检索结果-南通市图书馆

Nano-Micro Letters 2025年第3期17卷 1-18页

作者： Sukhwa Hong Jiseon Kim Jaebeom Park Sunmi im Michael R.Hoffmann Kangwoo Cho Division of Environmental Science and Engineering Pohang University of Science and Technology(POSTECH)Pohang 790−784Korea Linde Laboratory California Institute of TechnologyPasadenaCA 91125USA Institute for Convergence Research and Education in Advanced Technology(I‑CREATE) Yonsei University International CampusIncheon 21983Republic of Korea

Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2)production can reduce the carbon footprint associated with transportation of water,waste,and energy *** study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2)overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment *** dilute(0.1 M)NaCl solutions,the NFI/TiO_(2)marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).Robust operation in near-neutral pH was *** including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic *** electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive *** scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.

关键词： Wastewater electrolysis cell Ir-doped NiFe_(2)O_(4) Reactive chlorine species Decentralized H_(2)production On-site wastewater treatment

Numerical investigation on self-priming process of self-priming pump

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

排灌机械工程学报 2020年第11期38卷 1113-1118页

作者： FALL ibra PAN Zhongyong ZHANG Desheng DESMOND Appiah ALI Asad yANG Bo National Research Center of Pumps Jiangsu UniversityZhenjiangJiangsu 212013China

In order to investigate the self-priming process of the self-priming pump,an unsteady simulation was conducted where the Navier-Stokes equations were used with the Lagrangian-Eularian *** course of this investigation,the volume fractions,pressure distribution and self-priming time were carried *** analyzing the volume,velocity and pressure distribution of the gas-liquid two-phase flow at different time,the two-phase content via the variation law of the two-phase flow in the pump was carried *** monitoring and analyzing the gas-liquid flow at the outlet of the pump,the self-priming time and crucial periods were *** phenomena were mainly characterized by the self-priming process such as the gas-liquid mixing and separation,which occur in the early stage of self-priming *** that period the gas-liquid mixing clouds appear on the outer edge of the impeller,and the instantaneous void fraction at the inlet and outlet of the impeller decreases *** was also established from the transient study that the gas has a major influence on the hydraulic performance of the pump at the early stage of *** increase the usage of self-priming pump and to also understand the energy conversion of the pump,it is very essential to investigate and establish the basic working principle of the self-priming pump.

关键词： self-priming pump self-priming process numerical simulation

Spatial analysis of vegetation cover response to climate trends in Khakassia(South Siberia)

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2023年第10期20卷 2869-2884页

作者： im Sergei Institute of Natural Sciences and Mathematics Khakassian State University named after N.F.KatanovAbakan 655000Russia V.N.Sukachev Institute of Forest Krasnoyarsk Science Centre of the Siberian Branch of Russian Academy of ScienceKrasnoyarsk 660036Russia Institute of Ecology and Geography Siberian Federal UniversityKrasnoyarsk 660041Russia Institute of Space Research and High Technologies Reshetnev Siberian State University of Science and TechnologyKrasnoyarsk660014Russia

An analysis of the changes in vegetation cover on the territory of the Republic of Khakassia in 2000–2021 due to climatic trends was carried out based on the MODIS *** changes in vegetation cover were estimated based on trends in Normalized Difference Vegetation Index(NDVI)and Enhanced Vegetation Index(EVI).In general,in the 21st century,an increase in the biomass of vegetation cover is *** trends were observed in 16%–22%of the territory,and negative only in 1%–3%.For about 20%of the analyzed territory,a significant influence of climate on the changes in vegetation cover was *** most pronounced negative impact on vegetation cover was caused by summer air and soil temperatures,spring temperature,and summer winds,and the positive impact was caused by summer precipitation and soil *** response of the vegetation cover to climate was non-uniform concerning the ***,a significant correlation with the amount of precipitation was observed for~20%–35%of vegetation growing below 600 m above sea level and for less than 5%above this *** negative effect of summer temperatures on plants prevailed mainly at an elevation below~1400 m above sea *** climate change is likely to lead to significant degradation of vegetation in the steppe and foreststeppe in Khakassia in the coming decades.

关键词： Khakassia South Siberia Vegetation cover Climate trends Remote sensing MODIS NDVI EVI Relief

Stochastic structural optimization using particle swarm optimization, surrogate models and Bayesian statistics

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2013年第1期26卷 112-121页

作者： Jongbin im Jungsun Park Korea Aerospace Research Institute Department of Aerospace and Mechanical Engineering Korea Aerospace University

This paper focuses on a method to solve structural optimization problems using particle swarm optimization （PSO）, surrogate models and Bayesian statistics. PSO is a random/stochastic search algorithm designed to find the global optimum. However, PSO needs many evaluations compared to gradient-based optimization. This means PSO increases the analysis costs of structural optimization. One of the methods to reduce computing costs in stochastic optimization is to use approximation techniques. In this work, surrogate models are used, including the response surface method （RSM） and Kriging. When surrogate models are used, there are some errors between exact values and approximated values. These errors decrease the reliability of the optimum values and discard the realistic approximation of using surrogate models. In this paper, Bayesian statistics is used to obtain more reliable results. To verify and confirm the efficiency of the proposed method using surrogate models and Bayesian statistics for stochastic structural optimization, two numerical examples are optimized, and the optimization of a hub sleeve is demonstrated as a practical problem.

关键词： Bayesian statistics Kriging Particle swarm optimization (PSO) Response surface method (RSM)

Effect of anaerobic digestion on the high rate of nitritation,treating piggery wastewater

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2011年第11期23卷 1787-1793页

作者： Jiyeol im Kyungik Gil Department of Civil Engineering Seoul National University of Science and TechnologySeoulSouth Korea School of Civil Engineering Seoul National University of Science and TechnologySeoulSouth Korea

The amount of piggery wastewater as domestic livestock is *** volume of piggery wastewater produced is less than the volume of other wastewaters,but piggery wastewater has a heavy impact on wastewater streams due to an extremely high concentration of nitrogen and *** this study,laboratory reactors were operated using piggery wastewater and the effluent of anaerobic digester from piggery wastewater *** purpose of this study was to induce the nitritation process,which is an economically advantageous nitrogen removal method that converts ammonium nitrogen into *** results showed that the effluent of anaerobic digester from piggery wastewater was more efficient than raw piggery wastewater in terms of inducing *** can be deduced that nitritation is largely affected by an organic fraction of piggery *** can also be concluded that a small amount of biodegradable organic matter in piggery wastewater is efficient in inducing nitritation.

关键词： piggery wastewater anaerobic digestion nitritation nitrogen

Non-point source analysis of a railway bridge area using statistical method:Case study of a concrete road-bed

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2014年第6期26卷 1321-1324页

作者： Kyungik Gil Jiyeol im Department of Civil Engineering Seoul National University of Science and TechnologyNowon-gu Seoul 139-743 Korea School of Civil Environmental and Architectural Engineering Korea University Anam-Dong 5gaSeongbuk-Gu Seoul 163-701 Korea

In an effort to protect the quality of the water system, interest in non-point source pollution is increasing. Recently, studies of non-point sources pollution are continuing in relation to various land- use areas, but such studies have not been fully conducted in railway facility sites. Using monitoring data of railway bridge area with concrete road-bed, the runoff characteristics, pollutant unit loads, and first flush criteria were assessed. Railway bridge area with concrete road-bed typically show the first flush effect, and the pollutant unit load was determined to be higher than other public facilities areas. Further, the first flush criteria show an effective rainfall amount of 7 mm. In other words, from the runoff of railway facilities, considerable amounts of non-point source pollutants are occurred, indicating the need to create best management practices which are adequate for railway facility sites.

关键词： non-point source pollution railway concrete road-bed first flush criteria first flush effect

市政排涝自吸泵启动过程气液两相流动及压力脉动分析

在线全文

学校读者我要写书评

暂无评论

江苏大学学报（自然科学版） 2020年第5期41卷 516-522页

作者：杨波潘中永 ibra FALL 江苏大学国家水泵及系统工程技术研究中心江苏镇江212013

为了探明自吸泵的自吸机理.以外混式自吸泵为研究对象,利用CFX仿真软件中的VOF(volume of fluid)两相流模型和k-ε湍流模型,并结合网格滑移技术进行自吸过程非稳态数值模拟,分析了不同时刻下泵内气液两相体积、液相速度、出口气体体积... 详细信息

为了探明自吸泵的自吸机理.以外混式自吸泵为研究对象,利用CFX仿真软件中的VOF(volume of fluid)两相流模型和k-ε湍流模型,并结合网格滑移技术进行自吸过程非稳态数值模拟,分析了不同时刻下泵内气液两相体积、液相速度、出口气体体积分数和压力的分布情况.同时改变非稳态模拟的时间步长及总时长,监测自吸过程叶轮及蜗壳内监测点的压力变化.结果表明:自吸泵的吸气与排气主要集中在启动过程的初期和中期,叶轮入口和泵出口的气体体积分数分别超过60%和75%;叶轮出口的气液混合带导致了叶轮出口到蜗壳内侧大片区域内的流动紊乱现象,降低了叶轮的做功能力,进而影响了泵的正常排气;叶轮监测点压力脉动幅值与距叶片工作面的大小有关,蜗壳内监测点压力脉动幅值与距叶轮外缘的大小有关.

关键词：自吸泵气液两相流非定常数值模拟压力脉动瞬时体积分数

improved rate-distortion optimized video coding using non-integer bit estimation and multiple Lambda search

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2016年第1期10卷 157-166页

作者： Sio Kei im Mohammad Mahdi GHANDI MPI-QMUL Information Systems Research Centre Macao Polytechnic Institute Macao China Department of Electronic Systems Engineering University of Essex Colchestey CO4 3SQ UK

Many modern video encoders use the Lagrangian rate-distortion optimization （RDO） algorithm for mode deci- sions during the compression procedure. For each encoding stage, this approach involves minimizing a cost, which is a function of rate, distortion and a multiplier called Lambda. This paper proposes to improve the RDO process by applying two modifications. The first modification is to increase the ac- curacy of rate estimation, which is achieved by computing a non-integer number of bits for arithmetic coding of the syntax elements. This leads to a more accurate cost computation and therefore a better mode decision. The second modification is to search and adjust the value of Lambda based on the char- acteristics of each coding stage. For the encoder used, this paper proposes to search multiple values of Lambda for the intra-4x4 mode decision. Moreover, a simple shift in Lambda value is proposed for motion estimation. Each of these modi- fications offers a certain gain in RDO performance, and, when all are combined, an average bit-rate saving of up to 7.0% can be achieved for the H.264/AVC codec while the same concept is applicable to the H.265/HEVC codec as well. The extra added complexity is contained to a certain level, and is also adjustable according to the processing resources available.

关键词： rate distortion optimization Lambda adjust-ment non-integer bit estimation H.264/AVC H265/HEVCvideo coding

Key-Value Store Coupled with an Operating System for Storing Large-Scale Values

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第11期73卷 3333-3350页

作者： Jeonghwan im Hyuk-yoon Kwon Graduate School of Data Science Seoul National University of Science and TechnologySeoulKorea Department of Industrial Engineering Graduate School of Data ScienceResearch Center for Electrical and Information ScienceSeoul National University of Science and TechnologySeoulKorea

The key-value store can provide flexibility of data types because it does not need to specify the data types to be stored in advance and can store any types of data as the value of the key-value *** types of studies have been conducted to improve the performance of the key-value store while maintaining its ***,the research efforts storing the large-scale values such as multimedia data files(e.g.,images or videos)in the key-value store were *** this study,we propose a new key-value store,WR-Store++aiming to store the large-scale values ***,it provides a new design of separating data and index by working with the built-in data structure of the Windows operating system and the file *** utilization of the built-in data structure of the Windows operating system achieves the efficiency of the key-value store and that of the file system extends the limited space of the storage *** also present chunk-based memory management and parallel processing of WR-Store++to further improve its performance in the GET *** the experiments,we show that WR-Store++can store at least 32.74 times larger datasets than the existing baseline key-value store,WR-Store,which has the limitation in storing large-scale data ***,in terms of processing efficiency,we show that WR-Store++outperforms not only WR-Store but also the other state-ofthe-art key-value stores,LevelDB,RocksDB,and BerkeleyDB,for individual key-value operations and mixed workloads.

关键词： Key-value stores large-scale values chunk-based memory management parallel processing

Two-dimensional physical habitat modeling of effects of habitat structures on urban stream restoration

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 2011年第4期4卷 386-395页

作者： Dongkyun im Hyeongsik KANG Water Infrastructure Division Samsung C & T Corporation Seoul 1321-20 Korea Division of Water and Environment Korea Environment Institute Seoul 122-706 Korea

River corridors, even if highly modified or degraded, still provide important habitats for numerous biological species, and carry high aesthetic and economic values. One of the keys to urban stream restoration is recovery and maintenance of ecological flows sufficient to sustain aquatic ecosystems. In this study, the Hongje Stream in the Seoul metropolitan area of Korea was selected for evaluating a physically-based habitat with and without habitat structures. The potential value of the aquatic habitat was evaluated by a weighted usable area （WUA） using River2D, a two-dimensional hydraulic model. The habitat suitability for Zacco platypus in the Hongje Stream was simulated with and without habitat structures. The computed WUA values for the boulder, spur dike, and riffle increased by about 2%, 7%, and 131%, respectively, after their construction. Also, the three habitat structures, especially the riffle, can contribute to increasing hydraulic heterogeneity and enhancing habitat diversity.

关键词： stream restoration physical habitat River2D weighted usable area