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Underground Space 2024年第2期15卷 44-58页

作者： Yadong Zhang Ron Chik-kwong Wong Jianfeng Chen Wei Su Department of Civil Engineering Schulich School of EngineeringUniversity of CalgaryCalgaryAB T2N 1N4Canada Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China

During pipe installation,compacting soil at pipe sides causes an initial pipe deformation which is known as the"peaking"***,in conventional pipe design codes,only pipe deformation caused by vertical overburden is considered while the"peaking"effect is *** this study,a full-scale test was conducted on a Grade X52 steel pipe with a diameter of 600 mm to investigate the impacts of both soil compaction and vertical overburden on pipe *** compaction and external load were found to elongate and shorten the vertical pipe diameter,***"peaking"effect was observed during the installation procedure accompanied by the highest pipe stress measured at the pipe ***,a two-dimensional finite element model was created and validated based on the calculated pipe stresses from the experimental study.A parametric study was performed thereafter to numerically study the impacts of soil water content,pipe wall thickness,compaction pressure,and lift thickness on pipe responses due to soil compaction and external *** increase in the"peaking"effect is observed with increasing soil water content and compaction pressure,while an increase in pipe wall thickness or lift thickness would cause a decrease in the"peaking"effect.

关键词： X52 steel Soil compaction External load Peaking effect Pipe deflection Soil arching

Effect of non-uniform swelling on coal multiphysics during gas injection: The triangle approach

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1362-1372页

作者： Yifan Huang Jishan Liu Yaoyao Zhao Derek Elsworth Yee-kwong Leong Department of Chemical Engineering School of EngineeringThe University of Western Australia35 Stirling HighwayWA 6009Australia State Key Laboratory of Coal Resources & Safe Mining China University of Mining& TechnologyBeijing100803China Department of Energy and Mineral Engineering G3 Centre and Energy InstituteThe Pennsylvania State UniversityUniversity ParkPA16802USA

In current dual porosity/permeability models,there exists a fundamental assumption that the adsorption-induced swelling is distributed uniformly within the representative elementary volume (REV),irrespective of its internal structures and transient ***,both internal structures and transient processes can lead to the non-uniform *** this study,we hypothesize that the non-uniform swelling is responsible for why coal permeability in experimental measurements is not only controlled by the effective stress but also is affected by the adsorption-induced *** propose a concept of the swelling triangle composed of swelling paths to characterize the evolution of the non-uniform swelling and serve as a core link in coupled multiphysics.A swelling path is determined by a dimensionless volumetric ratio and a dimensionless swelling *** swelling paths have the same start and end point,and each swelling path represents a unique swelling *** swelling path as the diagonal of the triangle represents the case of the uniform swelling while that as the two perpendicular boundaries represents the case of the localized *** paths of all intermediate cases populate inside the *** corresponding relations between the swelling path and the response of coal multiphysics are established by a non-uniform swelling *** define this method as the triangle approach and corresponding models as swelling path-based *** proposed concept and models are verified against a long-term experimental measurement of permeability and strains under constant effective *** results demonstrate that during gas injection,coal multiphysics responses have a close dependence on the swelling path,and that in both future experiments and field predictions,this dependence must be considered.

关键词： Transient process Heterogeneity Swelling triangle Swelling path Non-uniform swelling coefficient

Oxidative spirolactonisation for modular access of γ-spirolactones via a radical tandem annulation pathway

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Chinese Chemical Letters 2024年第10期35卷 249-252页

作者： Jindian Duan Xiaojuan Ding Pui Ying Choy Binyan Xu Luchao Li Hong Qin Zheng Fang Fuk Yee kwong Kai Guo College of Biotechnology and Pharmaceutical Engineering State Key Laboratory of Materials-Oriented Chemical EngineeringNanjing Tech UniversityNanjing 211816China Department of Chemistry and State Key Laboratory of Synthetic Chemistry The Chinese University of Hong KongHong KongChina

An oxidative annulation of 2-arylidene-1,3-indanediones with Meldrum's acid has been developed for the divergent syntheses of spirolactones with a spirocenter located at theγ-position with respect to the carbonyl *** heteroannulation protocol tolerates various functional groups and delivers moderate-to-good product ***,the reaction outcomes are exclusively controlled by the reaction oxidant/*** annulation strategy can also be executed in the flow system with decent product *** experiments revealed that the reaction proceeds via a radical tandem annulation pathway.

关键词： Spirolactonisation y-Spirolactones 2-Arylidene-1,3-indanediones Meldrum's acid Divergentsynthesis

Low phase noise K-band signal generation using polarization diverse single-soliton integrated microcombs

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Photonics Research 2024年第6期12卷 1175-1185页

作者： ALWALEED ALDHAFEERI HSIAO-HSUAN CHIN TRISTAN MELTON DONG IL LEE ALLEN CHU WENTING WANG MINGBIN YU PATRICK GUO-QIANG LO DIM-LEE kwong CHEE WEI WONG Fang Lu Mesoscopic Optics and Quantum Electronics Laboratory University of CaliforniaLos AngelesCalifornia 90095USA Institute of Microelectronics A*STARSingapore 117865Singapore State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technologyand Shanghai Industrial Technology Research InstituteShanghai 200050China

Frequency microcombs with microwave and millimeter-wave repetition rates provide a compact solution for coherent communication and information *** implementation of these microcombs using a CMOS-compatible platform further paves the way for large-scale photonic integration and ***,we demonstrate free-running soliton microcombs with K-band repetition rates with very low phase noise over a 4 GHz pump detuning range reaching−117(−123)dBc/Hz at 10 kHz offset for a 19.7(10)GHz carrier without active pump stabilization,exceeding commercial electronic microwave oscillators at frequency offsets above 40 *** minimum laser noise to soliton microwave signal transduction factor observed is−*** noise performance is achieved using a hybridized dual-mode for soliton generation to achieve passive thermal stabilization and minimal soliton spectrum shift from prior Raman scattering and dispersive wave *** further examine the locking of the repetition rate to an external ultrastable photonic oscillator to illustrate the feasibility of phase noise suppression below the thermorefractive noise limits of microresonator frequency combs.

关键词： pump polarization millimeter

A Registry-Based Observational Study on the Maternal and Fetal Outcomes of COVID-19 Patients in Hong Kong,China

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Maternal-Fetal Medicine 2024年第3期6卷 156-163页

作者： Hillary HY Leung Teresa WL Ma Florrie NY Yu Meliza CW Kong Tsz Kin Lo Pauline PL So wing-cheong Leung Wendy Shu Ka Wang Cheung Sakita Moungmaithong Chi Chiu Wang Liona C.Poon Department of Obstetrics and Gynaecology The Chinese University of HongKongHong Kong 999077China Department of Obstetrics and Gynaecology Queen Elizabeth HospitalHong Kong 999077China Department of Obstetrics and Gynaecology United Christian HospitalHong Kong 999077China Department of Obstetrics and Gynaecology Princess Margaret HospitalHong Kong 999077China Department of Obstetrics and Gynaecology Tuen Mun HospitalHong Kong 999077China Department of Obstetrics and Gynaecology Kwong Wah HospitalHong Kong 999077China Department of Obstetrics and Gynaecology Pamela Youde Nethersole Eastern HospitalHong Kong 999077China Department of Obstetrics and Gynaecology Queen Mary HospitalHong Kong 999077China

Objective:To report the clinical maternal and fetal outcomes of pregnant women with coronavirus disease 2019(COVID-19),along with any associated pregnancy complications,in Hong Kong,China,and to assess the impact of COVID-19 vaccination on these ***:This prospective registry-based observational study included pregnant women who were recruited through convenient sampling and had a laboratory-confirmed severe acute respiratory syndrome coronavirus 2 infection with a cycle threshold(Ct)value result available on admission to eight local hospitals in Hong Kong,*** on clinical symptoms,laboratory results,medical treatments,delivery timing and mode,and pregnancy complications were extracted from the Hospital Authority’s electronic medical record ***,fetal,and pregnancy outcomes were compared between unvaccinated pregnant women with COVID-19 and those who had received at least one dose of COVID-19 vaccine before *** continuous variables and categorical variables were analyzed using the Mann-Whitney U test and the Pearson’s chi-squared test respectively.A P value less than 0.05 was considered statistically ***:A total of 164 pregnant women were included,of whom 78(47.56%)were ***-19 was diagnosed before 28 weeks’gestation in 30(18.29%),while 134(81.71%)were diagnosed at or after 28 weeks’***-two(37.80%)women received at least one dose of COVID-19 *** were no significant differences between vaccinated and unvaccinated groups in the time interval between COVID-19 diagnosis and delivery,the Ct value,and the gestational age at infection onset or delivery(P>0.05).The majority of women were symptomatic at diagnosis regardless of vaccination status 55(88.71%)in vaccinated group vs.78(76.47%)in unvaccinated group(P=0.052).Symptoms did not significantly differ between groups except for cough(62.90%vs.47.06%,P=0.049).The overall rate of severe COVID-19 in pregnant women was *** t

关键词： COVID-19 Maternal outcomes Fetal outcomes Pregnancy complications Severe COVID-19

Profiles and removal efficiency of polycyclic aromatic hydrocarbons by two different types of sewage treatment plants in Hong Kong

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Journal of Environmental Sciences 2017年第3期29卷 196-206页

作者： Yu Bon Man Ka Lai Chow Zhang Cheng wing Yin Mo Yung Hau Chan James Chung Wah Lam Frankie Tat kwong Lau wing cheong Fung Ming Hung Wong Consortium on Health EnvironmentEducation and Research(CHEER)and Department of Science and Environmental StudiesThe Education University of Hong KongTai PoHong KongChina Department of Environmental Engineering Jinan UniversityGuangzhou 510630China State Key Laboratory in Marine Pollution Croucher Institute for Environmental SciencesHong Kong Baptist University and City University of Hong KongKowloon TongHong KongChina Department of Geography Hong Kong Baptist UniversityKowloon TongHong KongChina College of Environment Sichuan Agricultural UniversityChengdu 611130China State Key Laboratory in Marine Pollution and Research Centre for the Oceans and Human Health City University of Hong KongKowioon TongHong KongChina The Drainage Services Department The Government of the Hong Kong Special Administrative RegionHong KongChina

Sewage discharge could be a major source of polycyclic aromatic hydrocarbons （PAHs） in the coastal waters. Stonecutters Island and Shatin Sewage Treatment Works （SCISTW and STSTW） in Hong Kong, adopted chemically enhanced primary treatment and biological treatment, respectively. This study aimed at （1） determining the removal efficiencies of PAHs, （2） comparing the capabilities in removing PAHs, and （3） characterizing the profile of each individual PAHs, in the two sewage treatment plants （STPs）. Quantification of 16 PAHs was conducted by a Gas Chromatography. The concentrations of total PAHs decreased gradually along the treatment processes （from 301 ± 255 and 307 ± 217 ns/L to 14.9 ± 12.1 and 63.3 ± 54.1 ng/L in STSTW and SCISTW, respectively）. It was noted that STSTW was more capable in removing total PAHs than SCISTW with average total removal effidency 94.4% ± 4.12% us. 79.2% ± 7.48% （p 〈 0.05）. The removal of PAHs was probably due to sorption in particular matter, confirmed by the higher distribution coefficient of individual and total PAHs in solid samples （dewatered sludge contained 92.5% and 74.7% of total PAHs in SCISTW and STSTW, respectively） than liquid samples （final efffluent-total contained 7.53% and 25.3% of total PAHs in STSTW and SCISTW, respectively）. Despite the impressive capability of STSTW and SCISTW in removing PAHs, there was still a considerable amount of total PAHs （1.85 and 39.3 ks/year, respectively for the two STPs） being discharged into Hone Kon coastal waters, which would be an environmental concern.

关键词： Sewage treatment plantsPAHsRemoval efficiencySludgeSewage

Gracilaria changii(Rhodophyta) alleviates bisphenol A-induced adverse reproductive abnormalities in mice

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Asian Pacific Journal of Tropical Medicine 2021年第1期14卷 34-60页

作者： Chong Lee Ng Gim cheong Tan Yoon-Yen Yow Mukesh Kumar Gupta Phek Jin kwong Department of Agricultural and Food Science Universiti Tunku Abdul Rahman31900Malaysia Department of Biomedical Science Universiti Tunku Abdul Rahman31900Malaysia Department of Biological Sciences School of Medical and Life SciencesSunway University47500Malaysia Department of Biotechnology and Medical Engineering National Institute of TechnologyRourkelaOdisha769008India

Objective:To evaluate the potential of Gracilaria changii extract in ameliorating the potential adverse effects of bisphenol ***:The antioxidant capacity of Gracilaria changii extracted using different solvents(methanol,ethanol,and aqueous)was *** mice were administered by oral gavage with bisphenol A(60 mg/kg body weight)for 6 weeks with or without Gracilaria changii aqueous ***,the mice were either euthanized for histology and immunohistochemistry studies or mated to evaluate the pregnancy ***:Gracilaria changii aqueous extract showed the highest antioxidant properties compared with extract using methanol and *** aqueous extract of Gracilaria changii improved the uterus index and uterine lipid peroxidation after bisphenol A exposure,although the uterine expressions of estrogen receptors and complement C3 were not *** evaluation of the uterus during the estrus stage has revealed that the extract could mitigate bisphenol A-induced adverse effects in the uterus as there was a lower percentage of mice showing abnormalities like decreased eosin staining in the myometrium,and decrease in the number of eosinophil and endometrial glands in the ***,Gracilaria changii aqueous extract improved the pregnancy rate of mice administered with bisphenol ***:Gracilaria changii extract protects against bisphenol A-induced female reproductive abnormalities in mice which may be mediated via modulation of eosinophil migration,endometrial gland formation,and protein expressions associated with prostaglandins in the myometrium.

关键词： Red seaweed Gracilaria changii Antioxidant Endocrine disruptor Bisphenol A Reproduction

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进化双层自适应局部特征选择

计算机应用 2024年第5期44卷 1408-1414页

作者：高麟周宇邝得互深圳大学计算机与软件学院广东深圳518060 岭南大学电脑及决策科学系中国香港999077

局部特征选择(LFS)方法将样本空间划分为多个局部区域,并为每个区域选择最优特征子集以反映局部异质信息。然而,现有的LFS方法以每个样本为中心划分局部区域并找到最优特征子集,导致优化效率低下且适用场景受限。为了解决这个问题,提出... 详细信息

局部特征选择(LFS)方法将样本空间划分为多个局部区域,并为每个区域选择最优特征子集以反映局部异质信息。然而,现有的LFS方法以每个样本为中心划分局部区域并找到最优特征子集,导致优化效率低下且适用场景受限。为了解决这个问题,提出一种进化双层自适应局部特征选择(BiLFS)算法。LFS问题被建模为双层优化问题,特征子集和待优化局部区域是该问题的两个决策变量。在问题的上层,使用非支配排序遗传算法-Ⅱ求解被选择的局部区域的最优特征子集,区域纯度和被选择特征比率是目标函数;在问题的下层,根据上层求解的最优特征子集,首先使用局部区域聚类分析得到区域内的中心样本,然后通过局部区域融合消除非必要区域并更新必要区域的种群。在11个UCI数据集上的测试结果表明,相较于基于进化算法的非自适应LFS方法,BiLFS的平均分类准确率达到前者的98.48%,而平均所需计算用时仅为前者的9.51%,运算效率得到大幅提升,且达到基于线性规划的LFS方法的水准。对迭代过程中BiLFS算法选择的用于优化的局部区域进行可视化分析,结果表明,BiLFS选择必要局部区域具有稳定性和可靠性。

关键词：特征选择双层优化遗传算法多目标优化聚类

钯催化的碳(sp^(3))-硅键转化实现碳(sp^(3))-碳(sp^(2))偶联制备三氟丙基(杂)芳烃

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有机化学 2024年第4期44卷 1319-1326页

作者：刘君君卢涛涛马平赵庆阳邝福儿中山大学·深圳药学院(深圳) 广东深圳518107 香港中文大学化学系中国香港

使用商业可得的三烷氧基三氟丙基硅试剂,通过钯催化的碳(sp^(3))-硅键转化实现了C(sp^(3))—C(sp^(2))偶联反应.该偶联反应方法具有良好的官能团兼容性,可以有效制备一系列含多种官能团的三氟丙基(杂)芳烃.氟离子添加剂和双膦配体的脂... 详细信息

使用商业可得的三烷氧基三氟丙基硅试剂,通过钯催化的碳(sp^(3))-硅键转化实现了C(sp^(3))—C(sp^(2))偶联反应.该偶联反应方法具有良好的官能团兼容性,可以有效制备一系列含多种官能团的三氟丙基(杂)芳烃.氟离子添加剂和双膦配体的脂肪链的调节对于提高反应效率有重要的作用.

关键词：钯催化桧山偶联反应氟烷基化有机硅试剂