bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic evolution assessing of Dongsha shoal of the Radial Sand Ridges in South Yellow Sea, based on the smallest enclosing rectangle centroids method
Authors: Liu Binglin , Jiang Shengnan , Zhang Zhenke , Wu Haotian , Wei Guoen , Shen Wei , Wang Qing 
Published: September 2020

Abstract
The smallest enclosing rectangle is an important parameter in the target features of geographic elements. Its centroid can indicate the general movement trend of geographic elements. Taking Dongsha in the radiant sandbar area off Jiangsu as an example, the shape was derived from long-period remote sensing images from 1973 to 2016, learning the concepts of the smallest enclosing rectangle and centroid, extract the Dongsha Shoal of each phase by ArcGIS. The smallest enclosing rectangle centroids compare the centroids of different periods to determine the overall movement trend of Dongsha Shoal in different periods. The study found that during the 43-year period, the overall movement direction of Dongsha shoal was north-north-east, specifically divided into five stages, each of which has a different direction and speed of movement. The smallest enclosing rectangle can be used as an useful method to study the dynamic change trend of marine sandbar.
A research on the seasonal difference of air pollution in Chengdu
Authors: Ma Chenwei , Ding Lijin 
Published: September 2020

Abstract
With the rapid development of Chengdu’s economy, the problem of air pollution has gradually drawn attention by scholars. Based on the time series data covers 2014 through 2019 of Chengdu, this research investigates the seasonal difference in air pollution and the possible influence of six pollutants on air pollution. The results indicated that there is a significant seasonal difference of air pollution in Chengdu and air pollutants are mainly fine particulate matter and ozone. Based on the findings, the government might consider achieve precise emission reductions for the pollution sources of PM2.5 and O3.
The ecological environment capacity of different functional zones in Lushan Scenic Area
Authors: Wen Li , Xie Dongming , Zhou Guohong , Qian Haiyan , Guo Ziwei 
Published: September 2020

Abstract
Eco-environment capacity assessment is to appraise the status of the ecoenvironment. Lushan Scenic Area is one of the global famous cultural landscapes in China. A multi-factor comprehensive analysis method and indicator weighting method are used to appraise the status of the eco-environment of different eco-function zones by building the ecoenvironmental capacity indicator system in Lushan Scenic Area. The results explain the different eco-function zones were various in the status of the eco-environment. The eco-protect zone was good status of eco-environment in middle and low hot tourism season, but it was bad status of eco-environment in high hot tourism season. However, the control developing zone, the natural landscape protect zone and eco-restoration zone were bad status of eco-environment in total tourism season. Many elements lead to the bad status of eco-environment, such as heavy tourist activity, high density buildings, water contaminating, and noise destroyed the eco-environment together.
Current application situation and developments of low-cost sand proppant in China
Authors: Zheng Xinquan , Wang Xin , Liang Tiancheng , Yang Nengyu , Cai Bo , Meng Chuanyou , Fu Haifeng 
Published: September 2020

Abstract
Since 2014, the petroleum companies in North American have adopted self-operated and self-supplying modes to cut costs for proppants, such as replacing ceramic with sand and building sand plants nearby, achieving win-win results of continuous growth in oil and gas production and economic benefits. Enlightened by such situation in North America, in this study, the feasibility of sand promotion is demonstrated systematically in terms of the basic theoretical research, experimental testing and field tests. The research results indicate that: (1) the sand currently used in China can completely meet unconventional reconstruction requirements, as it has a crushing resistance grade equivalent to that of the yellow sand from the U.S. and the crushing rate and flow conductivity basically close to those of such yellow sand; (2)based on the characteristics of unconventional petroleum reservoirs and fluids and the differences between their completion modes and those of conventional petroleum reservoirs, the beneficial development of unconventional petroleum that can be realized by increasing the laying concentration and using the sand with small particle sizes has been verified; (3) the development potential of Shixi, Jiangyou, Yiliang and Chuxiong is demonstrated by conducting the localization feasibility study of sand sources to lay the foundations of further cost cutting and efficiency enhancement for unconventional petroleum; (4) the field tests have indicated that, in China, the sand used for fracturing can fully meet the technical demands of the reconstruction for unconventional reservoirs not deeper than 3,500 m and shows good production effect and economic efficiency. In view of these research and understanding, the cost cutting of sand for more benefits shall be further enhanced to ensure the low-cost petroleum development in China. Specifically, the promotion and application of sand and building sand plants nearby shall be strengthened.
Differentiation characteristics of soil water under different landscape types in a desert-oasis region in the middle reaches of Heihe river basin, China
Authors: Sun Tesheng , Zhang Sijing , Bao Yaqin 
Published: September 2020

Abstract
The tillage of oasis farmlands and construction of artificial protection forests in native grasslands around the oases would significantly affect differentiation characteristics of soil water. In this study, the establishment of belt transect with 13 different landscape types in the middle reaches of Heihe River basin was determined to analyze differentiation characteristics of soil water. Our results showed that firstly vertical variability of soil water under different landscape types was significant. Secondly, horizontal variability of soil water under different landscape types showed a significant difference. Thirdly, differentiation characteristics of soil water under different landscape types were mainly caused by interaction of multiple factors such as vegetation type, soil properties and human management etc, and spatial variability of soil water can be enhanced by the tillage of oasis farmlands and construction of artificial protection forests. Our results suggest that it has very important value for enhancing the soil water effect of irrigated vegetation in this region to fully conform the water consumption of plants and the water holding capacity of soil, to especially strengthen the management of water-saving irrigation of farm crops and artificial plantations.
Laser-Raman spectral analysis of the Baoxingchang Cu-Mo deposit, Yunnan Province, SW China
Authors: Jian Long , Dao Yan , Zhang Yourong , Xu Shengchao 
Published: September 2020

Abstract
Baoxingchang Cu-Mo deposit is one of several Cu-Mo-(Au) polymetallic deposits have been found in the Tethys metallogenic province. Laser-Raman spectral analysis shows that the vapour-phase components of fluid inclusions in quartz are mainly composed of water vapour and a little CO2, while the fluid-phase components contain Na+ and Cl− metallogenic fluid, which generally belongs to a NaCl-H2O system. In conclusion, the characteristics of fluid inclusions in porphyry-type Cu-Mo polymetallic deposits in Baoxingchang are closely related to multi-stage intrusions along the Jinshajiang-Red River shear zone.
Zircon U-Pb dating of the Lower Cretaceous strata on the margin of the Erlian Basin, North China and its Constraints on basin evolution
Authors: Li Ying , Cheng Yinhang , Wang Shaoyi , Zhang Tianfu , Teng Xuejian , Li Yanfeng 
Published: September 2020

Abstract
A large number of Early Cretaceous magmatic rocks are exposed in the Erlian Basin in North China. LA-MC-ICP-MS zircon U-Pb dating of rhyolites with age of 122.8 ± 0.4 Ma is corresponded to basin subsidence, reflecting a large-scaled extension event occurred in North China. There was a structural inversion after the Neogene, which caused the migration of the Erlian Basin center from the NW to SE, with the center of the Early Cretaceous basin corresponding with the NW margin of the modern basin.
Analysis of stratification in underground space development and utilization: an example from Beisan county of Langfang city
Authors: Bai Yaonan , Liu Hongwei , Miao Jinjie , Du Dong , Jiang Wangjun 
Published: September 2020

Abstract
It is important to analyze underground urban spaces for their capacity to meet the needs of urban development without compromising important ecological resources. Through analyzing the soil structure of Beisan County of Langfang City, the cohesive soil has low bearing capacity and easy deformation, which affects the development of underground space; the sand has wide distribution, large thickness and high bearing capacity, which is beneficial to the development of underground space. In 18-22 meters and 50-70 meters underground, there are two cohesive soils with continuous distribution, which are natural protective barriers for groundwater resources. In order to coordinate the development and utilization of underground space with the protection of groundwater resources, a safe method for utilizing space is proposed that protects groundwater resources and avoids breaking continuous aquiclude by stratifying the underground space. The underground space is developed in three sections in the study area: 0∼18 meters is the shallow underground space;22∼50 meters is the sub-deep underground space; Below 70 meters is the deep underground space.
Experimental Study of Scissor-like-structure Vibration Isolator
Authors: Liu Yang , Zhang Wei , Li Shuangbao , Zhu Hengjia 
Published: September 2020

Abstract
Considering the problem of low-frequency vibration isolation and disadvantages of existing models, an optimized model is established. Based on optimized model, the expression of displacement transmissibility is derived. Then an experimental model of scissor-like-structure vibration isolator (SLS-VI) is established. The comparison of experimental curve and theoretical curve proves the feasibility of model optimization. The effective vibration isolation bandwidth is 10Hz-16Hz which proves the SLS-VI have excellent vibration isolation performance at low frequency. Experimental results are basically consistent with theoretical analysis in displacement transmissibility of the vibration isolator. It proves the correctness of the theoretical analysis of scissor-like-structure at low frequency.
Deformation Analysis of Rotating Linear Guide
Authors: Cao Jiangping , Peng Yuanhui , Yang Chang , Li Jieji , Yang Li 
Published: September 2020

Abstract
Rotating linear guide movement precision because of its flexible realization of two-dimensional space, and the advantages of compact structure, easy to install and debug, in more and more application in the industry and precision instruments, not only its application technology and rapid development in different areas, rotating linear guide itself material, structure and control technology have been rapidly increasing. Rotating linear guide application according to the use of the environment and the demand is different, have different requirements, but to control its deformation is the key to ensure the good operation to solve common technical problems. Rotating linear guide deformation is mainly composed of the weight of the structure itself and structure stiffness, support and fundamental cause, among them, the support (including support and support) and vehicle (including the distribution of vehicle quality, vehicle quality and vehicle movement way and the state) is a key factor, the deformation of the straight line guide rail and the trend of change over time, is crucial, especially in the condition of rotating linear guide. This paper focuses on the potential of several support state set of rotating linear guide bearing conditions of stress and deformation analysis, study its change trend, compared several different support condition state of linear guide.
The Development of Elderly Care Robot and Current Challenges for Functional Design
Authors: Wang Jiaying 
Published: September 2020

Abstract
The emergence and development of robot industry is one of the important achievements in the 20th century. After years of development, the elderly care robot can only complete some mobile auxiliary functions at the earliest, and now it can complete many functions such as detection, reminder, chat, etc. Even so, the elderly care robot is still in the direction of more functions and more wisdom. So, what is the function of elderly care robot? What should be paid attention to in the design and use of elderly care robot? Based on the needs of the elderly, this paper discusses the functions of the elderly care robot and the practical factors that the elderly care robot should consider on the premise of meeting the interests of the elderly and not violating the ethics.
Research on the Simplified Calculation Model of Large Phased Array Radar Reflector Mechanics Based on NASTRAN
Authors: Gu Ye Qing , Wang Jin Wei , Tang Bao Fu 
Published: September 2020

Abstract
there are many plates and beams on the radar array. In the process of finite element calculation, choosing the appropriate shell mesh finite element model to replace the solid finite element model can reduce the calculation amount. In this paper, the finite element solid mesh model is established based on the reflection panel model of a radar antenna array, and the simulation results are obtained. Secondly, the shell grid is used to perform finite element modeling and correction calculations on the reflective panel. The results show that the modified shell grid calculation results are very close to the solid grid model results, and can replace the solid grid to simplify the calculation of the array.
Aerodynamic Performance and Flow Structure Investigation of Contra-rotating Wind Turbines by CFD and Experimental Methods
Authors: Faisal M , Zhao X , Kang M-H , You K 
Published: September 2020

Abstract
Wind tunnel experiment was carried out to measure mechanical power of the contra-rotating wind turbine (CRWT) and single rotor wind turbine (SRWT) under various working conditions. Particle Image Velocimetry (PIV) device was employed to measure the transient flow field on the meridional plane of the rotors. The azimuthal velocity vector, magnitude and streamline were obtained by the average PIV image of ten intervals in a rotation cycle. CFD model of steady flow was developed to predict aerodynamic performance and flow structure of the CRWTs using S-A turbulent model. The single channel model was employed with periodic boundary condition. CFD results were validated with wind tunnel test in literature and experiment in this paper. Results show that CFD method has a satisfied accuracy in power prediction, with a relative error less than 34%. The azimuthal average velocity distributions predicted by experimental and CFD methods are close and the maximum value are approximate to each other. Results demonstrate a high velocity zone at the outside of the front rotor tip and a low velocity zone near the middle of the rear rotor. CRWT has a complicated flow structure. Particularly at the rear rotor, flow becomes uneven and streamline curvatures are more ununiformed.
Aerodynamic Performance Prediction of XH-59A Helicopter in Pop-up Flight
Authors: You K , Zhao X , Zhang Y-H , Zhao S-Z , Lin Y-F 
Published: September 2020

Abstract
The pop-up progress of the coaxial rigid rotor helicopter was decomposed into 5 stages. Quasi-steady flow assumption was adopted to analyze the helicopter performance. XH-59A helicopter was regarded as a solid body. Flow interactions between fuselage and rotor, rotor and tail were ignored. The aerodynamic performance of coaxial rotor, fuselage and horizontal tail were calculated based on Blade element moment theory, wind tunnel test data and theoretical calculation correspondingly. The Pitt/Peters inflow model was used to represent the inflow velocity on the rotor and flow interaction between upper and lower rotor were considered using interference factor. The net force and moment on the helicopter was derived and formulated into flight mechanics equations. To validate the calculation, a wind tunnel test of a coaxial rigid rotor helicopter was employed. The rotor lift coefficient, helicopter pitching and rolling moment coefficients were close to the experimental data. The controlled variables of the helicopter was composed of helicopter pitch angle (shaft angle), collective pitch, cyclic pitch of both rotors, deflection angle of the horizontal tail during the pop-up progress. The mathematical model presented in this paper provides the basic system structure to analyze the pop-up progress. The required power of the helicopter were formulated with altitude, rotor thrust, flight velocity, which help to obtain a rapid and primary evaluation of the integral performance of the progress.
Drilling and Migration Characteristics of Critical Size Lunar Soil Particles
Authors: Tong Lijie , Zhao Deming , Hu Ming , Gao Xingwen , Wang He 
Published: September 2020

Abstract
Critical size lunar soil particles refer to particles with a particle size similar to the diameter of the drill bit, which is an important factor affecting lunar soil drilling sampling, and its influence is uncertain. In this paper, the discrete element method is used to simulate the drilling sampling process of the critical size lunar soil particles and the influence of the size, position and shape of the lunar particles with critical diameter on the drilling load is analysed. It is found that the critical size lunar soil particles have special migration trajectories and load characteristics during drilling sampling. The size and shape of lunar soil particles are the key factors affecting the drilling load. This study can support the design of drilling tools for lunar soil exploration and sampling.
Creative Experiment on Decorative Products for Condominium using Responsive Technology
Authors: Sirikhvunchai Natcha , Wanichakorn Aran , Musikapan Ravitep 
Published: September 2020

Abstract
Creative experiment on decorative products for condominiums using responsive technology has the purpose of creating decorative products using responsive technology which can improve the interior atmosphere which can be controlled by the user and adjusted according to their needs. The constraint of the design is the interaction between the two emotional states of normal (heart rate of 60-80bpm) and high stress level (heart rate of 80-100bpm). Another constraint of the design is the technological constraint, which can control the lighting, noise level, and temperature according to the users’ needs. This research is conducted based on the previous one called “A Study of Interactive Media to Design and Develop Decorative Product in Condominium”. The knowledge gained from the previous research about incorporating technology into product design is utilized in this research to be experimented on decorative products with responsive technology. The results of this research can be divided in two parts. The first part is summarizing user behaviors in which the results are obtained from both primary and secondary methods. The results are then used to create product design constraints. The second part is the resulting product design which is aesthetically satisfying, suitably for the physical environment and the three factors which can be controlled by sensors include lighting, noise level and temperature lighting, which is controlled by, noise sensor and humidity sensor respectively. There are three resulting designs which have three levels of intelligence according to different usages of living room, dining room, and bedroom.
Develop Creative Brick Kiln Cultural Products by Powder Metallurgy Process Technique
Authors: Lee Yann-Long , Hung Yu-Ching , Chou Wen-Chih , Wang Chuan-Po , Peng Tzu-Hsua 
Published: September 2020

Abstract
Brick is one of the most common traditional building materials in the world. Located at the foot of the Bagua Mountain in Changhua, Taiwan, Qiaotou community residents make good use of mountain clay to develop the brick kiln industry, and once created a glorious history. With the increase in building materials regulations, the chimneys of brick kilns no longer smoke, and the industry has gradually declined. This study hopes that the traditional brick kiln industry will be improved through technological technique and input a new generation of innovative thinking. The general brick kiln cultural products will be re-granted to new life from the decline and showing the creative thinking in the local culture. The materials test method was used to study the processing technology of brick powder. It is expected to improve the precision of brick products and reduce the production cost through the application of the powder metallurgy process technique. And applied to the brick creative culture product design to create unique merchandise.
Double-pore structure porous Mo–Si–B intermetallics fabricated by elemental powder metallurgy method using NH4HCO3 as pore-forming agent
Authors: Huang Yongan , Zhang Laiqi , Wei Shizhong 
Published: September 2020

Abstract
The multiphase porous intermetallic compounds Mo3Si-Mo5Si3-Mo5SiB2 of a double-pore structure has been successfully fabricated by combining the in situ reaction synthesis with the pore-forming agent method. The effects of NH4HCO3 content and size on porosity, pore diameter distribution, permeability, and compressive strength were investigated systematically. The results show that: with the NH4HCO3 increasing from 0 to 60 vol%, the total porosity increases from 46.6% to 73.2%, the big pores volume increases from 2.3% to 69.4%, the gas permeability increases from 5.34 × 10−7 l/(min · cm2 · Pa) to 1.74 × 10−4 l/(min · cm2 · Pa), and the compressive strength decreases from 392 MPa to 14.8 MPa; on the other side, with the NH4HCO3 size increased from 48 μm to 230 μm, the parameters of this porous intermetallics changed slightly except to the significant increase of big pores diameter. An exponential equation of σ
c = σ
s (1-ρ)1/0.254 based on generalized mixture rule (GMR) has been put forward to quantitatively describe porosity-compressive strength behaviors. Results from this study indicate the potential applications in various filtration environments by tailoring the shape, contents, and size of the pore-forming agent.
Understanding the surface condition of gamma irradiated epoxy alumina nanocomposites adopting wavelets and fractal technique
Authors: Neelmani  , Suematsu H , Sarathi R 
Published: September 2020

Abstract
The influence of alumina nanofiller and gamma irradiation on the surface potential variation of epoxy-alumina nanocomposites was investigated. The surface potential decay rate of nanocomposites has increased and the trap depth decreased with alumina nanoparticles addition to the matrix as well as upon exposure to gamma irradiation, Surface roughness was estimated using the wavelets and fractal technique. Daubechies wavelet of order 4 (db4) wavelet was chosen as the most suitable mother wavelet for surface roughness measurement. Multi resolution signal decomposition (MRSD) analysis of surface profile has revealed that with increasing wt% of alumina nanofiller in the nanocomposites, reduction in surface roughness of nanocomposites was observed. Upon gamma irradiation, the surface roughness factor at each level of MRSD has increased marginally. Fractal dimension and lacunarity were calculated for unaged and gamma ray irradiated samples and it exhibits inverse correlation.