检索结果-南通市图书馆

Effective peroxydisulfate activation by CQDs-MnFe_(2)O_(4)@ZIF-8 catalyst for complementary degradation of bisphenol A by free radicals and non-radical pathways

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 Chemical Letters 2024年第5期35卷 371-379页

作者： Shuo Li Xinran Liu Yongjie zheng Jun Ma Shijie You Heshan zheng College of Chemistry and Chemical Engineering Qiqihar UniversityQiqihar 161006China State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China

The present study reported fabrication of novel carbon quantum dots-MnFe_(2)O_(4)@ZIF-8(CQDs-MFO@ZIF-8)by using co-precipitation hydrothermal method for activation of peroxydisulfate(PDS)to degrade bisphenol A(BPA),one of important emerging organic pollutants in water ***-MFO@ZIF-8 served as a highly efficient thermal activated PDS catalyst with high catalytic degradation efficiency,reusability and *** catalyst achieved almost completely removal of 20.0 mg/L BPA within 5.0 min,and the degradation efficiency remained higher than 83%after 5 consecutive *** radicals(^(·)OH,SO_(4)^(·-)and^(·)O_(2)^(-))and non-free radicals((1)O_(2))were generated in the thermal PDS-activation system,in which singlet oxygen((1)O_(2))played a dominant role in the degradation of *** potential toxicity of BPA degradation intermediates was analyzed upon the culture of *** and Chlorella sorokiniana by using Ecological Structure-Activity Relationship Model(ECOSAR)*** catalytic performances of BPA degradation by CQDs-MFO@ZIF-8 were evaluated for treatment of different practical water samples to further verify the feasibility of practical *** study provides proof-in-concept demonstration of new nanomaterials for enhanced catalytic water decontamination.

关键词： Bisphenol A Degradation Peroxydisulfate ^(1)O_(2) Toxicity analysis

Challenges and opportunities in Quaternary palynology

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第7期67卷 2148-2161页

作者： Qinghai XU Houyuan LU Zhuo zheng College of Geographical Sciences Hebei Key Laboratory of Environmental Change and Ecological ConstructionHebei Normal UniversityShijiazhuang 050024China Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China School of Earth Sciences and Engineering Sun Yat-sen UniversityZhuhai 519082China

Quaternary palynology plays a pivotal role in investigating global climate change and various other research fields,serving as an essential tool for the quantitative analysis of paleoenvironment ***,due to the vast diversity of terrestrial ecosystems and intricate interactions between vegetation,climate,and human activities,further advancements are required in the following aspects within this discipline.(1)The accuracy of classification in pollen morphology and fossil pollen identification needs improvement,particularly at the species *** represents a significant challenge in present Quaternary ***-aided intelligent recognition holds promise as a solution for species identification based on more detail pollen morphology.(2)Most pollen-based vegetation and climate reconstructions overlook the significance of bare *** bare ground can lead to substantial inaccuracies when quantitatively reconstructing past vegetation and climate.(3)While pollen records provide reliable information on paleoclimate changes,current quantitative climate reconstruction models heavily rely on modern pollen datasets derived from present-day vegetation disturbed more or less by human *** introduces bias and uncertainties into paleoclimate reconstruction.(4)Although pollen can serve as an indicator of human activities,accurately quantifying the intensity of human influence remains *** accurate identification of crop pollen,reconstructing reliable land cover/use data,and integrating multidisciplinary data may enhance the identification and quantification of signals related to human activity in pollen records.

关键词： Quaternary palynology Paleoclimate Paleovegetation Human activity

Recent progress in functional modification and crosslinking of bioprosthetic heart valves

在线全文

学校读者我要写书评

暂无评论

Regenerative Biomaterials 2024年第1期3卷 1-16页

作者： Cheng zheng Li Yang Yunbing Wang National Engineering Research Center for Biomaterials Sichuan UniversityChengdu 610064China

Valvular heart disease(VHD),clinically manifested as stenosis and regurgitation of native heart valve,is one of the most prevalent cardiovascular diseases with high *** valve replacement surgery has been recognized as golden standard for the treatment of *** to the clinical application of transcatheter heart valve replacement technic and the excellent hemodynamic performance of bioprosthetic heart valves(BHVs),implantation of BHVs has been increasing over recent years and gradually became the preferred choice for the treatment of ***,BHVs might fail within 10-15 years due to structural valvular degeneration(SVD),which was greatly associated with drawbacks of glutaraldehyde crosslinked BHVs,including cytotoxicity,calcification,component degradation,mechanical failure,thrombosis and immune *** prolong the service life of BHVs,much effort has been devoted to overcoming the drawbacks of BHVs and reducing the risk of *** this review,we summarized and analyzed the research and progress on:(i)modification strategies based on glutaraldehyde crosslinked BHVs and(ii)nonglutaraldehyde crosslinking strategies for BHVs.

关键词： bioprosthetic heart valves modification crosslinking anticalcification antithrombosis

Spatiotemporal Changes of Snow Depth in Western Jilin,China from 1987 to 2018

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 Geographical Science 2024年第2期34卷 357-368页

作者： WEI Yanlin LI Xiaofeng GU Lingjia zheng Zhaojun zheng Xingming JIANG Tao Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China University of Chinese Academy of Sciences Beijing 100049China Changchun Jingyuetan Remote Sensing Experiment Site Chinese Academy of SciencesChangchun 130102China College of Electronic Science and Engineering Jilin UniversityChangchun 130012 National Meteorological Satellite Meteorological Center Beijing 100081China

Seasonal snow cover is a key global climate and hydrological system component drawing considerable attention due to glob-al warming ***,the spatiotemporal snow cover patterns are challenging in western Jilin,China due to natural condi-tions and sparse ***,this study investigated the spatiotemporal patterns of snow cover using fine-resolution passive mi-crowave(PMW)snow depth(SD)data from 1987 to 2018,and revealed the potential influence of climate factors on SD *** results indicated that the interannual range of SD was between 2.90 cm and 9.60 cm during the snowy winter seasons and the annual mean SD showed a slightly increasing trend(P>0.05)at a rate of 0.009 cm/*** snowmelt periods,the snow cover contributed to an increase in volumetric soil water,and the change in SD was significantly affected by air *** correlation between SD and air temperature was negative,while the correlation between SD and precipitation was positive during December and *** March,the correlation coefficient exceeded 0.5 in Zhenlai,Da’an,Qianan,and Qianguo ***,the SD and precipitation were neg-atively correlated over western Jilin in October,and several subregions presented a negative correlation between SD and precipitation in November and April.

关键词： snow cover snow depth(SD) climate changes passive microwave(PMW) western Jilin,China

在线全文

学校读者我要写书评

暂无评论

动力煤的燃烧特性研究

燃料化学学报 1996年第6期24卷 565-570页

作者：郑明东姚伯元华东冶金学院

选择了挥发分从２０％至４０％的五种典型动力煤，结合常规分析和热失重技术得到了燃煤的燃烧热失重曲线、燃烧特征温度以及动力学参数。结果表明：不同的燃烧图意味着不同的燃烧特性；燃烧特征温度（Ｔ＿１＋Ｔ＿２）／２与煤的挥发分... 详细信息

选择了挥发分从２０％至４０％的五种典型动力煤，结合常规分析和热失重技术得到了燃煤的燃烧热失重曲线、燃烧特征温度以及动力学参数。结果表明：不同的燃烧图意味着不同的燃烧特性；燃烧特征温度（Ｔ＿１＋Ｔ＿２）／２与煤的挥发分存在一定的线性关系；五种煤的燃烧反应活化能大小顺序如下：淮北煤＞青龙山煤＞枣庄煤＞淮南煤＞柴里煤；燃烧反应可用相同的动力学模型不同的相应参数表示，ｄｘ／ｄτ＝Ａ·ｅ￣（－Ｅ／ＲＴ）·（１－ｘ）。

关键词：煤燃烧热重分析

在线全文

学校读者我要写书评

暂无评论

稀土元素对炼焦煤热分解特征的影响

燃料与化工 2008年第1期39卷 1-5页

作者：郑明东冯倩安徽工业大学马鞍山243002

研究了配合煤及脱灰配合煤添加0.2%稀土元素后的热解行为,结果表明,添加稀土元素后炼焦煤热分解特征发生显著变化,相同温度下最终失重量增大,快速热分解温度区间延长。DTG曲线表现为热解峰个数增加,塑性胶质体生成阶段(500～700℃)热解... 详细信息

研究了配合煤及脱灰配合煤添加0.2%稀土元素后的热解行为,结果表明,添加稀土元素后炼焦煤热分解特征发生显著变化,相同温度下最终失重量增大,快速热分解温度区间延长。DTG曲线表现为热解峰个数增加,塑性胶质体生成阶段(500～700℃)热解速率明显增大;550℃开始二次热解加剧;第三热解峰值向高温区移动。动力学分析结果也表明,在热解的三个阶段中,500℃以前反应活化能略升高;处于塑性阶段的第二、三阶段平均反应活化能降低,添加稀土元素后炼焦煤低温下显示出较高的催化作用。

关键词：炼焦煤稀土元素催化作用活化能

High Order IMEX Stochastic Galerkin Schemes for Linear Transport Equation with Random Inputs and Diffusive Scalings

在线全文

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第1期6卷 325-339页

作者： zheng Chen Lin Mu Department of Mathematics University of Massachusetts Dartmouth285 Old Westport RoadDartmouth02747MAUSA Department of Mathematics University of GeorgiaAthens30602GAUSA

In this paper,we consider the high order method for solving the linear transport equations under diffusive scaling and with random *** tackle the randomness in the problem,the stochastic Galerkin method of the generalized polynomial chaos approach has been ***,the high order implicit-explicit scheme under the micro-macro decomposition framework and the discontinuous Galerkin method have been *** provide several numerical experiments to validate the accuracy and the stochastic asymptotic-preserving property.

关键词： Stochastic Galerkin scheme linear transport equations generalized polynomial approach stochastic asymptotic-preserving property

High-Order Decoupled and Bound Preserving Local Discontinuous Galerkin Methods for a Class of Chemotaxis Models

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied Mathematics and Computation 2024年第1期6卷 372-398页

作者： Wei zheng Yan Xu School of Mathematical Sciences University of Science and Technology of ChinaHefei230026AnhuiChina

In this paper,we explore bound preserving and high-order accurate local discontinuous Galerkin(LDG)schemes to solve a class of chemotaxis models,including the classical Keller-Segel(KS)model and two other density-dependent *** use the convex splitting method,the variant energy quadratization method,and the scalar auxiliary variable method coupled with the LDG method to construct first-order temporal accurate schemes based on the gradient flow structure of the *** semi-implicit schemes are decoupled,energy stable,and can be extended to high accuracy schemes using the semi-implicit spectral deferred correction *** bound preserving DG discretizations are only worked on explicit time integration methods and are difficult to get high-order *** overcome these difficulties,we use the Lagrange multipliers to enforce the implicit or semi-implicit LDG schemes to satisfy the bound constraints at each time *** bound preserving limiter results in the Karush-Kuhn-Tucker condition,which can be solved by an efficient active set semi-smooth Newton *** numerical experiments illustrate the high-order accuracy and the effect of bound preserving.

关键词： Chemotaxis models Local discontinuous Galerkin(LDG)scheme Convex splitting method Variant energy quadratization method Scalar auxiliary variable method Spectral deferred correction method

An Integrated External Archive Local Disturbance Mechanism for Multi-Objective Snake Optimizer

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 Electronics 2024年第4期33卷 989-996页

作者： Leifu GAO zheng LIU Institute for Optimization and Decision Analytics Liaoning Technical University

It is an interesting research direction to develop new multi-objective optimization algorithms based on meta-heuristics. Both the convergence accuracy and population diversity of existing methods are not *** paper proposes an integrated external archive local disturbance mechanism for multi-objective snake optimizer(IMOSO) to overcome the above shortcomings. There are two improved strategies. The adaptive mating between subpopulations strategy introduces the special mating behavior of snakes with multiple husbands and wives into the original snake optimizer. Some positions are updated according to the dominated relationships between the newly created individuals and the original individuals. The external archive local disturbance mechanism is used to re-search partial non-inferior solutions with poor diversities. The perturbed solutions are non-dominated sorting with the generated solutions by the next iteration to update the next external archive. The main purpose of this mechanism is to make full use of the non-inferior solution information to better guide the population evolution. The comparison results of the IMOSO and 7 state-of-the-art algorithms on WFG benchmark functions show that IMOSO has better convergence and population diversity.

关键词： Accuracy Sociology Metaheuristics Diversity methods Benchmark testing Statistics Convergence