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Science China(Information Sciences) 2024年第8期67卷 24-34页

作者： Siyuan WANG Andrey POLYAKOV Min LI Gang ZHENG Driss BOUTAT INSA centre Val de Loire INRIA

The objective of the invariant ellipsoid method is to minimize the smallest invariant and attractive set of a linear control system operating under the influence of bounded external disturbances. This study extends the application of this method to address the leader-following consensus problem. Initially, a linear control protocol is designed for the multi-agent system in the absence of disturbances. Subsequently, in the presence of bounded disturbances, by employing a similar linear control protocol, a necessary and sufficient condition is introduced to derive the optimal control parameters for the multi-agent system such that the state of followers converges to and remains in a minimal invariant ellipsoid around the state of the leader.

关键词： multi-agent system leader-following consensus invariant ellipsoid disturbance

Assessment of spongy moth infestation impacts on forest productivity and carbon loss using the Sentinel-2 satellite remote sensing and eddy covariance flux data

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Ecological Processes 2024年第2期13卷 231-245页

作者： Nur Hussain Alemu Gonsamo Shusen Wang M.Altaf Arain School of Earth Environment and Society and McMaster Centre for Climate Change Mc Master University Canada centre for Remote Sensing Natural Resources Canada

Background Deciduous forests in eastern North America experienced a widespread and intense spongy moth（Lymantria dispar） infestation in 2021. This study quantified the impact of this spongy moth infestation on carbon（C） cycle in forests across the Great Lakes region in Canada, utilizing high-resolution（10 × 10 m2） Sentinel-2 satellite remote sensing images and eddy covariance（EC） flux data. Study results showed a significant reduction in leaf area index（LAI） and gross primary productivity（GPP） values in deciduous and mixed forests in the region in *** Remote sensing derived, growing season mean LAI values of deciduous（mixed） forests were 3.66（3.18）, 2.74（2.64）, and 3.53（2.94） m2m-2in 2020, 2021 and 2022, respectively, indicating about 24（14）% reduction in LAI, as compared to pre-and post-infestation years. Similarly, growing season GPP values in deciduous（mixed） forests were 1338（1208）, 868（932）, and 1367（1175） g C m-2, respectively in 2020, 2021 and 2022, showing about 35（22）% reduction in GPP in 2021 as compared to pre-and post-infestation years. This infestation induced reduction in GPP of deciduous and mixed forests, when upscaled to whole study area（178,000 km2）, resulted in 21.1（21.4） Mt of C loss as compared to 2020（2022）, respectively. It shows the large scale of C losses caused by this infestation in Canadian Great Lakes *** The methods developed in this study offer valuable tools to assess and quantify natural disturbance impacts on the regional C balance of forest ecosystems by integrating field observations, high-resolution remote sensing data and models. Study results will also help in developing sustainable forest management practices to achieve net-zero C emission goals through nature-based climate change solutions.

关键词： Spongy moth Infestation Carbon Gross ecosystem productivity Leaf area index Temperate forest Remote sensing Sentinel-2 Eddy covariance

Flexible bronchoscopy for foreign body aspiration in children:A single-centre experience

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World Journal of Clinical Pediatrics 2024年第2期13卷 127-134页

作者： Aleh Sautin Kirjl Marakhouski Aleh Pataleta Kirill Sanfirau Diagnostic Division Republican Scientific and Practical Centre of Paediatric SurgeryMinsk 220013Belarus

BACKGROUND The technological evolution of bronchoscopy has led to the widespread adoption of flexible techniques and their use for both diagnostic and therapeutic ***,there is an active debate regarding the comparative efficacy and safety of rigid vs flexible bronchoscopy in the treatment of foreign body *** To evaluate our experience with tracheobronchial foreign body extraction using flexible bronchoscopy and provide a literature *** This was a single-centre retrospective ***-four patients were enrolled between January 2017 and January *** records of patients aged below 18 years who were admitted to authors’affiliated institution with a suspected diagnosis of foreign body aspiration were collected from hospital’s database to Microsoft Excel *** were analysed using MedCalc Statistical *** Patient ages varied from 9 months to 11 *** median age was 23.5 months,95%confidence interval(CI)*** observed age clustering in children with foreign body aspiration at our institution with three age subgroups:(1)0-25 months;(2)40-60 months;and(3)120-140 *** expectancy of an organic tracheobronchial foreign body was significantly higher in 0-25 months subgroup than that in older ones when subgroups 40-60 and 120-140 months were combined together(odds ratio=10.0,95%CI:1.44-29.26,P=0.0197).Successful foreign body extraction was performed in all *** to a rigid bronchoscope was not required in any of the *** major complications(massive bleeding,tracheobronchial tree perforation,or asphyxia)were *** Flexible bronchoscopy is an effective and safe method for tracheobronchial foreign body extraction in children.

关键词： Foreign body aspiration Tracheobronchial foreign body Paediatric bronchoscopy Flexible bronchoscopy Rigid bronchoscopy

Hydrometallurgy two stage process for preparation of (Nd,La,Ce)_(2)O_(3) from end-of-life NiMH batteries

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Journal of Rare Earths 2024年第2期42卷 415-423,I0007页

作者： Karim Tanji Khalid Ouzaouit Mohamed Belghiti Isam Lamsayety Hakim Faqir Intissar Benzakour centre de recherche REMINEX-Groupe MANAGEM MarrakechMorocco

The present work aims to investigate the recovery of light rare earth elements(LREEs) oxides from end-oflife NiMH batteries using a hydro metallurgical process followed by effective *** operational leaching parameters such as phosphoric acid concentration,temperature,and the solid-liquid ratio were first optimized by Box-Behnken *** results reveal that under optimum conditions([H_(3)PO_(4)]=2 mol/L,T=80℃,and S/L=1:10 g/mL) the leaching efficiencies of Ni,Co reach 98.1% and99.3%.While La,Ce,and Nd elements remain in the leaching residue as(La,Ce,Nd)PO_(4) with yields of 98.2%,98.6%,and 99.6% for La,Ce,and Nd,***,the(La,Ce,Nd)PO_(4) is leached with HCl acid,then the rare earth oxalate was precipitated using oxalic acid at a pH of 1.8 and then the product was calcined at 800℃ for 2 h in order to synthesize the(Nd,La,Ce)_(2)O_(3).The analysis using scanning electron microscopy(SEM) coupled with energy dispersive X-ray spectroscopy(EDX) confirms the homogeneity of(Nd,La,Ce)_(2)O_(3) particles that have two morphologies,i.e.,flower and sticks with a particle size between 3and 6 μ*** unit cell parameters of(Nd,La,Ce)_(2)O_(3) were calculated after Rietveld refinement of the XRD patterns,in the space group of Fm-3m are a=b=c=0.57921 nm and the volume equal to 0.194322 nm^(3).

关键词： NiMH batteries Hydrometallurgical process Leaching Phosphoric acid Box-Behnken Light rare earth oxides

Small-signal Stability Criteria in Power Electronics-dominated Power Systems:A Comparative Review

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1003-1018页

作者： Qifan Chen Siqi Bu Chi Yung Chung Department of Electrical and Electronic Engineer The Hong Kong Polytechnic UniversityHong KongChina Department of Electrical and Electronic Engineering Shenzhen Research InstituteCentre for Grid ModernisationInternational Centre of Urban Energy NexusCentre for Advances in Reliability and SafetyResearch Institute for Smart Energyand Policy Research Centre for Innovation and TechnologyThe Hong Kong Polytechnic UniversityHong KongChina

To tackle emerging power system small-signal stability problems such as wideband oscillations induced by the large-scale integration of renewable energy and power electronics,it is crucial to review and compare existing small-signal stability analysis *** this basis,guidance can be provided on determining suitable analysis methods to solve relevant small-signal stability problems in power electronics-dominated power systems(PEDPSs).Various mature methods have been developed to analyze the small-signal stability of PEDPSs,including eigenvalue-based methods,Routh stability criterion,Nyquist/Bode plot based methods,passivity-based methods,positive-net-damping method,lumped impedance-based methods,bifurcation-based methods,*** this paper,the application conditions,advantages,and limitations of these criteria in identifying oscillation frequencies and stability margins are reviewed and compared to reveal and explain connections and discrepancies among ***,efforts are devoted to mathematically proving the equivalence between these small-signal stability ***,the performance of these criteria is demonstrated and compared in a 4-machine 2-area power system with a wind farm and an IEEE 39-bus power system with 3 wind farms.

关键词： Impedance-based method oscillation analysis power electronic converter power electronics-dominated power system renewable power generation small-signal stability

Cosmological constraints from the joint analysis of clustering and lensing with the DESI Legacy Imaging Surveys

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 169-170页

作者： Surhud More Inter-University centre for Astronomy and Astrophysics Pune 411007India

The comparison between the amplitude of density fluctuations in matter today as inferred from the observations of the Cosmic Microwave background by the Planck collaboration [1] to that from the observations of the late Universe,is a stringent test of the concordance cosmological model. A joint analysis of the clustering of galaxies and their galaxygalaxy lensing signal is a unique way to constrain cosmological parameters.

关键词： galaxy parameters. galaxies

In-situ synthesis of quantum dots in the nucleus of live cells

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National Science Review 2024年第3期11卷 172-182页

作者： Yusi Hu Zhi-Gang Wang Haohao Fu Chuanzheng Zhou Wensheng Cai Xueguang Shao Shu-Lin Liu Dai-Wen Pang State Key Laboratory of Medicinal Chemical Biology Frontiers Science Centre for New Organic MatterTianjin Key Laboratory of Biosensing and Molecular Recognition Research Centre for Analytical Sciences College of Chemistry School of Medicine and Frontiers Science Centre for Cell Responses Nankai University Haihe Laboratory of Sustainable Chemical Transformations

The cell nucleus is the main site for the storage and replication of genetic material, and the synthesis of substances in the nucleus is rhythmic, regular and strictly regulated by physiological processes. However,whether exogenous substances, such as nanoparticles, can be synthesized in situ in the nucleus of live cells has not been reported. Here, we have achieved in-situ synthesis of CdSxSe1-xquantum dots（QDs） in the nucleus by regulation of the glutathione（GSH） metabolic pathway. High enrichment of GSH in the nucleus can be accomplished by the addition of GSH with the help of the Bcl-2 protein. Then, high-valence Se is reduced to low-valence Se by glutathione-reductase-catalyzed GSH, and interacts with the Cd precursor formed through Cd and thiol-rich proteins, eventually generating QDs in the nucleus. Our work contributes to a new understanding of the syntheses of substances in the cell nucleus and will pave the way for the development of advanced ‘supercells’.

关键词： glutathione live cell nucleus quantum dot intracellular synthesis

Source parameters and aftershock pattern of the October 7,2021,M5.9 Harnai earthquake,Pakistan

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Earthquake Science 2024年第4期37卷 304-323页

作者： Mohammad Tahir Zeeshan Ahmad Sadia Sabahat Muhammad Naveed Mushtaq Talat Iqbal Muhammad Ali Shah Alam Aftab centre for Earthquake Studies National Centre for PhysicsIslamabad 44000Pakistan

On October 7,2021,a magnitude 5.9 earthquake struck the Harnai(Baluchistan)region of Pakistan,causing several fatalities and injuries within the epicentral ***-order tectonic deformation in this region is caused by the convergence of the Indian Plate with respect to the Eurasian *** Katwaz Block hinders the motion of the Indian Plate,resulting in the formation of strike-slip *** this study,the P-wave first-motion polarity technique was used to determine the mainshock faulting *** scanning of the polarity solutions was applied to determine the most suitable focal mechanism solution among the available solutions generated by the FOCMEC(focal mechanism)*** nodal planes correspond to different faulting styles(i.e.,thrust and strike-slip faulting).A nodal plane oriented in the NW-SE direction corresponded to a strike-slip mechanism,which was considered to be the fault ***,this earthquake was associated with the Harnai-Karahi strike-slip fault zone owing to the fault strike and direction of *** apparent stress drop,fault length,and moment magnitude of the Harnai earthquake were 35.4 bar,6.1 km,and 5.9,respectively.A lower b-value for the Gutenberg-Richter law was observed prior to the ***α-than b-values(α>b)indicate that this earthquake was governed by large events as opposed to small-magnitude *** Harnai sequence had a decay exponent close to unity,lasted for 145 days,and produced few *** study will help the future hazard mitigation in the region.

关键词： focal mechanism solution selection of fault plane FPFIT stress inversion oblique slip mechanism

Peat properties of a tropical forest reserve adjacent to a fire-break canal

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Journal of Forestry Research 2024年第1期35卷 155-167页

作者： Dayang Nur Sakinah Musa Mohd Zahirasri Mohd Tohir Xinyan Huang Luqman Chuah Abdullah Mohamad Syazaruddin Md Said Muhammad Firdaus Sulaiman Safety Engineering Interest Group(SEIG) Department of Chemical and Environmental EngineeringFaculty of EngineeringUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia International Tropical Forestry Programme Faculty of Tropical ForestryUniversiti Malaysia SabahSabahMalaysia Department of Land Management Faculty of AgricultureUniversiti Putra MalaysiaSelangorMalaysia Research centre for fire Safety Engineering Department of Building Environment and Energy EngineeringThe Hong Kong Polytechnic UniversityHong KongPeople’s Republic of China

Tropical peat comprises decomposed dead plant material and acts like a sponge to absorb water,making it fully ***,drought periods dry it readily and increases its vulnerability to *** fires emit greenhouse gases and particles contributing to haze,and prevention by constructing fire-break canals to reduce fire spread into forest reserves is *** paper aims to determine peat physical and chemical properties near a fire-break canal at different fire frequency *** sampling was conducted at two forest reserves in Malaysia which represent low fire frequency and high fire frequency *** results show that peat properties were not affected by the construction of a fire-break canal,however lignin and cellulose content increased significantly from the distance of the canal in both *** study concluded that fire frequency did not significantly influence peat properties except for *** higher fibre content in the high frequency area did not influence moisture content nor the ability to regain ***,fire frequency might contribute differently to changes in physical and chemical properties,hence management efforts to construct fire-break canals and restoration efforts should protect peatlands from further *** findings will benefit future management and planning for forest reserves.

关键词： Peat fire Peat properties fire-break canals Forest reserves

High performance in Zintl thermoelectrics via reduction in crystal field splitting energy

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Science China Materials 2024年第10期67卷 3424-3425页

作者： Anustoop Das Kanishka Biswas New Chemistry Unit School of Advanced Materials and International Centre for Materials ScienceJawaharlal Nehru Centre for Advanced Scientific Research(JNCASR)Jakkur P.O.Bangalore 560064India

Sustainable thermoelectric materials open an avenue of emission-free as well as fast-responding recycling of energy in terms of heat to *** efficiency(η)of such conversion is primarily guided by the dimensionless the... 详细信息

关键词： splitting energy crystal