检索结果-南通市图书馆

transfer of Highest Weight Modules and Small Unipotent Representations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第3期40卷 772-791页

作者： Hai An HE Jing Song HUANG Kayue daniel WONG Department of Mathematics College of SciencesShanghai UniversityShanghai 200444P.R.China Newtouch Center for Mathematics of Shanghai University Shanghai 200444P.R.China Mathematics Research Center School of Science and EngineeringThe Chinese University of Hong KongShenzhen 518172P.R.China

We study the transfer between small special unipotent representations for all equal rank real forms of type E_(6) and E_(7). As a consequence, one can verify these modules are unitarity using the results of Wallach an... 详细信息

关键词： Unipotent representations Wallach representations transfer of unitary modules

Flame Synthesis of Zr/ZSM-5 Catalysts with tunable Acidity for the Oxidative Dehydrogenation of Propane to Propene

在线全文

学校读者我要写书评

暂无评论

Journal of thermal Science 2024年第1期33卷 268-283页

作者： daniel Samuel FONZEU MONGUEN Cedric Karel WU Lingnan tIAN Zhenyu Institute of Engineering thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

tuning the surface acidity of ZSM-5 catalyst is essential to achieve desired propene selectivity and *** several ratios of Zr were utilized to modify ZSM-5 via flame spray pyrolysis technique coupled with a pulse spray evaporation *** interaction between Zr and ZSM-5 in the flame influenced the physicochemical and acidity properties of the Zr/*** increasing Zr ratio in ZSM-5 shows coated layers of irregular nano-sized Zr with an increase in crystallite sizes due to the synergetic effect between Zr and *** surface chemical analysis revealed increased lattice oxygen on the Zr modified ZSM-5(1:4) sample compared to other *** acidity analysis revealed the Lewis and br?nsted acid distribution in the weak and medium acid sites on the catalyst ***,the increase in Zr loading decreased the concentration of br?nsted acid sites and tuned the catalyst surface to more Lewis acidity,promoting propene selectivity and hindering the over-oxidation of *** modified ZSM-5 catalysts were examined in a fixed bed reactor within 300℃-700℃ at a gas hourly space velocity(GHSV) of 6000 mL·g(catalysts)^(-1)·h^(-1) for the oxidative dehydrogenation of propane(ODHP) to *** the catalysts,Zr/ZSM-5(1:4) exhibited the best propene yield, with 57.19% propane conversion and 75.54% selectivity to propene and the highest *** work provides a promising strategy for tuning the surface acidity of ZSM-5 with Zr for ODHP applications.

关键词： flame synthesis Zr modified ZSM-5 catalyst ODHP surface acidity lattice oxygen

Rapid growth in a large Cambrian apex predator

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第03期11卷 128-136页

作者：吴雨 Stephen Pates daniel Pauly 张兴亮傅东静 State Key Laboratory of Continental Dynamics and Shaanxi Key Laboratory of Early Life and Environment Department of Geology Northwest University Department of Zoology University of Cambridge Institute for the Oceans and Fisheries University of British Columbia Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences

Despite the importance of ontogenetic data on early diverging euarthropods to our understanding of the ecology and evolution of past life, the data are distinctly lacking, as reconstructing life histories of fossil animals is often challenging. Here we report the growth trajectory of frontal appendages of the apex predator Amplectobelua symbrachiata, one of the most common radiodont arthropods from the early Cambrian Chengjiang biota(c. 520 Ma) of China. Analysis of 432 specimens(9.1–137.1 mm length; 1.3–25.6 mm height) reveals that appendages grew isometrically, with an estimated maximum size of the whole animal of c. 90 cm. Individuals grew rapidly compared to extant arthropods, as assessed using the electronic length-frequency analysis(ELEFAN) approach. therefore, we show that the Cambrian apex predator A. symbrachiata was an extremely fast-growing arthropod, with an unusual life history strategy that formed as part of the escalatory ‘arms race’ that shaped the Cambrian explosion over 500 Ma.

关键词： stem-group Euarthropoda Radiodonta post-embryonic development growth dynamics Cambrian Explosion

Fundamental error in tree-based machine learning model selection for reservoir characterisation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Energy Geoscience

Energy Geoscience 2024年第2期5卷 214-224页

作者： daniel Asante Otchere Centre of Excellence in Subsurface Seismic Imaging and Hydrocarbon Prediction Universiti Teknologi PETRONAS32610Seri IskandarPerak Darul RidzuanMalaysia

Over the past two decades,machine learning techniques have been extensively used in predicting reservoir *** this approach has significantly contributed to the industry,selecting an appropriate model is still challenging for most *** solely on statistical metrics to select the best model for a particular problem may not always be the most effective *** study encourages researchers to incorporate data visualization in their analysis and model selection *** evaluate the suitability of different models in predicting horizontal permeability in the Volve field,wireline logs were used to train Extra-trees,Ridge,bagging,and XGboost *** Random Forest feature selection technique was applied to select the relevant logs as inputs for the *** on statistical metrics,the Extra-trees model achieved the highest test accuracy of 0.996,RMSE of 19.54 mD,and MAE of 3.18 mD,with XGboost coming in ***,when the results were visualised,it was discovered that the XGboost model was more suitable for the problem being *** XGboost model was a better predictor within the sandstone interval,while the Extra-trees model was more appropriate in non-sandstone *** this study aims to predict permeability in the reservoir interval,the XGboost model is the most *** contrasting results demonstrate the importance of incorporating data visualisation techniques as an evaluation *** the heterogeneity of the subsurface,relying solely on statistical metrics may not be sufficient to determine which model is best suited for a particular problem.

关键词： Data visualisation Permeability Machine learning Statistical metrics

Parkland trees on smallholder farms ameliorate soil physical-chemical properties in the semi-arid area of tigray,Ethiopia

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 Arid Land 2024年第1期16卷 1-13页

作者： Selam LJALEM Emiru bIRHANE Kassa tEKA daniel H bERHE Department of Land Resources Management and Environmental Protection College of Dryland Agriculture and Natural ResourcesMekelle UniversityMekelle 231Ethiopia Institute of Climate and Society Mekelle UniversityMekelle 231Ethiopia Faculty of Environmental Sciences and Natural Resource Management Norwegian University of Life Sciences(NMBU)Ås 1432Norway Department of Natural Resources Management Adigrat UniversityAdigrat 50Ethiopia

Proposed agroforestry options should begin with the species that farmers are most familiar with,which would be the native multipurpose trees that have evolved under smallholder farms and socioeconomic *** African birch(Anogeissus leiocarpa(DC.)Guill.&Perr.)and pink jacaranda(Stereospermum kunthianum Cham.)trees are the dominant species in the agroforestry parkland system in the drylands of tigray,*** farmers highly value these trees for their multifunctional uses including timber,firewood,charcoal,medicine,*** trees also could improve soil ***,the amount of soil physical and chemical properties enhanced by the two species must be determined to maintain the sustainable conservation of the species in the parklands and to scale up to similar agroecological ***,we selected twelve isolated trees,six from each species that had similar dendrometric characteristics and were growing in similar environmental *** divided the canopy cover of each tree into three radial distances:mid-canopy,canopy edge,and canopy gap(control).At each distance,we took soil samples from three different *** collected 216 soil samples(half disturbed and the other half undisturbed)from each canopy position and soil *** density(bD),soil moisture content(SMC),soil organic carbon(SOC),total nitrogen(tN),available phosphorus(AP),available potassium(AK),p H,electrical conductivity(EC),and cation exchange capacity(CEC)were *** revealed that soil physical and chemical properties significantly improved except for soil texture and EC under both species,CEC under ***,and soil p H under ***,all the studied soils were improved under both species canopy as compared with canopy ***,tN,AP,and AK under canopy of these trees were respectively 24.1%,11.1%,55.0%,and 9.3% higher than those soils under *** two parkland agroforestry species significantly enhanced soil fertility near the canopy of top

关键词： agroforestry bulk density carbon stock dispersed tree soil texture tree canopy

Accuracy comparison and improvement for state of health estimation of lithium-ion battery based on random partial recharges and feature engineering

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2024年第5期92卷 591-604页

作者： Xingjun Li Dan Yu Søren byg Vilsen daniel Ioan Stroe Department of Energy Aalborg UniversityAalborg 9220Denmark Department of Mathematical Sciences Aalborg UniversityAalborg 9220Denmark Walker Department of Mechanical Engineering The University of Texas at AustinAustinTX 78712USA

State of health(SOH)estimation of e-mobilities operated in real and dynamic conditions is essential and *** of existing estimations are based on a fixed constant current charging and discharging aging profiles,which overlooked the fact that the charging and discharging profiles are random and not complete in real *** work investigates the influence of feature engineering on the accuracy of different machine learning(ML)-based SOH estimations acting on different recharging sub-profiles where a realistic battery mission profile is *** features were extracted from the battery partial recharging profiles,considering different factors such as starting voltage values,charge amount,and charging sliding ***,features were selected based on a feature selection pipeline consisting of filtering and supervised ML-based subset *** linear regression(MLR),Gaussian process regression(GPR),and support vector regression(SVR)were applied to estimate SOH,and root mean square error(RMSE)was used to evaluate and compare the estimation *** results showed that the feature selection pipeline can improve SOH estimation accuracy by 55.05%,2.57%,and 2.82%for MLR,GPR and SVR *** was demonstrated that the estimation based on partial charging profiles with lower starting voltage,large charge,and large sliding window size is more likely to achieve higher *** work hopes to give some insights into the supervised ML-based feature engineering acting on random partial recharges on SOH estimation performance and tries to fill the gap of effective SOH estimation between theoretical study and real dynamic application.

关键词： Feature engineering Dynamic forklift aging profile State of health comparison Machine learning Lithium-ion batteries

Vonoprazan-amoxicillin dual regimen with Saccharomyces boulardii as a rescue therapy for Helicobacter pylori:Current perspectives and implications

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第10期30卷 1280-1286页

作者： Valerie Josephine Dirjayanto Jessica Audrey daniel Martin Simadibrata Faculty of Medicine Universitas IndonesiaJakarta Pusat 10430DKI JakartaIndonesia Division of Gastroenterology and Hepatology Mayo ClinicRochesterMinnesota 55905United States Nuffield Department of Population Health University of OxfordOxford OX37LFUnited Kingdom

Yu et al’s study in the World Journal of Gastroenterology(2023)introduced a novel regimen of Vonoprazan-amoxicillin dual therapy combined with Saccharomyces boulardii(***)for the rescue therapy against Helicobacter pylori(***),a pathogen responsible for peptic ulcers and gastric *** is a potassium-competitive acid blocker renowned for its rapid and long-lasting acid suppression,which is minimally affected by *** to proton pump inhibitors,which bind irreversibly to cysteine residues in the H+/K+-AtPase pump,Vonoprazan competes with the K+ions,prevents the ions from binding to the pump and blocks acid *** with increasing antibiotic resistance,effects on the gut microbiota,patient compliance,and side effects have led to the advent of a dual regimen for *** studies suggested that *** plays a role in stabilizing the gut barrier which improves *** eradication *** an acceptable safety profile,the dual-adjunct regimen was effective regardless of prior treatment failure and antibiotic resistance profile,thereby strengthening the applicability in clinical ***,*** comes in various formulations and dosages,warranting further exploration into the optimal dosage for supplementation in rescue ***,larger,randomized,double-blinded controlled trials are warranted to confirm these promising results.

关键词： Vonoprazan Saccharomyces boulardii Helicobacter pylori Rescue therapy Eradication rate

Mg/MgO interfaces as efficient hydrogen evolution cathodes causing accelerated corrosion of additive manufactured Mg alloys:A DFt analysis

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 Magnesium and Alloys 2024年第1期12卷 110-119页

作者： Man-Fai Ng Kai Xiang Kuah teck Leong tan daniel John blackwood Department of Materials Science&Engineering National University of Singapore9 Engineering Drive 1Singapore 117575Republic of Singapore Institute of High Performance Computing(IHPC) Agency for ScienceTechnology and Research(A∗STAR)1 Fusionopolis Way#16-16 ConnexisSingapore 138632Republic of Singapore

the corrosion rates of additive-manufactured Mg alloys are higher than their as-cast counterparts,possibly due to increased kinetics for the hydrogen evolution reaction on secondary phases,which may include oxide *** Kelvin Probe Force Microscopy demonstrated that MgO inclusions could act as cathodes for Mg corrosion,but their low conductivity likely precludes ***,the density of state calculations through density functional theory using hybrid HSE06 functional revealed overlapping electronic states at the Mg/MgO interface,which facilitates electron transfers and participates in redox *** determination of the hydrogen absorption energy at the Mg/MgO interface reveals it to be an excellent catalytic site,with HER being found to be a factor of 23x more efficient at the interface than on metallic *** results not only support the plausibility of the Mg/MgO interface being an effective cathode to the adjacent anodic Mg matrix during corrosion but also contribute to the understanding of the enhanced cathodic activities observed during the anodic dissolution of magnesium.

关键词： Magnesium Magnesium oxide Interface Hydrogen evolution DFt

twisted fiber microfluidics:a cutting-edge approach to 3D spiral devices

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第1期10卷 193-202页

作者： Shunsuke Kato daniel W.Carlson Amy Q.Shen Yuanyuan Guo Department of Electrical Information and Physics EngineeringSchool of EngineeringTohoku UniversityAoba-kuSendai 980-8579 MiyagiJapan Micro/bio/Nanofluidics Unit Okinawa Institute of Science and TechnologyOnnaKunigami-gun 904-0495 OkinawaJapan Frontier Research Institute for Interdisciplinary Sciences(FRIS) Tohoku UniversityAoba-kuSendai 980-0845 MiyagiJapan Graduate School of biomedical Engineering Tohoku UniversityAoba-kuSendai 980-8579 MiyagiJapan Department of Physiology Graduate School of MedicineTohoku UniversityAoba-kuSendai 980-8575 MiyagiJapan

the development of 3D spiral microfluidics has opened new avenues for leveraging inertial focusing to analyze small fluid volumes,thereby advancing research across chemical,physical,and biological *** traditional straight microchannels rely solely on inertial lift forces,the novel spiral geometry generates Dean drag forces,eliminating the necessity for external fields in fluid ***,fabricating 3D spiral microfluidics remains a labor-intensive and costly endeavor,hindering its widespread ***,conventional lithographic methods primarily yield 2D planar devices,thereby limiting the selection of materials and geometrical *** address these challenges,this work introduces a streamlined fabrication method for 3D spiral microfluidic devices,employing rotational force within a miniaturized thermal drawing process,termed as *** innovation allows for rapid prototyping of twisted fiber-based microfluidics featuring versatility in material selection and heightened geometric *** validate the performance of these devices,we combined computational modeling with microtomographic particle image velocimetry(utPiM)to comprehensively characterize the 3D flow *** results corroborate the presence of a steady secondary flow,underscoring the effectiveness of our *** 3D spiral microfluidics platform paves the way for exploring intricate microflow dynamics,with promising applications in areas such as drug delivery,diagnostics,and lab-on-a-chip systems.

关键词： thereby straight twisted