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Interannual evolution of the chemical composition,sources and processes of PM_(2.5)in Chengdu,China:Insights from observations in four winters

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Journal of Environmental Sciences 2024年第4期138卷 32-45页

作者： Junke Zhang Jiaqi Li Yunfei Su Chunying Chen Luyao Chen Xiaojuan huang Fangzheng Wang yawen huang Gehui Wang Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China Department of Environmental Science&Engineering Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention(LAP3)Fudan UniversityShanghai 200438China Key Lab of Geographic Information Science of the Ministry of Education School of Geographic SciencesEast China Normal UniversityShanghai 200241China

The air quality in China has improved significantly in the last decade and,correspondingly,the characteristics of PM_(2.5)have also changed.We studied the interannual variation of PM_(2.5)in Chengdu,one of the most heavily polluted megacities in southwest China,during the most polluted season(winter).Our results show that the mass concentrations of PM_(2.5)decreased significantly year-by-year,from 195.8±91.0μg/m~3in winter 2016 to 96.1±39.3μg/m^(3)in winter 2020.The mass concentrations of organic matter(OM),SO_()4^(2-),NH_(4)^(+)and NO_(3)^(-)decreased by 49.6%,57.1%,49.7% and 28.7%,respectively.The differential reduction in the concentrations of chemical components increased the contributions from secondary organic carbon and NO_(3)^(-)and there was a larger contribution from mobile sources.The contribution of OM and NO_(3)^(-)not only increased with increasing levels of pollution,but also increased year-by-year at the same level of pollution.Four sources of PM_(2.5)were identified:combustion sources,vehicular emissions,dust and secondary aerosols.Secondary aerosols made the highest contribution and increased year-by-year,from 40.6%in winter 2016 to 46.3% in winter 2020.By contrast,the contribution from combustion sources decreased from 14.4% to 8.7%.Our results show the effectiveness of earlier pollution reduction policies and emphasizes that priority should be given to key pollutants(e.g.,OM and NO_(3)^(-))and sources(secondary aerosols and vehicular emissions)in future policies for the reduction of pollution in Chengdu during the winter months.

关键词： PM_(2.5) Chemical composition Sources Interannual evolution Winter Chengdu

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Self-driven directional dehydration enabled eco-friendly manufacture of chrome-free leather

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Journal of Leather Science and Engineering 2022年第1期4卷 241-252页

作者： yawen huang Hanzhong Xiao Haoliang Pu Ni Xue Baicun Hao Xin huang Bi Shi National Engineering Laboratory for Clean Technology of Leather Manufacture Sichuan UniversityChengdu 610065People’s Republic of China Department of Biomass Chemistry and Engineering Sichuan UniversityChengdu 610065People’s Republic of China.

Manufacture of eco-friendly chrome-free leather is of great significance for realizing sustainable development of leather industry.Conventional tanning theory believes that it is impossible to convert raw hide to leather without the utilization of cross-linking agent(e.g.,chrome salts)among collagen fibers in raw hide.Here,we developed a brand-new leather manufacture strategy that relied on the composite dehydration media enabled self-driven directional dehydration mechanism to accomplish chrome-free leather manufacture for the first time,rather than followed the classic cross-linking mechanism that has been obeyed for more than one century in leather industry.We demonstrated that the essence of leather making is to regulate the water content in raw hide rather than to form cross-linkage among collagen fibers.The composite dehydration media comprised of anhydrous ethanol and molecular sieves(3A activated zeolite powder)successfully guaranteed continuous self-driven directional dehydration of raw hide by establishing stable water concentration gradient between raw hide and ethanol,which significantly increased the dispersity of collagen fibers in raw hide(with the water content reduced from 56.07%to 5.20%),thus obtaining chrome-free leather that is more ecological than chrome-tanned leather due to the elimination of any tanning agent.The as-prepared chrome-free leather exhibited outstanding tear force(174.86 N),tensile strength(24.56 N mm−2),elongation at break(53.28%)and dry-thermal stability,superior to chrome-tanned leather.Notably,the used compos-ite dehydration media was recyclable for chrome-free leather manufacture,therefore facilitating an environmentally benign leather manufacture process.Our investigations are expected to open up a new conceptual leather making strategy that is applicable for realizing substantial manufacture of eco-friendly leather.

关键词： Chrome-free leather Eco-friendly manufacture Regulation of water content Self-driven directional dehydration Recyclability of dehydration media

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电化学修饰氨基酸和多肽类化合物的研究进展

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有机化学 2024年第3期44卷 903-926页

作者：方新月黄雅雯胡新伟阮志雄广州医科大学药学院广州511436

随着多肽类化合物在治疗肿瘤疾病和生物医学应用中重要性的与日俱增,开发和构建多肽分子的新方法已成为有机合成化学家的研究热点.近年来有机电化学作为一种绿色高效的反应工具,被逐步运用于有机小分子合成领域,其温和可控的特征适合解... 详细信息

随着多肽类化合物在治疗肿瘤疾病和生物医学应用中重要性的与日俱增,开发和构建多肽分子的新方法已成为有机合成化学家的研究热点.近年来有机电化学作为一种绿色高效的反应工具,被逐步运用于有机小分子合成领域,其温和可控的特征适合解决现有生物偶联策略存在的化学和区域选择性问题,为多肽分子的选择性修饰提供了一种重要的合成手段.综述了近五年来利用电化学手段修饰氨基酸和多肽类化合物的反应,阐述了电化学合成技术的优势及其在开发新型生物相容性方法中的适用性.

关键词：有机电化学氨基酸多肽修饰化学和区域选择性

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Fabrication of solid CH-CD multilayer microspheres for inertial confinement fusion

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Matter and Radiation at Extremes 2021年第2期6卷 28-36页

作者： Meifang Liu Xing Ai Yiyang Liu Qiang Chen Shuai Zhang Zhibing He yawen huang Qiang Yin Research Center of Laser Fusion China Academy of Engineering PhysicsMianyangChina State Key Laboratory of Envronment-Friendly Energy Materials Southwest University of Science and TechnologyMianyangChina

Deuterated polymer microspheres can be used as a neutron source in conjunction with lasers because thermonuclear fusion neutrons can be produced efficiently by collisions of the resulting energetic deuterium ions.A new type of solid deuterated polymer microsphere with a carbon hydrogen–carbon deuterium(CH-CD)multilayer has been designed for preparing the target for inertial confinement fusion(ICF)experiments.To fabricate these solid CH-CD multilayer microspheres,CH beads are first fabricated by a microfluidic technique,and the CD coating layer is prepared by a plasma polymerization method.Both polystyrene(PS)and poly(α-methylstyrene)(PAMS)are used as the material sources for the CH beads.The effects of the PS and PAMS materials on the quality of the solid CH beads and the resulting CH-CD multilayer polymer microspheres are investigated.The solid PS beads have better sphericity and a smoother surface,but large vacuoles are observed in solid PS-CD multilayer microspheres owing to the presence of residual fluorobenzene in the beads and a glass transition temperature of the solid PS beads that is lower than the temperature of plasma polymerization.Therefore,solidPAMSbeads are more suitable as a mandrel for fabricating solid CH-CD multilayer polymer microspheres.Solid CH-CD multilayer microspheres with specified size have been successfully prepared by controlling the droplet size and the CD deposition rate and deposition time.Compared with the design value,the diameter deviation of the inner CH beads and the thickness deviation of the CD layer can be controlled within 20μmand 2μm,respectively.Thus,an approach has been developed to fabricate solid CH-CD multilayer microspheres that meet the physical design requirements for ICF.

关键词： method. multilayer beads

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Global pattern and change of cropland soil organic carbon during 1901-2010: Roles of climate, atmospheric chemistry, land use and management

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Geography and Sustainability 2020年第1期1卷 59-69页

作者： Wei Ren Kamaljit Banger Bo Tao Jia Yang yawen huang Hanqin Tian Department of Plant&Soil Sciences College of AgricultureFood and EnvironmentUniversity of KentuckyLexingtonKY 40506USA Plant Agriculture-University of Guelph Ontario N1G 2W1Canada Department of Forestry Mississippi State UniversityMississippi StateMS 39762USA International Center for Climate and Global Change Research and School of Forestry and Wildlife Sciences Auburn UniversityAuburnAL 36849USA

Soil organic carbon(SOC)in croplands is a key property of soil quality for ensuring food security and agricultural sustainability,and also plays a central role in the global carbon(C)budget.When managed sustainably,soils may play a critical role in mitigating climate change by sequestering C and decreasing greenhouse gas emissions into the atmosphere.However,the magnitude and spatio-temporal patterns of global cropland SOC are far from well constrained due to high land surface heterogeneity,complicated mechanisms,and multiple influencing factors.Here,we use a process-based agroecosystem model(DLEM-Ag)in combination with diverse spatially-explicit gridded environmental data to quantify the long-term trend of SOC storage in global cropland area during 1901-2010 and identify the relative impacts of climate change,elevated CO2,nitrogen deposition,land cover change,and land management practices such as nitrogen fertilizer use and irrigation.Model results show that the total SOC and SOC density in the 2000s increased by 125%and 48.8%,respectively,compared to the early 20th century.This SOC increase was primarily attributed to cropland expansion and nitrogen fertilizer use.Factorial analysis suggests that climate change reduced approximately 3.2%(or 2,166 Tg C)of the total SOC over the past 110 years.Our results indicate that croplands have a large potential to sequester C through implementing better land use management practices,which may partially offset SOC loss caused by climate change.

关键词： Global cropland Soil organic carbon Climate change Land management Process-based modeling

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精密器件尺寸的图像测量算法设计与实现

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福建电脑 2024年第2期40卷 45-49页

作者：黄雅雯李虹电子科技大学成都学院计算机系成都611700

为了实现精密器件的无接触精密快速测量,本文提出了一种利用精密器件图像对进行尺寸测量的方法。根据不同的参照物的比例关系及采用不同倍率的图像预处理测量算法,实现两点的距离、测量斜率、角度、半径、曲线弧度的测量。实验的结果表... 详细信息

为了实现精密器件的无接触精密快速测量,本文提出了一种利用精密器件图像对进行尺寸测量的方法。根据不同的参照物的比例关系及采用不同倍率的图像预处理测量算法,实现两点的距离、测量斜率、角度、半径、曲线弧度的测量。实验的结果表明,本文提出的图像测量算法具有灵活性高、测量结果准确的优点。

关键词：图像处理轮廓检测尺寸测量像素计算

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“全要素生命体”视角下的城市边缘区设计——以广东省清远职教城为例

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城市建筑 2024年第11期21卷 112-117页

作者：余灏深石芊杨毅衡黄雅文广州市城市规划设计有限公司

随着我国城市化由高速增长阶段转向高质量发展阶段,城市边缘区范围逐步稳定,并成为广受关注的“第三类”社会生态空间。通过分析城市边缘区发展特性和存在的问题,提出构建城市边缘区“全要素生命体”的概念,以一种新的规划设计思维导向... 详细信息

随着我国城市化由高速增长阶段转向高质量发展阶段,城市边缘区范围逐步稳定,并成为广受关注的“第三类”社会生态空间。通过分析城市边缘区发展特性和存在的问题,提出构建城市边缘区“全要素生命体”的概念,以一种新的规划设计思维导向,探索把城市边缘区内多元复杂的自然和人文要素视为一个“综合主体”,建立一个人工系统与自然系统相互支撑,物质与能量总体平衡、自我良性循环的有机综合系统。在具体实践中,以广东省清远职教城为例,通过“全要素生命体”视角下的城市设计策略,达成职教城“全要素生命体”健康运行的目标。

关键词：城市边缘区生态文明全要素生命体城市设计职教城

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新时代背景下高校辅导员网络思想政治教育能力提升路径探析

语言与文化研究

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语言与文化研究 2024年第1期32卷 100-102页

作者：黄亚文万柯彤李英男天津理工大学天津300384 天津中医药大学天津301617

互联网的应用和普及给高校辅导员网络思想政治教育工作带来了许多机遇和挑战,当前高校辅导员网络思想政治教育工作存在这许多不足,主要体现在对于网络思想政治教育的思想认识不到位、教育引导能力不充足以及相关机制不完善,针对以上问题... 详细信息

互联网的应用和普及给高校辅导员网络思想政治教育工作带来了许多机遇和挑战,当前高校辅导员网络思想政治教育工作存在这许多不足,主要体现在对于网络思想政治教育的思想认识不到位、教育引导能力不充足以及相关机制不完善,针对以上问题,本文从高校辅导员网络思想政治教育工作的教育理念、教育方式及教育机制上进行探讨,提出高校辅导员网络思想政治教育能力的提升策略。

关键词：网络思想政治教育教育理念高校辅导员能力提升

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室温快速自修复超疏水聚硅氧烷涂层制备及其自修复自清洁性能

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西南科技大学学报 2024年第2期39卷 1-7,47页

作者：刘丽莉周治白浩民林珂羽黄亚文西南科技大学材料与化学学院四川绵阳621010 西南科技大学环境友好能源材料国家重点实验室四川绵阳621010

赋予超疏水材料自修复的能力,可以改善材料性能,延长服役时间。将可逆动态亚胺键引入聚硅氧烷基体,制备了室温快速自修复的自清洁超疏水涂层。涂层的接触角154°,滚动角5°,在O_(2)等离子体刻蚀至表面接触角为0°之后,室温修复1 h即可... 详细信息

赋予超疏水材料自修复的能力,可以改善材料性能,延长服役时间。将可逆动态亚胺键引入聚硅氧烷基体,制备了室温快速自修复的自清洁超疏水涂层。涂层的接触角154°,滚动角5°,在O_(2)等离子体刻蚀至表面接触角为0°之后,室温修复1 h即可快速恢复超疏水特性,经6次损伤-修复循环后接触角依旧保持在150°以上。升高温度到80℃或者利用碳纳米管的光热效应还可实现涂层化学损伤10~20 min的超快修复。研究表明,构建100 nm/10μm微纳粗糙表面可赋予涂层超疏水特性,可逆动态亚胺键交换重组的化学修复与柔性分子链段运动翻转的物理修复共同作用是实现涂层室温快速自修复的关键。

关键词：超疏水涂层自修复能力聚硅氧烷亚胺键碳纳米管

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Progress and challenges in the fabrication of DPS shells for ICF

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Matter and Radiation at Extremes 2019年第1期4卷 24-31页

作者： Meifang Liu yawen huang Sufen Chen Dawei Pan Miao Chen Qiaomei Chu Yiyang Liu Qiang Yin Zhanwen Zhang Research Center of Laser Fusion China Academy of Engineering PhysicsMianyangChina School of Material Science and Engineering Southwest University of Science and TechnologyMianyangChina

To improve the quality of deuterated polystyrene(DPS)shells,the synthesis and purification of DPS as well as the fabrication of DPS shells are investigated.The molecular weight and molecular weight distribution,measured by GPC-MALLS,are about 350 kg mol^(-1) and less than 2.0,respectively.The results of TG and GC-MS indicate that the residual solvent is almost completely removed.DPS shells with;300 mm–2500 mmdiameter and;10 mm–100mmwall thickness are successfully prepared by a microfluidic device.The monodispersity of the diameter ismuchbetter than that of the wall thickness in a batch ofDPSshells.The vacuoles can be suppressed by both reducing hydrophilic residues in DPS and adding some salts into the outer water phase(W2).The defects appearing during the drying process decrease by heat treatment,ethanol exchange,and lowered drying temperature.The results presented in this work not only provide guidelines for the preparation of DPS shells of better quality,but also indicate challenges for the future.

关键词： shells DPS removed

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