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Inducing imperfections in germanium nanowires

Nano Research 2017年第5期10卷 1510-1523页

作者： Subhajit Biswas sven barth Justin D. Holmes Materials Chemistry & Analysis Group Department of Chemistry and the Tyndall National lnstitute University College Cork Cork Ireland AMBER@CRANN Trinity College Dublin Dublin 2 Ireland Vienna University of Technology Institute of Materials Chemistry Getreidemarkt 9/BCI02 1060 Vienna Austria

Nanowires with inhomogeneous heterostructures such as polytypes and periodic twin boundaries are interesting due to their potential use as components for optical, electrical, and thermophysical applications. Additionally, the incorporation of metal impurities in semiconductor nanowires could substantially alter their electronic and optical properties. In this highlight article, we review our recent progress and understanding in the deliberate induction of imperfections, in terms of both twin boundaries and additional impurities in germanium nanowires for new/enhanced functionalities. The role of catalysts and catalyst-nanowire interfaces for the growth of engineered nanowires via a three-phase paradigm is explored. Three-phase bottom-up growth is a feasible way to incorporate and engineer imperfections such as crystal defects and impurities in semiconductor nanowires via catalyst and/or interfacial manipulation. ＂Epitaxial defect transfer＂ process and catalyst-nanowire interfacial engineering are employed to induce twin defects parallel and perpendicular to the nanowire growth axis. By inducing and manipulating twin boundaries in the metal catalysts, twin formation and density are controlled in Ge nanowires. The formation of Ge polytypes is also observed in nanowires for the growth of highly dense lateral twin boundaries. Additionally, metal impurity in the form of Sn is injected and engineered via third-party metal catalysts resulting in above-equilibrium incorporation of Sn adatoms in Ge nanowires. Sn impurities are precipitated into Ge bi-layers during Ge nanowire growth, where the impurity Sn atoms become trapped with the deposition of successive layers, thus giving an extraordinary Sn content （〉6 at.%） in Ge nanowires. A larger amount of Sn impingement （〉9 at.%） is further encouraged by utilizing the eutectic solubility of Sn in Ge along with impurity trapping.

关键词： germamum nanowire vapor-liquid-solid (VLS)growth twinning impurity incorporation

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Revised barrier function-based adaptive finite-and fixed-time convergence super-twisting control

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Journal of Systems Engineering and Electronics 2023年第3期34卷 775-782页

作者： LIU Dakai ESCHE sven Department of Mechanical Engineering Stevens Institute of TechnologyHoboken 07030USA

This paper presents an adaptive gain,finite-and fixedtime convergence super-twisting-like algorithm based on a revised barrier function,which is robust to perturbations with unknown *** is shown that this algorithm can ensure a finite-and fixed-time convergence of the sliding variable to the equilibrium,no matter what the initial conditions of the system states are,and maintain it there in a predefined vicinity of the origin without ***,the proposed method avoids the problem of overestimation of the control gain that exists in the current fixed-time adaptive ***,it shows that the revised barrier function can effectively reduce the computation load by obviating the need of increasing the magnitude of sampling step compared with the conventional barrier *** feature will be beneficial when the algorithm is implemented in *** that,the estimation of the fixed convergence time of the proposed method is derived and the impractical requirement of the preceding fixed-time adaptive control that the adaptive gains must be large enough to engender the sliding mode at time t=0 is ***,the outperformance of the proposed method over the existing counterpart method is demonstrated with a numerical simulation.

关键词： super-twisting algorithm barrier function fixed-time sliding mode control adaptive control

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Alveolar echinococcosis-spreading disease challenging clinicians: A case report and literature review

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World Journal of Gastroenterology 2013年第26期19卷 4257-4261页

作者： Georgi Atanasov Christoph Benckert Armin Thelen Dennis Tappe Matthias Frosch Dieter Teichmann Thomas FE barth Christian Wittekind Stefan Schubert sven Jonas Department of Visceral Transplantation Thoracic and Vascular Surgery Universitaetsklinik Leipzig Institute of Hygiene and Microbiology University of Würzburg Department of Infectious Diseases and Tropical Medicine Community Hospital Dresden-Neustadt Department of Pathology Universitaetsklinikum Ulm Institute of Pathology Universit tsklinikum Leipzig Department of Gastroenterology and Rheumatology Universitaetsklinik Leipzig

Human alveolar echinococcosis (AE) is a potentially deadly disease; recent studies have shown that the endemic area of Echinococcus multilocularis , its causative agent, is larger than previously known. This disease has low prevalence and remains underreported in Europe. Emerging clinical data show that diagnostic difficulties are still common. We report on a 76-year old patient suffering from AE lesions restricted to the left lobe of the liver who underwent a curative extended left hemihepatectomy. Prior to the resection a liver biopsy under the suspicion of an atypical malignancy was performed. After the intervention he developed a pseudoaneurysm of the hepatic artery that was successfully coiled. Surprisingly, during surgery, the macroscopic appearance of the tumour revealed a growth pattern that was rather typical for cystic echinococcosis (CE), i.e. , a gross tumour composed of multiple large vesicles with several centimeters in diameter. In addition, there were neither extensive adhesions nor infiltrations of the neighboring pancreas and diaphragm as was expected from previous imaging results. The unexpected diagnosis of AE was confirmed by definite histopathology, specific polymerase chain reaction and serology results. This is a rare case of unusual macroscopic presentation of AE that posed immense diagnostic challenges and had an eventful course. To our knowledge this is the first case of an autochthonous infection in this particular geographic area of Germany, the federal state of Saxony. This report may provide new hints for an expanding area of risk for AE and emphasizes the risk of complications in the scope of diagnostic procedures and the limitations of modern radiological imaging.

关键词： Alveolar echinococcosis Echinococcus multilocularis Autochthonous infection Liver resection Hemihepatectomy

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Computer vision supported by 3D geometric modelling

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Advances in Manufacturing 2014年第1期2卷 22-31页

作者： sven Fjeldaas Department of Engineering Design and Materials Norwegian University of Science and Technology

This paper suggests four data structures, one based on the other, for a geometric modeller suitable for computer vision. The structures are the key to advance from two-dimensional to three-dimensional automatic picture processing. Three application areas are indicated： one in semisynthetic design of materials, another in measurements of large three-dimensional industrial constructions, and the third one in robotics. There are comments on the software development needed.

关键词： Picture processing 3D geometric modelling Measurements

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Shaping digital earth applications through open innovation - setting the scene for a digital earth living lab

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International Journal of Digital Earth 2014年第7期7卷 594-612页

作者： sven Schade Carlos Granell European Commission Joint Research CentreInstitute for Environment and SustainabilityIspraItaly

Science and policy increasingly request for sustainable development and ***,Digital Earth undergoes a paradigm shift to an open platform that actively supports user *** the public becomes able to contribute new content,we recognize a gap in user-driven validation,feedback and requirements capture,and innovative application *** than defining Digital Earth applications top down,we see a need for methods and tools that will help building applications bottom up and driven by community *** should include a technology toolbox of geospatial and environ-mental enablers,which allow to access functional building blocks and content in multiple ways,but-equally important-enable the collaboration within partially unknown stakeholder *** validation and testing in real-life scenarios will be a central requirement when approaching the Digital Earth 2020 goals,which were articulated *** particularly argue to follow a Living Lab approach for co-creation and awareness rising in relation to environmental and geospatial *** explain why and how such a Digital Earth Living Lab could lead to a sustainable approach for developing,deploying,and using Digital Earth applications and suggest a paradigm shift for Virtual Globes becoming forums for research and innovation.

关键词： sustainable development open innovation stakeholder engagement living laboratories governance methodologies virtual globes

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Air pumping for alleviation of heavy smog in Beijing

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Science China Earth Sciences 2018年第7期61卷 973-979页

作者： Yaping SHAO sven ULBRICH Dehui CHEN Institute for Geophysics and Meteorology Department of GeosciencesUniversity of CologneCologne 50923Germany China Meteorological Administration Beijing 100081China

Beijing often suffers under heavy *** such events which occur mostly in autumn and winter,people are desperate for fresh *** formation of heavy smog is due to foremost human induced air pollution,but geographic and meteorological conditions,especially below a surface inversion,play an important *** propose to destroy the inversion by pumping air from above the inversion layer to the surface layer to alleviate the severity of the *** long-term air quality improvement depends on the reduction of air pollution emission,air pumping may provide relief in the interim for the Beijing *** estimate that an air pumping at a rate 2×10~7m^3s^(–1)can lead to significantly improved air quality in Beijing,due to(1)direct clean air input;(2)increased instability and vertical mixing and(3)a positive radiation-mixing *** pumping requires an energy input of 10 GW,comparable with the energy consumption in Beijing for air conditioning in *** propose to use wind energy from Inner Mongolia for the pumping,which has currently an installed wind energy capacity of 70GW.

关键词： Beijing air quality Air pumping Numerical modelling Inversion

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Insights from the degradation mechanism of cyclin D into targeted therapy of the cancer cell cycle

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Signal Transduction and Targeted Therapy 2021年第9期6卷 2607-2608页

作者： Maiwen Caudron-Herger sven Diederichs Division of RNA Biology&Cancer German Cancer Research Center(DKFZ)HeidelbergGermany Division of Cancer Research Department of Thoracic SurgeryMedical Center-University of FreiburgUniversity of FreiburgGerman Cancer Consortium(DKTK)-Partner Site FreiburgFreiburgGermany

The control of cell proliferation is an essential feature in development and tissue homeostasis and is prominently deregulated in *** publications in Nature now uncover the mechanism underlying the degradation of cycl... 详细信息

关键词： targeted homeostasis cancer

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The big data challenge-and how polypharmacology supports the translation from pre-clinical research into clinical use against neurodegenerative diseases and beyond

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Neural Regeneration Research 2024年第8期19卷 1647-1648页

作者： sven Marcel Stefan Muhammad Rafehi Drug Development and Chemical Biology Lübeck Institute of Experimental Dermatology(LIED)University of Lübeck and University Medical Center Schleswig-HolsteinLübeckGermany Department of Pathology Section of NeuropathologyTranslational Neurodegeneration Research and Neuropathology LabUniversity of Oslo and Oslo University HospitalOsloNorway School of Medical Sciences Faculty of Medicine and HealthUniversity of SydneySydneyNSWAustralia Institute of Clinical Pharmacology University Medical Center GöttingenGöttingenGermany Department of Medical Education Augsburg University MedicineAugsburgGermany

Introductory comments:The identification and validation of disease-modifying proteins are fundamental aspects in drug ***,the m ultifactority of n eurodegen era tive diseases poses a real challenge for targeted ***,the behavior of individually(over-)expressed to rget proteins in vitro is likely to differ from their actual functional behavior when embedded in cascades and pathways in vivo.

关键词： translation beyond likely

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Early pregnancy in the horse revisited–does exception prove the rule?

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Journal of Animal Science and Biotechnology 2016年第2期7卷 117-124页

作者： Christine Aurich sven Budik Artificial Insemination and Embryo Transfer Vetmeduni ViennaVeterinarplatz 11210 ViennaAustria

Early equine pregnancy shares many features with that of more intensively assessed domestic animals species, but there are also characteristic differences. Some of those are poorly understood. Descent of the equine conceptus into the uterine lumen occurs at day 5 to 6 after ovulation but is only possible when the embryo secretes prostaglandin E2. Although maintenance of equine pregnancy probably involves secretion of a conceptus derived anti-luteolytic factor, this agent has not been identified. Rapid growth, conceptus mobility and presence of an acellular capsule at the time of maternal recognition of pregnancy, i.e. between days 12 and 14, are prerequisites to avoid pregnancy loss. Progesterone together with 5α-pregnanes is secreted by the corpus luteum and induces the production of endometrial histotroph which is responsible for conceptus nutrition until placention. A stable contact between the outer trophoblast layer of the allantochorion and the luminal epithelium of the endometrium is not established before days 40 to 42 of pregnancy.

关键词： Conceptus Horse Maternal recognition Pregnancy

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Towards Accurate Bit Error Simulation in Wireless Sensor Networks Including Environmental Influences

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Journal of Computer Science & Technology 2020年第4期35卷 809-824页

作者： sven Pullwitt Robert Hartung Ulf Kulau Lars Wolf Institute for Operating Systems and Computer Networks Technische Universitat BraunschweigBraunschweig 38106 Germany

Simulation is a common technique for the evaluation of new approaches and protocols in networked systems and provides many ***,it is also well known that the relevance of the simulation results for real-world applications depends on the various models which are used within the simulation,e.g.,for the characteristics of the radio *** this paper,we introduce the Extended Multipath Raytracing Model,an extension to the ray-tracing radio medium available in Cooja,to improve the modelling of wireless links in simulated Wireless Sensor *** extension allows the simulation of environmental influences onto links on a per node basis,allowing the analysis of various effects observed in experiments in a virtual ***,the packet-based modelling of transmission errors is extended to provide the simulation of bit errors,allowing new usage scenarios,like the simulation of error detection and Forward Error Correction codes in Cooja.

关键词： bit error Contiki Cooja environmental influence simulation wireless sensor network

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