Table of Content

25 March 2019, Volume 39 Issue 2

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A regularity result of entropy solutions

ZHANG Qi, WANG Lianhong, GAO Hongya

2019, 39(2):  113-117.  DOI: 10.3969/j.issn.1000-1565.2019.02.001

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This paper deals with nonhomogeneous boundary value problem for nonhomogeneous divergence type elliptic equation. A regularity result is derived for entropy solutions under some controllable and coercivity conditions, and some proper integrable assumptions on the nonlinear term,by using the classical Stampacchia Lemma and the methods in Sobolev spaces. The result obtained in this paper can be regarded as a generalization of the classical results.

Oscillation of higher order nonlinear neutral differential equations with forced term

LI Jing, CAI Hai, WANG Peiguang

2019, 39(2):  118-123.  DOI: 10.3969/j.issn.1000-1565.2019.02.002

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In this paper, we investigate a class of higher order nonlinear neutral differential equations with forced term.By using Krasnoselskii's fixed point theorem and analytical technique, new necessary and sufficient conditions are obtained for every bounded solution which either oscillates or tends to zero. In particular, the obtained results improve some known results and two examples are given to show the applications of the results.

Progress of transition metal nitride as counter electrodes for dye-sensitized solar cells

LI Xiaowei,ZHAO Kaifeng,LIU Sen,ZHOU Shengnan,ZHANG Xue, XIE Jianjun,ZHAO Yajun

2019, 39(2):  124-131.  DOI: 10.3969/j.issn.1000-1565.2019.02.003

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As one of the key components of dye-sensitized solar cells, the price, performance and preparation methods of the counter electrodes directly affect the development and application of DSSCs. The Pt electrode is commonly used for counter electrodes in DSSCs, but Pt is precious metal. Therefore, it is an effective way to reduce the cost of DSSCs by looking for low cost and high performance catalytic material instead of Pt electrode. The electronic structure of Pt and transition metal nitrides are similar, so it has high catalytic activity, but also has high corrosion resistance and low price, so that the metal nitride material has broad application prospects. This review focuses on the synergistic effect of carriers and transition metal nitrides or transition metal nitride prepared by the unique nanostructure(nanotubes and highly ordered arrays)to solve the problem of transition metal nitride agglomeration and limited mass transportation.Finally, it is suggested that the development of two -component or multi -component transition metal- DOI:10.3969/j.issn.1000-1565.2019.02.003染料敏化太阳能电池过渡金属氮化物对电极研究进展李晓苇¹,赵开封¹,刘森²,周盛楠¹,张雪¹,解建军¹,赵亚军¹(1. 河北大学 物理科学与技术学院,河北省光电信息材料重点实验室,河北 保定 071002;2.河北大学 医学部,河北 保定 071002)摘 要:对电极作为染料敏化太阳能电池(dye-sensitized solar cells, DSSCs)的核心部分之一,其材料的价格、性能和制备方法直接影响DSSCs的发展和应用.DSSCs常用Pt对电极价格昂贵,因此寻找低成本高性能的催化材料代替Pt对电极是降低DSSCs成本的有效途径之一.过渡金属氮化物的电子结构与Pt相似,具有高的催化活性和耐腐蚀性,价格低廉,使其具有广阔的应用前景.文章综述了利用载体与过渡金属氮化物的协同作用或将过渡金属氮化物制备成独特的纳米结构(纳米管和高度有序的阵列等)来解决过渡金属氮化物易团聚和大规模的物质运输受限制等问题.最后提出,开发双组元或多组元过渡金属氮化物和柔性过渡金属氮化物对电极可以作为未来发展方向.关键词:过渡金属氮化物;对电极;协同作用;染料敏化太阳能电池中图分类号:TK513 文献标志码:A 文章编号:1000-1565(2019)02-0124-08Progress of transition metal nitride as counterelectrodes for dye-sensitized solar cellsLI Xiaowei¹,ZHAO Kaifeng¹,LIU Sen²,ZHOU Shengnan¹,ZHANG Xue¹, XIE Jianjun¹,ZHAO Yajun¹(1.Key Lab of Optic-electronic Information and Materials of Hebei Province, College of Physics Science and Technology, Hebei University, Baoding 071002, China;2.Medical College, Hebe University, Baoding 071002,China)Abstract:As one of the key components of dye-sensitized solar cells, the price, performance and preparation methods of the counter electrodes directly affect the development and application of DSSCs. The Pt electrode is commonly used for counter electrodes in DSSCs, but Pt is precious metal. Therefore, it is an effective way to reduce the cost of DSSCs by looking for low cost and high performance catalytic material instead of Pt electrode. The electronic structure of Pt and transition metal nitrides are similar, so it has high catalytic activity, but also has high corrosion resistance and low price, so that the metal nitride material has broad application prospects. This review focuses on the synergistic effect of carriers and transition metal nitrides or transition metal nitride prepared by the unique nanostructure(nanotubes and highly ordered arrays)to solve the problem of transition metal nitride agglomeration and limited mass transportation.Finally, it is suggested that the development of two -component or multi -component transition metal- 收稿日期:2018-06-26 基金项目:河北大学研究生创新项目(hbu2018ss63); 河北大学2018年创新创业训练计划项目(2018242; 2018083); 河北大学2018年实验室开放项目(sy201849;sy201850) 第一作者:李晓苇(1955—),男,河北唐山人,河北大学教授,主要从事新型纳米光电材料与器件的研究.E-mail:laser@hbu.edu.cn 通信作者:赵亚军(1978—),男,河北邢台人,河北大学实验师,主要从事光电材料与器件的测试.E-mail:hbuzyj@126.com第2期李晓苇等:染料敏化太阳能电池过渡金属氮化物对电极研究进展nitride and flexible transition metal nitride can be the future direction of development.

Design and simulation of the finite-time observer of induction motor rotor flux

LI Jie, GUO Haijun, HUANG Yanbin, WU Xiaojing

2019, 39(2):  132-136.  DOI: 10.3969/j.issn.1000-1565.2019.02.004

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To solve the problem of observing rotor flux of the induction motor, based on the mathematic model of induction motor and the theory of finite-time, the state equation of induction motor is established and the finite time observer is designed by taking the stator current and rotor flux linkage as the state parameters of the system. In addition, the observation of the flux state is realized by making the observation error converge to a given boundary in a limited time and further converge to zero. Finally, based on the linear matrix inequality(LMI)approach, the gain value of the state observer is developed, and the finite time observation of the flux is realized by computer simulation, which further verifies the validity of the proposed design method.

Simultaneous determination of four organic acids in Mussaenda pubescens by QAMS

ZHANG Qianhua, LIN Queyue, ZHU Tao, HE Songhua, YANG Tao, ZHAO Lichun

2019, 39(2):  137-143.  DOI: 10.3969/j.issn.1000-1565.2019.02.005

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A method of quantitative analysis of multi-components by single-marker for the determination of organic acid content in the extract of Mussaenda pubescens is established, the application of the method for the quality control of the traditional Chinese medicine is discussed. Chlorogenic acid(3-caffeoylquinic acid), was used as the internal standard to establish the relative correction factors of isochlorogenic acid A(3,5-O-di-caffeoylquinic acid), isochlorogenic acid B(3,4-O-di-caffeoylquinic acid), and isochlorogenic acid C(4,5-O-di-caffeoylquinic acid),respectively. The external standard method and QAMS method were used to calculate four kinds of relative correction factors. The content of organic acids were determined and the relative error of the results of the two methods was compared. There is no significant difference between the two methods for the determination of four organic acid components in six different producing areas in Guangxi. The method of QAMS can be used to determine the content of four organic acids in Mussaenda Pubescens, and it shows good feasibility and high economic efficiency.

Local structure of colloid and hydrogen bonding fluids near a semipermeable vesical membrane

ZHANG Meng, YIN Luping, ZHAO Meng, WANG Qianqian, LI Jiangtao, GU Fang

2019, 39(2):  144-151.  DOI: 10.3969/j.issn.1000-1565.2019.02.006

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The structure of a solution consisting of colloid particles and hydrogen bonding(HB)fluid separated by a semipermeable vesical membrane was investigated. The semipermeable membrane allows the free passage of hydrogen bonding fluid but not colloid particles. Firstly, based on the density functional theory the grand potential of the system and the equilibrium density distribution of the fluids near the membrane were obtained. In addition, the effects of HB energy, HB functionality, bulk fluid density and the size ratio of two species on the local structure were also discussed. It was shown that the equilibrium density and local structure of the two components were closely related to these factors, and it was expected that the present results were helpful to reveal the local structure in the mesoscopic scale and the infiltration of biophysical processes.

Comparative analysis of three heavy metal elements in different parts of Schizonepeta tenuifolia Briq.

BU Yanyan,REN Hongmin,LIU Xiaohui,LIU Tinghui,ZHAO Yanyan

2019, 39(2):  152-158.  DOI: 10.3969/j.issn.1000-1565.2019.02.007

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The contents of lead(Pb), cadmium(Cd)and nickel(Ni)in different medicinal parts of Schizonepeta tenuifolia Briq.(STE)were determined. Meanwhile,the contamination status of STE was compared and analyzed.After pretreatment by wet digestion system,Pb, Cd and Ni were determined by graphite furnace atomic absorption spectrometry(GFAAS).2%NH₄H₂PO₄-1.67%Mg(NO₃)₂ were used as a matrix modifier to determine Pb and Cd; and 0.2%Pd(NO₃)₂-2%NH₄H₂PO₄ was used as a matrix modifier to determine Ni. The determination condition was as follows.The wavelengths of Pb,Cd,Ni were 283.3,228.8, and 232.0 nm; lamp currents were 10, 6,- DOI:10.3969/j.issn.1000-1565.2019.02.007荆芥不同部位3种重金属元素含量的比较分析步艳艳¹,任红敏²,刘晓慧²,刘廷辉³,赵燕燕¹(1.河北大学 药学院,河北省药物质量分析控制重点实验室,河北 保定 071002;2.中华人民共和国保定海关,河北 保定 071051;3.河北农业大学 植物保护学院,河北 保定 071001)摘 要:测定荆芥药材不同药用部位中铅(Pb)、镉(Cd)、镍(Ni)3种重金属元素的含量,比较分析荆芥不同部位的污染状况.对荆芥样品进行湿法消解,采用石墨炉原子吸收光谱法(GFAAS)测定样品中Pb、Cd、Ni含量,以质量分数2%磷酸二氢铵-1.67%硝酸镁作为基体改进剂测定Pb、Cd;以质量分数0.2%硝酸钯-2%磷酸二氢铵作为基体改进剂测定Ni.Pb、Cd、Ni的测定波长分别为283.3、228.8和232.0 nm,灯电流分别为10、6和25 mA;狭缝分别为0.7、0.7和0.2 L.Pb、Cd、Ni元素线性关系分别为Y=0.002 8X+0.002 7(r=0.998 9)、Y=0.034 8X+0.005 4(r=0.998 3)和Y=0.002 9X+0.004 3(r=0.998 4),回收率为98.2%~102.9%;荆芥梗中Pb、Cd和Ni的质量分数测定结果分别为0.55~0.95、0.05~0.11和0.1~1.22 mg/kg;荆芥穗质量分数测定结果分别为0.58~1.73、0.03~0.14和0.18~1.42 mg/kg.重金属元素Pb、Cd、Ni检测方法可靠,随着采收时间延长,重金属元素易由荆芥梗向荆芥穗中富集,为荆芥重金属限度质量标准制定以及临床用药部位的选择提供参考.关键词:荆芥梗;荆芥穗;重金属分布;原子吸收光谱法;Pb、Cd、Ni含量测定中图分类号:TKR917 文献标志码:A 文章编号:1000-1565(2019)02-0152-07Comparative analysis of three heavy metal elements in differentparts of Schizonepeta tenuifolia Briq.BU Yanyan¹,REN Hongmin²,LIU Xiaohui²,LIU Tinghui³,ZHAO Yanyan¹(1.Key Laboratory of Drug Quality Analysis and Control of Hebei Province,College of Pharmaceutical Sciences,Baoding 071002,China;2.Baoding Customs District P.R.China,Baoding 071051,China;3.College of Plant Protection,Agricultural University of Hebei,Baoding 071001,China)Abstract:The contents of lead(Pb), cadmium(Cd)and nickel(Ni)in different medicinal parts of Schizonepeta tenuifolia Briq.(STE)were determined. Meanwhile,the contamination status of STE was compared and analyzed.After pretreatment by wet digestion system,Pb, Cd and Ni were determined by graphite furnace atomic absorption spectrometry(GFAAS).2%NH₄H₂PO₄-1.67%Mg(NO₃)₂ were used as a matrix modifier to determine Pb and Cd; and 0.2%Pd(NO₃)₂-2%NH₄H₂PO₄ was used as a matrix modifier to determine Ni. The determination condition was as follows.The wavelengths of Pb,Cd,Ni were 283.3,228.8, and 232.0 nm; lamp currents were 10, 6,- 收稿日期:2018-09-20 基金项目:河北检验检疫局科技计划项目(HE2017K011); 河北省自然科学基金资助项目(H2013201203);河北省重点研发计划项目(17226404D) 第一作者:步艳艳(1992—),女,河北衡水人,河北大学在读硕士研究生,主要从事药学方面的研究.E-mail:1914172479@qq.com 通信作者:赵燕燕(1960—),女,天津市人,河北大学教授,主要从事药学以及将现代分离技术用于临床、药学、食品、环境等方面的研究工作.E-mail:zhaoyany606@163.com第2期步艳艳等:荆芥不同部位3种重金属元素含量的比较分析and 25 mA, respectively.Entrance slits were 0.7, 0.7, and 0.2 L, respectively.Calibration curves of three elements( Pb,Cd,Ni)were Y=0.002 8X+0.002 7(r=0.998 9),Y=0.034 8X+0.005 4(r=0.998 3),Y=0.002 9X+0.004 3(r=0.998 4),respectively.The recovery values were 98.2%-102.9%.The results of content determination of STE’s stem were 0.55-0.95,0.05-0.11 and 0.1-1.22 mg/kg, respectively. The results of content determination of STE’s ears were 0.58-1.73,0.03-0.14 and 0.18-1.42 mg/kg.The detection methods of heavy metal elements Pb, Cd and Ni are reliable. With the prolongation of harvest time, heavy metal elements are easily enriched from STE’s stem to STE’s ears. This paper provides a reference for the development of limit standards of heavy metals in STE and the selection of clinical drug sites.

Preparation and application of multifunctional waterborne aluminum pigment

TAO Chang, MA Zhiling, LIU Yuanbo, ZHANG Chunyan, XIE Fei

2019, 39(2):  159-165.  DOI: 10.3969/j.issn.1000-1565.2019.02.008

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SiO₂ encapsulated aluminum pigment(Al@SiO₂)is the most widely used waterborne metal pigment. However, Al@SiO₂ is still silvery and the anti-corrosion property in strong alkalinity and acidity media are limited. According to the characteristics of SnO₂, if SnO₂ is encapsulated on aluminum pigment, the waterborne aluminum pigment with superior corrosion resistance and photocatalytic activity would be obtained. Here, SnCl₄/isopropyl as precursor in isopropyl/H₂O at weak acidity media, the preparation principle of SnO₂ encapsulated aluminum pigment(Al@SnO₂)that used aluminum as core, SnO₂ as shell and Al(OH)₃ or Sn(OH)₂ as bridge were studied. The effect of preparation conditions on the anti-corrosion resistance, hue and photocatalytic activity of Al@SnO₂ were studied using optical microscopy, X-ray diffraction, anti-corrosion resistance and photocatalytic degradation efficiency test.

Species diversity of the fungus-beetle and its relationship with fungi

REN Guodong, JI Qiaoqiao

2019, 39(2):  166-174.  DOI: 10.3969/j.issn.1000-1565.2019.02.009

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Fungus-beetles use macrofungi as their nutrient source, and have evolved into rich species diversity. The species known worldwide are as many as 3 suborders, 16 superfamilies, 82 families, and 1 386 genera, over 8 000 species constituting a branch of complex insect diversity. These beetles have established complex interdependence with fungi because of feeding, and some species are closely related to human economic due to endangerment of mushroom agricultural production. Thus, this article mainly makes a preliminary overview of the domestic and international research status based on the literature information, bring attention to our country’s academic community to the survey and classification of the fungus-beetles resources.

Community composition and dynamic of bird in the airport

WU Tingting,WANG Yihong,REN Hongxin,GAO Lijie, HOU Jianhua

2019, 39(2):  175-182.  DOI: 10.3969/j.issn.1000-1565.2019.02.010

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In order to reduce the bird strike at airport, the bird community and dynamic in the southern airport of Hebei Province were studied by using the route survey in April 2017 to March 2018. The results showed that:66 species of birds belonging to 29 families and 12 orders were recorded, the density, activity frequency and Shannon-Weiner diversity index(H')of Passeriformes were the highest. In terms of spatial dynamic distribution, bird in various regions showed significant differences in species number, density, activity frequency, diversity index and Pielou evenness index(E)(P<0.05). Species number and activity frequency of sample area 4 were the highest; the bird density, diversity index and evenness index were the largest in the sample area 6. The similarity coefficients(S)of sample area 1 and sample area 4 were the highest. There were no significant differences in species number, density, activity frequency and evenness index among different seasons(P>0.05), but there was significant differences in diversity index(P<0.05). The highest species number was found in spring, diversity index and evenness index were the highest in spring and autumn, density and activity frequency were the highest in summer and winter, the- DOI:10.3969/j.issn.1000-1565.2019.02.010机场鸟类群落的组成与动态吴婷婷¹,王义弘¹,任洪新¹,高立杰²,侯建华¹(1. 河北大学 生命科学学院,河北 保定 071002;2. 河北农业大学 动物科技学院,河北 保定 071001)摘 要:为了减少机场鸟撞事故的发生,2017年4月至2018年3月,采用样线法对河北南部机场鸟类群落与动态进行了研究.结果显示:共记录鸟类12目29科66种,雀形目(Passeriformes)鸟类的密度、活动频率和Shannon-Weiner多样性指数(H')最高.在空间动态分布上,各样区的鸟类在物种数量、密度、活动频率、多样性指数和Pielou均匀性指数(E)上均存在着显著性差异(P<0.05),其中样区4的鸟类物种数和活动频率最高;样区6的鸟类密度、多样性指数和均匀性指数最大;样区1和样区4的相似性系数(S)最高.在季节动态分布上,各季节的鸟类在物种数量、密度、活动频率和均匀性指数上差异性不显著(P>0.05),但是在多样性指数上存在着显著性差异(P<0.05).春季鸟类物种数最高;春季和秋季鸟类多样性指数、均匀性指数最高;夏季和冬季鸟类密度、活动频率最高;春夏两季的相似性系数最高.因此,根据此特点和机场生境,结合对机场有威胁的29种鸟类,提出有关鸟类防治对策.关键词:机场;鸟类;群落组成;动态中图分类号:TK513 文献标志码:A 文章编号:1000-1565(2019)02-0175-08Community composition and dynamic of bird in the airportWU Tingting¹,WANG Yihong¹,REN Hongxin¹,GAO Lijie², HOU Jianhua¹(1. College of Life Sciences, Hebei University, Baoding 071002, China;2. College of Animal Science and Technology, Agricultural University of Hebei, Baoding 071001, China)Abstract:In order to reduce the bird strike at airport, the bird community and dynamic in the southern airport of Hebei Province were studied by using the route survey in April 2017 to March 2018. The results showed that:66 species of birds belonging to 29 families and 12 orders were recorded, the density, activity frequency and Shannon-Weiner diversity index(H')of Passeriformes were the highest. In terms of spatial dynamic distribution, bird in various regions showed significant differences in species number, density, activity frequency, diversity index and Pielou evenness index(E)(P<0.05). Species number and activity frequency of sample area 4 were the highest; the bird density, diversity index and evenness index were the largest in the sample area 6. The similarity coefficients(S)of sample area 1 and sample area 4 were the highest. There were no significant differences in species number, density, activity frequency and evenness index among different seasons(P>0.05), but there was significant differences in diversity index(P<0.05). The highest species number was found in spring, diversity index and evenness index were the highest in spring and autumn, density and activity frequency were the highest in summer and winter, the- 收稿日期:2018-09-19 基金项目:机场鸟撞综合防治研究项目(2017-2018);河北大学自然科学研究计划项目( 2014-299 ) 第一作者:吴婷婷(1994—),女,山西临汾人,河北大学在读硕士研究生.E-mail:673213638@qq.com 通信作者:侯建华(1968—),男,河北保定人,河北大学教授,博士,主要从事动物生态学研究.E-mail:13633325718@163.com第2期吴婷婷等:机场鸟类群落的组成与动态highest similarity coefficient in spring and summer. Therefore, according to the characteristic and airport habitat, and 29 kinds of birds threatening the airport, a bird control strategy can be proposed.

Enhancing effect of mushroom activating enzymes on Lentinus edodes

ZHANG Heying, LUO Junmian,YUAN Erying, GENG Liduo, WU Jinxia

2019, 39(2):  183-187.  DOI: 10.3969/j.issn.1000-1565.2019.02.011

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The influence of mushroom activating enzymes on mycelium growth cycle,mycelium extracellular enzyme activity,physical and chemical indicators of cultivation material,biological efficiency and nutrient content of the Lentinus edodes fruiting body were studied during the fruiting body growth stage when 0.2% of mushroom activating enzymes were added in culture and the solid strains were inoclulated into the culture.The results showed that the time of mycelium growing full of the bags was 70 days, being shortened by 15 days compared with control.The cellulase、protease and amylase activity of mycelium in the mushroom activating enzymes group increased continuously during the colour changing period and the enzyme activities were significantly higher than that of control.After fruiting, the L. edodes fruiting body were collected and analyzed.The biological efficiency of the mushroom activating enzymes group achieved 96.75%,21.99% higher than that of control.The nutrient content was slightly higher than that of control,however,there was no significant difference between the two groups.

Design of solar heating system combined with wall-mounted gas boiler

FANG Lide, CHEN Xingtong,WANG Dongxing,XIE Chen, ZHANG Chen

2019, 39(2):  188-193.  DOI: 10.3969/j.issn.1000-1565.2019.02.012

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In this paper, a solar energy and natural gas combined heating system is designed. The structure and circuit design of the control device are discussed in detail. The system is equipped with temperature sensors, circulating water pumps and valves. The temperature values of each point of the pipeline are measured by single chip computer control system, according to distinguish different working modes, the system can circulate cold and hot water and enhance heat transfer based on the pre-designed program, thus realizing the combination of the solar energy and natural gas heating systems. Through simulating different working conditions and testing, the results show that the expected effect has been achieved. The system can automatically switch the heat source through program control, and the water temperature provided by the heating device meets the specified requirements, The goal of energy saving and emission reduction has been achieved.

Optimized LEACH protocol based on distance and energy of cluster head

CHANG Tieyuan, LIU Weina, ZHANG Yan, LI Huiya

2019, 39(2):  194-200.  DOI: 10.3969/j.issn.1000-1565.2019.02.013

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The LEACH routing protocol balances the network energy consumption by selecting cluster heads circularly and randomly. However, when the selected cluster head has less residual energy or is far away from the base station, it will die prematurely, resulting in unstable network operation. We can improve it by considering the mean and standard deviation of residual energy of the node and the distance between the node and the base station. This can improve the stability of the network. But it will shorten the network lifetime if there are extremely large or small clusters. Aiming at this problem, an optimized LEACH protocol based on distance and energy of cluster head is proposed. It can optimize the clustering process by adding the residual energy of cluster head and distance between member nodes and cluster heads. The simulation results with MATLAB show that the improved algorithm can effectively prolong the network lifetime based on the improvement of network stability in the network with uniform distribution of nodes.

K-nearest neighbor algorithm for big data classification based on Spark and SimHash

ZHAI Junhai, SHEN Chu, ZHANG Sufang, WANG Tingting

2019, 39(2):  201-210.  DOI: 10.3969/j.issn.1000-1565.2019.02.014

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In our previous work, based on MapRecuce and SimHash, we proposed a K-Nearest Neighbor(K-NN)algorithm denoted by H-MR-K-NN for big data classification. Although H-MR-K-NN can effectively solve the computational efficiency problem of K-NN for big data classification, and the running time of H-MR-K-NN is far lower than the one of MapRecuce K-NN denoted by MR-K-NN. However, when one handles big data with MapReduce, it is inevitable to read data from disk and to write the intermediate result back to disk, which results in huge I/O overhead and greatly degenerates the efficiency of MapReduce. Different from MapReduce, Spark is a memory-based computing framework that reads data into memory from disk first and then generates an abstract memory object RDD(resilient distributed datasets). Therefore,Spark only manipulates RDD in memory, and the- DOI:10.3969/j.issn.1000-1565.2019.02.014基于Spark和SimHash的大数据K-近邻分类算法翟俊海¹,沈矗¹,张素芳²,王婷婷¹ (1. 河北大学 数学与信息科学学院 河北省机器学习与计算智能重点实验室,河北保定 071002;2. 中国气象局气象干部培训学院 河北分院,河北 保定 071000)摘 要: 在笔者之前的工作中,提出了一种基于MapReduce和SimHash的大数据K-近邻算法(H-MR-K-NN).虽然该算法能够有效解决大数据K-近邻算法的计算效率问题,运行时间远远低于基于MapReduce的K-近邻(MR-K-NN)所用的运行时间.然而,用MapReduce处理大数据时,需要从磁盘读取数据,再将中间结果写回磁盘,导致系统的I/O开销极大,这大大降低了MapReduce的效率.与MapReduce不同,Spark是一种基于内存的计算框架,它将数据第1次从磁盘读入内存,生成一种抽象的内存对象RDD(resilient distributed datasets).此后,Spark只操作内存中的RDD,计算过程只涉及内存读写,因此大幅提升了数据处理效率.基于这一事实,对算法H-MR-K-NN进行了改进,提出了一种改进的算法(简记为H-Spark-K-NN),可以进一步提高大数据K-近邻分类的运行效率.关键词:内存计算框架;K-近邻;哈希技术;分类算法;大数据集中图分类号:TP181 文献标志码:A 文章编号:1000-1565(2019)02-0201-10K-nearest neighbor algorithm for big data classification based onSpark and SimHashZHAI Junhai¹, SHEN Chu¹, ZHANG Sufang², WANG Tingting¹(1. Key Laboratory of Machine Learning and Computational Intelligence of Hebei Province, College of Mathematics and Information Science, Hebei University, Baoding 071002, China; 2. Hebei Branch of ChinaMeteorological Administration Training Centre, China Meteorological Administration, Baoding 071000, China)Abstract:In our previous work, based on MapRecuce and SimHash, we proposed a K-Nearest Neighbor(K-NN)algorithm denoted by H-MR-K-NN for big data classification. Although H-MR-K-NN can effectively solve the computational efficiency problem of K-NN for big data classification, and the running time of H-MR-K-NN is far lower than the one of MapRecuce K-NN denoted by MR-K-NN. However, when one handles big data with MapReduce, it is inevitable to read data from disk and to write the intermediate result back to disk, which results in huge I/O overhead and greatly degenerates the efficiency of MapReduce. Different from MapReduce, Spark is a memory-based computing framework that reads data into memory from disk first and then generates an abstract memory object RDD(resilient distributed datasets). Therefore,Spark only manipulates RDD in memory, and the- 收稿日期:2018-10-15 基金项目:河北省自然科学基金资助项目(F2017201026);河北大学自然科学研究计划项目(799207217071);河北大学研究生创新项目(hbu2018ss47);河北省研究生专业学位教学案例库建设项目(KCJSZ2018009) 第一作者:翟俊海(1964—),男,河北易县人,河北大学教授,博士,主要从事云计算与大数据处理和机器学习方向研究.E-mail:mczjh@hbu.cn 通信作者:张素芳(1966—),女,河北蠡县人,中国气象局气象干部培训学院副教授,主要从事机器学习方向研究.E-mail:mczsf@126.com第2期翟俊海等:基于Spark和SimHash的大数据K-近邻分类算法calculation process involves only memory reads and writes. Consequently, it greatly improves efficiency of data processing. Based on this fact, we improved the algorithm H-MR-K-NN, and proposed an improved algorithm denoted shortly by H-Spark-K-NN which can further improve the efficiency of K-NN for big data classification.

Detection algorithm of tea tender buds under complex background based on deep learning

SUN Xiaoxiao, MU Shaomin, XU Yongyu, CAO Zhihao, SU Tingting

2019, 39(2):  211-216.  DOI: 10.3969/j.issn.1000-1565.2019.02.015

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The traditional tea bud detection method based on machine vision has the problems of poor robustness and low accuracy in manual feature extraction. The target detection algorithm YOLO based on deep learning is applied to the detection of tea tender image under complex background for the first time, and the architecture of YOLO network is improved from the aspect of multi-scale detection, using large-scale and mesoscale detection instead of the original multi-scale detection. In the preprocessing stage, the image of tea shoots under complex background is segmented by combining the super green feature and the OSTU algorithm, which makes the tea tender bud area more obvious. The experimental results show that, by comparing with other algorithms, the target detection algorithm based on deep learning has a high detection precision for the tea tender shoots under complex background, which provides a basis for the research of intelligent picking equipment for tea tender shoots under complex background.

Application of DNA barcode on survey of zooplankton in Baiyangdian Watershed

ZHANG Meng,SUN Xiaoqiong, FANG Nan,CAO Zhihan, WANG Hongwei

2019, 39(2):  217-224.  DOI: 10.3969/j.issn.1000-1565.2019.02.016

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DNA barcode has been effectively used in identification of species, for taxonomy also biodiversity research. This study constructs phylogenetic trees,which based on mitochondrial COI gene sequences, using adjacency method(neighbor joining method, NJ)and maximum likelihood method(maximum likelihood, ML). It was a preliminary study on the acquisition of zooplankton samples in Baiyangdian Watershed in May 2018. The results showed that the phylogenetic tree analysis of copepods, NJ tree and the tree of ML is consistent with the results of morphological identification results. On the tree branch angle of system development analysis, the result of the NJ tree and ML tree was also different with the result of morphological identification. The reason may be due to the stitching part cut short sequences, the sequence error caused by smaller differences. Overall, based on the COI gene, DNA barcode can be effectively applied to zooplankton in Baiyangdian Watershed and it can gradually improve the identification and finally to create a complete DNA barcode database.