期刊文献+
共找到50,207篇文章
< 1 2 250 >
每页显示 20 50 100
Comparative analysis shows high level of lineage sorting in genomic regions with low recombination in the extended Picea likiangensis species complex
1
作者 Hui Zhu Weixiao Lei +2 位作者 Qing Lai Yongshuai Sun Dafu Ru 《Plant Diversity》 SCIE CAS CSCD 2024年第4期547-550,共4页
Genome-scale data,while promising for illuminating phylogenetic relationships,frequently pose a conundrum by yielding conflicting topologies and highly variable gene tree distributions(Pease et al.,2016).This complexi... Genome-scale data,while promising for illuminating phylogenetic relationships,frequently pose a conundrum by yielding conflicting topologies and highly variable gene tree distributions(Pease et al.,2016).This complexity likely arises from the reticulate evolution observed in many taxa,where genetic information exchange occurs through diverse biological processes. 展开更多
关键词 sorting PROCESSES YIELDING
下载PDF
A novel integrated microfluidic chip for on-demand electrostatic droplet charging and sorting
2
作者 Jinhui Yao Chunhua He +5 位作者 Jianxin Wang Canfeng Yang Ye Jiang Zhiyong Liu Guanglan Liao Tielin Shi 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第1期31-42,共12页
On-demand droplet sorting is extensively applied for the efficient manipulation and genome-wide analysis of individual cells.However,state-of-the-art microfluidic chips for droplet sorting still suffer from low sortin... On-demand droplet sorting is extensively applied for the efficient manipulation and genome-wide analysis of individual cells.However,state-of-the-art microfluidic chips for droplet sorting still suffer from low sorting speeds,sample loss,and labor-intensive preparation procedures.Here,we demonstrate the development of a novel microfluidic chip that integrates droplet generation,on-demand electrostatic droplet charging,and high-throughput sorting.The charging electrode is a copper wire buried above the nozzle of the microchannel,and the deflecting electrode is the phosphate buffered saline in the microchannel,which greatly simplifies the structure and fabrication process of the chip.Moreover,this chip is capable of high-frequency droplet generation and sorting,with a frequency of 11.757 kHz in the drop state.The chip completes the selective charging process via electrostatic induction during droplet generation.On-demand charged microdroplets can arbitrarilymove to specific exit channels in a three-dimensional(3D)-deflected electric field,which can be controlled according to user requirements,and the flux of droplet deflection is thereby significantly enhanced.Furthermore,a lossless modification strategy is presented to improve the accuracy of droplet deflection or harvest rate from 97.49% to 99.38% by monitoring the frequency of droplet generation in real time and feeding it back to the charging signal.This chip has great potential for quantitative processing and analysis of single cells for elucidating cell-to-cell variations. 展开更多
关键词 Copper wire Droplet generation Droplet sorting Microfluidic chips On-demand charging
下载PDF
Phylotranscriptomic discordance is best explained by incomplete lineage sorting within Allium subgenus Cyathophora and thus hemiplasy accounts for interspecific trait transition
3
作者 Zengzhu Zhang Gang Liu Minjie Li 《Plant Diversity》 SCIE CAS CSCD 2024年第1期28-38,共11页
The transition of traits between genetically related lineages is a fascinating topic that provides clues to understanding the drivers of speciation and diversification.Much can be learned about this process from phylo... The transition of traits between genetically related lineages is a fascinating topic that provides clues to understanding the drivers of speciation and diversification.Much can be learned about this process from phylogeny-based trait evolution.However,such inference is often plagued by genome-wide gene-tree discordance(GTD),mostly due to incomplete lineage sorting(ILS)and/or introgressive hybridization,especially when the genes underlying the traits appear discordant.Here,by collecting transcriptomes,whole chloroplast genomes(cpDNA),and population genetic datasets,we used the coalescent model to turn GTD into a source of information for ILS and employed hemiplasy to explain specific cases of apparent“phylogenetic discordance”between different morphological traits and probable species phylogeny in the Allium subg.Cyathophora.Both concatenation and coalescence methods consistently showed the same phylogenetic topology for species tree inference based on single-copy genes(SCGs),as supported by the KS distribution.However,GTD was high across the genomes of subg.Cyathophora:~27%e38.9%of the SCG trees were in conflict with the species tree.Plasmid and nuclear incongruence was also present.Our coalescent simulations indicated that such GTD was mainly a product of ILS.Our hemiplasy risk factor calculations supported that random fixation of ancient polymorphisms in different populations during successive speciation events along the subg.Cyathophora phylogeny may have caused the character transition,as well as the anomalous cpDNA tree.Our study exemplifies how phylogenetic noise can be transformed into evolutionary information for understanding character state transitions along species phylogenies. 展开更多
关键词 Hemiplasy Multispecies coalescence Lineage sorting Gene tree discordance Phylotranscriptomics Allium subg.Cyathophora
下载PDF
Enhancing XRF sensor-based sorting of porphyritic copper ore using particle swarm optimization-support vector machine(PSO-SVM)algorithm
4
作者 Zhengyu Liu Jue Kou +5 位作者 Zengxin Yan Peilong Wang Chang Liu Chunbao Sun Anlin Shao Bern Klein 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第4期545-556,共12页
X-ray fluorescence(XRF)sensor-based ore sorting enables efficient beneficiation of heterogeneous ores,while intraparticle heterogeneity can cause significant grade detection errors,leading to misclassifications and hi... X-ray fluorescence(XRF)sensor-based ore sorting enables efficient beneficiation of heterogeneous ores,while intraparticle heterogeneity can cause significant grade detection errors,leading to misclassifications and hindering widespread technology adoption.Accurate classification models are crucial to determine if actual grade exceeds the sorting threshold using localized XRF signals.Previous studies mainly used linear regression(LR)algorithms including simple linear regression(SLR),multivariable linear regression(MLR),and multivariable linear regression with interaction(MLRI)but often fell short attaining satisfactory results.This study employed the particle swarm optimization support vector machine(PSO-SVM)algorithm for sorting porphyritic copper ore pebble.Lab-scale results showed PSO-SVM out-performed LR and raw data(RD)models and the significant interaction effects among input features was observed.Despite poor input data quality,PSO-SVM demonstrated exceptional capabilities.Lab-scale sorting achieved 93.0%accuracy,0.24%grade increase,84.94%recovery rate,57.02%discard rate,and a remarkable 39.62 yuan/t net smelter return(NSR)increase compared to no sorting.These improvements were achieved by the PSO-SVM model with optimized input combinations and highest data quality(T=10,T is XRF testing times).The unsuitability of LR methods for XRF sensor-based sorting of investigated sample is illustrated.Input element selection and mineral association analysis elucidate element importance and influence mechanisms. 展开更多
关键词 XRF sensor-based sorting PSO-SVM algorithm Copper ore pebble Receiver operating curve(ROC) Net smelter return(NSR)
下载PDF
Improving path planning efficiency for underwater gravity-aided navigation based on a new depth sorting fast search algorithm
5
作者 Xiaocong Zhou Wei Zheng +2 位作者 Zhaowei Li Panlong Wu Yongjin Sun 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期285-296,共12页
This study focuses on the improvement of path planning efficiency for underwater gravity-aided navigation.Firstly,a Depth Sorting Fast Search(DSFS)algorithm was proposed to improve the planning speed of the Quick Rapi... This study focuses on the improvement of path planning efficiency for underwater gravity-aided navigation.Firstly,a Depth Sorting Fast Search(DSFS)algorithm was proposed to improve the planning speed of the Quick Rapidly-exploring Random Trees*(Q-RRT*)algorithm.A cost inequality relationship between an ancestor and its descendants was derived,and the ancestors were filtered accordingly.Secondly,the underwater gravity-aided navigation path planning system was designed based on the DSFS algorithm,taking into account the fitness,safety,and asymptotic optimality of the routes,according to the gravity suitability distribution of the navigation space.Finally,experimental comparisons of the computing performance of the ChooseParent procedure,the Rewire procedure,and the combination of the two procedures for Q-RRT*and DSFS were conducted under the same planning environment and parameter conditions,respectively.The results showed that the computational efficiency of the DSFS algorithm was improved by about 1.2 times compared with the Q-RRT*algorithm while ensuring correct computational results. 展开更多
关键词 Depth sorting Fast Search algorithm Underwater gravity-aided navigation Path planning efficiency Quick Rapidly-exploring Random Trees*(QRRT*)
下载PDF
Accelerating Large-Scale Sorting through Parallel Algorithms
6
作者 Yahya Alhabboub Fares Almutairi +3 位作者 Mohammed Safhi Yazan Alqahtani Adam Almeedani Yasir Alguwaifli 《Journal of Computer and Communications》 2024年第1期131-138,共8页
This study explores the application of parallel algorithms to enhance large-scale sorting, focusing on the QuickSort method. Implemented in both sequential and parallel forms, the paper provides a detailed comparison ... This study explores the application of parallel algorithms to enhance large-scale sorting, focusing on the QuickSort method. Implemented in both sequential and parallel forms, the paper provides a detailed comparison of their performance. This study investigates the efficacy of both techniques through the lens of array generation and pivot selection to manage datasets of varying sizes. This study meticulously documents the performance metrics, recording 16,499.2 milliseconds for the serial implementation and 16,339 milliseconds for the parallel implementation when sorting an array by using C++ chrono library. These results suggest that while the performance gains of the parallel approach over its serial counterpart are not immediately pronounced for smaller datasets, the benefits are expected to be more substantial as the dataset size increases. 展开更多
关键词 sorting Algorithm Quick Sort QuickSort Parallel Parallel Algorithms
下载PDF
Real-time ore sorting using color and texture analysis 被引量:1
7
作者 David G.Shatwell Victor Murray Augusto Barton 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第6期659-674,共16页
Sensor-based ore sorting is a technology used to classify high-grade mineralized rocks from low-grade waste rocks to reduce operation costs.Many ore-sorting algorithms using color images have been proposed in the past... Sensor-based ore sorting is a technology used to classify high-grade mineralized rocks from low-grade waste rocks to reduce operation costs.Many ore-sorting algorithms using color images have been proposed in the past,but only some validate their results using mineral grades or optimize the algorithms to classify rocks in real-time.This paper presents an ore-sorting algorithm based on image processing and machine learning that is able to classify rocks from a gold and silver mine based on their grade.The algorithm is composed of four main stages:(1)image segmentation and partition,(2)color and texture feature extraction,(3)sub-image classification using neural networks,and(4)a voting system to determine the overall class of the rock.The algorithm was trained using images of rocks that a geologist manually classified according to their mineral content and then was validated using a different set of rocks analyzed in a laboratory to determine their gold and silver grades.The proposed method achieved a Matthews correlation coefficient of 0.961 points,higher than other classification algorithms based on support vector machines and convolutional neural networks,and a processing time under 44 ms,promising for real-time ore sorting applications. 展开更多
关键词 Ore sorting Image color analysis Image texture analysis Machine learning
下载PDF
High-throughput sorting of two-color fluorescent-labeled zebrafish embryos
8
作者 Hongzhen Tang Linbo Wang +3 位作者 Xiaohu Chen Chong Chen Hui Li Guang Yang 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2023年第5期107-114,共8页
The zebrafish embryos were widely employed in genetics,development and drug discovery studies as miniatured animal models.Sorting of two-color fluorescent embryos is often required in large-scale experiments but it is... The zebrafish embryos were widely employed in genetics,development and drug discovery studies as miniatured animal models.Sorting of two-color fluorescent embryos is often required in large-scale experiments but it is challenging to manually sort with high efficiency.Here,we reported a high-throughput sorting system for two-color fluorescent zebraflsh embryos.The embryos can be automatically loaded from a sample pool and sorted based on the average fluorescent intensity.The two-color fluorescent signals were split into two lines and detected by an area array camera.The system achieves the sorting of 100 embryos in less than 10 min with an accuracy of greater than 95%. 展开更多
关键词 HIGH-THROUGHPUT zebrafish embryo two-color sorting automatic.
下载PDF
Improvement of Counting Sorting Algorithm
9
作者 Chenglong Song Haiming Li 《Journal of Computer and Communications》 2023年第10期12-22,共11页
By analyzing the internal features of counting sorting algorithm. Two improvements of counting sorting algorithms are proposed, which have a wide range of applications and better efficiency than the original counting ... By analyzing the internal features of counting sorting algorithm. Two improvements of counting sorting algorithms are proposed, which have a wide range of applications and better efficiency than the original counting sort while maintaining the original stability. Compared with the original counting sort, it has a wider scope of application and better time and space efficiency. In addition, the accuracy of the above conclusions can be proved by a large amount of experimental data. 展开更多
关键词 Sort Algorithm Counting sorting Algorithms COMPLEXITY Internal Features
下载PDF
Theoretical Justification of the Efficient Operation of the Seed Sorting Device
10
作者 Obidov Avazbek Azamatovich Abdullayev Abror Abdulkhamid Ugli 《Engineering(科研)》 2023年第10期720-728,共9页
In this article, the results of researches on the sorting of seeds in the cotton ginning enterprises were described. The main goal of the research work is to theoretically study the technology of separating various im... In this article, the results of researches on the sorting of seeds in the cotton ginning enterprises were described. The main goal of the research work is to theoretically study the technology of separating various impurities and immature seeds from the composition of seeds. As a result, the theoretical basis for increasing the efficiency of the sorting process is created. 展开更多
关键词 COTTON Ginning Seed Seeds Construction Parameter Seed sorting FORCES Aerodynamic Resistance Air Motion
下载PDF
Garbage Sorting
11
作者 谭依宸 彭卫冕(指导) 《疯狂英语(双语世界)》 2023年第3期70-71,共2页
Garbage sorting plays a crucial role in fostering a positive social climate that brings benefits not only to society but also to our personal well-being.While we dispose of trash on a daily basis,have you ever wondere... Garbage sorting plays a crucial role in fostering a positive social climate that brings benefits not only to society but also to our personal well-being.While we dispose of trash on a daily basis,have you ever wondered about their fate?Many items undergo processes like burning,grinding,or composting,which ensure safer and healthier outcomes for us.However,some end up accumulating in open spaces,leading to unpleasant odors and posing harm to the environment. 展开更多
关键词 SPACES GRINDING sorting
下载PDF
Fully Automated Paper Document Sorting Robot Design
12
作者 Guo-Long Yang Biao-Hua Zhang 《Journal of Electronic Research and Application》 2023年第6期1-9,共9页
A fully automated paper document sorting robot was developed in this project.This robot classifies documents efficiently and accurately.The objective of this project was to improve the efficiency of classifying or sor... A fully automated paper document sorting robot was developed in this project.This robot classifies documents efficiently and accurately.The objective of this project was to improve the efficiency of classifying or sorting paper documents,reduce costs,and save time.The robot can classify documents according to user-defined rules,such as keywords,dates,serial numbers,bar codes,and the meaning of paragraphs.Since it can classify or sort documents intelligently,it can complete large-scale document classification quickly.The robot is constructed using an aluminum profile to create a box-type truss gantry structure frame.It was built on the LubanCat 4 motherboard and controlled through Python language programming.Driven by a stepper motor to move the manipulator.The camera module is combined with an artificial intelligence algorithm to recognize paper in real time,and the text is recognized after taking pictures of the paper.The sorting function is performed by several sensors.In addition,a web-based human-computer interaction platform was developed using the Flask web framework in Python.Users could access this platform in a variety of ways,allowing them to easily and swiftly configure parameters and send operational instructions to perform various functions. 展开更多
关键词 Paper documents sorting robot PYTHON Human-computer interaction
下载PDF
煤矸分拣多机械臂任务分配问题研究
13
作者 董雅文 孙家祺 +1 位作者 张宝锋 刘文慧 《煤炭工程》 北大核心 2024年第1期170-176,共7页
针对煤矸分拣过程中分拣率低、大粒度矸石分拣效果差等问题,通过考虑矸石粒度、分拣时间、矸石与分拣区边界距离等因素,构建矸石优先级模型;采取分拣机械臂放置矸石后不复位的方式,提出了一种煤矸分拣多机械臂任务分配策略,并以分拣率... 针对煤矸分拣过程中分拣率低、大粒度矸石分拣效果差等问题,通过考虑矸石粒度、分拣时间、矸石与分拣区边界距离等因素,构建矸石优先级模型;采取分拣机械臂放置矸石后不复位的方式,提出了一种煤矸分拣多机械臂任务分配策略,并以分拣率为标准进行评判,最后,采用本研究分配策略和传统的分配策略进行仿真。结果表明:本研究分配策略比传统的分配策略分拣效果更好,提高了7%~10%的分拣率,减少了大粒度矸石的漏拣数量;当矸石的间距不变时,矸石数量变化对分拣率影响较小,分拣率波动在3%左右,验证了本研究分配策略的有效性;矸石间距对分拣率和分拣机械臂数量的影响较大,当矸石的间距增大时,分拣率得到提高;矸石间距在250 mm以上时,3个分拣机械臂能保证较高的分拣率。 展开更多
关键词 煤矸分拣 多机械臂 矸石优先级 分拣时间 分拣策略
下载PDF
煤矸石井下原位智能分选充填技术研究进展 被引量:1
14
作者 梁卫国 郭凤岐 +2 位作者 于永军 张泽寒 闫俊才 《煤炭科学技术》 EI CAS CSCD 北大核心 2024年第4期12-27,共16页
传统井下煤矸石需运输至地面处理,不仅占用地面国土空间、自燃或雨水淋滤造成大气与环境污染,而且长距离无效运输造成的能源消耗问题已成为制约煤矿低碳发展的关键瓶颈。为实现煤矿矸石不出井,从煤炭生产源头减少碳排放与单位产出能源... 传统井下煤矸石需运输至地面处理,不仅占用地面国土空间、自燃或雨水淋滤造成大气与环境污染,而且长距离无效运输造成的能源消耗问题已成为制约煤矿低碳发展的关键瓶颈。为实现煤矿矸石不出井,从煤炭生产源头减少碳排放与单位产出能源资源消耗,实现煤炭的绿色低碳智能开采,回顾了煤矸石井下分选充填技术现状及智能化进展,并在此基础上展望煤矸石井下分选充填技术发展趋势,提出了煤矸石井下原位绿色智能分选、充填新方法,详细阐述了煤矸智能分选机及新型充填液压支架的结构及原理,以最大化缩短矸石无效运输距离。为处理采煤工作面矸石,预防煤岩动力灾害,提出了包含少矸化智能开采系统、原位智能分选系统、工作面矿压反演系统、精准科学充填系统四大子系统的煤矿井下采选充智能一体化系统,并探讨了各子系统间的新环逻辑关系,以形成采煤利于分选、分选利于充填、充填利于采煤的良性循环。为处理掘进工作面矸石,提出了包含智能快掘系统、智能分选系统、煤矸分运系统、智能充填系统四大子系统的煤矿井下掘选充智能一体化系统,并对各子系统所负责工作及智能化实现进行了阐述。所提出的新工艺有望实现煤矿矸石不出井,并为煤矸石原位智能分选充填方法及采选充一体化系统的研究提供新思路。 展开更多
关键词 低碳开采 智能化 煤矸识别 原位分选充填 采选充一体化
下载PDF
我国高碱煤燃烧特性研究和工程应用进展 被引量:1
15
作者 张海 黄斌 +2 位作者 房凡 孙叶柱 吕俊复 《热力发电》 CAS CSCD 北大核心 2024年第1期1-12,共12页
我国具有丰富的高碱煤资源。从基础研究、关键技术和工程实践等方面对高碱煤燃烧技术的研究和工程应用进展做一个较为全面的综述和总结,特别介绍了液态排渣锅炉全烧新疆高碱煤的机理研究和实践最新状况,以期为后续开发更为经济、可长期... 我国具有丰富的高碱煤资源。从基础研究、关键技术和工程实践等方面对高碱煤燃烧技术的研究和工程应用进展做一个较为全面的综述和总结,特别介绍了液态排渣锅炉全烧新疆高碱煤的机理研究和实践最新状况,以期为后续开发更为经济、可长期安全大比例掺烧甚至纯烧新疆高碱煤的燃烧技术提供参考。 展开更多
关键词 高碱煤 碱(土)金属 燃烧技术 进展 综述
下载PDF
燃烧系统参数对商用车发动机燃烧和排放特性的影响研究
16
作者 雷基林 李臻卓 +3 位作者 刘懿 王伟超 宋国富 张海丰 《内燃机工程》 CAS CSCD 北大核心 2024年第2期54-63,74,共11页
为改善商用车发动机性能,采用计算流体力学(computational fluid dynamics,CFD)模拟、正交设计等方法,针对某商用车的燃烧室结构参数设计了4种新方案,并选取油束夹角、喷雾锥角、主喷正时等3个喷油参数开展多因素影响研究。结果表明:燃... 为改善商用车发动机性能,采用计算流体力学(computational fluid dynamics,CFD)模拟、正交设计等方法,针对某商用车的燃烧室结构参数设计了4种新方案,并选取油束夹角、喷雾锥角、主喷正时等3个喷油参数开展多因素影响研究。结果表明:燃烧室形状曲线向内收缩且最大半径增大的方案1燃烧室可提升缸内湍流特性,改善燃油浓度分布,使燃烧速度加快,油气混合更好,为最优方案。在喷油参数研究方案中,以碳烟(soot)排放为优化指标时,油束夹角对排放特性影响最大,最优匹配方案是油束夹角147°、喷雾锥角15°、主喷正时-1°,其缸内碳烟排放较原机下降13.91%,且NOx排放减少13.98%;以氮氧化物(nitrogen oxides,NOx)排放为优化指标时,主喷正时对排放特性影响最大,最优匹配方案是油束夹角160°、喷雾锥角25°、主喷正时-1°,其缸内NOx排放较原机降低37.79%。 展开更多
关键词 商用车 燃烧系统 燃烧室 喷油参数 燃烧特性 排放特性
下载PDF
基于可循环利用的建筑废弃物分类遴选研究 被引量:1
17
作者 石福周 龙朵 +2 位作者 景明成 岳立将 安宗仁 《建筑技术》 2024年第2期251-256,共6页
建筑废弃物主要来源于旧建筑物的拆除及“更新换代”过程,对于建筑废弃物的处理大多为填埋、随意废弃和焚烧,只有少量被回收利用,因而造成了大量建筑资源的浪费以及严重的生态环境污染问题。为此,如何实现建筑废弃物的高效绿色循环利用... 建筑废弃物主要来源于旧建筑物的拆除及“更新换代”过程,对于建筑废弃物的处理大多为填埋、随意废弃和焚烧,只有少量被回收利用,因而造成了大量建筑资源的浪费以及严重的生态环境污染问题。为此,如何实现建筑废弃物的高效绿色循环利用,变废为宝、物尽其用,成为亟须解决的问题。而建筑废弃物的分类遴选是提高其资源利用率的关键步骤,针对建筑废弃物循环利用中的分选过程及再利用途径进行相关的研究,总结了建筑废弃物循环再利用的分类遴选方式及其对建筑绿色可持续发展的重要性。 展开更多
关键词 建筑废弃物 循环利用 分选 资源化利用
下载PDF
动态称重式果品分选机设计与试验
18
作者 刘佳 杨莉玲 +2 位作者 马文强 祝兆帅 沈晓贺 《食品与机械》 CSCD 北大核心 2024年第4期84-89,共6页
目的:解决中国鲜果人工分选准确率低、效率低、劳动强度大和生产成本高的问题。方法:基于果品质量分类法研制一款新型动态称重式果品分选机,该机具基于高精度称重单元采集的果品质量,然后经信号处理模块和PLC协同对采集的数据进行处理... 目的:解决中国鲜果人工分选准确率低、效率低、劳动强度大和生产成本高的问题。方法:基于果品质量分类法研制一款新型动态称重式果品分选机,该机具基于高精度称重单元采集的果品质量,然后经信号处理模块和PLC协同对采集的数据进行处理并控制起弹器,根据水果质量实现果品的分级。该机具可连续实现果品(直径≤126 mm)的上料、称重、分选作业。结果:当分选效率分别为18327,14400,10473个/h时,分选准确率平均值分别为95.31%,96.12%,97.13%,损伤率分别为1.09%,1.11%,1.15%;水果分选速度显著影响分选的准确率,对果品损伤率影响不明显。结论:该新型动态称重式果品分选机能够在保持分选准确率>95%的前提下有效提升果品分选的效率且对果品损伤较小。 展开更多
关键词 果品分选 动态称重 连续作业 杏子
下载PDF
氨气/甲烷无焰燃烧污染物生成特性的实验研究
19
作者 王志超 谭厚章 +4 位作者 李宇航 周上坤 张波 崔保崇 晋中华 《燃烧科学与技术》 CAS CSCD 北大核心 2024年第3期277-286,共10页
为了深入了解氨气/甲烷无焰燃烧的污染物生成特性,本文在改进的旋风无焰燃烧炉中通过实验研究了氨气/甲烷燃料组成、当量比(φ)、热负荷(P)以及空气预热温度(Tin)对炉膛温度以及污染物排放的影响.研究结果表明:随着氨气热值比例的升高,... 为了深入了解氨气/甲烷无焰燃烧的污染物生成特性,本文在改进的旋风无焰燃烧炉中通过实验研究了氨气/甲烷燃料组成、当量比(φ)、热负荷(P)以及空气预热温度(Tin)对炉膛温度以及污染物排放的影响.研究结果表明:随着氨气热值比例的升高,炉膛温度和NO_(x)排放均是先升高后降低,并在中等掺氨比附近取得温度和排放的峰值.在相同条件下,纯氨和氨气/甲烷无焰燃烧都在理想当量比附近时取得最低排放.热负荷和预热温度的升高会提高炉膛温度造成NO_(x)排放的升高,热负荷的升高不利于控制氨逃逸,但预热温度的升高有利于降低氨逃逸. 展开更多
关键词 氨燃烧 甲烷燃烧 无焰燃烧 氮氧化物 氨逃逸
下载PDF
微流控粒子分选中圆形微凹槽容纳特性研究
20
作者 申峰 张杰 +2 位作者 艾明珠 张越东 刘赵淼 《力学学报》 EI CAS CSCD 北大核心 2024年第5期1317-1327,共11页
微流控技术由于具备操控微通道中微小体积流体的能力,已成为操控粒子和细胞的新平台.基于粒子惯性迁移和微凹槽涡胞捕获的粒子分选方法,是一种重要的微流控粒子操控技术.目前,微凹槽容纳的粒子数量不高,制约了该方法的效率.为了提高微... 微流控技术由于具备操控微通道中微小体积流体的能力,已成为操控粒子和细胞的新平台.基于粒子惯性迁移和微凹槽涡胞捕获的粒子分选方法,是一种重要的微流控粒子操控技术.目前,微凹槽容纳的粒子数量不高,制约了该方法的效率.为了提高微凹槽粒子容量,对圆形微凹槽进行结构设计,并利用高速显微成像技术和数值模拟,研究了不同圆形微凹槽的粒子容纳能力.研究发现,相同入口雷诺数(Re=37~555)下,带底腔的圆形微凹槽相较于普通圆形微凹槽容纳的粒子数量提升了45%,这是因为增加底腔后使得涡流线向下延展,形成更深的“U形”结构,可以容纳更多的粒子;当Re=482时,带底腔的直径500μm的圆凹槽比直径600μm的圆凹槽的粒子容量提高了93.9%,原因是前者凹槽内粒子运动轨道与流线更加吻合,粒子轨道面积与凹槽面积占比达到了97%;随着Re增加,从侧通道收集到的粒子富集浓度整体呈现先缓慢增大后减小的趋势,收集到的20μm粒子的最大富集浓度为初始悬浮液的126.7倍;不同微凹槽内粒子群的轨道运动受到涡流场特性、粒子物性及粒子间相互作用和壁面限制作用等因素的共同影响.研究结果对微凹槽结构设计和提高粒子分选性能有重要指导意义. 展开更多
关键词 微流控技术 粒子分选 微凹槽 粒子捕获 涡胞
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部