检索结果-南通市图书馆

Liquid superlubricity of lubricants containing hydroxyl groups and their aqueous solution under rolling/sliding conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第1期12卷 164-173页

作者： Tomáš POLÁČEk petr ŠPERkA Ivan kŘUPkA Faculty of Mechanical Engineering Brno University of TechnologyBrno 61669Czech Republic

Macroscale rolling/sliding conditions are in the superlubricity,a little-studied topic so *** purpose of this paper is to examine the formation of elastohydrodynamic lubrication(EHL)films by water-based lubricants(glycerol and polyethylene glycol(PEG)),providing superlubricous *** were carried out on an optical ball-on-disc tribometer under rolling/sliding *** film thickness was measured by the thin film colorimetric interferometry,and the viscosity of liquids was measured by rotational and high-pressure falling body *** results show that tribochemical reactions are not the mandatory reason for friction to reach the superlubricity level when using the water-based *** studied liquids themselves are almost *** the addition of water,the signs of shear thinning behavior disappear even *** conditions for this type of lubricant can be predicted using the known Hamrock–Dowson *** anomaly in the thickness of the lubricants was observed as an abrupt change at certain *** more PEG there is in the lubricant,the higher the thickness at the beginning of the jump.

关键词： macroscale superlubricity super low traction water-based lubricants elastohydrodynamic lubrication(EHL) film thickness

Hybrid LES/RANS Simulations of Compressible Flow in a Linear Cascade of Flat Blade Profiles

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 Thermal Science 2024年第5期33卷 1839-1850页

作者： Jaromír PRIHODA petr STRAkA David SIMURDA petr SIDLOF Jan LEPICOVSkY Institute of Thermomechanics of the Czech Academy of Sciences Dolejskova 1402/518200 Prague 5Czech Republic Aerospace Research and Test Centre Beranovych 13019905 PragueCzech Republic Technical University of Liberec Faculty of MechatronicsStudentska 246117 Liberec 1Czech Republic

The paper reports on 3D numerical simulations of unsteady compressible airflow in a blade cascade consisting of flat profiles using a hybrid LES/RANS approach including a transition *** a first step towards simulation of blade flutter in turbomachinery,various incidence angle offsets of the middle blade were *** simulations were run for the flow regime characterized by outlet isentropic Mach number M_(is)=0.5and zero *** results of the LES/RANS simulations(pressure and Mach number distributions)were compared to a baseline RANS model,and to experimental data measured in a high-speed wind *** numerical results show that both methods overpredict flow separation taking place at the leading *** this regard,the hybrid LES/RANS method does not provide superior results compared to the traditional RANS ***,the LES/RANS results also capture vortex shedding from the blunt trailing *** frequency of the trailing edge vortex shedding in CFD simulations matches perfectly the spectral peak recorded during wind tunnel measurements.

关键词： numerical simulation blade cascade hybrid LES/RANS

Energy management of buildings with energy storage and solar photovoltaic:A diversity in experience approach for deep reinforcement learning agents

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

Energy and AI 2024年第1期15卷 1-14页

作者： Akhtar Hussain petr Musilek Department of Electrical and Computer Engineering University of AlbertaEdmontonT6G 2G2ABCanada Department of Applied Cybernetics University of Hradec Králové50003Hradec KrálovéCzech Republic

Deep reinforcement learning(DRL)is a suitable approach to handle uncertainty in managing the energy consumption of buildings with energy storage ***,DRL agents are trained by randomly selecting samples from a data set,which can result in overexposure to some data categories and under/no exposure to other data ***,the trained model may be biased towards some data groups and underperform(provide suboptimal results)for data groups to which it was less *** address this issue,diversity in experience-based DRL agent training framework is proposed in this *** approach ensures the exposure of agents to all types of *** proposed framework is implemented in two *** the first step,raw data are grouped into different clusters using the k-means clustering *** clustered data is then arranged by stacking the data of one cluster on top of *** the second step,a selection algorithm is proposed to select data from each cluster to train the DRL *** frequency of selection from each cluster is in proportion to the number of data points in that cluster and therefore named the proportional selection *** analyze the performance of the proposed approach and compare the results with the conventional random selection method,two indices are proposed in this study:the flatness index and the divergence *** model is trained using different data sets(1-year,3-year,and 5-year)and also with the inclusion of solar *** simulation results confirmed the superior performance of the proposed approach to flatten the building’s load curve by optimally operating the energy storage system.

关键词： Battery energy storage Building demand management Deep reinforcement learning Diversity in experience Energy management

Efficient cold atom source from a single-layer atom chip

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第6期22卷 103-108页

作者： petr Skakunenko Darya Bykova Anton Afanasiev Alexey kalmykov Roman kirtaev Victor Balykin Institute of Spectroscopy Russian Academy of Sciences Moscow 108840Russia Moscow Institute of Physics and Technology Moscow 141700Russia Skolkovo Institute of Science and Technology Moscow 121205Russia National Research University Higher School of Economics Moscow 101000Russia Present affiliation:Emerging Technologies Research Center XPANCEODubaiUnited Arab Emirates

We developed a new single-layer atom chip with an additional U-shaped current-carrying *** new U-shaped microwire creates optimized magnetic field distribution,which increases the trapping volume of a magneto-optical trap(MOT) near the *** approach allows one to localize more atoms,while a setup remains relatively simple (single-layer approach) and consumes low current (up to 10 A). The total number of trapped^(87)Rb atoms in our setup is 5×10^(7).

关键词： atom chip cold atoms laser cooling magneto-optical trap U-MOT

Clinical and socioeconomic determinants of survival in biliary tract adenocarcinomas

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

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1374-1383页

作者： Laura Sahyoun kay Chen Cynthia Tsay George Chen petr Protiva Department of Gastroenterology and Hepatology Weill Cornell MedicineNew YorkNY 10065United States Gastroenterology Section Jennifer Moreno VA San Diego Healthcare SystemSan DiegoCA 92161United States Division of Gastroenterology Department of MedicineUniversity of California San DiegoLa JollaCA 92093United States Department of Gastroenterology and Hepatology John Hopkins HospitalBaltimoreMD 21287United States Department of Digestive Diseases Yale New Haven HospitalNew HavenCT 06520United States Department of Gastroenterology VA Connecticut Health Care SystemWest HavenCT 06516United States

BACkGROUND Despite advances in detection and treatments,biliary tract cancers continue to have poor survival ***,there is limited data investigating the significance of socioeconomic status,race/ethnicity,and environmental factors in biliary tract cancer *** from the Surveillance,Epidemiology,and End Results database for biliary and gallbladder adenocarcinomas were extracted from 1975 to ***-conomic data included smoking,poverty level,education,adjusted household income,and percentage of foreign-born persons and urban *** was calculated with Cox proportional hazards models for death in the 5-year period following *** Our study included 15883 gallbladder,11466 intrahepatic biliary,12869 extrahepatic biliary and 7268 ampulla of Vater adenocarcinoma *** analyzing county-specific demographics,patients from counties with higher incomes were associated with higher survival rates[hazard ratio(HR)=0.97,P<0.05].Similarly,counties with a higher percentage of patients with a college level education and counties with a higher urban population had higher 5-year survival rates(HR=0.96,P=0.002 and HR=0.97,P=0.004,respectively).CONCLUSION Worse survival outcomes were observed in lower income counties while higher income and education level were associated with higher 5-year overall survival among gallbladder and biliary malignancies.

关键词： Biliary tract cancers Survival Outcomes research Socioeconomic factors Healthcare disparities

Effect of sodium nitroprusside on the microrheological properties of red blood cells in di®erent media

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 Innovative Optical Health Sciences 2024年第5期17卷 23-31页

作者： petr Ermolinskiy Matvey Maksimov Andrei Lugovtsov Alexey Muravyov Irina Tikhomirova Alexander Priezzhev Faculty of Physics M.V.Lomonosov Moscow State University Moscow 119991Russia Faculty of Physical Education k.D.Ushinsky Yaroslavl State Pedagogical University Yaroslavl 150000 Russia Faculty of Natural Sciences k.D.Ushinsky Yaroslavl State Pedagogical University Yaroslavl 150000 Russia

Red blood cell(RBC)aggregation as well as their deformation signi¯cantly affects blood *** processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the *** purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in *** properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,*** study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged *** washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased ***-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.

关键词： Sodium nitroprusside nitric oxide red blood cells RBC aggregation diffuse light scattering laser diffractometer

Phylogenetic placement of bizarre karschiellid earwigs

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2024年第3期31卷 989-992页

作者： petr kocárek Ivona Horká Vojtěch Bonczek Markéta kirstová Department of Biology and Ecology University of OstravaOstravaCzech Republic

Dear Editor,karschiellidae are a mysterious group of earwigs that attract attention not only because of their interesting appearance and unexplained way of life but also mainly due to their unclear *** phylogenetic relationships of karschiellids remain speculative even 120 years since the family was described,above all due to the unavailability of DNA-grade material for molecular phylogenetic *** study includes successfully sequenced representatives of the karschiellidae for the first time,and a probable evolutionary scheme and natural classification of karschiellids are proposed based on the constructed multigene phylogeny.

关键词： classification. phylogeny evolutionary

A modified PVDF-HFP/PMMA crosslinked co-polymer for high-performance all-solid-state lithium metal batteries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第10期93卷 203-210页

作者： Sijia Wang Liang He Mengting Wang Xingtong Guo Xiangyun Qiu Shoudong Xu petr Senin Ting Bian Tao Wei School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang212003China Power&Energy Storage System Research Center College of Mechanical and Electrical EngineeringQingdao UniversityQingdao266071China College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan030024China Institute of Mechanics and Power Engineering Ogarev Mordovia State UniversitySaransk430005Russia

For all-solid-state lithium batteries(ASSLBs),polymer-blended solid composite electrolytes(SCEs)have drawn wide interest owing to their significance in improving the interfacial solid-solid contacts and inhibiting the growth of lithium *** this work,SCEs based on PVDF-HFP/PMMA matrix containing MOFs(NH2-MIL-53(Al))and LiTFSI were designed and synthesized employing an easy solution casting *** synthesized samples were examined by XRD,SEM,EDS,and electrochemical *** was found that MPP-2 SCE not only has excellent ionic conductivity at 60℃ of 5.54×10^(−4) S cm^(−1),but also exhibits superior interfacial compatibility in Li||Li symmetric batteries,which can constantly cycle for about 800 h at 0.1 mA cm^(−2) with no *** assembled Li|MPP-2|LiFePO4 cell exhibited a first discharge specific capacity of up to 157.1 mAh g^(−1) at 60℃ and 0.2 *** work may help to further advance the progress of ASSLBs in the future.

关键词： NH_(2)-MIL-53(AI) All solid-state lithium batteries(ASSLBs) PMMA PVDF-HFP Solid composite electrolytes(SCEs)

Changes in the adult sex ratio of six duck species breeding populations over two decades

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Avian Research 2024年第2期15卷 202-210页

作者： Monika Homolkova petr Musil Diego Pavon-Jordan Dorota Gajdosova Zuzana Musilova Sarka Neuzilova Jan Zouhar Department of Ecology Faculty of Environmental SciencesCzech University of Life Sciences PragueKamýcka 129CZ-16521Prague–SuchdolCzech Republic Department of Terrestrial Ecology Norwegian Institute for Nature Research(NINA)PO Box 5685 TorgardenTrondheimN-7485Norway Department of Econometrics Faculty of Informatics and StatisticsUniversity of Economicsnam.W.Churchilla 4CZ-13067Prague 3Czech Republic

Despite all efforts,long-term changes in the adult sex ratios of breeding duck populations are still unclear;this uncertainty is especially true for male-bias populations,which are often under the scrutiny of researchers lacking convenient results for the active protection of endangered *** with male-bias populations are usually strongly affected by a decline in population size that leads to a higher extinction *** this study,we examined our long-term data of the abundance of breeding populations in six duck species(Mallard Anas platyrhynchos,Gadwall Mareca strepera,Red-crested Pochard Netta rufina,Common Pochard Aythya ferina,Tufted Duck Aythya fuligula,and Common Goldeneye Bucephala clangula)from fishponds in South Bohemia,Czechia,between 2004 and *** evidence was used to assess long-term changes in the adult sex ratio in these breeding populations and investigate the possible effects of the NAO index(North Atlantic Oscillation index)on them,indicating climate conditions in *** determined a long-term decrease of the proportion of females in the breeding season in two of the six examined species:Common Pochard and Red-crested Pochard,which is driven by the long-term increase in the number of males in contrast to the decreasing or stable number of females likely caused by different migration behaviours between females and *** the case of Common Pochard,in breeding populations,we estimated 60-65%of males in the early 2000s rising to 75-80%in the early ***,we establish no significant effects linked to climate conditions of the previous winter in these species as a crucial cause of the changes of the proportion of females in the breeding population.

关键词： Adult sex ratio Breeding population Population dynamics Red-listed species Waterfowl Winter weather conditions