检索结果-南通市图书馆

滇东南薄竹山花岗岩年代学、地球化学特征及地质意义

在线全文

学校读者我要写书评

暂无评论

矿物岩石地球化学通报 2024年第3期43卷 621-635页

作者：黄建国任涛刘红卫罗光明管申进昆明理工大学国土资源工程学院昆明650093 云南省国土资源规划设计研究院昆明650216

滇东南薄竹山地区W-Sn-Pb-Zn多金属矿床与该区大型复式花岗岩体有密切的成因联系。为了探讨该花岗岩体的侵位时代、岩石成因及形成背景,对薄竹山花岗岩开展了岩石地球化学、锆石U-Pb定年及Hf同位素测试。结果表明,该花岗岩可划分为两期... 详细信息

滇东南薄竹山地区W-Sn-Pb-Zn多金属矿床与该区大型复式花岗岩体有密切的成因联系。为了探讨该花岗岩体的侵位时代、岩石成因及形成背景,对薄竹山花岗岩开展了岩石地球化学、锆石U-Pb定年及Hf同位素测试。结果表明,该花岗岩可划分为两期,其中晚期花岗岩LA-ICP-MS锆石U-Pb年龄为(87.08±0.55)~(87.29±0.69)Ma。两期花岗岩均具高的SiO_(2)(63.37%~72.07%)、K_(2)O(4.96%~6.19%),贫Fe、Mg的特征,A/CNK值为1.03~2.42,轻重稀土元素分异明显(LREE/HREE=14.0~26.5),Eu明显负异常(δEu=0.38~0.62),富含大离子亲石元素Rb、Th、U及稀土元素La、Ce、Nd,亏损Ba、Ta、Nb、Sr、Y和Yb,ε_(Hf)(t)值为−9.31~−5.14,具有高钾钙碱性过铝质S型花岗岩的地球化学和同位素特征;Hf同位素二阶段模式年龄(t_(DM2))为1476~1737 Ma,说明岩浆可能来源于早中元古代下地壳部分熔融。综合研究认为,薄竹山花岗岩是白垩纪伸展背景下软流圈地幔上涌导致的早中元古代下地壳物质部分熔融所形成。

关键词：锆石U-Pb定年地球化学 S型花岗岩薄竹山滇东南

Constant Barrier Strategies in a Two-state Markov-modulated Dual Risk Model

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2011年第4期27卷 679-690页

作者： Xue-min MA Kui luo guang-ming WANG Yi-jun HU School of Mathematics and Statistics Wuhan University Wuhan 430072 China

In this paper, we consider the dividend problem in a two-state Markov-modulated dual risk model, in which the gain arrivals, gain sizes and expenses are influenced by a Markov process. A system of integro-differential equations for the expected value of the discounted dividends until ruin is derived. In the case of exponential gain sizes, the equations are solved and the best barrier is obtained via numerical example. Finally, using numerical example, we compare the best barrier and the expected discounted dividends in the two-state Markov-modulated dual risk model with those in an associated averaged compound Poisson risk model. Numerical results suggest that one could use the results of the associated averaged compound Poisson risk model to approximate those for the two-state Markov-modulated dual risk model.

关键词： Dual risk model Markov-modulated risk model barrier strategy

Characterization of CoCrFeO_(4) Nanocrystals Prepared by a Sol-Gel Method

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2001年第5期18卷 692-694页

作者： XIONG Gang MAI Zhen-Hong WANG Chao-Ying NI Yong-ming ZHAO Zhong-Xian XU ming LIU Cui-Xiu luo guang-ming Institute of Physics and Centre for Condensed Matter Physics Chinese Academy of SciencesBeijing 100080 Department of Physics University of DurhamDurham DH13LEUK

CoCrFeO_(4) nanocrystals have been synthesized using a sol-gel *** specimen has an average grain size of 8.1 *** zero-field-cooled and field-cooled curves show a superparamagnetic transition occurring at a blocking temperature of TB≈249 *** increase in coercivity of CoCrFeO_(4) nanocrystals with the decreasing temperature has been detected below the blocking temperature and could be explained by the Stoner-Wohlfarth *** temperature dependence of saturation magnetization shows that Bloch's law holds but with the Bloch exponent lower than the bulk value.

关键词： holds magnetization

Synchrotron X-Ray Study on Structures of Ni_(80)Fe_(20)/Cu Superlattices

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2001年第3期18卷 405-407页

作者： XU ming luo guang-ming CHAI Chun-Lin YANG Tao MAI Zhen-Hong LAI Wu-Yan WU Zhong-Hua WANG De-Wu Institute of Physics&Center for Condensed Matter Physics Chinese Academy of SciencesBeijing 100080 Synchrotron Radiation Laboratory Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100039

We showed that,in contrast to the results in literature,the Bragg peak intensity of Ni_(80)Fe_(20)/Cu superlattices is enhanced at the incident x-ray energy slightly higher than the absorption edge of the heavier element(Cu).The atomic density at Ni_(80)Fe_(20)/Cu interface was analysed by the diffraction anomalous fine structure technology with the incident angle of x-ray fixed at the first Bragg *** results demonstrate the epitaxy growth of Ni_(80)Fe_(20)/Cu *** annealing,the epitaxity of Ni_(80)Fe_(20)/Cu multilayers becomes poor but the local crystallinity in each layer is improved.

关键词： incident annealing slightly

Counterion-Mediated Hydrogen Bonding Making Strong Polyelectrolytes pH-Responsive:Current Understanding and Perspectives

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第9期42卷 1270-1277,I0005页

作者： Yue Huang guang-Tao Mei Zan Hua guang-ming Liu Hefei National Research Center for Physical Sciences at the Microscale Department of Chemical PhysicsKey Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education InstitutesUniversity of Science and Technology of ChinaHefei230026China The Key Laboratory of Functional Molecular Solids Ministry of Educationand Department of Materials ChemistrySchool of Chemistry and Materials ScienceAnhui Normal UniversityWuhu214002China

The counterion-mediated hydrogen bonding(CMHB)is related to the hydrogen bonding between bound counterions and polyelectrolyte chains in polyelectrolyte systems,where the counterions can both electrostatically bind to the charged groups of polyelectrolyte chains and act as hydrogen bond donors or acceptors to form hydrogen bonds with the hydrogen bond sites associated with polyelectrolyte chains simultaneously.A large number of literatures illustrate that strong polyelectrolytes(SPs)are insensitive to pH,which severely limmits the applications of SPs as smart ***,our studies have demonstrated that the CMHB makes SPs *** perspective discusses the mechanism of pH responsiveness of SPs and the pH-tunable properties of SPs,based on the pH-controlled CMHB *** future research directions on the pH responsiveness of SPs are also discussed *** is anticipated that the study of the pH responsiveness of SPs not only will provide a new understanding of the fundamental properties of SPs,but also will greatly expand the applications of SPs in the field of smart materials.

关键词： Counterion binding Hydrogen bond Polyelectrolyte brush Polyelectrolyte complexation

Change of probability density distributions of summer temperatures in different climate zones

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2024年第1期18卷 1-16页

作者： Xinqiu OUYANG Weilin LIAO ming luo guangdong Key Laboratory for Urbanization and Geo-simulation School of Geography and PlanningSun Yat-sen UniversityGuangzhou 510006China Institute of Environment Energy and SustainabilityThe Chinese University of Hong KongHong Kong 999077China

Extreme events have become increasingly frequent worldwide which are reflected in diverse changes in the shape of the temperature probability density ***,few studies have paid attention to the heterogeneity of temperature at the scale of climate ***,we use the ERA5-land data set to explore interdecadal summer temperature changes and the distribution across different climate zones from 1981 to *** the minimum(Tmin)and maximum(Tmax)temperature of 1982–1991 and 2010–2019,the results imply that Tmin and Tmax in summer maintained a notable upward trend over the past 40 years,especially *** effects of a simple shift toward a warmer climate contributed most to all climate zones,while the standard deviation,skewness and kurtosis had minor effects on extreme temperature except for *** analysis shows that the probability of extreme events in all climate zones is increasing in frequency and intensity,especially Tmin and Tmax in temperate climate *** diverse reasons for climate change can assist us with taking different measures to address extreme climate in distinct climate zones.

关键词： Climate change probability density function extreme events

Spatiotemporal Prediction of Urban Traffics Based on Deep GNN

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 265-282页

作者： ming luo Huili Dou Ning Zheng School of Computer Science Hangzhou Dianzi UniversityHangzhou310018China Zhejiang Institute of Communications Hangzhou310012China School of Cyberspace Security Hangzhou Dianzi UniversityHangzhou310018China

Traffic prediction already plays a significant role in applications like traffic planning and urban management,but it is still difficult to capture the highly non-linear and complicated spatiotemporal correlations of traffic *** well as to fulfil both long-termand short-termprediction objectives,a better representation of the temporal dependency and global spatial correlation of traffic data is *** order to do this,the Spatiotemporal Graph Neural Network(S-GNN)is proposed in this research as amethod for traffic *** S-GNN simultaneously accepts various traffic data as inputs and investigates the non-linear correlations between the *** terms of modelling,the road network is initially represented as a spatiotemporal directed graph,with the features of the samples at the time step being captured by a convolution *** order to assign varying attention weights to various adjacent area nodes of the target node,the adjacent areas information of nodes in the road network is then aggregated using a graph *** data is output using a fully connected layer at the *** findings show that S-GNN can improve short-and long-term traffic prediction accuracy to a greater extent;in comparison to the control model,the RMSE of S-GNN is reduced by about 0.571 to 9.288 and the MAE(Mean Absolute Error)by about 0.314 to *** experimental results on two real datasets,Pe MSD7(M)and PEMS-BAY,also support this claim.

关键词： Urban traffic traffic temporal correlation GNN prediction

Two-stage extraction by partial grinding of impacted mandibular third molar in close proximity to the inferior alveolar nerve

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第10期12卷 1728-1732页

作者： guang-ming luo Zhang-Shun Yao Wei-Xiang Huang Lei-Yan Zou Yan Yang Kunbaida Outpatient Department Kunming Medical University School and Hospital of StomatologyKunming 650106Yunnan ProvinceChina Yunnan Key Laboratory of Stomatology Kunming 650106Yunnan ProvinceChina

BACKGROUND Extraction of impacted third molars often leads to severe complications caused by damage to the inferior alveolar nerve(IAN).AIM To proposes a method for the partial grinding of an impacted mandibular third molar(IMM3)near the IAN to prevent IAN injury during IMM3 *** Between January 1996 and March 2022,25 patients with IMM3 roots near the IAN were *** first stage of the operation consisted of grinding a major part of the IMM3 crown with a high-speed turbine dental drill to achieve sufficient space between the mandibular second molar and *** 6 months,when the root tips were observed to be away from the IAN on X-ray examination,the remaining part of the IMM3 was completely *** All IMM3s were extracted easily without symptoms of IAN injury after *** Partial IMM3 grinding may be a good alternative treatment option to avoid IAN injury in high-risk cases.

关键词： Partial grinding Impacted mandibular third molar Inferior alveolar nerve Cone-beam computed tomography

Swelling of Spherical Polyelectrolyte Gels

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第9期42卷 1386-1392,I0009页

作者： ming-Yu Duan Jia-Dong Chen Yi-ming Liu Zhao-Feng Peng guang Chen Department of Advanced Manufacturing and Robotics College of EngineeringPeking UniversityBeijing 100871China

Polyelectrolyte(PE)gels,distinguished by their unique stimuli-responsive swelling behavior,serve as the basis of broad applications,such as artificial muscles and drug *** this work,we present a theoretical model to analyze the electrostatics and its contribution to the swelling behavior of PE gels in salt *** minimizing the free energy of PE gels,we obtain two distinct scaling regimes for the swelling ratio at equilibrium with respect to the salt *** compare our predictions for the swelling ratio with experimental measurements,which show excellent *** addition,we employ a finite element method to assess the applicability range of our theoretical model and *** anticipate that our model will also provide valuable insights into drug adsorption and release,deformation of red blood cells,4D printing and soft robotics,where the underlying mechanism of swelling remains enigmatic.

关键词： Gels Polyelectrolytes Swelling Stimuli-responsive Electrostatic interaction Cell model