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Dehydration of sugars to 5-hydroxymethylfurfural and non-stoichiometric formic and levulinic acids over mesoporous Ta and Ta-W oxide solid acid catalysts

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chinese Journal of Catalysis 2020年第8期41卷 1248-1260页

作者： Bin Guo Lulu He Gangfeng Tang Li Zhang Lin Ye Bin Yue Shik chi Edman tsang Heyong He Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Collaborative Innovation Center of Chemistry for Energy MaterialsDepartment of ChemistryFudan UniversityShanghai 200433China Wolfson Catalysis Centre Department of ChemistryUniversity of OxfordOxford OX13QRUK

A series of mesoporous Ta and Ta-W oxides have been prepared and employed as solid acid catalysts for the dehydration of fructose and glucose to 5-hydroxymethylfurfural(HMF).Solid state 31 P MAS NMR spectroscopic results using trimethylphosphine(TMP)as a probe molecule show that the acid strength and the ratio of Br?nsted to Lewis acid sites increase gradually with the addition of tungsten in tantalum *** is found that high sugar conversion and HMF selectivity are achieved over catalyst with relatively high ratios of Br?nsted to Lewis acid *** stoichiometric excess of formic acid relative to levulinic acid can be observed mainly because of direct decomposition of fructose over Lewis acid *** addition of 2-butanol leads to the increase of sugars conversion and the HMF selectivity,especially for the catalyst with high ratio of Br?nsted to Lewis acid *** them,Ta7W3 oxide catalyst shows 54%HMF selectivity and good reusability with the addition of 2-butanol by extracting HMF from aqueous phase and removing humins deposed on the surface of the catalyst.

关键词： Glucose Fructose HMF Solid acid Tantalum oxide Ta-W oxide

Stress analysis of the TMSR graphite component under irradiation conditions

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Nuclear Science and Techniques 2018年第12期29卷 21-29页

作者： Xiong Yang Yan-Tao Gao Yang Zhong Dong Ding Derek-Kwong-Lai tsang Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of chinese Academy of Science Beijing 100049China

TMSR uses nuclear graphite as a neutron moderator, a reflector, and the structural material, and utilizes molten salt as a coolant. When running normally, the graphite components are immersed in the molten ***, the nuclear graphite comes into direct contact with the molten salt, which infiltrates the open pores of the nuclear graphite. This infiltration may influence the stress analysis of the graphite component. In this study, a User Material subroutine was used to analyze the stress distribution of the graphite component, both with and without molten salt infiltration. Many influence factors were taken into consideration, such as the dose gradient, the shape of the permeation zone, and the permeation area. The results show that the dose gradient, shape, and area of the permeation zone all significantly influence the stress distribution. Furthermore, the results of the stress analysis indicate that for a regular graphite component with a square cross section, the peak maximum principal stress value occurs at the center of the cross section, and the symmetry of the maximum principal stress distributions was modified by quarter circle and half ellipse permeation zones.

关键词：石墨部件压力分析直接接触影响因素压力分布熔融浸透

从分配正义到关系正义——西方教育公平探讨的新视角

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清华大学教育研究 2009年第5期30卷 14-21页

作者：钟景迅曾荣光香港中文大学教育学院

罗尔斯的分配正义论提出后对西方学界的教育公平研究产生了巨大的影响,他的很多理论在上个世纪的西方教育实践领域内均有深刻体现。然而近些年来,一些政治哲学家却指出,社会公平的问题不应该只在分配层面上讨论,他们认为不公平和非正义... 详细信息

罗尔斯的分配正义论提出后对西方学界的教育公平研究产生了巨大的影响,他的很多理论在上个世纪的西方教育实践领域内均有深刻体现。然而近些年来,一些政治哲学家却指出,社会公平的问题不应该只在分配层面上讨论,他们认为不公平和非正义在分配领域之外的人际互动的社会关系层面上也有明显表现,这一派新兴的关系正义论的观点已经在关于教育公平的理论研究,及包括教育政策在内的公共政策领域引起了广泛的关注。

关键词：分配正义关系正义教育公平

A three-dimensional feature extraction-based method for coal cleat characterization using X-ray μCT and its application to a Bowen Basin coal specimen

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 153-166页

作者： Yulai Zhang Matthew tsang Mark Knackstedt Michael Turner Shane Latham Euan Macaulay Rhys Pitchers ARC Training Centre for M3D Innovation Research School of PhysicsAustralian National UniversityCanberraACT2601Australia Department of Materials Physics Research School of PhysicsAustralian National UniversityCanberraACT2601Australia Anglo American Steelmaking Coal BrisbaneQLD4000Australia SCT Operations Pty Ltd. WollongongNSW2500Australia

Cleats are the dominant micro-fracture network controlling the macro-mechanical behavior of *** understanding of the spatial characteristics of cleat networks is therefore important to the coal mining *** fracture networks(DFNs)are increasingly used in engineering analyses to spatially model fractures at various *** reliability of coal DFNs largely depends on the confidence in the input cleat *** of these parameters can be made from image-based three-dimensional(3D)characterization of coal cleats using X-ray micro-computed tomography(m CT).One key step in this process,after cleat extraction,is the separation of individual cleats,without which the cleats are a connected network and statistics for different cleat sets cannot be *** this paper,a feature extraction-based image processing method is introduced to identify and separate distinct cleat groups from 3D X-ray m CT ***(filters)representing explicit cleat features of coal are built and cleat separation is successfully achieved by convolutional operations on 3D coal *** new method is applied to a coal specimen with 80 mm in diameter and 100 mm in length acquired from an Anglo American Steelmaking Coal mine in the Bowen Basin,Queensland,*** is demonstrated that the new method produces reliable cleat separation capable of defining individual cleats and preserving 3D topology after ***-parallel fractures are also identified and separated,which has his-torically been challenging to delineate and rarely reported.A variety of cleat/fracture statistics is measured which not only can quantitatively characterize the cleat/fracture system but also can be used for DFN ***,variability and heterogeneity with respect to the core axis are *** heterogeneity is observed and suggests that the representative elementary volume(REV)of the cleat groups for engineering purposes may be a complex problem requ

关键词： Cleat separation Cleat statistics Feature extraction Discrete fracture network(DFN)modeling

Chemical characteristics of aerosols at coastal station in Hong Kong.Ⅱ. Environmental behavior of trace elements during the April 1995 to April 1996

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Journal of Environmental Sciences 2004年第2期16卷 212-221页

作者： K.S.Lam Z.L.Cheng S.C.Kot C.W.tsang Department of Civil and Structural Engineering the Hong Kong Polytechnic UniversityResearch Center for Eco-Environmental Sciences Chinese Academy of SciencesDepartment of Mechanical Engineering The Hong Kong University of Science & Technology Clear Water BayDepartment of Applied Biology and Chemical Technology the Hong Kong Polytechnic University Hung Hom Hong Kong ChinaBeijing 100085 ChinaHong Kong ChinaHung Hom Hong Kong China

An one-year of sampling aerosol program was carried out during the period of April 1995 to April 1996 at coastal region, Cape D′Aguilar, in Hong Kong. The trace element composition of aerosol particles(TSP and PM 10 ) were measured and analyzed by using the Instrumental Neutron Activation Analysis(INAA) and Inductive Couple Plasma-Mass Spectrometry(ICP-MS) techniques. The results showed that the polluted elements such as: V, Zn, As, Pb, Cd, Sb, I, Se, Bi, with high enrichment factor(E.F) values, are derived from anthropogenic sources, while Sc, Al, Fe, Mn, Sm, La, Sr are less than 10 in E.F, these elements are related the crust and soil. The concentration of the trace elements are present seasonal variation i.e. summer low and winter high, whereas the V or noncrustal V(V *) present summer high and winter low, this phenomenon might be explained by local or regional oil combustion sources. Use three type of elemental ratio, e.g. La/Sm, Mn */V * and Bi/Al indicate that both TSP and PM 10 of La/Sm ratios are mainly related to soil and dust, Mn */V * are probably represent fossil combustion and Bi/Al are possibly associated with refuse incineration, ferromanganese alloys and aluminum production. The varimax rotation factor analysis for trace elements was performed. By means of the absolute principal component analysis(APCA) and multiple regression, the contribution of trace elements to possible sources and overall means of trace elements were estimated. The results showed that the present station is impacted by the anthropogenic species, although the quantities are different during the summertime and wintertime.

关键词： TSP PM 10 trace elements enhancement factor element ratios seasonal variation factor analysis

High genetic diversity and strong differentiation in dramatically fluctuating populations of Zostera japonica(Zosteraceae):implication for conservation

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Journal of Plant Ecology 2018年第5期11卷 789-797页

作者： Kai Jiang Po-Keung Eric tsang Na-Na Xu Xiao-Yong Chen School of Ecological and Environmental Sciences Shanghai Key Lab of Urban Ecological Processes and Eco-RestorationEast China Normal UniversityShanghai 200241China Shanghai Chenshan Plant Science Research Center Chinese Academy of SciencesChenshan Botanical GardenShanghai 201602China Department of Science and Environmental Studies The Education University of Hong KongHong KongChina School of Fishery Zhejiang Ocean UniversityZhoushan 326022China

Aims Seagrasses provide a variety of ecosystem goods and services,but they are subjected to frequently anthropogenic *** this study,we genotyped samples collected from Zostera japonica mead-ows with dramatic fluctuations in the area in order to understand the distribution of genetic variation within and among *** We collected samples from eight extant populations along coastal areas of southern *** polymorphic microsatellites were adopted to genotype the *** of genetic diversity and differentiation were calculated with general *** Findings High levels of genetic diversity were found in the studied populations,suggesting that the effective population size has not decreased signifi-cantly,which was supported by no signs of recent *** genetic diversity reflects an important role of sexual seedling recruit-ment in *** *** found a significant relationship between genetic differentiation and the shortest sea surface distance of populations,suggesting that ocean currents play a critical role in shap-ing the genetic structure of *** *** soft-ware analysis clustered the eight populations into two groups:western and eastern populations separated by the Qiongzhou Strait/Leizhou Peninsula,hinting that there was very limited gene flow through the narrow strait in this marine *** populations had high contribu-tion diversity and,thus,high priority for in situ conservation.

关键词： Seagrass Zostera japonica Genetic diversity Genetic differentiation Microsatellites

Fundamentals and applications of photonic waveguides with bound states in the continuum

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Journal of Semiconductors 2023年第10期44卷 11-24页

作者： Zejie Yu He Gao Yi Wang Yue Yu Hon Ki tsang Xiankai Sun Daoxin Dai Centre for Optical and Electromagnetic Research State Key Laboratory for Modern Optical InstrumentationZhejiang Provincial Key Labora-tory for Sensing TechnologiesInternational Research Center for Advanced PhotonicsCollege of Optical Science and EngineeringZhejiang Uni-versityHangzhou 310058China Department of Electronic Engineering The Chinese University of Hong KongShatinNew TerritoriesHong Kong SARChina Jiaxing Key Laboratory of Photonic Sensing&Intelligent Imaging Jiaxing 314000China Intelligent Optics&Photonics Research Center Jiaxing Research Institute Zhejiang UniversityJiaxing 314000China Ningbo Research Institute Zhejiang UniversityNingbo 315100China

Photonic waveguides are the most fundamental element for photonic integrated circuits(PICs).Waveguide properties,such as propagation loss,modal areas,nonlinear coefficients,etc.,directly determine the functionalities and performance of ***,the emerging waveguides with bound states in the continuum(BICs)have opened new opportunities for PICs because of their special properties in resonance and ***,we review the recent progress of PICs composed of waveguides with ***,fundamentals including background physics and design rules of a BIC-based waveguide will be ***,two types of BIC-based waveguide structures,including shallowly etched dielectric and hybrid waveguides,will be ***,the challenges and opportunities of PICs with BICs will be discussed.

关键词： photonic waveguide bound states in the continuum integrated photonics

High-intensity focused ultrasound ablation:An effective bridging therapy for hepatocellular carcinoma patients

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World Journal of Gastroenterology 2013年第20期19卷 3083-3089页

作者： Tan To Cheung Sheung Tat Fan See ching Chan Kenneth SH Chok Ferdinand SK Chu Caroline R Jenkins Regina CL Lo James YY Fung Albert CY Chan William W Sharr Simon HY tsang wing chiu Dai Ronnie TP Poon Chung Mau Lo Department of Surgery the University of Hong Kong State Key Laboratory for Liver Research the University of Hong Kong Department of Diagnostic Radiology the University of Hong Kong Department of Anaesthesiology The University of Hong Kong Department of Pathology the University of Hong Kong Department of Medicine the University of Hong Kong

AIM:To analyze whether high-intensity focused ultrasound(HIFU) ablation is an effective bridging therapy for patients with hepatocellular carcinoma(HCC).METHODS:From January 2007 to December 2010,49 consecutive HCC patients were listed for liver transplantation(UCSF criteria).The median waiting time for transplantation was 9.5 ***-nine patients received transarterial chemoembolization(TACE) as a bringing therapy and 16 patients received no treatment before *** patients received HIFU ablation as a bridging *** five patients with the same tumor staging(within the UCSF criteria) who received HIFU ablation but not on the transplant list were included for *** were comparable in terms of child-Pugh and model for end-stage liver disease scores,tumor size and number,and cause of ***:The HIFU group and TACE group showed no difference in terms of tumor size and tumor *** patient in the HIFU group and no patient in the TACE group had gross *** median hospital stay was 1 d(range,1-21 d) in the TACE group and two days(range,1-9 d) in the HIFU group(P < 0.000).No HIFU-related complication *** the HIFU group,nine patients(90%) had complete response and one patient(10%) had partial response to the *** the TACE group,only one patient(3%) had response to the treatment while 14 patients(48%) had stable disease and 14 patients(48%) had progressive disease(P = 0.00).Seven patients in the TACE group and no patient in the HIFU group dropped out from the transplant waiting list(P = 0.559).CONCLUSION:HIFU ablation is safe and effective in the treatment of HCC for patients with advanced *** may reduce the drop-out rate of liver transplant candidate.

关键词： Ablation Bridging therapy Cirrhosis Hepatocellular carcinoma High-intensity focused ultrasound Liver transplant New technology

Three-dimensional electric field calculations for wire chamber using element refinement method in ANSYS

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Nuclear Science and Techniques 2018年第12期29卷 96-101页

作者： Yao-Feng Zhang J. Barney M. B. tsang Chun-Lei Zhang The Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875 China Beijing Radiation Center Beijing 100875 China National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy Michigan State University East Lansing MI 48824 USA

Finite element analysis(FEA) method was employed to perform three-dimensional(3D) electric field simulations for gas detectors with multiple wire electrodes.A new element refinement method developed for use in conjunction with the FEA program ANSYS allows successful meshing of the wires without physically inputting the wires in the chamber geometry. First, we demonstrate a model with only one wire, for which we calculate the potential distributions on the central plane and the end-cap region. The results are compared to the calculations obtained using GARFIELD, a two-dimensional program that uses the nearly exact boundary element method. Then we extend the method to same model, but with seven *** results suggest that the new method can be applied easily to the 3D electric field calculations for complicated gas detectors with many wires and complicated geometry such as multiwire proportional chambers and time projection chambers.

关键词：有限元素分析 ANSYS 电场计算精炼方法电线房间三维电场模拟