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Atmospheric chemistry of 2-nitrobenzaldehyde:Initiated by photo-excitation,OH-oxidation,and small TiO_(2) clusters adsorption catalysis

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Journal of Environmental Sciences 2024年第5期139卷 123-137页

作者： Feng-yang Bai Xiang-Huan Liu Ting-Ting Meng Zhou Yu yi-chen Wang Shuang Ni Zhen Zhao Institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang 110034China

The fate of 2-nitrobenzaldehyde(2-NBA)is of interest in atmospheric chemistry as it is a semi-volatile organic compound with high *** study presents a quantum chemical study of the gas-phase reactions of 2-NBA photo-excitation and OH-oxidation in the absence and presence of small TiO_(2) *** further understand the unknown photolysis mechanism,the photo-reaction pathways of ground singlet state and the lying excited triplet state of 2-NBA were investigated including the initial and subsequent reactions of proton transfer,direct CO,NO_(2),and HCO elimination routes in the presence of O_(2) and ***,the OH-mediated degradation of 2-NBA proceeded via five H-extraction and six OH-addition channels by indirect mechanism,which follows a succession of reaction steps initiated by the formation of weakly stable intermediate *** H-extraction from the-CHO group was the dominant pathway with a negative activation energy of-1.22 kcal/*** calculated rate coefficients at 200–600 K were close to the experimental data in literature within 308-352 K,and the kinetic negative temperature independence was found in both experimental literature and computational ***,2-NBA was favored to be captured onto small TiO_(2) clusters via six adsorption configurations formed via various combination of three types of bonds of Ti…O,Ti…C,and O…H between the molecularly adsorbed 2-NBA and TiO_(2) *** indicted that the chemisorptions of aldehyde oxygen have largest *** results suggested adsorption conformations have a respectable impact on the catalysis *** study is significant for understanding the atmospheric chemistry of 2-nitrobenzaldehyde.

关键词： 2-nitrobenzaldehyde OH radical oxidation Rate coefficient Photolysis mechanism Adsorption catalysis

Highly Conductive Ag/pCF/MVQ Composite Rubber for Efficient Electromagnetic Interference Shielding

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Chinese Journal of Polymer Science 2024年第6期42卷 864-873页

作者： yang chen Xiao-Ming Shao Liang He yi-Nuo Xu Qi-Yuan Yao Ding Feng Wen-Cai Wang State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing100029China Key Laboratory of Beijing City for Preparation and Processing of Novel Polymer Materials Beijing University of Chemical TechnologyBeijing100029China Sino-german School of Engineering Qingdao University of Science and TechnologyQingdao266400China

In this study,flexible and highly conductive composite rubber at low filler content was successfully prepared through polydopamine-assisted electroless silver plating plus mechanical ***,carbon fibers(CF)were activated by polydopamine(PDA)to improve the surface activity by self-polymerization ***,because of the metal chelating ability of PDA,silver layer was firmly deposited on the surface of CF through a facile electroless silver plating ***,flexible silver-plated carbon fibers(Ag/pCF)silicone rubber composites prepared by mechanical *** using X-ray photoelectron spectroscopy(XPS)and X-ray diffraction(XRD),the chemical composition and crystal structure of Ag/pCF were examined,and scanning electron microscopy(SEM)was used to assess the surface morphology of the Ag/*** results showed that a uniform and dense silver layer was formed on the surface of the CF,and the conductivity of the Ag/pCF could reach 7885 S/*** was noteworthy that the composite rubber filled with only 45 phr Ag/pCF had a high electromagnetic interference shielding effectiveness(100 dB)due to the low density and high aspect ratio of Ag/*** composite rubber has excellent potential for application in the field of electromagnetic interference shielding.

关键词： Carbon fibers Polydopamine Electroless plating Silver Electromagnetic interference shielding

Evaluation of water management on arsenic methylation and volatilization in arsenic-contaminated soils strengthened by bioaugmentation and biostimulation

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Journal of Environmental Sciences 2024年第3期137卷 515-526页

作者： Peng chen yi Liu Guo-Xin Sun State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China

Arsenic(As) fate in paddy fields has been one of the most significant current issues due to the strong As accumulation potential of rice plants under fooded conditions. However,no attempt was done to explore As methylation and volatilization under non-fooded conditions. Herein, we investigated the effects of water management on As methylation and volatilization in three arsenic-contaminated soils enhanced by biostimulation with strawderived organic matter and bioaugmentation with genetic engineered Pseudomonas putida KT2440(GE P. putida). Under fooded conditions, the application of biochar(BC), rice straw(RS)and their combination(BC+RS) increased total As in porewater. However, these effects were greatly attenuated under non-fooded conditions. Compared with RS amendment alone, the combination of GE P. putida and RS further promoted the As methylation and volatilization,and the promotion percentage under non-fooded conditions were significantly higher than that under fooded conditions. The combined GE P. putida and RS showed the highest efficiency in As methylation(88 μg/L) and volatilization(415.4 μg/(kg·year)) in the non-fooded soil with moderate As contamination. Finally, stepwise multiple linear regression analysis presented that methylated As, DOC and p H in porewater were the most important factors contributing to As volatilization. Overall, our findings suggest that combination of bioaugmentation with GE P. putida and biostimulation with RS/BC+RS is a potential strategy for bioremediation of arsenic-contaminated soils by enhancing As methylation and volatilization under non-fooded conditions.

关键词： Arsenic methylation Arsenic volatilization Water management Straw incorporation Bioaugmentation

Investigation of high-quality-factor aluminum nitride MEMS cantilever resonators

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Nanotechnology and Precision Engineering 2024年第1期7卷 32-43页

作者： Shuai Shi Qingrui yang yi Yuan Haolin Li Pengfei Niu Wenlan Guo chen Sun Wei Pang State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

This paper presents the design,fabrication,and characterization of cantilever-type resonators with a novel stacked *** nitride is adopted as the material for both the structural layer and the piezoelectric layer;this simpliﬁes the fabrication process and improves the quality factor of the *** in-plane and out-of-planeﬂexural modes were *** effect of the structural dimensions and electrode patterns on the resonator’s performance were also ***-element simulations and experiments examining anchor loss and thermoelastic damping,which are the main loss mechanisms affecting the quality factor of these resonators,were carried *** optimal structural dimensions and electrode patterns of the cantilever-type resonators are presented.A quality factor of 7922 with a motional impedance of 88.52 kΩand a quality factor of 8851 with a motional impedance of 67.03 kΩwere achieved for the in-plane and out-of-planeﬂexural-mode resonators,*** proposed resonator design will contribute to the development of high-performance devices such as accelerometers,gyroscopes,and pressure sensors.

关键词： MEMS Cantilever-type micro-resonator AlN Finite-element simulation

Let-7i-5p maintains the stemness via R-spondin2/Wnt pathway in hepatocellular carcinoma

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Genes & Diseases 2024年第4期11卷 20-23页

作者： Qinghua Wei Xueshan Dai Jiahui Wei Wenwei Sun Xiaoqian yang Yuxin Zhang Xin Guo yi chen College of Pharmaceutical Sciences&Chinese Medicine Southwest UniversityChongqing 400716China Center for Basic Medical Research TEDA International Cardiovascular HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeTianjin 300457China Chongqing Key Laboratory of New Drug Screening from Traditional Chinese Medicine Chongqing 400716China pharmacology of Chinese Materia Medica-the Key Discipline Constructed by the State Administration of Traditional Chinese Medicine Chongqing 400716China Division of Cell Developmental and Integrative BiologySchool of MedicineSouth China University of TechnologyGuangzhouGuangdong 510006China National Demonstration Center for Experimental Pharmacy Education(Southwest University) Chongqing 400716China Engineering Research Center of Coptis Development and Utilization(Ministry of Education) College of Pharmaceutical Sciences and Chinese MedicineSouthwest UniversityChongqing 400716China

Cancer stem cells(CSCs)are related to tumorigenesis,recurrence,metastasis,and drug resistance in hepatocellular carcinoma(HCC).1 Let-7i is a noncoding small RNA,belonging to the famous miRNA let-7 ***,let-7i has been ... 详细信息

关键词： hepatocellular Cancer metastasis

Palladium single atoms from melting nanoparticles on WO_(3-x) for boosted hydrogen evolution reaction

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Journal of Energy Chemistry 2024年第4期91卷 637-644页

作者： Zhongmiao Gong Zhigang chen Hao Li Guang yang Min Yuan Zhiyun Li Xueying Wan yi Cui School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026AnhuiChina i-lab Vacuum Interconnected Nanotech WorkstationSuzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123JiangsuChina School of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China Key Laboratory of Precision and Intelligent Chemistry School of Chemistry and Materials ScienceHefei National Research Center for Physical Sciences at the MicroscaleNational Synchrotron Radiation LaboratorySchool of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei 230026AnhuiChina

Surface-supported isolated atoms in single-atom catalysts(SACs)grant maximum utilization of metals in heterogeneous ***,we report a feasible pyrolysis strategy to synthesize Pd single atoms by thermally melting Pd nanoparticles on an oxygen-vacancy-rich tungsten-oxide matrix at reduction *** ambient pressure X-ray photoelectron spectroscopy was used to monitor the formation of zero-valence Pd single atoms and the increased metallic feature of WO_(3-x)***,the as-obtained zero-valence Pd single-atom catalyst exhibits a markedly boosted HER activity with a low overpotential(η_(10)=70 mV)at the current density of 10 mA/cm2and a small Tafel slope(b=68 mV/dec),nearly 150 mV and a 3,0-fold enhancement than those of Pd nanoparticles(η_(10)=220 mV,b=133 mV/dec)under the same *** addition,quasi in situ XPS results suggest the hydrogen spillover effect is more likely to occur on Pd single atoms during the electrochemical *** work may pave an interesting route for the rational design of highly-efficient single-atom catalysts,and the elucidation of corresponding enhanced reaction mechanisms by the utilization of advanced characterization techniques.

关键词： Pd WO_(3-x) Single-atom catalysts NAP-XPS HER

Research progresses and prospects of multi-sphere compound extremes from the Earth System perspective

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Science China Earth Sciences 2024年第2期67卷 343-374页

作者： Zengchao HAO yang chen College of Water Sciences Beijing Normal UniversityBeijing100875China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing100081China

Compound extremes,whose socioeconomic and ecological impacts are severer than that caused by each event occurring in isolation,have evolved into a hot topic in Earth Science in the past *** the context of climate change,many compound extremes have exhibited increasing frequency and intensity,and shown novel fashions of combinations,posing more pressing demands and tougher challenges to scientific research and disaster prevention and *** article,via a perspective of multi-sphere interactions within the Earth System,systematically reviews the status quo,new scientific understanding,and deficiencies regarding the definition,mechanism,change,attribution,and projection of compound *** study also sorts out existing challenges and outlines a potential roadmap in advancing the study on compound extremes with respect to data requirement,mechanistic diagnosis,numerical modeling,attribution and projection,risk assessment,and adaptive *** directions of compound extremes studies and key research topics that warrant multi-disciplinary and multisectoral coordinated efforts are also *** that climate change has reshaped the type of extremes,a transformation from the traditional single-event perspective to a compound-event perspective is needed for scientific research,disaster prevention and mitigation,and climate change adaptation,calling for bottom-up innovation in research objects,ideas,and *** article will add value to promoting the research on compound extremes and interdisciplinary cooperations.

关键词： Extremes Compound extremes Climate change and risk Multi-sphere interactions

Acoustic characterization of hydrate formation and decomposition in clay-bearing sediments

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Petroleum Science 2024年第4期21卷 2830-2838页

作者： yi-Jian Zhu Xiao-Mei yang Xing Huang Hao Li Xiao-Hui Wang yi-Fei Sun Peng Xiao Chang-Yu Sun Guang-Jin chen State Key Laboratory of Heavy Oil Processing College of Chemical Engineering and Environment China University of Petroleum

Understanding the acoustic characteristics of hydrates in various sediments is crucial for hydrate resource detection and safe and efficient exploitation, as hydrate occurrence patterns vary greatly in different sediments. In this work, sediments with different bentonite contents, water saturations, and types were prepared to investigate the characteristics of P-wave velocity(reflecting the magnitude of hydrate saturation in the sediment) and amplitude(reflecting the degree of hydrate-sediment cementation) during hydrate formation and depressurization. During hydrate formation, the P-wave velocity and amplitude have similar trends. As clay content increases, the P-wave velocity increase rates quickened. On the other hand, the increased rate of P-wave velocity slows down with the increase of water saturation in the clay-bearing sediments. Comparing various types of sediment shows that the water absorption and swelling of bentonite reduce the pore space, speeding up the cementation of the hydrate with the sediment and increasing P-wave velocity at a faster rate. Correspondence between P-wave velocity and hydrate saturation is strongly related to sediment type, clay content, and water *** rapidly decreasing amplitude in the early stage of hydrate depressurization indicates that hydrate in clay-bearing sediments is weakly cemented to the sediments, which is prone to stratigraphic *** findings of this study offer guidance for hydrate resource assessments in clay-bearing sediments as well as geologic risk estimations during hydrate mining.

关键词： Gas hydrate Bentonite Illite P-wave velocity Amplitude

High-resolution ARPES endstation for in situ electronic structure investigations at SSRF

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Nuclear Science and Techniques 2021年第3期32卷 94-106页

作者： yi-chen yang Zheng-Tai Liu Ji-Shan Liu Zhong-Hao Liu Wan-Ling Liu Xiang-Le Lu Hong-Ping Mei Ang Li Mao Ye Shan Qiao Da-Wei Shen State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China University of Chinese Academy of Sciences Beijing 100049China

Angle-resolved photoemission spectroscopy(ARPES)is one of the most powerful experimental techniques in condensed matter *** ARPES,which uses photons with high flux and continuously tunable energy,has become particularly ***,an excellent synchrotron ARPES system must have features such as a small beam spot,super-high energy resolution,and a user-friendly operation interface.A synchrotron beamline and an endstation(BL03 U)were designed and constructed at the Shanghai Synchrotron Radiation *** beam spot size at the sample position is 7.5(V)μm×67(H)μm,and the fundamental photon range is 7-165 eV;the ARPES system enables photoemission with an energy resolution of 2.67 meV at21.2 *** addition,the ARPES system of this endstation is equipped with a six-axis cryogenic sample manipulator(the lowest temperature is 7 K)and is integrated with an oxide molecular beam epitaxy system and a scanning tunneling microscope,which can provide an advanced platform for in situ characterization of the fine electronic structure of condensed matter.

关键词： Synchrotron ARPES In situ VUV laser Quantum materials