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Particle size distributions, PM

Can DONG, Lingxiao YANG, Chao YAN, Qi YUAN, Yangchun YU, Wenxing WANG

《环境科学与工程前沿（英文）》 2013年 第7卷 第1期   页码 55-65 doi: 10.1007/s11783-012-0411-1

摘要： In this study, we collected particles with aerodynamic diameter≤2.5 μm (PM ) from three different public indoor places (a supermarket, a commercial office, and a university dining hall) in Jinan, a medium-sized city located in northern China. Water-soluble inorganic ions of PM and particle size distributions were also measured. Both indoor and outdoor PM levels (102.3–143.8 μg·m and 160.2–301.3 μg·m , respectively) were substantially higher than the value recommended by the World Health Organization (25 μg·m ), and outdoor sources were found to be the major contributors to indoor pollutants. Diurnal particle number size distributions were different, while the maximum volume concentrations all appeared to be approximately 300 nm in the three indoor locations. Concentrations of indoor and outdoor PM were shown to exhibit the same variation trends for the supermarket and dining hall. For the office, PM concentrations during nighttime were observed to decrease sharply. Among others, , and were found to be the dominant water-soluble ions of both indoor and outdoor particles. Concentrations of in the supermarket and office during the daytime were observed to decrease sharply, which might be attributed to the fact that the indoor temperature was much higher than the outdoor temperature. In addition, domestic activities such as cleaning, water usage, cooking, and smoking also played roles in degraded indoor air quality. However, the results obtained here might be negatively impacted by the small number of samples and short sampling durations.

关键词： indoor air quality     indoor/outdoor ratios     size distributions     particles with aerodynamic diameter≤2.5 μm (PM2.5)     water-soluble ions    

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A spectrometer for measuring particle size distributions in the range of 3 nm to 10 μm

Jieqiong LIU,Jingkun JIANG,Qiang ZHANG,Jianguo DENG,Jiming HAO

《环境科学与工程前沿（英文）》 2016年 第10卷 第1期   页码 63-72 doi: 10.1007/s11783-014-0754-x

摘要： A spectrometer combining electrical mobility sizing and aerodynamic sizing was developed to measure aerosol size distributions in the range of 3 nm to 10 μm. It includes three instruments which cover different size ranges (a nano scanning mobility particle sizer (NSMPS, 3 – 60 nm), a regular scanning mobility particle sizer (RSMPS, 40 – 700 nm), and an aerodynamic particle sizer (APS, 550 nm – 10 μm)). High voltage and sheath flow of the NSMPS and RSMPS were supplied using two home-built control boxes. A LabVIEW program was developed for spectrometer automatic operation. A linear inversion method was applied to correct particle multiple charging effects and to integrate data from the three instruments into a wide-range size distribution. Experiments were conducted to compare distributions in the overlap size ranges measured by three instruments. Good agreement between the NSMPS and RSMPS was achieved after correcting for the difference in counting efficiencies of the two particle counters. Aerodynamic size distributions reported by the APS were converted to mobility size distributions by applying an effective density method. Distributions measured by the RSMPS and APS were consistent in the overlap size range of 550 – 700 nm. A full spectrum in the size range of 3 nm to 10 μm was demonstrated by measuring aerosol generated using a mixture of different sized polystyrene latex spheres.

关键词： spectrometer     particle size distribution     electrical mobility     linear inversion     aerodynamic diameter    

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Comparison of droplet distributions from fluidic and impact sprinklers

Xingye ZHU,Shouqi YUAN,Junping LIU,Xingfa LIU

《农业科学与工程前沿（英文）》 2015年 第2卷 第1期   页码 53-59 doi: 10.15302/J-FASE-2015049

摘要： To adapt to the trend toward low-energy precision irrigation, the droplet distributions for two new prototype sprinklers, outside signal sprinkler (OS) and fluidic sprinkler (FS), were compared with impact sprinkler (IS). A laser precipitation monitor was used to measure the droplet distributions. Droplet size and velocity distributions were tested under four operating pressures for nozzles 1.5 m above the ground. For the operating pressures tested, the mean OS, FS and IS droplet diameters ranged from 0 to 3.4, 0 to 3.5, 0 to 4.0 mm, respectively. The mean OS and FS droplet velocities ranged from 0 to 6.3 m·s , whereas IS ranged from 0 to 6.3 m·s . Being gas-liquid fluidic sprinklers, droplet distributions of the OS and FS were similar, although not identical. IS mostly produced a 0.5 mm larger droplet diameter and a 0.5 m·s greater velocity than OS and FS. A new empirical equation is proposed for determination of droplet size for OS and FS, which is sufficiently accurate and simple to use. Basic statistics for droplet size and velocity were performed on data obtained by the photographic methods. The mean droplet diameter (arithmetic, volumetric and median) decreased and the mean velocity increased in operating pressure for the three types of sprinkler.

关键词： outside signal sprinkler     fluidic sprinkler     impact sprinkler     sprinkler irrigation     droplet size     droplet velocity    

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Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China

Xinfeng WANG, Wenxing WANG, Likun XUE, Xiaomei GAO, Wei NIE, Yangchun YU, Yang ZHOU, Lingxiao YANG, Qingzhu ZHANG, Tao WANG

《环境科学与工程前沿（英文）》 2013年 第7卷 第6期   页码 815-826 doi: 10.1007/s11783-013-0503-6

摘要： To understand the size-resolved aerosol ionic composition and the factors influencing secondary aerosol formation in the upper boundary layer in South Central China, size-segregated aerosol samples were collected using a micro-orifice uniform deposit impactor (MOUDI) in spring 2009 at the summit of Mount Heng (1269 m asl), followed by subsequent laboratory analyses of 13 inorganic and organic water-soluble ions. During non-dust-storm periods, the average PM concentration was 41.8 μg·m , contributing to 55% of the PM . Sulfates, nitrates, and ammonium, the dominant ions in the fine particles, amounted to 46.8% of the PM . Compared with Mount Tai in the North China Plain, the concentrations of both fine and coarse particles and the ions contained therein were substantially lower. When the air masses from Southeast Asia prevailed, intensive biomass burning there led to elevated concentrations of sulfates, nitrates, ammonium, potassium, and chloride in the fine particles at Mount Heng. The air masses originating from the north Gobi brought heavy dust storms that resulted in the remarkable production of sulfates, ammonium, methane sulfonic acid, and oxalates in the coarse particles. Generally, the sulfates were primarily produced in the form of (NH ) SO in the droplet mode via heterogeneous aqueous reactions. Only approximately one-third of the nitrates were distributed in the fine mode, and high humidity facilitated the secondary formation of fine nitrates. The heterogeneous formation of coarse nitrates and ammonium on dry alkaline dust surfaces was found to be less efficient than that on the coarse particles during non-dust-storm periods.

关键词： aerosol water-soluble ions     size distributions     secondary formation     dust storm     Mount Heng    

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Differences in distributions, assembly mechanisms, and putative interactions of AOB and NOB at a large

《环境科学与工程前沿（英文）》 2023年 第17卷 第10期 doi: 10.1007/s11783-023-1722-0

摘要：

● Nitrifiers in WWTP were investigated at large spatial scale.

关键词： Activated sludge     Spatial distributions     Microbial assembly     Co-occurrence patterns     Nitrifying bacteria    

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Seismic responses of subway station with different distributions of soft soil in Tianjin

Dejian YANG,Meiling DUAN

《结构与土木工程前沿（英文）》 2014年 第8卷 第2期   页码 187-193 doi: 10.1007/s11709-014-0252-z

摘要： In connection with the practical project of Kunming Road station of Tianjin subway Line 3, the paper established a two-dimensional finite element model with visco-elastic boundary by using ANSYS and analyzed seismic responses of subway station with different distribution of soft soil. The nonlinear dynamic properties of soft soils are modeled by the KINH. And obtain the response rules about displacement and internal force on subway station in the general field soil and five different distributions of soft soil. Provide reference for improving the seismic performance of subway stations in Tianjin soft soil.

关键词： distribution of soft soil     soft soil in Tianjin     seismic response     ANSYS    

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Effect of distributions of fuel concentration and temperature on ignition processes in a diesel PCCI

Yang YU, Wanhua SU,

《能源前沿（英文）》 2010年 第4卷 第2期   页码 269-279 doi: 10.1007/s11708-009-0046-5

摘要： The distributions of fuel concentration and temperature have significant effect on the ignition processes of diesel premixed charge compression ignition (PCCI) combustion. It was found in this study that the ignition process of PCCI combustion organized by multi-pulse injection was strongly influenced by conditions of fuel stratification. The start of low temperature reactions occurred in the leaner area of the combustion chamber in the test engine because the temperature here first reached the point of low temperature reactions. Ignition always occurred in the position where the mixture featured with equivalence ratios close to the mean equivalence ratio of the overall mixture, while the neighboring area of the initial ignition area accumulate heat with a finite speed until finally autoigniting. Moreover, the appearance of highest combustion temperature occurred in the same area at the combustion chamber. For more homogeneous mixture, a higher amount of mixture reached ignition simultaneously, resulting in a larger initial ignition area and a higher temperature at the ignition area. Furthermore, V-type distribution of equivalence ratio was found to be beneficial to retarding high temperature reaction.

关键词： PCCI     fuel stratification     multi-pulse injection     ignition    

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Analysis of radiation heat transfer and temperature distributions of solar thermochemical reactor for

Bachirou GUENE LOUGOU, Yong SHUAI, Xiang CHEN, Yuan YUAN, Heping TAN, Huang XING

《能源前沿（英文）》 2017年 第11卷 第4期   页码 480-492 doi: 10.1007/s11708-017-0506-2

摘要： This paper investigated radiation heat transfer and temperature distributions of solar thermochemical reactor for syngas production using the finite volume discrete ordinate method (fvDOM) and P1 approximation for radiation heat transfer. Different parameters including absorptivity, emissivity, reflection based radiation scattering, and carrier gas flow inlet velocity that would greatly affect the reactor thermal performance were sufficiently investigated. The fvDOM approximation was used to obtain the radiation intensity distribution along the reactor. The drop in the temperature resulted from the radiation scattering was further investigated using the P1 approximation. The results indicated that the reactor temperature difference between the P1 approximation and the fvDOM radiation model was very close under different operating conditions. However, a big temperature difference which increased with an increase in the radiation emissivity due to the thermal non-equilibrium was observed in the radiation inlet region. It was found that the incident radiation flux distribution had a strong impact on the temperature distribution throughout the reactor. This paper revealed that the temperature drop caused by the boundary radiation heat loss should not be neglected for the thermal performance analysis of solar thermochemical reactor.

关键词： solar thermochemical reactor     incident radiation flux     temperature distribution     radiation absorptivity     radiation emissivity     thermal performance analysis    

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The size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

《环境科学与工程前沿（英文）》 2021年 第15卷 第3期 doi: 10.1007/s11783-020-1356-4

摘要：

•Bacterial concentrations from eight stages were 104–105copies/m3.

关键词： Size distribution     Airborne bacteria     Biological diversity     Human pathogenic bacteria     Composting plants    

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Particle size distribution and shape control of Au nanoparticles used for particle gun

S. Kida, M. Ichiji, J. Watanabe, I. Hirasawa

《化学科学与工程前沿（英文）》 2013年 第7卷 第1期   页码 60-64 doi: 10.1007/s11705-013-1313-x

摘要： Au nanoparticles are expected for the media to transfer genes into plants. However, the control of particle size distribution (PSD) and shape of Au nanoparticles is too difficult to design and prepare particles with suitable quality for the gene supporting media. Reduction crystallization experiments were performed in aqueous solution in order to clarify the effect of feeding conditions such as feeding profile, feeding rate, and feeding amount on PSD and shape of Au nanoparticles. Ascorbic acid (AsA) was selected as a reducing agent because it is safe for plants. Au particles of 50 nm, 50–200 nm, and 150–400 nm were obtained in batch operation, single-jet, and double-jet, respectively. Moreover, in single-jet and double-jet, the mean size of the obtained Au particles increases with the decrease of feeding rate or the increase of feeding amount. It is concluded that PSD of Au nanoparticles can be controlled in the range of 50–400 nm by changing feeding conditions of AsA and HAuCl aqueous solution.

关键词： reduction crystallization     particle size distribution     gene transferring media    

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Diversity and vertical distributions of sediment bacteria in an urban river contaminated by nutrients

Xunan YANG, Shan HUANG, Qunhe WU, Renduo ZHANG, Guangli LIU

《环境科学与工程前沿（英文）》 2013年 第7卷 第6期   页码 851-859 doi: 10.1007/s11783-013-0569-1

摘要： The aim of this study was to investigate the benthic bacterial communities in different depths of an urban river sediment accumulated with high concentrations of nutrients and metals. Vertical distributions of bacterial operational taxonomic units (OTUs) and chemical parameters (nutrients: , , dissolved organic carbon, and acid volatile sulfur; metals: Fe, Zn, and Cu) were characterized in 30 cm sediment cores. The bacterial OTUs were measured using the terminal restriction fragment length polymorphism analysis. Biodiversity indexes and multivariate statistical analyses were used to characterize the spatial distributions of microbial diversity in response to the environmental parameters. Results showed that concentrations of the nutrients and metals in this river sediment were higher than those in similar studies. Furthermore, high microbial richness and diversity appeared in the sediment. The diversity did not vary obviously in the whole sediment profile. The change of the diversity indexes and the affiliations of the OTUs showed that the top layer had different bacterial community structure from deeper layers due to the hydrological disturbance and redox change in the surface sediment. The dominant bacterial OTUs ubiquitously existed in the deeper sediment layers (5–27 cm) corresponding to the distributions of the nutrients and metals. With much higher diversity than the dominant OTUs, the minor bacterial assemblages varied with depths, which might be affected by the sedimentation process and the environmental competition pressure.

关键词： heavy metals     nutrients     sediment profile     terminal restriction fragment length polymorphism    

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A better way to do small-for-size liver transplantation in rats

null

《医学前沿（英文）》 2011年 第5卷 第1期   页码 106-110 doi: 10.1007/s11684-011-0113-2

摘要：

Establishing a model for small-for-size liver transplantation is the basis for this study of partial and living donor graft liver transplantation. This study aims to explore a simpler and more effective way of establishing a 30% small-for-size liver transplantation in rats. Sprague-Dawley rats were selected as the donors and recipients. Small-for-size orthotopic liver transplantation was performed using Kamada’s two-cuff method. The donor’s liver was flushed via the abdominal aorta and hepatectomy was performed in situ. The animals were divided into three groups depending on the graft selected, with 40 pairs of rats in each group. In group I, the median lobe of the liver was used as graft; in group II, the right half of the median lobe and the right lobe were used as graft; and in group III, the median and right lobes were used as graft. In groups I and II, the bodyweights of donors were the same as those of recipients; however, in group III the bodyweights of donors were 100–120 g less than those of the recipients. The duration needed for transplantation, the 7-day survival rates, and the technical complication rates were compared among these three groups. The time required for hepatectomy was shorter in group III compared with groups I and II (8.8?±?0.7 min vs. 11.5?±?1.1 min and 10.1?±?1.0 min, P = 0.001). The cold ischemia time for the grafts, the anhepatic times, and the transplantation times for the recipients were not significantly different among the three groups. Compared with groups I and II, the incidence of bleeding, bile leakage, and inferior vena caval strictures were significantly decreased in group III (P<0.05). No significant differences between the three groups were found based on other complications after the operation (P>0.05). Group III had better 7-day survival rates and longer median survival times but the differences were not statistically significant. The method of small for donor bodyweight using the median and right lobes for grafting may be a more effective and simpler way of establishing a 30% small-for-size liver transplantation in rats, as shown by the shorter hepatectomy time and the occurrence of fewer complications after the operation.

关键词： liver transplantation     small-for-size     rats    

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Effect of Cu-ZSM-5 catalysts with different CuO particle size on selective catalytic oxidation of N,N-Dimethylformamide

《环境科学与工程前沿（英文）》 2022年 第16卷 第10期 doi: 10.1007/s11783-022-1557-0

摘要：

● A series of Cu-ZSM-5 catalysts were tested for DMF selective catalytic oxidation.

关键词： N     N-Dimethylformamide     Selective catalytic oxidation     Cu-ZSM-5     CuO particle size    

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Probability distributions of arsenic in soil from brownfield sites in Beijing (China): statistical characterization

Marina ACCORNERO,Lin JIANG,Eugenio NAPOLI,Marco CREMONINI,Giovanni FERRO,Federica BELLORO,Maosheng ZHONG

《环境科学与工程前沿（英文）》 2015年 第9卷 第3期   页码 465-474 doi: 10.1007/s11783-014-0678-5

摘要： A probabilistic analysis was performed on soil arsenic concentration data from 4 brownfield sites at Beijing (Chaoyang and Haidian Districts), involved in environmental assessment studies. The available data sets were processed to provide a statistical characterization of the background populations and differentiate “anomalous data” from the natural range of variation of arsenic concentrations in soil. The site-specific background distributions and the existing wide-scale background values defined for the Beijing area were compared, discussing related implications for the definition of metal contamination soil screening levels (SSLs) in site assessment studies. The statistical analysis of As data sets discriminated site-specific background populations, encompassing 88% to 94% of the sample data, from outliers values, associated with either subsoil natural enrichments or possible anthropogenic releases. Upper Baseline Concentration ( ) limits (+ 2 level), including most of the site-specific metal background variability, were derived based on the statistical characterization of the background populations. Sites in the Chaoyang South District area had values in the range 10.4–12.6 mg·kg . These ranges provide meaningful SSL values to be adopted for As in local site assessment studies. Using the wide-scale background value for the Beijing area would have erroneously classified most of the areas in the subject sites as potentially contaminated.

关键词： upper baseline concentration     site assessment     arsenic     probability plot    

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Influence of surface cracking, anchor head profile, and anchor head size on cast-in headed anchors in

《结构与土木工程前沿（英文）》   页码 1163-1187 doi: 10.1007/s11709-023-0987-5

摘要： In this study, the concrete cone capacity, concrete cone angle, and load–displacement response of cast-in headed anchors in geopolymer concrete are explored using numerical analyses. The concrete damaged plasticity (CDP) model in ABAQUS is used to simulate the behavior of concrete substrates. The tensile behavior of anchors in geopolymer concrete is compared with that in normal concrete as well as that predicted by the linear fracture mechanics (LFM) and concrete capacity design (CCD) models. The results show that the capacity of the anchors in geopolymer concrete is 30%–40% lower than that in normal concrete. The results also indicate that the CCD model overestimates the capacity of the anchors in geopolymer concrete, whereas the LFM model provides a much more conservative prediction. The extent of the difference between the predictions by the numerical analysis and those of the above prediction models depends on the effective embedment depth of the anchor and the anchor head size. The influence of concrete surface cracking on the capacity of the anchor is shown to depend on the location of the crack and the effective embedment depth. The influence of the anchor head profile on the tensile capacity of the anchors is found to be insignificant.

关键词： cast-in anchor     concrete cone capacity     geopolymer concrete     head size     surface crack     anchor profile    

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标题 作者 时间 类型 操作

Particle size distributions, PM

Can DONG, Lingxiao YANG, Chao YAN, Qi YUAN, Yangchun YU, Wenxing WANG

期刊论文

A spectrometer for measuring particle size distributions in the range of 3 nm to 10 μm

Jieqiong LIU,Jingkun JIANG,Qiang ZHANG,Jianguo DENG,Jiming HAO

期刊论文

Comparison of droplet distributions from fluidic and impact sprinklers

Xingye ZHU,Shouqi YUAN,Junping LIU,Xingfa LIU

期刊论文

Size-resolved aerosol ionic composition and secondary formation at Mount Heng in South Central China

Xinfeng WANG, Wenxing WANG, Likun XUE, Xiaomei GAO, Wei NIE, Yangchun YU, Yang ZHOU, Lingxiao YANG, Qingzhu ZHANG, Tao WANG

期刊论文

Differences in distributions, assembly mechanisms, and putative interactions of AOB and NOB at a large

期刊论文

Seismic responses of subway station with different distributions of soft soil in Tianjin

Dejian YANG,Meiling DUAN

期刊论文

Effect of distributions of fuel concentration and temperature on ignition processes in a diesel PCCI

Yang YU, Wanhua SU,

期刊论文

Analysis of radiation heat transfer and temperature distributions of solar thermochemical reactor for

Bachirou GUENE LOUGOU, Yong SHUAI, Xiang CHEN, Yuan YUAN, Heping TAN, Huang XING

期刊论文

The size distribution of airborne bacteria and human pathogenic bacteria in a commercial composting plant

期刊论文

Particle size distribution and shape control of Au nanoparticles used for particle gun

S. Kida, M. Ichiji, J. Watanabe, I. Hirasawa

期刊论文

Diversity and vertical distributions of sediment bacteria in an urban river contaminated by nutrients

Xunan YANG, Shan HUANG, Qunhe WU, Renduo ZHANG, Guangli LIU

期刊论文

A better way to do small-for-size liver transplantation in rats

null

期刊论文

Effect of Cu-ZSM-5 catalysts with different CuO particle size on selective catalytic oxidation of N,N-Dimethylformamide

期刊论文

Probability distributions of arsenic in soil from brownfield sites in Beijing (China): statistical characterization

Marina ACCORNERO,Lin JIANG,Eugenio NAPOLI,Marco CREMONINI,Giovanni FERRO,Federica BELLORO,Maosheng ZHONG

期刊论文

Influence of surface cracking, anchor head profile, and anchor head size on cast-in headed anchors in

期刊论文