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Optimized sintering and mechanical properties of y-TZP ceramics for dental restorations by adding lithium disilicate glass ceramics

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Journal of Advanced Ceramics 2021年第6期10卷 1326-1337页

作者： Ke LI Jiancun rao Congqin NING State Key Laboratory of High Performance Ceramics and Superfine Micro structure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China AIM Lab Maryland NanoCenterUniversity of MarylandCollege ParkMD 20742USA The Education Ministry Key Lab of Resource Chemistry and Shanghai Key Laboratory of Rare Earth Functional Materials Shanghai Normal UniversityShanghai 200234China

The novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics(LDGC)was used as an additive for yttria stabilized tetragonal zirconia polycrystalline(y-TZP)*** effect of LDGC on the sintering,mechanical,and translucent properties of y-TZP ceramics was investigated in the present *** results showed that the LDGC additive effectively improved the densification of y-TZP at 1100℃,which was much lower than the sintering temperature for pure *** sintered at 1100℃,the y-TZP with 1 wt%LDGC reached a relative density of 95.45%,and prossessed a flexural strength of 482.4 MPa and a fracture toughness of 5.94 ***,its translucency was also ***,the addition of LDGC could result in an escape of yttrium atoms from the grain lattice of zirconia,which induced the tetragonal-monoclinic transformation of zirconia and abnormal growth of monoclinic *** escaped yttrium atoms diffused into the intergranular glass *** results indicated that the novel y-TZP-LDGC ceramics has a great potential to be used for all-ceramic restorations.

关键词： yttria stabilized tetragonal zirconia polycrystalline(y-TZP) lithium disilicate glass ceramics(LDGC) sintering mechanical properties dental restoration

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Controversies in fecal incontinence

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World Journal of Gastroenterology 2025年第3期31卷 113-119页

作者： Andreia Albuquerque Satish S C rao School of Medicine and Biomedical Sciences Fernando Pessoa UniversityGondomar 4420-096PortoPortugal Precancerous Lesions and Early Cancer Management Research Group RISE@CI-IPO(Health Research Network) Portuguese Oncology Institute of PortoPorto 4200-072Portugal Division of Gastroenterology and Hepatology Department of Internal MedicineAugusta UniversityAugustaGA 30912United States

Fecal incontinence is a common condition that can significantly impact patients’quality of *** anal sphincter injury and anorectal surgeries are common *** ultrasound and anorectal manometry are important diagnostic tools for evaluating *** are various treatment options,including diet,lifestyle modifications,drugs,biofeedback therapy,tibial and sacral nerve neuromodulation therapy,and *** this editorial,we will discuss current controversies and novel approaches to fecal *** for asymptomatic anal sphincter defects after obstetric anal sphincter injury and in patients with inflammatory bowel disease is not generally recommended,but may be helpful in selected *** Garg incontinence score is a new score that includes the assessment of solid,liquid,flatus,mucous,stress and urge fecal *** tests such as translumbosacral anorectal magnetic stimulation and novel therapies such as translumbosacral neuromodulation therapy are promising diagnostic and treatment options,for both fecal incontinence and *** biofeedback therapy can overcome some limitations of the office-based *** muscle-derived cell implantation of the external anal sphincter has been further studied as a possible treatment *** neuromodulation may be useful in scleroderma,congenital fecal incontinence and inflammatory bowel disease but merits further study.

关键词： Fecal incontinence Endoanal ultrasound Anal sphincter defects Biofeedback Neuropathy Sacral neuromodulation

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Isogeometric analysis of multi-patch solid-shells in large deformation

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Acta Mechanica Sinica 2021年第5期37卷 844-860,I0003页

作者： Qingyuan Hu Davide Baroli Shuzhen rao School of Science Jiangnan UniversityWuxi 214122China AICES-Aachen Institute for Advanced Study in Computational Engineering Science 52062 AachenGermany

In the context of isogeometric analysis(IGA)of shell structures,the popularity of the solid-shell elements benefit from formulation simplicity and full 3D stress *** some basic questions remain unresolved when using solid-shell element,especially for large deformation cases with patch coupling,which is a common scene in real-life *** this research,after introduction of the solid-shell nonlinear formulation and a fundamental 3D model construction method,we present a non-symmetric variant of the standardNitsche’s formulation for multi-patch coupling in associationwith an empirical formula for its stabilization *** selective and reduced integration scheme is also presented to address the locking *** addition,the quasi-Newton iteration format is derived as solver,together with a step length control *** second order derivatives are totally neglected by the adoption of the non-symmetric Nitsche’s formulation and the quasi-Newton *** solid-shell elements are numerically studied by a linear elastic plate example,then we demonstrate the performance of the proposed formulation in large deformation,in terms of result verification,iteration history and continuity of displacement across the coupling interface.

关键词： Isogeometric Solid-shell Nitsche Patch coupling Quasi-Newton

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Fuel-optimal deorbit scheme of space debris using tethered space-tug based on pseudospectral method

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Chinese Journal of Aeronautics 2021年第9期34卷 210-223页

作者： Haiping rao Rui ZHONG Pengjie LI School of Astronautics Beihang UniversityBeijing 100191China

This paper proposes a fuel-optimal deorbit scheme for space debris deorbit using tethered space *** scheme contains three stages named respectively as dragging,maintenance and *** the first stage,the tug,propelled by continuous thrust,tows deorbit to a transfer orbit with a *** in the second stage,the combination of the tug and the debris flies unpowered and uncontrolled to a swing point on the transfer ***,in the third stage,the tug is propelled at the swing point and the rotation speed of the tethered system increases such that the debris obtains enough velocity *** trajectory optimization of the first stage is established considering the total fuel consumption of the three stages,whereas the dynamic model is simplified for computation *** solution to the optimal problem is obtained using a direct method based on Gauss pesudospectral *** a model predictive controller is designed to track the open-loop optimal reference trajectories,reducing the states’deviations caused by model simplification and ignorance of ***,it is proved that the fuel-optimal swing point is the apogee of the transfer *** paper analyzes the fuel consumption of a typical scenario and demonstrates effectiveness of the proposed deorbit scheme numerically.

关键词： Gauss pesudospectral Model predictive controller Fuel-optimal deorbit scheme Space tethered tug Space debris deorbit

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Strong (Weak) Exact Controllability and Strong (Weak) Exact Observability for Quasilinear Hyperbolic Systems

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Chinese Annals of Mathematics,Series B 2010年第5期31卷 723-742页

作者： Tatsien LI Bopeng rao School of Mathematical Sciences Fudan University Shanghai 200433 China Shanghai Key Laboratory for Contemporary Applied Mathematics Nonlinear Mathematical Modeling and Methods Laboratory. Institut de Recherche Mathematique Avancee Universite de Strasbourg 67084 Strasbourg France.

In this paper,the authors define the strong (weak) exact boundary controllability and the strong (weak) exact boundary observability for first order quasilinear hyperbolic systems,and study their properties and the re... 详细信息

关键词： Strong (weak) exact boundary controllability Strong (weak) exact boundary observability First order quasilinear hyperbolic system

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Exact Synchronization for a Coupled System of Wave Equations with Dirichlet Boundary Controls

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Chinese Annals of Mathematics,Series B 2013年第1期34卷 139-160页

作者： Tatsien LI Bopeng rao Nonlinear Mathematical Modeling and Methods Laboratory Shanghai Key Laboratory for Contemporary Applied Mathematic School of Mathematical Sciences Fudan University Institut de Recherche Mathématique Avancée Université de Strasbourg

In this paper, the exact synchronization for a coupled system of wave equations with Dirichlet boundary controls and some related concepts are introduced. By means of the exact null controllability of a reduced coupled system, under certain conditions of compatibility, the exact synchronization, the exact synchronization by groups, and the exact null controllability and synchronization by groups are all realized by suitable boundary controls.

关键词： Exact null controllability Exact synchronization Exact synchronizationby groups

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A Numerical Modelling Method of Fractured Reservoirs with Embedded Meshes and Topological Fracture Projection Configurations

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Computer Modeling in Engineering & Sciences 2022年第6期131卷 1403-1429页

作者： Xiang rao yina Liu Cooperative Innovation Center of Unconventional Oil and Gas(Ministry of Education&Hubei Province) Yangtze UniversityWuhanChina School of Petroleum Engineering Yangtze UniversityWuhanChina

Projection-based embedded discrete fracture model(pEDFM)is an effective numerical model to handle the flow in fractured reservoirs,with high efficiency and strong generalization of flow ***,this paper points out that pEDFM fails to handle flow barriers in most cases,and identifies the physical projection configuration of fractures is a key step in *** paper presents and proves the equivalence theorem,which explains the geometric nature of physical projection configurations of fractures,that is,the projection configuration of a fracture being physical is equivalent to it being topologically homeomorphic to the fracture,by analyzing the essence of *** projection configurations of fractures may be rigorously established based on this theorem,allowing pEDFM to obtain physical numerical results for many flow models,particularly those with flow ***,a natural idea emerges of employing flow barriers to flexibly‘cut’the formation to quickly handle the flow problems in the formation with complex geological conditions,and several numerical examples are implemented to test this idea and application of the improved pEDFM.

关键词： Numerical modeling method fractured reservoirs fracture-projection configuration flow barriers topologically homeomorphism

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Parallel Comparison of the 1982/83,1997/98 and 2015/16 Super El Nios and Their Effects on the Extratropical Stratosphere

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Advances in Atmospheric Sciences 2017年第9期34卷 1121-1133页

作者： Jian rao Rongcai REN Key Laboratory of Meteorological Disaster Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science and Technology State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences

This study uses multiple sea surface temperature （SST） datasets to perform a parallel comparison of three super El Nifios and their effects on the stratosphere. The results show that, different from ordinary El Nifios, warm SST anomalies appear earliest in the western tropical Pacific and precede the super El Nifio peak by more than 18 months. In the previous winter, relative to the mature phase of El Nifio, as a precursor, North Pacific Oscillation-like circulation anomalies are observed. A Pacific-North America （PNA） teleconnection appears in the extratropical troposphere during the mature phase, in spite of the subtle differences between the intensities, as well as the zonal position, of the PNA lobes. Related to the negative rainfall response over the tropical Indian Ocean, the PNA teleconnection in the winter of 1997/98 is the strongest among the three super El Nifios. The northern winter stratosphere shows large anomalies in the polar cap temperature and the circumpolar westerly, if the interferences from other factors are linearly filtered from the circulation data. Associated with the positive PNA response in a super El Nino winter, positive polar cap temperature anomalies and circumpolar easterly anomalies, though different in timing, are also observed in the mature winters of the three super El Nifios. The stratospheric polar vortex in the next winter relative to the 1982/83 and 1997/98 events is also anomalously weaker and warmer, and the stratospheric circulation conditions remain to be seen in the coming winter following the mature phase of the 2015/16 event.

关键词： super El Nifio Pacific-North America (PNA) teleconnection stratosphere proceeding winter

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EELS study on BST thin film under electron beam irradiation

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Science China(Technological Sciences) 2004年第6期47卷 659-666页

作者： rao Jie ZHU Jing Electron Microscopy Laboratory Department of Materials Science and EngineeringTsinghua Univer-sityBeijing 100084China

It was found that BST thin film was damaged by the irradiation of high density electron beam (the current density was about 2 nA/cm2). In-situ and real time EELS showed that the intensity ratio of Ti to O edge and the distance between Ti and O edge changed. It indicated that the film lost oxygen and thus the oxidation states of positive ions lowered. EELS study with high spatial resolution proved that compared with the inner of columnar grains, the grain boundaries with special structure and chemical environment were the main passageway of oxygen loss.

关键词： BST thin film irradiation damage EELS

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e-FILTERS OF MS-ALGEBRAS

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Acta Mathematica Scientia 2013年第3期33卷 738-746页

作者： M. Sambasiva rao Department of Mathematics M.V.G.R. College of EngineeringChintalavalasa Vizianagaram Andhra Pradesh India-535005

The notion of e-filters is introduced in an MS-algebra and characterized. The concept of D-filters is introduced and a set of equivalent conditions under which every D-filter is an e-filter are given. The properties of the space of all prime e-filters of an MS-algebra are observed. The concept of D-prime filters is introduced and then a set of equivalent conditions axe derived for a prime e-filter to become a D-prime filter in topological terms.

关键词： MS-algebra e-filter dense element D-filter D-prime filter minimal prime filter Hausdorff space

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