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Highly efficient fiber to Si waveguide free-form coupler for foundry-scale silicon photonics

Photonics Research 2024年第5期12卷 1055-1066页

作者： LUIGI RANNO JIA Xu BRIAN SIA COSMIN popescu DREW WENINGER SAMUEL SERNA SHAOLIANG YU LIONEL C.KIMERLING ANURADHA AGARWAL TIAN GU JUEJUN HU Department of Materials Science&Engineering Massachusetts Institute of TechnologyCambridgeMassachusetts 02139USA Centre for Micro-&Nano-Electronics(CMNE) Nanyang Technological UniversitySingapore 639798Singapore Department of Physics Photonics and Optical EngineeringBridgewater State UniversityBridgewaterMassachusetts 02324USA Zhejiang Laboratory Hangzhou 311100China Materials Research Laboratory Massachusetts Institute of TechnologyCambridgeMassachusetts 02139USA

As silicon photonics transitions from research to commercial deployment,packaging solutions that efficiently couple light into highly compact and functional sub-micrometer silicon waveguides are imperative but remain *** 220 nm silicon-on-insulator(SOI)platform,poised to enable large-scale integration,is the most widely adopted by foundries,resulting in established fabrication processes and extensive photonic component *** development of a highly efficient,scalable,and broadband coupling scheme for this platform is therefore of paramount *** two-photon polymerization(TPP)and a deterministic free-form micro-optics design methodology based on the Fermat’s principle,this work demonstrates an ultraefficient and broadband 3-D coupler interface between standard SMF-28 single-mode fibers and silicon waveguides on the 220 nm SOI *** coupler achieves a low coupling loss of 0.8 dB for the fundamental TE mode,along with 1 dB bandwidth exceeding 180 *** broadband operation enables diverse bandwidthdriven applications ranging from communications to ***,the 3-D free-form coupler also enables large tolerance to fiber misalignments and manufacturing variability,thereby relaxing packaging requirements toward cost reduction capitalizing on standard electronic packaging process flows.

关键词： fiber waveguide enable

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Electrochemical studies on cerium(Ⅲ) in molten fluoride mixtures

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Journal of Rare Earths 2010年第3期28卷 428-434页

作者： VIRGIL CONSTANTIN ANA-maria popescu MIRCEA OLTEANU Romanian Academy Institute of Physical Chemistry "Ilie Murgulescu"Department of Molten Salts Splaiul Independentei 202Bucharest-Romania

This study aims to determine the principal electrochemical characteristics of the electrodeposition of cerium metal from molten fluoride *** cathodic process of Ce3+ ions in LiF-NaF and LiF-NaF-CaF2 molten salts was studied using electrochemical techniques as steady state and cyclic voltammetry *** decomposition potential(Ed) and the overvoltage(η) were determined for NaCeF4 using current-potential curves under galvanostatic *** Ed was found to be 2.025 V in LiF-NaF and 2.045 V in...

关键词： cerium molten salts lanthanides NaCeF4 electrolysis cyclic voltammetry

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Potential roles of functional bacterial amyloid proteins,bacterial biosurfactants and other putative gut microbiota products in the etiopathogeny of Parkinson’s Disease

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BIOCELL 2021年第1期45卷 1-16页

作者： EMILIA MANOLE LAURA DUMITRESCU cristina NICULIȚE BOGDAN OVIDIU popescu LAURA cristina CEAFALAN Victor Babeș”National Institute of Pathology Bucharest050088Romania Colentina Clinical Hospital Bucharest020125Romania Carol Davila”University of Medicine and Pharmacy Bucharest020021Romania

An increasing number of studies provide evidence for the existence of a microbiota-gut-brain axis and its potential involvement in the development of sporadic Parkinson’s disease and other neurodegenerative *** neuropathologic hallmark of Parkinson’s disease is the presence of brain intraneuronal aggregates of misfolded alpha-synuclein,known as Lewy *** gut microbiota products may trigger alpha-synuclein conformational changes in the neurons of the enteric nervous system,which can then spread to the brain in a prion-like fashion through the vagus *** may interfere with neuroinflammatory pathways and susceptibility to *** this review,we assess the potential role of putative gut microbiota products in the etiopathogeny of Parkinson’s disease,with a special emphasis on functional bacterial amyloid proteins,bacterial biosurfactants,endotoxins and short-chain fatty *** possible roles of molecular hydrogen,a common byproduct of bacterial fermentation,are also addressed.

关键词： Alpha-synuclein Endotoxins Short-chain fatty acids

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Electromagnetic Characteristics and Corrosion Resistance of New Magnetosoft Materials Based on Capsulated Iron Powders

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Chemical Research in Chinese Universities 2020年第6期36卷 1326-1331页

作者： Alexander VETCHER Gennady GOVOR Olga DEMIDENKO Virgil CONSTANTIN Ana maria popescu Scientific-Practical Materials Research Centre National Academy of BelarusP.Brovki 19 Str.220072 MinskBelarus “IlieMurgulescu”Institute of Physical Chemistry of Romanian Academy Laboratory of Electrochemistry and CorrosionSplaiullndependentei 202Bucharest 060021Romania

A new method of depositing an insulating multifunctional oxide coating on metal particles was *** coatings increase corrosion resistance and insulate metal particles from each *** base of capsulated by oxide coating water-atomized iron powder ASC100.29,new composite soft magnetic materials were synthesized,which are able of replacing electrical steel in ***,electromagnetic properties and corrosion characte-ristics of the obtained composites were *** was found that the synthesized composite materials have low elec-tromagnetic losses,high values of magnetic induction(up to 2.1 T)and good corrosion *** results demon-strate that the use of such materials in power supplies,c hokes,transformers,stators and rotors of electric machines and other products ensures their stable operation under various conditions.

关键词： Soft magnetic composite material Iron powder Insulating cover High-frequency transformer Stators and rotors of electro machine

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Modeling of fluid dynamics interacting with ductile fraction propagation in high pressure pipeline

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Acta Mechanica Sinica 2009年第3期25卷 311-318页

作者： Mihaela popescu Department of Process Technology Flow Technology GroupSINTEF Materials and Chemistry

This paper presents a computational model for the fluid dynamics in a fractured ductile pipe under high pressure. The pressure profile in front of the crack tip, which is the driving source of crack propagation, is computed using a nonlinear wave equation. The solution is coupled with a one dimensional choked flow analysis behind the crack. The simulation utilizes a high order optimized prefactored compact-finite volume method in space, and low dispersion and dissipation Runge-Kutta in time. As the pipe fractures the rapid depressurization take place inside the pipe and the propagation of the crack-induced waves strongly influences the outflow dynamics. Consistent with the experimental observation, the model predicts the expansion wave inside the pipe, and the reflection and outflow of the wave. The model also helps characterize the propagation of the crack dynamics and fluid flows around the tip of the crack.

关键词： Fluid dynamics High pressure pipeline -Ductile fracture propagation - Finite volume method

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Electroreduction of Tungsten Oxide（VI） in Molten Salts with Added Metaphosphate

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Chemical Research in Chinese Universities 2013年第4期29卷 771-775页

作者： MALYSHEV Victor GAB Angelina popescu Ana-maria CONSTANT1N Virgil Faculty of Chemistry & Technology National Technical University of Ukraine "Kyiv Polytechnical Institute " Kyiv 05056 Ukraine" Open International University of Human Development of Ukraine Kyiv 04071 Ukraine Laboratory of Molten Salts Ilie Murgulescu" Institute of Physical Chemistry of the Romanian Academy Bucharest 006021 Roumania

Tungstate ions WO4^2- are not electrochemically active in chloride melts. Upon introduction of PO3 ions into the melt, two waves appear in the voltammograms at potentials -0.1-- -0.2 V and -0.3-- -0.5 V vs. Pb/Pb2＋ reference electrode. With a PO3- concentration ratio of 0.01〈[PO3-]/[WO42-]〈0.18, the potentiostatic electrolysis product of WO42 at the above mentioned potentials is metallic tungsten; a NaPO3 concentration increase for ratios [PO3-]/[WO42-]〉〉0.18 results in tungsten phosphide in electrolysis product. Cyclic voltammograms and dependence of half-peak potentials on electrode polarization rate indicate the irreversible character of the electrode process. Elec- trode process modeling allows us to state that the first wave in the voltammogram of KC1-NaC1-Na2WOa-NaPO3 sys- tem corresponds to tungsten oxychlorides discharge while the second wave appears due to the discharge of di- tungstate ions. In the voltammograms of Na2WOa-NaPO3 melts, reduction wave was observed at -1.1-- -1.2 V po- tentials. Proportionality of limiting current to NaPO3 concentration, constancy of ld/V1/2 ratio, and IJnFc constant ki- netic value equal to （8.3--9.5）×10-5 cm/s for steady-state wave indicate that electrode process rate is limited by elec- trochemically active particle diffusion to the electrode. Nascent ditungstate ions become electrochemically active in the overall electrode process. Charge transfer stage is reversible.

关键词： Tungsten oxide Electroreduction Molten salt Cyclic voltammetry

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Timing of paracentesis and outcomes in hospitalized patients with decompensated cirrhosis

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World Journal of Hepatology 2020年第12期12卷 1267-1275页

作者： cristina Tocia Andrei Dumitru Luana Alexandrescu Razvan popescu Eugen Dumitru Department of Gastroenterology Constanta County Clinical Emergency HospitalConstanta 900647Romania Department of General Surgery Constanta County Clinical Emergency HospitalConstanta 900647Romania

BACKGROUND Ascites is one of the most common complications of cirrhosis,placing a significant burden on the healthcare *** regarding the optimal time of paracentesis and outcomes among patients with cirrhosis and ascites are *** To assess the outcomes of patients who underwent paracentesis within 12 h after admission compared to patients who underwent paracentesis later than 12 *** The study included 185 patients with cirrhosis and ascites who underwent *** early paracentesis group was defined as paracentesis performed12 h after admission(120 patients).Newonset complications of cirrhosis,length of hospital stay,weekday or weekend admission,in-hospital mortality rate,and 90-d readmission rates were assessed and compared between the *** Significantly more patients in the delayed paracentesis group than in the early paracentesis group developed hepatic encephalopathy(45%vs 21.5%,P<0.01),hepato-renal syndrome(21.6%vs 9.2%,P=0.03)and infections(25%vs 10.7%,P=0.02)during *** were no statistically significant differences in the occurrence of spontaneous bacterial peritonitis and upper gastrointestinal bleeding between the two *** of stay was shorter in the early paracentesis group than in the delayed paracentesis group(6.7 d vs 12.2 d)and inhospital mortality was lower among patients in the early paracentesis *** in the delayed paracentesis group had a higher risk of developing complications during *** Early paracentesis(within 12 h after admission)could be a new inpatient quality metric among patients hospitalized with cirrhosis and ascites as it is associated with fewer complications of cirrhosis,lower in-hospital mortality and shorter length of stay.

关键词： Cirrhosis Ascites Hepatic encephalopathy Spontaneous bacterial peritonitis Early paracentesis Delayed paracentesis

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Transport Properties of Alkali Fluoride High Temperature Ionic Liquids and Application of Theories of Viscous Flow

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Chemical Research in Chinese Universities 2015年第5期31卷 858-864页

作者： popescu Anamaria Laboratory of Molten Salts "Hie Murgulescu" Institute of Physical Chemistry Romanian Academy Technology Transfer Center(CTT-ICF) Bucharest 060021 Romania

The transport properties of several alkali fluoride high temperature ionic liquids（LiF, NaF, KF, RbF and CsF） were studied in a range of 980-1400 K and the temperature dependences of the viscosity and density were interpreted, in agreement with the classical equations characterizing the viscous flow（Arrhenius, Batchinski, Eyring and Frenkel）. The experimental results reveal the validity of these equations even at high temperatures, suggesting that no significant structural changes of alkali fluorides occurred in the studied temperature range. Our results clearly demonstrate that the mentioned thermo-physical properties can be used as powerful tools in the further investigations of the ionic interactions governing the alkali fluoride molten salts.

关键词： Ionic liquid Alkali fluoride Viscosity Temperature dependence Correlation Fluidity

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High-resolution impedance mapping using electrically activated quantitative phase imaging

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Light(Science & Applications) 2021年第2期10卷 186-196页

作者： cristina Polonschii Mihaela Gheorghiu Sorin David Szilveszter Gáspár Sorin Melinte Hassaan Majeed Mikhail E.Kandel Gabriel popescu Eugen Gheorghiu International Centre of Biodynamics 060101 BucharestRomania Institute of Information and Communication Technologies Electronics and Applied MathematicsUniversite Catholique de Louvain1348 Louvain-la-NeuveBelgium Quantitative Light Imaging Laboratory Beckman Institute for Advanced Science and TechnologyUniversity of Illinois at Urbana-ChampaignUrbanaIL 61801USA

Retrieving electrical impedance maps at the nanoscale rapidly via nondestructive inspection with a high signal-to-noise ratio is an unmet need,likely to impact various applications from biomedicine to energy *** this study,we develop a multimodal functional imaging instrument that is characterized by the dual capability of impedance mapping and phase quantitation,high spatial resolution,and low temporal *** achieve this,we advance a quantitative phase imaging system,referred to as epi-magnified image spatial spectrum microscopy combined with electrical actuation,to provide complementary maps of the optical path and electrical *** demonstrate our system with high-resolution maps of optical path differences and electrical impedance variations that can distinguish nanosized,semi-transparent,structured coatings involving two materials with relatively similar electrical *** map heterogeneous interfaces corresponding to an indium tin oxide layer exposed by holes with diameters as small as~550 nm in a titanium(dioxide)over-layer deposited on a glass *** show that electrical modulation during the phase imaging of a macro-electrode is decisive for retrieving electrical impedance distributions with submicron spatial resolution-and beyond the limitations of electrode-based technologies(surface or scanning technologies).The findings,which are substantiated by a theoretical model that fits the experimental data very well enable achieving electro-optical maps with high spatial and temporal *** virtues and limitations of the novel optoelectrochemical method that provides grounds for a wider range of electrically modulated optical methods for measuring the electric field locally are critically discussed.

关键词： impedance resolution phase

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Influence of hepatitis viruses on clinico-pathological profiles and long-term outcome in patients undergoing surgery for hepatocellular carcinoma

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Hepatobiliary & Pancreatic Diseases International 2014年第2期13卷 162-172页

作者： Anna-maria Tanase Traian Dumitrascu Simona Dima Razvan Grigorie Agnes Marchio Pascal Pineau Irinel popescu Center of General Surgery and Liver Transplant Fundeni Clinical Institute Unité "Organisation nucléaire et oncogenèse" INSERM U993Institut

BACKGROUND: The global risk of hepatocellular carcinoma(HCC) is largely due to hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. In recent years, however, an increased prevalence of non-viral HCC has been noted. The clinical impact of the presence/absence of viral infections in HCC remains controversial. The present study aimed to assess the effect of hepatitis viruses on demographics, clinical and pathological features and long-term outcome in a large cohort of Romanian patients who underwent surgery for HCC. METHODS: The study included 404 patients with HCC who had undergone resection, transplantation or radiofrequency ablation at a single institution between 2001 and 2010. The patients were divided into four groups: 85 patients with hepatitis B virus infection (HBV group), 164 patients with hepatitis C virus infection (HCV group), 39 patients with hepatitis B and C virus co-infection (HBCV group), and 116 patients without viral infection (non-BC group). RESULTS: The patients of both HBV (56.0±11.3 years) and HBCV groups (56.0±9.9 years) were significantly younger than those of the HCV (61.0±8.5 years, P=0.001) and non-BC groups(61.0±13.0 years, P=0.002). Interestingly, the prevalence of liver cirrhosis was significantly lower in the non-BC group (47%)than in any other subsets (72%-90%, P<0.002). Furthermore, the non-BC patients were more advanced according to the Barcelona Clinic Liver Cancer stages than the patients of the HCV or HBCV groups (P<0.020); accordingly, they were more frequently assessed beyond the Milan criteria than any other groups (P=0.001). No significant differences in the disease-free or overall survival rates were observed among these groups. CONCLUSIONS: Patients with non-viral HCC are diagnosed at advanced ages and stages, a situation plausibly due to the poor effectiveness of cancer surveillance in community practice. The presence of viral infections does not appear to impair the longterm prognosis after surgical treatm

关键词： hepatitis B virus hepatitis Cvirus hepatocellular carcinoma recurrence prognosis

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