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Preparation of nano-crystalline tungsten powders from gaseous WO_(2)(OH)_(2)

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Tungsten 2022年第1期4卷 60-66页

作者： Markus Ostermann Valentin Dalbauer Wolf-Dieter Schubert roland haubner TU Wien A-1060 ViennaAustria

The industrial production of tungsten powder is carried out by the reduction of tungsten oxide powder via *** this process,the size of the W particles is limited to particle sizes larger than 100 *** get below this limit,alternative processes are *** the current work,the possibility of preparing W powder below 100 nm via a vapour phase reduction of volatile WO_(2)(OH)_(2)by hydrogen was *** process consists of two *** the first stag,e WO_(2)(OH)_(2)is formed by reacting WO3 with water vapour at temperatures of 1000–1100°*** the second stage,WO_(2)(OH)_(2)is reduced by hydrogen at about 1000°C to form metallic *** influence of process parameters such as furnace temperature,humidity and gas flow on the WO_(2)(OH)_(2)evaporation and formation of tungsten powder was *** characterization of the resulting powders was performed by X-ray diffraction(XRD),field emission scanning electron microscopy(FE-SEM)and transmission electron microscopy(TEM).By optimization of the reaction conditions,powder with a metallic tungsten content of about 70 at%besides tungsten oxides was produced with metal particle sizes down to 5 *** optimization should lead to a high tungsten content and a high product *** to the small particle size,applications in catalysis might be possible,although an industrial realization of the process seems unrealistic at moment.

关键词： Tungsten Chemical vapour transport Mechanism·Reduction Nano-sized powder WO_(2)(OH)_(2)

Acute lung injury and ARDS in acute pancreatitis: Mechanisms and potential intervention

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World Journal of Gastroenterology 2010年第17期16卷 2094-2099页

作者： roland Andersson Department of Surgery Clinical Sciences LundLund University Lund University Hospital SE-221 85 LundSweden

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in acute pancreatitis still represents a substantial problem,with a mortality rate in the range of 30%-40%.The present review evaluates underlying pathophysiological mechanisms in both ALI and ARDS and potential clinical *** mediators and pathophysiological pathways are involved during the different phases of ALI and *** initial exudative phase is characterized by diffuse alveolar damage,microvascular injury and influx of inflammatory *** phase is followed by a fibro-proliferative phase with lung repair,type Ⅱ pneumocyte hypoplasia and proliferation of *** derived from polymorphonuclear neutrophils,various pro-inflammatory mediators,and phospholipases are all involved,among *** factors that promote pancreatitis-associated ALI may be found in the gut and mesenteric *** is a lack of complete understanding of the underlying mechanisms,and by improving our knowledge,novel tools for prevention and intervention may be developed,thus contributing to improved outcome.

关键词： Acute lung injury Acute respiratory distress syndrome Acute pancreatitis Etiology Pathophysiology

Long-term monitoring of PCDD/PCDF and other unintentionally produced POPs-Concepts and case studies from Europe

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Science China Chemistry 2010年第5期53卷 1017-1024页

作者： REINMANN Jürgen WEBER roland HAAG roland Environnement S.A Deutschland Benzstrasse 1161352 Bad HomburgGermany POPs Environmental Consulting Ulmenstraβe 373035 GppingenGermany TüV Süd Industrie Service GmbH Grabenwiesenstraβe 473072 DonzdorfGermany

During the start-up and unstable combustion periods,even the state-of-the-art incinerators emit polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/PCDF) in stack gases at concentrations that are up to 1000 times higher than normal operation. Therefore,incinerators and other sources with variation of PCDD/PCDF release into air cannot be reliably monitored by the conventional short-term sampling that covers only 0.1%to 0.2%of the yearly operating time.A more comprehensive monitoring regime is *** paper describes different applications of continuous PCDD/PCDF sampling in some European *** cases demonstrate that flexible regimes for continuous sampling can be crafted and applied by governments or regional/local *** regimes range from a countrywide,continuous requirement for selected facility types(e.g.,waste incinerators) to a facility-specific regime that applies,for example,to new facilities for a defined time period until the facility has demonstrated continuous compliance with regulatory limits. Countries implementing the Stockholm Convention are suggested to evaluate in their Best available technology/Best environmental practice(BAT/BEP) activities the usefulness of long-term sampling by,for example,designating institutes related to the environmental ministry or regional authorities to supervise long-term sampling regimes at relevant facilities in their country/areas,beginning with priority sources(e.g.,facilities used for destruction of persistent organic pollutants(POPs) or hazardous waste processing) . This paper presents and discusses the results of the AMESA long-term monitoring system having demonstrated that in addition to PCDD/PCDF all other unintentionally produced POPs listed in the Stockholm Convention could be supervised.

关键词： PCDD/PCDF PCB continuous sampling unintentionally produced POPs Stockholm Convention BAT/BEP

Liquid-phase epitaxy of metal organic framework thin films

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Science China Chemistry 2011年第12期54卷 1851-1866页

作者： FISCHER roland A. Organometallics and Materials Chemistry Ruhr-Universitt Bochum

Metal-organic framework(MOF) thin films are multilayer materials ranging from nanometers to micrometers in thickness,physically or chemically adhesive to a(functionalized) substrate and,in an ideal case,exhibiting low roughness and high *** innovative approaches have been developed for MOF thin film *** these advanced materials,surface-attached metal-organic frameworks(SURMOFs) are an important class of MOF ***,fabricated in a step-by-step liquid phase epitaxial(LPE) fashion by alternating deposition of metal and organic linker precursors on a functionalized substrate,for example,thiolate-based self-assembled monolayers(SAMs),have already exhibited their utility in both research and potential *** combine surface science and the chemistry of MOFs,possessing the following unique advantages that cannot be accessed through other methods:(i) precisely controlling thickness,roughness and homogeneity as well as growth orientation,(ii) studying of MOF growth mechanism,(iii) modifying/tailoring MOFs' structures during the SURMOF growth and thus creating customizable properties,and(iv) existing in the form of thin film/membrane for direct applications,for example,as *** review discusses the oriented and crystalline SURMOFs fabricated by LPE approach,covering their preparation,growth mechanism,and characterization methodology as well as applications based upon the most newly updated knowledge.

关键词： coordination chemistry metal-organic frameworks (MOFs) liquid phase epitaxy step-by-step approach surface science thin film

A Penalty-Regularization-Operator Splitting Method for the Numerical Solution of a Scalar Eikonal Equation

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Chinese Annals of Mathematics,Series B 2015年第5期36卷 659-688页

作者： Alexandre CABOUSSAT roland GLOWINSKI Haute Ecole de Gestion de Genève HES-SO//University of Applied Sciences Department of Mathematics University of Houston

In this article, we discuss a numerical method for the computation of the minimal and maximal solutions of a steady scalar Eikonal equation. This method relies on a penalty treatment of the nonlinearity, a biharmonic regularization of the resulting variational problem, and the time discretization by operator-splitting of an initial value problem associated with the Euler-Lagrange equations of the regularized variational problem. A low-order finite element discretization is advocated since it is well-suited to the low regularity of the solutions. Numerical experiments show that the method sketched above can capture efficiently the extremal solutions of various two-dimensional test problems and that it has also the ability of handling easily domains with curved boundaries.

关键词： Eikonal equation Minimal and maximal solutions Regularization methods Penalization of equality constraints Dynamical flow Operator splitting Finite element methods

Conserved host-pathogen interactions identify novel treatment options in betacoronavirus infections

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Signal Transduction and Targeted Therapy 2021年第3期6卷 557-559页

作者： Soeren Lukassen roland Eils Charity-Universitatsmedizin Berlin corporate member of Freie Umversitat BerlinHumboldt-Universitat zu Berlinand Berlin Institute of HealthBerlinGermany Center for Digital Health Berlin Institute of Health(BIH)BerlinGermany Health Data Science Unit Heidelberg University Hospital and BioQuantHeidelbergGermany

In a recent study published in Science,1 Gordon et *** the host-pathogen interactome of the coronaviruses SARS-CoV-1,SARS-CoV-2,and MERS-CoV,all of which caused lethal outbreaks in the past two *** functionally characterize a number of these interactions,leveraging the information to identify promising candidate molecules for drug-repurposing.

关键词： identif interactions treatment

On the Numerical Solution to a Nonlinear Wave Equation Associated with the First Painlev Equation:an Operator-Splitting Approach

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Chinese Annals of Mathematics,Series B 2013年第2期34卷 237-254页

作者： roland GLOWINSKI Annalisa QUAINI Department of Mathematics University of Houston4800 Calhoun RdHouston(TX) 77204USA Laboratoire Jacques-Louis Lions Universit Pierre et Marie Curie4Place Jussieu75252 Paris CEDEX 05France

The main goal of this article is to discuss the numerical solution to a nonlinear wave equation associated with the first of the celebrated Painlevd transcendent ordinary differential equations. In order to solve numerically the above equation, whose solutions blow up in finite time, the authors advocate a numerical methodology based on the Strang＇s symmetrized operator-splitting scheme. With this approach, one can decouple nonlinearity and differential operators, leading to the alternate solution at every time step of the equation as follows：（i） The first Painlevd ordinary differential equation, （ii） a linear wave equation with a constant coefficient. Assuming that the space dimension is two, the authors consider a fully discrete variant of the above scheme, where the space-time discretization of the linear wave equation sub-steps is achieved via a Galerkin/finite element space approximation combined with a second order accurate centered time discretization scheme. To handle the nonlinear sub-steps, a second order accurate centered explicit time discretization scheme with adaptively variable time step is used, in order to follow accurately the fast dynamic of the solution before it blows up. The results of numerical experiments are presented for different coefficients and boundary conditions. They show that the above methodology is robust and describes fairly accurately the evolution of a rather ＂violent＂ phenomenon.

关键词： Painlevd equation Nonlinear wave equation Blow-up solution Operator-SDlitting

REGULARIZATION METHODS FOR THE NUMERICAL SOLUTION OF THE DIVERGENCE EQUATION △. u = f＊

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Journal of Computational Mathematics 2012年第4期30卷 354-380页

作者： Alexandre Caboussat roland Glowinski University of Houston Department of Mathematics Houston Texas USA

The problem of finding a L^∞-bounded two-dimensional vector field whose divergence is given in L2 is discussed from the numerical viewpoint. A systematic way to find such a vector field is to introduce a non-smooth variational problem involving a L^∞-norm. To solve this problem from calculus of variations, we use a method relying on a well- chosen augmented Lagrangian functional and on a mixed finite element approximation. An Uzawa algorithm allows to decouple the differential operators from the nonlinearities introduced by the L^∞-norm, and leads to the solution of a sequence of Stokes-like systems and of an infinite family of local nonlinear problems. A simpler method, based on a L2- regularization is also considered. Numerical experiments are performed, making use of appropriate numerical integration techniques when non-smooth data are considered; they allow to compare the merits of the two approaches discussed in this article and to show the ability of the related methods at capturing L^∞bounded solutions.

关键词： Divergence equation Bounded solutions Regularization methods AugmentedLagrangian Uzawa algorithm Nonlinear variational problems.

Plant Phenotyping:Past,Present,and Future

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Plant Phenomics 2019年第1期1卷 179-184页

作者： roland Pieruschka Uli Schurr IBG-2 Plant Sciences Forschungszentrum Julich GmbHD-52425 ulichGermany

A plant develops the dynamic phenotypes from the interaction of the plant with the *** these processes that span plant’s lifetime in a permanently changing environment is essential for the advancement of basic plant science and its translation into application including breeding and crop *** plant research community was thus confronted with the need to accurately measure diverse traits of an increasingly large number of plants to help plants to adapt to resource-limiting environment and low-input *** this overview,we outline the development of plant phenotyping as a multidisciplinary *** sketch the technological advancement that laid the foundation for the development of phenotyping centers and evaluate the upcoming challenges for further advancement of plant phenotyping specifically with respect to standardization of data acquisition and ***,we describe the development of the plant phenotyping community as an essential step to integrate the community and effectively use the emerging synergies.

关键词： Plant breeding sketch