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    28 December 2019, Volume 47 Issue 6
    Magnesiothermic Reduction of Rectorite for Preparing Si/C Composite and Its Electrochemical Properties
    ZHAO Jinwei,GAO Yimin,WANG Zhe,LUO Xiansheng,YU Guoxian
    2019, 47(6):  485-492.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.001
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    Porous Si from rectorite as raw materials was prepared with magnesiothermic reduction and then Si/C composite as anode materials was prepared by high-heat treatment of the carbon coating with glucose as carbon precursor in a nitrogenous atmosphere. The influences of magnesiothermic condition on structures of the samples were characterized by X-ray diffraction(XRD),nitrogen absorption and desorption(BET), scanning electron microscope (SEM)and thermogravimetric analysis(TG). The electrochemical performances of the Si/C anode material were investigated by an electrochemical workstation and a battery charge-discharge test system. The results shows that the pore volume,average pore diameter and silicon content of the porous silicon from rectorite with magnesiothermic reduction had important influences on the electrochemical performance of the Si/C composite. The electrochemical performances of the Si/C anode material increased first and then decreased while the magnesium powder dosage was increased in the magnesiothermic reduction. When the mass ratio of rectorite to magnesium was 1∶0. 4,the Si/C composite had the highest electrochemical performances. The sample maintained the reversible capacity of 1120 mAh/g after the first cycle and it still maintained 555 mAh/g after 200 charge-discharge cycles at a current density of 0. 1 A/g.
    Research Progress of Echelon Utilization of Power Lithium Battery
    GUO Jinglong, LOU Ping, XU Guohua, ZHANG Minggao, CHENG Qi, TANG Shun, CAO Yuancheng
    2019, 47(6):  493-498.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.002
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    With the rapid spread of new energy vehicles,the number of power lithium batteries in China is increasing day by day,the price of battery raw materials is rising and the pressure on the environment of a large number of discarded batteries is increasing, and the recycling of decommissioned power lithium batteries has also been put on the agenda. At present,power battery recycling includes two methods:echelon utilization and material recovery. This paper focused on the echelon utilization,and stated the necessity of the echelon utilization;the author analyzed all aspects including national policy,economic orientation,technology,and professional talents. The problems encountered at present were analyzed and corresponding suggestions were put forward.
    Study on Lithium-Rectorite Based Composite Cathode Materials for Lithium-Sulfur Battery
    LUO Xiansheng,ZHAO Jinwei,LI Jinghui,YU Guoxian
    2019, 47(6):  499-506.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.003
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    In the secondary battery,the lithium-sulfur battery is used as a battery form in which sulfur is used as a positive electrode active material,and it has the characteristics of environmentally friendly raw materials and higher specific capacity than other conventional materials. However,the sulfur conductivity is extremely poor,the expansion ratio is large,and the lithium sulfide formed by the charge and discharge process is easily dissolved in the electrolyte to form a ″shuttle effect″. In view of the above shortcomings,a sulfur host by lithium salt modified rectorite and a carbon-sulfur composite cathode material were designed to improve the electrochemical performance of lithiumsulfur batteries. It has been tested that the lithium salt modification can dredge the interlayer and pore structure of the rectorite to a large extent,increase the specific surface area and pore volume,thereby expanding the loading space of sulfur in the pores,and at the same time enriching lithium ions in a large amount. The material can effectively improve the transport of ions and electrons in charge and discharge. The modified positive electrode composite has a charge-discharge specific capacity of 877 mAh/g in the first cycle at 0. 1 C,and the specific capacity decay to 653 mAh/g after 60 cycles,and the capacity retention rate is 74. 5%,indicating that the components in the material can effectively adsorb polysulfide. The components inhibit the shuttle effect and makes the material have better cycle stability. The average specific capacities at current densities of 0. 1,0. 2,0. 5,1 C are 850,750,600,500 mAh/g,respectively,and show good rate performance. Its charge transfer impedance is 63 Ω, which is conducive to the conduction of electronic charges.
    Electric Field Distribution Model of Bipolar Wire-Tubular Precharger
    CHANG Yufeng,LI Mengling,YE Luowei,YANG Ruiyang,LI Shuaishuai
    2019, 47(6):  507-513.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.004
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    Electric field distribution is one of the key issues in the theoretical research of electrostatic precipitators(ESPs). In order to improve the collection efficiency for fine particles,a bipolar wiretubular precharger was developed. It is necessary to reveal the electric field distribution of the novel electrodes. According to Gauss flux theorem,the theoretical function of electric field distribution in wire-wire electrodes was derived. Based on electric field superposition law, the electric field distribution model of wire-tubular electrodes was deduced. The bipolar wire-tubular precharger could be divided into six corona regions symmetrically,and electric field distribution of each corona region could be solved respectively. The symmetric distribution of positive and negative electric fields in the bipolar wire-tubular precharger is beneficial to increase the electrostatic agglomeration efficiency and collection efficiency,and to reduce the cumulative charge and inhibit the back corona bag burning. The results of the research were used to enrich the particle removal mechanism,which was the fundamental support for the industrial application and popularization of the bipolar transverse plate ESPs.
    Study on Emission Factors for Pollutants from Residential Coal Combustion
    LIU Junxia,LIU Qiongyu,CHENG Jinjun,YE Xun,LIANG Zhifa
    2019, 47(6):  514-520.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.005
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    According to a self-designed simulating combustion-dilution sampling system,different residential coals with different combustion states from Henan,Shanxi,Shaanxi and Wuhan were chosen,the emission particles and gaseous pollutants of two kinds of bituminous coal,two kinds of anthracite coal,two kinds of honeycomb briquette and one kind of briquette were collected. The combustion emissions of different coals were compared and analyzed. The results showed that the combustion emission particles from different kind of coal were obviously different during firing;the emission factors of PM10 from bituminous coal were higher than those from anthracite coal and honeycomb briquette. The emission factors of PM10 were positively correlated with the volatile content in coal. The emission factors for gaseous pollutants from different kinds of coal were not obvious correlated with the form of coal,and the emission of SO2 was positively correlated with the sulfur content in coal. The influence of different combustion states on the gaseous pollutant emission was not obvious.
    Review of Technology of Aerosol Fibre Filtration
    ZHU Zhongkui,ZHANG Aili,FAN Ruihua,CHANG Yufeng,SHI Ling
    2019, 47(6):  521-528.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.006
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    Aerosol particulate emission pollution is an obstacle to the improvement of atmospheric environmental quality in our country. As the emission control of aerosol particles,the filter filtration and dust removal technology has the obvious characteristics of high filtration efficiency,stable operation,various kinds and wide selection of fiber filtration media. It is evidence that fiber filtration technology has formed a variety of filtration materials,and has more complete theoretical support and related technical specifications. In this paper,the filtration theory,key parameters,development of filtration media,filtration process and filtration technology of aerosol particle fiber filtration were comprehensively expounded,the new technologies in this field were introduced,to provide references for the domain of aerosol particle filtration and dust removal.
    Research on Execution Effect of Policy of Rice Minimum Purchase Price in Hunan Province
    ZHOU Jianming,HU Xiaoli
    2019, 47(6):  529-534.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.007
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    According to the minimum purchase price of rice in Hunan Province from 2005 to 2017,rice yield and farmers′ income were selected as evaluation indicators. Firstly,a logarithmic regression model of rice yield and minimum purchase price of rice was established;then a regression model of farmers′ income and minimum purchase price of rice was also established. The results showed that there was a very large positive correlation between the rice minimum purchase price and rice yield & farmers′ income. Finally,the effect of single rice minimum purchase price policy on increasing rice yield and farmers′ income was analyzed. Moreover,some relevant suggestions for improvements were proposed.
    Thickness Design of High Temperature Working Clothes Based on Heat Transfer Mathematical Model
    WANG Peipei,WANG Shuai,OU Xinxin,ZHOU Xin,XU Lu
    2019, 47(6):  535-540.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.008
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    Aiming at the problem of thickness selection of the layer II waterproof layer and the layer IV air layer of the high temperature working suit,the heat transfer model of three-layer of fabric,air layer,artificial human skin layer was established,the partial differential equation of the model was solved by the finite difference method and the MATLAB mathematical software was used for calculation. The data of temperature distribution were obtained,and a three-dimensional temperature distribution map was generated. Under hypothetical conditions,the optimal thicknesses of layer Ⅱ of waterproof layer and layer Ⅳ of air layer were 19. 06 mm and 5. 78 mm,respectively
    Epidemiological Characteristics of Pulmonary Tuberculosis Based on Curve Clustering
    CHEN Suisui,WU Lingqian,ZHAO Yu
    2019, 47(6):  541-548.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.009
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    Objective To analyze the epidemiological characteristics of pulmonary tuberculosis in China,and to provide reference for formulating strategies for prevention and control of pulmonary tuberculosis in China. Methods Descriptive epidemiological method was used to analyze the epidemiological characteristics of tuberculosis in China over the past 2005 to 2016 years,the method of functional curve clustering based on B-spline was applied for cluster analysis based on the similarity of incidence time trajectories in 32 regions. Results The incidence curve for 2005-2016 showed a downward trend. The number of reported cases of tuberculosis in 2016 decreased by 33. 59% compared with the same period in 2005;the incidences of infants and children aged 14 and below were relatively low,and the incidences of elderly people aged 60 and above were higher;the incidences of tuberculosis were highest in January and March each year, the incidences of tuberculosis were lowest in December every year;the incidences of tuberculosis in Hainan,Guangxi,Guizhou,Tibet and Xinjiang were relatively high,and the annual incidence rate of tuberculosis in Xinjiang was as high as 180. 42/100 thousand. The 32 regions of the country were divided into four categories based on the similarity of incidence time trajectories. The incidences of Guizhou and Xinjiang of the first type were generally higher than those of the other three types,and the fluctuations were larger;the epidemic situations of the first type and the second type in Qinghai and Tibet were more severe. Conclusion The country′s 60-year old and above is the key target of national prevention and control. Every year in January and March,the prevention and control measures to tuberculosis should be strengthened. The prevention and control of tuberculosis in Guizhou,Xinjiang,Qinghai and Tibet need focus and support of the state.
    Preparation and Stability Characterization of Flavonoids from Tulipa edulis
    WANG Daobing,GAO Qinghai,SUN Yujun
    2019, 47(6):  549-554.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.010
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    Flavonoids from leaves of Tulipa edulis were prepared with D-110 macroporous resin purification and 65% ethanol as extractant. The contents of flavonoids were determined by colorimetry. Their group characteristics were observed by infrared spectroscopy. The effects of temperature,pH,oxidant, reductant, illumination on their stability were investigated. The results showed that flavonoids from Tulipa edulis contained quercetin,rutin and other flavonoids,which had good alcohol solubility and water solubility. Flavonoids from Tulipa edulis were stable under the conditions of less than 85 ℃,natural light or shelter from light and acidic environment. The effect of oxidant H2O2 on their stability was not significant(P > 0. 05). However,reductant Na2SO3 had a significant effect on their stability(P < 0. 05). Therefore,in the test range,except for reducing agent Na2SO3,the flavonoids from Tulipa edulis were stable. They have good alcohol solubility and water solubility,which are suitable for development and utilization.
    Research Progress of Insulin-Like Growth Factor-1 Derivatives
    XIE Qian,LI Jianan
    2019, 47(6):  555-562.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.011
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    Insulin-like growth factor-1(IGF-1)is an active protein polypeptide closely related to the physiological process of growth hormone,which can promote the metabolism of sugars,lipids,proteins and inorganic salts. In order to expand the application prospect of IGF-1 in the medical field,researchers are actively developing IGF-1 derivatives due to the adverse drug reaction brought by its long-term use,which greatly restrict its application. In this paper,the derivatives of truncated IGF-1,lengthened IGF-1,IGF-1-Fc fusion protein,pegylated IGF-1 synthesized by genetic engineering and molecular biology technology were reviewed,and the excellent biological functions of IGF-1 derivatives were explained,they provide guidance for the research and development of other protein drugs in the future.
    Anaphylactic Shock Caused by Hydroxyethyl Starch 130/0.4 Sodium Chloride Solution During General Anesthesia:a Case Report and Correlation Analysis
    CHEN Qian,YAN Hong,LIU Caihua,YANG Shijie
    2019, 47(6):  563-566.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.012
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    Objective To investigate the clinical features of a case of anaphylactic shock caused by hydroxyethyl starch(HES)130/0.4 sodium chloride injection in general anesthesia and the new progress in application of HES at home and abroad. Methods On January 16,2019,an elderly male patient underwent laparoscopic gastrectomy under general anesthesia. Anaphylactic shock occurred during intravenous drip of HES,Through timely treatment according to anaphylactic shock,the patient recovered stable circulation and passed the operation safely. The author studied the drug characteristics of HES and understood the new progress of clinical application of HES by searching relevant literatures. Results After active rescue,the patient′s vital signs recovered stably,the operation was successfully completed,and there was no related adverse drug reaction after the operation. Conclusion In the application of HES in perioperative period,the doctors should weigh the advantages and disadvantages,strictly control its indications and contraindications as well,mastering the rescue process of anaphylactic shock is crucial for every anesthesiologist.
    Selection and Application of Garden Plants for Urban Greenway Construction in Wuhan City
    JIANG Xiwang
    2019, 47(6):  567-571.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.013
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    Based on current status of plant application in urban greenway construction in Wuhan City, the selection and configuration of garden plants in urban greenway construction were investigated in this article. The results showed that there were 150 kinds of garden plants in Wuhan′s urban greenway construction;they involved 45 families and 92 genera. Among them,there were 8 species of big trees,27 species of trees,53 species of shrubs(including subshrubs and vines)and 62 species of herbaceous plants(ground cover plants). The main ways of plants application in greenway were summarized as follow:water surface plant allocation,revetment plant allocation and terrestrial plant allocation. Some suggestions on the application of landscape plants in greenway construction in Wuhan City were put foward.
    Water Quality Analysis of Hanjiang National Wetland Park in Xiangyang and Its Relationship with Plants Distribution
    LI Honghai,XIA Mengyu,FENG Dejin
    2019, 47(6):  572-576.  doi:10.16389/j.cnki.cn42-1737/n.2019.06.014
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    According to the data released by the Environmental Protection Department of Xiangyang,the water quality of the Hanjiang National Wetland Park in Xiangyang in Hubei Province was monitored and analyzed in the past five years from 2014 to 2018 to further understand the plant characteristics and water quality in the wetland park,and to analyze the relationship between water quality and plants distribution in the area. The results showed that the water qualities at two monitoring sections of the Baijiawan inlet and the Yujiahu outlet of the wetland park were in Class II standard,and the chemical oxygen demand was superior to the national Class I water quality standard. Due to the discharge of organic pollutants in the Yujiahu section and the management was not in place,they resulted in a large fluctuation in the organic matter content of the Yujiahu section of 2017-2018,especially,the dissolved oxygen content decreased and the total phosphorus content increased. Different plants in different water environment growth areas have different effects on water quality,which affects the development trend of water quality in wetland parks.