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Significantly enhanced superconductivity in monolayer FeSe films on SrTiO3（001） via metallic δ-doping

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National Science Review 2024年第3期11卷 119-127页

作者： Xiaotong Jiao Wenfeng Dong Mingxia Shi Heng Wang Cui Ding Zhongxu Wei Guanming Gong Yanan Li Yuanzhao Li Binjie Zuo Jian Wang Ding Zhang Minghu Pan Lili Wang Qi-Kun Xue State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University School of Physics&Information Technology Shaanxi Normal University Beijing Academy of Quantum Information Sciences Department of Physics Southern University of Science and Technology International Center for Quantum Materials School of Physics Peking University Department of Physics The Pennsylvania State University Collaborative Innovation Center of Quantum Matter Hefei National Laboratory

Superconductivity transition temperature（Tc） marks the inception of a macroscopic quantum phase-coherent paired state in fermionic systems. For 2D superconductivity, the paired electrons condense into a coherent superfluid state at Tc, which is usually lower than the pairing temperature, between which intrinsic physics including Berezinskii–Kosterlitz–Thouless transition and pseudogap state are hotly debated. In the case of monolayer FeSe superconducting films on SrTiO3（001）, although the pairing temperature（Tp） is revealed to be 65–83 K by using spectroscopy characterization, the measured zero-resistance temperature（Tc0） is limited to 20 K. Here, we report significantly enhanced superconductivity in monolayer FeSe films by δ-doping of Eu or Al on SrTiO3（001） surface, in which Tc0is enhanced by 12 K with a narrowed transition width ΔTc～8 K, compared with non-doped samples. Using scanning tunneling microscopy/spectroscopy measurements, we demonstrate lowered work function of the δ-doped SrTiO3（001） surface and enlarged superconducting gaps in the monolayer FeSe with improved morphology/electronic homogeneity. Our work provides a practical route to enhance 2D superconductivity by using interface engineering.

关键词： monolayer FeSe interface superconductivity δ-doping zero-resistance temperature superconductivity transition temperature

Cost-Efficient Medium Frequency Propagation Research with Software Defined Radio

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World Journal of Engineering and Technology 2024年第1期12卷 158-169页

作者： Casey M. Hess Sohail Anwar Division of Business Engineering and Information Sciences and Technology Department of Electromechanical Engineering Technology Pennsylvania State University Altoona Campus Altoona Pennsylvania USA Division of Business Engineering and Information Sciences and Technology Department of Engineering Pennsylvania State University Altoona Campus Altoona Pennsylvania USA

Medium Frequency radio holds significance in modern society as it supports broadcasting and individual communications in the public, government, and military sectors. Enhancing the availability and quality of these communications is only possible by enhancing the understanding of medium frequency propagation. While traditional methods of radio wave propagation research can have a high material demand and cost, software defined radio presents itself as a versatile and low-cost platform for medium frequency signal reception and data acquisition. This paper details a research effort that utilizes software defined radio to help characterize medium frequency signal strength in relation to ionospheric and solar weather propagation determinants. Signal strength data from seven medium frequency stations of unique transmission locations and varying transmission powers were retrieved in 24-hour segments via a receiving loop antenna, Airspy HF+ Discovery software defined radio, and SDR Sharp software interface network. Retrieved data sets were visualized and analyzed in MATLAB for the identification of signal strength trends, which were subsequently compared to historical ionospheric and space weather indices in pursuit of a quantifiable correlation between such indices and medium frequency signal strengths. The results of the investigation prove that software defined radio, when used in conjunction with a receiving antenna and data analysis program, provides a versatile mechanism for cost-efficient propagation research.

关键词： Ionosphere Space Weather Airspy SDR SDR Sharp MATLAB Analysis

Enhancing Mobile Security through Comprehensive Penetration Testing

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Journal of Information Security 2024年第2期15卷 63-86页

作者： Maryam Roshanaei Department of IST Pennsylvania State University Abington USA

In today’s era, where mobile devices have become an integral part of our daily lives, ensuring the security of mobile applications has become increasingly crucial. Mobile penetration testing, a specialized subfield within the realm of cybersecurity, plays a vital role in safeguarding mobile ecosystems against the ever-evolving landscape of threats. The ubiquity of mobile devices has made them a prime target for cybercriminals, and the data and functionality accessed through mobile applications make them valuable assets to protect. Mobile penetration testing is designed to identify vulnerabilities, weaknesses, and potential exploits within mobile applications and the devices themselves. Unlike traditional penetration testing, which often focuses on network and server security, mobile penetration testing zeroes in on the unique challenges posed by mobile platforms. Mobile penetration testing, a specialized field within cybersecurity, is an essential tool in the Cybersecurity specialists’ toolkit to protect mobile ecosystems from emerging threats. This article introduces mobile penetration testing, emphasizing its significance, including comprehensive learning labs for Android and iOS platforms, and highlighting how it distinctly differs from traditional penetration testing methodologies.

关键词： Mobile Penetration Testing Cybersecurity Mobile Security Vulnerability Assessment

Kaiser criterion in factor models

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Acta Mathematica Sinica,English Series 2024年

作者： Changhu WANG Jianhua GUO Yanyuan MA Shurong ZHENG School of Mathematical Sciences Peking University KLAS and School of Mathematics and Statistics Northeast Normal University School of Mathematics and Statistics Beijing Technology and Business University Department of Statistics Pennsylvania State University University Park

Despite of the wide use of the factor models, the issue of determining the number of factors has not been resolved in the statistics literature. An ad hoc approach is to set the number of factors to be the number of eigenvalues of the data correlation matrix that are larger than one, and subsequent statistical analysis proceeds assuming the resulting factor number is correct. In this work, we study the relation between the number of such eigenvalues and the number of factors, and provide the if and only if conditions under which the two numbers are equal. We show that the equality only relies on the properties of the loading matrix of the factor model. Guided by the newly discovered condition,we further reveal how the model error affects the estimation of the number of factors.

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Harvesting Technologies and Costs for Switchgrass Production

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Advances in Bioscience and Biotechnology 2024年第2期15卷 112-128页

作者： Hana Toth Jude Liu Department of Agricultural and Biological Engineering The Pennsylvania State University University Park USA

As today’s society searches for renewable energy sources that could be an alternative to fossil fuels, biomass and biofuels provide a promising solution. Switchgrass is one of feedstocks that can be utilized as a renewable energy source. When farming, one of the most important considerations is efficiency. This consists of several factors, including time, fuel use, economic and power efficiencies of equipment. Inefficient field operations could increase harvesting costs and in turn could cause hesitation when a farmer decides to participate in biomass production. This literature review will cover the main elements of biomass and biomass handling relating to determining harvesting efficiency and biomass quality for switchgrass round bales. Specifically, the following sections include past research activities relating to biomass harvesting, biomass bale quality during outdoor storage, logistics models, and data collection methods during biomass harvesting. The objective of this review is to examine status and needs for switchgrass round bale harvesting operations and the expenses that come with it.

关键词： Biomass Baling Energy Crop Logistics

Childhood sleep:assessments,risk factors,and potential mechanisms

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World Journal of Pediatrics 2024年第2期20卷 105-121页

作者： Jianghong Liu Xiaopeng Ji Elizabeth Rovit Susannah Pitt Terri Lipman School of Nursing University of Pennsylvania418 Curie Blvd.Room 426Claire M.Fagin HallPhiladelphiaPA 19104USA School of Nursing College of Health SciencesUniversity of DelawareNewarkDE 19716USA Geisinger Commonwealth School of Medicine ScrantonPA 18510USA

Background Sleep problem is a highly prevalent health issue among pediatric populations across the *** this review,we aimed to identify risk factors contributing to sleep deficiency and poor sleep hygiene in *** biological,psychosocial,and environmental mechanisms as well as research gaps in the literature are also *** sources A comprehensive search for relevant English language full-text,peer-reviewed publications was performed focusing on pediatric sleep studies from prenatal to childhood and adolescence in a variety of indexes in PubMed,SCOPUS,and Psych *** relevant data based and systematic reviews are *** This paper summarizes many risk factors for childhood sleep problems,including biological(e.g.,genetics,gender,age and puberty,prenatal factors,postnatal factors);nutritional(e.g.,macronutrients,micronutrients,omega-3 fatty acids,obesity);environmental(e.g.,heavy metals,noise,light,air pollution);interpersonal(e.g.,family,exposure to violence,screen media use,physical injury);and community/socioeconomic variables(e.g.,racial/ethnicity and cultural factors,neighborhood conditions and socioeconomic status,school factors,public health disasters/emergencies),to better understand the development of sleep problems in *** Poor childhood sleep is a multifactorial issue affected by a wide range of prenatal and early-life biological,environmental,and psychosocial risk factors and contributors.A better understanding of these risk factors and their mechanisms is an important first step to develop future research and prevention programs focusing on pediatric sleep problems.

关键词： Child sleep Pediatrics Risk factor Mechanisms

Effect of non-uniform swelling on coal multiphysics during gas injection: The triangle approach

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1362-1372页

作者： Yifan Huang Jishan Liu Yaoyao Zhao Derek Elsworth Yee-Kwong Leong Department of Chemical Engineering School of EngineeringThe University of Western Australia35 Stirling HighwayWA 6009Australia State Key Laboratory of Coal Resources & Safe Mining China University of Mining& TechnologyBeijing100803China Department of Energy and Mineral Engineering G3 Centre and Energy InstituteThe Pennsylvania State UniversityUniversity ParkPA16802USA

In current dual porosity/permeability models,there exists a fundamental assumption that the adsorption-induced swelling is distributed uniformly within the representative elementary volume (REV),irrespective of its internal structures and transient ***,both internal structures and transient processes can lead to the non-uniform *** this study,we hypothesize that the non-uniform swelling is responsible for why coal permeability in experimental measurements is not only controlled by the effective stress but also is affected by the adsorption-induced *** propose a concept of the swelling triangle composed of swelling paths to characterize the evolution of the non-uniform swelling and serve as a core link in coupled multiphysics.A swelling path is determined by a dimensionless volumetric ratio and a dimensionless swelling *** swelling paths have the same start and end point,and each swelling path represents a unique swelling *** swelling path as the diagonal of the triangle represents the case of the uniform swelling while that as the two perpendicular boundaries represents the case of the localized *** paths of all intermediate cases populate inside the *** corresponding relations between the swelling path and the response of coal multiphysics are established by a non-uniform swelling *** define this method as the triangle approach and corresponding models as swelling path-based *** proposed concept and models are verified against a long-term experimental measurement of permeability and strains under constant effective *** results demonstrate that during gas injection,coal multiphysics responses have a close dependence on the swelling path,and that in both future experiments and field predictions,this dependence must be considered.

关键词： Transient process Heterogeneity Swelling triangle Swelling path Non-uniform swelling coefficient

Enhancing Cybersecurity through AI and ML: Strategies, Challenges, and Future Directions

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Journal of Information Security 2024年第3期15卷 320-339页

作者： Maryam Roshanaei Mahir R. Khan Natalie N. Sylvester Information Sciences and Technology Department Pennsylvania State University Abington USA

The landscape of cybersecurity is rapidly evolving due to the advancement and integration of Artificial Intelligence (AI) and Machine Learning (ML). This paper explores the crucial role of AI and ML in enhancing cybersecurity defenses against increasingly sophisticated cyber threats, while also highlighting the new vulnerabilities introduced by these technologies. Through a comprehensive analysis that includes historical trends, technological evaluations, and predictive modeling, the dual-edged nature of AI and ML in cybersecurity is examined. Significant challenges such as data privacy, continuous training of AI models, manipulation risks, and ethical concerns are addressed. The paper emphasizes a balanced approach that leverages technological innovation alongside rigorous ethical standards and robust cybersecurity practices. This approach facilitates collaboration among various stakeholders to develop guidelines that ensure responsible and effective use of AI in cybersecurity, aiming to enhance system integrity and privacy without compromising security.

关键词： Artificial Intelligence Machine Learning Cybersecurity Data Privacy and Security Ethical Standards

Calcium channels caught in peripheral glia’s tug-of-war on axon regeneration in Drosophila

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Neural Regeneration Research 2025年第2期20卷 475-476页

作者： Jackson Powell Tobias Steinschaden Rose Horowitz Yuanquan Song Raymond G.Perelman Center for Cellular and Molecular Therapeutics The Children’s Hospital of PhiladelphiaPhiladelphiaPAUSA The Neuroscience Graduate Group University of PennsylvaniaPhiladelphiaPAUSA Department of Pathology and Laboratory Medicine University of PennsylvaniaPhiladelphiaPAUSA Medical university of Vienna Center for Brain ResearchDepartment of NeuroimmunologyViennaAustria

Neural damage or degeneration is at the crux of many diseases,and treatment of these diseases will require the development of therapeutics to enhance and guide neural *** intrinsic and extrinsic factors dictate a neuron’s ability to regenerate,and the combination of these factors results in the great regenerative capacity of the peripheral nervous system(PNS)and the poor regenerative capacity of the central nervous system(CNS)following *** the core of a neuron’s function is its ability to relay electrochemical signals,and a neuron’s excitability is a key factor in its ability to *** works have focused on the changes in neuronal electrophysiological properties,firing patterns,and ion flux after injury,which differentially activate signaling pathways at the core of *** role of glia in neuron regeneration has long been studied.

关键词： degeneration firing system