Table of Content

17 June 2024, Volume 52 Issue 3

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Numerical Simulation Study on Rock Breaking Effect of Burn Cut in Hard Rock Tunnel Under Different Blocking Conditions

CHEN Siyou，YAO Yingkang，ZHU Dan，SUN Jinshan，JIA Yongsheng

2024, 52(3):  5-15.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.001

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In order to study the effect of different stemming materials and stemming lengths on the burn cut blasting of hard rock tunnels，based on engineering examples，a three-dimensional numerical model was established using ANSYS/LS-DYNA simulation software to compare and analyze five different blockage conditions. Based on the numerical model calculation results，qualitative analysis was conducted on the expansion of blasting cracks in the cutting area，and quantitative analysis was conducted on the stress situation of typical rock parts. The results indicate that，firstly，the free surface rock is mainly subjected to tensile stress to generate cracks，and the blockage of the blast hole prolongs the overall action time of the explosion load，resulting in a denser number of cracks on the free surface. Secondly，the surrounding rock near the air section between the explosive and the stemming material is first crushed by the explosive stress wave and then subjected to multiple transformations between tensile and compressive stresses，causing the crack to be amplified. Due to the ″ gas wedge″ effect of the explosive gas，the crack almost penetrates the model cross-section. Thirdly，after the blockage of the blast hole，the stress value of the explosive gas acting on the rocks around the explosive section is significantly increased，which is 1. 31 - 2. 34 times higher than the peak stress of the rock around the explosive section when it is not blocked. The blockage of the blast hole increases the compressive stress value of the explosive gas when it continues to play a stable role by 3. 70 - 4. 70 times. Finally，when using gun mud and water as blockage materials，the rock-breaking effect of a burn cut with a stemming length of 40 cm is better than that of a burn cut with a stemming length of 60 cm. The research results can provide a theoretical basis for optimizing the parameters of burn-cut blasting in hard rock tunnels.

One-time Application Effect of Slow-release Fertilizer on Ratoon Sugarcane in Different Ecological Regions

LIU Min ，BI Juanjuan ，WANG Huayu ，LI Suxia ，ZHOU Zhihua ，MO Xiaorong ，XU Yong ，NING Xian ，LI Qing

2024, 52(3):  16-24.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.002

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To explore the technology for fertilizing easily and efficiently on sugarcane in different ecological regions，the self-developed sugarcane special slow-release fertilizer and the local conventional sugarcane fertilizer were used for comparison in the field along with Guangxi Beibu Gulf coastal cities，Qinzhou，Beihai，and Fangchenggang. The mode of fertilizing in the field used by local conventional sugarcane fertilizer was base fertilizer + topdress + furrow application. The field used by self-developed sugarcane slow-release fertilizer adopted the fertilization mode of base fertilizer and furrow application or spreading. The results showed that compared with the local conventional fertilizer treatment，the treatment of special slow-release fertilizer for sugarcane significantly increased the number of millable canes， stem length， and stem circumference of sugarcane and significantly improved the observational brix，sugar degree，and sucrose content of sugarcane；the output of three cane areas of Fangchenggang，Beihai，and Qinzhou increased by 26. 62%，16. 54% and 21. 17%，respectively；the economic benefits of three cane areas increased by 32. 25%， 19. 83% and 27. 11%，respectively. Above all，the application of special slow-release fertilizer for sugarcane plays a significant and positive role in improving the agronomic traits， quality，yield，and benefits of different ecological regions，which is worthy of promotion.

Effect of Salt Stress on Growth，Physiological and Biochemical Properties of Sprouting Cuttings of Artemisia selengensis

XUE Tianyuan，ZHANG Qianqian，WANG Yuhang，HE Sixiao，DONG Yuanhuo，DAI Xigang，ZENG Changli

2024, 52(3):  25-31.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.003

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The wild and cultivated species of Artemisia selengensis collected from the Xiangkou base in Hannan，Wuhan，China，were subjected to three concentration gradients of 0，20，and 40 mmol/L NaCl solution，with the Hoagland nutrient solution without salt stress as the control. The half-lethal concentration of Artemisia selengensis cuttings was screened out， and the effect of salt stress on growth and physiological indicators of Artemisia selengensis cuttings was studied. The results showed that salt stress significantly reduced the survival rate of cultivated and wild species Artemisia selengensis cuttings compared to the control，with a half-lethal concentration of 53. 40 mmol/L for wild species Artemisia selengensis cuttings and 50. 99 mmol/L for cultivated species Artemisia selengensis cuttings. Under NaCl stress，the plant height，root length，and lateral root number of wild species Artemisia selengensis cuttings were not significantly inhibited and showed a trend of first increasing and then decreasing；the plant height，leaf number，root length，and lateral root number of cultivated species cuttings were significantly inhibited；the CAT，POD，APX，and SOD activities of the wild species Artemisia selengensis cuttings significantly increased under the influence of salt stress，and the MDA and proline contents showed a trend of first decreasing and then increasing；the activities of CAT，POD，APX，and SOD were significantly increased，and the contents of MDA and proline were significantly increased in the cuttings of cultivated Artemisia selengensis with the increase in salt concentration. In contrast，the activities of antioxidant enzymes（CAT，POD，and SOD）in the cuttings of wild species Artemisia selengensis were lower than those of cultivated species Artemisia selengensis. It can be assumed that the cultivated species of Artemisia selengensis are more vulnerable to salt stress and that the wild species of Artemisia selengensis cuttings are more salt tolerant.

Interference and Related Mechanism of 2，6-dichloro-1，4-benzo⁃ quinone on Carbohydrate Metabolism in the Heart of Grass Carp （Ctenopharyngodon idella）

XIONG Miao，ZOU Lunfei，XIAO Chen，ZHANG Qiwei ，ZHENG Qi

2024, 52(3):  32-43.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.004

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2，6-dichloro-1，4-benzoquinone（2，6-DCBQ）is a novel disinfection byproduct found in tap and swimming pool water，which is widely distributed and toxic， presenting a potential threat to human health. To explore the correlation between 2，6- DCBQ-induced cardiotoxicity and carbohydrate metabolism in organisms and its toxicological mechanisms，we investigated the morphological changes of heart and thyroid tissues of grass carp（Ctenopharyngodon idella）juveniles exposed to 2，6-DCBQ at different concentrations and times and measured the levels of carbohydrate metabolism-related hormones and the activities of related enzymes. The results showed that 2，6-DCBQ could induce cardiac pericardial edema and interstitial edema in juvenile fish，as well as the loss of thyroid follicular glial and epithelial cell proliferation. The exposure also interfered with the levels of the thyroid hormones T3 and insulin in the blood. The activities of some enzymes， such as hexokinase， fructose phosphokinase， and pyruvate kinase， were significantly reduced due to the exposure. Combined with the targeted metabolomics analysis， we inferred that after 2，6-DCBQ exposure，the activity of hexokinase in heart tissue had been inhibited，therefore interfering with the glycolysis pathway ；the conversion of α - ketoglutarate to succinate was blocked，thus affecting the tricarboxylic acid cycle in fish. This study contributes to a further understanding of the toxicological mechanisms of halobenzoquinone disinfection by-products and a comprehensive assessment of their health risks.

Tangeretin Alleviates Microglia Over-activation and Cognitive Impairment in APP/PS1 Mice

YU Jing，LIANG Zheng，HE Zishan，CHEN Honglin，SHI Chengying， GONG Xiaokang，BAO Jian，SHU Xiji

2024, 52(3):  44-50.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.005

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Objective To study the effects of tangeretin（TAN）on cognitive performance， microglia over-activation，and inflammatory factors released in APP/PS1 mice. Methods 2. 5-month-old male APP/PS1 mice were treated with TAN orally for 16 weeks. The effects of TAN on alleviating cognitive dysfunction of APP/PS1， microglia overactivation，and inflammatory factors released in the brain were observed. Results It was found that TAN significantly alleviated cognitive impairment in APP/PS1 mice by behavioral testing； the results of immunofluorescence staining demonstrated that TAN significantly alleviated microglia over-activation in the brain of APP/PS1 mice；the results of multifactor analysis showed that TAN significantly increased the levels of anti-inflammatory molecules IL-2 and IL-5 in the mouse brain. Conclusion TAN significantly reduces microglia over-activation，regulates the release of inflammatory factors in the brain of APP/PS1 mice，and alleviates cognitive impairment.

U-Net3+ Medical Image Segmentation Algorithm Based on Improved Channel Multi-head Attention Mechanism

ZHANG Quanxin，YE Xi，YANG Zhihong，XIANG Qing

2024, 52(3):  51-61.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.006

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Medical image segmentation is one of the current research hotspots，and the segmentation accuracy significantly impacts the subsequent medical diagnosis. In this paper， we proposed an improved U-Net3+ image segmentation algorithm that incorporated a channel attention mechanism to address the shortcomings of most current medical image segmentation techniques that can not fully utilize and fuse multi-scale feature information. Based on the global jump connection structure of U-Net3+ ，a new channel attention mechanism was designed and embedded into the decoding path of the U-Net3+ network to help the segmentation network adjust the training weights of important information when stitching the global feature map to fuse the global feature information efficiently. Finally，the model was compared and evaluated on two classical medical image segmentation datasets， and the average Dice coefficients reached 74. 31% and 77. 16%，respectively，were 3. 01% and 2. 98% higher than the original U-Net3+ Dice coefficients. The experimental results show that the improved network model effectively improves the segmentation accuracy of medical images.

Design of an Adaptive，Robust，Guaranteed Performance Controller

XU Wei，XU Junxiao，LI Qiang，WEI Hong

2024, 52(3):  62-73.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.007

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Based on the linear model of yaw control of rotor-craft flying robots with timevarying uncertainties， this paper discussed the problems in the design method of the controller for mobile robot systems and proposed the design method of an adaptive robust controller. In this method，the adaptive mechanism was introduced into the robust controller design method，and the design problem of the state feedback adaptive robust controller was transformed into an equivalent solvable problem of linear matrix inequalities so that the gain of the robust controller can be adjusted online and the stability of the closed-loop system can be guaranteed. Moreover，the method was compared with the technique of fixed-gain robust controller in the experimental simulation，which showed that the method performed better in the yaw control of flying robots.

Voting-based Framework for Auto Cyber Intrusion Detection System in Imbalanced Dataset Environment

LI Xi，MEI Qian，TAO Jie，YU Jiawei，FENG Changqi

2024, 52(3):  74-86.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.008

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Modern cyber attack intrusion detection systems apply network flows with artificial labels to build the ability to detect potential threats automatically. Errors，sample insufficiency，and lack of essential features in artificial labeling would severely restrict the system's capability. It is a fatal flaw that the system could not discern attacking samples from benign samples. Most researchers regard the overall performance measurements as the benchmarks for intrusion detection systems while omitting what they are. It was created to warn people about dangerous network attacks. Hence，the article proposed a voting-based framework for an auto cyber intrusion detection system in an imbalanced dataset environment. Based on the trainable voting network，the framework integrated machine learning techniques and deep learning techniques to solve the problem of imbalanced datasets. The article focused on increasing the precision of fatal attack detection without compromising the system's overall performance. The experimental results suggest that the proposed model runs stable and well overall in these different datasets，and the model promotes the detection rate of the minority class effectively.

Study on Seismic Performance of Infilled-frame Wall

FANG Xinxin，CHEN Yuexiang

2024, 52(3):  87-96.  doi:10.16389/j.cnki.cn42-1737/n.2024.03.009

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In order to study the influence of infill walls on the seismic performance of infilled in frame structures，the concrete frame，the wall with lightweight aggregate concrete block infilled frame wall， and the multi-story infilled-frame wall were analyzed by the ABAQUS. The structure's failure mode， hysteresis curve， skeleton curve， stiffness degradation performance，and energy dissipation capacity were compared. The results show that the lightweight aggregate concrete block infilled-frame wall has better mechanical performance. Adding an infilled wall inhances the structure's lateral force deformation resistance，and energy dissipation capacity. It improves the bending and shear performance of the multi-story frame structure. The wall with lightweight aggregate concrete block infilled frame is green， environmentally friendly， resilient， and has good seismic performance.