bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of treatment efficiency of coal mine drainage and impact on surrounding waters for selected coal mines
Authors: Shan Yao 
Published: October 2019

Abstract
Coal mine water usually has high content of trace elements, leading to contamination of surrounding water bodies. Water treatment technologies are used to remove organic and inorganic matters from coal mine water. To evaluate the treating efficiency of conventional and advanced treatment on coal mine drainage, samples of coal mine, carbonate, surface water, and treated water from the treatment processes were collected and analysed. It turns out that the conventional treatment processes can hardly remove both major ions and trace elements in coal mine water. Reverse osmosis technology can reject major ions effectively, but weak in trace elements removal. The analysis of surface water quality suggested contamination by coal mine water in the coal-mine district. To control the contamination and reuse the coal mine water effectively and safe, it is necessary to evaluate more carefully the efficiency of water treatment and potential environment impact of coal mine water on the surrounding surface and ground waters.
Effects of artificial grassland type on soil water content of degraded land restored by ecological measures in suburban Beijing
Authors: Pang Zhuo , Sun Tiejun , Kan Haiming , Wu Juying 
Published: October 2019

Abstract
Establishment of artificial grasslands is an effective and economic measurement for restoring degraded land, however, established grasslands consume soil water and disturb local water balance as well. To quantify the influence of artificial grasslands on soil water content, we monitored soil volumetric water content (VWC) at depths of 5 cm, 10 cm, 15 cm, 20 cm and 25 cm in artificial grasslands of Bromus inermis Leyss and Medicago sativa continuously throughout 2018. For Bromus inermis Leyss grassland, VWC peaked at depth of 20 cm (0.190±0.053 m3·m−3) and varied little among the rest depths, while for Medicago sativa grassland, VWC increased with depth and the highest value was 0.153±0.047 m3·m−3 at depth of 25 cm. Moreover, VWC in Bromus inermis Leyss grassland was obviously higher than that in Medicago sativa grassland for the whole year at depths of 5 cm, 15 cm and 20 cm, and slightly higher for part of the year at depth of 10 cm, but insignificantly lower at depth of 25 cm. As for water conservation, Bromus inermis Leyss grassland could perform better than Medicago sativa grassland. Under the identical climatic and edaphic conditions, the dramatic differences in VWC between grasslands of Bromus inermis Leyss and Medicago sativa imply that ecohydrological response should be taken into consideration, when selecting measures for ecological restoration.
Assessment of wastewater on-line monitoring system in an important industrial park in Tianjin, China
Authors: Liu Guangxun , Zhi Yanli , Xu Weinan , Yu Yang 
Published: October 2019

Abstract
Chemical oxygen demand and ammonia nitrogen were key water pollutants under state control, and key factories were required to conduct online monitoring. In order to evaluate the accuracy of the online instrument, the online equipment comparison monitoring of 20 key factories in 8 industries was conducted for 4 years. The wastewater of factories in the same industry has similar contaminant discharge concentration. The mean value of relative error absolute value was below 20% for medium and high concentration of chemical oxygen demand (above 30 mg/L) and ammonia nitrogen (above 1 mg/L) in water samples. For high chlorine concentration and coloured water samples, the online monitoring error was large, so the method needs to be improved.
Preparation of activated carbons from a kind of Chinese herbal medicine wastes by phosphoric acid and CO2 activation
Authors: Nie Gang , Hu Yeli , Mi Tie , Liu Yanxiang , Xin Shanzhi 
Published: October 2019

Abstract
The effects of parameters on the adsorption capacity of activated carbons (AC) prepared from Chinese Herbal Medicines Wastes (CHMWs) by phosphoric acid and CO2 activation were studied. Response surface methodology (RSM) was used to optimize the process parameters for preparing activated carbon from CHMWs. The results showed that the optimal conditions were as follows: impregnation ratio of 2.61, activation temperature of 700 °C, activation time of 2.5 h and the CO2 flow rate was 50mL/min. The adsorption value of iodine and methylene blue of the resultant activated carbon was 626.83 mg/g, 278.99 mg/g, respectively. The Activated Carbon prepared from Chinese Herbal Medicines Wastes (CHMWs) shows high adsorption capacity and well-developed pore structure.
Fracture-cave carbonate reservoir permeability modelling based on conventional log and well deliverability predication: A case study of the Amu Darya Gas field in Turkmenistan
Authors: Li Ming , Zhang Ming , Liu Lingli , Guo Tongcui , Lv Jietang , Zhang Liangjie , Chen Pengyu , Guo Chunqiu , Wang Hongjun 
Published: October 2019

Abstract
The carbonate fracture-cave reservoir is developing in carbonate gentle slope reef flat in east Amu Darya Gas field. Due to the serious heterogeneity of fracture-cave reservoirs, it is difficult to evaluate the productivity of different wells and different reservoir sections. Based on conventional log, core, image log and magnetic resonance log. The sensitive parameters contributed to reservoir permeability are studied, and the conventional log, magnetic log and image log of key well are set up to march core permeability and propagate other fracture-cave carbonate wells. Finally based on log porosity and permeability model result, the well deliverability is evaluated and the well deliverability evaluation results are match with the DST results. The Amu Darya Gas field carbonate fracture-cave permeability model and deliverability evaluation flowcharts and methods were build up and can give instructions for other fracture-cave carbonate reservoir.
Prototype geological model of distributary channel based on the high density well pattern
Authors: Wang Zhiqiang , Li Rubin , Song Baoquan , He Yuhang 
Published: October 2019

Abstract
The western part of the central zone lies in the middle of the Saertu anticline structure. It can be divided into 77 sedimentary units, with the permeability ranging from less than 10 mD to more than 1000 mD. Diversity of plane sand body morphology, phase change frequently. Based on the high density logging data in the west of the central district, the prototype geological model of distributary channel sand body is studied, and 6 sedimentary models of distributary channel in 3 sedimentary environments are established. The Upper plain was mainly developed: composite type. The lower plain is mainly developed: the split-band type and the interwoven network type; the delta front is furcated dendritic, single continuous and discontinuous type. Geometric parameters of different distributary channels are obviously affected by the sedimentary environment, and the scale, curvature and width-thickness ratio of distributary channels along the sedimentary direction all decrease from large to small.
Parametric electromagnetic transfer function estimation at USArray Site MNF34
Authors: Xu Xinyi , Butala Mark D. 
Published: October 2019

AbstractWe propose a new parametric approach to electromagnetic transfer function (EMTF) estimation which has attributes not found in the nonparametric approach most extensively used by the magentotelluric (MT) community. Firstly, parametric EMTFs are smooth by construction, which is consistent with the underlying physics. Secondly, fewer parameters are generally required to represent an EMTF by parametric means. Thirdly, our parametric approach can simplify data quality control and editing of time series because of the direct operation in the time domain. Our approach is based on the mature discipline of system identification which is concerned with parametric transfer function determination given system input and output. In this study, MT data from one USArray site are analyzed, showing a statistical advantage in reproducing measured geoelectric field time series using a parametric model EMTF versus the standard EMTF approach.
Numerical Simulations for the Tip-Jet Drive Rotor Based Upon Momentum-Source Method
Authors: Fei CUI , Zhuang Jian , Wang Bo 
Published: October 2019

Abstract
Based upon a momentum-source method, a numerical simulation method has been developed to calculate the tip-jet drive rotor/fuselage flowfield. The momentum-source term is used to describe the effect of rotor on its flowfield. The mass-source term is used to describe the tip-jet. According to the characteristics of rotor/fuselage flowfield and requirements of momentum-source and mass-source method, a hybrid mesh generation approach is developed. In the present method, on the basis of the known movement, geometric and aerodynamic characteristics on blade section, a scheme containing momentum-source and mass-source term is adopted for the solution of N-S equations. By the present method, the downwash flowfields of rotor and rotor/fuselage are simulated, and some meaningful conclusions are obtained.
Application of Arbitrary Vortex Method in Wind Tunnel Axial Fan Design
Authors: Dachuan Xu , Haifeng Wang , Xiaoli Qu , Yongsheng Yu , Yu Shi , Fang Zhao 
Published: October 2019

Abstract
The flow axial velocity is assumed equal everywhere in free vortex design method, and the pressure rise of flow pass through fan is assumed also equal at different radial height. But in arbitrary vortex design method, on the assumption that axial velocity along radial is variable, the flow rotational velocity along radial is not must an inverse distribution. Therefore, arbitrary vortex design method could have a more uniform axial velocity at the outlet of fan system by regulating the rotational velocity distribution. In the numerical simulation, the fan of a pilot wind tunnel is used as physical model. By comparison with the experimental data the reliability of the numerical simulation could be verified. Two fan physical models are established which are based on the designs of arbitrary vortex method and free vortex method. The result of numerical simulation indicated that compared to the free vortex method, the arbitrary vortex fan minished the separation on the tip and root of blade, obtained a more well uniform axial velocity distribution at the outlet of fan system. And the efficiency of blade is also increased by arbitrary vortex method.
Comparative Analysis of the Flow Field in the Lower Bend at Different Rotation Angles
Authors: Liu Zhaoliang , Wang Jinlong , Yuan Chengdong 
Published: October 2019

Abstract
In order to obtain the influence of the distribution of the flow field in the lower bend at different rotation angles on the fluid flow, Fluent software was used to conduct numerical simulation of the flow field in the bend at different rotation angles, and the influence rule of the shape difference of the secondary flow in the lower bend at different rotation angles was simulated. The simulation results show that the 90 °rotation Angle bend, its internal gas phase flow field better than other simulation Angle, secondary flow phenomena delay happened, reduce reflux area, syphon is helpful to improve the flow state; With the change of the rotation Angle, the tangential velocity of the outlet section of the bend increases continuously, which is conducive to the smooth gas-solid phase separation, but the pressure drop of the system also increases, resulting in the energy loss of the system. As a result, the Angle of 90 ° canary after rotation Angle for the simulation of the optimal point of view, for later engineering application provides data to support and help.
Study on Large-scale Dynamic Measurement of Lunar Rover with iGPS
Authors: Chen Qiwei , Tang Laiying , Yang Zaihua , Wang Linzheng , Feng Wei , Zheng Shengyu , Yi Wangmin 
Published: October 2019

Abstract
In the motion simulation test, the real-time position and orientation of lunar rover need to be measured accurately in a wide area to test lunar rover’s motion performance on simulated lunar soil. The iGPS system, whose accuracy is better than 1mm and sampling frequency is higher than 10 Hz, is applied to measure the position and orientation of lunar rover in the test. Large-scale dynamic measurement of lunar rover with iGPS is studied in this paper. This paper mainly discusses the layout methods of laser transmitters and receiving sensors, and analyzes the position and orientation measurement accuracy of different layout methods to achieve optimization layout. It can provide some reference for the research of large-scale dynamic measurement of other rigid objects.
Analysis on Synchronizing and Gear Shifting Force of Commercial Vehicle Powertrain
Authors: Yan Zhengfeng , Zhao Peisheng , Wu Yajun 
Published: October 2019

Abstract
Based on a commercial vehicle transmission as the research object, the paper analyses the influence for commercial vehicle powertrain synchronization and shift performance by the rotational inertia of the clutch driven plate assembly and transmission input speed. According to the synchronization and shifting mechanism of the transmission, transmission shift dynamics model was established. Analyzing the causes of shift impact and the critical shifting force for mis-engagement put forward the shift control strategy to avoid shift impact. We can draw a conclusion that optimizing the clutch driven plate inertia parameter during clutch design can effectively improve the shift performance of the transmission.
High-Speed Performance of a Tamping Machine with Closed-Type Hydrostatic Propulsion Drive
Authors: Zhou Zirong , Cai Xiong , Wang Wenlin 
Published: October 2019

Abstract
It is significant to understand and optimize the parameters of the hydraulic system to pursue both better low-speed operation and high-speed mobility performance of a tamping machine. A mathematical model formulating the high-speed performance of a tamping machine with a closed-type hydrostatic propulsion drive system is established in this study, a simulation model is built in the AMEsim software environment based on the mathematical model. Simulation results show that the tamping machine with a closed-type hydrostatic propulsion drive system has got a 35-100 km/h scope for high-speed mobility, and the acceleration performance is also satisfactory. The mathematical model established and results obtained in this work will be instructive for further parameter sensitivity analysis and tamping machine design optimizations.
Joint Trajectory Time Optimization of Cobot Based on Particle Swarm Optimization
Authors: Zhenyi Cheng 
Published: October 2019

Abstract
In order to improve the working efficiency of the robot and make the welding quality of the part of skin group improved greatly. We Researched on the end trajectory of the Cobot. In the application scenario of Friction Stir Welding (FSW) test bench, an algorithm of joint space trajectory is proposed according to the kinematics characteristics of the robot and the practical application needs.Based on particle swarm optimization (PSO), the motion trajectory of robot joint is fitted by high order polynomial interpolation. While ensuring the end trajectory, the stability of the joint motion is guaranteed. The simulation experiment is carried out by using MATLAB software. The joint space optimal motion planning is realized. The comparison algorithm is verified by experiments. According to the experimental results, the particle swarm optimization algorithm improves the efficiency of the cooperative robot significantly. It is helpful to the end stability of friction stir welding robot.
Study on Cure Deformation of Metal/CFRP Laminated Composites
Authors: Liu Xueshu , Li Jinlei , Lei Jianhua , Wang Qi , Gao Qian 
Published: October 2019

Abstract
During the curing process of composite materials, the differences of the heat transfer ability and mechanical properties of material in various directions result in residual stresses and curing deformation in the composite after curing. Curing deformation has adverse effect on the mechanical performance of composites. The development of internal stress during curing may cause matrix cracking, delamination, warpage and rebound deformation of composites. In this paper, numerical simulation is used to predict the curing deformation of components, thereby reducing production costs and improving production efficiency as well. According to the curing kinetic equation, the HETVAL subroutine was firstly developed to calculate the temperature field and the curing degree field of the curing process. UMAT and UEXPAN subroutines were then applied to solve the mechanical constants and thermal strain and curing shrinkage strain during the curing process. After the proposed model was verified, the deformation of the metal composite co-cured components was studied. It was found that when the thickness ratio of metal to CFRP is one to one the composite gains the greatest geometrical deviation after curing.
Performance Analysis of Drilling Test of Aramid Fiber Composite
Authors: lei Jin , jing Qi 
Published: October 2019

Abstract
Aramid fiber-reinforced polymer (AFRP) is a typical difficult material to machine. It is easy to occur defects such as ablation and burr in the drilling process due to the serious non-uniformity and heterotrophy of these material properties, as well as low heat transfer coefficient and high fibre toughness of the aramid fibre, which remarkable affects the machining quality and assembly accuracy. In this paper, three types of drills with different cutting edge shapes were compared to analyse the influence of drilling on cutting force, cutting temperature and machining quality. The results showed that the tool geometry has a great influence on the drilling performance of AFRP. Due to poor drilling quality, 8-face drill and twist drill are not suitable for drilling AFRP drilling tools. The machining quality of Brad & Spur drill is relatively good, which can meet the drilling requirements of AFRP.
Technological Rule of Ultrasonic Assisted Magnetic Abrasive Finishing of Titanium Alloy
Authors: Jiang T Y , Ma F J , Liu X , Liu Y , Zhang S F , Sha Z H 
Published: October 2019

Abstract
The influence of machining time, ultrasonic amplitude, spindle speed and machining gap on surface roughness and material removal rate were studied and analysed through the experiment of UAMAF of titanium alloy. The results show that the surface roughness decreases rapidly in the beginning and then gradually stabilizes as the machining time increases. The surface roughness reduces from the original Ra0.94μm to Ra0.10μm, when the machining time reaches 30min that is optimum machining time. The material removal rate drops approximately linearly with the increase of machining time. The surface roughness decreases significantly and the material removal rate increases rapidly as the ultrasonic amplitude rises. The surface roughness reduces to Ra0.12μm and the material removal rate increases to 30.5mg/h, when the ultrasonic amplitude is up to 14μm. The surface roughness decreases in the beginning and then increases, and the material removal rate rises in the beginning and then falls, as the spindle speed increases. The surface roughness achieves a minimum of Ra0.11μm and the material removal rate reaches a maximum of 22.74mg/h, when the spindle speed is 1400r/min. The surface roughness drops in the beginning and then rises, and the material removal rate increases in the beginning and then decreases, as the machining gap enlarges. The optimum machining gap is about 1.25mm. In this case, the surface roughness achieves a minimum of Ra0.16μm, and the material removal rate reaches a maximum of 17.7mg/h.
Study on the Interaction between Vibration Mode and Radiated Sound of Conical Shell
Authors: Jiang-Hai Wu , Fang An , Yong Duan , Yu-Dong Sun 
Published: October 2019

Abstract
Conical shell is one of the most common structures in engineering, especially in airplane and ship structures. In order to reduce its vibration and radiation sound, which were widely concerned, this paper used BEM method to analysis the vibration characteristic,radiated sound and the interaction between them. Three different models were established to study the difference between conical shell in the air and under water. The numerical results demonstrate that the existence of water has great influences on the frequency and amplitudes of the radiated sound power. Due to the low density, the natural frequency of conical shell dominants the peak frequency of radiation sound in the air. And the contribution of each vibration mode to the radiation sound different from each other. The results of this study can provide some valuable suggestions for the position selection of active control actuators on conical shell.
Development of Explosion-containment Vessel with 3 kg TNT Equivalent
Authors: Zhou Kan , Huang Ge , Fang Kai , Huang Huang , Bai Haijun 
Published: October 2019

Abstract
In this paper, the design theory of explosion-containment vessel is studied, the charge ratio distance, incident overpressure and reflection overpressure acting on the inner wall of the explosion-containment vessel are calculated when 3kg TNT is exploded in it, the transient load generated in the explosion is converted into equivalent static load by the method of dynamic coefficient, and the main wall thickness of 3kg TNT equivalent explosion-containment vessel is determined. A 3kg TNT equivalent capsule explosion-containment vessel is designed and tested the explosion performance, the explosion performance test results show that the design of the 3kg TNT equivalent explosion-containment vessel is reasonable, safe and reliable, and it is of great practical significance to apply it to the transportation and destruction of weapons and ammunition and emergency treatment.
Parametric Analysis of Wave-shaped Metal Sealing Ring Based on Hierarchical Solution Method
Authors: miaotian Zhang , shuangfu Suo , yu Feng , jianwen Shi , guoying Meng 
Published: October 2019

Abstract
The wave-shaped metal sealing ring is widely used in the aerospace field, whose failure will directly affect the flight safety and even cause major personal accidents and economic losses. The performance optimization problem of the wave-shaped seal is a multi-objective optimization problem, and the multiple targets are affected by the geometric design factors, and are not completely independent of each other. In this paper, for the sealing problem under the severe conditions of aero-engine, the corrugated metal sealing ring is taken as the research object. The W-shaped metal sealing ring is selected as an example, and the finite element model is established by using ANSYS software. Sealing, stability and resilience are chosen as indicators to evaluate the sealing performance. The multi-objective optimization problem is transformed into a single-objective optimization problem by hierarchical solution method, and the sealing structure is parameterized. The optimization results of the geometric parameters of the sealing ring are highly consistent with the product manual of the sealing ring. The correctness and feasibility of the optimization design method based on the analysis of three aspects of performance and the hierarchical solution for dimension reduction are verified.