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Journal of Computational Mathematics 2001年第5期19卷 449-458页

作者： Wan, z.-s. sun, z.-z. Institute of Applied Physics and CM P.O. Box 8009 Beijing 100088 China

In paper (J. Comput. Appl. Math., 76 (1996), 137-146), a difference scheme for a class of nonlocal parabolic equations with natural boundary conditions was derived by the method of reduction of order and the unique solvability and second order convergence in L2-norm are proved. In this paper, we prove that the scheme is second order convergent in L∞ norm and then obtain fourth order accuracy approximation in L∞ norm by extrapolation method. At last, one numerical example is presented.

关键词： Approximation theory Boundary conditions Convergence of numerical methods Extrapolation

High Dimension Multivariate Data Analysis for small Group samples of Chemical Volatile Profiles of African Nightshade species

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Journal of Data Analysis and Information Processing 2024年第2期12卷 210-231页

作者： Lorna Chepkemoi Daisy salifu Lucy Kananu Murungi Henri E. z. Tonnang International Centre of Insect Physiology and Ecology (ICIPE) Nairobi Kenya Department of Horticulture and Food security Jomo Kenyatta University of Agriculture and Technology (JKUAT) Nairobi Kenya

Quantitative headspace analysis of volatiles emitted by plants or any other living organisms in chemical ecology studies generates large multidimensional data that require extensive mining and refining to extract useful information. More often the number of variables and the quantified volatile compounds exceed the number of observations or samples and hence many traditional statistical analysis methods become inefficient. Here, we employed machine learning algorithm, random forest (RF) in combination with distance-based procedure, similarity percentage (sIMPER) as preprocessing steps to reduce the data dimensionality in the chemical profiles of volatiles from three African nightshade plant species before subjecting the data to non-metric multidimensional scaling (NMDs). In addition, non-parametric methods namely permutational multivariate analysis of variance (PERMANOVA) and analysis of similarities (ANOsIM) were applied to test hypothesis of differences among the African nightshade species based on the volatiles profiles and ascertain the patterns revealed by NMDs plots. Our results revealed that there were significant differences among the African nightshade species when the data’s dimension was reduced using RF variable importance and sIMPER, as also supported by NMDs plots that showed s. scabrum being separated from s. villosum and s. sarrachoides based on the reduced data variables. The novelty of our work is on the merits of using data reduction techniques to successfully reveal differences in groups which could have otherwise not been the case if the analysis were performed on the entire original data matrix characterized by small samples. The R code used in the analysis has been shared herein for interested researchers to customise it for their own data of similar nature.

关键词： Random Forest similarity Percentage PERMANOVA ANOsIM Non-Metric Multi-Dimensional scaling

青藏高原及其周边二叠纪综合地层、生物群以及古地理和古气候演化

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中国科学：地球科学 2024年第4期54卷 1125-1170页

作者：沈树忠张以春袁东勋徐海鹏琚琦张华郑全锋罗茂侯章帅南京大学地球科学与工程学院内生金属矿床成矿机制研究国家重点实验室关键地球物质循环前沿科学中心南京210023 中国科学院南京地质古生物研究所现代古生物学和地层学国家重点实验室南京210008 中国科学院大学南京学院南京210049 中国矿业大学资源与地球科学学院徐州221116

二叠纪是青藏高原各块体演化的关键时段,发生了一系列重大地质和生物事件,当时横跨南北半球统一的泛大陆演化到了鼎盛阶段,阻断了全球东西向的赤道暖流的同时,在泛大陆的东侧形成了一个半封闭的、具有重要历史意义的特提斯洋暖池,是古-... 详细信息

二叠纪是青藏高原各块体演化的关键时段,发生了一系列重大地质和生物事件,当时横跨南北半球统一的泛大陆演化到了鼎盛阶段,阻断了全球东西向的赤道暖流的同时,在泛大陆的东侧形成了一个半封闭的、具有重要历史意义的特提斯洋暖池,是古-中生代之交生物与环境演变的引擎.青藏高原二叠纪地层分布广泛、化石丰富,从南到北由于跨越不同的纬度带体现出不同的特点.雅鲁藏布江以南的喜马拉雅特提斯带当时位于冈瓦纳大陆印度板块北缘,整个二叠纪沉积含有典型的冈瓦纳冷水型生物群;雅鲁藏布江缝合带内的灰岩外来体时代集中在瓜德鲁普世(Guadalupian,中二叠世)中、晚期至早三叠世,古生物地理与喜马拉雅特提斯带有显著差异,最有可能为新特提斯洋中的海山型沉积.基墨里(Cimmerian)微地块群在乌拉尔世(Cisuralian,早二叠世)早期阿瑟尔期-萨克马尔期(Asselian-sakmarian)全部位于冈瓦纳大陆北缘,均发育冰海相沉积及冈瓦纳型冷水生物群.乌拉尔世中期(约290~280Ma)基墨里微地块群由于印度板块北缘Panjal Traps等大火成岩省岩浆活动与冈瓦纳大陆裂解,并以不同的速度向北漂移.可以分为两个条带,由南羌塘、保山和sibuma地块组成的北基墨里微地块群漂移速度较快,在亚丁斯克期(Artinskian)就已经出现大量碳酸盐岩沉积和暖水生物群,因此,它们最先从冈瓦纳大陆裂解并进入低纬度暖水区域;而由拉萨、腾冲和Irrawaddy地块组成的南基墨里微地块群,漂移速度相对较慢,在空谷(Kungurian)晚期才开始出现大规模碳酸盐岩沉积,并延续至乐平世(Lopingian,晚二叠世),瓜德鲁普世和乐平世地层中含暖水生物为主的动物群,因此,这些地块至少在空谷晚期已经从冈瓦纳大陆北缘分离,裂解时间稍晚于北基墨里微地块群;这种沉积和古生物地理的时空演变差异性表明乌拉尔世的裂解事件造成了中特提斯洋和新特提斯洋的开启和形成.更北的北羌塘地块由于整个二叠纪地层中均含有典型的暖水生物群,与华南地区、思茅地块和印支地块等可以比较,属于古特提斯洋北部的块体.因此,二叠纪中、晚期特提斯域形成了古、中、新特提斯多岛洋共存的局面,是当时构造活动最活跃的地区和全球生物多样性的中心.此外,青藏高原多个块体在二叠纪位于南半球中高纬度地区,完整记录了晚古生代大冰期、亚丁斯克期全球变暖和二叠纪末快速变暖等重大古气候事件,对于阐明板块运动和全球气候演变对生物群时空分布的影响具有举足轻重的作用.

关键词：二叠纪特提斯洋青藏高原生物群古地理

An illustrated guide to: Parsimonious multi-scale full-waveform inversion

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Earthquake science 2024年第6期37卷 574-583页

作者： Fichtner A. Thrastarson s. Herwaarden D.-P.V. Noe s. Department of Earth sciences ETH Zürich Zürich 8049 Switzerland

Having been a seemingly unreachable ideal for decades, 3-D full-waveform inversion applied to massive seismic datasets has become reality in recent years. Often achieving unprecedented resolution, it has provided new insight into the structure of the Earth, from the upper few metres of soil to the entire globe. Motivated by these successes, the technology is now being translated to medical ultrasound and non-destructive testing. Despite remarkable progress, the computational cost of full-waveform inversion continues to be a major concern. It limits the amount of data that can be exploited, and it largely inhibits quantitative and comprehensive uncertainty analyses. These notes complement a presentation on recent developments in full-waveform inversion that are intended to reduce computational cost and assimilate more data, thereby improving tomographic resolution. The suite of strategies includes flexible and user-friendly spectral-element simulations, the design of wavefield-adapted meshes that harness prior information on wavefield geometry, dynamic mini-batch optimisation that naturally takes advantage of data redundancies, and collaborative multi-scale updating to jointly constrain crustal and mantle structure. © 2023 The Authors

关键词： Earth full-waveform inversion model seismology

Coal/Gangue Volume Estimation with Convolutional Neural Network and separation Based on Predicted Volume and Weight

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Computers, Materials & Continua 2024年第4期79卷 279-306页

作者： zenglun Guan Murad s.Alfarzaeai Eryi Hu Taqiaden Alshmeri Wang Peng school of Mechatronic Engineering China University of Mining and TechnologyXuzhou221116China China National Coal Group Corp. Beijing100029China Information Institute Ministry of Emergency Management of the ChinaBeijing100029China school of Mechanical Engineering Sana’a UniversitySana’a31220Yemen

In the coal mining industry,the gangue separation phase imposes a key challenge due to the high visual similaritybetween coal and ***,separation methods have become more intelligent and efficient,using newtechnologies and applying different features for *** such method exploits the difference in substancedensity,leading to excellent coal/gangue ***,this study uses density differences to distinguishcoal from gangue by performing volume prediction on the *** training samples maintain a record of3-side images as input,volume,and weight as the ground truth for the *** prediction process relieson a Convolutional neural network(CGVP-CNN)model that receives an input of a 3-side image and then extractsthe needed features to estimate an approximation for the *** classification was comparatively performedvia ten different classifiers,namely,K-Nearest Neighbors(KNN),Linear support Vector Machines(Linear sVM),Radial Basis Function(RBF)sVM,Gaussian Process,Decision Tree,Random Forest,Multi-Layer Perceptron(MLP),Adaptive Boosting(AdaBosst),Naive Bayes,and Quadratic Discriminant Analysis(QDA).After severalexperiments on testing and training data,results yield a classification accuracy of 100%,92%,95%,96%,100%,100%,100%,96%,81%,and 92%,*** test reveals the best timing with KNN,which maintained anaccuracy level of 100%.Assessing themodel generalization capability to newdata is essential to ensure the efficiencyof the model,so by applying a cross-validation experiment,the model generalization was *** useddataset was isolated based on the volume values to ensure the model generalization not only on new images of thesame volume but with a volume outside the trained ***,the predicted volume values were passed to theclassifiers group,where classification reported accuracy was found to be(100%,100%,100%,98%,88%,87%,100%,87%,97%,100%),*** obtaining a classification with hi

关键词： Coal coal gangue convolutional neural network CNN object classification volume estimation separation system

search for production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at√s=8 TeV using CMs open data

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Chinese Physics C 2024年第4期48卷 6-13页

作者： Y.Mahmoud H.Abdallah M.T.Hussein s.Elgammal Centre for theoretical physics The British University in EgyptEgypt Physics Department Faculty of ScienceCairo UniversityEgypt

In this study,we conducted a search for dark matter using a part of the data recorded by the CMs experiment during run-I of the LHC in 2012 with a center of mass energy of 8 TeV and an integrated luminosity of 11.6 fb−*** data were gathered from the CMs open *** matter,in the framework of the simplified model(mono-z′),can be produced from proton-proton collisions in association with a new hypothetical gauge boson,z′.Thus,the search was conducted in the dimuon plus large missing transverse momentum *** benchmark scenario of mono-z′,which is known as light vector,was used for interpreting the CMs open *** evidence of dark matter was observed,and exclusion limits were set on the masses of dark matter and z′at 95%confidence level.

关键词： dark matter large hadron collider CMs open data search for new physics dark fermion

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影响青藏高原植被生产力的极端气候阈值

中国科学：地球科学 2024年第6期54卷 1996-2007页

作者：朴正刚李湘怡徐浩王锴汤舒畅阚飞洪松柏北京大学城市与环境学院北京100871

多种与水分和热量相关的极端气候事件对青藏高原植被生长造成了不利影响.然而,目前尚不清楚多大程度的极端气候胁迫水平会导致植被生长出现强烈响应.为了填补这一知识空白,我们综合利用水文气象数据和卫星遥感获取的植被指数,检测了2001... 详细信息

多种与水分和热量相关的极端气候事件对青藏高原植被生长造成了不利影响.然而,目前尚不清楚多大程度的极端气候胁迫水平会导致植被生长出现强烈响应.为了填补这一知识空白,我们综合利用水文气象数据和卫星遥感获取的植被指数,检测了2001~2018年间影响植被生产力对干旱、极端高温和极端低温响应的两个关键气候阈值(反映植被生产力响应发生突变和对植被损害达到最大).结果表明,当土壤湿度下降到正常水平的(-1.41±0.6)个标准差(σ)以下时,植被生产力对干旱事件的响应频率会迅速增加;当土壤湿度低于(-2.98±0.9)σ时,干旱对植被生产力造成的损害达到最大.区域上极端低温的阈值平均值为(-1.44±0.5)σ和(-2.53±0.8)σ,而极端高温的阈值平均值为(1.34±0.4)σ和(2.31±0.4)σ.这表明,极端高温比极端低温更易引发植被生产力的强烈响应.此外,我们发现极端温度事件中土壤水分亏缺的复合效应降低了极端低温和极端高温的阈值.基于地球系统模式预测,到2100年,青藏高原的西南部和东北部的部分地区将有极高的风险受到超过阈值的极端气候事件影响.本研究基于极端气候阈值识别了青藏高原地区具有高影响力的极端气候事件,提高了对不同极端气候事件植被生长响应的认识,为评估极端气候事件对区域生态系统的影响提供了研究范例.

关键词：青藏高原极端气候阈值植被生产力

Coherent nonlinear structures in dense electron positron plasma

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Chinese Physics B 2013年第2期22卷 335-340页

作者： s.A.Khan z.Wazir National Centre for Physics Quaid-i-Azam University CampusIslamabad 45320Pakistan Department of Physics Riphah International UniversityIslamabadPakistan

It is shown that rarefactive-type double layer structures exist in ultradense electron-positron *** this purpose,an extended Korteweg de Vries equation is derived and solved analytically in the low amplitude limit by employing the appropriate fluid equations.A strong influence of quantum degeneracy pressure of electrons and positrons,quantum diffraction effects and concentration of background positive ions on double layer is *** is also pointed out that the amplitude and steepness of the double layer increases with an increase in ion concentration or ion charge *** results are examined numerically for some interesting cases of dense plasmas with illustrations.

关键词： degenerate plasma nonlinear structures double layers

Amplitude analysis of the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)

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Chinese Physics C 2024年第8期48卷 6-33页

作者： M.Ablikim M.N.Achasov P.Adlarson O.Afedulidis X.C.Ai R.Aliberti A.Amoroso Q.An Y.Bai O.Bakina I.Balossino Y.Ban H.-R.Bao V.Batozskaya K.Begzsuren N.Berger M.Berlowski M.Bertani D.Bettoni F.Bianchi E.Bianco A.Bortone I.Boyko R.A.Briere A.Brueggemann H.Cai X.Cai A.Calcaterra G.F.Cao N.Cao s.A.Cetin J.F.Chang W.L.Chang G.R.Che G.Chelkov C.Chen C.H.Chen Chao Chen G.Chen H.s.Chen M.L.Chen s.J.Chen s.L.Chen s.M.Chen T.Chen X.R.Chen X.T.Chen Y.B.Chen Y.Q.Chen z.J.Chen z.Y.Chen s.K.Choi X.Chu G.Cibinetto F.Cossio J.J.Cui H.L.Dai J.P.Dai A.Dbeyssi R.E.de Boer D.Dedovich C.Q.Deng z.Y.Deng A.Denig I.Denysenko M.Destefanis F.De Mori B.Fang s.s.Fang W.X.Fang Y.Fang Y.Q.Fang R.Farinelli L.Fava F.Feldbauer G.Felici C.Q.Feng J.H.Feng Y.T.Feng K.Fischer M.Fritsch C.D.Fu J.L.Fu Y.W.Fu H.Gao Y.N.Gao Yang Gao s.Garbolino I.Garzia P.T.Ge z.W.Ge C.Geng E.M.Gersabeck B.Ding X.X.Ding Y.Ding Y.Ding J.Dong L.Y.Dong M.Y.Dong X.Dong M.C.Du s.X.Du z.H.Duan P.Egorov Y.H.Fan J.Fang JA.Gilman K.Goetzen L.Gong W.X.Gong W.Gradl s.Gramigna M.Greco M.H.Gu Y.T.Gu C.Y.Guan z.L.Guan A.Q.Guo L.B.Guo M.J.Guo R.P.Guo Y.P.Guo A.Guskov J.Gutierrez K.L.Han T.T.Han X.Q.Hao F.A.Harris K.K.He K.L.He F.H.Heinsius C.H.Heinz Y.K.Heng C.Herold T.Holtmann P.C.Hong G.Y.Hou X.T.Hou Y.R.Hou z.L.Hou B.Y.Hu H.M.Hu J.F.Hu T.Hu Y.Hu G.s.Huang K.X.Huang L.Q.Huang X.T.Huang Y.P.Huang T.Hussain F.H\"olzken N.H\"usken N.in der Wiesche M.Irshad J.Jackson s.Janchiv J.H.Jeong Q.Ji Q.P.Ji W.Ji X.B.Ji X.L.Ji Y.Y.Ji X.Q.Jia z.K.Jia D.Jiang H.B.Jiang P.C.Jiang s.s.Jiang T.J.Jiang X.s.Jiang Y.Jiang J.B.Jiao J.K.Jiao z.Jiao s.Jin Y.Jin M.Q.Jing X.M.Jing T.Johansson s.Kabana N.Kalantar-Nayestanaki X.L.Kang X.s.Kang M.Kavatsyuk B.C.Ke V.Khachatryan A.Khoukaz R.Kiuchi O.B.Kolcu B.Kopf M.Kuessner X.Kui A.Kupsc W.K\"uhn J.J.Lane P.Larin L.Lavezzi T.T.Lei z.H.Lei H.Leithoff M.Lellmann T.Lenz C.Li C.Li C.H.Li Cheng Li D.M.Li F.Li G.Li H.Li H.B.Li H.J.Li H.N.Li Hui Li J.R.Li J.s.Li K.Li L.J.Li L.K.Li Lei Li M.H.Li P.R.Li Q.M.Li Q.X.Li R.Li s.X.Li T.Li W.D.Li W.G.Li X.Li X.H.Li X.L.Li X.Y.Li Y Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Beihang University Beijing 100191China Bochum Ruhr-University D-44780 BochumGermany Budker Institute of Nuclear Physics sB RAs(BINP) Novosibirsk 630090Russia Carnegie Mellon University PittsburghPennsylvania 15213USA Central China Normal University Wuhan 430079China Central south University Changsha 410083China China Center of Advanced science and Technology Beijing 100190China China University of Geosciences Wuhan 430074China Chung-Ang University Seoul06974Republic of Korea COMsATs University Islamabad Lahore CampusDefence RoadOff Raiwind Road54000 LahorePakistan Fudan University Shanghai 200433China GsI Helmholtzcentre for Heavy Ion Research GmbH D-64291 DarmstadtGermany Guangxi Normal University Guilin 541004China Guangxi University Nanning 530004China Hangzhou Normal University Hangzhou 310036China Hebei University Baoding 071002China Helmholtz Institute Mainz Staudinger Weg 18D-55099 MainzGermany Henan Normal University Xinxiang 453007China Henan University Kaifeng 475004China Henan University of science and Technology Luoyang 471003China Henan University of Technology Zhengzhou 450001China Huangshan College Huangshan 245000China Hunan Normal University Changsha 410081China Hunan University Changsha 410082China Indian Institute of Technology Madras Chennai 600036India Indiana University BloomingtonIndiana 47405USA INFN Laboratori Nazionali di Frascati INFN Laboratori Nazionali di FrascatiI-00044FrascatiItaly INFN Laboratori Nazionali di Frascati INFN Sezione di PerugiaI-06100PerugiaItaly INFN Laboratori Nazionali di Frascati University of PerugiaI-06100PerugiaItaly INFN sezione di Ferrara INFN Sezione di FerraraI-44122FerraraItaly INFN sezione di Ferrara University of FerraraI-44122FerraraItaly Inner Mongolia University Hohhot 010021China Institute of Modern Physics Lanzhou 730000China Institute of Physics and Technology Peace Avenue 54BUlaanbaatar 13330Mongolia Instituto de A

Using e^(+)e^(−)annihilation data corresponding to an integrated luminosity of 2.93 fb^(−1)taken at the center-of-mass energy√s=3.773 GeV with the BEsIII detector,a joint amplitude analysis is performed on the decays D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η).The fit fractions of individual components are obtained,and large interferences among the dominant components of the decays D^(0)→a_(1)(1260)π,D^(0)→π(1300)π,D^(0)→ρ(770)ρ(770),and D^(0)→2(ππ)_(s)are observed in both *** the obtained amplitude model,the CP-even fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are determined to be(75.2±1.1_(stat).±1.5_(syst.))%and(68.9±1.5_(stat).±2.4_(syst.))%,*** branching fractions of D^(0)→π^(+)π^(−)π^(+)π^(−)and D^(0)→π^(+)π^(−)π^(0)π^(0)(non-η)are measured to be(0.688±0.010_(stat.)±0.010_(syst.))%and(0.951±0.025_(stat.)±0.021_(syst.))%,*** amplitude analysis provides an important model for the binning strategy in measuring the strong phase parameters of D^(0)→4πwhen used to determine the CKM angleγ(ϕ_(3))via the B^(−)→DK^(−)decay.

关键词： BEsIII D^(0)meson decays amplitude analysis CP-even fraction

Biomimetic amelioration of zirconium nanoparticles on a rigid substrate over viscous slime--a physiological approach

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Applied Mathematics and Mechanics(English Edition) 2023年第9期44卷 1563-1576页

作者： s.I.ABDELsALAM A.z.zAHER Instituto de Ciencias MatemHu DINGticas ICMAT Madrid 28049Spain Basic science Faculty of EngineeringThe British University in EgyptAl-Shorouk CityCairo 11837Egypt Basic science Department Faculty of EngineeringShubra-Benha UniversityCairo 11884Egypt

In this article,an investigation is conducted to study the precise role of zirconium nanoparticles that exist in a slime-like fluid subject to specific *** gliding is a technique of mobility used by bacteria that lack motility components,bacteria travel on their own strength in gliding locomotion by secreting a layer of slime on the substrate.A model of an undulating sheet over a layer of slime of a Rabinowitsch fluid is investigated as a potential model of bacteria’s gliding *** the aid of long wavelength approximation,the equations governing the circulation of slime underneath the cells are established and analytically *** effects of pseudoplasticity,dilatation and non-Newtonian parameter on the behavior of zirconium concentration,speed of microorganism(bacteria),streamline patterns,and pressure rise for non-Newtonian and Newtonian fluids are *** power required for propulsion is also *** interpretation for the pertinent variables has been graphically discussed against the parameters under *** is found that with the increase in the concentration of zirconium nanoparticles,the bacterial flow is accelerated and attains its maximum near the rigid substrate wall while an opposite behavior is noticed in the rest region.

关键词： zirconium nanoparticle gliding bacterium Grashof heat transfer glider's speed Rabinowitsch fluid