检索结果-南通市图书馆

Method for the fruit tree recognition and navigation in complex environment of an agricultural robot

International Journal of Agricultural and Biological Engineering 2024年第2期17卷 221-229页

作者： Xiaolin Xie Yuchao Li Lijun Zhao xin jin Shengsheng Wang Xiaobing Han College of Agricultural Equipment Engineering Henan University of Science and TechnologyLuoyang 471003HenanChina Collaborative Innovation Center of Machinery Equipment Advanced Manufacturing of Henan Province Luoyang 471003HenanChina Longmen Laboratory Luoyang 471003HenanChina College of Intelligent and Manufacturing Engineering Chongqing University of Arts and SciencesChongqing 402160China

To realize the visual navigation of agricultural robots in the complex environment of orchards,this study proposed a method for fruit tree recognition and navigation based on *** YOLOv5s model was selected and trained to identify the trunks of the left and right rows of fruit trees;the quadratic curve was fitted to the bottom center of the fruit tree recognition box,and the identified fruit trees were divided into left and right columns by using the extreme value point of the quadratic curve to obtain the left and right rows of fruit trees;the straight-line equation of the left and right fruit tree rows was further solved,the median line of the two straight lines was taken as the expected navigation path of the robot,and the path tracing navigation experiment was carried out by using the improved LQR control *** experimental results show that under the guidance of the machine vision system and guided by the improved LQR control algorithm,the lateral error and heading error can converge quickly to the desired navigation path in the four initial states of[0 m,−0.34 rad],[0.10 m,0.34 rad],[0.15 m,0 rad]and[0.20 m,−0.34 rad].When the initial speed was 0.5 m/s,the average lateral error was 0.059 m and the average heading error was 0.2787 rad for the navigation trials in the four different initial *** average driving was 5.3 m into the steady state,the average value of steady state lateral error was 0.0102 m,the average value of steady state heading error was 0.0253 rad,and the average relative error of the robot driving along the desired navigation path was 4.6%.The results indicate that the navigation algorithm proposed in this study has good robustness,meets the operational requirements of robot autonomous navigation in orchard environment,and improves the reliability of robot driving in orchard.

关键词： fruit tree recognition visual navigation YOLOv5 complex environments orchards

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Gluing Affine Vortices

引用

Acta Mathematica Sinica,English Series 2024年第1期40卷 250-312页

作者： guang Bo XU Department of Mathematics Rutgers UniversityHill Center-Busch Campus 110 Frelinghuysen RoadPiscatawayNJ 08854-8019USA

We provide an analytical construction of the gluing map for stable affine vortices over the upper half plane with the Lagrangian boundary *** result is a necessary ingredient in studies of the relation between gauged ... 详细信息

关键词： Affine vortices gauged linear sigma model adiabatic limit symplectic reduction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Online diagnosis platform for tomato seedling diseases in greenhouse production

引用

International Journal of Agricultural and Biological Engineering 2024年第1期17卷 80-89页

作者： xin jin Xiaowu Zhu Jiangtao Ji Mingyong Li Xiaolin Xie Bo Zhao College of Agricultural Equipment Engineering Henan University of Science and TechnologyLuoyang 471003HenanChina Science&Technology Innovation Center for Completed Set Equipment Longmen LaboratoryLuoyang 471023HenanChina Institute of Mechatronics Technology and Application China Mechanized Agriculture Science Research Institute Group Co.LtdBeijing 100020China

The facility-based production method is an important stage in the development of modern agriculture,lifting natural light and temperature restrictions and helping to improve agricultural production *** address the problems of difficulty and low accuracy in detecting pests and diseases in the dense production environment of tomato facilities,an online diagnosis platform for tomato plant diseases based on deep learning and cluster fusion was proposed by collecting images of eight major prevalent pests and diseases during the growing period of tomatoes in a facility-based *** diagnostic platform consists of three main parts:pest and disease information detection,clustering and decision-making of detection results,and platform diagnostic ***,based on the You Only Look Once(YOLO)algorithm,the key information of the disease was extracted by adding attention module(CBAM),multi-scale feature fusion was performed using weighted bi-directional feature pyramid network(BiFPN),and the overall construction was designed to be compressed and lightweight;Secondly,the k-means clustering algorithm is used to fuse with the deep learning results to output pest identification decision values to further improve the accuracy of identification applications;Finally,a detection platform was designed and developed using Python,including the front-end,back-end,and database of the system to realize online diagnosis and interaction of tomato plant pests and *** experiment shows that the algorithm detects tomato plant diseases and insect pests with mAP(mean Average Precision)of 92.7%,weights of 12.8 Megabyte(M),inference time of 33.6 *** with the current mainstream single-stage detection series algorithms,the improved algorithm model has achieved better performance;The accuracy rate of the platform diagnosis output pests and diseases information of 91.2%for images and 95.2%for *** is a great significance to tomato pest control research and t

关键词： pest and disease detection YOLO diagnosis platform k-means clustering facility production base

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Metasurface-assisted low-frequency performance enhancement of ultra-broadband honeycomb absorber based on carbon nanotubes

引用

Nano Research 2024年第9期17卷 8542-8551页

作者： Cai-Liang Wang Shuang Bai Pei-Yan Zhao Tao Zhou Hui-Ya Wang Jun-Peng Wang Luo-xin Wang guang-Sheng Wang School of Chemistry Beihang UniversityBeijing 100191China Aerospace Science and Industry Corporation of Wuhan Magnetoelectricity Co. Ltd.Wuhan 430070China College of Materials Science and Engineering Key Laboratory for New Textile Materials and Applications of Hubei ProvinceWuhan Textile UniversityWuhan 430200China School of Chemistry and Chemical Engineering Lingnan Normal UniversityZhanjiang 524048China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China

Here,we present a unique method to enhance the low-frequency absorption performance of a honeycomb absorber by integrating a *** geometrical dimensions of the proposed metasurface have been numerically *** introduction of the metasurface allows exploitation of its robust resonance and superior impedance matching in low-frequency bands,thereby improving microwave absorption *** incorporation of the metasurface does not impact the wave transmission performance of the honeycomb core absorber at high-frequency band,thus preserving its high-frequency *** broadens the absorption range,leading to an expanded *** results reveal that the composite absorber(CA)exhibits strong absorption performance with an incident angle stability up to 45°for both transverse electric(TE)and transverse magnetic(TM)*** absorption mechanism of the CA has been investigated by using an equivalent circuit model and electromagnetic field analysis.A prototype was designed,fabricated,and tested to validate the proposed *** simulation and measurement results demonstrate that the prototype can achieve an average absorption rate exceeding 90%across a 1.0-18.0 GHz *** study introduces an innovative technique for creating microwave absorbers for low-frequency wideband applications.

关键词： low frequency metasurface radar absorption impedance matching

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Two missense STK11 gene variations impaired LKB1/adenosine monophosphate-activated protein kinase signaling in Peutz-Jeghers syndrome

引用

World Journal of Gastrointestinal Oncology 2024年第4期16卷 1532-1546页

作者： jin Liu Si-Cong Zeng An Wang Hai-Ying Cheng Qian-Jun Zhang guang-Xiu Lu Hunan guangxiu Hospital Hunan Normal UniversityChangsha 410000Hunan ProvinceChina Scientific Research Department Reproductive and Genetic Hospital of Citic-XiangyaChangsha 410000Hunan ProvinceChina

BACKGROUND Peutz-Jeghers syndrome(PJS)is a rare hereditary neoplastic disorder mainly associated with serine/threonine kinase 11(STK11/LKB1)gene *** genetic testing can protect a patient’s offspring from mutated genes;however,some variations in this gene have been interpreted as variants of uncertain significance(VUS),which complicate reproductive decision-making in genetic *** To identify the pathogenicity of two missense variants and provide clinical *** Whole exome gene sequencing and Sanger sequencing were performed on the peripheral blood of patients with PJS treated at the Reproductive and Genetic Hospital of *** was employed to predict the protein structure,conservation,and pathogenicity of the two missense variation sites in patients with ***,plasmids were constructed and transfected into HeLa cells to observe cell *** differences in signal pathway expression between the variant group and the wild-type group were compared using western blot and *** analysis was performed using one-way analysis of variance.PG(***297Gly)and c.733C>T(***245Phe)]in 9 unrelated PJS families who were seeking reproductive *** two missense VUS were located in the catalytic domain of serine/threonine kinase,which is a key structure of the liver kinase B1(LKB1)*** vitro experiments showed that the phosphorylation levels of adenosine monophosphate-activated protein kinase(AMPK)at Thr172 and LKB1 at Ser428 were significantly higher in transfected variation-type cells than in wild-type *** addition,the two missense STK11 variants promoted the proliferation of HeLa *** immunohistochemical analysis showed that phosphorylated-AMPK(Thr172)expression was significantly lower in gastric,colonic,and uterine polyps from PJS patients with misse

关键词： Missense STK11 Peutz-Jeghers syndrome Rare disease Genetic counseling Assisted reproductive technique

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Counterion-Mediated Hydrogen Bonding Making Strong Polyelectrolytes pH-Responsive:Current Understanding and Perspectives

引用

Chinese Journal of Polymer Science 2024年第9期42卷 1270-1277,I0005页

作者： Yue Huang guang-Tao Mei Zan Hua guang-Ming Liu Hefei National Research Center for Physical Sciences at the Microscale Department of Chemical PhysicsKey Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesUniversity of Science and Technology of ChinaHefei230026China The Key Laboratory of Functional Molecular Solids Ministry of Educationand Department of Materials ChemistrySchool of Chemistry and Materials ScienceAnhui Normal UniversityWuhu214002China

The counterion-mediated hydrogen bonding(CMHB)is related to the hydrogen bonding between bound counterions and polyelectrolyte chains in polyelectrolyte systems,where the counterions can both electrostatically bind to the charged groups of polyelectrolyte chains and act as hydrogen bond donors or acceptors to form hydrogen bonds with the hydrogen bond sites associated with polyelectrolyte chains simultaneously.A large number of literatures illustrate that strong polyelectrolytes(SPs)are insensitive to pH,which severely limmits the applications of SPs as smart ***,our studies have demonstrated that the CMHB makes SPs *** perspective discusses the mechanism of pH responsiveness of SPs and the pH-tunable properties of SPs,based on the pH-controlled CMHB *** future research directions on the pH responsiveness of SPs are also discussed *** is anticipated that the study of the pH responsiveness of SPs not only will provide a new understanding of the fundamental properties of SPs,but also will greatly expand the applications of SPs in the field of smart materials.

关键词： Counterion binding Hydrogen bond Polyelectrolyte brush Polyelectrolyte complexation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Association between serum estradiol level and appendicular lean mass index in middle-aged postmenopausal women

引用

World Journal of Orthopedics 2024年第1期15卷 45-51页

作者： Fang jin Yan-Fei Wang Zhong-xin Zhu Department of Osteoporosis Care and Control Xiaoshan Affiliated Hospital of Wenzhou Medical UniversityHangzhou 311200Zhejiang ProvinceChina

BACKGROUND Previous studies investigating the association between loss of estrogen at menopause and skeletal muscle mass came to contradictory *** To evaluate the association between serum estradiol level and appendicular lean mass index in middle-aged postmenopausal women using population-based *** This study included 673 postmenopausal women,aged 40-59 years,from the National Health and Nutrition Examination Survey between 2013 and *** multivariable linear regression models were used to evaluate the association between serum E2 Level and appendicular lean mass index(ALMI).When non-linear associations were found by using weighted generalized additive model and smooth curve fitting,two-piecewise linear regression models were further applied to examine the threshold *** There was a positive association between serum E2 level and *** to individuals in quartile 1 group,those in other quartiles had higher ALMI *** inverted U-shaped curve relationship between serum E2 Level and ALMI was found on performing weighted generalized additive model and smooth curve fitting,and the inflection point was identified as a serum E2 level of 85 pg/*** Our results demonstrated an inverted U-shaped curve relationship between serum E2 levels and ALMI in middle-aged postmenopausal women,suggesting that low serum E2 levels play an important in the loss of muscle mass in middleaged postmenopausal women.

关键词： Estradiol Skeletal muscle Menopause Health The National Health and Nutrition Examination Survey

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Highly anti-corrosive NiFe LDHs–NiFe alloy hybrid enables long-term stable alkaline seawater electrolysis

引用

Rare Metals 2024年第9期43卷 4321-4332页

作者： Jia-Hong Li Hao Chen Si-Hang You Gan-xin Yang Peng Liu Meng-Qi Gao Shu-guang Chen Fei-Fei Zhang School of Materials Science and Engineering Changsha University of Science and Technology Department of Materials Science and Engineering Faculty of Engineering National University of Singapore School of Materials Science and Engineering Jilin University

Owing to the significant potential of alkalin seawater electrolysis for converting surplus power into eco friendly hydrogen fuel,we developed bifunctional elec trodes that integrate low-crystalline NiFe LDHs and amorphous NiFe alloy on a Ni foam （NF） substrate to enhance this *** by the battery-like charac teristics of NiFe LDHs,an anti-corrosive and active oute layer of NiFevacOOH continuously forms over time in th hybrid on the anode for the oxygen evolution reaction（OER）,effectively mitigating powder shedding caused by corrosion induced by multiple anions in *** while,the strong bond between the hybrid and the NF substrate maintains intact hybrid coatings to ensure a rel atively high overall conductivity of the electrodes,signif icantly reducing the negative effects of structura degradation during the OER and hydrogen evolution reaction （HER）,as well as the accumulation of contami nants on the electrode *** long-term tests,thes bifunctionalhybridelectrodesmaintained stable performance,even at a high current density o500 mA·*** cell voltage increased by only 88 m V over 1000 h to 1.970 V during saline electrolysis and by103 mV over 500 h to 2.062 V during seawater electroly ***,this study provides valuable insights into efficient and stable seawater electrolysis using NiFe LDHs–NiFe alloy hybrids.

关键词： Bifunctional Corrosion NiFe LDHs Seawater electrolysis Stability

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Incidence,Risk Factors,and Prognosis of Patients with Hepatocellular Carcinoma and Brain Metastases

引用

Current Medical Science 2024年第1期44卷 180-186页

作者： jin-cheng FENG Ying HE Georgios Polychronidis Jian xin Shen YOU Jun XIONG Department of Liver Transplantation Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430022China Key Laboratory of Transplant Engineering and Immunology Laboratory of Liver TransplantationFrontiers Science Center for Disease-Related Molecular NetworkWest China HospitalSichuan UniversityChengdu 610041China Department of General Visceral and Transplant SurgeryUniversity of HeidelbergIm Neuenheimer Feld 110Heidelberg 69120Germany Department of Hepatobiliary and Pancreatic Surgery Fujian Provincial HospitalFuzhou 350001China

Objective Brain metastases significantly impact the clinical course of patients with hepatocellular carcinoma(HCC).This study aimed to examine the age-related incidence,demographics,and survival of patients with HCC and brain *** Data of HCC patients from 2010 to 2015 in the Surveillance,Epidemiology,and End Results(SEER)Registry were screened for the presence of brain *** were stratified by age and *** logistic and Cox regression analyses were used to identify factors associated with brain metastases and those with overall survival(OS)and liver cancer-specific survival(CSS),*** A total of 141 HCC patients presenting with brain metastases were identified,accounting for 0.35% of all HCC patients and 2.37% of patients with metastatic *** all HCC patients,the incidence rate was the highest among patients aged 30-49 years old(0.47%).Ethnicity was not associated with the presence of brain metastases at the time of HCC ***,African-American patients presented with a significantly lower disease-specific survival[median time:1 month;interquartile range(IQR):0-3.0 months].Initial lung or bone metastasis was independently associated with an increased risk of the presence of brain metastases[odds ratio(OR):12.62,95% confidence interval(CI):8.40-18.97]but was not associated with a worse OS or CSS among those with brain *** This study identified the age-related incidence and risk factors of brain metastases in HCC *** results may contribute to the consideration of brain screening among patients with initial metastatic HCC with lung or bone metastases,and influence the counseling of this patient population regarding their prognosis.

关键词： brain metastases hepatocellular carcinoma age-related incidence cancer-specific survival overall survival

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insight into vertical piezoelectric characteristics regulated thermal transport in van der Waals two-dimensional materials

引用

Rare Metals 2024年第2期43卷 770-779页

作者： Dong-Hai Wei E Zhou jin-Yuan Xu Hui-Min Wang Chen Shen Hong-Bin Zhang Zhen-Zhen Qin guang-Zhao Qin State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082China Hunan Key Laboratory for Micro-Nano Energy Materials and Device and School of Physics and Optoelectronics Xiangtan UniversityXiangtan411105China Institute of Materials Science Technical University of DarmstadtAlarich-Weiss-Str.264287DarmstadtGermany School of Physics and Microelectronics Zhengzhou UniversityZhengzhou450001China

The urgent demand of extreme(ultra-high/low)thermal conductivity materials is triggered by the high-power device,where exploring the theories and mechanisms of regulating thermal transport properties plays a key ***,we elaborately investigate the effect of vertical(out-of-plane)piezoelectric characteristics on thermal transport,which is historically *** different stacking-order(AA and AB)bilayer boron nitride(Bi-BN)in two-dimensional(2D)materials are selected as study *** performing state-of-the-art first-principles calculations,it is found that the polarization charge along the out-of-plane orientation ascends significantly with the increasing piezoelectric response in AB stacked Bi-BN(Bi-BN-AB)followed by the enhanced interlayer B–N atomic ***,the amplitude of phonon anharmonicity in Bi-BN-AB increases larger than that in the AA stacked Bi-BN(Bi-BN-AA),resulting in the dramatic weakening of the thermal conductivity by 20.34%under 18%*** research reveals the significant role of the vertical(out-of-plane)piezoelectric characteristic in regulating thermal transport and provides new insight into accurately exploring the thermal transport performance of 2D van der Waals materials.

关键词： Thermal conductivity Piezoelectric effect 2D materials Bilayer BN Strain engineering

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：