检索结果-南通市图书馆

Responses of diff erent biodiversity indices to subsampling efforts in lotic macroinvertebrate assemblages

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and limnology 2019年第1期37卷 122-133页

作者： WANG Jun li zhengfei SONG Zhuoyan ZHANG Yun JIANG Xiaoming XIE Zhicai CAS Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Biological Sciences University of Alberta

As a less time-consuming procedure, subsampling technology has been widely used in biological monitoring and assessment programs. It is clear that subsampling counts af fect the value of traditional biodiversity indices, but its ef fect on taxonomic distinctness(TD) indices is less well studied. Here, we examined the responses of traditional(species richness, Shannon-Wiener diversity) and TD(average taxonomic distinctness: Δ +, and variation in taxonomic distinctness: Λ +) indices to subsample counts using a random subsampling procedure from 50 to 400 individuals, based on macroinvertebrate datasets from three dif ferent river systems in China. At regional scale, taxa richness asymptotically increased with ?xed-count size; ≥250–300 individuals to express 95% information of the raw data. In contrast, TD indices were less sensitive to the subsampling procedure. At local scale, TD indices were more stable and had less deviation than species richness and Shannon-Wiener index, even at low subsample counts, with ≥100 individuals needed to estimate 95% of the information of the actual Δ + and Λ + in the three river basins. We also found that abundance had a certain ef fect on diversity indices during the subsampling procedure, with dif ferent subsampling counts for species richness and TD indices varying by regions. Therefore, we suggest that TD indices are suitable for biodiversity assessment and environment monitoring. Meanwhile, pilot analyses are necessary when to determine the appropriate subsample counts for bioassessment in a new region or habitat type.

关键词： subsampling macroinvertebrates taxonomic distinctness indices taxa richness Shannon-Wiener index

Integrated treatment for lower-limb stage Ⅱ thromboangiitis obliterans by interventional therapy and oral administration of Chinese medicine: a randomized controlled clinical trial

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2015年第1期35卷 41-46页

作者： Chang Yaowen li Fenqiang Wang Wenhui Song Laichang li li li zhengfei Su Dongjun Fu Zhaoliang Department of Integrated Chinese and Western Medicine with Interventional Therapy the First Affiliated Hospital of Lanzhou University Department of Integrated Chinese and Western Medicine Gansu University of Traditional Chinese Medicine

OBJECTIVE： To observe if integrated treatment is better than other therapies for lower-limb stage Ⅱ thromboangiitis obliterans （TAO）. METHODS： Ninety lower-limb stage Ⅱ or worse TAO patients were randomly divided into three groups： group A （30 cases） treated by intervention and oral administration of Chinese medicine; group B （30 cases） treated by intervention alone; and group C （30 cases） treated only with oral adminis- tration of Chinese medicine. Therapeutic effects were observed, including the cure rate; the recurrence rate after one month, three months, six months, nine months, and one year; the ankle brachial indexes; the incidence of complications; and the level of C-reactive protein and erythrocyte sedimentation ***： Group A had significantly better clinically curative effects, related indexes, and outcomes during the long-term follow-up survey, than that of groups B and C. CONCLUSION： Integrated treatment is more effective for treating lower-limb stage Ⅱ or worseTAO.

关键词： Thromboangiitis obliterans Lower ex-tremity Intervention studies Medicine, Chinese traditional Treatment outcome Randomized controlled trials

Environmental filtering and spatial processes equally contributed to macroinvertebrate metacommunity dynamics in the highly urbanized river networks in Shenzhen, South China

在线全文

学校读者我要写书评

暂无评论

Ecological Processes 2021年第1期10卷 316-327页

作者： Zhenyuan liu Tingting Zhou Yongde Cui zhengfei li Weimin Wang Yushun Chen Zhicai Xie Institute of Hydrobiology Chinese Academy of SciencesWuhan 430072HubeiChina University of Chinese Academy of Sciences Beijing 100049China Central Station for Environmental Monitoring and Assessment Shenzhen 518049GuangdongChina.

Background:Disentangling the relative roles of environmental filtering and spatial processes in structuring ecological communities is a central topic in metacommunity *** ecology in the temperate river ecosystems has been well developed,while less attention has been paid to subtropical urban river ***,we examined the ecological factors and seasonal difference in structuring macroinvertebrates metacommunity assembly in the subtropical urban river networks in Shenzhen,South ***:Our results revealed that there was no significant distinction of macroinvertebrate community composition among seasons,with only the relative abundance of Mollusca and Odonata significantly differed in both wet and dry *** possible explanation was that most macroinvertebrates are generally pollution-tolerant taxa characterized with nonseasonal life *** addition,distance-based redundancy analysis and variation partitioning approach revealed that metacommunity was determined equally by the environmental and dispersal-related ***,our results showed that,although a slight temporal variation of relative contribution,the identity and explanation power of ecological factors were different among ***,stronger environmental filtering structuring community dynamics was observed in the dry than wet seasons,which might be owing to higher environmental heterogeneity under a low water-flow ***,we detected that the influence of spatial processes was stronger in the wet than dry seasons,indicating an obvious dispersal processes due to high connectivity among ***:Overall,our results revealed that environmental and spatial factors equally explained variations of macroinvertebrate metacommunity,implying the necessity of considering dispersal-related processes structuring ecological communities in river bioassessment ***,degraded habitat conditions and water quality were the predominant factors

关键词： Community assembly Seasonal variation Macroinvertebrate metacommunity Environmental filtering Spatial processes Urban river

From source to lake:Multi‒taxon alpha and beta diversity patterns along a river above 4500 m AMSL on the Qinghai‒Tibetan Plateau

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Water Biology and Security

Water Biology and Security 2024年第4期3卷 55-64页

作者： Yintao Jia Huan Zhu Tingfeng Xie Xiong Xiong zhengfei li Yongde Cui Guoxiang liu Mingdian liu Yifeng Chen Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture(CAS) Institute of HydrobiologyChinese Academy of SciencesWuhan430072China Institute of Hydrobiology Chinese Academy of SciencesWuhan430072China Yangtze River Fisheries Research Institute Chinese Academy of Fishery SciencesWuhan430223China

Understanding the distribution of species is highly important for optimizing future conservation priorities and strategies at the regional *** little attention has been given to multi-taxon aquatic biota in extreme alpine *** examined the spatial and temporal patterns of alpha and beta diversity,site-specific contributions to beta diversity and assembly mechanisms of four taxonomic groups(fishes,macroinvertebrates,zooplankton and phytoplankton)from the source to the estuary of the Za'gya Zangbo River above 4500 m AMSL(above mean sea level)on the northern Qinghai-Tibetan(Q–T)Plateau.A total of 4 fish species,45 macroinvertebrate taxa,17 zooplankton taxa and 56 phytoplankton taxa were found in the study *** consistent patterns in taxonomic richness were observed across taxa from upstream to *** fish communities had the lowest dissimilarity between communities,the phytoplankton community had the highest dissimilarity in the dry season,and the macroinvertebrate community had the highest dissimilarity in the wet *** relative importance of the turnover and nestedness components varied considerably across taxa and along spatial *** diversity patterns of macroinvertebrate,zooplankton and phytoplankton communities were significantly correlated with several environmental factors,whereas only the beta diversity of fish was correlated with *** processes dominated in shaping the macroinvertebrate communities whereas deterministic processes dominated the assembly of the phytoplankton *** congruence of diversity patterns across taxonomic groups suggested that biological groups cannot serve as reliable surrogates for one another and that multiple biological groups should be included in the biomonitoring of high-altitude rivers on the Q‒T *** relatively unique species in the upstream area and estuary of the Za'gya Zangbo River harbor should receive more attention in future conservation and man

关键词： Diversity patterns Spatiotemporal variation Community assembly High altitude

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

创始人特质、家族涉入与小微企业成长

东岳论丛 2020年第6期41卷 110-120,192页

作者：李拯非张宏山东大学经济学院山东济南250100

小微企业是中国经济保持高速增长的微观动力,多数小微企业都有家族成员参与。那么,嵌入家族因素的小微企业成长是否更优?创始人特质在家族涉入对小微企业成长影响中的作用又是什么?本文以中国的小微企业为例,研究创始人特质、家族涉入... 详细信息

小微企业是中国经济保持高速增长的微观动力,多数小微企业都有家族成员参与。那么,嵌入家族因素的小微企业成长是否更优?创始人特质在家族涉入对小微企业成长影响中的作用又是什么?本文以中国的小微企业为例,研究创始人特质、家族涉入与小微企业成长的关系。结果表明:家族涉入与小微企业成长之间为倒"U"型关系,家族涉入在创始人特质与小微企业成长之间起到了中介作用。对于小微企业管理者,应综合考虑创始人特质和家族涉入的直接与间接效应,提高它们之间的匹配性,从而改善小微企业成长水平。

关键词：创始人特质家族涉入小微企业企业成长职业经理人

OFDI逆向技术溢出、制度创新与中国经济高质量发展——基于30省际面板数据的空间效应分析

在线全文

学校读者我要写书评

暂无评论

山东大学学报（哲学社会科学版） 2022年第3期 115-127页

作者：张宏李拯非山东大学经济学院济南250100

OFDI逆向技术溢出直接影响到中国经济发展的质量,同时它又受到制度环境的影响。基于中国30个省级行政区2003-2018年的数据,采用熵权法计算经济高质量发展水平,然后运用空间自回归固定效应模型分析了OFDI逆向技术溢出和制度环境对中国经... 详细信息

OFDI逆向技术溢出直接影响到中国经济发展的质量,同时它又受到制度环境的影响。基于中国30个省级行政区2003-2018年的数据,采用熵权法计算经济高质量发展水平,然后运用空间自回归固定效应模型分析了OFDI逆向技术溢出和制度环境对中国经济发展质量的作用方向与影响程度。研究发现:(1)中国30个省级行政区的经济高质量发展水平在空间分布上表现为空间集聚,存在显著的正相关性;(2)OFDI逆向技术溢出对中国中西部地区经济高质量发展具有促进作用,而且制度创新有利于中国实现经济高质量发展;(3)中国各省级行政区的OFDI逆向技术溢出在对本地区经济发展质量产生影响的同时,还对周边地区的经济发展质量产生显著影响,说明中国各地区积极发展经济的学习赶超效应明显,加强区域合作有利于共同推进中国经济实现高质量发展。

关键词： OFDI逆向技术溢出制度环境经济高质量发展空间自相关

同方期刊数据库

在线全文

学校读者我要写书评

暂无评论

U-Rh体系非晶合金的成分设计与形成特性

稀有金属材料与工程 2023年第9期52卷 3126-3131页

作者：李正飞韩录会张培法涛黄火根中国工程物理研究院材料研究所四川江油621907

为了进一步认识U合金体系的非晶形成规律,探究了U-Rh体系的非晶形成特性。在富U端共晶区65%~80%U(原子分数)范围内设计了系列U-Rh合金,通过真空电弧熔炼制备母锭样品与甩带技术制备条带样品,采用X射线衍射和热分析手段研究了2种样品的... 详细信息

为了进一步认识U合金体系的非晶形成规律,探究了U-Rh体系的非晶形成特性。在富U端共晶区65%~80%U(原子分数)范围内设计了系列U-Rh合金,通过真空电弧熔炼制备母锭样品与甩带技术制备条带样品,采用X射线衍射和热分析手段研究了2种样品的相组成与热行为。发现U_(70)Rh_(30)合金在急冷凝固条件下形成了部分非晶相,晶化温度为642 K,晶化激活能接近200 kJ/mol,与之共生的是γ-U高温固溶体相,这是U基非晶合金通过急冷冻结高温U固溶体的首次证据,反映出U-Rh合金非平衡凝固相变行为的独特性。结果表明,U-Rh是一个新的铀基非晶合金体系,其非晶形成能力不强,这很可能与γ-U高温固溶体能被急冷直接捕获有关。

关键词：非晶合金金属玻璃铀合金贵金属

电针通过增强AMPK/mTOR通路介导的自噬治疗神经源性尿潴留

在线全文

学校读者我要写书评

暂无评论

中南大学学报（医学版） 2022年第4期47卷 488-496页

作者：李正飞张任赵国瑞匡尧天津中医药大学第一附属医院推拿科天津300193 国家中医针灸临床研究中心天津300193

目的:电针可通过增强自噬流、促进神经元再生、重塑轴突和髓鞘等实现对脊髓损伤的保护作用,但其在神经源性尿潴留中的作用尚不明确。本研究探讨电针通过增强腺苷活化蛋白激酶(AMP activated protein kinase,AMPK)/哺乳动物雷帕霉素靶蛋... 详细信息

目的:电针可通过增强自噬流、促进神经元再生、重塑轴突和髓鞘等实现对脊髓损伤的保护作用,但其在神经源性尿潴留中的作用尚不明确。本研究探讨电针通过增强腺苷活化蛋白激酶(AMP activated protein kinase,AMPK)/哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)通路介导的自噬治疗神经源性尿潴留的作用机制。方法:建立骶髓损伤后神经源性尿潴留大鼠模型。将造模成功的大鼠随机分为模型组、电针组(采用电子刺激针对次髎、中极、三阴交行电针,每天1次,每次20 min,共7 d)、电针+AMPK抑制剂组(在电针组处理的基础上,在第1和4天,于L_(2~3)椎间隙周围肌内注射100μg的AMPK抑制剂compound C)。另设正常组不进行任何处理。采用多通道生理记录仪记录膀胱最大容量、膀胱基础压力、漏尿点压力、膀胱顺应性;HE染色观察膀胱组织形态;透射电镜观察自噬情况;免疫荧光染色观察微管相关蛋白1轻链3(LC3)II、Beclin1蛋白质的表达;蛋白质印迹法检测膀胱组织中AMPK、磷酸化的AMPK(p-AMPK)、mTOR、磷酸化的mTOR(p-mTOR)、LC3II、Beclin1的蛋白质表达水平。结果:与正常组相比,模型组膀胱最大容量、漏尿点压力、膀胱顺应性,膀胱组织中p-AMPK、LC3II、Beclin1蛋白质表达水平升高,p-mTOR蛋白质表达水平降低(均Plin1蛋白质水平升高(均Plin1蛋白质水平降低(P<0.05)。模型组膀胱体积变大,各层次不清,出现不同程度变性,组织损伤严重,出现自噬小体;电针组膀胱较模型组小,各层次清晰可见,出现自噬小体;电针+AMPK抑制剂组各层次稍凌乱,出现损伤。结论:电针通过AMPK/mTOR通路激活自噬,从而减轻脊髓损伤导致的神经源性尿潴留。

关键词：电针磷酸腺苷活化蛋白激酶哺乳动物雷帕霉素靶蛋白自噬神经源性尿潴留

在线全文

学校读者我要写书评

暂无评论

信湖煤矿人工冻结温度场预测分析

中州煤炭 2013年第2期 31-33页

作者：李郑飞安徽理工大学土木建筑学院安徽淮南232001

通过对淮北信湖煤矿冻结法凿井施工现场的实测,得到适时温度监控数据,根据温度数据的时间序列,建立基于支持向量机的温度预测模型,分析研究人工冻结温度场的特性。预测结果表明,这种基于支持向量机的人工冻土温度场模型较准确地揭示了... 详细信息

通过对淮北信湖煤矿冻结法凿井施工现场的实测,得到适时温度监控数据,根据温度数据的时间序列,建立基于支持向量机的温度预测模型,分析研究人工冻结温度场的特性。预测结果表明,这种基于支持向量机的人工冻土温度场模型较准确地揭示了温度随时间变化的规律,是人工冻土温度场预测较为有效的尝试。

关键词：人工冻土温度场预测分析支持向量机