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30 June 2021, Volume 31 Issue 2 Previous Issue    Next Issue
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Technology Theory and Application


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Technology Theory and Application

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Spatial and Temporal Variation and Characteristics of Meteorological and Hydrological Droughts in the Mekong River Basin ZHANG Xue-jun, LV Juan, QU Yan-ping, SU Zhi-cheng, MA Miao-miao 2021, 31(2): 1-6+16.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.001 Abstract ( )   PDF (1486KB) ( )   Drought has been recognized as one of the most wide-spread and costly natural disasters in the Mekong River basin.To investigate the spatiotemporal characteristics of drought can largely facilitate scientific drought management and risk mitigation.Using the global long-term (1901-2016)monthly precipitation data from CRU and the nearly 30-year(1985-2016)observational streamflow record from 4 hydrological gauging stations,this study investigates the characteristics of meteorological drought in the past half century and the trend of hydrological drought in the past 30years in the Mekong River basin,through estimations of multi-scale Standardized Precipitation Index(SPI)and Standardized Streamflow Index(SSI).Results indicate that while with slight upward trend from the whole-basin perspective,the SPI is found with obvious downward trend in the northeastern Thailand,most of Cambodia and Myanmar,suggesting these regions are overall subject to intensified drying during the past half century,especially in the northeastern Thailand.The long sequence analysis indicates that most of the Mekong River basin is found with drought frequency over 25%.In the southern Cambodia and Mekong delta of Vietnam,the frequency of extreme drought is even close to 10%.Further analyses on hydrological drought show that the trend of SSI greatly varies with gauging station location over the past 30-yr(1986-2016).The SSI of upstreamflow station(Chiang Saen)shows obvious decreasing trend,especially after 2010.In contrast,the SSI estimates from NongKhai and Mukdahan are both found with evident upward trend.As for the downstream station(Stung Treng),the trend of SSI seems little change over the past 30 years,but the SSI estimation is mostly less than zero since 2005,suggesting that this region is susceptible to hydrological droughts recently.These above analyses can provide scientific decision support for drought management and drought prevention in the Mekong River basin. References | Related Articles | Metrics

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Stability Analysis of Embankment on Ring Reinforced Gravel Pile Composite Foundation WANG Chao 2021, 31(2): 17-22.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.003 Abstract ( )   PDF (2035KB) ( )   Ring reinforced gravel pile composite foundation has been widely used in the reinforcement of soft foundation engineering.The stability of the embankment on composite foundation reinforced by geosynthetic-encased stone columns is an important factor that affects engineering safety.In this paper,by establishing a three-dimensional finite element model of embankment on ring reinforced gravel pile composite foundation,the failure mode of the ring reinforced gravel pile is revealed and the stability of embankment slopes under different soil strengths is analyzed.On this basis,the applicability of Sweden slice method,Bishop slice method and circular arc slice method in calculating the stability of embankment slope are compared and analyzed.The results show that the numerical model established in this paper can reflect the stability of embankment on ring reinforced gravel pile composite foundation.When the embankment is unstable,the stone columns confined by geosynthetics will suffer bending failure.Due to the lack of consideration of the restraint effect of the geosynthetics,the results of Sweden slice method,Bishop slice method and standard circular arc slice method are conservative.Bishop method is the closest to the numerical results. References | Related Articles | Metrics

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The Characteristics of Shallow Groundwater Storage Variables and Its Influencing Factors in Plain Area of Hebei Province CHEN Xue-ying 2021, 31(2): 34-38.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.006 Abstract ( )   PDF (537KB) ( )   The plain area in Hebei province is an important grain producing area and a densely populated area.However,the over exploitation of groundwater resources has seriously affected the sustainable development of regional economy and society.Based on the data from 2007to 2016in the plain area of Hebei Province,this paper analyzes the characteristics of shallow groundwater depth and storage variables,and identifies the effects of precipitation,extraction and runoff on the groundwater storage variables.The study found that the groundwater depth of shallow groundwater gradually transited to 10-20mfrom the front of the mountain to 2-5mof the coastal sea.During the year,the groundwater level varied from 5-10m in the Piedmont Plain and 1-3min the other plain areas.The characteristics of shallow groundwater storage variables in different plain areas are different,and the storage variables appeared the highest value in 2012and 2016,and the groundwater level rose obviously.Precipitation and storage variables show a significant positive correlation;the runoff and storage variables show a logarithmic relationship,but the correlation is poor;and there is no significant correlation between extraction and storage variables. References | Related Articles | Metrics

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Comparative Observation and Error Analysis of Bucket Rain Gauge ZHANG Meng-na 2021, 31(2): 39-44.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.007 Abstract ( )   PDF (234KB) ( )   The tipping bucket rain gauge equipped with intelligent rainfall measurement and control terminal realizes the automatic rainfall measurement and report function of automatic data acquisition,storage,remote transmission,display,control and alarm.Sanhe Station first used this equipment to observe rainfall in 1992.Through years of observation and application,it shows that the equipment has the characteristics of exquisite structure design,less equipment cost,low operation cost,large data storage capacity,fast information transmission,easy management and wide application.In this paper,the error data of 174times of daily rainfall measured by bucket rain gauge and manual observation in five typical years of Sanhe Station in 2012,2017,2018,2019and 2020are statistically analyzed.The results show that the operation of the bucket rain gauge in Sanhe Station is stable,the observation accuracy is high,and the observation error is less than 4%,in line with the requirements of The Specification for Precipitation Observation(SL21-2015). References | Related Articles | Metrics

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Research on Coordinated Control Strategy and Grid Connection of Wind-solar Complementary Power Generation System MENG De-yue, LIU Wei, CUI Mao-qi 2021, 31(2): 51-55+66.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.009 Abstract ( )   PDF (1832KB) ( )   Photovoltaic power generation and wind power generation are characterized by intermittenency and volatility.Combining the two can effectively alleviate power supply imbalance and improve the reliability of power generation system.In this paper，the photovoltaic electronic module，wind electronic module and battery sub-module in wind-solar complementary power generation system are analyzed and modeled，and the maximum power tracking simulink simulation of photovoltaic power generation system and wind power generation system is completed.On this basis，a wind-solar complementary coordinated control and grid connection strategy is proposed，and the simulation results verify the feasibility of the control strategy. References | Related Articles | Metrics

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Application of Sponge City Related Technology in Substation ZHANG Peng, LI Peng-cheng, ZHAO Biao, Wang Lei 2021, 31(2): 56-60.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.010 Abstract ( )   PDF (2038KB) ( )   This paper studies the applicability and promotion prospect of sponge city technology in substation,and summarizes the underlying surface conditions of substation.Combined with the characteristics of relevant technologies and combination measures of sponge city,the coupling mechanism of the two is studied,the technical application and layout scheme of substation sponge city are formulated,and the solutions for rainwater purification and comprehensive utilization are provided.The application of appropriate sponge city technology in substation has good promotion value for rainwater collection and utilization. References | Related Articles | Metrics

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Research on Baxter Robot Arm Following System Based on Visual Servo WANG Zheng-bo, TANG Yong, LIU Hai-bo, SUN Dong-lai, LI Meng-yuan 2021, 31(2): 61-66.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.011 Abstract ( )   PDF (1290KB) ( )   This paper introduces the control mode of Baxter robot and a potential function based visual servo control method of robot arm following motion,which provides technical support for the development of service robot and cooperative robot.In this paper,the relative orientation information of the following object was obtained from the camera based on OpenCV color detection method,and the manipulator was controlled by ROS system.Finally,vision and robot were used to complete the design of the robot arm following system.By analyzing the precision of the following track,it is shown that the arrangement of the intraocular vision sensor can provide relatively high precision and avoid visual collision,thus realizing accurate following motion,and the effectiveness of the method is verified. References | Related Articles | Metrics

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Design and Implementation of an Efficient Universal Data Access Layer Based on Interface Programming XU Zhao-xing 2021, 31(2): 72-76.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.013 Abstract ( )   PDF (557KB) ( )   In the development process of large and medium-sized systems,in order to improve the scalability,reusability and maintainability of the system,multi-tier architecture is generally adopted.In the design of multi-tier architecture,the design of data access layer is particularly critical.Through the analysis and research of several open source frameworks,combined with theoretical thinking and practical development experience,the key technologies of optimizing data access layer step by step are analyzed and elaborated from making full use of code and interface reusability,reducing maintenance costs and improving software scalability.A set of universal data access layer technology is formed.At the same time,the code implemented by Entity Framework technology on.Net platform is given.Thus,it can deepen the understanding of common technical ideas of data access layer for software technology developers,and provide a technical reference for peers to implement data access layer.Practice shows that the system using this data access layer technology in multi-tier architecture system has the characteristics of high decoupling,high expansion,high availability and high development efficiency,and has a wide application prospect. References | Related Articles | Metrics

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Reconstruction Design of Fire Fighting Facilities in 31.5 MN Hydraulic Forging Workshop of Kunming Iron and Steel Heavy Equipment Group XU Jian-yu, LI Yan, TIAN Jun-dong, TAO Ya-li, HUANG Ling 2021, 31(2): 77-80.  DOI: 10.16046/j.cnki.issn2096-5680.2021.02.014 Abstract ( )   PDF (169KB) ( )   In response to the call of the state,Kunming Iron and Steel Co.,Ltd.has deepened the structural reform of the supply side,accelerated the transformation of the old and new kinetic energy,promoted the high-quality development of the enterprise,adhered to the new development road of extending the industrial chain,circular economy,science and technology leading,green development and industry city integration,and transformed the old iron and steel production plant into a modern iron and steel deep processing production base.In the reconstruction of old factory buildings,the design of fire water supply and drainage system is the key content to be concerned.In this paper,the original No.1Steelmaking Plant of Kunming Iron and steel company is transformed into a hydraulic forging workshop as an example,the problems existing in the transformation design of the fire water supply and drainage system are analyzed, and the corresponding design scheme is put forward. References | Related Articles | Metrics