检索结果-南通市图书馆

long-term monitoring of cycles in Clethrionomys rutilus in the Yukon boreal forest

Integrative Zoology 2024年第1期19卷 27-36页

作者： Charles j.KREBS Alice j.KENNEY B.Scott GIlBERT Rudy BOONSTRA Department of Zoology University of British ColumbiaVancouverBritish ColumbiaCanada Renewable Resources Management Program Yukon UniversityWhitehorseYukonCanada Department of Biological Sciences University of Toronto ScarboroughTorontoOntarioCanada

Baseline studies of small rodent populations in undisturbed ecosystems are *** report here 50 years of mon-itoring and experimentation in Yukon of a dominant rodent species in the North American boreal forest,the red-backed vole Clethrionomys *** voles breed in summer,weigh 20–25 g,and reach a maximum density of 20 to 25 per *** populations have shown consistent 3–4-year cycles for the last 50 years with the only change being that peak densities averaged 8/ha until 2000 and 18/ha since that *** the last 25 years,we have measured food resources,predator numbers,and winter weather,and for 1-year social interactions,to estimate their contribution to changes in the rate of summer increase and the rate of overwinter *** these potential limiting factors could contribute to changes in density,and we measured their relative contributions statistically with multiple *** rate of winter decline in density was related to both food supply and winter *** rate of summer increase was related to summer berry crops and white spruce cone *** measure of predator numbers was related to winter or summer changes in vole *** was a large signal of climate change effects in these *** is no density dependence in summer population growth and only a weak one in winter population *** of our results provide a clear understanding of what generates 3–4-year cycles in these voles,and the major missing piece may be an understanding of social interactions at high density.

关键词： boreal forest climate change density dependence population cycles predation winter severity

来源：

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

Adaptive neural network control of a 2-DOF helicopter system considering input constraints and global prescribed performance

引用

Science China(Information Sciences) 2024年第7期67卷 224-239页

作者： Zhijia ZHAO jiale WU Zhijie lIU We HE C.l.Philip CHEN School of Mechanical and Electrical Engineering Guangzhou University School of Intelligence Science and Technology and Key laboratory of Intelligent Bionic Unmanned Systems of Ministry of Education University of Science and Technology Beijing School of Computer Science and Engineering South China University of Technology Pazhou lab

In this study, an adaptive neural network(NN) control is proposed for nonlinear two-degree-offreedom(2-DOF) helicopter systems considering the input constraints and global prescribed ***, radial basis function NN(RBFNN) is employed to estimate the unknown dynamics of the helicopter system. Second, a smooth nonaffine function is exploited to approximate and address nonlinear constraint functions. Subsequently, a new prescribed function is proposed, and an original constrained error is transformed into an equivalent unconstrained error using the error transformation and barrier function transformation methods. The analysis of the established lyapunov function proves that the controlled system is globally uniformly bounded. Finally, the simulation and experimental results on a constructed Quanser's test platform verify the rationality and feasibility of the proposed control.

关键词： adaptive NN control 2-DOF helicopter global prescribed performance input constraints

来源：

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The Generalized Stackelberg Equilibrium of the Two-Person Stopping Game

引用

journal of the Operations Research Society of China 2024年第1期12卷 155-168页

作者： Marek Skarupski Krzysztof j.Szajowski Faculty of Pure and Applied Mathematics Wroclaw University of Science and Technology50-370WrocƚawDolonoslaskiePoland

In modeling the bilateral selection of states of the process,Dynkin(Dokl Akad Nauk USSR 185:241–288,1969)proposed a two-person game in which players use stopping moments as *** purpose of this work is to present a model of the game in which the players have different information about the process itself,as well as various laws to stop the process and accept its *** game model uses the stochastic process apparatus,in particular,the ability to create different filters for the same *** sets of stopping moments based on different filters are not identical,which allows us to model different sets of strategies for *** show that the follower,by observing the behavior of a rational leader,can recover information that is lost due to the lack of complete observation of the state of the *** the competition of two opponents for the maximum of the ***,one of whom has access to full information and the other only knows their relative ranks,we found the generalized Stackelberg *** the priority of a player observing the relative ranks is less than 50%,then that player modifies his strategy based on the behavior of the second *** a player with full information,information about the behavior of the player observing the relative ranks is useless.

关键词： No-zero-sum game Optional stopping Equilibrium Filtration

来源：

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

Extracellular vesicles and angiotensin-converting enzyme 2 in COVID-19 disease

引用

BIOCEll 2024年第1期48卷 1-8页

作者： YU lIU ROBERT j.KASPER NATAlIE j.S.CHOI Department of Family and Community Medicine Northwestern University Feinberg School of MedicineChicagoIllinois

Extracellular vesicles(EVs)are membranous vesicular structures released from almost all eukaryotic cell types under different physiological or pathological *** evidence demonstrates that EVs can serve as mediators of intercellular communication between donor and recipient cells or microorganism-infected and noninfected *** disease 2019(COVID-19)disease is caused by infection of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)of host cells in the respiratory system and various extra-pulmonary tissue/organs,resulting in complications of multiple organ *** the cell surface receptor,angiotensin-converting enzyme 2(ACE2)mediates cellular entry of SARS-CoV-2 into the host cells in patients with *** studies have found that ACE2 can be released with EVs,which have been shown to interfere with the entry of the virus into host cells and thus may be involved in COVID-19 *** addition,ACE2,neprilysin(NEP),and thimet oligopeptidase(TOP)are the key enzymes that regulate angiotensin metabolism by converting angiotensin II or angiotensin I to angiotensin 1-7,the latter of which has protective effects in counterbalancing the harmful effects of angiotensin II in COVID-19 *** review summarizes the recent research progress regarding EV-associated ACE2,NEP,and TOP and the perspectives of their potential involvement in the pathophysiology of COVID-19 disease.

关键词： Extracellular vesicles COVID-19 Angiotensin converting enzyme 2 Thimet oligopeptidase

来源：

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

Invasive ant learning is not affected by seven potential neuroactive chemicals

引用

Current Zoology 2024年第1期70卷 87-97页

作者： Henrique Galante Tomer j.Czaczkes Department of Zoology and Evolutionary Biology Animal Comparative Economics LaboratoryUniversity of Regensburg93053 Regensburg Germany

Argentine ants linepithema humile are one of the most damaging invasive alien species *** or disrupting cognitive abilities,such as learning,has the potential to improve management efforts,for example by increasing preference for a bait,or improving ants'ability to learn its characteristics or ***-feeding insects are often the victims of psychoactive manipulation,with plants lacing their nectar with secondary metabolites such as alkaloids and non-protein amino acids which often alter learning,foraging,or ***,the effect of neuroactive chemicals has seldomly been explored in ***,we test the effects of seven potential neuroactive chemicals-two alkaloids:caffeine and nicotine;two biogenic amines:dopamine and octopamine,and three nonprotein amino acids:β-alanine,GABA and taurineon the cognitive abilities of invasive *** using bifurcation *** results confirm that these ants are strong associative learners,requiring as little as one experience to develop an ***,we show no short-term effect of any of the chemicals tested on spatial learning,and in addition no effect of caffeine on short-term olfactory *** lack of effect is surprising,given the extensive reports of the tested chemicals affecting learning and foraging in *** mismatch could be due to the heavy bias towards bees in the literature,a positive result publicationbias,ordifferences inmethodology.

关键词： associativelearning caffeine memory neuroactivechemicals

来源：

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

Resistive field generation in intense proton beam interaction with solid targets

引用

Matter and Radiation at Extremes 2024年第1期9卷 35-43页

作者： W.Q.Wang j.j.Honrubia Y.Yin X.H.Yang F.Q.Shao Department of Physics National University of Defense TechnologyHunanChina ETSI Aeronáutica y del Espacio Universidad Politécnica de MadridMadridSpain Department of Nuclear Science and Technology National University of Defense TechnologyHunanChina

The Brown-Preston-Singleton(BPS)stopping power model is added to our previously developed hybrid code to model ion beam-plasma *** simulations show that both resistive field and ion scattering effects are important for proton beam transport in a solid target,in which they compete with each *** the target is not completely ionized,the self-generated resistive field effect dominates over the ion scattering ***,when the target is completely ionized,this situation is ***,it is found that Ohmic heating is important for higher current densities and materials with high *** energy fraction deposited as Ohmic heating can be as high as 20%-30%.Typical ion divergences with half-angles of about 5°-10°will modify the proton energy deposition substantially and should be taken into account.

关键词： interaction beam intense

来源：

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

Continuity of care by a primary midwife(caseload midwifery):a cost analysis using results from the COSMOS randomised controlled trial

引用

Gynecology and Obstetrics Clinical Medicine 2024年第2期4卷 94-101页

作者： Emily j Callander Hannah jackson Helen l Mclachlan Mary-Ann Davey Della A Forster University of Technology Sydney SydneyNew South WalesAustralia The Royal Women's Hospital MelbourneVictoriaAustralia Faculty of Health University of Technology SydneyBroadwayNew South WalesAustralia judith lumley Centre La Trobe UniversityMelbourneVictoriaAustralia School of Nursing and Midwifery a Trobe UniversityMelbourneVictoriaAustralia Department of Obstetrics and Gynaecology Monash UniversityClaytonVictoriaAustralia

Introduction Caseload midwifery(continuity of midwifery carer)offers benefits including lower caesarean section rates,lower risks of preterm birth and stilbirth,and improved maternal satisfaction of *** these advantages,concerns about additional costs hinder widespread *** study examinesthecost of caseload midwifery compared with standard maternity care from the perspective of both public hospitals and public *** A cost analysis was conducted using data from a randomised controlled trial of 2314 low-risk pregnant women in Melbourne,*** randomised to caseload care received antenatal,intrapartum and postpartum care from a primary midwife,with some care provided by a‘back-up'*** in standard care received midwifery-led care with varying levels of continuity,junior obstetric care or community-based medical *** cost analysis compared differences in mean costs of health resources to public hospitals and to public ***,a budget impact analysis estimated total costs to the health system between 2023 and *** For public hospitals,there was no significant difference in overall costs between women receiving caseload midwifery(n=1146)versus standard care(n=1151)($SA12363(SD:$A4967)vs$A12323(SD:$A7404);p=0.85).Conversely,public funders incurred lower expenditures for women receiving caseload midwifery($A20330(SD:$A8312))versus standard care($A21637(SD:$A11818);plysis estimated savings of sA625million to the health system over the next 5 years with expanded access to caseloadmidwifery *** Caseloadmidwifery in low-risk women is cost-neutral to public hospitals and cost-saving to public *** abstract Continuity of midwifery for low-risk women reduces costs to public funders,with no additional costs to hospitals.

关键词： random continuity Continuity

来源：

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

Applications of genetic code expansion technology in eukaryotes

引用

Protein & Cell 2024年第5期15卷 331-363页

作者： Qiao-ru Guo Yu j.Cao State Key laboratory of Chemical Oncogenomic Guangdong Provincial Key Laboratory of Chemical GenomicsPeking University Shenzhen Graduate SchoolShenzhen 518055China Institute of Chemical Biology Shenzhen Bay LaboratoryShenzhen 518132China

Unnatural amino acids(UAAs)have gained significant attention in protein engineering and drug development owing to their ability to introduce new chemical functionalities to *** eukaryotes,genetic code expansion(GCE)enables the incorporation of UAAs and facilitates posttranscriptional modification(PTM),which is not feasible in prokaryotic *** is also a powerful tool for cell or animal imaging,the monitoring of protein interactions in target cells,drug development,and switch ***,there is keen interest in utilizing GCE in eukaryotic *** review provides an overview of the application of GCE in eukaryotic systems and discusses current challenges that need to be addressed.

关键词： genetic code expansion unnatural amino acid eukaryotes basic research therapeutic applications

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Solid-liquid extraction for yttrium recovery using porous polymeric resin（XAD-7） functionalized with D2EHPA

引用

journal of Rare Earths 2024年第9期42卷 1764-1773页

作者： P.A.Martínez-Montoya R.G.Sanchez-Alvarado D.Y.Medina-Velazquez M.l.Carrera-jota P.Garnica-Chávez A.de j.Morales-Ramirez Higher School of Chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical Engineering Metropolitan Autonomous University Department of MaterialsBasic Sciences and Engineering Center for Research and Technological Innovation CIITECIPN

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid（D2EHPA） as extracting *** extracting agents were supported on a macro porous polymeric resin XAD-7（solid phase）.Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/l Y（liquid phase） at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid（S/l）ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% D2EHPA functionalized resin,pH=1.5 and an S/l ratio of 10 mg/ml The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/l [H2SO4] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H2SO4,demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Fluorescent lamps recycling Rare earth solid-liquid extraction Solid-liquid kinetics extraction XAD-7 resin Yttrium recovery

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring

引用

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 819-836页

作者： D.lEE S.CHANG j.lEE Department of Automotive Engineering Hanyang UniversitySeoul 04763Republic of Korea School of Mechanical Engineering Chungnam National UniversityDaejeon 34134Republic of Korea Department of Mechanical Robotics and Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea

This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random *** method consists of a generalized polynomial chaos expansion(GPCE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data *** the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random *** allows for avoiding repeated computations of invariant substructures while generating the input-output data *** substructuring with static condensation further improves the computational efficiency of the reanalysis without losing ***,the GPCE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional *** numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCE using full finite element analyses(FEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs.

关键词： forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPCE) static reanalysis method static condensation substructuring

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：