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An open-source albedo-wand for the measurement of sea ice albedo

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Advances in Polar Science 2019年第2期30卷 106-117页

作者： christian KATLEIN Alfred-wegener-Institut Helmholtz Zentrum für Polar-und Meeresforschung Takuvik Joint International Laboratory Université Laval and CNRS

Surface albedo is defined as the ratio of incident and reflected solar irradiance and describes the ability of a surface to reflect, rather than absorb incident solar shortwave radiation. It is thus a crucial parameter in the climate system, particularly in the polar oceans. Sea ice albedo is a main driver for light transmission into the polar oceans and thus has a high impact on ocean warming, ice melting and marine primary production. During spring and summer, sea ice albedo can exhibit a significant spatial variability caused by meltwater accumulations on the ice. While complex and expensive solutions for albedo measurements are already available, we want to present a simple open-source design that allows for affordable mapping of spatially varying surface albedo on sea ice and beyond. Our solution is based on off-the-shelf components, such as an Arduino microcontroller integrating affordable light sensors, a GPS unit, data recording on memory card and data display into a simple field strengthened unit. We provide example data from two Arctic field deployments showing the capabilities and limitations of this system.

关键词： sea ice albedo spatial variability mapping GPS open-source

Biologically Inspired Girder Structure for the Synchrotron Radiation Facility PETRA IV

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Journal of Bionic Engineering 2023年第5期20卷 1996-2017页

作者： Simone Andresen Norbert Meyners Daniel Thoden Markus Körfer christian Hamm Bionic Lightweight Design&Functional Morphology Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research(AWI)Am Handelshafen 1227570BremerhavenGermany Deutsches Elektronen-Synchrotron(DESY) Notkestraße 8522607HamburgGermany

Lightweight structures are widely used across different industry ***,they get easily excited by external influences,such as *** high vibration amplitudes can be avoided by shifting the structural eigenfrequencies,which can be achieved adapting the structural design considering optimisation procedures and structures primarily inspired by *** procedures has been applied to the development process of a girder structure installed in a synchrotron radiation facility to support heavy magnets and other *** objective was to design a 2.9 m long girder structure with high eigenfrequencies,a high stiffness and a low *** on a topology optimisation result,a parametric beam–shell model including biologically inspired structures(e.g.,Voronoi combs,ribs,and soft and organic-looking transitions)was built *** subsequent cross-sectional optimisation using evolutionary strategic optimisation revealed an optimum girder structure,which was successfully manufactured using the casting *** measurements validated the numerical *** changes in the specifications can be implemented in the bio-inspired development process to obtain adapted girder structures.

关键词： Biomimetics Eigenfrequency maximisation Evolutionary structural optimisation Lightweight design Topology optimisation Voronoi combs

Upper limits for chlorophyll a changes with brine volume in sea ice during the austral spring in the Weddell Sea,Antarctica

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Acta Oceanologica Sinica 2016年第2期35卷 68-75页

作者： LI Zhijun LI Runling WANG Zipan HAAS christian DIECKMANN Gerhard State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China Department of Earth and Space Science and Engineering York University Toronto M3J1P3 Canada Alfred wegener Institute Helmholtz Centre for Polar and Marine Research Bremerhaven D-27570 Germany

During the winter and spring of 2006, we investigated the sea ice physics and marine biology in the northwest Weddell Sea, Antarctica aboard R/V Polarstern. We determined the texture of each ice core and 71 ice crystal thin sections from 27 ice cores. We analyzed 393 ice cores, their temperatures, 348 block density and salinity samples,and 311 chlorophyll a（Chl a） and phaeophytin samples along the cruise route during the investigation. Based on the vertical distributions of 302 groups of data for the ice porosity and Chl a content in the ice at the same position, we obtained new evidence that ice physical parameters influence the Chl a content in ice. We collected snow and ice thickness data, and established the effects of the snow and ice thickness on the Chl a blooms under the ice, as well as the relationships between the activity of ice algae cells and the brine volume in ice according to the principle of environmental control of the ecological balance. We determined the upper limits for Chl a in the brine volume of granular and columnar ice in the Antarctica, thereby demonstrating the effects of ice crystals on brine drainage, and the contributions of the physical properties of sea ice to Chl a blooms near the ice bottom and on the ice-water interface in the austral spring. Moreover, we found that the physical properties of sea ice affect ice algae and they are key control elements that modulate marine phytoplankton blooms in the ice-covered waters around Antarctica.

关键词： Antarctic brine volume chlorophyll a ice crystal mode sea ice

Oxidative stress in Microcystis aeruginosa as a consequence of global climate change

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BIOCELL 2016年第1期40卷 23-25页

作者： MARCELO HERNANDO christian HOUGHTON LEDA GIANNUZZI BERND KROCK DARIO ANDRINOLO GABRIELA MALANGA Departamento de Radiobiología Comisión Nacional de Energía AtómicaBuenos AiresArgentina Area de Toxicología Dpto.de Cs BiológicasFacultad de Ciencias Exactas.UNLP Alfred wegener Institute BremerhavenGermany Instituto de Bioquímica y Medicina Molecular(IBIMOL)-Universidad de Buenos Aires(UBA) CONICETFisicoquímicaFacultad de Farmacia y BioquímicaJunín 956(C1113AAD)Buenos Aires.Argentina

Cyanobacteria are phototrophic organisms with great ecological and economical *** of the genus Microcystis are known for their potential ability to synthesize toxins,notably *** is a growing interest in the evaluation of oxidative stress in relation to the impact of global climate change on natural ecosystems in different trophic *** studies have focused on the analysis of organismal responses to mitigate the damage by controlling the generation of reactive oxygen *** in environ-mental factors caused by climate change generate a situation of oxidative damage in Microcystis aeruginosa as a direct or indirect *** this study we evaluate the effects of ultraviolet radiation and temperature on physiological and biochemical responses of a native ***(strain CAAT 2005-3).The results from the exposure to ultraviolet radiation doses and temperature changes suggest a high ability of *** to detect a potential stress situation as a consequence of reactive species production and to rapidly initiate antioxidant *** catalase activity is an antioxidant protection mechanism in *** for short and long term exposure to different changes in environmental ***,we found a ultraviolet-B radiation threshold dose above which oxidative stress exceeds the antioxidant protection and damage *** addition our results are in agreement with recent findings suggesting that microcystins may act as protein-modulating metabolites and protection against reactive oxygen *** is concluded that cyanobacteria have adaptative mechanisms that could lead to the replacement of species highly susceptible to oxidative stress by others with a higher system of antioxidant protection.

关键词： oxidative stress Cyanobacteria UVR temperature

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南极威德尔海冬季冰脊形拖曳力

水科学进展 2012年第6期23卷 869-874页

作者：谭冰卢鹏李志军 HAAS christian NICOLAUS Marcel 大连理工大学海岸和近海工程国家重点实验室南阳师范学院数学与统计学院 Department of Earth and Atmospheric Sciences University of AlbertaEdmonton T6G 2E3Canada Alfred wegener Institute for Polar and Marine Research Bremerhaven 24 27570Germany

利用2006年南极威德尔海冬季科学考察期间由机载激光高度计测得的海冰上表面形态数据,以拖曳分割理论为基础研究了冰脊形拖曳力及其对冰-气总拖曳力的贡献以及中性条件下对应10 m高度处风速的冰-气拖曳系数Cdn(10)。结果显示,在密集冰区... 详细信息

利用2006年南极威德尔海冬季科学考察期间由机载激光高度计测得的海冰上表面形态数据,以拖曳分割理论为基础研究了冰脊形拖曳力及其对冰-气总拖曳力的贡献以及中性条件下对应10 m高度处风速的冰-气拖曳系数Cdn(10)。结果显示,在密集冰区,冰脊形拖曳力及其对总拖曳力的贡献随冰脊强度(脊高/脊距)的增大呈递增趋势,而随粗糙长度的增大而减小,对应于威德尔海冬季典型冰脊强度和粗糙长度,占总拖曳力的35%,说明了冰脊形拖曳力在冰-气界面动量交换中的重要作用。Cdn(10)随冰脊强度的增大而增大,但冰脊强度较小时,Cdn(10)随粗糙长度增大而增大;而对较大的冰脊强度,Cdn(10)则随粗糙长度增大而减小。

关键词：南极冰脊形拖曳力拖曳系数威德尔海

南极春季海冰物理对叶绿素控制作用的统计分析

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中国环境科学 2015年第9期35卷 2813-2819页

作者：李志军李润玲王自磐 christian Haas Gehard Dieckmann 大连理工大学海岸和近海工程国家重点实验室辽宁大连116024 国家海洋局第二海洋研究所浙江杭州310012 Department of Earth and Space Science and Engineering York UniversityToronto M3J1P3Canada Alfred wegener Institute Helmholtz Centre for Polar and Marine Research D-27570BremerhavenGermany

利用2006年南极威德尔海西北海域冬末春初的冰芯晶体结构,和302组冰芯温度、盐度、密度、叶绿素-a、脱镁叶绿素数据,以及冰底面叶绿素a垂直分布数据,进一步确定积雪/海冰厚度、冰内温度、盐度、密度对冰内和冰下叶绿素a的贡献.利用环境... 详细信息

利用2006年南极威德尔海西北海域冬末春初的冰芯晶体结构,和302组冰芯温度、盐度、密度、叶绿素-a、脱镁叶绿素数据,以及冰底面叶绿素a垂直分布数据,进一步确定积雪/海冰厚度、冰内温度、盐度、密度对冰内和冰下叶绿素a的贡献.利用环境制约与生态平衡原理,阐明积雪/海冰厚度通过阻碍光通量对冰底叶绿素的效应,以及卤水体积通过冰温度和盐度体现对冰藻细胞活性的抑制作用.统计分析不仅确立了南极海冰冰内卤水体积-内叶绿素a的逻辑斯蒂上限含量曲线,并体现出粒状冰同柱状冰卤水排泄方式的差异及其对冰底春季叶绿素a快速增长的冰物理贡献.冰藻细胞活性指标小于0.5的仅占4.3%,该数据为南极冰藻是维持南极冰区浮游植物旺发的主导因子提供了重要依据.

关键词：南极海冰晶体结构卤水体积叶绿素a 模式

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南极冬季威德尔海冰脊的表面形态

水科学进展 2012年第1期23卷 117-123页

作者：谭冰李志军卢鹏 HASS christian NICOLAUS Marcel 大连理工大学海岸和近海工程国家重点实验室河南省南阳师范学院数学与统计学院 Department of Earth and Atmospheric Sciences University of AlbertaEdmonton T6G 2E3Canada Alfred wegener Institute for Polar and Marine Research Bremerhaven 24 27570Germany

基于2006年南极威德尔海冬季科学考察期间由机载激光测高仪测得的海冰上表面高度数据,以脊高和脊距的理论与实测概率密度的相对误差之和为性能指标,以切断高度为控制变量建立优化模型。结果表明,W'80型分布和对数正态分布分别与实测脊... 详细信息

基于2006年南极威德尔海冬季科学考察期间由机载激光测高仪测得的海冰上表面高度数据,以脊高和脊距的理论与实测概率密度的相对误差之和为性能指标,以切断高度为控制变量建立优化模型。结果表明,W'80型分布和对数正态分布分别与实测脊高和脊距分布吻合较好;最优切断高度为0.62 m。进而从海冰表面起伏中确定出冰脊。利用k均值聚类算法以冰脊强度(Ri)为标准将剖面分为3类(Ri≤0.01,0.010.026)。对应各类剖面分别有:平均脊高为0.99 m,1.12 m和1.17 m;平均脊距为232 m,54 m和31 m。利用数学模型估算并分析了多脊冰平均厚度、有效厚度,帆横截面积及冰脊所占面积,这些参数值均随冰脊强度增大而增大。

关键词：南极冰脊参数辨识形态

Indirect targeting of MYC sensitizes pancreatic cancer cells to mechanistic target of rapamycin (mTOR) inhibition

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Cancer Communications 2022年第4期42卷 360-364页

作者： christian Schneeweis Zonera HassanKatja Ascherl Matthias Wirth Stella Koutsouli Felix Orben Lukas Krauß Carolin Schneider Rupert Ollinger Oliver HKrämer Roland Rad Maximilian Reichert Maria SRobles Dieter Saur Günter Schneider Medical Clinic and Polyclinic II Klinikum rechts der IsarTechnical University MunichMunich 81675Germany Department of Hematology Oncology and Tumor ImmunologyCharite-Universitatsmedizin BerlinCorporate Member of Freie Universitat BerlinHumboldt-Universitat zu Berlin and Berlin Institute of HealthBerlin 12203Germany Institute of Medical Psychology and Biomedical Center(BMC) Faculty of MedicineLMU MunichMunich 80336Germany Institute of Molecular Oncology and Functional Genomics TUM School of MedicineTechnical University MunichMunich 81675Germany Department of Toxicology University of Mainz Medical CenterMainz 55131Germany German Cancer Research Center(DKFZ)and German Cancer Consortium(DKTK) Heidelberg 69120Germany Center for Protein Assemblies(CPA) Technical University of MunichGarching 85747Germany Institute for Translational Cancer Research and Experimental Cancer Therapy Technical University MunichMunich 81675Germany Department of General Visceral and Pediatric SurgeryUniversity Medical Center GottingenGottingen 37075Germany

Dear Editor,Pancreatic ductal adenocarcinoma(PDAC)remains a significant health problem with an increase in the incidence and a five-year survival rate of only 10%[1].The Phosphoinositide 3-kinase-protein kinase-B-mechanistic target of rapamycin(PI3K-AKT-mTOR)pathway is a driver pathway in PDAC and an important therapeutic target[2].We[3]and others[4–6]have demonstrated that the mTOR kinase is a therapeutic target in PDAC,and rationally designed mTOR inhibitor(mTORi)-based combination therapies are emerging[2].

关键词： rapamycin therapeutic adenocarcinoma

X-ray focusing with efficient high-NA multilayer Laue lenses

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Light(Science & Applications) 2017年第1期6卷 95-103页

作者： Saša Bajt Mauro Prasciolu Holger Fleckenstein Martin Domaracký Henry N Chapman Andrew J Morgan Oleksandr Yefanov Marc Messerschmidt Yang Du Kevin T Murray Valerio Mariani Manuela Kuhn Steven Aplin Kanupriya Pande Pablo Villanueva-Perez Karolina Stachnik Joe PJ Chen Andrzej Andrejczuk Alke Meents Anja Burkhardt David Pennicard Xiaojing Huang Hanfei Yan Evgeny Nazaretski Yong S Chu christian E Hamm Photon Science DESYNotkestrasse 85Hamburg 22607Germany Center for Free-Electron Laser Science DESYNotkestrasse 85Hamburg 22607Germany Department of Physics University of HamburgLuruper Chaussee 149Hamburg 22607Germany Centre for Ultrafast Imaging Luruper Chaussee 149Hamburg 22607Germany National Science Foundation BioXFEL Science and Technology Center 700 Ellicott StreetBuffaloNY 14203USA Department of Physics Arizona State UniversityTempeAZ 85287USA Faculty of Physics University of BialystokCiolkowskiego 1L Str.Bialystok 15-245Poland National Synchrotron Light Source II Brookhaven National LaboratoryUptonNY 11973USA Alfred-wegener Institute Helmholtz Center for Polar and Marine ResearchBussestr.27Bremerhaven 27570Germany

Multilayer Laue lenses are volume diffraction elements for the efficient focusing of *** a new manufacturing technique that we introduced,it is possible to fabricate lenses of sufficiently high numerical aperture(NA)to achieve focal spot sizes below 10 *** alternating layers of the materials that form the lens must span a broad range of thicknesses on the nanometer scale to achieve the necessary range of X-ray deflection angles required to achieve a high *** poses a challenge to both the accuracy of the deposition process and the control of the materials properties,which often vary with layer *** introduced a new pair of materials—tungsten carbide and silicon carbide—to prepare layered structures with smooth and sharp interfaces and with no material phase transitions that hampered the manufacture of previous *** a pair of multilayer Laue lenses(MLLs)fabricated from this system,we achieved a two-dimensional focus of 8.4×6.8 nm2 at a photon energy of 16.3 keV with high diffraction efficiency and demonstrated scanning-based imaging of samples with a resolution well below 10 *** high NA also allowed projection holographic imaging with strong phase contrast over a large range of *** error analysis indicates the possibility of achieving 1 nm focusing.

关键词： multilayer Laue lenses multilayers ptychography X-ray holography X-ray optics