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南水回补区地下水水质敏感指标识别及关联性研究

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北京师范大学学报（自然科学版） 2023年第2期59卷 288-298页

作者：王琦郭学茹段小刚王树芳左锐王金生刘鑫翟远征孟利北京师范大学统计学院北京100875 地下水污染控制与修复教育部工程研究中心北京100875 北京市地质环境监测所北京100195 北京师范大学水科学研究院北京100875 天津师范大学天津市水资源与水环境重点实验室天津300387

基于北京市通州区2011-2019年地下水位及水质数据,构建了区内南水北调回补前后多个水质指标的ROC曲线;通过识别受回补影响的、AUC>0.7的高度敏感性指标Fe^(3+)质量浓度,以及AUC为0.6~0.7的中度敏感性指标NO_(3)^(-)、NO_(2)^(-)和F^(-)... 详细信息

基于北京市通州区2011-2019年地下水位及水质数据,构建了区内南水北调回补前后多个水质指标的ROC曲线;通过识别受回补影响的、AUC>0.7的高度敏感性指标Fe^(3+)质量浓度,以及AUC为0.6~0.7的中度敏感性指标NO_(3)^(-)、NO_(2)^(-)和F^(-)质量浓度后发现:Fe^(3+)在回补后总体质量浓度变小;NO_(3)^(-)、NO_(2)^(-)和F^(-)质量浓度变大.以F^(-)为例,构建了R-V copula模型,结果表明:与F^(-)敏感性密切相关的指标分别为Ca^(2+)、Mg^(2+)、Na^(+)、Cl^(-)质量浓度和pH;关联性的具体表现是Ca^(2+)质量浓度与F^(-)质量浓度明显负相关,区内地下水回补后Ca^(2+)质量浓度下降,激发了F^(-)的活跃度;pH与F^(-)通过Ca^(2+)产生间接相关关系,当pH增大、环境偏碱性时,水中Ca^(2+)的活性降低,利于F^(-)富集;Mg^(2+)、Na^(+)、Cl^(-)与F^(-)的质量浓度表现为正相关关系,其中Mg^(2+)与F^(-)的质量浓度相关关系受溶滤作用以及水力联系的影响,Cl^(-)与F^(-)的质量浓度同时增大,这是由于存在置换反应;Na^(+)在Ca^(2+)质量浓度较低时与F^(-)发生吸附解吸,从而得以富集.区内控制回补后地下水中F^(-)敏感富集,主要是因为回补不但激发了原生地质成因的含氟矿物溶解与混合稀释作用对含氟矿物溶解的促进,而且也加速了Cl^(-)与F^(-)的相互置换、Na^(+)与F^(-)的吸附解吸.研究成果可深化对南水北调回补区水质演化机制的认识,为北京城市副中心未来的地下水监测管理与供水安全保障提供理论支撑和决策依据.

关键词：南水北调地下水回补 ROC曲线敏感指标 R-V copula

插管与非插管麻醉在单孔胸腔镜下行胸交感神经节切断术的效果

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山西医科大学学报 2017年第3期48卷 296-300页

作者：温健段娜李小刚景桂霞王强肖颖西安交通大学第一附属医院麻醉科西安710061

目的比较插管和非插管两种麻醉方法在单孔胸腔镜下行胸交感神经链切断术的效果。方法 60例在电视胸腔镜下行双侧交感神经干切断术的手汗症患者,按随机数字表法分为非气管插管组和气管插管组,每组30例。非气管插管组采用T_4-5硬膜外阻滞... 详细信息

目的比较插管和非插管两种麻醉方法在单孔胸腔镜下行胸交感神经链切断术的效果。方法 60例在电视胸腔镜下行双侧交感神经干切断术的手汗症患者,按随机数字表法分为非气管插管组和气管插管组,每组30例。非气管插管组采用T_4-5硬膜外阻滞复合胸内迷走神经阻滞,气管插管组采用左侧双腔气管插管全身麻醉。分别于麻醉前(T_0)、右侧胸腔开放后5 min(T_1)、右侧膨肺前(T_2)、右侧胸腔关闭后5 min(T_3)、左侧胸腔开放后5 min(T_4)、左侧膨肺前(T_5)、左侧胸腔关闭后5min(T_6)、返回病房(T_7),分别记录患者SBP、DBP、HR、RR、SpO_2、P_(ET)CO_2及术中视野暴露情况、麻醉效果、麻醉时间、手术时间、术后相关并发症、术后护理强度、麻醉费用、术后开始进食时间、术后开始下地活动时间、住院时间和患者满意度。结果所有手术均顺利完成,没有中转开胸情况发生。围术期两组患者SBP、DBP、HR均在正常范围内,非插管组患者氧饱和度在在T_1-T_5时点较术前下降,最低值91%,呼吸末二氧化碳在T_2、T_5时点较术前升高,最高值65 mmHg,高于插管组患者(P0.05),非插管组麻醉时间、术后护理强度、术后开始进食、下地活动时间、住院时间、术后咽喉不适、恶心呕吐情况低于插管组(P<0.05)。非插管组患者的满意度评分高于插管组(P<0.05)。结论应用非插管麻醉方式在单孔胸腔镜下胸交感神经干切断术中,具有术后并发症少、恢复快和花费少的优势,但是需要严格把握适应证,术前做好应急预案,保证患者安全。

关键词：气管插管非气管插管单孔胸腔镜胸交感神经节切断术电视胸腔镜手术

Mathematical and computational approaches to epidemic modeling： a comprehensive review

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Frontiers of Computer Science 2015年第5期9卷 806-826页

作者： Wei duan Zongchen FAN Peng ZHANG Gang GUO xiaogang QIU Center of Computational Experiments and Parallel Systems Technology College of Information Systems and Management National University of Defense Technology Chang sha 410073 China

Mathematical and computational approaches are important tools for understanding epidemic spread patterns and evaluating policies of disease control. In recent years, epidemiology has become increasingly integrated with mathematics, sociology, management science, complexity science, and computer science. The cross of multiple disciplines has caused rapid development of mathematical and computational approaches to epidemic modeling. In this article, we carry out a comprehensive review of epidemic models to provide an insight into the literature of epidemic modeling and *** introduce major epidemic models in three directions, including mathematical models, complex network models, and agent-based models. We discuss the principles, applications, advantages, and limitations of these models. Meanwhile, we also propose some future research directions in epidemic modeling.

关键词： mathematics complex networks agent-basedmodels epidemic modeling human dynamics infectious diseases

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基于树莓派平台的柑橘智能识别与采摘

中南林业科技大学学报 2023年第8期43卷 192-201页

作者：杨环宇黄文静李义华段小刚康思宇王子怡罗肖媛蒋勉中南林业科技大学材料科学与工程学院湖南长沙410004 中南林业科技大学物流与交通学院湖南长沙410004 中国科学技术大学大数据学院安徽合肥230026 中南智能湖南工业4.0创新中心湖南长沙410017 佛山科学技术学院机电工程与自动化学院广东佛山528000

【目的】基于树莓派平台,设计轻便式的柑橘智能识别与机器人采摘,为柑橘采摘减轻劳动力与机械智能化提供理论与实验依据。【方法】制作柑橘数据集,使用深度卷积神经网络(YOLOv4-tiny)验证柑橘数据集的有效性,同时在电脑上离线训练好YOLO... 详细信息

【目的】基于树莓派平台,设计轻便式的柑橘智能识别与机器人采摘,为柑橘采摘减轻劳动力与机械智能化提供理论与实验依据。【方法】制作柑橘数据集,使用深度卷积神经网络(YOLOv4-tiny)验证柑橘数据集的有效性,同时在电脑上离线训练好YOLOv4-tiny柑橘识别模型;基于树莓派平台,嵌入YOLOv4-tiny模型,设计柑橘智能识别系统;建立五自由度机械臂运动学模型与轨迹规划函数,嵌入树莓派平台。使用树莓派开发板、一个摄像头以及小型五自由度机器人,手动启动树莓派中的YOLOv4-tiny模型,系统自动完成柑橘识别与采摘,具体步骤为:调用OpenCV开启摄像头,将摄像头采集到的视频转换为Im格式,并输入YOLOv4-tiny模型中,模型识别出待采摘柑橘的位置,机械臂再进行实际采摘。【结果】深度卷积神经网络(YOLOv4-tiny)模型对橘子二维坐标识别率为98%,嵌入树莓派后,结合目标到相机距离相似三角形计算法,能准确识别柑橘位置三维坐标(-3.2,19.7,16);驱动机械臂到达位置坐标后,再令夹持器夹紧并摘取柑橘,先后共调试80次,得到机械臂运动最佳时间为1000ms、夹持器末端采摘动作的最佳运动时间为500ms,末端夹持器摘取的平均角度为-60度,这样采摘时速度合适也不会发生抖动;进行了20次采摘测试,平均成功摘取率达到了90%以上。【结论】基于树莓派平台设计的柑橘深度识别与采摘系统,能实现柑橘三维位置坐标的识别并准确采摘,为机器人柑橘采摘的智能化提供了一定的理论基础与实验借鉴。

关键词：深度卷积神经网络(YOLOv4-tiny) 树莓派机械臂运动学轨迹规划

Thiocytochalasins A−D,four sulfur-containing cytochalasans from an endophytic fungus Phoma multirostrata XJ-2-1

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Chinese Chemical Letters 2022年第10期33卷 4572-4576页

作者： xiaogang Peng Jinling Chang Ying Gao Fangfang duan Hanli Ruan School of Pharmacy Tongji Medical CollegeHuazhong University of Science and TechnologyHubei Key Laboratory of Natural Medicinal Chemistry and Resource EvaluationWuhan 430030China

Four unprecedented sulfur-containing cytochalasans,thiocytochalasins A−D(1−4),were isolated from an endophytic fungus Phoma multirostrata *** A(1)and B(2)feature a novel 5/6/14/5 tetracyclic scaffold,which are the first examples of cytochalasan containing a thiophene *** C(3)and D(4)are epimeric cytochalasan homodimers formed via a thioether *** structures with absolute configurations were established by detailed analysis of the HRESIMS,NMR,and X-ray *** plausible biogenetic pathway of 1−4 was *** 3 and 4 exhibited significant cytotoxicity against CT26 cells with IC_(50) values of 0.85 and 0.76µmol/L,respectively.

关键词： Phoma multirostrata XJ-2-1 Sulfur-containing cytochalasans Thiocytochalasins A-D Cytotoxicity Cell cycle

Analysis of elastoplasticity and rheology due to mining subsidence

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Science China Earth Sciences 2008年第6期51卷 826-836页

作者： WU Xiong WANG xiaogang duan QingWei JIA ZhiXin XU NengXiong SUN YanDong School of Water Resources and Environment China University of GeosciencesBeijing 100083China China Institute of Water Resources and Hydropower Research Beijing 100044China

At present, as the easily mining resources are being increasingly depleted, the exploitation of coal under buildings, water-bodies and railways is imminent for the sustainable production. Probability in-tegral method is a general method for mining subsidence in the coal system. Because of poor under-standing of mining subsidence for other sections, the authors suggest probability integral method for the study of coal mining under buildings, water-bodies and railways. Moreover, the calculation result of probability integral method should be corrected by numerical simulation method. Based on practical projects, the impact has been evaluated on the security of Xifeihe left embankment under coal mining. Combining with the results of probability integral method, we propose that the 600 m far from em-bankment is a good rationality. This article provides the basis for the rational exploitation of coal re-source which is a major practical problem under the premise of Water Infrastructure Security. Fur-thermore, it also can be served as a reference for the similar projects, such as mining Xiaolangdi res-ervoir area, mining Yuecheng reservoir and mining the major channels of Middle Route South to North Water Transfer.

关键词： mining subsidence numerical simulation the elastoplasticity model rheological model the evaluation of embankment safety

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茶树树体管理技术研究进展

中国茶叶 2024年第8期46卷 23-29页

作者：何永雷小刚马媛春段玉江杰朱旭君房婉萍南京农业大学园艺学院江苏南京210032

茶树树体管理是对茶树进行的一系列栽培和管理措施,旨在优化树体结构、提高茶叶产量和品质,是确保茶园高产优质的重要手段。目前,国内外关于茶树树体管理的研究,多是从修剪时间、修剪方式、机械管理、水肥管理和对茶树生长的调节等方面... 详细信息

茶树树体管理是对茶树进行的一系列栽培和管理措施,旨在优化树体结构、提高茶叶产量和品质,是确保茶园高产优质的重要手段。目前,国内外关于茶树树体管理的研究,多是从修剪时间、修剪方式、机械管理、水肥管理和对茶树生长的调节等方面进行探讨。文章以茶树树体管理技术相关研究为主线,对现有领域的研究状况进行了分析,并对当前茶树管理中存在的问题进行了探讨,为建立健全茶树树体管理技术体系提供相关的研究思路和方向。

关键词：茶树修剪机械化管理水肥管理

维普期刊数据库博看期刊

Indirectly extruded biodegradable Zn-0.05wt%Mg alloy with improved strength and ductility： In vitro and in vivo studies

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Journal of Materials Science & Technology 2018年第9期34卷 1618-1627页

作者： Chi Xiao Liqing Wang Yuping Ren Shineng Sun Erlin Zhang Chongnan Yan Qi Liu xiaogang Sun Fenyong Shou Jingzhu duan Huang Wang Gaowu Qin Department of Spine Surgery Shengjing Hospital of China Medical University. Shenyang 110004 China Key LaboratoryforAnisotropy and Texture of Materials (Ministry of Education) School of Materials Science and Engineering. Northeastern UniversityShenyang 110819 China Department of Orthopedics Affiliated Zhongshan Hospital of Dalian University Dalian 116001 China

As compared to permanent orthopedic implants for load-bearing applications, biodegradable orthopedic implants have the advantage of no need for removing after healing, but they suffer from the ＂trilemma＂ problem of compromising among sufficiently high mechanical properties, good biocompatibility and proper degradation rate conforming to the growth rate of new bones. In the present work, in vitro and in vivo studies of a Zn-0.05 wt%Mg alloy（namely, Zn-0.05 Mg alloy） were conducted with pure Zn as a control. The Zn-0.05 Mg alloy is composed of a small amount of Mg2 Zn11 phase embedded in the refined Zn matrix with an average grain size of ～20 μm. The addition of 0.05 wt% Mg into Zn significantly increases the ultimate tensile strength up to 225 MPa and the elongation to fracture to 26%, but has little influence on the in vitro degradation rate. Both Zn and Zn-0.05 Mg alloy exhibit homogeneous in vitro degradation with a rate of about 0.15 mm/year. Based on the cytotoxicity evaluation, Zn and Zn-0.05 Mg alloy do not induce toxicity to L-929 cells, indicating that they have little toxicity to the general functions of the animal. An in vivo biocompatibility study of Zn and Zn-0.05 Mg alloy samples by placing them in a rabbit model for 4.12 and 24 weeks, respectively did not show any inflammatory cells, and demonstrated that new bone tissue formed at the bone/implant interface, suggesting that Zn and Zn-0.05 Mg alloy promote the formation of new bone tissue. The in vivo degradation of Zn and Zn-0.05 Mg alloy does not bring harm to the important organs and their cell structures. More interestingly, Zn and Zn-0.05 Mg alloy exhibit strong antibacterial activity against Escherichia coli and Staphylococcus aureus. The above results clearly demonstrate that the Zn-0.05 Mg alloy could be a potential biodegradable orthopedic implant material.

关键词： Zn-Mg alloy Mechanical properties Biodegradability Biocompatibility Antibacterial activity

Photoic crystal nanobeam cavity devices for on-chip integrated silicon photonics

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Journal of Semiconductors 2021年第2期42卷 40-50页

作者： Daquan Yang Xiao Liu xiaogang Li Bing duan Aiqiang Wang Yunfeng Xiao State Key Laboratory of Information Photonics and Optical Communications and School of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory for Artificial Microstructure and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Frontiers Science Center for Nano-Optoelectronics&Collaborative Innovation Center of Quantum Matter Beijing 100871China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China Beijing Academy of Quantum Information Sciences Beijing 100193China

Integrated circuit(IC)industry has fully considered the fact that the Moore’s Law is slowing down or *** solutions are highly and urgently desired to break the physical size limits in the More-than-Moore *** silicon photonics technology exhibits distinguished potential to achieve faster operation speed,less power dissipation,and lower cost in IC industry,because their COMS compatibility,fast response,and high monolithic integration ***,compared with other on-chip resonators(***,2D photonic crystal cavities)silicon-on-insulator(SOI)-based photonic crystal nanobeam cavity(PCNC)has emerged as a promising platform for on-chip integration,due to their attractive properties of ultra-high Q/V,ultra-compact footprints and convenient integration with silicon *** this paper,we present a comprehensive review on recent progress of on-chip PCNC devices for lasing,modulation,switching/filting and label-free sensing,etc.

关键词： PCNC integrated silicon photonics More-than-Moore lab-on-a-chip hybrid devices