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Table of Content

    28 October 2020, Volume 48 Issue 5
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    Effects of Nitrogen Plasma Doping on Visible Light Photocatalytic Performance of ZnO/TiO2 Core-Shell Nanorods
    PENG Jiliang，FU Qiuming，TU Yafang
    2020, 48(5):  5-13.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.001
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    ZnO/TiO2 core-shell nanorod arrays were prepared via hydrothermal method and liquid phase deposition. Then N-doped ZnO/TiO2 core-shell nanorod arrays were obtained by ECR nitrogen plasma. The morphology and structural properties were characterized by SEM，TEM，XRD，XPS，and the effect of nitrogen doping on its crystalline structure，element composition，and surface electronic state were studied. The optical performance and visible light photocatalytic performance were investigated using ultraviolet-visible spectrophotometer and photocatalytic performance testing device. The results indicate that nitrogen plasma treatment has no significant impacts on the crystalline structure of the nanorods and the nitrogen exists mainly in the form of substitutional N. With the decrease of the working pressure，the concentration of the substitutional N increases，while the optical bandgap of the nanorod arrays decreases. The photocatalytic activity tests show that the visible light photocatalytic efficiency of the N-doped ZnO/TiO2 core-shell nanorod arrays increases with the concentration of the substitutional N. Based on the energy band theory，the enhancement mechanism of visible light photocatalytic performance was discussed.
    Mechanism Analysis and Solution Strategy for Thermal Runaway of Lithium-Ion Batteries
    YANG Kun，LEI Hongjun，XIAO Bowen，WU Meilin，CAI Jiancheng，ZHENG Yun，CHENG Xin，LIU Zhihong
    2020, 48(5):  14-20.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.002
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    The recent progress of the thermal runaway research of lithium-ion batteries is reviewed. The main reasons and characteristics for the thermal runaway of lithium-ion batteries are summarized including the internal and external perspectives factors. It is shown that to improve battery safety，the more thermally stable cathode material，anode material，flame retardant electrolyte， and separator should be used， and a battery thermal management system should be established. Finally，the development of the next generation of high-safety， high-energy-density new lithium-ion batteries， and their thermal runaway behavior is prospected.
    Research on Time-Space Characteristics of Innovation Efficiency in Yangtze River Economic Belt Based on Three-Stage DEA-windows and Spatial Correlation
    LU Xiaolan，ZHANG Keyi
    2020, 48(5):  21-35.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.003
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    Using the three-stage DEA-windows and spatial statistical analysis methods，the innovation efficiency of the Yangtze River Economic Belt from 2006 to 2017 was measured，and the time-space characteristics of the innovation efficiency of the provinces and cities in the Yangtze River Economic Belt and the upper，middle and lower reaches of the Yangtze River Economic Belt were analyzed. The results show that before and after excluding management inefficiencies and random disturbances，11 provinces and cities have not achieved DEA effectiveness， and the temporal and spatial differences in innovation efficiency are obvious. After the adjustment，the average values of innovation comprehensive efficiency and innovation scale efficiency of the Yangtze Economic Belt are significantly smaller than before the adjustment，and the average values of pure technical efficiency are higher. The comprehensive efficiency and scale efficiency of the Yangtze River Economic Belt increase monotonously with time，while the pure technical efficiency does not fluctuate much with time，and the low comprehensive efficiency of innovation is mainly caused by the ineffective scale efficiency. The spatial difference and spatial positive correlation of the comprehensive efficiency and scale efficiency of the Yangtze River Economic Belt are obvious，but these spatial characteristics are gradually weakened. Meanwhile，the spatial difference and spatial correlation of the pure technical efficiency are not obvious. After the adjustment，the innovation efficiency of the Yangtze River Economic Belt shows a decreasing trend from east to west，which is different from that of the middle reaches of the Yangtze River with the lowest innovation efficiency before the adjustment. Also，the impact of environmental variables on the redundancy of three inputs is basically the same，which shows that the enhancement of environmental regulation，financial support，and education level is conducive to the improvement of innovation efficiency，while the improvement of economic conditions，R&D scale，and industrial structure may lead to the redundancy of inputs.
    Hamilton Properties of Second-Order Cyclic Graphs of Uniform Matroid
    LIU Bin，DENG Zijian，DU Qingsong，HUO Bofeng，b，LI Faxu
    2020, 48(5):  36-41.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.004
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    Hamilton properties of second-order cyclic graphs of uniform matroid under certain conditions were studied. From Hamilton properties of second-order cyclic graphs of U2,n and U3,n under certain conditions，generalizing to Hamilton properties of second-order cyclic graphs of Um,n under certain conditions. We discovered second-order cyclic graphs of Um,n was Hamiltonian-connected and uniformly Hamilton，if n = m + 2,m + 3,?,2m，m，n were positive integer and m ≥ 2,n ≥ m + 2.
    Quality and Validity Analysis of Improved Whole Blood DNA Extraction Method
    ZUO Wenbo，WANG Jiazheng，XU Ying，YANG Xiaoting，NI Wei，HU Song
    2020, 48(5):  42-46.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.005
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    Objective To meet the demand for large-scale extraction of peripheral blood DNA，we make improvements in the existing kit extraction method. Methods Eighty blood samples from healthy people in Wuhan were randomly divided into two groups with 40 samples in each group. Improved whole blood DNA extraction method and PBMC（peripheral blood mononuclear cell） DNA extraction method were used to extract DNA respectively， and their validity and quality were compared. Results By comparing and analyzing the experimental time，the quality and purity of the extracted DNA，and the PCR results， it was found that the improved whole blood DNA extraction method took significantly less time than the whole blood PBMC DNA extraction method， and the extracted DNA quality was significantly higher than the whole blood PBMC DNA extraction method（P < 0. 05），while the OD260/OD280 values of the genomic DNA extracted by the two methods were not statistically different（P > 0. 05），and single and bright bands can be seen in the PCR products of the two methods. Conclusion The improved whole blood DNA extraction method is a fast，economical，and efficient DNA extraction method，which can play a role in clinical transplantation matching and clinical genetic diversity detection.
    Investigation on Cognition and Vaccination Willingness of Female Medical Students of Jianghan University on HPV and HPV Vaccine
    OUYANG Lichen，WANG Shiqi，HU Meiling，GONG Yeli
    2020, 48(5):  47-54.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.006
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    Objective To assess the cognition and vaccination willingness of female college students of Jianghan University in Wuhan about human papillomavirus （HPV） and HPV vaccine， and analyze the relevant factors that affect willingness of HPV vaccination. Methods Using the cluster sampling method，364 female medical students from School of Medicine in Jianghan University were selected as research subjects to investigate their HPV cognition and HPV vaccination willingness. Results Among 364 participants，74. 2% of them had heard of HPV，and 78. 0% of them had heard of HPV vaccine. The awareness rate of senior students was significantly higher than that of junior students，and the awareness rate of clinical medicine students was significantly higher than that of nursing students. 84. 3% of participants had willingness to be vaccinated against HPV. Logistic regression analysis found that the factors that affect the willingness to receive the HPV vaccine were whether they knew that the HPV vaccine can prevent HPV infection and whether they knew that routine cervical cancer screening was required after HPV vaccine injection. Conclusion Female medical students of Jianghan University in Wuhan have a high awareness rate of HPV and its vaccine，but they have a more partial understanding. The willingness to receive vaccination is also high. Senior medical students can carry out health education activities in school to improve the understanding of HPV-related knowledge of junior medical students and non-medical students，and lay a foundation for the popularization of HPV vaccination.
    A Case of Gastrojejunocolic Fistula After Subtotal Gastrectomy and Literature Review
    HUANG Xing，CHEN Wei
    2020, 48(5):  55-58.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.007
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    Objective To establish a rapid detection system for harmful food-borne microorganisms. Methods In this study，5 kinds of harmful bacteria such as Escherichia coli，Staphylococcus aureus，Shigella，Salmonella，and Listeria monocytogenes were detected. The rapid extraction of genomic DNA in 30 seconds and multiplex PCR were used as experimental techniques. Results 8 pairs of specific primers of the 5 bacteria were screened out，and it was found that Escherichia coli and Listeria monocytogenes could be detected by DNA rapid extraction and PCR. A multiplex PCR system based on DNA rapid extraction of Escherichia coli and Listeria monocytogenes was established. Four pairs of primer combinations：rfbE/Hly，fbE/HlyA1，rfbE/HlyA2，and eaeA/HlyA2，were screened out successfully in multiplex PCR experiments，and the experiments were optimized. Conclusion It is feasible to detect harmful food-borne microorganisms by DNA rapid extraction and multiplex PCR. However，it is necessary to take measures to optimize the experiments. The design of primers for multiplex PCR may be the key to optimize the experiments.
    A Case of Mixed Cryptorchidism Germ Cell Tumor and Literature Review
    LIU Jun，CHENG Ping，FANG Dengpan，ZHU Tao
    2020, 48(5):  59-64.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.008
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    Objective Mixed cryptorchidism germ cell tumor is extremely rare in clinical practice. This paper aims to improve the comprehensive understanding of the disease，provide reasonable and effective treatment methods for the disease，and improve the survival rate. Methods The retrospective analysis was performed on the clinical data of 1 case of mixed cryptorchidism germ cell tumor confirmed by pathology，which contained 4 tumor components （seminoma about 50% + immature teratoma about 25% + yolk sac tumor about 20% + embryonal carcinoma about 5%）. Results The patient was admitted to hospital with“acute abdominal pain”，and the blood levels of AFP，HCG，and LDH were all elevated. Imaging examination showed space-occupying lesions in the abdominal cavity. The tumor and some surrounding tissues were surgically removed. After 6 months of follow-up， no tumor recurrence， and metastasis. Conclusion The treatment of mixed cryptorchidism germ cell tumor should be done as early as possible. Orchidopexy before the age of 2 can effectively reduce the occurrence of this disease. The treatment was radical resection combined with BEP （bleomycin， etoposide， cisplatin） chemotherapy. The prognosis varies according to the tumor components. The prognosis which contains choriocarcinoma is poor，while the seminoma is generally good.
    Study on Optimization and Performance of Fracturing Fluid System in Coal Seams of Qinshui Basin
    TIAN Yueru，ZHANG Shuangshuang，LI Yunyun
    2020, 48(5):  65-70.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.009
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    Coal seams have the characteristics of low Young's modulus，large Poisson's ratio，strong adsorption，and strong anisotropy. Ordinary fracturing fluids are likely to cause damage to the coal seams，and the coal seams are prone to produce a large amount of pulverized coal due to high pressure during the fracturing process. Based on the characteristics of Qinyuan block 2# coalbed，the systems of active water fracturing fluid and anti-pulverizing coal fracturing fluid are obtained through indoor simulation experiments. The results show that the damage rate of active water fracturing fluid to the coal matrix is 11. 92%. The anti-pulverizing coal fracturing fluid can effectively carry out the coal powder，and the damage rate to the coal rock matrix is 22. 65%. Both fracturing fluid systems can satisfy the requirements.
    Study on Flow and Heat Transfer of Large-and-Small-Hole Segmental Baffle Heat Exchanger with Small Fins
    WANG Xiaoyu，LUO Ziqiang
    2020, 48(5):  71-82.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.010
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    The heat exchanger with large-and-small-hole segmental baffles can reduce the flow dead zone and the pressure drop，which behind the baffle，but the heat transfer enhancement effect on the shell side is not obvious. The longitudinal vortex generator can make the fluid produce strong disturbance，which can enhance the heat transfer and reduce the flow loss. Given this situation，the heat exchanger structure of large-and-small-hole segmental baffles coupled with longitudinal vortex generators is proposed， and the longitudinal vortex generators are called small fins. The model of the heat exchanger with small fins and large-and-small-hole segmental baffles was built and the structure was numerically simulated by ANSYS-Fluent software. The thermal-hydraulic performance of three kinds of small fins with different structures was compared and analyzed. The results show that when the small fins are arranged in alignment with the rectangular wing array，the thermal performance of the heat exchanger is the highest，compared with the segmental baffle heat exchanger with large-and-small-hole. The comprehensive performance of the large-and-small-hole segmental baffle heat exchanger without small fins is the highest.
    Economics Research of Basement Frame Beam Based on PKPM Simulation
    XU Chang，DU Chuanguo
    2020, 48(5):  83-88.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.011
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    This paper established the cost objective function for the unit volume of concrete and unit volume of reinforced steel. Then，combined with the computation formula and assumptions of the double-reinforced cross-section beam，the calculation formula of the double-reinforced cross-section beam was deduced and evolved. Finally，the index of the excellent economic reinforcing rate of the double-reinforced cross-section beam was obtained. On the base of that，the two layers of the pure basement（16 palace diagram was used）were modeled and simulated by PKPM software，and the different section sizes of the basement roof beams of the model were tested. The statistical analysis of the trial calculation results verifies the correctness of the excellent economic reinforcement ratio index of the double-reinforced cross-section beam. The proposal of this idea provides a reference for structure designers to design economical beam sections，provides a basis for real estate development enterprises to evaluate the design results of design companies，and opens up a new direction for structural optimization work.
    Experiment Research on Multi-Point Dynamic Displacement Detection System Based on Digital Image Processing Technology
    CHENG Bin，CHENG Hui
    2020, 48(5):  89-96.  doi:10.16389/j.cnki.cn42-1737/n.2020.05.012
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    Dynamic deflection is a critical parameter to evaluate the overall structural performance of a bridge，and it is very important to carry out a scientific and reliable test on it. However，there are few methods and equipment for dynamic testing of the bridge，especially the direct measurement of bridge dynamic deflection is still lack of scientific and convenient methods. The conventional measurement methods such as leveling， dial indicator，and total station are difficult for dynamic measurement；even though GPS can realize the dynamic measurement，the accuracy is limited，and the debugging and installation are very tedious. Based on the theory of digital image processing technology，this paper conducts a comparison experiment on photoelectric deflectometer instruments and health monitoring deflection in Wuhan Sino-French Friendship Bridge. The results show that test results are consistent with the existing health monitoring system of the bridge，which verifies the accuracy and reliability of the system，which also can meet the requirements of bridge health monitoring.