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世界建筑导报 2017年第6期32卷 23-28页

作者：林纯正 Samson Lau Yu-Wei Chang Eric Wong jens Kongstad olesen 伦敦大学巴特莱特学院

"鬣蜥栖息在写字楼和百货商店的玻璃窗上,冻僵的脑袋生硬地摆动,镜中同伴在四处爬行。如果没有这些爬行类动物,淹没过半的写字楼四周的泻湖和河湾本应是一道另类的、梦幻般的风景,但鬣蜥和皇冠鬣蜥的存在瞬间将人们从梦幻之中带回现实... 详细信息

"鬣蜥栖息在写字楼和百货商店的玻璃窗上,冻僵的脑袋生硬地摆动,镜中同伴在四处爬行。如果没有这些爬行类动物,淹没过半的写字楼四周的泻湖和河湾本应是一道另类的、梦幻般的风景,但鬣蜥和皇冠鬣蜥的存在瞬间将人们从梦幻之中带回现实。随着鬣蜥端坐在废弃的会议室内,伦敦已被爬行类动物占领。"——詹姆斯·巴拉德《沉没的世界》(1962年)

关键词：巴拉德英国民众诺亚方舟

Implications of tree species–environment relationships for the responsiveness of Himalayan krummholz treelines to climate change

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Journal of mountain Science 2017年第3期14卷 453-473页

作者： Niels SCHWAB Udo SCHICKHOFF Birgit BURZLE michael mULLER Jurgen BOHNER Ram Prasad CHAUDHARY Thomas SCHOLTEN jens OLDELAND CEN Center for Earth System Research and Sustainability Institute of GeographyUniversity of HamburgBundesstrafle 5520146 HamburgGermany Department of Geosciences Chair of Soil Science and CeomorphologyUniversity of TübingenGermany Research Centre for Applied Science and Technology&Central Department of Botany Tribhuvan UniversityNepal Biocentre Klein Flottbek University of HamburgOhnhorststr.1822609 HamburgGermany

Climate warming is expected to advance treelines to higher elevations. However, empirical studies in diverse mountain ranges give evidence of both advancing alpine treelines as well as rather insignificant responses. In this context, we aim at investigating the sensitivity and responsiveness of the near-natural treeline ecotone in Rolwaling Himal, Nepal, to climate warming. We analysed population densities of tree species along the treeline ecotone from closed forest stands via the krummholz belt to alpine dwarf shrub heaths(3700-4200 m) at 50 plots in 2013 and 2014. We quantified species-environment relationships, i.e. the change ofenvironmental conditions(e.g., nutrient and thermal deficits, plant interactions) across the ecotone by means of redundancy analyses, variation partitioning and distance-based moran's eigenvector maps. In particular, we focus on explaining the high competitiveness of Rhododendron campanulatum forming a dense krummholz belt and on the implications for the responsiveness of Himalayan krummholz treelines to climate change. Results indicate that treeline trees in the ecotone show species-specific responses to the influence of environmental parameters, and that juvenile and adult tree responses are modulated by environmental constraints in differing intensity. moreover, the species-environment relationships suggest that the investigated krummholz belt will largely prevent theupward migration of other tree species and thus constrain the future response of Himalayan krummholz treelines to climate warming.

关键词： Himalaya 尼泊尔人口结构杜鹃花属 campanulatum 空间模式种类环境关系看台密度划分的变化

Human-driven topographic effects on the distribution of forest in a flat, lowland agricultural region

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Journal of Geographical Sciences 2014年第1期24卷 76-92页

作者： mette V. ODGAARD Peder K. BOCHER Tommy DALGAARD Jesper E. mOESLUND jens-Christian SVENNING Department of Agroecology Aarhus University Blichers AIIe 20 DK-8830 Tjele Denmark Ecoinformatics & Biodiversity Group Department of Bioscience Aarhus University Ny Munkegade 114DK-8000 Aarhus C Denmark Department of Computer Science Aarhus University Abogade 34 DK-8200 Aarhus N Denmark

Complex topography buffers forests against deforestation in mountainous regions. However, it is unknown if terrain also shapes forest distribution in lowlands where human impacts are likely to be less constrained by terrain. In such regions, if important at all, to- pographic effects will depend on cultural-historical factors and thus be human-driven （an- thropogenic） rather than natural, except in regions where the general climate or extreme soils limit the occurrence of forests. We used spatial regression modeling to assess the extent to which topographic factors explain forest distribution （presence-absence at a 48x48 m resolu- tion） in a lowland agricultural region （Denmark, 43,075 km2） at regional and landscape scales （whole study area and 10x10 km grid cells, respectively）, how landscape-scale for- est-topography relationships vary geographically, and which potential drivers （topographic heterogeneity, forest cover, clay content, coastal/inland location） determine this geographic heterogeneity. Given a moist temperate climate and non-extreme soils all landscapes in Denmark would naturally be largely forest covered, and any topographic relationships will be totally or primarily human-driven. At regional scale, topographic predictors explained only 5% of the distribution of forest. In contrast, the explanatory power of topography varied from 0%-61% at landscape scale, with clear geographic patterning. Explanatory power of topog- raphy at landscape scale was moderately dependent on the potential drivers, with topog- raphic control being strongest in areas with high topographic heterogeneity and little forest cover. However, these conditioning effects were themselves geographically variable. Our findings show that topography by shaping human land-use can affect forest distribution even in flat, lowland regions, but especially via localized, geographically variable effects.

关键词： Europe forest cover geographically weighted regression human impact landscape development topography vegetation distribution.

Hydrothermally induced diagenesis: Evidence from shallow marinedeltaic sediments, WilhelmØya, Svalbard

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Geoscience Frontiers 2019年第2期10卷 629-649页

作者： Beyene G.Haile Urszula Czarniecka Kelai Xi Aleksandra Smyrak-Sikora jens Jahren Alvar Braathen Helge Hellevang Department of Geosciences University of Oslo Institute of Geological Sciences Polish Academy of Sciences School of Geosciences China University of Petroleum The University Centre in Svalbard (UNIS)

Sedimentary basins containing igneous intrusions within sedimentary reservoir units represent an important risk in petroleum exploration. The Upper Triassic to Lower Jurassic sediments at Wilhelm?ya(Svalbard) contains reservoir heterogeneity as a result of sill emplacement and represent a unique case study to better understand the effect of magmatic intrusions on the general burial diagenesis of siliciclastic sediments. Sills develop contact metamorphic aureoles by conduction as presented in many earlier studies. However, there is significant impact of localized hydrothermal circulation systems affecting reservoir sediments at considerable distance from the sill intrusions. Dolerite sill intrusions in the studied area are of limited vertical extent(～12 m thick), but created localized hydrothermal convection cells affecting sediments at considerable distance(more than five times the thickness of the sill)from the intrusions. We present evidence that the sedimentary sequence can be divided into two units:(1) the bulk poorly lithified sediment with a maximum burial temperature much lower than 60-70 ℃,and(2) thinner intervals outside the contact zone that have experienced hydrothermal temperatures(around 140 ℃). The main diagenetic alteration associated with normal burial diagenesis is minor mechanical plastic deformation of ductile grains such as mica. mineral grain contacts show no evidence of pressure dissolution and the vitrinite reflectance suggests a maximum temperature of ～40 ℃. Contrary to this, part of the sediment, preferentially along calcite cemented flow baffles, show evidence of hydrothermal alteration. These hydrothermally altered sediment sections are characterized by recrystallized carbonate cemented intervals. Further, the hydrothermal solutions have resulted in localized sericitization(illitization) of feldspars, albitization of both K-feldspar and plagioclase and the formation of fibrous illite nucleated on kaolinite. These observations suggest hydro

关键词： Diagenesis Sill intrusions Hydrothermal convection cells Carbonate cement Sericitization of feldspars

microscopic Image Analysis for Life Science Applications 1 Har/Cdr

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Obeticholic acid for severe bile acid diarrhea with intestinal failure:A case report and review of the literature

丛书名： Bioinformatics & Biomedical Imaging

2008年

作者： Wong, Stephen T. C. machiraju, Raghu Rittscher, jens

ISBN: (数字)9781596932371

ISBN: (纸本)9781596932364;9781596932371

Bioimaging in life sciences is a burgeoning area that is of growing interest to today's professionals and researchers in the field. This is the first book that bridges the gap between biomedical imaging and the bioscience community. This unique resource gives professionals a detailed understanding of imaging platforms, fluorescence imaging, and fundamental image processing algorithms. Further, it guides readers through the application of advanced image analysis methods and techniques to specific biological problems. The book presents applications that span a wide range of scales, from the detection of signaling events in sub-cellular structures, to the automated analysis of tissue structures. Other critical areas discussed include the dynamics of cell populations and in vivo microscopy. A DVD is also included. It contains full-color images, movies and other valuable supplementary material that further illustrate topics discussed in the book

关键词： Image analysis microscopy Imaging systems

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World Journal of Gastroenterology 2018年第21期24卷 2320-2326页

作者： Christian Lodberg Hvas Peter Ott Peter Paine Simon Lal Soren Peter Jorgensen jens Frederik Dahlerup Department of Hepatology and Gastroenterology Aarhus University HospitalAarhus C 8000Denmark Department of Gastroenterology Salford Royal NHS Foundation TrustSalfordManchester M6 8HDUnited Kingdom

Bile acid diarrhea results from excessive amounts of bile acids entering the colon due to hepatic overexcretion of bile acids or bile acid malabsorption in the terminal ileum. The main therapies include bile acid sequestrants, such as colestyramine and colesevelam, which may be given in combination with the opioid receptor agonist loperamide. Some patients are refractory to conventional treatments. We report the use of the farnesoid X receptor agonist obeticholic acid in a patient with refractory bile acid diarrhea and subsequent intestinal failure. A 32-year-old woman with quiescent colonic Crohn's disease and a normal terminal ileum had been diagnosed with severe bile acid malabsorption and complained of watery diarrhea and fatigue. The diarrhea resulted in hypokalemia and sodium depletion that made her dependent on twice weekly intravenous fluid and electrolyte infusions. Conventional therapies with colestyramine, colesevelam, and loperamide had no effect. Second-line antisecretory therapies with pantoprazole, liraglutide, and octreotide also failed. Third-line treatment with obeticholic acid reduced the number of stools from an average of 13 to an average of 7 per 24h and improved the patient's quality of life. The fluid and electrolyte balances normalized. The effect was sustained during follow-up for 6 mo with treatment at a daily dosage of 25 mg. The diarrhea worsened shortly after cessation of obeticholic acid. This case report supports the initial report that obeticholic acid may reduce bile acid production and improve symptoms in patients with bile acid diarrhea.

关键词： Bile acid malabsorption Diarrhea Farnesoid X-activated receptor Crohn’s disease

Stimulated emission at 1.54 μm from erbium/oxygen-doped silicon-based light-emitting diodes

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Photonics Research 2021年第5期9卷 714-721页

作者： JIN HONG HUImIN WEN JIAJING HE JINGQUAN LIU YAPING DAN jens W.TOmm FANGYU YUE JUNHAO CHU CHUNGANG DUAN Key Laboratory of Polar materials and Devices Ministry of EducationEast China Normal UniversityShanghai 200241China National Key Laboratory of Science and Technology on micro/Nano Fabrication Laboratory Department of Micro/Nano ElectronicsUniversity of Michigan-Shanghai Jiao Tong University Joint InstituteShanghai Jiao Tong UniversityShanghai 200240China max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie 12489 BerlinGermany National Laboratory for Infrared Physics Shanghai Institute of Technical PhysicsChinese Academy of SciencesShanghai 200083China

Silicon-based light sources, including light-emitting diodes(LEDs) and laser diodes(LDs) for information transmission, are urgently needed for developing monolithic integrated silicon photonics. Silicon with erbium ions(Er^(3+)) doped by ion implantation is considered a promising approach, but it suffers from an extremely low quantum efficiency. Here we report an electrically pumped superlinear emission at 1.54 μm from Er/O-doped silicon planar LEDs, which are produced by applying a new deep cooling process. Stimulated emission at room temperature is realized with a low threshold current of ~6 mA(~0.8 A∕cm^(2)). Time-resolved photoluminescence and photocurrent results have revealed the complex carrier transfer dynamics by relaxing electrons from the Si conduction band to the Er^(3+) ion. This picture differs from the frequently assumed energy transfer via electron–hole pair recombination of the silicon host. moreover, the amplified emission from the LEDs is likely due to a quasi-continuous Er/O-related donor band created by the deep cooling technique. This work paves the way for fabricating superluminescent diodes or efficient LEDs at communication wavelengths based on rare-earth-doped silicon.

关键词： diodes pumped light

mont Terri试验场mine-by巷道开挖近场响应模拟分析

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岩石力学与工程学报 2014年第8期33卷 1626-1634页

作者：李连崇 Liu Huihai Birkholzer jens Vietor Tim 大连理工大学土木工程学院辽宁大连116024 劳伦斯伯克利国家实验室地球科学部美国伯克利94720 瑞士国家放射性废物处置公司

瑞士mont Terri地下实验室于2008年构建mine-by(mB)Niche巷道,并围绕其中的mB Niche 2进行开挖诱发Opalinus Clay黏土岩围岩变形及流固耦合特征的现场实测分析。以mB Niche 2巷道为背景工程,利用基于双应变胡克模型(TPHm)的数值模拟方法... 详细信息

瑞士mont Terri地下实验室于2008年构建mine-by(mB)Niche巷道,并围绕其中的mB Niche 2进行开挖诱发Opalinus Clay黏土岩围岩变形及流固耦合特征的现场实测分析。以mB Niche 2巷道为背景工程,利用基于双应变胡克模型(TPHm)的数值模拟方法,对mB Niche 2巷道的开挖过程进行模拟分析,计算结果较为准确地反映开挖卸载诱发的近场围岩变形行为、损伤区及孔隙水压力演化特征。模拟结果显示,巷道拱顶径向位移可达甚至超过10 mm,两帮破坏深度可达1.4 m,孔隙压力的扰动区最远可出现在掌子面前方11 m左右,最大孔隙压力可抬升至3.3 mPa,模拟结果与现场实测值表现出较好的一致性。基于双应变胡克模型TPHm的计算结果较基于传统胡克模型SPHm的计算结果更趋于符合实际,这在一定程度上反映出TPHm较好地捕捉到岩石中孔隙、裂隙等的自然应变(真应变)的物理本质,强调合适的本构模型在卸荷开挖工程问题模拟分析中的重要性。

关键词：隧道工程 mont Terri试验场 mine-by巷道开挖胡克定律数值模拟

Ultrasonic Testing Combined with Pattern Recognition for the Detection of Kissing Bonds

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Open Journal of Composite materials 2019年第3期9卷 260-270页

作者： jens Schuster David müller ming-Hong Chen Quentin Govignon Institute for Polymer Technology West-Palatinate University of Applied Sciences Kaiserslautern Pirmasens Germany Institut Clément Ader école des Mines d’Albi Albi France

Kissing bonds are defects in the adhesive bonds with intimate contact of touching surface but considerably lowered shear strength. Their detection specifically in the aerospace area is so not satisfactory. Usually, kissing bonds are inconspicuous in ultrasonic C-scans. However, the determination of attributes in the time domain and the frequency domain of an ultrasound signal provides the opportunity to derive a pattern for bonded area. Deviations from the pattern found in inconspicuous bonding areas indicate kissing bonds. The survey described here deals with the manufacturing of adhesively joint samples that purposefully include kissing bonds, as well as potential solutions for detecting them through ultrasonic testing combined with pattern recognition. The properties of the epoxy-based adhesive were varied by changing the mixing ratios between resin and hardener. Samples with a mixing ratio far apart from the manufacturer’s recommendation with an inconspicuous appearance in a C-scan, but low shear strength values were taken for further evaluation. After a definition and learning phase, a 100 percent hit rate to separate good bondings from kissing bonds could be derived in a blind test. The discriminating feature found is due to the frequency shift between good and kissing bonds as well as the relative amplitude of the second peak.

关键词： Ultrasonic Testing Time Domain Frequency Domain Pattern Recognition Bond Quality Kissing Bond