检索结果-南通市图书馆

Nonlinear Schrödinger Approximation for the Electron Euler-Poisson Equation

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2023年第3期44卷 361-378页

作者： huimin liu Xueke PU Faculty of Applied Mathematics Shanxi University of Finance and EconomicsTaiyuan030006China School of Mathematics and Information Sciences Guangzhou UniversityGuangzhou510006China

The nonlinear Schr?dinger(NLS for short)equation plays an important role in describing slow modulations in time and space of an underlying spatially and temporarily oscillating wave *** this paper,the authors study the NLS approximation by providing rigorous error estimates in Sobolev spaces for the electron Euler-Poisson equation,an important model to describe Langmuir waves in a *** derive an approximate wave packet-like solution to the evolution equations by the multiscale analysis,then they construct the modified energy functional based on the quadratic terms and use the rotating coordinate transform to obtain uniform estimates of the error between the true and approximate solutions.

关键词： Modulation approximation Nonlinear Schrödinger equation Electron Euler-Poisson equation

The removal of inevitable NOx species in catalysts and the selection of appropriate membrane for measuring electrocatalytic ammonia synthesis accurately

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2020年第10期29卷 51-58页

作者： huimin liu Yidan Zhang Jingshan Luo Institute of Photoelectronic Thin Film Devices and Technology Key Laboratory of Photoelectronic Thin Film Devices and Technology of TianjinMinistry of Education Engineering Research Center of Thin Film Photoelectronic TechnologyRenewable Energy Conversion and Storage CenterNankai UniversityTianjin 300350China

Ammonia synthesis by electrocatalytic nitrogen reduction reaction(NRR)is considered as a promising alternative to the Haber−Bosch ***,due to the extremely low ammonia yield and easily accessible extraneous contamination in the laboratory,NRR study always suffers from fluctuation and *** and eliminating all kinds of possible extraneous contamination is crucial to evaluate the performance of electrocatalytic ammonia synthesis *** this work,we systematically explored two factors that affect NRR results but are easy to be ignored:the selection of membrane for NRR and the unconscious N-source in NRR *** series of experiments,we proposed a low-cost and almost pollution-free Celgard 3501 membrane as the separator for NRR to avoid the adsorption and release of ammonia by the *** addition,we proposed a pre-reduction strategy to remove residual or adsorbed NOx contaminants in *** two solutions will help the community to evaluate the NRR activity more accurately.

关键词： Electrocatalysis Nitrogen reduction reaction Nafion membrane Nitrate impurity Pre-reduction

S-scheme photocatalyst Bi2O3/TiO2 nanofiber with improved photocatalytic performance

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第17期52卷 145-151页

作者： Rongan He Haijuan liu huimin liu Difa Xu liuyang Zhang Hunan Province Key Laboratory of Applied Environmental Photocatalysis Changsha UniversityChangsha 410022China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

In this study,a hierarchical Bi2O3/TiO2 fibrous composite was in-situ fabricated on an electrospun TiO2 nanofiber at ambient *** the Bi2O3/TiO2 composite,S-scheme electron migration occurred between Bi2O3 and *** the photocatalytic degradation of phenol under simulated sunlight,the asprepared Bi2O3/TiO2 nanofibers considerably outperformed Bi2O3 nanoparticles and TiO2 *** improvement is contributed by maintaining and effectively utilizing the useful carriers and consuming the useless holes and electrons,realized by the S-scheme heterojunction and hierarchical *** study also provides an alternative design fashion for photocatalysts.

关键词： Electrospinning Bismuth Fiber In-situ synthesis

Characterizing the spatial and temporal variation of the land surface temperature hotspots in Wuhan from a local scale

在线全文

学校读者我要写书评

暂无评论

Geo-Spatial Information Science 2020年第4期23卷 327-340页

作者： Chen Yang Qingming Zhan Sihang Gao huimin liu School of Urban Design Wuhan UniversityWuhanChina Institute of Space and Earth Information Science The Chinese University of Hong KongHong KongChina Collaborative Innovation Center of Geospatial Technology WuhanChina

Land Surface Temperature(LST)derived from space-borne Thermal-infrared(TIR)sensors is a key parameter of urban climate *** studies are inefficient to capture the spatial and temporal variations of LST for only one snapshot adopted at one *** on the characterization of the spatial and temporal of LST variations at local scales,the latent patterns,and morphological characteristics are extracted in this ***,sixteen MODerate-resolution Imaging Spectroradiometer(MODIS)eight-day synthesized LST products(MYD11A2)in 2002,2007,2012,and 2017 are ***,the non-parametric Multi-Task Gaussian Process Model(MTGP)is used to extract the smooth and continuous Latent LST(LLST)patterns using one LST subset and its temporally adjacent ***,the Multi-Scale Shape Index(MSSI)is then applied to quantify the morphological characteristics at the optimal ***,the LLST patterns and MSSI maps are clustered into multiple spatial *** specific clusters with the highest LLST and MSSI values are considered as local LLST *** Hotspots Weighted Mean Center(HSWMC)and standard deviation ellipse are adopted to further investigate the spatiotemporal change of hotspots orientation,direction,and *** revealed that Impervious Surfaces(IS)composition is the most significant external forcing of local LST *** configuration factors(e.g.,shape index,aggregation index)also have a noticeable local warming *** study represents a latent pattern and morphology-based framework for LST hotspots spatial and temporal variations characterization,catering to the zoning and grading strategies in urban planning.

关键词： Land Surface Temperature(LST) latent pattern morphology spatiotemporal variation Gaussian process

The pitfalls in electrocatalytic nitrogen reduction for ammonia synthesis

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

Journal of Energy Chemistry 2021年第10期30卷 149-154,I0005页

作者： huimin liu Néstor Guijarro Jingshan Luo Institute of Photoelectronic Thin Film Devices and Technology Solar Energy Research CenterKey Laboratory of Photoelectronic Thin Film Devices and Technology of TianjinMinistry of Education Engineering Research Center of Thin Film Photoelectronic TechnologyRenewable Energy Conversion and Storage CenterNankai UniversityTianjin 300350China Institute of Electrochemistry University of AlicanteAlicante E-03080Spain

Ammonia synthesis by electrocatalytic nitrogen reduction reaction(EC-NRR)has gained momentum in recent years fueled by its potential to operate at ambient conditions,unlike the highly energyintensive yet long-standing Haber-Bosch ***,the large disparity of the yields and Faradic efficiencies reported for EC-NRR raises serious concerns about the reliability of the experimental *** this perspective,we elaborate on the potential sources of error when assessing EC-NRR and update the testing protocols to circumvent them,and more importantly,we pose a general call for consensus on ammonia production analysis and reporting to lay the solid foundations that this burgeoning field requires to thrive.

关键词： Electrocatalytic nitrogen reduction Ammonia synthesis Pitfalls Standard protocols

Hollow PtNi alloy nanospheres with enhanced activity and methanol tolerance for the oxygen reduction reaction

在线全文

学校读者我要写书评

暂无评论

Nano Research 2016年第11期9卷 3494-3503页

作者： huimin liu Xinyu liu Yumei Li Yufeng Jia Yawen Tang Yu Chen Key Laboratory of Macromolecular Science of Shaanxi Province School of Materials Science and Engineering Shaanxi Normal University Ki'an 710062 China Jiangsu Key Laboratory of New Power Batteries Jiangsu Collaborotive Innovation Center of Biomedical Functional Moterials School of Chemistry and Materiols Science Nanjing Normal University Nonjing 210023 China

The development of active and methanol-tolerant cathode electrocatalysts for the oxygen reduction reaction （ORR） is extremely important for accelerating the commercial viability of direct methanol fuel cells （DMFCs）. In this work, we present an efficient and template-free route for facile synthesis of cyanide （CN^-）-functionalized PtNi hollow nanospheres （PtNi@CN HNSs） with a high alloying degree using a simple cyanogel reduction method at room temperature. The physical and electrocatalytic properties of the PtNi@CN HNSs were investigated by various physical and electrochemical techniques. The PtNi@CN HNSs exhibited significantly enhanced electrocatalytic activity, durability, and particular methanol tolerance for the ORR as compared to commercial Pt black, and thus they are promising cathode electrocatalysts for DMFCs.

关键词： cyanogel PtNi alloy chemical functionalization oxygen reduction reaction methanol tolerance

Formation Conditions and Sedimentary Model of Over-Flooding Lake Deltas within Continental Lake Basins: An Example from the Paleogene in the Jiyang Subbasin, Bohai Bay Basin

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

Acta Geologica Sinica(English Edition) 2015年第1期89卷 270-284页

作者： WANG Jian CAO Yingchang liu huimin GAO Yongjin School of Geosciences China University of Petroleum (East China) Post-doctoral Research Center of Geological Resources and Geological Engineering China University of Petroleum (East China) Institute of Geology Sinopec Shengli Oil Field Company

A large quantity of drilling core, paleontology, geochemistry and geophysics data revealed several features of the Jiyang subbasin during the deposition of the Ekl-ES4x members：（1） the paleotopography of the gentle slope belt had an extremely low gradient; （2） the paleoclimate frequently alternated between dry and wet periods in a generally arid setting; （3） there was strong weathering around the periphery of the basin; （4） the lake was very shallow; （5） the lake level frequently rose and fell; and （6） the sedimentary environment of the gentle slope belt was an over- flooding lake. All of these factors provided favorable geological conditions for the development of an over-flooding lake delta. The lithologies of the continental over-flooding lake delta deposits are complex and diverse. The compositional maturity is moderate to low, and the grain size distribution curves and sedimentary structures indicate the presence of both gravity and traction currents. The sedimentary microfacies associations consist of a combination of ordered superposition of flood channels, distributary channels and sheet sands. The delta exhibits a weak foreset seismic reflection. The over-flooding lake delta deposits are laterally extensive. The sandstone content is high, and the individual sandstone beds are thin. The flood channel and distributary channel deposits exhibit evidence of bifurcation and lateral migration. The distribution of the sandbodies and the oxidation color of the mudstones provide evidence of cyclic deposition. The paleoclimate was the dominant factor controlling the development of the over-flooding lake delta. Due to the frequently alternating wet and dry paleoclimates, the over-flooding lake delta is characterized by the development of a broad upper plain and a lower delta plain. The upper delta plain is characterized by flood channel deposits, whereas the lower delta plain is represented by distributary channel deposits. The transition zone is characterized by the

关键词： Jiyang subbasin continental basin over-flooding lake delta sedimentary model oil andgas exploration

Diagenetic Evolution and Formation Mechanisms of High-Quality Reservoirs under Multiple Diagenetic Environmental Constraints:An Example from the Paleogene Beach-Bar Sandstone Reservoirs in the Dongying Depression,Bohai Bay Basin

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2017年第1期91卷 232-248页

作者： WANG Jian CAO Yingchang SONG Guoqi liu huimin School of Geosciences China University of Petroleum(East China)Qingdao 266580ShandongChina Sinopec Shengli Oil Field Company Dongying 257000ShandongChina Institute of Geology Sinopec Shengli Oil Field CompanyDongying 257015ShandongChina

The diagenetic environment, diagenetic responses, diagenetic transformation model and formation mechanisms of high-quality reservoirs（beach-bar sandstones of the Paleogene fourth member） in the Dongying depression were studied through the analysis of fluid inclusions, thin section and burial evolution history. The diagenetic fluids of the beach-bar sandstone reservoirs evolved from early high salinity and weak alkalinity to low salinity and strong acidity, late high salinity and strong alkalinity and late low salinity and acidity, which were accompanied by two stages of oil and gas filling. The fluids at the margins of the sandbodies were continuously highly saline and strongly alkaline. The western（eastern） reservoirs experienced early open（closed）, middle open, and late closed diagenetic environments during their burial history. The flow pattern was characterized by upwelling during the majority of the diagenesis（in the east, a non-circulating pattern transitioned into an upwelling current）. Due to the evolution of the diagenetic fluids, the diagenetic sequence of the beach-bar reservoirs was as follows： early weak carbonate cementation; feldspar and carbonate cement dissolution and authigenic quartz cementation; late carbonate and anhydrite cementation, authigenic feldspar cementation, and late quartz dissolution; and late carbonate cementation, feldspar dissolution, and authigenic quartz cementation. The diagenetic strength during these stages varied or was absent altogether in different parts of the reservoirs. Due to the closeness of the diagenetic environment and the flow pattern of the diagenetic fluids, the diagenetic products are variably distributed in the sandstones interbedded with mudstones and in the fault blocks. The evolution of multiple alternating alkaline and acidic diagenetic environments controlled the distribution patterns of the reservoir diagenesis and reservoir space, and the reservoir quality index, RQI, increased gradually from the margin

关键词： diagenetic environment diagenesis diagenetic fluids beach-bar high quality reservoir Dongying depression

Comparison of continuous homogenous azeotropic and pressure-swing distillation for a minimum azeotropic system ethyl acetate/nhexane separation

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10期26卷 2023-2033页

作者： Liping Lü Lin Zhu huimin liu Hang Li Shirui Sun Key Laboratory of Gas Process Engineering School of Chemistry and Chemical Engineering Southwest Petroleum University School of Chemistry and Chemical Engineering Yangtze Normal University

Continuous homogenous azeotropic distillation(CHAD) and pressure-swing distillation(PSD) are explored to separate a minimum-boiling azeotropic system of ethyl acetate and n-hexane. The CHAD process with acetone as the entrainer and the PSD process with the pressures of 0.1 MPa and 0.6 MPa in two columns are designed and simulated by Aspen Plus. The operating conditions of the two processes are optimized via a sequential modular approach to obtain the minimum total annual cost(TAC). The computational results show that the partially heat integrated pressure-swing distillation(HIPSD) has reduced in the energy cost and TAC by 40.79% and 35.94%, respectively, than the conventional PSD, and has more greatly reduced the energy cost and TAC by 62.61% and 49.26% respectively compared with the CHAD process. The comparison of CHAD process and partially HIPSD process illustrates that the partially HIPSD has more advantages in averting the product pollution, energy saving, and economy.

关键词： Continuous homogenous azeotropic distillation Pressure-swing distillation Ethyl acetate/n-hexane Azeotrope