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Formation of secondary inorganic aerosol in a frigid urban atmosphere

Frontiers of Environmental science & Engineering 2022年第2期16卷 39-50页

作者： Yuan Cheng Qinqin Yu Jiumeng Liu Youwen Sun Linlin Liang Zhenyu Du Guannan Geng Wanli Ma Hong Qi Qiang Zhang Kebin He State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China Key Laboratory of Environmental Optics and Technology Anhui Institute of Optics and Fine MechanicsChinese Academy of SciencesHefei 230031China State Key Laboratory of Severe Weather&CMA Key Laboratory of Atmospheric Chemistry Chinese Academy of Meteorological SciencesBeijing 100081China National Research Center for Environmental Analysis and Measurement Environmental Development Center of the Ministry of Ecology and EnvironmentBeijing 100029China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Department of Earth System Science Tsinghua UniversityBeijing 100084China

Formation of secondary inorganic aerosol(SIA)was investigated during a six-month long heating season in Harbin,*** sulfate formation was observed at high relative humidity(RH),with the same threshold RH(80%)for both colder and warmer measurement *** to wintertime results from Beijing,the threshold RH was considerably higher in Harbin,whereas the RH-dependent enhancement of sulfur oxidation ratio(SOR)was less *** addition,the high RH events were rarely encountered,and for other periods,the SOR were typically as low as~***,the sulfate formation was considered inefficient in this *** excluding the several cases with high RH,both SOR and the nitrogen oxidation ratio(NOR)exhibited increasing trends as the temperature increased,with the increase of NOR being *** nitrate to sulfate ratio tended to increase with increasing temperature as *** on a semi-quantitative approach,this trend was attributed primarily to the temperature-dependent variations of precursors including SO_(2) and NO_(2).The influence of biomass burning emissions on SIA formation was also *** stronger impact of biomass burning,an enhancement in NOR was observed whereas SOR was largely *** different patterns were identified as the dominant driver of the larger nitrate to sulfate ratios measured at higher concentrations of fine particulate matter.

关键词： Haze Sulfate Nitrate Heterogeneous chemistry Biomass burning

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A W-band All-Dielectric Lens Antenna with Flat-Top Radiation Pattern

A W-band All-Dielectric Lens Antenna with Flat-Top Radiation...

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International Conference on Microwave and Millimeter Wave technology Proceedings

作者： Yong-Han Lu Jing Ma Zhi-Hao Li Jia-Jia Huang Kun-Shan Mo Lin Peng Key Laboratory of Cognitive Radio and Information Processing (Ministry of Education) Guilin University of Electronic Technology Guilin China Education Department of Guangxi Zhuang Autonomous Region Key Laboratory of Microwave and Optical Wave Application Technology (Guilin University of Electronic Technology) Guilin China Science and Technology on Special System Simulation Laboratory Beijing Simulation Center Beijing China

This paper proposes a W-band all-dielectric lens antenna with the characteristic flat-top beam. The lens loaded on the horn is composed of 10 concentric elliptical rings and a tapered matching layer. Its geometries are optimized by the non-dominated sorting genetic algorithm II (NSGA-II). The lens antenna designed at 92-97 GHz achieves a beamwidth of 40° with ripple level less than 1 dB in E-plane and H-plane. In addition, the proposed antenna can be prototyped easily using 3D-printing technology with low cost.

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Design of UHF Low-profile Monopole Antenna for Ground Penetrating Radar

Design of UHF Low-profile Monopole Antenna for Ground Penetr...

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International Conference on Microwave and Millimeter Wave technology Proceedings

作者： Jia-Jia Huang Jing Ma Zhi-Hao Li Yong-Han Lu Li-Wei Guo Lin Peng Key Laboratory of Cognitive Radio and Information Processing (Ministry of Education) Guilin University of Electronic Technology Guangxi China Education Department of Guangxi Zhuang Autonomous Region Key Laboratory of Microwave and Optical Wave Application Technology Guilin University of Electronic Technology Guangxi China Science and Technology on Special System Simulation Laboratory Beijing Simulation Center Beijing China

A low-profile and ultra-wideband unidirectional monopole antenna with absorbing material loading is proposed for ground-penetrating radar (GPR) applications in the UHF band. The overall dimensions of the antenna is 0.472λ 0 × 0.152λ 0 ×0.006λ 0 , where λ 0 is the free-space wavelength at the lowest frequency of 0.38GHz. The monopole antenna with low profile operates in the 0.38GHz-3GHz band with standing-wave ratio<2, a realized gain between -8.13 and 0.04 dBi. Good unidirectional radiation patterns were obtained in the whole band. The composed array antenna can be applied to the transmit signal and receive signal modules of the system.

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Effectiveness Evaluation of Communication Network based on BP neural network 5

Effectiveness Evaluation of Communication Network based on B...

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5th IEEE Information technology, Networking, Electronic and Automation Control Conference, ITNEC 2021

作者： Han, Chi Xiong, Wei Jian, Ping Aerospace Engineering University Aerospace Information Institute Beijing China Aerospace Engineering University Science and Technology on Complex Electronic System Simulation Laboratory Beijing China

ISBN: (纸本)9781665415989

In order to solve the problem of effectiveness evaluation of military communication network (MCN) under complex application conditions, an intelligent evaluation method based on BP neural network is proposed. Based on the establishment of hierarchical evaluation index system, a neural network model is used to describe the mapping relationship between the index value and the overall effectiveness, and samples are extracted from experts' experience to train the neural network, so as to realize the intelligent evaluation and calculation of MCN's effectiveness. The simulation results show that this method has high accuracy, simplicity and can meet the requirements of MCN effectiveness evaluation under various military application conditions. © 2021 IEEE.

关键词： Neural networks

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Effectiveness Evaluation of Space-based Information system based on Improved SVR 5

Effectiveness Evaluation of Space-based Information System b...

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5th IEEE Information technology, Networking, Electronic and Automation Control Conference, ITNEC 2021

ISBN: (纸本)9781665415989

The evaluation of effectiveness of space-based information system (SIS) is of great significance for modern warfare in integrated operations. In view of characteristics of complex impact factors, small number of samples and strong nonlinearity of effectiveness evaluation, support vector regression (SVR) is adopted to evaluate effectiveness. At the same time, cuckoo search optimizer (CSO) is introduced to optimize the three parameters of SVR. The simulation results indicate that improved SVR has higher accuracy than the traditional SVR and BP neural network, and can effectively evaluate the effectiveness of SIS. © 2021 IEEE.

关键词： Vector spaces

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Operational Effectiveness Evaluation of Reconnaissance Satellite system based on system Dynamics Model 2

Operational Effectiveness Evaluation of Reconnaissance Satel...

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2nd IEEE International Conference on Information technology, Big Data and Artificial Intelligence, ICIBA 2021

作者： Han, Chi Xiong, Wei Liu, Wenwen Yu, Xiaolan Jian, Ping Aerospace Information Institute Space Engineering University Beijing China Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China

ISBN: (纸本)9781665428767

In order to study changes in the effectiveness of reconnaissance satellite system (RSS) in supporting maritime operations, based on the key factors of dynamic confrontation system of the offensive and defensive parties, the feedback relationships between variables are analyzed. According to the feedback relationship, a system dynamics (SD) model based on Lanchester equation was established and simulated on the VENSIM platform to compare and analyze operational effectiveness of different RSS allocation schemes. simulation analysis shows that RSS can increase the rate of detection and acquisition of information and accelerate the loss of the enemy. At the same time, when the sensor parameters are similar, increasing the number of weapons can significantly reduce the loss, which provides a certain theoretical support for decision-making analysis in combat. © 2021 IEEE.

关键词： Feedback

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Data-driven Operational Effectiveness Evaluation of Space-based Information system 5

Data-driven Operational Effectiveness Evaluation of Space-ba...

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5th IEEE Information technology, Networking, Electronic and Automation Control Conference, ITNEC 2021

ISBN: (纸本)9781665415989

Aiming at the complexity of space-based information system (SIS) effectiveness evaluation and the coupling and interaction of various combat capabilities, a data-driven operational effectiveness evaluation model is proposed. By introducing the PSO-BPNN to fit the performance evaluation I/O data, design the mapping relationship between the neural network input layer, hidden layer, output layer and hierarchical index system. On this basis, the affiliation relationship among the indicators at each level and the association relationship between the indicators are excavated, and the SIS effectiveness evaluation model is constructed. Taking the maritime integrated joint operations supported by space-based information as an example, the effectiveness data is obtained by using MATLAB, VENSIM and STK co-simulation. By quantitatively analyzing the coupling interaction between indexes, the operational effectiveness of SIS was evaluated, and the accuracy of the model and the feasibility of the evaluation method were verified. © 2021 IEEE.

关键词： MATLAB

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Bulk Quantification and Molecular Characterization of Thermal Decomposition from the Thermal Desorption of Organic Aerosol

ACS ES&T Air

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ACS ES&T Air 2024年第7期1卷 628-636页

作者： Qingfeng Guo Wei Hu Min Hu Yujue Wang Song Guo Zhijun Wu Jing Zheng Limin Zeng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering International Joint Laboratory for Regional Pollution Control Ministry of Education (IJRC) Peking University Beijing 100871 China Institute of Surface-Earth System Science School of Earth System Science Tianjin University Tianjin 300072 China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science & Technology Nanjing 210044 China Key Laboratory of Marine Environment and Ecology Ministry of Education of China Ocean University of China Qingdao 266100 China

The thermal desorption (TD) technique has been widely employed to measure the molecular composition and volatility of organic aerosols through coupling to mass spectrometry. Although the impact of thermal decomposition on TD instruments has been discussed in the literature, its extent has not yet been quantified. Here, we quantify the decomposition of organic aerosol at the bulk level and qualitatively distinguish between compounds evaporating and decomposing at the molecular level through the combination of online thermodenuder aerosol mass spectrometer (TD-AMS), offline organic carbon/elemental carbon (OC/EC) analyzer, and ultra-high resolution mass spectrometer. Results show that up to 56% of organic mass in ambient aerosol decomposes at a desorption temperature lower than 180 °C, which means that large amounts of organics cannot be detected by TD-coupled instruments. Sulfur-containing compounds with larger molecular masses exhibit weaker thermal stability, making them more susceptible to thermal decomposition than other compounds not containing sulfur. This work provides a means to obtain quantitative and qualitative insights into the thermal decomposition of organic aerosol, which will aid in understanding secondary organic aerosol (SOA) formation and reducing the gap between SOA measurements and model simulations.

关键词： Aerosols Desorption Organic compounds Organic reactions Thermodynamic properties

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Effectiveness Evaluation of Reconnaissance Satellite system based on Analytic Hierarchy Process and Cloud Model 5

Effectiveness Evaluation of Reconnaissance Satellite System ...

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5th IEEE Information technology, Networking, Electronic and Automation Control Conference, ITNEC 2021

作者： Han, Chi Xiong, Wei Xiong, Minghui Liu, Zhen Liu, Wenwen Yu, Xiaolan Jian, Ping Space Engineering University Aerospace Information Institute Beijing China Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China

ISBN: (纸本)9781665415989

Considering the complexity of effectiveness evaluation index of reconnaissance satellite system (RSS), the cloud model theory and AHP method are combined. A fuzzy evaluation method of combat effectiveness based on cloud model is proposed. A multi-layer evaluation index system is constructed through the AHP method, and the weight of each level index is calculated. Combining the multi-dimensional cloud model with the AHP method, a quantitative fuzzy evaluation method for qualitative indicators and quantitative data is designed, and the qualitative evaluation results are obtained. The experimental results show that the proposed evaluation method can effectively realize the fuzzy quantitative evaluation under the complex evaluation index system with good performance in terms of calculation accuracy and fuzziness. © 2021 IEEE.

关键词： Analytic hierarchy process

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Experimental Study on the Relationship Between Performance and Structural Parameters of Metal Fiber 29

Experimental Study on the Relationship Between Performance a...

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2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Li, Lintai Zhou, Yanmin Li, Yuanyuan Sun, Zhongning Wang, Yin Gu, Haifeng Ma, Song Heilongjiang Provincial Key Laboratory of Nuclear Power System & Equipment Harbin Engineering University Harbin150001 China Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering University Harbin150001 China China Nuclear Power Engineering Co. Ltd Beijing100005 China

ISBN: (纸本)9780791886502

As a new filter material, metal fiber has good high-temperature resistance, moisture resistance, and radiation resistance. To explore the influence of the fiber's primary structural parameters on the fiber's performance, this paper experimentally studied the relationship between the flow resistance, filtration efficiency, and dust holding capacity of the metal fiber filter material and the thickness and solid volume fraction (SVF). Under the condition of ensuring uniform deposition of NaCl aerosol, we found that the deposition law of NaCl polydisperse aerosol is the same as that of monodisperse aerosol. The results show that for the same fiber diameter, increasing the fiber's thickness and SVF will increase the flow resistance of the fiber under the same dust holding capacity;that is, reducing the dust holding capacity of the fiber. In the depth filtration, the efficiency increases rapidly due to the aerosol deposition in the fiber, while the efficiency changes gently when the filter cake is covered on the filtration surface. At the same time, for each high filtration efficiency fiber, the variation characteristics of resistance with dust holding capacity in the deep filtration stage are the same. After the filter cake is completely covered on the filter surface, the growth trend of resistance is the same, independent of the fiber's structural parameters. © 2022 by ASME.

关键词： Fibers

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