检索结果-南通市图书馆

Construction of daily precipitation series and the observational characteristics of extreme precipitation in Tianjin,China during 1888-2022

引用

Advances in Climate Change Research 2024年第1期15卷 52-61页

作者： peng SI Qing-Xiang LI xiao-Yang CHEN Min WANG Chuan-Jun LUO Tianjin Meteorological Information Center Tianjin Meteorological BureauTianjin 300074China Research Centerfor Ecology and Environment of Central Asia Chinese Academy of SciencesWulumuqi 830011China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 528478China Key Laboratory of Tropical Amosphere-Ocean System Ministry of EducationZhuhai 528478China Shaoguan Meteorological Service Shaoguan 512028China

Given the difficulties in rescuing and ensuring the quality of long-term climate data,current studies on century-scale climate change are usually limited to annual and monthly data,resulting in the poor detection of extreme climate events and their changes before *** this study,we reconstructed a daily precipitation series for Tianjin from 15 September 1887 to 31 December 2022 on the basis of the most comprehensive daily precipitation records collected from the Tianjin Meteorological Archive,China,and in reference to the precipitation analysis results based on the datasets developed by the Climatic Research Unit Time-Series version 4.06,Global Precipitation Climatology Centre and University of Delaware along with the application of various homogenisation methods for climate *** approach provides a complete and reliable century-long daily precipitation series for the study of regional or local extreme weather and climate *** reconstructed daily dataset reveals that the annual precipitation amount and R95 intensity in Tianjin during 1888-2022 lack significant trends and have values of 0.74±6.99 and-1.84±3.22 mm per decade,*** the annual and seasonal scales,the precipitation amount and R95 intensity,particularly those in autumn,have increased since the latter half of the 20th century relative to those in ***,the increase in precipitation amount and R95 intensity is relatively limited compared with that in atmospheric water vapour content due to surface warming,indicating the highly sensitive response of extreme precipitation events to *** addition,the estimates for the return periods of 5,10,20,50 and 100 years covering 1888-2022,1888-1950 and 1951-2022 depict that the intensity of heavy rain and above magnitude was highest in 1888-1950 and decreased in 1951-2022.

关键词： Over a century-long timescale Daily precipitation series Extreme precipitation Return period

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

基于机器视觉的车铣刀具磨损检测方法

引用

组合机床与自动化加工技术 2022年第10期 105-108,114页

作者：邓晓鹏胡小锋上海交通大学机械与动力工程学院上海200240

针对加工过程中人工检测刀具磨损效率较低、难以获取刀具磨损全局信息等问题,提出一种基于机器视觉的车铣刀具磨损检测方法。首先通过傅里叶变换将刀具图像映射到频域空间,去除刀体条纹对应的频率分量,消除刀具图像中的条纹干扰。通过... 详细信息

针对加工过程中人工检测刀具磨损效率较低、难以获取刀具磨损全局信息等问题,提出一种基于机器视觉的车铣刀具磨损检测方法。首先通过傅里叶变换将刀具图像映射到频域空间,去除刀体条纹对应的频率分量,消除刀具图像中的条纹干扰。通过自适应区域生长算法分割图像背景区域,并以分割结果为模板,实现图像对比度自适应增强与刀体非磨损区域分割。合并两次分割结果,得到磨损区域二值图像,实现刀具磨损量的自动测量。最后,通过磨损数据的一致性分析验证算法的有效性。结果表明:所提方法测量结果与人工测量结果具有较强的一致性;相较于已有的视觉检测算法,该方法抗干扰能力强,可从低质量图像中准确提取刀具磨损信息,从而实现刀具磨损状态的有效检测。

关键词：车铣刀具机器视觉傅里叶变换区域生长算法一致性分析

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

点源照射的单随机相位菲涅耳域光学图像加密

引用

激光技术 2006年第3期30卷 327-328+331页

作者：邓晓鹏邹凯怀化学院物理电子科学技术系泸州医学院物理系

为了简化系统设置,根据双随机相位编码加密方法中两块相位掩模的作用,提出用点光源照射系统,结合球面波的相位因子,实现了只用一块相位掩模在菲涅耳域进行图像加密。理论分析和计算机仿真实验结果表明,该方法不仅能获得与双随机相位编... 详细信息

为了简化系统设置,根据双随机相位编码加密方法中两块相位掩模的作用,提出用点光源照射系统,结合球面波的相位因子,实现了只用一块相位掩模在菲涅耳域进行图像加密。理论分析和计算机仿真实验结果表明,该方法不仅能获得与双随机相位编码加密技术一样的效果和安全性能,而且还能减少相位掩模数量,简化系统设置,增强了该方法的实用性。

关键词：傅里叶光学与光信号处理图像加密双随机相位掩模点光源单随机相位掩模菲涅耳域

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

基于干涉的二值图像逻辑运算加密技术

引用

激光技术 2010年第3期34卷 401-404页

作者：邓晓鹏文伟怀化学院物理与信息工程系

为了对二值图像的内容进行保密,针对以往二值图像加密技术的缺陷,提出了一种基于干涉的二值图像逻辑运算加密技术。加密时,先选择一幅携带一定信息的二值图像作为加密后图像;然后根据被加密图像、加密后图像和解密密匙的逻辑关系在计算... 详细信息

为了对二值图像的内容进行保密,针对以往二值图像加密技术的缺陷,提出了一种基于干涉的二值图像逻辑运算加密技术。加密时,先选择一幅携带一定信息的二值图像作为加密后图像;然后根据被加密图像、加密后图像和解密密匙的逻辑关系在计算机中求出解密匙;最后利用光的干涉原理对图像进行解密。结果表明,该方法加密方便,解密系统设置简单,不需要精确对准,而且能够实现多重认证,安全性能非常高。

关键词：图像处理加密干涉二值图像逻辑

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

Systematic analysis and modeling of the FLASH sparing effect as a function of dose and dose rate

引用

NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-8页

作者： Fu, Qi-Bin Zhang, Yan Wang, Yu-Cheng Huang, Tu-Chen Zhu, Hong-Yu deng, xiao-Wu Sun Yat Sen Univ Sino French Inst Nucl Engn & Technol Zhuhai 519082 Peoples R China Sun Yat Sen Univ Collaborat Innovat Ctr Canc Med Dept Radiat Oncol State Key Lab Oncol South ChinaCanc Ctr Guangzhou 510060 Peoples R China

Ultrahigh-dose-rate radiotherapy (FLASH-RT) is a revolutionary radiotherapy technology that can spare normal tissues without compromising tumor control. Although qualitative experimental results have been reported, quantitative and systematic analysis of data is necessary. Particularly, the FLASH effect response model to the dose or dose rate is still unclear. This study investigated the relationships between the FLASH effect and experimental parameters, such as dose, dose rate, and other factors by analyzing published in vivo experimental data from animal models. The data were modeled based on logistic regression analysis using the sigmoid function. The model was evaluated using prediction accuracy, receiver operating characteristic (ROC) curve, and area under the ROC curve. Results showed that the FLASH effect was closely related to the dose, mean dose rate, tissue type, and corresponding biological endpoints. The dose rate corresponding to a 50% probability of triggering cognitive protection in the brain was 45 Gy s-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${-1}$$\end{document}. The dose rate corresponding to a 50% probability of triggering intestinal crypt survival and regeneration was 140 Gy s-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${-1}$$\end{document}. For the skin toxicity effect, the dose corresponding to a 50% probability of triggering the FLASH effect was 24 Gy. This study helps to characterize the conditions underlying the FLASH effect and provides important information for optimizing experiments.

关键词： FLASH radiotherapy Sparing effect Systematic analysis Dose rate Dose Biological endpoints IRRADIATION DESIGN

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

Upgrade from aerated static pile to agitated bed systems promotes lignocellulose degradation in large-scale composting through enhanced microbial functional diversity

引用

Journal of Environmental Sciences 2024年第10期144卷 55-66页

作者： Hanxia Yu Haoyan xiao Huiyu deng Adam Frew Md.Akhter Hossain Wenbing Tan Beidou Xi School of Geographical Sciences Fujian Normal UniversityFuzhou 350007China Hawkesbury Institute for the Environment Western Sydney UniversityLocked Bag 1797PenrithNSW 2751Australia State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China

Composting presents a viable management solution for lignocellulose-rich municipal solid ***,our understanding about the microbial metabolic mechanisms involved in the biodegradation of lignocellulose,particularly in industrial-scale composting plants,remains *** study employed metaproteomics to compare the impact of upgrading from aerated static pile(ASP)to agitated bed(AB)systems on physicochemical parameters,lignocellulose biodegradation,and microbial metabolic pathways during largescale biowaste composting process,marking the first investigation of its *** degradation rates of lignocellulose including cellulose,hemicellulose,and lignin were significantly higher in AB(8.21%-32.54%,10.21%-39.41%,and 6.21%-26.78%)than those(5.72%-23.15%,7.01%-33.26%,and 4.79%-19.76%)in ASP at three thermal stages,*** AB system in comparison to ASP increased the carbohydrate-active enzymes(CAZymes)abundance and production of the three essential enzymes required for lignocellulose decomposition involving a mixture of bacteria and fungi(i.e.,Actinobacteria,Bacilli,Sordariomycetes and Eurotiomycetes).Conversely,ASP primarily produced exoglucanase andβ-glucosidase via fungi(i.e.,Ascomycota).Moreover,AB effectively mitigated microbial stress caused by acetic acid accumulation by regulating the key enzymes involved in acetate conversion,including acetyl-coenzyme A synthetase and acetate ***,the AB upgraded from ASP facilitated the lignocellulose degradation and fostered more diverse functional microbial communities in large-scale *** findings offer a valuable scientific basis to guide the engineering feasibility and environmental sustainability for large-scale industrial composting plants for treating lignocellulose-rich *** findings have important implications for establishing green sustainable development models(e.g.,a circular economy based onmaterial recovery)and for achieving sustainable development goals.

关键词： Bacterial and fungal community Large-scale composting Lignocellulose degradation Microbial metabolism Metaproteomic analysis

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

Hierarchical assembly of NiFe-PB-derived bimetallic phosphides on 3D Ti_(3)C_(2) MXene ribbon networks for efficient oxygen evolution

引用

ChemPhysMater 2024年第1期3卷 118-124页

作者： Chulong Jin Hanlei peng xiaojun Zeng Zhenyuan Liu deng Ding School of Materials Science and Engineering Jingdezhen Ceramic UniversityJingdezhen 333403China School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China College of Chemistry and Environmental Engineering Wuhan Polytechnic UniversityWuhan 430023China

The development of MXene-based heterostructures for electrocatalysis has garnered significant attention owing to their potential as high-performance catalysts that play a pivotal role in hydrogen ***,we present a multistep strategy for the synthesis of a Ti_(3)C_(2) MXene ribbon/NiFePx@graphitic N-doped carbon(NC)heterostructure that enables the formation of three-dimensional(3D)Ti_(3)C_(2) MXene ribbon networks and bimetallic phosphide *** the assistance of HF etching and KOH shearing,the MXene sheets were successfully transformed into 3D MXene networks with interlaced MXene ***,a hydrothermal method,ion exchange route,and phosphorization process were used to anchor NiFeP_(x)@NC nanocubes derived from Ni(OH)_(2)/NiFe-based Prussian blue(NiFe-PB)onto the MXene ribbon *** resulting MXene ribbon/NiFeP_(x)@NC heterostructure demonstrated enhanced oxygen evolution reaction(OER)activity,characterized by a low overpotential(164 mV at a current density of 10 mA cm^(-2))and a low Tafel slope(45 mV dec^(-1)).At the same time,the MXene ribbons/NiFeP_(x)@NC heterostructure exhibited outstanding long-term stability,with a 12 mV potential decay after 5000 cyclic voltammetry(CV)*** study provides a robust pathway for the design of efficient MXene-based heterostructured electrocatalysts for water splitting.

关键词： Metal phosphides Prussian blue nanocubes Ti_(3)C_(2)MXene ribbons Interfacial matching OER

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

Low-concentration and multi-component NMHCs capture from oil field exhaust using porous ZIF-8/iso-hexadecane slurry

引用

Green Chemical Engineering 2024年第2期5卷 245-256页

作者： Kun Li Han Tang Jin Cai Chun deng Bei Liu Yunlei peng Changyu Sun Guangjin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China

Non-methane hydrocarbons(NMHCs)are a common type of volatile organic compounds(VOCs)pollutant in the petrochemical industry and have attracted widespread attention because of their adverse health effects and environmental *** this paper,we report a new porous slurry formed with zeolitic imidazolate framework-8(ZIF-8)and iso-hexadecane to capture the low-concentration and multi-component NMHCs(mainly ethane(C_(2)H_(6)),propane(C_(3)H_(8)),and n-butane(n-C_(4)H_(10)))from the oil field *** sorption capacity of C_(2)H_(6)in the slurry is significantly higher than that of nitrogen(N_(2))and methane(CH_(4)).Moreover,the slurry demonstrated a clear advantage for C_(2)H_(6)over N_(2)and CH_(4)in competitive adsorption through the pressure-drop *** the NMHCs capture experiments,the C_(3)H_(8)and n-C_(4)H_(10)concentrations after purification can be reduced to below 100 ppm,while the C_(2)H_(6)concentration can reach approximately 180 *** encouragingly,in the breakthrough tests,the slurry exhibits a perfect kinetic separation selectivity for multi-component ***,to avoid structural collapse of ZIF-8 material during long-term use in acidic and wet environments,a certain amount of 2-methylimidazole was retained in the slurry as a protective agent in the material synthesis *** this way,the ZIF-8 materials in the slurry can retain the stable characteristic structure in an aqueous and acidic environment and keep the capture capacity for NMHCs without *** believe the porous ZIF-8/iso-hexadecane slurry is a promising capture agent for low-concentration and multi-component NMHCs with strong purification capacity and stability.

关键词： VOCs capture NMHCs capture MOFs ZIF-8 Porous slurry

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

Evaluation on cutting performance of novel PDC cutter for pipe jacking machine

引用

Underground Space 2024年第1期14卷 34-52页

作者： Long-Chuan deng Yi-Xiang Yuan xiao-Zhao Li Qian-Wei Zhuang Chi Zhang Yi-Wei Chen School of Earth Sciences and Engineering Nanjing UniversityNanjingJiangsu 210023China Shanghai Tunnel Engineering Co.Ltd. Shanghai 200232China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhouJiangsu 221116China School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China

It is inevitable to cut reinforced concrete(RC)appeared in cross passage of city metro by cutting tools when constructing in densely populated *** previous cutters employed to cut RC are insufficient and easily damaged,so a new polycrystalline diamond compact(PDC)cutter is used to solve this *** on the theoretical analysis of cutting mechanism,both circular and tapered PDC cutters with cutting edge angle of 90and negative front rack angle of 10are used to cut *** peeling and breaking patterns of cutting concrete are proposed,the nodular and grainy chips are the preferred modes in cutting steel *** LS-DYNA is employed to investigate the cutting performance in *** simulation results show that the average and peak cutting forces increase with the growth of penetration depth,cutting speed,and roundness,and subsequently the recommended penetration depth less than 1.2 mm is obtained to cut RC due to the existence of steel ***,the linear cutting platform is adopted to investigate the force ability and damage state of PDC *** is concluded that the cutting force increases abruptly and fluctuates heavily when cutting the coarse *** patterns occurred in both numerical and experimental results are generally ***,the steel bar is pulled out and the PDC cutter is damaged at the penetration depth of 0.8 mm,while a good cut occurs at the penetration depth of 0.3 *** tapered PDC cutter with a relatively low cutting force is prone to be broken compared with circular PDC *** is suggested that the circular PDC cutter at the penetration depth of 0.3 mm should be used to cut RC in practical engineering.

关键词： PDC cutter RC Pipe jacking machine Linear cutting tests Damage and wear LS-DYNA

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

Two-dimensional bifunctional electrocatalyst(Mo-NiFe-LDH)with multilevel structure for highly efficient overall water splitting

引用

Rare Metals 2024年第6期43卷 2613-2622页

作者： Bao-Jie Zhang Bin Chang Shi-peng Qiu Gang Zhao xiao Wang Xi-Jin Xu Lan Mu Wen-Bo Liao xiao-Jing Dong School of Physics and Technology University of JinanJinan 250000China KAUST Catalysis Center(KCC) King Abdullah University of Science and Technology(KAUST)Thuwal 23955-6900Kingdomof SaudiArabia School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China School of Physics and Physical Engineering Qufu Normal UniversityQufu273100China

To effectively address energy challenges,it is crucial to explore efficient and stable bifunctional nonprecious metal *** this study,a Mo-doped nickeliron layered double hydroxide with flower-cluster architecture was successfully prepared by a one-step hydrothermal method,which demonstrated a good water splitting *** an appropriate amount of Mo doping,some lattice distortions in the material provided reactive sites for the adsorption and conversion of intermediates,thus optimising the charge distribution of the ***,the multidimensional void structures formed after doping had a larger specific surface area and accelerated the penetration of the electrolyte,which significantly improved the activity of the catalyst in alkaline *** 10 mA·cm^(-2),the hydrogen and oxygen evolution overpotentials of Mo-doped nickel-iron double hydroxides(Mo-NiFe LDH/NF-0.2)were 167 and 220 mV,respectively,with an excellent durability up to 24 *** the Mo-NiFe LDH/NF-0,2 catalyst was used as the cathode and anode of an electrolytic cell,the catalyst achieved a current density of 10 mA·cm^(-2)at an applied voltage of 1.643 *** study provides a novel approach for designing excellent bifunctional electrocatalysts containing nonprecious metals.

关键词： Bifunctional electrocatalysts 2D multilevel structure Overall water splitting Mo-doped Ni-Fe LDH

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：