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Key features of new particle formation events at background sites in China and their influence on cloud

Xiaojing SHEN,Junying SUN,Xiaoye ZHANG,Yangmei ZHANG,Lu ZHANG,Ruxia FAN

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0833-2

摘要： New particle formation (NPF) event at multi rural sites in China Identifying the characteristics of NPF event Comparing NPF event between clean and polluted conditions Quantifying contribution to the cloud condensation nuclei Implication of climate and air quality Long-term continuous measurements of particle number size distributions with mobility diameter sizes ranging from 3 to 800 nm were performed to study new particle formation (NPF) events at Shangdianzi (SDZ), Mt. Tai (TS), and Lin’an (LAN) stations representing the background atmospheric conditions in the North China Plain (NCP), Central East China (CEC), and Yangtze River Delta (YRD) regions, respectively. The mean formation rate of 3-nm particles was 6.3, 3.7, and 5.8 cm ·s , and the mean particle growth rate was 3.6, 6.0, and 6.2 nm·h at SDZ, TS, and LAN, respectively. The NPF event characteristics at the three sites indicate that there may be a stronger source of low volatile vapors and higher condensational sink of pre-existing particles in the YRD region. The formation rate of NPF events at these sites, as well as the condensation sink, is approximately 10 times higher than some results reported at rural/urban sites in western countries. However, the growth rates appear to be 1–2 times higher. Approximately 12%–17% of all NPF events with nucleated particles grow to a climate-relevant size (>50 nm). These kinds of NPF events were normally observed with higher growth rate than the other NPF cases. Generally, the cloud condensation nuclei (CCN) number concentration can be enhanced by approximately a factor of 2–6 on these event days. The mean value of the enhancement factor is lowest at LAN (2–3) and highest at SDZ (~4). NPF events have also been found to have greater impact on CCN production in China at the regional scale than in the other background sites worldwide.

关键词： New particle formation Regional background Cloud condensation nuclei Growth rate Formation rate

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On secondary new particle formation in China

Markku Kulmala,Tuukka Petäjä,Veli-Matti Kerminen,Joni Kujansuu,Taina Ruuskanen,Aijun Ding,Wei Nie,Min Hu,Zhibin Wang,Zhijun Wu,Lin Wang,Douglas R. Worsnop

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0850-1

摘要： Formation of new atmospheric aerosol particles is a global phenomenon that has been observed to take place in even heavily-polluted environments. In China, new particle production has been observed at very high pollution levels (condensation sink about 0.1s ) in several megacities. A holistic scientific understanding on the atmospheric phenomena associated with air quality as a whole, as well as on the connection between air quality and climate, is lacking at the moment.With a network of observation stations, we will be able to understand the interactions and feedbacks associated with the urban pollution mixture, and ultimately, are ready to make targeted strategies for the pollution control. This paper summaries the recent advances in studying secondary new aerosol formation in China and shows how increased process-level understanding will help us to understand air quality-climate-weather interactions and how the feedbacks and interactions affect the air quality in highly-polluted environments such as those frequently encountered in Chinese megacities. Formation of new atmospheric aerosol particles is a global phenomenon that has been observed to take place in even heavily-polluted environments. However, in all environments there appears to be a threshold value of the condensation sink (due to pre-existing aerosol particles) after which the formation rate of 3 nm particles is no longer detected. In China, new particle production has been observed at very high pollution levels (condensation sink about 0.1 s ) in several megacities, including Beijing, Shanghai and Nanjing as well as in Pearl River Delta (PRD). Here we summarize the recent findings obtained from these studies and discuss the various implications these findings will have on future research and policy.

关键词： Aerosol particles Heavily-polluted environments Condensation sink New particle production Megacities

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Temporal evolution of charged and neutral nanoparticle concentrations during atmospheric new particleformation events and its implications for ion-induced nucleation

E. Rohan Jayaratne, Buddhi Pushpawela, Lidia Morawska

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0862-x

摘要： Over 100 new particle formation events were studied. In 50 events, charged and neutral particles were not formed at the same time. In 42 of these events the charged particles formed before the neutral particles. Their subsequent growth rates were not determined by the particle charge. The result suggests that ion induced nucleation plays a role in particle formation. Time series of nanoparticle number concentration during new particle formation (NPF) events in the urban environment of Brisbane, Australia, showed that the formation of charged particles often occurred before that of neutral particles. We monitored 241 days during the calendar year 2012 over which NPF events were observed on 108 days. We studied the times at which the charged and neutral particle concentrations in the size range 1.8–3.2 nm reached their peak values and found that they were clearly different in 50 events with the peak neutral particle concentration lagging behind the charged particle concentration during 42 of these events with a mean time lag of 24±12 min. While the charged particles were more likely to form before the neutral particles, once formed, the growth rate of the particles did not depend on their charge. While ion-induced nucleation is not the dominant mechanism of NPF in the atmosphere, our observations suggest that the presence of ions in the atmosphere plays a role that cannot be ignored.

关键词： Charged particles Cluster ions Secondary particles Environmental pollution

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Erratum to: On secondary new particle formation in China

Markku KULMAMA,Tuukka Petäjä,Veli-Matti KERMINEN,Joni KUJANSUU,Taina RUUSKANEN,Aijun DING,Wei NIE,Min HU,Zhibin WANG,Zhijun WU,Lin WANG,Douglas R. WORSNOP

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0857-7

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Particle formation of hydroxyapatite precursor containing two components in a spray pyrolysis process

W. Widiyastuti, Adhi Setiawan, Sugeng Winardi, Tantular Nurtono, Heru Setyawan

《化学科学与工程前沿（英文）》 2014年第8卷第1期页码 104-113 doi: 10.1007/s11705-014-1406-1

摘要： The particle formation mechanism of hydroxyapatite precursor containing two components, Ca(OOCCH ) and (NH ) HPO with a ratio of Ca/P= 1.67, in a spray pyrolysis process has been studied by computational fluid dynamics (CFD) simulation on the transfer of heat and mass from droplets to the surrounding media. The focus included the evaporation of the solvent in the droplets, a second evaporation due to crust formation, the decomposition reaction of each component of the precursor, and a solid-state reaction that included the kinetic parameters of the precursor regarding its two components that formed the hydroxyapatite product. The rate of evaporation and the reacted fraction of the precursor both increased with temperature. The predicted average size of the hydroxyapatite particles agreed well with the experimental results. Therefore, the selected models were also suitable for predicting the average size of particles that contain two components in the precursor solution.

关键词： droplet hydroxyapatite particle CFD tubular furnace spray pyrolysis

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Particle therapy for cancers: a new weapon in radiation therapy

null

《医学前沿（英文）》 2012年第6卷第2期页码 165-172 doi: 10.1007/s11684-012-0196-4

摘要：

Particle irradiation started to draw attention in the past decade and has now become a hotspot in the radiation oncology community. This article reviews the most advanced developments in particle irradiation, focusing on the characteristics of proton and carbon ions in radiation physics and radiobiology. The Bragg peak of physical dose distribution causes proton and carbon beams to optimally meet the requirement for cancer irradiation because the Bragg peak permits the accurate concentration of the dose on the tumor, thus sparing the adjacent normal tissues. Moreover, carbon ion has more radiobiological benefits than photon and proton beams. These benefits include stronger sterilization effects on intrinsic radio-resistant tumors and more effective killing of hypoxic, G₀, and S phase cells. Compared with the most advanced radiation techniques using photon, such as three-dimensional conformal radiation therapy and intensity-modulated radiation therapy, proton therapy has yielded more promising outcomes in local control and survival for head and neck cancers, prostate carcinoma, and pediatric cancers. Carbon therapy in Japan showed even more promising results than proton therapy. The local controls and overall survivals were as good as that treated by surgery in early stages of non-small cell lung cancer, hepatocellular carcinoma, prostate carcinoma, and head and neck cancers, especially for such highly resistant tumors as melanoma. The non-invasive nature of particle therapy affords more patients with chances to receive and benefit from treatment. Particle therapy is gradually getting attention from the oncology community. However, the cost of particle therapy facilities has limited the worldwide use of this technology.

关键词： radiation therapy particle therapy proton carbon cancer

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Crack detection of the cantilever beam using new triple hybrid algorithms based on Particle Swarm Optimization

Amin GHANNADIASL; Saeedeh GHAEMIFARD

《结构与土木工程前沿（英文）》 2022年第16卷第9期页码 1127-1140 doi: 10.1007/s11709-022-0838-9

摘要： The presence of cracks in a concrete structure reduces its performance and increases in the size of cracks result in the failure of the structure. Therefore, the accurate determination of crack characteristics, such as location and depth, is one of the key engineering issues for assessment of the reliability of structures. This paper deals with the inverse analysis of the crack detection problems using triple hybrid algorithms based on Particle Swarm Optimization (PSO); these hybrids are Particle Swarm Optimization-Genetic Algorithm-Firefly Algorithm (PSO-GA-FA), Particle Swarm Optimization-Grey Wolf Optimization-Firefly Algorithm (PSO-GWO-FA), and Particle Swarm Optimization-Genetic Algorithm-Grey Wolf Optimization (PSO-GA-GWO). A strong correlation exists between the changes in the natural frequency of a concrete beam and the crack parameters. Thus, the location and depth of a crack in a beam can be predicted by measuring its natural frequency. Hence, the measured natural frequency can be used as the input parameter of the algorithm. In this paper, this is applied to identify crack location and depth in a cantilever beam using the new hybrid algorithms. The results show that among the proposed triple hybrid algorithms, the PSO-GA-FA and PSO-GWO-FA algorithms are much more effective than PSO-GA-GWO algorithm for the crack detection.

关键词： crack cantilever beam triple hybrid algorithms Particle Swarm Optimization

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New insights into the formation of ammonium nitrate from a physical and chemical level perspective

《环境科学与工程前沿（英文）》 2023年第17卷第11期 doi: 10.1007/s11783-023-1737-6

摘要：

● Factor analysis of ammonium nitrate formation based on thermodynamic theory.

关键词： Ammonium nitrate formation Thermodynamic theory Aerosol liquid water content Source apportionment

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Resampling methods for particle filtering: identical distribution, a new method, and comparable study

Tian-cheng LI,Gabriel VILLARRUBIA,Shu-dong SUN,Juan M. CORCHADO,Javier BAJO

《信息与电子工程前沿（英文）》 2015年第16卷第11期页码 969-984 doi: 10.1631/FITEE.1500199

摘要： Resampling is a critical procedure that is of both theoretical and practical significance for efficient implementation of the particle filter. To gain an insight of the resampling process and the filter, this paper contributes in three further respects as a sequel to the tutorial (Li et al., 2015). First, identical distribution (ID) is established as a general principle for the resampling design, which requires the distribution of particles before and after resampling to be statistically identical. Three consistent metrics including the (symmetrical) Kullback-Leibler divergence, Kolmogorov-Smirnov statistic, and the sampling variance are introduced for assessment of the ID attribute of resampling, and a corresponding, qualitative ID analysis of representative resampling methods is given. Second, a novel resampling scheme that obtains the optimal ID attribute in the sense of minimum sampling variance is proposed. Third, more than a dozen typical resampling methods are compared via simulations in terms of sample size variation, sampling variance, computing speed, and estimation accuracy. These form a more comprehensive understanding of the algorithm, providing solid guidelines for either selection of existing resampling methods or new implementations.

关键词： Particle filter Resampling Kullback-Leibler divergence Kolmogorov-Smirnov statistic

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Formation of free-charging industry alliance for new energy vehicles

Zhengdong YANG, Feng JIN, Shiyu DU, Jingwen LI

《工程管理前沿（英文）》 2018年第5卷第2期页码 268-275 doi: 10.15302/J-FEM-2018058

摘要： At present, the further development of new energy vehicles industry is hindered by limited consumer’s participation or capital investment. Therefore, a new multilateral model of cross-industry alliance needs to arise. The advanced charging technology of Internet-distributed mobile energy can link up with many market participants closely and form an effective and multilateral win-win cross-industry alliance. This new industry alliance can realize unexpected multiple goals, for example, (1) consumers who have purchased new energy vehicles can avail free charging; (2) potential vehicle buyers can be encouraged to use new energy vehicles; (3) the new energy vehicle manufacturers can expand their production scale; (4) the new energy vehicles sellers (4S shop) can expand their sales volume; (5) large shopping malls can attain more income; (6) financial institutions can absorb more deposits; (7) governments can further promote low-carbon traffic. This article analyzes the cross-industry alliance and its forming mechanism.

关键词： industry alliance mobile energy new energy vehicles free charging low carbon

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上海海洋新城建设构想

宗源远,王志群,阮伟,楼飞

《中国工程科学》 2013年第15卷第6期页码 25-29

摘要：

上海肩负着建设“四个中心”的重任，同时又面临着众多的发展瓶颈，其中土地资源的短缺是制约上海发展的重要因素。横沙岛是一个集“区位、土地、岸线、航道”等众多优势资源于一身的区域，其可成陆的土地面积约为480 km2，可形成的岸线近100 km，同时利用其东侧直接面向大海的优势，有建设深水大港的条件。横沙新城的建设即可突破城市瓶颈，再造第二个“浦东”，为未来上海的发展提供广阔空间。

关键词：上海横沙岛造陆海洋新城构想

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Catalyst particle shapes and pore structure engineering for hydrodesulfurization and hydrodenitrogenation

《化学科学与工程前沿（英文）》 2022年第16卷第6期页码 897-908 doi: 10.1007/s11705-021-2127-x

摘要： Catalyst particle shapes and pore structure engineering are crucial for alleviating internal diffusion limitations in the hydrodesulfurization (HDS)/hydrodenitrogenation (HDN) of gas oil. The effects of catalyst particle shapes (sphere, cylinder, trilobe, and tetralobe) and pore structures (pore diameter and porosity) on HDS/HDN performance at the particle scale are investigated via mathematical modeling. The relationship between particle shape and effectiveness factor is first established, and the specific surface areas of different catalyst particles show a positive correlation with the average HDS/HDN reaction rates. The catalyst particle shapes primarily alter the average HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor. An optimal average HDS/HDN reaction rate exists as the catalyst pore diameter and porosity increase, and this optimum value indicates a tradeoff between diffusion and reaction. In contrast to catalyst particle shapes, the catalyst pore diameter and the porosity of catalyst particles primarily alter the surface HDS/HDN reaction rate to adjust the HDS/HDN effectiveness factor. This study provides insights into the engineering of catalyst particle shapes and pore structures for improving HDS/HDN catalyst particle efficiency.

关键词： hydrodesulfurization hydrodenitrogenation particle shape pore structure

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A novel light fluctuation spectrum method for in-line particle sizing

Shouxuan QIN, Xiaoshu CAI, Li MA

《能源前沿（英文）》 2012年第6卷第1期页码 89-97 doi: 10.1007/s11708-012-0176-z

摘要： This paper discusses two problems in in-line particle sizing when using light fluctuation method. First, by retrieving the ratio of particle concentrations at different time, the intensity of incident light is obtained. There exists narrow error between the calculated and pre-detected value of the intensity of incident light. Secondly, by combining spectrum analysis with Gregory’s theory, a multi-sub-size zone model is proposed, with which the relationship between the distribution of turbidity and the particle size distribution (PSD) can be established, and an algorithm developed to determine the distribution of turbidity. Experiments conducted in the laboratory indicate that the measured size distribution of pulverized coal conforms well with the imaging result.

关键词： in-line measurement particle size distribution (PSD) incident light intensity particle concentration light fluctuation

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Time-varying formation tracking for uncertain second-order nonlinearmulti-agent systems

Mao-peng RAN, Li-hua XIE, Jun-cheng LI

《信息与电子工程前沿（英文）》 2019年第20卷第1期页码 76-87 doi: 10.1631/FITEE.1800557

摘要：

Our study is concerned with the time-varying formation tracking problem for second-order multi-agent systems that are subject to unknown nonlinear dynamics and external disturbance, and the states of the followers form a predefined time-varying formation while tracking the state of the leader. The total uncertainty lumps the unknown nonlinear dynamics and the external disturbance, and is regarded as an extended state of the agent. To estimate the total uncertainty, we design an extended state observer (ESO). Then we propose a novel ESO based time-varying formation tracking protocol. It is proved that, under the proposed protocol, the ESO estimation error and the time-varying formation tracking error can be made arbitrarily small. An application to the target enclosing problem for multiple unmanned aerial vehicles (UAVs) verifies the effectiveness and superiority of the proposed approach.

关键词： Multi-agent system Time-varying formation Formation tracking Nonlinear dynamics Extended state observer (ESO)

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Independent cover meshless particle method for complex geotechnical engineering

Jianqiu WU, Yongchang CAI

《结构与土木工程前沿（英文）》 2018年第12卷第4期页码 515-526 doi: 10.1007/s11709-017-0428-4

摘要： A new Independent Cover Meshless Particle (ICMP) method is proposed for the analysis of complex geotechnical engineering. In the ICMP method, the independent rectangular cover regardless of the shape of the analysis model is employed as the influence domain of each discrete node, the general polynomial is employed as the meshless interpolation function of the independent nodal cover, and the Cartesian Transformation Method (CTM) is used for the numerical integration of the nodal covers cut by material interfaces, joints, cracks and faults. The present method has a simple formulation and a low computational cost, and is easy for the numerical analysis and modeling of complex geotechnical engineering. Several typical numerical examples are presented to demonstrate the accuracy and robustness of the proposed method.

关键词： meshless method particle method independent cover CTM geotechnical engineering

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标题作者时间类型操作

Key features of new particle formation events at background sites in China and their influence on cloud

Xiaojing SHEN,Junying SUN,Xiaoye ZHANG,Yangmei ZHANG,Lu ZHANG,Ruxia FAN

期刊论文

On secondary new particle formation in China

Markku Kulmala,Tuukka Petäjä,Veli-Matti Kerminen,Joni Kujansuu,Taina Ruuskanen,Aijun Ding,Wei Nie,Min Hu,Zhibin Wang,Zhijun Wu,Lin Wang,Douglas R. Worsnop

期刊论文

Temporal evolution of charged and neutral nanoparticle concentrations during atmospheric new particleformation events and its implications for ion-induced nucleation

E. Rohan Jayaratne, Buddhi Pushpawela, Lidia Morawska

期刊论文

Erratum to: On secondary new particle formation in China

Markku KULMAMA,Tuukka Petäjä,Veli-Matti KERMINEN,Joni KUJANSUU,Taina RUUSKANEN,Aijun DING,Wei NIE,Min HU,Zhibin WANG,Zhijun WU,Lin WANG,Douglas R. WORSNOP

期刊论文

Particle formation of hydroxyapatite precursor containing two components in a spray pyrolysis process

W. Widiyastuti, Adhi Setiawan, Sugeng Winardi, Tantular Nurtono, Heru Setyawan

期刊论文

Particle therapy for cancers: a new weapon in radiation therapy

null

期刊论文

Crack detection of the cantilever beam using new triple hybrid algorithms based on Particle Swarm Optimization

Amin GHANNADIASL; Saeedeh GHAEMIFARD

期刊论文

New insights into the formation of ammonium nitrate from a physical and chemical level perspective

期刊论文