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煤炭工程 2009年第2期41卷 35-37页

作者：徐继民平顶山煤业集团公司基建处河南平顶山467000

根据装载硐室的工程特征及工程地质条件,结合现有的施工设备及安全技术条件,通过优化施工方案,采用下行分段掘砌作业,依次从上向下掘砌成形,并合理安排施工顺序,加强劳动组织,实现了平煤天安十一矿新主井双箕斗装载硐室的快速施工。

关键词：主井井筒改扩建箕斗装载硐室

Thermal stability of permafrost under U-shaped crushed rock embankment of the Qinghai-Tibet Railway

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Advances in Climate Change Research 2024年第1期15卷 158-169页

作者： Kun-ming xu Guan-Li jiANG ji CHEN Qing-Bai WU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Beiluhe Observation Station of Frozen Soil Environment and Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China

The U-shaped crushed rock embankment(UCRE),of which widely utilized in the permafrost regions along the Qinghai-Tibet Railway,has the capability to rapidly reduce the ground temperature of the underlying ***,there remains uncertainty regarding the adaptation of UCRE to climate change and its long-term cooling *** study focuses on nine UCRE monitoring sites along the Qinghai-Tibet Railway to analyze the dynamic variations of the ground temperature underlying permafrost from 2006 to *** efficiency of UCRE in stabilizing permafrost temperature in different permafrost zones is evaluated by considering the permafrost table,ground temperature,and MAGT,as well as the temperature difference between the top and bottom of the crushed rock layer and the ground temperature variation index(GTVI).The results show that UCRE is suitable for application in extremely unstable warm permafrost regions where the MAGT is higher than-0.5℃.Moreover,UCRE effectively diminishes the disparity in permafrost thermal stability between the sunny and shaded shoulders of the *** short-term and long-term effect of cooling permafrost is experiencing a change related with permafrost ***,in stable cold permafrost regions with MAGT lower than-1.5℃,the long-term cooling effect of UCRE on permafrost seems to gradually di-minishes,but UCRE continues to fulfill the role of stabilizing the underlying permafrost thermal state over the *** results show that UCRE can quickly restore and stabilize the thermal state of permafrost in the early stages of construction,and adapt to the influence of future climate *** findings provide important guidance for understanding the variations of permafrost thermal stability beneath the embankment in permafrost regions,as well as for improving the embankment stability and operational safety of the Qinghai-Tibet Railway.

关键词： Qinghai-Tibet Railway U-shaped crushed rock embankment Climate change Permafrost zone Ground temperature variation index Long-term coolingrole

Large-disturbance Stability Analysis of Power Systems with Synchronous Generator and Converter-interfaced Generation

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 997-1002页

作者： Lei Chen Yong min Liangshuai Hao Guangzheng Xing Yalou Li Shiyun xu Department of Electrical Engineering Tsinghua UniversityBeijing 100084China China Electric Power Research Institute Beijing 100192China

This letter studies large-disturbance stability of the power system with a synchronous generator(SG)and a converter-interfaced generation(CIG)connected to infinite *** power system is multi-timescale and first *** is shown that the boundary of region of attraction(ROA)of the simplified model is composed of stable manifolds of unstable equilibrium point(UEP)or semi-singular point(SSP),named anchor points,and singular surface *** type of anchor point determines the dominant instability pattern of the power *** the anchor point is UEP or SSP,the dominant instability pattern is the instability of rotor angle of SG or the instability of phase-locked loop and outer control loop(OCL)of CIG,*** of dominant instability pattern can be analyzed with the relative position relationship between UEP and *** effect of OCL is *** the OCL is activated,the ROA becomes smaller and the system is more prone to instability of *** is necessary to consider the OCL when studying the large-disturbance stability of the power system.

关键词： Converter-interfaced generation large-disturbance stability outer control loop phase-locked loop synchronous generator voltage source converter

An intelligent control method based on artificial neural network for numerical flight simulation of the basic finner projectile with pitching maneuver

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Defence Technology（防务技术） 2024年第2期32卷 663-674页

作者： Yiming Liang Guangning Li min xu Junmin Zhao Feng Hao Hongbo Shi Northwestern Polytechnical University School of Astronautics Xi’an 710072China China North Industries Group Corporation No 203 Research Institute Xi’an 710065China

In this paper,an intelligent control method applying on numerical virtual flight is *** proposed algorithm is verified and evaluated by combining with the case of the basic finner projectile model and shows a good application ***,a numerical virtual flight simulation model based on overlapping dynamic mesh technology is *** order to verify the accuracy of the dynamic grid technology and the calculation of unsteady flow,a numerical simulation of the basic finner projectile without control is carried *** simulation results are in good agreement with the experiment data which shows that the algorithm used in this paper can also be used in the design and evaluation of the intelligent controller in the numerical virtual flight ***,combined with the real-time control requirements of aerodynamic,attitude and displacement parameters of the projectile during the flight process,the numerical simulations of the basic finner projectile’s pitch channel are carried out under the traditional PID(Proportional-Integral-Derivative)control strategy and the intelligent PID control strategy *** intelligent PID controller based on BP(Back Propagation)neural network can realize online learning and self-optimization of control parameters according to the acquired real-time flight *** with the traditional PID controller,the concerned control variable overshoot,rise time,transition time and steady state error and other performance indicators have been greatly improved,and the higher the learning efficiency or the inertia coefficient,the faster the system,the larger the overshoot,and the smaller the stability *** intelligent control method applying on numerical virtual flight is capable of solving the complicated unsteady motion and flow with the intelligent PID control strategy and has a strong promotion to engineering application.

关键词： Numerical virtual flight Intelligent control BP neural network PID Moving chimera grid

Intelligent representation method of image flatness for cold rolled strip

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Journal of Iron and Steel Research International 2024年第5期31卷 1177-1195页

作者： Yang-huan xu Dong-cheng Wang Hong-min Liu Bo-wei Duan National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment China National Heavy Machinery Research Institute Co.Ltd.Xi’an710018ShaanxiChina State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004HebeiChina

Real flatness images are the bases for flatness detection based on machine vision of cold rolled *** characteristics of a real flatness image are analyzed,and a lightweight strip location detection(SLD)model with deep semantic segmentation networks is *** interference areas in the real flatness image can be eliminated by the SLD model,and valid information can be *** this basis,the concept of image flatness is proposed for the first *** image flatness representation(IFAR)model is established on the basis of an autoencoder with a new *** optimal structure of the bottleneck layer is 16×16×4,and the IFAR model exhibits a good representation ***,interpretability analysis of the representation factors is carried out,and the difference and physical meaning of the representation factors for image flatness with different categories are *** flatness with new defect morphologies(bilateral quarter waves and large middle waves)that are not present in the original dataset are generated by modifying the representation factors of the no wave ***,the SLD and IFAR models are used to detect and represent all the real flatness images on the test *** average processing time for a single image is 11.42 ms,which is suitable for industrial *** research results provide effective methods and ideas for intelligent flatness detection technology based on machine vision.

关键词： Cold rolled strip Image flatness Location detection Representation learning Bottleneck layer

Unveiling the performance of a novel alkalizing bacterium Enterobacter ***-2 in immobilization of available Cd

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Journal of Environmental Sciences 2024年第3期137卷 245-257页

作者： Yixin Luo min Liao Xiongxiong Lu Na xu Xiaomei Xie Weiming Gao College of Environmental and Resource Science Zhejiang UniversityHangzhou 310058China Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment Hangzhou 310058China National Demonstration Center for Experimental Environmental and Resources Education Zhejiang UniversityHangzhou 310058China

A novel alkalizing strain Enterobacter ***-2 that could resist 400 mg/L Cd was isolated from Cd-contaminated soil,which immobilized 96.05%Cd^(2+)from *** distribution analysis demonstrated that more than half of the Cd^(2+)was converted into extracellular precipitated Cd through mobilization of the alkali-producing mechanism by the strain LYX-2,achieving the high immobilization efficiency of Cd^(2+).Biosorption experiments revealed that strain LYX-2 had superior biosorption capacity of 48.28 mg/g for *** experiments with Brassica rapa *** performed with and without strain *** to control,15.92%bioavailable Cd was converted to non-bioavailable Cd and Cd content in aboveground vegetables was decreased by 37.10%with addition of strain *** Cd was mainly immobilized through extracellular precipitation,cell-surface biosorption and intracellular accumulation of strain LYX-2,which was investigated through Cd distribution,Scanning Electron Microscope and Energy-Dispersive X-ray Spectroscopy(SEM-EDS),Fourier Transform Infrared Spectroscopy(FT-IR),X-ray Photoelectron Spectroscopy(XPS)and Transmission Electron Microscopy(TEM)*** addition,the application of strain LYX-2 significantly promoted the growth of vegetables about *** results indicated that highly Cd-resistant alkalizing strain LYX-2,as a novel microbial passivator,had excellent ability and reuse value to achieve the remediation of Cd-contaminated soil coupled with safe production of vegetables simultaneously.

关键词： Cadmium Enterobacter sp.LYX-2 Cd Immobilization Microbial passivator

Multiparameter Numerical Investigation of Two Types of Moving Interactions Between the Deep-Sea mining Vehicle Track Plate and Seabed Soil:Digging and Rotating Motions

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China Ocean Engineering 2024年第3期38卷 408-423页

作者： SUN Peng-fei LYU Hai-ning YANG jian-min xu Zhi-yong State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Yazhou Bay Institute of Deepsea SCI-TECH Shanghai Jiao Tong UniversitySanya 572024China Institute of Marine Equipment Shanghai Jiao Tong UniversityShanghai 200240China

To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track *** rotation and digging motions of the track plate are important links in the contact between the driving mechanism of the DSMV and seabed *** this study,a numerical simulation is conducted using the coupled Eulerian–Lagrangian(CEL)large deformation numerical method to investigate the interaction between the track plate of the DSMV and the seabed soil under two working conditions:rotating condition and digging ***,a soil numerical model is established based on the elastoplastic mechanical characterization using the basic physical and mechanical properties of the seabed soil obtained by in situ ***,the soil disturbance mechanism and the dynamic mechanical response of the track plate under rotating and digging conditions are obtained through the analysis of the sensitivity of the motion parameters,the grouser structure,the layered soil features and the soil *** results indicate that the above parameters remarkably influence the interaction between the DSMV and the seabed ***,it is important to consider the rotating and digging motion of the DSMV in practical engineering to develop a detailed optimization design of the track plate.

关键词： deep-sea mining vehicle rotating motion digging motion track plate-seabed soil interaction CEL numerical method

Upwelling current and its relationship to the enrichment of organic matter in the Lower Silurian Longmaxi Formation, northern Chongqing-western Hubei area, southern China

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Journal of Palaeogeography 2024年第4期13卷 993-1015页

作者： Jun-Jun Shen jia-Kai Yan Peng-Wan Wang Yu-Man Wang Lin Zhou Yu-Bing ji min xu Hubei Cooperative Innovation Center of Unconventional Oil and Gas of Yangtze University Hydrogeology and Engineering Geology Institute of Hubei Geological Bureau PetroChina Hangzhou Institute of Petroleum Geology PetroChina Research Institute of Petroleum Exploration and Development Exploration and Production Research Institute Zhejiang Oilfield Company Integrated Center of Exploration and Development

Upwelling currents play a crucial role in the enrichment of organic matter, yet the mechanisms driving this process remain incompletely understood due to methodological and data resolution limitations. In this paper, we employ a combination of biostratigraphic classification, qualitative methods, and quantitative methods to systematically analyze the sedimentological and geochemical characteristics of the Lower Silurian Longmaxi Formation in the northern Chongqing-western Hubei area, southern China. The relationship between the upwelling currents and organic matter enrichment in the shale of the Longmaxi Formation is investigated. Results indicate that the upwelling currents in the study area were primarily influenced by the foreland flexure process. From the Rhuddanian(flexure-sedimentation stage) to the Aeronian(flexure-migration stage), the more intense tectonic activity led to gradual opening of the barrier between the South Qinling Ocean and the Yangtze Platform, resulting in an increase in the influx of the oceanic current. The upwelling currents significantly contributed to the organic matter production, albeit without substantially affecting the preservation conditions. Throughout the succession of the Longmaxi Formation, the organic matter content decreased gradually from the passive continental margin to the foreland flexural stagnant basin, which was mainly due to deterioration of the preservation conditions as a result of sea level fall and increased terrigenous input. Despite the increase in the upwelling currents, they did not decisively control the organic matter enrichment. Spatially, during the Rhuddanian to Aeronian period, the organic matter content decreased similarly from the passive continental margin to the foreland flexural stagnant basin, influenced by reduced organic matter production caused by weakening of the upwelling currents and the worsening preservation conditions caused by sea-level fall. The terrigenous input had a relatively minor

关键词： Middle–Upper Yangtze Ordovician–Silurian transition Black shale Passive continental margin Foreland flexural stagnant basin Sedimentary paleoenvironment

Detection Algorithm of Laboratory Personnel Irregularities Based on Improved YOLOv7

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Computers, Materials & Continua 2024年第2期78卷 2741-2765页

作者： Yongliang Yang Linghua xu Maolin Luo Xiao Wang min Cao School of Electrical Engineering Guizhou UniversityGuiyang550025China

Due to the complex environment of the university laboratory,personnel flow intensive,personnel irregular behavior is easy to cause security *** using mainstream detection algorithms suffers from low detection accuracy and slow ***,the current management of personnel behavior mainly relies on institutional constraints,education and training,on-site supervision,etc.,which is time-consuming and *** the above situation,this paper proposes an improved You Only Look Once version 7(YOLOv7)to achieve the purpose of quickly detecting irregular behaviors of laboratory personnel while ensuring high detection ***,to better capture the shape features of the target,deformable convolutional networks(DCN)is used in the backbone part of the model to replace the traditional convolution to improve the detection accuracy and ***,to enhance the extraction of important features and suppress useless features,this paper proposes a new convolutional block attention module_efficient channel attention(CBAM_E)for embedding the neck network to improve the model’s ability to extract features from complex ***,to reduce the influence of angle factor and bounding box regression accuracy,this paper proposes a newα-SCYLLA intersection over union(α-SIoU)instead of the complete intersection over union(CIoU),which improves the regression accuracy while increasing the convergence *** experiments on public and homemade datasets show that the improved algorithm outperforms the original algorithm in all evaluation indexes,with an increase of 2.92%in the precision rate,4.14%in the recall rate,0.0356 in the weighted harmonic mean,3.60%in the mAP@0.5 value,and a reduction in the number of parameters and *** with the mainstream algorithm,the improved algorithm has higher detection accuracy,faster convergence speed,and better actual recognition effect,indicating the effectiveness of the improved algorithm in this p

关键词： University laboratory personnel behavior YOLOv7 deformable convolutional networks attention module intersection over union

Influence of transcatheter arterial embolization on symptom distress and fatigue in liver cancer patients

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 810-818页

作者： xu-min Yang xu-Yan Yang Xin-Yu Wang Yue-Xia Gu Department of Nursing The First Affiliated Hospital of Naval Medical University(Changhai Hospital)Shanghai 200433China Department of Thyroid Breast and Vascular SurgeryShanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China Department of Nursing Shanghai Fourth People’s Hospital Affiliated to Tongji University School of MedicineShanghai 200434China

BACKGROUND Hepatocellular carcinoma(HCC)is a prevalent malignancy,and transcatheter arterial embolization(TAE)has emerged as a pivotal therapeutic ***-ever,TAE may induce symptom distress and fatigue,adversely affecting the quality of life of *** To investigate symptom distress,fatigue,and associated factors in HCC patients undergoing *** We used a cross-sectional design and purposive sampling to enroll HCC patients who underwent TAE at our institution from January to December ***-naires were utilized to collect data on symptom distress and fatigue scores from the first to the third day after *** Our study revealed a significant reduction in fatigue and symptom distress among patients after ***,fatigue,insomnia,fever and abdominal dis-tension were the most common symptoms troubling patients during the first 3 d *** status,presence of family support,physical functional status,age,and symptom distress were identified as predictors of fatigue in *** Healthcare professionals should educate HCC patients on symptom distress and INTRODUCTION Hepatocellular carcinoma(HCC)ranks as the fifth most prevalent cancer and the third leading cause of cancer-related mortality *** intervention remains the cornerstone of HCC treatment;however,due to the challenges associated with early diagnosis and the lack of specific diagnostic markers,a considerable proportion of patients are diagnosed at advanced stages,rendering them ineligible for surgical *** arterial embolization(TAE)is an interventional therapeutic approach involving the insertion of a fine catheter via the femoral artery to reach the vasculature near the tumor *** aims to obstruct the arterial supply to the tumor by deploying embolic agents,thereby inducing necrosis in cancer *** procedure is suitable for patients with good liver function and overall health,particularly those with large HCCs that ha

关键词： Transcatheter arterial embolization Fatigue Symptom distress Hepatocellular carcinoma Influencing factors