检索结果-南通市图书馆

Derivative Spectroscopy and its Application at Detecting the Weak Emission/Absorption lines

Research in Astronomy and Astrophysics 2024年第3期24卷 205-223页

作者： lihuan Yu Jiangdan li Jinliang Wang Jiajia li Jiao li Qiang xi Zhanwen Han Yunnan Observatories Chinese Academy of Sciences(CAS)Kunming 650011China Key Lab of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

The development of spectroscopic survey telescopes like Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST),Apache Point Observatory Galactic Evolution Experiment and Sloan Digital Sky Survey has opened up unprecedented opportunities for stellar *** types of stars,such as early-type emission-line stars and those with stellar winds,can be distinguished by the profiles of their spectral *** this paper,we introduce a method based on derivative spectroscopy(DS)designed to detect signals within complex backgrounds and provide a preliminary estimation of curve *** method exhibits a unique advantage in identifying weak signals and unusual spectral line profiles when compared to other popular line detection *** validated our approach using synthesis spectra,demonstrating that DS can detect emission signals three times fainter than Gaussian ***,we applied our method to 579,680 co-added spectra from LAMOST Medium-Resolution Spectroscopic Survey,identifying 16,629 spectra with emission peaks around the Hαline from 10,963 *** spectra were classified into three distinct morphological groups,resulting in nine subclasses as follows.(1)Emission peak above the pseudo-continuum line(single peak,double peaks,emission peak situated within an absorption line,P Cygni profile,Inverse P Cygni profile);(2)Emission peak below the pseudo-continuum line(sharp emission peak,double absorption peaks,emission peak shifted to one side of the absorption line);(3)Emission peak between the pseudo-continuum line.

关键词： line identification-line profiles-methods data analysis-techniques spectroscopic-techniques radial velocities

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

The nitrogen transformation behavior based on the pyrolysis products of wheat straw

引用

Chinese Journal of Chemical Engineering 2024年第7期71卷 58-65页

作者： Shun guo Yunfei li Shengwei Tang Tao Zhang School of Chemical Engineering Sichuan UniversityChengdu 610065China

In order to provide basic design parameters for the industrial pyrolysis process,the transformation behavior of nitrogen was investigated using wheat straw as raw *** distributions of nitrogen in pyrolysis char,oil,and gas were obtained and the nitrogenous components in the products were analyzed systematically by X-ray photoelectron spectroscopy(XPS),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and thermogravimetric-Fourier transform infrared spectrometry(TG-FTIR).The nitrogen distribution ranges of the pyrolysis char,oil,and gas were 37.34%–54.82%,32.87%–40.94%and 10.20%–28.83%,*** nitrogen was retained in char at lower pyrolysis temperature and the nitrogen distribution of oil was from rise to decline with increasing *** most abundant N-containing compounds in three-phase products were pyrrole-N,amines,and HCN,*** addition,the transformation mechanism of nitrogen from wheat straw to pyrolysis products was concluded.

关键词： Pyrolysis Nitrogen transformation Wheat straw Py-GC/MS TG-FTIR

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Variational Neural Inference Enhanced Text Semantic Communication System

引用

China Communications 2024年第7期21卷 50-64页

作者： Zhang xi Zhang Yiqian li Congduan Ma xiao School of Electronics and Communication Engineering Sun Yat-Sen UniversityShenzhen 518107China Guizhou University State Key Laboratory of Public Big Data Guiyang 550025China Shenzhen Key Laboratory of Navigation and Communication Integration Shenzhen 518107China School of Computer Science and Engineering Sun Yat-Sen UniversityGuangzhou 510006China

Recently,deep learning-based semantic communication has garnered widespread attention,with numerous systems designed for transmitting diverse data sources,including text,image,and speech,*** efforts have been directed toward improving system performance,many studies have concentrated on enhancing the structure of the encoder and ***,this often overlooks the resulting increase in model complexity,imposing additional storage and computational burdens on smart ***,existing work tends to prioritize explicit semantics,neglecting the potential of implicit *** paper aims to easily and effectively enhance the receiver's decoding capability without modifying the encoder and decoder *** propose a novel semantic communication system with variational neural inference for text ***,we introduce a simple but effective variational neural inferer at the receiver to infer the latent semantic information within the received *** information is then utilized to assist in the decoding *** simulation results show a significant enhancement in system performance and improved robustness.

关键词： deep learning semantic communication variational neural inference

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

产品模块可拓变型设计方法

引用

计算机集成制造系统 2008年第7期14卷 1256-1267,1312页

作者：龚京忠邱静李国喜李伟国防科技大学机电工程与自动化学院湖南长沙410073

为更好地支持产品多样化设计,提出了一种基于功构变换的产品模块可拓变型设计方法。针对产品模块变型设计需求,采用功能-行为-结构的迭代映射方法,建立存在模块的功构分解模型。通过数学模型中功构的可拓变换与分解,建立期望模块的功构... 详细信息

为更好地支持产品多样化设计,提出了一种基于功构变换的产品模块可拓变型设计方法。针对产品模块变型设计需求,采用功能-行为-结构的迭代映射方法,建立存在模块的功构分解模型。通过数学模型中功构的可拓变换与分解,建立期望模块的功构分解模型,并采用功能流和功能模型IDEF0相结合的功能建模方法,建立期望模块的功能模型;基于功能模型的约束,通过结构单元的删除和聚合,进行模块功构要素可拓变换的传导变换分析,展开期望模块功构综合与结构设计,从而实现模块的变型设计。将该方法应用于堆垛机推拉机构的变型设计,双倍程推拉机构变型为三倍程推拉机构,验证了该方法的可行性和有效性。

关键词：产品设计变型设计功能-行为-结构模块功构单元可拓变换堆垛机

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Compound extreme inundation risk of coastal wetlands caused by climate change and anthropogenic activities in the Yellow River Delta,China

引用

Advances in Climate Change Research 2024年第1期15卷 134-147页

作者： xiao-li WANG Ai-Qing FENG xi-Yong HOU Qing-Chen CHAO Bai-Yuan SONG Yu-Bin liU Qi-Guang WANG He XU Yu-xin ZHANG Dong li li-Jie DONG Yu guo CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation Yantai Institute of Coastal Zone ResearchChinese Academy of SciencesYantai 264003China Shandong Key Laboratory of Coastal Environmental Processes Yantai 264003China China Meteorological Administration Key Laboratory for Climate Prediction Studies National Climate CentreBeijing 100081China Tongji Urban Planning Design Research Institute Shanghai 200092China School of Geography and Tourism Qilu Normal UniversityJinan 250200China China Meteorological Administration Training Centre China Meteorological AdministrationBeijing 10008China University of Chinese Academy of Sciences Beijing 100049China Marine Science and Technology College Zhejiang Ocean UniversityZhoushan 316022China

The coastal wetlands of the Yellow River Delta(YRD)in China are crucial for their valuable resources,environmental significance,and economic ***,these wetlands are also vulnerable to the dual threats of climate change and human *** substantial attention to the historical shifts in YRD's coastal wetlands,uncertainties remain regarding their future trajectory in the face of compound risks from climate change and anthropogenic *** on a range of remote sensing data sources,this study undertakes a comprehensive investigation into the evolution of YRD's coastal wetlands between 2000 and ***,the potential fate of coastal wetlands is thoroughly analyzed through the Land Use/Cover Change(LUCC)simulation using System Dynamic-Future Land Use Simulation(SD-FLUS)model and the extreme water levels projection integrated future sea-level rise,storm surge,and astronomical high tide in 2030,2050,and 2100 under scenarios of SSP1-2.6,SSP2-4.5,and *** revealed that YRD's coastal wetlands underwent a marked reduction,shrinking by 1688.72 km²from 2000 to *** decline was mostly attributed to the substantial expansion in the areas of artificial wetlands(increasing by 823.78 km2),construction land(increasing by 767.71 km²),and shallow water(increasing by 274.58 km²).Looking ahead to 2030-2100,the fate of coastal wetlands appears to diverge based on different *** the SSP1-2.6 scenario,the area of coastal wetland is projected to experience considerable *** contrast,the SSP5-8.5 scenario anticipates a notable decrease in coastal *** to the inundated area suffered from the current extreme water levels,the study projects a decrease of 6.8%-10.6%in submerged coastal wetlands by 2030 and 9.4%-18.2%by 2050 across all *** 2100,these percentages are projected to decrease by 0.4%(SSP2-4.5)and 27.1%(SSP5-8.5),but increase by 35.7%(SSP1-2.6).Results suggest that coastal wetlands in th

关键词： Climate change Anthropogenic activities Compound extreme risk Coastal wetlands Yellow River Delta

来源：

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

Surface plasmon decorated InGaO deep-UV photodetector array for image sensing and water quality monitoring via highly effective hot electron excitation and interfacial injection

引用

Science China(Technological Sciences) 2024年第8期67卷 2449-2460页

作者： SHU linCong SHA Shulin xi ZhaoYing li Lei YAO SuHao ZHANG JiaHan JI XueQiang ZHANG ShaoHui BIAN Ang JIANG MingMing guo YuFeng TANG WeiHua liU Zeng Innovation Center of Gallium Oxide Semiconductor(IC-GAO) College of Integrated Circuit Science and EngineeringNanjing University of Posts and TelecommunicationsNanjing 210023China School of Electronic Information Engineering Inner Mongolia UniversityHohhot 010021China College of Science MIIT Key Laboratory of Aerospace Information Materials and PhysicsNanjing University of Aeronautics and AstronauticsNanjing 211106China Collaborative Innovation Center of Advanced Microstructures School of Electronic Science and EngineeringNanjing UniversityNanjing 210093China Institute of Biological and Medical Engineering Guangdong Academy of SciencesGuangzhou 510316China School of Science Jiangsu University of Science and TechnologyZhenjiang 212100China School of Integrated Circuits Beijing University of Posts and TelecommunicationsBeijing 100876China

In addition to the plasmon-mediated resonant coupling mechanism,the excitation of hot electron induced by plasmon presents a promising path for developing high-performance optoelectronic devices tailored for various *** study introduces a sophisticated design for a solar-blind ultraviolet(UV)detector array using linear In-doped Ga_(2)O_(3) (InGaO)modulated by platinum(Pt)nanoparticles(PtNPs).The construction of this array involves depositing a thin film of Ga_(2)O_(3) through the plasmonenhanced chemical vapor deposition(PECVD)***,PtNPs were synthesized via radio-frequency magnetron sputtering and annealing *** performance of these highly uniform arrays is significantly enhanced owing to the generation of high-energy hot *** process is facilitated by non-radiative decay processes induced by ***,the array achieves maximum responsivity(R)of 353 mA/W,external quantum efficiency(EQE)of 173%,detectivity(D*)of approximately 10~(13)Jones,and photoconductive gain of *** addition,the standard deviation for photocurrent stays below17%for more than 80%of the array units within the ***,the application of this array extends to photon detection in the deep-UV(DUV)*** includes critical areas such as imaging sensing and water quality *** leveraging surface plasmon coupling,the array achieves high-performance DUV photon *** approach enables a broad spectrum of practical applications,underscoring the significant potential of this technology for the advancement of DUV detectors.

关键词： InGaO PECVD surface plasmon solar-blind UV photodetector array optoelectronic applications

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Landslide hazard susceptibility evaluation based on SBAS-InSAR technology and SSA-BP neural network algorithm:A case study of Baihetan Reservoir Area

引用

Journal of Mountain Science 2024年第3期21卷 952-972页

作者： guo Junqi xi Wenfei YANG Zhiquan SHI Zhengtao HUANG Guangcai YANG Zhengrong YANG Dongqing Faculty of Geography Yunnan Normal UniversityKunming 650500China Key Laboratory of Early Rapid Identification Prevention and Control of Geological Diseases in Traffic Corridor of High Intensity Earthquake Mountainous Area of Yunnan ProvinceKunming 650093China Faculty of Public Safety and Emergency Management Kunming University of Science and TechnologyKunming 650093China Key Laboratory of Geological Disaster Risk Prevention and Control and Emergency Disaster Reduction of Ministry of Emergency Management of the People’s Republic of China Kunming University of Science and TechnologyKunming 650093China Guizhou Geological Survey Institute Guiyang 550081China College of Big Data and Intelligent Engineering Southwest Forestry UniversityKunming 650224China

Landslide hazard susceptibility evaluation takes on critical significance in early warning and disaster prevention and *** order to solve the problems of poor effectiveness of landslide data and complex calculation of weights for multiple evaluation factors in the existing landslide susceptibility evaluation models,in this study,a method of landslide hazard susceptibility evaluation is proposed by combining SBAS-InSAR(Small Baseline Subsets-Interferometric Synthetic Aperture Radar)and SSA-BP(Sparrow Search Algorithm-Back Propagation)neural network *** SBAS-InSAR technology is adopted to identify potential landslide hazards in the study area,update the cataloging data of landslide hazards,and 11 evaluation factors are chosen for constructing the SSA-BP model for training and *** Reservoir area is selected as a case study for *** indicated by the results,the application of SBAS-InSAR technology,combined with both ascending and descending orbit data,effectively addresses the incomplete identification of landslide hazards caused by geometric distortion of single orbit SAR data(e.g.,shadow,overlay,and perspective contraction)in deep canyon areas,thereby enabling the acquisition of up-to-date landslide hazard ***,in comparison to the conventional BP(Back Propagation)algorithm,the accuracy of the model constructed by the SSA-BP algorithm exhibits a significant increase,with mean squared error and mean absolute error reduced by 0.0142 and 0.0607,***,during the process of susceptibility evaluation,the SSA-BP model effectively circumvents the issue of considerable manual interventions in calculating the weight of evaluation *** area under the curve of this model reaches 0.909,surpassing BP(0.835),random forest(0.792),and the information value method(0.699).The risk of landslide occurrence in the Baihetan Reservoir area is positively correlated with slope,surface temperature,and deformation ra

关键词： Baihetan SBAS-InSAR SSA-BP Landslide hazard susceptibility evaluation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Geochemical Characteristics and Development Significances of Constant and Trace Elements from Coalbed Methane Co-Produced Water:A Case Study of the Shizhuangnan Block,the Southern Qinshui Basin

引用

Journal of Earth Science 2024年第1期35卷 51-61页

作者： Yang li Shuheng Tang Jian Chen Songhang Zhang Zhaodong xi Key Laboratory of Universities in Anhui Province for Prevention of Mine Geological Disasters Anhui University of Science and TechnologyHuainan 232001China School of Earth and Environment Anhui University of Science and TechnologyHuainan 232001China National Key Laboratory of Petroleum Resources and Engineering China University of PetroleumBeijing 102249China School of Energy Resource China University of GeosciencesBeijing 100083China Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism Ministry of EducationBeijing 100083China Key Laboratory of Strategy Evaluation for Shale Gas Ministry of Land and ResourcesBeijing 100083China

As an unconventional natural gas resource,coalbed methane(CBM)development releases a large amount of CBM wells co-produced *** characteristics of the co-produced water provide an essential foundation for the production dynamics of CBM reservoirs if the impacts of fracturing fluids and other aquifers can be *** the Shizhuangnan Block of the southern Qinshui Basin,constant and trace elements in CBM co-produced water from the wellheads were collected and determined,which is applied to assess water source,fracturing fluid effect,and CBM *** on principle component analysis and hierarchical clustering analysis,the water samples are divided into four *** suggests that different characteristics affected by water-rock interaction,reservoir environment,aquifer recharge,and hydraulic fracturing result in the various ratios of Na^(+)/Cl^(-),alkalinity(HCO_(3)^(-)+CO_(3)^(2-))/Cl^(-)and other specific ***,Cl^(-)is selected as a dividing line for complete fracturing fluid flow back,associated with organic-bound chlorine complexes in the original coal seam *** to constant elements,there is a significant correlation between li and Sr concentrations and CBM productivity,so templates regarding trace elements can be used to distinguish various sources of the co-produced water.

关键词： coalbad methane CBM co-produced water hydraulic fracturing Qinshui Basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimal pivot path of the simplex method for linear programming based on reinforcement learning

引用

Science China Mathematics 2024年第6期67卷 1263-1286页

作者： Anqi li Tiande guo Congying Han Bonan li Haoran li School of Mathematical Sciences University of Chinese Academy of SciencesBeijing100049China

Based on the existing pivot rules,the simplex method for linear programming is not polynomial in the worst ***,the optimal pivot of the simplex method is *** this paper,we propose the optimal rule to find all the shortest pivot paths of the simplex method for linear programming problems based on Monte Carlo tree ***,we first propose the SimplexPseudoTree to transfer the simplex method into tree search mode while avoiding repeated basis ***,we propose four reinforcement learning models with two actions and two rewards to make the Monte Carlo tree search suitable for the simplex ***,we set a new action selection criterion to ameliorate the inaccurate evaluation in the initial *** is proved that when the number of vertices in the feasible region is C_(n)^(m),our method can generate all the shortest pivot paths,which is the polynomial of the number of *** addition,we experimentally validate that the proposed schedule can avoid unnecessary search and provide the optimal pivot ***,this method can provide the best pivot labels for all kinds of supervised learning methods to solve linear programming problems.

关键词： simplex method linear programming pivot rules reinforcement learning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efficacy and safety of Chinese herbal medicine as adjunctive therapy in sepsis patients with bloodstream infection:a propensity-matched analysis

引用

Journal of Traditional Chinese Medicine 2024年第1期44卷 197-204页

作者： ZHOU xianshi ZHONG Minlin xi xiaotu li Jun TANG Guanghua the Second Clinical College of Guangzhou University of Chinese Medicine Guangzhou 510120China Emergency Department Guangdong Provincial Hospital of Chinese MedicineGuangzhou 510120China Guangdong Provincial Key Laboratory of Research on Emergency in TCM Guangzhou 510120China Guangzhou Key Laboratory of Traditional Chinese Medicine for Prevention and Treatment of Emerging Infectious Diseases Guangzhou 510120China Administration Department the First Hospital of Guangzhou University of Chinese MedicineGuangzhou 510405China

OBJECTIVE:To investigate the efficacy and safety of Chinese herbal medicine in treating sepsis patients with bloodstream ***:A 6-year retrospective study was carried out at a university hospital in *** sepsis patients with bloodstream infection were *** primary outcome was 28-day mortality after *** score method was used to adjust for possible confounding.28-day mortality was estimated by KaplanMeier analysis and compared using the log-rank *** regression analysis was carried out to identify factors impacting in-hospital mortality ***:Following the application of the propensity score method,a total of 176 patients were *** all-cause 28-day mortality in the control group and Chinese herbal medicine group was 21.6%and 14.8%,***-Meier survival analysis showed that Chinese herbal medicine was associated with a lower hazard ratio(HR)in all-cause 28-day death compared with the control group[HR=0.44,95%CI(0.22,0.90),Plications were similar between the two groups(P>0.05).Blood-activating and stasis-eliminating herb administration was associated with reduced inhospital mortality among sepsis patients with bloodstream infection[HR=0.54,95%CI(0.34,0.94),Pliminating herb,might have certain efficacy and safety in treating sepsis patients with bloodstream *** should prescribe blood-activating and stasis-eliminating herb in treating these two coalescent critical diseases as long as no contraindications ***,further studies are needed to validate our results.

关键词： bacteremia medicine Chinese traditional herbal medicine sepsis propensity-matched analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：