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Rationality of quotients by linear actions of affine groups

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Science China Mathematics 2011年第8期54卷 1521-1532页

作者： BOGOMOLOv Fedor BHNING Christian graf vON BOTHMER Hans-Christian Department of Mathematics Courant Institute of Mathematical Sciences New York University Mathematisches Institut University of Gottingen

LetG = SLn(C)Cn be the (special) affine group. In this paper we study the representation theory of G and in particular the question of rationality for v/G, where v is a generically free G-representation. We show that the answer to this question is positive (Theorem 6.1) if the dimension of v is sufficiently large and v is indecomposable. We explicitly characterize two-step extensions 0 → S → v → Q → 0, with completely reducible S and Q, whose rationality cannot be obtained by the methods presented here (Theorem 5.3).

关键词： rationality linear group quotients affine groups

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Effect of wire-arc directed energy deposition on the microstructural formation and age-hardening response of the Mg-9Al-1Zn(AZ91)alloy

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镁合金学报(英文) 2023年第6期11卷 1944-1958页

作者： Gloria graf Petra Spoerk-Erdely Emad Maawad Michael Burtscher Daniel Kiener Helmut Clemens Thomas Klein Department of Materials Science Montanuniversität LeobenFranz Josef-Straße 188700 LeobenAustria Institute of Materials Physics Helmholtz-Zentrum HereonMax-Planck-Straße 121502 GeesthachtGermany LKR Light Metals Technologies Ranshofen Austrian Institute of TechnologyLamprechtshausener Straße 615282 RanshofenAustria Institute of Materials Science Joining and FormingGraz University of TechnologyKopernikusgasse 24/I8010 GrazAustria

In recent years,wire-arc directed energy deposition(wa DED),which is also commonly known as wire-arc additive manufacturing(WAAM),has emerged as a promising new fabrication technique for magnesium *** major reason for this is the possibility of producing parts with a complex geometry as well as a fine-grained *** the process has been shown to be applicable for Mg-Al-Zn alloys,there is still a lack of knowledge in terms of the influence of the WAAM process on the age-hardening ***,this study deals with the aging response of a WAAM AZ91 *** order to fully understand the mechanisms during aging,first,the as-built condition was analyzed by means of high-energy X-ray diffraction(HEXRD)and scanning electron *** investigations revealed a finegrained,equiaxed microstructure with adjacent areas of alternating Al ***,the difference between single-and double-step aging as well as conventional and direct aging was studied on the as-built WAAM AZ91 alloy for the first *** aging response during the various heat treatments was monitored via in situ HEXRD *** electron microscopy and hardness studies were *** results showed that the application of a double-step aging heat treatment at 325℃with pre-aging at 250℃slightly improves the mechanical properties when compared to the single-step heat treatment at 325℃.However,the hardness decreases considerably after the pre-aging ***,aging at lower temperatures is preferable within the investigated temperature range of 250-325℃.Moreover,no significant difference between the conventionally aged and directly aged samples was ***,the specimens showed enhanced precipitation kinetics during aging as compared to cast *** could be attributed to a higher amount of nucleation sites and the particular temperature profile of the solution heat treatment.

关键词： Wire-arc directed energy deposition Additive manufacturing High-energy X-ray diffraction Synchrotron Mg-Al-Zn alloys Age-hardening

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Mortality and Long-Term Outcome of Neonates with Congenital Heart Disease and Acute Perinatal Stroke:A Population-Based Case-Control Study

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Congenital Heart Disease 2022年第4期17卷 447-461页

作者： Eszter vojcek vAnna Gyarmathy Rozsa graf Anna M.Laszlo Laszlo Ablonczy Zsolt Prodan Istvan Seri First Department of Pediatrics Semmelweis UniversityMTA Centre of ExcellenceBudapestHungary Department of Pediatrics Saint John Hospital and North-Buda Unified HospitalsBudapestHungary Epiconsult BioMedical Consulting and Medical Communications Agency DoverUSA Department of Epidemiology Johns Hopkins UniversityBaltimoreUSA Department of Rehabilitation Saint John Hospital and North-Buda Unified HospitalsBudapestHungary Institute of Mathematics and Base Sciences Hungarian University of Agriculture and Life SciencesGödöllőHungary Gottsegen National Cardiovascular Center BudapestHungary Children’s Hospital Los Angeles University of Southern CaliforniaLos AngelesUSA

Objective:Neonates with congenital heart disease(CHD)and perinatal stroke have high mortality and survivors are at risk for poor long-term neurodevelopmental *** aim of this study was to assess the risk factors and outcome of neonates with both CHD and MRI-confirmed perinatal stroke(Study Group)and compare those to the risk factors and outcome of infants matched for CHD without stroke(Control-1)and of infants matched for MRI-confirmed stroke without CHD(Control-2).Methods:We conducted a population-based case-control study enrolling 28 term neonates with CHD and MRI-confirmed acute perinatal stroke born between 2007–2017 in the Central-Hungarian *** of the control groups included 56 *** Bayley Scales of Infant Development-II,the Brunet-Lézine test and the Binet Intelligence scales-v were used for neurodevelopmental follow-up at a median age of 61 ***:Mortality was highest in the Study Group(25%compared to 5%and 2%,respectively,p=0.001).Adverse neurodevelopmental outcome was prevalent in the Study(53%)and Control-2 Groups(52%,p=0.03).Significantly different parameters among the three groups included Apgar scores,mode of delivery,gestational age at birth,cardiac interventions and twin *** a multivariable regression analysis adjusted for clinically relevant parameters,patients in the Study Group had significantly higher odds for mortality compared to patients in the Control-1 Group(OR:6.595%CI:1.1–39.4).Conclusions:Neonates with perinatal stroke and CHD are at a higher risk for dying compared to neonates with CHD without *** addition,the stroke-associated direct insult to the brain likely plays an important role in the development of neurodevelopmental morbidity in these patients.

关键词： Congenital heart disease perinatal stroke neurodevelopmental outcome mortality

Pushing the Limits of Microfocus X-ray Sources for Biological Crystallography

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Pushing the Limits of Microfocus X-ray Sources for Biologica...

Non-linear modeling of kinetic and equilibrium data for the adsorption of hexavalent chromium by carbon nanomaterials:Dimension and functionalization

中国晶体学会第六届学术年会暨会员代表大会（大分子晶体学分会）

作者： L.Kuttnik H.Li J.Wiesmann v.Smith S.Freisz J.graf C.Michaelsen Incoatec GmbH Bruker AXS GmbH

Modern microfocus X-ray sources define the state-of-the-art for most applications in X-ray *** sources are usually combined with multilayer X-ray mirrors which are excellent X-ray optical devices for beam shaping and preserving the brightness of the *** performance of the newest generation comes close to the performance of modern microfocus

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Chinese Journal of Chemical Engineering 2019年第4期27卷 912-919页

作者： Miguel de la Luz-Asunción Eduardo E.Pérez-Ramírez Ana L.Martínez-Hernández victor M.Castano víctor Sánchez-Mendieta Carlos velasco-Santos Facultad de Quimica Universidad Autonoma del Estado de Mexico Km. 12 de la carretera Toluca-Atlacomulco C.P. 50200 San Cayetano Toluca Estado de Mexico Mexico Tecnologico Nacional de Mexico-Instituto Tecnologico de Queretaro Division de Estudios de Posgrado e Investigacion Av. Tecnologico s/n esq. GraL Mariano Escobedo Col. Centro Historico C.P. 76000 Santiago de Queretaro Queretaro Mexico Centro de Fisica Aplicada y Tecnologia Avanzada Universidad Nacional Autonoma de Mexico Boulevard Juriquilla 3001 Queretaro 76230 Mexico

The adsorption capacities for the removal of hexavalent chromium from aqueous solutions by six carbon nanomaterials have been evaluated. Single-walled and multi-walled carbon nanotubes as received and after oxidation treatment, graphene oxide and reduced graphene oxide are the materials with different dimension and functionalization compared in this research. Carbon nanotubes have been modified using hydrogen peroxide as oxidizing agent under microwave radiation. The oxidation treatment on carbon nanotubes has a positive effect increasing the adsorbent–adsorbate interaction. Rate-controlling mechanisms and equilibrium data are analyzed using non-linear models. Non-linear method is proposed as the most suitable method for determining the kinetic and equilibrium parameters. The values of adsorption energy(E) obtained from the Dubinin–Radushkevich isotherm,have been found around 0.371 and 0.870 k J·mol-1, indicating physical adsorption. Therefore, the pseudo-second order model represents better the kinetic experimental data. The results show that the Langmuir isotherm provides a slightly better fit to the experimental data compared with the Freundlich isotherm, indicating homogeneous distribution of active sites on carbon nanomaterials and monolayer adsorption. The separation factors RLare found in the range of 0–1, suggesting that the adsorption process is suitable for all adsorbents. The mechanisms for hexavalent chromium removal have been proposed as electrostatic interactions and hydrogen bonding.

关键词： Carbon nanotubes Graphene Adsorption Hexavalent chromium Kinetic

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静脉与肌肉给予胰高血糖素与东莨菪碱对小肠抗蠕动作用的对照性评价

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国际医学放射学杂志 2012年第4期 401-401页

作者： A. Gutzeit C.A. Binkert D.M. Koh K. Hergan C. von Weymarn N. graf 唐光健 Department of Radiology Cantonal Hospital WinterthurBrauerstrasse 15 8401 Winterthur Switzerland

摘要目的前瞻性评价不同给药途径对于胰高血糖素(GLU)或N-丁基溴化东莨菪碱(HBB)对蠕动抑制的时间与功效。方法6例志愿者在标准化口服液体准备后随机接受了5次单独的MRI检查,检查前均给予解痉剂[静脉(i.v.)或肌肉(i.m.)注射HBB,i.v.或i... 详细信息

摘要目的前瞻性评价不同给药途径对于胰高血糖素(GLU)或N-丁基溴化东莨菪碱(HBB)对蠕动抑制的时间与功效。方法6例志愿者在标准化口服液体准备后随机接受了5次单独的MRI检查,检查前均给予解痉剂[静脉(i.v.)或肌肉(i.m.)注射HBB,i.v.或i.m.给予GLU,或按方案结合给药]。MRI扫

关键词：胰高血糖素 N-丁基溴化东莨菪碱小肠胃肠道运动抗蠕动作用