检索结果-南通市图书馆

CO_(2)enrichment accelerates successional development of an understory plant community

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2010年第1期3卷 33-39页

作者： lara Souza R.Travis Belote Paul Kardol Jake F.Weltzin Richard J.Norby Environmental Sciences Division Oak Ridge National LaboratoryBuilding 1062PO Box 2008Oak RidgeTN 37831USA Department of Ecology and Evolutionary Biology 569 Dabney HallUniversity of TennesseeKnoxvilleTN 37996USA The Wilderness Society 503 West Mendenhall St BozemanMT 59715USA USA National Phenology Network National Coordinating officeTucsonAZ 85721USA

Aims Rising concentrations of atmospheric carbon dioxide([CO_(2)])may influence forest successional development and species composition of understory plant communities by altering biomass production of plant species of functional ***,we describe how elevated[CO_(2)](eCO_(2))affects aboveground biomass within the understory community of a temperate deciduous forest at the Oak Ridge National Laboratory sweetgum(Liquidambar styraciflua)free-air carbon dioxide enrichment(FACE)facility in eastern Tennessee,*** asked if(i)CO_(2)enrichment affected total understory biomass and(ii)whether total biomass responses could be explained by changes in understory species composition or changes in relative abundance of functional groups through *** and methods The FACE experiment started in 1998 with three rings receiving ambient[CO_(2)](aCO_(2))and two rings receiving eCO_(2).From 2001 to 2003,we estimated species-specific,woody versus herbaceous and total aboveground biomass by harvesting four 130.5-m subplots within the established understory plant community in each FACE *** 2008,we estimated herbaceous biomass as previously but used allometric relationships to estimate woody biomass across two 535-m quadrats in each FACE *** findings Across years,aboveground biomass of the understory community was on average 25%greater in eCO_(2)than in aCO_(2)*** could not detect differences in plant species composition between aCO_(2)and eCO_(2)***,we did observe shifts in the relative abundance of plant functional groups,which reflect important structural changes in the understory *** 2001-03,little of the understory biomass was in woody species;herbaceous species made up 94%of the total understory biomass across[CO_(2)]*** time,woody species increased in importance,mostly in eCO_(2),and in 2008,the contribution of herbaceous species to total understory biomass was 61%in aCO_(2)and only 33%in eCO_(2)***

关键词： community composition FACE aboveground biomass woody herbaceous sweetgum Microstegium vimineum Lonicera japonica

Relationships between testate amoeba communities and water quality in Lake Donghu, a large alkaline lake in Wuhan, China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2013年第2期7卷 182-190页

作者： Yangmin QIN Bertrand FOURNIER Enrique lara Yansheng GU Hongmei WANG Yongde CUI Xiaoke ZHANG Edward A. D. MITCHELL State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Wuhan 430074 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China Laboratory of Soil Biology University of Neuchatel Rue Emile Argand 11 CH-2000 Neuchatel Switzerland Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China

The middle Yangtze Reach is one of the most developed regions of China. As a result, most lakes in this area have suffered from eutrophication and serious environmental pollution during recent decades. The aquatic biodiversity in the lakes of the area is thus currently under significant threat from continuous human activities. Testate amoebae （TA） are benthic （rarely planktonic） microorganisms characterized by an agglutinated or autogenous shell. Owing to their high abundance, preservation potential in lacustrine sediments, and distinct response to environmental stress, they are increasingly used as indicators for monitoring water quality and reconstructing palaeoenvironmental changes. However this approach has not yet been developed in China. This study presents an initial assessment of benthic TA assemblages in eight lakes of Lake Donghu in the region of Wuhan, China. Testate amoeba community structure was most strongly correlated to water pH. In more alkaline conditions, communities were dominated by Centropyxis aculeata, Difflugia oblonga, Pontigulasia compressa, Pon. elisa and Lesquereusia modesta. These results are consistent with previous studies and show that TA could be useful for reconstructing past water pH fluctuations in China. To achieve this, the next step will be to expand the database and build transfer function models.

关键词： testate amoebae (TA) water quality water pH Lake Donghu China

Development of Mathematical Model for Control Wear in Backup Roll for Hot Strip Mill

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2014年第1期21卷 46-51页

作者： R.Servin-Castaeda A.M.Garcia-lara R.D.Mercado-Solís C.A.Vega-Lebrun UAdeC University UANL University UPAEP University

The precision of strip flatness depends on several factors; wear of rolls is one of the main variables that have influence on the surface quality of the strip. The wear of the roils represents a complex friction condition, sometimes the wear in the backup roll is not analyzed because the strip is not in contact with the backup roll; however, after several campaigns of rolling, the wear in the backup roll becomes dangerous because the pressure distribution is not uniform. Investigation of mechanism of the surface deterioration of the backup roll for the hot strip rolling is very important for the development of the automatic strip shape control system used in hot strip mills. A mathematical model is developed considering the Hertzian pressure distribution between two cylinders with parallel axes. It is used in real time for calculating the wear in the backup roll and in this manner take deci- sions for preventing finished product reworking or damage of equipments, which result in accidents caused by excessive wear in the backup rolls.

关键词： strip flatness backup roll dress crown rolling campaign

Efficient metallization of magnetite concentrate by reduction with agave bagasse as a source of reducing agents

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第4期28卷 603-611页

作者： Diana Cholico-González NoemíOrtiz lara Mario Alberto Sánchez Miranda Ricardo Morales Estrella Ramiro Escudero García Carlos ALeón Patiño CONACYT-Metallurgy and Materials Research Institute Michoacana University of San Nicolás de HidalgoMorelia CP 58030Mexico Metallurgy and Materials Research Institute Michoacana University of San Nicolás de HidalgoMorelia CP 58030Mexico

The reduction behavior and metallization degree of magnetite concentrate with agave bagasse were investigated in an inert *** effects of temperature,biomass content,and residence time on reduction experiments and metallization degree were investigated by X-ray diffraction and scanning electron *** with other types of biomass,agave bagasse had lower contents of nitrogen,sulfur,and ash.X-ray diffraction analysis showed that the metallization degree improved with increasing temperature and biomass *** metallization was achieved at 1100℃ for 30 min with 65:35 and 50:50 ratios of the magnetite concentrate to the agave *** results demonstrate that agave bagasse promotes the efficient metallization of magnetite concentrate without the external addition of a reducing ***,this biomass is a technical suitable alternative to replace fossil fuels in steelmaking.

关键词： magnetite concentrate agave bagasse biomass reduction metallization degree

Hybridisation in kiwi(Apteryx;Apterygidae)requires taxonomic revision for the Great Spotted Kiwi

在线全文

学校读者我要写书评

暂无评论

Avian Research 2021年第2期12卷 195-207页

作者： lara D.Shepherd Alan J.D.Tennyson Hugh A.Robertson Rogan M.Colbourne Kristina M.Ramstad Museum of New Zealand Te Papa Tongarewa Wellington 6011New Zealand Biodiversity Group Department of Conservation PO Box 10420Welling-ton 6011New Zealand Department of Biology and Geology University of South Carolina Aiken471 University ParkwayAikenSC 29801USA

Background:Kiwi(Apteryx spp.)are flightless ratites from New Zealand whose numbers and distributions have declined following human *** of the kiwi species are known to hybridise but the extent of hybridization is ***:We reviewed hybridisation in kiwi(Apteryx spp.)and present new genetic data examining the extent of hybridisation between Rowi(***)and Little Spotted Kiwi(***)at Okarito,the location of the only remaining natural population of the threatened *** also genetically examined the syntype specimens of *** Potts,1872,collected from near Okarito in the 1870s,which have unusual ***:We found evidence of recurrent hybridisation between Rowi and Little Spotted Kiwi over the last 150 years,including one F1 hybrid found in the last 15 years,despite Little Spotted Kiwi’s likely extinction on the mainland in the ***,we found little evidence of introgression of Little Spotted Kiwi alleles into the extant Rowi *** syntype specimens of *** were also found to be hybrids between Little Spotted Kiwi and ***:Our genetic analyses indicate that,although we detected multiple instances of hybridisation between Rowi and Little Spotted Kiwi,it does not appear to be an ongoing threat to *** the syntype specimens of *** are hybrids and therefore not representative of the prevailing usage of the name for the Great Spotted Kiwi(***),we resurrect the nomen oblitum *** Sclater and Hochstetter,1861 for the large spotted kiwi species.

关键词： Apteryx Apteryx haastii DNA Hybridisation Kiwi Taxonomy

Molecular genetics and genomics of the Rosoideae: state of theart and future perspectives

在线全文

学校读者我要写书评

暂无评论

Horticulture Research 2014年第1期1卷 304-321页

作者： Sara Longhi lara Giongo Matteo Buti Nada Surbanovski Roberto Viola Riccardo Velasco Judson AWard Daniel J Sargent Research and Innovation Centre Fondazione Edmund MachSan Michele all’AdigeItaly Driscoll’s WatsonvilleCAUSA

The Rosoideae is a subfamily of the Rosaceae that contains a number of species of economic importance,including the soft fruit species strawberry(Fragaria 3ananassa),red(Rubus idaeus)and black(Rubus occidentalis)raspberries,blackberries(Rubus spp.)and one of the most economically important cut flower genera,the roses(Rosa spp.).Molecular genetics and genomics resources for the Rosoideae have developed rapidly over the past two decades,beginning with the development and application of a number of molecular marker types including restriction fragment length polymorphisms,amplified fragment length polymorphisms and microsatellites,and culminating in the recent publication of the genome sequence of the woodland strawberry,Fragaria vesca,and the development of high throughput single nucleotide polymorphism(SNP)-genotyping resources for Fragaria,Rosa and *** tools have been used to identify genes and other functional elements that control traits of economic importance,to study the evolution of plant genome structure within the subfamily,and are beginning to facilitate genomic-assisted breeding through the development and deployment of markers linked to traits such as aspects of fruit quality,disease resistance and the timing of *** this review,we report on the developments that have been made over the last 20 years in the field of molecular genetics and structural genomics within the Rosoideae,comment on how the knowledge gained will improve the efficiency of cultivar development and discuss how these advances will enhance our understanding of the biological processes determining agronomically important traits in all Rosoideae species.

关键词： spp. Fragaria breeding

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

未知 lara Zankoul的情绪世界

数码摄影 2015年第9期 28-37页

作者： lara Zankoul 冯富裕

浮于真相之上的往往是一团和气抑或完美到无暇,然而世事皆有两面。摄影师lara Zankoul将表象以外的另一面昭示给大家,亦真亦幻哪一个才是事物本来的样子,这些充满情绪冲突的作品或许能够让你找到答案。在The Unseen这组作品的背后,是一... 详细信息

浮于真相之上的往往是一团和气抑或完美到无暇,然而世事皆有两面。摄影师lara Zankoul将表象以外的另一面昭示给大家,亦真亦幻哪一个才是事物本来的样子,这些充满情绪冲突的作品或许能够让你找到答案。在The Unseen这组作品的背后,是一些看不到的经历。而这些经历正是源于摄影师lara Zankoul自身经验的积累,于是这些经历也成就了这组作品的主题。这些不可复制的人生经历让lara Zankoul意识到,在很多时候,人们并非看上去那样简单透明,每个人都有自己想要隐藏起来的秘密,并且很多事实也同样证明了,一些积极正面的表象却有着阴暗消极的另一面。

关键词：摄影师摄影工作者贝鲁特黎巴嫩拍摄过程 lara Zankoul 个展照片另一面梦幻情绪画廊相机日报创作风格

Gum Chewing and Cognition: An Overview

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neuroscience & Medicine 2012年第3期3卷 243-250页

作者： lara Tucha Janneke Koerts Department of Clinical and Developmental Neuropsychology University of Groningen Groningen The Netherlands

In recent years, there was a debate about the effects of gum chewing on various aspects of cognitive functioning. In this review, the results of previous studies are presented and summarized. There is a clear indication that gum chewing can improve various aspects of cognitive functioning including memory, attention and both executive and intellectual functioning. However, there is also clear evidence that chewing gum during cognitive tasks can adversely affect task performance. Therefore, it can be concluded that the replication of (beneficial or detrimental) effects of gum chewing on cognition has been proven to be very difficult. Consequently, the robustness of reported effects of gum chewing on cognition has to be questioned. Suggestions for future research are given.

关键词： Gum Chewing Mastication Cognition Memory Review

Increasing power plant efficiency with clustering methods and Variable Importance Index assessment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and AI 2021年第3期5卷 82-90页

作者： Jéssica Duarte lara Werncke Vieira Augusto Delavald Marques Paulo Smith Schneider Guilherme Pumi Taiane Schaedler Prass Department of Mechanical Engineering Federal University of Rio Grande do SulPorto AlegreBrazil Graduate Program in Statistics Federal University of Rio Grande do SulPorto AlegreBrazil

Power plant performance can decrease along with its life span,and move away from the design and commissioning *** issues,operational practices,market restrictions,and financial objectives may lead to that behavior,and the knowledge of appropriate actions could support the system to retake its original operational *** paper applies unsupervised machine learning techniques to identify operating patterns based on the power plant’s historical data which leads to the identification of appropriate steam generator efficiency *** selected operational variables are evaluated in respect to their impact on the system performance,quantified by the Variable Importance *** metric is proposed to identify the variables among a much wide set of monitored data whose variation impacts the overall power plant operation,and should be controlled with more *** Component Analysis(PCA)and k-means++clustering techniques are used to identify suitable operational conditions from a one-year-long data set with 27 recorded variables from a steam generator of a 360MW thermal power *** adequate number of clusters is identified by the average Silhouette coefficient and the Variable Importance Index sorts nine variables as the most relevant ones,to finally group recommended settings to achieve the target *** show performance gains in respect to the average historical values of 73.5%and the lowest efficiency condition records of 68%,to the target steam generator efficiency of 76%.

关键词： Thermal power plant performance enhancement Operating patterns identification K-means clustering Principal component analysis Unsupervised machine learning