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Improving the underwater navigation performance of an IMU with acoustic long baseline calibration

Satellite Navigation 2024年第1期5卷 224-239页

作者： Paipai Wu Wenfeng Nie Yangfan Liu Tianhe Xu Shandong Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai264209ShandongChina Research group of Astronomy and Geomatics(gAGE) Universitat Politecnica de Catalunya(UPC)BarcelonaSpain

Underwater acoustic Long-Baseline System(LBL)is an important technique for submarine positioning and ***,the high cost of the seafloor equipment and complex construction of a seafloor network restrict the distribution of the LBL within a small area,making an underwater vehicle difficult for long-distance and high-precision acoustic-based or inertial-based *** therefore propose an acoustic LBL-based Inertial Measurement Unit(IMU)calibration *** the underwater vehicle can receive the acoustic signal from a seafloor beacon,the IMU is precisely calibrated to reduce the cumulative error of Strapdown Inertial Navigation System(SINS).In this way,the IMU is expected to maintain a certain degree of accuracy by relying solely on SINS when the vehicle reaches out the range of the LBL network and cannot receive the acoustic *** present the acoustic LBL-based IMU online calibration model and analyze the factors that affect the accuracy of IMU *** results fulfill the expectation that the gyroscope bias and accelerometer bias are the main error sources that affect the divergence of SINS position errors,and the track line of the underwater vehicle directly affects the accuracy of the calibration *** addition,we deduce that an optimal calibration trajectory needs to consider the effects of the three-dimensional observability and position dilution of *** the experiment,we compare the effects of seven calibration trajectories:straight and diamond-shaped with and without the change of depth,and three sets of curves with the change of depth:circular,S-shaped,and *** them,we find that the figure-eight is the optimal trajectory for acoustic LBL-based IMU online *** take the maintenance period during which the accumulated SINS Three Dimensional(3D)position errors are below 1 km to evaluate the calibration *** filed experimental results show that for the Micro-electromechanical System

关键词： Acoustic LBL Online IMU calibration SINS Relay reference network

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Mechanical properties of steel mesh in anchor-mesh support for rocky tunnels

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Journal of Mountain Science 2024年第10期21卷 3487-3502页

作者： SUN Keguo JIA Jinglong XU Weiping ZHANG Yu WANG Jinjin WANG Yichao LIU Yongkui Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSchool of Civil EngineeringSouthwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Intelligent Geotechnics and Tunnelling Chengdu 610031China Chengdu Rail Transit group Co. Ltd.Chengdu 610036China China Railway 14th Bureau group 2nd Engineering Corporation Limited China Railway Construction Corporation LimitedTaian 271000China

Underground geotechnical engineering encounters persistent challenges in ensuring the stability and safety of surrounding rock structures, particularly within rocky tunnels. Rock reinforcement techniques, including the use of steel mesh, are critical to achieving this goal. However, there exists a knowledge gap regarding the comprehensive understanding of the mechanical behavior and failure mechanisms exhibited by steel mesh under diverse loading conditions. This study thoroughly explored the steel mesh's performance throughout the entire loading-failure process, innovating with detailed analysis and modeling techniques. By integrating advanced numerical modeling with laboratory experiments, the study examines the influence of varying reinforcement levels and geometric parameters on the steel mesh strength and deformation characteristics. Sensitivity analysis, employing gray correlation theory, identifies the key factors affecting the mesh performance, while a BP (Backpropagation) neural network model predicts maximum vertical deformation with high accuracy. The findings underscore the critical role of steel diameter and mesh spacing in optimizing peak load capacity, displacement, and energy absorption, offering practical guidelines for design improvements. The use of a Bayesian Regularization (BR) algorithm further enhances the predictive accuracy compared to traditional methods. This research provides new insights into optimizing steel mesh design for underground applications, offering an innovative approach to enhancing structural safety in geotechnical projects.

关键词： Tunnel Steel mesh BP neural network Anchor-mesh support Rock reinforcement technique

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A Method of Evaluation Efficacy of Cosmetics Exfoliator and Its Application

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China Detergent & Cosmetics 2024年第2期9卷 43-48页

作者： Lai Qinrun Xu Sisi Ai Yan Zhu Siyang Hua An Tang Biological and Technology group China

Measuring the tanning skin can provide a scientific method to evaluate the efficacy of cosmetics ***(DHA,5.0%(w/w))was used to stain the inner forearms cuticle of *** skin surface L*and b*were determined,then ITA and its recovery rate were calculated to evaluate the exfoliating efficacy of *** results showed that no significant(P≥0.05)differences were observed for L*,b*and ITA on different skin surface of unstained *** staining with DHA,no adverse reaction was found in the stained areas,and the changes of L*,b*and ITA on different skin surface were consistent(P≥0.05).Two different cosmetics were used continuously to exfoliate the skin in different *** treatment for 7 days,the corresponding areas of skin L*,b*and ITA had significant(P<0.05)improvement in comparison with negative control *** there were differences in the evaluation results of the exfoliation efficacy using these three *** recovery rate of ITA of two samples improved significantly(P<0.05)than the negative control *** work indicated that using 5.0%DHA for skin browning and measuring the skin surface color change by ITA recovery rate can accurately and sensitively assess the skin cuticle renewal rate *** method can be used as one of the effective way to evaluate the efficacy of cosmetics exfoliation.

关键词： dihydroxyacetone exfoliator individual typology angle recovery rate

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China stroke surveillance report 2021

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Military Medical Research 2024年第3期11卷 374-399页

作者： Wen-Jun Tu Long-De Wang 无 Department of Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China School of Public Health Peking UniversityBeijing 100191China Special Writing group of China Stroke Surveillance Report

Since 2015,stroke has become the leading cause of death and disability in China,posing a significant threat to the health of its citizens as a major chronic non-communicable *** to the China Stroke High-risk Population Screening and Intervention Program,an estimated 17.8 million[95%confidence interval(CI)17.6–18.0million]adults in China had experienced a stroke in 2020,with 3.4 million(95%CI 3.3–3.5 million)experiencing their first-ever stroke and another 2.3 million(95%CI 2.2–2.4 million)dying as a ***,approximately 12.5%(95%CI 12.4%–12.5%)of stroke survivors were left disabled,as defined by a modified Rankin Scale score greater than 1,equating to 2.2 million(95%CI 2.1–2.2 million)stroke-related disabilities in *** the population ages and the prevalence of risk factors like diabetes,hypertension,and hyperlipidemia continues to rise and remains poorly controlled,the burden of stroke in China is also increasing.A large national epidemiological survey initiated by the China Hypertension League in 2017 showed that the prevalence of hypertension was 24.7%;the awareness,treatment,and control rates in hypertensive patients were:60.1%,42.5%,and 25.4%,respectively.A nationally representative sample of the Chinese mainland population showed that the weighted prevalence of total diabetes diagnosed by the American Diabetes Association criteria was 12.8%,suggesting there are 120 million adults with diabetes in China,and the awareness,treatment,and control rates in diabetic patients were:43.3%,49.0%,and 49.4%,***“Sixth National Health Service Statistical Survey Report in 2018”showed that the proportion of the obese population in China was 37.4%,an increase of 7.2 points from *** from 1599 hospitals in the Hospital Quality Monitoring System and Bigdata Observatory Platform for Stroke of China(BOSC)showed that a total of 3,418,432 stroke cases[mean age±standard error(SE)was(65.700±0.006)years,and 59.1%were male]were admitted dur

关键词： Stroke Epidemiological characteristics Treatment Prognosis China

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Three-dimensional Modeling of Ore-forming Elements and Mineralization Prognosis for the Yechangping Mo Deposit,Henan Province,China

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 736-752页

作者： DING Gaoming JI Genyuan YAN Guolong XU Yongzhong WANG Kunming XIAO Chun WANG Quanle GUO Dongbao China National Administration of Coal Geology Beijing 100038China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesCAGSBeijing 100037China China Gold group Geological Co. Ltd.Beijing 100011China China Gold group ZhongYuan Mining Co. Ltd.SanmenxiaHenan 472000China Lanzhou Mineral Exploration Institute of Gansu Nonferrous Metal Geological Exploration Bureau Lanzhou 730046China

Three-dimensional geochemical modeling of ore-forming elements is crucial for predicting deep *** approach provides key information for the quantitative prediction of deep mineral localization,three-dimensional fine interpolation,analysis of spatial distribution patterns,and extraction of quantitative mineral-seeking *** Yechangping molybdenum(Mo)deposit is a significant and extensive porphyry-skarn deposit in the East Qinling-Dabie Mo polymetallic metallogenic belt at the southern margin of the North China *** borehole data on oreforming elements underpin deep geochemical *** methodology includes the following steps:(1)Threedimensional geological modeling of the deposit was established.(2)Correlation,cluster,and factor analyses post delineation of mineralization stages and determination of mineral generation sequence to identify(Cu,Pb,Zn,Ag)and(Mo,W,mfe)assemblages.(3)A three-dimensional geochemical block model was constructed for Mo,W,mfe,Cu,Zn,Pb,and Ag using the ordinary kriging method,and the variational function was developed.(4)Spatial distribution and enrichment characteristics analysis of ore-forming elements are performed to extract geological information,employing the variogram and w(Cu+Pb+Zn+Ag)/w(Mo+W)as predictive indicators.(5)Identifying the western,northwestern,and southwestern areas of the mine with limited mineralization potential,contrasted by the northeastern and southeastern areas favorable for mineral exploration.

关键词： 3D geochemical model ore-forming elements geostatistics deep mineralization prediction Yechangping Mo deposit

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Study of plasma parameters of coaxial plasma source using triple Langmuir probe and Faraday cup diagnostics

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Plasma Science and Technology 2024年第4期26卷 94-100页

作者： Sunil KANCHI Rohit SHUKLA Archana SHARMA Pulsed Power and Electromagnetics Division Bhabha Atomic Research CentreVisakhapatnam 531011India Homi Bhabha National Institute Mumbai 400085India Beam Technology Development group Bhabha Atomic Research CentreMumbai 400085India

Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In this work, a 120° opening angle of CPG nozzle is used as a plasma gun configuration that operates at the energy of 150 J. The ionization of polyethylene insulator between the electrodes of the gun produces a cloud of hydrogen and carbon *** triple Langmuir probe and Faraday cup are used to measure plasma density and plasma temperature. These methods are used to measure the on-axis and off-axis plasma divergence of the coaxial plasma gun. The peak values of ion densities measured at a distance of 25 mm on-axis from the plasma gun are(1.6±0.5)×10^(19)m^(-3)and(2.8±0.6)×10^(19)m^(-3)for hydrogen and carbon plasma respectively and the peak temperature is 3.02±0.5 eV. The mean propagation velocity of plasma is calculated using the transit times of plasma at different distances from the plasma gun and is found to be 4.54±0.25 cm/μs and 1.81±0.18 cm/μs for hydrogen and carbon plasma respectively. The Debye radius is obtained from the measured experimental data that satisfies the thin sheath approximation. The shot-to-shot stability of plasma parameters facilitates the use of plasma guns in laboratory experiments. These types of plasma sources can be used in many applications like plasma opening switches, plasma devices, and as plasma sources.

关键词： coaxial plasma source triple Langmuir probe Faraday cup plasma density plasma temperature

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Controllable self-transport of bouncing droplets on ultraslippery surfaces with wedge-shaped grooves

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Droplet 2024年第2期3卷 138-145页

作者： Chuchen Yue Qingwen Dai Xiaolong Yang Carsten Gachot Wei Huang Xiaolei Wang College of Mechanical and Electrical Engineering Nanjing University of Aeronautics&AstronauticsNanjingChina Institute of Engineering Design and Product Development Tribology Research GroupTU WienViennaAustria

Preventing the accretion of droplets on surfaces is vital and slippery liquid-infused porous surfaces(SLIPS)have promising application prospects,such as surface self-cleaning and droplet *** this work,controllable self-transport of bouncing droplets on ultraslippery surfaces with wedge-shaped grooves is *** impact behaviors of droplets on SLIPS under various impact velocities and diameters are explored,which can be classified as hover,total bounce,partial bounce,Worthington jet,and *** with wedge-shaped grooves were designed to transport accreted *** energy and transport model is established to explain the impact and self-transport mechanism,where the Laplace pressure and moving resistance between droplets play a key ***,SLIPS with branched wedge-shaped grooves were designed for droplet self-transport and demonstrated *** work provides a general reference for spontaneous motion control of sessile droplets,droplets with initial impacting velocity,or even liquid films.

关键词： wedge shaped droplets

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Cleaner production of 3.5 valent vanadium electrolyte from ammonium metavanadate by ammonia reduction-sulfuric acid dissolution method

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Tungsten 2024年第3期6卷 555-560页

作者： Cheng Wang Lan-Jie Li Hao Du College of Chemical Engineering University of Chinese Academy of Sciences Institute of Process Engineering National Engineering Research Center of Green Recycling for Strategic Metal Resources Chinese Academy of Sciences Hesteel group Company Limited

The vanadium redox flow battery(VRFB) has been widely used in large-scale energy storage areas due to the advantages of long lifespan and high safety. However, the high preparation cost of vanadium electrolyte limits ... 详细信息

关键词： Ammonia

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Detection of Novel BEST1 Variations in Autosomal Recessive Bestrophinopathy Using Third-generation Sequencing

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Current Medical Science 2024年第2期44卷 419-425页

作者： Jia-xun LI Ling-rui MENG Bao-ke HOU Xiao-lu HAO Da-jiang WANG Ling-hui QU Zhao-hui LI Lei ZHANG Xin JIN Department of Senior Ophthalmology the Third Medical Center of PLA General HospitalBeijing 100853China Department of Ophthalmology the 74th Army Group HospitalGuangzhou 510318China

Objective:Autosomal recessive bestrophinopathy(ARB),a retinal degenerative disease,is characterized by central visual loss,yellowish multifocal diffuse subretinal deposits,and a dramatic decrease in the light peak on *** potential pathogenic mechanism involves mutations in the BEST1 gene,which encodes Ca2+-activated Cl−channels in the retinal pigment epithelium(RPE),resulting in degeneration of RPE and *** this study,the complete clinical characteristics of two Chinese ARB families were ***:Pacific Biosciences(PacBio)single-molecule real-time(SMRT)sequencing was performed on the probands to screen for disease-causing gene mutations,and Sanger sequencing was applied to validate variants in the patients and their family ***:Two novel mutations,c.202T>C(chr11:61722628,p.Y68H)and c.867+97G>A,in the BEST1 gene were identified in the two Chinese ARB *** novel missense mutation BEST1 c.202T>C(p.Y68H)resulted in the substitution of tyrosine with histidine in the N-terminal region of transmembrane domain 2 of *** novel variant,BEST1 c.867+97G>A(chr11:61725867),located in intron 7,might be considered a regulatory variant that changes allele-specific binding affinity based on motifs of important transcriptional ***:Our findings represent the first use of third-generation sequencing(TGS)to identify novel BEST1 mutations in patients with ARB,indicating that TGS can be a more accurate and efficient tool for identifying mutations in specific *** novel variants identified further broaden the mutation spectrum of BEST1 in the Chinese population.

关键词： autosomal recessive bestrophinopathy BEST1 gene third-generation sequencing mutation

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Development and validation of a nomogram prediction model for the risk of parastomal hernia

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Intelligent Medicine 2024年第2期4卷 128-133页

作者： Huasheng Liu Weiqin Wang Chen Qin Hongxia Wang Wei Qi Yanhua Wei Longbo Zheng Jilin Hu Department of Gastroenterology Affiliated Hospital of Qingdao UniversityQingdaoShandong 266003China Qingdao Municipal Hospital group QingdaoShandong 266300China Qingdao Center Medical group QingdaoShandong 266042China

Background Parastomal hernia is one of the potential complications after *** is currently no early risk assessment tool for parastomal *** The current investigation was conducted using retrospective studies.A total of 302 cases were used develop and internally to validate a nomogram prediction model,and 67 cases were used for external *** risk factors for parastomal hernia after permanent sigmoid colostomy were assessed via univariate analysis and binary logistic regression *** nomogram prediction model was established based on independent risk *** Body mass index,serum albumin,age,sex,and stoma diameter were independent risk factors for parastomal *** areas under the receiver operating characteristic curves were 0.909 in the development group and 0.801 in the validation *** Hosmer-Lemeshow test(P>0.05)and calibration curves indicated good consistency between actual observations and predicted *** A nomogram prediction model was constructed and validated based on risk factors for parastomal *** nomogram could be generalized to patients undergoing surgery for stoma by specialized surgeons to provide relevant references for stoma patients.

关键词： Nomogram Parastomal hernia Risk factors

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