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Experimental and numerical investigation of Weibullian behavior of grain crushing strength

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Geoscience Frontiers 2020年第2期11卷 401-411页

作者： Quanshui Huang Wei Zhou Gang ma Tang-Tat ng Kun Xu State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering Wuhan UniversityMinistry of EducationWuhan 430072China University of New Mexico AlbuquerqueNM87131USA

The Weibullian behavior of single grain crushing strength was investigated experimentally and numerically with the aim of enhancing the understanding of rock grain *** morphologies of pebble grains were obtained using white light 3D laser scanning and image processing.A grain shape library was constructed for grain shape analysis with different shape *** use of the shape library and grain stability analysis is discussed for a suggested procedure to rotate a grain to its most stable *** grain crushing tests were performed for 30 pebbles to obtain force-displacement curves and fracture *** grain was compressed diametrically between flat *** expected,the values of the stress at bulk fracture follow a Weibull distribution.A procedure for generating crushable agglomerates with realistic particle shapes was demonstrated,which was accomplished in the discrete element modeling(DEM)of the single grain crushing *** work presented here is novel in that both the heterogeneous micro-structures and randomly distributed flaws are *** DEM results demonstrate that the proposed modeling approach and calibrated parameters are reliable and can reflect the crushing behavior of rock ***,three parametric studies were presented evaluating the effects of micro-crack density,micro-crack disorder,and grain morphology on the Weibullian behavior of the crushing strength,none of which has previously been thoroughly *** three studies provide a deeper insight into the origin of the Weibullian behavior of single grain crushing strength.

关键词： Rock grain Grain crushing test Discrete element modeling 3D scanning technique Grain stability Weibullian behavior

Etiology,diagnosis, management and outcomes of epiphora referrals to an oculoplastic practice

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International Journal of Ophthalmology(English edition) 2016年第12期9卷 1751-1755页

作者： Guang-Lin Shen John D.ng Xiao-Ping ma Department of Ophthalmology Zhongshan Hospital of Fudan University Casey Eye Institute Oregon Health and Science University

AIM： To investigate the etiology, diagnosis, management and outcome of epiphora referrals to an oculoplastic ***： Retrospective chart review of patients referred for epiphora to an oculoplastic clinic between 2005 and 2009. Patient demographics, past history, ophthalmic examination, treatment and outcome were ***： There were 237 subjects with a primary complaint of epiphora. They included 130 （55%） females and 107 （45%） males with an average age of 55.9±25.9y. The most common cause of epiphora was lacrimal obstruction （46%）; followed by multifactorial epiphora （22%）, reflex tearing （22%） and eyelid malposition （11%）. Differences in prevalence of etiology were noted in terms of age and gender distribution. Of the 182 （77%） patients who returned for follow up, 41 （23%） reported a complete resolution and 102 （56%） reported a significant improvement in their ***： Epiphora is a common condition with many causes. A thorough history and examination are required to provide the appropriate treatment tailored to the underlying cause.

关键词： epiphora etiology lacrimal disease dry eye

Novel optical properties and induced magnetic moments in Ru-doped hybrid improper ferroelectric Ca3Ti2O7

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Journal of Advanced Ceramics 2021年第1期10卷 120-128页

作者： Xingxing WU Shouyu WAng Winnie WOng-ng Qiang GU Yao JIAng Chao WAng Shuang ma Weifang LIU Tianjin Key Laboratory of Low Dimensional materials Physics and Preparing Technology School of ScienceTianjin UniversityTianjin 300072China College of Physics and material Science Tianjin Normal UniversityTianjin 300074China materials Measurement Science Division National Institute of Standards and TechnologyGaithersburgMaryland 20899USA

Hybrid improper ferroelectric Ca3Ti2O7 and Ca3Tii ***7 ceramics were successfully synthesized by conventional solid-state reaction *** strongest diffraction peaks located around 2θ=33°shifted towards the lower angle region with Ru substitution,reflecting structure *** growth and higher oxygen vacancy concentration after doping resulted in a reduction in the coercive field about 20 kV/*** bandgap estimated by UV-vis diffuse reflectance(DR)spectrum and X-ray photoelectron spectroscopy(XPS)valence band spectra showed a decreasing trend due to the existence of impurity energy level upon Ru doping,which was consistent with the results of first-principles *** origin of the unexpected induced magnetic moments in Ru-dope Ca3Ti2O7 is also discussed.

关键词： oxides electronic materials optical properties X-ray diffraction defects lectronic structure ferroelectricity

A monolithic InP/SOI platform for integrated photonics

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Light(Science & Applications) 2021年第11期10卷 2143-2152页

作者： Zhao Yan Yu Han Liying Lin Ying Xue Chao ma Wai Kit ng Kam Sing Wong Kei may Lau Department of Electronic and Computer Engineering Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Department of Physics and William Mong Institute of Nano Science and Technology Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina

The deployment of photonic integrated circuits(PICs)necessitates an integration platform that is scalable,high-throughput,cost-effective,and *** we present a monolithic InP on SOI platform to synergize the advantages of two mainstream photonic integration platforms:Si photonics and InP *** monolithic InP/SOI platform is realized through the selective growth of both InP sub-micron wires and large dimension InP membranes on industry-standard(001)-oriented silicon-on-insulator(SOI)*** epitaxial InP is in-plane,dislocation-free,site-controlled,intimately positioned with the Si device layer,and placed right on top of the buried oxide layer to form“InP-on-insulator”.These attributes allow for the realization of various photonic functionalities using the epitaxial InP,with efficient light interfacing between the III-V devices and the Si-based *** exemplify the potential of this InP/SOI platform for integrated photonics through the demonstration of lasers with different cavity designs including subwavelength wires,square cavities,and *** results here mark a critical step forward towards fully-integrated Si-based PICs.

关键词： SOI monolithic integration

Topology modulation of tetraphenylethylene graphdiyne at a liquid-liquid interface

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Nano Research 2024年第6期17卷 4661-4667页

作者： Tingting Xu Pei Wen ng Shaofei Wu Danjun Fu Yunhan ma Yao Liu Lidao Li Xiaofei Zhang Jun Zhu Department of Chemistry National University of SingaporeSingapore 117543Singapore Institute of materials Research and Engineering(IMRE) Agency for ScienceTechnology and Research(A*STAR)Singapore 138634Singapore

Monomers with low symmetries can form different topological structures in the preparation of organic two-dimensional(2D)***,it remains challenging to modulate the topologies in practical *** theoretical insights into the formation energy of potential structural configurations,we report the topology modulation of a graphdiyne(GDY)derivative constructed from two-fold symmetric tetrakis(4-ethynylphenyl)ethene precursor by changing solvent combinations in a liquid-liquid interfacial *** aqueous-organic(water-dichloromethane)interface afforded GDY with a kagome topology while a rhombic topology was formed at an organic-organic(hexane-acetonitrile)interface.A comprehensive evaluation of their structures and optoelectronic properties was conducted through various characterization techniques and theoretical *** study provided new insights to modulate the topology of not only GDY but also other framework structures and obtain topologically pure materials in situations where different topologies are possible during practical synthesis.

关键词： graphdiyne derivative tetraphenylethylene topology modulation aggregation-induced emission(AIE)two-dimensional(2D)polymers interfacial synthesis

A major pathway for carbon and nitrogen losses-Gas emissions during storage of solid pig manure in China

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Journal of Integrative Agriculture 2019年第1期18卷 190-200页

作者： SHAN Nan LI Hu LI Jian-zheng Ee Ling ng ma Yan WAng Li-gang CHEN Qing College of Resources and Environmental Sciences China Agricultural University Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Faculty of Veterinary and Agricultural Sciences University of Melbourne

This study investigated the carbon(C) and nitrogen(N) gas emissions(N_2O,NH_3,CO_2 and CH_4) from solid pig manure management in *** emissions were quantified from static piles over 60 days during summer in China's Yangtze River Basin,using Drager-Tube and static chamber-gas chromatography *** emissions of NH_3 and N_2 O were observed at the early stage of storage,but high emission of CH_4 occured later during ***,62% of the total C in the original pile was lost; CO_2 and CH_4 emissions accounted for 57 and 0.2% of C lost *** the same time,41% of the total N in the original pile was lost; NH_3 and N_2 O emissions accounted for 15 and 0.3% of N lost *** volatilization of NH_3 during storage in summer was 4.56 g NH_3 per kg dry *** total greenhouse gas(GHG) emissions during storage accounted for 67.93 g CO_2 equivalent per kg dry weight; N_2 O and CH_4 contributed to 46 and 55% of total GHG emissions *** China's major role in pig production,further attention should given to pig manure management to mitigate its contribution to atmospheric pollution.

关键词： storage static pile ammonia nitrogen and carbon emissions greenhouse gas emission pig manure management

TWO MODELS FOR ROLL WAVES IN A MUD LAYER

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Journal of Hydrodynamics 1995年第2期7卷 1-16页

作者： Chiang C. Mei Ko-fei Liu Chiu-on ng(Department of Civil and Environmental Engineering massachusetts Institute of Technology,Cambridge,ma USA) massachusetts Inst of Technology Cambridge United States

As has been extensively reported by hydraulic engineers in China, the flow of hyperconcentrated fluid mud in rivers is often pulsating and appears as roll waves. We report here two theories for such pulsating flows besed on two constitutive laws: the power law and Bingham plastic law. In order to account for the nonlinear bores convective inertia is kept in the approximate long wave equations. Kar man's momentum integral method with an assumed velocity profile is then employed. Results of the linearized instability analyses are *** bores are obtained either as stationary wave solutions or as the long- time limit of unstable disturbances which are initially infinitesimal. Implications on ho scour is examined.

关键词： hyperconcentrated fluid mud pulsating flow power law Bingham plastic Law

Prostate health index can stratify patients with Prostate Imaging Reporting and Data System score 3 lesions on magnetic resonance imaging to reduce prostate biopsies

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Asian Journal of Andrology 2024年第1期26卷 20-24页

作者： John Shung-Lai Leung Wai-Kit ma Brian Sze-Ho Ho Stacia Tsun-Tsun Chun Rong Na Yongle Zhan Chi-Yuen ng Chi-Ho Ip Ada Tsui-Lin ng Yiu-Chung Lam Division of Urology Department of SurgeryQueen Mary HospitalUniversity of Hong KongHong KongChina Division of Urology Department of SurgeryPrincess Margaret HospitalHongKongChina

We aim to evaluate prostate health index as an additional risk-stratification tool in patients with Prostate Imaging Reporting and Data System score 3 lesions on multiparametric magnetic resonance *** with biochemical or clinical suspicion of having prostate cancer who underwent multiparametric magnetic resonance imaging in two tertiary centers(Queen mary Hospital and Princess margaret Hospital,Hong Kong,China)between January 2017 and June 2022 were ***-magnetic resonance imaging fusion biopsies were performed after prostate health index *** who only had Prostate Imaging Reporting and Data System score 3 lesions were further stratified into four prostate health index risk groups and the cancer detection rates were *** of the 747 patients,47.3%had Prostate Imaging Reporting and Data System score 3 lesions *** detection rate of clinically significant prostate cancer in this group was 15.0%.The cancer detection rates of clinically significant prostate cancer had statistically significant differences:5.3%in prostate health indexng the patients,26.9%could have avoided a biopsy with a prostate health indexng clinically significant prostate *** health index could be used as an additional risk stratification tool for patients with Prostate Imaging Reporting and Data System score 3 *** could be avoided in patients with low prostate health index,with a small risk of missing clinically significant prostate cancer.

关键词： biopsy fusion biopsy magnetic resonance imaging prostate cancer prostate health index

Progresses in pharmaceutical and surgical management of premature ejaculation

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Chinese Medical Journal 2019年第19期132卷 2362-2372页

作者： Qin-Bo Hu Dong Zhang Liang ma Derry Mingyao ng maria Haleem Qi ma Department of Reproductive Medicine Ningbo First HospitalThe Affiliated Hospital of Ningbo UniversityNingboZhejiang 315010China School of Medicine Ningbo UniversityNingboZhejiang 315000China Translational Research Laboratory for Urology The Key Laboratory of Ningbo CityNingbo First HospitalThe Affiliated Hospital of Ningbo UniversityNingboZhejiang 315010China Department of Urology Ningbo First HospitalThe Affiliated Hospital of Ningbo UniversityNingboZhejiang 315010China

Objective:Premature ejaculation(PE)is regarded as one of the most common male sexual *** review introduced several pharmaceutical and surgical methods for the management of *** definition,etiology,behavioral,and psychological therapy of PE were also *** sources:"Premature,""ejaculation,"or"sexual dysfuction"were used as the medical subject headings(MeSH)to obtain relevant articles before June 2019 on Pubmed,Google Scholar and *** articles used were written in English and several Chinese articles were also *** selection:Full-text articles of retrospective/prospective/randomized controlled trials were *** experiments and letters were ***:There are four PE sub-types:lifelong PE,acquired PE,natural variable PE,and subjective *** therapy,psychotherapy,medication,topical anesthetics,and surgery are currently used for the treatment of ***,all the above treatments have ***,novel ways should be investigated to more efficiently control ***:The pharmaceutical therapy that is currently being used in clinical practice for the management of PE is still the main choice globally due to its good *** may be a choice for patients who are resistant to ***,it should be performed cautiously.

关键词： Premature ejaculation Selective serotonin reuptake inhibitors Penile dorsal nerve neurotomy