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Analysis of amino acid enantiomers in ambient aerosols:Effects and removal of coexistent aerosol matrix

Journal of Environmental Sciences 2024年第3期137卷 732-740页

作者： Ying Li xiaoying Li Libin Wu Luhan shi ShanWang Pingqing Fu Yingyi Zhang Senchao Lai The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of EducationSchool of Environment and EnergySouth China University of TechnologyGuangzhou 510006China Institute of Surface-Earth System Science School of Earth System ScienceTianjin UniversityTianjin 300072China now at Hong Kong University of Science and Technology Hong Kong 00852China

Amino acids(AAs)including D-and L-enantiomers are a group of organic nitrogen species in ambient aerosol.Due to the low abundances of AAs(level of ng/m^(3))and the matrix effects by coexistent components,it is challenging to quantify AA enantiomers in ambient aerosols especially under pollution conditions.In this study,we present an optimized method for analyzing AA enantiomers in atmospheric aerosol samples including a pretreatment process and the detection by high performance liquid chromatography coupled to a fuorescence detector(HPLC-FLD).Matrix effects caused by coexistent chemicals on AA enantiomers analysis in ambient aerosol samples were investigated especially for those collected in pollution episodes.The results revealed that the determination of AA enantiomers is significantly affected by the coexistent organic carbon(as a proxy of organic matter)and water-soluble ion of NH_(4)^(+).To remove the matrix effects,we applied a pretreatment using the solid phase extraction column coupled with alkaline adjustment to sample extract.After pretreatment,18 AAs including 6 pairs of D-and L-enantiomers(i.e.,leucine,isoleucine,valine,alanine,serine,and aspartic acid)can be successfully separated and quantified in aerosol samples by HPLC-FLD.The recoveries are in the range of 67%-106%.This method was successfully applied to the urban aerosol samples from pollution and non-pollution periods for AA enantiomers determination.We suggest that the concentrations of D-AAs and the ratio of D-AA/L-AA are indicative of the contribution of bacterial sources and the infuence of biomass burning.

关键词： Amino acid enantiomers Atmospheric aerosol Organic carbon Ammonia Chiral ratio

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Influences of the Fresh Air Volume on the Removal of Cough-Released Droplets in a Passenger Car of a High-Speed Train Using CFD

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2727-2748页

作者： Jun Xu Kai Bi Yibin Lu TiantianWang Hang Zhang Zeyuan Zheng Fushan shi Yaxin Zheng xiaoying Li Jingping Yang CRRC Changchun Railway Vehicles Co. Ltd.Changchun130062China Key Laboratory of Traffic Safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410075China College of Mechanical and Vehicle Engineering Hunan UniversityChangsha410082China

The spread and removal of pollution sources,namely,cough-released droplets in three different areas(front,middle,and rear areas)of a fully-loaded passenger car in a high-speed train under different fresh air flow volume were studied using computational fluid dynamics(CFD)method.In addition,the structure of indoor flow fields was also analysed.The results show that the large eddies are more stable and flow faster in the air supply under Mode 2(fresh air volume:2200m3/h)compared to Mode 1(fresh air volume:1100m3/h).By analysing the spreading process of droplets sprayed at different locations in the passenger car and with different particle sizes,the removal trends for droplets are found to be similar under the two air supply modes.However,when increasing the fresh air flow volume,the droplets in the middle and front areas of the passenger car are removed faster.When the droplets had dispersed for 60s,Mode 2 exhibited a removal rate approximately 1%–3%higher than Mode 1 for small and medium-sized droplets with diameters of 10 and 50μm.While those in the rear area,the situation is reversed,with Mode 1 slightly surpassing Mode 2 by 1%–3%.For large droplets with a diameter of 100μm,both modes achieved a removal rate of over 96%in all three regions at the 60 s.The results can provide guidance for air supply modes of passenger cars of high-speed trains,thus suppressing the spread of virus-carrying droplets and reducing the risk of viral infection among passengers.

关键词： Cough-released pollutants CFD ventilation inside trains supply air volume

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Exfoliation of bulk 2H-MoS_(2)into bilayer 1T-phase nanosheets via ether-induced superlattices

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Nano Research 2024年第6期17卷 5705-5711页

作者： Xiuling shi Dongmei Lin Zhuorui Xiao Yibo Weng Hanxiang Zhou xiaoying Long Zhiyu Ding Fuyuan Liang Yan Huang Guohua Chen Kaikai Li Tong-Yi Zhang School of Materials Science and Engineering Harbin Institute of TechnologyShenzhen 518055China Department of Mechanical Engineering Research Institute for Smart EnergyThe Hong Kong Polytechnic UniversityHong KongChina School of Energy and Environment City University of Hong KongTat Chee AvenueKowloonHong KongChina The Hong Kong University of Science and Technology(Guangzhou) Guangzhou Municipal Key Laboratory of Materials InformaticsAdvanced Materials Thrust and Sustainable Energy and Environment ThrustNanshaGuangzhou 511400China

The exfoliation of bulk 2H-molybdenum disulfide(2H-MoS_(2))into few-layer nanosheets with 1T-phase and controlled layers represents a daunting challenge towards the device applications of MoS_(2).Conventional ion intercalation assisted exfoliation needs the use of hazardous n-butyllithium and/or elaborate control of the intercalation potential to avoid the decomposition of the MoS_(2).This work reports a facile strategy by intercalating Li ions electrochemically with ether-based electrolyte into the van der Waals(vdW)channels of MoS_(2),which successfully avoids the decomposition of MoS_(2)at low potentials.The co-intercalation of Li+and the ether solvent into MoS_(2)makes a first-order phase transformation,forming a superlattice phase,which preserves the layered structure and hence enables the exfoliation of bulk 2H-MoS_(2)into bilayer nanosheets with 1T-phase.Compared with the pristine 2H-MoS_(2),the bilayer 1T-MoS_(2)nanosheets exhibit better electrocatalytic performance for the hydrogen evolution reaction(HER).This facile method should be easily extended to the exfoliation of various transition metal dichalcogenides(TMDs).

关键词： exfoliation of MoS_(2) phase transformations superlattices ether electrolyte hydrogen evolution reaction(HER)

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基于双流-非局部时空残差卷积神经网络的人体行为识别

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电子与信息学报 2024年第3期46卷 1100-1108页

作者：钱惠敏陈实皇甫晓瑛河海大学南京211100

3维卷积神经网络(3D CNN)与双流卷积神经网络(two-stream CNN)是视频中人体行为识别研究的常用架构,且各有优势。该文旨在研究结合两种架构且复杂度低、识别精度高的人体行为识别模型。具体地,该文提出基于通道剪枝的双流-非局部时空残... 详细信息

3维卷积神经网络(3D CNN)与双流卷积神经网络(two-stream CNN)是视频中人体行为识别研究的常用架构,且各有优势。该文旨在研究结合两种架构且复杂度低、识别精度高的人体行为识别模型。具体地,该文提出基于通道剪枝的双流-非局部时空残差卷积神经网络(TPNLST-ResCNN),该网络采用双流架构,分别在时间流子网络和空间流子网络采用时空残差卷积神经网络(ST-ResCNN),并采用均值融合算法融合两个子网络的识别结果。进一步地,为了降低网络的复杂度,该文提出了针对时空残差卷积神经网络的通道剪枝方案,在实现模型压缩的同时,可基本保持模型的识别精度;为了使得压缩后网络能更好地学习到输入视频中人体行为变化的长距离时空依赖关系,提高网络的识别精度,该文提出在剪枝后网络的首个残差型时空卷积块前引入一个非局部模块。实验结果表明,该文提出的人体行为识别模型在公共数据集UCF101和HMDB51上的识别准确率分别为98.33%和74.63%。与现有方法相比,该文模型具有参数量小、识别精度高的优点。

关键词：人体行为识别双流卷积神经网络 3维卷积神经网络网络剪枝非局部模块

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Multi-style video stylization based on texture advection

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Science China(Information Sciences) 2015年第11期58卷 90-102页

作者： TANG Ying ZHANG Yan shi xiaoying FAN Jing School of Computer Science and Technology Zhejiang University of Technology Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province School of Software Engineering Hangzhou Dianzi University

Artistic video stylization, which is widely used in multimedia entertainment, transforms a given video into different artistic styles. Most of the existing video stylization algorithms can simulate single or limited video artistic styles. Although some algorithms can achieve multi-style video processing, these algorithms are complex and difficult to implement. To solve this problem, we propose a multi-styled video stylization algorithm based on texture advection, where different artistic styles are synthesized and transferred from user-specified texture samples of desired styles. We use the direction field-guided texture synthesis to compute the texture layer that represents the artistic style. Painterly directional video styles are simulated competently by the orientation changes in the synthesized anisotropic textures. There appeared local distorted region of the texture layer during texture advection under the optical flow field. To address this issue, we propose the texture inpaint to synthesize the limited distorted region and make the stylized video temporally coherent. We also accelerate the video stylization by using the CUDA parallel computing framework that parallelly computes the morphological operations used for video abstraction. Finally, we produce stylized videos of multiple artistic styles with satisfactory experimental results, including the styles of oil painting, watercolor painting and stylized lines drawing.

关键词： non-photorealistic rendering video stylization texture synthesis direction field CUDA

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Preface-Understanding the coevolution of life and environment in great turning periods of Earth history

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Science China Earth Sciences 2008年第11期51卷 1513-1515页

作者： TONG JinNan shi xiaoying Key Laboratory of Biogeology and Environmental Geology of Ministry of Education State Key Laboratory of Geological Process and Mineral ResourcesChina University of Geosciences Wuhan 430074China State Key Laboratory of Geological Process and Mineral Resources China University of Geosciences Beijing 10083China

Wherever the first life originated, the Earth has grown organisms. The Earth provides life with all the basicelements required for the composition and growth of life. And of more importance is that the Earth has

关键词： life Preface-Understanding the coevolution of life and environment in great turning periods of Earth history

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Methane seeps,methane hydrate destabilization,and the late Neoproterozoic postglacial cap carbonates

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Chinese Science Bulletin 2006年第10期51卷 1152-1173页

作者： JIANG Ganqing shi xiaoying ZHANG shihong Department of Geoscience University of Nevada Las Vegas NV 89154-4010 USA School of Earth Science and Resources and the State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China

甲烷水合物在地球组成容易地可交换的碳的最大的水池“ s 沉积甲壳并且可以使动摇，在一些情况中灾难的联盟者，在全球规模的温暖或海的时间期间，水平变化。在 Neoproterozoicice 年龄期间给极端寒冷，如此的事件的余殃也许在在 Earthh... 详细信息

甲烷水合物在地球组成容易地可交换的碳的最大的水池“ s 沉积甲壳并且可以使动摇，在一些情况中灾难的联盟者，在全球规模的温暖或海的时间期间，水平变化。在 Neoproterozoicice 年龄期间给极端寒冷，如此的事件的余殃也许在在 Earthhistory 的最可能的间隔之中见证局部性却普遍的甲烷象渗出一样组织的甲烷和质地，导出甲烷的同位素的信号，低硫酸盐集中，海洋的重晶石，并且一突出，短命的碳同位素旅行(delta~( 13 ) C < =-5 每千)在迟了的 Neoproterozoic 期间为一个甲烷水合物 destabilization 事件从 post-Marinoan 帽子碳酸盐(约 635 妈)提供充分证据冰期后的温暖和违反。从水合物的甲烷版本能引起积极反馈到全球温暖，甲烷的氧化能导致海洋血缺氧和大气中的氧气的变化，提供为在最近的 Neoproterozoic 的早动物进化的环境力量。尚待为这个事件被澄清的问题包括有生物革新的甲烷水合物de稳定，起始的甲烷版本的时间，预言的海洋血缺氧事件和它的关系的扳机，响应甲烷版本的 additionalgeochemical 信号，并且帽子的地区性、全球的 synchrony 焦化降水。在华南的 Doushantuo 帽子碳酸盐为这些问题的更好的理解提供它的年龄的最好的例子之一。

关键词：甲烷渗出物甲烷水合物新元古代冰河作用碳酸盐覆盖层碳同位素多细胞动物气候变化

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An optimized texture-by-numbers synthesis method and its visual applications

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Science China(Information Sciences) 2013年第5期56卷 50-63页

作者： FAN Jing shi xiaoying ZHOU Zhan TANG Ying School of Computer Science and Technology Zhejiang University of Technology Key Laboratory of Visual Media Intelligent Processing Technology of Zhejiang Province School of Information Engineering Zhejiang University of Technology

The framework of texture-by-numbers(TBN) synthesizes images of global-varying patterns with intuitive user control.Previous TBN synthesis methods have difficulties in achieving high-quality synthesis results and efficiency simultaneously.This paper proposes a fast TBN synthesis method based on texture optimization,which uses global optimization to solve the controllable non-homogeneous texture synthesis problem.Our algorithm produces high quality synthesis results by combining texture optimization into TBN framework with two improvements.The initialization process is adopted to generate the initial output of the global optimization algorithm,which speeds up the algorithm’s convergence rate and enhances synthesis quality.Besides distance metrics to measure image similarities are specifically designed for different images to better match human visual perception for structural patterns and a user study is conducted to verify the effectiveness of the metrics.To further improve the synthesis speed,the algorithm is entirely implemented on GPU based on CUDA architecture.The optimized TBN method is applied to various visual applications including not only traditional TBN applications,but also image in-painting and texture-based flow visualization.The experimental results show that our method synthesizes images of higher or comparable qualities with higher efficiency than other state-of-art synthesis methods.

关键词： texture-by-number texture optimization feature synthesis CUDA

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基于主动式阻尼的混合式步进电机转速振荡抑制控制

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电工技术学报 2024年第8期39卷 2459-2469页

作者：施雨武志涛苏晓英佟文明辽宁科技大学电子与信息工程学院鞍山114051 沈阳工业大学特种电机与高压电器教育部重点实验室沈阳110870

混合式步进电机因其特殊的机械结构导致自身阻尼极小,在实际运行过程中会发生振荡过大,甚至失步的问题。为提高混合式步进电机的控制品质,提出一种基于主动式阻尼的步进电机转速振荡抑制方法。首先,将电机模型转化至同步旋转dq坐标系,... 详细信息

混合式步进电机因其特殊的机械结构导致自身阻尼极小,在实际运行过程中会发生振荡过大,甚至失步的问题。为提高混合式步进电机的控制品质,提出一种基于主动式阻尼的步进电机转速振荡抑制方法。首先,将电机模型转化至同步旋转dq坐标系,将电流i_d控制恒为额定电流,利用位置误差和速度误差调节电流i_q生成瞬时转矩,抑制电机运行时存在的振荡现象。其次,为实现电机闭环反馈控制,提出一种将同步频率提取滤波器(SFF)与三阶锁相环(PLL~3rd)相结合的无传感器控制方法。SFF可以滤除反电动势信号中的高次谐波,PLL~3rd能消除转速变化过程中的稳态误差。实验证明,该方法有效抑制了步进电机运行过程中的振荡现象,提升了电机的运行品质。

关键词：混合式步进电机双闭环控制主动式阻尼控制锁相环同步频率提取滤波器

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Chemocline instability and isotope variations of the Ediacaran Doushantuo basin in South China

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Science China Earth Sciences 2008年第11期51卷 1560-1569页

作者： JIANG GanQing ZHANG shiHong shi xiaoying WANG XinQiang Department of Geoscience University of NevadaLas VegasNV 89154-4010USA School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China State Key Laboratory of Geological Process and Mineral Resources Beijing 100083China

Stable isotope analyses in sections across a shelf to basinal transect of the Ediacaran Doushantuo basin show substantial isotope variabilities. In Songlin section where sediments were deposited in an intrashelf basin, δ 13C values are persistently negative (_3‰ to _5‰, VPDB) through the entire Doushantuo Formation, similar to those obtained from the slope section in Wuhe (_5‰ to _10‰, VPDB). Shallow water sections in Weng'an and Duoding show two broad δ 13C anomalies overprinted with significant meter-scale variations, but none of the curves has similar absolute δ 13C values compared to the Yangtze Gorges areas in South China and other sections globally. Such isotope variations, if partially recording ancient seawater signature, imply spatial and temporal chemocline instability in the Doushantuo basin. In combination with available δ 13C records from other Ediacaran successions globally, the data from the Doushantuo basin are consistent, in first order, with the existence and oxidation of a large dissolved organic carbon (DOC) reservoir in Ediacaran oceans, but imply local environmental controls on Neoproterozoic isotope values and call attentions for using δ 13C anomalies as time lines in stratigraphic correlation.

关键词： Ediacaran isotopes chemocline early animals Doushantuo Formation South China

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