bluuebunny/crossref_metadata_2025 huggingface dataset:
Design, manufacturing and tests of the LIPAc high energy beam transport line
Authors: Brañas B. , Castellanos J. , Nomen O. , Oliver C. , Aragón F. , Arranz F. , Chamorro M. , Duglue D. , Ferreira J.A. , García R. , García J.M. , Gex D. , Iglesias D. , Jiménez-Rey D. , Kirpitchev I. , Marroncle J. , Mas A. , Méndez P. , Melón L. , Mollá J. , Ogando F. , Podadera I. , Roncolato C. , Ros A. , Sauvan P. , Soleto A. , Toral F. , Villamayor V. , Ibarra A.
Published: September 2020

The International Fusion Materials Irradiation Facility (IFMIF) is a projected accelerator-based, D-Li neutron source for fusion reactor materials qualification. LIPAc (Linear IFMIF Prototype Accelerator) is an accelerator aiming to generate a 125 mA, 9 MeV continuous wave deuteron beam, which is currently being commissioned in Rokkasho (Japan) with the objective of validating the IFMIF accelerator design.

In LIPAc, a 10 m long High Energy Beam Transport line (HEBT) will connect the exit of the superconducting linac to the beam dump (BD). The HEBT line must accommodate the diagnostics for beam characterization and open the beam at the end to allow its stopping at the BD. The line contains several magnets to control the beam shape and its trajectory, maintaining beam losses below 1 W m−1 along the beamline to limit activation of surrounding elements and allow hands-on maintenance.

In this work, the LIPAc HEBT line project is described since its origins. A summary of the beam dynamics calculations and other studies (vacuum, radioprotection, assembly, alignment) that led to the conceptual design of the line is done. After that, the detailed design of the line is presented, justifying the main design decisions taken and finally, the manufacturing and procurement process and the acceptance tests performed are summarized.
Numerical viscosity in simulations of the two-dimensional Kelvin-Helmholtz instability
Authors: Obergaulinger M. , Aloy M.Á.
Published: September 2020

The Kelvin-Helmholtz instability serves as a simple, well-defined setup for assessing the accuracy of different numerical methods for solving the equations of hydrodynamics. We use it to extend our previous analysis of the convergence and the numerical dissipation in models of the propagation of waves and in the tearing-mode instability in magnetohydrodynamic models. To this end, we perform two-dimensional simulations with and without explicit physical viscosity at different resolutions. A comparison of the growth of the modes excited by our initial perturbations allows us to estimate the effective numerical viscosity of two spatial reconstruction schemes (fifth-order monotonicity preserving and second-order piecewise linear schemes).
On Entropy Conservation and Kinetic Energy Preservation Methods
Authors: Yee H. C. , Sjögreen Björn
Published: September 2020

The Tadmor-type entropy conservative method using the mathematical logarithmic entropy function and two forms of the Sjogreen & Yee entropy conservative methods using the Harten entropy function are examined for their nonlinear stability and accuracy in very long time integration of the Euler equations of compressible gas dynamics. Following the same procedure as Ranocha [6] these entropy conservative methods can be made kinetic energy preserving with minimum added computational effort. The focus of this work is to examine the nonlinear stability and accuracy of these newly introduced high order entropy conserving and kinetic energy preserving methods for very long time integration of selected test cases when compared with their original methods. Computed entropy, and kinetic energy errors for these methods are compared with the Ducros et al. and the Kennedy-Gruber-Pirozzoli skew-symmetric splittings.
Toxicity of the water-accommodated fraction of diesel on veliger stage larvae of the fluted Giant Clam (Tridacna squamosa)
Authors: Werorilangi S , Yusuf S , Massinai A , Rastina  , Niartiningsih A. , Afdal M , Nimzet R , Karimah A Z
Published: September 2020

The giant clams (Tridacnidae) found in tropical coral reef ecosystems of the Indo-Pacific are considered endangered, with declining populations throughout most of their range. One anthropogenic impact which could have adverse effects on giant clam populations is hydrocarbon pollution. We conducted an acute toxicity test to assess the effect of the water-accommodated fraction (WAF) of diesel on the mortality, morphology, and behavior of fluted giant clam (Tridacna squamosa) veliger phase larvae. The D-veliger larvae (ten per experimental unit) were exposed to different concentrations of diesel (control, 0.1, 1, 2.5, 5, and10 ml L−1) using a 24-hr static nonrenewal test with four replicates per treatment. The 24-hr LC50 of diesel was 1.14 ml L−1 (CI: 0.65- 1.98 ml L−1) based on Finney’s Probit Method. There were no morphological abnormalities (shell deformation) detected at the concentrations tested. However, the expulsion of zooxanthellae was observed at the higher concentrations (2.5, 5, and 10 ml L−1), and the severity of this phenomenon increased in line with diesel concentration. The decreased density of zooxanthellae detected in some living veliger larvae could weaken the larvae and lead to increased mortality.
Investigation and motion characteristics analysis of dangerous rock in high and steep slope based on UAV
Authors: Xiong Chaozheng , Ji Feng , Zhou Chunhong , Pan Yongjie
Published: September 2020

The geological conditions in Southwest China are complex, and the dangerous rock hazards developed in the high and steep slopes has extremely high harmfulness and concealment. The traditional contact survey method is difficult to find out the geological hazard effectively under the limitation of complex and changeable terrain conditions. Unmanned aerial vehicle photogrammetric system has high flexibility and can obtain high-efficient, high precision and high resolution remote sensing images of geological disaster investigation area. By using the UAV photogrammetry system, the dangerous rock mass of the intake slope of Jinping secondary hydropower station is investigated. The working principle of UAV, the acquisition of high-definition image data and the construction of 3D model are discussed, and the feasibility of using the model data obtained by the system to investigate dangerous rock mass is demonstrated. Through repeated analysis and interpretation of the 3D real-scene model, the distribution characteristics of the dangerous rock hazard points of the intake slope are found out. On this basis, four sections are selected to simulate the movement track of unstable dangerous rock mass with Rocfall software, and the movement velocity, jump height and impact energy of different characteristic points of falling rock are calculated quantitatively with the formula.The research results provide an important reference value for the investigation of dangerous rock mass of high and steep slope in southwest China.
Low resolution remote sensing image processing and productions development for earthquake disaster monitoring application
Authors: Wang Shumin , Dou Aixia , Ding Ling , Yuan Xiaoxiang
Published: September 2020

Satellite remote sensing data has the advantages of wide coverage, short imaging cycle, and nocturnal imaging. It has important applications in earthquake disaster monitoring. The built up remote sensing satellite receiving station of our lab could collect the MODIS, NOAA, FY3 Series data. In this paper, we developed a geometric correction algorithm based on conjugate triangles and affine transformation for remote sensing satellite data in the first, and then produce land surface temperature (LST), Vegetation Index (NDVI), and aerosol products for seismic disaster monitoring. In the future work, the products will be applied for earthquake disaster monitoring.
Pre-Assessment of earthquake-induced losses: a case study from Xiangning County, Shanxi Province, China
Authors: Zhao Jie , Wang Feijian , Zhang Congcong
Published: September 2020

Rapid assessment of earthquake disaster loss is the main method of earthquake emergency response after an earthquake. China has a vast territory, the accuracy and current situation of regional basic data are generally low, and the houses in rural areas are not subject to mandatory seismic fortification requirements, which are the key factors affecting the accuracy of rapid assessment results. The regional field investigation is applied to the process of earthquake disaster loss pre-assessment. Through the investigation of the building structure, personnel mobility and major hazard sources, the accuracy of rapid assessment of casualties will be improved. Taking Xiangning County of Shanxi Province as an example, the method of earthquake disaster loss pre-assessment is studied.
Study on the relationship between radon characteristics of underground water and seismicity in the Longxian - Baoji fault zone, NW China
Authors: Liu Jie , Zhao Xiaomao , Wang Xin , Wang Jingli , Qiu Yurong
Published: September 2020

Destructive earthquakes are mostly located in the active fault zones. The underground gas anomalies result to basically be consistent with the inferred distribution of active fault systems. Among them, radon is the earliest used as the effective prediction index of fault zone earthquake prediction. In this paper, radon concentrations in groundwater from the Longxian – Baoji fault zone in the Northwestern China are analyzed. Results show that the NW sector has a lower radon concentration (∼12 Bq/L) than that of the SE sector (40 ∼ 50 Bq/L). It indicated that the connectivity between the shallow and deep crust is relatively poor in the NW sector, which is not conducive to the upward diffusion and migration of deep fluids. Given that there is a seismic gap with no rupture of M ≥ 61/2 strong earthquake in the NW sector, it can be infered that the NW sector of the Longxian - Baoji fault zone has a higher risk of strong earthquakes than that in the SE sector.
Wave-induced liquefaction hazard assessment and liquefaction depth distribution: A case study in the Yellow River Estuary, China
Authors: Du Xing , Sun Yongfu , Song Yupeng , Xiu Zongxiang
Published: September 2020

Predicting the potential depth of wave-induced liquefaction is of vital importance of hazard assessment. Prevention and mitigation of liquefaction hazard can be carried out after predicting the liquefaction potential depth. Sediment geotechnical parameters were summarized from historical engineering projects and calculated liquefaction depth with data of actually measured water depth, sediment types and different wave recurrence periods. Then the study area was divided into different liquefaction zones. Results showed that both liquefaction range and depth increased with wave return period, which remained steady when increased to a certain extent. The calculated liquefaction depth was compared with the thickness of liquefied layers, which obtained by geophysical methods. Result shows that the average difference was about 1m, which means the method of liquefaction depth calculation was applicable in this study area. At last, in order to reduce harm of liquefaction, potential maximum liquefaction depth (PMLD) is put forward. PMLD is the smaller one between the thickness of seabed liquefiable sediment and the maximum calculated liquefaction depth. The calculation and partition of liquefaction depth can be more accurate after considering PMLD.
Experimental study on the performance of goaf filling materials with high content of fly ash
Authors: Wang Xiaodong
Published: September 2020

In this paper, fly ash is studied as the main cementing material for coal mine goaf filling. The performance of the filling materials with 90% fly ash such as compressive strength, impermeability, viscosity, additive effect and diffusion rule are studied experimentally and theoretically. The results show that compressive strength and impermeability are positively correlated with cement content when water-solid ratio is 0.7:1.0 with 90% fly ash. The compressive strength increases slowly in the early stage while it increases with a faster speed in the later stage. The compressive strength of the material after 60 days of curing is 1.90 times that of 28 days. Additive could promote the activity of fly ash and improve hydration reaction. The interparticle porosity is reduced, but strength at early stage and impermeability are increased. The viscosity of the filling material has an obvious shear thinning phenomenon as shear rate increases. An inflection point appears when shear rate is 30s−1. The filling material with high content of fly ash presents the rule of horizontal diffusion and longitudinal accumulation in goaf filling treatment. The diffusion distance and accumulation height are positively correlated with grouting pressure.
Experimental research on smoldering combustion for oily sludge
Authors: Wang Tianyu , Jiang Wenming , Liu Yang , Chen Shaoqi , Ding Juhua
Published: September 2020

Petroleum contaminants like oily sludge and oily spills cause a great damage to the environment. Compared to the conventional treatments to remove the oily contaminants of the soil, smoldering combustion can satisfy the further treatment of contaminants with low oil content. This paper presents the experimental research of smoldering combustion for oily sludge with low oil content. Experimental results showed that petroleum contaminants could be further removed with the condition of continuous heating. However, without external heating, smoldering would not be self-sustaining. Experimental results show that smoldering has the potential to further remove petroleum contaminants in low oil content oily sludge which cannot be treated by other methods.
Decoupling between industrial environmental pollution and industrial economic growth in Guangxi Beibu Gulf Economic Zone
Authors: Liu Yanhua , Ye Guohua , Han Shijing
Published: September 2020

In order to gain a deeper understanding of the decoupling change trajectory of the industrial environment pollution and industrial economic growth in Guangxi Beibu Gulf Economic Zone, and to better solve the problem of sustainable economic development under the concept of low-carbon economy, based on the decoupling theory, six major indicators such as COD, ammonia nitrogen, SO2, NOx, PM and industrial added value were selected to conduct the empirical analysis of the decoupling relationship between industrial environmental pollution and industrial economic growth in Guangxi Beibu Gulf Economic Zone from 2009 to 2016. The results showed that they were basically in an unstable state of incomplete decoupling, most of which were manifested as strong decoupling, accompanied by other types of decoupling, and no obvious evolutionary law. In terms of time, the decoupling reached its best in 2013 and 2016. In terms of space, the decoupling in Nanning was the best.
Analysis on the difficulties and countermeasures of energy saving reconstruction of existing rural residential buildings
Authors: Huang Mingqiang , Lin Ruijuan
Published: September 2020

The energy-saving reconstruction of existing rural residential buildings can not only improve the living environment of rural residents, but also achieve energy conservation and emission reduction of the construction industry and sustainable development. At present, the energy-saving reconstruction of existing rural residential buildings has become a topic of global concern. Many countries begin to pay attention to the energy-saving reconstruction of existing rural residential buildings and begin to formulate relevant policies and regulations. Based on the analysis of the construction situation about the existing rural residential buildings, this study expounds the difficulties of the energy-saving reconstruction of existing rural residential buildings, and puts forward corresponding suggestions, so as to realize the development of the energy-saving construction of the residential buildings in the villages and towns.
Comparison on techno-economic analysis of ammonia production using urea from SCR denitration reducing agen in 300MW coal-fired unit
Authors: Feng Qianwei , Li Cunwen , Zhang Peng , Zhang Yang , Wang Fengji , Zhu Yue
Published: September 2020

Under the current environmental protection situation, comparison on techno-economic analysis of the ammonia production using urea can provide reference and guidance for the coal plant’s transformation project of replacing liquid ammonia with urea. Taking eleven 300MW SCR denitrification reducing agent urea replacing liquid ammonia in 4 power plants as an example, the technical characteristic and material consumptions, investment cost and operation cost were compared on urea pyrolysis with electric heater, urea pyrolysis with gas heat exchanger and urea hydrolysis, the main influence factors and reasons of Urea to replace liquid ammonia transformation project on such unit had been mastered. The results show that the processes of ammonia production by urea pyrolysis and urea hydrolysis were mature and feasible, and both had their advantages and disadvantages.
Effect of matured compost and exogenous microbial inoculants on the composting process of digestate eluted from dry anaerobic digestion
Authors: Tan Wenbing , Liu Ping , Zhang Xiaohui , Xi Beidou
Published: September 2020

Biogas and digestate can be produced by anaerobic digestion of pig manure and straw. However, further treatment of digestate should be carried on. The digestion efficiency is affected by the addition of extra biodegradable materials or inoculants. This study was conducted to reach a less emission and higher efficient of the composting process. The windrow composting of the digestate by adding mature compost and exogenous commercial microbial inoculants was performed by two assays per variation. The composting process showed that the digestate treated with exogenous microbial inoculants reached a 10-20% higher organic matter loss than the digestate without exogenous microbial inoculants. The plant-nutrients (N, P, K) were significantly increased due to the positive effect of exogenous microbial inoculants, especially the HK microbial inoculants. Adding matured compost can reduce the plant-nutrients loss caused by leaching from digestate, which is with high moisture content. Meanwhile, the concentrations of toxicant heavy metals in digestate were also increased after composting due to organic compounds decomposition and concentration effect. Additionally, the heavy metals concentrations in compost are still under the standard. In general, the results illustrated that windrow composting can be added to enhance the composting efficiency and resource recovery of pig manure and straw.
Low-temperature alkali-modified fly ash as an effective adsorbent for removal of ammonia nitrogen, phosphorus and COD from the wastewater
Authors: Meng Ruihong , Lv Pengcheng , Yang Yang , Xu Dong , Gao Tengfei , Fu Yanchun
Published: September 2020

In this study, low-temperature alkali-modified fly ash and polymeric aluminum chloride(PAC) for the removal of total phosphorus, COD and ammonia nitrogen, from wastewater was systematacially investigated. The removal rate of ammonia nitrogen was 81.10%, and the removal rates of phosphorus and COD were 90.21% and 55.48%, respectively., when a dosage of the alkali-modified fly ash was 5g/L, the amount of PAC was 50mg/L, and the mixing time was 39min. In comparison with raw fly ash, the removal rate of ammonia nitrogen is 80.16% higher than that of the original fly ash, and the removal rate of total phosphorus is 35.48% higher. Fly ash with improved surface can be used as an alternative adsorbent to flocculate and precipitate in cooperation with polymeric aluminum chloride, which can be applied to the treatment of total phosphorus, COD and ammonia nitrogen in the sewage. This study provides a theoretical basis for the coagulation adsorption method and realizes the utilization of fly ash.
Molecular simulation study on the radon adsorption behavior in carbon nanotube bundles
Authors: Wang Qingbo , Cheng Jinxing , Wu Youpeng , Wen Weiwei , Han Junjie , Yu Ai
Published: September 2020

As we know radon is harmful to people because of its radioactivity. Focusing on the technical requirements of radon mitigation by adsorption, the radon adsorption behavior of carbon nanotube bundles was studied under different diameter tube bundles and different tube spacing using the grand cononical ensemble Monte Carlo (GCMC) simulation method. The results show that the (10:10) type nanotubes have the strongest ability to adsorb radon with a tube spacing of 1 nm, followed by (7:7) type nanotubes with a tube spacing of 1 nm. The bundle of carbon nanotubes of the (8:8) type has the worst adsorption capacity. Moreover, the nanotube bundles of each type of tube have an increased ability to adsorb radon as the tube spacing increases.
Numerical simulation study of quench tower in flue gas purification system
Authors: Long Peng , Li Zhiwei , Li Mengdi
Published: September 2020

By establishing a numerical simulation model of the high-temperature flue gas spray evaporation process, the heat transfer and flow processes in the quench tower using 4 different numbers of atomizing nozzles were simulated. Research and analysis were conducted under specific conditions. Different number of atomizing nozzles, the flow field above the quench tower is different, the greater the number of atomizing nozzles, the smaller the area occupied by the air flow, the smaller the conical volume formed by the droplets, the less time it takes to fully evaporate. A single atomizing nozzle cools down faster within 2m from the top of the tower, have the longest trajectory length of the droplet movement, but the time for the droplet to completely evaporate is the longest.
Organic pollutants treatment in a water aerosol reactor by pulsed corona discharge at atmospheric pressure
Authors: Wu Haixia , Fan Jiawei , Xu Yanhua , Liu Feng , Fang Zhi
Published: September 2020

An atomization reactor with a gas cycler is designed, and the phenol is treated as wastewater by pulse corona discharge, which is sprayed into the reactor through a pneumatic atomization nozzle. To fully utilize the ozone and enhance organic pollutant removal, we maintained continuous gas circulation in the reactor. The resulting phenol solution was subjected to six passes of decomposition treatment. Approximately 87.4% of 100 mg/L phenol concentration was decomposed in the plasma system gas circulation, whereas only 51.9% was decomposed in the same system but without gas circulation after the sixth pass treatment. The decomposition efficiency increased with applied voltage and pH. In addition, homogeneous catalysts such as hydrogen peroxide (H2O2) and iron (II) (Fe2+) enhanced the removal of phenol. The novel reactor was also used for the deep treatment of phenolic compounds in coking wastewater. Compared with systems using ozonation, the plasma system working under optimal conditions considerably improved the performance of industrial wastewater treatment, which can be regarded as a promising alternative AOP for wastewater remediation.
Research on the comprehensive benefits and driving forces of various typical types of marine development in Jiangsu Province
Authors: Gao Sheng , Sun Huihui , Zhao Lin , Cao Guangxi , Liu Wei
Published: September 2020

The comprehensive benefit assessment of marine development type is an important basis for marine development according to local conditions. It is of great significance to realize the rationality of marine development and promote the sustainable development of the ocean. This paper calculates the economic net benefit, ecosystem service function loss value, fishery resource loss value and ecological profit and loss value of four main types of marine development projects in Jiangsu Province. The evaluation, correlation and driving force analysis of the comprehensive benefit value per unit area of marine development type are carried out. It is found that the sequence of economic net benefit and comprehensive benefit value is the same, from the highest to the lowest, they are port industry, offshore wind power, sewage dumping and aquaculture. After deducting the economic benefit value, the comprehensive benefit value is in the order of offshore wind power, aquaculture, port industry, sewage dumping, and the evaluation value is very close. Economic net benefit, ecosystem service function loss value and comprehensive benefit value have the most significant correlation. Through principal component analysis, it is found that economic net benefit is the key driving factor.
Research on risk assessment of offshore supply vessels carrying dangerous cargoes
Authors: Liu Baozhan , Jin Weiwei , Zhao Jianping , Song Shasha , An Wei
Published: September 2020

In view of the lack of effective quantitative risk of dangerous cargoes carried by offshore supply vessels under the influence of multi-level, multi-variable and non-quantitative factors, the paper adopts the multi-level fuzzy comprehensive assessment method to screen the key risk sources of dangerous cargoes carried by offshore supply vessels, and has respectively constructed the risk possibility and hazard consequence assessment index systems and carried out the risk classification calculation. Through the calculation of the risk of carrying dangerous cargoes on an offshore supply vessel in Bohai Sea, the results show that the risk possibility of the supply vessel is medium to low level, the hazard consequence is medium to high level, and the comprehensive risk level is medium. Therefore, the minimum reasonable and feasible ALARP principle should be followed to reduce the risk. The assessment method can judge the risk level of dangerous cargoes carried by offshore supply vessels and provide technical support for emergency response of offshore supply vessels.
Soil microbial remediation to soybean field of Northeast China: Dynamic changes of fomesafen residues and phospholipid fatty acids in the black soil after application of Shigella flexneri FB5
Authors: Yang Fengshan , Sun Cong , Lai Yang , Ma Yukun , Fu Haiyan , Liu Chunguang
Published: September 2020

Fomesafen is widely used to control broad-leaved weeds in oil-bearing crops such as soybean and peanut. However, fomesafen has a long residual period in soil. If it is not used properly, it will cause damage to sensitive crops in different degrees. In this paper, the effects of fomesafen-degrading strains on the residue of fomesafen and the structure of soil microbial community were studied. Under field experiments, a microbial solution containing fomesafen-degrading Shigella flexneri FB5 was sprayed. We then detected residual fomesafen in the soil using high-performance liquid chromatography and phospholipid fatty acid content using gas chromatography-mass spectrometry. Analysis of variance suggested that the addition of fomesafen-degrading strains had a significant effect on soil microorganisms, as revealed by changes in the fungi/bacteria index, gram-negative/gram-positive bacteria ratio, stress indicators, and total phospholipid fatty acids. To sum up, our results show that the use of fomesafen-degrading strains can reduce the toxicity of fomesafen.
Effects of forest belt in park on the chemical composition for PM2.5
Authors: Chen Bo , Liu Chunhe , Fan Jihong , Shi Jinchao , Yu Haiqun
Published: September 2020

This paper represents results on the effects of forest belt on seasonal variation on the main chemical components for PM2.5 in the park environment in Beijing. PM2.5 samples were collected inside and outside a conifer forest simultaneously for 1 year in Beijing Olympic Forest Park. Chemical components including organic carbon (OC), elemental carbon (EC), water-soluble ions and elements in PM2.5 were measured. Results indicated that forest belt had significant impacts on PM2.5 chemical compositions of park. Organic matter, SO4
2-, NO3
−, NH4+, and crustal matter were the dominant components of PM2.5. The measured OC was divided into primary OC (POC) and second OC (SOC) parts following the method of EC tracer. Concentrations of OC, SOC, as well as SO4
2-, NO3
−, NH4+ and K+ in PM2.5 inside of forest were markedly higher than those outside of forest. The highest concentrations of OC, EC, and SO4
2- were observed in winter and the lowest values were found in summer. In contrast, the highest concentrations of most crustal elements were observed in spring, and the highest levels of pollutant elements were found in winter. Among these elements, annual mean concentrations of As and Cr exceeded WHO standard during monitoring period.
The application of principal component cluster analysis in environment classification for Chinese cities
Authors: Wang Jingcheng , Zhang Lunwu , Zhang Dingfei , Zhao Fangchao , Yang Xiaokui
Published: September 2020

In order to investigate the dissimilarities of different cities in China, an approach combining principal component analysis and hierarchical clustering is proposed. Three rather than two principal components are reserved to conduct a more elaborate analysis. Based on corresponding component scores, dissimilarity between each city is measured during clustering. These cities are classified into seven types, and they are marked on the map of China. The result of this classification is consistent to our traditional cognition. Therefore, the principal component cluster analysis is suitable for analyzing numerous observations with variables on a large scale. This approach helps to enhance the environmental adaptability of equipments by recognizing the environment type of each city.
Characteristics of heavy air pollution in Beijing-Tianjin-Hebei and the surrounding areas during autumn and winter and policy recommendations
Authors: Tang Qian , Lei Yu , Yan Gang , Xue Wenbo , Wang Xuying
Published: September 2020

Beijing-Tianjin-Hebei and its surrounding areas is the most polluted region in China. Autumn and winter are the most heavily polluted seasons. It is essential to reduce the PM2.5 pollution in autumn and winter in this region for winning the blue sky defense war. The characteristics of PM2.5 pollution during autumn and winter in this region were analysed and crucial issues in atmospheric pollution prevention were identified from the perspectives of time, space and pollution sources, using a combination of techniques including air quality observation, emission inventory, PM2.5 source apportionment and air quality model simulation. The results showed that average PM2.5 concentrations in autumn and winter were twice that in spring and summer, and frequent heavy pollution elevated PM2.5 concentration significantly. Six cities including Handan, Xingtai, Shijiazhuang, Xinxiang, Anyang and Baoding, located along the south-western transport channel in the region, have great effects on regional air quality. The severe PM2.5 pollution in this region could be attributed to heavy industrial structure, large NOx emissions from mobile sources, re-burn of loose coal, insufficient dust control and impacts from cities out of the region. Suggestions for air pollution control in autumn and winter in this region were proposed. More efforts should be devoted to the most vulnerable links in the key cities.
Analysis on the characteristics of urban expansion in Urumqi
Authors: Yang Han , Guo Xiao , Wang Yaqi
Published: September 2020

The urban spatial structure change caused by urban expansion is the most intuitive manifestation of urbanization in space. In this study, Landsat TM remote sensing image maps from 2000, 2010, and 2017 were used as the main data sources. A combination of supervised classification and manual visual interpretation was used to extract the current distribution maps of the three impermeable surfaces in Urumqi Based on the dynamic changes from 2000 to 2010 and 2000 to 2017, the changes in Urumqi’s built-up areas from 2000 to 2017 were analyzed, and the characteristics and causes of urban expansion in Urumqi were analyzed. The results show that the interior of Urumqi city tends to be saturated. Due to the limitation of topographical factors outside the urban area, the overall urban form is axially distributed in a diagonal “T” shape. From 2000 to 2010, the area increased from 163.31km2 to 332.66km2, with a net increase of 169.35km2. The average annual growth rate was 10.37%, and from 2010 to 2017, the area increased to 434.02km2, a net increase of 101.36km2, the average annual growth rate was 3.05%. The average annual growth rate from 2000 to 2010 was greater than 2010 to 2017; Comparing the area and changes of various jurisdictions, the development advantages of the new urban area are obvious. From 2000 to 2010, the development advantages of the new urban area are obvious. From 2000 to 2010, the development advantages of the new urban area were obvious. Midong District and Toutunhe District developed rapidly, while Shaibak District had the fastest growth.
Data processing of Zhuhai-1 hyperspectral satellite
Authors: Gao Peng , Zheng Yichao , Ai Jingjing , Fang Li
Published: September 2020

The Zhuhai-1 hyperspectral satellite (The Qust No.1), which was launched on 26 April 2018 is the learning and research crystallization of Qingdao university of science and technology in cooperation with Obit aerospace technology company. The Qust No.1 satellite is equipped with a high-resolution hyperspectral camera, achieving global remote sensing coverage and providing high-quality hyperspectral data for relevant scientific and commercial remote sensing applications. Based on the Qust No.1 imagery for Jiaozhou bay, the radiation, atmospheric, orthographical corrections together with the image enhancement and spectral information extraction are analysed and discussed in detail in this paper. The results indicate that there are high imaging quality and excellent information collection ability for the Zhuhai-1 satellite, which has good application prospect in many aspects such as vegetation monitoring, precision agriculture, etc.
Establishment and application of the modified Chen NDVI model integrated with ground object classification
Authors: Luan Haijun , Wan Yunya
Published: September 2020

Heterogeneous land surface causes the scale effect of remotely sensed land surface parameters. Addressing on quantitatively describing the influence of different ground objects on scale effect of the common surface parameter normalized difference vegetation index (NDVI), the paper proposed an improved NDVI scale transformation model. The model integrated accurate classification information from medium- or high- spatial resolution remote sensing images to improve the traditional Chen NDVI scale conversion model, and showed its superiority for NDVI scale effect description. Xiamen was taken as the experimental area for the study and the conclusions could be obtained from the experimental results. Compared with the traditional Chen NDVI model with rough information, the improved Chen NDVI model incorporating fine ground information provides a finer and more quantitative description of the influence of different land types on the NDVI scale effect. Furthermore, it is found that the presence of water is the key factor underlying the NDVI scale effect. The conclusions of this study have important implications for the scale effect research of other NDVI-like surface parameters such as ratio vegetation index (RVI), normalized difference built-up index (NDBI), normalized burn ratio (NBR).
Availability analysis of the Chen NDVI model in MOD13 Q1 validation
Authors: Luan Haijun , Wan Yunya
Published: September 2020

The MODIS normalized difference vegetation index (NDVI) product plays an important role in the eco-environmental monitoring of natural disasters. However, its validation has been a long standing and important scientific problem. The paper proposed a method to integrate accurate classification information for medium-high spatial resolution remote sensing images to improve the traditional Chen NDVI scale conversion model and perform MOD13 Q1 validation. The authors had verified the method in the research area of Xiamen, Fujian Province, China, and the experimental results proved its effectiveness. This paper focuses on the availability research of the model in different experimental areas. Taking Fuzhou City of Jiangxi Province, China, as the study area, the MOD13 Q1 validation experiment was implemented. The conclusions are obtained from the experimental results: the Chen NDVI scale transformation model is not robust, and in some experimental areas there is significant transformation error when the conversion factor is too large (such as eightfold from 30 m OLI NDVI to 240 m up-scaled NDVI). In these bad cases, other more robust scale transformation models should be elected for the validation of the low-resolution land surface parameter images.
Wind direction retrieval of tropical cyclone from SAR imagery using improved local gradient method
Authors: Wang Yan , Zheng Gang , Zhou Lizhang , Qiu Zhou , Li Xiaohui , Zhou Yinfei
Published: September 2020

Tropical cyclones (TCs) have caused heavy losses of human life and property. Hence, it is necessary to study TC. Additionally, the retrieval of wind direction is an important part among many researches of TC. Fortunately, Typhoon Iselle, Typhoon Nuri, and Tropical Storm Haima were captured by RADARSAT-2, Typhoon Hermine, Tropical Storm Harvey, and Super Typhoon Jose were captured by Sentinel-1A. In this paper, the wind directions of the six TCs are retrieved from SAR images by improved local gradient (ILG) method. The results show that the sea surface wind directions retrieved by ILG method have good correlation with the texture of the six TCs, respectively. This research is helpful for estimating wind speeds and constructing wind field of a TC.
Big data-based applied research on hazardous chemical safety regulation
Authors: Ban Ya , Liu Hongjing , Fei Tianhao , Luo Hao , Yu Ling , Yang Qinghui
Published: September 2020

With the rapid development of modern industry in China, a large number of hazardous chemicals are put into the production and use of chemical enterprises, increasing the probability of hazardous chemical accidents to a certain extent. Because hazardous chemicals are extremely dangerous and destructive, timely and efficient regulation of hazardous chemical safety is of particular importance. The application of China’s Beidou satellite navigation system for safety supervision is of great significance, with its advantages of high accuracy and allweather weather, and the rapid development of related technologies and applications in recent years, has been widely applied in the field of safety monitoring of bridges, earthquakes, dams and other areas. Based on the investigation and analysis of emergency management of critical chemical enterprises, this paper explores the construction of an innovative application system for the safety supervision of critical chemicals based on big data of Beidou positioning system, including a platform for dynamic supervision and traceability of the whole process of critical chemicals based on big data, a platform for dynamic supervision of critical chemical transport safety based on big data, a prediction and early warning application of social public bg data in the critical chemical industry, and a platform for emergency information mining and analysis of critical chemical incidents based on social media big data to form a more scientific safety supervision system for critical chemicals.
Research on GIS and CAE cooperative coupled dynamic geographical situational response
Authors: Liang Ming , Zhu Xiaojun
Published: September 2020

The relationship between geographic entities and geographical environment is a vital research topic of geography, and the response characteristics of geographic entities to geographical environment are the basis of Geo-design and geographical decision. Building entities and geography modeling is the key to intelligent cities and disaster response. In the traditional GIS domain, the modeling of building entities was limited to the representation of geometric features and spatial relations, which was unable to simulate the "action-response" relationship between geographic entities and geographical environments for the lack of the expression of the structural characteristics of architectural entities. In this paper, the structural model of the building, which is taken as a link between the organic coupling of GIS and CAE two heterogeneous systems, is built to achieve geographical entities on the dynamic response of the geography of the environment simulation, thus providing the support for the intelligent geographic decision and disaster emergency. This paper focuses on the definition, composition and expression of the building structure model, which is geared to the coupling of GIS and CAE. It also discusses the methods of GIS-based dynamic geographical simulation and CAE-based response analysis. Moreover, the "role-response" model taken the building structure model as the core is built between "Model-simulation-evaluation-decision" geographic entities and geographical environment. The results of structural analysis and the evaluation of diagnosis results are visualized by means of "3D thematic map", and the components are modified and optimized based on the interactive modification method. The structure analysis and design efficiency are improved and the iteration cycle of structure design is accelerated. Design of building structure and modeling quality are been improved. This research extends the static spatial characteristics expression of GIS to dynamic geography scene simulation, further expending the study category of relationship between geography entities and geography environment.
Mapping urbanization dynamic of mainland china using dmsp/ols night time light data
Authors: Xu Pengfei , Jin Pingbin , Cheng Qian
Published: September 2020

Knowledge of spatial-temporal changes of urbanization is highly required nowadays and DMSP/OLS nigh time light provides new insights to detect changes of urbanization in the global and regional scale. However, most researches focus on the spatial pattern while ignoring the temporal dynamics of urbanization process. In this study, the raw Night time Light data (NTL) were calibrated to form a comparable time series. New metrics of GNTL (growth of NTL), max GNTL, min GNTL, mean GNTL, GNTL amplitude and accumulated GNTL derived from time series DMSP/OLS data were applied to detect the urbanization dynamics of Mainland China from 1992 to 2013.The results show that NTL-derived metrics are good indicators to trace the urban dynamics on the contexts of both spatial and temporal scales, from which the urbanization dynamic features can be detected. With the combined utilization of NTL and NTL derived metrics, 3 types of urbanization are summarized, namely constant rapid urbanization, active improving urbanization and steady improving urbanization. Classification methods were also applied to test the performance of NTL derived metrics for urban structure discrimination. The study reported here is a novel attempt to trace urbanization process using the NTL derived metrics, and we foresee its wide applications in future in relevant studies.
The characteristics of climate changes over Nantong during the period 1951-2018
Authors: Chen Feng , Yin Jie , Li Yan
Published: September 2020

Climate change is a hot issue concerned by governments, society and scientists all over the world. Some measures will be developed by the governments after studying district climate change. Based on climate dates such as average temperature, average maximum temperature, average minimum temperature, and precipitation at the monthly scale obtained from eight meteorological stations over the Nantong region in Jiangsu province during the Period 1951-2018 in this paper. Climate change law was studied. This research methods include accumulative anomaly method, linear trend estimation, Mann-Kendall trend test and Morlet wavelet analysis. Results showed as following: (1) temperature has an obviously upward trend, but the differences between annual average temperature, annual average maximum temperature, and annual average minimum temperature are at little level. The trend in precipitation is not prominent in the period. The average values for the first 10 years of this century and the last 30 years are the chronological and period maximum. (2) The increase rate of temperature in spring is greatest during four seasons, and the significant is also the biggest. The increase rate of temperature in winter is greater than autumn, but the significant is reverse. Precipitation increases in summer and winter, but decrease in spring. (3) Mutation years of temperature and precipitation change were mainly in 1996-1998 and 2002-2004. (4) For period change, temperature and precipitation showed stable changes at a shorter time scale, such as 10 years or 2-3 years, and some longer scale period change for 30 years for mean average temperature. Overall, climate change over Nantong was consistent with other regions in China, and it also had its own unique features in some aspects.
Evaluation on sustainable utilization of water resources in Nansi Lake Basin
Authors: Hou Xiangdong , Wang Xunshi , Chen Lifeng , Zhu Shicheng , Wang Junnuo , Sun Xinru , Diao Yanfang
Published: September 2020

Based on the influencing factors of sustainable development by Bossel, the evaluation index system of sustainable utilization of water resources was constructed, which includes 18 indexes considering the development and utilization of water resources, social economy and ecological environment. The evaluation grade was classified into five levels: special, strong, intermediate, light and tiny. Because there were many fuzzy characteristics in this evaluation, this study was constructed an evaluation method of sustainable utilization of water resources based on the variable fuzzy sets model. Taking the Nansi Lake Basin in China as an example, the evaluation method was introduced in detail. The example showed that the evaluation index system constructed in this paper was reasonable and generalized, and the evaluation method was easy to understand, easy to operate and high credibility of the results. In addition, the evaluation results had a certain guiding significance for the sustainable development of water resources.
Comparative study on the dynamic calculation method of river ecological water demand
Authors: Jiang Xuechen , Zhang Jing , Song Yongyu , Lai Yuequn
Published: September 2020

In order to maximize the seasonal ecological hydrological demand of the river, this paper introduces three improved dynamic calculation methods. Taking the downstream channel of the Jilintai-I Hydropower Station on the Kashi River in Xinjiang as an example, three methods are applied to calculate the ecological water demand of the channel. Meanwhile, it is compared with the improved classification standard of Tennant method, and a method that is more suitable for the calculation of the ecological water demand of the river in this basin is selected, so that the calculation results can meet the seasonal dynamic demand of runoff while ensuring the basic ecological and hydrological demand of the basin, and benefit to the sustainable development of the river habitat. And reduce the losses caused by hydrological disasters, and achieve the coordinated development of economy and ecology.