bluuebunny/crossref_metadata_2025 huggingface dataset:
A negotiation‐based right‐of‐way assignment strategy to ensure traffic safety and efficiency in lane changes
Authors: Zhao Can , Li Zhiheng , Li Li , Wu Xiangbin , Wang Fei‐Yue
Published: July 2021

It is widely acknowledged that verifying the safety of autonomous driving strategies requires a substantial body of simulation testing and road testing. In recent years, the formal safety methods represented by Responsibility‐Sensitive Safety (RSS) have encouraged low‐cost autonomous driving safety research, benefitting from its accurate assessment of safety and clear division of responsibilities. However, how to maintain traffic efficiency while ensuring safety remains a challenge. To address this problem, this paper proposes a formulized negotiation‐based lane‐changing strategy that makes a trade‐off between safety and efficiency. Both theoretical analysis and numerical experimental results shows that compared to RSS, our strategy can noticeably improve the success rate of changing lanes on the premise of safety.
Guest Editorial: Papers from the SEE International Conference RADAR 2019
Authors: Marc Lesturgie , Laurent Savy
Published: July 2021

This Editorial introduces a Special Issue of papers from the SEE International Conference RADAR 2019, which took place in Toulon, France, 23–27 September 2019. The papers are expanded versions of ones that were judged in the reviewing process to be of the highest quality and relevance. Benefitting from the unique location of the conference centre on the French Riviera, the conference was given the theme ‘Sensing from sea to space’, attracting nearly 400 attendees from 26 countries from all over the world (Figure ). Engineers and researchers coming from private or public sector (universities and laboratories) shared their knowledge and experience on radar topics of common interests from physics to signal processing, from sensor validation to system design, and also on emerging technologies based on artificial intelligence; all topics being supported by 200 papers presented either in oral (150 papers in 36 sessions), or poster sessions (50 papers). Figure  shows the range of topics of the papers.

Conference attendees by country

image

Conference paper topics

image
Spectroscopic measurements of CH3OH in layered and mixed interstellar ice analogues
Authors: Müller B. , Giuliano B. M. , Goto M. , Caselli P.
Published: July 2021

Context. The molecular composition of interstellar ice mantles is defined by gas-grain processes in molecular clouds, with the main components being H2O, CO, and CO2. Methanol (CH3OH) ice is detected towards the denser pre-stellar cores and star-forming regions, where large amounts of CO molecules freeze out and get hydrogenated on top of the icy grains. The thermal heating from nearby protostars can further change the ice structure and composition. Despite the several observations of icy features carried out towards molecular clouds and along the line of site of protostars, it is not yet clear if interstellar ices are mixed or if they have a layered structure.

Aims. We aim to examine the effect of mixed and layered ice growth in dust grain mantle analogues, with specific focus on the position and shape of methanol infrared bands, so dedicated future observations could shed light on the structure of interstellar ices in different environments.

Methods. Mixed and layered ice samples were deposited on a cold substrate kept at a temperature of 10 K using a closed-cycle cryostat placed in a vacuum chamber. The spectroscopic features were analysed by Fourier transform infrared spectroscopy. Different proportions of the most abundant four molecular species in ice mantles, namely H2O, CO, CO2, and CH3OH, were investigated, with a special attention placed on the analysis of the CH3OH bands.

Results. We measure changes in the position and shape of the CH and CO stretching bands of CH3OH depending on the mixed or layered nature of the ice sample. Spectroscopic features of methanol are also found to change due to heating.

Conclusions. A layered ice structure best reproduces the CH3OH band position recently observed towards a pre-stellar core and in star-forming regions. Based on our experimental results, we conclude that observations of CH3OH ice features in space can provide information about the structure of interstellar ices, and we expect the James Webb Space Telescope to put stringent constraints on the layered or mixed nature of ices in different interstellar environments, from molecular clouds to pre-stellar cores to protostars and protoplanetary discs.
Stark broadening for Br VI and Kr V-VII lines in hot star atmospheres
Authors: Sahal-Bréchot S. , Elabidi H.
Published: July 2021

Context. This paper provides missing Stark broadening of the Br VI and Kr V-VII lines recently discovered in the ultraviolet spectrum of the hot white dwarf RE 0503–289 and investigates the importance of the Stark broadening mechanism versus the Doppler mechanism in that star. As far as we know, this is the first time that Stark widths of Br VI and Kr V-VII lines have been calculated.

Aims. The recent discovery of new lines of Br VI and Kr V-VII encourages us to provide their Stark broadening to enrich the STARK-B database and for use in interpretations of the observed spectra.

Methods. We used our quantum mechanical method for calculating electron impact broadening to provide Stark widths. The method starts with an evaluation of the structure and collision parameters using the University College London codes SUPERSTRUCTURE/DISTORTED WAVE/JAJOM, which are adapted to the line broadening calculations. We then used the collision parameters to calculate the line widths using our programs.

Results. We provide the missing widths of 35 lines of Br VI and Kr V-VII at different electron temperatures and at density Ne = 1017 cm−3. We find that the Stark broadening mechanism is preponderant compared to the Doppler one for almost all the plasma conditions of the considered DO white dwarf atmospheres.
Origin of the ring structures in Hercules A
Authors: Timmerman R. , van Weeren R. J. , Callingham J. R. , Cotton W. D. , Perley R. , Morabito L. K. , Gizani N. A. B. , Bridle A. H. , O’Dea C. P. , Baum S. A. , Tremblay G. R. , Kharb P. , Kassim N. E. , Röttgering H. J. A. , Botteon A. , Sweijen F. , Tasse C. , Brüggen M. , Moldon J. , Shimwell T. , Brunetti G.
Published: July 2021

The prominent radio source Hercules A features complex structures in its radio lobes. Although it is one of the most comprehensively studied sources in the radio sky, the origin of the ring structures in the Hercules A radio lobes remains an open question. We present the first sub-arcsecond angular resolution images at low frequencies (<300 MHz) of Hercules A, made with the International LOFAR Telescope. With the addition of data from the Karl G. Jansky Very Large Array, we mapped the structure of the lobes from 144 MHz to 7 GHz. We explore the origin of the rings within the lobes of Hercules A, and test whether their properties are best described by a shock model, where shock waves are produced by the jet propagating in the radio lobe, or by an inner-lobe model, where the rings are formed by decelerated jetted plasma. From spectral index mapping our large frequency coverage reveals that the curvature of the different ring spectra increases with distance away from the central active galactic nucleus. We demonstrate that the spectral shape of the rings is consistent with synchrotron aging, which speaks in favor of an inner-lobe model where the rings are formed from the deposition of material from past periods of intermittent core activity.
A meeting at z ∼ 3: Young massive galaxies and an AGN within 30 kpc of the luminous QSO LBQS 0302–0019
Authors: Husemann B. , Worseck G. , Arrigoni Battaia F. , Sander A. A. C. , Shanks T.
Published: July 2021

Context. Contrary to expectations from scenarios of black hole growth driven by galaxy interactions and mergers, dual active galactic nuclei (AGN) with kiloparsec separations are rarely observed and are very difficult to identify, in particular at high redshifts (i.e. z > 2).

Aims. Focussing on the recently discovered dual AGN system LBQS 0302−0019 at z = 3.29, we seek to identify further group members in its environment and to understand their formation history through deep high-angular-resolution imaging.

Methods. We present deep Hubble Space Telescope (HST) Wide-field Camera 3 near-infrared imaging of LBQS 0302−0019. In combination with ground-based VLT/HAWK-I imaging, we infer accurate sizes, colours, ages, and stellar masses of companion galaxies.

Results. We clearly detect four companion objects close to LBQS 0302−0019 that also have faint signatures in the ground-based images. We constrain light-weighted ages and masses for the two most prominent companions, Jil1 and Jil2, to t⋆ = 252−109+222 Myr with log(M⋆/[M⊙]) = 11.2−0.1+0.3 and t⋆ = 19−14+74 Myr with log(M⋆/[M⊙]) = 9.4−0.4+0.9, respectively. The HST data also show that the obscured AGN, previously identified by strong nebular He II emission, is associated with the young massive companion Jil2. Because very massive stars of the starburst cannot be solely responsible for the He II emission, we strengthen our initial conclusion that Jil2 has been hosting an AGN.

Conclusions. If the young starburst of Jil2 had been accompanied by sustained black hole growth, Jil2 may have contributed He II-ionising flux to create the large He II Lyα proximity zone around LBQS 0302−0019. Hence, the duration of the current luminous AGN episode of LBQS 0302−0019 may have been overestimated.
The A-shell star ϕ Leo revisited: its photospheric and circumstellar spectra
Authors: Eiroa C. , Montesinos B. , Rebollido I. , Henning Th. , Launhardt R. , Maldonado J. , Meeus G. , Mora A. , Rivière-Marichalar P. , Villaver E.
Published: July 2021

Context. We previously suggested that variable red- and blueshifted absorption features observed in the Ca II K line towards the A-type shell star ϕ Leo are likely due to solid, comet-like bodies in the circumstellar (CS) environment.

Aims. Our aim is to expand our observational study of ϕ Leo to other characteristic spectral lines of A-type photospheres as well as to lines arising in their CS shells.

Methods. We obtained more than 500 high-resolution optical spectra collected at different telescopes over 37 nights in several observing runs from December 2015 to January 2019. Consecutive time-series spectra were taken, covering intervals of up to ~9 h on some nights. We analysed some photospheric lines, in particular Ca I 4226 Å and Mg II 4481 Å, as well as the circumstellar shell lines Ca II H and K, the Ca II IR triplet, Fe II 4924, 5018, and 5169 Å, Ti II 3685, 3759, and 3761 Å, and the Balmer lines Hα and Hβ.

Results. Our observational study reveals that ϕ Leo is a variable δ Scuti star whose spectra show remarkable dumps and bumps superimposed on the photospheric line profiles, which vary in strength and sharpness, propagate from blue- to more redshifted radial velocities, and persist for a few hours. Similarly to other δ Scuti stars, these features are likely produced by non-radial pulsations. At the same time, all shell lines present emission at ~3 km s−1 centred at the core of the CS features, and two variable absorption minima at both sides of the emission; those absorption minima occur at almost the same velocity for each line, that is, no apparent dynamical evolution is observed. The variations observed in the Ca II H and K, Fe II, and Ti II lines occur on a range of timescales from minutes to days and between observing runs, but without any clear correlation or recognisable temporal pattern among the different lines. In the case of Hα, the CS contribution is also variable in just one of the observing runs.

Conclusions. We suggest that ϕ Leo is a rapidly rotating δ Scuti star surrounded by a variable, (nearly) edge-on CS disk possibly re-supplied by the δ Scuti pulsations. The behaviour of the CS shell lines is reminiscent of that of rapidly rotating Be shell stars with an edge-on CS disk, and is clear evidence that the variations observed in the CS features of ϕ Leo are highly unlikely to be produced by exocomets. In addition, the observational results presented in this work, together with some recent results concerning the shell star HR 10, highlight the need for critical revision of the Ca II K features, which have been attributed to exocomets in other shell stars.
Evaluation Index System of Marine Ecological Environment
Authors: Xing Congcong , Li Jing , Li Xiuren , Zhao Bei
Published: July 2021

Based on the model of ecological environment evolution in the process of the economic development, this paper constructed the evaluation index system of marine ecological environment. The results were shown as follows: the evaluation index system of marine ecological environment consists of 1 object layer, 3 element layers (state of marine ecological environment pressure of marine ecological environment and response of marine ecological environment), and 15 factor layers. Index weight was calculated through combination weighting approach of subjective and objective evaluation method of analytic hierarchy process(AHP) and entropy method. The evaluation indicator system and evaluation method have general applicability and strong operability.
Ecological planning strategies for urban parks based on biodiversity conservation and promotion: a case study of Qingxiushan Forest Park in Nanning City
Authors: Ming Shuang , Du Qin
Published: July 2021

Urban biodiversity plays an important role in maintaining urban ecosystem, beautifying urban environment, improving economic benefits and human well-being, and urban park, as an important habitat of urban biology, is an important part of urban biodiversity. Taking Qingxiu Mountain Park in Nanning City as an example, this paper analyzes the main problems and challenges of biodiversity conservation and promotion, and puts forward a scientific reference basis for the promotion and protection of biodiversity in Qingxiu Mountain Park in Nanning City.
Comparison of Soil Moisture Dynamics in Fixed Dune and Sandy Grassland on Korqin Sandy Land
Authors: Yao Shuxia , Zhao Chuancheng
Published: July 2021

Based on the fixed-point observation data of soil moisture in different soil layers (0~150 cm) of fixed dunes and sandy grassland in the semi-arid region of Horqin Sandy Land, in the growing season (May to September) from 2005 to 2014, we conducted a comparative study on the seasonal, inter-annual, and spatial dynamics of soil moisture in the two types of sandy land. The results revealed that: (1) in the growing season, the soil moisture in sandy grassland was significantly higher than that in fixed dunes, and the multi-year average soil moisture in both types of sandy land was higher in July than in other months; (2) from 2005 to 2014, the average soil moisture in both types of sandy land was relatively high in 2010, and the average soil moisture in sandy grassland increased gradually with each year; specifically, there was a significant increase in soil moisture in June, while the average soil moisture in fixed dunes did not show an obvious increase; (3) the soil moisture in fixed dunes and sandy grassland generally showed a trend of “first increase, then decrease, and finally increase again”, with the increase in soil depth, and this change was more obvious for sandy grassland.
Analysis on Spatial and Temporal Evolution Characteristics of National Land Structure of the Lanzhou-Xining Urban Agglomeration in the Upper Reaches of the Yellow River
Authors: Nie Xiaoying , Li Kaiming , Huang Wanzhuang , Li Xin
Published: July 2021

Based on the land utilization data of the Lanzhou-Xining urban agglomerations in 2000, 2005, 2010 and 2015, using the methods of transfer matrix, the paper makes a quantitative analysis of the spatial and temporal evolution process, characteristics and laws of various types of national land space from 2000 to 2015. The results are as follows. 1) Urban construction space, industrial and mining construction space and rural living space continued to increase, while agricultural production space showed a decreasing trend, and green ecological space and other ecological space showed an overall increasing trend from 2000 to 2015. 2) The characteristics of national land space transfer are as follows: the transition is relatively active from 2000 to 2005 and from 2010 to 2015, mainly from green ecological space and agricultural production space to urban construction space, rural living space and industrial and mining construction space.
Analysis of metal element contents in soil sample of different altitude from lead-zinc tailing mine mount in Longnan City, Gansu Province
Authors: Yin Zhuoxin , Zheng Yao , Wang Zhengzhou , Yue Bin , Chang Guohua
Published: July 2021

Contents of metal elements in soil covered lead-zinc tailing mine should be determined after long-term exposured with tailing ores, results should be compared with the requirements of metal contents in National Standards in order to measure the the application level of land. The investigation of this paper chose the representative soil samples of different altitude from multiple soil samples collected from the soil covered lead-zinc tailings mine mount in Cheng County, Longnan City, Gansu Province in China. XRF analysis was used to determine the kind and content of metal elements of the soil sample. The data were compared to make sure the changes of metal elements contents of soil samples with the altitude. The result found that the maximum content of Fe in each sample, and the content of Fe is quite different of the content of other metal elements in samples, while the samples had relatively low contents of Pb and Zn. Content of Cu in soil samples is lower than the Risk Screening Value of Soil Pollution in Construction Land, while contents of Pb and Cr were higher than that in Risk Screening Value of Soil Pollution in Construction Land.
The thinking and practice of Marine Ecological Conservation Red Line Delineation in China
Authors: Zhao Bei , Zhou Yanrong , Liu Nana , Yang Kun , Li Jing
Published: July 2021

China has established and implemented marine ecological conservation red line (MECRL) system to strengthen the bottom line constraints and ensure ecological security. This paper introduces the concept of MECRL and the process of overall consideration of the national MECRL delineation, which is defined “spatial-division + differential control measures”. The MECRL in Bohai Sea pilot and delineation of MECRL nationwide are introduced. At present, MECRL accounts for about 30 percent of the total coastal management area, providing a good institutional guarantee for protecting marine ecology and guiding the good formation of a scientific marine spatial layout in china.
Metabolic activity of an anammox population affected by major environmental factors
Authors: Rao Yifu , Meng Jia , Tian Yajie , Li Jianzheng
Published: July 2021

Anammox is known as a cost-effective approach to nitrogen removal from ammonium-rich wastewater. However, the eco-physiological characteristics of anammox population have not well been understood so far, which has obstructed the practical application of anammox process. In the present research work, an enrichment culture of anammox population was collected from an expanded granular sludge bed (EGSB) reactor, and the anammox activity was evaluated by various pH, temperature and reactant density, progressively. The results showed that the optimal ecological amplitude of pH and temperature for the anammox population was ranged from 7.0-7.5 and 30°C-35°C, respectively. To make anammox process more efficient, the density of NH4+-N and NO2−-N should be around 10.0 and 4.0 mmol·L−1, respectively. It was found that anammox population was more sensitive to NO2−-N density than NH4+-N density, and then NO2−-N density was proposed as a key indicator to practicing anammox process in engineering. With the findings, the present research will be significant in practicing annamox process.
Determination of effective medicinal components in Lonicera macranthoides flower buds
Authors: Cai Jing , Zhang Xinyang , Dai Huan
Published: July 2021

This study is to determination of active medicinal components in Lonicera macranthoides. The results of High-performance liquid chromatography showed that the contents of chlorogenic acid were as follows: Baiyun: 6.297%, jincuilei: 5.293%, yincuilei: 5.288%, common variety: 7.455%, common variety (after flowering): 4.140%. The contents of Luteolin in different Lonicera macranthoides varieties were as follows: Baiyun: 0.0264%; Jincuilei: 0.0573%; Yincuilei: 0.0347%; common variety: 0.0394%; common variety (after flowering) : 0.0197%.
Influence on indoor comfort due to the application of Covid-19 natural ventilation protocols for schools at subtropical climate during winter season
Authors: Melgar Sergio Gómez , Cordero Antonio Sánchez , Rodríguez Marta Videras , Márquez José M Andújar
Published: July 2021

Thermal comfort and energy performance of our buildings has been seriously improved during the last decades with the introduction of better envelope airtightness and mechanical ventilation systems. The arrival of Covid-19 has forced us to accept new natural ventilation protocols to improve the air quality inside buildings over other characteristics of the buildings. As a consequence, it brings some negative effects, like a reduction in the control of indoor dry bulb temperature (T), and an increase in energy demand for heating and air conditioning. To evaluate these influences during a winter season, a standard classroom from a school located at subtropical climate has been selected to be monitored with air quality and comfort devices. The experiment considers two different scenarios in 2018, and 2021. At them, data have been compared with several comfort ranges from international standards and the recommendations from the Spanish Government, obtaining opposite results. The results from 2018 showed that the comfort T ranges were adequate, but CO2 concentrations rise over 2000 ppm which was unhealthy. On the contrary, in 2021 when the Covid-19 natural ventilation protocol is activated, the CO2 concentration becomes less than 700 ppm. Finally, the suggested natural ventilation protocol was proved as an efficient measure to improve air quality, but it reduces the performance of the building in terms of comfort and energy demand. Therefore, several alternative ventilation methods should be considered to keep both energy air quality building’s performance.
Research on uplift model test of single pile in sand
Authors: Huang Liuqing , Ma Huibiao , Li Qiang , Hu Ling , Li Xinyi
Published: July 2021

This paper mainly uses the method of model test to study the ultimate uplift bearing characteristics of a single pile with different length-to-diameter ratios, mainly from the distribution laws of the uplift bearing capacity of the pile, the axial force of the pile and the side friction of the pile perform analysis. The model pile is made of PVC pipe, and resistance strain gauges are attached to both sides of the pipe. The strain value of the PVC pipe under different load conditions is measured to obtain the working behavior of the pile during the process of pulling out the pile. The result shows that the model test data is in good agreement with the numerical simulation.
Test of AC - 20 asphalt mixture ratio on the runway of Da Lian Airport
Authors: Tian Shuaituan , Guo Lei , Su Jixiang , Zhao Kunyang
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 AC-20 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.
Research on the influence of boulder powder content on concrete performance
Authors: Meng Guangcheng
Published: July 2021

To solve the problem of environmental pollution caused by the accumulation of granite powder and the shortage of traditional mineral admixtures, the influence of the amount of granite powder on the mechanical properties of concrete was studied by replacing cement with different amount of granite powder Different amount of granite powder can be used to prepare concrete with satisfactory performance. When the amount of granite powder is small (not more than 5%), granite powder will not reduce the compressive strength of concrete, or even slightly improve the compressive strength of pure cement concrete. When the amount of granite powder is more than 5%, the compressive strength of concrete will gradually decrease; when the amount of granite powder is more than 5%, the compressive strength of concrete will gradually decrease. The elastic modulus of concrete decreased, and the electric flux increased with the increase of the amount of admixture.
Application of J2 Integral Method in Calculating Complicated Stress Intensity Factors on Three-dimensional Components
Authors: Li Long. , Deng Yousheng. , Meng Liqing , Li Lingtao , Zheng Yunfang
Published: July 2021

In this paper, a technique to determine complicated stress intensity factors on three-dimensional components, which based on the conservation law and the elementary mechanics is proposed, it only needs the geometric relationship between multiple singular stress fields from the crack section, and obtaind the relationship between the stress at different crack tips. In the expression of the stress intensity factor K, K is proportional to the stress σ at the crack tip, and we can get the supplementary equation of between different stress fields K according to the ratio of the stress at the crack tip, then use the J-integral method to calculate the stress intensity factors of different stress fields. In order to verify the feasibility of this method, a cracked R-fluted shells model was constructed. Under the action of the bending moment, the corner crack propagation is simulated through the reserved corner crack, and two crack tips with different stress fields are generated during the simulation. The experimental result indicates that the proposed method is effective for cracked R-fluted shells. It is also shown that the method has universal applicability for solving complex stress intensity factors on three-dimensional components.
New iterative methods for dense linear systems
Authors: Wang Jinmei , Yin Lizi , Wang Ke
Published: July 2021

Solving dense linear systems of equations is quite time consuming and requires an efficient parallel implementation on powerful supercomputers. Du, Zheng and Wang presented some new iterative methods for linear systems [Journal of Applied Analysis and Computation, 2011, 1(3): 351-360]. This paper shows that their methods are suitable for solving dense linear system of equations, compared with the classical Jacobi and Gauss-Seidel iterative methods.
Development Trend of Hotel Architectural Space in The Post-Epidemic Era
Authors: Yaoyao Zhang
Published: July 2021

At the beginning of 2020, the epidemic of COVID-19 broke out rapidly in countries all over the world. The sudden epidemic poses a significant impact on the operation of China’s industrial economy. With the changes in the social and economic environment, hotels and tourism seem to have been pressed the “pause button” in a second, and instantly entered the “extremely cold” moment. The hotel occupancy rate plummeted to the “freezing point”. In view of the large-scale outbreak of the epidemic in various countries, many architects and urbanists are rethinking the development direction of the hotel construction model in the post-epidemic era.
Study on the technology of strengthening concrete by impregnation with modified sodium silicate compound strengthening fluid
Authors: Dishan Yang , Tongyu Yan , Xiaoyu Huang , Ying Xiong , Xi Lin , Hong Zhou , Jianguang Shi
Published: July 2021

It is the key to the concrete repair and strengthening construction that the base concrete has a certain quality and strength. Based on the strengthening mechanism of sodium silicate, the sodium silicate was modified to develop a kind of compound strengthening liquid. Through the contrast test results of concrete impregnation. The strength of C5 concrete before and after strengthening is increased by 42.5%, while the strength of C10 concrete is increased by 21.4%, and the strength of C15 concrete is increased by 10%.
Influence of boulder machine-made sand powder on compressive strength of concrete
Authors: Wang Pengtao
Published: July 2021

In order to recycle the boulder powder produced in the process of manufactured sand production and reduce the cost of engineering concrete, this article studied the influence of boulders powder on the compressive strength of concrete. The results show that in the early stage of concrete test, the compressive strength of rock powder concrete is slightly lower than of fly ash and mineral powder concrete. With the development of curing age, the strength of boulders powder concrete developed slower. As the increase of boulders powder content, the compressive strength of different curing age gradually decreased, and it was suggested that the content of boulders powder should be controlled within 20% of cementitious materials mass. The positive effect of boulders powder fineness on the strength of concrete is limited, so it is suggested to use unprocessed collected boulders powder in the project, which is economical and environmentally friendly. With the adjustment of water-to-binder ratio, boulders powder can be prepared with different strength grades of concrete to meet the needs of engineering; the composite of boulders powder with traditional mineral admixtures, such as fly ash, and especially granulated blast furnace slag powder, can significantly improve the strength of concrete.
Study on Crack Resistance of Hydraulic Roller Compacted Concrete Dam with Fly Ash Admixture
Authors: Li Xiaogang
Published: July 2021

With the continuous improvement of the level of construction industry in modern industry, at the same time, the requirements of the construction industry for the crack resistance of concrete dams are also higher and higher. In the preparation stage of the experiment, the corresponding experimental materials and equipment are provided. In order to ensure that the concrete can meet the requirements of workability and strength grade, the proportion of materials is designed; During the experiment, the activity characteristics of fly ash admixture are extracted, the particle size distribution of admixture is tested, and the fracture data of hydraulic RCC dam is monitored; The experimental results show that when the ratio of cement and fly ash is 0.7:0.1, the number, width and area of concrete cracks are the minimum, which proves that the fly ash admixture under this ratio is more suitable for construction engineering.
Wind Resistant Analysis of 5000m Hyperbolic Parabolic Spatial Mixed Cable Suspension Bridge
Authors: Chen ZhaoYang , Xu WenPing
Published: July 2021

Combined with the engineering background of a 5000-meter Strait Suspension Bridge, the configuration study of the hyperbolic parabolic space cable suspension bridge was carried out, and the ANSYS finite element analysis model was established to analyze and study the structural internal force and dynamic modal characteristics. The research shows that the hyperbolic parabolic space mixed cable suspension bridge has excellent spatial stiffness and wind stability performance, its torsional frequency and torsional frequency ratio are significantly improved, the critical wind speed of flutter is greatly improved. In order to further improve the wind stability of the hyperbolic parabolic space mixed cable suspension bridge, temporary wind resistance cable measures adopted during strong typhoons are proposed. This method can ensure that the 5000-meter-level hyperbolic parabolic space mixed cable suspension bridge has the ability to withstand 120 m / s rare extreme typhoons.
Seismic vulnerability assessment of multi-storey subway station structure
Authors: Liu Tong , Li Zhixin , Wang Qinghe , Xu Huaiyu
Published: July 2021

The safety of underground structure under seismic load is an important basis of the normal operation of underground rail transit system. Structural seismic vulnerability assessment based on incremental dynamic analysis method can evaluate the probability of the structure exceeding a certain limit state under a specific seismic intensity in terms of probability. In this paper, the seismic vulnerability of a multi-storey subway station structure is evaluated using this method, and a two-dimensional finite element model of both soil and structure is established by finite element software ABAQUS. The vulnerability curve is obtained through incremental dynamic analysis and mathematical statistics. Based on this curve, the probabilities of the structure exceeding four seismic limit states are obtained under the design seismic intensity and the rarely occurred seismic intensity at 7 degree. Results show that this station may attain slight damage under design seismic intensity of 7 degree, and may attain life safety at the rarely occurred seismic intensity at 7 degree.
Effect of adding waste boulder powder on mechanical properties of green concrete
Authors: Li Xiaohui
Published: July 2021

Reusing of stone powder formed in the production of manufactured sand is of great significance to environmental protection and resource utilization. In this paper, C30 and C40 environment-friendly manufactured sand concrete were prepared by adding 6%, 9%, 12% and 15% of waste boulder powder from manufactured sand production line into concrete and controlling the total weight of manufactured sand and rock powder to be constant. The influence of stone powder on concrete fluidity, compressive strength and elastic modulus were analysed. It was found that with the increase of stone powder content, the compressive strength of fresh paste and C30 concrete first increased and then decreased, while the elastic modulus of concrete and the compressive strength of C40 concrete continued to decrease. It is suggested that the content of rock powder should not exceed 9%.
Research on the Design of Disaster Prevention Plan for 22km Ultra-long Highway Tunnel with Multiple Intersections
Authors: Zhang Xuan , Li Xuefeng , Liu Xialin
Published: July 2021

The Tianshan Shengli Tunnel is currently the longest high-altitude highway tunnel. In order to ensure the safe operation of the tunnel, the SES software is used to investigate the wind speed laws in the tunnel, and the tunnel is divided into 16 disaster prevention sections based on the shaft and critical wind speed. The principles of disaster prevention and rescue of Tianshan Shengli Highway Tunnel are given, and the emergency treatment process of tunnel disaster prevention and rescue is given. The disaster prevention and rescue plan of Tianshan Shengli Tunnel from fire occurrence, personnel and vehicle evacuation, and fire treatment are discussed in detail.
Development status and Countermeasures of renewable energy in China
Authors: Hu XueBin
Published: July 2021

This paper studies the development status of renewable energy in China. In this field, there are some problems in China, such as imperfect legal and policy system, insufficient market operation, weak public awareness of environmental protection, imperfect scientific research system and so on. At the end of the paper, the corresponding improvement measures are put forward.
Discussion on the Construction and Application of Navigation Electronic Map Quality Inspection Sample Database
Authors: Bai Jin , Gao Jingnan , Ma Wei , Yan Qingqing , Wang Xiaodi , Dong Shuai
Published: July 2021

In order to improve the scientificity and efficiency of quality inspection of navigation electronic map, and save the cost of quality inspection, it is necessary to establish the national navigation electronic map quality inspection sample database. In this paper, the construction goal, data acquisition technology process, and database construction method of navigation electronic map quality inspection sample database are described in detail, and the construction content and technical indicators are discussed. The quality test is carried out by combining the in-house verification with the field comparison of the navigation electronic map quality test sample database, and the test results are analyzed and evaluated. The effective application of the sample database in the quality test and evaluation of the internet navigation electronic map in the pilot area is carried out. At the same time, the application of navigation electronic map quality inspection sample database in the research of urban fine management and solid waste recycling economy ecological park planning is prospected.
Multi objective optimization of window to wall ratio of University Gymnasium in severe cold area by coupling natural lighting and energy consumption
Authors: Junlin Zong , Longwei Zhang
Published: July 2021

Objective To explore the relationship between window opening ratio and natural lighting and energy consumption of University Gymnasiums in severe cold area, and put forward optimization strategies. Methods Digital simulation technology was used to simulate the energy consumption and natural lighting of University Gymnasium window opening ratio, and the window opening scheme with natural lighting and low energy consumption was obtained. Conclusion The side window lighting should be used in the window opening scheme of small and medium-sized university gymnasiums. Within the range of experimental data, the North-South lighting is the main lighting mode, and the East-West lighting is the auxiliary.
Measurement and analysis of bridge expansion joint noise
Authors: Mao Dingtao , Ding Yong
Published: July 2021

The structure-borne noise while the vehicle passing across the bridge expansion joint is the main source of urban bridge noise. In order to control this noise pollution, 20 bridges including three types of typical expansion joints in Ningbo City were selected, and the noises were measured while vehicle passed across the bridge expansion joints. The measured results are expressed by the Z-weighted sound pressure level, which kept the effect of the low-frequency noise. Then the influence factors of this noise are discussed. The results show that: (1) The sound pressure while vehicle on the bridge expansion joints is much greater than that on the normal road or mid-span of the bridges, which results in significant environmental noise pollution; (2) The wider the gap of the bridge expansion joints, the greater the noise level; (3) The noises produced by the modular expansion joints and comb-plate expansion joints are greater than that from the single-gap expansion joints.
Grey prediction analysis of cutoff wall affected by construction effect
Authors: Yuan Hong-Hu , Yao Dai , Yu Wang
Published: July 2021

The long-term stability analysis of cutoff wall affected by construction effect is crucial. The longterm stability of the cutoff wall of Daning Reservoir is mainly affected by the combined action of highway vehicle load, extreme highway load and water load under different water storage loads. In this paper, the prediction model and method of grey theory are used to predict the horizontal displacement at the top of the cutoff wall, the settlement at the top, the maximum principal stress of the reinforced concrete wall, and the maximum principal stress of the plastic concrete wall based on grey analysis with each storage and drainage cycle as the time series point combined with the actual situation of the project. The long-term stability of the cutoff wall under load is predicted and evaluated. The results show that the maximum stress of the monitoring 2 – 2 section cutoff wall gradually tend to be stable during the whole storage and drainage cycle. The limit maximum compressive stress of reinforced concrete wall is 4.320 MPa, and the limit maximum compressive stress of plastic concrete wall is 1.758 MPa. Judging from the material strength, the maximum principal stress is within the design strength of the material, and the plastic failure of the wall does not occur, indicating that the combined anti-seepage system of rigid cutoff wall and plastic cutoff wall adopted by the Daning Reservoir is stable and safe in the later normal operation period.
Discussion of 800m Composite Bridge with CFST Flying Swallow Arch and Self-anchored Suspension Cable
Authors: Chen ZhaoYang , Xu WenPing
Published: July 2021

In view of the demand of 800 meters Super Long Span CFST arch bridge, the composite bridge of CFST flying swallow arch and self-anchored suspension cable is proposed. The thrust of flying-bird CFST arch bridge and the tension of self-anchored suspension bridge are balanced, forming a self-balanced structure system. The arch rib structure is mainly stressed, supplemented by the self-anchored suspension system, which works together and has complementary advantages. Using the single leaf hyperboloid variable section steel tube four limb space truss arch rib structure, the self-weight of the mid span arch rib section structure is reduced, the risk of construction and hoisting of the mid span section is reduced, the section size at the arch foot is increased, the mass center and stiffness center of the arch bridge structure are effectively reduced, and the stability of the super long span concrete-filled steel tube arch bridge is increased. Combined with the actual project, the parameters are designed, the Midas finite element model is established, the internal force analysis and calculation, modal analysis and buckling analysis are carried out, and the superiority of the structural technical measures is verified.
Test Study on Composite Strengthened Beam with CFRP Board, Angle Steel and External Prestressed Steel Strand
Authors: Jiang Tao , Li BiQing , Chen Kai
Published: July 2021

The composite strengthening beam combined with a variety of reinforcement technology, complementary advantages.In order to study the mechanical behavior of T-beam strengthened with CFRP board, external angle steel and external prestressed steel strand, six reinforced test beams were fabricated to compare and analyze the structural characteristics of bending stiffness, crack development and bearing capacity. The research shows that the beam strengthened by CFRP board, external angle steel and external prestressed steel strand has good working performance. The rebound force of the bending deformation of the external angle steel and the upward force of the external prestressed steel strand reliably anchor the carbon fiber board, avoiding the bond failure and slippage of the CFRP.The three kinds of reinforcing materials work together and complement each other, which can give full play to their respective strength. The composite strengthened beam with CFRP board, external angle steel and external prestressed steel strand can greatly improve the cracking load, structural stiffness and ultimate bearing capacity of the original beam, and the reinforcement effect is optima.
Energy Demand Forecast in Yunnan Province Based on Seq2Seq Model
Authors: Li Anrui , Su Shi , Han Tong , Yin Chunlin , Li Jie , Chen Linjie , Wang Xinkai , Wang Shichen , Liu Siyang
Published: July 2021

Energy demand forecast has an important practical significance for the sustainable development of the national economy, the reasonable allocation of resources, and the construction of modernization goals. This study is based on the analysis of coal, electricity, natural gas, and other energy data in Yunnan Province from 2011 to 2018 and uses long short-term memory, sequence to sequence, deep learning, and ridge regression coupling methods to construct an energy demand forecast model in Yunnan Province. Forecast results show the following. The total energy consumption of Yunnan Province from 2021 to 2025 will continue to increase. Moreover, the coal consumption of Yunnan Province will continue to decline from 2021 to 2025. Furthermore, the electricity consumption of Yunnan will increase by about 8.02% year-on-year from 2021 to 2025. The experiment proves that the forecasting effect of the energy demand forecast model proposed in this study is excellent.
Comprehensive Evaluation of Cultivated Land Resources in China Based on Three Dimensions: Quantity, Quality and Ecology Danger
Authors: Yang Renyi , Yang Zisheng , Liu Fenglian
Published: July 2021

Based on TOPSIS-Grey Relational Analysis Method, the three dimensions of cultivated land quantity, quality and ecological danger are organically integrated to build a comprehensive evaluation indicator system of practical and national cultivated land resources and quantitative calculation method by taking the province-level administrative region as the evaluation unit. The index of cultivated land quantity, quality, and ecological danger and the comprehensive index of cultivated land resources are calculated quantitatively in 31 province-level administrative regions of China. The comprehensive endowment and superiority of cultivated land resources in each province are also analysed systematically. The results show that there are 10 provinces (municipalities directly under the Central Government and autonomous regions) classified as “high superiority” provinces in terms of cultivated land resources. There are 9 provinces classified as “relatively high superiority” provinces. The dominant types of cultivated land resources in China can be classified into six types: superiority type of quantity, superiority type of quantity and ecology, superiority type of quality and ecology, superiority type of ecology, comprehensive superiority type, and unclear superiority type. Most provinces have a certain “single superiority”, “double superiority”, or “comprehensive superiority”.
The Sustainable Development of Smart Cities: A Case Study of the Design of driverless bus stops in Zhengzhou
Authors: Chen Xiaoguang , Sui Jinting , Tai Xufeng , Li Heqi
Published: July 2021

With the arrival of the “5G” era and the digital economy era, the development of the city has permeated all aspects of the city, and with the emergence of “smart city”, it is likely to have “smart” everywhere in the future city. At the same time, “Future Smart Transportation” was proposed as a discussion topic at the “2019 (8th) International Smart City Summit and Smart Ecology Expo”. The research and development of the driverless bus stops will spur the driverless bus stops to take on the past with a brand-new look, welcome the future, and contribute to the sustainable development of the smart city. Taking the driverless bus station in Zhengdong New District as an example, this paper explores the sustainable development of a smart city through the creation of manned (open)-shared (transition space)-driverless (semi-enclosed space) space and the introduction of modular design approach. To connect people’s work, life and transportation, and derive a new public transportation environment based on manned bus stops, namely, intelligence, sustainability, environmental friendliness and safety, thus create a smart transportation pilot to embrace the bright future of sustainable smart cities.
Research on the application of GIS technology in the spatial status grooming of village areas
Authors: Hao Song
Published: July 2021

The preparation of five levels and three categories of territorial spatial planning includes many aspects, and this article mainly deals with one of the levels and categories: detailed territorial spatial planning of village areas; it focuses on the preliminary work of planning preparation: the current situation combing of village territorial spatial areas. The article firstly outlines the basic application of GIS technology in the current situation combing; then introduces the relevant contents of the Third National Land Survey. Finally, with actual cases, we focus on the significant role played by GIS technology in the integration of land use data in the base period of village territorial space, the location of permanent basic farmland indicators, the location of ecological protection red line, and the statistics of conflicting patches of ecological environmental protection and basic farmland protection.