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中国半城市化地区城中村的非正规性及其开发和拆除

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城市规划学刊 2015年第1期 120-121页

作者： WU f L ZHANG f Z WEBSTER C 徐望悦

中国城中村的命运引发了研究和政策方面的关注。有两个重要的问题悬而未决:①是什么导致了有序的中国城市中的非正规开发?②农村再开发能否消除这种非正规?全文分为六个部分。第一部分是论述了研究背景、研究目的和研究思路。作者首先... 详细信息

中国城中村的命运引发了研究和政策方面的关注。有两个重要的问题悬而未决:①是什么导致了有序的中国城市中的非正规开发?②农村再开发能否消除这种非正规?全文分为六个部分。第一部分是论述了研究背景、研究目的和研究思路。作者首先介绍了研究的背景。中国在过去30年经历了快速城市化,向城市迁移的农村人口主要集中在东部沿海地区,特别是大都市的半城市化地区。早期研究集中在农民工的社会结构和被劳动力

关键词：半城市化地区非正规城中村中华人民共和国

Scalable Jet-Based fabrication of PEI-Hydrogel Particles for CO_(2) Capture

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Energy & Environmental Materials 2024年第6期7卷 351-358页

作者： Jieke Jiang Eline van Daatselaar Hylke Wijnja Tessa de Koning Gans Michel Schellevis Cornelis H.Venner Derk W.f.Brilman Claas Willem Visser Engineering fluid Dynamics Group Department of Thermal and Fluid EngineeringFaculty of Engineering TechnologyUniversity of Twente7500AEEnschedeThe Netherlands Sustainable Process Technology Faculty of Science and TechnologyUniversity of Twente7500AEEnschedeThe Netherlands

The capture,regeneration,and conversion of CO_(2) from ambient air and flue gas streams are critical aspects of mitigating global *** sorbents for CO_(2) absorption are very promising as they have high mass transfer areas without energy input and reduce emissions and minimize corrosion as compared to liquid ***,precisely tunable solid CO_(2) sorbents are difficult to ***,we demonstrate the high-throughput production of hydrogel-based CO_(2)-absorbing particles via liquid *** wrapping a liquid jet consisting of an aqueous solution of cross-linkable branched polyethylenimine(PEI)with a layer of suspension containing hydrophobic silica nanoparticles,monodisperse droplets with a silica nanoparticle coating layer was formed in the air.A stable Pickering emulsion containing PEI droplets was obtained after these ejected droplets were collected in a heated oil *** droplets turn into mm-sized particles after thermal curing in the *** diameter,PEI content,and silica content of the particles were systematically varied,and their CO_(2) absorption was measured as a function of *** regeneration of the particles enabled cyclic testing,revealing a CO_(2) absorption capacity of 6.5±0.5 mol kg^(−1)solid PEI in pure CO_(2) environments and 0.7±0.3 mol kg^(−1)solid PEI for direct air *** thousands of particles were produced per second at a rate of around 0.5 kg per hour,with a single *** process can be further scaled by *** complete toolbox for the design,fabrication,testing,and regeneration of functional hydrogel particles provides a powerful route toward novel solid sorbents for regenerative CO_(2) capture.

关键词： CO_(2) capture droplet hydrogel liquid jet particle steam regeneration

Assessment of Ballast flying in the National Railway Network of Ethiopia

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Engineering（科研） 2021年第7期13卷 420-429页

作者： fikadu Mengistu Henok f. Gebregziabher Awash-Kombolcha-Haragebeya Railway Project Ethiopian Railways Corporation Addis Ababa Ethiopia

One of the major problems in ballasted railroads is ballast flying, which is the projection of ballast particles from the at-rest position as the train passes over the track of a railway structure, mainly due to high speed. In this research, the possibility of railway ballast flying for the double track Addis-Adama section of the new Addis-Djibouti railway line is assessed by determining the major causes of ballast flying and applying Discrete Element Modeling (DEM) with the aid of Particle flow Code (PfC3D) software. The analysis comprised of an impact load and ballast material behavior which were used to determine the vibrational speed of individual ballast particles. The governing result from the series of discrete element analyses performed by considering fouled ballast gradation with grain-size diameter of 22.4 mm gives rise to a ballast maximum vibrational speed of 0.014 m/s. Since the ballast vibrational speed for Addis Ababa-Adama line is less than 0.02 m/s that is recommended by the literature, no ballast flight is expected under the present traffic and ballast conditions.

关键词： Railway Track Ballast flying Discrete Element Modeling Ballast Vibrational Speed Particle flow Code

Accelerating ions with high-energy short laser pulses from submicrometer thick targets

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High Power Laser Science and Engineering 2016年第4期4卷 1-8页

作者： f.Wagner C.Brabetz O.Deppert M.Roth T.Stohlker An.Tauschwitz A.Tebartz B.Zielbauer V.Bagnoud GSI Helmholtzzentrum für Schwerionenforschung GmbH Helmholtz Institut Jena Institut für Kernphysik Technische Universitat Darmstadt Institute for Theoretical Physics Frankfurt University

Using the example of the PHELIX high-energy short pulse laser we discuss the technical preconditions to investigate ion acceleration with submicrometer thick targets. We show how the temporal contrast of this system was improved to prevent pre-ionization of such targets on the nanosecond timescale. furthermore the influence of typical fluctuations or uncertainties of the on-target intensity on ion acceleration experiments is discussed. We report how these uncertainties were reduced by improving the assessment and control of the on-shot intensity and by optimizing the positioning of the target into the focal plane. finally we report on experimental results showing maximum proton energies in excess of 85 MeV for ion acceleration via the target normal sheath acceleration mechanism using target thicknesses on the order of one micrometer.

关键词： high-power laser technique laser-ion acceleration relativistic laser plasma interaction target normal sheath acceleration temporal contrast

Do Cytokines Play a Role in Predicting Some features and Outcome in Infective Endocarditis?

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Advances in Infectious Diseases 2013年第2期3卷 115-119页

作者： Maria Carmo Pereira Nunes Izabella Rodrigues de Araújo Andréa teixeira de Carvalho Letícia Alves Andrade Marcio Henrique Lima Resende José Luiz Padilha da Silva Teresa Cristina Abreu ferrari Universidade federal de Minas Gerais Faculdade de Medicina Departamento de Clínica Médica Belo Horizonte Brazil

Objective: This study aimed to measure the serum concentrations of several cytokines in patients with infective endocarditis (IE), and correlate them with the C-reactive protein serum levels, echocardiographic findings and infecting microorganisms. Methods: forty-five patients with definite IE according to the Duke’s criteria were included in the study. Ten healthy blood donors formed the control group. Serum levels of interleukin (IL) 1β, IL-6, IL-8, IL-10, IL-12 and tumor necrosis factor-α (TNf-α) were measured and compared between the groups, and also with some clinical and laboratory parameters of IE. Results: Patients with IE had significantly higher serum concentrations of the inflammatory mediators than the control patients. Median IL-12 and IL-1β levels were higher in staphylococcal than streptococcal IE. Except for TNf-α, the levels of all the other cytokines correlated with the C-reactive protein concentrations. In multivariate analysis, IL-10 and IL-12 serum levels remained as independent factors associated with the C-reactive protein concentrations. There was a significant correlation between IL-10 concentration and vegetation length. Conclusion: The inflammatory serum cytokines levels were elevated in IE in comparison to healthy controls. C-reactive protein concentrations correlated with cytokines levels. IL-1β and IL-12 serum concentrations were higher in staphylococcal when compared to streptococcal IE. IL-10 levels were associated with vegetation size.

关键词： Infective Endocarditis Inflammatory Cytokines C-Reactive Protein

维苏威和武尔卡诺火山碎屑物中磷灰石挥发组分的研究

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矿物学报 2011年第2期31卷 180-184页

作者：刘羽 Stoppa f. 福州大学紫金矿业学院 Dipartimento Scienze della Terra Università G.d'AnnunzioChieti66013Italy

磷灰石中挥发分的类质同象替换可以反映其结晶时岩浆体系的成分特点。采用扫描电镜、能谱、电子探针、X射线单晶晶胞参数测定和红外、拉曼光谱,对维苏威和武尔卡诺火山碎屑物中磷灰石进行了初步研究,发现其Ca、P位置上不出现替换,主要... 详细信息

磷灰石中挥发分的类质同象替换可以反映其结晶时岩浆体系的成分特点。采用扫描电镜、能谱、电子探针、X射线单晶晶胞参数测定和红外、拉曼光谱,对维苏威和武尔卡诺火山碎屑物中磷灰石进行了初步研究,发现其Ca、P位置上不出现替换,主要替换形成于通道位置上。武尔卡诺磷灰石低硫富Cl,晶胞参数c/a值很小,在低压高温下形成;而维苏威磷灰石含硫稍多,通道离子主要由OH-f组成,形成于压力较大、温度较低的环境,Cl趋向于在早期喷发物中富集,而f则趋向于在晚期喷发物中富集。

关键词：磷灰石挥发分结构通道替换

Thin-Shell Wormholes Admitting Conformal Motions in Spacetimes of Embedding Class One

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International Journal of Astronomy and Astrophysics 2024年第3期14卷 162-171页

作者： Peter K. f. Kuhfittig Department of Mathematics Milwaukee School of Engineering Milwaukee USA

This paper discusses the feasibility of thin-shell wormholes in spacetimes of embedding class one admitting a one-parameter group of conformal motions. It is shown that the surface energy density σis positive, while the surface pressure is negative, resulting in , thereby signaling a violation of the null energy condition, a necessary condition for holding a wormhole open. for a Morris-Thorne wormhole, matter that violates the null energy condition is referred to as “exotic”. for the thin-shell wormholes in this paper, however, the violation has a physical explanation since it is a direct consequence of the embedding theory in conjunction with the assumption of conformal symmetry. These properties avoid the need to hypothesize the existence of the highly problematical exotic matter.

关键词： Thin-Shell Wormholes Conformal Symmetry Embedding Class One Exotic Matter

OBSERVING THE HEAT EQUATION ON A TORUS ALONG A DENSE GEODESIC

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Systems Science and Mathematical Sciences 1991年第2期4卷 186-192页

作者： Lance D.Drager Robert L.foote Clyde f.Martin Department of Mathematics Texas Tech.University.LubbockTX 79409USA Department of Mathematics Wabash CollegeCrawfordsvilleIN 47933USA Department of Mathematics Texas Tech.UniversityLubbockTX 79409USA

Several authors have considered observability problems for the heat equation and relatedpartial differential equations.A basic problem is to determine what kinds of sampling providesufficient information to uniquely determine the initial heat *** address the case wherethe temperature is measured while travelling along a *** consider the special case where the space is a flat torus(of arbitrary dimension)and thecurve is a *** is shown that,in this case,the observed temperature is sufficient informationto uniquely determine the initial heat distribution if and only if the geodesic is dense in the *** the case of a torus,fourier analysis techniques can be used to write down the solution of theheat *** allows us to derive an explicit representation of the observed temperature interms of the initial *** use this representation and some ideas from the theory ofalmost periodic functions to show that the fourier coefficients of the initial distribution can berecovered from the observation.

关键词： Observability heat equation inverse problems

Streptococcus agalactiae:Sensitivity profile in pregnant women attending health units in northeastern Brazil

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World Journal of Obstetrics and Gynecology 2020年第1期9卷 11-17页

作者： Tais Viana Ledo de Oliveira fabrícia Almeida fernandes Santana Caline Novais teixeira Oliveira Maria Luísa Cordeiro Santos fabrício freire de Melo Cláudio Lima Souza Márcio Vasconcelos Oliveira Instituto Multidisciplinar em Saúde Universidade Federal da BahiaVitória da Conquista 45029-094BahiaBrazil

BACKGROUNDG roup B Streptococcus agalactiae (GBS) is the main etiologic agent associated withearly-onset neonatal sepsis, and of all newborns of parturients colonized by GBS,approximately 1%-2% develop invasive, early-onset disease. The risk of infectionincreases to 15.2% in premature neonates, to 10.7% when the parturient haschorioamnionitis or premature rupture of membranes for more than 24 h and to9.7% if the mother has postpartum bacteremia. In addition to causing perinatal,neonatal and postnatal deaths, neonatal hospital infection is associated with highcosts, as hospitalization is three times longer than in uninfected children. Theidentification of pregnant women colonized by GBS, through universal screening,associated with the adoption of appropriate antibiotics at the time of delivery arethe most successful preventive *** evaluate the sensitivity profile of GBS isolated from pregnant womenattending Vitória da *** This is a cross-sectional study with a quantitative approach carried out in themunicipality of Vitória da Conquista-Bahia between february 2017 and March2018. The study population was composed of 210 pregnant women, with agestational age of 32 to 40 wk, who were aged 18 years or older living in the urbanarea of the municipality of Vitória da Conquista. After a brief explanation aboutthe research and obtaining a signed an informed consent form, data andvaginorectal swabs were collected from the women for GBS research. Examinationof the samples in order to identify the presence of GBS was by culture on sheep blood agar and chromogenic agar for GBS and then, seeded on plates containingstreptococcal culture medium and incubated for 18 h to 24 h at 35°C. Theantimicrobial sensitivity profile of positive GBS samples was determined by thedisk diffusion technique, according to the Clinical and Laboratory StandardsInstitute manual (2017). The data obtained were stored in a database usingMicrosoft Office Excel spreadsheets and a des

关键词： Streptococcus agalactiae Sensitivity profile Pregnancy Clindamycin Erythromycin Group B streptococcal disease