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Slow and fast light in quantum-well and quantum-dot semiconductor optical amplifiers Invited Paper

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Chinese Optics Letters 2008年第10期6卷 736-742页

作者： Piotr konrad Kondratko Akira Matsudaira Department of Electrical and Computer Engineering University of Illinois at Urbana-ChampaignUrbana IL61801USA

Slow and fast light in quantum-well （QW） and quantum-dot （QD） semiconductor optical amplifiers （SOAs） using nonlinear quantum optical effects are presented. We demonstrate electrical and optical controls of fast light using the coherent population oscillation （CPO） and four wave mixing （FWM） in the gain regime of QW SOAs. We then consider the dependence on the wavelength and modal gain of the pump in QW SOAs. To enhance the tunable photonic delay of a single QW SOA, we explore a serial cascade of multiple amplifiers. A model for the number of QW SOAs in series with variable optical attenuation is developed and matched to the experimental data. We demonstrate the scaling law and the bandwidth control by using the serial cascade of multiple QW SOAs. Experimentally, we achieve a phase change of 160^o and a scaling factor of four at 1 GHz using the cascade of four QW SOAs. Finally, we investigate CPO and FWM slow and fast light of QD SOAs. The experiment shows that the bandwidth of the time delay as a function of the modulation frequency changes in the absorption and gain regimes due to the carrier-lifetime variation. The tunable phase shift in QD SOA is compared between the ground- and first excited-state transitions with different modal gains.

关键词： SOA CPO Slow and fast light in quantum-well and quantum-dot semiconductor optical amplifiers Invited Paper FWM well

Gap formation around Ω_e/2 and generation of low-band whistler waves by Landau-resonant electrons in the magnetosphere: Predictions from dispersion theory

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Earth and Planetary Physics 2020年第2期4卷 138-150页

作者： konrad Sauer Klaus Baumgartel Richard Sydora Max-Planck-Institute for Solar System Research GöttingenGermany(up to 2005 Leibnitz-Institut für Astrophysik(AIP) PotsdamGermany(up to 2008 Institute for Geophysical Research University of AlbertaEdmontonCanada

In this paper we show that two significant phenomena of magnetospheric chorus emission can be explained by the participation of beam-like electron structures,created by Landau-resonant interaction with growing oblique whistler *** first concerns the widely observed spectral gap near half the electron cyclotron frequency Ωe;the second is related to the observation of very obliquely propagating lower-band waves that cannot be directly generated by temperature *** the gap,kinetic dispersion theory reveals that interference of the beam-related cyclotron mode ω~Ωe-kVb with the conventional whistler mode leads to mode splitting and the appearance of a ’forbidden’ area in the ω-k *** the beam velocity appears as an essential *** is directly related to the phase velocity of the most unstable whistler wave mode,which is close to VAe/2 for sufficiently hot electrons(VAe is the electron Alfven velocity).To clarify the second point,we show that Landau-resonant beams with Vb Vb

关键词： important role play Landau-resonant electrons modification of the electron distribution function gap formation at half the electron cyclotron frequency

DNA barcoding-based species delimitation increases species count of Eois （Geometridae） moths in a well-studied tropical mountain forest by up to 50%

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Insect Science 2011年第3期18卷 349-362页

作者： Patrick Strutzenberger Gunnar Brehm konrad Fiedler Department of Animal Biodiversity University of Vienna Rennweg 14 1030 Wien Austria Institut for Spezielle Zoologie und Evolutionsbiologie mit Phyletischem Museum Friedrich Schiller Universitat Erbertstrasse 1 07743 Jena Germany

The genus Eois comprises an important part of megadiverse assemblages of geometrid moths in mountain rainforests of southern Ecuador. In this study we report：（i） on the construction of a DNA barcode library of Eois for identification purposes; and （ii） the exploration of species diversity through species delimitation by pair-wise distance thresholds. COl barcode sequences were generated from 408 individuals （at least 105 species） collected on a narrow geographic scale （-40 km2） in the Reserva Bioldgica San Francisco. Analyses of barcode sequence divergence showed that species delimitations based solely on external morphology result in broad overlap of intra- and interspecific distances. Species delimitation at a 2% pair-wise distance threshold reveals a clear barcoding gap. Fifty-two previously unrecognized species were identified, 31 of which could only be distinguished by an integrative taxonomy approach. Twelve additional putative species could only be recognized by threshold-based delimitation. Most splits resulted in two or three newly perceived cryptic taxa. The present study increased the number of Eois species recorded from that small area of Andean mountain forest from 102 to 154 （morphology- plus integrative taxonomy-based） or even 166 （sequence-based）, leaving the species accumulation curve still far from reaching an asymptote. Notably, in no case did two or more previously distinguished morphospecies have to be lumped. This barcode inventory can be used to match larvae to known adult samples without rearing, and will therefore be of vital help to extend the currently limited knowledge about food plant relationships and host specialization.

关键词： cryptic species Ecuador integrative taxonomy Larentiinae larvae

Synthesis, structural and spectroscopic studies on GdBO_3:Yb^(3+)/Tb^(3+)@SiO_2 core-shell nanostructures

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Journal of Rare Earths 2015年第11期33卷 1148-1154页

作者： konrad Kubasiewicz Marcin Runowski Stefan Lis Agata Szczeszak Department of Rare Earths Faculty of Chemistry Adam Mickiewicz University

The presented study concerned up-converting core/shell type nanomaterials based on lanthanide（Ⅲ） ions, Ln（Ⅲ）, doped orthoborates. The system studied composed of the GdBO3 doped with Yb^3＋/Tb^3＋ luminescent core ensured an effective cooperative sensitization up-conversion, resulting in a bright green luminescence. The silica coating process was performed by a modified St？ber method, which resulted in the formation of core-shell nanostructures, making them suitable for bioapplications. The nanophosphors and nanocomposites were obtained by various methods, such as co-precipitation in the presence of Triton X-100 and micelle synthesis with ethylenediaminetetraacetic acid（EDTA） as organic modifiers/surfactants. The synthesized nanomaterials were characterized with the use of powder X-ray diffraction（XRD）, infrared light absorption with Fourier transform FT-IR spectra, transmission electron microscopy（TEM）, up-conversion emission spectra under IR light, as well as excitation spectra, emission spectra and fluorescence lifetimes under UV light, and their photophysical properties were compared.

关键词： Ln(Ⅲ) ions GdB O3 silica coating core-shell nanocomposites up-conversion cooperative sensitization rare earths

Percutaneous endoscopic gastrostomy—Too often?Too late?Who are the right patients for gastrostomy?

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World Journal of Gastroenterology 2020年第20期26卷 2464-2471页

作者： Christoph G Dietrich konrad Schoppmeyer Dietrich Medical ClinicBethlehem-Gesundheitszentrum Stolberg/Rhld.Stolberg D-52222Germany Medical Clinic Ⅱ Euregio-Klinik NordhornNordhorn D-48529Germany

Percutaneous endoscopic gastrostomy is an established method to provide nutrition to patients with restricted oral uptake of fluids and ***,we review the methods,indications and complications of this *** gastrostomy can be safely and easily performed during gastroscopy,the right patients and timing for this intervention are not always *** in patients with dementia,the indication for and timing of gastrostomies are often *** this patient group,clear data for enteral nutrition are lacking;however,some evidence suggests that patients with advanced dementia do not benefit,whereas patients with mild to moderate dementia might benefit from early enteral ***,other patient groups with temporary or permanent restriction of oral uptake might be a useful target population for early enteral nutrition to maintain mobilization and muscle *** plead for a coordinated study program for these patient groups to identify suitable patients and the best timing for tube implantation.

关键词： Gastrostomy Nutrition Dementia Percutaneous endoscopic gastrostomy Oncologic diseases Endoscopy Neurodegenerative disorders

Recent progress in Ni-rich layered oxides and related cathode materials for Li-ion cells

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International Journal of Minerals,Metallurgy and Materials 2024年第11期31卷 2345-2367页

作者： Boyang Fu Maciej Moździerz Andrzej Kulka konrad Świerczek Faculty of Energy and Fuels AGH University of Krakowal.A.Mickiewicza 3030-059 KrakowPoland AGH Centre of Energy AGH University of Krakowul.Czarnowiejska 3630-054 KrakowPoland

Undoubtedly,the enormous progress observed in recent years in the Ni-rich layered cathode materials has been crucial in terms of pushing boundaries of the Li-ion battery(LIB)*** achieved improvements in the energy density,cyclability,charging speed,reduced costs,as well as safety and stability,already contribute to the wider adoption of LIBs,which extends nowadays beyond mobile electronics,power tools,and electric vehicles,to the new range of applications,including grid storage *** numerous published papers and broad reviews already available on the subject of Ni-rich oxides,this review focuses more on the most recent progress and new ideas presented in the literature *** covered topics include doping and composition optimization,advanced coating,concentration gradient and single crystal materials,as well as innovations concerning new electrolytes and their modification,with the application of Ni-rich cathodes in solid-state batteries also *** cathode materials are briefly mentioned,with the high-entropy approach and zero-strain concept presented as well.A critical overview of the still unresolved issues is given,with perspectives on the further directions of studies and the expected gains provided.

关键词： lithium-ion batteries cathode materials nickel-rich layered oxides recent progress critical issues improvement strategies

Encapsulation Protocol for Flexible Perovskite Solar Cells Enabling Stability in Accelerated Aging Tests

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Energy & Environmental Materials 2023年第5期6卷 432-439页

作者： Taimoor Ahmad Shyantan Dasgupta Samy Almosni Alina Dudkowiak konrad Wojciechowski Saule Technologies Wroclaw Technology Park11 Dunska StreetSigma Building 54-130 WrocławPoland Department of Electronics Engineering University of Rome"Tor Vergata"Via del Politecnico 100133 RomeItaly Saule Research Institute Wroclaw Technology Park11 Dunska StreetSigma Building54-130 WrocławPoland Faculty of Materials Engineering and Technical Physics Poznan University of TechnologyPiotrowo 360-965 PoznanPoland

Flexible perovskite solar cells(f-PSCs)offer attractive commercial prospects in the near future,enabled by new value propositions,such as mechanical flexibility,or high specific *** long-term reliability of these devices requires appropriate encapsulation to prevent degradation caused by environmental ***,a lamination protocol is developed,incorporating adhesive materials,barrier foils,and edge sealants,which results in a robust device *** applying the developed procedure to three different perovskite solar cell configurations(p-i-n with carbon,p-i-n with silver,and n-i with carbon),fabricated with large active areas(1 cm^(2)),the universality of this approach is *** best devices preserved over 85%of the initial performance after a sequence of accelerated aging tests based on industry standards(compliant with the IEC 61215 and IEC 61646)comprised of 1400 h of damp heat,50 thermal cycles,and 10 cycles of the humidity-freeze test.

关键词： encapsulation flexible photovoltaics perovskite solar cell stability

Pitying Animals konrad Lorenz

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大学英语 1988年第6期 41-45页

作者： konrad Lorenz 邹愉

Now which are the animals really to be pitied in captivity?I havealready given a partial answer to this question:In the first place,thoseclever and highly developed beings whose lively mentality and urge foractivity can find no outlet behind the bars of the ***,all those animals which are ruled by strong drives that cannot be sat-isfied in *** is most conspicuous,even for the uninitiated,in the case of animals which,when living in a free state,are accustomedto roam about widely and therefore have a correspondingly strong drive

关键词： Th Pitying Animals konrad Lorenz 灵长目

Biology and control of the fruit borer, Conopomorpha sinensis Bradley on litchi （Litchi chinensis Sonn.） in northern Thailand

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Insect Science 2007年第6期14卷 525-529页

作者： MARIE JOY SCHULTE konrad MARTIN JOACHIM SAUERBORN Institute of Plant Production and Agroecology in the Tropics and Subtropics University of Hohenheim Stuttgart Germany

Fruit and leaf shoot of litchi （Litchi chinensis） infestation by naturally occurring populations of the fruit bprer, Conopomorpha sinensis larvae and C. sinensis parasitization rates were determined in litchi orchards in northern Thailand at high （ca. 1 400 m ASL） and low （ca. 800 m ASL） elevations with different, non-overlapping fruiting seasons. In addition, spray applications of Bacillus thuringiensis var. aizawai, the natural compound spinosad and the chemical pesticide imidacloprid were conducted in the field to test the effects of these agents on C. sinensis fruit infestation rate. Fruit infestation rate and fruit growth, studied in a low elevation orchard, were sigmoidal and showed a highly significant positive correlation （P ≤ 0.01）. Leaf shoot infestation rate in the low elevation orchard decreased in the course of the fruiting season （March until May）, but increased in the high elevation orchard, where no fruits were present within the same period of time. Together, these results indicate that females of C. sinensis clearly prefer fruits over shoots for oviposition. If no fruits are available, which was the case in the high elevation orchard during that time, they are constrained to lay their eggs on shoots. The parasitization rate of C. sinensis larvae in untreated fruits was 54.3%. The parasitoid species were Chelonus chailini （90.8%） and Phanerotoma sp. （9.2%）. In the leaf shoots, C. sinensis was found to be parasitized by Phanerotoma sp. and Apanteles briareus. The applications of the different active agents had no significant effect on C. sinensis fruit infestation compared to the untreated control. Besides the cryptic life of the larvae, this is most probably explained by the fact that C. sinensis has several generations during the fruiting season. Because of the high parasitization rates recorded, an alternative and more effective control measure than the application of pesticides might be the augmentative release of parasitoids.

关键词： Conopomorpha sinensis fruit infestation Litchi chinensis northern Thailand,parasitoids pest control