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Identi?cation and Analysis of the Intermediates from Photodegradation of 3,3′-diamino-4,4′-azoxyfurazan (DAAF)by SERS and HPLC–MS/MS

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Journal of Analysis and Testing 2024年第3期8卷 351-360页

作者： Qi Wu Zhenqi zhang Wenxu Zheng Juan li nan Ma Rui li Bo Yang Weimiao Wang Xiaodong li Meikun Fan Faculty of Geosciences and Environmental Engineering Southwest Jiaotong University Institute of Chemical Materials China Academy of Engineering Physics College of Materials and Energy South China Agricultural University Southwest University of Science and Technology

Understanding the structural changes and degradation mechanisms of organic pollutants is critical in environmental *** this work, a xenon lamp was used as an analog light source to simulate the eff ect of sunlight on 3,3′-diamino-4,4′-azoxyfurazan (DAAF) in aqueous solution. Combining high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS), surface-enhanced Raman spectroscopy (SERS) with density functional theory (DFT), the degradation intermediates and mechanisms of DAAF were investigated. The sequential breakdown of the–NH 2and–O–N=bonds, followed by the removal of atomic O from–N=N(O)–, was emphasized and investigated using two-dimensional correlation spectroscopy (2D-COS) and SERS spectra. Three intermediates with mass-to-charge ratios (m/z) 181, 251 and180 were identifi ed and characterized by integrating experimental SERS data with DFT-calculated Raman spectra based on structures hypothesized from MS spectra. The fi ndings from HPLC–MS and SERS not only corroborate each other but also provide a foundation for a detailed examination of the DAAF degradation process.

关键词： DAAF High-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS) Photodegradation products Reaction pathways Surface-enhanced Raman spectroscopy (SERS)

Enhanced quality of Al2O3/SiC gate stack via microwave plasma annealing

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Rare Metals 2024年第10期43卷 5362-5371页

作者： nan-nan You Xin-Yu liu Qian zhang Zhen Wang Jia-Yi Wang Yang Xu Xiu-Yan li Yu-Zheng Guo Sheng-Kai Wang High-Frequency High-Voltage Device and Integrated Circuits R&D Center Institute of Microelectronics of the Chinese Academy of Sciences School of Integrated Circuits University of Chinese Academy of Sciences School of Electrical Engineering and Automation Wuhan University Department of Micro/nano Electronics School of Electronic Information and Electrical EngineeringShanghai Jiao Tong University

The high-quality gate dielectric on silicon carbide （SiC） surface is critical to fabricate high-performance SiC metal-oxide-semiconductor field-effect transistors（MOSFETs）.This research employs microwave plasma annealing （MPA） to obtain high-quality Al2O3/SiC gate *** designing MPA atmosphere and optimizing the plasma power,the SiC MOS capacitor with a Al2O3dielectric film shows the enhanced *** interface state density is reduced by 1 order of magnitude to 6×1011cm-2·eV-1,the breakdown electric field is increased,and the voltage shift is effectively suppressed Besides,the mechanism of MPA process is discussed in terms of the thermal effect and reactant species.X-ray photoelectron spectroscopy （XPS） results unveil oxygen plasma plays the main *** plasma power during the MPA process results in defect repairs of the firstneighbor Al-O bonding and partial removal of Al-O-H bond from the interface *** study demonstrates that MPA process is an effective option to realize highquality dielectric and interface on SiC.

关键词： Al2O3 Defect repairs Metal–oxide–semiconductor Microwave plasma annealing Silicon carbide X-ray photoelectron spectroscopy

Utilizing a metal-forging inspired chain combing strategy to enhance properties and expand applications of Nylon 66 plastic via heat inducing

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nano Research 2024年第3期17卷 2164-2171页

作者： Junyu Yang Jiangwei zhang nan Wang Guangyuan Zhou Division of Energy Materials Daglian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Innovation Center of Energy Material and Chemistry College of Chemistry and Chemical EngineeringInner Mongolia UniversityHohhot 010021China

The mechanical properties of engineering plastics can be enhanced through effective surface mechanical treatment(SMT),which can be applied to various types of engineering plastics,eliminating the limitations of conventional polymer processing and could potentially extend their applications and improve their performance and reliability as structural-functional *** by metal forging,this work proposes a simple and effective SMT strategy to enhance the mechanical properties of polyamide 66(PA66).Tensile tests have shown that SMTed PA66 samples exhibit significant improvements in both Young’s modulus and ultimate tensile strength(UTS),with a 2104 MPa Young’s modulus,almost double that of the pristine samples,and a 35.56%increase in UTS,reaching 183 ***,the modulus within the localized SMTed surface layer could reach up to 14 GPa,which is approximately 14 times higher than that of the pristine *** Vickers hardness within the localized SMTed surface layer can be doubled,reaching 10.72 Hv,and the crystallinity can increase by approximately 20%compared to the untreated ***,force field molecular dynamics(FFMD)simulations were conducted to investigate the ternary relationship between the SMT method,PA66’s molecular structure,and its *** combination of MD simulations and versatile structural characterizations provides evidence that the SMT method’s mechanism,under heat induction,results in a chain-combing procedure that changes the polymer’s molecular morphology microscopically and enhances its mechanical properties macroscopically.

关键词： Nylon 66 mechanical properties hardness crystallinity structural characterizations molecular dynamics simulation

Feasibility of using Vis-NIR spectroscopy and PXRF spectrometry to estimate regional soil cadmium concentration

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Journal of Environmental Sciences 2024年第11期145卷 88-96页

作者： Mengxue Wan Fan Ya’nan Wentao Jiao Wenyou Hu Mingchao Lyu Weidong li Chuanrong zhang Biao Huang Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Department of Environmental Science Zhejiang UniversityHangzhou 310058China Guangdong Provincial Academy of Environmental Science Guangzhou 510045China Department of Geography University of ConnecticutStorrsCT 06269USA

Conventionally,soil cadmium(Cd)measurements in the laboratory are expensive and timeconsuming,involving complex processes of sample preparation and chemical *** study aimed to identify the feasibility of using sensor data of visible near-infrared reflectance(Vis-NIR)spectroscopy and portable X-ray fluorescence spectrometry(PXRF)to estimate regional soil Cd concentration in a time-and *** sensor data of Vis-NIR and PXRF,and Cd concentrations of 128 surface soils from Yunnan Province,China,were ***-product analysis(OPA)was used for synthesizing the sensor data and Granger-Ramanathan averaging(GRA)was applied to fuse the model *** neural network(ANN)models were built using Vis-NIR data,PXRF data,and OPA data,*** showed that:(1)ANN model based on PXRF data performed better than that based on Vis-NIR data for soil Cd estimation;(2)Fusion methods of both OPA and GRA had higher predictive power(R^(2))=0.89,ratios of performance to interquartile range(RPIQ)=4.14,and lower root mean squared error(RMSE)=0.06,in ANN model based on OPA fusion;R^(2)=0.88,RMSE=0.06,and RPIQ=3.53 in GRA model)than those based on either Vis-NIR data or PXRF *** conclusion,there exists a great potential for the combination of OPA fusion and ANN to estimate soil Cd concentration rapidly and accurately.

关键词： Artificial neural network Outer-product analysis Granger-Ramanathan averaging Soil Cd concentration Fusion method

Ultrasonic vibration enabled under-liquid forming of metallic glasses

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Science Bulletin 2024年第2期69卷 163-166页

作者： Xin li Luyao li Sajad Sohrabi Jia'nan Fu Zhen li Zhe Chen Rongce Sun Yu zhang Jinbiao Huang Heting zhang Jian Zhu Xiangyan Chen Kaikai Song Jiang Ma School of Mechanical Electrical&Information EngineeringShandong UniversityWeihai 264209China State Key Laboratory of Radio Frequency Heterogeneous Integration College of Mechatronics and Control EngineeringShenzhen UniversityShenzhen 518060China Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhen 518055China Shenzhen Research Institute of Shandong University Shenzhen 518057China

Advancements in forming technology offer significant advantages for the manufacturing industry,including enhanced efficiency,energy conservation,and improved material utilization[1].However,traditional additive manufacturing[2],thermoplastic forming[3],and laser cutting[4]encounter challenges when applied in under-liquid environments,mainly due to difficulties in temperature control and heat source provision.

关键词： glasses liquid metallic

Channel estimation-based time-frequency neural network for post-equalization in underwater visible light communication

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Chinese Optics Letters 2024年第6期22卷 116-122页

作者： Haoyu zhang li Yao Chaoxu Chen Yuan Wei Chao Shen Jianyang Shi Junwen zhang Ziwei li nan Chi Key Laboratory for Information Science of Electromagnetic Waves(MoE) Department of Communication Science and EngineeringSchool of Information Science and TechnologyFudan UniversityShanghai 200433China Shanghai CIC of LEO Satellite Communication Technology Fudan UniversityShanghai 200433China Shanghai ERC of LEO Satellite Communication and Application Fudan UniversityShanghai 200433China

This Letter proposes a post-equalizer for underwater visible light communication(UVLC) systems that combines channel estimation and joint time-frequency analysis, named channel-estimation-based bandpass variable-order time-frequency network(CBV-TFNet). By utilizing a bandpass variable-order loss function with communication prior knowledge, CBVTFNet enhances communication performance and training stability. It enables lightweight implementation and faster convergence through a channel estimation-based mask. The superior performance of the proposed equalization method over Volterra and deep neural network(DNN)-based methods has been studied experimentally. Using bit-power loading discrete multitone (DMT) modulation, the proposed method achieves a transmission bitrate of 4.956 Gbps through a 1.2 m underwater channel utilizing only 38.15% of real multiplication calculations compared to the DNN equalizer and achieving a bitrate gain of440 Mbps and a significantly larger dynamic range over the LMS-Volterra equalizer. Results highlight CBV-TFNet's potential for future post-equalization in UVLC systems.

关键词： underwater visible light communication channel estimation post-equalizer neural network

Solution-processed rare-earth thulium oxide with high permittivity for low-voltage transistor and inverters applications

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Journal of Rare Earths 2024年第8期42卷 1604-1609,I0007页

作者： Daiming liu Fei Wang Yongtao zhang Ya'nan Ding Shandong Engineering Laboratory for Preparation and Application of High-performance Carbon-Materials College of Electromechanical EngineeringQingdao University of Science&TechnologyQingdao266061China College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao266590China

The use of high-permittivity(high-k) thin films as gate dielectrics is essential in the development of lowpower electronics,In this work,rare-earth thulium oxide(Tm_(2)O_(3)) thin films were prepared by a facile solution process and annealed at various temperatures from 400 to 700℃.The evolution of the physical and dielectric properties of Tm_(2)O_(3) thin film with annealing temperature was *** is demonstrated that the Tm_(2)O_(3) thin film annealed at 600℃ exhibits the optimal performance,including a low leakage current of 3×10^(-10) A/cm^(2),a large areal capacitance of 250 nF/cm^(2) at 100 Hz,and a high permittivity value of *** Tm_(2)O_(3) thin film as a gate insulator was integrated into the thin film transistor(TFT) employing In_(2)O_(3)-based semiconducting *** In_(2)O_(3) TFT with 600℃-annealed Tm_(2)O_(3) dielectric exhibits the superior perfo rmance,with a high I_(on)/I_(off) of 1.65×10^(7),a small subthre shold swing(SS) value of 0.2 V/dec,a V_(TH) of+1.8 V,and a mobility of 1.68 cm^(2)/(V·s).Furthermore,an inverter constructed by connecting the TFT with a resistor exhibits full-swing *** work provides a facile and appealing method for preparing the high-k Tm_(2)O_(3) thin films as alternative gate dielectrics with the potential for use in low-power electronics and logic circuit applications.

关键词： Rare earths Tm_(2)O_(3) Dielectric Transistor Inverter

High-performance localized high-concentration electrolytes by diluent design for long-cycling lithium metal batteries

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Chinese Chemical Letters 2024年第4期35卷 244-247页

作者： Zhe Wang li-Peng Hou Qian-Kui zhang nan Yao Aibing Chen Jia-Qi Huang Xue-Qiang zhang College of Chemical and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang 050018China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Advanced Research Institute of Multidisciplinary Science Beijing Institute of TechnologyBeijing 100081China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China

Electrolyte design is essential for stabilizing lithium metal anodes and localized high-concentration electrolyte(LHCE) is a promising one. However, the state-of-the-art LHCE remains insufficient to ensure long-cycling lithium metal anodes. Herein, regulating the solvation structure of lithium ions in LHCE by weakening the solvating power of diluents is proposed for improving LHCE performance. A diluent,1,1,2,2,3,3,4,4-octafluoro-5-(1,1,2,2-tetrafluoroethoxy) pentane(OFE), with weaker solvating power is introduced to increase the proportion of aggregates(an anion interacts with more than two lithium ions,AGG-n) in electrolyte compared with the commonly used 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(TTE). The decomposition of AGG-n in OFE-based LHCE intensifies the formation of anion-derived solid electrolyte interphase and improves the uniformity of lithium deposition. lithium metal batteries with OFE-based LHCE deliver a superior lifespan of 190 cycles compared with 90 cycles of TTE-based LHCE under demanding conditions. Furthermore, a pouch cell with OFE-based LHCE delivers a specific energy of 417 Wh/kg and undergoes 49 cycles. This work provides guidance for designing high-performance electrolytes for lithium metal batteries.

关键词： lithium metal anodes Electrolyte Diluents Solid electrolyte interphase Pouch cells

Climate and topography regulate the spatial pattern of soil salinization and its effects on shrub community structure in Northwest China

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Journal of Arid Land 2024年第7期16卷 925-942页

作者： DU Lan TIAN Shengchuan ZHAO nan zhang Bin MU Xiaohan TANG lisong ZHENG Xinjun li Yan State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China Fukang Station of Desert Ecology Chinese Academy of SciencesFukang 831505China State Key Laboratory of Subtropical Silviculture Zhejiang A&F UniversityHangzhou 311300China

Soil salinization may affect biodiversity and species composition,leading to changes in the plant community ***,few studies have explored the spatial pattern of soil salinization and its effects on shrub community structure at the ecosystem ***,we conducted a transect sampling of desert shrublands in Northwest China during the growing season(June–September)in *** salinization(both the degree and type),shrub community structure(e.g.,shrub density and height),and biodiversity parameters(e.g.,Simpson diversity,Margalf abundance,Shannon-Wiener diversity,and Pielou evenness indices)were used to assess the effects of soil salinization on shrub community *** results showed that the primary degree of soil salinization in the study area was light salinization,with the area proportion of 69.8%.Whereas the main type of soil salinization was characterized as sulfate saline soil,also accounting for 69.8%of the total ***,there was a significant reduction in the degree of soil salinization and a shift in the type of soil salinization from chloride saline soil to sulfate saline soil,with an increase in *** mean annual precipitation(MAP),mean annual evapotranspiration(MAE),elevation,and slope significantly contributed to soil salinization and its geochemical *** soil salinization intensified,shrub community structure displayed increased diversity and evenness,as indicated by the increases in the Simpson diversity,Shannon-Wiener diversity,and Pielou evenness ***,the succulent stems and leaves of Chenopodiaceae and Tamaricaceae exhibited clear advantages under these ***,regional climate and topography,such as MAP,MAE,and elevation,had greater effects on the distribution of shrub plants than soil *** results provide a reference for the origin and pattern of soil salinization in drylands and their effects on the community structure of halophyte shrub species.

关键词： soil salinization halophytes shrubland climate change biodiversity drylands Northwest China