检索结果-南通市图书馆

Hierarchical cluster-tendency analysis of the group structure in the foreign exchange market

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2013年第4期8卷 451-460页

作者： Xin-ye wu Zhi-Gang Zheng Department of Physics and the Beijing-Hong Kong Singapore Joint Center for Nonlinear and Complex Systems Beijing Normal University Beijing 100875 China

A hierarchical cluster-tendency （HCT） method in analyzing the group structure of networks of the global foreign exchange （FX） market is proposed by combining the advantages of both the minimal spanning tree （MST） and the hierarchical tree （HT）. Fifty currencies of the top 50 World GDP in 2010 according to World Bank＇s database are chosen as the underlying system. By using the HCT method, all nodes in the FX market network can be ＂colored＂ and distinguished. We reveal that the FX networks can be divided into two groups, i.e., the Asia-Pacific group and the Pan-European group. The results given by the hierarchical cluster-tendency method agree well with the formerly observed geographical aggregation behavior in the FX market. Moreover, an oil-resource aggregation phenomenon is discovered by using our method. We find that gold could be a better numeraire for the weekly-frequency FX data.

关键词： foreign-exchange market hiergrchical cluster-tendency method hierarchical tree,minimum spanning tree

Non-Contact Physiological Measurement System for Wearing Masks During the Epidemic

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第5期75卷 2509-2526页

作者： Shu-Yin Chiang Dong-ye wu Department of Information and Telecommunications Engineering Ming Chuan UniversityNo.5 De Ming Rd.Gui Shan DistrictTaoyuan City333Taiwan

Physiological signals indicate a person’s physical and mental state at any given ***,many studies extract physiological signals from the human body with non-contact methods,and most of them require facial feature ***,under COVID-19,wearing a mask has become a must in many places,so how non-contact physiological information measurements can still be performed correctly even when a mask covers the facial information has become a focus of *** this study,RGB and thermal infrared cameras were used to execute non-contact physiological information measurement systems for heart rate,blood pressure,respiratory rate,and forehead temperature for peoplewearing masks due to the *** the green(G)minus red(R)signal in the RGB image,the region of interest(ROI)is established in the forehead and nose bridge *** photoplethysmography(PPG)waveforms of the two regions are obtained after the acquired PPG signal is subjected to the optical flow method,baseline drift calibration,normalization,and bandpass *** relevant parameters in Deep Neural Networks(DNN)for the regression model can correctly predict the heartbeat and blood *** addition,the temperature change in the ROI of the mask after thermal image processing and filtering can be used to correctly determine the number of ***,the thermal image can be used to read the temperature average of the ROI of the forehead,and the forehead temperature can be obtained *** experimental results show that the above-mentioned physiological signals of a subject can be obtained in 6-s images with the error for both heart rate and blood pressure within 2%∼3%and the error of forehead temperature within±0.5°C.

关键词： PPG DNN heart rate blood pressure prediction face mask

Operando modeling and measurements:Powerful tools for revealing the mechanism of alkali carbonate-based sorbents for CO_(2)capture in real conditions

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

Frontiers in Energy 2023年第3期17卷 380-389页

作者： Tianyi CAI Mengshi WANG Xiaoping CHEN ye wu Jiliang MA wu ZHOU School of Energy and Power Engineering Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Energy Thermal Conversion and Control of the Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing 210096China Key Laboratory of Thermal Control of Electronic Equipment and Advanced Combustion Laboratory of the Ministry of Industry and Information Technology School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing 210094China

Alkalicarbonate-based sorbents(ACSs),including Na_(2)CO_(3)-and K2CO_(3)-based sorbents,are promising for CO_(2)***,the complex sorbent components and operation conditions lead to the versatile kinetics of CO_(2)sorption on these *** paper proposed that operando modeling and measurements are powerful tools to understand the mechanism of sorbents in real operating conditions,facilitating the sorbent development,reactor design,and operation parameter *** reviewed the theoretical simulation achievements during the development of *** elucidated the findings obtained by utilizing density functional theory(DFT)calculations,ab initio molecular dynamics(AIMD)simulations,and classical molecular dynamics(CMD)simulations as *** hygroscopicity of sorbent and the humidity of gas flow are crucial to shifting the carbonation reaction from the gas-solid mode to the gas-liquid mode,boosting the ***,it briefly introduced a machine learning(ML)approach as a promising method to aid sorbent ***,it demonstrated a conceptual compact operando measurement system in order to understand the behavior of ACSs in the real operation *** proposed measurement system includes a micro fluidizedbed(MFB)reactor for kinetic analysis,a multi-camera sub-system for 3D particle movement tracking,and a combined Raman and IR sub-system for solid/gas components and temperature *** is believed that this system is useful to evaluate the real-time sorbent performance,validating the theoretical prediction and promoting the industrial scale-up of ACSs for CO_(2)capture.

关键词： CO_(2)capture carbonation theoretical modeling operando techniques reaction visualization

City-specific vehicle emission control strategies to achieve stringent emission reduction targets in China's Yangtze River Delta region

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2017年第1期29卷 75-87页

作者： Shaojun Zhang ye wu Bin Zhao Xiaomeng wu Jiawei Shu Jiming Hao University of Michigan Department of Mechanical EngineeringAnn ArborMI 48109USA Tsinghua University State Key Joint Laboratory of Environment Simulation and Pollution ControlSchool of EnuironmentBeijing 100084China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China Joint Institute for Regional Earth System Science and Engineering Department of Atmospheric and Oceanic SciencesUniversity of CaliforniaLos AngelesCalifornia 90095USA

The Yangtze River Delta（YRD） region is one of the most prosperous and densely populated regions in China and is facing tremendous pressure to mitigate vehicle emissions and improve air *** assessment has revealed that mitigating vehicle emissions of NOx would be more difficult than reducing the emissions of other major vehicular pollutants（e.g.,CO,HC and PM_（2.5）） in the YRD *** in Shanghai,where the emission control implemented are more stringent than in Jiangsu and Zhejiang,we observed little to no reduction in NOx emissions from 2000 to ***-reduction targets for HC,NOx and PM_（2.5） are determined using a response surface modeling tool for better air *** design city-specific emission control strategies for three vehicle-populated cities in the YRD region：Shanghai and Nanjing and wuxi in *** results indicate that even if stringent emission control consisting of the Euro 6/VI standards,the limitation of vehicle population and usage,and the scrappage of older vehicles is applied,Nanjing and wuxi will not be able to meet the NOx emissions target by ***,additional control measures are proposed for Nanjing and wuxi to further mitigate NOx emissions from heavy-duty diesel vehicles.

关键词： Vehicle Emission control Scenario Yangtze River Delta

Recent advances in the construction of axially chiral arylpyrroles

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2023年第9期66卷 2480-2491页

作者： Yang-Bo Chen ye-Nan Yang Xuan-Zhu Huo Long-wu ye Bo Zhou Key Laboratory of Chemical Biology of Fujian Province State Key Laboratory of Physical Chemistry of Solid SurfacesCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

Catalytic enantioselective preparation of axially chiral molecules has gained considerable interest over the past decades, due to their numerous applications in bioactive molecules, natural products, pharmaceuticals, materials, ligands, and catalysts. Compared with the well-established synthetic approaches for six-membered axially chiral skeletons, methodologies directed towards five-membered axially chiral compounds are relatively rare. Among these, axially chiral arylpyrroles are especially important structural motifs with wide utility, and the atroposelective synthesis of them is highly desirable. In recent years, novel strategies have been developed based on transition-metal catalysis and organocatalysis. This review summarizes the recent achievements in atroposelective preparation of arylpyrroles, by emphasizing the synthetic methods for each axially chiral framework, reaction mechanisms, and applications.

关键词： axial chirality pyrrole atropisomers transition-metal catalysis organocatalysis

同方期刊数据库

Structural and functional alterations in the brains of patients with anisometropic and strabismic amblyopia:a systematic review of magnetic resonance imaging studies

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2023年第11期18卷 2348-2356页

作者： Yuxia Wang ye wu Lekai Luo Fei Li Huaxi MR Research Center(HMRRC) Department of RadiologyWest China Hospital of Sichuan UniversityChengduSichuan ProvinceChina Department of Ophthalmology Laboratory of Optometry and Vision SciencesWest China Hospital/West China School of MedicineSichuan UniversityChengduSichuan ProvinceChina Department of Radiology West China Second Hospital of Sichuan UniversityChengduSichuan ProvinceChina

Amblyopia is the most common cause of vision loss in children and can persist into adulthood in the absence of effective *** clinical and neuroimaging studies have suggested that the neural mechanisms underlying strabismic amblyopia and anisometropic amblyopia may be ***,we performed a systematic review of magnetic resonance imaging studies investigating brain alterations in patients with these two subtypes of amblyopia;this study is registered with PROSPERO(registration ID:CRD42022349191).We searched three online databases(PubMed,EMBASE,and Web of Science) from inception to April 1,2022;39 studies with 633 patients(324patients with anisometropic amblyo pia and 309 patients with strabismic amblyopia) and 580 healthy controls met the inclusion criteria(e.g.,case-control designed,pee r-reviewed articles) and were included in this *** studies highlighted that both strabismic amblyopia and anisometropic amblyopia patients showed reduced activation and distorted topological cortical activated maps in the striate and extrastriate co rtices during tas k-based functional magnetic resonance imaging with spatial-frequency stimulus and retinotopic representations,respectively;these may have arisen from abnormal visual *** for amblyopia that are reflected in enhanced spontaneous brain function have been reported in the early visual cortices in the resting state,as well as reduced functional connectivity in the dorsal pathway and structural connections in the ventral pathway in both anisometro pic amblyopia and strabismic amblyopia *** shared dysfunction of anisometro pic amblyopia and strabismic amblyopia patients,relative to controls,is also chara cterized by reduced spontaneous brain activity in the oculomotor co rtex,mainly involving the frontal and parietal eye fields and the cerebellu m;this may underlie the neural mechanisms of fixation instability and anomalous saccades in *** regards to

关键词： amblyopia anisometropia brain function magnetic resonance imaging oculomotor system precortical pathway strabismus structure visual cortex

Genome-wide identification and expression analysis of the bZIP gene family in silver birch ( Betula pendula Roth.)

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2022年第5期33卷 1615-1636页

作者： YaNan Jing Yue Yu Hanzeng Wang ye wu Chenghao Li State Key Laboratory of Tree Genetics and Breeding Northeast Forestry University26 Hexing RoadHarbin 150040People’s Republic of China

Basic Leu zipper ( bZIP ) genes play pivotal, versatile roles in abiotic or biotic stress responses and in other biological processes. Knowledge on the evolutionary relationships and patterns of gene expression of bZIP family members in woody plants, however, has been limited. Here we identified and characterized 47 BpbZIP genes across the silver birch ( Betula pendula Roth.) genome. With reference to bZIP classifications for Arabidopsis thaliana , all BpbZIP proteins clustered among 10 groups in phylogeny. The bZIP domains were divided into five patterns based on intron positions and splicing phases. A total of 24 conserved motifs were detected in BpbZIPs with high group specificity. We also analyzed the protein structure of the BpAREB/ABF/ ABI5 subfamily, the most important subfamily in the bZIP family. Expression analyses demonstrated that BpbZIP genes were widely involved in abscisic acid, salt, drought, and heat stress responses, with BpbZIP07/ABF4 and BpbZIP21/ABF2 most highly expressed. Our results on genome-wide identification, evolutionary relationships, gene structure, and motif and promoter element identification for BpbZIP family members in silver birch provide a comprehensive understanding of bZIP transcription factors in birch and will lead to a deeper understanding of their evolution and potential biological functions.

关键词： Basic Leu zipper gene Birch Abscisic acid Abiotic stress Gene expression

Clustering analysis of telecommunication customers

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2009年第2期16卷 114-116,128页

作者： REN Hong ZHENG Yan wu ye-rong School of Electronic Engineering Beijing University of Posts and Telecommunications Beijing 100876 China School of Computer Science and Technology Beijing University of Posts and Telecommunications Beijing 100876 China

In this article, a clustering method based on genetic algorithm （GA） for telecommunication customer subdivision is presented. First, the features of telecommunication customers （such as the calling behavior and consuming behavior） are extracted. Second, the similarities between the multidimensional feature vectors of telecommunication customers are computed and mapped as the distance between samples on a two-dimensional plane. Finally, the distances are adjusted to approximate the similarities gradually by GA. One advantage of this method is the independent distribution of the sample space. The experiments demonstrate the feasibility of the proposed method.

关键词： genetic algorithm similarity matrix customer subdivision

Gold-catalyzed intermolecular reaction of ynamides with 3-indolyl azides via an unexpected 1,2-alkyl migration

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2017年第17期62卷 1201-1206页

作者： Bo Zhou Ying-Qi Zhang Xin Liu Long-wu ye State Key Laboratory of Physical Chemistry of Solid Surfaces and The Key Laboratory for Chemical Biology of Fujian Province College of Chemistry and Chemical EngineeringXiamen University State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences

A gold-catalyzed intermolecular reaction of ynamides with 3-indolyl azides via the presumable α-imino gold carbenes has been developed, providing an alternative and efficient way for the synthesis of valuable 3-amino-β-carbolines in generally good to excellent yields. Importantly, this new protocol involves an unexpected 1,2-alkyl migration pathway.

关键词： Gold Heterocycles Migration Cyclization Tandem reaction