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Acta Mathematicae Applicatae Sinica 2024年

作者： Ling-hai ZHANG Department of Mathematics Lehigh University

We couple together existing ideas, existing results, special structure and novel ideas to accomplish the exact limits and improved decay estimates with sharp rates for all order derivatives of the global weak solutions of the Cauchy problem for an n-dimensional incompressible Navier-Stokes equations. We also use the global smooth solution of the corresponding heat equation to approximate the global weak solutions of the incompressible Navier-Stokes equations.

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Accelerated intermetallic phase amorphization in a Mg-based high-entropy alloy powder

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Journal of Magnesium and Alloys 2024年第5期12卷 1792-1798页

作者： Prince Sharma Purvam Mehulkumar Gandhi Kerri-Lee Chintersingh Mirko Schoenitz Edward L.Dreizin Sz-Chian Liou Ganesh Balasubramanian Institute for Functional Materials&Devices Lehigh UniversityBethlehemPA 18015USA Center of Materials for Advanced Energetics New Jersey Institute of TechnologyNewarkNJ 07102USA

We describe a novel mechanism for the synthesis of a stable high-entropy alloy powder from an otherwise immiscible Mg-Ti rich metallic mixture by employing high-energy mechanical *** presented methodology expedites the synthesis of amorphous alloy powder by strategically injecting entropic disorder through the inclusion of multi-principal elements in the alloy *** from first principles and materials theory corroborate the results from microscopic characterizations that reveal a transition of the amorphous phase from a precursor intermetallic *** transformation,characterized by the emergence of antisite disorder,lattice expansion,and the presence of nanograin boundaries,signifies a departure from the precursor intermetallic ***,this phase transformation is accelerated by the presence of multiple principal elements that induce severe lattice distortion and a higher configurational *** atomic size mismatch of the dissimilar elements present in the alloy produces a stable amorphous phase that resists reverting to an ordered lattice even on annealing.

关键词： High-entropy alloy High-energy milling Antisite disorder Amorphous Intermetallic

Sigmoid Micro-Perforation and Pelvic Abscess Masquerading as Hyperactive Delirium

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Case Reports in Clinical Medicine 2024年第8期13卷 315-320页

作者： Samer Alkhuja Susheer Gandotra Hirenkumar Faldu Pravinkumar Patel Olutunde Odeyemi Department of Medicine Thomas Jefferson Medical School Thomas Jefferson University Lehigh Valley Health Network-Pocono Stroudsburg PA USA

Diagnoses Background: Delirium is a common finding in elderly patients with sepsis. Early identification of the cause of delirium and treatment is important to avoid any worsening of mental or physical status. Sepsis secondary to colonic micro-perforation (CMP) in a patient with a history of diverticulosis should be high on the list of differential diagnosis. Case Report: We present a case of a patient who presented with hyperactive sepsis-associated delirium (SAD). Six days after the presentation, the patient started complaining of abdominal pain. An abdominal and pelvic computed tomography (CT) scan showed free air in the abdomen. The patient underwent surgical intervention and treatment with intravenous antibiotics. Pathological examination showed CMP connected to the patient’s history of diverticulosis. Delirium superimposed on dementia (DSD) resulted in the worsening of both the mental and physical status of our patient with the need for placement in a nursing home.

关键词： Delirium Dementia Colon Perforation Sepsis Diverticulosis

Left bundle branch pacing vs biventricular pacing in heart failure patients with left bundle branch block:A systematic review and meta-analysis

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World Journal of Cardiology 2024年第1期16卷 40-48页

作者： Farah Yasmin Abdul Moeed Rohan Kumar Ochani Hamna Raheel Malik Ali Ehtsham Awan Ayesha Liaquat Arisha Saleem Muhammad Aamir Nael Hawwa Salim Surani Department of Internal Medicine Yale University School of MedicineNew HavenCT 06511United States Department of Medicine Dow University of Health ScienceKarachi 74200SindhPakistan Department of Medicine SUNNY Upstate Medical UniversitySyracuseNY 13210United States Department of Cardiovascular Medicine Lehigh Valley Heart and Vascular InstituteAllentownPA 18105United States Department of Medicine Cleveland ClinicClevelandOH 44195United States Department of Medicine&Pharmacology Texas A&M UniversityCollege StationTX 77843United States

BACKGROUND Left bundle branch pacing(LBBP)is a novel pacing modality of cardiac resynchronization therapy(CRT)that achieves more physiologic native ventricular activation than biventricular pacing(BiVP).AIM To explore the validity of electromechanical resynchronization,clinical and echocardiographic response of *** Systematic review and Meta-analysis were conducted in accordance with the standard guidelines as mentioned in detail in the methodology *** In our analysis,the success rate of LBBP-CRT was determined to be 91.1%.LBBP CRT significantly shortened QRS duration,with significant improvement in echocardiographic parameters,including left ventricular ejection fraction,left ventricular end-diastolic diameter and left ventricular end-systolic diameter in comparison with *** A significant reduction in New York Heart Association class and B-type natriuretic peptide levels was also observed in the LBBP-CRT group vs BiVP-CRT ***,the LBBP-CRT cohort had a reduced pacing threshold at follow-up as compared to BiVP-CRT.

关键词： Left bundle branch pacing Biventricular pacing QRS duration Left ventricular ejection fraction Heart failure

Distributed Virtual Inertia Based Control of Multiple Photovoltaic Systems in Autonomous Microgrid

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IEEE/CAA Journal of Automatica Sinica 2017年第3期4卷 512-519页

作者： Won-Sang Im Cheng Wang Wenxin Liu Liming Liu Jang-Mok Kim lehigh university IEEE ABB Inc. Pusan National university

The large inertia of a traditional power system slows down system's frequency response but also allows decent time for controlling the *** an autonomous renewable microgrid usually has much smaller inertia,the control system must be very fast and accurate to fight against the small inertia and *** reduce the demanding requirements on control,this paper proposes to increase the inertia of photovoltaic(PV) system through inertia *** inertia emulation is realized by controlling the charging/discharging of the direct current(DC)-link capacitor over a certain range and adjusting the PV generation when it is feasible and/or *** well designing the inertia,the DC-link capacitor parameters and the control range,the negative impact of inertia emulation on energy efficiency can be *** proposed algorithm can be integrated with distributed generation setting algorithms to improve dynamic performance and lower implementation *** studies demonstrate the effectiveness of the proposed solution.

关键词： Inertia emulation microgrid photovoltaic system renewable energy voltage source converter

Quantum cascade lasers operating from 1.4 to 4 THz

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Chinese Optics Letters 2011年第11期9卷 9-15页

作者： Sushil Kumar Department of Electrical and Computer Engineering and Center for Optical Technologies Lehigh University

The development of teranertz （THz） quantum cascade lasers （QCLs） has progressed considerably since their advent almost a decade *** QCLs operating in a frequency range from 1.4 to 4 THz with electron-phonon scattering mediated depopulation schemes are *** different types of GaAs/AlGaAs superlattice designs are *** of the best temperature performances are obtained by the so-called resonant-phonon designs that are *** above a temperature of 160 K has been obtained across the spectrum for THz QCLs operating at ν 〉 1.8 *** maximum operating temperature of previously reported THz QCLs has empirically been limited to a value of ～ω/k B.A new design scheme for THz QCLs with scattering-assisted injection is shown to surpass this empirical temperature barrier,and is promising to improve the maximum operating temperatures of THz QCLs even further.

关键词： Quantum cascade lasers operating from 1.4 to 4 THz QCL

Symmetry-aware recursive image similarity exploration for materials microscopy

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npj Computational Materials 2021年第1期7卷 1508-1521页

作者： Tri N.M.Nguyen Yichen Guo Shuyu Qin Kylie S.Frew Ruijuan Xu Joshua C.Agar Department of Materials Science and Engineering Lehigh UniversityBethlehemPA 18015USA Department of Computer Science and Engineering Lehigh UniversityBethlehemPA 18015USA Department of Mechanical Engineering Lehigh UniversityBethlehemPA 18015USA Department of Applied Physics Stanford UniversityStanfordCA 94305USA

In pursuit of scientific discovery,vast collections of unstructured structural and functional images are acquired;however,only an infinitesimally small fraction of this data is rigorously analyzed,with an even smaller fraction ever being *** method to accelerate scientific discovery is to extract more insight from costly scientific experiments already ***,data from scientific experiments tend only to be accessible by the originator who knows the experiments and ***,there are no robust methods to search unstructured databases of images to deduce correlations and ***,we develop a machine learning approach to create image similarity projections to search unstructured image *** improve these projections,we develop and train a model to include symmetry-aware *** an exemplar,we use a set of 25,133 piezoresponse force microscopy images collected on diverse materials systems over five *** demonstrate how this tool can be used for interactive recursive image searching and exploration,highlighting structural similarities at various length *** tool justifies continued investment in federated scientific databases with standardized metadata schemas where the combination of filtering and recursive interactive searching can uncover synthesis-structure-property *** provide a customizable open-source package(https://***/m3-learning/Recursive_Symmetry_Aware_Materials_Microstructure_Explorer)of this interactive tool for researchers to use with their data.

关键词： interactive image similarity

Role of MR-DWI and MR-PWI in the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbits

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Chinese Journal of Cancer Research 2014年第5期26卷 532-542页

作者： Qiang Zhang Mingmin Zhang Zhaoxin Liu Baoqi Shi Fuliang Qi Haijiang Wang Yuan Lv Haijiao Jin Weijing Zhang Department of Radiology Baotou Cancer Hospital lehigh university

Objective： To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging（MR-DWI） and magnetic resonance perfusion weighted imaging（MR-PWI）, and to evaluate the effectiveness and safety of the radiotherapy based on the changes in the MR-DWI and MR-PWI parameters at different treatment stages.Methods： A total of 56 rabbit models with implanted pulmonary VX-2 carcinoma were established, and then equally divided into treatment group and control group. MR-DWI and MR-PWI were separately performed using a Philips Acheiva 1.5T MRI machine（Philips, Netherland）. MRI image processing was performed using special perfusion software and the WORKSPACE advanced workstation for MRI. MRDWI was applied for the observation of tumor signals and the measurement of apparent diffusion coefficient（ADC） values; whereas MR-PWI was used for the measurement of wash in rate（WIR）, wash out rate（WOR）, and maximum enhancement rate（MER）. The radiation treatment was performed using Siemens PRIMUS linear accelerator. In the treatment group, the radiotherapy was performed 21 days later on a once weekly dosage of 1,000 c Gy to yield a total dosage of 5,000 c Gy.Results： The ADC parameters in the region of interest on DWI were as follows： on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values at the center and the edge of the lesions were 1.352 and 1.461 in the treatment group and control group（P〉0.05）. During weeks 0-1 after treatment, the t values at the center and the edge of the lesions were 1.336 and 1.137（P〉0.05）. During weeks 1-2, the t values were 1.731 and 1.736（P〈0.05）. During weeks 2-3, the t values were 1.742 and 1.749（P〈0.05）. During weeks 3-4, the t values were 2.050 and 2.127（P〈0.05）. During weeks 4-5, the t values were 2.764 and 2.985（P〈0.05）. The ADC values in the treatment group were significantly higher than in the contr

关键词： Magnetic resonance diffusion-weighted imaging(MR-DWI) magnetic resonance perfusion weighted imaging(MR-PWI) implanted pulmonary VX-2 carcinoma in rabbits radiotherapy

Web C: toward a portable framework for deploying legacy code in web browsers

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Science China(Information Sciences) 2015年第7期58卷 113-127页

作者： YIN Jie TAN Gang BAI XiaoLong HU ShiMin Department of Computer Science and Technology Tsinghua University Department of Computer Science and Engineering Lehigh University

For security, most web applications are developed in some type-safe language, such as Java Script or Java. However, there is a huge amount of legacy codes developed in unsafe languages, which provide rich functionality and are more efficient than their type-safe counterparts. To allow browsers to incorporate type-safe components in a secure way, previous approaches use the software-based fault isolation(SFI) to isolate untrusted legacy code. The SFI approach performs machine-code transformation for security, but the downside is the loss of architecture independence. We propose Web C, a system that allows legacy code transmitted over the web via the Low Level Virtual Machine(LLVM) bitcode format. The untrusted bitcode is transformed by Web C into code in the Web C security language, which enforces both memory isolation and control-flow integrity. Compared with previous approaches, Web C is more portable, provides stronger security, and allows more flexible memory management. Experimental results show that the average runtime overhead of Web C is modest.

关键词： Web C software fault isolation symbol link shadow memory area portable

Modelling and control of a spatial dynamic cable

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Acta Mechanica Sinica 2019年第4期35卷 866-878页

作者： Bo Tian Subhrajit Bhattacharya Department of Mechanical Engineering and Mechanics Lehigh University Bethlehem PA 18015 USA

We study the problem of dynamically controlling the shape of a cable that is fixed at one end and attached to an actuated robot at another end. This problem is relevant to unmanned aerial vehicles (UAVs) tethered to a base. While rotorcrafts, such as quadcopters, are agile and versatile in their applications and have been widely used in scientific, industrial and military applications, one of the biggest challenges with such UAVs is their limited battery life that make the flight time for a typical UAVs limited to twenty to thirty minutes for most practical purposes. A solution to this problem lies in the use of cables that tether the UAV to a power outlet for constant power supply. However, the cable needs to be controlled effectively in order to avoid obstacles or other UAVs. In this paper, we develop methods for controlling the shape of a cable using actuation at one end. We propose a discrete model for the spatial cable and derive the equations governing the cable dynamics for both force controlled system and position controlled system. We design a controller to control the shape of the cable to attain the desired shape and perform simulations under different conditions. Finally, we propose a quasi-static model for the spatial cable and discuss the stability of this system and the proposed controller.

关键词： Lagrangian mechanics Discrete model of cable Control of under-actuated systems