检索结果-南通市图书馆

Improving the real-time probabilistic channel flood forecasting by incorporating the uncertainty of inflow using the particle filter

引用

Journal of Hydrodynamics 2018年第5期30卷 828-840页

作者： Xing-ya Xu Xuesong Zhang Hong-wei Fang Rui-xun Lai Yue-feng Zhang Lei Huang xiao-bo liu Changjiang Institute of Survey PlanningDesign and ResearchWuhan 430010China State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China Joint Global Change Research Institute Pacific Northwest National LaboratoryCollege ParkMDUSA Great Lakes Bioenergy Research Center Michigan State UniversityEast LansingMichiganUSA Yellow River Institute of Hydraulic Research Zhengzhou 450003China Development Research Center of the Ministry of Water Resources of People＇s Republic of China Beo＇ing 100038China Department of Water Environment China Institute of Water Resources and Hydropower ResearchBeo＇ing 100038China

An accurate and reliable real-time flood forecast is crucial for mitigating flood disasters. The errors associated with the inflow boundary forcing data are considered as an important source of uncertainties in hydraulic model. In this paper, a real-time probabilistic channel flood forecasting model is developed with a novel function to incorporate the uncertainty of the forcing inflow. This new approach couples a hydraulic model with the particle filter（PF） data assimilation algorithm, a sequential Bayesian Monte Carlo method. The stage observations at hydrological stations are assimilated at each time step to update the model states in order to improve the next time step＇s forecasting. This new approach is tested against a real flood event occurred in the upper Yangtze River. As compared with the open loop simulations, the evaluations of model performance with several deterministic and probabilistic metrics indicate that the accuracy of the ensemble mean prediction and the reliability of the uncertainty quantification are improved pronouncedly as a result of the PF assimilation. Further assessment of the prediction results at different lead times shows that the improvement of model performance deteriorates with the increase of the lead time due to the gradual diminishing of the updating effect for the initial conditions. Based on the analyses of the number of particles and the assimilation frequency, we find that the optimal number of particles can be determined by balancing the model performance and the computation cost, while a high assimilation frequency is preferred to incorporate the emerging observations to update the model states to match the real conditions.

关键词： Channel flood forecasting probabilistic forecast particle filter hydraulic model data assimilation inflow uncertainty

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

Lumbar and neck injuries of occupants in different reclining postures

引用

Chinese Journal of Traumatology 2024年第4期27卷 211-217页

作者： Di-Yi liu Sen xiao Fei-Fei Han bo-Tao Hu School of Mechanical Engineering Hebei University of TechnologyTianjin300131China CATARC(Tianjin) Automotive Engineering Research Institute Co.Ltd.Tianjin300399China

Purpose:With the increasing level of automation in automobiles,the advent of autonomous vehicles hasreduced the tendency of drivers and passengers to focus on the task of *** increasing automation in automobiles reduced the drivers'and passengers'focus on driving,which allowed occupants tochoose a more relaxed and comfortable sitting ***,the occupant's sitting position wentfrom a frontal,upright position to a more relaxed and reclined one,which resulted in the existing restraint systems cannot to keep occupants safe and *** study aimed to determine the effects ofdifferent reclining states on occupants'lumbar and neck ***:This is an original research on the field of automotive safety *** indifferent initial sitting positions(25°,35°,45°,and 55°)were adapted to changes in seat back angle andrestraint systems and placed in the same frontal impact *** injury indexes,lumbar axialcompression force and acceleration,as well as occupant dynamic response during the impact,werecompared in different sitting *** injury response and kinematic characteristics of occupants indifferent reclining positions were analyzed by the control variable ***:As the sitting angle increased,the occupant's head acceleration decreased,and the forward-leanangle *** in the standard sitting position had the greatest neck injury,with an Nij of0.95,and were susceptible to abbreviated injury scale 2+cervical medullary *** the seatbackangle increased,the geometric position of the lumbar spine tended to be horizontal,and the impact loadtransmitted greater forces to the lumbar *** occupant's lumbar injury was greatest in the lyingposition,with a peak axial compression force on the lumbar region of 5.5 KN,which was 2.3 KN greaterthan in the standard sitting ***:The study of occupant lumbar and neck injuries based on different recline states can providea theoretical bas

关键词： Frontal impact Recline position Lumbar injury Neck injury Kinematics Road traffic injury Road safety

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

Recent advances in Pt catalysts and membrane electrode assemblies fabrication for proton exchange membrane fuel cells

引用

Rare Metals 2024年第9期43卷 4198-4221页

作者： Miao Ma Li-xiao Shen Jing liu Bin Xu Yun-Long Zhang Lei Zhao Zhen-bo Wang School of Chemistry and Chemical Engineering Harbin Instituteof Technology College of Environmental and Chemical Engineering YanshanUniversity Unipower Hydrogen Technology (Jiangsu) Corporation

Proton exchange membrane fuel cells(PEMFCs) have been identified as a highly promising means of achieving sustainable energy conversion. A crucial factor in enhancing the performance of PEMFCs for further potential energy applications is the advancement in the field of catalyst engineering that has led to remarkable performance enhancement in facilitating the oxygen reduction reaction(ORR). Subsequently, it is important to acknowledge that the techniques used in preparation of membrane electrode assemblies(MEAs), the vital constituents of PEMFCs, also possess direct and critical influence on exhibiting the full catalytic activity of meticulously crafted catalysts. Here, a succinct summary of the most recent advancements in Pt catalysts for ORR was offered and their underly catalytic mechanism were discussed. Then, both laboratory-scale and industrial-scale MEA fabrication techniques of Pt catalysts were summarized. Furthermore, a detailed analysis of the connections between materials, process, and performance in MEA fabrication was presented in order to facilitate the development of optimal catalyst layers.

关键词： MEA fabrication techniques Membrane electrode assemblies Oxygen reduction reaction Pt catalysts

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

Experimental Study on Vortex-Induced Vibration of Rough Risers Coupling with Interference Effect in Tandem Arrangement

引用

China Ocean Engineering 2024年第3期38卷 394-407页

作者： HU Ze-bo liu Zhen LI Peng GUO Hai-yan REN xiao-hui HOU Hao HAO Lian-hong College of Civil Engineering and Architecture Shandong University of Science and TechnologyQingdao 266590China Qingdao Key Laboratory of Marine Civil Engineering Materials and Structures Qingdao 266590China College of Engineering Ocean University of ChinaQingdao 266100China

In order to study the response law of vortex-induced vibration(VIV)of marine risers under the combined action of roughness and interference effects,and to reveal the coupling mechanism of roughness and interference effects on the riser,a VIV experiment of rough risers in tandem arrangement was conducted in a wave−current combined *** experiment characterized the risers’roughness by arranging different specifications of attachments on the surface of the *** rough risers with different roughness and smooth risers were arranged in tandem arrangement,with the rough risers arranged *** experimental results indicate that the suppression of the attachments on the downstream risers’vibration are more significant both in the CF and IL directions as the reduced velocity *** the downstream riser,the amplitude response of rough riser is more significantly weakened compared with the smooth one at high reduced *** the upstream risers,changes in the roughness and spacing ratio have an impact on their‘lock-in’*** the roughness of downstream risers is relatively large(0.1300)and the spacing between risers is small(S/D=4.0),the reduced velocity range of‘lock-in’region in the CF direction of upstream risers is obviously expanded,and the displacement in the‘lock-in’region is severer.

关键词： marine riser vortex-induced vibration tandem arrangement roughness interference effect

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

Three-stage niobium mineralization at Bayan Obo, China

引用

National Science Review 2024年第4期11卷 102-110页

作者： Yan Yu Yang Li Yu liu xiao-xiao Ling Li-Guang Wu Li Yang Lan Yang bo Yang Yong-Gang Zhao Xian-Hua Li State Key Laboratory of Lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences College of Earth and Planetary Science University of Chinese Academy of Sciences Ministry of Education Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking University Mining Research Institute Baotou Iron and Steel(Group) Co.LTD State Key Laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization

The Chinese Bayan Obo deposit is a world-class rare earth element(REE) deposit with considerable niobium(Nb) and iron(Fe) resources. A complete genetic understanding on all metals is fundamental for establishing genetic models at Bayan Obo. With extensive research being focused on REE enrichment, the timing and controls of Nb enrichment remain unresolved at Bayan Obo, which is mainly due to the challenges in dating, i.e. multistage thermal events, fine-grained minerals with complex textures and the rare occurrence of uranium-enriched minerals with mature dating methods. Based on robust geological and petrographic frameworks, here we conducted ion probe uranium-lead(U-Pb) dating of ferrocolumbite to unravel the timing, hence the genesis of Nb mineralization. Three types of hydrothermal ferrocolumbites—key Nb-bearing minerals—are identified based on their textures and mineral assemblages. They yield U-Pb ages of 1312 ± 47 Ma(n = 99), 438 ± 7 Ma(n = 93), and 268 ± 5 Ma(n = 19), respectively. In line with deposit geology, we tentatively link the first, second and third stage Nb mineralization to Mesoproterozoic carbonatite magmatism, ubiquitous early Paleozoic hydrothermal activity, and Permian granitic magmatism, respectively. While quantifying the contribution of metal endowment from each stage requires further investigation, our new dates highlight that multi-stage mineralization is critical for Nb enrichment at Bayan Obo, which may also have implications for the enrichment mechanism of Nb in REE deposits in general.

关键词： niobium mineralization U-Pb dating ferrocolumbite Bayan Obo

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

Eco-friendly calcium alginate microspheres enable enhanced profile control and oil displacement

引用

Petroleum Science 2024年第3期21卷 1928-1943页

作者： xiao-Han Zhang Chang-Jing Zhou Yuan-Xiang xiao bo Hui Yong-Gang Xie Yu-Bin Su Xin-Ru Li Jie Huang Mao-Chang liu International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi'an Jiaotong UniversityXi'an710049ShaanxiPR.China Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs School of Petroleum EngineeringXi'an Shiyou UniversityXi'an 710065ShaanxiPR.China Oil&Gas Technology Research Institute Changqing Oilfield Branch CompanyPetroChinaXi'an710021ShaanxiPR China Suzhou Academy of Xi'an Jiaotong University Suzhou215123JiangsuPR China

Polymer microspheres(PMs),such as polyacrylamide,have been widely applied for enhanced oil recovery(EOR),yet with environmental ***,we report a microfluid displacement technology containing a bio-based eco-friendly material,i.e.,calcium alginate(CaAlg)microspheres for *** dominant mechanisms responsible for EOR over Ca Alg fluid have been verified,including the microscopic oil displacement efficacy augmented by regulating capillary force(determined by the joint action of interfacial tension and wettability between different phases)and macroscopic sweep volume increment through profile control and mobility ratio *** comprehensive effectiveness can be further impacted when the CaAlg microsphere is embellished ulteriorly by using appropriate amount of sodium dodecyl sulfonate(SDS).The core flooding and nuclear magnetic resonance(NMR)tests demonstrate that CaAlg-SDS microsphere can balance the interphase property regulation(wettability alteration and IFT reduction)and rheology properties,enabling simultaneous profile control and oil *** introduction of SDS will have a negative impact on rheological properties,which is not favored for *** results show that the involvement of 4-m M SDS will provide the best behavior,with an EOR rate of 34.38%.This cost-effective and environmentally-friendly bio-microspherebased microfluidic displacement technology is expected to achieve“green”oil recovery in future oilfield exploitation.

关键词： Calcium alginate microspheres Wettability Interfacial tension Rheology Viscoelasticity Enhanced oil recovery(EOR)

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

Signifying quantum uncertainty relations by optimal observable sets and the tightest uncertainty constants

引用

Science China(Physics,Mechanics & Astronomy) 2024年第9期67卷 43-50页

作者： xiao-Bin Liang bo Li Shao-Ming Fei School of Mathematics and Computer Science Shangrao Normal UniversityShangrao 334001China Quantum Information Research Center Shangrao Normal UniversityShangrao 334001China School of Mathematical Sciences Capital Normal UniversityBeijing 100048China

Quantum uncertainty relations constrain the precision of measurements across multiple non-commuting quantum mechanical ***,we introduce the concept of optimal observable sets and define the tightest uncertainty constants to accurately describe these measurement *** any quantum state,we establish optimal sets of three observables for both product and summation forms of uncertainty relations,and analytically derive the corresponding tightest uncertainty *** demonstrate that the optimality of these sets remains consistent regardless of the uncertainty relation ***,the existence of the tightest constants excludes the validity of standard real quantum mechanics,underscoring the essential role of complex numbers in this ***,our findings resolve the conjecture posed in[***.118,180402(2017)],offering novel insights and potential applications in understanding preparation uncertainties.

关键词： uncertainty relation the tightest uncertainty constants optimal observable sets

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

Microstructure and Mechanical Behavior of Mg-Based Bimetal Plates with High Formability Sleeve by Co-extrusion

引用

Acta Metallurgica Sinica(English Letters) 2024年第3期37卷 499-512页

作者： Yue-Hui Dang Sheng-Lin liu xiao-Lei Ai xiao-Wei Feng bo Feng Zhuo Tian Ying-Fei Lin Huan-Tao Chen Kai-Hong Zheng School of Materials Science and Engineering Chang’an UniversityShaanxi 710064China Guangdong Key Laboratory of Metal Toughening Technology and Application Institute of New MaterialsGuangdong Academy of SciencesGuangzhou 510650China

In this study,microstructure and mechanical behavior of two types of Mg-based bimetal plates with a high formability sleeve were systematically studied,with a great emphasis on the effect of the interface characteristic and the sleeve fraction on the plasticity of composite *** rule of mixtures(ROM)for elongation was also *** results show that when there is no or thin diffusion layer with thickness of about 3μm,Mg-based bimetal plates have a good plasticity with elongation of about 19-24%,and the ROM predicted elongations are very close to the experimental *** contrast,with a diffusion layer about 95-155μm thick,Mg-based bimetal plates exhibit a poor plasticity with elongation of about 11-17%,and the experimental elongations largely deviate from the ROM *** plasticity of Mg-based bimetal plates increases with increasing sleeve *** study provides new insights on the plastic deformation of Mg-based bimetal composites with a high formability sleeve.

关键词： Mg-based composites Co-extrusion Microstructure Mechanical behavior Plastic deformation

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

Bioinspired design of integral molded Janus silk fibroin-MXene evaporator for efficient solar vapor generation

引用

Nano Research 2024年第4期17卷 2824-2835页

作者： Ling-Qing Kong Zhi-Cheng Zeng Guang-Zong Min Zhao-Hui Meng Guo-Qing Meng xiao-xiao Guo Nai-bo Lin Xiang-Yang liu The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province Research Center of Biomedical Engineering of XiamenDepartment of BiomaterialsCollege of MaterialsXiamen UniversityXiamen 361005China The State Key Laboratory of Marine Environmental Science(MEL) College of Ocean and Earth SciencesXiamen UniversityXiamen 361005China

Solar vapor generation is a promising sustainable technology that uses solar distillation to produce fresh water from seawater and wastewater,helping relieve global water resource ***,inspired by naturally grown integrally molded mulberry leaves with a Janus hydrophilic and hydrophobic structure,a novel,simple,and efficient integrated molding method is proposed to break through the limitations of the traditional split manufacturing strategy and realizes the integrated formation of Janus *** on the spontaneous sedimentation characteristics of MXene in silk fibroin solution and its regulation of mesoscopic structure and hydrophilicity of silk fibroin,layered structures with different compositions and hydrophilicities were obtained in one ***,ethanol and glutaraldehyde were added to construct a physical crystallization-chemical crosslinking dual stabilization structure in silk *** evaporator has the evaporation rate of 3.07 kg·m^(-2)·h^(-1) and the efficiency of 86.8%under 1 sun and maintains high evaporation performance under various extreme test conditions including vigorous washing,repeated compression,and high-intensity ultraviolet(UV)***,the evaporator performs well in practical application scenarios,its evaporation rate in the simulated Dead Sea seawater exceeds 2.13 kg·m^(-2)·h^(-1),and more than 99.9%of the salt,heavy metal ions,oil pollution,and dyes are purified.

关键词： silk fibroin MXene bioinspired integrated molding Janus structure solar vapor generation

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

Effect of Plastic Deformation on Microstructure and Properties of Cu-(1 wt%-6 wt%) Ag Alloy

引用

Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 747-753页

作者：茹亚东 ZHANG Zhongyuan 高召顺 ZHANG Ling ZUO Tingting XUE Jiangli TANG Zhixiang DA bo liu Yongsheng xiao Liye Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China Department of Physics Shanghai University of Electric PowerShanghai 201306China University of Chinese Academy of Sciences Beijing 100190China International Joint Labora-tory for Light Alloys(MOE) College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Research and Services Division of Materials Data and Integrated System National Institute for Materials ScienceTsukuba 305-0047Japan

In the present study,the Cu-(1 wt%-6 wt%)Ag alloys were prepared by melting,forging and wire *** effects of plastic deformation on microstructure evolution and properties of the alloys were *** results show that non-equilibrium eutectic colonies exist in the Cu-(3 wt%-6 wt%)Ag alloy and no eutectic colonies in the 1 wt%-2 wt%Ag containing *** eutectic colonies are aligned along the drawing direction and refined with the increase of draw *** to the refinement of eutectic colonies,the Cu-Ag alloy exhibits higher strength with the increase of draw *** Cu-6Ag alloy exhibits excellent comprehensive properties with a strength of 930 MPa and a conductivity of 82%IACS when the draw ratio reaches 5.7.

关键词： Cu-Ag alloy high strength and high conductivity microstructure eutectic structure strengthening mechanism

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：