bluuebunny/crossref_metadata_2025 huggingface dataset:
Anti-fatigue effect of enzymatic protein hydrolysate from Macadamia
Authors: Shuai Xixiang , Li Ya , Zhang Ming , Ma Feiyue , Du Liqing
Published: May 2021

The anti-fatigue effect of macadamia (Macadamia integrifolia) protein and hydrolysate prepared with basic protease were investigated. Random mice grouping was carried out to create 4 groups including the control group and protein hydrolysate groups at low (150 mg/kg·d), medium (500 mg/kg·d) and high (1500 mg/kg·d) doses. All groups were treated by gavage for 28 consecutive days. Weight-loaded swimming test, serum urea nitrogen, serum creatine kinase activity, blood lactic acid and liver glycogen assays were performed to assess its anti-fatigue effect. The results showed that macadamia protein hydrolysate could significantly prolong weight-loaded swimming time, promote synthesis of liver glycogen and decrease blood urea nitrogen and lactic acid. Moreover, it can also significantly reduce serum creatine kinase activity. Therefore, macadamia protein hydrolysate had significant anti-fatigue function.
Amino Acid Composition and Functional Properties of Different Molecular Weight Segments of Macadamia Peptides
Authors: Shuai Xixiang , Li Ya , Zhang Ming , Ma Feiyue , Du Liqing
Published: May 2021

In this study, macadamia peptides were produced by ultrasonic-assisted alkaline protease, and five components were separated by ultrafiltration centrifuge with different molecular weight (1kDa, 3kDa, 10kDa, 30kDa). The amino acid composition, solubility, water absorption capacity and emulsifying properties of five components were compared. Results showed that all macadamia peptide components were rich in amino acid species, the contents of essential and hydrophobic amino acids ranged from 189.59 to 281.10mg/g and 204.26 to 258.78mg/g, respectively. Meanwhile, the small molecular weight components (MP-1) showed the best solubility and water absorption capacity, large molecular weight components (MP-5) had the best emulsifying properties. This result indicated that the distribution of molecular weight had significant effects on the amino acid composition and functional properties of macadamia peptide components. This study provides a theoretical basis for the further development of macadamia peptide products.
The Influence of Urbanization on Storm Runoff
Authors: Sun Xiaomei , Zhang Haiou , Hua Dongwen , Wei Binmeng
Published: May 2021

With the development of economy society, urbanization process are accelerated, the tension of the urban land using leads that the cities develop to the low-lying parts, and even occupy river, landfill ditch pond, it makes perched water space of the city narrow, rainfall runoff coefficient increasing, the confluence time speeding up, it increases urban flood risk. Urbanization has changed the urban hydrologic cycle characteristics, so as to make the urban rain flood characteristics changing, it easily causes short duration rainstorm seeper-waterlogging, so as to directly influence the urban residents’ lives and causes great economic losses, even casualties. City is the political, economic and cultural center, once suffered from floods, it will cause great political influence and economic losses, so, it’s necessary to analysis urban storm flood reason and put forward the corresponding countermeasures. This paper mainly discusses the urban waterlogging reason and influence on storm runoff, and discusses the countermeasures.
Current status, causes and harm of soil arsenic pollution
Authors: Yan Bo , Zhang Xin
Published: May 2021

Soil arsenic pollution is a global problem that seriously threatens human health and environmental safety. Excessive arsenic content in the soil will inhibit the growth and development of plants, kill beneficial microorganisms in the soil, and damage human health after entering the human body through the food chain. This article describes the current status of soil arsenic pollution, the sources of arsenic pollutants, and the hazards of arsenic pollution to plants, microorganisms and human health. And the prospects for the treatment of arsenic pollution were prospected.
Measuring influential factors for air pollution in New-York-Newark-Jersey City by grey relation analysis
Authors: Chen Baoxin , Lu Qin , Zhang Tao
Published: May 2021

This study investigates variations of air quality index (AQI) for air pollutants in the metropolitan area (New-York-Newark-Jersey City; NY-NJ-PA) during 2010 - 2019 to identify the key influential factors for air pollution using grey relation analysis method. The results show that the annual averages of daily AQI values for multiple pollutants in NY-NJ-PA generally decreased except O3. The AQI values of O3 fluctuate greatly. The main factors affecting AQI values of CO, PM2.5, O3, SO2, and PM10 are the emissions of CO2, SO2, and NOx, whereas the main factors affecting AQI values of NO are the emissions of SO2, population, and NOx.
Remediation Effect of Biochar on Heavy Metal Contaminated Soil
Authors: Sun Sha , Zhang Yabo , Cao Xiaohui
Published: May 2021

The remediation effect of biochar on Cu, Cd, Pb and Hg compound contaminated soil was studied by adding different concentrations (0%, 5%, 10%) of pig manure carbon and fruit charcoal into the soil contaminated by tailings by biochar and plant pot experiment. The results showed that the addition of biochar could effectively reduce the content of heavy metals in soil, and the effect of fruit charcoal was significantly better than that of pig manure charcoal, and when the addition of fruit charcoal was 10%, the remediation effect of copper, cadmium, lead and mercury compound contaminated soil was the best.
Thiobacillus Acidophilus Removes Lead and Copper From Wastewater Containing Low Concentration of Heavy Metals
Authors: Xu Linlin , Gu Weihua , Bai Jianfeng
Published: May 2021

One of the main source of heavy metal wastewater is the electronics industry. If treated ineffectively, it may be discharged into water bodies, causing water body pollution and endangering human health. Traditional treatment methods have a poor quality of wastewater and high treatment process costs. This subject takes the low concentration of lead and copper wastewater from a lead storage battery factory as the research object, and uses the principle of the precipitation of Thiobacillus acidophilus to remove lead and copper from the wastewater. The results show that at a temperature of 30°C, pH of 2.5, and rotation speed of 130r/min, acidophils have the highest removal rate of 74.69%, 38.48% for lead and copper, respectively.
The effects of Exocarpium Citri Grandis on the volatile components of Green teabased on HS-SPME-GC-MS
Authors: Wu Xiaorong , Wu Juxian , Huang Baoling , Chen Haibin , Ling Haohao , Huang Baiqi
Published: May 2021

Aroma is an important factor in the quality of green tea. In order to explore the effect of Exocarpium Citri Grandis(ECG) on the aroma formation of green tea, the aroma components of green tea were extracted and identified by HS-SPME-GC-MS. The results showed that the main aroma components of green tea were D-Limonene (58.69%), γ-Terpinene (14.51%), Myrcene (9.82%), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (3.98%) and caffeine (2.67%).After co-fermentation with ECG, the main aroma components of green tea were changed to D-Limonene (33.64%), 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (11.7%), γ-Terpinene (9.38%), 2-pentadecanone (8.93%) and caffeine (6.04%).The content of terpenessuch as D-Limonene decreased, while the content of aromatic components such as linalool increased, and the types of volatile components increased in green tea. Among the newly added volatile components, the higher ones were2-pentadecanone (8.93%), β-ionone (2.76%) and dihydroactinidiolide (2.17%), which can give green tea fruity, violet and coumarin aroma. This study indicated that ECG contributes to the enrichment of greentea aroma, which provides theoretical support for the development of mixed tea with unique aroma.
Study on the Harm of Waste Activated Carbon and Novel Regeneration Technology of it
Authors: Ma Yuanze , Zhang Xiuxia , Wen Jingyang
Published: May 2021

Activated carbon is widely employed as an adsorbent in environmental protection, food, medicine, chemical industry, energy and other fields due to its good physical and chemical properties and low price. However, the resulting large amount of saturated activated carbon is easy to release harmful substances in the high temperature environment. Even if the saturated activated carbon is treated with harmless regeneration technology, it may lead to secondary pollution owing to improper disposal. Therefore, on the basis of summarizing the traditional methods of activated carbon regeneration, combined with the research progress in the laboratory, frontier progress of new activated carbon regeneration technology are elaborated in recent years in this paper, and the development direction of activated carbon regeneration technology are also presented in the end of the paper.
Effectiveness of environmental protection and low carbon work based on 5P model. - A case study of Boxing County in Shandong Province
Authors: Li Yawei , Nnodim Osai
Published: May 2021

Human resource exists in all management work. The 5P model is the top priority of human resource management and the foundation of human resource management. Applying the 5P model to public institutions in China, a reasonable management system can be established, which takes job design as the premise, personnel selection as the key, performance management as the core, salary management as the focus, and improving work enthusiasm as the auxiliary.
Research on Key Technologies of Energy Conservation and Emission Reduction in the New Era
Authors: Liu Yujie
Published: May 2021

The adjustment of coal energy resource tax is an important price control method to realize energy saving and emission reduction and promote low-carbon economy. The global financial crisis and my country’s economic recovery provide a favourable opportunity for coal resource tax adjustment. Combining the current background of the new era of energy conservation and emission reduction, the paper builds a China Energy CGE model based on the actual situation in China, and calculates the impact of ad valorem tax rates on different coal resources. The results of the study found that the coal resource tax reform has a weak negative impact on the economy. Considering the tax return scenario, it cannot only offset the impact, but also drive a small increase in GDP; the coal resource tax reform will not push up the CPI, deregulate electricity prices, and considering the tax rebate has a more obvious restraining effect on prices; the coal resource tax reform is conducive to improving the structure of domestic demand. Similarly, considering the tax rebate scenario, the effect is more obvious. Coal resource tax reform can reduce the output of high-energy-consuming industries, which is conducive to energy conservation and emission reduction.
Application of PSPL Method in Urban Street Public Space——An Example of Tianlin Road (Guilin Road—Liuzhou Section) in Xuhui District, Shanghai
Authors: Fan Geqin , Shi Zhengguang
Published: May 2021

Based on Yang Gail’s “people-oriented” public space theory and related research methods, this paper applies pspl research method to Tianlin road street in Xuhui District of Shanghai, investigates and analyzes the spatial scale of street road, the quality of street facade and the flow of people, evaluates the quality of street space, and puts forward some suggestions and ideas.
Determination of Available Lead in Greenhouse Soil by Solid Phase Dispersion Extraction Coupled with Atomic Absorption Spectrometry based on Primary Secondary Amine
Authors: Zhang Feilong , Wei Na , Wang Jun , Liu Qinghai , Zhaxi Cidan , Li Jirong , Dawa Zhuoma , Zhang Yifan , Pu Jifeng , Yang Zhen , Qiu Cheng
Published: May 2021

In order to effectively evaluate the pollution status of available lead (Pb) in farmland environment, a method for the determination of available Pb in greenhouse soil by atomic absorption spectrometry with primary secondary amine (PSA) as solid phase dispersion adsorption material was established. In combination with neutral salt (such as 0.01 mol/L CaCl2) extraction technology, neutral lead-containing aqueous solution was obtained. Based on the rapid adsorption of Pb in neutral environment and the rapid desorption of Pb under acidic conditions, the pretreatment method of sample enrichment and purification based on PSA was established by optimizing the parameters. The samples after enrichment and purification were determined by atomic absorption spectrometry. Results showed that the linearity of the method was good in the range of 0.010 ∼ 0.050 mg/kg (R2 = 0.9990). The limit of detection was 0.0051 mg/kg and the limit of quantity was 0.017 mg/kg. The recoveries were 97.6% to 99.2% and the relative standard deviation was 0.79% ∼ 1.56% at the concentrations of 0.010, 0.030 and 0.050 mg/kg.
Research on Evaluation Method of Gas Environment in Metro Station
Authors: Tian Qing , Hou Yuan , Gao Guofei
Published: May 2021

With the development of rail transit, subway has become one of the main means of transportation in most cities. However, the particularity and tightness of the subway station, the continuous growth of passenger traffic has also brought some negative environmental problems, such as the comfort and safety of subway station staff and passengers. In this paper, a comprehensive evaluation model of gas environment for metro station is proposed. The micro environment quality evaluation index of metro station is divided into two parts, one is the air quality evaluation index, the other is the thermal comfort evaluation index. From the construction and calculation of these two indexes, the comprehensive evaluation of gas environment of metro station is realized. In order to verify the applicability of the proposed method, we collected the environmental parameter data of six subway stations and evaluated them by using the environmental assessment method. The results show that the proposed method can not only realize the evaluation and monitoring of the station environment, but also has great significance for the improvement and decision-making of public transport environment.
Design and Implementation of the Informatization Management System for the Meteorological Station Network Basic Data
Authors: Chen Lihua , Guo Haiping
Published: May 2021

The basic data of the meteorological station network has such problems as inaccuracy, untimely review and inconsistency among operational systems. Aiming to solve these problems, we design an informatization management system for the meteorological station network through the WeChat enterprise. It employs the area verification and the altitude validation based on the digital elevation model, and it performs a regular comparison with the data from the China Integrated Meteorological Information Sharing System. This system realizes the dynamic management for the filling, submitting and reviewing of the station network basic data. It has functions such as intelligent verification of the input data of the station network, efficient and convenient data review, timely reminder message and flexible data service interface. Therefore, the system effectively improves the accuracy of the station network basic data and the review efficiency.
Advances in the Quality Control Methods of Air Temperature Data at Surface Automatic Weather Stations
Authors: Liu Tianqi , Zhang Delong
Published: May 2021

There are errors and deviations in the meteorological data for many reasons. With the increasing scientific requirements for the quality of the meteorological data, the quality control technology of the meteorological data has been explored and developed. The air temperature is one of the routine and important factors in surface meteorological observation with one of the longest observation histories since records began. Therefore, the quality control methods for air temperature data at home and abroad are summarized in this paper. The advantages, disadvantages, and applicability of the methods are analysed.
Simulation of irradiation intensity distribution of electrodeless ultraviolet lamp in cylindrical resonator by CFD
Authors: Guan Jie , Liu Chang , Yuan Hao
Published: May 2021

To improve the catalytic efficiency of the microwave single-mode sintering furnace to heat the catalyst and the carrier to catalyse the oxidation of toluene, the SJ-1 microwave single-mode sintering furnace was modified to place a microwave electrodeless ultraviolet lamp in the resonant cavity. The distribution of pollutants in the reactor and the intensity of UV light were calculated by CFD and visualized. The distribution of UV field can be seen from the results of light field, which provides a scientific basis for the placement of catalyst and a reference for the simulation of UV field. Under the conditions of relative humidity of 50%, space velocity of 6336.93 h−1, input power of 392.8 W, bed height of manganese oxide catalyst is 30 mm, initial toluene concentration of 235.23 mg/m3, input power of 595.3 W, toluene conversion efficiency of 94%. It has certain guiding significance.
Research on the Design Language of Planting Landscape in the Environment of Chengxiang District, Shanghai
Authors: Zhou Fan
Published: May 2021

This Research investigates the planting landscape in the environment of Chengxiang District. The method of visual simulation has been used, and questionnaire survey has been conducted to obtain the visual perception identity of respondents on different forms of planting in different environments. With the statistical analysis, we can get the design language of planting that the respondents have a sense of identity. The results show that the combinations of planting species identified in the environment of Chengxiang District, Shanghai, include: local planting species with extensive line branches are easier to get identity in the environment of Old Chengxiang District; cluster planting can better reflect the vitality of business atmosphere at Shikumen; delicate planting texture and bright color can make people have the identity of local Shanghai culture. Based on these design language, this Research tries to integrate it with the urban environment, so as to make the urban planting landscape inherit the urban context spirit and gain a sense of identity in the renovation of small-scale urban landscape.
Research on the Evolution of Population Distribution and Influencing Factors in Xi’an During the COVID-19 Epidemic Control Period: Based on a Perspective of Multi-source Spatio-Temporal Big Data
Authors: Zhao Kaixu , Zhang Shuaibing , Li Enlong , Chen Xiaolan , Wu Fengqi
Published: May 2021

Under the “ultra-conventional” control measures of the COVID-19 period, urban population distribution is different from usual time. Studying its evolution laws has a certain reference effect for the judgment of urban population aggregations, the division of precise control zoning, and the differentiated management of places during the COVID-19 control period. Based on the data of Baidu heat maps and points of interest (POIs), this paper uses three models of the population density index (PDI), the exploratory spatial data analysis (ESDA) and the geological detector (Geodetector) to analyze the characteristics and the influencing factors of the evolution of population distribution of Xi’an in three stages which are closed control stage, unsealed control stage and slack control stage. The results show that: in the three stages, 1) The value of the PDI and the range of the PDI change in Xi’an continue to increase. The single-day PDI curve shows “low-high-low” changing characteristics from morning to night in and within the third ring zone, and “high-low-high” in the suburb. And, by comparison, it is found that the social vitality of the first and second ring zone is more strongly impacted because of COVID-19 control measures. 2) The overall population density in Xi’an is gradually increasing, this is represented by gradual increase of the very high- and the high-density areas, and continuous decrease of the low- and the very low-density areas. And the centripetal distribution of population density, which is high inside the city and low outside the city, is becoming more and more obvious. 3) The spatial distribution of population density represents obvious high-value clusters or low-value clusters in the three stages, ESDA shows a circle structure of inner heat and outer cold, and this trend continues to be reinforced. 4) The intensity order of influencing factors of the 7 types of facilities on population distribution is: residential communities > catering facilities > living service facilities > healthy facilities > commercial facilities > office places > green spaces and squares, and the influencing factor intensities show a continuous increasing or a continuous decreasing process in the three stages.
Design and Implementation of the Weather Radar Mobile Monitoring System Based on WeChat Enterprise
Authors: Guo Haiping
Published: May 2021

In order to solve the problems of China’s new generation Doppler weather radar observation network, such as the lack of mobile monitoring platform, the untimely malfunction alarm and the slow interaction, a mobile operation monitoring system based on WeChat Enterprise has been designed, which is mainly composed of collection, processing, dispersal and feedback of radar’s operational status information, and interactive communication between different radar facilities and support personnel. This system can realize weather radar operating status monitoring based on cell phone, hierarchical automatic warning of operating status information, automatic video push of maintenance support activities and interactive feedback and exchange of information among maintenance support personnel, etc. Based on this system, the operational monitoring and technical support capabilities of China’s new generation Doppler weather radar are greatly improved, and it plays an important role in promoting the operational efficiency of the weather radar.
Luminescence properties of Li+/Mg2+-doped Cr3+: ZrSiO4
Authors: Zhang Shaobo , Yang Qiuhong , Hu Juan
Published: May 2021

Cr3+: ZrSiO4 ceramics with different concentrations of Cr3+-doped were prepared by a simple solid-state reaction method, and the effect of Cr3+ concentration on the photoluminescence of ZrSiO4 samples was investigated. The X-ray powder diffractometer (XRD) was used to analyze the structural characteristics of the samples. The XRD results show that zirconium silicate has been completely synthesized at 1400°C, which indicates that Cr3+ enters into the lattice of ZrSiO4, but does not change the structure of it. The emission spectra of ZrSiO4 were measured by the fluorescence spectrometer. The strongest emission peak was at 689nm, which was attributed by the 2E-4A2 of Cr3+. The influence of different concentrations of Cr3+ on the luminescence of zirconium silicate was investigated. When the concentration of Cr3+ is 0.1mol%, the luminescence intensity of the samples is the highest. When the concentration of Cr3+ is 0.5mol%, the intensity of the emission spectrum decreases, which is due to the concentration quenching of Cr3+ in the crystal lattice. Finally, the influence of charge compensator ions on the emission intensity of the sample is explored. The results show that the emission intensity of the zirconium silicate samples is improved when the appropriate amount of Li ion is added.
Study on the influence of urban construction land expansion on carbon emission based on VAR Model - a case study of Nanchang City
Authors: Zhou Laiyou
Published: May 2021

In the context of promoting high-quality economic development, it is of great significance to study the relationship between the expansion of urban construction land and carbon emission for the transformation of economic development mode and the implementation of green and low-carbon development. Based on the time series data of Nanchang City from 1995 to 2017, this paper analyzes the relationship between urban construction land expansion and carbon emission by constructing carbon emission measurement model, VAR model, using co integration test, Granger causality test, pulse analysis and other research methods. The results show that there is a co integration relationship between urban construction land expansion and carbon emissions, and Granger causality test shows that urban construction land expansion is the Granger cause of carbon emissions, while impulse response analysis confirms that the impact of urban construction land expansion on carbon emissions at the early stage is not significant, and the subsequent impact increases gradually, and the impact on carbon emissions will reach a stable state when urbanization is mature And put forward policy suggestions.
Study on Evaluation of Urban and Rural High-quality Living Space Based on Accessibility Analysis——Taking Shahe City, Hebei Province as an example
Authors: Meng Yuan , Li Yunqing , Liu Hongjie , Huang Yanchao
Published: May 2021

The change of planning thought from “taking things as the center” to “taking people as the center” requires that the allocation mode of supporting public service facilities in urban and rural residential areas should also change from simple service radius to accessibility analysis. In this study, Dijkstra algorithm is used to analyze the spatial network with the help of the spatial data of urban transportation network and six types of public service facilities. Based on the concept of equalization of urban and rural public service facilities, this paper constructs an evaluation index system of high-quality living space of urban and rural residents based on accessibility, determines the weight by calculating the information entropy of each index, and compares and analyzes the accessibility evaluation results on the scale of urban and rural residential areas. Try to construct the full coverage and partial coverage of the 15-minute living circle of various facilities under four modes of driving at higher or lower speeds and walking for adults or the elderly. The research results show that the hardware construction of the city’s transportation network system and public service facilities is efficient and convenient, with high accessibility and accessibility, showing the characteristics of urban-rural equivalence. However, under the low speed and walking mode, there is still room for layout optimization and improvement of some road systems and facilities.
Modeling and Microstructure Analysis of Three-Dimension Direct Writing for Zn-Al Alloy
Authors: Rong Wenjuan , Shan Zhongde , Wang Jialin , Wang Yongwei
Published: May 2021

This paper presents a systematic numerical experimental investigation of single-track forming of 3D metal melting direct writing. A forming track width was fitted by multivariate nonlinear regression method, and the numerical model had a fair level of uniformity with the experiment results. Two phase flow model based on volume-of-fluid (VOF) method was adapted to build up the coupled calculative models for direct writing deposition and solidification. The results show that when the forming track width approximately equals to the solidification layer width, it is the optimum time for forming the next layer. Based on the above research, the pre-remelting time was proposed, which is helpful to create next layer forming quality, and could also be used to guide the creation of a proper default of process parameters.
Numerical Simulation of Random Vibration Analysis for Ball Grid Array Package
Authors: Luo Wenhao , Su Wei , Dong Xianshan , Nie Zhenhua , Tomar Agam
Published: May 2021

This paper uses ANSYS Workbench (a finite element analysis software) to simulate BGA ceramic packing. The author models fixture, ceramic and metal steel. Then different thickness papers are laid on the BGA product. By random vibration analysis, the natural frequency and mode of the sample are obtained. According the results, the author discusses the relationship between different thickness papers and PSD-frequency curve. It provides a benefit instruction for the design of BGA packing.
Effect of Consecutive 3-yr Sand-Covering on the Physicochemical Properties of Saline-alkaline Soil in Northern Shaanxi, China
Authors: Wang Jian , Yang Chenxi , Li Jinbin
Published: May 2021

In order to study the effect of sand-covering on the improvement of saline-alkali land in in northern Shaanxi, the soil samples of consecutive 4-yr were taken as the research object, and the effects of sand-covering on the physical and chemical properties of the saline-alkali soil in the area were compared and studied by statistical methods. The study found that the soil pH, water-soluble salt content, degree of alkalinity and bulk density of the tillage layer were significantly lower by covering sand than the sand-covering free, and decreased with the extension of the cultivation period year by year. In addition, the soil porosity, available phosphorus and available potassium content increased significantly, and increased with the extension of the cultivation period year by year. The results showed that sand-covering significantly improved the physicochemical properties of the soil in the cultivated layer of saline arable land in the area; with the increase of the cultivation period, the improvement effect increased year by year, which further indicated that sand-covering is an effective measure to improve the salinized arable land in the area.
Research on the Maximum Amount of Reclaimed Asphalt Pavement Based on Balanced Design of Performance and Economy
Authors: Chen Chengyong , Yang Fei , Zhang Huan
Published: May 2021

By controlling the variability of Reclaimed Asphalt Pavement (RAP) and achieving the goal of high content, it is proposed that the milling speed of RAP should be controlled at 5 ∼ 7m / min, the moisture content should not be greater than 2%, and there should be at least two levels of pretreatment technology. The maximum RAP content of AC-25 hot recycling is 50% according to the grading calculation curve under the condition that the current standard grading range and powder binder ratio are not greater than 1.3. At the same time, according to the grading calculation of the project, the empirical formula of coarse and fine aggregate mix to realize the balanced design of utilization and economy is put forward.
Analysis of Cutting Tool Wearing of Tunnel Boring Machines in Singapore Mixed Face Ground Condition
Authors: Su Wenyang
Published: May 2021

During shield tunneling in composite stratum, especially in granite stratum with high rock strength and high-water content, the abnormal damage of disc cutter is frequent. This paper analyzes the law of wear of disc cutter and obtains the wear coefficient, and then predicts the number of disc cutters needed for shield machines in tunneling section and reduces the number of disc cutters needed, so as to reduce the extra cost of shield construction.
Variation characteristics of phosphorus and potassium content in slope farmland
Authors: Guo Zhen , Yang Chenxi
Published: May 2021

It is of great significance to study the effect of different planting patterns on the maintenance of soil nutrients in slope farmland. Compared with planting soybeans, the available phosphorus content of the 2° and 5° test fields increased by 17.89% and 21.02%, respectively, and the 3° test field decreased by 7.87%. In the experimental field for planting soybeans, the average effective potassium content decreased with the increase of slope, and the content of 0-10cm soil layer was higher than that of 10-20cm soil layer. Different planting patterns led to differences in the distribution of available phosphorus and available potassium, but the content of 0-10cm soil layer was higher than that of 10-20cm soil layer.
Research on the Ecological Risk Monitoring and Restoration Evaluation System of Petroleum Exploitation
Authors: Wang Xiaohui
Published: May 2021

According to the characteristics of petroleum development projects, the paper identifies the impact of its ecological environment factors. Among the ecological environment factors, the soil is the most affected, and the accident risk among the acting factors has the greatest impact on the ecological environment. The specific analysis of the ecological environment factors Finally, the corresponding ecological protection measures are proposed.
Study on the Performance Identification of OpenCV in Cashew Nut Shell-based Activated Carbon
Authors: Wang Jingchen
Published: May 2021

The demand for drinking water treatment in Cambodia is extremely urgent, which poses important obstacles to local construction and development. Activated carbon is a commonly used adsorption material in water treatment. In this experiment, Cambodian cashew nut shells were used as raw materials to prepare activated carbon. The total pore volume, specific surface area, pore size distribution, and micromorphology of the activated carbon were tested. Subsequently, using the characteristics of water exchange with air in activated carbon, OpenCV was used to characterize the pore structure and activity of activated carbon, and a mathematical model was established. The results show that cashew nut shell can successfully prepare activated carbon. OpenCV can be used to analyze the pore structure of activated carbon. The efficiency of OpenCV recognition is 94.3%. The pore size affects the ease of entry of water. When the pore size is less than 7.67 nm, water cannot enter. This study provides a feasible solution for water treatment in Cambodia.
Summary of Research on Geomagnetic Navigation Technology
Authors: Zhao Heda , Zhang Ning , Xu Lei , Lin Penglong , Liu Yonglu , Li Xu
Published: May 2021

Summarizes the technical principles of geomagnetic matching navigation, expounds the navigation solution process of MAGCOM, SITAN and ICCP three main matching navigation algorithms, and discusses the application status of geomagnetic navigation technology from the three geographical environments of satellite, air and underwater. It points out the research prospects of geomagnetic matching navigation and provides reference for the research and development of geomagnetic navigation technology.
Study on Irrigation Pattern in Irrigation Area of Semi-arid Region
Authors: Dong Zijia
Published: May 2021

This paper takes 75% precipitation guarantee rate of Taoer River irrigation area in semi-arid area as an example, establishes the economic loss accounting model of irrigation area, studies the predicament of water resources allocation in irrigation area and the economic profit and loss under different irrigation modes in irrigation area. This paper discusses irrigation mode and transition development path. The study shows that in the dry year of 75% precipitation guarantee rate, adjusting the irrigation area diversion plan to make the region III into full surface water irrigation can reduce the loss of 26.23 million yuan. Although the region I and region II groundwater single irrigation than mixed irrigation model loss of 23.33 million yuan, but the development of paddy field to dry field soybean and water-saving total income can increase 1.99128 million yuan. Therefore, under the background of climate change, adjusting the water diversion plan of irrigation area and changing groundwater to dry field will be the transformation and development direction of irrigation area in semi-arid area.
Research on Fengjiashan Reservoir Ecological Compensation Mechanism Based on Ecosystem Service Function
Authors: Tian Ruogu , Meng Zhaowei , Xu Jun , Liu Yang
Published: May 2021

The impact of hydropower projects on the ecosystem is dynamic and complex. Constructing a complete ecological compensation mechanism can ensure the effective progress of ecological compensation. The ecosystem service value of the Fengjiashan Reservoir such as water supply, fish farming, hydropower, water regulation, water resources accumulation, biodiversity, and environmental purification, is calculated with market value method, alternative engineering method and other evaluation methods, and the ecological compensation mechanism of the reservoir is studied. The results show that the value of its ecosystem services is 230,912,700 yuan, and the amount of ecological compensation determined on the basis of ecosystem service functions is 101,866,200 yuan. The main sources of compensation funds are taxes, water surcharges and government financial subsidies.
Kinematics modeling and workspace analysis of large offshore trestle based on wave compensation
Authors: Wang Xingyao , Xue Yifan , Liu Yanjun
Published: May 2021

Referring to the modeling method of the series manipulator, the D-H parameter method is used to model the kinematics of the large-scale offshore trestle, and the forward kinematics equation of the offshore trestle is calculated, and the algebraic method is used to solve the inverse kinematics. At the same time, using the robotics toolbox in Matlab to verify the feasibility of the D-H parameter method modeling and the correctness of the forward and inverse solutions of the kinematics equation, and using the Monte Carlo method to analyze the working space of the offshore trestle in Matlab, finally, the motion of the offshore trestle is wave compensated. It provides a theoretical basis for the kinematics modeling, workspace analysis and control system design of large-scale offshore trestle.
Stability analysis of Jiguanshan Tunnel construction under karst tiankeng
Authors: Wan Fei , Zhang Xuan , Li Tangjun
Published: May 2021

The overlying rock mass under the tiankeng developes karst and thus has poor mechanical properties, which brings about great risks for the tunnel undercrossing construction. In order to determine the safety conditions of the tunnel and karst tiankeng during the undercrossing construction of the Jiguanshan Tunnel, a three-dimensional elastoplastic numerical model was established to analyze the deformation laws of the surrounding, deep and surface rock mass. The calculation results showed that the deformation of surrounding rock was dominated by settlement. With the longitudinal deformation of 57.3mm, the stability of the tunnel face was poor and the surrounding rock of the arch was prone to instability. The deformation of the surface tiankeng was slight. However, given that the uncertainty of karst development at the bottom of the karst tiankeng and the influence of tunnel construction blasting vibration, the surface rock was still at high risk of instability. The research results can provide references for the design of similar projects.
Study on Influencing Factors of Leakage of Epoxy Resin Grouting
Authors: Yu Tao , Su Huifeng , Zhang Xiudong
Published: May 2021

As a kind of grouting material, epoxy resin is often used to repair cracks in concrete structures and as grouting filling for reserved joints in prefabricated buildings. However, in engineering applications, gaps can be found between water-stop tape and concrete. Due to the low viscosity of epoxy resin, leaks easily occur during the grouting process. In order to study the influencing factors of leakage, numerical simulations were used to determine the leakage rate of epoxy resin between the size of the leakage aperture, the grouting pressure, and the viscosity of epoxy resin. The change of pressure at the position of the leak under different conditions was also obtained. The results showed that under different viscosities, the leakage velocity exhibits different laws to the area of the hole and the grouting pressure.
The application of SAP2000 in the recheck of Traffic Bridge of a certain sluice
Authors: Li Fei , Jin Quanhua
Published: May 2021

Using the bridge module of SAP2000 structure calculation software, can easily build bridge model, calculate bridge stress. Combination reinforcement module to check the condition of bridge reinforcement, thus to evaluate the whole safety of bridge. It is more convenient and reliable to use finite element software instead of traditional structure mechanics method.
Model test and analysis of soil displacement of cone-perforated column composite pipe pile under static pressure
Authors: Yang Yansong , Lei Jinbo , Deng Dingzhe , Zou Yongqiang
Published: May 2021

In view of the fact that there is relatively little research on soil squeezing effe ct of conical-perforated column composite pipe pile, the lateral displacement and surfa ce uplift of conical-perforated column composite pipe pile after single pile is pressed i nto soil are observed by static pressure pile sinking method, and the change law of soil lateral displacement and surface uplift during pile sinking is analyzed. It is found that the lateral displacement increases with the increase of pipe pile driving depth, and whe n the pipe pile is fully penetrated, the soil lateral displacement ends, and the influence range of soil lateral displacement is 2 days.
Analysis of factors affecting long-term coal demand in China Error correction model based on co-integration
Authors: Feng Xiwen , Xin Mingshang
Published: May 2021

This paper studies the long-term equilibrium relationship of coal in China fro m the perspective of energy structure and economic structure by using co-integration t echnology, data of China from 1980 to 2018 are selected in this paper and estimates th e long-term income elasticity, price elasticity, and the elasticity of economic structure and cross-price elasticity with natural gas; It simulates the evolution of long-term coal demand of various explanatory variables at different growth rates and gives policy cho ices. The results of the study indicate that the demand for coal is very sensitive to the c hange of economic structure and the adjustment of economic structure will greatly rest rain the demand for coal.; The change of producer price has little influence on the chan ge of coal demand; Considering the long-term course of economic development, the im pact of natural gas consumption on coal demand is increasing.
A Comparative Study on the Spatial Characteristics of Traditional Residential Houses in Zhangguying and Laodong Villages Based on Space Syntax
Authors: Zou Han , Liu Yang
Published: May 2021

This article is based on space syntax theoy combined with field surveys and mapping data, Using AutoCad and Depthmap to analyze and interpret the spatial characteristics of traditonal houses in Zhangguying Village and Laodong Village in Xiangxi Prefecture. clarifying the difference in spatial characteristics between the two spaces and the influencing factors behind the difference by comparing the integration degree of visible layer and the degree of integration of the feasible layer.
Application of Glass Fiber Concrete under Thin-Walled Middle Partition Wall Construction in Tunnel
Authors: Tian Yuanyuan , Wang Yigong , Nie Haixiang , You Hongyue , Zhang Junjie , Shao Tangsha , Pang Chuming , Zhang Xu , Wang Dong , Huang Peng , Wang Qingbiao
Published: May 2021

Aiming at the feasibility of applying glass fiber concrete as a new material to tunnel engineering, with the help of a combination of theoretical analysis, laboratory tests and engineering applications, the effect of glass fiber on the mechanical properties of concrete under different dosages and different lengths is studied. By monitoring the cracks in the middle partition wall, and applying the glass fiber to the middle partition wall in Laoshan Tunnel, to achieve the verification of the optimal length and the optimal mixing amount. The main conclusions are: (1) When the length of glass fiber is 12 mm, the tensile and compressive strength reach the maximum value; (2) Determine the optimal volume rate is 1% in order to prevent the concrete cracking effectively; (3) The crack resistance of the mid-board with glass fiber concrete is better than the ordinary concrete, which proves the feasibility of practical application of glass fiber concrete.
Stability control measures of soft and broken surrounding rocks of super-large section tunnel constructed using benching tunneling method
Authors: Wan Fei , Wang Bo , Fu Chongtao , Li Lei , Li Xuefeng
Published: May 2021

The tunnel face of the super-large section tunnel constructed using benching tunneling method tends to loss stability in the stratum with very poor surrounding rock grade (grade V). Therefore it is necessary to employ advanced support or optimize bench construction parameters to improve the stability of tunnel construction. In order to determine the stability control measures for the super-large section tunnel constructed using benching tunneling method in soft and broken surrounding rock, a three-dimensional elastoplastic model is established. Taking the extrusion displacement of tunnel face and the failure zone of surrounding rock as indices, the influences of bench height, bench length, circulating footage and other construction parameters and the construction of advanced large pipe shed on tunnel stability were analyzed. The calculation results show that when the tunnel is constructed using benching tunneling method, the surrounding rock within 4.5m in front of the tunnel face and 1.5m above the arch collapses, and the failure develops from the arch top down to the arch foot. The measures such as shortening the circulating footage, shortening the length of the bench and reducing the height of the upper bench have little effect on the stability of the tunnel, and the maximum difference among the strength reduction coefficients of the surrounding rock is 0.1 when the tunnel losses stability. The advanced large pipe shed can significantly improve the stability of benching tunneling method construction. The deformation and failure of the tunnel mainly concentrates in the side wall area, which gradually develops from the arch foot to the wall foot, and the depth of the surrounding rock failure zone is very limited.
Effect of Tempering Temperature on Microstructure and Uniformity of LP Steel Plate under HOP Process
Authors: Xiong Jie , Tang Shuai , Wu Chengyuan , Xu Ronghui , Sheng Xinjun , Liu Zhengyu , Wang Guodong
Published: May 2021

Longitudinal profiled steel plate (LP steel plate) is a green steel product, which is widely used in steel structure fields such as ships and bridges. In this paper, the effect of Heat-treatment Online Process (HOP) on microstructure and uniformity of LP steel plate was investigated by thermal simulation test. The results show that the microstructure consists of grain boundary allotriomorphs, upper bainite, acicular ferrite and carbon-enriched austenite at 550°C. During the isothermal process, the austenite transforms into bainite, the acicular ferrite grows and coarsens, and the bainite laths gradually “fuse” to form large granular bainite. After online tempering at 650°C, the austenite transforms into ferrite, acicular ferrite and bainite undergo tempering transformation, in which the size of bainite decreases and some acicular ferrite transforms into polygonal ferrite. After tempering at different temperatures (650∼750°C), the microstructure consists of grain boundary allotriomorphs, coarsened acicular ferrite and a small amount of granular bainite. With the increase of tempering temperature, the tempering transformation degree of acicular ferrite and bainite is intensified. Elongated carbides at grain boundaries become short rods and particles, which decreases the size and aggregation of carbides. Compared with the traditional process, the difference of microstructure and hardness of LP steel plate with different thickness specifications after HOP process is reduced, and the hardness is higher, which is beneficial to improve the performance and uniformity.
Study on New Type of Double-Sided Cooling Packaging Technology for Semiconductor Lasers
Authors: Wang Yuancheng , Qu Hongwei , Zheng Wanhua
Published: May 2021

A new type of double-sided cooling packaging technology for semiconductor lasers has been designed and fabricated. The Simulation results showed that the highest temperature of semiconductor has been reduced from 48.5°C to 40°C by using double-sided cooling design. Experimental results show that the maximum power increased form 14.1W to 15.1W, which proved that the thermal saturation effect of the laser is effectively alleviated by using double-sided cooling.