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Nearest Neighbor Sampling of Point Sets Using Rays

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1131-1174页

作者： Liangchen Liu Louis Ly colin B.Macdonald Richard Tsai Department of Mathematics The University of Texas at Austin2515 SpeedwayAustinTX 78712USA Oden Institute for Computational Engineering and Sciences The University of Texas at Austin201 E24th StAustinTX 78712USA Department of Mathematics University of British Columbia1984 Mathematics RdVancouverBCV6T1Z2Canada

We propose a new framework for the sampling,compression,and analysis of distributions of point sets and other geometric objects embedded in Euclidean *** approach involves constructing a tensor called the RaySense sketch,which captures nearest neighbors from the underlying geometry of points along a set of *** explore various operations that can be performed on the RaySense sketch,leading to different properties and potential *** information about the data set can be extracted from the sketch,independent of the ray *** integrals on point sets can be efficiently computed using the *** also present several examples illustrating applications of the proposed strategy in practical scenarios.

关键词： Point clouds Sampling Classification Registration Deep learning Voronoi cell analysis

Recent Progress of the Solar Wind Magnetosphere Ionosphere Link Explorer (SMILE) Mission

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空间科学学报 2024年第4期44卷 692-698页

作者： WANG Chi ESCOUBET Philippe FORSYTH colin LI Jing AGNOLON David State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190 European Space Agency/European Space Research and Technology Centre Noordwijk 2201 AZ Mullard Space Science Laboratory University College LondonLondon RH56 NT

The SMILE(Solar wind Magnetosphere Ionosphere Link Explorer)mission is a joint space science mission between the Chinese Academy of Sciences(CAS)and the European Space Agency(ESA),aiming to understand the interaction of the solar wind with the Earth’s magnetosphere in a global *** of May 2024,the SMILE mission is in phase-D with an expected launch date of September *** report summarizes developments in the mission during the past two years.

关键词： SMILE Soft X-ray Imager Ultra-Violet Imager Light Ion Analyzer Magnetometer

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Thin-film flow technology in controlling the organization of materials and their properties Special Collection:Distinguished Australian Researchers

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Aggregate 2024年第1期5卷 115-129页

作者： Clarence Chuah Xuan Luo Javad Tavakoli Youhong Tang colin L.Raston Flinders Institute for Nanoscale Science and Technology College of Science and EngineeringFlinders UniversityAdelaideSouth AustraliaAustralia Centre for Health Technologies School of Biomedical EngineeringFaculty of Engineering and Information TechnologyUniversity of Technology SydneySydneyNew South WalesAustralia

Centrifugal and shear forces are produced when solids or liquids *** systems and devices that use these forces,such as dynamic thin-film flow technology,are evolving continuously,improve material structure-property relationships at the nanoscale,representing a rapidly thriving and expanding field of research high with green chemistry metrics,consolidated at the inception of *** vortex fluidic device(VFD)provides many advantages over conventional batch processing,with fluidic waves causing high shear and producing large surface areas for micro-mixing as well as rapid mass and heat transfer,enabling reactions beyond diffusion *** these abilities allows for a green and innovative approach to altering materials for various research and industry applications by controlling small-scale flows and regulating molecular and macromolecular chemical reactivity,self-organization phenomena,and the synthesis of novel *** review highlights the aptitude of the VFD as clean technology,with an increase in efficiency for a diversity of top-down,bottom-up,and novel material transformations which benefit from effective vortex-based processing to control material structure-property relationships.

关键词： material nanoscale structure-property relationship thin film flow technology vortex fluidic device

Chemical-assisted MMP reduction on methane-oil systems:Implications for natural gas injection to enhanced oil recovery

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Petroleum 2024年第1期10卷 101-108页

作者： Mohamed Almobarak Matthew B.Myers colin D.Wood Yongbing Liu Ali Saeedi Quan Xie Discipline of Petroleum Engineering WA School of Mines: Minerals Energy and Chemical Engineering Curtin University Commonwealth Scientific and Industrial Research Organization Curtin University Oil and Gas Innovation Centre Management State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation

Miscible natural gas injection is widely considered as a practical and efficient enhanced oil recovery technique. However, the main challenge in this process is the high minimum miscibility pressure（MMP）between natural gas and crude oil, which limits its application and recovery factor, especially in hightemperature reservoirs. Therefore, we present a novel investigation to quantify the effect of chemicalassisted MMP reduction on the oil recovery factor. Firstly, we measured the interfacial tension（IFT） of the methane-oil system in the presence of chemical or CO2to calculate the MMP reduction at a constant temperature（373K） using the vanishing interfacial tension（VIT） method. Afterwards, we performed three coreflooding experiments to quantify the effect of MMP reduction on the oil recovery factor under different injection *** interfacial tension measurements show that adding a small fraction（1.5 wt%） of the tested surfactant（SOLOTERRA ME-6） achieved 9% of MMP reduction, while adding 20 wt% of CO2to the methane yields 13% of MMP reduction. Then, the coreflooding results highlight the significance of achieving miscibility during gas injection, as the ultimate recovery factor increased from 65.5% under immiscible conditions to 77.2% using chemical-assisted methane, and to 79% using gas mixture after achieving near miscible condition. The results demonstrate the promising potential of the MMP reduction to significantly increase the oil recovery factor during gas injection. Furthermore, these results will likely expand the application envelop of the miscible gas injection, in addition to the environmental benefits of utilizing the produced gas by re-injection/recycling instead of flaring which contributes to reducing the greenhouse gas emissions.

关键词： Gas injection Enhanced oil recovery Miscibility Coreflooding

The Influence of Variable (Monsoon) Rainfall on Sedimentation in the Roaches Grit and Other Upper Carboniferous Delta Sequences in the UK Pennine Basin

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International Journal of Geosciences 2024年第8期15卷 632-666页

作者： colin Michael Jones Retired Cambridge UK

The Roaches Grit in the UK Pennine Basin was a complex deep water deltaic sequence deposited during the Late Carboniferous glacial period. The channels of the upper part of the Roaches Grit, deposited towards the end of the cyclothem after the eustatic minimum, contain evidence for very high seasonal discharges related to strong monsoon rainfall in the catchment areas. In some channels, intense turbulence near the delta front, led to knick point recession and deep incision. These channels were filled with sediments during reduced discharge, including very large sets of cross-bedding up to 16 m thick. channels were short-lived with frequent avulsions. Over time slightly lower discharges formed laterally migrating channels dominated by bar forms. Different discharge-controlled processes operated on the reactivated delta slope. Incised channels generated turbidity currents during floods which transported sediments directly into the basin far from the delta. Migrating channels built mouth bars;resedimentation during floods formed density currents which then deposited sediment on the lower parts of the slope.

关键词： Carboniferous Delta Climate Monsoon Rainfall ITCZ Precession

Subsequent total joint arthroplasty: Are we learning from the first stage?

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World Journal of Orthopedics 2024年第3期15卷 230-237页

作者： Christine Jiang Wu colin Penrose Sean Patrick Ryan Michael Paul Bolognesi Thorsten Markus Seyler Samuel Secord Wellman Department of Orthopaedic Surgery Duke University HospitalDurhamNC 27710United States Department of Orthopaedic Surgery Midwest Center for Joint ReplacementIndianapolisIN 46241United States

BACKGROUND With the increasing incidence of total joint arthroplasty(TJA),there is a desire to reduce peri-operative complications and resource *** degenerative conditions progress in multiple joints,many patients undergo multiple *** To determine if both physicians and patients learn from the patient’s initial arth-roplasty,resulting in improved outcomes following the second *** The institutional database was retrospectively queried for primary total hip arth-roplasty(THA)and total knee arthroplasty(TKA).Patients with only unilateral THA or TKA,and patients undergoing same-day bilateral TJA,were *** demographics,comorbidities,and implant sizes were collected at the time of each procedure and patients were stratified by first vs second *** metrics evaluated included operative time,length of stay(LOS),disposition,90-d readmissions and emergency department(ED)*** A total of 642 patients,including 364 undergoing staged bilateral TKA and 278 undergoing bilateral THA,were *** was no significant difference in demographics or comorbidities between the first and second procedure,which were separated by a mean of 285 *** THA and TKA,LOS was significantly less for the second surgery,with 66%of patients having a shorter hospitalization(Pchange in disposition was present from the first surgery,patients were significantly more likely to be discharged to home after the second procedure(P=0.033).There was no difference between procedures for post-operative readmissions(P=0.438)or ED visits(P=0.915).CONCLUSION After gaining valuable experience recovering from the initial surgery,a patient’s perioperative outcomes are improved for their second *** may

关键词： Staged total joint arthroplasty Asynchronous total joint arthroplasty Subsequent total joint arthroplasty Contralateral total joint arthroplasty Perioperative outcomes

Assessment of molecular markers and marker-assisted selection for drought tolerance in barley(Hordeum vulgare L.)

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Journal of Integrative Agriculture 2024年第1期23卷 20-38页

作者： Akmaral Baidyussen Gulmira Khassanova Maral Utebayev Satyvaldy Jatayev Rystay Kushanova Sholpan Khalbayeva Aigul Amangeldiyeva Raushan Yerzhebayeva KulpashBulatova Carly Schramm Peter Anderson colin L.D.Jenkins Kathleen LSoole Yuri Shavrukov Faculty of Agronomy S.Seifullin Kazakh AgroTechnical Research UniversityAstana 010000Kazakhstan A.I.Barayev Research and Production Centre of Grain Farming Shortandy 021601Kazakhstan Kazakh Research Institute of Agriculture and Plant Growing AlmalybakAlmaty District 040909Kazakhstan College of Science and Engineering Biological SciencesFlinders UniversityAdelaideSA 5042Australia

This review updates the present status of the field of molecular markers and marker-assisted selection(MAS),using the example of drought tolerance in *** accuracy of selected quantitative trait loci(QTLs),candidate genes and suggested markers was assessed in the barley genome *** common strategies are described for molecular marker development,candidate gene identification and verification,and their possible applications in MAS to improve the grain yield and yield components in barley under drought *** strategies are based on the following five principles:(1)Molecular markers are designated as genomic‘tags’,and their‘prediction’is strongly dependent on their distance from a candidate gene on genetic or physical maps;(2)plants react differently under favourable and stressful conditions or depending on their stage of development;(3)each candidate gene must be verified by confirming its expression in the relevant conditions,e.g.,drought;(4)the molecular marker identified must be validated for MAS for tolerance to drought stress and improved grain yield;and(5)the small number of molecular markers realized for MAS in breeding,from among the many studies targeting candidate genes,can be explained by the complex nature of drought stress,and multiple stress-responsive genes in each barley genotype that are expressed differentially depending on many other factors.

关键词： barley candidate genes drought tolerance gene verification via expression grain yield marker-assisted selection(MAS) molecular markers quantitative trait loci(QTLs) strategy for MAS

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先进的教育技术:机遇、风险与责任

中国高教研究 2024年第3期 17-21页

作者： Coin Baiey 伦敦玛丽女王大学伦敦E14NS 英国皇家工程院伦敦SW1Y 5DG

随着教育的纵深发展以及学生需求的不断变化,数字教育的进步突飞猛进。每一项创新都伴随着机遇和风险,数字教育的发展也不例外。以伦敦玛丽女王大学以及世界其他大学在数字教育方面的创新实践为案例,对人工智能(AI)使用中涉及的伦理问... 详细信息

随着教育的纵深发展以及学生需求的不断变化,数字教育的进步突飞猛进。每一项创新都伴随着机遇和风险,数字教育的发展也不例外。以伦敦玛丽女王大学以及世界其他大学在数字教育方面的创新实践为案例,对人工智能(AI)使用中涉及的伦理问题进行探讨。首先概述了混合同步教学的概念和模式,继而对增强现实和虚拟现实以及触觉技术进行了评估。作者讨论人工智能涉及的伦理问题以及有效使用,对数字教育的未来进行了思考。

关键词：数字教育人工智能人工智能伦理

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自适应正则化滤波化极方法研究

地球物理学报 2024年第3期67卷 1255-1272页

作者：何涛王皓张义蜜王万银 colin G.Farquharson J.Kim Welford 长安大学地质工程与测绘学院西安710054 海洋油气勘探国家工程研究中心北京100028 中国科学院海洋地质与环境重点实验室山东青岛266071 Department of Earth Sciences Memorial University of NewfoundlandSt.John'sAlB 3X5Canada

化极是消除磁力异常斜磁化影响的关键步骤,可以在波数域(频率域)和空间域中实现.相比于空间域,在波数域(频率域)进行化极简单且高效,但在低纬度地区存在不稳定性问题,因此明确低纬度地区的范围,研究稳定、实用、精度高的低纬度地区化极... 详细信息

化极是消除磁力异常斜磁化影响的关键步骤,可以在波数域(频率域)和空间域中实现.相比于空间域,在波数域(频率域)进行化极简单且高效,但在低纬度地区存在不稳定性问题,因此明确低纬度地区的范围,研究稳定、实用、精度高的低纬度地区化极方法具有重要意义.本文通过理论研究得出化极因子振幅的最大值为2时,对应的磁化倾角的值为±45°,当磁化倾角在该范围内时,引起化极不稳定.因此采用正则化思想,提出了自适应正则化滤波化极方法(ARF-RTP),该方法利用化极因子振幅构建正则化滤波函数,并以振幅值等于2作为约束计算化极方法的参数值,从而实现自适应化极处理,提高了化极方法的稳定性及实用性.同时结合迭代算法提高了此方法的精度,有效地解决了低纬度地区化极的不稳定性问题.自适应正则化滤波这一思想不但可以解决化极的不稳定性问题,而且可以解决分量转换或者磁化方向转换的不稳定性问题以及类似数据处理中的不稳定性问题,具有广阔的推广应用前景.

关键词：化极低纬度地区振幅自适应正则化滤波迭代算法

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