检索结果-南通市图书馆

N-Heterocyclic carbene catalyzed c-acylation reaction for access to linear aminoenones

在线全文

学校读者我要写书评

暂无评论

chinese chemical Letters 2023年第1期34卷 357-361页

作者： Jie Lv Yingling Nong Kai chen Qingyun Wang Jiamiao Jin Tingting Li Zhichao Jin Yonggui robin chi State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of EducationGuizhou UniversityGuiyang 550025China

An N-heterocyclic carbene(NHc)-catalyzed carbonyl nucleophilic substitution reaction between 1-cyclopropylcarbaldehydes and N-sulfonyl imines is developed for access to linearβ-aminoenone ***β-aminoenones containing cyclopropyl fragments can be afforded in moderate to excellent yields under mild *** reaction features excellent trans-diastereoselectivities and the desired aminoenone products are all afforded as Z-isomers.

关键词： N-Heterocyclic carbene Organocatalysis c-Acylation reaction Animoenone synthesis

Heat and drought impact on carbon exchange in an age-sequence of temperate pine forests

在线全文

学校读者我要写书评

暂无评论

Ecological Processes 2022年第1期11卷 108-125页

作者： M.Altaf Arain Bing Xu Jason J.Brodeur Myroslava Khomik Matthias Peichl Eric Beamesderfer Natalia Restrepo‑couple robin Thorne School of Earth Environment and Society and McMaster Centre for Climate ChangeMcMaster University1280 Main Street WestHamiltonON L8S 4K1Canada Department of Biological Sciences University of CalgaryAlbertaCanada Department of Geography and Environmental Management University of WaterlooWaterlooONCanada Department of Forest Ecology and Management Swedish University of Agricultural SciencesUmeåSweden School of Informatics Computingand Cyber SystemsNorthern Arizona UniversityFlagstaffAZUSA Department of Ecology and Evolutionary Biology University of ArizonaTucsonAZUSA Department of Geography Wilfrid Laurier UniversityWaterlooONCanada

Background:Most North American temperate forests are plantation or regrowth forests,which are actively *** forests are in different stages of their growth cycles and their ability to sequester atmospheric carbon is affected by extreme weather *** this study,the impact of heat and drought events on carbon sequestration in an age‑sequence(80,45,and 17 years as of 2019)of eastern white pine(Pinus strobus L.)forests in southern Ontario,canada was examined using eddy covariance flux measurements from 2003 to ***:Over the 17‑year study period,the mean annual values of net ecosystem productivity(NEP)were 180±96,538±177 and 64±165 g c m^(–2)yr^(–1)in the 80‑,45‑and 17‑year‑old stands,respectively,with the highest annual carbon sequestration rate observed in the 45‑year‑old *** found that air temperature(Ta)was the dominant control on NEP in all three different‑aged stands and drought,which was a limiting factor for both gross ecosystem productivity(GEP)and ecosystems respiration(RE),had a smaller impact on ***,the simultaneous occurrence of heat and drought events during the early growing seasons or over the consecutive years had a significant negative impact on annual NEP in all three *** observed a similar trend of NEP decline in all three stands over three consecutive years that experienced extreme weather events,with 2016 being a hot and dry,2017 being a dry,and 2018 being a hot *** youngest stand became a net source of carbon for all three of these years and the oldest stand became a small source of carbon for the first time in 2018 since observations started in ***,in 2019,all three stands reverted to annual net carbon ***:Our study results indicate that the timing,frequency and concurrent or consecutive occurrence of extreme weather events may have significant implications for carbon sequestration in temperate conifer forests in Eastern North *** study is one of few globally available t

关键词： carbon fluxes Net ecosystem productivity Ecosystem respiration Extreme weather events Drought Temperate forest White pine Eddy covariance

Hydro-mechanical interaction effects and channelling in threedimensional fracture networks undergoing growth and nucleation

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2020年第4期12卷 707-719页

作者： Adriana Paluszny robin NThomas Maria cSaceanu Robert WZimmerman Department of Earth Science and Engineering Imperial College LondonLondonSW72AZUK

The flow properties of geomechanically generated discrete fracture networks are examined in the context of *** networks are generated by growing fractures in tension,modelling the low permeability rock as a linear elastic *** are modelled as discrete surfaces which grow quasi-statically within a three-dimensional(3D)*** may have their locations specified as a simulation input,or be generated as a function of damage,quantified using the local variation in equivalent *** properties of the grown networks are shown to be a product of in situ stress,relative orientation of initial flaws,and competitive process of fracture interaction and *** grow preferentially in the direction perpendicular to the direction of maximum tension and may deviate from this path due to mechanical fracture *** is significantly channelled through a subset of the fractures in the full domain,consistent with observations of other real and simulated *** the fracture networks grow,small changes in the geometry of the fractures lead to large changes in the locations and scale of primary flow *** flow variability and formation of channels are examined for two growing networks,one with a fixed amount of fractures,and another with nucleating *** interaction between fractures is shown to modify the local stress field,and in turn the aperture of the *** for single-phase flow are the results of hydro-mechanical effects in fracture networks during *** are the results of changes to the topology of the network as well as the result of mechanical self-organisation which occurs during interaction leading to growth and intersection.

关键词： Fracture growth Fracture mechanics Stress intensity factor(SIF) Quasi-static growth Finite elements

An Uncertainty-aware Workflow for Keyhole Surgery Planning using Hierarchical Image Semantics

在线全文

学校读者我要写书评

暂无评论

Visual Informatics 2018年第1期2卷 26-36页

作者： christina Gillmann robin G.c.Maack Tobias Post Thomas Wischgoll Hans Hagen University of Kaiserslautern Erwin-Schroedinger-Strasse 167663 Kaiserslautern Wright State University 3640 Colonel Glenn HwyDaytonOH

Keyhole surgeries become mcreasingly important in clinical daily routine as they help minimizing the damage of a patient's healthy *** planning of keyhole surgeries is based on medical imaging and an important factor that influences the surgeries**** to the image reconstruction process,medical image data contains uncertainty that exacerbates the planning of a keyhole *** this paper we present a visual workflow that helps clinicians to examine and compare different surgery paths as well as visualizing the patientsJ affected *** analysis is based on the concept of hierarchical image semantics,that segment the underlying image data with respect to the input images'uncertainty and the users understanding of tissue *** can define arbitrary surgery paths that they need to investigate *** defined paths can be queried by a rating function to identify paths that fulfill user-defined *** workflow allows a visual inspection of the affected tissues and its ***,the workflow includes a linked view system indicating the three-dimensional location of selected surgery paths as well as how these paths affect the patients *** show the effectiveness of the presented approach,we applied it to the planning of a keyhole surgery of a brain tumor removal and a kneecap surgery.

关键词： Wsual Analytics Workflow Uncertainty sualization Keyhole Surgery Planning

Gym-ANM: Reinforcement learning environments for active network management tasks in electricity distribution systems

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

能源与人工智能(英文) 2021年第3期5卷 171-193页

作者： robin Henry Damien Ernst School of Engineering Sanderson BuildingThe University of EdinburghEdinburgh EH93FBUK Department of Electrical Engineering and computer Science Montefiore InstituteUniversity of LiegeLiege B-4000Belgium

Active network management(ANM)of electricity distribution networks include many complex stochastic sequential optimization *** problems need to be solved for integrating renewable energies and distributed storage into future electrical *** this work,we introduce Gym-ANM,a framework for designing reinforcement learning(RL)environments that model ANM tasks in electricity distribution *** environments provide new playgrounds for RL research in the management of electricity networks that do not require an extensive knowledge of the underlying dynamics of such *** with this work,we are releasing an implementation of an introductory toy-environment,ANM6-Easy,designed to emphasize common challenges in *** also show that state-of-the-art RL algorithms can already achieve good performance on ANM6-Easy when compared against a model predictive control(MPc)***,we provide guidelines to create new Gym-ANM environments differing in terms of(a)the distribution network topology and param-eters,(b)the observation space,(c)the modeling of the stochastic processes present in the system,and(d)a set of hyperparameters influencing the reward ***-ANM can be downloaded at https://***/robinhenr y/gym-anm.

关键词： Gym-ANM Reinforcement learning Active network management Distribution networks Renewable energy

Influence of climatic conditions,topography and soil attributes on the spatial distribution of site productivity index of the species rich forests of Jalisco,Mexico

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 Forestry Research 2014年第1期25卷 87-95页

作者： Adel Mohamed robin M.Reich Raj Khosla c.Aguirre-Bravo Martin Mendoza Briseo Department of Ecology and Rangeland Stewardship Desert Research Center Department of Forest and Rangeland Stewardship Colorado State University Department of Soil and crop Sciences Colorado State University USDA Forest Service colegio de Postgraduados

This paper presents an approach based on field data to model the spatial distribution of the site productivity index （SPI） of the diverse forest types in Jalisco, Mexico and the response in SPI to site and cli-matic conditions. A linear regression model was constructed to test the hypothesis that site and climate variables can be used to predict the SPI of the major forest types in Jalisco. SPI varied significantly with topog-raphy （elevation, aspect and slope）, soil attributes （pH, sand and silt）, climate （temperature and precipitation zones） and forest type. The most important variable in the model was forest type, which accounted for 35% of the variability in SPI. Temperature and precipitation accounted for 8 to 9% of the variability in SPI while the soil attributes accounted for less than 4% of the variability observed in SPI. No significant differences were detected between the observed and predicted SPI for the individual forest types. The linear regression model was used to develop maps of the spatial variability in predicted SPI for the individual forest types in the state. The spatial site productivity models developed in this study provides a basis for understanding the complex relationship that exists between forest productivity and site and climatic conditions in the state. Findings of this study will assist resource managers in making cost-effective decisions about the management of individual forest types in the state of Jalisco, Mexico.

关键词： Best management practices climate change spatial predic-tions tropical dry forests weighted least squares

Zwitterion-doped liquid crystal speckle reducers for immersive displays and vectorial imaging

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2023年第11期12卷 2363-2377页

作者： Yihan Jin Nathan P.spiller chao He Grahame Faulkner Martin J.Booth Steve J.Elston Stephen M.Morris Department of Engineering Science University of OxfordParks RoadOxford OX13PJUK

Lasers possess many attractive features(e.g.,high brightness,narrow linewidth,well-defined polarization)that make them the ideal illumination source for many different scientific and technological endeavors relating to imaging and the display of high-resolution ***,their high-level of coherence can result in the formation of noise,referred to as speckle,that can corrupt and degrade ***,we demonstrate a new electro-optic technology for combatting laser speckle using a chiral nematic liquid crystal(Lc)dispersed with zwitterionic *** are presented that demonstrate when driven at the optimum electric field conditions,the speckle noise can be reduced by>90%resulting in speckle contrast(c)values of c=0.07,which is approaching that required to be imperceptible to the human *** Lc technology is then showcased in an array of different display and imaging applications,including a demonstration of speckle reduction in modern vectorial laser-based imaging.

关键词： polarization speckle crystal

Muscle force and movement variability before and after total knee arthroplasty: A review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Orthopedics 2014年第2期5卷 69-79页

作者： Jessica W Smith Jesse c christensen robin L Marcus Paul c LaStayo Department of Bioengineering University of Utah Salt Lake City UT 84108-1290 United States Department of Physical Therapy University of Utah Salt Lake City UT 84108-1290 United States Department of Orthopedics University of Utah Salt Lake City UT 84108-1290 United States Department of Exercise and Sport Science University of Utah Salt Lake City UT 84108-1290 United States

Variability in muscle force output and movement variability are important aspects of identifying individuals with mobility deficits, central nervous system impairments, and future risk of falling. This has been investigated in elderly healthy and impaired adults, as well as in adults with osteoarthritis(OA), but the question of whether the same correlations also apply to those who have undergone a surgical intervention such as total knee arthroplasty(TKA) is still being investigated. While there is a growing body of literature identifying potential rehabilitation targets for individuals who have undergone TKA, it is important to first understand the underlying post-operative impairments to more efficiently target functional deficits that may lead to improvedlong-term outcomes. The purpose of this article is to review the potential role of muscle force output and movement variability in TKA recipients. The narrative review relies on existing literature in elderly healthy and impaired individuals, as well as in those with OA before and following TKA. The variables that may predict longterm functional abilities and deficits are discussed in the context of existing literature in healthy older adults and older adults with OA and following TKA, as well as the role future research in this field may play in providing evidence-based data for improved rehabilitation targets.

关键词： Osteoarthritis Elderly Total knee arthroplasty Movement variability

Serotonin type 3 receptor subunit gene polymorphisms associated with psychosomatic symptoms in irritable bowel syndrome:A multicenter retrospective study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2022年第21期28卷 2334-2349页

作者： Sabrina Berens Yuanjun Dong Nikola Fritz Jutta Walstab Mauro D'Amato Tenghao Zheng Verena Wahl Felix Boekstegers Justo Lorenzo Bermejo cristina Martinez Stefanie Schmitteckert Egbert clevers Felicitas Engel Annika Gauss Wolfgang Herzog robin spiller Miriam Goebel-Stengel Hubert Mönnikes Viola Andresen Frieling Thomas Jutta Keller christian Pehl christoph Stein-Thöringer Gerard clarke Timothy G Dinan Eamonn M Quigley Gregory Sayuk Magnus Simrén Jonas Tesarz Gudrun Rappold Lukas van Oudenhove Rainer Schaefert Beate Niesler Department of General Internal Medicine and Psychosomatics University Hospital HeidelbergHeidelberg 69120Germany Department of Human Molecular Genetics Institute of Human GeneticsUniversity of HeidelbergHeidelberg 69120Germany Department of General Internal Medicine and Psychosomatics Internal Medicine IIUniversity Hospital HeidelbergHeidelberg 69120Germany Department of Human Molecular Genetics University of HeidelbergHeidelberg 69120Germany Gastrointestinal Genetics Lab CIC bioGUNE-BRTADerio 48160Spain IKERBASQUE Basque Foundation for ScienceBilbao 48001Spain Unit of clinical Epidemiology Department of Medicine SolnaKarolinska InstitutetStockholm 17177Sweden Institute of Medical Biometry and Informatics Heidelberg UniversityHeidelberg 69120Germany Lleida Institute for Biomedical Research Dr.PifarréFoundation(IRBLleida) Av.Alcalde Rovira RoureLleida 25198Spain Department of clinical and Experimental Medicine Translational Research Center for Gastrointestinal DisordersKU LeuvenLeuven 3000Belgium Department of Gastroenterology Infectious Diseases and IntoxicationsUniversity of HeidelbergHeidelberg 69120Germany Department of General Internal Medicine and Psychosomatics Heidelberg UniversityHeidelberg 69120Germany Nottingham Digestive Diseases centre University of NottinghamNottingham NG72QLUnited Kingdom Helios Klinikum Rottweil Rottweil 78628Germany Department of Medicine Institute of Neurogastroenterology(H.M.)Martin-Luther-HospitalBelin 14193Germany Israelitisches Krankenhaus in Hamburg Hamburg 22297Germany Internal Medicine II Helios Klinikum KrefeldKrefeld 47805Germany Israelitisches Krankenhaus Hamburg Hamburg 22297Ghana Krankenhaus Vilsbiburg Vilsbiburg 84137Germany Division of Microbiome and cancer German Cancer Research Center(DKFZ)Heidelberg 69120Germany Department of Psychiatry and Neurobehavioral Science University College CorkCork T23Ireland Medicine in Digestive Disorders Department of MedicineLynda K.and David M.Underwood Center for Digestive DisordersHou

BAcKGROUND Single-nucleotide polymorphisms(SNPs)of the serotonin type 3 receptor subunit(HTR3)genes have been associated with psychosomatic symptoms,but it is not clear whether these associations exist in irritable bowel syndrome(IBS).AIM To assess the association of HTR3 polymorphisms with depressive,anxiety,and somatization symptoms in individuals with *** In this retrospective study,623 participants with IBS were recruited from five specialty centers in Germany,Sweden,the United States,the United Kingdom,and ***,anxiety,and somatization symptoms and sociodemographic characteristics were *** functional SNPs—HTR3A c.-42c>T,HTR3B c.386A>c,HTR3c c.489c>A,and HTR3E c.*76G>A—were genotyped and analyzed using the dominant and recessive *** also performed separate analyses for sex and IBS *** scores were calculated as the number of minor alleles of the SNPs *** impact of HTR3c c.489c>A was tested by radioligand-binding and calcium influx *** Depressive and anxiety symptoms significantly worsened with increasing numbers of minor HTR3c c.489c>A alleles in the dominant model(F_(depressive)=7.475,P_(depressive)=0.006;F_(anxiety)=6.535,P_(anxiety)=0.011).A higher SNP score(range 0-6)was linked to a worsened depressive symptoms score(F=7.710,P-linear trend=0.006)in *** potential relevance of the HTR3c SNP was corroborated,showing changes in the expression level of 5-HT3Ac variant *** We have provided the first evidence that HTR3c c.489c>A is involved in depressive and anxiety symptoms in individuals with *** SNP score indicated that an increasing number of minor alleles is linked to the worsening of depressive symptoms in IBS.

关键词： Irritable bowel syndrome 5-HT3 receptor subunit gene polymorphisms Single-nucleotide polymorphism score Depression Anxiety Somatization