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High Q-factor reconfigurable microresonators induced in side-coupled optical fibres

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Light(Science & Applications) 2023年第12期12卷 1867-1876页

作者： Victor Vassiliev michael Sumetsky Aston Institute of Photonic Technologies Aston UniversityBirmingham B47ETUK

High Q-factor monolithic optical microresonators found numerous applications in classical and quantum optical signal processing,microwave photonics,ultraprecise sensing,as well as fundamental optical and physical ***,due to the solid structure of these microresonators,attaining the free spectral range tunability of most of them,critical for several of these applications,was,so far,*** address this problem,here we experimentally demonstrate that the side-coupling of coplanar bent optical fibres can induce a high Q-factor whispering gallery mode optical *** changing the curvature radius of fibres from the centimetre order to the millimetre order,we demonstrate fully mechanically reconfigurable optical microresonators with dimensions varying from the millimetre order to 100-micron order and free spectral range varying from a picometre to ten picometre *** developed theory describes the formation of the discovered microresonators and their major properties in a reasonable agreement with the experimental *** new microresonators may find applications in cavity QED,microresonator optomechanics,frequency comb generation with tuneable repetition rate,tuneable lasing,and tuneable processing and delay of optical pulses.

关键词： reconfigurable resonator repetition

Transfer of CrylAc and Cry2Ab proteins from genetically engineered Bt cotton to herbivores and predators

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Insect Science 2018年第5期25卷 823-832页

作者： michael Meissle Jorg Romeis Agroscope Research Division Agroecology and Environment Zurich Switzerland

With the cukivation of Bt cotton, the produced insecticidal Cry proteins are ingested by herbivores and potentially transferred along the food chain to natural enemies, such as predators. In laboratory experiments with Bollgard II cotton, concentrations of CrylAc and Cry2Ab were measured in Lepidoptera larvae （Spodoptera littoralis, Hello- this virescens）, plant bugs （Euschistus heros）, aphids （Aphis gossypii）, whiteflies （Bemisia tabaci）, thrips （ Thrips tabaci, Frankliniella occidentalis）, and spider mites （Tetranychus urticae）. Tritrophic experiments were conducted with caterpillars ofS. littoralis as prey and larvae of ladybird beetles （Harmonia axyridis, Adalia bipunctata） and lacewings （Chrysop- erla carnea） as predators. Immunological measurements （ELISA） indicated that herbivores feeding on Bt cotton contained 5%-50% of the Bt protein concentrations in leaves except whiteflies and aphids, which contained no or only traces of Bt protein, and spider mites, which contained 7 times more Cry 1Ac than leaves. Similarly, predators contained 1%-30% of the Cry protein concentration in prey. For the nontarget risk assessment, this indicates that Bt protein concentrations decrease considerably from one trophic level to the next in the food web, except for spider mites that contain Bt protein concentrations higher than those measured in the leaves. Exposure of phloem sucking hemipterans is negligible.

关键词： arthropod food web Bacillus thuringiensis Bt cotton Cry protein ELISA transgenic plants

Uncovering the secrets of hidden twists

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National Science Review 2023年第9期10卷 119-120页

作者： Oded Hod michael Urbakh Department of Physical Chemistry School of Chemistry The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science Tel Aviv University

Twisted layered material junctions,and in particular twisted graphene interfaces,exhibit fascinating physical properties of diverse nature including unique structural,tribological,electronic,as well as heat and electron transport characteristics [1].These properties are intimately related to the moire superstructure formed at the twisted interface,which induces atomic lattice reconstruction patterns that balance between inter-layer registry optimization and intra-layer strain minimization [2].

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The singularities of light:intensity,phase,polarisation

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Light(Science & Applications) 2023年第10期12卷 2023-2026页

作者： michael V.Berry H H Wills Physics Laboratory BristolBS81TLUK

In modern optics,light can be described at different levels:as rays,as scalar waves,as vector fields,and as quantum *** the first three levels,there are singularities—characteristic features,useful in interpreting phenomena at that *** geometrical optics,the singularities are ray caustics;in scalar wave optics,they are phase singularities(=wave dislocations=wave vortices=nodal manifolds);in vector waves,they are singularities where the polarisation of light is purely linear or purely *** singularities at each level are dissolved at the next *** singularities occur in all waves,not just light.

关键词： optics purely polar

A simple human cell model for TAU trafficking and tauopathy-related TAU pathology

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Neural Regeneration Research 2022年第4期17卷 770-772页

作者： michael Bell Hans Zempel Institute of Human Genetics Faculty of Medicine and University Hospital CologneUniversity of CologneCenter for Molecular Medicine Cologne(CMMC)University of CologneCologneGermany

The microtubule(MT)-associated protein TAU is highly abundant in the axon of human brain neurons,where it binds to and stabilizes MT ***,TAU regulates the dynamic(dis)assembly of MT strands and is involved in a wide range of neuronal *** Alzheimer's disease(AD)and other tauopathies,TAU is missorted into the somatodendritic *** missorting is accompanied by(or leads to)abnormal TAU phosphorylation,MT destabilization,and loss of dendritic spines and mitochondria,eventually resulting in TAU aggregation,neuronal dysfunction and cell death(Arendt et al.,2016).Strikingly,the mechanisms of TAU sorting,and the detrimental cascade upon its failure,are still not fully understood.

关键词： tau sorting eventually

Comparison of rectangular and circular bored twin tunnels in weak ground

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Underground Space 2019年第4期4卷 328-339页

作者： michael Vinod Hadi Khabbaz School of Civil and Environmental Engineering University of Technology Sydney(UTS)Australia

The recent innovation of a rectangular tunnel boring machine(TBM),and its use in the Hongzhuan Road tunnel underpass by the China Railway Engineering Group(CREG),has revitalized shallow depth soft soil *** paper presents the findings of a numerical study using PLAXIS to determine the surface settlements and moments produced in tunnel linings for circular and rectangular twin *** effects of the relative positions of twin tunnels,critical distances,volume losses,depths of burial,and tunnel sizes for both circular and rectangular tunnels are the key parameters of this *** results indicate that rectangular tunnels are suitable for shallow depths in weak ground as they have lesser settlement compared with circular *** is crucial for tunneling beneath important structures such as railway lines and existing ***,the maximum bending moment produced in the rectangular tunnel lining is higher than that for circular *** use of rectangular TBMs is an unconventional method in modern day tunneling;however,the analysis in this project recommends that tunnel industry engineers consider this method for shallow depth weak ground tunneling.

关键词： Twin tunnels Clay Numerical modeling Rectangular TBM

The crossed phrenic phenomenon

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Neural Regeneration Research 2017年第6期12卷 845-864页

作者： michael George Zaki Ghali Department of Neurobiology & Anatomy Drexel University College of Medicine

The cervical spine is the most common site of traumatic vertebral column injuries. Respiratory insufficiency constitutes a significant proportion of the morbidity burden and is the most common cause of mortality in these patients. In seeking to enhance our capacity to treat specifically the respiratory dysfunction following spinal cord injury, investigators have studied the “crossed phrenic phenomenon”, wherein contraction of a hemidiaphragm paralyzed by a complete hemisection of the ipsilateral cervical spinal cord above the phrenic nucleus can be induced by respiratory stressors and recovers spontaneously over time. Strengthening of latent contralateral projections to the phrenic nucleus and sprouting of new descending axons have been proposed as mechanisms contributing to the observed recovery. We have recently demonstrated recovery of spontaneous crossed phrenic activity occurring over minutes to hours in C_1-hemisected unanesthetized decerebrate rats. The specific neurochemical and molecular pathways underlying crossed phrenic activity following injury require further clarification. A thorough understanding of these is necessary in order to develop targeted therapies for respiratory neurorehabilitation following spinal trauma. Animal studies provide preliminary evidence for the utility of neuropharmacological manipulation of serotonergic and adenosinergic pathways, nerve grafts, olfactory ensheathing cells, intraspinal microstimulation and a possible role for dorsal rhizotomy in recovering phrenic activity following spinal cord injury.

关键词： crossed traumatic spontaneously olfactory diaphragm descending vertebral spine sprouting minutes

Preliminary attempt to distinguish the domesticated pigs from wild boars by the methods of carbon and nitrogen stable isotope analysis

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Science China Earth Sciences 2009年第1期52卷 85-92页

作者： michael P.RICHARDS Department of Human Evolution Max-Planck Institute for Evolutionary AnthropologyDeutscher Platz 6D-04103LeipzigGermany

Despite great achievements in the origins of domestic pigs made by the methods of zooarchaeology and molecular biology,how to scientifically distinguish the domesticated pigs from wild boars during the early stage of pig domestication is still poorly *** to wild boar's diets which come from the natural environment,the diets of domestic pigs are more easily influenced by human feeding ***,in principle,exploration of the dietary differences among pigs and understanding the impact on pig diets fed by humans can have great potential to differentiate between wild boars and domesticated *** reveal dietary differences among pigs and distinguish the domesticated pigs from wild boars based on comparison with the diets of humans and other animals,we analyzed the carbon and nitrogen stable isotopes of human bones from Xiaojingshan Site and animal bones from Yuezhuang Site,both of which belong to Houli Culture in Shandong Province and date to about 8500―7500 years *** mean δ 13C value((-17.8 ± 0.3)‰) and δ 15N value((9.0±0.6)‰) in human collagen indicate that although millet agriculture began it was not the main subsistence strategy as millets are typical of C4 plants and that humans made a living mainly by gathering,hunting or raising some domesticated *** δ 13C value(-16.1‰) and δ 15N value(6.9‰) in the bovine suggest that C3 plants were dominant in its diet with some C4 plants *** fish has lower δ 13C value(-24.9‰) and higher δ 15N value(8.8‰) than the bovine,which is the characteristic of the isotopic values from Eurasian freshwater *** on the differences in carbon and nitrogen isotope values,the pigs can be divided into three groups.A group,composed of two pigs,has low δ 13C values(-18.1‰,-20.0‰) and low δ 15N values(4.7‰,6.0‰).B group,only one pig,has the highest δ 13C value(-10.6‰) and mediate δ 15N value(6.4‰).As for the C group,also only one pig,low δ 13C value(-19.0‰) and the highest δ 15N value(9.1‰

关键词： origins of domestic pigs early stage of domestication differentiation of domesticated pigs from wild boars carbon and nitrogen stable isotope analysis millet agriculture

Challenge of global climate change:Prospects for a new energy paradigm

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Frontiers of Environmental Science & Engineering 2010年第1期4卷 2-11页

作者： michael B.MCELROY School of Engineering and Applied Sciences and Department of Earth and Planetary Sciences Harvard UniversityCambridgeMA 02138USA

Perspectives on the challenge posed by potential future climate change are presented including a discussion of prospects for carbon capture followed either by sequestration or reuse including opportunities for alternatives to the use of oil in the transportation *** potential for wind energy as an alternative to fossil fuel energy as a source of electricity is outlined including the related opportunities for cost effective curtailment of future growth in emissions of CO_(2).

关键词： climate change carbon capture wind ethanol CO_(2) radiative forcing