bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stress Relationship between Ecological Security and Urban Expansion Suitability
Authors: Sun Yanzhi , Zhang Tongsheng 
Published: August 2020

Abstract
Systems integration assessment can provide the comprehensive information for practice and policy, reducing conflict in decision-making. Using Beijing city as a case study, this paper proposed a systematic stress assessment method to describe the stress relationship between urban expansion suitability and ecological security. Firstly, Minimum Cumulative Resistance Model (MCR) was adopted to depict the ecological security pattern from 2000 to 2018, and the pattern of high, moderate and low ecological security was protracted. Secondly, the index weights of urban expansion suitability were calculated by Analytic Hierarchy Process (AHP) to eliminate subjectivity, and 5 levels of urban expansion suitability were established by weighted overlay. Finally, this study evaluated the stress effect. Results showed that the overall regional ecological security of Beijing decreased first (2000-2010) and then increased (2010-2018). The suitable area for urban expansion was getting larger, but the expansion rate dropped. Stress effect on urban expansion from ecological security pattern raised from 2000 to 2010 and then dropped. However, the stress effect on ecological security from urban expansion was continuously increasing, stimulating potential risks to the natural ecosystem. The changes of stress effect were stimulated by the policy and planning, driving urban expansion in early period and ecological conservation latterly. Comprehensively, the integrated stress effect assessment improved the recognition of the spatiotemporal variation of ecological security patterns and urban expansion in Beijing.
Spatial Distribution Pattern Analysis of Unsafe Setting of Electric Wires in Urban Area Using K-function Methods: A Case Study of Guangming District
Authors: Liao Cong , Pang Xiao , Cai Heng , Tian Yuan 
Published: August 2020

Abstract
Hidden fire risk are important disaster-inducing factors for potential fire accidents, which provides a breakthrough point for early intervention and prevention of potential fire accidents. Unsafe setting of electric wires is a very dangerous type of hidden fire risk that could cause fire accidents. It is of great significance to analyze the distribution pattern of hidden fire risk and related factors of this type of hidden fire hazard for early intervention. However, few researches have been done in the field of hidden fire risk. In this study, two network K-function methods, the univariate network K-function method and the bivariate network K-function method, were applied to analyze spatial patterns and its related factors of unsafe setting of electric wires as a hidden fire risk. The research data came from daily inspection in urban grid management of Guangming district, Shenzhen. The results indicated that the spatial distribution of unsafe setting of electric wires is highly related to the transportation network in the study area. The distribution pattern is influenced by the distribution of residential quarters and office buildings. The methods in this study can also be used to analyze other types of hidden fire hazards.
Research on the Countermeasures of Rural Ecological Environment Governance: Taking Qingyanggang Village in Hubei Province
Authors: Peng Xianze , Zhang Yingqi 
Published: August 2020

Abstract
The problem of inadequate development and inadequate development in my country is evident in rural areas, especially in ecological governance. This article takes Qingyanggang Village, a village in the Jianghan Plain, a land of fish and rice as an example, to focus on analyzing and studying the difficulties and problems in its ecological governance: lack of infrastructure for domestic sewage treatment, the slow accumulation of domestic garbage, lack of environmental awareness among villagers, and serious rural agricultural pollution. In view of the existing problems, and in accordance with the basic requirements of national ecological civilization construction and rural ecological revitalization, corresponding suggestions were put forward to promote the Qingyanggang village revitalization plan as a whole, increase the effective utilization of resources, accelerate the ecological environment governance, and promote Qingyanggang village Revitalize green and sustainable development.
Economic Optimization of Multiple Microgrids System Based on Alliance Theory
Authors: Zhou Yibin , Zhou Fengquan , Liu Yang , Wang Zixuan , Li Peng 
Published: August 2020

Abstract
Aiming at the problem of economic operation of multiple microgrids system, a coordinated optimized operation method of multiple microgrids in integrated energy system based on alliance theory was proposed. Firstly, energy storage station was introduced into multiple microgrids optimal scheduling, the energy flow relationship between various links was studied, and an economic optimal dispatch model was established under the alliance mode of multiple microgrids and energy storage station; Secondly, constructed a Shapely value benefits distribution mechanism to carry out the initial benefits distribution of the alliance and the secondary distribution of the multiple microgrids internal benefits. Finally, taking a typical daily scenario as an example, the optimal operation scheduling strategy of multiple microgrids with the participation of energy storage station was obtained. The results showed that the method proposed in this paper can effectively improve the benefits of all participants and ensure the economic operation of multiple microgrids, at the same time, it realized the full consumption of renewable energy.
Experimental Research on Destruction Characteristics of Mud Inrush on Tunnel in Argillaceous Fault Fracture Zone
Authors: Yang Teng , Zhang Qingsong , Zhang Xiao , Wang Deming 
Published: August 2020

Abstract
The argillaceous fault fracture zone is a special area which bears the most concentrated stress when it forms and develops. Therefore, the tunnel under construction is subject to serious water and mud inrush when excavated through this area. In order to explore the destruction characteristics of mud inrush, a large-scale three-dimensional geological model test was carried out, which overcomes the “black box” problem of the traditional test, and a cone-shaped and parabolic body model were proposed to depict the shape of soil disturbance. In addition, the evolution law of displacement field inside medium was studied and the change regulation of actual disaster influence area also was been revealed. Finally, the tunnel mud inrush mechanics were revealed according to destroyed characteristics. As the results showed, the location of the initial mud inrush occurred at the spandrel of the tunnel face, the displacement of soil near the location of mud inrush increased with proceeding time, but there was a sudden saltation of the increasing rate when the disaster occurred. Besides, the shape of surface subsidence above the location of the inrush gradually transferred from “W” to “V” in the process of mud inrush. With the increase of the number of mud inrush, the soil disturbance develops from the local to the whole. When the local disturbance occurs, the soil form is cone, while when the whole disturbance occurs, the soil form is parabola. In addition, it is found that soil displacement is related to the seepage pressure under different disturbance modes. Finally, the conclusion of the model test may shed light on the catastrophic process and evolution law of the mud inrush in fault fracture zone. which has certain guidance and reference significance for the prevention of mud inrush in similar projects.
Description of HVAC System and Identification of Flow Rates and Pressures in HVAC Based on Collective Intelligence System
Authors: Li Huai , Yu Zhen , Li Li 
Published: August 2020

Abstract
The efficient control of the HVAC system is important for the reduction of energy consumption in buildings. The water and air distribution network of HVAC system not only consume energy but also determine whether the cold and heat are delivered properly in the building according to the cooling and heating loads. The optimal control of the HVAC distribution system is complex due to the scale of the network and the coupling effects between HVAC devices. This paper proposes a novel distributed control system using standard computing process nodes, which is called the Collective Intelligence System (CIS). The proposed method is validated using a typical HVAC system in a real office building. The description of the HVAC system and the identification of flow rates and pressures of the distribution network is demonstrated using the decentralized identification algorithm.
Based on Numerical Control Fold the Speed of Curved Robot System from Meet Speed with Swing to Study
Authors: She Minghui , Weng Wei , Chen Huihuang , Yang Adi , Yu Lun 
Published: August 2020

Abstract
In order to solve the current domestic sheet metal enterprise users has increased rapidly, but there are still most bending machine or manual operation problem, involving the employment difficult problems, according to labor shortage problem, must promote intelligent enterprise transformation, realize the exchange Labour “machine”, the development and application of nc bending robot system is the inevitable developing trend of sheet metal industry, speed adaptive speed and oscillation is important in the development and application of nc bending robot system. This paper describes the system model of the speed adaptive speed and swing of the CNC bending robot system, and analyzes the performance of the speed adaptive speed and swing system comprehensively. The results of computer simulation show the consistency between simulation and theory.
Data-Dirven Method for Wake Effect Analysis on Nacelle Anemometer
Authors: Jing Bo , Qian Zheng , Chen Tianyang , Pei Yan , Kang Dahai 
Published: August 2020

Abstract
For most wind turbines, blade wakes affect the measurement of nacelle anemometer, result in the inconsistency between nacelle wind speed (NWS) and free stream wind speed, which seriously affects the power forecasting and performance evaluation of wind turbine. This paper proposes a data-driven method to analyse the wake effect on nacelle anemometer. At first, we use Relevance Vector Machine to establish a site calibration model between Lidar wind speed (LWS) and NWS. After that, we can use the calibrated LWS to replace the free stream wind speed, and wake effect on nacelle anemometer can be evaluated by comparing the calibrated LWS and NWS. Then, Wind Turbine Power Curve (WTPC) is applied to make a detail analysis of wake effect on nacelle anemometer. The experimental results show that wake effect accelerates the air velocity behind the impeller. Therefore, WTPC fitted by NWS is “lower” than the real one. However, SCADA system overcorrects the wake effect, thus WTPC fitted by SCADA data is “higher” than the real power curve.
The Reducing Ambience Analysis under the Low Nitrogen Mode Operation of a Boiler
Authors: Xiang Baixiang , Huang Jun , Li Yan , Han Binqiao 
Published: August 2020

Abstract
In 2014, the electricity industry boilers are required to meet the ultra-low emissions standard. Specifically, the dust, SO2, NOx are required to reach 5, 35, 50 mg/m3, respectively. Hence, the boiler operated under lean oxygen will be widely and long-term existed. In this paper, the distributions of velocity, temperature and flue gas composition were simulated under different air distribution modes. The numerical simulations demonstrated that both the CO and H2S contents in the major burner zone increased with the SOFA rate increasing. However, there is almost no CO and H2S in the burnout zone due to the increase of SOFA. Besides, as the SOFA rate increasing, NO in the burnout zone slightly increased, but the NO in the main combustion zone significantly reduced.
An Approximate Analysis of Insulation Thickness of Elliptic Pipe
Authors: Shi Jinsheng , Zhang Qiaozhen 
Published: August 2020

Abstract
The thermal insulation characteristics of elliptic pipe were analyzed preliminarily. Thermal resistances between elliptic pipe line to surrounding ambient were studied in dimensionless form. The expression for critical insulation thickness was obtained. The lower bound thickness and heat transfer rate were researched. Influences of different factors were discussed. It is found that for cases of small Biot number, the lower bound thickness is obviously greater than the critical thickness. And the addition of insulation material upon elliptic pipe line should be conducted enough so that the insulation layer exceeds the lower bound thickness in order the insulation investment play a positive role.
Exploration on Teaching Method Improvement in the Course of Design Principle of Steel Structure
Authors: Li Qiang , Mao Jianghong , Zhang Jun , Fan Weijie , Wang Yinhui 
Published: August 2020

Abstract
The course “design principle of steel structure” is one of the main professional courses in civil engineering, which has the characteristics of many contents, strong theory and high requirement of innovative design ability. Based on the analysis of the present situation of the teaching of the steel structure course in the college, this paper puts forward the existing teaching problems and probes into the concrete methods of the innovation and reform of the steel structure course, which is of great practical significance to improve the teaching effect and the education quality.
Practice of Training Building Industrialization Talents under the Background of New Engineering by Course Reconstruction
Authors: Zhang Jun , Mao Jianghong , Fan Weijie , Li Qiang , Wang Yinhui 
Published: August 2020

Abstract
Targets of training building industrialization talents under the background of new engineering are to develop the engineering practice ability, innovation ability and cross-border ability. As a part of traditional civil engineering comprehensive experiment course, bending experiment of reinforced concrete (RC) beam was reconstructed based on PC project in this paper. By simulating the stakeholders in the actual project, students’ autonomous learning ability is well stimulated. Both traditional professional knowledge and expanded professional knowledge were involved in the new mode. Practice of this paper demonstrate that higher education should be student-centered and design of reconstructed course should conform to the most typical engineering project.
Random Seismic Response Analysis of Long-Span Steel-Concrete Composite Structure
Authors: Gu Zhenyuan , Kan Xinjia , Zhang Zhenting , Cao Xiaojian , Shen Qiangru 
Published: August 2020

Abstract
Considering the randomness of seismic input and the nonlinear characteristic of long-span structures, the probability density evolution method is used to study the dynamic response of the long-span steel-concrete composite structure under random earthquake. Three-dimensional structural model is established in the finite element software SAP2000, and then the displacements between layers and the response rule of vertical displacements of truss roof of the composite structure are obtained. The results show that under the input of three-dimensional earthquake, the vertical displacement of the grid roof of the isolated long-span steel-concrete composite structure is an order of magnitude larger than the horizontal direction of each layer. The probability density evolution method can offer comprehensive probability information of nodal displacements, and provide a reasonable way for the seismic reliability analysis of long-span isolated structures.
A Comparative Study on Wellbore Pressure Transmission of Water and Carbon Dioxide during Fracturing
Authors: Xiao Caiyun , Ni Hongjian , Zhao Bo , Li Ning 
Published: August 2020

Abstract
Hydraulic fracturing is one of the most effective ways for the development of unconventional oil and gas resources, CO2 has been regarded as an excellent alternative to water as its broad application prospects in unconventional reservoir development and benefit for CO2 utilization. The wellbore pressure will keep rising before fracture initiation during hydraulic fracturing, and fluid properties have significant influence of wellbore pressure transmission especially for CO2 fracturing. In this paper, a wellbore pressure transmission model based on the definition of fluid compressibility is established and coupled with wellbore flow model of compressible fluid to calculate the borehole pressurization rate for water-based and CO2 fracturing. The model has been verified by field data. The results show that the borehole pressurization rate for both water-based and CO2 fracturing reveal rising trend as pump rate increasing, and borehole pressurization rate of water-based fracturing is 10∼20 times that of CO2 fracturing with same pump rate. Moreover, the borehole pressurization rate increases linearly with pump rate of water-based fracturing, but excessive pump rate might reduce borehole pressurization rate of CO2 fracturing. The research results can simulate more perceptions for the optimizing design of actual hydraulic fracturing operating.
An ETA-PDE Method for the Fragility Analysis of Concrete Dam
Authors: Xu Qiang , Xu Shutong , Chen Jianyun , Li Jing , Jia Qibin 
Published: August 2020

Abstract
A nonlinear damage ETA-PDE method is proposed for the fragility analysis of concrete dam. The endurance time analysis (ETA) method and the generalized probability density evolution (PDE) method are constructed by optimization and the method of lines (MOL) algorithm especially for the randomness of ground motion. Then, by integrating the ETA method and generalized PDE method, a nonlinear damage ETA-PDE method is established. To verify the applicability and reliability of the proposed ETA-PDE method, by using the tensile damage model, the nonlinear damage dynamic calculation and the fragility analysis are carried out for the Koyna concrete gravity dam. The results show the proposed PDE method can capture details of the probability density distribution for the fragility indicators (such as the plastic dissipation energy, the damage dissipation energy, the damage volume and so on). The proposed ETA-PDE method has special advantages on the calculating scale and solving probability density. Thus, it is suitable for practical engineering applications.
Safety Risk of Flammable and Explosive Dangerous Goods through the Ship Lock
Authors: Xie Tiansheng , Han Chao , Wang Guobo , Fengyun Chen 
Published: August 2020

Abstract
Based on the analysis of the current situation on flammable and explosive dangerous goods passing through the Three Gorges ship lock, evaluate leakage, fire, and explosion hazards through typical accident simulation calculations to find out the hazardous characteristics and safety risks of flammable and explosive dangerous goods through the Three Gorges ship lock. The study indicates the main safety risks of flammable and explosive dangerous goods passing through the ship lock are ship collision, grounding, leakage, fire and explosion, as well as the facilities strength declining in lock chamber, cracks or other structural destructions due to the long-time high temperature under flame or overpressure of the explosion.
Oxidation response of additively manufactured eutectic Mo-Si-B alloys
Authors: Becker J , Fichtner D , Schmigalla S , Schultze S , Heinze C , Küsters Y , Hasemann G , Schmelzer J , Krüger M 
Published: August 2020

Abstract
Previous studies showed the technical feasibility of additive manufacturing (AM) of Mo-Si-B alloys using the laser powder bed fusion (L-PBF) process. The competitiveness of the properties of AM alloys was demonstrated by a comparison to literature data from conventionally processed Mo-Si-B materials. In addition to the excellent mechanical properties at ambient and elevated temperatures, the oxidation resistance in a wide temperature range is another decisive aspect for the potential use of AM Mo-Si-B alloys. The present work shows investigations on the cyclic oxidation performance of a eutectic AM Mo-16.5Si-7.5B alloy. Depending on the temperature (800 °C, 1100 °C, 1300 °C), the oxidation mechanisms are different, which is due to different reactions at the surface of the alloys accompanied with mass changes of samples. These mass changes can be explained on the basis of microstructural investigations. However, compared to a directionally solidified (DS) alloy, the AM alloy shows improved oxidation resistance.
Microstructure and surface investigations of TiAl6V4 and CoCr28Mo6 orthopaedic femoral stems
Authors: Crackau M , Harnisch K , Baierl T , Rosemann P , Lohmann C H , Bertrand J , Halle T 
Published: August 2020

Abstract
Total hip arthroplasties (THA) achieve very good clinical results and show annually increasing numbers of implantation. Interactions of the bone with the implants surface are of major importance for a stabile fixation and longevity of the implant. Therefore, manufacturing of the material and the implants as well as their surface properties can have a decisive influence on the functionality of the implant. The aim of the present study is the investigation of two commercially available femur stems with analytical methods. One stem is made of a TiAl6V4 wrought alloy for cementless application and the other one is made of a CoCr28Mo6 cast alloy for cemented fixation. The change of the production-related microstructure within the implant, differences between surface and bulk properties and potential correlations between the production-related changes to predict failures are addressed. Longitudinal cross sections of tested stems were prepared metallographically, investigated using optical and scanning electron microscopy including EDS and EBSD and correlated with micro hardness depth profiles. Due to production and processing, a subsurface layer is formed in both alloys. The TiAl6V4 wrought alloy stem exhibits a homogenous recrystallization microstructure with fine grains of micrometre size. The subsurface layer of the stem is deformed in parts with embedded corundum particles within the depth of 10 µm. Corundum residues were detected on the entire stem surface and partially covered by the applied calcium phosphate spray coating. The CoCr28Mo6 cast alloy stem shows a dendritic microstructure with chromium- and molybdenum-rich interdendritic precipitations and a surface layer of smaller globular grains in the size of 50 µm to 200 µm. The face centred cubic (fcc) crystal structure was predominantly detected in the phase analysis. The brittle hexagonal close packed (hcp) phase was evident at the implants surface. Similar to the TiAl6V4 alloy stem, embedded residues of corundum particles were detected on the implant surface. This study shows different surface integrities for both stems in comparison to the base material. The observed residues from the manufacturing processes are generally well-embedded into the implant surface, however if released they could impair the functionality of the endoprosthesis as the particles might negatively affect the sterilization process or might reduce metal corrosion resistance.
Preceramic polymer-derived ceramic foams with lamellar strut porosity
Authors: Dammler K , Schelm K , Kniep D , Hasemann G , Scheffler M 
Published: August 2020

AbstractOpen porous replica foams with additional lamellar strut pores were prepared by preceramic polymer processing combined with a freeze-drying process. Polymer foam templates were coated with an aqueous polymethylsilesquioxane system followed by freezing at - 20 °C to generate hierarchical porosity within the foam struts. The cellular structure was preserved during freeze drying, cross-linking, template removal and pyrolysis, and additional strut porosity was formed. The size of the lamellar strut pores was found to depend on the solid load of the preceramic slurry and its pretreatment procedure. The cellular materials obtained in this work possess additional lamellar strut pore channels with a thickness of approximately 40 µm and a total foam porosity of > 90 %.