bluuebunny/crossref_metadata_2025 huggingface dataset:
Newtonalized orthogonal matching pursuit for the linear frequency‐modulated pulse frequency agile radar
Authors: Zhu Jiang , Guo Honghui , Zhang Ning , Song Chunyi , Xu Zhiwei
Published: July 2021

The linear frequency‐modulated frequency agile radar (FAR) can be used for synthesizing high‐range‐resolution profiles (HRRP), and also has excellent electronic counter‐countermeasures performance. Similar to the Newtonalized orthogonal matching pursuit (NOMP) for line spectral estimation problem, the NOMP for the FAR radar termed as NOMP‐FAR is designed to process each coarse range bin to extract the HRRP and velocities of multiple targets, including the guide for determining the oversampling factor and the stopping criterion. In addition, it is shown that the target will cause false alarm in the nearby coarse range bins, and a post‐processing algorithm is proposed to suppress the ghost targets. Numerical simulations are conducted to demonstrate the effectiveness of NOMP‐FAR.
Radio study of HESS J1857+026: Gamma-rays from a superbubble?
Authors: Petriella A. , Duvidovich L. , Giacani E.
Published: July 2021

Aims. We provide new insights into the nature of HESS J1857+026, a very-high-energy γ-ray source whose complex morphology in the TeV band was attributed to the superposition of two distinct sources.

Methods. We performed radio continuum observations to look for the pulsar wind nebula and the supernova remnant associated with the pulsar PSR J1856+0245, which might be powering part of the γ-ray emission. We observed HESS J1857+026 with the Karl G. Jansky Very Large Array (VLA) at 1.5 GHz in the C configuration. In addition, using the same array configuration, we observed a region of 0.4° × 0.4° towards PSR J1856+0245 at 6.0 GHz. We obtained complementary data for the neutral hydrogen and molecular gas emission from public surveys in order to investigate the properties of the interstellar medium in the direction of HESS J1857+026.

Results. The new observations at 1.5 GHz do not show evidence of emission above the noise level of 0.7 mJy beam−1 that could be associated with either HESS J1857+026 or PSR J1856+0245. Also, in the new image at 6.0 GHz we do not detect radio emission from a pulsar wind nebula powered by PSR J1856+0245. The neutral gas analysis shows the existence of a superbubble in the direction of the γ-ray source. We suggest that this structure is located at ~5.5 kpc, compatible with the distance to the pulsar PSR J1856+0245.

Conclusions. We conclude that TeV emission from HESS J1857+026 originates in a superbubble, arguing in favour of a single γ-ray source rather than the superposition of two distinct sources. The pulsar PSR J1856+0245 could also be contributing as a source of γ-rays within the bubble.
Impacts of long-term nitrogen addition on nitrous oxide in a temperate grassland
Authors: Chen Si , Gao Tianpeng , Hao Tianxiang , Li Kaihui , Liu Xuejun
Published: July 2021

Atmospheric nitrogen (N) deposition has increased dramatically due to increased human activities since the industrial revolution. However, it is still unclear what the responses of soil nitrous oxide (N2O) is to long-term elevated N deposition in a temperate grassland. Here, we conducted an in situ field experiment to investigate these responses to long-term high N addition on a temperate steppe in Inner Mongolia, China, from April 2017 to October 2018. Soil N2O emissions significantly increased by long-term N addition, use of structural equation modeling (SEM) showed that topsoil (0-5 cm) NH4+-N content was the most important limiting factor for N2O emission. Our results indicate that long-term high N addition showed a significantly increase in N2O emission in this temperate grassland.
Changes on available phosphorus and total nitrogen contents from soil around roots of two desert plants
Authors: Chang Guo-Hua , Wang Wang-jiang , Yin Zhuo-Xin , Yue Bin , Wang Jin-xiang , Gao Tian-peng
Published: July 2021

In order to understand variation characteristics of the soil available phosphorus and total nitrogen (TN) content around the roots of typical desert plants Peganum harmala Linn. (PHL) and Asterothamnus centrali-asiaticus (AC), which are widely distributed in Jinchang mining area of Gansu Province, the soil samples around the roots of the two plants were collected, and the contents of available phosphorus and TN were analyzed. The results showed that the change trend of soil available phosphorus content was not the same in the range of 0-60 cm around the roots of PHL and AC. In most areas the change of available phosphorus content in the soil from around the root of PHL was U-shaped, and the content of phosphorus around the roots of AC increased firstly and then decreased, while the change trends of TN content around AC was decreased gradually.
Analysis of The Migration and Accumulation Process of Nitrate-nitrogen Pollutants in The Unsaturated Zone of Soil
Authors: Li Xiangcai , Jing Ping
Published: July 2021

In order to understand the migration process of nitrate-nitrogen pollutants in the shallow unsaturated zone of the soil, the Tianjin coastal dredger and typical fluvo-aquic soils in North China were used as the research objects. The Hydrus-1D software was used to establish a numerical model to simulate nitrate. The pollution process of nitrogen pollutants in the unsaturated zone of soil, the results show that: during the migration process of the two kinds of shallow vadose zones of soil, the nitrate-nitrogen pollutants migrate downward at the maximum concentration before reaching the maximum concentration. After the maximum concentration, the concentration of nitrate nitrogen in the soil no longer increases; due to the difference in the average particle size of the soil, the migration rate of nitrate nitrogen in fluvo-aquic soil is significantly greater than that in artificial dredger soil. Nitrate nitrogen is in the simulation period completely passing through the simulated soil layer, the fluvo-aquic soil is completely passed through by nitrate nitrogen at 2d, and the artificial dredge fill is completely passed through by nitrate nitrogen at 2.5d.
Advances in Studies on Nitrogen and Phosphorus Removal by Microalgal-Bacterial Consortia
Authors: Mu Ruimin , Guo Qingyang , Qi Feng , Jia Yantian , Meng Qianya , Yu Gejiang
Published: July 2021

With the development of life and industry, the nutrients in sewage increased gradually. The emerging symbiotic system of algal and bacteria has remarkable effect in removing nutrients such as nitrogen and phosphorus. In this paper, the influence of nitrogen and phosphorus on bacteria-algal consortia and the absorption mechanism of nitrogen and phosphorus by the interaction of bacteria-algal consortia were analyzed, and a variety of methods for studying bacteria-algal consortia were summarized, mainly using isotope tracer technology to study the research results of bacteria and algae absorbing nitrogen and phosphorus in water. This method is of great significance for analyzing the mechanism of the treatment of nitrogen and phosphorus by the bacterial-algal symbiosis system from the microscopic point of view.
Reservoir characteristics and control factors of Tongbomiao formation in Hongqi sag
Authors: Haibo Wu , Yue Zhou , Hao Chen
Published: July 2021

Hongqi sag is located in the north of Beiehur depression in Hailar Basin, which is a secondary structural unit in the peripheral depression of Hailar Basin, with great exploration potential. Based on SEM, conventional thin sheet, cast thin sheet, mercury pressure and physical property data, this paper discusses the reservoir characteristics, types and control factors of high quality reservoir in Tongbomiao formation, Hongqi sag, so as to provide a strong geological basis for the exploration of oil and gas in this area. The reservoir space of Hongqi sag is mainly composed of four types: primary intergranular pore, micro fracture, feldspar dissolution pore and debris dissolution pore. It is of the type of ultra low porosity and low permeability. Although Tongbomiao formation in Hongqi sag is of very low porosity and low permeability type, high quality reservoir is still developed, and its reason is mainly controlled by sedimentary environment, diagenesis and structural fracture.
Analysis of the Current Wastewater Recycling Standards
Authors: Xiaoxin Zhang , Jin Huang , Ling Lin , Xiuteng Wang , Jing Liu , Fei Fang , Sinan Zhang
Published: July 2021

This study summarized the current development of wastewater recycling standards in China by analyzing published policies, existing national, industrial and local standards, as well as related activities in typical provinces. Meanwhile, further prospects for standardization in the area were also suggested in order to promote this industry.
Research on Evaluation of Ecological Carrying Capacity of Qinghai Province Based on PSR Model
Authors: Li Xiaoyong , Jia Haifa , Zhao Falan
Published: July 2021

Quantitative research and evaluation of ecological carrying capacity in Qinghai Province is in line with the requirements of the 13th five-year plan, and is of practical significance to the construction of ecological civilization in Qinghai Province. Based on the PSR model, this paper constructs the evaluation index system of ecological carrying capacity from three aspects of pressure, state ,and response, uses the entropy method to determine the index weight coefficient, and comprehensively evaluates the changing trend of ecological carrying capacity since the 12th Five Year Plan of Qinghai Province from the perspectives of economy, society, resources, and environment. The results show that: from 2011 to 2019, the comprehensive evaluation of ecological carrying capacity in Qinghai Province shows a trend of first decreasing and then increasing, the response index evaluation increases greatly, the state index evaluation shows a fluctuating growth, and the pressure index is relatively stable. Based on this, the PSR model and entropy method are typical and quantifiable, which can provide a reference for Qinghai provincial government to control the ecological environment, study ecological sustainability and delimit the ecological red line.
Analysis and Diagnosis of Water Environment Pollution Sources of Tonggu Lake in Fuling District, Chongqing City
Authors: Zheng Xiaolei , Yang Tao , Liu Gaoxiang
Published: July 2021

As an important urban lake in Fuling District, Chongqing City, there is water blooms in Tonggu Lake, which affect the ecological environment. This study analyzed and studied the external and internal status of water pollution through site survey, water quality testing and analysis, and laboratory data analysis, and diagnosed the water environment of Tonggu Lake, which is helpful for providing strong data support for the follow-up solution to the problem of water bloom in Tonggu Lake.
Evaluating pollution degree of oil spills on the sea surface
Authors: Zhou Xuan , Kou Jie , Chao Hao , Wang Taiyang
Published: July 2021

This article analyses influencing factors of pollution degree of oil spills on the sea surface and establishes corresponding evaluation system, thus combines fuzzy comprehensive evaluation method and analytic hierarchy process to evaluate pollution degree of oil spill accidents in the Bohai Sea. Based on the evaluation system, oil spill accidents in Penglai 19-3 oilfield and Suizhong 36-1 oilfield central platform are classified as serious pollution and light pollution respectively, which is consistent with relevant institutions and scholars, proving the rationality of the evaluation system and parameter selected.
An eco-friendly and effective method to fabricate flame retardant cotton fabrics
Authors: Zhang Xiaotao , Zhou Chunrong , Pan Haifeng
Published: July 2021

To reduce the flammability of cotton fabrics, an environmentally benign, simple and effective method was proposed. Coatings composed of phosphoguanidine/ATMP/alginate were deposited on the surface of the cotton fabrics through layer-by-layer (LbL) assembly. FTIR spectra indicate that the layer-by-layer deposition process is successfully carried out on the surface of cotton fabrics. TGA suggested that LbL coating can significantly increase the char residue. The results of MCC and vertical flame tests showed that the LbL coatings can remarkably enhance the fire safety properties of the cotton fabrics and a higher concentration of ATMP (2 wt%) can bring better effect of flame retardancy.
Research on ecological compensation of urban residual space to promote social integration
Authors: Chen Yu , Zhang Longwei , Wang Chao , Ding Xue
Published: July 2021

The continuous urbanization leads to a large number of land lost farmers pouring into the city, and the social integration of these people has become an important research topic of urban renewal. By means of field exploration and in-depth visit, this paper investigates and collates the data of some typical urban residual spaces where new industrial workers live, and finds that these spaces have common spatial characteristics, such as single spatial level, poor ecological environment and lack of landscape facilities. Then, by using statistical analysis and structural model, the comparative analysis of different types of space, and finds that the use of ecological compensation regulation can form a reasonable spatial layout, high-quality ecological effects and rich service facilities, so as to improve the spatial quality of urban residual space and provide highquality space environment for new industrial workers, Promote social integration, social integration of workers in new industries.
The ability of UHPC prepared with unpurified sea sand and seawater to protect embedded steel against corrosion
Authors: Wang Zuqi , Wang Jing , Zhou Yongxiang , Song Putao , Guan Qingfeng , Zhou Zhiren
Published: July 2021

Preparing concrete with unpurified sea sand and seawater is of great significance for the construction in coastal areas short of river sand and pure water. However, unpurified sea sand and seawater contain a lot of chloride ions which may cause steel corrosion problems. In this paper, unpurified sea sand and seawater are used to prepare ultra-high performance concrete (UHPC), and the potential differences between the steel bars with protective layer thickness of 5mm and 15mm and the Cu/CuSO4 reference electrode under two types of dry-wet cycle and the chloride ion concentrations at different depths from UHPC specimen surface after 40 dry-wet cycles are tested, the UHPC specimens are broken to observe corrosion of embedded steel bars. The results show that UHPC prepared with unpurified sea sand and seawater has good ability to protect embedded steel reinforcement against corrosion under dry-wet cycle conditions in lab.
Isolation and identification of a high-efficiency phenol-degrading bacteria and optimization of its degradation conditions
Authors: Sun Haili , Gao Tianpeng , Chang Guohua , Tai Xisheng , Yang Ruiqi , Zhang Qing , Yue Bin
Published: July 2021

Phenol is widely used in China, it not only pollutes the environment, but also accumulates toxic substances in the human body through the food chain, further harming humans. In this experiment, a strain of high-efficiency low-temperature degradation phenol bacteria B5 was selected from the soil contaminated by organic matter of Lanzhou. Through research methods such as Gram staining observation, DNA extraction, PCR amplification, sequencing and comparison, it was found that this strain was Pantoea agglomerans. Through the subsequent optimization of degradation conditions, it was found that the B5 strain can degrade 500mg/L of phenol to 24.8mg/L in 36h. The ability to degrade phenol is stronger between pH5.5-pH6.0, and the ability to degrade phenol is higher in a medium containing 4-8g/L sodium chloride. This research can provide certain theoretical guidance for phenol degradation.
Detection and analysis of surface currents in western Guangdong by compact surface wave radar
Authors: Li zili , Li Junjie
Published: July 2021

In order to study the detection performance of compact surface wave radar on ocean surface current in the west of Guangdong Province, firstly, the bistatic radar is set up to collect ocean echo data on the west coast of Guangdong Province. Then, by using the Multiple Signal Classification (MUSIC) algorithm, the comparative analysis results of ocean surface current information and the actual measurement results of DVS Current Meter are obtained. The root mean square error of flow velocity less than 10cm/s and the root mean square error of flow direction less than 25 degrees were obtained. It shows that compact surface wave radar can achieve good results and has good detection capability in the west of Guangdong, china.
Study on collapsibility of typical structural loess by multi-parameter comparative analysis
Authors: Hongcheng Liu , Changwei Lu , Yinxia Wang , Yi Song , Xiangfeng Guan , Rui Fu , Jingfeng Cao , Zhao Yang
Published: July 2021

To study the collapsibility of typical loess and its influencing factors in different areas, the samples in Jingyang, Lanzhou and Yili were studied. The correlation between initial moisture content, dry density, composition of particle size, structural parameters and the coefficient of subsidence is analyzed. The results show that: the coefficient of collapsibility is negatively correlated with the initial moisture content and dry density. In the experiments of multiple groups, the collapsibility coefficient has a certain correlation with the clay content, but not a uniform correlation with the particle content. The collapse coefficient is approximately positively correlated with the composite structure potential.
Research on environmental impact assessment system and legalization in China
Authors: Mingtsung Chen , Zhi’an Feng , Wei Qian , Yujing Zhang
Published: July 2021

In order to solve the conflict between economic growth and environmental protection, the environmental impact assessment system used by western countries has been gradually introduced into China. It is a scientific and professional assessment system, which is regarded as the best tool to solve the conflict between economic growth and environmental protection. The implementation of the environmental impact assessment system can undoubtedly prevent some construction projects from having serious adverse impact on the environment. Through the comparison and selection of the feasibility schemes, the environmental impact of some construction projects can be minimized. Therefore, the environmental impact assessment system is regarded as an important pillar and effective legal system for the implementation of predictive environmental policy, which has attracted more and more attention in the world. In order to implement the strategy of sustainable development, prevent the adverse impact on the environment caused by the implementation of planning and construction projects, and promote the coordinated development of economy, society and environment, China has formulated the environmental impact assessment law. The law came into force on September 1, 2003 and was amended for the second time on December 29, 2018.
Research on Site Selection and Capacity Determination of Mobile Energy Storage in Extreme Scenarios Considering the Behaviour of Decision
Authors: Deng Shiyu , Liu Chang , Liu Wenxia , Liu Zongqi
Published: July 2021

In order to ensure that the power supply can be restored quickly and efficiently under extreme conditions, an evaluation and decision-making method for mobile energy storage site selection and capacity planning considering the behaviour of decision makers is proposed. The prospect value is calculated based on the prospect theory to describe the bounded rationality and loss aversion of decision makers, and the attribute weight is calculated based on the relative closeness, and then the comprehensive value is obtained. Based on this, we can choose a mobile energy storage installation plan that is more in line with the psychology of decision makers.
Research on Different Applications of SMA in Seismic Resistance of Building Structures
Authors: Zhe Zhang
Published: July 2021

SMA(Shape memory alloys) are unique materials with many excellent properties, such as excellent wear resistance, corrosion resistance, high power/weight ratio and biocompatibility, high damping, shape memory effect, super elasticity, etc. In civil engineering, scientists try to use the advantages of SMA by making it into different components and they have already made some types of components that are SMA bracing, SMA constrains RC columns, SMA ring springs and base isolation bearing. All of these components can make contributions to seismic resistance, therefore, this article mainly focuses on the the contribution of SMA bracings and SMA constrains RC columns to the seismic resistance of the structure and the relationship between the improvement of their own performance and SMA.
Kaczmarz method for saddle point systems
Authors: Wang Jinmei , Yin Lizi , Wang Ke
Published: July 2021

The Kaczmarz method is presented for solving saddle point systems. The convergence is analyzed. Numerical examples, compared with classical Krylov subspace methods, SOR-like method (2001) and recent modified SOR-like method (2014), show that the Kaczmarz algorithm is efficient in convergence rate and CPU time.
Subsection construction technology of rectangular concrete independent column with super high cross section
Authors: Li Guangjun , Mo Tianfang , Xu Ningbo , Zhang Weixiong , Lu Hanwen , Deng Deyuan , Yi Mingbo
Published: July 2021

With the progress of engineering technology, the ability of design and construction has been significantly improved, which the number of long-span construction and long-span Bridges and long-span steel structures are increasing more and more. As the main supporting members of Bridges and steel structures, the quality assurance of rectangular reinforced concrete independent columns is particularly important. In the implementation process of No.18 Maintenance Hangar Project of GAMECO Aircraft Maintenance Facility Phase III in Guangzhou Baiyun International Airport of China Southern Airlines, through research and practice, our company applied the subsection construction technology of super high section rectangular concrete independent columns, which can not only guarantee the quality and forming effect of the column body, but also reduce the input of formwork materials. Improve the utilization rate of formwork and scaffold effectively, and then reduce the input of turnover materials, and achieve remarkable results.
Risk assessment of water and mud inrush in a tunnel in Chongqing based on analytic hierarchy process
Authors: Wang Yong
Published: July 2021

Water and mud inrush is one of the typical geological hazards during tunnel construction in karst area. In weight of water or mud inrush risks of karst tunnels are studied and the index system for water and mud inrush risk evaluation is established based on analytic hierarchy process. The analysis shows that geological structure, formation lithology and groundwater level are the main control ingredients of water or mud inrush risk；geographic and geomorphic conditions, attitude of rock formation are the minor significant factors；surrounding rock mass classification , rainfall are the least important elements. Aiming at a tunnel in Chongqing, combining with the actual geological situation of the tunnel site, the evaluation model is used to evaluate the risk of water and mud inrush in each section, which provides a certain theoretical basis for the prevention and control of water and mud inrush disaster during the tunnel construction.
Research on the Structural Design of Academic Report Complex Building in a University
Authors: Ren Haibo
Published: July 2021

This project is the construction project of the academic report comprehensive building of the Central Youth League School. The main function of the project is the academic report room, including an 800-person lecture hall, a 300-person multi-function lecture hall, a 500-person multi-function lecture hall, an exhibition hall, etc., and three underground floors. There are three floors above the ground, and one floor is partially high. There are 12.8, 13.8, 15.7, 18.2, 18.6, 20.8, 27.8 meters in the sub-regions of the roof structure elevation. This article introduces the structural system, the judgment of structural out-of-limit situations, prestress design, steel truss design, suspension steel structure design, cantilevered large-span concrete beams, etc., through a variety of structural calculation and analysis methods, and find out structural weaknesses, and adopt Corresponding seismic strengthening measures, the calculation results show that the structure has good seismic performance and can meet the requirements of the code.
Simulation Analysis of Vertical Movement of Nitrate Nitrogen in Vadose Zone of Fluvo-aquic Soil Based on HYDRUS-1D
Authors: Jing Ping , Zhang Hui
Published: July 2021

Wastewater reuse has significant social, economic and ecological benefits, and has become an important measure to alleviate the water crisis. In this paper, in the simulation analysis of soil nitrate nitrogen, the method of combining soil column leaching and model simulation is used to test the accuracy of the model. The Pearson correlation coefficient is as high as 0.99 and the Nash coefficient is also over 0.9. It shows that the simulation results of the simulation model are credible. The Hydrus-1D model is used to visually simulate the change process of Tianjin fluvo-aquic soil over time. In the simulation, the process of solute migration in the 6-18 cm of the ground surface is basically the same, and they all reach a stable state about 4 hours, and show a linear increase trend four hours ago, and then the concentration remains stable and unchanged.
Design of Flying-Bird Type Cable Stayed Arch Bridge with Three-Leaf Rose Shaped CFST Arch Rib
Authors: Wang Weisheng , Wang Jilin
Published: July 2021

According to the geometric figure of three-leaf rose curve, this paper puts forward a flying-bird type cable-stayed arch bridge with three-leaf rose curve shaped CFST arch rib, which has beautiful appearance and one bridge leads to three banks.The space cables are set between the three-leaf rose linear space arch ribs to resist negative bending moment, and the tie cables are set between the arch feet to resist positive bending moment. On the inclined pylon at the tail of the flying-bird type cable-stayed arch bridge, the stay-cables are arranged to balance the arch thrust, and the suspension-cables are arranged on the three leaf rose linear spatial arch ribs to hang the three fork bridge deck.The flying-bird type cable-stayed arch bridge with three-leaf rose linear CFST arch rib adopts spatial cable structure system, which has good structural stability.Combined with the actual project, the engineering parameters are designed, the Midas finite element analysis model is established, the internal force analysis and modal analysis are carried out, and the rationality of flying-bird type cable-stayed arch bridge with three-leaf rose linear CFST arch rib is verified.
The influence of soft clay saturation characteristics on unconfined compressive strength in Guangdong-Hong Kong-Macao Greater Bay Area
Authors: Guan DaShu , Zheng JiaXi , Huang WenHao , Zhong JunZhi , Du WenWen , Luo ZhiDe , Zhou YinShi
Published: July 2021

In order to study the influence of saturated characteristics of soft clay on unconfined compressive strength, the soft clay of Guangdong-Hong Kong-Macao Bay Area is taken as the research object, comparing and contrasting on unconfined compression test of saturated clay and unsaturated clay in laboratory, studying the variation law of unconfined compressive strength and sensitivity of unsaturated and saturated soft clay. The test results show that: 1. During the failure of unsaturated soft clay samples, oblique fractures appear, showing brittle shear failure, while the saturated clay samples appear constant bulging in the middle, and finally a “cross” is broken in the central bulging part, showing plastic shear failure.2. The unconfined compressive strength of unsaturated clay is about 10kPa higher than that of saturated soft clay, and its corresponding sensitivity is also about 0.4 higher. It can be shown that the soil saturation has a certain influence on the soil strength. The difference between saturated soil and unsaturated soil is the existence of gas phase. To be more precise, the existence of gas phase in unsaturated soil, i.e. the existence of suction, makes the soil stronger and presents the brittle shear failure form, while the saturated soil basically presents the plastic shear failure form.
Study on the adhesion performance of medium weathered igneous rock aggregate and asphalt
Authors: Jiao Xuxue , Tao Yuanhong , Ren Longfang
Published: July 2021

In view of the current situation of the shortage of alkaline aggregate and the abundance of weakly acidic weathered igneous rocks around Nairobi, Kenya, in order to fully improve the adhesion performance of asphalt and acidic igneous rocks, this paper studies the effects of different anti-stripping agents separately and combined on the adhesion performance of asphalt aggregates. The results show that the anti-stripping agent can improve the anti-stripping property of the medium weathered igneous rock aggregate and asphalt, and the effect is better when the anti-stripping agent is combined.
Spatial simulation of population in Shandong Province based on night-time imagery and land cover data
Authors: Yang Keyi , Li Yunling , Liu Yang
Published: July 2021

Population spatial data can more truly express the actual distribution characteristics of the population, and provide data support for the regional environment and population development. Use Shandong Province as the research area, township-level census data, revised DMSP/OLS night-time data, and Globaland30 land cover data as data sources, partitions based on population agglomeration, and uses a stepwise regression method to build a population data spatial model. Use the model to simulate population density with a resolution of 100m. The experimental results show: Stepwise regression model good precision, the average relative error was 23.56%, and Root Mean Square Error, Mean Absolute Error are better than the other two public datasets. The simulation results are better than the two public datasets.
Structural dynamic response of underground structure with vertical ground motion input
Authors: Liu Tong , Xu Fuwang , Wang Qinghe , Xu Huaiyu
Published: July 2021

Since many cases of structural damage in past earthquakes have been attributed to strong vertical ground motion, our understanding of vertical seismic load effects and their influence on seismic performance of subway station structure is limited. In this study, the Daikai subway station is taken as a typical example. A two-dimensional finite element model of both soil and structure was established using finite element software ABAQUS. Two input approaches of ground motion are considered, including the horizontal component alone and the vertical and horizontal motions simultaneously. Four groups of ground motion records are selected according to the site type of this station and scaled to the strong intensity which can make the station damage. Results show that the vertical seismic load increases the axial force of the column component apparently, while horizontal seismic load has little effect on axial compression ratio.
Research and Analysis of concrete facilities’ corrosion in coastal substaion of fujian
Authors: Dishan Yang , Jinbo Zhang , Xi Lin , HuanXin Huang
Published: July 2021

Corrosion problems of outdoor concrete facilities was summarized through research on coastal substation of Fujian, such as serious corrosion of steel ring and weld in the joints of cement poles, exposure and corrosion of reinforcement, cracking and falling off of concrete cover. The information of concrete facilities’ assessment reports was summarized, and it was found that concrete compressive strength of present age satisfied early design drawings. In addition, appraisal of reliability revealed that all facilities couldn’t satisfy the requirements of current standards and seismic appraisal revealed that all facilities couldn’t meet the seismic requirements. The analysis of concrete facilities’ corrosion mechanism was made, and it was found that concrete facilities in coastal substation suffered triple effects of carbonation, chloride corrosion and stray current corrosion. The power failure schemes needed for present repairing and strengthening measures of concrete facilities lack of feasibility. Research on repairing and strengthening measures of concrete facilities that requiring no or small-scale power cut would be of great significance.
Research progress of rice husk ash in solidified soil
Authors: Tong HAO , Qian LIU , Leng Fa-Guang , Qiao Tian-Long
Published: July 2021

Rice husk ash is a kind of volcanic ash material with high silicon. This also provides a feasibility for rice husk ash as cement-based auxiliary cementing material. China is rich in rice husk resources, and the rice husk ash is stacked. Using rice husk ash (RHA) instead of traditional cementitious materials can effectively solve the environmental pollution caused by the accumulation of rice husk ash. Domestic and international scholar have added rice husk ash as mineral admixture to concrete, but the utilization rate is very low. In order to increase the added value of rice husk ash, the high silicon property of rice husk ash was used to solidify soil. The application range of solidified soil is wide, the requirements for materials are not high, and the functions are different, which can realize the extensive use of rice husk ash. This paper summarizes the literature on comprehensive utilization of rice husk ash at home and abroad, systematically expounds the physicochemical properties and production process of rice husk ash, introduces the application of rice husk ash in solidified soil, and points out the unsolved problems in this field, which provides a direction for the further development.
Seismic vulnerability assessment of RC curved bridges piers subjected to bidirectional earthquake
Authors: Li Rui
Published: July 2021

Curved beam bridge is a kind of irregular structure, which has the advantage of adapting to complex terrain, but it is more vulnerable to damage than regular bridge under earthquake. This paper investigates the vulnerability of curved continuous girder bridges under the action of bidirectional earthquake horizontal earthquake, and the difference of vulnerability between side pier and intermediate pier is analyzed. Fragility assessment is performed using an incremental dynamic analysis method subjected to a wide range of as-recorded sequences. A proper engineering demand parameter (EDP) which can result in the most probability of failure at bridges employed in this study is determined. Result indicates that only considering the unidirectional seismic input will underestimate the seismic response and potential damage of the structure, which is not accurate for the seismic performance evaluation of the bridge. Result also shows that the damage probability of the intermediate pier of the curved bridge is higher than that of the side pier, and the more serious the failure, the smaller the difference between the two piers.
The Study of Wind Turbine Blade Fatigue Test
Authors: Zheng Jiaqi , Yu Qiming , Zhu Botao , Wu Changqing , Huang Yiling , Sa Haoliang , Wu Mengwei , He Shanqing
Published: July 2021

The fatigue test of wind turbine blade is an important means to verify the fatigue life of wind turbine blade. This paper analyses the problems existing in the fatigue test of wind turbine blade, focuses on the excitation mode, the relationship between excitation amplitude and vibration frequency and the vibration principle, and puts forward feasible solutions in practical operation.
Design and Characteristic Analysis of a New Type of Hydraulic Pulsation Suppressor
Authors: Yuan Jun , Jiang Hang , Fang Zheng-yan , Wang Tian-sheng , Luo Zhi , Jiang Feng-xian , Yin Gui-hong
Published: July 2021

In order to decrease the pressure pulsation of high-pressure hydraulic system and speed up the process of high-pressure hydraulic system, a new type of hydraulic pulsation suppressor is designed. The hydraulic pulsation suppressor is designed on the basis of the structural characteristics and attenuation performance of the expansion chamber attenuator and H-type muffler. The theoretical model of the modern hydraulic pulsation suppressor is established based on the fluid theory, and the attenuation performance of the new hydraulic pulsation suppressor is analyzed. The results demonstrate that the designed new hydraulic pulsation suppressor can attenuate the pressure pulsation with a pulsation frequency of 20 Hz～2000 Hz, and attenuate the frequency bandwidth; the attenuation effect is above 50dB, and the attenuation effect is ideal.
High Temperature Performance of SBS and LM-S Modified Asphalt Mixtures by Triaxial Test
Authors: Tang-Baoli  , Ren-yongqiang  , Chen-Xiangmei  , Hou-Huifang  , Liang-Jianping
Published: July 2021

In order to study the high temperature performance of LM-S modified asphalt mixture and SBS modified asphalt mixture, repeated loading creep test was used to study the influence of temperature and deviatoric stress on the axial permanent deformation of the two kinds of asphalt mixture. At the same time, Permanent deformation, ε@5000, flow number FN and creep rate were select to evaluation of high temperature performance from different directions. The results show that the ε@5000 and creep rate are failed in the condition of high temperature and large deviatoric stress, so it hast widely practicable. The flow number FN is also limited by the conditions, which leads to the distortion of the flow number at lower temperature and smaller deviatoric stress so it is not easy to direct used as the evaluation index. Axial permanent deformation can reflect the permanent deformation in different cycles which is an excellent index to evaluate the high temperature performance of the two kinds of asphalt mixture, it is recommended to use axial permanent deformation to compare the LM-S modified asphalt mixture and SBS modified asphalt mixture The experimental results show that the axial permanent deformation of the LM-S modified asphalt mixture is always less than that of SBS modified asphalt mixture,it indicating that the high temperature rutting resistance of the LM-S modified asphalt mixture is better than that of SBS modified asphalt mixture.
Construction and application of factory digital twin model based on BIM and point cloud
Authors: Qin Guocheng , Wang Ling , Hou YiMei , Gui HaoRan , Jian YingHao
Published: July 2021

The digital twin model of the factory is the basis for the construction of a digital factory, and the professional system of the factory is complex. The traditional BIM model is not completely consistent with the actual position of the corresponding component, and it is difficult to directly replace the digital twin model. In response to this situation, relying on a certain factory project, the point cloud is used to eliminate the positional deviation between the BIM model and the factory during the construction phase, improve the efficiency and accuracy and reliability of model adjustment and optimization, and , realize the conversion from BIM model to digital twin model. A novel algorithm is developed to quickly detect and evaluate the construction quality of the local structure of the factory, so as to input the initial deformation data of the structure into the corresponding model and feed back to the construction party for improvement. The results show that the digital twin model, which is highly consistent with the actual location of the factory components, not only lays a solid foundation for the construction of a digital factory, but also further deepens the integration and application of BIM and point clouds.
Influence of Silica Fume on the Performance of Moderately Weathered Phonolite Concrete
Authors: Wu Xiaowei , Tang Zhaoxi
Published: July 2021

The effect of silica fume on the performance, mechanical properties, durability and air tightness of airtight concrete was studied. The results showed that with the increase of silica fume content, the concrete performance will decrease, the compressive strength of airtight concrete will increase first, and reach the highest when the silica fume content was 8%, and then it will decrease gradually. With the increase of silica fume content, the corrosion resistance coefficient of concrete increased gradually, then decreased. The permeability coefficient of concrete decreases with the increase of silica fume content, and the air tightness of concrete was improved obviously; In the project, it was advisable to use silica fume to prepare airtight concrete, and the amount of silica fume should be controlled at 4% - 8%.
The project design of closure with cofferdam in a large reclamation project
Authors: Jin Hai-Sheng , Xu Ji , Ge Guo-Chang
Published: July 2021

The closure of the reclamation project generally requires that the sluice has been built and can be normally opened and closed for drainage. There is a large amount of follow-up work after closured of this project. In order to reach the safe flood control standard for the next typhoon season after the closure, reduce the flood control risk, and strive for sufficient time for the subsequent construction of the seawall, it is necessary to closure in advance under the condition that the sluice has not yet been opened. Therefore, this project demonstrated the feasibility of the closure with cofferdam based on the premise of think outside the box and theoretical calculation. The successful completion and acceptance of the reclamation project proved that the project is successful.
The design of super long span pedestrian landscape cable stayed bridge with sightseeing bridge tower
Authors: Jiang Tao , Li BiQing
Published: July 2021

According to the design requirements of the super long-span pedestrian landscape cable-stayed bridge in Lake view Park, a kind of sightseeing tower-style pedestrian landscape three-tower cable-stayed bridge structure system was proposed. Sightseeing tower type bridge tower structure and duck egg arched bridge tower replace traditional cable-stayed bridge tower structure. Through the establishment of Midas finite element analysis model, dynamic modal analysis research was carried out. The analysis shows that: the sightseeing tower structure and the cable-stayed bridge tower structure are combined into one, and the two have good structural matching.
Test of SMA - 16 asphalt mixture ratio on the runway of Da Lian Airport
Authors: Tian Shuaituan , Zhao Kunyang , Guo Lei , Wang Hanxun
Published: July 2021

After years of use, there’s oil loss on the asphalt pavement. the bond strength of aggregate decreases. Loose threshing is serious. In order to improve the pavement performance, Extend the service life of pavement , Improve the safety of aircraft operation. we test the SMA-16 modified asphalt mixture on the runway of Da Lian Airport from many factors, including raw materials, admixtures, gradation design, optimum ratio of oil to stone, then we find the best ways to resolve it.
Comparison and analysis of conversion methods for self-balancing test of pile bearing capacity
Authors: Qiu Yonggang , Huang Chuansheng , Hong Renhao , Chen Chunhan , Yi Jinxiang , Li Weixiong
Published: July 2021

The principle and method of self-balancing test are introduced briefly. In this article, through comparison of common Q-S curve of equivalent transformation to transform from the balance of the measured load-displacement curve for the traditional method of load - displacement curve, puts forward the advantages and disadvantages of each, through the three bored piles in static load test of pile reaction from balance to detect vertical compressive ultimate bearing capacity of single pile is in line with the requirements and compare the load-displacement curve after conversion. Some problems of the self-balancing method in engineering are pointed out, which is of certain reference value to the popularization and application of the self-balancing test of pile bearing capacity.
Mechanical Properties of Gangue Cement Stabilized Road Foundation Mixture
Authors: Zhang Dongsheng , Liu Naicheng , Mao Mingjie , Li Jiabin
Published: July 2021

In this study, coal gangue was used to replace the four single-graded natural gravels of 0~5 mm, 5~10 mm, 10~20 mm, and 20~26.5 mm to design the mix ratio and to study the influence in particle size changes of coal gangue on the mechanical properties of the mixture. The research results show that: The maximum dry density of the mixture with coal gangue is lower than the density of the natural crushed stone water-stable mixture, and the optimal moisture content is higher than that of natural crushed stone water-stable mixture; coal gangue aggregate is mixed with cement stabilized in the crushed stone mixture, and the 7d and 28d unconfined compressive strength, splitting strength, and compression rebound modulus values of the mixture are all reduced, which has a degrading effect on the mechanical properties of the mixture; however, both can attain high speed, which is the basic strength requirements for expressways, including first-class highways.
Four-Cable-Plane Spatial Cable Stayed Bridge with Two-Amplitude Curved Deck for Canyon-River
Authors: Wang Jilin , Xu JinFa
Published: July 2021

On the basis of the original design of Ruck Bridge by Mr. Lin Tongyan, this paper modifies the single-amplitude curved cable-stayed bridge of Ruck Bridge to be an elliptical ring main beam of two-amplitude curved deck, with a duck-egg-shaped arch tower and a spatial cable net with four cable planes, to form a spatial four-cable-plane two-amplitude-curve cable-stayed bridge for the canyon-river topography, so as to improve the structural stress performance of the curved-beam cable-stayed bridge, promote the traffic function and improve the landscape. Combined with the 400m-span New Ruck Cable-stayed Bridge, engineering parameters are designed, a Midas finite element analysis model is established, and the dynamic modal analysis is carried out to verify the structural superiority of this new four-cable-plane spatial cable-stayed bridge with two-amplitude curved deck.
Building integrated photovoltaic design of nonlinear airport roof based on ruled surface fitting
Authors: Sui Jinting , Zhang Longwei
Published: July 2021

Solar energy is a new renewable energy. Using solar energy to generate electricity is an effective means to achieve sustainable development. The huge roof at the top of the airport is a natural interface to receive solar energy, which can be used to supply the energy needed by the airport through building integrated photovoltaic design. However, due to the curved shape of the airport roof, there are limitations in solar energy acquisition and construction of the airport roof. In this paper, the method of “ruled surface fitting-solar radiation analysis-modular unit arrangement” is used to optimize the shape of the non-linear airport roof, and convert the complex roof surface shape into a straight line with good sunlight performance and easy construction. The ruled surface can better integrate BIPV and nonlinear airport, and improve the solar power generation efficiency of the building, thus improving the sustainable performance of the building.
Research on safety risk early warning of tunnel construction based on BIM and RFID Technology
Authors: Yong Chen , Xudong He , Guojun Lin , Ping Wu
Published: July 2021

Due to the frequent occurrence of safety accidents in tunnel construction, it poses a great threat to property safety and the life safety of construction personnel. According to the classification of accident types, this paper standardizes the data of influential risk factors, delimits the boundary of dangerous areas, and proposes the specific steps of inputting field information into BIM database. The results show that the combination of BIM and RFID technology can monitor the conditions of the construction site in real time, and realize the automatic early warning of the dangerous sources in the tunnel construction.