检索结果-南通市图书馆

Preparation of Novel Ultrathin Co doped MoS2 Nanosheets Piezocatalyst for Fast Simultaneous Decomposition of Cr(Ⅵ) and MB in Dark

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2019年第5期35卷 892-900页

作者： win Thi Yein WANG Qun JIAN Jiahuang LI Yang WU Xiaohong MIIT Key Laboratory of Critical Materials Technology for New energy Conversion and Storage School of Chemistry and Chemical Engineerings Harbin Institute of Technology Harbin 150001P.R.China

Ultrathin Co doped MoS2 nanosheets(NSs) with thickness of 3.2 nm was used to simultaneously decompose Cr(Ⅵ) and MB in dark through ultrasonic vibration-assisted piezocatalytic effect. The significantly enhanced piezocatalytic performance of Co doped MoS2 NSs was found in comparison to the pristine MoS2 NSs. The high piezocatalytic activity of Co doped MoS2 NSs may originate from the large amount of charge carriers due to Co doping. The efficient separation of electron-hole pairs under spontaneous polarization were also investigated ill detail, which is responsible for reduction of Cr(Ⅵ) and oxidation of methylene blue(MB). The active species trapping experiments demonstrate that e and ·O2^- are main active substances for Cr(Ⅵ) reduction, while h+,·OH, and ·O2^- participate in MB degradation.

关键词： Co doped MoS2 Piezocatalytic Organic dyes Cr(Ⅵ)

Building an e-Portfolio with a learning plan centric approach

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 C(Computers and electronics) 2012年第1期13卷 37-47页

作者： lam-for KWOK Ka-shing CHAN Department of Computer Science City University of Hong Kong

A portfolio records achievements in the personal growth process. A personal development e-Portfolio assists an individual in planning his/her development path and reflecting upon his/her own learning. In this article, we propose an approach to constructing a personal development portfolio. An abstract information model is presented to support such a portfolio. The information model is proposed based upon and according to IMS standards. The use of this approach is illustrated by way of a prototype e-Portfolio system. The usage scenario and limitations of such a portfolio are also discussed.

关键词： e-Portfolio educational technology system Lifelong learning

effect of extrusion ratio on the microstructure and texture evolution of AZ31 magnesium alloy by the staggered extrusion(Se)

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2020年第4期8卷 1304-1313页

作者： Yan-peng Wang Feng Li Ye Wang Xue-wen Li Wen-win Fang School of Materials Science and engineering Harbin University of Science and TechnologyNo.4Lin Yuan StreetXiang FangHarbinHeilongjiang 150040China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China

There are many problems with the conventional processes of magnesium alloy bending products,such as long processes and difficulty in controlling the product *** paper provides a staggered extrusion(Se)process to solve the above manufacturing *** effects of different extrusion ratios(λ)on the AZ31 magnesium alloy bending products prepared by the Se process was investigated in this *** results show that the bending radii of the AZ31 Mg bending products increase with the increase ofλat the same staggered distance(h=16 mm).When A is in creased from 11.11 to 44.44,the average bending radius of bending products is decreased from 14.7 mm to 9 mm,and the average grain size is decreased by 59.43%.After the Se process,the extruded fiber texture of the AZ31 Mg bending products is obvious,and the deformed texture is a mixed texture of{0001}(10-10)deformation texture and{10-11}(11-20)recrystallization *** results of XRD and eBSD showed that pyramidal slip is an important mode of crystal slip systems in AZ31 magnesium alloys during the Se *** provided a scientific basis for forming AZ31 Mg alloy bending products with excellent microstructure by the Se process.

关键词： Magnesium alloy Staggered extrusion(Se) Bending behavior Texture Slip

energy-efficient Approaches for a Machine Tool Building in a University through Field Measurement and energy Modelling

在线全文

学校读者我要写书评

暂无评论

energy engineering 2023年第6期120卷 1387-1399页

作者： Kusnandar win-Jet Luo Indra Permana Fu-Jen Wang Gantulga Bayarkhuu Graduate Institute of Precision Manufacturing National Chin-Yi University of TechnologyTaichungTaiwanChina Department of Refrigeration Air Conditioning and Energy EngineeringNational Chin-Yi University of TechnologyTaichungTaiwanChina

The heating,ventilating,and air conditioning(HVAC)system consumes nearly 50%of the building’s energy,especially in Taiwan with a hot and humid *** to the challenges in obtaining energy sources and the negative impacts of excessive energy use on the environment,it is essential to employ an energy-efficient HVAC *** study conducted the machine tools building in a *** field measurement was carried out,and the data were used to conduct energymodelling with energyPlus(eP)in order to discover some improvements in energy-efficient *** validation between fieldmeasurement and energymodelling was performed,and the error rate was less than 10%.The following strategies were proposed in this study based on several energy-efficient approaches,including room temperature settings,chilled water supply temperature settings,chiller coefficient of performance(COP),shading,and building ***-efficient approaches have been evaluated and could reduce energy consumption *** results reveal that the proposed energy-efficient approaches of room temperature settings(3.8%),chilled water supply temperature settings(2.1%),chiller COP(5.9%),using shading(9.1%),and building location(3.0%),respectively,could reduce energy *** analysis discovered that using a well-performing HVAC system and building shading were effective in lowering the amount of energy used,and the energy modelling method could be an effective and satisfactory tool in determining potential energy savings.

关键词： energy-efficient energy modelling field measurement BeMS machine tools building

Investigation of the hydrodynamic behavior of diatom aggregates using particle image velocimetry

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 environmental Sciences 2012年第7期24卷 1157-1164页

作者： Feng Xiao Xiaoyan Li Kitming lam Dongsheng Wang State Key Laboratory of environmental Aquatic Chemistry Research Center for Eco-Environrnental SciencesChinese Academy of SciencesBeijing 100085China environmental engineering Research Centre Department of Civil EngineeringUniversity of Hong KongHong KongChina

The hydrodynamic behavior of diatom aggregates has a significant influence on the interactions and flocculation kinetics of algae. However, characterization of the hydrodynamics of diatoms and diatom aggregates in water is rather difficult. In this laboratory study, an advanced visualization technique in particle image velocimetry （PIV） was employed to investigate the hydrodynamic properties of settling diatom aggregates. The experiments were conducted in a settling column filled with a suspension of fluorescent polymeric beads as seed tracers. A laser light sheet was generated by the PIV setup to illuminate a thin vertical planar region in the settling column, while the motions of particles were recorded by a high speed charge-coupled device （CCD） camera. This technique was able to capture the trajectories of the tracers when a diatom aggregate settled through the tracer suspension. The PIV results indicated directly the curvilinear feature of the streamlines around diatom aggregates. The rectilinear collision model largely overestimated the collision areas of the settling particles. Algae aggregates appeared to be highly porous and fractal, which allowed streamlines to penetrate into the aggregate interior. The diatom aggregates have a fluid collection efficiency of 10%-40%. The permeable feature of aggregates can significantly enhance the collisions and flocculation between the aggregates and other small particles including algal cells in water.

关键词： diatom aggregate fluid collection efficiency fractal particle image velocimetry

Finite element implementation of coupled hydro-mechanical modeling of transversely isotropic porous media in ***

在线全文

学校读者我要写书评

暂无评论

International Journal of Modeling, Simulation, and Scientific Computing 2021年第1期12卷 173-184页

作者： Hong-lam Dang Duc-Phi Do Faculty of Civil engineering University of Transport and Communications No.3 Cau Giay HanoiVietnam lam´e Laboratory F-45072University of Orl´eans University of ToursINSA CVLOrl´eansFrance

In geotechnical engineering,modeling geo-structures is challenging,particularly in cases where the interaction between the structures and soil or rock is *** wellknown commercial modeling software is based on homogenous and isotropic ***,soil and rock are often modeled in heterogeneous and anisotropic media because of the inherent anisotropy of sedimentary rock masses and their stratified *** recent decades,coupled hydro-mechanical(HM)interactions in isotropic porous media have been studied;however,the behavior of transversely isotropic porous media is rarely *** addition,it is difficult for commercial software such as Plaxis and Flac3D to express complex rock formation where the anisotropy of the material and the associated cracks and fractures could be assembled into a single *** this study,a finite element implementation using Differential equation Analysis Library(***),an open-source library of finite element codes,was developed to model the fully coupled HM behavior of transversely isotropic porous *** proposed implementation can be applied to both isotropic and transversely isotropic porous media based on Biot’s *** developed code can be used to model poroelastic media with(1)equations of linear elasticity for the solid matrix and(2)diffusion equations for fluid flow based on mass and linear-momentum conservation *** verified the performance and accuracy of the code through two examples,i.e.,Mandel’s problem with a compared analytical solution and a tunnel excavation process with the Flac3D *** the basis of these numerical applications,we present the code to model the behavior of various geo-structures such as tunnels and pile–soil interactions with anisotropic materials.

关键词： Coupled hydro-mechanical modeling transversely isotropic porous media Biot’s theory finite element method DeAL.II

Characterizations of Sobolev spaces in euclidean spaces and Heisenberg groups

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2013年第4期28卷 531-547页

作者： CUI Xiao-yue lam Nguyen LU Guo-zhen Department of Mathematics Wayne State UniversityDetroit MI 48202 USA

Recently, many new features of Sobolev spaces W k,p ？RN ？ were studied in [4-6, 32]. This paper is devoted to giving a brief review of some known characterizations of Sobolev spaces in euclidean spaces and describing our recent study of new characterizations of Sobolev spaces on both Heisenberg groups and euclidean spaces obtained in [12] and [13] and outlining their proofs. Our results extend those characterizations of first order Sobolev spaces in [32] to the Heisenberg group setting. Moreover, our theorems also provide diff erent characterizations for the second order Sobolev spaces in euclidean spaces from those in [4, 5].

关键词： characterization of Sobelev spaces Folland-Stein space Poincar′e inequalities Heisenberg group second order Sobolev space

Visible light positioning: moving from 2D planes to 3D spaces [Invited]

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2019年第3期17卷 27-35页

作者： e.W.lam T.D.C.Little electrical and Computer engineering Department Boston University

The global navigation satellite system(GNSS) is a well-established outdoor positioning system with industry-wide impact due to the multifaceted applications of navigation, tracking, and automation. At large, however, is the indoor equivalent. One hierarchy of solutions, visible light positioning(VLP) with its promise of centimeter-scale accuracy and widespread coverage indoors, has emerged as a viable, easy to configure, and inexpensive candidate. We investigate how the state-of-the-art VLP systems fare against two hard barriers in indoor positioning: the need for high accuracy and the need to position in the threedimensions(3D). We find that although most schemes claim centimeter-level accuracy for some proposed space or plane, those accuracies do not translate into a realistic 3D space due to diminishing field-of-view in 3D and assumptions made on the operating space. We do find two favorable solutions in ray–surface positioning and gain differentials. Both schemes show good positioning errors, low-cost potential, and single-luminaire positioning functionality.

关键词： Visible light positioning moving from 2D planes to 3D spaces [Invited]

Responses in gas exchange and water status between drought-tolerant and-susceptible soybean genotypes with ABA application

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2015年第6期3卷 500-506页

作者： Md.Mokter Hossain Hon-Ming lam Jianhua Zhang School of Life Sciences and Center for Soybean Research of the State Key Laboratory of Agrobiotechnology The Chinese University of Hong Kong

The purpose of this study was to investigate the physiological responses of drought-tolerant and drought-susceptible soybean genotypes to exogenous abscisic acid(ABA) application during progressive soil drying at seedling stages. Five-day old soybean seedlings were transplanted into PVC tubes filled with soil mixture. Seedlings were watered daily with similar water volumes until second trifoliate leaves emerged, and thereafter soil drying with or without exogenous ABA application was imposed. Half of the seedlings of each genotype were left for regular watering as control plants. Soil water status declined significantly over seven days of withholding water supply for both genotypes. Leaf expansion rate, stomatal conductance(g_s), leaf water potential(ψ_w), and relative water content of leaves(%RWC) declined significantly under soil drying as well as soil drying with ABA application, compared to their values for well-watered soybean genotypes. However, a drought-tolerant genotype(C12) responded more rapidly than a drought-susceptible genotype(C08) after imposition of soil drying and soil drying with exogenous ABA. In addition, application of exogenous ABA to water-restricted soybeans resulted in higher %RWC and ψwin the drought-tolerant than in the drought-susceptible genotype. Compared to the drought-susceptible genotype, the drought-tolerant genotype was more responsive to exogenous ABA application, resulting in a higher root-to-shoot ratio.

关键词： Drought stress exogenous ABA Leaf relative water content Stomatal conductance Soybean genotypes