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    25 November 2020, Volume 40 Issue 6
    A nonmonotone flexible filter method for minimax problems
    SU Ke, LIN Yumeng, LI Xiaochuan
    2020, 40(6):  561-568.  DOI: 10.3969/j.issn.1000-1565.2020.06.001
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    A nonmonotone flexible filter method for minimax problems is proposed. This new method has more flexibility for the acceptance of the trial step compared to the traditional filter methods, and requires less computational costs compared with the monotone-type methods. Moreover, we use a self-adaptive parameter to adjust the acceptance criteria, so that Maratos effect can be avoided to a certain degree. Under reasonable assumptions, the proposed algorithm is globally convergent. Numerical tests are presented that confirm the efficiency of the approach.
    Effects of the prestressed tension friction loss for the suspended dome structure
    QIE Luwen, XU Chenyu, LIU Jing, ZHAO Ruoxu, CHEN Zongxue
    2020, 40(6):  569-577.  DOI: 10.3969/j.issn.1000-1565.2020.06.002
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    When tension cable is used to apply prestress to the suspended-dome structure, the determination of prestress loss value caused by sliding friction at the cabl-strut joint is one of the important contents in the structure forming theory. In this paper, the suspended-dome of Hebei North University gymnasium is taken as the research object. Based on the improved friction loss algorithm of freezing temperature cable, five calculation models of friction coefficient of cable-strut joints are established, which are 0.03, 0.1, 0.2, 0.3 and 0.4. The influence of sliding friction of cable-strut joints on internal force and deformation of cable-strut dome structure is explored. The results show that: in the whole process of tension,- DOI:10.3969/j.issn.1000-1565.2020.06.002弦支穹顶结构预应力张拉摩擦损失影响分析郄禄文1,徐辰昱1,刘静1,赵若旭1,陈宗学2( 1.河北大学 建筑工程学院,河北 保定 071002;2.河北建设集团股份有限公司 钢结构分公司,河北 保定 071052)摘 要:弦支穹顶结构采用张拉环索方式施加预应力时,在索撑节点处因滑移摩擦产生预应力损失值大小的确定是结构成形理论中重要内容之一.以河北北方学院体育馆弦支穹顶屋盖为研究对象,基于改进的冷冻升温环索预应力摩擦损失算法,建立索撑节点摩擦因数为0.03、0.1、0.2、0.3、0.4的5种计算模型,探究索撑节点滑移摩擦大小对弦支穹顶结构内力及变形等参数的影响.研究结果表明:弦支穹顶结构张拉全过程中,取5种不同摩擦因数时各圈环索预应力变化趋势基本一致;结构第1~2两内圈环索因相邻索段间夹角较小使得索撑节点处滑移摩擦力增加,导致索撑节点平均预应力损失分别高达20.50%、15.19%,此值均大于取相同摩擦因数时的3~5圈环索;下部索撑体系的撑杆和拉杆最大应力随摩擦因数增加均逐渐增大且皆出现在屋盖短轴两端;索撑节点摩擦因数取值大小不影响上部网壳竖向位移分布规律,且对网壳下凹和上凸最大位移值影响很小;上部网壳采用类圆角矩形拓扑结构导致网壳节点竖向位移在张拉过程中,位于第3圈环索以内沿环向和径向上凸且呈均匀对称发展,周边支座至第3圈环索区域的网壳节点位移由长、短轴两端上凸向45°方向逐渐凹陷.关键词:弦支穹顶;预应力损失;摩擦因数;网壳中图分类号:TU984.2 文献标志码:A 文章编号:1000-1565(2020)06-0569-09Effects of the prestressed tension friction loss for the suspended dome structureQIE Luwen1, XU Chenyu1, LIU Jing1, ZHAO Ruoxu1, CHEN Zongxue2(1. College of Civil Engineering and Architecture, Hebei University, Baoding 071002, China;2. Steel Structure Branch, Hebei Construction Group Corporation Limited, Baoding 071052, China)Abstract: When tension cable is used to apply prestress to the suspended-dome structure, the determination of prestress loss value caused by sliding friction at the cabl-strut joint is one of the important contents in the structure forming theory. In this paper, the suspended-dome of Hebei North University gymnasium is taken as the research object. Based on the improved friction loss algorithm of freezing temperature cable, five calculation models of friction coefficient of cable-strut joints are established, which are 0.03, 0.1, 0.2, 0.3 and 0.4. The influence of sliding friction of cable-strut joints on internal force and deformation of cable-strut dome structure is explored. The results show that: in the whole process of tension,- 收稿日期:2019-12-27 基金项目:河北省自然科学基金资助项目(E2017201158);河北省高等学校科学技术研究项目(QN2016171);2016年“一省一校”专项经费资助项目 第一作者:郄禄文(1966—),男,河北阜平人,河北大学教授,博士,主要从事结构可靠度理论分析研究. E-mail:qieluwen@hbu.edu.cn 通信作者:刘静(1981—),女,内蒙古赤峰人,蒙古族,河北大学讲师,博士,主要从事钢结构与空间结构研究. E-mail:cimeng2005@163.com第6期郄禄文等:弦支穹顶结构预应力张拉摩擦损失影响分析when five different friction coefficients are taken, the change trend of the prestressing force of each ring of cable is basically the same. The angle of adjacent cable located on the first and second rings of the structure is smaller, which results in the average prestress loss of the cable-strut joints as high as 20.50% and 15.19%, respectively, which is greater than 3~5 rings of the same friction coefficient; with the increasing of friction coefficient, the maximum stress of struts and tention members in the lower cable support system increases gradually and appears at both ends of the roofs short shaft; the value of friction coefficient of cable-strut joint does not affect the vertical displacement distribution of the upper shell, and has little influence on the maximum displacement of the concave and convex of the shell. In the process of tension, the topological structure of rectangle like fillet is adopted in the upper shell, which causes the vertical displacement of the grid shell node located in the third ring of the cable, runs convexly along the ring and radial direction, and develops in a uniform and symmetrical way. The displacement of the grid shell node from the peripheral support to the third ring of the cable area run gradually concavely from the long axis and the short axis to the 45° direction.
    Rutting prediction of asphalt concrete pavement based on COMSOL
    GAO Yu, TENG Xuqiu
    2020, 40(6):  578-584.  DOI: 10.3969/j.issn.1000-1565.2020.06.003
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    This paper simulates the creep of matrix asphalt pavement and high modulus asphalt pavement under high temperature field. With the help of COMSOL software, temperature field and temperature induced creep model are introduced to conduct thermal radiation and solid mechanics coupling effect on matrix asphalt concrete pavement and HMAC pavement. The permanent deformation of matrix asphalt concrete pavement and HMAC pavement is analyzed and compared under vehicle load. The influence of external environment temperature, solar radiation and vehicle load on the development of rutting deformation is studied. It can accurately predict the depth of pavement rutting, study and analyze the creep deformation caused by rutting, put forward reasonable prevention measures for pavement rutting, reduce the permanent deformation of pavement, provide reference value for pavement material selection and structure optimization, and extend the service life of asphalt pavement.
    Optical properties of CsPbI3 quantum dots in different polar solvents
    SUN Chunyu, LI Jing, WANG Xinzhan, GUO Chengsuo, YU Wei
    2020, 40(6):  585-590.  DOI: 10.3969/j.issn.1000-1565.2020.06.004
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    All-inorganic perovskite CsPbI3 quantum dots have the characteristics of narrow emission spectrum lines, high fluorescence quantum yield, and strong stability. They have broad application prospects in the fields of red LEDs and new solar cells. In this paper, CsPbI3 quantum dots were synthesized in n-hexane solvent by hot injection method, and their structure and optical characteristics were characterized. The results show that the main light-emitting mechanism of quantum dots is free exciton recombination in the weak quantum confinement region. The optical properties of the quantum dots were adjusted by changing the type of solvent(n-hexane, toluene, ethyl acetate, methyl acetate). It was found that the luminescence peak position shifted from 615 to 660 nm as the polarity of the solvent increased. This is because the polar solvent has a modification effect on the surface of the quantum dots, and the conditions for adjusting the emission peak position of CsPbI3 quantum dots by changing the polarity of the solution provide an experimental reference for the preparation of wavelength-tunable photovoltaic devices.
    Effects of crosslinking point functionality and network entanglement on buckling instability of hydrogel films
    LI Tao, YANG Qingsheng
    2020, 40(6):  591-596.  DOI: 10.3969/j.issn.1000-1565.2020.06.005
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    The research on the buckling instability of hydrogel films has been the focus of the application of hydrogel films. In this paper, effects of topological network structure of hydrogels and network entanglement effect of polymer network that constitutes hydrogels on large coupling deformation of hydrogels are taken into account. A free energy equation combining the slip-link model proposed by Edwards-Vilgis with Flory-Huggins theory is introduced to demonstrate the real influence of polymer network on large deformation of hydrogels in the chemo-mechanical coupling field. The critical stress and wavelength of unidirectional nonlinear buckling of two-dimensional hydrogel films were solved by analytical method, and the influence of the microstructure of polymer network that constitutes hydrogels on the buckling of hydrogel films under different external solution environment conditions was discussed.- DOI:10.3969/j.issn.1000-1565.2020.06.005交联点官能度和网络缠结效应对凝胶薄膜屈曲失稳的影响李涛,杨庆生(北京工业大学 机械工程与应用电子技术学院,北京 100124)摘 要:对于响应型水凝胶薄膜屈曲失稳行为的研究一直是水凝胶薄膜应用中的重点.本文考虑水凝胶拓扑网络结构以及构成水凝胶的高分子网络缠结效应凝胶耦合大变形中的影响,引入了一种将Edwards-Vilgis的slip-link模型与Flory-Huggins理论相结合的自由能方程,旨在还原水凝胶在化学-力学耦合场作用下发生大变形时真实高分子网络的作用.通过解析方法求解了二维水凝胶薄膜单向非线性屈曲的临界应力和波长,探讨了外部溶液环境变化时,构成水凝胶的高分子网络微结构对凝胶薄膜屈曲的影响.结果表明:水凝胶的微结构参数在较小数值变化时对水凝胶增量模量以及凝胶薄膜屈曲的临界应力和波长有显著影响,当微结构参数不断变大这种影响逐渐减弱.关键词:水凝胶薄膜;屈曲;化学-力学耦合;解析解中图分类号:O345 文献标志码:A 文章编号:1000-1565(2020)06-0591-06Effects of crosslinking point functionality and network entanglement on buckling instability of hydrogel filmsLI Tao, YANG Qingsheng(College of Engineering Mechanics, Beijing University of Technology, Beijing 100124, China)Abstract: The research on the buckling instability of hydrogel films has been the focus of the application of hydrogel films. In this paper, effects of topological network structure of hydrogels and network entanglement effect of polymer network that constitutes hydrogels on large coupling deformation of hydrogels are taken into account. A free energy equation combining the slip-link model proposed by Edwards-Vilgis with Flory-Huggins theory is introduced to demonstrate the real influence of polymer network on large deformation of hydrogels in the chemo-mechanical coupling field. The critical stress and wavelength of unidirectional nonlinear buckling of two-dimensional hydrogel films were solved by analytical method, and the influence of the microstructure of polymer network that constitutes hydrogels on the buckling of hydrogel films under different external solution environment conditions was discussed.- 收稿日期:2020-03-02 基金项目:国家自然科学基金资助项目(11572109;11632005);河北省自然科学基金资助项目(11572109);河北省高校技术研究项目(ZD2017006) 第一作者:李涛(1989—),男,河北保定人,北京工业大学在读博士,主要从事智能软材料多物理场耦合行为研究. E-mail:1047427142@emails.bjut.edu.cn 通信作者:杨庆生(1962—),男,河北故城人,北京工业大学教授,博士,主要从事智能软材料多物理场耦合行为研究.E-mail:qsyang@bjut.edu.cn第6期李涛等:交联点官能度和网络缠结效应对凝胶薄膜屈曲失稳的影响The results show that the microstructure parameters of hydrogels have a significant influence on the incremental modulus of hydrogels and the critical stress and wavelength of the buckling of hydrogel firms when the value change of parameter is small.
    Effect of boron content on magnetic properties of amorphous alloy Co-Ni-B
    FANG Zhigang, QIN Yu, ZHANG Wei, LIAO Wei, XU You
    2020, 40(6):  597-605.  DOI: 10.3969/j.issn.1000-1565.2020.06.006
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    In order to explore the effect of different B content on the magnetic properties of amorphous alloy Co-Ni-B system, based on the existing Co-Ni atomic ratio, different B atom numbers were selected to construct the cluster Co3NiB and cluster Co3NiB2. Based on density functional theory method, the cluster models were constructed under the level of B3LYP/Lanl2dz by using the Gaussian09 and Multiwfn programs. By analyzing the number of unpaired electrons and density-of-states maps of s, p and d orbitals in different cluster models, it is found that regardless of the single-boron model or the double-boron model, the magnetic properties of clusters are mainly determined by the spin-up alpha electron in d orbitals. After analyzing the density-of-states maps, it is revealed that the alpha and beta electrons could convert to each other under certain conditions, and energy for the convention is different in different orbitals. From the perspective of electron spin density, the results show that in all configurations, the electrons of s orbitals will change spin direction somewhere, but not in d orbitals. The p orbitals electrons that have never been explored will change spin direction somewhere, which can convincingly prove and supplement the conclusions of Stern-Gerlach experiment from a theoretical perspective.- DOI:10.3969/j.issn.1000-1565.2020.06.006硼元素含量对非晶态合金Co-Ni-B磁性的影响方志刚,秦渝,张伟,廖薇,许友(辽宁科技大学 化学工程学院,辽宁 鞍山 114051)摘 要:为探究不同B元素含量对非晶态合金Co-Ni-B体系磁学性质的影响,在已有Co-Ni原子比例基础上分别构建出单硼模型Co3NiB与双硼模型Co3NiB2.基于密度泛函理论在B3LYP/Lanl2dz水平下运用Gaussian09和Multiwfn程序对各团簇模型进行相关理论计算,通过着重分析不同团簇模型s、p、d轨道上未成对电子数和态密度图发现,无论是单硼模型还是双硼模型,团簇的磁性均主要由d轨道中自旋向上的α成单电子贡献;仔细研究团簇的态密度图发现,α电子与β电子在一定条件下可以相互转化,且针对不同的轨道使电子自旋方向发生改变的能量值不同;从电子自旋态密度入手对团簇进行分析发现,所有构型s轨道一定会在某处发生电子自旋方向的改变,d轨道则无此现象,而从未被探究过的p轨道同s轨道一样,其上电子的自旋方向一定会在某处发生改变,这从理论上对Stern-Gerlach实验的结论进行了有力的论证与补充.关键词:非晶态合金Co-Ni-B;硼元素含量;态密度;磁学性质;Stern-Gerlach实验;密度泛函理论中图分类号:O641.12 文献标志码:A 文章编号:1000-1565(2020)06-0597-09Effect of boron content on magnetic properties of amorphous alloy Co-Ni-BFANG Zhigang, QIN Yu, ZHANG Wei, LIAO Wei, XU You(School of Chemical Engineering,University of Science and Technology Liaoning,Anshan 114051,China)Abstract: In order to explore the effect of different B content on the magnetic properties of amorphous alloy Co-Ni-B system, based on the existing Co-Ni atomic ratio, different B atom numbers were selected to construct the cluster Co3NiB and cluster Co3NiB2. Based on density functional theory method, the cluster models were constructed under the level of B3LYP/Lanl2dz by using the Gaussian09 and Multiwfn programs. By analyzing the number of unpaired electrons and density-of-states maps of s, p and d orbitals in different cluster models, it is found that regardless of the single-boron model or the double-boron model, the magnetic properties of clusters are mainly determined by the spin-up alpha electron in d orbitals. After analyzing the density-of-states maps, it is revealed that the alpha and beta electrons could convert to each other under certain conditions, and energy for the convention is different in different orbitals. From the perspective of electron spin density, the results show that in all configurations, the electrons of s orbitals will change spin direction somewhere, but not in d orbitals. The p orbitals electrons that have never been explored will change spin direction somewhere, which can convincingly prove and supplement the conclusions of Stern-Gerlach experiment from a theoretical perspective.- 收稿日期:2020-01-10 基金项目:国家自然科学基金重点资助项目(51634004);国家级大学生创新创业训练计划(202010146009;202010146016);辽宁省大学生创新创业训练计划(202010146015;202010146052;202010146059) 第一作者:方志刚(1964—),男,辽宁鞍山人,辽宁科技大学教授,博士生导师,主要从事量子化学、物理化学及表面催化方面研究.E-mail:lnfzg@163.com第6期方志刚等:硼元素含量对非晶态合金Co-Ni-B磁性的影响
    Preparation of carbon quantum dot fluorescence probe with prickly ash and detection of acetylcholine in milk
    LI Zhiying, DUAN Yaqin, ZHANG Hui, LEI Jiaxi
    2020, 40(6):  606-611.  DOI: 10.3969/j.issn.1000-1565.2020.06.007
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    Fluorescent carbon quantum dots(CDs)were prepared from edible prickly ash by pyrolysis method and CDs was further modified β-CD. The optical properties and macroscopic features of CDs were respectively characterized by fluorescence spectroscopy and transmission electron microscopey(TEM). The results showed that the wavelength of fluorescence excitation and emission were at 315 nm and 429 nm, respectively. The fluorescence quantum yield was 0.60 and the average diameter of the carbon dots was 4.2 nm. Owing to acetylcholine bromide can sensitize the fluorescence of carbon quantum dots, it can be used for the analysis and detection of acetylcholine bromide in milk. With the pH7.0 and the temperature is 25 ℃, the fluorescence intensity is proportional to the amount of acetylcholine bromide, the linear regression equation is ΔF=314.72c+134.54, the linear range is from 0.08 to 1.6 μmol/L, r=0.997 9, the standard deviation is 1.75, and the detection limit is 1.62×10-8mol/L. This method was used to detect the acetylcholine content in milk and yogurt, and the recovery rate is between 98% and 102%.
    Analysis of mineral elements in longyao jitui onions
    WANG Tingxin, XIAO Meng,SHI Mengfan,ZHAO Jie,LIU Zhenghao
    2020, 40(6):  612-617.  DOI: 10.3969/j.issn.1000-1565.2020.06.008
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    Longyao jitui onion and Laiwu jitui onion are geographical indication products. In order to explore the mineral content in Longyao jitui onion. Analysis of mineral element content of Laiwu jitui onion as control and Longyao chicken leg onion. The content of K, Ca, Na, Mg, Cu, Fe, Mn, Zn in geographical indication products Longyao jitui onion, Laiwu jitui onion and their corresponding soil were analyzed by flame atomic absorption spectrometry. The results showed that the content of essential mineral elements(Ca, K, Mg, etc.)in Longyao jitui onion was significantly higher than that in Laiwu jitui onion. The standard curves of 8 kinds of mineral elements show good linear correlation, with correlation coefficient R2 >0.997 8. The precision is 0.90%—3.61%, and the recovery is 88.86%—105.56%.There is a significant correlation between 8 mineral elements in Longyao jitui onion and the corresponding soil mineral elements. There is a significant positive correlation between the content of Ca, Mg, Fe, Cu and the corresponding elements in Longyao jitui onion. The results of this study will provide a scientific basis for the cultivation of Longyao jitui onion.
    Microwave mutagenesis of Monascus purpureus and optimization of fermentation conditions for Monascus pigment production
    WU Jinxia, WANG Yan, TAN Zhenghao, LIU Shuang, SUI Siqiang, ZHANG Heying
    2020, 40(6):  618-624.  DOI: 10.3969/j.issn.1000-1565.2020.06.009
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    The microwave mutagenesis was carried out when Monascus purpureus S1 was used as the original strain. M.purpureus S1-29 was screened with the highest Monascus pigment value of 3 240 U/g dry base, which was increased by 57% compared with that of the original strain. The conditions for the production of Monascus pigment by solid-state fermentation of strain S1-29 were optimized. The effects of carbon sources, nitrogen sources and inorganic salts on pigment production were investigated and orthogonal experiments were carried out. The results showed that when 4% glucose, 6% peptone, 0.4% magnesium sulfate and 0.3% dipotassium hydrogen phosphate were added into the rice media and cultured at 32 ℃ for 11 days, the Monascus pigment value of M.purpureus S1-29 reached 4 003 U/g dry base, which was increased by 23.55% compared with that of control.
    Physiological changes of Phytophthora infestans caused by antagonistic bacterium HT-6
    HOU Ning, SHEN Fen, TIAN Huiyao, LI Chengbin, MENG Cuili, JIANG Jizhi
    2020, 40(6):  625-630.  DOI: 10.3969/j.issn.1000-1565.2020.06.010
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    In order to understand the inhibitory mechanism of endophytic bacterium HT-6 on Phytophthora infestans, the dual culture method combined with traditional methods were adopted to detect the changes of some active substances, resistant enzyme activities, electrical conductibility, and dissolved oxygen in P. infestans mycelia after inhibition by HT-6 at different times. The results showed that soluble sugar and starch contents increased, and protein content decreased in P. infestans in both treated and untreated groups with the prolonged culture, but the contents of three substances in treatment group were- DOI:10.3969/j.issn.1000-1565.2020.06.010拮抗菌HT-6引起致病疫霉菌体的生理变化侯宁1,申芬1,田荟遥1,李成斌1,孟翠丽2,蒋继志1(1. 河北大学 生命科学学院, 河北 保定 071002;2. 邢台医学高等专科学校 基础医学部,河北 邢台 054000)摘 要:为了解核桃内生细菌HT-6对致病疫霉的抑制作用机理,采用对峙培养和传统培养相结合的方法检测了受拮抗菌HT-6抑制不同阶段后致病疫霉菌丝体内部分活性物质、抗性相关酶活、电导率以及溶氧量的变化.结果显示,随对峙培养时间延长,受抑制组与对照组中致病疫霉菌丝体内可溶性糖和淀粉含量虽然均呈增加趋势,蛋白质含量均呈下降趋势,但受抑制组可溶性糖、淀粉及蛋白质含量均远低于对照组,且均在对峙培养第15天时差异最大(P<0.01);受抑制组和对照组菌丝体内苯丙氨酸解氨酶、多酚氧化酶和过氧化物酶3种酶活的变化趋势与上述3种物质的变化趋势相似,但均在培养的第12天达到最高,且受抑制组菌体内3种酶活均远高于对照组,与对照达到极显著差异(P<0.01).此外,受拮抗菌HT-6抑制后致病疫霉菌丝体内的电导率(162.77 μS/cm)显著高于对照组(60.03 μS/cm),而溶氧量(47.13%)显著低于对照组(56.1%).这些结果表明:HT-6菌株可通过抑制或大量消耗致病疫霉菌丝体内部分活性物质,同时增加细胞膜透性、降低呼吸作用实现对致病疫霉菌丝体生长的抑制作用.关键词:内生细菌;致病疫霉;生理变化;抑制作用中图分类号:S435.32 文献标志码:A 文章编号:1000-1565(2020)06-0625-06Physiological changes of Phytophthora infestans caused by antagonistic bacterium HT-6HOU Ning1, SHEN Fen1, TIAN Huiyao1, LI Chengbin1, MENG Cuili2, JIANG Jizhi1(1.School of Life Sciences, Hebei University, Baoding 071002,China; 2. Department of Basic Medicine, Xingtai Medical College, Xingtai 054000, China)Abstract: In order to understand the inhibitory mechanism of endophytic bacterium HT-6 on Phytophthora infestans, the dual culture method combined with traditional methods were adopted to detect the changes of some active substances, resistant enzyme activities, electrical conductibility, and dissolved oxygen in P. infestans mycelia after inhibition by HT-6 at different times. The results showed that soluble sugar and starch contents increased, and protein content decreased in P. infestans in both treated and untreated groups with the prolonged culture, but the contents of three substances in treatment group were- 收稿日期:2019-06-21 基金项目:河北省自然科学基金资助项目(C 2015201231);公益性(农业)行业科研专项(201303018) 第一作者:侯宁(1992—),女,山西盂县人,河北大学在读硕士研究生,主要从事植物与微生物相互作用的分子机理研究.E-mail:15930297278@163.com 通信作者:孟翠丽(1979—),女,河北巨鹿人,邢台医学高等专科学校讲师,主要从事生物化学研究. E-mail: mclant@163.com蒋继志(1960—),男,宁夏中宁人,河北大学教授,博士生导师,主要从事植物与微生物分子互作机理研究. E-mail:jizhijiang909@163.com第6期侯宁等:拮抗菌HT-6引起致病疫霉菌体的生理变化much lower than that in control group, and the maximum differences between treatment and control were found at 15th d after dual culture(P<0.01). The changes of PAL, PPO and POD activities in P. infestans in both treatment and control were similar to soluble sugar, starch, and protein, but all three enzyme activities reached peaks at 12th d for culture. And it was found that three enzyme activities in treated group were much higher than in control group at various culture times(P<0.01). In addition, the electrical conductivity in P. infestans mycelia inhibited by HT-6(162.77 μS/cm)was significantly higher than that in control(60.03 μS/cm), while the dissolved oxygen amount in treatment(47.13%)was significantly lower than that in control(56.1%). These findings suggest that the HT-6 strain inhibits P. infestans mycelia growth via preventing or consuming the partial active substances, and increasing cell membrane permeability and reducing respiration.
    Progress in research on the mechanism of norfloxacin on cytochrome P450 in aquatic organisms
    WANG Hongwei, CUI Tiefeng, ZHANG Meng, SUN Xiaoqiong,FANG Nan
    2020, 40(6):  631-636.  DOI: 10.3969/j.issn.1000-1565.2020.06.011
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    Main sources of antibiotics in the environment were detected in sewage, medical wastewater and aquaculture wastewater. In 2013, the weight of the total use of antibiotics in China was about 1.62×105 t, of which 48% were human antibiotics and the rest were veterinary antibiotics. A lot of them still have the activity of antibiotics. They were accumulated in rivers and lakes by the surface runoff, and urban sewage pipe in end. These active substances are harmful to aquatic organisms, especially over longer time spans, and this hazard will expand further. The article briefly outlined the research about the ecotoxicological effects of norfloxacin(NFLX)on some aquatic organisms in recent years, based on cytochrome P450(CYP450)as an indicator of detection. The influencing mechanism of NFLX on CYP450 as selected indicators was introduced, and the feasibility methods for testing these indicators was discussed.
    Distribution pattern and risk analysis of alien invasive animals in China
    CHEN Fengxin, MENG Yanliang, CHEN Mingqing, ZHANG Fengjuan
    2020, 40(6):  637-646.  DOI: 10.3969/j.issn.1000-1565.2020.06.012
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    Based on the reference that come from journals, monograph and related database and field investigation, the number of exotic plant and the trade data of 27 provinces(regions)in China were collected. The relationship between the number of exotic plants and the total imports and exports for each province(region)was analyzed. The model with the best fitting degree is selected as the prediction model and S-model was used to predict the total import and export of each province(region)from 2018 to 2021. Finally, the number of invasive plants in each province(region)was predicted and the increase in the number of invasive plants in each province(region)was predicted. The results showed that 1)the number of exotic plants increased rapidly with the increase of trade in recent years, there were 260 species by the end of 2018, the ratio of intentional introduction and unintentional introduction accounted for 96%, the distribution of invasive animals is high in eastern and southern provinces(regions), but low in western and northern provinces. 2)There is a correlation between the cumulative volume of import and export and the- DOI:10.3969/j.issn.1000-1565.2020.06.012外来入侵动物在中国的分布格局及增长预测陈凤新1,蒙彦良2,陈名清2,张风娟2(1.河北大学 经济学院,河北 保定 071002;2.河北大学 生命科学学院, 河北 保定 071002)摘 要:通过调研期刊、专著和数据库等资料,并结合实际调查,首先获知中国27个省(区)入侵动物数量及贸易数据,然后分析其进出口总额与外来入侵动物数量的相关性,筛选出拟合度最佳的模型作为预测模型,并采用S型曲线对各省(区)2018—2021年进出口总额进行模拟,最后基于模拟结果预测各省(区)外来入侵动物的数量,获知各省(区)外来入侵动物的数量增加量.结果表明:1)中国外来入侵动物数量随着贸易量的不断增加也在迅速增长,至2018年底已有260种,其中96%是由贸易有意和无意引入的;外来入侵动物的分布呈现东部和南部省(区)高,而西部和北部省(区)低的空间格局.2)中国进出口额累积量与外来入侵动物数量之间存在相关关系,曲线估计结果为对数模型拟合效果最佳.3)预测结果表明中国在未来仍面临大规模的外来动物入侵风险.截至2021年,安徽、福建、广东、广西、贵州、海南、河南、湖北、湖南、陕西、四川和云南12省(区)入侵种增量最高,将高于20种,而青海、甘肃、西藏、新疆和宁夏5省(区)入侵种增量将低于10种,并且入侵热点地区呈现出由南方及沿海地区向中部地区扩散的趋势.关键词:外来入侵动物;分布格局;增长预测;进出口总额中图分类号:Q948 文献标志码:A 文章编号:1000-1565(2020)06-0637-10Distribution pattern and risk analysis of alien invasive animals in ChinaCHEN Fengxin1, MENG Yanliang2, CHEN Mingqing2, ZHANG Fengjuan2(1.School of Economics, Hebei University, Baoding 071002, China; 2.School of Life Sciences, Hebei University, Baoding 071002, China)Abstract: Based on the reference that come from journals, monograph and related database and field investigation, the number of exotic plant and the trade data of 27 provinces(regions)in China were collected. The relationship between the number of exotic plants and the total imports and exports for each province(region)was analyzed. The model with the best fitting degree is selected as the prediction model and S-model was used to predict the total import and export of each province(region)from 2018 to 2021. Finally, the number of invasive plants in each province(region)was predicted and the increase in the number of invasive plants in each province(region)was predicted. The results showed that 1)the number of exotic plants increased rapidly with the increase of trade in recent years, there were 260 species by the end of 2018, the ratio of intentional introduction and unintentional introduction accounted for 96%, the distribution of invasive animals is high in eastern and southern provinces(regions), but low in western and northern provinces. 2)There is a correlation between the cumulative volume of import and export and the- 收稿日期:2020-01-11 基金项目:国家自然科学基金资助项目(31972343);河北省科技厅软科学项目(20557676D) 第一作者:陈凤新(1966—),男,河北秦皇岛人,河北大学副教授,主要从事国际贸易学方向研究.E-mail: fengxinchen@126.com 通信作者:张风娟(1969—),女,河北唐山人,河北大学教授,主要从事入侵生物学方向研究.E-mail: fengjuanzhang@126.com第6期陈凤新等:外来入侵动物在中国的分布格局及增长预测number of invasive animals in China, the curve estimation results show that the logarithmic model has the best fitting effect. 3)The results show that China still faces the risk of large-scale foreign plant invasion in the future. By 2021, the invasive species of 12 provinces(regions)(Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Henan, Hubei, Hunan, Shaanxi, Sichuan, and Yunnan)have the highest increments, whose number will be more than 20 species. While the increase of invasive species in Qinghai, Gansu, Tibet, Xinjiang and Ningxia provinces(regions)will be less than 10. Invasion hotspots show a tendency to spread from the south and coastal areas to the central areas.
    One-versus-one weighted twin support vector machine with pinball loss function
    LI Kai, LI Jie
    2020, 40(6):  647-656.  DOI: 10.3969/j.issn.1000-1565.2020.06.013
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    Twin support vector machine obtains a pair of non-parallel hyperplanes by solving two smaller quadratic programming problems, which improves the performance of the classifier in terms of time and accuracy. Because this method uses the Hinge loss function, the twin support vector function is more sensitive to noise and the resampling is unstable. Therefore, in view of the multi-classification problem, the pinball loss function and weights of samples are introduced into the twin support vector machine, and the binary classifiers obtained are combined by a one-versus-one method,and a one-versus-one weighted twin support vector machine based on pinball loss is proposed. It solves the problems of the sensitivity of twin support vector machines to noise and the instability of resampling. In addition, for the different effects of samples, some methods for calculating the weights of samples are given. In the experiment, standard data sets and artificial synthetic data sets are selected to verify the proposed algorithm Pin-OVO-TWSVM and compared the performance with OVO-TWSVM, OVA-TWSVM and Pin-OVO-TWSVM to show the effectiveness of the proposed method.
    A multi-attribute fuzzy retrieval model for ancient Chinese charater images
    QI Yanmei, TIAN Xuedong, ZHANG Chong, LI Yakang
    2020, 40(6):  657-665.  DOI: 10.3969/j.issn.1000-1565.2020.06.014
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    The traditional character image retrieval technology was difficult to meet the needs of users when it was applied to retrieve ancient Chinese character images because of the complex structure of ancient Chinese characters, changing of font styles, and degradation of font images. To address this problem, a multi-attribute fuzzy retrieval model of Chinese characters in ancient books was proposed by introducing the theory of hesitant fuzzy set. Firstly, an overlapping fuzzy normalized Bi elastic mesh generation for Chinese character images of ancient books was designed. A hesitant fuzzy set containing the query images and target images was established by investigating the geometric and statistical characteristics of various glyph elements between the current grid and its adjacent grids, and defining corresponding hesitant fuzzy elements. Secondly, the weighted distance measure of hesitant fuzzy sets was used to the similarity measure between the query image and the target image, then obtaining the orderly output of the retrieval results. The precision rate and recall rate of retrieval experiments on 11 574 ancient Chinese character images are 78.9% and 76.5%, respectively.
    Improved model predictive direct torque control of permanent magnet synchronous motors
    SU Dandan, LI Haodong, YIN Yanzhou, LI Zhiyuan, SU Jianwen
    2020, 40(6):  666-672.  DOI: 10.3969/j.issn.1000-1565.2020.06.015
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    Direct torque control has some drawbacks such as changing inverter switching frequency and high torque and stator flux ripple. Model predictive direct torque control needs a large amount of computation. In order to overcome this drawback, an improved model predictive direct torque control strategy was proposed for permanent magnet synchronous machines. Only the torque and stator flux under zero voltage vector were predicted. If the errors of torque and stator flux were permitted, zero voltage vector would be applied. Otherwise, optimal non-zero voltage vector would be selected based on the zoning map of different voltage vectors and the selection table of voltage vectors. Thus, the proposed algorithm can reduce computation burden obviously. The evaluation function which is necessary in traditional model predictive direct torque control is also eliminated. The proposed algorithm was simulated in MATLAB. The simulation results show that the torque and stator flux of proposed approach can track the reference values quickly and accurately.- DOI:10.3969/j.issn.1000-1565.2020.06.015改进的永磁同步电机模型预测直接转矩控制策略苏丹丹1,李浩东1,尹延周2,李志远1,苏建文1(1. 河北大学 质量技术监督学院,河北 保定 071002;2. 河北长安汽车有限公司,河北 定州 073000)摘 要:针对永磁同步电机直接转矩控制逆变器开关频率不固定、转矩和定子磁链脉动大等问题,以及模型预测直接转矩控制计算工作量大的缺点,提出了改进的模型预测直接转矩控制策略.该策略只需预测零电压矢量作用下的转矩和定子磁链,当转矩和定子磁链误差在阈值以内时,零电压矢量为最优电压矢量;否则,基于传统直接转矩控制理论中定子磁链的分区和电压矢量选择表确定最优非零电压矢量.由于只有零电压矢量作用下的转矩和定子磁链需要预测并取消了评价函数,因此计算工作量大大降低.最后,基于MATLAB建立了仿真模型.仿真结果表明,永磁同步电机采用改进的模型预测直接转矩控制策略时,电机转矩和定子磁链均能快速准确地跟踪参考值.关键词:永磁同步电机;模型预测控制;直接转矩控制;零电压矢量中图分类号:TM351 文献标志码:A 文章编号:1000-1565(2020)06-0666-07Improved model predictive direct torque control of permanent magnet synchronous motorsSU Dandan1, LI Haodong1, YIN Yanzhou2, LI Zhiyuan1, SU Jianwen1(1. College of Quality and Technology Supervision, Hebei University, Baoding 071002, China;2. Hebei Changan Automobile Co., Ltd., Dingzhou 073000, China )Abstract: Direct torque control has some drawbacks such as changing inverter switching frequency and high torque and stator flux ripple. Model predictive direct torque control needs a large amount of computation. In order to overcome this drawback, an improved model predictive direct torque control strategy was proposed for permanent magnet synchronous machines. Only the torque and stator flux under zero voltage vector were predicted. If the errors of torque and stator flux were permitted, zero voltage vector would be applied. Otherwise, optimal non-zero voltage vector would be selected based on the zoning map of different voltage vectors and the selection table of voltage vectors. Thus, the proposed algorithm can reduce computation burden obviously. The evaluation function which is necessary in traditional model predictive direct torque control is also eliminated. The proposed algorithm was simulated in MATLAB. The simulation results show that the torque and stator flux of proposed approach can track the reference values quickly and accurately.- 收稿日期:2019-05-24 基金项目:河北省高等学校科学技术研究项目(QN2019209);保定市科技计划项目(2074P019) 第一作者:苏丹丹(1983—),女,河北衡水人,河北大学讲师,博士,主要从事永磁同步电机控制、电动汽车驱动技术研究. E-mail:84885596@qq.com 通信作者:李志远(1975—),男,河北保定人,河北大学副教授,博士,主要从事电动汽车驱动技术研究. E-mail:lzyhsy@126.com第6期苏丹丹等:改进的永磁同步电机模型预测直接转矩控制策略