检索结果-南通市图书馆

维普期刊数据库博看期刊

河南栾川县马丢大型萤石矿矿床地质特征及其找矿潜力预测

在线全文

学校读者我要写书评

暂无评论

中国地质 2024年第4期51卷 1161-1174页

作者：马红义张博张娅姚健张林兵张沐张林飞刘亚南河南省地质局生态环境地质服务中心河南郑州450053 河南省深部探矿工程技术研究中心河南郑州450053 河南省自然资源科技创新中心河南郑州450053

【研究目的】萤石矿是现代工业必须的重要矿产资源,河南省把萤石矿的找矿列为非金属矿产的重中之重。近年来,河南省多个地勘单位均在栾川县合峪地区从事萤石矿找矿工作,马丢萤石矿是第一个探明的大型矿床,估算萤石矿矿石量884万t、CaF_... 详细信息

【研究目的】萤石矿是现代工业必须的重要矿产资源,河南省把萤石矿的找矿列为非金属矿产的重中之重。近年来,河南省多个地勘单位均在栾川县合峪地区从事萤石矿找矿工作,马丢萤石矿是第一个探明的大型矿床,估算萤石矿矿石量884万t、CaF_(2)矿物量476万t,CaF_(2)平均品位53.83%,矿体沿走向东西两端均未封闭。总结马丢萤石矿矿床地质特征对指导该区找矿具有重要意义。【研究方法】通过近5年来对马丢萤石矿的普查—详查工作,对矿床成矿地质条件、矿床地质特征、质量特征、找矿标志等进行系统总结。【研究结果】马丢萤石矿床目前是河南省及其周边省份资源量规模最大的萤石单矿体。矿脉数量多,规模大小不一,具有沿倾向等间距分布,沿走向近平行展布的特征,在其周边还分散着众多的萤石矿体。【结论】马丢萤石矿成矿与花岗岩体和北西向构造有关,矿床类型为硅酸盐岩石中的裂隙充填中—低温脉状矿床。

关键词：萤石矿矿床地质特征找矿潜力矿产勘查工程栾川县马丢河南省

Vision-Based Adaptive Prescribed-Time Control of UAV for Uncooperative Target Tracking with Performance Constraint

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第5期37卷 1956-1977页

作者： SHE Xuehua ma Hui REN Hongru LI hongyi School of Automation and the Guangdong Provincial Key Laboratory of Intelligent Decision and Cooperative Control Guangdong University of Technology School of mathematics and Statistics Guangdong University of Technology College of Electronic and Information Engineering and Chongqing Key Laboratory of Generic Technology and System of Service Robots Southwest University

This paper discusses the uncooperative target tracking control problem for the unmanned aerial vehicle(UAV) under the performance constraint and scaled relative velocity constraint, in which the states of the uncooperative target can only be estimated through a vision sensor. Considering the limited detection range, a prescribed performance function is designed to ensure the transient and steady-state performances of the tracking system. Meanwhile, the scaled relative velocity constraint in the dynamic phase is taken into account, and a time-varying nonlinear transformation is used to solve the constraint problem, which not only overcomes the feasibility condition but also fails to violate the constraint boundaries. Finally, the practically prescribed-time stability technique is incorporated into the controller design procedure to guarantee that all signals within the closed-loop system are *** is proved that the UAV can follow the uncooperative target at the desired relative position within a prescribed time, thereby improving the applicability of the vision-based tracking approach. Simulation results have been presented to prove the validity of the proposed control strategy.

关键词：

Angiosperm-wide analysis of fruit and ovary evolution aided by a new nuclear phylogeny supports association of the same ovary type with both dry and fleshy fruits

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2024年第2期66卷 228-251页

作者： Yezi Xiang Taikui Zhang Yiyong Zhao Hongjin Dong hongyi Chen Yi Hu Chien-Hsun Huang Jun Xiang Hong ma State Key Laboratory of Genetic Engineering Ministry of Education Key Laboratory of Biodiversity and Ecological EngineeringInstitute of Plant BiologyCenter of Evolutionary BiologySchool of Life SciencesFudan UniversityShanghai 200438China Department of Biology Howard Hughes Medical InstituteDuke UniversityDurhamNC 27708USA Department of Biology the Eberly College of Scienceand the Huck Institutes of the Life Sciencesthe Pennsylvania State UniversityUniversity ParkPA 16802USA Hubei Key Laboratory of Economic Forest Germplasm Improvement and Resources Comprehensive Utilization College of Biology and Agricultural ResourcesHuanggang Normal UniversityHuanggang 438000China

Fruit functions in seed protection and dispersal and belongs to many dry and fleshy types,yet their evolutionary pattern remains unclear in part due to uncertainties in the phylogenetic relationships among several orders and *** we used nuclear genes of 502 angiosperm species representing 231 families to reconstruct a well supported phylogeny,with resolved relationships for orders and families with previously uncertain *** this phylogeny as a framework,molecular dating supports a Triassic origin of the crown angiosperms,followed by the emergence of most orders in the Jurassic and Cretaceous and their rise to ecological dominance during the Cretaceous Terrestrial *** robust phylogeny allowed an examination of the evolutionary pattern of fruit and ovary types,revealing a trend of parallel carpel fusions during early diversifications in eudicots,monocots,and ***,taxa in the same order or family with the same ovary type can develop either dry or fleshy fruits with strong correlations between specific types of dry and fleshy fruits;such associations of ovary,dry and fleshy fruits define several ovaryfruit"modules"each found in multiple *** of the frequent modules has an ovary containing multiple ovules,capsules and berries,and another with an ovary having one or two ovules,achenes(or other single-seeded dry fruits)and *** new perspective of relationships among fruit types highlights the closeness of specific dry and fleshy fruit types,such as capsule and berry,that develop from the same ovary type and belong to the same module relative to dry and fleshy fruits of other modules(such as achenes and drupes).Further analyses of gene families containing known genes for ovary and fruit development identified phylogenetic nodes with multiple gene duplications,supporting a possible role of whole-genome duplications,in combination with climate changes and animal behaviors,in angiosperm fruit and ovary diversificat

关键词： angiosperm fruit evolution maDS-box molecular clock nuclear phylogeny ovary and fruit developmental genes

Asymmetric frequency multiplexing topological devices based on a floating edge band

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第6期12卷 1201-1212页

作者： JIAJUN ma CHUNMEI OUYANG YUTING YANG DONGYANG WANG hongyi LI LI NIU YI LIU QUAN XU YANFENG LI ZHEN TIAN JIAGUANG HAN WEILI ZHANG Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering and Key Laboratory of Optoelectronics Information and TechnologyTianjin UniversityTianjin 300072China School of materials Science and Physics China University of Mining and TechnologyXuzhou 221116China Optoelectronics Research Centre University of SouthamptonSouthampton SO171BJUK Guangxi Key Laboratory of Optoelectronic Information Processing School of Optoelectronic EngineeringGuilin University of Electronic TechnologyGuilin 541004China School of Electrical and Computer Engineering Oklahoma State UniversityStillwaterOklahoma 74078USA

Topological photonics provides a platform for robust energy transport regardless of sharp corners and ***,the frequency multiplexing topological devices have attracted much attention due to the ability to separate optical signals by wavelength and hence the potential application in optical communication *** frequency multiplexing topological devices are generally based on the slow light ***,the resulting static local spatial mode or finely tuned flat band has zero-group velocity,making it difficult for both experimental excitation and channel ***,we propose and experimentally demonstrate an alternative prototype of asymmetric frequency multiplexing devices including a topological rainbow and frequency router based on floating topological edge mode(instead of localized ones);hence the multiple wavelength channels can be collectively excited with a point source and efficiently routed to separate output *** channel separation in our design is achieved by gradually tuning the band gap truncation on a topological edge band over a wide range of frequencies.A crucial feature lies in that the topological edge band is detached from bulk states and floating within the upper and lower photonic band *** interestingly,due to the sandwiched morphology of the edge band,the top and bottom band gaps will each truncate into transport channels that support topological propagation towards opposite directions,and the asymmetrical transportation is realized for the frequency multiplexing topological devices.

关键词： tuning floating hence

不同类型大块树脂固化深度、硬度及对乳牙微渗漏影响的对比研究

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

中华口腔医学杂志 2023年第11期58卷 1131-1137页

作者：马鸿翼丁宁马平杨东梅首都医科大学口腔医学院儿童口腔科北京100050 首都医科大学口腔医学院口腔医学研究所北京100050

目的比较3种类型大块树脂的固化深度、硬度及应用于乳牙的微渗漏情况,为临床应用提供参考。方法对照组为A组(常用复合树脂Filtek^(TM)Z350 XT)和B组(树脂复合体BeautifilⅡ);大块树脂组分别为C组(高黏型Filtek^(TM)Bulk Fill)、D组(黏... 详细信息

目的比较3种类型大块树脂的固化深度、硬度及应用于乳牙的微渗漏情况,为临床应用提供参考。方法对照组为A组(常用复合树脂Filtek^(TM)Z350 XT)和B组(树脂复合体BeautifilⅡ);大块树脂组分别为C组(高黏型Filtek^(TM)Bulk Fill)、D组(黏度可变型SonicFill 2)和E组(低黏型SDR®flow+)。扫描电镜观察各组材料固化后微观形貌;制备各组树脂固化试件(每组6个),显微硬度计测量各组试件表层及不同深度的维氏硬度值并计算固化深度;分别用各组树脂充填离体乳磨牙(每组5颗),切片、老化、银离子染色、显影,扫描电镜下观察各组标本微渗漏情况,对5组银离子渗漏占比评定分级,采用了Jonckheere-Terpstra秩和检验进行统计学分析。结果扫描电镜观察显示:A、C组填料颗粒呈球形且分布均匀;B、D和E组填料颗粒为多角形且分布不均匀。A、B、C、D、E组表面硬度分别为(84.97±6.30)、(65.04±5.95)、(57.80±1.18)、(60.77±2.34)、(33.32±1.83)MPa,A组硬度最高,E组硬度最低,A、E组与其他各组相比差异均有统计学意义(P0.05)。A、B、C、D和E组的固化深度分别为2.6、3.4、5.8、3.8和7.8 mm。E组微渗漏最严重[0级占2%(1/50)、1级占22%(11/50)、2级占30%(15/50)、3级占24%(12/50)、4级占22%(11/50)],其微渗漏分级分布与其他组相比差异均有统计学意义(P0.05)。结论高黏型和黏度可变型大块树脂硬度和微渗漏与树脂复合体相似,固化深度更大,可作为乳牙充填的一种选择。

关键词：复合树脂类大块树脂乳牙固化深度硬度微渗漏

在线全文

学校读者我要写书评

暂无评论

大块充填树脂在乳牙修复中的应用和研究进展

口腔医学研究 2022年第12期38卷 1124-1127页

作者：马鸿翼杨东梅首都医科大学附属北京口腔医院儿童口腔科北京100050

大块充填树脂因可以一次性固化4~5 mm的深度而显著缩短了充填时间,并且在聚合收缩、微渗漏、机械强度等方面不逊于传统复合树脂。本文就大块充填树脂的分类、性能、在乳牙修复中的应用等方面进行阐述和讨论。

关键词：大块充填树脂乳牙树脂充填机械性能临床应用

在线全文

学校读者我要写书评

暂无评论

领导者引导与支配解进化的多目标矮猫鼬算法

计算机科学与探索 2024年第2期18卷 403-424页

作者：赵世杰张红易马世林辽宁工程技术大学智能科学与优化研究所辽宁阜新123000 辽宁工程技术大学运筹与优化研究院辽宁阜新123000

面对现实中日益复杂的多目标优化问题,需要发展新型多目标优化算法应对挑战。提出一种基于领导者引导与支配解动态缩减进化的多目标矮猫鼬优化算法(MODMO)。领导者引导机制通过引入动态权衡因子以调控侦察猫鼬探寻土丘的搜索半径,同时... 详细信息

面对现实中日益复杂的多目标优化问题,需要发展新型多目标优化算法应对挑战。提出一种基于领导者引导与支配解动态缩减进化的多目标矮猫鼬优化算法(MODMO)。领导者引导机制通过引入动态权衡因子以调控侦察猫鼬探寻土丘的搜索半径,同时以非劣解集构建外部存档并根据非支配排序层级确定出领导者,进而引导侦察猫鼬向多目标前沿面推进以改善算法的收敛性;支配解动态缩减进化策略是为克服非劣解外部存档维护过程中的解冗余问题而构建,其以支配关系和拥挤距离动态筛选支配解并存入外部存档,以支配解信息融入种群进化实现多目标潜在前沿的挖掘并增强算法的多样性。在ZDT、DTLZ与WFG基准函数上,与5种代表性比较算法的实验结果表明MODMO算法在收敛性与多样性上均具有显著优势。

关键词：多目标优化矮猫鼬优化算法领导者引导机制外部存档支配解动态缩减进化策略

Uniform decomposition of velocity gradient tensor

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第1期36卷 24-34页

作者： Chenxi ma Chaoqun Liu Department of mathematics University of Texas at ArlingtonArlingtonTXUSA

In this paper,the principal decomposition of the velocity gradient tensor[∇v]is discussed in 3 cases based on the discriminant∆:∆0 with 3 distinct real eigen values,and∆=0 with 1 or 2 distinct real eigen *** velocity gradient tensor can also be classified as rotation point,which can be decomposed into three parts,i.e.,rotation[R],shear[S]and stretching/compression[SC],and non-rotation point,we defined a new resistance term[L],and the tensor can be decomposed into three parts,i.e.,resistance[L],shear[S]and stretching/compression[SC].Example matric are also displayed to demonstrate the new *** of principal decomposition between 3 different cases,and between Resistance and Liutex will also be discussed.

关键词： Velocity gradient Liutex resistance fluid kinematics

VOC emitted by biopharmaceutical industries:Source profiles,health risks,and secondary pollution

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

Journal of Environmental Sciences 2024年第1期135卷 570-584页

作者： Jiawei ma Lin Li State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China National Engineering Laboratory for VOCs Pollution Control material&Technology University of Chinese Academy of SciencesBeijing 101408China

The biopharmaceutical industry contributes substantially to volatile organic compounds(VOCs)emissions,causing growing concerns and social developmental *** study conducted an on-site investigation of the process-based emission of VOCs from three biopharmaceutical *** the workshops of the three enterprises,26 VOCs were detected,which could be sorted into 4 classes:hydrocarbons,aromatic hydrocarbons,oxygen-containing compounds,and nitrogen-containing *** were the main components of waste gases,accounting for 44.13%-77.85%of the overall ***-based source profiles were compiled for each process unit,with the fermentation and extraction units of tiamulin fumarate being the main source of VOC *** heptanone,vinyl acetate,diethylamine,propylene glycol methyl ether(PGME),and benzene were screened as priority pollutants through a fuzzy comprehensive evaluation *** level concentration simulation results of the Gauss plume diffusion model demonstrated that the diffusivity of VOCs in the atmosphere was relatively high,indicating potential non-carcinogenic and carcinogenic risks 1.5-2 km ***,the process-based formation potentials of ozone and secondary organic aerosols(SOAs)were determined and indicated that N-methyl-2-pyrrolidone,dimethyl heptanone,and PGME should be preferentially controlled to reduce the ozone formation potential,whereas the control of benzene and chlorobenzene should be prioritized to reduce the generation of *** results provide a basis for understanding the characteristics of VOC emission by biopharmaceutical industries and their diffusion,potentially allowing the development of measures to reduce health risks and secondary pollution.

关键词： Biopharmaceutical Volatile organic compound Priority pollutant Exposure risk Secondary pollution