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Robust interface and excellent as-built mechanical properties of Ti–6Al–4V fabricated through laser-aided additive manufacturing with powder and wire

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 154-168页

作者： Fei w.ng Guijun Bi Youxiang Chew Shang Sui Chaolin Tan Zhenglin Du Jinlong Su Fern Lan ng Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong Engineering&Technology Research Center for Superhard MaterialSchool of Materials Science and EngineeringShandong UniversityJinan 250061China Institute of Intelligent Manufacturing Guangdong Academy of SciencesGuangzhou 510095China Singapore Institute of Manufacturing Technology 5 Cleantech Loop636732Singapore

The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),*** the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire *** characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α *** mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and *** mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat *** fracture occurred within the interfacial area,further suggesting the robust *** findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.

关键词： laser-aided additive manufacturing powder deposition wire deposition interfacial characteristic mechanical behavior

Perspective on the relationship between microbiota dysbiosis and neuroinflammation:probiotics as a treatment option

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Neural Regeneration Research 2022年第9期17卷 1969-1970页

作者： Chiao w.ng Zahoor A.Shah Department of Medicinal and Biological Chemistry College of Pharmacy and Pharmaceutical SciencesUniversity of ToledoToledoOHUSA

Introduction:In the 1680s,Antonie van Leewenhoek was the first to observe the differences in the human gut microbiome versus the oral cavity diversity,and it led to the birth of a new term,“microbiota”.Later,the link between the brain and the gut was observed to be facilitated by the vagus nerve,allow.ng for neurotransmitters secreted in the gastrointestinal tract to travel to the brain,directing signals that influence brain *** gut microbiome is linked to various diseases ranging from autism spectrum disorder to Parkinson’s disease(PD)and is projected to be the new“disease-causing mechanism,”calling for interventions that can modulate gut microbiota and mitigate brain *** dysbiosis is observed before and after the onset of various neurodegenerative diseases and often manifests itself into gut-related diseases such as.

关键词： inflammation diseases treatment

Calibration of the Solar X-ray Detector on-board the Macao Science Satellite-1B for Soft X-ray Detection

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Science China Earth Sciences 2025年第1期68卷 11-26页

作者： Man-Hei ng Xiaoping ZHAng Jianwu CHEN Yongqiang SHI Fuchang ZUO wenxi PEng weichun FU Liansheng LI Pengwei LUO Chi-Long TAng Guozheng ZHAng Zhiwu MEI Li w.ng Cunhui LI Jiaming OU Yanyan XU State Key Laboratory of Lunar and Planetary Sciences Macau University of Science and Technology China National Space Administration (CNSA) Macau Center for Space Exploration and Science Space Optoelectronic Measurement and Perception Laboratory Beijing Institute of Control Engineering Institute of High Energy Physics Chinese Academy of Sciences Science and Technology on Vacuum Technology and Physics Laboratory Lanzhou Institute of Physics

The Solar X-ray Detector(SXD) on-board the Macao Science Satellite-1B(MSS-1B) was successfully launched via the Chinese Long March-2C rocket on 21 May 2023, and commenced operations in early June of the same year. The MSS-1B/Soft X-ray Detection Units(SXDUs) employ two silicon drift detectors(SDDs), providing a wide range of energy spectra spanning from 0.7 to 24 keV. Notably, the SXDUs deliver a high-resolution capability of 0.14 keV@5.9 keV and operate with a time cadence of 1 second. Here, we perform thorough calibrations of the MSS-1B/SXDUs, employing a combination of ground experiments and simulations. In addition, quantitative analysis comparing the flux measurements obtained by the MSS-1B/SXDUs to the data collected by the Geostationary Operational Environmental Satellite(GOES), provides compelling evidence of their consistency. Furthermore, the preliminary spectral analysis results showcase the robustness and expected performance of the MSS-1B/SXDUs, unlocking their potential for facilitating the study of dynamic evolution of solar flares. Moreover, the innovative MSS-1B/Solar X-ray Detector facilitates concurrent observations of solar soft and hard X-rays, thereby making valuable contributions to the advancements in solar research.

关键词： Macao Science Satellite-1B (MSS-1B) Calibration Solar X-Ray Detector Spectrometer Soft X-rays Solar flares Solar abundances

Physical scientists research biomedicine: a call for caution

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Chinese Journal of Cancer Research 2015年第1期27卷 94-95页

作者： Yì-Xiáng J.w.ng Department of Imaging and Interventional Radiology Faculty of Medicine The Chinese University of Hong Kong Prince of Wales Hospital

It is noticeable that nowadays there are more and more scientists with physical science or engineering background working on or started to work on biomedical projects, but rarely vice versa. This reflects the multi-discipline nature of some projects, however, also at least partially can be explained that biomedical research is seen as trendy, fundable, and likely to get more citations and with results more publishable in high impact journals （1,2）. It is also apparent with some publications and lectures that not all these physical scientists/engineers are well-prepared to work on projects which do not align with their own expertise. Some studies are against very basic principles of pharmacology or biology, while others try to solve medical problems which do not exist clinically. I reviewed a number of submissions including a few from prestigious American universities to Nature journals which made no sense with the study design. Much of manpower and financial resource are being wasteful spent. There are also examples of clinical trials which were ill-planned right from the start and in the end only causing much inconvenience to patients to say at the least. In addition, ample examples exist where experienced physical scientists worked with inexperienced medical scientists and resulted in avoidable failures.

关键词： a call for caution very Physical scientists research biomedicine

Effect of suction change on water content and total volume of an expansive clay

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第5期8卷 699-706页

作者： ZHAN Liang-tong CHEN Ping ng C.w.w. ~ Department of Civil Engineering Zhejiang University Hangzhou 310027 China Department of Civil Engineering Zhejiang Sci- Tech University Hangzhou 310018 China Department of Civil Engineering Hong Kong University of Science and Technology Hong Kong China

A laboratory study was carried out on both natural and compacted specimens to investigate the complex soil-water interaction in an unsaturated expansive clay. The laboratory study includes the measurement of soil-water characteristic curves, 1D free swelling tests, measurement of swelling pressure and shrinkage tests. The test results revealed that the air-entry value of the natural specimen was quite low due to cracks and fissures present. The hydraulic hysteresis of the natural specimen was relatively insignificant as compared with the compacted specimen. within a suction range 0 to 500 kPa, a bilinear relationship between free swelling strain (or swelling pressure) and initial soil suction was observed for both the natural and compacted specimens. As a result of over-consolidation and secondary structures such as cementation and cracks, the natural specimens exhibited significant lower swelling (or swelling pressure) than the compacted specimen. The change of matric suction exerts a more significant effect on the water phase than on the soil skeleton for this expansive clay.

关键词： Expansive soil water content Suction Swelling Shrinkage

Interaction of oblique waves with an array of long horizontal circular cylinders

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Science China(Technological Sciences) 2007年第4期50卷 490-509页

作者： ng Chiu-On Department of Mechanical Engineering the University of Hong Kong Pokfulam Road Hong Kong China

The scattering and radiations of linear oblique waves by multiple long horizontal circular cylinders submerged in water of finite depth are investigated using the multipole expansion method. Analytical expressions for the diffracted and radiated potentials are given as a linear combination of infinite multipoles. The unknown coefficients in the expressions are determined by using the addition theorem of the Bessel function and the cylinder boundary conditions. Also analytical expressions for wave forces, hydrodynamic coefficients and reflection and transmission coeffi-cients are derived. The present analytical solution is verified through the boundary element method and applied to investigate three different cases of the interaction of oblique waves with multiple submerged horizontal circular cylinders. The results show that the number of cylinders, the arrangement and spacing between cylinders play an important role in wave forces, hydrodynamic coefficients and reflection and transmission coefficients. Some interesting and important phenomena are ob-served in numerical experiments.

关键词： scattering and radiation water waves analytical technique hydrodynamic characteristics

Nonlinear dynamical characteristics of bed load motion

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Science China(Technological Sciences) 2006年第3期49卷 365-384页

作者： Chiu-On ng Department of Mechanical Engineering the University of Hong Kong Hong Kong China

Bed forms of various kinds that evolve naturally on the bottom of sandy coasts and rivers are a result of the kinematics of bed load transport. Based on the group motion of particles in the bed load within the bottom layer, a study on the nonlinear dy- namics of bed load transport is presented in this paper. It is found that some development stages, such as the initiation, the equilibrium sediment transport, and the transition from a smooth bed to sand dunes, can be accounted for by different states in the nonlinear sys- tem of the bed load transport. It is verified by comparison with experimental data reported by Laboratoire Nationae D’Hydraulique, Chatou, France, that the evolution from a smooth bed to sand dunes is determined by mutation in the bed load transport. This paper pre- sents results that may offer theoretical explanations to the experimental observations. It is also an attempt to apply the state-of-the-art nonlinear science to the classical sediment transport mechanics.

关键词： bed load, bed form, nonlinear dynamics.

A review of Leishmaniasis in Eastern Africa

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Journal of Nanjing Medical University 2009年第2期23卷 79-86页

作者： Peter K.ngure Albert Kimutai Zipporah w.ng'ang'a Geoffrey Rukunga willy K.Tonui Science Department Daystar University Kenyatta University Jomo Kenyatta University of Agriculture and Technology Kenya Medical Research Institute

The review presents the epidemiology of leishmaniasis in the Eastern Africa region. we searched PUB MED and MEDLINE with several key words-namely,＂leishmaniasis＇;＂cutaneous＇,＂diffuse cutaneous ＂,＂ mucosal＂, and ＂visceral leishmaniasis＂; ＂kala azar＂ and ＂post kala azar dermal leishmaniasis＂ -for recent clinical and basic science articles related to leishmaniasis in countries in the Eastern Africa region. Poverty, wars, conflicts and migration have significantly aggravated leishmaniases in Eastern Africa. Of particular concern is the increasing incidence of Leishmania-HIV co-infection in Ethiopia where 20-40% of the persons affected by visceral leishmaniasis are HIV-co-infected. Sudan has the highest prevalence rate of post kala-azar dermal leishmaniasis（PKDL） in the world, a skin complication of visceral leishmaniasis（VL） that mainly afflicts children below age ten. In view of its spread to previously non-endemic areas and an increase in imported cases, leishmaniasis in Eastern Africa should be considered a health emergency.

关键词： Leishmaniasis cutaneous visceral Eastern Africa

Effects of Risk Perception on Disaster Preparedness Toward Typhoons:An Application of the Extended Theory of Planned Behavior

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International Journal of Disaster Risk Science 2022年第1期13卷 100-113页

作者： Sai Leung ng Graduate Institute of Earth Science Chinese Culture UniversityTaipei 11114TaiwanChina

This study adopted an extended theory of planned behavior to understand how risk perception affected disaster preparedness *** intercept survey(N=286)was conducted at a typhoon-prone district of Hong Kong,China in 2019,then the data were analyzed using structural equation *** results indicated that risk perception and intention of preparedness were predictors of disaster preparedness *** perception significantly affected intention of preparedness and the effect was partially mediated by subjective *** perception also significantly affected attitude and perceived behavioral control,but attitude and perceived behavioral control were not significantly correlated with intention of *** only may this study supplement the existing literature of disaster preparedness toward typhoons,but also it provides insights for the planning and management of natural hazards and disaster risk reduction in Hong Kong,China.

关键词： Disaster preparedness behaviour Hong Kong,China Risk perception Structural equation modelling Theory of planned behaviour Typhoon preparedness