检索结果-南通市图书馆

One-year observation of the mixing states of oxygenated organics-containing single particles in Guangzhou,China

Frontiers of Environmental Science & Engineering 2024年第5期18卷 155-169页

作者： Liyuan Mao Suxia Yang Xiaoya cheng Sulin Liu Duanying Chen Zhen Zhou Mei Li chenglei Pei chunlei cheng Institute of Mass Spectrometry and Atmospheric Environment Guangdong Provincial Engineering Research Center for the On-line Source Apportionment System of Air PollutionJinan UniversityGuangzhou510632China Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Guangzhou510632China Guangzhou Research Institute of Environment Protection Co. Ltd.Guangzhou510620China Guangzhou Ecological and Environmental Monitoring Center of Guangdong Province Guangzhou510030China State Key Laboratory of Marine Resource Utilization in South China Sea Hainan UniversityHaikou570228China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy SciencesXi’an710061China

Oxygenated organic molecules(OOMs)play an important role in the formation of secondary organic aerosols(SOAs),but the mixing states of OOMs are still *** study investigates the mixing states of OOM-containing single particles from the measurements taken using a single particle aerosol mass spectrometer in Guangzhou,China in ***,the particle counts of OOM particles and the mass concentration of secondary organic carbon(SOC)exhibited similar temporal trends throughout the entire *** OOM particles were consistently enriched in secondary ions,including ^(16)O^(−),^(26)CN^(−),^(46)NO_(2)^(−),^(62)NO_(3)^(−),and ^(97)HSO_(4)^(−).In contrast,the number fractions and diurnal patterns of OOM particles among the total detected particles showed similar distributions in August and October;however,the SOC ratios in fine particulate matter were quite different,suggesting that there were different mixing states of single-particle oxygenated *** addition,further classification results indicated that the OOM particles were more aged in October than August,even though the SOC ratios were higher in ***,the distribution of hydrocarbon fragments exhibited a notable decrease from January to October,emphasizing the more aged state of the organics in *** addition,the sharp increase in elemental carbon(EC)-OOM particles in the afternoon in October suggests the potential role of EC in the aging process of ***,in contrast to the bulk analysis of SOC mass concentration,the mixing states of the OOM particles provide insights into the formation process of SOAs in field studies.

关键词： Oxygenated organics Single particles Mixing state Secondary formation Photochemistry

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Mixing states and secondary formation processes of organic nitrogen-containing single particles in Guangzhou,China

引用

Journal of Environmental Sciences 2024年第4期138卷 62-73页

作者： Lijun Yun chunlei cheng Suxia Yang Zaihua Wang Mei Li Qi En Zhong LiyuanMao Sulin Liu Xiaoya cheng Duanying Chen Fan Yang Zhen Zhou Institute of Mass Spectrometry and Atmospheric Environment Guangdong Provincial Engineering Research Center for on-line source apportionment system of air pollutionJinan UniversityGuangzhou 510632China Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Guangzhou 510632China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy ScienceXi’an 710061China Institute for Environment and Climate Research Jinan UniversityGuangzhou 510632China Guangdong Academy of Sciences Institute of Resources Utilization and Rare Earth DevelopmentGuangzhou 510650China Environmental Monitoring Station of Pudong New District Shanghai 201200China

Organic nitrogen(ON)compounds play a significant role in the light absorption of brown carbon and the formation of organic aerosols,however,the mixing state,secondary formation processes,and influencing factors of ON compounds are still *** paper reports on the mixing state of ON-containing particles based on measurements obtained using a highperformance single particle aerosol mass spectrometer in January 2020 in *** ON-containing particles accounted for 21% of the total detected single particles,and the particle count and number fraction of the ON-containing particles were two times higher at night than during the *** prominent increase in the content of ON-containing particles with the enhancement of NO_xmainly occurred at night,and accompanied by high relative humidity and nitrate,which were associated with heterogeneous reactions between organics and gaseous NO_(x)and/or NO_(3)*** synchronous decreases in ON-containing particles and the mass absorption coefficient of water-soluble extracts at 365 nm in the afternoon may be associated with photo-bleaching of the ON species in the *** addition,the positive matrix factorization analysis found five factors dominated the formation processes of ON particles,and the nitrate factor(33%)mainly contributed to the production of ON particles at *** results of this study provide unique insights into the mixing states and secondary formation processes of the ON-containing particles.

关键词： Organic nitrogen compounds Single particles Mixing state Secondary formation Nighttime chemistry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于LC-MS/MS技术的水蛭配方颗粒中7种碱基和核苷成分分析方法的建立

引用

环境化学 2024年第1期43卷 359-362页

作者：姜俊程春雷杨昊山东省食品药品检验研究院(国家药品监督管理局仿制药研究与评价重点实验室) 济南250000

本文建立了一种使用岛津超高效液相色谱仪Nexera X2和三重四极杆质谱仪LCMS-8050联用测定水蛭配方颗粒中7种碱基和核苷成分的分析方法.水蛭配方颗粒以10%甲醇50℃超声提取30 min,MRM正负模式同时检测.以Discovery■HS F5-3色谱柱进行分... 详细信息

本文建立了一种使用岛津超高效液相色谱仪Nexera X2和三重四极杆质谱仪LCMS-8050联用测定水蛭配方颗粒中7种碱基和核苷成分的分析方法.水蛭配方颗粒以10%甲醇50℃超声提取30 min,MRM正负模式同时检测.以Discovery■HS F5-3色谱柱进行分离,流动相为0.15%甲酸水溶液和甲醇,10 min内完成梯度洗脱.本方法采用外标法定量,7种化合物在相应的浓度范围内线性关系良好,判定系数(R^(2))均大于0.996,定量限在0.42—3.94μg·g^(-1)之间. 10 ng·mL^(-1)的混合标准品溶液连续进样6次,待测化合物峰面积RSD均小于6%,精密度良好.平行6份加标回收试验,7种化合物平均回收率在87.09%—105.81%之间,RSD%在1.35%—4.70%之间.残留实验结果为阴性.该方法准确可靠,可为水蛭配方颗粒的质量控制提供参考依据.

关键词： LC-MS/MS 水蛭配方颗粒碱基核苷

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

基于异构图表示的中医电子病历分类方法

引用

计算机应用 2024年第2期44卷 411-417页

作者：王楷天叶青程春雷江西中医药大学计算机学院南昌330004 江西省中医人工智能重点研究室(江西中医药大学) 南昌330004

中医(TCM)电子病历由于结构复杂多样与诊疗术语不规范的特点导致数据挖掘难度大、利用率低、难以抽取到有效信息。针对上述问题,提出基于LERT(Linguistically-motivated bidirectional Encoder Representation from Transformer)预训练... 详细信息

中医(TCM)电子病历由于结构复杂多样与诊疗术语不规范的特点导致数据挖掘难度大、利用率低、难以抽取到有效信息。针对上述问题,提出基于LERT(Linguistically-motivated bidirectional Encoder Representation from Transformer)预训练模型与图卷积网络(GCN)并用异构图表示的中医电子病历分类模型TCM-GCN,用于改善中医电子病历特征有效表征的提取与分类。首先,利用LERT层词嵌入的方式将病历转换为句向量融入异构图中,以补全图结构缺失的病历整体语义特征;随后,为了缓解中医电子病历结构特点对特征提取产生的负面影响,异构图将关键词加入节点,使用BM25与点间互信息(PMI)算法构建图中“病历-关键词”“关键词-关键词”的边以表达病历的特征;最后,TCM-GCN依靠LERT-BM25-PMI构建的异构图对病历之间的特征关系进行聚合与抽取,完成病历分类的任务。在中医电子病历数据集上的实验结果表明,相较于次优的LERT,TCM-GCN加权平均后的准确率、召回率、F1值分别提升了2.24%、2.38%、2.32%,验证了算法在捕捉病历间隐含特征与中医电子病历分类工作上的有效性。

关键词：异构图图卷积网络预训练模型文本分类自然语言处理中医电子病历

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

两阶段多标签分类探索中医证素辨证规律

引用

现代信息科技 2024年第4期8卷 153-161,166页

作者：蓝勇程春雷叶青胡杭乐沈友志江西中医药大学计算机学院江西南昌330004 江西中医药大学中医人工智能重点研究室江西南昌330004

探索证素辨证规律能更好地辅助临床决策和促进中医辨证理论的传承。中医文本句式结构复杂、表述标准不一,难以匹配符号规则,且神经网络黑盒特性又难以直接解释其辨证过程。为探索中医证素辨证规律,第一阶段使用神经网络模型对证素进行... 详细信息

探索证素辨证规律能更好地辅助临床决策和促进中医辨证理论的传承。中医文本句式结构复杂、表述标准不一,难以匹配符号规则,且神经网络黑盒特性又难以直接解释其辨证过程。为探索中医证素辨证规律,第一阶段使用神经网络模型对证素进行多标签分类,通过稀疏注意力捕获与证素相关的关键词及其权重生成证素表征;第二阶段使用随机森林对融入相关证素标签的证素表征进行分类训练,后对随机森林规则提取以探索辨证规律,提高证素辨证的可解释性。实验结果表明,该方法提升了证素辨识的准确率,同时F1保持较高水平,有利于探索证素辨证规律。

关键词：证素辨证规律稀疏注意力多标签分类随机森林模型可解释性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Detection of polycyclic aromatic hydrocarbons using a high performance-single particle aerosol mass spectrometer

引用

Journal of Environmental Sciences 2023年第2期124卷 806-822页

作者： Yao Zhang chenglei Pei Jinwen Zhang chunlei cheng Xiufeng Lian Mubai Chen Bo Huang Zhong Fu Zhen Zhou Mei Li Institute of Mass Spectrometry and Atmospheric Environment Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air pollutionJinan UniversityGuangzhou 510632China Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Guangzhou 510632China Guangzhou Environmental Monitoring Center Guangzhou 510030China Guangzhou Hexin Analytical Instrument Company Limited Guangzhou 510530China

The real-time detection of the mixing states of polycyclic aromatic hydrocarbons(PAHs)and nitro-PAHs in ambient particles is of great significance for analyzing the source,aging process,and health effects of PAHs and nitro-PAHs;yet there is still few effective technology to achieve this type of *** this study,11 types of PAH and nitro-PAH standard sampleswere analyzed using a high performance-single particle aerosolmass spectrometer(HP-SPAMS)in lab *** identification principles‘parent ions’and‘mass-to-charge(m/z)=77’of each compound were obtained in this *** was found that different laser energies did not affect the identification of the parent *** comparative experiments of ambient atmospheric particles,cooking and biomass burning emitted particles with and without the addition of PAHs were conducted and ruled out the interferences from primary and secondary organics on the identification of ***,the reliability of the characteristic ions extraction method was evaluated through the comparative study of similarity algorithm and deep learning *** addition,the real PAH-containing particles from vehicle exhaust emissions and ambient particles were also *** study improves the ability of single particle mass spectrometry technology to detect PAHs and nitro-PAHs,and HP-SPAMS was superior to SPAMS for detecting single particles containing PAHs and *** study provides support for subsequent ambient observations to identify the characteristic spectrum of single particles containing PAHs and nitro-PAHs.

关键词： Single particle Polycyclic aromatic hydrocarbons Identification principles Mass spectrometry Aerosol

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhanced mixing state of black carbon with nitrate in single particles during haze periods in Zhengzhou, China

引用

Journal of Environmental Sciences 2022年第1期34卷 185-196页

作者： Qianni Zhou chunlei cheng Suxia Yang Minghao Yuan Jingjing Meng Haifeng Gong Qien Zhong Yao Zhang Yutong Xie Zhen Zhou Mei Li Institute of Mass Spectrometry and Atmospheric Environment Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air PollutionJinan UniversityGuangzhou 510632China Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality Guangzhou 510632China School of Environment and Planning Liaocheng UniversityLiaocheng 252000China Institute for Environment and Climate Research Jinan UniversityGuangzhou 510632China Zhengzhou Environmental Protection Monitoring Center Station Zhengzhou 450007China

Black carbon(BC)plays an important role in air quality and climate change,which is closely associated with its mixing state and chemical *** this work the mixing state of BC-containing single particles was investigated to explore the evolution process of ambient BC particles using a single particle aerosol mass spectrometer(SPAMS)in March 2018 in Zhengzhou,*** BC-containing particles accounted for 61.4%of total detected ambient single particles and were classified into five types including BC-nitrate(BC-N,52.3%)as the most abundant species,followed by BC-nitrate-sulfate(BC-NS,22.4%),BCOC(16.8%),BC-fresh(BC-F,4.5%)and BC-sulfate particles(BC-S,4.0%).With enhancement of the ambient nitrate concentration,the relative peak area(RPA)of nitrate in BC-N and BC–NS particles both increased,yet only the number fraction(N_(f))of BC–N particles increased while the N_(f) of BC-NS particles decreased,suggesting that the enhanced mixing state of BC with nitrate was mainly due to the increase in the ambient nitrate mass *** addition,the Nfof BC-N decreased from 65.3%to 28.4%as the absorbing Angstrom exponents(AAE)of e BC increased from 0.75 to 1.45,which indicated the reduction of light absorption ability of aged BC particles with the enhanced formation of BC-N *** results of this work indicated a change in the mixing state of BC particles due to the dominance of nitrate in PM_(2.5),which also influenced the optical properties of aged BC particles.

关键词： Single particle Black carbon Mixing state Nitrate Aging process

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

威海市夏季臭氧及大气氧化性特征分析

引用

地球环境学报 2024年第3期15卷 447-458,486页

作者：张峰李侃许昭昭张玲丽成春雷李建军威海市生态环境监控中心威海264200 威海市生态环境事务服务中心威海264200 暨南大学质谱仪器与大气环境研究所广东省大气污染在线源解析系统工程技术研究中心广州510632 中国科学院地球环境研究所黄土与第四纪地质国家重点实验室西安710061

威海市属于我国北方典型沿海城市,近年来的持续观测发现夏季易出现臭氧(O_(3))污染。以2023年夏季观测数据为约束,利用零维盒子模式分析威海市夏季O_(3)及大气氧化性特征,给出O_(3)污染防治的建议。2023年5月30日—6月30日,威海市污染... 详细信息

威海市属于我国北方典型沿海城市,近年来的持续观测发现夏季易出现臭氧(O_(3))污染。以2023年夏季观测数据为约束,利用零维盒子模式分析威海市夏季O_(3)及大气氧化性特征,给出O_(3)污染防治的建议。2023年5月30日—6月30日,威海市污染天的首要污染物是O_(3),烷烃是挥发性有机物(VOCs)中浓度占比最高的组分,烯烃则是活性占比最高的组分。从清洁日到污染日烯烃活性增强最显著,O_(3)的化学生成和大气氧化性在污染日均有增加,促进了二次污染过程的发生。威海夏季大气氧化性水平较强,O_(3)对前体物的敏感区处于氮氧化物(NOx)和VOCs的过渡区,O_(3)污染防控需结合NOx和VOCs进行协同防控。O_(3)对前体物烯烃减排的变化最敏感,因此其污染防控过程需结合VOCs反应活性开展。基于威海市夏季观测数据分析O_(3)及大气氧化性特征,从O_(3)敏感性区域变化及VOCs反应活性角度为O_(3)污染防治策略提供了思路。

关键词：威海臭氧大气氧化性挥发性有机物(VOCs) VOCs反应活性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Design of artificial biomimetic channels with Na^(+)permeation rate and selectivity potentially outperforming the natural sodium channel

引用

Nano Research 2024年第9期17卷 8638-8646页

作者： Zhi Zhu Yan Zhao Chao Chang Shaojian Yan Tingyu Sun Shiyu Gu Yangmei Li Dengsong Zhang chunlei Wang Xiao cheng Zeng School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China Innovation Laboratory of Terahertz Biophysics National Innovation Institute of Defense TechnologyBeijing 100071China School of Physics Peking UniversityBeijing 100871China International Joint Laboratory of Catalytic Chemistry College of SciencesShanghai UniversityShanghai 200444China Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China

Artificial ion channels that enable high-efficiency ion transport have important implications in nanofluidics and biomedical applications such as drug ***,we show a simulation-based chemical design of a biomimetic sodium channel that possesses permeation rate and selectivity potentially higher than those of the state-of-the-art natural vertebrate voltage-gated sodium ***,our theoretical findings have undergone empirical testing,aligning well with the Arrhenius law as derived from a diverse range of experimental *** high-efficiency ion transport is achieved by anchoring the carboxylate functional groups within the channel filter.A key chemical guiding principle underlying the ion channel design is that the free-energy barrier for the Na^(+)passage across the channel should be comparable to typical thermal energy at room *** the implementation of the chemical design,we found that the relatively low free-energy barrier can be attributed to the compensation effect of the carboxylate groups to the partially lost oxygen shell of the ion within the ion channel,as well as to the consonant vibration of the ions inside and outside the *** mechanistic understanding brings new insight,at the molecular level,into the high-efficiency ion transport across the designed membrane *** proof of principle achieved from the simulations will stimulate future experimental confirmation and potential applications of the high-performance artificial channels in nanofluidics and in bioinspired iontronics.

关键词： sodium channels anchoring carboxylate functional groups molecular dynamics simulations low free-energy barrier for ion passage thermal kinetic energy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Parameterization, sensitivity, and uncertainty of 1-D thermodynamic thin-ice thickness retrieval

引用

Acta Oceanologica Sinica 2024年第7期43卷 93-111页

作者： Tianyu Zhang Mohammed Shokr Zhida Zhang Fengming Hui Xiao cheng Zhilun Zhang Jiechen Zhao chunlei Mi School of Geospatial Engineering and Science Sun Yat-Sen University/Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Key Laboratory of Comprehensive Observation of Polar Environment(Sun Yat-Sen University) Ministry of EducationZhuhai 519082China State Key Laboratory of Remote Sensing Science College of Global Change and Earth System ScienceBeijing Normal UniversityBeijing 100875China Science and Technology Branch Environment and Climate Change CanadaToronto M3H5T4Canada Qingdao Innovation and Development Base(Centre) Harbin Engineering UniversityQingdao 266500China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Retrieval of Thin-Ice Thickness(TIT)using thermodynamic modeling is sensitive to the parameterization of the independent variables(coded in the model)and the uncertainty of the measured input *** article examines the deviation of the classical model’s TIT output when using different parameterization schemes and the sensitivity of the output to the ice ***,it estimates the uncertainty of the output in response to the uncertainties of the input *** parameterized independent variables include atmospheric longwave emissivity,air density,specific heat of air,latent heat of ice,conductivity of ice,snow depth,and snow *** input parameters include air temperature,ice surface temperature,and wind *** the independent variables,the results show that the highest deviation is caused by adjusting the parameterization of snow conductivity and depth,followed ice *** sensitivity of the output TIT to ice thickness is highest when using parameterization of ice conductivity,atmospheric emissivity,and snow conductivity and *** retrieved TIT obtained using each parameterization scheme is validated using in situ measurements and satellite-retrieved *** in situ measurements,the uncertainties of the measured air temperature and surface temperature are found to be *** resulting uncertainties of TIT are evaluated using perturbations of the input data selected based on the probability distribution of the measurement *** results show that the overall uncertainty of TIT to air temperature,surface temperature,and wind speed uncertainty is around 0.09 m,0.049 m,and−0.005 m,respectively.

关键词： Arctic sea ice 1-D thermodynamic ice model thin-ice thickness sea ice parameterization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：