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A novel indicator system for catalytic spectrophotometric determination and speciation of inorganic selenium species (Se(Ⅳ), Se(Ⅵ)) at trace levels in natural lake and river water samples

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Rare Metals 2011年第5期30卷 477-487页

作者： ramazan gürkan Halil brahim Ulusoy Mehmet Akay pinar Bulut Department of Chemistry Faculty of Science University of Cumhuriyet

A novel catalytic kinetic method is proposed for the determination of Se（Ⅳ）, Se（Ⅵ）, and total inorganic selenium in water based on the catalytic effect of Se（Ⅳ） on the reduction of Celestine blue by sodium sulfide at pH 7.0 phosphate buffer. The fixed-time method was adopted for the determination and speciation of inorganic selenium. Under the optimum conditions, the two calibration graphs are linear with a good correlation coefficient in the range 2-20 and 20-200 μg·L-1 of Se（Ⅳ） for the fixed-time method at 30℃. The experimental and theo- retical detection limits of the developed kinetic method were found to be 0.21 and 2.50 μg·L-1 for the fixed-time method （3 min）. All of the variables that affect the sensitivity at 645 nm were investigated, and the optimum conditions were established. The interference effect of various cations and anions on the Se（Ⅳ） determination was also studied. The selectivity of the selenium determination was greatly improved with the use of the strongly cation exchange resin such as Amberlite IR120 plus as long as chelating agents of thiourea and thiosulphate. The proposed kinetic method was validated statistically and through recovery studies in natural water samples. The relative standard deviations （RSDs） for ten replicate measurements of 2, 10, and 20 μg·L-1 of Se（Ⅳ） change between 0.35% and 5.58%, while the RSDs for ten replicate measurements of 3, 6, and 12 μg·L-1 of Se（Ⅵ） change between 0.49% and 1.61%. Analyses of a certified standard reference material （NIST SRM 1643e） for selenium using the fixed-time method showed that the proposed kinetic method has good accuracy. The Se（Ⅳ）, Se（Ⅵ）, and total inorganic selenium in lake and river water samples have been successfully determined by this method after selective reduction of Se（Ⅵ） to Se（Ⅳ）.

关键词： selenium speciation Celestine blue catalytic effect kinetic spectrophotometry natural waters

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

System integration analysis of a zeolite 13x thermal energy storage

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Energy and Built Environment 2024年第4期5卷 568-579页

作者： S.De Antonellis L.p.M.Colombo p.Castellazzi A.Rossetti L.Marocco politecnico di Milano Department of Energyvia Lambruschini 4Milan 20156Italy Ricerca sul Sistema Energetico-RSE S.p.A. Tecnologie di Generazione e Materialivia R.Rubattino 54Milan 20134Italy

Nowadays a major energy transition aimed at cutting CO 2 emissions has begun,with the ambitious goal of drasti-cally reducing the dependence on fossil fuels and promoting the use of renewable energy *** this context,energy storage systems play a key role in ensuring a stable,secure and time-aligned energy *** sorption thermal energy storages(TESs)can contribute to such transition,since they are simple and cheap devices able to provide a hot airflow with a high energy density and to store energy for long *** this work,open sorption TES systems operated with Zeolite13X are investigated with a focus on the integration in practical ***,the experimental analysis and modelling of the sole TES system is ***,the integration of the TES at system level is carried *** analysis evidences that a significant reduction of storage capac-ity occurs if air humidification is necessary before the adsorption process or afterwards to keep adequate indoor comfort conditions for the *** the exemplary case study considered,an energy density of 150 kWhm^(−3) can drop to 40 kWhm−3 in case of complete compensation of the adsorbed water through a *** paper provides useful guidelines for evaluating the performance of a TES integrated system in terms of specific energy and *** also identifies applications involving high latent loads(e.g.,swimming.pools,locker rooms)or for which low relative air humidity is required(*** of vehicles to prevent condensation on windows)as particularly beneficial for using a TES system.

关键词： Energy storage Adsorption Zeolite System integration Numerical model

Quantitative Mapping of Transient Thermodynamic States in Ultrafast Laser Nanostructuring of Quartz

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Ultrafast Science 2024年第2期4卷 9-18页

作者： H.D.Nguyen A.Tsaturyan S.Sao Joao R.Dwivedi A.Melkonyan C.D’Amico E.Kachan J.p.Colombier g.Kermouche R.Stoian Laboratoire Hubert Curien UMR 5516 CNRSUniversite Jean Monnet42000 Saint EtienneFrance Laboratoire george Friedel UMR 5307 CNRSEcole des Mines de Saint Etienne42000 Saint EtienneFrance

Understanding material structural reaction to light is of utmost importance to advance processing resolution in ultrafast laser volume structuring into the *** thermodynamic pathways are required to quench energy transport in the most rapid manner and to confine the process to nanometer lengths,bypassing optical *** material dynamics under confinement,with in situ access to transient local temperature and density parameters,thus becomes key in understanding the *** report in situ reconstruction of thermodynamic states over the entire matter relaxation path in bulkα-quartz irradiated by ultrafast nondiffractive laser beams using time-resolved qualitative and quantitative optical phase *** dynamics indicate rapid spatially confined crystalline-to-amorphous transition to a hot dense fused silica *** exceeds 20%and the matrix temperature rises to more than 2,000 K in the first *** structural state relaxes in hundreds of *** dispersion and time design of the optical beam to picosecond durations increases the spatial confinement and triggers an extreme nanostructuring.process based on nanocavitation that occurs within the amorphizing material,where the low-viscosity phase lowers the mechanical requirements for the *** feature scales of less than a tenth of the optical wavelength are obtained in the *** allows for structural and morphological nanoscale material features under 3D confinement that can engineer optical materials.

关键词： Quartz hundreds qualitative

Effect of biochar on the metabolome of soybean seedlings

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Oil Crop Science 2024年第1期9卷 60-68页

作者： Nathalia E.Silva Mariana g.Aguilar Osania E.Ferreira gleicia M.paulino Jaqueline C.L.Carvalho Lúcia p.S.pimenta Alan R.T.Machado programa de pos-graduaçao em Ciencias Ambientais Universidade do Estado de Minas GeraisFrutalMinas Gerais38202-436Brazil Departamento de Química Universidade Federal de Minas GeraisMinas GeraisBelo Horizonte31270-901Brazil Departamento de Engenharia Aplicada e Tecnologias Ambientais Universidade do Estado de Minas GeraisJoao MonlevadeMinas Gerais35930-314Brazil Departamento de Ciencias Exatas Universidade do Estado de Minas GeraisJoao MonlevadeMinas Gerais35930-314Brazil

The use of biochar can have several effects on plant germination,depending on raw material,preparation method and application ***,the molecular mechanisms that lead to those results have yet to be *** aim of this research was to improve the understanding of these mechanisms by characterizing the metabolic effects of sugarcane bagasse biochar on soybean *** types of biochars were prepared by pyrolysis at 300℃(SCB300),400℃(SCB400)and 600℃(SCB600).Then,each one was mixed into sand at 1%,3%,5%(w/w)dose,*** experiment was performed in 8 days of incubation,when the number of germinated seeds and the average radicle length were *** evaluate the metabolome,the dry biomass(DB)was subjected to extraction with a mixture of methanol-d4 and D2O(1:1 v/v).The extracts were submitted to metabolomics analysis by proton Nuclear Magnetic *** Relative germination,Relative Average Radicle growth and germination Index increased in all treatments compared to *** the other hand,the DB increased in all treatments,except for SCB300,at doses of 1%and 3%w/*** metabolites(alanine,asparagine,acetic acid,citric acid,glycerol,fatty acids and sucrose)were identified and quantified in DB extracts as the most influential finding for the separation of *** together,these results strongly suggested that biochars accelerated the catabolism of triacylglycerols to sucrose and induced a slight osmotic stress.

关键词： germination Metabolomics 1H NMR pyrolysis Sugarcane bagasse

performance and Emission Characteristics of a CRDI Diesel Engine Fuelled by SiO_(2) Nanoparticle-Waste Fat Biodiesel Blends

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China petroleum processing & petrochemical Technology 2024年第1期26卷 56-66页

作者： Babu Aurtherson p Dinesh Babu Munuswamy Ravikumar Jayabal Yuvarajan Devarajan Department of Mechanical Engineering Mahat Amma Institute of Engineering and TechnologyPudukkottaiTamil NaduIndia Department of Mechanical Engineering Rajalakshmi Institute of TechnologyChennaiTamil NaduIndia Department of Thermal Engineering Saveetha School of EngineeringSaveetha Institute of Medical and Technical SciencesChennaiTamil NaduIndia

This study investigates the use of waste fat biodiesel(WFB)from the leather industry as a substitute for diesel ***,it examines the diesel engine performance of WFB,a blend of WFB and diesel(B50),and different blends of WFB and silicon dioxide(SiO_(2))nanoparticles(B50SiO_(2)40,B50SiO_(2)80,and B50SiO_(2)120μg/g).The results indicate that the B50SiO_(2)120 blend increases brake thermal efficiency by 10.03%compared to pure biodiesel but falls 1.93%short of neat ***,the B50SiO_(2)120 mixture reduces smoke,hydrocarbon,and carbon monoxide emissions by 31.87%,34.14%,and 43.97%respectively,compared to ***,the B50SiO_(2)120 blend shows a 4.91%increase in nitrogen oxide emissions compared to diesel.

关键词： waste fat transesterification biodiesel silicon dioxide emission

Assembly of peptide nanostructures with controllable sizes

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Nano Research 2024年第1期17卷 151-161页

作者： Dan Cheng Fan Jia Yun-Bao Jiang Vincent p.Conticello Tao Jiang The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian province(IKKEM) Xiamen 361005China Department of Chemistry Emory UniversityAtlanta 30033USA

Controlled peptide assembly offers significant promise to develop synthetic supramolecular nanostructures to display material and biological properties that mimic protein assemblies in *** the progress in forming.peptide nanostructures of various morphology,there exists a distinct g.p between natural and synthetic assembly systems in terms of size *** nanostructures with a narrow size distribution that can be tuned over a wide range of length-scales is essential for applications that require precise spacing between *** approach provides the opportunity to correlate materials and biological properties of interest with assembly *** this review,we discuss representative endeavors over the past two decades for design of size-controllable peptide nanostructures using tunable building *** mechanisms for size control,e.g.,molecular frustration,template-directed peptide assembly,and multi-component peptide co-assembly,will also be *** also demonstrate the applicable scopes of these strategies and suggest potential future avenues for scientific advances in this field.

关键词： peptide assembly controllable size template multi-component

Effect of high temperature short time infrared roasting of peanuts

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Journal of Future Foods 2024年第2期4卷 173-178页

作者： Rahi golani Chinglen Leishangthem Hongwei Xiao Qi Zhang.p.p.Sutar Department of Food process Engineering National Institute of Technology RourkelaOdisha 769008India College of Engineering China Agricultural UniversityBeijing 100083China College of Mechanical Engineering Yangzhou UniversityYangzhou 225127China

Roasting is the most common processing method that enhances color,and *** this study,infrared roasting of peanuts was done using an infrared rotary *** was operated at 90%infrared power(630 W)with different rotating speed(1 and 2 r/min).The effect of roasting was studied at different moisture levels(7.66%,11.49%,and 13.72%db).From the study,the color parameter,L*value,was found to be significantly different(pg speed,and the∆E value varies from 2.32 to *** also showed that the antioxidant activity decreased with the reduction in rotating speed as lesser revolutions took longer roasting time,and the values decreased from 84.34%to 71.74%.Minimal changes in total phenolic content were found and varied from 3.62 to 2.10 mg/g gAE,an appropriate limit for good-quality roasted *** hardness of roasted peanuts ranged from 12.25 to 39.43 *** content 13.72%,and 1 r/min is the best possible treatment for infrared peanut roasting,significantly enhancing the quality of *** study concluded that high-power short-time infrared roasting could give good-quality roasted peanuts with optimum bioactive compounds.

关键词： Roasting Infrared Total phenolic content Antioxidant activity

Heterogeneity of mature oligodendrocytes in the central nervous system

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Neural Regeneration Research 2025年第5期20卷 1336-1349页

作者： Chao Weng Adam M.R.groh Moein Yaqubi Qiao-Ling Cui Jo Anne Stratton g.R.Wayne Moore Jack p.Antel Neuroimmunology Unit Montreal Neurological Institute-HospitalDepartment of Neurology and NeurosurgeryMcGill UniversityMontrealQCCanada Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous *** evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to *** the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is *** delve into early 20th-century studies by Robertson and Río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature ***,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination ***,modern molecular investigations,employing techniques such as single cell/nucleus RNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system *** and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric ***,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined *** studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte *** research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,

关键词： aging central nervous system diseases electron microscopy heterogeneity immunohistochemistry myelin sheath natural history neuroglia oligodendroglia single-cell gene expression analysis