bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of a design-based elective STEM course on pre-service chemistry teachers’ content knowledge, STEM conceptions, and engineering views
Authors: Aydin-Gunbatar Sevgi , Tarkin-Celikkiran Aysegul , Kutucu Elif Selcan , Ekiz-Kiran Betul
Published: June 2018

In this study, we sought to examine the influence of a 12 week design-based elective Science, Technology, Engineering, and Mathematics (STEM) course on pre-service chemistry teachers’ content knowledge, STEM conceptions, and engineering and engineering design views. To attain the goals determined, we utilized five STEM activities starting with a daily-life problem and an iterative engineering design process to solve the problem. A chemistry test with 11 two-tier items, and interviews focusing on STEM and engineering conceptions were administered at the beginning and at the end of the course. Moreover, a reflection paper was collected after each activity. Eight junior pre-service chemistry teachers participated in the study voluntarily. Deductive and inductive data analyses were used to investigate the influence of the course on participants’ content knowledge, STEM conceptions, and engineering and engineering design views. The results revealed that the design-based STEM course helped pre-service teachers deepen their content knowledge. Additionally, most of the participants defined integrated STEM education as an acronym (n = 6) and very few mentioned the interdisciplinary dimension of STEM education superficially at the beginning (n = 3). At the end, they mentioned interdisciplinary nature as connecting at least two dimensions of STEM, and they emphasized engaging in real-world problems, designing a product or process and inquiry-based and/or problem-based learning. Regarding engineering and engineering design views, a similar development was observed. Although their views were undeveloped or underdeveloped at the beginning, they enriched their views and mentioned defining criteria, creativity and integration to science and mathematics that are characteristics of engineering and design processes. Implications for including STEM courses in pre-service teacher education programs were provided.
Modeling optical and UV polarization of AGNs
Authors: Marin F.
Published: June 2018

Context. One of the main challenges for polarimetric observations of active galactic nuclei (AGN) is to properly estimate the amount of parasitic light that contaminates the polarization signal. Removing this unpolarized flux is a complex task that has only been achieved in a couple of objects.

Aims. In this fifth paper of the series, we present a new version of the Monte Carlo code STOKES that accounts for dilution by interstellar polarization and host starlight in radiative transfer modeling.

Methods. We upgraded our code by including spectral energy distribution (SED) templates for a set of representative host galaxies. The unpolarized light emitted by those hosts alters the observer polarization while being coherently radiatively coupled to the AGN structure. We also included in our analysis tool a routine that may add, depending on the user’s objectives, an interstellar component.

Results. Using a generic AGN model, we illustrate how interstellar polarization and starlight dilution impact the observed polarimetric signal of AGN. We applied our code to NGC 1068, an archetypal edge-on AGN and demonstrate that STOKES can reproduce its SED, the expected wavelength-dependent polarimetric signatures, and the observed high-angular resolution polarimetric maps. Using the flexibility of the code, we derived several intrinsic parameters such as the system inclination and the torus opening angle.

Conclusions. The new version of our publicly available code now allows observers to better prepare their observations, interpret their data and simulate the three-dimensional geometry and physics of AGN in order to probe unresolved structures. Additionally, the radiative interaction between the host and the AGN can be used to probe the co-evolution of the system.
Method of Harmonic Source Identification Based on Harmonic Apparent Power
Authors: Xu Lin , Lin Rui Xing , Xu Shuang Ting
Published: June 2018

Based on the harmonic apparent power defined by the IEEE 1459-2010 power standard, the paper proposed a new method of identifying the main harmonic source at the point of common coupling (PCC). Using the reference impedance method, the utility and customer harmonic voltage and current contributions are calculated. And then combined with the IEEE 1459-2010 standard, defined the harmonic apparent power caused by the independent action of the equivalent harmonic source on the system side and the user side, by directly comparing the size of the two to determine the location of the main harmonic source. The method can consider the comprehensive influence of harmonic voltage and harmonic current, then identify the main harmonic source at PCC point. Finally, the rationality of the method is verified by the simulation of the IEEE 13 node system.
PFC Performance Improvement of Ultra-supercritical Secondary Reheat Unit
Authors: Li Jun , Li WeiWei , Hu XingWang , Sun WenChuan , Kong Gang
Published: June 2018

Ultra-supercritical secondary reheat unit has been widely used in the world because of its advantages of large capacity, low consumption and high efficiency etc., but rapid load change ability of the turbines to be weakened which caused by its system organization, cannot meet the requirements of power grid frequency modulation. Based on the analysis of the control characteristics of ultra-supercritical once-through reheat unit, the primary frequency control based on feed-water flow overshoot compensation is proposed. The main steam pressure generated by the feed-water is changed to improve the primary frequency control capability. The relevant control strategy has been applied to the 1000MW secondary reheating unit. The results show that the technology is feasible and has high economical efficiency.
Study on the fiber fouling in drying exhaust heat utilization of wood industry
Authors: Pan Yadi , Shan Shuya , Wei Yao , Ji Feng , Weng Jinping , Tian Yulan , Qian Jin
Published: June 2018

Based on the viscoelastic and creep deformation properties, a new deposition mechanism model for slender wood fiber particles in wast heat utilization is proposed in this paper. And the equivalent sphere method is used to describe the particle feature size in the model. With the proposed deposition model of flexible slender particles, the critical criteria are obtained. The influence of particle size, aspect ratio and damping factor on particle deposition has been investigated. The results indicate that particle deposition increases with the particle size decrease, aspect ratio and damping factor increase. According to the present deposition model, a coupling simulation with FLUENT and EDEM method was carried out for the flow field of fiber drying tail gas in heat piping exchanger, which indicated that particle deposition mainly occurred at the central windward area of fin due to the direction changer and the magnitude decrease of collision velocity between fiber particles and wall. Experiment of heat recovery of drying tail gas revealed that using the H fin tubes instead of rectangular fin tubes can greatly relieve the deposition of wood fiber particles, which provided a useful way to save energy in wood industries.
Quantitative analysis of factors that affect oil pipeline network accident based on Bayesian networks: A case study in China
Authors: Zhang Chao , Qin Ting Xin , Huang Shuai , Wu Jian Song , Meng Xin Yan
Published: June 2018

Some factors can affect the consequences of oil pipeline accident and their effects should be analyzed to improve emergency preparation and emergency response. Although there are some qualitative analysis models of risk factors’ effects, the quantitative analysis model still should be researched. In this study, we introduce a Bayesian network (BN) model of risk factors’ effects analysis in an oil pipeline accident case that happened in China. The incident evolution diagram is built to identify the risk factors. And the BN model is built based on the deployment rule for factor nodes in BN and the expert knowledge by Dempster-Shafer evidence theory. Then the probabilities of incident consequences and risk factors’ effects can be calculated. The most likely consequences given by this model are consilient with the case. Meanwhile, the quantitative estimations of risk factors’ effects may provide a theoretical basis to take optimal risk treatment measures for oil pipeline management, which can be used in emergency preparation and emergency response.
Evaluation of Water Resources Carrying Capacity in Shandong Province Based on Fuzzy Comprehensive Evaluation
Authors: Zhao Qiang , Gao Qian , Zhu Mingyue , Li Xiumei
Published: June 2018

Water resources carrying capacity is the maximum available water resources supporting by the social and economic development. Based on investigating and statisticing on the current situation of water resources in Shandong Province, this paper selects 13 factors including per capita water resources, water resources utilization, water supply modulus, rainfall, per capita GDP, population density, per capita water consumption, water consumption per million yuan, The water consumption of industrial output value, the agricultural output value of farmland, the irrigation rate of cultivated land, the water consumption rate of ecological environment and the forest coverage rate were used as the evaluation factors. Then,the fuzzy comprehensive evaluation model was used to analyze the water resources carrying capacity Force status evaluation. The results showed : The comprehensive evaluation results of water resources in Shandong Province were lower than 0.6 in 2001-2009 and higher than 0.6 in 2010-2015, which indicating that the water resources carrying capacity of Shandong Province has been improved.; In addition, most of the years a value of less than 0.6, individual years below 0.4, the interannual changes are relatively large, from that we can see the level of water resources is generally weak, the greater the interannual changes in Shandong Province.
Research of Variable Application Control System Based on Fuzzy Control
Authors: Huang JinXia , Zhang Yu , Su XiaoGuang , Tian SiQing
Published: June 2018

The AT89C52 microcontroller and the fuzzy control algorithm is used to design the automatic control system of variable Spraying pesticides. The system adjusts automatically the electric regulating valve according to given Spraying pesticides per unit area so that the actual amount of Spraying pesticides equal to the set value. The simulation model of automatic control system of variable pesticide application was established, and the controller was simulated by MATLAB / SIMULINK software fuzzy control toolbox. The simulation results show that the structure and algorithm of the proposed automatic control system of pesticide application is feasible, The system improves greatly pesticide utilization, reduce pesticide residues and environmental pollution.
Temporal and spatial evolution characteristics of water environment quality in Heze
Authors: Gao Qian , Zhao Qiang , Li Xiumei
Published: June 2018

The evolution of water environment is relatively complicated. The study of its characteristics is helpful to grasp the general direction of spatial and temporal evolution of water environment in Heze city, and to carry out water resources development and water environment protection more rationally. The comprehensive pollution index method for calculation, and the observed data are handled by Excel. In order to facilitate the analysis of the basin, Arcgis is utilized to map the watershed map. In addition, for the spatial evolution, surfer12 is used to analyze the spatial evolution characteristics the spatial evolution, and to draw the pictures of spatial evolution of chemical oxygen demand and water quality evolution. The study shows that: (1) In Heze, the quality of water environment has been improved year by year from 2006 to 2013. In 2014, the water environment has deteriorated. The content of volatile phenol has increased greatly, and the evolution trend of COD is close to the trend of the comprehensive pollution index. (2) In terms of Spatial state of water environment, the water quality of Zhuzhao New River and Wanfu River is poor, and Dongyu River water quality is better. Zhuzhao New River and Wanfu River water qualityis often worse than grade V or V, and Dongyu River water quality is mostly maintained in the grade Ⅳ. Through the analysis on the spatial revolution characteristics of water quality and chemical oxygen demand(COD),as a result, water quality is poor in the northern region,and the water quality in the southern region is better in Heze. Although the water quality has changed in recent years, the overall pattern is relatively stable.
Research characteristics and status on Environmental Psychology: a bibliometric and knowledge mapping analysis
Authors: Xu Jun Hua , Zhu Lei Ye , Wang Hai Bin
Published: June 2018

Environmental psychology is an interdisciplinary field that focuses on the interplay between individuals and their built and natural environments. Great progress has been made in the areas of environmental psychology by researchers form many countries. However, a thorough quantitative analysis to the emergent research trends and topics has not been found. To reveal the research characteristics and status on Environmental Psychology, 853 related papers from Web of Science core collection were analysed by CiteSpace II. The results show that: (1) the domain of Environmental Psychology was started in 1960s and showed a low growth over the past half century, which reaches a historical peak in 2017. Gifford, USA and the Journal of Environmental Psychology top the list of contributing authors, country and publication respectively. (2) “Environmental Psychology” is the most frequently keywords and has the longest span of the bursts. “ambient scent”, “recycling”, “children as outsiders” and “ambient temperature” are the top four largest clusters, which are the popular research topics in the domain of environmental psychology.
Linking Structural Equation Modelling with Bayesian Network and Coastal Phytoplankton Dynamics in Bohai Bay
Authors: Chu Jiangtao , Yang Yue
Published: June 2018

Bayesian networks (BN) have many advantages over other methods in ecological modelling and have become an increasingly popular modelling tool. However, BN are flawed in regard to building models based on inadequate existing knowledge. To overcome this limitation, we propose a new method that links BN with structural equation modelling (SEM). In this method, SEM is used to improve the model structure for BN. This method was used to simulate coastal phytoplankton dynamics in Bohai Bay. We demonstrate that this hybrid approach minimizes the need for expert elicitation, generates more reasonable structures for BN models and increases the BN model’s accuracy and reliability. These results suggest that the inclusion of SEM for testing and verifying the theoretical structure during the initial construction stage improves the effectiveness of BN models, especially for complex eco-environment systems. The results also demonstrate that in Bohai Bay, while phytoplankton biomass has the greatest influence on phytoplankton dynamics, the impact of nutrients on phytoplankton dynamics is larger than the influence of the physical environment in summer. Furthermore, despite the Redfield ratio indicating that phosphorus should be the primary nutrient limiting factor, our results indicate that silicate plays the most important role in regulating phytoplankton dynamics in Bohai Bay.
An Unmanned Aerial Vehicle Cluster Network Cruise System for Monitor
Authors: Jiang Jirong , Tao Jinpeng , Xin Guipeng
Published: June 2018

The existing maritime cruising system mainly uses manned motorboats to monitor the quality of coastal water and patrol and maintenance of the navigation -aiding facility, which has the problems of high energy consumption, small range of cruise for monitoring, insufficient information control and low visualization. In recent years, the application of UAS in the maritime field has alleviated the phenomenon above to some extent. A cluster-based unmanned network monitoring cruise system designed in this project uses the floating small UAV self-powered launching platform as a carrier, applys the idea of cluster, and combines the strong controllability of the multi-rotor UAV and the capability to carry customized modules, constituting a unmanned, visualized and normalized monitoring cruise network to realize the functions of maritime cruise, maintenance of navigational-aiding and monitoring the quality of coastal water.
Analysis of day rainfall characteristics of Zhengzhou
Authors: Shen Zhenzhou , Yao Wenyi , Xiao Peiqing , Yang Xueqin
Published: June 2018

Raindrop characteristics, including speed and size of raindrops, in Zhengzhou city of Yellow River basin were analyzed through a natural rainfall on the loess slope. Results showed that the process of natural rainfall belonged to a parabola and counts, size and terminal velocity would increase with the rainfall intensity rising. Besides, the size and terminal velocity of natural raindrops were relatively scattered; In the process of individual rainfall, the terminal velocity and its peak value were mainly focused between 0.8~5m/s and 1m/s, respectively. Size of raindrops were mainly consisted of 0.125-0.5mm, among which the terminal velocity of raindrops with a size of 0.125mm, 0.25mm, 0.375mm, 0.5mm were primarily 0.8-3.4m/s, 0.6-3.4m/s, 0.8-1m/s, 1-1.4m/s, respectively.
Effect of vegetation construction on runoff and sediment yield and runoff erosion ability on slope surface
Authors: Yang Chun Xia , Xiao PeiQing , Li Li , Jiao Peng
Published: June 2018

Land consolidation measures affected the underlying surface erosion environment during the early stage of vegetation construction, and then had an impact on rainfall infiltration, erosion and sediment yield. This paper adopted the field simulated rainfall experiments to analyze the function that pockets site preparation measures affected on rainfall infiltration, runoff sediment yield and runoff erosion ability. The results showed that，the measures can delay the rainfall runoff formation time of the slope by 3'17" and 1'04" respectively，Compared with the same condition of the bare land and natural grassland，The rainfall infiltration coefficient each increased by 76.47% and 14.49%, and infiltration rate increased by 0.26 mm/min and 0.11mm/min respectively; The amount of runoff and sediment yield were reduced because of the pockets site preparation ，The amount of runoff reducing rate were 33.51% and 30.49%, and sediment reduction rate were 81.35% and 65.66%, The sediment concentration was decreased by 71.99% and 50.58%; Runoff velocity of bare slope and natural grassland slope decreased by 38.12% and 34.59% respectively after pockets site preparation . The runoff erosion rate decreased by 67.92% and 79.68% respectively. The results will have a great significance for recognizing the effect of water and sediment reduction about vegetation and the existence of its plowing measures at the early period of restoration.
Effects of water and soil conservation works on runoff and sediment variation in the areas with high and coarse sediment yield of the middle Yellow River
Authors: Sun Wei Ying , Zhang Pan , Li Li , Chen Jiang Nan
Published: June 2018

The areas with high and coarse sediment yield of the middle Yellow River is well known for its severe erosion, high sediment yields. Since 1982 when the 8 key soil and water conservation harnessing regions has been built, the ecological environment has been gradually improved and the amount of sediment and runoff entering the Yellow River has been reduced continuously. Some researchers considered that it was owing to the water and soil conservation works (WSCW), while others believed that it was caused by the rainfall variation, but this has not been quantified for the effect respectively. This paper deals with the effects of WSCW on runoff and sediment variation. The study has been carried out in the Sanchuanhe River watershed, where was listed as one of the 8 key soil and water conservation harnessing regions. The results show that the contribution rate of human activities was 80.2% after 1st harnessing stage (1970-1979), 43.0% after 2nd harnessing stage (1980-1989), in 3rd harnessing stage (1990-1996) it reached 98.4%, and was 44.8% after 4th harnessing stage (1997-2006). With regard to the influence on runoff reduction in the watershed, the contribution rate of human activities was 62.5% compared with the natural factors after 1st harnessing stage (1970-1979), 28.4% after 2nd harnessing stage (1980-1989), in 3rd harnessing stage (1990-1996) it reached 69.6%, and was 37.0% after 4th harnessing stage (1997-2006). The results revealed that human activities exerted the largest effects on the sediment reduction and explained 66.6% of the variation in the specific sediment yield. This study suggests that a combination of human activities and rainfall variation effectively reduces runoff and sediment delivery of the Loess Plateau. Generally The runoff reduction and contribution of rainfall variation to runoff reduction in this area were as large as human activities. After many years' harnessing the great benefit have been obtained in water and soil loss control in this watershed.
Contrast Experiment on Advanced Treatment of Pharmaceutical and Paper-making Wastewater through Cinder Fenton-like Process
Authors: Xiaofeng Jia , Xiaoyu Chen , Wenning Mai
Published: June 2018

The Fenton-like process of catalyzing H2O2 with Fe2+ and cinder is adopted to subject pharmaceutical and paper-making wastewater to advanced treatment. The influence of each factor is determined using orthogonal experiment and single factor test. The optimal combination of influencing factors is 0.3mmol · L-1 of FeSO4 · 7H2O, [H2O2]:[Fe2+]=8:1 and 10g · L-1 of pyrites cinder. The reaction time in pharmaceutical wastewater and paper-making wastewater is 30min and 60min respectively, testifying to the fact that the reaction in pharmaceutical wastewater is faster than that in paper-making wastewater and the lower utilization rate of cinder in pharmaceutical wastewater. Under the optimal reaction condition, the COD removal rate of these two kinds of wastewater can reach as high as 65% and 72%. Characterized by simple operation and requiring less reagent dosage, this method does not have to regulate the pH of flooding water and allows the repeated usage of cinder.
The Location Analysis on Dry Port of the Inland in Jinan City
Authors: Sun Jianmeng , Wang Haining
Published: June 2018

The port competition is more and more intense, starts to be the initial infrastructure and the operation ability competition, now is in the port economy hinterland competition. Dry Port has the functions of customs declaration, forwarder, inspection and quarantine, warehousing, loading and unloading, circulation processing etc. At present, the construction and layout of the inland dry port, the possibility and feasibility of construction are the focus of the research. The location of dry port in Jinan is fully analyzed on the basis of reference to the advanced operation mode and development experience of the excellent non-water port in the country and abroad. This paper first analyzed Location factors; Then center of gravity method were analyzed. Finally, the location of the dry port is determined.
Research on layout of multimodal transport center in Jinan City
Authors: Zhang Xue Qin , Cui Ying Ran , Li Yuan , Liang Xiu Feng
Published: June 2018

Multimodal operation is an efficient form of transportation organization. By integrating various modes of transport, the advantages of each mode are fully exerted, and the efficiency and quality of transportation are improved to meet the demand for personalized transport. This article first analyzes the status of multimodal transport development in various regions of Shandong Province; through the analysis of the external environment in which Jinan City is located, it proposes the layout of the Jinan Multimodal Transport Center; finally, it proposes various solutions based on the actual development status.
The Study of Sand-blocking Characteristic and Flow Field Simulation Analysis of the Ring-shaped Sand-barrier
Authors: Zheng Wei Qiang , Wei Wen Jun , Liu Ping Yi
Published: June 2018

Aiming at the complexity of wind direction and irregular sand flow in a desert area, a combinatorial ring-shaped sand barrier is used. Stokes law of inertia force and centrifugal force and gravity sedimentation are used. With CFD fluid software Fluent, laminar flow model Equation and κ-ε turbulence model, the wind speed of the sand in the sand-gas-solid two-phase flow passing through the circular sand barrier is studied at different distances and different altitudes after the sand barrier, the wind speeds before and after the sand barrier are compared and analyzed . The mean minimum wind speed behind the single sand barrier was reduced by 32.5% -49.4% compared with that before the sand barrier. The wind speed at different height of the composite sand barrier was reduced by 30% -58.3% compared with the inlet wind speed, which solved the problem of irregular wind and sand control in the desert wind direction.
Biogas production of Chicken Manure by Two-stage fermentation process
Authors: Liu Xin Yuan , Wang Jing Jing , Nie Jia Min , Wu Nan , Yang Fang , Yang Ren Jie
Published: June 2018

This paper performs a batch experiment for pre-acidification treatment and methane production from chicken manure by the two-stage anaerobic fermentation process. Results shows that the acetate was the main component in volatile fatty acids produced at the end of pre-acidification stage, accounting for 68% of the total amount. The daily biogas production experienced three peak period in methane production stage, and the methane content reached 60% in the second period and then slowly reduced to 44.5% in the third period. The cumulative methane production was fitted by modified Gompertz equation, and the kinetic parameters of the methane production potential, the maximum methane production rate and lag phase time were 345.2 ml, 0.948 ml/h and 343.5 h, respectively. The methane yield of 183 ml-CH4/g-VSremovedduring the methane production stage and VS removal efficiency of 52.7% for the whole fermentation process were achieved.
The design and implementation of automotive radar system based on MFSK waveform
Authors: Song Yong Kun , Liu Yong Ji , Song Zhan Long
Published: June 2018

As a driving aid system, automotive radar plays a more and more important role in reducing traffic accidents. In this paper, a simple and efficient automotive radar system based on MFSK (Multiple frequency shift keying) is designed, the system structure and implementation algorithm is presented. This system uses FPGA as the signal processing unit to ensure the response speed. In addition, the designed MFSK waveform algorithm achieved high precision and unambiguous measurement. The effectiveness of the system is verified by experiments and field measurements.
Optimization and research of primary frequency compensation strategy of the unit with supercritical forced circulation boiler
Authors: Han Ying-kun , Mou Lin , Liu Wei-ming , Yang Peng-wei , Pang Xiang-Kun
Published: June 2018

The paper introduces the theory and application of Power Plant's primary frequency compensation(PFC) on the unit with the supercritical forced circulation boiler. First of all,the paper gives the typical parameters Setting and logic design of PFC. Then it explains some adverse factors which affect the PFC of the unit. With some problems in the operative process, the typical control strategy and some advices are given , which can improve PFC ability of Power Plant's PFC.
Simulation of dissolved nutrient export from the Dongjiang river basin with a grid-based NEWS model
Authors: Rong Qiangqiang , Su Meirong , Yang Zhifeng , Cai Yanpeng , Yue Wencong , Dang Zhi
Published: June 2018

In this research, a grid-based NEWS model was proposed through coupling the geographic information system (GIS) with the Global NEWS model framework. The model was then applied to the Dongjiang River basin to simulate the dissolved nutrient export from this area. The model results showed that the total amounts of the dissolved nitrogen and phosphorus exported from the Dongjiang River basin were approximately 27154.87 and 1389.33 t, respectively. 90 % of the two loads were inorganic forms (i.e. dissolved inorganic nitrogen and phosphorus, DIN and DIP). Also, the nutrient export loads did not evenly distributed in the basin. The main stream watershed of the Dongjiang River basin has the largest DIN and DIP export loads, while the largest dissolved organic nitrogen and phosphorus (DON and DOP) loads were observed in the middle and upper stream watersheds of the basin, respectively. As for the nutrient exported from each subbasin, different sources had different influences on the output of each nutrient form. For the DIN load in each subbasin, fertilization application, atmospheric deposition and biological fixation were the three main contributors, while eluviation was the most important source for DON. In terms of DIP load, fertilizer application and breeding wastewater were the main contributors, while eluviation and fertilizer application were the two main sources for DOP.
Water-Sediment Partition of Polycyclic Aromatic Hydrocarbons (PAHs) in Nansi Lake
Authors: Zhang Guizhai , Diao Youjiang
Published: June 2018

Based on field data of polycyclic aromatic hydrocarbons (PAHs) in water and sediment in Nansi Lake. The concentrations and the partitioning characteristic of PAHs in the water and sediment were studied. The lgKd of high molecular weight PAHs were higher than the low molecular weight PAHs. The most of PAHs Kd values were negligible correlated with TOC, soluble salt, clay and pH of the sediment in Nansi Lake.
Corrosion resistance of the microarc oxidation coatings prepared on magnesium alloy
Authors: Lv Ying , Li Jun Gang , Wu Ming Zhong , Ma Zhen , Zhang Jing Qiang , Wang Le Le
Published: June 2018

Ceramic coatings were prepared on the surface of AZ91D magnesium alloy by microarc oxidation technology. The effects of different voltages on morphology, phase composition and thickness of the coatings were characterized by SEM and XRD. The corrosion resistance of the coatings was measured by electrochemical workstation. Results indicated that the microarc oxidation coatings prepared in sodium silicate electrolyte exhibited porous surface and mainly comprised MgO, Mg2SiO4 and a small amount of MgAl2O4. The thickness of the oxide coatings increased rapidly with the increase of voltage. The coating prepared at 400V voltage had good electrochemical corrosion resistance in 3.5wt% NaCl solution.
Lodging markedly reduced the biomass of sweet sorghum via decreasing photosynthesis in saline-alkali field
Authors: Guo Jian Rong , Fan Hai , Wang Bao Shan
Published: June 2018

Lodging is a serious problem in plant growth, especially in crops growth of the natural habitat. In order to determine the influence of lodging on the growth characters of sweet sorghum, plants grown in natural saline-alkali environment were used to investigate the fresh weight, dry weight, sugar content in the stalks and the photosynthesis index of salt tolerant crop sweet sorghum. Results showed that lodging significantly reduced the growth of sweet sorghum, the fresh weight and dry weight was only 28.3% and 22.5% of the normal plants when lodging occurred after 49 days. Lodging also reduced the stalks sugar content of sweet sorghum, the stalk sugar content of lodged plants was only 45.4% of that in the normal plants, when lodging occurred for 49 days. Lodging reduced the growth and sugar content by reducing the photosynthesis parameters of sweet sorghum grown in the saline-alkali field, thus, affected the accumulation of photosynthate. Interestingly, with the extension of the lodging time, lodging led to a decrease in photosynthetic rate of sweet sorghum mainly due to non-stomatal factors.
Application of BIM technology in green building material management system
Authors: Zhineng Tong
Published: June 2018

The current green building materials management system in China's construction industry is not perfect, and there are still many shortcomings. Active construction of green building materials management system based on BIM technology, combined with the characteristics of green building materials and its relationship with BIM technology application, is urgently needed to better realize the scientific management of green building materials.
Rigid-flexible Coupling Analysis of Backhoe Hydraulic Excavator Working Device
Authors: Yuan Yongliang
Published: June 2018

This paper develops a rigid-flexible coupling approach to predict the dynamic performance of the excavator, including the stress distribution and stress diagram of curves. In order to study the dynamic performance of the excavator during the mining process, the rigid-flexible coupling model of a excavator is established and carried out for dynamics simulation. The results show that the strength of excavator meets the expected requirement and there is a large optimization space. In order to reduce the mass of the excavator's boom, this paper optimizes the design of the boom. Based on the results of the optimization design, the rigid-flexible coupling simulation of the excavator was performed again, which verified that the strength of the boom is sufficient. Simulation results show that the virtual prototype software can effectively predict the dynamic performance of the excavator. This paper provides a solid foundation for further study of the lightweight design of the whole excavator component.
Study on environment-frientdly UV-led ceramic ink transfer film
Authors: Jia Jingru , Zhang Jinhai
Published: June 2018

UV polyurethane acrylate (PUA-1) oligomer was synthesized and used to prepare the UV-LED ceramic ink transfer film. The effects of active thinner (or active monomer), photosensitizer type, photo-sen-sitizer percentage, photosensitizer consumption, etc. on the ceramic ink transfer film performance was studied. The results showed that the prepared PUA prepolymer, single functional group thinner, and the UV-LED curing system consisting of 2,4,6-Trimethyl Benzoyl Diphenyl Phosphine Oxide (TPO), 2,4-Diethyl-9H-Thioxanthen-9-one(DETX) and Reactive Amine (P115) could meet the technical requirements of transfer film.
Experimental study on flame propagation characteristics of
Hydrogen premixed gas in gas pipeline
Authors: Ma Danzhu , Li Zhuang , Jia Fengrui , Li Zhou
Published: June 2018

Hydrogen is the cleanest high-energy gas fuel, and also is the main industrial material. However, hydrogen is more explosive and more powerful than conventional gas fuels, which restricts its application. In particular, the expansion of premixed combustion under a strong constraint is more complicated, the reaction spreads faster. The flame propagation characteristics of premixed hydrogen/air were investigated by experiment. The mechanism of reaction acceleration is discussed, and then the speed of the flame propagation and the reaction pressure were tested and analysed.
Research on Closed Residential Area Based on Balanced
Distribution Theory
Authors: Lan Si , Fang Ni , Lin Hai Peng , Ye Shi Qi
Published: June 2018

With the promotion of the street system, residential quarters and units of the compound gradually open. In this paper, the relationship between traffic flow and traffic flow is established for external roads, and the road resistance model is established by internal roads. We propose a balanced distribution model from the two aspects of road opening conditions and traffic flow inside and outside the district, and quantitatively analyze the impact of the opening and closing on the surrounding roads. Finally, it puts forward feasible suggestions to improve the traffic situation and optimize the network structure.
Application of Digital Technology and PDA+APPS Mobile Terminal in Historical Architecture Culture Protection and Development
Authors: Liu Zhi Feng , Wang Ying , Huang Dong Hui
Published: June 2018

In the wake of big data and Internet plus era, continuous infiltration of digital technology has been happening in various fields of social and economic development. As the most important material carrier of historical culture, the historical value of historical buildings is produced and accumulated in its historical evolution, and it can only be protected from being created again. Based on the background of digitization of cultural resources, this paper summarizes the relevant digital technologies for the digital translation of information on buildings of historical and cultural heritage, as a means to promote the spread of the PDA+APPS mobile terminal, so as to achieve the purpose of preservation, protection, management and publicity. Meanwhile, this paper analyzes the application of digital technology in this field and the prospect of its function.
Experimental Study on Load-Displacement Relationship of
Prestressed Cable in Red Clay Stratum
Authors: Ji Yong Xing , Xiang Yuan Jie , Zhao Xiao Yong
Published: June 2018

The P-S curves of prestressed anchor cable are obtained by field pull-out tests in the red-clay stratum in Guiyang area. The P-S curves of different theoretical models are discussed base on the theoretical analysis. The elastic and plastic displacement of prestressed anchor cable are analyzed. The results shows that, the anchoring effect are mainly effected by the red-clay mechanic properties in the red-clay stratum; the P-S curve of anchor bolt can be fitted well by the exponential model and conformed to the actual; the plastic displacement is used to anchor’s damage index are more truthfulness in the red-clay stratum.
One-dimensional soil temperature assimilation experiment based on unscented particle filter and Common Land Model
Authors: Fu Xiao Lei , Jin Bao Ming , Jiang Xiao Lei , Chen Cheng
Published: June 2018

Data assimilation is an efficient way to improve the simulation/prediction accuracy in many fields of geosciences especially in meteorological and hydrological applications. This study takes unscented particle filter (UPF) as an example to test its performance at different two probability distribution, Gaussian and Uniform distributions with two different assimilation frequencies experiments (1) assimilating hourly in situ soil surface temperature, (2) assimilating the original Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) once per day. The numerical experiment results show that the filter performs better when increasing the assimilation frequency. In addition, UPF is efficient for improving the soil variables (e.g., soil temperature) simulation/prediction accuracy, though it is not sensitive to the probability distribution for observation error in soil temperature assimilation.
Analysis of the Psychological Conflict of Contemporary Street Aesthetics in China from the Views of Media Communications
Authors: Feng Chen , Xu Hua Wei
Published: June 2018

New media patterns generate more complicated and diversified space forms. Spatial experiences that are instant, fragmented, reality-virtuality interlaced are ubiquitous. Such interlacing brings an enormous impact on traditional Chinese streetscapes, increases the risks of the fragmentation of streetscapes, and leads to the disorder of visual aesthetics. Moreover, it necessarily imposes a great impact on traditional street aesthetics, and causes various psychological conflicts. This study aims to describe this phenomenon and try to explore the reason behind it in new view.
Study on load test of 100m cross-reinforced deck type concrete box arch bridge
Authors: Shi Jing Xian , Cheng Ying Jie
Published: June 2018

Found in the routine quality inspection of highway bridge that many vertical fractures on the main beam (10mT beam) of the steel reinforced concrete arch bridge near the hydropower station. In order to grasp the bearing capacity of this bridge under working conditions with cracks, the static load and dynamic load test of box arch bridge are carried out. The Midas civil theory is calculated by using the special plate trailer - 300 as the calculation load, and the deflection and stress of the critical section are tested by the equivalent cloth load in the test vehicle. The pulsation test, obstacles and no obstacle driving test were carried out. Experimental results show that the bridge under the condition of the test loads is in safe condition, main bearing component of the strength and stiffness meet the design requirements, the crack width does not increase, in the process of loading bridge overall work performance is good.
Design and development of Building energy simulation Software for prefabricated cabin type of industrial building (PCES)
Authors: Zhang Jun , Li Ri Yi
Published: June 2018

Building energy simulation is an important supporting tool for green building design and building energy consumption assessment, At present, Building energy simulation software can't meet the needs of energy consumption analysis and cabinet level micro environment control design of prefabricated building. thermal physical model of prefabricated building is proposed in this paper, based on the physical model, the energy consumption calculation software of prefabricated cabin building(PCES) is developed. we can achieve building parameter setting, energy consumption simulation and building thermal process and energy consumption analysis by PCES.
Influence of Soil Structure on the Mechanical Response of Soft Soil
Authors: Xu Bin Bin
Published: June 2018

Usually the natural sedimentary soils possess structure more or less, which makes their mechanical response much different from the fully remolded soils. In this paper, the influence of soil structure on the mechanical response such as compressibility, shear, permeability is literately reviewed. It is found that the compressibility and consolidation behavior of structured and remolded soils can be divided clearly before or after the structural yield stress. The stress-strain relationship can be divided into two segments before and after the structural yield stress. Before the yield stress, the curve is elevating and after the yield stress the curve is decreasing. The increasing rate of pore water pressure increases after the soil reached yield stress.
Study on the Old Girders in the Widening Hollow Slab Girder Bridge
Authors: Wang Ying , Zhang Li Fang , Ma Hai Yan
Published: June 2018

Taking the bridge widening project of Shanghai-Hangzhou-Ningbo expressway widening construction project (China) as the background in this paper, the variation law of the internal force of the old bridge in the widening hollow slab girder bridge under vehicle load is studied, which is under the condition of different span lengths and different widening widths. Three different span lengths of the pre-tensioned prestressed hollow slab girder bridges are selected, the spatial finite element models of both the old bridge and the whole structure of widening bridge are established and calculated respectively by Midas/Civil software. The influences of widening and load increasing on the old bridges under the vehicle load are compared and analyzed. In addition, the authors also analyze the influences of different widening widths on the force state of old bridges under the condition of widening the same number of lane. Moreover , the effects on the old bridges that are caused by the uneven foundation settlement of widening bridge structure are also studied in this paper. This paper can provide some references for widening design of hollow slab bridges.
Flexural Behavior of Ultra-High Performance Fiber Reinforced Concrete Scale Tunnel Segment
Authors: Ni Kun , Zhang Fa Sheng , Shi Yun Xing , Zhang Yan Gang , Shi Jing Bin
Published: June 2018

To reduce the weight of precast tunnel segment, ultra-high performance fiber reinforced concrete (UHPFRC) was studied to cast the segment. The flexural performance of UHPFRC scale tunnel segments were tested in this work. The weight of the UHPFRC thinner scale tunnel segment was only 80% of reinforced concrete (RC) segment. The segments were loaded as per CJJ/T 164-2011, and the four-point bending system was used. The results showed that the cracking load increased 50%, and 0.2 mm crack width load increased 22%, and the yield load increased 11%, and the ultimate load only decreased 1%. The stiffness of elastic stage of UHPFRC segment looked the same compared to RC segment. In a word, the UHPFRC thinner segments showed excellent flexural performance beyond the traditional RC segment.
Overview of Anti-Seismic Researches of Underground Structures
Authors: Liao Ran
Published: June 2018

With the vigorous development of urban rail transit system, especially the construction of
subway system, the safety of subway system draws more and more attention. The study of anti-seismic for
underground structures has also become an important problem to be solved in the construction of Metro
system. Based on the typical underground structure seismic damage phenomenon, this paper summarizes the
seismic characteristics, research methods and design methods of underground structures to offer a guide for
engineers.
The Researches on Construction Response and Excavation Method Optimization of Extra-large Cross-section Urban Subway Tunnel
Authors: Wu Bo , Huang Wei , Zhao Yong Bo
Published: June 2018

In the extra-large cross-section urban subway underground station projects, the key problem is to choose the appropriate excavation method and grasp the mechanical behavior of the surrounding rock after excavation. The double side drift method is widely used in the urban subway underground station construction with extra-large cross-section in China. This paper presents the deformation characteristics of the extra-large cross-section tunnel of urban subway and a comparison with the numerical simulation results. In the city subway underground excavation of large section station, the mechanical behavior of surrounding rock change and its influence on the surrounding area mainly depend on the selection of construction methods. The convergent deformation of tunnel cavern, the subsidence of the surface and the force failure of the surrounding rock associated the construction approaches are demonstrated. This study provides a more in-depth demonstration of the way to optimize the excavation method of the extra-large cross-section tunnel to achieve the purpose of controlling the deformation of the surface and surrounding rock.
Discussion on runoff purification technology of highway bridge deck based on water quality safety
Authors: Tan Sheng-guang , Liu Xue-xin , Zou Guo-ping , Xiong Xin-zhu , Tao Shuang-cheng
Published: June 2018

Aiming at the actual problems existing, including a poor purification effect of highway bridge runoff collection and treatment system across sensitive water and necessary manual emergency operation, three kinds of technology, three pools system of bridge runoff purification, the integral pool of bridge runoff purification and ecological planting tank, are put forward by optimizing the structure of purification unit and system setting. At the same time, we come up with an emergency strategy for hazardous material leakage basing on automatic identification and remote control of traffic accidents. On the basis of combining these with the optimized pool structure, sensitive water safety can be guaranteed and water pollution, from directly discharging of bridge runoff, can be decreased. For making up for the shortages of green highway construction technology, the technique has important reference value.