检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2021年第11期34卷 154-161页

作者： majid masteri-farahani Samaneh Shahsavarifar Research Institute of Green Chemistry Faculty of ChemistryKharazmi UniversityTehranIran

Chemical functionalization of chitosan biopolymer and chitosan-magnetite nanocomposite was performed with sulfonic acid functional groups to achieve new solid acid *** sulfonic acid functional groups were created through the ring opening nucleophilic reaction of amine groups of chitosan with 1,4-butane *** transform infrared spectroscopy(FT-IR)and X-ray photoelectron spectroscopies(XPS)verified the successful sulfonic acid functionalization of *** obtained sulfonic acid functionalized chitosan-magnetite nanocomposite showed superparamagnetic properties according to the vibrating sample magnetometry analysis and exhibited magnetic separation feature from dispersed *** adsorption-desorption analysis indicated the increase in surface area after formation of chitosan-magnetite nanocomposite and functionalization with sulfonic *** of the prepared solid acids exhibited high catalytic activities in the acid-catalyzed acetic acid esterification with n-butanol and benzaldehyde acetalization with ethylene glycol as model ***,they can be reused several times without considerable loss of their activities.

关键词： Chitosan Magnetite Nanostructure Sulfonic acid Catalysis Esterification

Nonlinear vibration of Timoshenko FG porous sandwich beams subjected to a harmonic axial load

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

Earthquake Engineering and Engineering Vibration 2024年第3期23卷 649-662页

作者： Milad Lezgi Moein Zanjanchi Nikoo majid Ghadiri Department of Civil Engineering Sharif University of TechnologyTehran ***Iran Civil Engineering Department K.N.Toosi University of TechnologyTehran ***Iran Faculty of Engineering Department of MechanicsImam Khomeini International UniversityQazvin ***Iran

In this study,the instability and bifurcation diagrams of a functionally graded(FG)porous sandwich beam on an elastic,viscous foundation which is influenced by an axial load,are investigated with an analytical *** do so,the Timoshenko beam theory is utilized to take the shear deformations into account,and the nonlinear Von-Karman approach is adopted to acquire the equations of ***,to turn the partial differential equations(PDEs)into ordinary differential equations(ODEs)in the case of equations of motion,the method of Galerkin is employed,followed by the multiple time scale method to solve the resulting *** impact of parameters affecting the response of the beam,including the porosity distribution,porosity coefficient,temperature increments,slenderness,thickness,and damping ratios,are explicitly *** is found that the parameters mentioned above affect the bifurcation points and instability of the sandwich porous beams,some of which,including the effect of temperature and porosity distribution,are less noticeable.

关键词： sandwich beam Timoshenko beam parametric excitation bifurcation diagrams dynamic instability

Sensitivity of optimal double-layer grid designs to geometrical imperfections and geometric nonlinearity conditions in the analysis phase

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

Frontiers of Structural and Civil Engineering 2024年第8期18卷 1209-1224页

作者： Amirali REZAEIZADEH Mahsa ZANDI majid ILCHI GHAZAAN School of Civil Engineering Iran University of Science and TechnologyTehran 16846-13114Iran

This study focuses on exploring the effects of geometrical imperfections and different analysis methods on the optimum design of Double-Layer Grids(DLGs),as used in the construction industry.A total of 12 notable metaheuristics are assessed and contrasted,and as a result,the Slime Mold Algorithm is identified as the most effective approach for size optimization of *** evaluate the influence of geometric imperfections and nonlinearity on the optimal design of real-size DLGs,the optimization process is carried out by considering and disregarding geometric nonlinearity while incorporating three distinct forms of geometrical imperfections,namely local imperfections,global imperfections,and combinations of *** light of the uncertain nature of geometrical imperfections,probabilistic distributions are used to define these imperfections randomly in direction and *** results demonstrate that it is necessary to account for these imperfections to obtain an optimal ***’s worth noting that structural imperfections can increase the maximum stress ratio by up to 70%.The analysis also reveals that the initial curvature of members has a more significant impact on the optimal design of structures than the nodal installation error,indicating the need for greater attention to local imperfection issues in space structure construction.

关键词： double-layer grid sizing optimization metaheuristic algorithms geometrical imperfections analysis approach

Reinforcing the management of type 1 gastric esophageal varices

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 2024年第19期30卷 2615-2617页

作者： Zain majid Ghazi Abrar Department of Gastroenterology Sindh Institute of Urology and TransplantationKarachi 75500Pakistan

Variceal bleed represents an important complication of cirrhosis,with its presence reflecting the severity of liver *** varices,though less frequently seen than esophageal varices,present a distinct clinical challenge due to its higher intensity of bleeding and associated *** upon the Sarin classification,GOV1 is the most common subtype of gastric varices seen in clinical practice.

关键词： Gastric varices Sarin classification Gastroesophageal varices Cyanoacrylate Endoscopic variceal ligation Trans jugular intrahepatic portosystemic shunt

Elevating haptic interfaces:Dual-rate sampling and field programmable gate array implementation for multi-degree-of-freedom performance enhancement

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Mechanical System Dynamics 2024年第2期4卷 171-187页

作者： majid Koul Suhail Khosa Babar Ahmad Mechanical Engineering Islamic University of Science and TechnologyKashmirJammu and KashmirIndia Mechanical Engineering National Institute of Technology SrinagarJammu and KashmirIndia

In this work,our primary focus centered on exploring the adaptability of the dualrate sampling scheme proposed earlier to enhance the performance of multi-degreeof-freedom(multi-DOF)impedance-based haptic *** scheme employed independent sampling rates in a haptics controller,effectively mitigating the issue of reduced Z-width at higher sampling rates.A key aspect of our investigation was the intricate implementation of the dual-rate sampling scheme on a field programmable gate array(FPGA).This implementation on a logic hardware FPGA was challenging and led to the effective comparison of the uniform-rate and dual-rate sampling schemes of the multi-DOF haptic *** used an in-house developed two-DOF pantograph as the haptic interface and an FPGA for implementing the controller ***-based implementation presented challenges that were vital in testing controller performances at higher sampling *** wall experiments were conducted to determine the stable and unstable interactions with the virtual *** complement the experimental results,we simulated the haptics force law for multi-DOF system on Simulink/***,the dual-rate sampling approach maintained the Z-width of the two-DOF haptic interface,even at higher controller sampling rates,distinguishing it from the conventional two-DOF uniform-rate control *** example,employing a dual-rate sampling combination of 20–2 kHz consistently ensured the stable rendering of a maximum virtual stiffness of approximately 700 N/mm and maintained a reliable virtual damping range spanning from 0 to 5 Ns/*** contrast,the 20 kHz uniform-rate sampling approach failed to ensure interface stability in the presence of virtual damping,ultimately resulting in the unsuccessful implementation of any virtual stiffness at higher sampling *** work,therefore,establishes the potential of dual-rate sampling in the realm of haptic technology,with practical applications in multi-DOF systems.

关键词： control FPGA haptic device simulation virtual reality Z-width

Grow-light smart monitoring system leveraging lightweight deep learning for plant disease classification

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Artificial Intelligence in Agriculture

Artificial Intelligence in Agriculture 2024年第2期12卷 44-56页

作者： William Macdonald Yuksel Asli Sari majid Pahlevani Department of Electrical&Computer Engineering Queen's UniversityKingstonON K7L 3N6Canada The Robert M.Buchan Department of Mining Queen's UniversityKingstonON K7L 3N6Canada

This work focuses on a novel lightweight machine learning approach to the task of plant disease classification,posing as a core component of a larger grow-light smart monitoring *** the extent of our knowledge,this work is the first to implement lightweight convolutional neural network architectures leveraging down-scaled versions of inception blocks,residual connections,and dense residual connections applied without pre-training to the PlantVillage *** novel contributions of this work include the proposal of a smart monitor-ing framework outline;responsible for detection and classification of ailments via the devised lightweight net-works as well as interfacing with LED grow-light fixtures to optimize environmental parameters and lighting control for the growth of plants in a greenhouse *** adaptation of dense residual connections achieved the best balance of minimizing model parameters and maximizing performance metrics with accuracy,precision,recall,and F1-scores of 96.75%,97.62%,97.59%,and 97.58%respectively,while consisting of only 228,479 model *** results are further compared against various full-scale state-of-the-art model architectures trained on the PlantVillage dataset,of which the proposed down-scaled lightweight models were capable of performing equally to,if not better than many large-scale counterparts with drastically less com-putational requirements.

关键词： Plant disease classification Smart monitoring Deep learning Residual connections Inception Dense residual connections

Applicability of denoising-based artificial intelligence to forecast the environmental externalities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第3期15卷 469-483页

作者： Dongsheng Cai Ghazala Aziz Suleman Sarwar majid Ibrahim Alsaggaf Avik Sinha The College of Nuclear Technology and Automation Engineering Chengdu University of TechnologySichuan Province 610059China Department of Business Administration College of Administrative and Financial SciencesSaudi Electronic UniversityJeddahSaudi Arabia Department of Finance and Economics College of BusinessUniversity of JeddahJeddahSaudi Arabia Management Development Institute Gurgaon India

The current study attempts to compare the hybrid artificial intelligence models to forecast the environmental externalities in Saudi *** have used the denoising based artificial intelligence models to construct hybrid *** comparing the denoising techniques,the CSD-based denoising has ***,we have used the CSD-based hybrid ***-ANN and CSD-RNN are used for denoising-based artificial intelligence models,whereas CSD-ARIMA is used for denoising-based traditional *** these models are used to check and compare their performance in terms of level and direction of prediction for PM_(10).The results show that the CSD-based ANN model has a higher predictability for PM_(10) levels in Saudi Arabia due to low error values and higher Dstat *** comparing original and forecasted data,the superiority of CSD-ANN is evident in predicting the PM_(10) in Saudi ***,this hybrid model can predict the environmental externalities for non-linear and highly noised ***,the findings can be useful in achieving the sustainable development goal.

关键词： Hybrid artificial intelligence Forecasting Saudi Arabia Environment PM_(10)

Energy evolution and structural health monitoring of coal under different failure modes:An experimental 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

International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 917-928页

作者： Yarong Xue Xueqiu He Dazhao Song Zhenlei Li majid Khan Taoping Zhong Fei Yang School of Civil and Resources Engineering University of Science and Technology BeijingBeijing 100083China Zhong-an Academy of Safety Engineering Beijing 100083China

Structural instability in underground engineering,especially in coal-rock structures,poses significant safety ***,the development of an accurate monitoring method for the health of coal-rock bodies is *** focus of this work is on understanding energy evolution patterns in coal-rock bodies under complex conditions by using shear,splitting,and uniaxial compression *** examine the changes in energy parameters during various loading stages and the effects of various failure modes,resulting in an innovative energy dissipation-based health evaluation technique for *** results show that coal bodies go through transitions between strain hardening and softening mechanisms during loading,indicated by fluctuations in elastic energy and dissipation energy *** tensile failure,the energy profile of coal shows a pattern of “high dissipation and low accumulation” before peak *** the other hand,shear failure is described by “high accumulation and low dissipation” in energy *** failure modes correlate with an accelerated increase in the dissipation energy before destabilization,and a significant positive correlation is present between the energy dissipation rate and the stress state of the coal samples.A novel mathematical and statistical approach is developed,establishing a dissipation energy anomaly index,W,which categorizes the structural health of coal into different danger *** method provides a quantitative standard for early warning systems and is adaptable for monitoring structural health in complex underground engineering environments,contributing to the development of structural health monitoring technology.

关键词： energy dissipation structural health monitoring early warning coal-rock mechanics failure mode

Surface and structure engineering of MXenes for rechargeable batteries beyond lithium

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

Journal of Materiomics 2024年第1期10卷 253-268页

作者： Zefu Huang majid Farahmandjou Frederick Marlton Xin Guo Hong Gao Bing Sun Guoxiu Wang Centre for Clean Energy Technology School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNSW2007Australia Joint International Laboratory on Environmental and Energy Frontier Materials School of Environmental and Chemical Engineering Shanghai UniversityShanghai200444China

With the rapid growth in renewable energy,researchers worldwide are trying to expand energy storage *** development of beyond-lithium battery technologies has accelerated in recent years,amid concerns regarding the sustainability of battery ***,the absence of suitable high-performance materials has hampered the development of the next-generation battery ***,a family of 2D transition metal carbides and/or nitrides,have drawn significant attention recently for electrochemical energy storage,owing to their unique physical and chemical *** extraordinary electronic conductivity,compositional diversity,expandable crystal structure,superior hydrophilicity,and rich surface chemistries make MXenes promising materials for electrode and other components in rechargeable *** report especially focuses on the recent MXene applications as novel electrode materials and functional separator modifiers in rechargeable batteries beyond *** particular,we highlight the recent advances of surface and structure engineering strategies for improving the electrochemical performance of the MXene-based materials,including surface termination modifications,heteroatom doping strategies,surface coating,interlayer space changes,nanostructure engineering,and heterostructures and secondary materials ***,perspectives for building future sustainable rechargeable batteries with MXenes and MXene-based composite materials are presented based upon material design and a fundamental understanding of the reaction mechanisms.

关键词： MXenes Energy storage materials 2D materials Surface engineering Structure engineering

Design parameter optimization method for a prestressed steel structure driven by multi-factor coupling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第7期18卷 1066-1083页

作者： Guo-Liang SHI Zhan-Sheng LIU De-Chun LU Qing-Wen ZHANG majid DEZHKAM Ze-Qiang WANG Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China The Key Laboratory of Urban Security and Disaster Engineering of the Ministry of Education Beijing University of TechnologyBeijing 100124China Beijing Building Construction Research Institute Co. Ltd.Beijing 100039China

To achieve efficient structural design,it is crucial to reduce the cost of materials while ensuring structural *** study proposes an optimization method for design parameters(DPs)in a prestressed steel structure driven by multi-factor *** accomplish this,a numerical proxy model of prestressed steel structures is established with integration of DPs and mechanical parameters(MPs).A data association-parameter analysis-optimization selection system is established.A correlation between DPs and MPs is established using a back propagation(BP)neural *** correlation provides samples for parameter analysis and optimization *** are used to characterize the safety of the *** on the safety grade analysis,the key DPs that affect the mechanical properties of the structure are obtained.A mapping function is created to match the MPs and the key *** optimal structural DPs are obtained by setting structural materials as the optimization objective and safety energy as the constraint *** theoretical model is applied to an 80-m-span gymnasium and verified with a scale test physical *** MPs obtained using the proposed method are in good agreement with the experimental *** with the traditional design method,the design cycle can be shortened by more than 90%.Driven by the optimal selection method,a saving of more than 20% can be achieved through reduction of structural material ***,the cross-sectional dimensions of radial cables have a substantial influence on vertical *** initial tension and cross-sectional size of the upper radial cable exhibit the most pronounced impact on the stress distribution in that *** initial tension and cross-sectional size of the lower radial cable hold the greatest sway over the stress distribution in that cable.

关键词： structure design association relationship performance analysis optimum selection experimental verification