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Collar performance in bridge pier scour with debris accumulation

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International Journal of Sediment Research 2022年第3期37卷 328-334页

作者： hossein Hamidifar Seyed Mohammad Bagher Shahabi-Haghighi yee Meng Chiew Water Engineering Department Shiraz University School of Civil and Environmental Engineering Nanyang Technological University

The mechanism of bridge pier scour becomes more complex in the presence of debris accumulation upstream of the pier. While using countermeasures may be effective in reducing scour, their efficacy could be undermined in such a situation. The current study investigates the effectiveness of using a collar in the presence of different types of floating debris accumulation in reducing scour around a cylindrical bridge pier with non-cohesive bed sediment. The experimental results reveal that using a collar can reduce the scour depth by up to 39% when compared to that without the collar in the absence of debris accumulation under the same flow conditions. Also, the collar’s efficiency is reduced by up to 25% when debris accumulation is present. however, depending on the relative size of the accumulated debris and collar, the effectiveness of collars may be increased as a pier-scour protection device. A new parameter,which is defined as the Debris Protrusion Ratio(DPR), is used to quantify the effect of debris layout size on scour depth. Moreover, a semi-empirical equation that may be used to predict the depth of the scour hole that forms around cylindrical collar-fitted piers with floating debris accumulation is proposed. The equation’s performance is evaluated using the available data in the literature. Based on the analysis, the current study shows that the accuracy of the proposed equation is satisfactory in predicting the maximum scour depth.

关键词： Bridge pier Scour Debris Collar Blockage

Self-assembly of single walled carbon nanotubes onto cotton to make conductive yarn

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Particuology 2012年第4期10卷 517-521页

作者： Wei Zhang yee Yuan Tan Chengwei Wu S.Ravi P.Silva Nanoelectronics Centre Advanced Technology InstituteUniversity of SurreyGuild fordSurrey GU27XHUnited Kingdom School of Materials Science and Engineering Dalian University of TechnologyDalian 116024China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China

A simple, economical and scalable technique is demonstrated to make conductive yarn. Single wailed carbon nanotubes （SWCNTs） are non-covalently functionalized with dye （Acid Red 91） and dispersed in water; while cotton yarn is treated with poly （ethylene imine）. When the resulting yarn is immersed in the SWCNT dispersion, SWCNTs self-assemble onto the yarn due to electrostatic forces between the functionalJzed nanotubes and yarn. Scanning electron microscopy, transmission electron microscopy and Raman spectroscopy indicate the assembly of carbon nanotubes. The SWCNT functionalized yarn exhibits reasonable electrical conduction behaviour and are then used to make chemiresistors. The electrical resistance of the chemiresistors used as sensors increases on exposure to ammonia gas, which can be explained in terms of electron transfer between gas molecules and SWCNTs.

关键词： Carbon nanotubesElectrical conductionSensorAmmonia

Design of an all-day electrical power generator based on thermoradiative devices

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Science China(Technological Sciences) 2021年第10期64卷 2166-2173页

作者： ZHANG Xin YANG GuoFeng YAN MengQi ANG Lay Kee ANG yee Sin CHEN JinCan School of Science Jiangnan UniversityWuxi 214122China Science Mathematics and TechnologySingapore University of Technology and DesignSingapore 487372Singapore Department of Physics Xiamen UniversityXiamen 361005China

Energy harvesting from sun and outer space using thermoradiative devices(TRDs),despite being promising renewable energy sources,is limited only to daytime and nighttime period,*** a system with 24-hour continuous electric power generation remains an open question thus ***,a TRD-based power generator that harvests solar energy via concentrated solar irradiation during daytime and via thermal infrared emission towards the outer space at nighttime is proposed,thus achieving the much sought-after 24-hour electrical power ***,a rigorous thermodynamical model is developed to investigate the all-day performance characteristics,parametric optimum design,and the role of various energy loss *** calculated results predict that the daytime TRD-based system yields a peak efficiency of 12.6%under 10 suns,thus sig-nificantly outperforming the state-of-art record-setting solar thermoelectric *** work reveals the potential of TRD towards 24-hour electricity generation and future renewable energy technology.

关键词： sustainable energy HgCdTe solar energy thermoradiative optimum design

Chromaticity of Complete 6-Partite Graphs with Certain Star or Matching Deleted Ⅱ

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Acta Mathematicae Applicatae Sinica 2013年第1期29卷 35-42页

作者： Roslan Hasni Ameen Shaman Ameen yee-hock Peng Hai-xing Zhao School of Mathematical Sciences Universiti Sains Malaysia Department of Mathematics and Institute for Mathematical Research University Putra Malaysia Department of Mathematics Qinghai Normal University

Let P（G, λ） be the chromatic polynomial of a graph G. Two graphs G and H are said to be chromatically equivalent, denoted G N H, if P（G, λ） = P（H, λ）. We write [G] = {HIH - G}. If [G] = {G}, then G is said to be chromatically unique. In this paper, we first characterize certain complete 6-partite graphs with 6rid＋1 vertices according to the number of 7-independent partitions of G. Using these results, we investigate the chromaticity of G with certain star or matching deleted. As a by-product, many new families of chromatically unique complete 6-partite graphs with certain star or matching deleted are obtained.

关键词： chromatic polynomial chromatically closed chromatic uniqueness

Effects of nano-sized aluminum on detonation characteristics and metal acceleration for RDX-based aluminized explosive

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Defence Technology（防务技术） 2021年第2期17卷 327-337页

作者： Dan-yang Liu Pin Zhao Serene Hay-yee Chan Huey hoon Hng Lang Chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Materials Science and Engineering Nanyang Technological University639798Singapore

Nano-sized aluminum(Nano-Al)powders hold promise in enhancing the total energy of explosives and the metal acceleration ability at the same ***,the near-detonation zone effects of reaction between Nano-Al with detonation products remain *** this study,the overall reaction process of 170 nm Al with RDX explosive and its effect on detonation characteristics,detonation reaction zone,and the metal acceleration ability were comprehensively investigated through a variety of experiments such as the detonation velocity test,detonation pressure test,explosive/window interface velocity test and confined plate push test using high-resolution laser *** fluoride(LiF),which has an inert behavior during the explosion,was used as a control to compare the contribution of the reaction of aluminum.A thermochemical approach that took into account the reactivity of aluminum and ensuing detonation products was adopted to calculate the additional energy release by *** the numerical simulations based on the calculated afterburn energy and experimental results,the parameters in the detonation equation of state describing the Nano-Al reaction characteristics were *** study found that when the 170 nm Al content is from 0%to 15%,every 5%increase of aluminum resulted in about a 1.3%decrease in detonation *** pressure gauge measurement showed no significant enhancement in detonation *** detonation reaction time and reaction zone length of RDX/Al/wax/80/15/5 explosive is 64 ns and 0.47 mm,which is respectively 14%and 8%higher than that of RDX/wax/95/5 explosive(57 ns and 0.39 mm).Explosive/window interface velocity curves show that 170 nm Al mainly reacted with the RDX detonation products after the detonation *** the recording time of about 10 ms throughout the plate push test duration,the maximum plate velocity and plate acceleration time accelerated by RDX/Al/wax/80/15/5 explosive is 12%and 2.9 ms higher

关键词： Nano-sized aluminum Detonation reaction zone Explosive metal acceleration Thermodynamic equilibrium calculation Laser interferometry

Relationships Between Vertical Jump Metrics and Sprint Performance,and Qualities that Distinguish Between Faster and Slower Sprinters

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Journal of Science in Sport and Exercise 2022年第2期4卷 135-144页

作者： Jad Adrian Washif Lian-yee Kok High-Performance Branch Sports Performance DivisionNational Sports Institute of MalaysiaNational Sports ComplexBukit Jalil57000 Kuala LumpurMalaysia Department of Sport Science Tunku Abdul Rahman University CollegeKuala LumpurMalaysia

Purpose This study aimed to investigate the relationships between vertical jump metrics and phases during a 60 m *** variances in strength qualities between sprinters of different ability levels were also *** Eighteen young male elite sprinters(age:18.1±1.3 years;stature:1.72±0.07 m;body mass:66.3±6.2 kg)were assessed for squat(SJ),countermovement(CMJ),drop(DJ),and standing long jumps,a maximal load back-squat,and a 60-m sprint from a *** relationships between sprint performances with all variables were analysed using correlation and multiple regression while discriminative parameters between fast(100 m time:~10.50 s)and slow(~11.00 s)sprint groups were assessed using independent *** Higher associations existed between vertical jumps and longer sprint distances,especially between SJ height and relative peak power with 10 m(r=−0.47 and−0.47,respectively),30 m(−0.71 and−0.74),60 m(−0.76 and−0.81),10-30 m(−0.80 and−0.86),and 30-60 m(−0.78 and−0.84)sprint ***,variables such as relative maximal-strength,relative SJ parameters(height,peak force,and peak power),relative CMJ peak power,and reactive strength index(DJ from 35 cm height)had significant discriminative ability and correlations(Pung male elite sprinters.

关键词： Acceleration Mechanical power Maximum strength Neuromuscular abilities Reactive strength Track and field

Reply to the commentary on “The efficiency of pathological response after preoperative transcatheter arterial chemoembolization for microvascular invasion and early tumor recurrence in hepatocellular carcinoma”

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Hepatobiliary Surgery and Nutrition 2023年第1期12卷 144-147页

作者： Yun Yang Weiping Zhou Wan yee Lau Eastern Hepatobiliary Surgery hospital ShanghaiChina Faculty of Medicine The Chinese University of Hong KongHong KongChina

We thank He et *** their interest in our recent article(1)and for their thoughtful *** first question raised by He et *** on the total number of patients in the PSM cohort in Table 1,which they considered *** this study,we first analyzed the incidences of MVI in the groups of patients with or without preoperative *** PSM,there were 737 patients who received preoperative TACE,and 1,233 patients who did not receive preoperative TACE.

关键词： preoperative invasion

Lateral displacement of soft ground under vacuum pressure and surcharge load

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Frontiers of Structural and Civil Engineering 2011年第2期5卷 239-248页

作者： Chin-yee ONG Jin-Chun CHAI Department of Civil Engineering and Architecture Saga UniversitySaga 840-8502Japan

Surcharge load(*** fill)will induce settlement and outward lateral displacement,while vacuum pressure will induce settlement and inward lateral displacement of a ***,combination of surcharge load and vacuum pressure can reduce or minimize the lateral *** large scale model(length:1.50 m,width:~0.62 m,height:0.85 m)tests and finite element analyses(FEA)were conducted to investigate the main influencing factors on lateral displacement of a soft clayey ground under the combination of vacuum pressure and surcharge *** the conditions investigated,the results indicate that the outward lateral displacement increases with the increase of the ratio of surcharge load to vacuum pressure(RL)and the loading rate of the surcharge load(LR).Also,it is shown that for a given RL and LR condition,lateral displacement reduces with the increase of the initial undrained shear strength(Su)of the *** predict the lateral displacement of a ground under the combination of surcharge load and vacuum pressure,the loading conditions in terms of RL and LR,and Su value of the ground have to be considered.

关键词： vacuum consolidation lateral displacement PVD finite element analysis surcharge load

Mutation of autophagy-related gene ATG7 increases the risk of severe disease in patients with non-alcoholic fatty liver disease

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Liver Research 2023年第4期7卷 365-366页

作者： Mary Miu yee Waye The Nethersole School of Nursing Croucher Laboratory for Human GenomicsThe Chinese University of Hong KongHong KongChina

Non-alcoholic fatty liver disease(NAFLD)is the most common chronic liver disease *** mechanism of NAFLD has been well studied and it has been previously reported that there are some predisposing genetic polymorphisms of NAFLD,e.g.,genes such as fat mass and obesity-associated(FTO)overexpression,leading to triglyceride accumulation,via upregulation of lipogenic genes has been reported.1 An earlier study of a 20-gene set published in 2014 has been correlated with NAFLD severity.2 Adiposity plays an important role in the amplification of the genetic risk of NAFLD-including three variants:PNPLA3,TM6SF2,and GCKR genes.

关键词： NAFLD liver patients