检索结果-南通市图书馆

Simultaneous estimation of surface soil moisture and soil properties with a dual ensemble Kalman smoother

Science China Earth Sciences 2015年第12期58卷 2327-2339页

作者： chu nan HUANG chunLin LI Xin DU PeiJun School of Environment Science and Spatial Informatics China University of Mining and Technology Key Laboratory of Remote Sensing of Gansu Province Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Heihe Remote Sensing Experimental Research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of Sciences

In this paper, a new state-parameter estimation approach is presented based on the dual ensemble Kalman smoother(DEn KS) and simple biosphere model(Si B2) to sequentially estimate both the soil properties and soil moisture profile by assimilating surface soil moisture observations. The Arou observation station, located in the upper reaches of the Heihe River in northwestern China, was selected to test the proposed method. Three numeric experiments were designed and performed to analyze the influence of uncertainties in model parameters, atmospheric forcing, and the model's physical mechanics on soil moisture estimates. Several assimilation schemes based on the ensemble Kalman filter(En KF), ensemble Kalman smoother(En KS), and dual En KF(DEn KF) were also compared in this study. The results demonstrate that soil moisture and soil properties can be simultaneously estimated by state-parameter estimation methods, which can provide more accurate estimation of soil moisture than traditional filter methods such as En KF and En KS. The estimation accuracy of the model parameters decreased with increasing error sources. DEn KS outperformed DEn KF in estimating soil moisture in most cases, especially where few observations were available. This study demonstrates that the DEn KS approach is a useful and practical way to improve soil moisture estimation.

关键词： soil moisture soil properties data assimilation state-parameter estimation dual ensemble Kalman smoother

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

1-Planar Graphs with Girth at Least 7 are(1,1,1,0)-Colorable

引用

Journal of Mathematical Research with Applications 2016年第6期36卷 643-650页

作者： Ya-nan chu Lei SUN School of Mathematics and Statistics Shandong Normal University

A graph is 1-planar if it can be drawn on the plane so that each edge is crossed by at most one other *** this paper,it is shown that 1-planar graphs with girth at least7 are(1,1,1,0)-colorable.

关键词： 1-planar improper coloring discharging important 4-vertex

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

Heterogeneous Catalytic Ozonization of Sulfosalicylic Acid

引用

Chinese Chemical Letters 2002年第6期13卷 579-582页

作者： Shao Ping TONG Wen Hua LENG Jiang Qing ZHANG chu nan CAO Department of Chemistry Zhejiang UniversityHangzhou 310027

This paper describes the potential of heterogeneous catalytic ozonization of sulfo-salicylic acid (SSal). It was found that catalytic ozonization in the presence of Mn-Zr-O (a modified manganese dioxide supported on silica gel) had significantly enhanced the removal rate (72%) of total organic carbon (TOC) compared with that of ozonization alone (19%). The efficient removal rate of TOC was probably due to increasing the adsorption ability of catalyst and accelerating decomposition of ozone to produce more powerful oxidants than ozone. .

关键词： Ozone catalytic ozonization total organic carbon sulfosalicylic acid.

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

PRODUCT IMAGE RETRIEVAL BASED ON CO-FEATURES OF THE OBJECT

引用

Journal of Electronics(China) 2010年第6期27卷 815-821页

作者： Fu Haiyan Kong Xiangwei t Yang nan Zhou Jianhui chu Fengtao （Faculty of Electronic Information and Electrical Engineering Dalian University of Technology Dalian 116023 China）

In this paper, we propose a product image retrieval method based on the object contour corners, image texture and color. The product image mainly highlights the object and its background is very simple. According to these characteristics, we represent the object using its contour, and detect the corners of contour to reduce the number of pixels. Every corner is described using its approximate curvature based on distance. In addition, the Block Difference of Inverse Probabilities (BDIP) and Block Variation of Local Correlation (BVLC) texture features and color moment are extracted from image's HIS color space. Finally, dynamic time warping method is used to match features with different length. In order to demonstrate the effect of the proposed method, we carry out experiments in Mi-crosoft product image database, and compare it with other feature descriptors. The retrieval precision and recall curves show that our method is feasible.

关键词： Product image retrieval Multi-features Approximate curvature based on distance Block Difference of Inverse Probabilities (BDIP) and Block Variation of Local Correlation (BVLC) texture features Color moment

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

Re-understanding of land surface albedo and related terms in satellite-based retrievals

引用

Big Earth Data 2020年第1期4卷 45-67页

作者： Yanmin Shuai Latipa Tuerhanjiang Congying Shao Feng Gao Yuyu Zhou Donghui Xie Tao Liu Ji Liang nan chu School of Geomatics and Geography Liaoning Technical UniversityFuxinLiaoningChina State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and Geographyand Research Center for Ecology and Environment of Central AsiaCASUrumqiChina School for the Environment University of MassachusettsBostonMAUSA College of Resource and Environment Sciences Xinjiang UniversityXinjiangChina USDA-ARS Hydrology and Remote Sensing Laboratory BeltsvilleMDUSA Department of Geological and Atmospheric Sciences Iowa State UniversityAmesIAUSA School of Geography and Remote Sensing Science Beijing Normal UniversityBeijingChina National-Local Joint Engineering Laboratory of Geo-Spatial Information Technology Hunan University of Science and TechnologyXiangtanHunanChina

Land surface albedo is a critical variable in determining surface energy balance,and regulating climate and ecosystem processes through feedback ***,climatic modelers and radiative monitoring require accurate estimates of land surface *** the instrument development,algorithm upgrade,spectral-band-adjustment in wavelength center or band width,and the increasing distinct requirement from diversified communities,various albedo terms have been generated in related satellite-based *** lack of understanding on the divergence of these terminologies can introduce potential considerable errors in the subsequent applications,or an elevated probability to invert the deduced *** surveyed the basic concepts of reflectance quantities,retrieval strategies,and models developed since the 1970s,and discuss both strength and opportunity for improvements on land surface albedo extraction,and product *** addition,we exemplified the difference of albedo terms using the daily MODIS product(MCD43A)to emphasize the potential risk of the ambiguous usage,over typical IGBP land covers in Northern *** investigation shows that relative differences among various albedo terms can reach up to 181%and 50%,while 0.266 and 0.118 of absolute variance respectively in the narrow and broad-band surface albedo,which illuminated cautions against the ambiguous understanding of albedo terminologies or erroneous usage of albedo products.

关键词： Surface albedo BRDF satellite-based albedo product hemispheric reflectance

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

Predictors of irreversible intestinal resection in patients with acute mesenteric venous thrombosis

引用

World Journal of Gastroenterology 2020年第25期26卷 3625-3637页

作者： Shi-Long Sun Xin-Yu Wang Cheng-nan chu Bao-Chen Liu Qiu-Rong Li Wei-Wei Ding Division of Trauma and Surgical Intensive Care Unit Research Institute of General SurgeryJinling HospitalMedical School of Nanjing UniversityNanjing 210002Jiangsu ProvinceChina

BACKGROUND Acute mesenteric venous thrombosis(AMVT)can cause a poor *** transcatheter thrombolysis(TT)can achieve early mesenteric ***,irreversible intestinal ischemia still occurs and the mechanism is still *** To evaluate the clinical outcomes of and to identify predictive factors for irreversible intestinal ischemia requiring surgical resection in AMVT patients treated by *** The records of consecutive patients with AMVT treated by TT from January 2010 to October 2017 were retrospectively *** compared patients who required resection of irreversible intestinal ischemia to patients who did not *** Among 58 patients,prompt TT was carried out 28.5 h after admission.A total of 42(72.4%)patients underwent arteriovenous combined thrombolysis,and 16(27.6%)underwent arterial thrombolysis *** overall 30-d mortality rate was 8.6%.Irreversible intestinal ischemia was indicated in 32(55.2%)patients,who had a higher 30-d mortality and a longer in-hospital stay than patients without *** significant independent predictors of irreversible intestinal ischemia were Acute Physiology and Chronic Health Evaluation(APACHE)II score(odds ratio=2.368,95% confidence interval:1.047-5.357,P=0.038)and leukocytosis(odds ratio=2.058,95% confidence interval:1.085-3.903,P=0.027).Using the receiver operating characteristic curve,the cutoff values of the APACHE II score and leukocytosis for predicting the onset of irreversible intestinal ischemia were calculated to be 8.5 and 12×10^9/L,*** Prompt TT could achieve a favorable outcome in AMVT *** APACHE II score and leukocytosis can significantly predict the occurrence of irreversible intestinal ***,close monitoring of these factors may help with the early identification of patients with irreversible intestinal ischemia,in whom ultimately surgical resection is required,before the initiation of TT.

关键词： Acute mesenteric venous thrombosis Transcatheter thrombolysis Irreversible intestinal ischemia Surgical resection Acute Physiology and Chronic Health Evaluation II score Leukocytosis

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

Magnetic field topology modeling under resonant magnetic perturbations on EAST

引用

Plasma Science and Technology 2019年第6期21卷 98-105页

作者： Jie HUANG Yasuhiro SUZUKI Yunfeng LIANG Manni JIA Youwen SUN nan chu Jichan XU Muquan WU Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 People's Republic of China University of Science and Technology of China Hefei 230026 People's Republic of China National Institutes of Fusion Sciences National Institutes of Natural Sciences Oroshi-cho 322-6 Toki 509-5292 Japan SOKENDAI The Graduate University for Advanced Studies Oroshi-cho 322-6 Toki 509-5292 Japan Institute for Energy and Climate Reserch-Plasma Physics Forschungszentrum Juelich Association EURATOM-FZJ Trilateral Euregio Cluster D-52425 Juelich Germany

In order to understand the mechanism by which the resonant magnetic perturbation (RMP)mitigates or suppresses the edge-localized mode (ELM),the topological study of the edge magnetic field in ELM mitigation or suppression phase is a critical *** model the three-dimensional magnetic field topology superposed RMP on Experimental Advanced Superconducting Tokamak,a numerical model using the field line tracing method for both vacuum and ideal plasma response approximations is *** the numerical model,the topological change and the penetration depth of the stochastic field lines in the edge magnetic field are studied in an RMP *** profiles of minimum9 on edge stochastic field lines and the particle flux pattem,the ideal plasma response changes the field line penetration depth while remaining similar profile relative to vacuum *** mitigate and suppress ELM strongly,the deep penetration of RMP fields and topological changes of the edge magnetic field is a key from our modeling.

关键词： magnetic topology ideal plasma response tokamaks resonant magnetic perturbation

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

Suppression and mitigation of inter-ELM high-frequency Alfvén-like mode by resonant magnetic perturbation in EAST

引用

Plasma Science and Technology 2021年第9期23卷 7-12页

作者： Jiquan ZHAO Youwen SUN nan chu Tonghui SHI Qun MA Yumin WANG Kaiyang HE Youjun HU EAST Team Institute of Plasma Physics HFIPSChinese Academy of Sciences University of Science and Technology of China Hefei 230026People's Republic of China

Suppression and mitigation of a high-frequency Alfvén-like mode(HFAM)between type-I edge localized modes(ELMs)during ELM mitigation by resonant magnetic perturbation(RMP)is observed for the first time in the EAST *** mode is located near the edge pedestal *** modeling result of the Alfvén continuum shows that the HFAM is located near the elipical Alfvén eigenmode(EAE)*** the application of n=1 RMP for ELM mitigation,the HFAM can be fully suppressed when the RMP amplitude exceeds a threshold,below which the HFAM is *** suppression is caused by a reduction of pedestal height induced by *** the case using n=3 RMP,the mode is localized toroidally at specific phase depending on the phase of applied RMP,*** in the three-dimensional equilibrium formed by *** dominant toroidal mode number of HFAM is around n=-6 and it reduces to-3 during the application of n=3 RMP,which indicates the existence of possible nonlinear coupling between the HFAM and *** the negative mode number denotes that the mode rotates in electron diamagnetic drift *** observation reported here improves the understanding of pedestal dynamics and its stability in RMP ELM control.

关键词： Alfvén-like mode RMP HFAM mode inter-ELM

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

Effect of Potential Perturbation Polarization on the Stress Corrosion Cracking of Type 321 Stainless Steel

引用

Chinese Chemical Letters 1998年第7期9卷 695-696页

作者： Lin NIU Hai Chao LIN chu nan CAO (Institute of Corrosion and Protection of Metals, State Key Laboratory for Cormsion and Protection, Chinese Academy of Sciences, Shenyang 110015) Chinese Acad Sci State key Lab Corros & Protect Inst Corros & Protect Met Shenyang 110015 Peoples R China

The SCC susceptibility of type 321 stainless steel in acidic chloride solution has been studied by slow strain rate testing (SSRT) and SEM. During the slow rate tensile process, the specimen was polarized with different potential perturbation modes such as cyclic potential scan and cyclic potential step methods. The results indicated that the potential scan rate or step frequency played an essential role in the initiation and propagation of crack.

关键词： stress corrosion cracking stainless steel potential perturbation

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

Effect of Cobalt Precursor on Microstructures and Visible Light Photoactivity of Doped TiO2 Powders

引用

Chinese Journal of Chemical Physics 2006年第5期19卷 463-468页

作者： Jing-ying Shi Wen-hua Leng Jiang-lin Cao Jian-qing Zhang chu-nan Cao Department of Chemistry Yuquan Campus Zhejiang University Hangzhou 310027 China Department of Chemistry Quanzhou Normal College Quanzhou 352000 China

In order to develop photoactive cobalt-doped TiO2 for the degradation of organic pollutants using visible light irradiation, the effects of cobalt precursor on TiO2 microstructure were investigated. Three cobaltprecursors, i.e. COCl2, Co（NO3）2 and COSO4 with two doping levels （nominally 1% and 10%）, and two annealing temperatures （400 and 800 ℃） were adopted to prepare tile doped titania through the sol-gel method. The powder samples were characterized with XRD, SEM, BET surface area analysis and UV-Vis absorption spectroscopy, and their photocatalytic activities were evaluated by the degradation of aniline under visible light irradiation. The results showed that the distribution of titania phases, particle size, morphology, surface area and the optical absorption of the catalysts were greatly dependent on the cobalt precursors. Samples prepared from Co（NO3）2, especially for those doped at 1% and calcined at 400 ℃, showed the highest photocatalytic activity towards the degradation of aniline, and the possible reasons are discussed briefly.

关键词： Cobalt precursor Doped titania Photocatalysis Visible light

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：