bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical simulation of the effects of Yangtze River runoff on pollutant transport and diffusion in the Yangtze River estuary
Authors: Ren Zhuoyu , Li Kai , Han Songlin , Han Jibin 
Published: November 2020

Abstract
The coastal-estuary area is one of the areas most seriously affected by human activities, and the quality of the water environment has received extensive attention from society and scholars. In order to analyze the characteristics of pollutant transport in the Yangtze River Estuary, a two-dimensional hydrodynamic model of the Yangtze River Estuary waters was established, and the model was verified using measured hydrological data. On this basis, the effects of the dilution and diffusion of pollutants (COD) under different runoff rates are studied and the transport characteristics of the pollutants of the Yangtze River estuary are studied. The results show that after the calculation reaches a relatively stable level, the concentration at the measuring point of the pollutant input from the Yangtze River in the high and low water period is about 6mg/L and 1.2mg/L, which is diluted by 42.9% and 88.6% respectively compared with the pollutant concentration at the discharge outlet. When the sewage is discharged from the sewage outlet, the highest COD concentration does not exceed 3mg/l during the high and low water periods, indicating that the sewage discharged from the planned sewage project will not have a serious impact on water quality.
Sedimentation study on separation tailings and backwater of a water-quenched copper slag
Authors: Shi Guiming , Zeng Li , Wang Jie , He Chunyan , Wang Chengdong , Zhu Lang , Zhou Yichao 
Published: November 2020

Abstract
The sedimentation test of separation tailings and backwater of a water-quenched copper slag were carried out. The experimental contents included: chemical analysis of multi-elements of tailings, particle size analysis of tailings, tailings sedimentation test, natural sedimentation of backwater, sedimentation test of backwater with reagents, etc. The results shown that the tailing granularity was very thin, almost all passed the 0.037 mm sieve. Under different concentration, when the settling time of 180 min, tailings could be settled completely and concentration without influence, thus settling time determined to 180 min. With the same dosage, KAl(SO4)2 had a better sedimentation effect than CaCl2. In this test, KAl(SO4)2 200 g/m3 was recommended in consideration of reagents dosage and backwater sedimentation rate and CaCl2 200 g/m3 was recommended in consideration of drug price and treatment cost.
Study on Environmental Risk Assessment and Control Countermeasures of Tailings pond in a Mountainous Area of North China
Authors: Song Shuang , Chu Jinglong , Zhang Hua 
Published: November 2020

Abstract
The safety and environmental accidents of the tailings pond are likely to cause pollution of surrounding soil and water bodies, and endanger the safety of life and production of surrounding residents. In this study, the analytic hierarchy process (ahp) was used to score environmental sensitivity and control mechanism reliability of tailings ponds. The environmental risk rating model was used to characterize the environmental risk rating of tailings pond. The risk level characterization and evaluation results show that the four tailings ponds were general risks to downstream residents and the environment. Suggestions on environmental risk control of the upstream tailings pond were put forward.
Analysis of groundwater pollution caused by mine leachate leakage considering natural impermeable layer
Authors: Chu Jinglong , Song Shuang , Tan Haiwei , Liu Nannan , Liu Fang 
Published: November 2020

Abstract
Aiming at the problem of groundwater pollution caused by mine leachate leakage, a numerical model of saturated-unsaturated groundwater is established by using FEFLOW software, and the spatial and temporal distribution of pollutants in vadose zone and aquifer is predicted, in this paper. The results show that the impervious layer of natural clay can slow down the entry of pollutants into the aquifer and reduce the impact of pollutants diffusion on the aquifer. This paper can provide some references for mine groundwater pollution prevention and control.
Deformation behavior and damage analysis of underground high-voltage cable duct bank encased by concrete
Authors: Guo Jingen , Wang Yanfeng , Cai Liangyi , Liu Tingjin , Yang Yubing 
Published: November 2020

Abstract
Due to the shallow burial depth, the concrete duct bank for underground cables frequently encountered differential settlement, tilt and other damage like cracking when construction activity was carried out in the vicinity. This paper briefly presents an experimental study of concrete duct bank with a 1/4 part of real structure under a monotonic static loading, which was put into a soil box in the laboratory. And then numerical simulations were performed for the 1/4 part of real structure and a real-scale concrete duct bank respectively, to investigate the deformation and damage pattern of concrete structure and the wrapped inside conduits. Both the test and numerical results indicated that the failure of concrete duct bank presented a distinct brittle pattern. The mechanical properties of underlying soil play a more dominant role in the bearing capacity, mid-span vertical displacement and mid-span deflection of concrete duct bank. It is proposed that the vertical displacement of concrete duct bank can be set as the monitoring item to reveal its safety state, and the minimum curvature radius of longitudinal deformation profile obtained from vertical settlement at different locations can be computed and be taken as the control index.
Construction of Spatial local C-vine model and application of air temperature interpolation
Authors: Dai Lin , Liu Jianxiu 
Published: November 2020

Abstract
Based on the daily average temperature of 73 meteorological stations and the geographical location information of each station from 1980 to 2010 in Yunnan Province, spatial interpolation method of temperature data suitable for Yunnan province was explored. Based on the definition of spatial local C-Vine, the full model, horizontal distance model and vertical distance model were constructed. Using maximum likelihood, Akaike information criterion (AIC)and Bayesian information criterion (BIC) select the three models to obtain full model as the optimal model. 6 stations in the region were randomly selected and temperature interpolation was made using full model, Ordinary Kriging and Inverse Distance Weighting method. The results showed that full model based on Spatial local C-vine had better prediction accuracy.
Test research on flow patterns at intake area of a pumping station
Authors: Zhou Minzhe , Ding Yuan , Li Tongchun , Qi Huijun , Gao Lingang 
Published: November 2020

Abstract
This paper focuses on the problem of the flow pattern in the inlet area of a drainage pumping station for its safety. Limited to the restrictions on terrain conditions and surrounding constructions, this pumping station was designed with a compact layout which could not followed by regular standards. The small size may affect the hydraulic conditions at the intake of this pumping station, which in turn will affect the safe operation of the project. Therefore, in order to ensure whether the pumping station works stably, it is necessary to conduct an intensive study on the flow pattern at the intake area of this pumping station via a model test. Research shows that the original design may bring hydraulic problems. In the test, we found intermittent suction vortexes in the inlet area. This hydraulic phenomenon should be avoided in the inlet area of pump stations. In this case, it is proposed to reduce the elevation of the water intake system to increase the depth of submergence. According to the test results, harmful vortexes disappeared and the water flow became smoother in all operating conditions after adopting improvement measures. This shows that the proposal is effective and makes the project safer.
Application of Structural Mechanics Solver in Internal Force Calculation of Frame Structure
Authors: Liu Xiaoling , Du Peng , Wu Shengchao , Zheng Jie 
Published: November 2020

Abstract
The internal force calculation of frame structure is a difficult problem in civil engineering graduation design. This article introduces the basic principles of bending moment distribution method and structural mechanics solver method. Taking a two-story, two-span frame structure as an example, a comparative study is carried out and the results show that there is Certain error, and analyze the cause of the error. The research has certain guiding significance for the teaching of structural mechanics and civil engineering graduation design.
The research on the influence of boiler operating parameters on thermal efficiency
Authors: Cai Qin , Wu Xiaoyang , Huang Yong , Wang Xi 
Published: November 2020

Abstract
The influence of operating parameters on thermal efficiency was analyzed by thermal balance experiment of the boiler. The mathematical model of thermal efficiency was obtained by thermal balance equation. The results showed that the thermal efficiency decreased with the increase of exhaust gas temperature. The excess air coefficient had an important effect on thermal efficiency of the boiler. The thermal efficiency decreased with the increase of excess air coefficient. The increase of inlet air temperature leaded to the increase of thermal efficiency when other operating parameters remained unchanged. The thermal efficiency increased with the increase of fuel calorific value. As a result, in order to improve thermal efficiency, the optimum excess air coefficient should be adjusted as much as possible to ensure combustion condition of the boiler. For running boiler, the economizer should be installed on heated surface at the end of boiler.
Research on thermal aging life of cable based on second-order dynamics modification equation
Authors: Lin Jindong , Yang Yue , Liao Xiaoyong 
Published: November 2020

Abstract
With the increasing application of cable in various fields, more and more attention has been paid to the aging of cable. In order to ensure the operation safety of instruments and all kinds of equipment, it is urgent to find a fast and accurate method to evaluate the residual life of cable. In this paper, a second-order kinetic model is adopted and the Arrhenius thermal aging equation is improved. In view of the working environment with relatively high temperature, the thermal aging life prediction model for cable is obtained to calculate the residual life rapidly. It provides theoretical support for timely detection of risks and elimination of potential accidents.
Research on vibration elimination of a 350 MW heat supply unit during cold start
Authors: Ma Lyuzhou 
Published: November 2020

Abstract
A 350MW heat supply unit in a power plant encountered abnormal vibration of IP rotor bearing during cold start after overhaul. By analyzing the vibration data in the start-up process, the reason for abnormal vibration was found out to be excessive vibration of IP rotor passing through critical speed and rubbing between IP rotor and casing. Through the field high dynamic balancing test and adopting the most suitable operation control mode of this type of heat supply unit, the abnormal vibration of the unit was eliminated.
A Microgrid Operation Control Strategy Based on Wide Area Information
Authors: Wang Mingjin 
Published: November 2020

Abstract
Distributed Generator (DG) has many environmental benefits and potential values, but it is not controllable power for the large power grid, and brings many bad influences to the power grid, so that the power grid takes the way of isolation and restrictions that greatly limits the development of DG. In order to effectively solve the contradictions between DG and the power grid, the microgrid concept is putted forward. Microgrid is a small power system containing micro powers and local loads, which can operate with connecting to the power grid, or run in isolated island way with breaking away from the power grid. On the basis of analyzing the principle of DG, two control methods are established: PQ Control and V/f Control. And then, a microgrid operation control strategy based on wide area information is proposed. Using wide area information to get the following data: the switching power and the breaker state of the Point of Common Coupling (PCC); the output of DG; the local loads and so on. In the operation of isolated island, the control strategy controls and adjusts the DGs and loads quickly, makes the power balance, ensures that the voltage and frequency in the microgrid conforms to the standard, and ensures the important loads working steadily and reliably. Finally, the feasibility and effectiveness of the proposed control strategy are verified by matlab/simulink simulation.
A Weight Calculation Method for Reducing Mutual Interference of Transformer State Evaluation Indicators
Authors: Yigang He , Wei Wu , Jin Tong 
Published: November 2020

Abstract
Aiming at the problem that the traditional indicator weight calculation method ignores the mutual influence between indicators and causes the deviation of the calculation results, this paper proposes a transformer state evaluation calculation methods combining of FAHP(Fuzzy Analytical Hierarchy Process) — DEMATEL (Decision-making Trial and Evaluation Laboratory) method and CRITIC (Criteria Importance Though Intercriteria Correlation) method; after selecting the index parameters and dividing the state level, the state evaluation index system is established; based on the combination weighting method to calculate the two methods The optimal weight is combined with the transformer status score to obtain the status evaluation of the transformer. After the case analysis, it can be seen that the method is practical compared with the actual situation obtained from the maintenance; based on the traditional FAHP method and the experimental method in this paper, the Gaussian white noise is added to experimental data increase the interference between enhancement indicators. After simulation analysis, it is found the final state score of the transformer obtained by this method is smoother and more stable. Compared with traditional methods, this paper reduces the errors caused by the mutual influence of indicators and makes the evaluation results more accurate.
Research on wide-range micro force generator based on interdigital capacitor array modules
Authors: Xu Li , Li Qian , Wang Shuxiang , Zheng Peiliang , Huang Zhenyu , Luo Xudong 
Published: November 2020

Abstract
The micro Newton level standard force generator was important in the micro/nano force measurement and traceability device. How to obtain a stable and wide-range standard micro force at a lower voltage (≤220V) was a important technical problems for improving the measurement accuracy and range. The interdigital capacitor array modules were used to generator the standard micro force at a lower voltage. The research results showed that the device could achieve stable, high-accuracy, wide-range micro force output under a relatively low constant voltage. The device output range would be expanded and the output resolution would be improved without increasing the complexity of the device. The symmetrical arrangement of the micro force generator array modules and the interdigital capacitor structure greatly reduced the influence of the unbalanced load of the device and the deformation of the elastic support structure on the output micro force value. These structures were ensuring the accuracy of the micro force generator. It provided a useful basis for the design and manufacture of low-voltage and wide-range force generator in micro force measurement and value traceability devices.
Influence of growth rate on minority carrier lifetime of multicrystalline silicon ingot
Authors: Yang Xiufan , Zhang Dianxi , Guo Zhongzheng , Yan Wanjun , Zhang Houyong 
Published: November 2020

Abstract
Multicrystalline silicon was grown by directional solidification method, and different growth rates was obtained by optimizing the growth process. The influence of the growth rate on the minority carrier lifetime of the multicrystalline silicon ingot was studied. The results show that the infrared image of the middle and lower part of the silicon block with an average growth rate of 1.0cm/h has a lighter shade. The area with minority carrier lifetime of the silicon block is less than 4 us accounts for about 50%, and the average minority carrier lifetime is 5.28 us. Reduce the growth rate to 0.94cm/h, the infrared image of the crystal is pure and the crystal grains are coarse, the average minority carrier lifetime of the silicon block is increase to 5.65 us. When the growth rate is further reduced to 0.87cm/h, the crystal growth deviates from the vertical direction. The area of silicon block less than 4 us accounts for about 40%, and the average minority carrier lifetime is reduced to 5.39 us. The phase field method is used to calculate the growth of multicrystalline silicon. The results show that the greater the flow rate, the faster the growth of crystal nucleus and the easier the formation of competitive growth, which is in good agreement with the experiment.
Research on Optimization of cold chain logistics distribution path of fresh products based on Hybrid Genetic Algorithm
Authors: Fu Mian , Wang Dandan 
Published: November 2020

Abstract
In view of the actual situation of cold chain logistics distribution path of fresh products, taking the minimum total cost of fixed cost, variable cost, refrigeration cost, damage cost and penalty cost as the optimization objective, this paper constructs the optimization model of cold chain logistics distribution path of fresh products, and makes an empirical study on the distribution path of an enterprise by using hybrid genetic algorithm, and solves it by coding on MATLAB. It is found that the optimized scheme improves the vehicle loading rate and reduces the distribution cost, which proves the feasibility and effectiveness of the model and algorithm.
Fluid simulation model and analysis of partial discharge characteristics of tip defects
Authors: Zhen-hua Xing , Zhi-guo Zhao , Xing Xu , Zhao-fei Li , Jun Ye , Yu-yan Guo 
Published: November 2020

Abstract
The tip discharge is modeled and the micro discharge characteristics are studied. The hydrodynamic model of tip discharge in transformer oil is established. The development process of streamer discharge under pulse voltage is analyzed. The distribution of space charge density and space electric field under different pulse voltage amplitude and rising edge is obtained. The numerical results show that: with the increase of applied voltage amplitude, the average velocity of streamer development changes more significantly with the same discharge spacing; the steeper the rising edge pulse is, the faster the average discharge development speed is and the larger the discharge radius is. At the same time, according to the change law of streamer morphology development under AC voltage, the discharge frequency is less, the amplitude is higher, and the phase distribution is narrow when the applied voltage is positive half cycle. When the applied voltage is negative half cycle, the discharge times are more and the phase distribution is wide, and the tip discharge has obvious polarity effect.
Sex-specific impacts on the accumulation of polycyclic aromatic hydrocarbons and the development of offspring of sea urchins exposed to heavy fuel oil
Authors: Wang Xuanbo , Li Xishan , Ren Hang , Chen Huishu , Ju Zhonglei , Xiong Deqi 
Published: November 2020

Abstract
The sensitivity of female and male individuals of the same species to environmental stress is often different. The present study investigated sea urchins (Strongylocentrotus intermedius) of both sexes that were exposed to water-accommodated fractions of heavy fuel oil (HFO-WAF) for 7 d. Polycyclic aromatic hydrocarbons (PAHs) bioaccumulation in sea urchin gonad tissue was significantly increased following the exposure to HFO-WAF. However, PAHs bioaccumulation significantly differed between females and males, which may be related to the lipid content of gonad tissue. We found a significant increase in the percentage of anomalies in their larvae 24 h post fertilization. This indicates that parental exposure to HFO-WAF can have an adverse effect on the offspring, which may consequently affect population recovery and maintenance.
Preparation and Evaluation of PPGs for High-Temperature Conformance Control
Authors: Wu Hao , Song Longfei , Ge Jijiang 
Published: November 2020

Abstract
In this paper, the synthesis and thermal behavior of nanocomposite performed particle gels (PPGs) was investigated. The nanocomposite PPGs were synthesized via free radical polymerization at room temperature, using acrylamide (AM), N-vinylpyrrolidone (NVP) as monomers and N, N-methylenebis (acrylamide) (MBA) as crosslinker. Thermal stability evolutions were conducted by aging PPGs at 130°C and salinity of 2.2×105 mg/L for 90 days. Swelling ratio (Sw) and modulus were measured as a function of aging time. A three-stage swollen history was discovered by means of rheological experiments and swelling measurements. Eexperimental results show that increasing the concentration of monomer, crosslinker and clay leaded to higher swelling ratio and lower modulus during the aging term. PPGs prepared with 30 wt % monomers, NVP: AM ratio of 6:4, 0.25 wt % crosslinker and 3.0 wt % clay exhibited optimum properties for conformance control at high temperature reservoir condition.
Research on Indoor Comprehensive Sensor Layout Method Based on Grid Method
Authors: Han Ninghui , Li Fei , Chen Songsong , Zhang Kai , Feng Jian 
Published: November 2020

Abstract
With the development of key technologies for environment change perception, accurate perception of user load status becomes possible. Sensing the user’s load status can reduce the transformation of the medium-voltage power grid, save the investment cost of the equipment for supporting the construction of the power grid, and improve the investment efficiency of the power grid. In this paper, based on the consideration of the user’s indoor scene, space area, flexible device distribution and building structure, etc., with the goal of maximizing the credibility of the indoor perception network, an optimal networked indoor sensor layout model is established. The weight of each sensing grid is calculated based on the sawing mapping, and the layout method with the highest trust is selected as the optimal indoor comprehensive sensor layout scheme. Finally, based on the case of an actual house, the effectiveness and correctness of the proposed model and method in indoor sensor layout are verified.
The influence of pressure and thinner on the bonding properties of adhesives to metal and composite materials
Authors: Li Qinghua , Tian Ranran , Zhang Yan , Zeng Yu , Zhao Ming 
Published: November 2020

Abstract
In order to judge the influence of pressure and thinner on the bonding shear strength of composite material and metal, the experiment uses different proportions of thinner epoxy resin to impregnate 3K 240G carbon fiber cloth; Kevlar fiber is subjected to different curing pressures the 45 steel specimens bonded with cloth composite materials were cured at high temperature. Through the international standard ISO1747-1976 determination of the adhesive shear strength of vulcanized rubber and rigid metal plate-four-plate shear method, the shear strength of specimens under different proportions of thinner and different curing pressures is measured. The results show that the fiber cloth composite material with the same immersion time will not increase the shear strength of the specimen when a certain pressure is applied during the bonding and curing process with the metal. At the same time, the thinner in the adhesive of the immersion fiber cloth is 10% When, better shear strength can be obtained.