检索结果-南通市图书馆

Chinese Science Bulletin 1999年第S2期44卷 230-232页

作者： wang Zuwei~1, ZHANG Haihua~2. YAO Dongliang~2.and ZHOU Yongzhang~3 1. department of Geography, Tianjin Normal University, Tianjin 300071, {2. 2. guangzhou Institute of Geochemistry, Chinese Academy of Sciences, guangzhou 510640, {2. 3. department of Earth Sciences, zhongshan University, guangzhou 510275, {2. eeszhou@*** department of Geography Tianjin Normal University Tianjin 300071 China guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China department of Earth Sciences Zhongshan University Guangzhou 510275 China

THE altered deformation zone type Au (Ag) deposits share an important part from the precious metallicore deposits in the Yunkai area, South china. Their formation is a history of poly-stage evolution. pre- liminary source strata, Calidoniam metamorphism, Indosinian-Yanshanian ductile shear deformation andassociated hydrotheraml alteration all play certain roles in the history. This note discusses the geochemical conditional of the hydrothermal fluids during mineralization. Two representative ore deposits, the pangxidong Ag(Au) deposit and Hetai Au deposits are selectedfor this study. They are hosted in altered ductile shear zones. Wall-rock hydrothermal alteration is bothspatially and temporally associated with the development of the ductile shear system. Silicification occurred throughout the whole alteration process. There are three groups of quartz: thepredeformational quartz, the early stage hydrothermal quartz, and the late stage hydrothermal quartz asso-

关键词： precious metallic deposit fluid inclusions mineralizing fluid South china.

MANIFOLDS WITH pOINTWISE pINCHED rICCI CUrVATUrE

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2010年第3期30卷 819-829页

作者：顾会玲 department of mathematics Sun Yat-sen University

In this article, the author proves a compactness result about riemannian manifolds with an arbitrary pointwisely pinched ricci curvature tensor.

关键词： ricci pinching condition Yamabe flow asymptotic behavior

periodic Number for Anosov Maps

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 1997年第2期13卷 169-174页

作者： Sun Wenxiang (department of Computer Science,zhongshan University,{2.,china) department of Computer Science Zhongshan University

Let X be a compact metric space and let f:X→X be an Anosov map,i.e.,an expansive selfmap with the pseudoorbit tracing property(***)(see Lemma 1).If Nn(f) denotes the number of fixed points of f^n which we name here the n-periodic number then we prove in the case as n tends to infinity that n^M ≤N_n(f)≤H^n,where M and H are two positive integers.

关键词： Specification property pOTp Anosov map

The generalized roper-Suffridge extension operator in Banach spaces (Ⅲ)

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2009年第11期52卷 2432-2446页

作者： ZHU YuCan1 & LIU MingSheng2.1 department of mathematics,Fuzhou University,Fuzhou 350002.{2. 2.department of mathematics,South {2. Normal University,guangzhou 510631,{2. 1. department of mathematics Fuzhou University Fuzhou 350002 China 2. department of mathematics South China Normal University Guangzhou 510631 China

Suppose that X is a complex Banach space with the norm ||·|| and n is a positive integer with dim X ≥n≥ 2. In this paper,we consider the generalized roper-Suffridge extension operator Φn,β2.γ2....,βn+1,γn+1(f)... 详细信息

关键词： roper-Suffridge extension operator biholomorphic starlike mapping almost spirallike mapping of type β and order α spirallike mapping of type β and order α

properties of rotating Neutron Stars in the relativistic σ-ω Model

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical physics 2004年第1期41卷 51-54页

作者： WEN De-Hua~(1,2. CHEN Wei~3 wang Xian-Ju~1 AI Bao-Quan~1 LIU Guo-Tao~1 LIU Liang-Gang~1 1 department of physics,{2. University,guangzhou 510275,china2.department of physics,South china University of Technology,guangzhou 510641,china3 department of physics,Jinan University,guangzhou 510632.china department of physics Jinan University Guangzhou 510632 China

The properties such as the moment of inertia,the surface redshift and the radius of gyration of rotatingneutron stars in the relativistic σ-ω model are studied with the Hartle’s *** relation between the angularvelocity of the fluid relative to the local inertial frame and the uniform angular velocity relative to the infinite iscalculated.

关键词： relativistic σ-ω model rotating neutron star equation of state

Study of rLT Filtration for Staircase and Normal pulse Voltammetry

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1997年第11期8卷 0-0页

作者： Xiao ping ZHENG Min ZHANG Jin Yuan MO (department of Chemistry, zhongshan University, {2.) zhongshan Univ Dept Chem Guangzhou 510275 Peoples R China

rLT filtration-a new method to separate faradaic current from extraneous currents applied in potential step scan voltammetry was first proposed. The current equation of potential step scan voltammetry has been deduced. The theory and the process of rLT filtration are presented. The curve shapes and the properties of normal pulse voltammetry of reversible reactions have been studied.

关键词： rLT

Space/Air Covert Communications:potentials,Scenarios,and Key Technologies

在线全文

学校读者我要写书评

暂无评论

china Communications 2024年第3期21卷 1-18页

作者： Mao Haobin Liu yanming Zhu Lipeng Mao Tianqi Xiao Zhenyu Zhang rui Han Zhu Xia Xianggen School of Electronic and Information Engineering Beihang UniversityBeijing 100191China department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore School of Science and Engineering Shenzhen Research Institute of Big Datathe Chinese University of Hong KongShenzhenGuangdong 518172China department of Electrical and Computer Engineering University of HoustonHoustonTX 77004USA department of Computer Science and Engineering Kyung Hee UniversitySeoulSouth Korea446-701 department of Electrical and Computer Engineering University of DelawareNewarkDE 19716USA

Space/air communications have been envisioned as an essential part of the next-generation mobile communication networks for providing highquality global connectivity. However, the inherent broadcasting nature of wireless propagation environment and the broad coverage pose severe threats to the protection of private data. Emerging covert communications provides a promising solution to achieve robust communication security. Aiming at facilitating the practical implementation of covert communications in space/air networks, we present a tutorial overview of its potentials, scenarios, and key technologies. Specifically, first, the commonly used covertness constraint model, covert performance metrics, and potential application scenarios are briefly introduced. Then, several efficient methods that introduce uncertainty into the covert system are thoroughly summarized, followed by several critical enabling technologies, including joint resource allocation and deployment/trajectory design, multi-antenna and beamforming techniques, reconfigurable intelligent surface(rIS), and artificial intelligence algorithms. Finally, we highlight some open issues for future investigation.

关键词： artificial intelligence(AI) sixth generation(6G) space-air-ground integrated networks(SAGINs) space/air covert communications

Geochemical behavior of elements at fossil sea floor water/sediment interface

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第S2期44卷 232-233页

作者： ZHANG Haihua~1, XIA Yu~1, wang Zuwei~2.and ZHOU Yongzhang~3 1. guangzhou Institute of Geochemistry, Chinese Academy of Science, guangzhou 510640, china 2. department of Geography, Tianjin Normal University, Tianjin 300071, china 3. department of Earth Sciences, zhongshan University, guangzhou 510275, china guangzhou Institute of Geochemistry Chinese Academy of Science Guangzhou 510640 China department of Geography Tianjin Normal University Tianjin 300071 China department of Earth Sciences Zhongshan University Guangzhou 510275 China

THIS note deals with the geochemical behavior of elements near the water/sediment interface of a fossil seafloor. The Nandan-Hechi basin, located in northwest Guangxi, Southern china, is selected for exemplified study. It is an elongated basin, and developed on a Caledonian basement. Its Devonian strata hosthydrtothermally sedimentary formations, and are typical of the intra-platformal basin facies sediments oversouthern china. A steady sedimentary sequence may be observed, commonly going from carboniferouspelite at bottom, upward through bedded chert, thickly banded argillaceous limestone, thinly bandedsiliceous limestone and small lensiod argillaceous limestone in the middle, to coarse lensoid siliceousand/or argillaceous limestone at the top. The chert and some argillaceous limestone are related to hydrothermally sedimentary origin. The present study focuses on the lensoid argillaceous limestone formation. This formation contains the following characteristic sedimentary structures: small lensoid structure,vermiform structure, wave-shaped banded structure, massive structure, white framboid structure, andcage netting structure.

关键词： water/sediment interface sedimentation periodicity sedimentary geochemistry basin.

LArGE TIME BEHAVIOr OF SOLUTIONS TO NEWTONIAN FILTrATION EQUATIONS WITH SOUrCES

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2010年第3期30卷 968-974页

作者：王路生尹景学王泽佳 department of mathematics Jilin University department of mathematics South China Normal University

This article is concerned with large time behavior of solutions to the Neumann or Dirichlet problem for a class of Newtonian filtration equations ｜x｜λ＋Эt^-Эu=div（｜x｜^k∨u^m）＋｜x｜λ＋ku^p with 0 〈 m 〈 1,p 〉 1,λ≥0, k ∈ r. An interesting phenomenon is that there exist two thresholds k∞ and kl for the exponent k, such that the critical Fujita exponent pc for p exists and is finite if k E （k∞, k1）, otherwise, pc is infinite or does not exist.

关键词： Newtonian filtration equation critical exponent exterior problem Thresh -old

EXISTENCE AND NONEXISTENCE OF GLOBAL CONTINUOUS SOLUTIONS OF rIEMANN prOBLEM FOr QUASILINEAr HYpErBOLIC SYSTEMS^(**)

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of mathematics,Series B 1991年第1期12卷 13-25页

作者：林龙威 department of mathematics Zhongshan UniversityGuangzhouGuangdongChina.

Consider riemann problem(E),(r)under the condition(M).It is proved that,as0<r≤1,there exists a unique global continuous solution whose structure is similar to thelocal solution;as 1<r<3,if the variation of the initia... 详细信息

Consider riemann problem(E),(r)under the condition(M).It is proved that,as0r≤1,there exists a unique global continuous solution whose structure is similar to thelocal solution;as 1rriation of the initial data is sufficiently large,then thesolution must be breakdown in a finite time.

关键词： riemann breakdown sufficiently proof vertex 切二成子 inequal implies belongs