检索结果-南通市图书馆

Integrated stratigraphy and Mineralogy of the Doushantuo Formation in Weng’an,south China,and Implications for Ediacaran Phosphogenesis

引用

Journal of Earth science 2024年第2期35卷 476-503页

作者： Liangxuan Jiao Zhenbing she Dominic Papineau Yaguan Zhang Matthew s.Dodd Kenan Cao Qun Chen Guoyong Chen state Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan430078China school of Earth sciences China University of GeosciencesWuhan430047China london Centre for Nanotechnology University College London17-19 Gordon StreetLondonWC1E 6BTUK department of Earth sciences University College LondonLondonWC1E 6BTUK Centre for Planetary science University College London and Birkbeck CollegeLondonWC1E 7HXUK Innovation Center of Ore Resources Exploration Technology in the Region of Bedrock Ministry of Natural Resources of People’s Republic of China’Guiyang550000China Guizhou Bureau of Geology and Mineral Exploration and Development Guiyang550000China

The Ediacaran–Cambrian Phosphogenic Episode is the Earth’s first true phosphogenic event and resulted in worldwide phosphate deposits,which occurred during the processes of the Neoproterozoic Oxygenation *** Ediacaran Doushantuo Formation(ca.635–551 Ma)of Weng’an area in central Guizhou,south China,contains two economic phosphorite beds(the Lower and Upper Phosphorite Beds).This paper presents a detailed stratigraphic,sedimentological and mineralogical study of multiple outcrop and drill core sections of the Doushantuo Formation across the Weng’an area,and identified 11 lithofacies and 4 types of phosphatic *** differences in lithofacies and grain types between the upper and lower phosphate deposits are observed,indicating that the two sets of phosphate deposits are the products of two distinct phosphogenic *** Lower Phosphorite Bed mainly consists of banded and laminated phosphorites,contains micro-oncoids formed by microbially-mediated precipitation and peloids formed by in-situ chemically oscillating reactions,indicating a biochemical and chemical enrichment of phosphorus to sediments during the Early Ediacaran *** Upper Phosphorite Bed is mainly composed of carbonaceous,massive,and stromatolitic phosphorites,contains bioclasts(phosphatized spheroidal fossils),and intraclasts formed by hydrodynamic agitation,suggesting that the major accesses of phosphorus to sediments were the remineralization of organic *** of the two economic phosphorite beds was controlled by two sea-level *** differences have also been documented in contemporaneous phosphate-bearing successions in Brazil and Mangolia,indicating a significant shift in global phosphogenic mechanism during the early and middle Ediacaran,which may be due to the changes in redox conditions in seawater,associated with the Neoproterozoic Oxygenation *** regional active P-cycle processes could produce more free oxygen,which may have contributed to the up

关键词： phosphorite lithofacies phosphatic grains phosphogenic paragenesis phosphorus cycle mineralogy

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

基于自适应神经模糊推理系统的高速公路临界安全车距研究

引用

计算机工程与应用 2004年第8期40卷 199-201,208页

作者：侯志祥吴义虎刘振闻长沙交通学院汽车与机电工程系

汽车高速追尾是我国高速公路交通事故的主要形式之一,研究高速公路汽车临界安全车距对预防汽车追尾事故的发生具有积极的意义。文章通过对高速公路汽车临界安全车距的分析,提出了一种高速公路汽车临界安全车距的ANFIs(自适应神经模糊推... 详细信息

汽车高速追尾是我国高速公路交通事故的主要形式之一,研究高速公路汽车临界安全车距对预防汽车追尾事故的发生具有积极的意义。文章通过对高速公路汽车临界安全车距的分析,提出了一种高速公路汽车临界安全车距的ANFIs(自适应神经模糊推理系统)模型,经计算和对比分析,验证了该模型的有效性。

关键词：高速公路临界安全车距 ANFIs 模型仿真

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

Wireless sequential dual light delivery for programmed PDT in vivo

引用

Light(science & Applications) 2024年第6期13卷 1047-1061页

作者： Jiayi Liu Bowen sun Wenkai Li Han-Joon Kim shu Uin Gan John s.Ho Juwita Norasmara Bte Rahmat Yong Zhang department of Oncology The Second Xiangya HospitalCentral South UniversityChangshaHunan410011China department of Biomedical engineering College of Design and EngineeringNational University of SingaporeSingapore117585Singapore department of mechanical engineering College of Design and EngineeringNational University of SingaporeSingapore117576Singapore department of Electrical and Computer engineering College of Design and EngineeringNational University of SingaporeSingapore117583Singapore department of Medical IT Convergence engineering Kumoh National Institute of TechnologyGumi39253Republic of Korea department of surgery Yong Loo Lin School of MedicineNational University of SingaporeSingapore119228Singapore The N.1 Institute for Health National University of SingaporeSingapore117456Singapore Institute for Health Innovation and Technology National University of SingaporeSingapore119276Singapore department of Biomedical engineering College of EngineeringCity University of Hong KongKowloonHong Kong SARChina

Using photodynamic therapy(PDT)to treat deep-seated cancers is limited due to inefficient delivery of photosensitizers and low tissue penetration of *** nanocarriers are widely used for photosensitizer delivery,while the self-quenching of the encapsulated photosensitizers would impair the PDT ***,the generated short-lived reactive oxygen spieces(ROs)can hardly diffuse out of nanocarriers,resulting in low PDT ***,a smart nanocarrier system which can be degraded by light,followed by photosensitizer activation can potentially overcome these limitations and enhance the PDT efficacy.A light-sensitive polymer nanocarrier encapsulating photosensitizer(RB-M)was *** implantable wireless dual wavelength microLED device which delivers the two light wavelengths sequentially was developed to programmatically control the release and activation of the loaded *** transmitter coils with matching resonant frequencies allow activation of the connected LEDs to emit different wavelengths *** irradiation time,dose,and RB-M concentration were determined using an agent-based digital simulation *** vitro and in vivo validation experiments in an orthotopic rat liver hepatocellular carcinoma disease model confirmed that the nanocarrier rupture and sequential low dose light irradiation strategy resulted in successful PDT at reduced photosensitizer and irradiation dose,which is a clinically significant event that enhances treatment safety.

关键词： PDT overcome hardly

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

THEORETICAL DEsIGN AND MOTION PLANNING OF NONHOLONOMIC MANIPULATOR

引用

Chinese Journal of mechanical engineering 2004年第2期17卷 222-225页

作者： Tan Yuegang Deng Yuhui WU Zhengping school of mechanical and Electronic engineering,Wuhan university of Technology,Wuhan 430070, China department of science and Technology studies University College London WC1E 6BT UK school of mechanical and Electronic engineering Wuhan University of Technology Wuhan 430070 China

A new nonholonomic transmission mechanism is proposed based on thenonholonomic theory and nonlinear control principle, and combined with conditions of thenonholonomic motion planning and control, that is researched to compose method of the motiontransfer chain from this transmission mechanism, on which a new nonholonomic manipulator isdesigned. This nonholonomic manipulator is a controllable multi-joint manipulator that actuated onlyby two-servo electromotor. Its motion expresses the characteristic of nonholonomy constraint andnonlinear, and that also satisfies the chained form convertibility. And then, using the nonlinearcontrol principle of chained system, motion characteristic of the nonholonomic manipulator isapplied. From simulation verification and analysis, the usefulness of the theoretical design andcontrol strategies is shown, and that is important in design and research of handiness robot andmulti-finger robot hand.

关键词： Nonholonomic system Nonholonomic motion planning Nonlinear controlMulti-joint Manipulator

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

stiffness Characteristics of a Basic Nonlinear Air spring Model

引用

World Journal of engineering and Technology 2024年第3期12卷 455-465页

作者： Abdullah s. Alsuwaiyan department of mechanical engineering College of Engineering Qassim University Buraydah Saudi Arabia

This study predicts the characteristics of a compressible polytropic air spring model. A second-order nonlinear autonomous air spring model is presented. The proposed model is based on the assumption that polytropic processes occur. Isothermal and isentropic compression and expansion of the air within the spring chambers are the two scenarios that are taken into consideration. In these situations, the air inside the spring chambers compresses and expands, resulting in nonlinear spring restoring forces. The MATLAB/simulink software environment is used to build a numerical simulation model for the dynamic behavior of the air spring. To quantify the values of the stiffnesses of the proposed models, a numerical solution is run over time for various values of the design parameters. The isentropic process case has a higher dynamic air spring stiffness than the isothermal process case, according to the results. The size of the air spring chamber and the area of the air spring piston influence the air spring stiffness in both situations. It is demonstrated that the stiffness of the air spring increases linearly with increasing piston area and decreases nonlinearly with increasing air chamber length. As long as the ratio of the vibration’s amplitude to the air spring’s chamber length is small, there is good agreement in both scenarios between the linearized model and the full nonlinear model. This implies that linear modeling is a reasonable approximation of the complete nonlinear model in this particular scenario.

关键词： Air spring Dynamic stiffness state space Polytropic Modeling Isentropic Process Isothermal Process

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

煤层注水参数的数量化理论正交设计优化法

引用

系统工程理论与实践 2004年第3期24卷 139-143页

作者：秦书玉秦伟瀚李健辽宁工程技术大学电子与信息工程系辽宁阜新123000 天津工业大学机械电子学院天津300160

应用正交设计确定煤层注水工艺参数的最佳组合 ,对地质条件稳定的煤层是一种较好的方法 .但是 ,随着煤层注水工程的推进 ,地质因素不断变化 ,若仍采用该方法确定的工艺参数注水 ,其效果不一定满足注水工程的要求 .针对这种情况及影响煤... 详细信息

应用正交设计确定煤层注水工艺参数的最佳组合 ,对地质条件稳定的煤层是一种较好的方法 .但是 ,随着煤层注水工程的推进 ,地质因素不断变化 ,若仍采用该方法确定的工艺参数注水 ,其效果不一定满足注水工程的要求 .针对这种情况及影响煤层注水的地质因素既有定性变量 ,又有定量变量的特征 ,本文在利用正交设计优化研究的基础上 ,提出利用数量化理论确定地质因素为不稳定状态下的煤层注水工艺参数的最优组合 ,并结合实例进行了优化研究 .试验表明 ,此法节省注水试验工程量 ,接近实际工程要求 .

关键词：数量化理论优化工艺参数正交设计煤层注水

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

Use the Combination Finite Element Method to solve the Crack Cylinder of the Torsion Problem

Use the Combination Finite Element Method to Solve the Crack...

引用

2010 International Conference on Test and Measurement (ICTM2010)

作者： Xinyan Tang department of mechanical engineering engineering college of Nanjing Agricultural university Nanjing Jiangsu 210031 China

Based on Muskhelishvili’s theoretical expressions of the saint-Venant’s problem,using the combination of Crack3D code and Ansys software,a new combination finite element method to calculate the saint-Venant’s torsion problem including crack is *** order to illustrate its application,the numerical example for a torsion cylinder with crack are given and the numerical results are satisfactory.

关键词： combination finite element method crack cylinder torsion problem

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

高强度聚酰亚胺/Ag复合纳米纤维的制备与表征

引用

江西师范大学学报（自然科学版） 2012年第1期36卷 1-4页

作者：简绍菊胡晓婺邹燕陈水亮侯豪情武夷学院环境与建筑工程系福建武夷山354300 江西师范大学化学化工学院江西南昌330022

采用电纺及热亚胺化技术制备了聚酰亚胺/Ag纳米纤维复合材料,用X-射线衍射(XRD)、扫描电子显微镜(sEM)及透射电子显微镜(TEM)对纤维表面形貌及结构进行了表征,并研究其电学性能及力学性能.结果显示,随着银含量的增加复合纳米纤维膜的电... 详细信息

采用电纺及热亚胺化技术制备了聚酰亚胺/Ag纳米纤维复合材料,用X-射线衍射(XRD)、扫描电子显微镜(sEM)及透射电子显微镜(TEM)对纤维表面形貌及结构进行了表征,并研究其电学性能及力学性能.结果显示,随着银含量的增加复合纳米纤维膜的电导率逐渐提高.当Ag的质量分数为35%时,复合纳米纤维膜的导电率为2.8μs/cm,同时其拉伸强度高达240 MPa。

关键词：聚酰亚胺银静电纺丝力学性能

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

An Adaptive Model and Algorithm for an Electro-hydraulic Position servo system in Auto Gauge Control for Aluminum Hot Tandem Mill

引用

工程科学（英文版） 2007年第3期5卷 64-68页

作者： Li Fengyi1,Jin Xiaohong2,3,,Liu Yilun2(1.CHINALCO sWA Co.,,Chongqing,China,401326 2.college of mechanical and Electrical engineering,Central south university,Changsha,China,410083 3.Fluid Power Transmission and Control Institute,Wuhan university of science and Technology,Wuhan,China,430081)

The electro-hydraulic servo position control system(HPC) is the core of an auto gap control for a modern four-high continuous hot strip *** actuators are loaded with considerable external disturbances,rolling forces,and the system stiffness and position accuracy will become hypersensitive to the leakage and the compressibility of the *** efforts have being made to increase the position *** conventional resources are proportion-integral-differential(PID) *** the PID controller is faint for a considerable external *** this paper,by introducing the adaptive control strategy of model reference the reciprocities of the system structure with the loads were *** the Lyapunov energy function,an adaptive control algorithm applied to improve the system accuracy was *** system simulations and the selection of parameters of the model were also *** simulations show the static state errors at 0.02%.Finally,the industrial experimental result was given.

关键词： Lyapunov function adaptive control hydraulic position system four-high hot strip mill

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

Physiological Control of Rotary Left Ventricular Assist Device

Physiological Control of Rotary Left Ventricular Assist Devi...

引用

第二十六届中国控制会议

作者： Wu Yi department of mechanical engineering,Pennsylvania state university Erie,the Behrend college,Erie,PA 16563,U.s.A.

In rotary left ventricular assist device（LVAD）,physiological control system is the element to automatically regulate the pump speed to ensure enough perfusion of *** this paper,the design of the physiological control system of rotary LVADs is reviewed first,such as criteria of physiological control system,sensors/signals,and control *** the design of an adaptive optimal controller for permanent LVADs is discussed.A Matlab simulation program and an experimental mock circulatory loop are employed as test environments for the *** physiological conditions,such as the variation of left ventricular failures and the variation of activities are simulated to study the performance of the designed physiological *** and experimental results consistently show that the abnormal hemodynamic variables of a congestive heart failure patient are restored back to the normal physiological range by the designed controller.

关键词： physiological control rotary artificial heart pump left ventricular assist device pump head adaptive control

来源： cnki会议评论

在线全文

cnki会议

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：