检索结果-南通市图书馆

Local Hybrid Linear State Estimation for Electric Power Systems Using Stream Processing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第3期10卷 1259-1268页

作者： kang sun Manyun Huang Zhinong Wei Yuzhang Lin Guoqiang sun College of Energy and Electrical Engineering Hohai UniversityNanjing 210098China Department of Department of Electrical and Computer Engineering University of Massachusetts LowellLowell MA 01854USA IEEE

The increasing penetration of renewable energy resources with highly fluctuating outputs has placed increasing concern on the accuracy and timeliness of electric power system state estimation(SE).Meanwhile,we note that only a fraction of system states fluctuate at the millisecond level and require to be *** such,refreshing only those states with significant variation would enhance the computational efficiency of SE and make fast-continuous update of states ***,this is difficult to achieve with conventional SE methods,which generally refresh states of the entire system every 4–5 *** this context,we propose a local hybrid linear SE framework using stream processing,in which synchronized measurements received from phasor measurement units(PMUs),and trigger/timingmode measurements received from remote terminal units(RTUs)are used to update the associated local ***,the measurement update process efficiency and timeliness are enhanced by proposing a trigger measurement-based fast dynamic partitioning algorithm for determining the areas of the system with states requiring *** particular,non-iterative hybrid linear formulations with both RTUs and PMUs are employed to solve the local SE *** timeliness,accuracy,and computational efficiency of the proposed method are demonstrated by extensive simulations based on IEEE 118-,300-,and 2383-bus systems.

关键词： Fast dynamic partitioning local hybrid linear state estimation phasor measurement units stream processing timeliness trigger/timing-mode measurements

Photolysis and photooxidation of typical gaseous VOCs by UV Irradiation： Removal performance and mechanisms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2018年第3期12卷 107-120页

作者： in-sun kang Jinying Xi Hong-Ying Hu Environmental Simulation and Pollution Control State Key Joint Laboratory School of Environment Tsinghua University Beijing 100084 China

Photodegradation by ultraviolet irradiation （UV） is increasingly applied in volatile organic compound （VOC） and odor gas treatments. In this study, 27 typical VOCs, including 11 hydrocarbons and 16 hydrocarbon derivatives, at 150-200 ppm in air and nitrogen gas were treated by a laboratory-scale UV reactor with 185/254 nm irradiation to systematically investigate their removal and conversion by UV irradiation. For the tested 27 VOCs, the VOC removal efficiencies in air were within the range of 13 %- 97% （with an average of 80%） at a retention time of 53 s, which showed a moderate positive correlation with the -molecular weight of the VOCs （R = 0.53）. The respective contributions of photolysis and photooxidation to VOC removal were identified for each VOC. According to the CO2 results, the mineralization rate of the tested VOCs was within the range of 9%-90%, with an average of 41% and were negatively correlated to the molecular weight （R = -0.63）. Many of the tested VOCs exhibited high concentration particulate matters in the off-gases with a 3-283 mg/m^3 PM10 range and a 2-40 mg/m^3 PM2.5 range. The carbon balance of each VOC during UV irradiation was analyzed based on the VOC, CO2 and PM10 concentrations. Certain organic intermediates and 23-218 ppm ozone were also identified in the off-gases. Although the UV technique exhibited a high VOC removal efficiency, its drawbacks, specifically low mineralization, particulate matters production, and ozone emission, must be considered prior to its application in VOC gas treatments.

关键词： VOCs UV photodegradation Particulate matters Ozone

Cost-effective bifunctional lignin-derived carbon supported tin oxide with efficient production of 5-hydroxymethylfurfural from glucose

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第10期74卷 154-164页

作者： Sien Yan Linhuo Gan Kui Wang kang sun College of Chemical Engineering Huaqiao UniversityXiamen 361021China Key Laboratory of Biomass Energy and Materials of Jiangsu Province Nanjing 210042China Institute of Chemical Industry of Forest Products Chinese Academy of ForestryNanjing 210042China Fujian Provincial Key Laboratory of Biomass Low-Carbon Conversion Huaqiao UniversityXiamen 361021China

5-Hydroxymethylfurfural(5-HMF)is one of the important bio-based platform compounds,and the catalytic conversion of glucose to 5-HMF is a highly desirable approach that is receiving increasing ***,we reported the synthesis of lignin-derived carbon supported tin oxides(SnOx/LC)catalyst via a two-step hydrothermal-pyrolytic method using wheat straw alkali lignin as a cost-effective carbon source with high carbon *** key preparation conditions of the catalyst and its catalytic conditions for the conversion of glucose to 5-HMF were investigated,*** show that under the preparation conditions of tin tetrachloride dosage of 3.0 mmol and pyrolysis temperature of 500 ℃,the optimized catalyst(3.0-SnOx/LC-500)with a high yield of 63.4%exhibits good catalytic performance of 5-HMF yield of 50.1%and reaction selectivity of 86.0%under the optimum conditions of reaction temperature and time of 190 ℃ and 3 h,initial glucose concentration of 10%(mass),3.0-SnOx/LC-500 dosage of 100 mg in a biphasic solvent system of volume ratio of water to tetrahydrofuran of 1:*** addition,3.0-SnOx/LC-500 exerts an excellent reusability in a five-cycle ***,SnOx/LC was characterized in detail using X-ray diffraction patterns(XRD),X-ray photoelectron spectroscopy(XPS),Brunauer-Emmett-Teller(BET),ammonia temperature-programmed-desorption(NH3-TPD),pyridine adsorption infrared spectroscopy(Py-FTIR),scanning electron microscope(SEM)and thermal gravimetric analysis(TGA).Results indicate that Brønsted acid sites and Lewis acid sites coexist on 3.0-SnOx/LC-500,and more Sn^(4+),as well as a proper ratio of weak acidity to medium acidity,are conductive to its catalytic performance in glucose-to-5-HMF reaction.

关键词： Lignin Biomass Catalyst support Selectivity Biphasic solvent system

Catalytic Mechanism of KCl during Carbothermic Reduction of Pre-Oxidized Ilmenite

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2001年第2期8卷 7-11页

作者： sun kang WU Jian-hui Northeastern University

As alkali additive,KC1 catalyzes effectively the carbothermic reduction of pre-oxidized ilmenite,and the catalytic effect becomes more remarkable as the amount of KC1 *** the carbothermic reduction,the gaseous product consists mainly of CO,and the partial pressure of which increases with reaction *** EPMA and XPS of the partially reduced ilmenite ore and that of the used graphite as reductant showed that the potassium ions enter both ilmenite particles and graphite powders during *** above-mentioned phenomena result in the distortion of ilmenite and carbon structure by potassium ions and reaction activity of carbon and ilmenite was *** a result,the overall carbothermic reduction was catalyzed by KC1.

关键词： carbothermic reduction catalytic effect reaction mechanism alkali additives preoxidized ilmenite

A double-edged sword of immuno-microenvironment in cardiac homeostasis and injury repair

在线全文

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2021年第3期6卷 779-794页

作者： kang sun Yi-yuan Li Jin Jin MOE Laboratory of Biosystem Homeostasis and Protection and Life Sciences InstituteZhejiang UniversityHangzhou 310058China Key Laboratory for Developmental Genes and Human Disease Ministry of EducationInstitute of Life SciencesJiangsu Province High-Tech Key Laboratory for Bio-Medical ResearchSoutheast UniversityNanjing 210096China Sir Run Run Shaw Hospital College of Medicine Zhejiang UniversityHangzhou 310016China

The response of immune cells in cardiac injury is divided into three continuous phases:inflammation,proliferation and *** kinetics of the inflammatory and proliferation phases directly influence the tissue *** cardiac homeostasis,cardiac tissue resident macrophages(cTMs)phagocytose bacteria and apoptotic ***,NK cells prevent the maturation and transport of inflammatory *** cardiac injury,cTMs phagocytose the dead cardiomyocytes(CMs),regulate the proliferation and angiogenesis of cardiac progenitor *** cells prevent the cardiac fibrosis,and promote vascularization and *** 1 macrophages trigger the cardioprotective responses and promote tissue fibrosis in the early ***,type 2 macrophages promote cardiac remodeling and angiogenesis in the late *** macrophages and neutrophils firstly lead to chronic inflammation by secreting proinflammatory cytokines,and then release anti-inflammatory cytokines and growth factors,which regulate cardiac *** this process,dendritic cells(DCs)mediate the regulation of monocyte and macrophage *** eosinophils and Mast cells(MCs)release some mediators which contribute to coronary vasoconstriction,leukocyte recruitment,formation of new blood vessels,scar *** adaptive immunity,effector T cells,especially Th17 cells,lead to the pathogenesis of cardiac fibrosis,including the distal fibrosis and scar *** protectors,Treg cells,inhibit reduce the inflammatory response,then directly trigger the regeneration of local progenitor cell via IL-10.B cells reduce myocardial injury by preserving cardiac function during the resolution of inflammation.

关键词： cardiac homeostasis inflammation

Non-negative matrix factorization based unmixing for principal component transformed hyperspectral data

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2016年第5期17卷 403-412页

作者： Xiu-rui GENG Lu-yan JI kang sun Key Laboratory of Technology in Geo-spatial Information Processing and Application System Institute of Electronics Chinese Academy of Sciences Beijing 100190 China MOE Key Laboratory for Earth System Modeling Center for Earth System Science Tsinghua University Beijing 100084 China The 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang 050000 China

Non-negative matrix factorization(NMF) has been widely used in mixture analysis for hyperspectral remote sensing. When used for spectral unmixing analysis, however, it has two main shortcomings:(1) since the dimensionality of hyperspectral data is usually very large, NMF tends to suffer from large computational complexity for the popular multiplicative iteration rule;(2) NMF is sensitive to noise(outliers), and thus the corrupted data will make the results of NMF meaningless. Although principal component analysis(PCA) can be used to mitigate these two problems, the transformed data will contain negative numbers, hindering the direct use of the multiplicative iteration rule of NMF. In this paper, we analyze the impact of PCA on NMF, and find that multiplicative NMF can also be applicable to data after principal component transformation. Based on this conclusion, we present a method to perform NMF in the principal component space, named ‘principal component NMF'(PCNMF). Experimental results show that PCNMF is both accurate and time-saving.

关键词： Non-negative matrix factorization(NMF) Principal component analysis(PCA) Endmember Hyperspectral

An improved theoretical procedure for the pore-size analysis of activated carbon by gas adsorption

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第3期26卷 551-559页

作者： Guodong Wang Jianchun Jiang kang sun Jianzhong Wu College of Chemical Engineering Nanjing Forestry University Department of Chemical and Environmental Engineering University of California Institute of Chemical Industry of Forest Products Chinese Academy of Forestry

Amorphous carbon materials play a vital role in adsorbed natural gas(ANG) storage. One of the key issues in the more prevalent use of ANG is the limited adsorption capacity, which is primarily determined by the porosity and surface characteristics of porous materials. To identify suitable adsorbents, we need a reliable computational tool for pore characterization and, subsequently, quantitative prediction of the adsorption behavior. Within the framework of adsorption integral equation(AIE), the pore-size distribution(PSD) is sensitive to the adopted theoretical models and numerical algorithms through isotherm fitting. In recent years, the classical density functional theory(DFT) has emerged as a common choice to describe adsorption isotherms for AIE kernel construction. However,rarely considered is the accuracy of the mean-field approximation(MFA) commonly used in commercial software. In this work, we calibrate four versions of DFT methods with grand canonical Monte Carlo(GCMC) molecular simulation for the adsorption of CH_4 and CO_2 gas in slit pores at 298 K with the pore width varying from 0.65 to 5.00 nm and pressure from 0.2 to 2.0 MPa. It is found that a weighted-density approximation proposed by Yu(WDA-Yu) is more accurate than MFA and other non-local DFT methods. In combination with the trapezoid discretization of AIE, the WDA-Yu method provides a faithful representation of experimental data, with the accuracy and stability improved by 90.0% and 91.2%, respectively, in comparison with the corresponding results from MFA for fitting CO_2 isotherms. In particular, those distributions in the feature pore width range(FPWR)are proved more representative for the pore-size analysis. The new theoretical procedure for pore characterization has also been tested with the methane adsorption capacity in seven activated carbon samples.

关键词： Non-local density functional theory Amorphous porous materials Pore size characterization Gas adsorption Adsorption integral equation

Pylorus-preserving gastrectomy for early gastric cancer

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Oncology 2024年第3期16卷 653-658页

作者： Ke-kang sun Yong-You Wu Department of Gastrointestinal Surgery The Affiliated Kunshan Hospital to Jiangsu UniversitySuzhou 215300Jiangsu ProvinceChina Department of Gastrointestinal Surgery The Second Affiliated Hospital of Soochow UniversitySuzhou 215008Jiangsu ProvinceChina

Pylorus-preserving gastrectomy(PPG)has been widely accepted as a function-preserving gastrectomy for middle-third early gastric cancer(EGC)with a distal tumor border at least 4 cm proximal to the *** procedure essentially preserves the function of the pyloric sphincter,which requires to preserve the upper third of the stomach and a pyloric cuff at least 2.5 *** suprapyloric and infrapyloric vessels are usually preserved,as are the hepatic and pyloric branches of the vagus *** with distal gastrectomy,PPG has significant advantages in preventing dumping syndrome,body weight loss and bile reflux *** postoperative complications after PPG have reached an acceptable *** can be considered a safe,effective,and superior choice in EGC,and is expected to be extensively performed in the future.

关键词： Gastric cancer Pylorus-preserving gastrectomy Oncological safety Gastric stasis

Steady-state response of a saturated half-space with an overlying dry layer subjected to a moving load

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第1期13卷 33-43页

作者： An-feng HU Bo sun kang-he XIE MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering Zhejiang University Hangzhou 310058 China

In this paper,the steady-state response of a saturated half-space with an overlying dry layer subjected to a moving rectangular load is *** governing partial differential equations are solved using the Fourier *** solutions in time-space domain are expressed in terms of infinite Fourier type integrals,which can be evaluated only by numerical *** results show that the influence of a drained or undrained interface on the response is related to the permeability of the underlying saturated ***,the effect due to the upper dry layer is associated with the thickness of the layer.

关键词： Steady-state response Moving load Saturated half-space Overlying dry layer Fourier transform Drained orundrained interface