的准确率至少提高6%,同时生成的摘要质量更好。 展开更多
关键词 TextRank 摘要提取 冗余处理 sinica Treebank 篇章结构
下载PDF
Effects of probiotic on microfloral structure of live feed used in larval breeding of turbot Scophthalmus maximus 被引量:7
7
作者 JIANG Yan ZHANG Zheng +6 位作者 WANG Yingeng JING Yayun LIAO Meijie RONG Xiaojun LI Bin CHEN auiping ZHANG Hesen 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第3期1002-1012,共11页
The effects of an exogenous probiotic( Bacillus amyloliquefaciens) on microbial community structure of B ranchionus plicatils and A rtemia sinica were evaluated in this study during turbot( Scophthalmus maximus) larva... The effects of an exogenous probiotic( Bacillus amyloliquefaciens) on microbial community structure of B ranchionus plicatils and A rtemia sinica were evaluated in this study during turbot( Scophthalmus maximus) larval breeding. The analysis and comparison of the microfloral composition of live feed with probiotic was conducted using the Illumina HiSeq PE250. The abundance of microbial species and diversity of microflora in live feed with B. amyloliquefaciens were higher than those in the control. The microfloral composition was similar among the three replicate experimental groups of B. plicatils compared with the control after enrichment. L actococcus, Pseudoalteromonas, and Alteromonas were always dominant. Additionally, some other bacterial species became dominant during the enrichment process. The microbial community during nutrient enrichment of A. sinica was rather similar among the three control replicates. Relative abundance of Cobetia sp., the most dominant species, was 54%–65.2%. Similarity in the microbial community was still high after adding B. amyloliquefaciens. Furthermore, P seudoalteromonas and Alteromonas replaced Cobetia as the dominant species, and the abundance of Cobetia decreased to 4.3%–25.3%. Mean common ratios at the operational taxonomic unit level were 50%–60% between the two B. plicatils and A. sinica treatments. Therefore, the microbial community structure changed after adding B. amyloliquefaciens during nutrient enrichment of B. plicatils or A. sinica and tended to stabilize. Additionally, the abundance of V ibrio in any kind of live feed was not significantly dif ferent from that in the control. These results will help improve the microflora of B. plicatils and A. sinica and can be used to understand the multiple-level transfer role of probiotic species among probiotic products, microflora of live feed, and fish larvae. 展开更多
关键词 Branchionus plicatils Artemia sinica microfloral structure Bacillus amyloliquefaciens Scophthalmus maximus larval breeding
下载PDF
Reproductive biology of Magnolia sinica(Magnoliaecea),a threatened species with extremely small populations in Yunnan,China 被引量:5
8
作者 Ye Chen Gao Chen +1 位作者 Jing Yang Weibang Sun 《Plant Diversity》 SCIE CAS CSCD 北大核心 2016年第5期253-258,共6页
Magnolia sinica is one of the most threatened trees endemic to Southeast Yunnan.Based on our investigations,only 52 individuals and eight populations are found in the wild.M.sinica has been categorized as Critically E... Magnolia sinica is one of the most threatened trees endemic to Southeast Yunnan.Based on our investigations,only 52 individuals and eight populations are found in the wild.M.sinica has been categorized as Critically Endangered on the IUCN Red List and identified as a "Plant Species with Extremely Small Populations(PSESP)".Its fruit/seed set is very low and seedlings are rarely found in the wild.It is hypothesized that it may encounter obstacles to reproductive success.This study,therefore,focuses on its reproductive biology,knowledge of which is essential for effective conservation.Flowers of this species are protogynous and nocturnal,and possess a two-day rhythm of sexual presentation.For the first night of anthesis,the flowers are in the pistillate stage during which tepals open at dusk and close approx.1 h later(except for the open outer ones).They remain closed until the next afternoon,when flowers,now in the staminate stage,re-open and remain so until the tepals drop.Nocturnal beetles enter into the flowers and remain trapped throughout the night as the flower closes,during which time they feed on tepals.Pollen-gathering bees are found to visit the re-opened flowers and the beetles are released during this stage.Two species of Pleocomidae and Curculionidae beetles appear to be effective pollinators.M.sinica is a self-compatible,pollinator-dependent species,and its fruit/seed set can be significantly increased by hand-pollination.No functional seed dispersers have been found in its extant natural habitats.These findings suggest that it may face both pollination and seed disperser insufficiencies in its current fragmented habitats,which may account for its low regeneration.Here we propose conservation strategies based on our findings. 展开更多
关键词 Magnolia sinica PSESP Flowering process POLLINATION Seed dispersal GERMINATION
下载PDF
Effect of regional warming on the abundance of P seudeuphausia sinica Wang et Chen(Euphausiacea)off the Changjiang River(Yangtze River)Estuary 被引量:4
9
作者 GAO Qian XU Zhaoli 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第6期122-128,共7页
Distribution and abundance of Pseudeuphausia sinica off the Changjiang River Estuary (30 ° 00′ – 32 ° 00′ N, 122 ° 00′ –123 ° 30 ′E), the East China Sea were studied in relation to environm... Distribution and abundance of Pseudeuphausia sinica off the Changjiang River Estuary (30 ° 00′ – 32 ° 00′ N, 122 ° 00′ –123 ° 30 ′E), the East China Sea were studied in relation to environmental features associated with the regional warming. P. sinica is a subtropical species. Off the Changjiang River Estuary, its abundance reached maximum in summer. To examine spatial and temporal changes of P. sinica off the Changjiang River Estuary, the authors have combined all available sampling data in 1979, 1981, and 2000–2007. This database shows that a significant increase in abundances of P. sinica was observed in spring of 2000–2007 as compared with 1979, 1981. The abundance of P. sinica increased from 0.18–0.21 ind./m 3 in 1979 and 1981 to 0.68–4.00 ind./m 3 in 2000–2007. Accordingly, the sea temperature increased obviously from spring of 1979, 1981 to the 2000s. The authors further found a positive relationship between average surface temperature and average abundance of P. sinica. Regional warming, together with the release of predator induced stress due to a sharp decline in the abundance of its predator (e.g., fishes), were thought to be responsible for the increase in abundance of P. sinica in water off the Changjiang River Estuary. 展开更多
关键词 Changjiang River (Yangtze River) Estuary East China Sea Pseudeuphausia sinica temperature adaptation ZOOPLANKTON
下载PDF
水分胁迫对锦鸡儿和砂生槐种子萌发及幼苗生长的影响 被引量:4
10
作者 刘成凤 曾加芹 王梦妍 《湖北农业科学》 2021年第15期85-89,共5页
试验以锦鸡儿(Caragana sinica)和砂生槐(Sophora moorcroftiana)为试验材料,采用不同浓度的PEG溶液模拟水分胁迫,研究水分胁迫对锦鸡儿和砂生槐种子萌发及幼苗生长的影响。结果表明,在PEG浓度为0-100 g/L范围内,随着水分胁迫程度的加剧... 试验以锦鸡儿(Caragana sinica)和砂生槐(Sophora moorcroftiana)为试验材料,采用不同浓度的PEG溶液模拟水分胁迫,研究水分胁迫对锦鸡儿和砂生槐种子萌发及幼苗生长的影响。结果表明,在PEG浓度为0-100 g/L范围内,随着水分胁迫程度的加剧,锦鸡儿和砂生槐的发芽率、发芽势、发芽指数、活力指数以及萌发幼苗胚根和胚芽长度均总体呈下降趋势,且砂生槐在持续水分胁迫条件下生理响应的抑制现象表现得更为突出,说明水分胁迫对砂生槐的影响作用更大;PEG胁迫浓度达到150 g/L时,两种植物种子均无法萌发,表明锦鸡儿和砂生槐种子萌发的临界PEG胁迫值小于150 g/L。从总体来看,与砂生槐相比,锦鸡儿具有较强的抗旱能力,更适合在干旱环境中生长。 展开更多
关键词 锦鸡儿(Caragana sinica) 砂生槐(Sophora moorcroftiana) 水分胁迫 种子萌发 幼苗生长
下载PDF
Identification of Two Cold Water-Soluble Polysaccharides from the Stems of Ephedra sinica Stapf 被引量:4
11
作者 Yonggang Xia Jun Liang +2 位作者 Bingyou Yang Qiuhong Wang Haixue Kuang 《Chinese Medicine》 2010年第3期63-68,共6页
Two polysaccharides (ESP-A1 and ESP-A2) were isolated from the cold water extract of Ephedra sinica Stapf and purified through ethanol precipitation, deproteinization and by ion exchange and gel-filtration chromatogra... Two polysaccharides (ESP-A1 and ESP-A2) were isolated from the cold water extract of Ephedra sinica Stapf and purified through ethanol precipitation, deproteinization and by ion exchange and gel-filtration chromatography. Their molecular weight was determined using high performance size exclusion chromatog-raphy and evaporative light scattering detector (HPSEC-ELSD) and their monosaccharide composition was analyzed by high performance capillary electrophoresis (HPCE) based on pre-column derivatization with 1-phenyl-3-methyl-5-pyrazolone (PMP). It was shown that ESP-A1 consisted of xylose, arabinose, glucose, mannose and galactose and ESP-A2 consisted of xylose, arabinose, rhamnose and galactose, in a molar ratio (%) of 3.2: 61.1: 11.1: 12.9: 11.6 and 20.6: 67.7: 5.0: 6.7, respectively. The molecular weights (Mw) of ESP-A1 and ESP-A2 were 5.83 × 104 Da and more than 200 × 104 Da, respectively. To the best of our knowledge, two neutral polysaccharides are now being reported for the first time in this study. 展开更多
关键词 EPHEDRA sinica Stapf POLYSACCHARIDES Isolation and PURIFICATION Molecular Weight MONOSACCHARIDE Composition
下载PDF
中华卤虫无节幼体蛋白质组的双向凝胶电泳分析 被引量:4
12
作者 周茜 吴长功 +2 位作者 刘凤岐 黄冰心 相建海 《海洋科学》 CAS CSCD 北大核心 2008年第7期62-64,共3页
应用双向凝胶电泳和图像分析手段,对比了卤虫(Artemia)初孵无节幼体和孵化24 h无节幼体中蛋白表达的变化情况。结果显示,随着卤虫幼体的发育,蛋白表达的种类和个数均明显增多,仅有个别蛋白的表达量下调。这些差异表达的蛋白可能跟卤虫... 应用双向凝胶电泳和图像分析手段,对比了卤虫(Artemia)初孵无节幼体和孵化24 h无节幼体中蛋白表达的变化情况。结果显示,随着卤虫幼体的发育,蛋白表达的种类和个数均明显增多,仅有个别蛋白的表达量下调。这些差异表达的蛋白可能跟卤虫幼体的发育过程密切相关或起重要的调节作用。 展开更多
关键词 蛋白质组 中华卤虫(Artemia sinica) 幼体 双向电泳
下载PDF
A new tetrastilbene from Caragana sinica 被引量:4
13
作者 Ke Jun Cheng Da You Ma Guo Xun Yang Chang Qi Hu 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第6期711-715,共5页
A new tetrastilbene named carasinol D (1) was isolated from the roots of Caragana sinica. Its structure was elucidated by spectroscopic analysis. Compound 1 was obtained from carasinol B (2) by an acid-catalyzed c... A new tetrastilbene named carasinol D (1) was isolated from the roots of Caragana sinica. Its structure was elucidated by spectroscopic analysis. Compound 1 was obtained from carasinol B (2) by an acid-catalyzed conversion. 展开更多
关键词 Caragana sinica STILBENOIDS Carasinol D Carasinol B
下载PDF
Proteomic analysis of acute responses to copper sulfate stress in larvae of the brine shrimp,Artemia sinica 被引量:5
14
作者 周茜 吴长功 +3 位作者 董波 李富花 刘凤岐 相建海 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第2期224-232,共9页
Proteomics was used to reveal the differential protein expression profiles of acute responses to copper sulfate exposure in larvae of Artemia sinica.Fourteen differentially displayed protein spots were detected and se... Proteomics was used to reveal the differential protein expression profiles of acute responses to copper sulfate exposure in larvae of Artemia sinica.Fourteen differentially displayed protein spots were detected and seven of them were identified.Three spots were up-expressed and identified:actin, heat shock protein 70,and chaperone subunit 1;three down-regulated proteins were identified:arginine kinase,elongation factor-2,and glycine-rich protein;and a newly expressed protein was identified as peroxiredoxin.The study indicates the involvement of all the differentially expressed proteins in the early responses of protein expression,and in the survival of A.sinica in the presence of copper and other heavy metals;the findings improve understanding of the organism’s adaptive responses and resistance. 展开更多
关键词 proteomic analysis Artemia sinica copper sulfate acute stress response
下载PDF
ACTA METEOROLOGICA SINICA INDEX TO CONTENTS OF 1999 AMS VOL.13 1999 被引量:5
15
《Acta meteorologica Sinica》 SCIE 1999年第4期509-512,共4页
关键词 Simulation VOL.13 ACTA METEOROLOGICA sinica INDEX TO CONTENTS OF 1999 AMS AMS
原文传递
黄杨属植物化学成分的研究进展 被引量:5
16
作者 吕霞 胡明通 于盱 《安徽农业科学》 CAS 2012年第24期12028-12030,12034,共4页
综述了近20年来黄杨属植物中生物碱、黄酮、甾醇、香豆素、木脂素和酸类化合物等7大类化学成分的研究结果,并介绍了黄杨的抑制酶活性、抗HIV病毒、抗菌及抗肿瘤等新的药理作用,为我国丰富的黄杨资源的开发利用提供参考。
关键词 黄杨属(Buxus sinica) 黄杨生物碱 化学成分 生物活性
下载PDF
Effects of Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) medicated serum on chemotactic migration of alveolar macrophages and inters regions macrophages in rats 被引量:3
17
作者 Yuan Yiping Zhai Huaqiang +7 位作者 Zhang Tian Guo Zhaojuan Kong Liting Jia Xiaoyu Wang Ningning Dai Ying Liu Guoxiu Wang Yanping 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2017年第5期607-615,共9页
OBJECTIVE: To observe the effects of serum containing Mahuang(Herba Ephedra Sinica) or Wuweizi(Fructus Schisandrae Chinensis) on the migration of alveolar macrophages(AM) and interstitial macrophages(IM) from normal r... OBJECTIVE: To observe the effects of serum containing Mahuang(Herba Ephedra Sinica) or Wuweizi(Fructus Schisandrae Chinensis) on the migration of alveolar macrophages(AM) and interstitial macrophages(IM) from normal rats, and to analyze and compare the mechanisms leading to cell migration differences.METHODS: Rats were randomly divided into three groups: Mahuang(Herba Ephedra Sinica), Wuweizi(Fructus Schisandrae Chinensis), and blank serum. After treatment with the herbs, serum was extracted from the rats. AM and IM were isolated from normal rats and cultured. The effects of Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) medicated serum on normal rat AM and IM chemotactic migration were determined by transwell assays. The CC chemokine receptor(CCR) 2, CCR5, voltage-gated Kvl. 3 K^+channel(Kv1. 3), and voltage-gated Kvl. 5 K^+channel(Kv1. 5) protein levels were analyzed by western blotting.RESULTS: The migration quantities of AM and IM in the Mahuang(Herba Ephedra Sinica) and Wuweizi(Fructus Schisandrae Chinensis) medicated serum groups were significantly higher than those in the blank serum group(P < 0.01). Compared with the Wuweizi(Fructus Schisandrae Chinensis) medicated serum group, the migration quantity of cultured rat AM in the Mahuang(Herba Ephedra Sinica) medicated serum group was significantly increased(P <0.01). Meanwhile, compared with the Mahuang(Herba Ephedra Sinica) medicated serum group, the migration quantity of cultured rat IM in the Wuweizi(Fructus Schisandrae Chinensis) medicated serum group was significantly increased(P < 0.01).CCR2, CCR5, Kv1. 3, and Kv1. 5 proteins were expressed on the AM cell surface, and showed significantly higher expression in the Mahuang(Herba Ephedra Sinica) medicated serum group compared with the Wuweizi(Fructus Schisandrae Chinensis)medicated serum group. In contrast, CCR5, Kv1.3,and Kv1.5 proteins were expressed on the IM cell surface, and showed significantly higher expression in the Wuweizi(Fructus Schisandrae Chinensis)medicated serum g 展开更多
关键词 Ephedra sinica Schisandra Chinensis Macrophage Receptors CCR Delayed rectifier po tassium channel Chemotaxis
原文传递
Comparative analysis of volatile oils in the stems and roots of Ephedra sinica via GC-MS-based plant metabolomics 被引量:3
18
作者 LV Meng-Ying SUN Jian-Bo +3 位作者 WANG Min FAN Hong-Yan ZHANG Zun-Jian XU Feng-Guo 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2016年第2期133-140,共8页
With a great difference in therapeutic effects of Mahuang(MH, the stems of Ephedra sinica) and Mahuanggen(MHG, the roots of Ephedra sinica), chemical differences between MH and MHG should be investigated. In the prese... With a great difference in therapeutic effects of Mahuang(MH, the stems of Ephedra sinica) and Mahuanggen(MHG, the roots of Ephedra sinica), chemical differences between MH and MHG should be investigated. In the present study, gas chromatography-mass spectrometry(GC-MS)-based plant metabolomics was employed to compare volatile oil profiles of MH and MHG. The antioxidant activities of volatile oils from MH and MHG were also compared. 32 differential chemical markers were identified according to the variable importance in the projection(VIP) value of orthogonal partial least squares discriminant analysis(OPLS-DA) and P value of Mann-Whitney test. Among them, chemical markers of tetramethylpyrazine(TMP) and α-terpineol were quantified. Their contents were much higher in most MH samples compared with MHG. The antioxidant assay demonstrated that MH had significantly higher free radical-scavenging activity than MHG. Although MH and MHG derived from the same medicinal plant, there was much difference in their volatile oil profiles. MH samples had significantly higher content of two reported pharmacologically important chemical markers of TMP and α-terpineol, which may account for their different antioxidant activities. 展开更多
关键词 Ephedra sinica GC-MS Volatile oil Plant metabolomics Antioxidant activity
原文传递
Structural Characterization of Lignins Isolated from Caragana sinica Using FT-IR and NMR Spectroscopy 被引量:3
19
作者 XIAO Ling-ping SHI Zheng-jun +2 位作者 XU Feng SUN Run-cang Amar K Mohanty 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2011年第9期2369-2376,共8页
In order to efficiently explore and use woody biomass,six lignin fractions were isolated from dewaxed Caragana sinica via successive extraction with organic solvents and alkaline solutions.The lignin structures were c... In order to efficiently explore and use woody biomass,six lignin fractions were isolated from dewaxed Caragana sinica via successive extraction with organic solvents and alkaline solutions.The lignin structures were characterized by Fourier transform infrared spectroscopy(FT-IR) and 1D and 2D Nuclear Magnetic Resonance(NMR).FT-IR spectra revealed that the "core" of the lignin structure did not significantly change during the treatment under the conditions given.The results of 1H and 13C NMR demonstrated that the lignin fraction L2,isolated with 70% ethanol containing 1% NaOH,was mainly composed of β-O-4 ether bonds together with G and S units and trace p-hydroxyphenyl unit.Based on the 2D HSQC NMR spectrum,the ethanol organosolv lignin fraction L1,extracted with 70% ethanol,presents a predominance of β-O-4′ aryl ether linkages(61% of total side chains),and a low abundance of condensed carbon-carbon linked structures(such as ββ′,β-1′,and β-5′) and a lower S/G ratio.Furthermore,a small percentage(ca.9%) of the linkage side chain was found to be acylated at the γ-carbon. 展开更多
关键词 Caragana sinica LIGNIN Structural characterization FT-IR NMR
下载PDF
揭阳市紫薇长斑蚜与中华草蛉的分布动态
20
作者 卢泽彬 《中南农业科技》 2023年第12期6-8,共3页
大花紫薇(Lagerstroemia speciosa)是中国热带和南亚热带地区重要的园林树种,紫薇长斑蚜(Tinocallis kahawaluokalani)是大花紫薇常见且危害程度大的病虫害。为了解紫薇长斑蚜在大花紫薇上的动态分布规律,调查了紫薇长斑蚜与天敌中华草... 大花紫薇(Lagerstroemia speciosa)是中国热带和南亚热带地区重要的园林树种,紫薇长斑蚜(Tinocallis kahawaluokalani)是大花紫薇常见且危害程度大的病虫害。为了解紫薇长斑蚜在大花紫薇上的动态分布规律,调查了紫薇长斑蚜与天敌中华草蛉(Chrysoperla sinica)在大花紫薇树冠不同方向的动态分布特征。结果表明,紫薇长斑蚜在树冠不同方向上以北向种群密度最大,西向其次,南向第三,东向最小。而不同方向的紫薇长斑蚜与整株大花紫薇的蚜虫总量均呈极显著正相关关系,其中以树冠北向枝条上的蚜虫数量与整株大花紫薇的蚜虫总量的相关系数最高,为0.9966,可通过调查树冠某一方向的蚜虫数量监测紫薇长斑蚜总量的动态情况。且紫薇长斑蚜与天敌中华草蛉联系紧密,二者在数量上随时间的变化表现出高度的一致性,在防治上可考虑采用生物和化学防治相结合,确保防治效果。 展开更多
关键词 紫薇长斑蚜(Tinocallis kahawaluokalani) 中华草蛉(Chrysoperla sinica) 分布规律 动态特征 揭阳市
下载PDF
上一页 1 2 63 下一页 到第
使用帮助 返回顶部