检索结果-南通市图书馆

Local and regional flood frequency analysis based on hierarchical Bayesian model in Dongting Lake Basin,China

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

Water Science and Engineering 2019年第4期12卷 253-262页

作者： Yun-biao Wu lian-qing xue Yuan-hong Liu College of Hydrology and Water Resources Hohai UniversityNanjing 210098China Department of Fundamental Education Wanjiang University of TechnologyMaanshan 243031China College of Water and Architectural Engineering Shihezi UniversityShihezi 832003China

This study developed a hierarchical Bayesian(HB)model for local and regional flood frequency analysis in the Dongting Lake Basin,in China.The annual maximum daily flows from 15 streamflow-gauged sites in the study area were analyzed with the HB model.The generalized extreme value(GEV)distribution was selected as the extreme flood distribution,and the GEV distribution location and scale parameters were spatially modeled through a regression approach with the drainage area as a covariate.The Markov chain Monte Carlo(MCMC)method with Gibbs sampling was employed to calculate the posterior distribution in the HB model.The results showed that the proposed HB model provided satisfactory Bayesian credible intervals for flood quantiles,while the traditional delta method could not provide reliable uncertainty estimations for large flood quantiles,due to the fact that the lower confidence bounds tended to decrease as the return periods increased.Furthermore,the HB model for regional analysis allowed for a reduction in the value of some restrictive assumptions in the traditional index flood method,such as the homogeneity region assumption and the scale invariance assumption.The HB model can also provide an uncertainty band of flood quantile prediction at a poorly gauged or ungauged site,but the index flood method with L-moments does not demonstrate this uncertainty directly.Therefore,the HB model is an effective method of implementing the flexible local and regional frequency analysis scheme,and of quantifying the associated predictive uncertainty.

关键词： Flood frequency analysis Hierarchical Bayesian model Index flood method Generalized extreme value distribution Dongting Lake Basin

All types of base conversions allowed by base editors

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2024年第2期67卷 431-433页

作者： Shun-qing liang Wen xue RNA Therapeutics Institute UMass Chan Medical SchoolWorcester 01655USA Department of Molecular Cell and Cancer BiologyUMass Chan Medical SchoolWorcester 01655USA Department of Molecular Medicine UMass Chan Medical SchoolWorcester 01655USA Li Weibo Institute for Rare Diseases Research UMass Chan Medical SchoolWorcester 01655USA

Base editors(BEs) hold great promise as tools for introducing single-base-pair changes in both basic research and therapeutic applications(Rees and Liu,2018).Base editors are composed of a Cas9 nickase fused to a DNA-modifying enzyme,which chemically modifies nucleobases within a specific targeting window near the Cas9-binding site.

关键词： base bases allowed

Acid-rock reaction kinetics in a two-scale model based on reaction order correction

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第3期21卷 2089-2101页

作者： xue-Song Li Ning Qi Ze-Hui Zhang lian Liu Xia-qing Li Xu-Hang Su School of Petroleum Engineering China University of Petroleum(East China) Key Lab of Unconventional Oil & Gas Development Ministry of Education China University of Petroleum(East China) SINOPEC Northwest Oilfield Branch Company Petroleum Engineering Technology Research Institute SINOPEC Shengli Oilfield Company

The reaction order plays a crucial role in evaluating the response rate of acid-rock. However, the conventional two-scale model typically assumes that the reaction order is constant as one, which can lead to significant deviations from reality. To address this issue, this study proposes a novel multi-order dynamic model for acid-rock reaction by combining rotating disk experimental data with theoretical derivation.Through numerical simulations, this model allows for the investigation of the impact of acidification conditions on different orders of reaction, thereby providing valuable insights for on-site construction.The analysis reveals that higher response orders require higher optimal acid liquid flow rates, and lower optimal H+diffusion coefficients, and demonstrate no significant correlation with acid concentration.Consequently, it is recommended to increase the displacement and use high-viscosity acid for reservoirs with high calcite content, while reducing the displacement and using low-viscosity acid for reservoirs with high dolomite content.

关键词： Reaction order Two-scale model Wormhole propagation Carbonate rocks Numerical simulation

Open-Shell Oligomers and Polymers: Theory, Characterization Methods, Molecular Design, and Applications

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第4期42卷 417-436页

作者： xue-qing Wang Cheng Song Ting Lei Key Laboratory of Polymer Chemistry and Physics(Ministry of Education) School of Materials Science and EngineeringPeking UniversityBeijing100871China

Open-shell oligomers and polymers have exhibited intriguing electronic and magnetic properties, making them highly desirable for a wide range of applications, including ambipolar organic field-effect transistors (OFETs), photodetectors, organic thermoelectrics, and spintronics. Although open-shell ground states have been observed in certain small molecules and doped organic semiconductors, the exploration of open-shell ground-state conjugated polymers is still limited, and the strategies for designing these polymers remain obscure. This review aims to briefly introduce the theory and characterization methods of open-shell conjugated polymers, along with an overview of recent progress and applications. The objective is to stimulate further advancements and investigations in this promising area by shedding light on the potential of open-shell conjugated polymers and the challenges that lie ahead.

关键词： Conjugated polymers Open-shell molecules High-spin ground state Donor-acceptor(D-A)polymers Optoelectronic and magnetic properties

Personal Thermal Management by Radiative Cooling and Heating

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第8期16卷 225-267页

作者： Shidong xue Guanghan Huang qing Chen Xungai Wang Jintu Fan Dahua Shou School of Fashion and Textiles The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077People’s Republic of China Future Intelligent Wear Centre The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077People’s Republic of China State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006People’s Republic of China Shanghai International Fashion Innovation Center Donghua UniversityShanghai 200051People’s Republic of China Research Centre of Textiles for Future Fashion The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077People’s Republic of China Research Institute for Smart Energy The Hong Kong Polytechnic UniversityHung HomKowloonHong Kong 999077People’s Republic of China

Maintaining thermal comfort within the human body is crucial for optimal health and overall well-being.By merely broadening the setpoint of indoor temperatures,we could significantly slash energy usage in building heating,ventilation,and air-conditioning systems.In recent years,there has been a surge in advancements in personal thermal management(PTM),aiming to regulate heat and moisture transfer within our immediate surroundings,clothing,and skin.The advent of PTM is driven by the rapid development in nano/micro-materials and energy science and engineering.An emerging research area in PTM is personal radiative thermal management(PRTM),which demonstrates immense potential with its high radiative heat transfer efficiency and ease of regulation.However,it is less taken into account in traditional textiles,and there currently lies a gap in our knowledge and understanding of PRTM.In this review,we aim to present a thorough analysis of advanced textile materials and technologies for PRTM.Specifically,we will introduce and discuss the underlying radiation heat transfer mechanisms,fabrication methods of textiles,and various indoor/outdoor applications in light of their different regulation functionalities,including radiative cooling,radiative heating,and dual-mode thermoregulation.Furthermore,we will shine a light on the current hurdles,propose potential strategies,and delve into future technology trends for PRTM with an emphasis on functionalities and applications.

关键词： Personal thermal management Radiative cooling and heating Thermal comfort Dynamic thermoregulation

High-resolution neutronics model for ^(238)Pu production in high-flux reactors

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第5期35卷 226-236页

作者： qing-Quan Pan qing-Fei Zhao lian-Jie Wang Bang-Yang Xia Yun Cai Jin-Biao Xiong Xiao-Jing Liu School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610200China

We proposed and compared three methods(filter burnup,single energy burnup,and burnup extremum analysis)to build a high-resolution neutronics model for 238Pu production in high-flux reactors.The filter burnup and single energy burnup methods have no theoretical approximation and can achieve a spectrum resolution of up to~1 eV,thereby constructing the importance curve and yield curve of the full energy range.The burnup extreme analysis method combines the importance and yield curves to consider the influence of irradiation time on production efficiency,thereby constructing extreme curves.The three curves,which quantify the transmutation rate of the nuclei in each energy region,are of physical significance because they have similar distributions.A high-resolution neutronics model for ^(238)Pu production was established based on these three curves,and its universality and feasibility were proven.The neutronics model can guide the neutron spectrum optimization and improve the yield of ^(238)Pu by up to 18.81%.The neutronics model revealed the law of nuclei transmutation in all energy regions with high spectrum resolution,thus providing theoretical support for high-flux reactor design and irradiation production of ^(238)Pu.

关键词： ^(238)Pu Neutronics model High-flux reactor Spectrum resolution Spectrum optimization

MTTSNet:Military time-sensitive targets stealth network via real-time mask generation

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 601-612页

作者： Siyu Wang Xiaogang Yang Ruitao Lu Zhengjie Zhu Fangjia lian qing-ge Li Jiwei Fan PLA Rocket Force University of Engineering Xi'an 710025China

The automatic stealth task of military time-sensitive targets plays a crucial role in maintaining national military security and mastering battlefield dynamics in military applications.We propose a novel Military Time-sensitive Targets Stealth Network via Real-time Mask Generation(MTTSNet).According to our knowledge,this is the first technology to automatically remove military targets in real-time from videos.The critical steps of MTTSNet are as follows:First,we designed a real-time mask generation network based on the encoder-decoder framework,combined with the domain expansion structure,to effectively extract mask images.Specifically,the ASPP structure in the encoder could achieve advanced semantic feature fusion.The decoder stacked high-dimensional information with low-dimensional information to obtain an effective mask layer.Subsequently,the domain expansion module guided the adaptive expansion of mask images.Second,a context adversarial generation network based on gated convolution was constructed to achieve background restoration of mask positions in the original image.In addition,our method worked in an end-to-end manner.A particular semantic segmentation dataset for military time-sensitive targets has been constructed,called the Military Time-sensitive Target Masking Dataset(MTMD).The MTMD dataset experiment successfully demonstrated that this method could create a mask that completely occludes the target and that the target could be hidden in real time using this mask.We demonstrated the concealment performance of our proposed method by comparing it to a number of well-known and highly optimized baselines.

关键词： Deep learning Military application Targets stealth network Mask generation Generative adversarial network

Characterization of the CpsQ Regulon Reveals Its Role in the Transcription of Type Ⅵ Secretion System 2 Genes in Vibrio parahaemolyticus

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2024年第4期37卷 436-439页

作者： LUO Xi LI xue ZHANG Miao Miao HUANG qing lian ZHANG Yi Quan JI Shen Jie LU Ren Fei Department of Clinical Laboratory Affiliated Nantong Hospital 3 of Nantong UniversityNantong Third People’s HospitalNantong 226006JiangsuChina Department of Clinical Laboratory Qidong People’s HospitalQidong 226200JiangsuChina

Vibrio parahaemolyticus,a gram-negative halophilic bacterium that naturally inhabits coastal waters,causes gastroenteritis,skin infections,and septicemia in human beings[1].This bacterium produces multiple virulence factors,including thermostable direct hemolysin(TDH),TDH-related hemolysin(TRH),type Ⅲ secretion system 1(T3SS1),T3SS2,type Ⅵ secretion system 1(T6SS1),and T6SS2[1].Furthermore,Ⅴ.parahaemolyticus forms biofilms on the surface,which help it in adapting to unfavorable conditions[2].Mature biofilm formation requires special structures,including lateral and polar flagella,exopolysaccharide(EPS),and type Ⅳ pili[2].

关键词： coastal system T3SS

Chemical derivatization strategies for enhancing the HPLC analytical performance of natural active triterpenoids

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2024年第3期14卷 295-307页

作者： Xiao-Feng Huang Ying xue Li Yong Tian-Tian Wang Pei Luo Lin-Sen qing Chengdu Institute of Biology Chinese Academy of SciencesChengdu610041China State Key Laboratory for Quality Research in Chinese Medicines Macao University of Science and TechnologyMacaoChina Sichuan Center for Disease Control and Prevention Chengdu610041China University of Chinese Academy of Sciences Beijing100049China

riterpenoids widely exist in nature,displaying a variety of pharmacological activities.Determining triterpenoids in different matrices,especially in biological samples holds great significance.High-performance liquid chromatography(HPLC)has become the predominant method for triterpenoids analysis due to its exceptional analytical performance.However,due to the structural similarities among botanical samples,achieving effective separation of each triterpenoid proves challenging,necessitating significant improvements in analytical methods.Additionally,triterpenoids are characterized by a lack of ultraviolet(UV)absorption groups and chromophores,along with low ionization efficiency in mass spectrometry.Consequently,routine HPLC analysis suffers from poor sensitivity.Chemical derivatization emerges as an indispensable technique in HPLC analysis to enhance its performance.Considering the structural characteristics of triterpenoids,various derivatization reagents such as acid chlorides,rhodamines,isocyanates,sulfonic esters,and amines have been employed for the derivatization analysis of triterpenoids.This review comprehensively summarized the research progress made in derivatization strategies for HPLC detection of triterpenoids.Moreover,the limitations and challenges encountered in previous studies are discussed,and future research directions are proposed to develop more effective derivatization methods.

关键词： Triterpenoid HPLC Derivatization Quantification