检索结果-南通市图书馆

Journal of Contemporary Educational Research 2024年第4期8卷 241-246页

作者： Hong Tian liquan sun Hao Gu School of Life Science Beijing Institute of TechnologyBeijing 100081China

In order to deeply understand the status of ideological and political research on experimental courses in colleges and universities,the relevant literature collected by China National Knowledge Infrastructure(CNKI)was taken as the research object,and the analysis was carried out by using CiteSpace software.The results show that research authors of ideological and political education in experimental courses have not yet formed cross-regional cooperation,and there is no core author.The ideological and political construction of experimental courses mainly focuses on experimental courses such as medicine,chemistry,and physics.The research focus on ideological and political education in experimental courses focuses on the concept of educating people,the construction of teaching systems,teaching modes,and the combination of new experimental teaching methods and ideological and political elements.The ideological and political education of experimental courses needs more attention and support from colleges and universities.

关键词： Ideological and political education Experimental course CiteSpace Visualization Bibliometrics

Check dam extraction from remote sensing images using deep learning and geospatial analysis:A case study in the Yanhe River Basin of the Loess Plateau,China

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Journal of Arid Land 2023年第1期15卷 34-51页

作者： sun liquan GUO Huili CHEN Ziyu YIN Ziming FENG Hao WU Shufang Kadambot H M SIDDIQUE Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling 712100China Institute of Water-Saving Agriculture in Arid Areas of China Northwest A&F UniversityYangling 712100China College of Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China The UWA Institute of Agriculture and School of Agriculture&Environment The University of Western AustraliaPerth 6001Australia

Check dams are widely used on the Loess Plateau in China to control soil and water losses,develop agricultural land,and improve watershed ecology.Detailed information on the number and spatial distribution of check dams is critical for quantitatively evaluating hydrological and ecological effects and planning the construction of new dams.Thus,this study developed a check dam detection framework for broad areas from high-resolution remote sensing images using an ensemble approach of deep learning and geospatial analysis.First,we made a sample dataset of check dams using GaoFen-2(GF-2)and Google Earth images.Next,we evaluated five popular deep-learning-based object detectors,including Faster R-CNN,You Only Look Once(version 3)(YOLOv3),Cascade R-CNN,YOLOX,and VarifocalNet(VFNet),to identify the best one for check dam detection.Finally,we analyzed the location characteristics of the check dams and used geographical constraints to optimize the detection results.Precision,recall,average precision at intersection over union(IoU)threshold of 0.50(AP_(50)),IoU threshold of 0.75(AP_(75)),and average value for 10 IoU thresholds ranging from 0.50-0.95 with a 0.05 step(AP_(50-95)),and inference time were used to evaluate model performance.All the five deep learning networks could identify check dams quickly and accurately,with AP_(50-95),AP_(50),and AP_(75)values higher than 60.0%,90.0%,and 70.0%,respectively,except for YOLOv3.The VFNet had the best performance,followed by YOLOX.The proposed framework was tested in the Yanhe River Basin and yielded promising results,with a recall rate of 87.0%for 521 check dams.Furthermore,the geographic analysis deleted about 50%of the false detection boxes,increasing the identification accuracy of check dams from 78.6%to 87.6%.Simultaneously,this framework recognized 568 recently constructed check dams and small check dams not recorded in the known check dam survey datasets.The extraction results will support efficient watershed management and guide future studies on soil erosion in the Loe

关键词： check dam deep learning geospatial analysis remote sensing Faster R-CNN Loess Plateau

基于适航符合性的短舱风扇一体化迎角与侧风特性

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航空动力学报 2024年第3期39卷 77-89页

作者：傅文广郭重佳孙鹏陶立权中国民航大学安全科学与工程学院天津300300 大连海事大学轮机工程学院辽宁大连116026

以某小型涡扇发动机为研究对象,采用数值模拟方法对0°、15°、25°迎角和±10、±20、±30 m/s的90°横向侧风条件下短舱风扇一体化的特性及流场进行研究。结果表明:随着迎角的增大,相同风速条件下逆向侧风对短舱进气道和风扇性能的负... 详细信息

以某小型涡扇发动机为研究对象,采用数值模拟方法对0°、15°、25°迎角和±10、±20、±30 m/s的90°横向侧风条件下短舱风扇一体化的特性及流场进行研究。结果表明:随着迎角的增大,相同风速条件下逆向侧风对短舱进气道和风扇性能的负面影响更大,依据机动性、风速和喘振/失速特性的适航条款要求,得到迎角为25°时,短舱风扇一体化性能可承受的正、逆向侧风范围分别约为0~23 m/s和0~18 m/s,相应得到侧风速度为±30 m/s时,所允许的机动迎角范围分别约为0°~3°和0°~2°。

关键词：进气畸变喘振/失速短舱进气道风扇适航符合性

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警察防卫与控制课程思政建设研究

语言与文化研究

语言与文化研究 2024年第3期32卷 91-94页

作者：孙立全中国人民警察大学廊坊065000

在全面推进高校课程思政建设的大背景下,为适应当前阶段的教学课堂改革的需求,本文聚焦讨论公安院校警察防卫与控制课程思政建设,分析研究建设过程中存在的问题并提出了加强创新意识、优化设计课程内容、提升教师课程思政教学能力、优... 详细信息

在全面推进高校课程思政建设的大背景下,为适应当前阶段的教学课堂改革的需求,本文聚焦讨论公安院校警察防卫与控制课程思政建设,分析研究建设过程中存在的问题并提出了加强创新意识、优化设计课程内容、提升教师课程思政教学能力、优化课程思政教学设计和方法、建立和完善课程思政考核标准与评价体系等解决措施,旨在为警察防卫与控制课程思政建设提供理论思路和实践指导,着力形成富有特色的课程体系。

关键词：警察防卫与控制课程思政课程建设教学实施

400km/h高铁隧道出入口缓冲结构开口率对微压波影响研究

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铁道科学与工程学报 2024年第2期21卷 433-443页

作者：孙浩程王英学古理全张子为马伟斌西南交通大学交通隧道工程教育部重点实验室四川成都610031 中国铁道科学研究院铁道建筑研究所北京100081

随着高速列车运行时速的提升,车-隧气动效应加剧、微压波超限问题愈发严重。以往研究表明,隧道洞口设置缓冲结构是解决微压波问题的有效手段之一,但是随着隧道长度增加、列车时速提升,仅以入口缓冲结构作为标准的设计方法存在一定局限... 详细信息

随着高速列车运行时速的提升,车-隧气动效应加剧、微压波超限问题愈发严重。以往研究表明,隧道洞口设置缓冲结构是解决微压波问题的有效手段之一,但是随着隧道长度增加、列车时速提升,仅以入口缓冲结构作为标准的设计方法存在一定局限性。并且国内外的研究重点更多集中在入口缓冲结构,对出口缓冲结构及隧道出入口均设置缓冲结构的设计方法研究相对较少。针对这一问题,利用控制容积法分析出口开口式缓冲结构的关键影响参数。基于LES湍流模型和动网格技术建立三维数值仿真模型,对关键参数的正确性做出验证。分析隧道出入口对称、非对称设置缓冲结构对微压波特性的影响,提出适用于单线和双线隧道的洞口开口式缓冲结构的设计方法。研究结果表明:1)隧道出口缓冲结构开口率是影响出口缓冲结构对微压波压力缓解效率的关键参数,开口率越大,微压波压力最大值越低;2)隧道入口以压力梯度为控制标准设置最优缓冲结构、隧道出口提高缓冲结构开口率的形式,在单线隧道缓冲结构设计中对微压波有更高的缓解率,出口缓冲结构开口率越大,对微压波压力缓解效率越高;3)双线隧道洞口开口式缓冲结构设计时,应当增加其总开口率,同时选择小面积、多个数的开口形式并在隧道出入口对称设置。

关键词： 400km/h高速铁路隧道出口缓冲结构微压波控制容积法出入口缓冲结构设计

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美国一流院校流式细胞平台管理经验启示

实验室研究与探索 2024年第3期43卷 243-247,259页

作者：罗茂国杨正丛勇孙立权北京理工大学生命学院北京100081 北京理工大学生物与医学工程公共实验中心北京100081 北京理工大学资产与实验室管理处北京100081

通过在线访谈、官网检索、书报查询等方法,对美国一流院校流式细胞平台的仪器设备、人员队伍、政策规定、实验操作指引、收费标准、科研与技术开发等进行统计分析,并与国内高校管理情况进行比较。研究发现,国内外流式细胞平台的设备性... 详细信息

通过在线访谈、官网检索、书报查询等方法,对美国一流院校流式细胞平台的仪器设备、人员队伍、政策规定、实验操作指引、收费标准、科研与技术开发等进行统计分析,并与国内高校管理情况进行比较。研究发现,国内外流式细胞平台的设备性能良好且由专人操作,但国外一流平台的设备数量更多、性能更齐全先进、用户自主上机占比更高、管理人员参与用户科研程度更深且自身科研背景更强;此外,国外平台收费更规范更有弹性。对比来看,国外流式细胞平台精细的管理、详尽的技术指导和稳定的技术队伍值得学习,而我国分类布局、集中管理、集约服务的特点也值得提倡。借鉴国内外优秀经验,在传统工科高校建立了一套精细化管理的流式细胞平台运营体系,充分发挥仪器性能,显著提升效率。

关键词：美国一流院校流式细胞平台平台管理开放共享

Regulating the self-assembly of rigid 2D ribbon-like amphiphilic homopolymer via tailoring its holistic conformation

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Science China Chemistry 2023年第8期66卷 2339-2346页

作者： Yumeng Gao Weisheng Feng Yao sun Yuan Yao liquan Wang Shaoliang Lin Shanghai Key Laboratory of Advanced Polymeric Materials Frontiers Science Center for Materiobiology and Dynamic Chemistry of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China

Amphiphilic rigid backbone polymers are traditionally seemed as one-dimensional(1D)rods and show distinct self-assembly behavior to flexible polymers,but they could hardly adapt morphology-tunable self-assembly by changing their holistic conformation upon external stimuli.In this study,we synthesized a series of amphiphilic homopolymers poly(acetylene azobenzene oligoethylene glycol)(P(AAzo-EGx))containing conjugated polyacetylene mainchain,azobenzene pendants and oligo ethylene glycol tails in each unit.This comb-like amphiphilic polymer could be treated as two-dimensional(2D)nanoribbons with tunable holistic conformation via meticulous tailoring intrastrand repulsion and interchainπ-πinteraction of azobenzene pendants by light,temperature,and solvent swelling.P(AAzo-EG_(2))could self-assemble into large vesicles in ambient,whereas transformed to supramolecular helix bundles(SHBs)at 65℃as well as depicted by dissipative particle dynamics(DPD)simulation,and then turned into grass leaf-like micelles upon sequential ultraviolet(UV)and blue light irradiation.The three assemblies featured different stacking mode of PAAzo skeletons although showed similar aggregate induce emission(AIE)effect.In this holistic macromolecular chain conformation-induced self-assembly and morphology transformation,temperature influenced the stacking of hydrophobic parts mainly by tuning the torsion of PAAzo skeleton.Certain amount of good solvent played a vital role by swelling of hydrophobic PAAzo skeleton,and helping the movement and rearrangement of azobenzene pendants and polyacetylene mainchains like a lubricant.The length and diameter of SHBs could be tuned by changing EGxtails.This work uncovered a facile strategy to tailor the self-assembly of rigid backbone polymers for fabrication of functional nanodevices.

关键词： self-assembly tunable conformation rigid skeleton two-dimensional nanoribbon stimuli response

山东省某区2018-2022年城市饮用水氯化消毒副产物的健康风险评估

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安徽预防医学杂志 2024年第2期30卷 129-133页

作者：孙煜邢月梅张静张利泉蓬莱区疾病预防控制中心山东烟台265600 福山区疾病预防控制中心山东烟台265500

目的了解山东省某区城市饮用水中消毒副产物含量,并对其进行健康风险评估。方法 2018-2022年分别在枯水期及丰水期采集山东省某区城市饮用水水样共90份,按照GB/T 5750.10-2006《生活饮用水标准检验方法消毒副产物指标》进行检测;按照GB... 详细信息

目的了解山东省某区城市饮用水中消毒副产物含量,并对其进行健康风险评估。方法 2018-2022年分别在枯水期及丰水期采集山东省某区城市饮用水水样共90份,按照GB/T 5750.10-2006《生活饮用水标准检验方法消毒副产物指标》进行检测;按照GB 5749-2006《生活饮用水卫生标准》进行评价,并采用美国环保署推荐的健康风险模型进行风险评价。结果 2018-2022年山东省某区城市饮用水中消毒副产物合格率为76.67%,超标指标为三卤甲烷和三氯乙醛,超标率分别为23.33%和4.44%;消毒副产物中除氯化氰、二氯甲烷、2,4,6-三氯酚未检出外,其他指标均有不同程度的检出;丰水期三卤甲烷、三氯甲烷、二氯一溴甲烷含量均高于枯水期(P0.05);某区城市饮用水消毒副产物致癌风险均在1.0×10^(-6)~1.0×10^(-4)范围内,部分监测点一氯二溴甲烷和二氯乙酸致癌风险>1.0×10-4;各消毒副产物的非致癌风险均<1.0。结论山东省某区城市饮用水消毒副产物非致癌风险在可接受范围内,而致癌健康风险应高度重视,尤其一氯二溴甲烷和二氯乙酸是重点风险管理指标。

关键词：城市饮用水消毒副产物健康风险评估

A β-cyclodextrin covalent organic framework used as a chiral stationary phase for chiral separation in gas chromatography

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Chinese Chemical Letters 2022年第2期33卷 898-902页

作者： Bo Tang Wei Wang Huipeng Hou Yiquan Liu Zongkun Liu Lina Geng liquan sun Aiqin Luo Key Laboratory of Molecular Medicine and Biotherapy School of Life ScienceBeijing Institute of TechnologyBeijing 100081China

Chiral covalent organic frameworks(CCOFs) featuring chirality, stability, and good porosity have attracted a considerable amount of attention due to their important applications, such as asymmetric catalysis, chiral separation, and chiral recognition. In this study, a β-cyclodextrin(β-CD) covalent organic framework(β-CD-COF) diluted with polysiloxane OV-1701 was explored as a novel chiral stationary phase(CSP) for gas chromatography(GC) separation of racemates. The β-CD-COF coated capillary column had excellent selectivity, not only for the separation of linear alkanes, linear alcohols, fatty acid methyl esters mixture, the Grob mixture and positional isomers, but also for the resolution of chiral compounds, including chiral alcohols, aldehydes, ethers, and amino acid derivatives. In addition, the β-CD-COF-coated capillary column presented good repeatability and reproducibility. This work indicated the great potential of the CCOFs coated capillary column for the chromatographic separation of enantiomers.

关键词： β-Cyclodextrin Covalent organic framework Chiral stationary phase Gas chromatography Enantioseparation

Effects of mixed fertilizers formed by the compounding of two targeted controlled-release nitrogen fertilizers on yield,nitrogen use efficiency,and ammonia volatilization in double-cropping rice

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The Crop Journal 2023年第2期11卷 628-637页

作者： Jian Ke Jie sun Tingting Chen Shibao Tao Tiezhong Zhu Chuanjun Yin Haibing He Cuicui You liquan Wu Shuangshuang Guo College of Agronomy Anhui Agricultural UniversityHefei 230031AnhuiChina Zoomlion Intelligent Agriculture Co. Ltd.Wuhu 241000AnhuiChina

One-time application of mixed fertilizer formed by the compounding of two controlled-release nitrogen fertilizers(CRUs)with targeted N supply during the periods from transplantation(TS)to panicle initiation(PI)and from PI to heading(HS)is expected to synchronize the double-peak N demand of rice.However,its effects on the yield and N use efficiency(NUE)of labor-intensive double-cropping rice were unknown.Two targeted CRU(CRU_(A)and CRU_(B))were compounded in five ratios(CRU_(A):CRU_(B)=10:0,7:3,5:5,3:7,and 0:10)to form five mixed fertilizers(BBFs):BBF1-5.A field experiment was performed to investigate the characteristics of N supply in early and late seasons under different BBFs and their effects on N uptake,yield,and ammonia volatilization(AV)loss from paddy fields of double-cropping rice.Conventional high-yield fertilization(CK,three split applications of urea)and zero-N treatments were established as controls.The N supply dropped significantly with the increased compound ratio of CRU_(B)during the period from TS to PI,but increased during the period from PI to HS.With the exception of the period from TS to PI in the late rice season,the N uptake of early and late rice maintained close synchronicity with the N supply of BBFs during the double-peak periods.Excessive N supply(BBF1 and BBF2)in the late rice season during the period from TS to PI increased N loss by AV.The effect of BBF on grain yield increase varied widely between seasons,irrespective of year.Among the BBFs,the BBF2 treatment of early rice not only stabilized the spikelets per panicle but also ensured a high number of effective panicles by promoting N uptake during the period from TS to PI and a high grain-filling percentage by appropriately reducing the N supply at the later PI stage,resulting in the highest rice yield.While stabilizing the effective panicle number,the BBF4 treatment of late rice increased the number of spikelets per panicle by promoting N uptake during the period from PI to HS,resulting in the highest rice yield.The two-year aver

关键词： Targeted controlled-release fertilizer Mixed fertilizer Double-cropping rice N uptake Yield