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Atmospheric chemistry of trifluorodicarbonyls initiated by Cl atoms:Reactivity trends,mechanism,and acid formation yields

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journal of Environmental Sciences 2025年第5期151卷 12-25页

作者： Pedro L.Lugo Vianni G.Straccia Cynthia b.Rivela Mariano A.Teruel María b.blanco Laboratorio Universitario de Química y Contaminación del Aire(L.U.Q.C.A) Instituto de Investigaciones en Fisicoquímica de Córdoba(I.N.F.I.Q.C.)Dpto.de Fisicoquímica.Facultad de Ciencias QuímicasUniversidad Nacional de Córdoba.Ciudad Universitaria5000 CórdobaArgentina Institute for Atmospheric and Environmental Research University of WuppertalDE-42097 WuppertalGermany

Rate coefficients of the gas-phase reactions of Cl atoms with a series of fluorinated diketones(FDKs):CF_(3)C(O)CH_(2)C(O)CH_(3)(TFP),CF_(3)C(O)CH_(2)C(O)CH_(2)CH_(3)(TFH)and CF_(3)C(O)CH_(2)C(O)CH(CH_(3))2(TFMH),have been measured at(298±2)K and under atmospheric *** experiments were performed using the relative-rate method with a GC-FID detection *** different determinations and references used,the following rate coefficients were obtained(in cm3/(molecule·sec)):k_(4)(TFP+Cl)=(1.75±0.21)×10^(−10),k_(5)(TFH+Cl)=(2.05±0.23)×10^(−10),k_(6)(TFMH+Cl)=(2.71±0.34)×10^(−10).Reactivity trends of FDKs were discussed and Free Energy Relationships analysis was *** expression lgkOH=1.68 lgkCl+5.71 was obtained for the reactivity of the studied FDKs together with similar unsaturated VOCs with Cl and OH radicals Additionally,acetic acid(CH_(3)C(O)OH)and trifluoroacetic acid(CF_(3)C(O)OH)were positively identified and quantified as degradation products using in situ FTIR *** to the identified products,atmospheric chemical mechanisms were *** atmospheric implications of the studied reactions were assessed by the estimation of the tropospheric lifetimes of TFP,TFH,and TFMH concerning their reaction with Cl atoms to be 48,41,and 31 hours,*** relatively short residence in the atmosphere of the fluorocarbons studied will have a local/regional impact with restricted *** warming potential(GWP(20 yr))calculated for the studied fluoro diketones were 0.014,0.003 and 0.001 for TFP,TFH and TFMH,respectively with a negligible contribution to the greenhouse effect.

关键词： Fluorinated diketones Kinetics SPME-GC-FID FTIR in situ SAR Free energy relationships

美国的东南亚云服务战略:动向、影响与中国应对

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情报杂志 2025年第1期44卷 60-66页

作者：崔梦崔莹佳邢亚杰对外经济贸易大学国际关系学院北京100029 南开大学周恩来政府管理学院天津300350 清华大学社会科学学院北京100084

[研究目的]东南亚地区是当前全球范围内数字竞争最激烈的地区之一,中美在东南亚云服务市场存在着显著的竞争关系。通过剖析美国在东南亚的云服务战略动向,分析其对中国的影响,探寻中国的因应之策。[研究方法]综合采用文献梳理、案例分... 详细信息

[研究目的]东南亚地区是当前全球范围内数字竞争最激烈的地区之一,中美在东南亚云服务市场存在着显著的竞争关系。通过剖析美国在东南亚的云服务战略动向,分析其对中国的影响,探寻中国的因应之策。[研究方法]综合采用文献梳理、案例分析、对比研究的方法对美国在东南亚的云服务战略的具体举措、对中国产生的影响以及中国的应对之举进行多层次深入分析。[研究结果/结论]云服务是数字化的基础,在国家战略制定和国际竞争中发挥着至关重要的作用。美国在东南亚的云服务战略部署是其寻求全球数字霸权的重要内容,具体举措包括加强影响力、扩大产业规模以及重点遏制中国,在产业、制度、关系层面对中国产生了巨大影响。中国应因时而变、顺势而为,进一步强化与东南亚国家的政府间合作,提升企业竞争力,回击抹黑中国的行径,提升东南亚国家对中国的战略信任,有效维护中国企业在该地区的正当利益。

关键词：大数据云服务数字经济东南亚中美关系

biopolymer Decorated Pencil Graphite Electrode for the In-situ Quantification of L-Tryptophan in Dietary Supplements

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journal of Analysis and Testing 2025年第01期 82-95页

作者： V.Devika P.j.Sreelekshmi b.Vedhanarayanan Sandhya Sadanandan R.Rejithamol Department of Chemistry Amrita Vishwa Vidyapeetham Graduate School of Science Chiba University Department of Chemistry School of Advanced SciencesVIT-AP University

A simplistic and novel electrochemical sensor for selectively detecting the essential amino acid tryptophan in dietary supplements was fabricated on a pencil graphite electrode modified with a tryptophan-based dipeptide. The dipeptide was synthesized using common synthetic strategy for amino acid couplings. The modified electrode was characterized by scanning electron microscopy, impedance spectroscopy, cyclic voltammetry, and infrared spectroscopy. Differential pulse voltammetry was used to study the electrochemical response of the fabricated electrode to tryptophan in dietary supplements. Under the optimized experimental conditions, a distinct oxidation peak at + 0.671 V corresponding to tryptophan was noticed in differential pulse voltammetry, which indicated the detection of tryptophan by the fabricated electrode. The oxidation peak current for tryptophan was found to be linear within a concentration range of 10–350 μM with a lower detection limit of 1.2 μM, and the sensitivity of the fabricated electrode was 6.9 μA/μM/cm 2. Excellent selectivity, permissible reproducibility, and good stability of the sensor make it undoubtedly suitable for determining tryptophan in dietary supplements.

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Enhanced interfacial polarization of SiC/C nanofibers loaded with cobalt ferrite nanoparticles for improved electromagnetic wave absorption

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Science China Technological Sciences 2025年第3期68卷 129-141页

作者： Yixuan WANG Wei cui Zhenxiong LI Lei ZHANG Yang REN Xiongxiong WU Zhihui HE Yashan HUO Center for Optoelectronic Information and Transform School of Physics and Electronic Information Yan'an University School of Chemistry and Chemical Engineering Yan'an University

The unique advantages of heterogeneous interface engineering and its superior electromagnetic properties provide new momentum for designing advanced wave-absorbing materials. Most researchers focus on enhancing wave-absorbing capabilities by increasing interfacial polarization, often overlooking material cost and engineering feasibility. To address this,we enhance the heterogeneous interfaces of SiC/C nanofibers(NFs) by loading cobalt ferrite nanoparticles(CFO NPs),exploring a simple, cost-effective strategy to develop high-performance wave-absorbing composites. by adjusting the CFO concentration, we optimize the dielectric and magnetic losses of the composite to achieve impedance matching and improve absorption performance. The results show that the SiC/C/CFO20 composite exhibits excellent microwave absorption(MA),achieving a reflection loss(RL) value of-56.52 db at 11.60 GHz with a matching thickness of 2 mm and an effective absorption bandwidth(EAb) of 5.05 GHz. Furthermore, the composite shows outstanding performance in both monostatic and bistatic radar cross section(RCS) simulations, with optimal values reaching-49.04 and-51.16 d b, respectively. This performance demonstrates a wide detection angle, supporting its potential for practical engineering applications. Overall, this approach provides a new perspective for designing high-efficiency, low-cost, and scalable wave-absorbing materials for engineering applications.

关键词： composite nanofibers magnetoelectric synergistic effect interface engineering radar cross section

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Stretchable All-Small-Molecule Organic Solar Cells Enabled by Polymer Elastomer Confinement

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Chinese journal of Polymer Science 2025年第2期43卷 271-277页

作者： Chen-Yi Zhang Yu-Qiang Liu Hong-Xiang Li Xin-Yue cui Zheng-Dong Wei Yue-Heng Liu Ming-Hua Li An-Dong Zhang Pei Cheng Zhi-Shan bo College of Textiles&Clothing State Key Laboratory of Bio-fibers and Eco-textilesQingdao UniversityQingdao266071China State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China College of Materials Science and Engineering Qingdao UniversityQingdao266071China beijing Key Laboratory of Energy Conversion and Storage Materials College of ChemistryBeijing Normal UniversityBeijing100875China

Intrinsic stretchability is a promising attribute of polymer organic solar cells(OSCs).However,rigid molecular blocks typically exhibit poor tensile properties,rendering polymers vulnerable to mechanical *** this study,we introduce a different approach utilizing all-small-molecule donors and acceptors to fabricate stretchable *** elastomer,styrene-b-ethylene-butylene-styrene(SEbS),was embedded to modulate film crystallization and *** effectively confines the growth process of donors and acceptors,leading to enhancement of the crystallization quality,thus contributing to enhanced device ***,SEbS can absorb and release mechanical stress during stretching,thereby preventing mechanical degradation of donors and *** mechanical properties of the OSCs were significantly improved by the incorporation of ***,the crack-onset strain increased from 1.03% to 5.99% with SEbS *** findings present a straightforward strategy for achieving stretchable OSCs using all small molecules,offering a different perspective for realizing stretchable devices.

关键词： All-small-molecule Organic solar cells Elastomer Stretchability Flexibility

通风风速对分岔巷道内火灾烟气分布的影响数值研究

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煤矿安全 2025年第1期56卷 93-99页

作者：丁翠中国劳动关系学院安全工程学院北京100048

为探究通风风速对分岔巷道内火灾烟气流动的影响,采用CFD数值模拟方法研究了火源位于主巷分岔口上游附近时,通风风速对烟气逆流长度、主巷下游和分巷内温度及CO质量浓度纵向分布的影响规律。研究结果表明:主巷内烟气逆流长度随着通风风... 详细信息

为探究通风风速对分岔巷道内火灾烟气流动的影响,采用CFD数值模拟方法研究了火源位于主巷分岔口上游附近时,通风风速对烟气逆流长度、主巷下游和分巷内温度及CO质量浓度纵向分布的影响规律。研究结果表明:主巷内烟气逆流长度随着通风风速的增大呈现线性降低规律;不同通风风速下,呼吸带高度处分巷内平均温度略高于主巷下游,最大温差8℃;随着通风风速增大,主巷下游和分巷内呼吸带高度平均温度呈现出幂函数下降规律;随着通风风速的增大,呼吸带高度处主巷下游和分巷内CO质量浓度差值逐渐降低,最小质量浓度差为9.25 mg/m^(3),主巷下游和分巷内CO平均质量浓度均符合幂函数的下降趋势;当通风风速为1~3 m/s时,分巷道内工作人员不易受到火灾烟气有毒气体侵害,当通风风速为1.5~3 m/s时主巷下游内工作人员不易受到火灾烟气有毒气体侵害。

关键词：矿井火灾分岔巷道通风风速烟气分布数值模拟

High-precision trajectory tracking control of helicopter based on ant colony optimization-slime mould algorithm

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Chinese journal of Aeronautics 2025年第1期38卷 395-408页

作者： binwu REN Siliang DU Zhuangzhuang cui Yousong XU Qijun ZHAO National Key Laboratory of Helicopter Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China Faculty of Mechanical&Material Engineering HuaiYin Institute of TechnologyHuaian 223003China

To achieve high-precision trajectory following during helicopter maneuver tasks and reduce the disruptive influences of unknown variabilities,this study introduces a cascaded-loop helicopter trajectory tracking controller,whose parameters are set using an Ant Colony OptimizationSlime Mould Algorithm(ACO-SMA).Initially,a nonlinear flight dynamics model of the helicopter is *** gain functions and nonlinear feedback from a vibrational suppression function to improve the tracking performance of the controller,addressing issues in disturbance estimation and compensation of the Active Disturbance Rejection Control(ADRC).Simultaneously,a cascaded loop system,comprising an internal attitude loop and an external position loop,is created,and the ant colony-slime mold hybrid algorithm optimizes the system parameters of the trajectory tracking ***,helicopter trajectory tracking simulation experiments are conducted,including spiral ascending and“8”shape climbing *** findings indicate that the ADRC employed for helicopter trajectory tracking exhibits outstanding performance in rejecting disturbances caused by gusts and accurately tracking *** trajectory tracking controller,whose parameters are optimized by the ACO-SMA,shows higher tracking precision compared to the conventional PID and ADRC,thereby substantially improving the precision of maneuver tasks.

关键词： Flight control systems Helicopter ADRC Trajectory tracking ACO-SMA Spiral ascent "8"shape climbing

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隧道超前长管棚力学响应特性研究与工程应用

隧道建设(中英文) 2025年第1期45卷 120-131页

作者：崔凌岳中铁十八局集团第一工程有限公司河北保定072750

为研究隧道超前长管棚的承载机制和结构响应,考虑管棚搭接和两端支承条件的影响,建立超前长管棚力学响应理论模型,基于有限差分原理给出管棚不同位置挠度的计算方法。利用所建模型分析不同管棚直径、不同开挖步距和考虑管棚搭接对管棚... 详细信息

为研究隧道超前长管棚的承载机制和结构响应,考虑管棚搭接和两端支承条件的影响,建立超前长管棚力学响应理论模型,基于有限差分原理给出管棚不同位置挠度的计算方法。利用所建模型分析不同管棚直径、不同开挖步距和考虑管棚搭接对管棚挠度变化的影响规律。以厦门第二西通道海沧隧道为工程背景,对该隧道合理开挖步距进行优选。计算结果表明:1)所建模型相较于现场试验结果的最大误差仅为8.14%;相较于不考虑管棚搭接的悬臂梁模型,考虑管棚搭接可以消除管棚挠度不合理上拱的现象。2)随着管棚直径不断增大,管棚最大挠度逐渐降低,但降低效果逐渐减弱。3)海沧隧道开挖步距为1.2 m时,相较于无管棚时拱顶挠度降低67.35%,并调整初期支护最大主应力至更加均匀的状态。

关键词：隧道工程超前长管棚荷载空间效应管棚承载机制工程应用

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生产双链RNA工程菌的研究进展

生物工程学报 2025年第2期41卷 546-558页

作者：崔锦程崔洁卞小莹山东大学微生物技术国家重点实验室山东青岛266237

保障粮食安全需要新型绿色农药。双链RNA(double-stranded RNA,dsRNA)农药通过外源添加特异性靶向病虫害的dsRNA来触发RNA干扰,抑制病原菌或害虫的关键基因表达,从而实现对特定病虫害的有效控制。双链RNA农药是一种环境友好型的农药,具... 详细信息

保障粮食安全需要新型绿色农药。双链RNA(double-stranded RNA,dsRNA)农药通过外源添加特异性靶向病虫害的dsRNA来触发RNA干扰,抑制病原菌或害虫的关键基因表达,从而实现对特定病虫害的有效控制。双链RNA农药是一种环境友好型的农药,具有较强的特异性和高效的基因沉默能力,但目前还存在生产成本高等问题。利用工程菌株生产dsRNA是一种可行的策略,然而目前还没有具有经济效益的dsRNA生产工程菌株出现。本文综述了利用微生物生产dsRNA的研究进展和生产策略,为dsRNA生产提供了参考。

关键词： RNA干扰双链RNA 工程菌株底盘

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