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Correlation between structural phase transition and physical properties of Co2+/Gd3+ co-substituted copper ferrite

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Journal of Rare Earths 2024年第7期42卷 1344-1353页

作者： Mohsen Choupani ahmad Gholizadeh School of Physics Damghan University

The doping of the spinel ferrites with selective cations usually improves the properties of the parent ferrite.The effect of Co2+/Gd3+co-substitution on the microstructure,optical,and magnetic properties of Cu1-xCoxFe2-xGdxO4prepared by the citrate-nitrate auto-combustion synthesis was investigated.Characterization of the samples was performed with powder X-ray diffraction（XRD）,Raman and Fouriertransform infrared（FTIR） spectroscopy,field-emission scanning electron microscopy,X-ray energydispersive spectroscopy,UV-Vis spectroscopy,and a vibrating sample magnetometer.The results of XRD,Raman,and FTIR analysis show a gradual structural phase transition from a tetragonal（I41/amd）structure to a cubic（Fd 3 m） structure.The bandgap energy of the studied samples is in a range of1.57-1.75 eV with a minimum in sample x=0,06 and then increases.Magnetic investigations show that the presence of Co2+/Gd3+cations in an octahedral site of the copper ferrite structure could increase saturation magnetization and coercive field from 567.9 Oe and 23.62 emu/g to 929.4 Oe and 28.27 emu/g,respectively.

关键词： Citrate-nitrate method Magnetic properties Microstructure properties Rare earths Spinel copper ferrite Structure phase transition

Federated Learning Security and Privacy-Preserving Algorithm and Experiments Research Under Internet of Things Critical Infrastructure

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Tsinghua Science and Technology 2024年第2期29卷 400-414页

作者： Nasir ahmad Jalali Hongsong Chen Department of Computer Science University of Science and Technology Beijing(USTB)Beijing 100083China

The widespread use of the Internet of Things(IoTs)and the rapid development of artificial intelligence technologies have enabled applications to cross commercial and industrial band settings.Within such systems,all participants related to commercial and industrial systems must communicate and generate data.However,due to the small storage capacities of IoT devices,they are required to store and transfer the generated data to third-party entity called“cloud”,which creates one single point to store their data.However,as the number of participants increases,the size of generated data also increases.Therefore,such a centralized mechanism for data collection and exchange between participants is likely to face numerous challenges in terms of security,privacy,and performance.To address these challenges,Federated Learning(FL)has been proposed as a reasonable decentralizing approach,in which clients no longer need to transfer and store real data in the central server.Instead,they only share updated training models that are trained over their private datasets.At the same time,FL enables clients in distributed systems to share their machine learning models collaboratively without their training data,thus reducing data privacy and security challeges.However,slow model training and the execution of additional unnecessary communication rounds may hinder FL applications from operating properly in a distributed system.Furthermore,these unnecessary communication rounds make the system vulnerable to security and privacy issues,because irrelevant model updates are sent between clients and servers.Thus,in this work,we propose an algorithm for fully homomorphic encryption called Cheon-Kim-Kim-Song(CKKS)to encrypt model parameters for their local information privacy-preserving function.The proposed solution uses the impetus term to speed up model convergence during the model training process.Furthermore,it establishes a secure communication channel between IoT devices and the server.We also use a lightweight secure transport protocol

关键词： Federated Learning(FL) Internet of Things(IoTs) lightweight Transport Layer Security(iTLS) Cheon-Kim-Kim-Song(CKKS)

Evaluation of soil loss severity and ecological restoration approach for sustainable agriculture in the Hindu Kush, Karakoram and Himalaya region

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Journal of Mountain Science 2024年第5期21卷 1509-1521页

作者： Arshad ASHRAF Imran ahmad Climate Energy and Water Research InstituteNational Agricultural Research Centre(NARC)Islamabad 44000Pakistan

Soil erosion has resulted in removal of the topsoils containing fine soil particles and plant nutrients, causing decrease in soil fertility in the Hindu Kush, Karakoram and Himalaya(HKH) region. The existing production of cereal crop grains has been reduced to one third of the potential crop grains production owing to land degradation and poor farming practices. It is necessary to assess risk of soil loss and identify appropriate controlling measures to address issues of low agriculture productivity and water insecurity in the region. In the present study, severity of soil loss was predicted using Revised Universal Loss Equation(RUSLE) and ecological measures were identified for sustainable mountain agriculture in the HKH region of Upper Indus Basin, Pakistan. Overall 62.6% area was found to have very low risk of soil loss, i.e., 100 t/(ha·yr) in about 6.8% and 7.4% areas respectively. The mean rate of soil loss was about 41.9 t/(ha·yr) in the Hindu Kush, 31.1 t/(ha·yr) in the Himalayas, 18.8 t/(ha·yr) in the Karakoram and overall 29.7 t/(ha·yr) in the three HKH ranges. As such no considerable measures have been adopted by the communities for restoration of the degraded areas except raising fruit/farm trees and supporting limited social forestry for their livelihoods. The slopes cleared for cultivation and susceptible to erosion may be stabilized through sowing/planting of multi-purpose plant species and formation of proper bench terraces. The conservation of forest ecosystem and pastures at higher elevations would help in reducing overland water flow, risk of flash flood hazard and minimizing sediment loads in the downstream. It is essential to adopt site-specific resource conservation techniques and restore possible ecosystem health for sustainable agriculture and economic development in the region in future.

关键词： Climate change Erodibility Indus basin Land degradation Slope stabilization

维普期刊数据库

Recent advances in the diagnosis of drug-induced liver injury

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World Journal of Hepatology 2024年第2期16卷 186-192页

作者： Taqwa Ahmed Jawad ahmad Department of Medicine Icahn School of Medicine at Mount SinaiNew YorkNY 10029United States Department of Recanati-Miller Transplantation Institute Icahn School of Medicine at Mount SinaiNew YorkNY 10029United States

Drug-induced liver injury(DILI)is a major problem in the United States,commonly leading to hospital admission.Diagnosing DILI is difficult as it is a diagnosis of exclusion requiring a temporal relationship between drug exposure and liver injury and a thorough work up for other causes.In addition,DILI has a very variable clinical and histologic presentation that can mimic many different etiologies of liver disease.Objective scoring systems can assess the probability that a drug caused the liver injury but liver biopsy findings are not part of the criteria used in these systems.This review will address some of the recent updates to the scoring systems and the role of liver biopsy in the diagnosis of DILI.

关键词： Drug induced liver injury Liver biopsy Diagnosis RUCAM RECAM

Influence of Brownian Motion, Thermophoresis and Magnetic Effects on a Fluid Containing Nanoparticles Flowing over a Stretchable Cylinder

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Fluid Dynamics & Materials Processing 2024年第3期20卷 525-536页

作者： Aaqib Majeed ahmad Zeeshan Department of Mathematics The University of FaisalabadFaisalabad38000Pakistan Department of Mathematics and Statistics FBASInternational Islamic University IslamabadIslamabad44000Pakistan

The influence of Brownian motion and thermophoresis on a fluid containing nanoparticles flowing over a stretchable cylinder is examined.The classical Navier-Stokes equations are considered in a porous frame.In addition,the Lorentz force is taken into account.The controlling coupled nonlinear partial differential equations are transformed into a system of first order ordinary differential equations by means of a similarity transformation.The resulting system of equations is solved by employing a shooting approach properly implemented in MATLAB.The evolution of the boundary layer and the growing velocity is shown graphically together with the related profiles of concentration and temperature.The magnetic field has a different influence(in terms of trends)on velocity and concentration.

关键词： Mixed convection Brownian motion heat transfer porous surface velocity slip

Nrf2 as a potential target for the treatment of epilepsy

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Neural Regeneration Research 2024年第9期19卷 1865-1866页

作者： Prince Kumar Singh Tawfeeq Shekh-ahmad Institute for Drug Research School of PharmacyFaculty of MedicineThe Hebrew University of JerusalemJerusalemIsrael

Epilepsy is a prevalent chronic brain disorder that is characterized by a persistent predisposition to recurrently generate epileptic seizures and is often associated with cognitive and psychological consequences.Epilepsy affects approximately 65 million individuals,including both males and females of all ages worldwide,and poses a significant burden on patients,their families,and the health system(Vezzani et al.,2019).

关键词： epilepsy Nrf2

维普期刊数据库

A convolutional neural network to detect possible hidden data in spatial domain images

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Cybersecurity 2024年第1期7卷 37-52页

作者： Jean De La Croix Ntivuguruzwa Tohari ahmad Department of Informatics Institut Teknologi Sepuluh Nopember(ITS)Kampus ITS Keputih SukoliloSurabaya60111Indonesia African Center of Excellence in the Internet of Things College of Science and TechnologyUniversity of Rwanda3900KigaliRwanda

Hiding secret data in digital multimedia has been essential to protect the data.Nevertheless,attackers with a steganalysis technique may break them.Existing steganalysis methods have good results with conventional Machine Learning(ML)techniques;however,the introduction of Convolutional Neural Network(CNN),a deep learning paradigm,achieved better performance over the previously proposed ML-based techniques.Though the existing CNN-based approaches yield good results,they present performance issues in classification accuracy and stability in the network training phase.This research proposes a new method with a CNN architecture to improve the hidden data detection accuracy and the training phase stability in spatial domain images.The proposed method comprises three phases:pre-processing,feature extraction,and classification.Firstly,in the pre-processing phase,we use spatial rich model filters to enhance the noise within images altered by data hiding;secondly,in the feature extraction phase,we use two-dimensional depthwise separable convolutions to improve the signal-to-noise and regular convolutions to model local features;and finally,in the classification,we use multi-scale average pooling for local features aggregation and representability enhancement regardless of the input size variation,followed by three fully connected layers to form the final feature maps that we transform into class probabilities using the softmax function.The results identify an improvement in the accuracy of the considered recent scheme ranging between 4.6 and 10.2%with reduced training time up to 30.81%.

关键词： Information security Spatial domain steganalysis Deep learning Convolutional neural network Infrastructure

Applying the Protective Mn-Co-La_(2)O_(3)Coating on Crofer 22 APU Ferritic Stainless Steel Used as Solid Oxide Fuel Cell Interconnects

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 872-888页

作者： Farhad Mohsenifar Hadi Ebrahimifar ahmad Irannejad Department of Materials Engineering and Metallurgy Faculty of EngineeringShahid Bahonar University of KermanKermanIran Mechanical Engineering Department Faculty of EngineeringHigher Education Complex of Bam76615-314BamIran Department of Materials Engineering Faculty of Mechanical and Materials EngineeringGraduate University of Advanced TechnologyKerman ***Iran

This research studies the effect of Mn-Co-La_(2)O_(3) coating synthesized by the electrodeposition method on the oxidation resistance and electrical conductivity of the Crofer 22 APU stainless steel interconnect plates in solid oxide fuel cells.The test samples were characterized by a field emission scanning electron microscope(FESEM)equipped with energy dispersive spectroscopy(EDS),X-ray diffraction(XRD),and X-ray photoelectron spectroscopy(XPS).The oxidation kinetics of the coated and uncoated samples were studied by tracking their weight changes over time at 800°C,showing that the oxidation mechanism for all samples follows the parabolic law.Lower oxidation rate constant(k_(p))values of the coated sample compared with that of the uncoated one indicated a reduction in the oxidation rate of the steel substrate in the presence of the Mn-Co-La_(2)O_(3) coating.The examination of the cross-section of different samples after the isothermal oxidation for 500 h at 800°C exhibited that applying the composite coating leads to a decrease in the thickness of the chromia layer formed on the steel surface.Furthermore,under these conditions,the area-specific resistance(ASR)of the coated sample(13.11 mΩcm^(2))is significantly lower than that of the uncoated one(41.45 mΩcm^(2)).

关键词： Area specific resistance Oxidation Fuel cell Composite coating

Optimizing calcination of coal by-products for maximizing REE leaching recovery and minimizing Al,Ca,and Fe contamination

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Journal of Rare Earths 2024年第7期42卷 1354-1365页

作者： Tushar Gupta ahmad Nawab Rick Honaker MP Materials Mountain Pass Mine Department of Mining Engineering University of Kentucky

High-temperature calcination is effective in improving the leaching characteristics of rare earth elements(REEs) from conventional REE-bearing minerals by transforming them into more leachable forms.However,the recovery of contaminants such as Al,Fe,and Ca also increases significantly.The objective of the study was to maximize the REE extraction while minimizing the concentration of contaminant ions(Al,Ca,and Fe) in the leach solution.Representative density fractions of the coarse refuse from the Baker and Fire Clay seam coal refuse were pulverized to a top size of 180 μm and used as a feedstock for the study.All the samples generated from thermal treatment were leached at 1%(w/v) using 1.2 mol/L sulfuric acid at 75℃ for 2 h.Test results from a parametric program based on a Box-Behnken design were used for modeling and optimization of three operating parameters associated with the lab-scale calcination process.The parameters included temperature(400-800℃),ramp rate(2-10℃/min) and holding time(0-120 min).It was determined that the calcination temperature was the most significant parameter influencing REE recovery.The majority of the heavy rare earth elements(HREEs) were found to be present in an insoluble form in the calcination products and were marginally affected by thermal treatment.A strong correlation between light rare earth elements recovery(LREEs) and Al suggested a possible association with clays.The optimum operating conditions for high REE recovery with comparatively lower contaminant concentration for 1.6 specific gravity float and 2.2 sink fractions of Baker and Fire Clay seam material were determined to be at 776,800℃ and 407,800℃,calcining temperatures,respectively.A higher optimum temperature of 1.6 float fraction of Baker seam relative to Fire Clay seam material was due to elevated pyrite concentration in Baker seam material.Thermal treatment at 400℃ converted pyrite into a soluble intermedium iron oxide,resulting in a high Fe content in the leachate.Calcining at 776℃ converted most of the solubl

关键词： Calcination Coal refuse Optimization Rare earth elements