检索结果-南通市图书馆

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

DeepLogic:Priority Testing of Deep Learning Through Interpretable Logic Units

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第4期33卷 948-964页

作者： Chenhao LIN Xingliang ZHANG Chao SHEN faculty of Electronic and Infomation engineering Xi'an Jiaotong University

With the increasing deployment of deep learning-based systems in various scenes, it is becoming important to conduct sufficient testing and evaluation of deep learning models to improve their interpretability and robustness. Recent studies have proposed different criteria and strategies for deep neural network(DNN) ***, they rarely conduct effective testing on the robustness of DNN models and lack interpretability. This paper proposes a new priority testing criterion, called DeepLogic, to analyze the robustness of the DNN models from the perspective of model interpretability. We first define the neural units in DNN with the highest average activation probability as “interpretable logic units”. We analyze the changes in these units to evaluate the model's robustness by conducting adversarial attacks. After that, the interpretable logic units of the inputs are taken as context attributes, and the probability distribution of the softmax layer in the model is taken as internal attributes to establish a comprehensive test prioritization framework. The weight fusion of context and internal factors is carried out, and the test cases are sorted according to this priority. The experimental results on four popular DNN models using eight testing metrics show that our DeepLogic significantly outperforms existing state-of-the-art methods.

关键词： Deep learning Measurement Analytical models Artificial neural networks Robustness Probability distribution Logic

Effect of Sc on Al_(3)Fe phase and mechanical properties of as-cast AA5052 aluminum alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2024年第3期21卷 257-264页

作者： Yang Li Qing Yu Feng-feng Chen Jia-wen He Hong-mei Yang Meng-nie Li faculty of Materials Science and engineering Kunming University of Science and TechnologyKunming 650093China

The AA5052 aluminum alloy is widely used in automobile and aerospace manufacturing,and with the development of light-weight alloys,it is required that these materials exhibit better mechanical *** studies have demonstrated that the addition of Sc to aluminum alloys can improve both the microstructure and properties of the *** this study,the effect of Sc on the Fe-rich phase and properties of the AA5052 aluminum alloy was studied by adding 0%,0.05%,0.2%,and 0.3%*** results show that with the increase of Sc,the coarse needle-like Fe-rich phase gradually transforms into Chinese-script and then nearly spherical particles,reduce the size of Fe-rich phase,and refine the grain with increase of high angle grain boundaries(HAGBs).These microstructure changes enhance the strength of the AA5052 alloy through Sc *** ductility of the alloy is obviously improved because the addition of a lower amount of Sc changes the morphology of Fe-rich phase from needle-like into a Chinese-script,and it is subsequently reduced as a result of significant increase in HAGBs with increasing Sc content.

关键词： AA5052 aluminum alloy Al3Fe phase mechanical properties grain boundary

CFD simulation and optimization of an industrial cement gas-solid air classifier

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第6期89卷 172-184页

作者： Mohamadreza Esmaeilpour Ali Mohebbi Vahab Ghalandari Department of Chemical engineering Faculty of EngineeringShahid Bahonar University of KermanKermanIran Kerman Momtazan Cement Company KermanIran

An air classifier is one of the main and effective devices in cement *** this study,a three-dimensional,steady and two-phase(solid-gas)computational fluid dynamics(CFD)simulation was performed to optimize the performance of this device in the Kerman Momtazan cement plant,*** the validation of CFD results,the air flow field and air path lines between fixed blades were checked carefully and the non-uniformity in velocity distribution and the formation of vortex flows between the blades close to particle inlets were *** study tried to improve the device efficiency by changing the method of entering particles into the device,resulting in a reduction in air classifier electrical energy consumption(from 41 to 35(kW h)/t)and an increase in production rate(from 203 to 214 t/h).Additionally,the study investigated the effects of other modifiable operating conditions like rotary cage rotation speed,pressure difference,and inlet air temperature on the particle size distribution and classifier *** results showed that increasing the cage rotation speed decreased the product rate and the product particles mean diameter while increasing pressure difference or increasing temperature increased the product rate and the product particles mean *** was concluded that these modifiable operating conditions can significantly affect the performance of the air classifier in the cement industry.

关键词： Cement air classifier Computational fluid dynamics Gas-solid two-phase flow Optimization Eulerian-Lagrangian method Efficiency

Blade Wrap Angle Impact on Centrifugal Pump Performance:Entropy Generation and Fluid-Structure Interaction Analysis

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

Computer Modeling in engineering & Sciences 2024年第7期140卷 109-137页

作者： Hayder Kareem Sakran Mohd Sharizal Abdul Aziz Chu Yee Khor School of Mechanical engineering Universiti Sains MalaysiaEngineering CampusNibong TebalPenang14300Malaysia Chemical engineering Department Faculty of EngineeringAl-Muthanna UniversityMuthanna66001Iraq faculty of Mechanical engineering&Technology Universiti Malaysia Perlis(UniMAP)ArauPerlis02600Malaysia

The centrifugal pump is a prevalent power equipment widely used in different engineering patterns,and the impeller blade wrap angle significantly impacts its performance.A numerical investigation was conducted to analyze the influence of the blade wrap angle on flow characteristics and energy distribution of a centrifugal pump evaluated as a low specific speed with a value of *** study investigates six impellermodels that possess varying blade wrap angles(95°,105°,115°,125°,135°,and 145°)that were created while maintaining the same volute and other geometrical *** investigation of energy loss was conducted to evaluate the values of total and entropy generation rates(TEG,EGR).The fluid-structure interaction was considered numerically using the software tools ANSYS Fluent and *** elastic structural dynamic equation was used to estimate the structural response,while the shear stress transport k–ωturbulence model was utilized for the fluid domain *** findings suggest that the blade wrap angle has a significant influence on the efficiency of the *** impeller featuring a blade wrap angle of 145°exhibits higher efficiency,with a notable increase of 3.76%relative to the original *** in the blade wrap angle impact the energy loss,shaft power,and pump *** model with a 145°angle exhibited a maximum equivalent stress of 14.8MPa and a total deformation of 0.084 *** results provide valuable insights into the intricate flow mechanism of the centrifugal pump,particularly when considering various blade wrap angles.

关键词： Centrifugal pump blade wrap angle entropy generation theory fluid-structure interaction hydraulic performance

Intelligent Fractional-Order Controller for SMES Systems in Renewable Energy-Based Microgrid

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

Computer Modeling in engineering & Sciences 2024年第8期140卷 1807-1830页

作者： Aadel M.Alatwi Abualkasim Bakeer Sherif A.Zaid Ibrahem E.Atawi Hani Albalawi Ahmed M.Kassem Electrical engineering Department Faculty of EngineeringUniversity of TabukTabuk47913Saudi Arabia Industrial Innovation and Robotic Center(IIRC) University of TabukTabuk47731Saudi Arabia Department of Electrical engineering Faculty of EngineeringAswan UniversityAswan81542Egypt Renewable Energy and Environmental Technology Centre University of TabukTabuk47913Saudi Arabia Electrical engineering Department Faculty of EngineeringSohag UniversitySohag82524Egypt

An autonomous microgrid that runs on renewable energy sources is presented in this *** has a supercon-ducting magnetic energy storage(SMES)device,wind energy-producing devices,and an energy storage ***,because such microgrids are nonlinear and the energy they create varies with time,controlling and managing the energy inside them is a difficult ***-order proportional integral(FOPI)controller is recommended for the current research to enhance a standalone microgrid’s energy management and *** suggested dedicated control for the SMES comprises two loops:the outer loop,which uses the FOPI to regulate the DC-link voltage,and the inner loop,responsible for regulating the SMES current,is constructed using the intelligent FOPI(iFOPI).The FOPI+iFOPI parameters are best developed using the dandelion optimizer(DO)approach to achieve the optimum *** suggested FOPI+iFOPI controller’s performance is contrasted with a conventional PI controller for variations in wind speed and microgrid *** optimal FOPI+iFOPI controller manages the voltage and frequency of the *** behavior of the microgrid as a reaction to step changes in load and wind speed was measured using the proposed *** simulations were used to evaluate the recommended system’s *** results of the simulations showed that throughout all interruptions,the recommended microgrid provided the load with AC power with a constant amplitude and *** addition,the required load demand was accurately ***,the microgrid functioned incredibly well despite SMES and varying wind *** obtained under identical conditions were compared with and without the best FOPI+iFOPI *** utilizing the optimal FOPI+iFOPI controller with SMES,it was found that the microgrid performed better than the microgrid without SMES.

关键词： Fractional-order proportional integral(FOPI) intelligent controller renewable energy resources superconducting magnetic energy storage optimization

Annual growth of Fagus orientalis is limited by spring drought conditions in Iran’s Golestan Province

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

Journal of Forestry Research 2024年第1期35卷 128-142页

作者： Khalil Ghorbani Jahangir Mohammadi Laleh Rezaei Ghaleh Department of Water engineering Faculty of Water and Soil EngineeringGorgan University of Agricultural Sciences and Natural ResourcesGorganIran Department of Forestry Gorgan University of Agricultural Sciences and Natural ResourcesGorganIran Department of Water engineering Faculty of AgricultureUrmia UniversityUrmiaIran

Due to the lack of a uniform and accurate defi-nition of‘drought’,several indicators have been introduced based on different variables and methods,and the efficiency of each of these is determined according to their relationship with *** relationship between two drought indices,SPI(standardized precipitation index)and SPEI(standard-ized precipitation-evapotranspiration index)in different sea-sons was investigated using annual rings of 15 tree samples to determine the effect of drought on the growth of oriental beech(Fagus orientalis Lipsky)in the Hyrcanian forests of northern *** different evapotranspiration calcula-tion methods were evaluated on SPEI efficiency based on Hargreaves-Samani,Thornthwaite,and Penman-Monteith methods using the step-by-step M5 decision tree regression *** results show that SPEI based on the Penman-Monteith in a three-month time scale(spring)had similar temporal changes and a better relationship with annual tree rings(R^(2)=0.81)at a 0.05 significant *** change and a decreasing trend in the time series of annual tree rings are similar to the variation in the SPEI based on the Penman-Monteith *** affecting evapotranspiration,temperature,wind speed,and sunshine hours(used in the Penman-Monteith method),increased but precipitation *** non-linear modeling methods,SPEI based on Penman-Monteith best illustrated climate changes affecting tree growth.

关键词： Climate change Drought index Hyrcanian forests SPEI'Annual growth rings Fagus orientalis

Quasi-static and dynamic compressive behaviour of additively manufactured Menger fractal cube structures

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第7期37卷 39-49页

作者： Damith Mohotti Dakshitha Weerasinghe Madhusha Bogahawaththa Hongxu Wang Kasun Wijesooriya Paul JHazell School of engineering and Technology UNSWCanberraACT2600Australia School of Civil Mining and Environmental EngineeringFaculty of Engineering and Information SciencesUniversity of WollongongWollongongNSWAustralia

This paper presents the first-ever investigation of Menger fractal cubes'quasi-static compression and impact *** cubes with different void ratios were 3D printed using polylactic acid(PLA)with dimensions of 40 mm×40 mm×40 *** different orders of Menger cubes with different void ratios were considered,namely M1 with a void ratio of 0.26,M2 with a void ratio of 0.45,and M3with a void ratio of ***-static Compression tests were conducted using a universal testing machine,while the drop hammer was used to observe the behaviour under impact *** fracture mechanism,energy efficiency and force-time histories were *** the structured nature of the void formation and predictability of the failure modes,the Menger geometry showed some promise compared to other alternatives,such as foams and *** the increasing void ratio,the Menger geometries show force-displacement behaviour similar to hyper-elastic materials such as rubber and *** third-order Menger cubes showed the highest energy absorption efficiency compared to the other two geometries in this *** findings of the present work reveal the possibility of using additively manufactured Menger geometries as an energy-efficient system capable of reducing the transmitting force in applications such as crash barriers.

关键词： Additive manufacturing Fractal geometries Menger cube Energy absorption Quasi-static

Advancements in enhancing corrosion protection of Mg alloys:A comprehensive review on the synergistic effects of combining inhibitors with PEO coating

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第2期12卷 465-489页

作者： Arash Fattah-alhosseini Abdelhameed Fardosi Minoo Karbasi Mosab Kaseem Department of Materials engineering Faculty of EngineeringBu-Ali Sina UniversityHamedanIran Department of Nanotechnology and Advanced Materials engineering Sejong UniversitySeoul 05006Republic of Korea

Magnesium(Mg)alloys are lightweight materials with excellent mechanical properties,making them attractive for various applications,including aerospace,automotive,and biomedical ***,the practical application of Mg alloys is limited due to their high susceptibility to *** electrolytic oxidation(PEO),or micro-arc oxidation(MAO),is a coating method that boosts Mg alloys'corrosion ***,despite the benefits of PEO coatings,they can still exhibit certain limitations,such as failing to maintain long-term protection as a result of their inherent *** address these challenges,researchers have suggested the use of inhibitors in combination with PEO coatings on Mg *** are chemical compounds that can be incorporated into the coating or applied as a post-treatment to further boost the corrosion resistance of the PEO-coated Mg *** inhibitors,whether organic or inorganic,can act by forming a protective barrier,hindering the corrosion process,or modifying the surface properties to reduce susceptibility to *** can be made of various materials,including polyelectrolyte shells,layered double hydroxides,polymer shells,and mesoporous inorganic *** corrosion inhibitors in containers fully compatible with the coating matrix and substrate is a promising approach for their *** studies of the combination of inhibitors with PEO coatings on Mg alloys have shown promising results,demonstrating significant corrosion mitigation,extending the service life of Mg alloy components in aggressive environments,and providing self-healing *** general,this review presents available information on the incorporation of inhibitors with PEO coatings,which can lead to improved performance of Mg alloy components in demanding environments.

关键词： Inhibitor Mg alloy Self-healing coating Plasma electrolytic oxidation(PEO) Corrosion protection

Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： N.D.NGUYEN T.N.NGUYEN faculty of Civil engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam faculty of engineering and Technology Kien Giang UniversityChau Thanh 92000Viet Nam

This study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(TD)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBT)