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The initial stages of Li_(2)O_(2) formation during oxygen reduction reaction in Li-O_(2) batteries:The significance of Li_(2)O_(2) in charge-transfer reactions within devices

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Journal of Energy Chemistry 2024年第1期88卷 223-231,I0006页

作者： Daniela M.Josepetti Bianca P.Sousa Simone A.J.Rodrigues Renato G.Freitas Gustavo Doubek Advanced Energy Storage Division LABCenter for Innovation on New EnergiesSchool of Chemical EngineeringUniversity of CampinasAv Albert Einstein 50013083-852CampinasSPBrazil Institute of Physics&Department of Chemistry Laboratory of Computational MaterialsFederal University of Mato Grosso78060-900CuiabáMTBrazil

Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion ***,this theoretical characteristic has not yet been converted into a real device with high *** with air contamination,metallic lithium reactivity,and complex discharge and charge reactions are the main issues for this technology.A fast and reversible oxygen reduction reaction(ORR)is crucial for good performance of secondary batteries',but the partial knowledge of its mechanisms,especially when devices are concerned,hinders further *** this perspective,the present work uses operando Raman experiments and electrochemical impedance spectroscopy(EIS)to assess the first stages of the discharge processes in porous carbon electrodes,following their changes cycle by cycle at initial operation.A growth kinetic formation of the discharge product signal(Li_(2)O_(2))was observed with operando Raman,indicating a first-order reaction and enabling an analysis by a microkinetic *** solution mechanism in the evaluated system was ascribed for an equivalent circuit with three time *** the time constant for the anode interface reveals to remain relatively constant after the first discharge,its surface seemed to be more *** model indicated that the reaction occurs at the Li_(2)O_(2) surface,decreasing the associated resistance during the initial discharge ***,the growth of Li_(2)O_(2) forms a hetero-phase between Li_(2)O_(2)/electrolyte,while creating a more compact and homogeneous on the Li_(2)O_(2)/cathode *** methodology here described thus offers a way of directly probing changes in surface chemistry evolution during cycling from a device through EIS analysis.

关键词： Li-O_(2)battery Operando Raman analysis Equivalent circuit modeling Time-constant distribution

Structural and Luminescent Properties of Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)Green-Emitting Transparent Ceramic Phosphor

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 533-540页

作者：郝留成 MIAO Xiaojun LI Kai ZHONG Jianying 涂兵田 YANG Zhangfu 王皓 Pinggao Group Co. LtdPingdingshan 467001China State Key lab of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China Hubei Longzhong laboratory Xiangyang 430070China School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan 232001China

A series of spinel-type Mg_(0.25-x)Al_(2.57)O_(3.79)N_(0.21):xMn^(2+)(MgAlON:xMn^(2+))phosphors were synthesized by the solid-state reaction *** transparent ceramic phosphors were fabricated by pressureless sintering followed by hot-isostatic pressing(HIP).The crystal structure,luminescence and mechanical properties of the samples were systematically *** transparent ceramic phosphors with tetrahedrally coordinated Mn^(2+)show strong green emission centered around 515 nm under blue light *** the Mn^(2+)concentration increases,the crystal lattice expands slightly,resulting in a variation of crystal field and a slight red-shift of green emission *** weak absorption peaks in the transmittance spectra originate from the spin-forbidden ^(4)T_(1)(^(4)G)→^(6)A_(1) transition of Mn^(2+).The decay time was found to decrease from 5.66 to 5.16 ms with the Mn^(2+)*** present study contributes to the systematic understanding of crystal structure and properties of MgAlON:xMn^(2+)green-emitting transparent ceramic phosphor which has a potential application in high-power light-emitting diodes.

关键词： transparent ceramic phosphor green emission MgAlON photoluminescence

Synthesis,chemical bonding and reactivity of new medium-sized polyarsenides

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Chinese Chemical Letters 2024年第7期35卷 497-501页

作者： Xu-Hui Yue Xiang-Wen Zhang Hui-Min He Lei Qiao Zhong-Ming Sun State Key laboratory of Element-Organic Chemistry Tianjin Key Lab for Institution Rare Earth Materials and ApplicationsSchool of Materials Science and EngineeringNankai UniversityTianjin 300350China Department of Physics Institute of Computational and Applied PhysicsTaiyuan Normal UniversityJinzhong 030619China

Gaining an understanding of the growth mechanism from single atoms to clusters and bulk materials continues to present a ***,it is important to explore the evolving trends of clusters in the structure and properties during the size *** this work,we report the synthesis and characterization of two medium-sized chain-like polyarsenic anions.[As_(21)]^(3-)represents a trimeric example of polyarsenic anion assembled through oxidative coupling of As_(7)^(3-)*** anion As_(18)^(4-)included in[As_(18)MO_(2)(CO)_(8)]^(4-)is regarded as formed by two realgar-type As_(8)subunits connected by a dinuclear AsAs *** As_(18)cluster was previously predicted by theory,and this is the first time successfully synthesized using wet chemistry ***,small-sized polyarsenides As_(2)^(2-)and As_(10)^(2-)were found in compound[K(18-crown-6)]_(3)[As_(10)]_(0.5)[As_(4){Mo(CO)_(3)}_(2)]_(0.5)·*** these,the former exhibits coordination with metal ***-crystal X-ray diffraction combined with quantum chemical calculations revealed the formation of double bonded As_(2)^(2-)stabilized by metal carbonyl *** work demonstrates a novel synthetic approach for the preparation of new polyarsenides and highlights their intriguing bonding characteristics,laying the foundation for the synthesis of such compounds and paving the way for their potential applications.

关键词： Polyarsenide Zintl anions Chain-like cluster DFT calculations AdNDP

Higher ambient temperatures may worsen obstructive sleep apnea:A nationwide smartwatch-based analysis of 6.2 million person-days

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Science Bulletin 2024年第13期69卷 2114-2121页

作者： Anni Li Qingli Zhang Yuan Yao Xinlei Zhu Cong Liu Yutao Guo Haidong Kan Renjie Chen School of Public Health Key Lab of Public Health Safety of the Ministry of Education and NHC Key Lab of Health Technology AssessmentFudan UniversityShanghai 200032China Ministry of Education-Shanghai Key laboratory of Children’s Environmental Health Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200092China Department of Pulmonary Vessel and Thrombotic Disease Sixth Medical CenterChinese PLA General HospitalBeijing 100048China Institute for Hospital Management Research Chinese PLA General HospitalBeijing 100048China Children’s Hospital of Fudan University National Children’s Medical CenterShanghai 201102China School of Public Health Hengyang Medical SchoolUniversity of South ChinaHengyang 421001China

Obstructive sleep apnea(OSA)is a serious type of sleep disorder that can lead to cardiometabolic and neurocognitive *** utilized smart device-based photoplethysmography technology to collect sleep data from the Chinese population from 2019 to *** lag nonlinear models combined with a generalized nonlinear model or a linear mixed effects model were used to investigate the shortterm associations between daily temperature and indicators of OSA *** included a total of 6,232,056 d of sleep monitoring data from 51,842 participants with moderate to severe risk of OSA from 313 Chinese *** relationships between ambient temperature and OSA exacerbation,apneahypopnea index(AHI),and minimum oxygen saturation(MinSpO_(2))were almost linear and present only on the same *** temperatures were associated with a greater risk of OSA exacerbation,with an 8.4%(95%confidence interval(CI):7.6%–9.3%)increase per 10℃increase in temperature.A 10℃increase in daily temperature corresponded to an AHI increase of 0.70 events/h(95%CI:0.65–0.76)and a MinSpO_(2)decrease of 0.18%(95%CI:0.16%–0.19%).Exposure to elevated temperatures during the night can also lead to adverse *** effects of higher temperatures on OSA severity were stronger among men,participants with a body mass index24 kg/m2,those aged 45 years and older,individuals with a history of hypertension and diabetes,and during the cold *** large-scale,nationwide,longitudinal study provides robust evidence suggesting that higher ambient temperatures may immediately worsen OSA.

关键词： Obstructive sleep apnea Temperature Apnea-hypopnea index Oxygen saturation Smart device

Two H3K36 methyltransferases differentially associate with transcriptional activity and enrichment of facultative heterochromatin in rice blast fungus

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aBIOTECH 2024年第1期5卷 1-16页

作者： Mengting Xu Ziyue Sun Huanbin Shi Jiangnan Yue Xiaohui Xiong Zhongling Wu Yanjun Kou Zeng Tao Ministry of Agriculture Key laboratory of Molecular Biology of Crop Pathogens and Insects Institute of BiotechnologyZhejiang UniversityHangzhou 310058China State Key lab of Rice Biology and Breeding China National Rice Research InstituteHangzhou 310021China

Di-and tri-methylation of lysine 36 on histone H3(H3K36me2/3)is catalysed by histone methyltransferase Set2,which plays an essential role in transcriptional *** there is a single H3K36 methyltransferase in yeast and higher eukaryotes,two H3K36 methyltransferases,Ash1 and Set2,were present in many filamentous ***,their roles in H3K36 methylation and transcriptional regulation remained *** with methods of RNA-seq and ChIP-seq,we revealed that both Ash1 and Set2 are redundantly required for the full H3K36me2/3 activity in Magnaporthe oryzae,which causes the devastating worldwide rice blast ***1 and Set2 distinguish genomic H3K36me2/3-marked regions and are differentially associated with repressed and activated transcription,***,Ash1-catalysed H3K36me2 was co-localized with H3K27me3 at the chromatin,and Ash1 was required for the enrichment and transcriptional silencing of H3K27me3-occupied *** the different roles of Ash1 and Set2,in H3K36me2/3 enrichment and transcriptional regulation on the stress-responsive genes,they differentially respond to various stresses in ***,we reveal a novel mechanism by which two H3K36 methyltransferases catalyze H3K36me2/3 that differentially associate with transcriptional activities and contribute to enrichment of facultative heterochromatin in eukaryotes.

关键词： Ash1 Facultative heterochromatin H3K36me2/3 Magnaporthe oryzae Set2 Transcriptional regulation

To improve robustness of mechanical properties of semi-solid cast A356 alloy using taguchi design method

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China Foundry 2024年第2期21卷 175-184页

作者： Yi-wu Xu Hong-yi Zhan Wei Tong Jin-ping Li Le-peng Zhang De-jiang Li Xiao-qin Zeng School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China China Science lab General Motors Global Research&DevelopmentShanghai 201206China General Motors(China)Investment Co. Ltd.Shanghai 201206China China International Intellectech Corporation(CIIC) Beijing 100004China

Mechanical properties of semi-solid casting are dependent on multiple processing parameters,and improper processing parameters will not only reduce mean data but also increase *** present study investigated the impact of parameters in slurry preparation and heat treatment on the yield strength and ductility of T6 heat-treated A356 Al-Si alloy using rapid slurry forming(RSF)semi-solid *** focus was primarily on the robustness of mechanical properties based on Taguchi design *** analyzing signal-to-noise ratio and minimum value calculated from-3S,the optimum slurry preparation parameters and heat treatment parameters were determined to be no quench,enthalpy exchange material(EEM)temperature of 140℃,EEM-to-melt ratio of 6mass%,stirring time of 18 s,solution heat treated at 520℃ for 2 h,and ageing heat treated at 190℃ for 6 *** a small batch validation,the-3S yield strength and-3S elongation reach 256.1 MPa and 5.03% respectively,showing a satisfactory *** hardness and microstructure of heat-treated samples with the best and worst properties were characterized to gain insight into the underlying mechanisms affecting the mean value and variations of mechanical properties.

关键词： semi-solid casting taguchi design method signal-to-noise ratio mechanical property microstructure

Detachment Behavior of Gecko Toe in Functional Strategies for Bionic Toe

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Journal of Bionic Engineering 2024年第2期21卷 707-717页

作者： Qingfei Han Wei Wang Huan Shen Xincheng Feng Haoran Zhang Qian Li Yi Sun Huapeng Wu Aihong Ji lab of Locomotion Bioinspiration and Intelligent Robots College of Mechanical and Electrical EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China laboratory of Intelligent Machines School of Energy SystemsLappeenranta-Lahti University of Technology53850LappeenrantaFinland State Key laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

Geckos can efficiently navigate complex terrains due to their multi-level adhesive system that is present on their *** setae are responsible for the gecko’s extraordinary adhesion and have garnered wide attention from the scientific *** majority of the reported works in the literature that have dealt with the peeling models mainly focus on the gecko hierarchical adhesive system,with limited attention given to investigating the influence of gecko toe structure on the *** these lines,to gain a deeper understanding of the rapid and effortless detachment abilities of gecko toes,the peeling behavior of gecko toes on vertical surfaces was primarily investigated in this *** specifically,the detachment time of a single toe on a smooth acrylic plate was measured to be 0.41±0.21 ***,it was observed that the toe assumed a"U"-shaped structure upon complete ***,Finite Element Analysis(FEA)models for three different types of gecko toes were developed to simulate both the displacement-peel and the moment-peel *** the segmentation of the adhesive layer led to a gradual decrease in the resultant force,as well as the normal and tangential ***,a gecko-inspired toe model was constructed and powered by Shape Memory Alloy(SMA).A systematic comparison between the vertical drag separation and the outward flip separation was also *** our analysis,it was clearly demonstrated that outward peel separation significantly necessitated the reduction of the peeling force,thus confirming the advantageous nature of the outward motion in gecko toe *** data not only contribute to a deeper understanding of the gecko detachment behavior but also offer valuable insights for the advancement of the wall-climbing robot feet.

关键词： Gecko toes Detachment behavior Finite element analysis Gecko-inspired toe

Cyclotriphosphazene Fibre Reinforced Poly(benzoxazine-co-ε-caprolactam) Nanocomposites for Flame Retardant Applications

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Chinese Journal of Polymer Science 2014年第8期32卷 1086-1098页

作者： M.Selvi S.Devaraju K.Sethuraman R.Revathi M.Alagar Polymer Composite lab Department of Chemical Engineering Anna University Next mems lab School of Mechanical Engineering Pusan National University

Cyclophosphazene nanotube （PZT） incorporated poly（benzoxazine-co-g-caprolactam）（P（BZ-co-CPL）） nano- composites were developed for improving flame retardant properties. The effects of PZT on the flammability properties of P（BZ-co-CPL） matrix were evaluated through UL-94 flammability test and limiting oxygen index （LOI）. The UL-94 results of P（BZ-co-CPL）/PZT hybrid nanocomposites showed V-1 rating, whereas neat P（BZ-co-CPL） showed burning rating. The LOI values are increased from 25.4 to 31.4 for 1.5 wt% PZT incorporated P（BZ-co-CPL） nanocomposite systems. SEM was used to study the char morphology of P（BZ-co-CPL）/PZT after being exposed to UL-94 flammability test. Data from thermal studies indicate that the PZT incorporated P（BZ-co-CPL） systems possess better Tg and thermal degradation behavior when compared to the neat P（BZ-co-CPL）. The values of dielectric constant are decreased with increasing temperature. From the values, it is ascertained that the P（BZ-co-CPL）/PZT systems exhibit stable dielectric behavior with regard to variation in temperature. The TEM images ascertain the uniform dispersion of PZT in the P（BZ-co-CPL） matrix.

关键词： Polybenzoxazine Phosphazene Flame retardant Dielectric properties.

Analysis of amino acid enantiomers in ambient aerosols:Effects and removal of coexistent aerosol matrix

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Journal of Environmental Sciences 2024年第3期137卷 732-740页

作者： Ying Li Xiaoying Li Libin Wu Luhan Shi ShanWang Pingqing Fu Yingyi Zhang Senchao Lai The Key lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Institute of Surface-Earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China now at Hong Kong University of Science and Technology Hong Kong 00852China

Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient *** to the low abundances of AAs(level of ng/m^(3))and the matrix effects by coexistent components,it is challenging to quantify AA enantiomers in ambient aerosols especially under pollution *** this study,we present an optimized method for analyzing AA enantiomers in atmospheric aerosol samples including a pretreatment process and the detection by high performance liquid chromatography coupled to a fuorescence detector(HPLC-FLD).Matrix effects caused by coexistent chemicals on AA enantiomers analysis in ambient aerosol samples were investigated especially for those collected in pollution *** results revealed that the determination of AA enantiomers is significantly affected by the coexistent organic carbon(as a proxy of organic matter)and water-soluble ion of NH_(4)^(+).To remove the matrix effects,we applied a pretreatment using the solid phase extraction column coupled with alkaline adjustment to sample *** pretreatment,18 AAs including 6 pairs of D-and L-enantiomers(i.e.,leucine,isoleucine,valine,alanine,serine,and aspartic acid)can be successfully separated and quantified in aerosol samples by *** recoveries are in the range of 67%-106%.This method was successfully applied to the urban aerosol samples from pollution and non-pollution periods for AA enantiomers *** suggest that the concentrations of D-AAs and the ratio of D-AA/L-AA are indicative of the contribution of bacterial sources and the infuence of biomass burning.

关键词： Amino acid enantiomers Atmospheric aerosol Organic carbon Ammonia Chiral ratio