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Moiré superlattices arising from growth induced by screw dislocations in layered materials

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Chinese Physics B 2024年第7期33卷 72-77页

作者：田伏钰 muhammad faizan 贺欣孙远慧张立军 State Key Laboratory of Integrated Optoelectronics Key Laboratory of Automobile Materials of MOE and College of Materials Science and Engineering Jilin UniversityChangchun 130012China Suzhou Laboratory Suzhou 215123China

Moiré superlattices(MSLs) are modulated structures produced from homogeneous or heterogeneous two-dimensional layers stacked with a twist angle and/or lattice mismatch. Enriching the methods for fabricating MSL and realizing the unique emergent properties are key challenges in its investigation. Here we recommend that the spiral dislocation driven growth is another optional method for the preparation of high quality MSL samples. The spiral structure stabilizes the constant out-of-plane lattice distance, causing the variations in electronic and optical properties. Taking SnS_(2) MSL as an example, we find prominent properties including large band gap reduction(~ 0.4 e V) and enhanced optical activity. Firstprinciples calculations reveal that these unusual properties can be ascribed to the locally enhanced interlayer interaction associated with the Moiré potential modulation. We believe that the spiral dislocation driven growth would be a powerful method to expand the MSL family and broaden their scope of application.

关键词： Moirésuperlattices interlayer interaction spiral dislocation layered materials

空位有序双钙钛矿A2BX6的弹性和热电性质的第一性原理研究

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物理化学学报 2024年第1期40卷 46-47页

作者： muhammad faizan 赵国琪张天旭王啸宇贺欣张立军吉林大学材料科学与工程学院长春130012

卤化物钙钛矿在热电应用中表现出了巨大的潜力。准确了解卤化物钙钛矿的热电传输性质对于进一步提高热电设备的应用效率至关重要。本研究采用了Perdew-Burke-Ernzerhof(PBE)和修正的Becke Johnson(mBJ)交换关联泛函探究了卤化物双钙钛矿... 详细信息

卤化物钙钛矿在热电应用中表现出了巨大的潜力。准确了解卤化物钙钛矿的热电传输性质对于进一步提高热电设备的应用效率至关重要。本研究采用了Perdew-Burke-Ernzerhof(PBE)和修正的Becke Johnson(mBJ)交换关联泛函探究了卤化物双钙钛矿Rb_(2)SnI6、Rb_(2)PdI6和Cs_(2)PtI6的弹性和热电性质。通过对这些材料的力学稳定性、有效质量、塞贝克系数、功率因子和热电品质因数的研究,我们发现,这三种化合物都是力学稳定的,并且具有可塑性。这些化合物是窄带隙半导体,具有简并的带边结构,结合低的载流子有效质量使得它们具有热电应用潜力。Cs_(2)PtI6在空穴掺杂在500 K温度下可以达到0.76 mV·K^(−1)的高塞贝克系数。由于高塞贝克系数和最大功率因子,Rb_(2)SnI6、Rb_(2)PdI6和Cs_(2)PtI6在p型掺杂下具有高的热电品质因数,分别为0.91、0.96和0.98。总体而言,我们的研究为卤化物钙钛矿的热电性能提供了新的见解,为这些化合物的实验合成提供了有价值的参考。

关键词：电子结构有效质量 Seebeck系数热电品质因数卤化物双钙钛矿

Rare earth metal based DES assisted the VPO synthesis for n-butane selective oxidation toward maleic anhydride

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Green Energy & Environment 2023年第6期8卷 1737-1752页

作者： muhammad faizan Yingwei Li Xingsheng Wang Piao Song Ruirui Zhang Ruixia Liu Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemInstitute of Process Engineering Chinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China Zhengzhou Institute of Emerging Industrial Technology Zhengzhou450000China

Deep eutectic solvents(DESs) are now considered a new class of ionic liquid analogs that have been generously used in various ***, vanadium phosphorus oxide(VPO) catalysts are synthesized in combination with a deep eutectic solvent containing rare earth metal(rE-DES), and their catalytic performance in n-butane selective oxidation to produce maleic anhydride(MA) is evaluated. The rE-DES is produced from the interaction of choline chloride(ChCl) and rare earth metal salts(Cerium, Europium, Lanthanum, and Samarium metal salt)(ChCl:rE = 1:0.5–1:3) under mild conditions. It was found that DESs served as structural modifiers and electronic promoters during VPO synthesis. It regulated the chemical state of the catalyst surface, such as the vanadium valence state, acid-base properties, and ratios of V^(4+)/V^(5+),Lat–O/Sur–O and P/V. Various characterization techniques, such as FT-IR, DSC, XRD, SEM, EDS, TEM, Raman, TGA, NH3-TPD, and XPS,were used to examine its physical and chemical characteristics. These characteristics were correlated with the catalytic performance. The VPO catalyst modified by rE-DES showed a significant enhancement of n-butane conversion and MA selectivity while suppressing the selectivity of CO and CO_(2)as well as the CO/CO_(2)ratio compared to the unpromoted VPO catalyst. Especially for Ce-DES-VPO, it increased the n-butane conversion and MA mass yield up to approximately 11% and 10%, respectively. In addition, we evaluated the catalytic performance under different activation atmospheres.

关键词： earth anhydride vanadium

Progress of vanadium phosphorous oxide catalyst for n-butane selective oxidation

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Chinese Journal of Chemical Engineering 2022年第3期35卷 297-315页

作者： muhammad faizan Yingwei Li Ruirui Zhang Xingsheng Wang Piao Song Ruixia Liu Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex SystemInstitute of Process Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The utilization of lighter alkanes into useful chemical products is essential for modern chemistry and reducing the CO_(2)***,n-butane has gained special attention across the globe due to the abundant production of maleic anhydride(MA).Vanadium phosphorous oxide(VPO)is the most effective catalyst for selective oxidation of n-butane to MA so ***,the VPO complex exists in more or less fifteen different structures,each one having distinct phase composition and exclusive surface morphology and physiochemical properties such as valence state,lattice oxygen,acidity etc.,which relies on precursor preparation method and the activation conditions of *** catalytic performance of VPO catalyst is improved by adding different promoters or co-catalyst such as various metals dopants,or either introducing template or structural-directing ***,new preparation strategies such as electrospinning,ball milling,hydrothermal,barothermal,ultrasound,microwave irradiation,calcination,sol-gel method and solvothermal synthesis are also employed for introducing improvement in catalytic *** in above-mentioned different aspects will be ascribed in current review in addition to summarizing overall catalysis activity and final *** analyze the performance of the catalytic precursor,the reaction mechanism and reaction kinetics both are discussed in this review to help clarify the key issues such as strong exothermic reaction,phosphorus supplement,water supplement,deactivation,and air/n-butane pretreatment *** to the various industrial applications of VPO.

关键词： N-butane selective oxidation Oxidation of light alkanes Vanadium phosphorus oxide(VPO) Maleic anhydride

Exploration of B-site alloying in partially reducing Pb toxicity and regulating thermodynamic stability and electronic properties of halide perovskites

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Science China(Physics,Mechanics & Astronomy) 2023年第3期66卷 130-138页

作者： Xinjiang Wang muhammad faizan Kun Zhou Hongshuai Zou Qiaoling Xu Yuhao Fu Lijun Zhang State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China State Key Laboratory of Integrated Optoelectronics Key Laboratory of Automobile Materials of MOECollege of Materials Science and EngineeringJilin UniversityChangchun 130012China College of Physics and Electronic Engineering Center for Computational SciencesSichuan Normal UniversityChengdu 610068China International Center of Computational Method and Software Jilin UniversityChangchun 130012China

Alloying strategies provide a high degree of freedom for reducing lead toxicity,improving thermodynamic stability, tuning the optoelectronic properties of ABX3 halide perovskites by varying the alloying element species and their *** the key role of B-site cations in contributing band edge states and modulating structure factors in halide perovskites,the partial replacement of Pb2+with different B-site metal ions has been *** several experimental attempts have been made to date,the effect of B-site alloying on the stability and electronic properties of halide perovskites has not been fully ***,we take cubic CsPbBr3 perovskite as the prototype material and systematically explore the effects of B-site alloying on Pb-containing *** to the presence or absence of the corresponding perovskite phase,the ten alloying elements investigated are classified into three types(i.e.,Type Ⅰ:Sn Ge,Ca,Sr;Type Ⅱ:Cd,Mg,Mn;Type Ⅲ:Ba,Zn,Cu).Based on the first-principles calculations,we obtain the following ***,these B-site alloys will exist as disordered solid solutions rather than ordered structures at room temperature throughout the composition ***,the alloying of Sn and Ge enhances the thermodynamic stability of the cubic perovskite host,whereas the alloying of the other elements has no remarkable effect on the thermodynamic stability of the cubic perovskite ***,the underlying physical mechanism for bandgap tuning can be attributed to the atomic orbital energy mismatch or quantum confinement ***,the alloying of different elements demonstrates the diversity in the regulation of crystal structure and electronic properties,indicating potential applications in photovoltaic s and self-trapped exciton-based light-emitting *** work provides theoretical guidance for using alloying strategies to reduce lead toxicity,enhance stability,and optimize the electronic properties of halide perovsk

关键词： lead-based halide perovskites alloying thermodynamic stability first-principles calculations optoelectronic applications

An enhanced scheme for mutual authentication for healthcare services

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Digital Communications and Networks 2022年第2期8卷 150-161页

作者： Salman Shamshad muhammad faizan Ayub Khalid Mahmood Saru Kumari Shehzad Ashraf Chaudhry Chien-Ming Chen Department of Computer Science COMSATS University IslamabadSahiwal Campus57000Pakistan Department of Mathematics Ch.Charan Singh UniversityMeerutUttar Pradesh250004India Department of Computer Engineering Faculty of Engineering and ArchitectureIstanbul Gelisim UniversityIstanbulTurkey College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao266590China Riphah School of Computing&Innovation(RSCI) Riphah International UniversityLahore CampusLahore 55150Pakistan Department of Mathematics University of Padua35131 PaduaItaly

With the advent of state-of-art technologies,the Telecare Medicine Information System(TMIS)now offers fast and convenient healthcare services to patients at their ***,this architecture engenders new risks and challenges to patients'and the server's confidentiality,integrity and *** order to avoid any resource abuse and malicious attack,employing an authentication scheme is widely considered as the most effective approach for the TMIS to verify the legitimacy of patients and the ***,several authentication protocols have been proposed to this *** recently,Chaudhry et *** that there are vulnerabilities of impersonation attacks in Islam et al.'s ***,they introduced an improved protocol to mitigate those security ***,Qiu et *** that these schemes are vulnerable to the man-in-the-middle,impersonation and offline password guessing ***,they introduced an improved scheme based on the fuzzy verifier techniques,which overcome all the security flaws of Chaudhry et al.'s ***,there are still some security flaws in Qiu et al.'s *** this article,we prove that Qiu et al.'s protocol has an incorrect notion of perfect user anonymity and is vulnerable to user impersonation ***,we introduce an improved protocol for authentication,which reduces all the security flaws of Qiu et al.'s *** also make a comparison of our protocol with related protocols,which shows that our introduced protocol is more secure and efficient than previous protocols.

关键词： Authentication protocol Security protocol Anonymous protocol Impersonation attack TMIS

An Innovative Approach Utilizing Binary-View Transformer for Speech Recognition Task

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Computers, Materials & Continua 2022年第9期72卷 5547-5562页

作者： muhammad Babar Kamal Arfat Ahmad Khan faizan Ahmed Khan Malik muhammad Ali Shahid Chitapong Wechtaisong muhammad Daud Kamal muhammad Junaid Ali Peerapong Uthansakul COMSATS University Islamabad Islamabad Campus45550Pakistan Suranaree University of Technology Nakhon Ratchasima30000Thailand COMSATS University Islamabad Lahore Campus54000Pakistan COMSATS University Islamabad Vehari Campus61100Pakistan National University of Sciences&Technology Islamabad45550Pakistan Virtual University of Pakistan Islamabad Campus45550Pakistan

The deep learning advancements have greatly improved the performance of speech recognition systems,and most recent systems are based on the Recurrent Neural Network(RNN).Overall,the RNN works fine with the small sequence data,but suffers from the gradient vanishing problem in case of large *** transformer networks have neutralized this issue and have shown state-of-the-art results on sequential or speech-related ***,in speech recognition,the input audio is converted into an image using Mel-spectrogram to illustrate frequencies and *** image is classified by the machine learning mechanism to generate a classification ***,the audio frequency in the image has low resolution and causing inaccurate *** paper presents a novel end-to-end binary view transformer-based architecture for speech recognition to cope with the frequency resolution ***,the input audio signal is transformed into a 2D image using ***,the modified universal transformers utilize the multi-head attention to derive contextual information and derive different speech-related ***,a feedforward neural network is also deployed for *** proposed system has generated robust results on Google’s speech command dataset with an accuracy of 95.16%and with minimal *** binary-view transformer eradicates the eventuality of the over-fitting problem by deploying a multiview mechanism to diversify the input data,and multi-head attention captures multiple contexts from the data’s feature map.

关键词： Convolution neural network multi-head attention multi-view RNN self-attention speech recognition transformer

Brain Tumor Segmentation using Multi-View Attention based Ensemble Network

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Computers, Materials & Continua 2022年第9期72卷 5793-5806页

作者： Noreen Mushtaq Arfat Ahmad Khan faizan Ahmed Khan muhammad Junaid Ali Malik muhammad Ali Shahid Chitapong Wechtaisong Peerapong Uthansakul COMSATS University Islamabad Islamabad Campus45550Pakistan Suranaree University of Technology Nakhon Ratchasima30000Thailand COMSATS University Islamabad Lahore Campus54000Pakistan Virtual University of Pakistan Islamabad Campus45550Pakistan COMSATS University Islamabad Vehari Campus61100Pakistan

Astrocytoma IV or glioblastoma is one of the fatal and dangerous types of brain *** detection of brain tumor increases the survival rate and helps in reducing the fatality *** imaging modalities have been used for diagnosing by expert radiologists,and Medical Resonance Image(MRI)is considered a better option for detecting brain tumors as MRI is a non-invasive technique and provides better visualization of the brain *** of the challenging issues is to identify the tumorous region from the MRI scans *** segmentation is performed by medical experts,which is a time-consuming task and got chances of *** overcome this issue,automatic segmentation is performed for quick and accurate *** proposed approach is to capture inter-slice information and reduce the *** learning-based brain tumor segmentation techniques proved best among available segmentation ***,deep learning may miss some preliminary info while using MRI images during *** MRI volumes are volumetric,3D U-Net-based models are used but *** of multiple 2D U-Net predictions in axial,sagittal,and coronal views help to capture inter-slice *** approach may reduce the system ***,the Conditional Random Fields(CRF)reduce the predictions’false positives and improve the segmentation *** model is applied to Brain Tumor Segmentation(BraTS)2019 dataset,and cross-validation is performed to check the accuracy of *** proposed approach achieves Dice Similarity Score(DSC)of 0.77 on Enhancing Tumor(ET),0.90 on Whole Tumor(WT),and 0.84 on Tumor Core(TC)with reduced Hausdorff Distance(HD)of 3.05 on ET,5.12 on WT and 3.89 on TC.

关键词： Brain tumor deep learning detection conditional random field segmentation

Smart MobiNet:A Deep Learning Approach for Accurate Skin Cancer Diagnosis

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Computers, Materials & Continua 2023年第12期77卷 3533-3549页

作者： muhammad Suleman faizan Ullah Ghadah Aldehim Dilawar Shah Mohammad Abrar Asma Irshad Sarra Ayouni Department of Computer Science Bacha Khan UniversityCharsaddaPakistan Department of Information Systems College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Faculty of Computer Studies Arab Open UniversityMuscatOman School of Biochemistry and Biotechnology University of the PunjabLahorePakistan

The early detection of skin cancer,particularly melanoma,presents a substantial risk to human *** study aims to examine the necessity of implementing efficient early detection systems through the utilization of deep learning ***,the existing methods exhibit certain constraints in terms of accessibility,diagnostic precision,data availability,and *** address these obstacles,we put out a lightweight model known as Smart MobiNet,which is derived from MobileNet and incorporates additional distinctive *** model utilizes a multi-scale feature extraction methodology by using various convolutional *** ISIC 2019 dataset,sourced from the International Skin Imaging Collaboration,is employed in this *** data augmentation approaches are implemented to address the issue of model *** this study,we conduct experiments to evaluate and compare the performance of three different models,namely CNN,MobileNet,and Smart MobiNet,in the task of skin cancer *** findings of our study indicate that the proposed model outperforms other architectures,achieving an accuracy of ***,the model exhibits balanced precision,sensitivity,and F1 scores,all measuring at *** model serves as a vital instrument that assists clinicians efficiently and precisely detecting skin cancer.

关键词： Deep learning Smart MobiNet machine learning skin lesion melanoma skin cancer classification