检索结果-南通市图书馆

Geochemistry of the E-MORB type ophiolite and related volcanic rocks from the Wushan area,West Qinling

Science China Earth Sciences 2007年第Z2期50卷 234-245页

作者： DONG YunPeng ZHANG GuoWei YANG Zhao ZHAO Xia MA HaiYong yao anping State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an 710069China

The mafic-ultramafic assemblages,which thrustthrust into the Wushan-Tangzang boundary fault as some blocks and outcropped in the Yuanyangzhen,Lijiahe,Lubangou and Gaojiahe area,consist mainly of meta-peridotites,gabbros and *** meta-peridotites are characterized by high SiO_(2) and MgO contents,lowΣREE,as well as their chondrite-normalized rare earth element patterns show some similarities to that of middle oceanic *** basalts from the Yuanyangzhen,Lijiahe and Lubangou area are characterized by relatively high TiO_(2) content,low Al_(2)O_(3) content and Na_(2)O>>K_(2)*** all,it is the slight enrichment or flat REE distribution patterns and the unfractionated in HFS elements in the primitive-normalized trace elements distribution patterns that indicate these basalts are similar to that of the typical *** comparison,the basalts from the Gaojiahe section are featured by depletion in Nb and Ta contents and enrichment in Th content which show that these were derived from an island-arc *** studies of the regional geology,petrology,geochemistry,geo-chronology and all above evidence,it can be suggested that the mafic-ultramafic rocks from the Wushan area are mainly dismembered E-MORB type ophiolite,which represent the fragments of the lithosphere of the Early-Paleozoic Qinling *** is preferred that these rocks were formed in an initial mid-ocean ridge setting during the beginning stage of the oceanic basin *** ophiolite together with the Gaojiahe island-arc basalts shows that there exists an ophiolitic mélange along the Wushan-Tangzang boundary fault,and marks the suture zone after the closure of the Qinling ocean in early Paleozoic.

关键词： E-MORB geochemistry Shangdan suture zone west Qinling tectonics

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geological characteristics,metallogenic background,and genesis of the Tongyu VHMS copper deposit in the west part of the North Qinling,Shaanxi Province

引用

Science China Earth Sciences 2010年第10期53卷 1460-1485页

作者： Ben Lee LaiMin Zhu GuoWei Zhang Bo Guo HuJun Gong anping yao NW Univ Xian Dept Geol State Key Lab Continental Dynam Xian 710069 Peoples R China

The Tongyu volcanic-hosted massive sulfide(VHMS) copper deposit is located in the west part of the North Qinling(NQL),Shaanxi *** we report geological features and trace elemental characteristics of ores,mineralized rocks,and volcanic host rocks of this *** also conducted in situ zircon U-Pb and Lu-Hf LA-ICP-MS dating and lithogeochemical study of the Meigou granodiorite,which is intruded in the south of the Tongyu mining *** is inferred that the volcanic host rocks of the Tongyu Cu deposit belong to calc-alkaline island arc volcanic rocks,and the volcanic host rocks and the ore-forming materials share common material *** subduction of the Paleo-Qinling oceanic slab at around 472 Ma,high oxygen-fugacity aqueous fluid released by dehydration reaction of the subducting slab rose into the mantle wedge,leached Cu and other metal elements,and triggered partial melting of the mantle *** with the ore-forming materials,the arc calc-alkaline magmas erupted and formed the Tongyu VHMS *** weighted average zircon U-Pb age of the Meigou granodiorite is 439.3±3 Ma,suggesting its genesis is associated with the subduction event of the Paleo-Qinling oceanic plate around 440 *** terms of the granitoid's geochemical characteristics,the Mg#,Ni,and Cr contents are *** show strongly fractionated patterns with unobvious Eu *** contents are high while Y contents are low,resulting in high Sr/Y ***-stage zircon Hf model ages mostly range between 908 and 723 Ma,with εHf(t)>***,we classify Meigou granodiorite as island arc granite with adakitic geochemical *** was generated by interaction between mantle wedge and melt produced by partial melting of the subducted basaltic slab of the Paleo-Qinling *** Tongyu VHMS deposit was formed in the island arc tectonic setting during Ordovician-Silurian between 439.3±3 Ma and 472±11 *** volcanic exhalation-sedimentation,which was contemporaneous with t

关键词： west part of the North Qinling VHMS copper deposit metallogenic background and genesis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tectonics of South China Continent and its implications

引用

Science China Earth Sciences 2013年第10期56卷 1804-1828页

作者： ZHANG GuoWei GUO AnLin WANG YueJun LI SanZhong DONG YunPeng LIU ShaoFeng HE DengFa CHENG ShunYou LU RuKui yao anping State Key Laboratory of Continental Dynamics/Department of Geology Northwest University Guangzhou Institute of Geochemistry Chinese Academy of Sciences Key Lab of Submarine Geosciences and Exploration Techniques Ministry of Education College of Marine GeoscienceOcean University of China State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences

This paper aims at exploring the tectonic characteristics of the South China Continent(SCC)and extracting the universal tectonic rules from these characteristics,to help enrich the plate tectonic theory and better understand the continental dynamic *** this purpose,here we conduct a multi-disciplinary investigation and combine it with the previous studies to reassess the tectonics and evolution of SCC and propose that the tectonic framework of the continent comprises two blocks,three types of tectonic units,four deformation systems,and four evolutionary stages with distinctive mechanism and tectonic characteristics since the *** four evolutionary stages are:(1)The amalgamation and break-up of the Neoproterozoic plates,typically the intracontinental rifting.(2)The early Paleozoic and Mesozoic intracontinental orogeny confined by plate tectonics,forming two composite tectonic domains.(3)The parallel operation of the Yangtze cratonization and intracontinental orogeny,and multi-phase reactivation of the Yangtze craton.(4)The association and differentiation evolution of plate tectonics and intracontinental tectonics,and the dynamic characteristics under the Meso-Cenozoic modern global plate tectonic regime.

关键词：构造意义中国大陆板块构造理论板块构造体制陆内裂谷陆内造山动态特性动力学系统

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pharmacological effects of volatile oil from chrysanthemum and its associated mechanisms:a review

引用

Acupuncture and Herbal Medicine 2024年第1期4卷 79-91页

作者： Jing Zhang Weiqiang Su Nina Filipczak Ying Luo anping Wan yao He Shijuan Yan Xiang Li Ming Yang Key Laboratory of Modern Preparation of TCM Ministry of EducationJiangxi University of Chinese MedicineNanchangChina Center for Pharmaceutical Biotechnology and Nanomedicine Northeastern UniversityBostonUSA National Pharmaceutical Engineering Center for Solid Preparation in Chinese Herbal Medicine Jiangxi University of Chinese MedicineJiangxi University of Chinese MedicineNanchangChina

Volatile oil(VO)is the main chemical component of common plants in Chrysanthemum genus,and it possesses several beneficial pharmacological properties,including bacteriostatic,antioxidant,anti-tumor,anti-inflammatory,antipyretic,analgesic,antiosteoporotic,antihypertensive,sedative,and hypnotic *** date,research on the effective components of Chrysanthemum extract has mainly focused on flavonoids,whereas limited data are available on the chemical constituents and underlying mechanisms of action of the VO *** this review,the pharmacological activities and mechanisms of VO are comprehensively reviewed with the aim of providing a foundation for further development for medicinal,aromatherapy,and diet therapy applications.

关键词： Action mechanisms Chrysanthemum Pharmacological activity Volatile oil

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A novel topology with controllable wideband baseband impedance for power amplifiers

引用

Frontiers of Information Technology & Electronic Engineering 2024年第2期25卷 308-315页

作者： yao yao Zhijiang DAI Mingyu LI School of Intelligent Technology and Engineering Chongqing University of Science and TechnologyChongqing400065China School of Microelectronics and Communication Engineering Chongqing UniversityChongqing400065China

This paper presents a novel topology to control the baseband impedance of a power amplifier(PA)to avoid performance deterioration in concurrent dual-band *** topology can avoid pure resonance of capacitors and inductors LC,which leads to a high impedance at some frequency ***,it can be applied to transmitters that are excited by broadband *** particular,by adjusting the circuit parameters and increasing stages,the impedance of the key frequency bands can be flexibly controlled.A PA is designed to support this design *** saturated output power is around 46.7 dBm,and the drain efficiency is>68.2%(1.8-2.3 GHz).Under concurrent two-tone excitation,the drain efficiency reaches around 40%even under 5.5 dB back-off power with the tone spacing from 10 MHz to 500 *** results demonstrate that the proposed topology is capable of controlling wideband baseband impedance.

关键词： Baseband impedance Concurrent dual-band Power amplifier

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Thoughts on studies of China continental geology and tectonics

引用

Progress in Natural Science:Materials International 2006年第10期16卷 1022-1026页

作者： ZHANG Guowei, GUO Anlin and yao anping (Ministry of Education Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi’an 710069, China) Ministry of Education Key Laboratory of Continental Dynamics Department of Geology Northwest University Xi'an 710069 China

As an important part of the global continents, China continent has long been situated in the peculiar tectonic position and experienced extremely complicated activities, which resulted in the regional unique characteristics for China continent on the global common geological background. These characteristics contain abundant information regarding scientific key issues of modern geological frontier. Thus, China continent can be a natural laboratory and excellent arena for the modern geosciences. The modern earth sciences have started entering the era featured with earth systematic science and beyond plate tectonics. How to take the regional advantage and exploit the treasure resource to participate the new theoretical and methodological creation is a historic opportunity and great challenge we are facing. This paper generalizes research priorities in four fields on China continental geology and tectonics for discussion. They are: China continental tectonics and dynamics; Mesozoic-Cenozoic crustal deformation and deep-seated processes in China continent and the adjacent regions; deep-seated dynamic background and evolutionary trend of crustal tectonic activities on the time scale of human existence; deep-seated background and processes of conjunction and transformation of different tectonic systems.

关键词： China continental geology and continental tectonics plate tectonics continental dynamics key scientific issues.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Fresh-Keeping Decision and Coordination of Fresh Agricultural Product Supply Chain Considering Carbon Cap-and-Trade under Different Dominance

引用

Journal of Systems Science and Systems Engineering 2024年第1期33卷 30-51页

作者： Yang Yang Guanxin yao China Institute for Agricultural Equipment Industrial Development Jiangsu UniversityZhenjiang212013China Jiangsu Modern Logistics Research Base Yangzhou UniversityYangzhou225009China

In the context of low carbon,this paper discussed the impact of the carbon cap-and-trade policy on the fresh-keeping decision-making of two-echelon fresh agricultural product supply chains under different dominance,and designed cost-sharing contracts to coordinate the supply chain of fresh agricultural products dominated by suppliers and retailers *** results showed that:dominance has no effect on the fresh-keeping decision and total revenue of fresh agricultural product supply chain,but it affects the internal income distribution,and dominance does not always bring more benefits;the implementation of carbon cap-and-trade reduces the fresh-keeping decision-making of fresh agricultural products supply chain and reduces the free-rider income of followers;the role of higher carbon trading price is twofold,which not only brings about the speculation of leading enterprises,but also promotes the application of low-carbon technologies;consumers’high preference for freshness,low-cost and high-efficiency low-carbon technology are all conducive to improving the fresh-keeping efforts and benefits of the supply chain;cost-sharing contracts can coordinate the supply chain of fresh agricultural products.

关键词： Dominant power carbon cap-and-trade policy fresh agricultural product supply chain fresh-keeping decision-making

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Numerical investigation of non-uniform temperature fields for proppant and fluid phases in supercritical CO_(2)fracturing

引用

Particuology 2024年第7期90卷 149-163页

作者： Boyu Liu Jun yao Research Center of Multiphase Flow in Porous Media China University of Petroleum(East China)Qingdao 266000China

The non-uniform temperature distribution in supercritical CO_(2)(Sc-CO_(2))fracturing influences the density,viscosity,and volume expansion or shrinkage rate of Sc-CO_(2),impacting proppant *** study presents a coupled computational fluid dynamics-discrete element method and heat transfer model to examine the effects of proppant bed shape and the heat transfers of proppant-wall,proppant-fluid,and fluid-wall on the fluid and proppant temperature *** Sc-CO_(2)volume expansion is assessed under various temperature conditions by evaluating the volume-averaged Sc-CO_(2)*** factors,including proppant size,shape,thermal conductivity,concentration,temperature difference,and injection velocity,are carefully analyzed to elucidate their *** findings elucidate the existence of four distinct zones in the fluid temperature *** zone exhibits different magnitudes of temperature change under diverse conditions and undergoes dynamic transformations with the development of the proppant *** fluid-wall heat transfer and the fluid temperatures in Zones C and D are significantly subject to the fluid injection velocity(governing the heating duration),the temperature difference between fluid and formation(impacting the magnitude of heat flux),and the proppant bed shape(controlling the effective heating area).Additionally,the proppant-wall and proppant-fluid heat transfers determine the temperatures of both the proppant bed and the fluid within Zone B,showing a strong correlation with proppant thermal conductivity,proppant size,injection velocity,and temperature *** proposed coupled model provides valuable insights into the temperature distributions and flow behaviors of temperature-dependent fracturing fluids and proppants.

关键词： CFD-DEM Heat transfer Compressible fluid CO_(2)sequestration Proppant transport

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Limits of Uneven Battery Power in Modular Multilevel Converter-based Battery Energy Storage Systems

引用

CSEE Journal of Power and Energy Systems 2024年第2期10卷 686-695页

作者： yao Pan Xiaofeng Sun Wei Zhao Xin Li yao Cai Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004China

For modular multilevel converter-based battery energy storage systems (MMC-BESS), uneven power among batteries of SMs will be deduced by battery aging, battery fault, etc., which will degrade performance and even lead to system failure. For maintaining the balance of capacitor voltage, this paper analyzes the limits of the uneven power of batteries, which are presented as the current limits in this paper. According to analysis, an analytical method is proposed that only the dc and fundamental frequency components of the arm current are used to calculate current limits. With the current limits it is able to evaluate the reasonability of power distribution among batteries. Meanwhile, increase of fundamental frequency component will enhance the current limits, and the dc component determines the size relationship between the absolute values of the upper and lower current limits. Finally, simulation model and experiment prototype are built for verifying the theoretical analysis and current limits calculation method, and satisfactory results are provided.

关键词： Arm current balance of capacitor voltage current limits MMC-BESS uneven power

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Reinforcement learning based adaptive control for uncertain mechanical systems with asymptotic tracking

引用

Defence Technology（防务技术） 2024年第4期34卷 19-28页

作者： Xiang-long Liang Zhi-kai yao yao-wen Ge Jian-yong yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China College of Automation&College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing210023China

This paper mainly focuses on the development of a learning-based controller for a class of uncertain mechanical systems modeled by the Euler-Lagrange *** considered system can depict the behavior of a large class of engineering systems,such as vehicular systems,robot manipulators and *** these systems are often characterized by highly nonlinear characteristics,heavy modeling uncertainties and unknown perturbations,therefore,accurate-model-based nonlinear control approaches become *** by the challenge,a reinforcement learning(RL)adaptive control methodology based on the actor-critic framework is investigated to compensate the uncertain mechanical *** approximation inaccuracies caused by RL and the exogenous unknown disturbances are circumvented via a continuous robust integral of the sign of the error(RISE)control *** from a classical RISE control law,a tanh(·)function is utilized instead of a sign(·)function to acquire a more smooth control *** developed controller requires very little prior knowledge of the dynamic model,is robust to unknown dynamics and exogenous disturbances,and can achieve asymptotic output ***,co-simulations through ADAMS and MATLAB/Simulink on a three degrees-of-freedom(3-DOF)manipulator and experiments on a real-time electromechanical servo system are performed to verify the performance of the proposed approach.

关键词： Adaptive control Reinforcement learning Uncertain mechanical systems Asymptotic tracking

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：