检索结果-南通市图书馆

Control system design for a pressure-tube-type supercritical water-cooled nuclear reactor via a higher order sliding mode method

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第1期35卷 145-154页

作者： M.Hajipour G.r.Ansarifar department of Nuclear Engineering Faculty of PhysicsUniversity of IsfahanIsfahan 81746-73441Iran

Nuclear power plants exhibit non-linear and time-variable ***,designing a control system that sets the reactor power and forces it to follow the desired load is complicated.A supercritical water reactor(SCWr)is a fourth-generation conceptual *** an SCWr,the non-linear dynamics of the reactor require a controller capable of control-ling the *** this study,a pressure-tube-type SCWr was controlled during reactor power maneuvering with a higher order sliding mode,and the reactor outgoing steam temperature and pressure were controlled *** an SCWr,the temperature,pressure,and power must be maintained at a setpoint(desired value)during power *** point kinetics equations with three groups of delayed neutrons were used in the ***-order and classic sliding mode controllers were separately manufactured to control the plant and were compared with the PI controllers speci-fied in previous *** controlled parameters were reactor power,steam temperature,and ***,for these parameters,the PI controller had certain instabilities in the presence of *** classic sliding mode controller had a higher accuracy and stability;however its main drawback was the chattering *** was highly accurate and stable and had a small computational *** reality,it followed the desired values without oscillations and chattering.

关键词： Supercritical water nuclear reactor Higher order sliding mode controller Steam temperature Steam pressure Point kinetics model

Viscoelastic potential flow instability theory of rivlin-Ericksen electrified fluids of cylindrical interface

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean Engineering and Science 2024年第4期9卷 311-316页

作者： d.M.Mostafa department of Mathematics College of ScienceQassim UniversityPO Box 6644Buraidah 51452Saudi Arabia department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

A linear electrohydrodynamic Kelvin-Helmholtz instability of the interface between two viscoelastic rivlin-Ericksen fluids enclosed by two concentric horizontal cylinders has been studied via the viscoelastic potential flow *** dispersion equation of complex coefficients for asymmetric disturbance has been obtained by using normal mode *** stability criteria are analyzed theoretically and illustrated *** imaginary part of growth rate is plotted versus the wave *** influences of dynamic viscoelastic,uniform velocities,reynolds number,electric field,dynamic viscosity,density fluids ratio,dielectric constant ratio and inner fluid fraction on the stability of the system are *** study finds its significance in Ocean pipelines to transfer oil or gas such as Eastern Siberia-Pacific Ocean oil pipeline.

关键词： rivlin-Ericksen fluid Cylindrical flow Viscoelastic potential flow Electrohydrodynamics stability

Flexible ultra-thin super-resolution endoscopy

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

Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 171-172页

作者： George S.d.Gordon department of Electrical and Electronic Engineering University of NottinghamNottingham NG7 2RDUK

In recent years, multimode fiber(MMF) has become an important tool for high-resolution endoscopic imaging in narrow channels(e.g., in the brain via needles or inside blood vessels) due to its high mode density and fine diameter, typically r, a major obstacle to widespread deployment in applications is that realistic perturbations, including bending, twisting and changes in temperature, cause unacceptable image degradation.

关键词： fiber resolution typically

Performance analysis of deep borehole heat exchangers for decarbonization of heating systems

在线全文

学校读者我要写书评

暂无评论

deep Underground Science and Engineering 2024年第3期3卷 349-357页

作者： Andreas E.d.Lund department of Electrical Engineering and Automation Aalto UniversityEspooFinland

Meeting the climate change mitigation targets will require a substantial shift from fossil to clean fuels in the heating *** pumps with deep borehole exchangers are a promising solution to reduce *** the thermal behavior of deep borehole exchangers(dBHEs)ranging from 1 to 2 km was analyzed for various heat flow profiles.A strong correlation between thermal energy extraction and power output from dBHEs was found,also influenced by the heating profile *** operating time over the year typically resulted in higher energy production,while shorter one yielded higher average thermal power output,highlighting the importance of the choice of heating strategy and system design for optimal performance of *** breaks in operation for regenerating the borehole,for example,with waste heat,proved to be favorable for the performance yielding an overall heat output close to the same as with continuous extraction of *** results demonstrate the usefulness of deep boreholes for dense urban areas with less available *** the heat production from a single dBHE in Finnish conditions ranges from half up to even a few GWh a year,the technology is best suitable for larger heat loads.

关键词： clean energy deep borehole exchangers energy transition geothermal heat ground-coupled heat pump

维普期刊数据库博看期刊

Sex-specific life-history trait expression in hybrids of a cave- and surface-dwelling fish (Poecilia mexicana, Poecilidae)

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2024年第4期70卷 421-429页

作者： rüdiger riesch Luis r.Arriaga Ingo Schlupp department of Biological Sciences Royal Holloway University of LondonEghamTW20 OEXUK CEFE CNRSUnivMontpellierEPHEIRDMontpellierFrance department of Biology University of OklahomaNormanOK 73019USA

Evaluating the fitness of hybrids can provide important insights into genetic differences between species or diverging *** focused on surface-and cave-ecotypes of the widespread Atlantic molly Poecilia mexicana and raised F1 hybrids of reciprocal crosses to sexual maturity in a common-garden *** were reared in a fully factorial 2 x 2 design consisting of lighting(light ***)and resource availability(high *** food).We quantified survival,ability to realize their full reproductive potential(i.e.,completed maturation for males and 3 consecutive births for females)and essential life-history *** to the performance of pure cave and surface fish from a previous experiment,F1s had the highest death rate and the lowest proportion of fish that reached their full reproductive *** also uncovered an intriguing pattern of sex-specific phenotype expression,because male hybrids expressed cave molly life histories,while female hybrids expressed surface molly life *** results provide evidence for strong selection against hybrids in the cave molly system,but also sug-gest a complex pattern of sex-specific(opposing)dominance,with certain surface molly genes being dominant in female hybrids and certain cavemollygenes beingdominant in malehybrids.

关键词： dominance life-history evolution local adaptation postzygotic isolation selection against hybrids.

A perspective on greenhouse gas emission studies integrating arbuscular mycorrhiza

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

Pedosphere 2024年第3期34卷 525-529页

作者： Stavros d.VErESOGLOU Junjiang CHEN State Key Laboratory of Biocontrol School of EcologySun Yat-sen UniversityShenzhen 518107(China)

Climate change is a global *** is only possible to pace down global change through addressing the triggers of it,greenhouse gas *** commendable progress,we think that there is plenty of room to further make the studies addressing global change realistic,through integrating into them biotic *** make a case for this statement through a bibliometrics analysis on agricultural studies exploring greenhouse gas emissions that consider arbuscular *** show that even though mycorrhizal studies account right now for a small fraction of the agricultural literature,they get cited more *** further demonstrate that mycorrhizal studies are typically more descriptive in their nature,which we support through comparing the keywords they *** subsequently use the opportunity to identify shortcomings and opportunities to further integrate mycorrhiza into agricultural studies assaying greenhouse gas *** finally make a call to better integrate arbuscular mycorrhiza into global change studies.

关键词： bibliometric analysis biochemical models global change biology Glomeromycota sustainable agricultural intensification

Effect of proton irradiation on the optical properties of thermal control coating based on polystyrene with silica filler

在线全文

学校读者我要写书评

暂无评论

Propulsion and Power research 2024年第1期13卷 1-11页

作者： N.I.Cherkashina V.I.Pavlenko M.M.Mikhailov A.N.Lapin S.A.Yuriev r.V.Sidelnikov d.S.romanyuk Belgorod State Technological University named after V.G.Shoukhov Kostyukov Str.46Belgorod 308012Russia Tomsk State University of Control Systems and radioelectronics 40Prospect LeninaTomsk 634050Russia

This paper presents the results of studying the surface properties changes of a ther-moregulating coating based on polystyrene and silicaﬁller after proton irradiation with an en-ergy of 50 keV at afluence of 3�1015 cm�*** proton irradiation,the values of the contact angle of wetting with water increase by 3.5%and 14.9%for polystyrene and the coating,*** free surface energy(energy of the surface layer)of polystyrene and the coat-ings before and after proton irradiation was calculated using the Owens-Wendt-rabel-Kaelble *** was a signiﬁcant increase in the polarity of the polystyrene surface(gp increased by a factor of 2.2)after proton *** the coating,an increase in gp by a factor of 3.89 was observed after proton *** changes in the coating were presented by Ir Fourier spectroscopy.A slight decrease in the absorption intensity of all characteristic bands compared to the unirradiated sample was *** was found that the irradiation of the coating with protons led to the formation of macromolecules with hydroxyl,carbonyl,and carboxyl bonds,as well as the formation of dimeric and oligomeric siloxane *** was also found that after irradiation of a pure polystyrene sample with protons,the value of the solar absorption as increased by only 4.2%;whereas for the coating with silicaﬁller,the value of as increased by 28.6%.

关键词： Thermal control coating Proton irradiation Hydrophobicity Free surface energy radiation crosslinking

Quaternionic Monge–Ampère Measure on Pluripolar Set

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

Acta Mathematica Sinica,English Series 2024年第6期40卷 1431-1457页

作者： Hichame AMAL Saïd ASSErdA Fadoua BOUKHArI department of Mathematics Laboratory LaREAMIRegional Centre of Trades of Education and TrainingKenitraMorocco Ibn Tofail University Faculty of SciencesDepartment of MathematicsPO 242 KenitraMorroco

In this paper, we prove that in a hyperconvex domain Ω in H^(n), if a non-negative Borel measure is dominated by a quaternionic Monge–Ampère measure, then it is a quaternionic Monge–Ampère measure of a function i... 详细信息

关键词： Quaternion space Monge-Amp`ere operator plurisubharmonic function

Changes in snow cover extent in the Central Taurus Mountains from 1981 to 2021 in relation to temperature, precipitation, and atmospheric teleconnections

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第1期21卷 49-67页

作者： Ecmel ErLAT Fulya AYdIN-KANdEMİr department of Geography Ege UniversityIzmir 35100Türkiye Climate Change and Zero Waste department Antalya Metropolitan MunicipalityAntalya 07310Türkiye Hydropolitics Association Ankara 06680Türkiye

The snow cover over the Taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly Snow Cover Extent(SCE) from November to April in the Central Taurus Mountains(Bolkar, Aladaglar, Tahtali and Binboga Mountains) from 1981 to 2021. Linear trends of snow cover season(November to April) over the last 41 years showed decreases in SCE primarily at lower elevations. The downward trend in SCE was found to be more pronounced and statistically significant for only November and March. SCE in the Central Taurus Mountains has declined about-6.3% per decade for 2500-3000 m in November and about-6.0% per decade for 1000-1500 m and 3000+ m in March over the last 41 years. The loss of SCE has become evident since the 2000s, and the lowest negative anomalies in SCE have been observed in 2014, 2001, and 2007 in the last 41 years, which are consistent with an increase in air temperature and decreased precipitation. SCE was correlated with both mean temperature and precipitation, with temperature having a greater relative importance at all elevated gradients. results showed that there is a strong linear relationship between SCE and the mean air temperature(r =-0.80) and precipitation(r = 0.44) for all elevated gradients during the snow season. The Arctic Oscillation(AO), the North Atlantic Oscillation(NAO), and the Mediterranean Oscillation(MO) winter indices were used to explain the year-to-year variability in SCE over the Central Taurus Mountains. The results showed that the inter-annual variability observed in the winter SCE on the Central Taurus Mountains was positively correlated with the phases of the winter AO, NAO and MO, especially below 2000 m elevation.

关键词： Snow cover extent Atmospheric teleconnection Central Taurus Mountains Air temperature and precipitation Geographic Information Systems Türkiye