检索结果-南通市图书馆

Bolt support mechanism based on elastic theory

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2013年第4期23卷 468-473页

作者： Guo Xiaoqian Mao Xianbiao Ma Chao huang jinglong State Key Laboratory of Geomechanics & Deep Underground Engineering China University of Mining & Technology School of Mechanics & Civil Engineering China University of Mining & Technology Hunan Provincial Key Laboratory of Healthy Maintenance for Mechanical Equipment Hunan University of Science and Technology

Mechanical model of anchorage surrounding rock considering tray effect was established based on elastic theory,in order to study the mechanism of bolt supporting.Elastic solutions of normal force at point in the interior of a semi-infnite solid were obtained by means of classical displacement function method in elasticity.The factors which influence stress of bolted surrounding rock,such as the length of bolt and tray effect,were analyzed.The absolute value of stress along bolt axes decreased rapidly with an increase in radical distance and the maximum appeared near ends of bolt.With increasing radical distance,the value of radical stress changed from positive to negative roughly and then increased to zero,with maximum at the middle of bolt.The evolution of hoop stress as radical distance increasing was similar with stress along bolt axes.With an increase in depth,the radical effect ranges of all normal stress components were reduced.These suggest that the effect from tray on stress along bolt axes of bolted surrounding rock could be neglected,except near surface of surrounding rock.

关键词： Elastic theory Bolt support Displacement function method Stress along bolt axes

Action mechanism of a mechanical end-anchorage bolt

在线全文

学校读者我要写书评

暂无评论

Mining Science and Technology 2010年第4期20卷 625-628页

作者： WU Yu MAO Xianbiao huang jinglong SUN Fengjuan YAO Banghua State Key Laboratory of Geomechanics and Deep Underground Engineering China University of Mining & Technology Xuzhou 221008 China School of Mechanics and Civil Engineering China University of Mining & Technology Xuzhou 221116 China

Axial compression stress, produced by the pre-tightening force of a bolt, is a necessary condition for surrounding rock to form a whole structure. For this study, we built a mechanical model for an end-anchorage bolt, which represented the effect of a bolt on the surrounding rock in roadways in order to obtain its elastic solution. Simultaneously, we analyzed factors affecting the axial compression of the bolt on the surrounding rock and obtained the axial stress contours of the anchorage area through this elastic solution. The results indicate that 1) the axial compression stress in the anchorage area is proportional to the pre-tightening force and confirms the rule that stress declines sharply with the increase in axial distance from the bolt, with an effective stress radius of 1 m; 2) the maximum axial compression stress declines first and then rises with the increase in depth from the surface of the anchorage surrounding rock and 3) the size of the axial compression area is mainly determined by the length of the bolt.

关键词：锚固螺栓轴向应力螺栓预紧力机制机械巷道围岩弹性力学模型压应力

HS-SPME-GC-MS与ROAV相结合的4种柑橘果皮精油关键香气物质分析

在线全文

学校读者我要写书评

暂无评论

现代食品科技 2024年第5期40卷 221-230页

作者：李丽蒋景龙胡佳乐师一璇黄佩丁德宽陕西理工大学化学与环境科学学院陕西省催化基础与应用重点实验室陕西汉中723001 陕西理工大学生物科学与工程学院陕西汉中723001 城固县果业技术指导站陕西汉中723200

采用顶空-固相微萃取-气相色谱质谱联用法(HS-SPME-GC-MS)对4种柑橘果皮精油挥发性物质的组成和含量进行分析鉴定,结合相对气味活度值(Relative Odor Activity Value,ROAV)对4种柑橘果皮精油中的关键香气成分进行分析,以期为柑橘果皮精... 详细信息

采用顶空-固相微萃取-气相色谱质谱联用法(HS-SPME-GC-MS)对4种柑橘果皮精油挥发性物质的组成和含量进行分析鉴定,结合相对气味活度值(Relative Odor Activity Value,ROAV)对4种柑橘果皮精油中的关键香气成分进行分析,以期为柑橘果皮精油品质评价与发掘特殊香气柑橘精油提供依据。结果表明,4种柑橘果皮精油共鉴定出62种挥发性成分,包括13种单萜、14种倍半萜、5种烷烃、12种醇类、8种醛类、4种酯类、3种酮类、2种醚类和1种酸类。4种柑橘果皮精油均以单萜化合物相对含量最高(83.00%~91.93%)。按照化合物组成,可将4种柑橘分为2个化学类型:柠檬烯/γ-萜品烯型和柠檬烯/3-蒈烯型。ROAV法从4种柑橘果皮精油中筛选出24种关键香气物质,其中北京柠檬果皮精油中风味贡献最大的物质为紫苏醛,关键香气物质共10种;温州蜜柑、酸橙和枳雀果皮精油中风味贡献最大的物质均为芳樟醇,关键香气物质分别为12种、20种和20种。这些关键香气物质对柑橘果皮精油的香气品质起着重要的作用。

关键词：柑橘果皮精油顶空-固相微萃取挥发性成分相对气味活度值

A new noise network and gradient parallelisation‐based asynchronous advantage actor‐critic algorithm

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

IET Cyber-Systems and Robotics 2022年第3期4卷 175-188页

作者： Zhengshun Fei Yanping Wang jinglong Wang Kangling Liu Bingqiang huang Ping Tan Provincial Key Institute of Robotics School of Automation and Electrical EngineeringZhejiang University of Science and TechnologyHangzhouChina State Key Lab of Industrial Control Technology College of Control Science and EngineeringZhejiang UniversityHangzhouChina

Asynchronous advantage actor‐critic(A3C)algorithm is a commonly used policy opti-mization algorithm in reinforcement learning,in which asynchronous is parallel inter-active sampling and training,and advantage is a sampling multi‐step reward estimation method for computing weights.In order to address the problem of low efficiency and insufficient convergence caused by the traditional heuristic exploration of A3C algorithm in reinforcement learning,an improved A3C algorithm is proposed in this paper.In this algorithm,a noise network function,which updates the noise tensor in an explicit way is constructed to train the agent.Generalised advantage estimation(GAE)is also adopted to describe the dominance function.Finally,a new mean gradient parallelisation method is designed to update the parameters in both the primary and secondary networks by summing and averaging the gradients passed from all the sub‐processes to the main process.Simulation experiments were conducted in a gym environment using the PyTorch Agent Net(PTAN)advanced reinforcement learning library,and the results show that the method enables the agent to complete the learning training faster and its convergence during the training process is better.The improved A3C algorithm has a better performance than the original algorithm,which can provide new ideas for sub-sequent research on reinforcement learning algorithms.

关键词： asynchronous advantage actorcritic (A3C) generalised advantage estimation (GAE) parallelisation reinforcement learning

铝土矿尾矿协同钒钛磁铁矿尾矿制备刚玉质复相陶瓷

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

矿产保护与利用 2024年第2期44卷 99-105页

作者：陈靖龙郎增瑞杨帆陈新义闵鑫房明浩黄朝晖黄妃慧中国地质大学(北京)材料科学与工程学院地质碳储与资源低碳利用教育部工程研究中心非金属矿物与固废资源材料化利用北京市重点实验室矿物材料国家专业实验室北京100083 凌源钢铁股份有限公司辽宁凌源122504 山东奥福环保科技股份有限公司山东德州251599

以铝土矿尾矿和钒钛磁铁矿尾矿为原料,经混料、成型和高温烧成等工艺制备了刚玉质复相陶瓷,研究了钒钛磁铁矿尾矿添加量、烧成温度等因素对制得复相陶瓷材料的物相、显微形貌及力学性能的影响规律。结果表明:当铝土矿尾矿与钒钛磁铁矿... 详细信息

以铝土矿尾矿和钒钛磁铁矿尾矿为原料,经混料、成型和高温烧成等工艺制备了刚玉质复相陶瓷,研究了钒钛磁铁矿尾矿添加量、烧成温度等因素对制得复相陶瓷材料的物相、显微形貌及力学性能的影响规律。结果表明:当铝土矿尾矿与钒钛磁铁矿尾矿质量比为9∶1时,在1100℃下保温3 h制得刚玉质复相陶瓷材料的性能最优,其体积密度为2.71 g/cm^(3),抗压强度为276.9 MPa,抗折强度为67.3 MPa。

关键词：铝土矿尾矿钒钛磁铁矿尾矿烧成温度力学性能刚玉质复相陶瓷

Artificial intelligence-based medical image segmentation for 3D printing and naked eye 3D visualization

在线全文

学校读者我要写书评

暂无评论

Intelligent Medicine 2022年第1期2卷 48-53页

作者： Guang Jia Xunan huang Sen Tao Xianghuai Zhang Yue Zhao Hongcai Wang Jie He Jiaxue Hao Bo Liu Jiejing Zhou Tanping Li Xiaoling Zhang jinglong Gao School of Computer Science and Technology Xidian UniversityXi’anShaanxi 710068China Shaanxi Xinweitai Biological Technology Co. Ltd.Xi’anShaanxi 710065China Department of Radiation Oncology Tangdu Hospital Affiliated to Air Force Medical UniversityXi’anShaanxi 710071China School of Physics and Optoelectronic Engineering Xidian UniversityXi’anShaanxi 710071China Shaanxi Provincial People’s Hospital Xi’anShaanxi 710068China

Image segmentation for 3D printing and 3D visualization has become an essential component in many fields of medical research,teaching,and clinical practice.Medical image segmentation requires sophisticated computerized quantifications and visualization tools.Recently,with the development of artificial intelligence(AI)technology,tumors or organs can be quickly and accurately detected and automatically contoured from medical images.This paper introduces a platform-independent,multi-modality image registration,segmentation,and 3D visualization program,named artificial intelligence-based medical image segmentation for 3D printing and naked eye 3D visualization(AIMIS3D).YOLOV3 algorithm was used to recognize prostate organ from T2-weighted MRI images with proper training.Prostate cancer and bladder cancer were segmented based on U-net from MRI images.CT images of osteosarcoma were loaded into the platform for the segmentation of lumbar spine,osteosarcoma,vessels,and local nerves for 3D printing.Breast displacement during each radiation therapy was quantitatively evaluated by automatically identifying the position of the 3D printed plastic breast bra.Brain vessel from multimodality MRI images was segmented by using model-based transfer learning for 3D printing and naked eye 3D visualization in AIMIS3D platform.

关键词： Medical image segmentation Artificial intelligence Tumor segmentation 3D printing Voice recognition Gesture recognition

A critical review on the biomechanical study of cervical interbody fusion cage

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Medicine in Novel Technology and Devices 2021年第3期11卷 47-84页

作者： Huiwen huang jinglong Liu Lizhen Wang Yubo Fan Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education Beijing Advanced Innovation Center for Biomedical EngineeringSchool of Biological Science and Medical EngineeringBeihang UniversityBeijingChina

Anterior Cervical Discectomy and Fusion(ACDF)is the preferred surgical method for the treatment of severe cervical degenerative disc disease with radiculopathy or myelopathy,of which the objectives are to restore the normal height of intervertebral space and cervical lordosis through the implantation of cervical interbody fusion cage.The biomechanical performance of a cervical interbody fusion cage,which plays a significant role in achieving the goals of ACDF,is influenced by multiple factors.In this paper,various studies focusing on the biomechanical performance of cervical interbody fusion cage are reviewed.Furthermore,the research methods,biomechanical evaluation parameters and data analysis methods of these research are analyzed in order to obtain a comprehensive understanding of the progress and limitations of research in this field.Although great progress has been made to clarify the biomechanical behaviors of cervical interbody fusion cage,there is still controversy regarding the issues such as the relative contribution of multiple factors to the performance of cage,the interactions among these factors,as well as whether the effects of factors change with the process of intervertebral osseointegration and so on.Thus,investigations are still needed to improve the comprehension of cervical interbody fusion cage biomechanically.

关键词： Anterior cervical discectomy and fusion Cervical interbody fusion cage Biomechanical performance Mechanical stability Cage subsidence Adjacent segment degeneration

Cu基金属卤化物发光材料(C_(12)H_(24)O_(6))NaCuBr_(2)及其全光谱照明应用

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

发光学报 2023年第3期44卷 528-536页

作者：黄敬龙金建策苏彬彬夏志国华南理工大学材料科学与工程学院发光材料与器件国家重点实验室广东省光纤激光材料与应用技术重点实验室广东省特种光纤材料与器件工程技术研究开发中心广东广州510641 华南理工大学物理与光电学院广东广州510641

铜(Ⅰ)基金属卤化物作为新一代环境友好的发光材料受到了研究者的广泛关注。本文采用溶剂辅助结晶法设计制备了一种新型零维金属卤化物发光材料(C_(12)H_(24)O_(6))NaCuBr_(2)。在365 nm激发下,该化合物呈现出半峰宽为346 nm的超宽带橙... 详细信息

铜(Ⅰ)基金属卤化物作为新一代环境友好的发光材料受到了研究者的广泛关注。本文采用溶剂辅助结晶法设计制备了一种新型零维金属卤化物发光材料(C_(12)H_(24)O_(6))NaCuBr_(2)。在365 nm激发下,该化合物呈现出半峰宽为346 nm的超宽带橙红色发射,光致发光量子产率为42.6%。基于低温光谱、激发波长依赖的发射光谱和理论计算研究表明,峰值700 nm处的超宽带发射来自于Cu^(+)离子3d轨道和Br^(-)离子4p轨道间相互作用形成的简并能级。在低温下,(C_(12)H_(24)O_(6))NaCuBr_(2)的晶格畸变导致能级的简并度降低,其荧光发射包含峰值为629 nm和735 nm的两个发射带。在高能激发下,电子跃迁到(C_(12)H_(24)O_(6))NaCuBr_(2)的更高能级S3而带来的发射与77 K下观测到的480 nm处的发射峰相对应。采用(C_(12)H_(24)O_(6))NaCuBr_(2)制备的白光发光二极管(LED)器件的显色指数高达90.6,表明其在全光谱照明领域具有潜在的应用前景。

关键词：零维结构 Cu基金属卤化物全光谱照明

Establishment of a selective evaluation method for DPP4 inhibitors based on recombinant human DPP8 and DPP9 proteins

在线全文

学校读者我要写书评

暂无评论

Acta Pharmaceutica Sinica B 2014年第2期4卷 135-140页

作者： jinglong Liu Yi Huan Caina Li Minzhi Liu Zhufang Shen State Key Laboratory of Bioactive Substances and Functions of Natural Medicines Diabetes Research CenterInstitute of Materia MedicaChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100050China

Dipeptidyl peptidase 4(DPP4)is recognised as an attractive anti-diabetic drug target,and several DPP4 inhibitors are already on the market.As members of the same gene family,dipeptidyl peptidase 8(DPP8)and dipeptidyl peptidase 9(DPP9)share high sequence and structural homology as well as functional activity with DPP4.However,the inhibition of their activities was reported to cause severe toxicities.Thus,the development of DPP4 inhibitors that do not have DPP8 and DPP9 inhibitory activity is critical for safe anti-diabetic therapy.To achieve this goal,we established a selective evaluation method for DPP4 inhibitors based on recombinant human DPP8 and DPP9 proteins expressed by Rosetta cells.In this method,we used purified recombinant 120 kDa DPP8 or DPP9 protein from the Rosetta expression system.The optimum concentrations of the recombinant DPP8 and DPP9 proteins were 30 ng/mL and 20 ng/mL,respectively,and the corresponding concentrations of their substrates were both 0.2 mmol/L.This method was highly reproducible and reliable for the evaluation of the DPP8 and DPP9 selectivity for DPP4 inhibitor candidates,which would provide valuable guidance in the development of safe DPP4 inhibitors.

关键词： DPP4 DPP8 DPP9 Inhibitor Selective evaluation method