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Table of Content

    28 December 2021, Volume 49 Issue 6
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    Preparation and Electrochemical Properties of High-Capacitance MgCo2O4 Nanowires
    NI Hang，LIU Wanneng，KE Zunjie，TIAN Yu，ZHU Xiaolong，ZHENG Guang
    2021, 49(6):  5-19.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.001
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    MgCo2O4，cobalt-based metal oxides with spinel-type，possesses ultra-high theoretical specific capacitance（3 122 F/g），becoming a hot topic for supercapacitors. To get high-capacitance MgCo2O4 electrode materials for supercapacitors，MgCo2O4 precursor on nickel foam was synthesized by hydrothermal route with different amounts of surfactant sodium dodecyl sulphate. Then MgCo2O4 nanowires were obtained through a lower temperature calcination process in this work. It showed that the surfactant sodium dodecyl sulphate affected not only the micromorphology of MgCo2O4 electrode material，but also its electrochemistry performance. When 1 mmol of surfactant sodium dodecyl sulphate was added ，the as-prepared MgCo2O4 nanowires exhibited a superior specific capacitance of 4 914 F/g at the current density of 1 mA/cm2. After 1 000 cycles at the current density of 20 mA/cm2，53. 48% of initial capacitance was retained when it was used as a binder-free electrode material for supercapacitors. The asymmetric supercapacitor was assembled with MgCo2O4 nanowires and activated carbon respectively set as the positive and negative electrode，which exhibited 72. 59 F/g at the current density of 1 A/g，meanwhile，the energy density can reach 25. 8 Wh/kg at the power density of 920. 86 W/kg. Additionally，after 1 000 cycles of the asymmetric supercapacitor，the specific capacitance was maintained at 94. 77%，manifesting the great potential of MgCo2O4 as excellent material for energy storage.
    Research Progress of High-Safety Flame-Retardant Polymer Electrolytes for Lithium-Ion Batteries
    CHEN Jia，LIU Xueqing，LIU Zhihong，LIU Jiyan
    2021, 49(6):  20-28.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.002
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    Flammable polymer electrolytes are prone to fire after the abuse of short circuits，mechanical shock，and thermal runaway. Therefore，flame-retardant modification for lithiumion batteries polymer electrolytes exhibits particularly necessary. This paper reviews the research progress of flame-retardant polymer electrolytes. First，the two flame-retardant mechanisms of gas-phase and condensed phase during the combustion of polymer electrolytes，as well as various evaluation indicators for flame-retardant performance，are introduced. Then it summarizes the advantages and disadvantages of different flame-retardant compounds， and the flame retardants of polymer electrolytes have been classified for discussion according to the differences in flame-retardant elements. Finally，the application prospects for polyphosphonate and phosphazene compounds in the field of flame-retardant polymer electrolytes are predicted，and the future research directions of flame-retardant polymer electrolytes are prospected.
    Improvement of Cauchy′s Inequality and its Application
    HU Xiaoli，QIAO Longkun
    2021, 49(6):  29-33.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.003
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    Cauchy′s inequality has an important application in the study of unitary uncertainty. The authors use Cauchy′s inequality to improve itself and apply it to the calculation of unitary uncertainty. Firstly，the idea of using low-dimensional Cauchy′s inequality to optimize high-dimensional Cauchy′s inequality is used to obtain the first sequence of Cauchy′s inequality. Then， by introducing a convex function， the second sequence of Cauchy′s inequality is obtained. Finally，the obtained sequence of Cauchy′s inequality is applied to study the variance-based quantum uncertainty. The results show that the Cauchy′s inequality sequence constructed by us can effectively optimize the bounds of variance product-based uncertainty for two unitary operators.
    Pricing of Typhoon Storm Surge Bonds Based on Compound Fractional Poisson Model
    ZHANG Yong，ZHANG Jiesong
    2021, 49(6):  34-41.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.004
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    In order to describe the memory characteristics of the occurrence time interval of typhoon storm surge in China，the compound fractional Poisson model，was adopted to describe the risk of typhoon storm surge and to study the pricing problem of typhoon storm surge bonds. Based on the Monte Carlo simulation method，the probability solution of cumulative loss distribution was obtained，and the price problem of typhoon storm surge disaster bonds in China was given by Wang two factor pricing model. The results showed that with the increase of maturity，the bond price tended to decrease，increase first and then decrease，or increase monotonously，which was closely related to memory parameters. It provides theoretical support for the more accurate assessment of typhoon storm surge catastrophe risk and the scientific pricing of bonds in China.
    Effects of High Temperature Treatment on the Physiological and Biochemical Characteristics of Three Aromatic Plants
    WU Jing，YUAN Pingcheng
    2021, 49(6):  42-47.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.005
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    Using one-year-old cutting seedlings of three aromatic plants （Cymbopogon citratus，Melissa officinalis，Rosmarinus officinalis ′Severn Sea′）as experimental materials，contents of chlorophyll， the relative electrical conductivity， activities of superoxide dismutase（SOD），malondialdehyde（MDA），soluble sugar and soluble protein in leaves were measured and analyzed under 35 ℃ simulated by intelligent artificial climate box. The results showed that the chlorophyll a，chlorophyll b，total chlorophyll content and carotenoid content of C. citratus showed a downward trend，while that of M. officinalis increased，and that of ′ Severn Sea′ increased first and then decreased. The relative conductivity，MDA content，soluble sugar and soluble protein content of C. citratus and M. officinalis were significantly increased，and SOD activity was significantly decreased. The relative electrical conductivity，MDA content and SOD activity of ′Severn Sea′ changed little. To sum up，C. citratus is more sensitive to high temperature than M. officinalis and ′Severn Sea′.
    Research Progress on Approaches to Improve Nitrogen Efficiency and Evaluation Index of Nitrogen Efficiency in Rapeseed
    CHEN Jingdong，JI Qiangqiang，YU Yi，WANG Yuhang，ZENG Changli
    2021, 49(6):  48-57.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.006
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    Rapeseed is an essential oil crop in China，which has a wide planting range，a large area，and high economic value. The growth and development of rapeseed require a large amount of nitrogen. Hence establishing a set of efficient and accurate evaluation criteria for nitrogen efficiency of rapeseed is of great significance for screening and exploring nitrogen efficient genotypes of rapeseed. This paper described the effects of nitrogen on the growth of rapeseed， the concept of nitrogen efficiency and the effective ways to improve it， and compared and analyzed several commonly used evaluation methods of nitrogen efficiency in rapeseed，which provided a theoretical basis for further guidance of rapeseed high-efficiency production of high yield and cultivation of new nitrogen efficient germplasm.
    Investigation on Molecular Mechanism of Ursolic Acid in the Treatment of Cervical Cancer Based on Bioinformatics and Molecular Docking
    YANG Guang
    2021, 49(6):  63-71.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.008
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    Objective To investigate the molecular targets and mechanism of ursolic acid in the treatment of cervical cancer by bioinformatics and molecular docking. Methods The potential disease targets of ursolic acid were searched by TCMSP and DrugBank databases. In GeneCards and GEO databases，the disease“cervical cancer”was searched，and the limited species was“Homo sapiens”. Through analysis and screening，the GSE63514 gene expression profile chip data were obtained，and 39 potential targets for the treatment of cervical cancer were obtained by comprehensive screening. The target gene protein interaction network was established by BisoGenet and CytoNCA plugin under Cytoscape3.8.0 software，and the GO and gene-KEGG pathways of drug and disease genes were analyzed. AutoDock was used for molecular docking to predict the binding degree of ursolic acid and the core target of the disease. PyMOL software was used for plotting. Results There were 39 potential targets of ursolic acid in the treatment of cervical cancer，including 1 171 GO functions and 172 KEGG pathways. The main tumor-related signalling pathways were screened out as follows：pathways in cancer，TNF signalling pathway，PI3K-Akt signalling pathway，p53 signalling pathway，apoptosis，etc. Molecular docking of ursolic acid with RELA，JUN，CDKN1A，ICAM1，STAT3 and NFKBIA genes was successfully verified. Conclusion In this study，bioinformatical methods are used to reveal that ursolic acid plays a multi-target and multi-pathway role in anti-cervical cancer by inhibiting tumor cell proliferation，inducing apoptosis，anti-angiogenesis and anti-inflammatory genes and pathways.
    Expression and Clinicopathological Research of ALDH1 in Breast Cancer and Breast Cancer Adjacent Tissues
    YU Liying，ZHAN Xinyu，ZENG Siyu，CHEN Mingfu，GAO Huan，CHEN Qiongxia，CHEN Ying，ZHEN Hongyan
    2021, 49(6):  72-77.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.009
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    Objective To investigate the expression and clinicopathological significance of aldehyde dehydrogenase 1 （ALDH1） in breast cancer tissues and its adjacent tissues. Methods Breast cancer tissues of 71 cases and adjacent tissues of 29 cases were collected，and ALDH1 was detected by immunohistochemical Envision method and the clinicopathological features of the tumor were analyzed. Results The expression of adjacent tissues of breast cancer was localized in the nucleus and the expression of breast cancer tissues was localized in the cytoplasm. Some cancer tissues showed scattered expression，and others were diffusely expressed. The positive rate of ALDH1 in T1-T2 tumors was 51. 9%，which was significantly higher than that in T3 tumors（23. 5%）. The positive rate of ALDH1 in histological grade I tumors was 75. 0%，which was significantly higher than that in grade III tumors （55. 6%）. The positive rate of ALDH1 in patients with axillary lymph node metastasis was 42. 1%，which was significantly higher than that in patients without metastasis （30. 0%）. Conclusion The difference in the positivity of ALDH1 expression may be a marker of benign and malignant breast tumors. The expression of ALDH1 may be correlated with tumor growth，differentiation，and invasion.
    Attitude Control Strategy of Two-DOF Helicopter Based on LabVIEW
    LIU Zhiqiang，YE Xi，QIAN Tonghui
    2021, 49(6):  78-86.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.010
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    To achieve fast and stable control of a two-DOF helicopter，a state feedback control method based on LabVIEW platform has been designed for the problem of high coupling of helicopters that can′t be solved by traditional PID controllers. According to the mechanical structure model of the helicopter system，the dynamics model of this control system in pitch and yaw directions was established. For solving the problem of the obvious coupling characteristics of the system，the state feedback controller had been designed using the LQR control strategy. Finally，the flexible online programming method of the LabVIEW platform had been used to realize the real-time and effective tracking of the pitch angle and yaw angle of the two-DOF helicopter. The experimental results showed that the signal tracking performance and decoupling performance of the LQR controller were better，which could basically meet the performance requirements of the system.
    Environment Monitoring of Glass Greenhouse Based on Fuzzy Decoupling Control
    SHU Rendong，MENG Lingqi，LI Jin，YUE Lang
    2021, 49(6):  87-96.  doi:10.16389/j.cnki.cn42-1737/n.2021.06.011
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    Aiming at the phenomena of complex data，strong coupling and poor control accuracy in the environmental control of agricultural greenhouse，an adaptive control strategy combining multi-sensor data fusion，decoupling control and fuzzy PID control is proposed，and the coupling controller and fuzzy PID controller are designed. Through the weighted optimization of the median value average filtering algorithm，the optimized data are input into the controller for processing，and the environmental data are tracked in real-time to realize the accurate control of the agricultural greenhouse environment. The control system is simulated by Simulink，and the results show that compared with traditional PID control and fuzzy PID control， the response speed and stability of this control strategy are significantly improved，and in the practical application of intelligent control of agricultural greenhouse，good results are obtained.