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Statistical evaluation of 571 GaAs quantum point contact transistors showing the 0.7 anomaly in quantized conductance using cryogenic on-chip multiplexing

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Chip 2024年第3期3卷 21-28页

作者： Pengcheng Ma Kaveh Delfanazari Reuben K.Puddy jiahui Li Moda Cao Teng Yi jonathan P.griffiths Harvey E.Beere David A.Ritchie Michael j.Kelly Charles G.Smith Cavendish Laboratory Department of PhysicsUniversity of CambridgeCambridge CB30HEUK james Watt School of Engineering University of GlasgowGlasgow G128QQUK Electrical Engineering Division University of CambridgeCambridge CB30FAUK

Themass production and the practical number of cryogenic quantum devices producible in a single chip are limited to the number of electrical contact pads and wiring of the cryostat or dilution *** is,therefore,beneficial to contrast themeasurements of hundreds of devices fabricated in a single chip in one cooldown process to promote the scalability,integrability,reliability,and reproducibility of quantum devices and to save evaluation time,cost and ***,we used a cryogenic on-chip multiplexer architecture and investigated the statistics of the 0.7 anomaly observed on the first three plateaus of the quantized conductance of semiconductor quantum point contact(QPC)*** single chips contain 256 split gate field-effect QPC transistors(QFET)each,with two 16-branch multiplexed source-drain and gate pads,allowing individual transistors to be selected,addressed and controlled through an electrostatic gate voltage process.A total of 1280 quantum transistors with nano-scale dimensions are patterned in 5 different chips of GaAs *** the measurements of 571 functioning QFETs taken at temperatures T[1.4 K and T[40 mK,it is found that the spontaneous polarisation model and Kondo effect do not fit our ***,some of the features in our data largely agreed with van Hove model with short-range *** approach provides further insight into the quantum mechanical properties and microscopic origin of the 0.7 anomaly in QFETs,paving the way for the development of semiconducting quantum circuits and integrated cryogenic electronics,for scalable quantum logic control,readout,synthesis,and processing applications.

关键词： Cryogenic chip Cryogenic quantum multiplexer Semi-conductor quantum integrated circuit Quantumﬁeld effect transistors Quantum point contacts Chip-scale cryogenic electronics

Does a giant tortoise taxon substitute enhance seed germination of exotic fleshy-fruited plants?

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journal of Plant Ecology 2013年第1期6卷 57-63页

作者： Annika Waibel Christine j.griffiths Nicolas Zuel Bernhard Schmid Matthias Albrecht Institute of Evolutionary Biology and Environmental Studies University of ZurichWinterthurerstrasse 1908057 ZurichSwitzerland Mauritian Wildlife Foundation Grannum RoadVacoasMauritius School of Biological Sciences University of BristolWoodland RoadBristol BS81UGUK Present address:Mediterranean Institute for Advanced Studies Department of Biodiversity and Conservation (‘Consejo Superior de Investigaciones Cientı´ficas-Universitat de les Illes Balears’)Miquel Marques 2107190 EsporlesMallorcaBalearic IslandsSpain

Aims The use of exotic species as taxon substitutes to restore lost ecological interactions is currently hotly *** gigantea giant tortoises have recently been introduced to three islands in the Mascarene archipelago(Ile aux Aigrettes,Round Island and Rodrigues)to resurrect herbivory and seed dispersal functions once performed by extinct giant ***,potential unintended impacts by frugivore substitutes on native ecosystems,*** they will facilitate the germination of exotic plant species,are largely *** investigated whether *** introduced to Rodrigues in 2006 could enhance the germination percentage of four widespread fleshy-fruited exotic species on the *** germination trials to forecast unintended impacts that could arise from the introduction of a frugivorous taxon substitute enables conservation managers to limit potential adverse negative interactions before they *** In germination trials that ran over 4 months,we investigated the effects of ingestion(gut passage and deposition in faeces)by subadult and adult *** on the germination percentage of four exotic fleshy-fruited plant species introduced to *** fed fruits of these plant species to sub-adult and adult *** to test how variation in age and size of the frugivore would affect seed *** of distinctly coloured plastic pellets together with the fruits allowed us to test for individual tortoise effects on seed *** Findings Ingestion by *** increased the percentage of seeds germinating of Mimusops coriacea and Lantana camara,but not percentage of germination of Veitchia merrillii or Wikstroemia *** were more likely to germinate following ingestion by sub-adult rather than adult tortoises,which may be a consequence of the shorter gut passage time observed for *** results demonstrate that introduced frugivorous taxon substitutes could facilitate germination of exot

关键词： ecological analogues exotic species invasion gut passage plant–frugivore interactions seed germination

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分子轨道论在染料光谱中的实际应用

染料与染色 1986年第6期 9-16+37页

作者： j.griffiths 吴祖望燕果英国Leeds大学色化学系大连工学院大连工学院

引言目前,染料研究正在经历着一场重大的变化,由于纺织工业对于新染料的需求下降,因而,研究的重点在于提高已有染料品种的经济效益,而不是发展新品种。但是,除了纺织品外,某些特殊的领域对于新染料的需求正在增长。染料所具有的有效地... 详细信息

引言目前,染料研究正在经历着一场重大的变化,由于纺织工业对于新染料的需求下降,因而,研究的重点在于提高已有染料品种的经济效益,而不是发展新品种。但是,除了纺织品外,某些特殊的领域对于新染料的需求正在增长。染料所具有的有效地吸收光的能力,不仅从审美角度作为颜色被应用,在其它许多领域也得到了开发。这些新领域对于应用染料的性

关键词：染料吸收波长 PPP 实际应用 CNDO 染剂发色体电子受体

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现代染料化学

世界科学 1987年第8期 12-16页

作者： j.griffiths 姚庆伟

第一个合成染料——苯胺紫是在1856年由威廉·H·珀金(W·H·Perkin)发现的。差不多在100年之后,即1953年,帕里瑟(Pariser)和帕尔(Parr)以及波普尔(Pople)独立地创立了一种新的、革命性的分子轨道理论方法,即现在所谓的PPP-MO法。化学... 详细信息

第一个合成染料——苯胺紫是在1856年由威廉·H·珀金(W·H·Perkin)发现的。差不多在100年之后,即1953年,帕里瑟(Pariser)和帕尔(Parr)以及波普尔(Pople)独立地创立了一种新的、革命性的分子轨道理论方法,即现在所谓的PPP-MO法。化学上这两块看似乎风马牛不相及的里程碑,都在表明理论化学是怎样为化学工业技术做出重大贡献的。在现代化学工业中,染料化学一直起着举足轻重的作用。在我们的生活中染料和颜料可以说是最为广泛的合成有机物质。继珀金的这一首次发现之后,染

关键词：偶氮染料入射光染料化学发色团有序参数 PPP 电矢量跃迁矩分子轨道法分子轨道理论颜色对比

Classification of thermal ageing impact of ester fluid-impregnated pressboard material adopting LIBS

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High Voltage 2021年第4期6卷 655-664页

作者： Arputhasamy j.Amalanathan Nilesh j.Vasa Noureddine Harid Huw griffiths Ramanujam Sarathi Department of Electrical Engineering Indian Institute of Technology MadrasChennaiIndia Department of Engineering Design Indian Institute of Technology MadrasChennaiIndia HVDM Research Group APECKhalifa UniversityAbu DhabiUAE

This article reports the thermal ageing of ester fluid-impregnated pressboard material along with its performance evaluation using optical emission spectroscopy(OES)and classifi-cation using machine-learning algorithms adopting laser-induced breakdown spectroscopy(LIBS).The surface discharge analysis on ester-impregnated pressboard(EIP)is studied using OES and the plasma temperature was evaluated based on the Cu I emission lines which were higher under the negative DC compared with the positive DC and AC *** LIBS analysis was performed on the EIP material operated at different energy levels in order to acquire the optimal energy required to be used for its classification *** intensity ratio and electron density evaluated from LIBS studies correlated well with the plasma *** lower limit of detection(LOD)calculated based on linear regression analysis for copper peak was around 3.5 times higher than the identification of carbon *** machine-learning techniques like principal component analysis and neural network algorithm have been performed on the LIBS spectral dataset in order to classify the ageing of EIP *** neural network adopting LIBS provided a better classi-fication accuracy on all the aged samples compared with principal component analysis which classified only for the samples aged at higher temperatures.

关键词： thermal analysis fluid

Improving rice photosynthesis and yield through trehalose 6-phosphate signaling

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Molecular Plant 2022年第4期15卷 586-588页

作者： Matthew j.Paul javier A.Miret Cara A.griffiths Plant Science Rothamsted ResearchAL52JQ HarpendenHertfordshireUK

THE T6P-SnRK1 SIGNALING PATHWAY IN PLANTS,The biosynthetic route for the synthesis of trehalose in plants is through a low-flux pathway that leads to the accumulation of micromolar amounts of trehalose 6-phosphate(T6P)and trehalose when sucrose is available.T6P accumulates in proportion to sucrose(Lunn et al.,2006)as an indispensable regulator of carbohydrate utilization(Schluepmann et al.,2003).At least some of the indispensability of T6P and its profound and widespread effects on plant growth and development can be explained through T6P inhibition of the SNF1-related protein kinase SnRK1(Zhang et al.,2009),a central regulator of plant responses to carbon and energy status.

关键词： molar synthesis explained

Unsupervised ore/waste classification on open-cut mine faces using close-range hyperspectral data

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Geoscience Frontiers 2023年第4期14卷 89-99页

作者： lloyd Windrim Arman Melkumyan Richard j.Murphy Anna Chlingaryan Raymond Leung Rio Tinto Centre for Mine Automation Australian Centre for Field RoboticsThe University of SydneySydney 2006Australia

The remote mapping of minerals and discrimination of ore and waste on surfaces are important tasks for geological applications such as those in *** tasks have become possible using ground-based,close-range hyperspectral sensors which can remotely measure the reflectance properties of the environ-ment with high spatial and spectral ***,autonomous mapping of mineral spectra mea-sured on an open-cut mine face remains a challenging problem due to the subtleness of differences in spectral absorption features between mineral and rock classes as well as variability in the illumination of the *** additional layer of difficulty arises when there is no annotated data available to train a supervised learning algorithm.A pipeline for unsupervised mapping of spectra on a mine face is pro-posed which draws from several recent advances in the hyperspectral machine learning *** proposed pipeline brings together unsupervised and self-supervised algorithms in a unified system to map minerals on a mine face without the need for human-annotated training *** pipeline is eval-uated with a hyperspectral image dataset of an open-cut mine face comprising mineral ore martite and non-mineralised *** combined system is shown to produce a superior map to its constituent algo-rithms,and the consistency of its mapping capability is demonstrated using data acquired at two differ-ent times of day.

关键词： Hyperspectral imaging Mineral mapping Open-cut mine face Machine learning Convolutional neural networks Illumination invariance

The complexities underlying age-related macular degeneration： could amyloid beta play an important role？

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Neural Regeneration Research 2017年第4期12卷 538-548页

作者： Savannah A. Lynn Eloise Keeling Rosie Munday Gagandeep Gabha Helen griffiths Andrew j.Lotery j.Arjuna Ratnayaka Clinical and Experimental Sciences Faculty of Medicine University of Southampton Southampton United Kingdom Eye Unit University Southampton NHS Trust Southampton United Kingdom

e-related macular degeneration （AMD） causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer＇s-linked amyloid beta （Aβ） group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer＇s disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for latestage AMD.

关键词： amyloid beta (Aβ) retinal neurons retina mouse models age related macular degeneration(AMD)

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Identification of Differentially Senescing Mutants of Wheat and Impacts on Yield,Biomass and Nitrogen Partitioning

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journal of Integrative Plant Biology 2012年第8期54卷 555-566页

作者： Adinda P.Derkx Simon Orford Simon griffiths M.john Foulkes Malcolm j. Hawkesford Plant Biology and Crop Science Department Rothamsted ResearchHarpendenHertfordshireAL5 2JQUK Division of Plant&Crop Sciences School of BiosciencesUniversity of NottinghamSutton Bonington CampusNr LoughboroughLE12 5RDUK john Innes Centre Norwich Research ParkColneyNorwich NR4 7UHUK

Increasing photosynthetic capacity by extending canopy longevity during grain filling using slow senescing stay-green genotypes is a possible means to improve yield in wheat. Ethyl methanesulfonate （EMS） mutated wheat lines （Triticum aestivum L. cv. Paragon） were screened for fast and slow canopy senescence to investigate the impact on yield and nitrogen partitioning. Stay-green and fast-senescing lines with similar anthesis dates were characterised in detail. Delayed senescence was only apparent at higher nitrogen supply with low nitrogen supply enhancing the rate of senescence in all lines. In the stay-green line 3 （SG3）, on a whole plant basis, tiller and seed number increased whilst thousand grain weight （TGW） decreased; although a greater N uptake was observed in the main tiller, yield was not affected. In fast-senescing line 2 （FS2）, yield decreased, principally as a result of decreased TGW. Analysis of N-partitioning in the main stem indicated that although the slow-senescing line had lower biomass and consequently less nitrogen in all plant parts, the proportion of biomass and nitrogen in the flag leaf was greater at anthesis compared to the other lines; this contributed to the grain N and yield of the slow-senescing line at maturity in both the main tiller and in the whole plant. A field trial confirmed senescence patterns of the two lines, and the negative impact on yield for FS2 and a positive impact for SG3 at low N only. The lack of increased yield in the slow-senescing line was likely due to decreased biomass and additionally a possible sink limitation.

关键词： Wheat senescence stay-green grain-filling yield nitrogen.

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