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Facile synthesis of samarium and cerium doped double perovskite cobaltite with enhanced dielectric response

Journal of Rare Earths 2024年第7期42卷 1317-1327,I0005页

作者： Yasir Abbas m.Kamran m.anis-ur.rehman Applied Thermal Physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

The investigation of Sm-Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm_(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are *** the specimens were synthesized by a facile synthesis technique named the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice parameters,lattice strain,unit cell volume,and bulk density were determined using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were examined using calculations based on the density functional *** and experimental values discrepancy is less than 1%.A scanning electron microscope was used for performing a microstructural *** SEm images demonstrate the homogeneous distribution of grains with a range of sizes(0.054-0.090μm).The alternating current(ac)conductivity,dielectric permittivity,and tangent loss were also studied as a function of frequency(20 Hz-3 mHz)at different temperatures(100-500℃).All synthesized samples were examined using non-linear Debye's function to determine their spreading factor and relaxation *** specimen with the lowest crystallite size(∼23 nm)exhibits a high dielectric permittivity(∼3.80×10^(6)).The conduction mechanism was examined in the studied samples with the use of Jonscher's power *** power law indicates that the BCSCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 and 0.075 compositions follow non-overlapping polaron *** studied specimen Bi_(2)Ca_(1.9)0Sm_(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm^(3))displays a high electrical conductivity(∼46.1 S/cm).These findings correspond to those published for ceramics made from calcium cobaltite using solid-state reactions(5.0-26.0 S/cm).

关键词： Bismuth calcium samarium cerium cobaltite (BCSCCO) Spreading factor Conduction mechanism Rare earths

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Fabrication and application prospects of Pr-Fe-B/Alnico nanocomposite alloys

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Journal of Rare Earths 2024年第9期42卷 1717-1723,I0003页

作者： Hui Liang Sajjad ur.rehman Ruibiao Zhang Yongqiang Deng Haihua Liu munan Yang National Rare Earth Functional materials Innovation Center College of Rare EarthsJiangxi University of Science and TechnologyGanzhou341000China Zhejiang Tiantong Electronic Information materials Research Institute Co. Ltd.Haining314400China

The potentials of rare earth-based nanocomposite alloys have never been realized due to strict microstructural *** to the easy demagnetization it is challenging to increase the soft magnetic phase *** avoid the easy demagnetization,Pr-Fe-B/Alnico magnets were fabricated and reported in this *** content of the Alnico phase is increased from 0 to 25 wt%,while the content of Pr element is reduced to below the sub-stoichiometry of the 2:14:1 main *** maximum magnetic energy product,which is the figure-of-merit for permanent magnets,is increased from 122 kJ/m^(3) for the standard alloy to 146 kJ/m^(3) for the alloy with 15 wt% Alnico which shows a significant improvement considering the fact that the Curie point of the magnet is also increased by~66 *** special microstructure contains distinctly and heterogeneously distributed 2:14:1 and Alnico *** dimensions of neither the 2:14:1 nor the Alnico phases meet the dimensional requirements of the nanocomposite magnets,but still the smooth demagnetization curves are noted for the *** behavior of effective anisotropy,the performance of the magnets in applied magnetic field and the magnetic interactions among the various constituent grains were quantitatively studied by reversible susceptibility,irreversible susceptibility and re coil loop *** study may provide some guiding principles for the development of nanocomposite magnetic alloys with excellent magnetic properties by using much less RE elements.

关键词： Composite alloys High performance magnets magnetic properties Alnico alloys Rare earth magnets

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Simultaneously enhancing coercivity and remanence of hot-deformed Nd-Fe-B magnets by flake copper powder assisted DyF_(3) interflake addition

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Journal of Rare Earths 2024年第7期42卷 1282-1288,I0003页

作者： Yikuan Hu Jiajie Li Shengyu Sun Shuwei Zhong munan Yang Xiaoqiang Yu Sajjad ur.rehman Xi Yu Jiangxi Key Laboratory for Rare Earth magnetic materials and Devices College of Rare EarthsJiangxi University of Science and TechnologyGanzhou341000 National Rare Earth Functional materials Innovation Center Ganzhou341000China Ganzhou Fortune Electronic Ltd. Ganzhou341000China

It is still a challenge to simultaneously enhance coercivity(H_(cj))and remanence(J_(r))of hot-deformed Nd-Fe-B magnet due to the coercivity-remanence trade-off ***,we achieved this balance between H_(cj)and Jr by flake Cu powder assisted DyF_(3)interflake *** Hcj increases from 1218 to 1496 kA/m and Jr increases from 1.32 to 1.34 T compared with the original *** show that the width of coarse grain layers reduces because of the introduction of flake Cu,which increases the contact areas of the adjacent grains at ribbon interfaces and suppresses the excessive growth of *** stronger degree of texture and higher density compared with the original magnet should take the responsibility for the increase of J_(r).Additionally,the aggregation regions of rare earth rich(RE-rich)phase reduce and the betterment of the microstructure is another reason for the enhancement of Jr in the flake Cu aided DyF_(3)hot-deformed *** strategy of using flake powder additives provides a promising method for optimizing microstructure and enhancing magnetic properties of hot-deformed Nd-Fe-B magnets.

关键词： Rare earths Nd-Fe-B Hot-deformed magnet Flake powder Interflake addition Remanence

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The Impact of Domain Name Server(DNS)over Hypertext Transfer Protocol Secure(HTTPS)on Cyber Security:Limitations,Challenges,and Detection Techniques

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Computers, materials & Continua 2024年第9期80卷 4513-4542页

作者： muhammad Dawood Shanshan Tu Chuangbai Xiao muhammad Haris Hisham Alasmary muhammad Waqas Sadaqat ur.rehman Faculty of Information Technology Beijing University of TechnologyBeijing100124China National Center of Robotics and Automation University of Engineering and TechnologyPeshawar25000Pakistan Department of Computer Science College of Computer ScienceKing Khalid UniversityAbha61421Saudi Arabia School of Computing and Engineering Sciences Faculty of Engineering and ScienceUniversity of GreenwichLondonSE109LSUnited Kingdom School of Engineering Edith Cowan UniversityPerthWA 6027Australia School of Computer Science and Engineering University of SalfordManchesterM54BRUnited Kingdom

The DNS over HTTPS(Hypertext Transfer Protocol Secure)(DoH)is a new technology that encrypts DNS traffic,enhancing the privacy and security of ***,the adoption of DoH is still facing several research challenges,such as ensuring security,compatibility,standardization,performance,privacy,and increasing user *** significantly impacts network security,including better end-user privacy and security,challenges for network security professionals,increasing usage of encrypted malware communication,and difficulty adapting DNS-based security ***,it is important to understand the impact of DoH on network security and develop newprivacy-preserving techniques to allowthe analysis of DoH traffic without compromising user *** paper provides an in-depth analysis of the effects of DoH on *** discuss various techniques for detecting DoH tunneling and identify essential research challenges that need to be addressed in future security ***,this paper highlights the need for continued research and development to ensure the effectiveness of DoH as a tool for improving privacy and security.

关键词： DNS DNS over HTTPS cybersecurity machine learning

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Artificial Intelligence Based meteorological Parameter Forecasting for Optimizing Response of Nuclear Emergency Decision Support System

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原子能科学技术 2024年第10期58卷 2068-2076页

作者： BILAL Ahmed Khan HASEEB ur.rehman QAISAR Nadeem mUHAmmAD Ahmad Naveed Qureshi JAWARIA Ahad mUHAmmAD Naveed Akhtar AmJAD Farooq mASROOR Ahmad Pakistan Institute of Engineering and Applied Sciences Islamabad 44000Pakistan

This paper presents a novel artificial intelligence (AI) based approach to predict crucial meteorological parameters such as temperature,pressure,and wind speed,typically calculated from computationally intensive weather research and forecasting (WRF) *** meteorological data is indispensable for simulating the release of radioactive effluents,especially in dispersion modeling for nuclear emergency decision support *** of meteorological conditions during nuclear emergencies using the conventional WRF model is very complex and ***,a new artificial neural network (ANN) based technique was proposed as a viable alternative for meteorological prediction.A multi-input multi-output neural network was trained using historical site-specific meteorological data to forecast the meteorological *** evaluation of this technique was conducted to test its performance in forecasting various parameters including atmospheric pressure,temperature,and wind speed components in both East-West and North-South *** performance of developed network was evaluated on an unknown dataset,and acquired results are within the acceptable range for all meteorological *** show that ANNs possess the capability to forecast meteorological parameters,such as temperature and pressure,at multiple spatial locations within a grid with high accuracy,utilizing input data from a single ***,accuracy is slightly compromised when predicting wind speed *** mean square error (RmSE) was utilized to report the accuracy of predicted results,with values of 1.453℃for temperature,77 Pa for predicted pressure,1.058 m/s for the wind speed of U-component and 0.959 m/s for the wind speed of *** conclusion,this approach offers a precise,efficient,and wellinformed method for administrative decision-making during nuclear emergencies.

关键词： prediction of meteorological parameters weather research and forecasting model artificial neural networks nuclear emergency support system

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中巴经济走廊洪扎段潜在滑坡SBAS-InSAR早期识别及发育特征分析

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遥感学报 2024年第4期28卷 885-899页

作者：苏晓军张毅孟兴民 rehman mohib ur Khalid Zainab 赵富萌岳东霞郭富赟周自强兰州大学资源环境学院兰州730000 兰州大学地质科学与矿产资源学院兰州730000 甘肃省环境地质与灾害防治技术创新中心兰州730000 兰州大学西部环境教育部重点实验室兰州730000 甘肃省地质环境监测院兰州730050 甘肃省科学院地质自然灾害防治研究所兰州730000

中巴经济走廊巴基斯坦境内洪扎河谷(Hunza Valley)段地形高差巨大、地质环境复杂,滑坡灾害多发,对河谷内村镇威胁极大,也严重制约中巴经济走廊安全建设与运行。为了加深对Hunza河谷滑坡灾害的认识,亟待进行滑坡识别编目和发育特征研究... 详细信息

中巴经济走廊巴基斯坦境内洪扎河谷(Hunza Valley)段地形高差巨大、地质环境复杂,滑坡灾害多发,对河谷内村镇威胁极大,也严重制约中巴经济走廊安全建设与运行。为了加深对Hunza河谷滑坡灾害的认识,亟待进行滑坡识别编目和发育特征研究。本研究基于升、降轨获取的87景哨兵一号(Sentinel-1)数据,利用SBAS-InSAR技术获取了洪扎河谷地表形变,计算了地表斜坡向形变速率。并综合利用光学遥感影像解译和野外实地调查验证,成功识别了洪扎河谷53处潜在滑坡,并讨论了滑坡识别效果,对Ghulmet和Humarri两个典型大型滑坡监测形变、影像解译和验证特征进行了分析。在此基础上,选取11个地形地质环境因素作为影响滑坡发育的因子,分析了滑坡分布发育特征。结果表明,升轨和降轨数据监测到研究区内斜坡向最大形变速率分别为−311 mm/a和−490 mm/a,洪扎河谷区不稳定形变阈值为−20 mm/a。大型滑坡受河流侵蚀作用,形变剧烈,次级滑坡发育。识别的潜在滑坡主要集中在河流两岸、公路上下边坡;潜在滑坡主要分布在风化堆积层以及千枚岩、板岩等变质岩区;高差200—1000 m、坡度30°—40°和坡向南、南西向为滑坡发育的优势地形条件;斜坡地表裸露、植被稀疏地段(NDVI<0.2)物源充足,滑坡较为发育。研究结果可用于巴基斯坦洪扎河谷防灾减灾工作,保障中巴经济走廊畅通运营,为具有毁路与堵江风险的滑坡重点监测和评价研究提供科学参考和数据支持。

关键词：中巴经济走廊洪扎河谷滑坡 SBAS-InSAR 地表形变早期识别发育特征

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Symmetries,optimal system,exact and soliton solutions of(3+1)-dimensional Gardner-KP equation

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Journal of Ocean Engineering and Science 2024年第2期9卷 178-190页

作者： Amjad Hussain Ashreen Anjum m.Junaid-U-rehman Ilyas Khan mariam A.Sameh Amnah S.Al-Johani Department of mathematics Quaid-I-Azam University 45320Islamabad 44000Pakistan Department of mathematics College of Science Al-ZulfiMajmaah UniversityAl-MajmaahP.O Box 66Majmaah 11952Saudi Arabia Electrical Engineering Department Faculty of Engineering and TechnologyFuture University in EgyptNew Cairo 11845Egypt mathematics Department Faculty of ScienceUniversity of TabukTabukSaudi Arabia

In this research article,the(3+1)-dimensional nonlinear Gardner-Kadomtsov-Petviashvili(Gardner-KP)equation which depicts the nonlinear modulation of periodic waves,is analyzed through the Lie group-theoretic *** the Lie invariance condition,we find the symmetry *** pro-posed model yields eight-dimensional Lie ***,an optimal system of sub-algebras is com-puted,and similarity reductions are *** considered nonlinear partial differential equation is re-duced into ordinary differential equations(ODEs)by utilizing the similarity transformation method(STm),which has the benefit of yielding a large number of accurate traveling wave *** ODEs are further solved to get closed-form solutions of the Gardner-KP equation in some cases,while in other cases,we use the new auxiliary equation method to get its soliton *** evolution profiles of the obtained solutions are examined graphically under the appropriate selection of arbitrary parameters.

关键词： Gardner-KP equation Lie symmetry analysis Optimal system New auxiliary equation method Solitary wave solutions

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Deep Insight of Design,mechanism,and Cancer Theranostic Strategy of Nanozymes

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Nano-micro Letters 2024年第2期16卷 165-217页

作者： Lu Yang Shuming Dong Shili Gai Dan Yang He Ding Lili Feng Guixin Yang Ziaur.rehman Piaoping Yang Key Laboratory of Superlight materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001People’s Republic of China Yantai Research Institute Harbin Engineering UniversityYantai 264000People’s Republic of China Key Laboratory of Green Chemical Engineering and Technology of Heilongjiang Province College of Material Science and Chemical EngineeringHarbin University of Science and TechnologyHarbin 150040People’s Republic of China Department of Chemistry Quaid-i-Azam UniversityIslamabad 45320Pakistan

Since the discovery of enzyme-like activity of Fe3O4 nanoparticles in 2007,nanozymes are becoming the promising substitutes for natural enzymes due to their advantages of high catalytic activity,low cost,mild reaction conditions,good stability,and suitable for large-scale ***,with the cross fusion of nanomedicine and nanocatalysis,nanozyme-based theranostic strategies attract great attention,since the enzymatic reactions can be triggered in the tumor microenvironment to achieve good curative effect with substrate specificity and low side ***,various nanozymes have been developed and used for tumor *** this review,more than 270 research articles are discussed systematically to present progress in the past five ***,the discovery and development of nanozymes are ***,classification and catalytic mechanism of nanozymes are ***,activity prediction and rational design of nanozymes are focused by highlighting the methods of density functional theory,machine learning,biomimetic and chemical ***,synergistic theranostic strategy of nanozymes are ***,current challenges and future prospects of nanozymes used for tumor theranostic are outlined,including selectivity,biosafety,repeatability and stability,in-depth catalytic mechanism,predicting and evaluating activities.

关键词： Nanozymes Classification Prediction and design Catalytic mechanism Tumor theranostics

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Seed Priming with Potassium Nitrate Can Enhance Salt Stress Tolerance in maize

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Phyton-International Journal of Experimental Botany 2024年第8期93卷 1819-1838页

作者： Bushra rehman Asma Zulfiqar Houneida Attia Rehana Sardar muneera A.Saleh Khalid H.Alamer Ibtisam m.Alsudays Faisal mehmood Qamar uz Zaman Institute of Botany University of the PunjabLahore54590Pakistan Department of Biology College of ScienceTaif UniversityTaif21944Saudi Arabia Department of Botany Emerson UniversityMultan60000Pakistan Biological Sciences Department Faculty of Science and ArtsKing Abdulaziz UniversityRabigh21911Saudi Arabia Department of Biology College of ScienceQassim UniversityBurydah52571Saudi Arabia Department of Chemistry Sciences The University of LahoreLahore54590Pakistan Department of Environmental Sciences The University of LahoreLahore54590Pakistan

Salinity is a major abiotic stress that hinders plant development and productivity and influences agricultural *** priming is a technique used to boost germination and seedling growth under abiotic stress.A pot experiment was conducted to evaluate the impact of seed priming with potassium nitrate(KNO_(3))at various levels(0%,0.50%,1.00%and 1.50%)under salt stress(0,75,100 mm NaCl)on two maize verities(mNH360 and 30T60)for the growth,development and metabolic attributes results revealed that in maize variety mNH360,KNO_(3)priming’s significantly enhanced growth parameters than in maize variety 30T60 under control and salt-stressed *** with KNO_(3)enhanced carotenoids and total chlorophyll in the 30T60 variety that protected the maize plants from salt ***,it was shown that priming with 1.00%KNO_(3)acts as safeguarded to protect them from oxidative damage by salt stress minimizing reactive oxygen species(ROS)formation through increased levels of malondialdehyde(mDA),catalase(CAT),peroxidase(POD),ascorbate peroxidase(APX),and total soluble *** findings of the present study confirm that the use of the KNO_(3)seed priming technique is a lowcost,environmentally friendly technique for mitigating adverse impacts of salt stress in maize crops by activating the antioxidant defense system and improving chlorophyll and osmolyte contents.

关键词： Salinity Zea mays antioxidant enzymes growth seedlings oxidative damage

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Fabrication of NiO coated SiO_2 and SiO_2 coated NiO for the removal of Pb^(2+) ions

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Chinese Chemical Letters 2014年第5期25卷 819-822页

作者： Saba Noor muhammad Waseem Umer Rashid muhammad anis-ur.rehman Wajid rehman Khalid mahmood Department of Chemistry Hazara University Department of Physics COMSATS Institute of Information Technology

We have prepared silica,SiO2coated NiO and NiO coated SiO2by sol-gel *** physicochemical properties of the desired materials were investigated by surface charge properties,scanning electron microscopy（SEm）,energy dispersive X-ray（EDX） spectroscopy,surface area measurements and X-ray diffraction（XRD） *** point of zero charge（PZC） of the solid was determined by the salt addition *** coated materials,two PZC values were noted representing the surface charge of their *** SEm image of SiO2coated NiO displays a uniform coating of silica on the surface of NiO whereas in case of NiO coated SiO2,a honeycomb like appearance was observed with highly porous *** the diffractograms of NiO,the characteristic peaks were suppressed in NiO coated silica however,no diffraction peak could be seen in SiO2coated *** adsorption technique was applied for the removal of Pb2＋ions from aqueous *** sorption trend for Pb2＋ions was observed in the order of NiO coated SiO2〉 SiO2coated NiO 〉 NiO 〉 *** trend confirms that the coated materials have more sorption capacities than their parent counterparts.

关键词： Characterization Coated materials Lead removal Sol–gel

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