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南京地区大气灰霾的数值模拟

环境科学学报 2009年第4期29卷 808-814页

作者：胡荣章刘红年张美根蒋维楣张予燕南京大学大气科学学院南京210093 中国科学院大气物理研究所大气边界层物理与大气化学国家重点实验宝北京100029 南京市环境监测中心站南京210013

从环境角度出发,在化学成分分析的基础上,利用灰霾与能见度的关系,数值模拟了南京地区能见度分布及灰霾天气现象.研究表明:冬夏两季SO42-/NO3-质量比为5.39;风速、相对湿度、PM2.5浓度是灰霾天气形成的主要影响因素;能见度模拟结果很好... 详细信息

从环境角度出发,在化学成分分析的基础上,利用灰霾与能见度的关系,数值模拟了南京地区能见度分布及灰霾天气现象.研究表明:冬夏两季SO42-/NO3-质量比为5.39;风速、相对湿度、PM2.5浓度是灰霾天气形成的主要影响因素;能见度模拟结果很好地体现了细粒子成分的污染分布特征,在南京地区,硫酸盐和有机气溶胶是能见度下降最重要的贡献者,其次为黑碳气溶胶.

关键词：灰霾能见度南京

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垂直比例因子对分形插值精度的影响

黑龙江大学自然科学学报 2007年第5期24卷 662-665页

作者：李信富李小凡张美根中国地质大学地质过程与矿产资源国家重点实验室和地下信息探测技术与仪器教育部重点实验室中国科学院地质与地球物理研究所岩石圈演化国家重点实验室北京100029

在数值分析的许多领域中,许多方法都是借助于插值公式导出的。几乎所有的经典数值微分、数值求积和常微分方程的数值积分公式都可以从插值公式推导出来。分形插值方法是近几十年发展起来的一种局部非线性插值方法,它提供了拟合实验数据... 详细信息

在数值分析的许多领域中,许多方法都是借助于插值公式导出的。几乎所有的经典数值微分、数值求积和常微分方程的数值积分公式都可以从插值公式推导出来。分形插值方法是近几十年发展起来的一种局部非线性插值方法,它提供了拟合实验数据的一种新方法。在分形插值方法中,垂直比例因子是影响插值精度的主要因素。在实验的基础上给出了垂直比例因子的局部显式表达式。通过比较固定比例因子和变化比例因子分形插值的精度,说明了显式垂直比例因子分形插值方法的高精度和高效率。

关键词：分形插值垂直比例因子显式表达

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非规则网带断层地震数据的网格化

地球物理学进展 1999年第1期14卷 69-77页

作者：张美根乌达巴拉王妙月中国科学院地球物理研究所北京100101 中国地质大学(北京)物探系北京100083

非规则网地震勘探中，由解释人员解释出来的层位信息包括大量不规则分布的高程数据和断层构造的断点数据，因而其构造图成图前的网格化是一件相当复杂而又难度较大的工作．本文较全面地研究了非规则网带断层地震数据的网格化过程（本文... 详细信息

非规则网地震勘探中，由解释人员解释出来的层位信息包括大量不规则分布的高程数据和断层构造的断点数据，因而其构造图成图前的网格化是一件相当复杂而又难度较大的工作．本文较全面地研究了非规则网带断层地震数据的网格化过程（本文针对的是正断层情况），提出了一种快速实用的正方形网格化方法．经对实际资料处理证明，它能够适用于非常复杂的情况，并且处理效果理想．

关键词：网格化构造图非规则网断层地震数据

2008年奥运会期间北京地区大气O_3浓度模拟分析

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气候与环境研究 2010年第5期15卷 643-651页

作者：高怡张美根朱凌云唐贵谦中国科学院大气物理研究所大气边界层物理与大气化学国家重点实验室北京100029 山西省气象科学研究所太原030002

利用空气质量模式系统RAMS-CMAQ模拟分析了2008年8月北京及周边地区近地面O3浓度的时空变化。分析结果表明,模式系统可以较好地模拟污染物以及气象要素的变化特征和区域分布情况;奥运会期间的污染控制对O3浓度的降低有明显的作用,但是... 详细信息

利用空气质量模式系统RAMS-CMAQ模拟分析了2008年8月北京及周边地区近地面O3浓度的时空变化。分析结果表明,模式系统可以较好地模拟污染物以及气象要素的变化特征和区域分布情况;奥运会期间的污染控制对O3浓度的降低有明显的作用,但是在一些有利的气象条件下,O3易达到较高浓度:8月2日、24日14时(北京时间)左右O3浓度都在0.22mg.m-3以上,其中2日北京地区处于辐合的弱风场中,风速为1.5～2.5m.s-1,24日则是处于自南向北的有输送作用的风场中,风速为3.5～6.5m.s-1;污染控制对北京周边地区的效果要好于北京市区。

关键词：空气质量模式 RAMS-CMAQ O3

Seismic scalar wave equation with variable coefficients modeling by a new convolutional differentiator

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Seismic scalar wave equation with variable coefficients mode...

Diatomic Pd catalyst with conjugated backbone for synergistic electrochemical CO_(2)reduction

中国科学院地质与地球物理研究所第十届(2010年度)学术年会

作者： Xiaofan Li~*,Tong Zhu,meigen zhang,Guihua Long Key Laboratory of the Earth’s Deep Interior,CAS,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,PR China

Studying seismic wavefields in the Earth’s interior requires an accurate calculation of wave propagation using accurate and efficient numerical *** this paper,we present an alternative method for accurately and efficiently modeling seismic wavefields using a convolutional generalized orthogonal polynomial *** approach uses optimization and truncation to form a localized operator. This preserves the fine structure of the wavefield in complex media and avoids non-causal interaction when parameter discontinuities are present in the *** demonstrate this approach for scalar wavefield modeling in heterogeneous media and conclude that the method could be readily extended to elastic wavefield *** numerical results indicate that this method can suppress numerical dispersion and allow for the study of wavefields in heterogeneous *** results hold promise not only for future seismic studies,but also for any field that requires high-precision numerical solution of partial differential equation with variable coefficients.

关键词： Wave equation with variable coefficients Heterogeneous media Accurate modeling of seismic wave Localized operator Suppression of numerical dispersion

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Nano Research 2024年第6期17卷 4850-4855页

作者： Wenxuan zhang Mengran zhang Hongjuan Wang Wen zhang Min zhang MOE International Joint Laboratory of Materials Microstructure Institute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion School of Chemistry and Chemical EngineeringTianjin University of TechnologyTianjin 300384China

Double-site catalysts have attracted widespread attention in the field of electrocatalysis due to their high metal loading,adjustable active centres,and electronic valence ***,the development of bimetallic sites catalysts that coordinate with definite atoms is still in the exploratory ***,we designed and synthesized a bimetallic palladium complex(BPB-Pd_(2))with conjugated *** supported BPB-Pd_(2)was applied to electrochemical CO_(2)reduction reaction(CO_(2)RR)for the first *** as-obtained BPB-Pd_(2)gives an exceptional Faradaic efficiency of CO(FECO)of 94.4%at−0.80 V *** hydrogen electrode(RHE),which is significantly superior to monoatomic palladium catalyst(BPB-Pd1).The density functional theory(DFT)calculations revealed that the essential reason for the outstanding activity of BPB-Pd_(2)toward CO_(2)RR was that the electronic effect between diatomic palladium reduces the free energy change for CO_(2)RR ***,BPB-Pd_(2)exhibits moderate free energy change to form COOH*intermediate,which was beneficial for the generation of CO in CO_(2)RR.

关键词： synthesis electrocatalysis CO_(2)reduction bimetallic palladium complex synergistic catalysis

N-doped graphene quantum dot-decorated N-TiO2/P-doped porous hollow g-C_(3)N_(4) nanotube composite photocatalysts for antibiotic photodegradation and H2 production

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 165-178页

作者： Jingshu Yuan Yao zhang Xiaoyan zhang Junjie zhang Shen’gen zhang Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China Xi’an Fanyi University Xi’an 710105China Shunde Graduate School of University of Science and Technology Beijing Foshan 528399China State Key Laboratory of Lunar and Planetary Sciences Macao University of Science and TechnologyMacao SAR 820000China

Exclusive responsiveness to ultraviolet light (~3.2 eV) and high photogenerated charge recombination rate are the two primary drawbacks of pure TiO_(2). We combined N-doped graphene quantum dots (N-GQDs), morphology regulation, and heterojunction construction strategies to synthesize N-GQD/N-doped TiO_(2)/P-doped porous hollow g-C_(3)N_(4) nanotube (PCN) composite photocatalysts (denoted as G-TPCN). The optimal sample (G-TPCN doped with 0.1wt% N-GQD, denoted as 0.1% G-TPCN) exhibits significantly enhanced photoabsorption, which is attributed to the change in bandgap caused by elemental doping (P and N), the improved light-harvesting resulting from the tube structure, and the upconversion effect of N-GQDs. In addition, the internal charge separation and transfer capability of0.1% G-TPCN are dramatically boosted, and its carrier concentration is 3.7, 2.3, and 1.9 times that of N-TiO_(2), PCN, and N-TiO_(2)/PCN(TPCN-1), respectively. This phenomenon is attributed to the formation of Z-scheme heterojunction between N-TiO_(2) and PCNs, the excellent electron conduction ability of N-GQDs, and the short transfer distance caused by the porous nanotube structure. Compared with those of N-TiO_(2), PCNs, and TPCN-1, the H2 production activity of 0.1%G-TPCN under visible light is enhanced by 12.4, 2.3, and 1.4times, respectively, and its ciprofloxacin (CIP) degradation rate is increased by 7.9, 5.7, and 2.9 times, respectively. The optimized performance benefits from excellent photoresponsiveness and improved carrier separation and migration efficiencies. Finally, the photocatalytic mechanism of 0.1% G-TPCN and five possible degradation pathways of CIP are proposed. This study clarifies the mechanism of multiple modification strategies to synergistically improve the photocatalytic performance of 0.1% G-TPCN and provides a potential strategy for rationally designing novel photocatalysts for environmental remediation and solar energy conversion.

关键词： N-doped TiO_(2) N-doped graphene quantum dots P-doped g-C_(3)N_(4) porous hollow nanotube heterojunction photocatalysis

Reversing free-electron transfer of sulfide cocatalyst for exceptional photocatalytic H_(2)evolution

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Journal of Materials Science & Technology 2024年第4期171卷 147-149页

作者： Yanfeng zhang Zhenyi zhang National Experimental Chemistry Teaching Center Hebei Key Laboratory of Inorganic Nano-materialsCollege of Chemistry and Materials ScienceHebei Normal UniversityShijiazhuang 050024China Key Laboratory of New Energy and Rare Earth Resource Utilization of State Ethnic Affairs Commission Key Laboratory of Photosensitive Materials and Devices of Liaoning ProvinceSchool of Physics and Materials EngineeringDalian Minzu UniversityDalian 116600China

Recently,Yu and co-workers deeply explore the potential impact of free electron transfer between co-catalysts and photocatalyst carriers on H_(2)evolution efficiency of active sites over MoS_(2+x).They pro-pose an electron-reversal tactics to evade the unexpected electron transfer and synchronously regulate the above transfer in a beneficial orientation for weakening hydrogen adsorption on S ***,this highlight not only discusses and summarizes the essences of electron reversal and the optimized H ad-sorption/desorption mechanism,but also emphasizes the significance of femtosecond transient absorp-tion spectroscopy(fs-TAS)and in-situ irradiated X-ray photoelectron spectroscopy(ISI-XPS)for revealing charge transfer dynamics and *** anticipate that this highlight can disseminate a new per-spective on the roles of photocatalyst carriers in improving cocatalytic H_(2)-production kinetics.

关键词： Photocatalysis Cocatalyst Electron reversal Antibonding-orbital occupancy S–H bonds

近年来云南省PM2.5浓度变化趋势与潜在区域来源分析

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气候与环境研究 2023年第5期28卷 509-517页

作者：刘芮男寇星霞高怡赵靖川张美根云南大学地球科学学院昆明650504 中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室北京100029 浙江省乐清市气象局浙江乐清325600 北京城市气象研究院北京100089 中国科学院大学北京100049

云南省地处低纬高原地区,毗邻东南亚,空气污染物质除受本地排放外也受东南亚地区跨境输送的影响。本文收集整理了2017~2021年云南省16个州市40个国控站观测数据,分析云南省污染特征和变化趋势;并利用后向轨迹(HYSPLIT)聚类分析和浓度权... 详细信息

云南省地处低纬高原地区,毗邻东南亚,空气污染物质除受本地排放外也受东南亚地区跨境输送的影响。本文收集整理了2017~2021年云南省16个州市40个国控站观测数据,分析云南省污染特征和变化趋势;并利用后向轨迹(HYSPLIT)聚类分析和浓度权重轨迹(CWT)方法分析了PM2.5的主要区域来源。结果表明,云南省PM2.5年均浓度呈下降趋势,下降率为0.91±0.23μg m^(-3) a^(-1)。在季节变化上,春季浓度最高,全省平均为31.92±9.08μg m^(-3),夏季浓度最低,为13.50±2.69μg m^(-3)。春季东南亚地区生物质燃烧导致云南省PM2.5的污染最严重,最大贡献值超过40μg m^(-3),此外广西西南部也是云南省春季高潜在源区之一。在日变化上,PM2.5浓度呈现“双峰型”特征,最大值出现在09:00(北京时间,下同)至12:00和21:00至01:00,主要是人为活动与较低的边界层高度和风速等气象因素共同作用的结果。研究显示,云南省春季PM2.5浓度多源于跨境输送,这将为云南省空气污染物治理提供新的启示。

关键词：云南省 PM2.5 跨境输送潜在源区