检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

智能信息处理与神经网络研究

数据采集与处理 2001年第1期16卷 10-13页

作者：阎平凡清华大学自动化系北京100084

从智能信息处理的角度讨论了模式识别研究中存在的一些主要问题 ,如 :特征抽取问题、结构识别问题、统计识别中的有限样本 (小样本 )问题及不适定问题。指出神经网络的研究不能停留在作为实现现有模式识别方法的一种工具上 ,而应着眼于... 详细信息

从智能信息处理的角度讨论了模式识别研究中存在的一些主要问题 ,如 :特征抽取问题、结构识别问题、统计识别中的有限样本 (小样本 )问题及不适定问题。指出神经网络的研究不能停留在作为实现现有模式识别方法的一种工具上 ,而应着眼于解决模式识别中的一些根本问题上。

关键词：智能信息处理模式识别神经网络统计学

The formation mechanism of high-quality dolomite reservoir in the deep of Puguang Gas Field

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2008年第S1期51卷 53-64页

作者： MA YongSheng 1 ,GUO TongLou 1 ,ZHAO XueFeng 2 &CAI XunYu 1 1 Southern Exploration&Production Company,Sinopec,Kunming 650200,china 2 china university of Mining and Technology,{3. 100083.china Southern Exploration & Production Company Sinopec Kunming 650200 China china university of Mining and Technology Beijing 100083 China

The discovery of Puguang Gas Field provides the exploration of china deep marine carbonate rock with important *** Puguang Gas Field,the dolomite reservoirs discovered in the deep are the best in the present of china,which present big thickness and wide-range distribution,and develop abundant secondary *** researches show that Puguang Gas Field bears the characteristics of early gas-filling time,deep burial,high matured organic matter and long-term interaction of hydrocarbon(oil and gas)-water-rock(carbonate reservoir).The developments of secondary pores in this area are affected by multiple diagenesis and their formation mechanisms are *** the research on depositional environment,sedimentary facies and reservoir porosity characters of Changxing and Feixianguan Formations,it is thought that high-quality dolomite reservoirs of Puguang Gas Field form on the favorable sedimentary facies belts,which are the integrate result affected by several factors including superficial corrosion,burial corrosion,overpressure and tectonic movement,among which burial corrosion of TSR to reservoir and overpressure formed by thermal evolution of organic matter have great effect on the formation of secondary porosity of Changxing and Feixianguan Formations.

关键词： deep high-quality reservoir dolomite corrosion Puguang Gas Field Sichuan Basin

Teleoperation System For Multiple Mobile Robots

在线全文

学校读者我要写书评

暂无评论

Teleoperation System For Multiple Mobile Robots

A quasi-geostrophic wavelet-spectrum model for barotropic atmosphere and its numerical solution

2011 Chinese Control and Decision Conference（CCDC）

作者： Xinda Song is with the Taiyuan university of Technology,ShanXi,china,.Xiangwei Hao is with the tsinghua university,{3. china..Huaping liu is with the tsinghua university,{3. china. Kezhong He is with the tsinghua university,{3. china. Meng Gao is with Shijiazhuang Railway Institute,Shijiazhuang,Hebei Province,china.

Teleoperation is an important strategy for controlling outdoor mobile *** determines the reliability and the fields of the mobile *** paper introduced a type of teleoperation system for multiple mobile *** image radio system ensured the image transmission channels of coherent image *** new data transmission system ensured that the data transmission is stable and *** of the guided remote control mode has increased operating *** of adding the GPS electronic map,the operator has wider *** we also designed a friendly man-machine interface and a good manipulative multi-functionary teleoperation *** preliminary experimental results verified the stability and the reliability of the system in performing teleoperation in complex environments in variety of fields.

关键词： Mobile Robots Teleoperation Guided Remote

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

Progress in Natural Science:Materials International 2004年第11期 48-54页

作者： DAI Xingang 1,2*, WANG Ping 3. and CHOU Jifan 2 (1. Key Laboratory of Regional Climate-Environment for Temperate East Asia, Institute of Atmospheric Physics, Chinese Academy of Sciences, START Regional Center for Temperate East Asia, beijing 100029, china 2. Department of Atmospheric Sciences, Lanzhou {3., Lanzhou 73.000, china 3. College of Physics, Peking {3., beijing 100871, china) KeyLaboratoryofRegionalClimate-EnvironmentforTemperateEastAsia InstituteofAtmosphericPhysicsChineseAcademyofSciencesSTARTRegionalCenterforTemperateEastAsiaBeijing100029China CollegeofPhysics PekingUniversity.Beijing100871China DepartmentofAtmosphericSciences LanzhouUniversityLanzhou730000.China

A quasi-geostrophic wavelet-spectrum model of barotropic atmosphere has been constructed by wavelet-Galerkin method with the periodic orthogonal wavelet bases. In this study a wavelet grid-spectrum transform method is designed to decrease the tremendous computation of the non{3.near interaction term in the model, and a two-dimensional Helmholtz equation from the model in a wavelet spectrum form is derived, and a solution with high precision under the periodic boundary condition is obtained. The numerical investigation manifests that the wavelet-spectrum model (WSM) could keep on running for a long time under the forcing of heating and topography. Although its numerical solution is compatible with the grid model (GM), the WSM is of a higher precision and faster convergence rate than GM's. A stationary solution comes forth when the model is forced only by the surface heating, whereas a quasi-periodic oscillation with a period about 15 days appears as considering the topography in the model. The latter oscillation, to some extent, is very similar to the Rossby index cycle of atmosphere over middle and high latitudes.

关键词： plane barotropic atmosphere wavelet-spectrum model wavelet grid-spectrum transform.

The Effect of Nb on Mechanical Properties of Quenching and Partitioning Steels

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 306-309页

作者： ZHU Shuai,KANG Yong-lin,REN Kang-kang,WANG Chuan (School of Materials Science and Engineering.university of Science and Technology beijing,beijing 100083.china) Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China

In order to study the effect of alloy elements on mechanical properties of quenching and partitioning steels,the Q and P heat treatments on different chemical composition steels were carried on in *** tensile test results indicated the strength of Nb+Ti-bearing steel was not increasing as expected,but lower than that of the Nb+Ti-free steel,and the elongation was raised to 26% from 9%.The Nb+Ti-bearing steel microstructures after tensile test were detected by TEM and found a certain amount of twins in the deformed microstructure while the deformed microstructure mainly was lath martensite in Nb+Ti-free steel,which means the addition of Nb and Ti elements could cause the twinning induced plasticity by inhibiting the phase transformation from austenite to *** on above analysis,adding trace Nb element could greatly increase the stacking fault energy of the retained austenite,which is beneficial to the formation of twins,and the formation of twins would lower the strength s{3.ghtly and raise the elongation drastically.

关键词： quenching and partitioning twinning induced plasticity niobium stacking fault energy

lithospheric seismic fabrics of Sulu ultrahigh-pressure metamorphic belt

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2005年第5期48卷 585-600页

作者： YANG Wencai 1 , YANG Wuyang 1 , JIN Zhenmin 2 & CHENG Zhenyan 1 1. Institute of Geology, Chinese Academy of Geological Sciences, beijing 10003., china 2. china {3. of Geosciences, Wuhan 43.074, china 1. Chinese Academy of Geological Sciences Institute of Geology 100037 Beijing China 2. china university of Geosciences 430074 Wuhan China

Calibration of seismic reflectors appearing in the crust of the Chinese continent sci- entific drilling site can be completed through the correlation studies between direct evidences, such as the drill cores, and geophysical signatures; therefore the interpretation of geophysical data could produce reliable results of crustal structure and composition. On the other hand, there are two Cenozoic volcanoes close to the scientific drilling site; analyzing composition of xenoliths existent in the volcanoes and evaluating their seismic velocities can also offer information about the mantle and lower crust. After the calibration via cores and well-logging data, the seismic re- flectors appearing in the UHP belt can be caused by lithological changes within the UHP rock slice, ductile shearing rock-suites, and later fracture zones. Among these sources, ductile shearing resulted in displacement and detachment of original rock-sheets, producing some rock-interbeds of several hundred meters thick that are named the ductile shearing rock-suites. A suite consists of mylonized gneiss and eclogite slices that underwent shearing, becoming the major mechanism responsible to generate regional strong reflections. The UHP rock-slice is characterized by complicated structures and high density, high seismic velocity and high electri- cal resistivity, its thickness is usually less than 11 km. Velocity and density of the gneiss-layer beneath gradually tend to normal with increasing depth. Based on the xenoliths we can infer that the middle crust contains a lot of gneisses, and the lower crust consists of different granulites. The lithospheric mantle has multi-layer structures and consists mainly of spinal lherzolite and harzburgite, implying late Mesozoic lithospheric thinning. The seismic fabrics with different ori- gins were possible products of different geodynamic processes. For instance, the UHP rock-slice was produced by the UHP metamorphic process and the exhumation of subducted supe

关键词： deep seismic reflection, ultrahigh-pressure belt, Sulu china, calibration of reflectors, lithospheric fabrics.

THE DEVELOPMENT OF A MICROCOMPUTER PROGRAM FOR THE THREE-DIMENSIONAL NON-liNEAR FEM

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 1993年第1期3卷 10-15,26页

作者： Ma. Mingjun liao, Guohua Fang Zulie university of Science Technology of {3., {3. 100083. china

This paper presents a microcomputer program system for the three-dimensional non-linear finite element method (FEM), which is developed for applications in mining engineering, such as excavation, filling, caving, damming, etc. Our attention is focused on some of the key aspects of the programing techniques for an applicable microcomputer program, such as the structure of the program, data processing in the core, communication between the core and mass storage, input and output systems, etc. In the last part of this paper, two test examples are presented verifying the computational accuracy of this programing system and illustrating its applicability in practical engineering.

关键词： Finite Element Method (FEM) Microcomputer Mining Engineering

Chemical characteristics of long-term acid rain and its impact on lake water chemistry:A case study in Southwest china

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第4期138卷 121-131页

作者： liuyi Zhang JiaWang Shuxiao Wang Chunbo Wang Fumo Yang Tingzhen li Chongqing Key Laboratory of Water Environment Evolution and Pollution Control in Three Gorges Reservoir Chongqing Three Gorges UniversityWanzhou 404000China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China College of Carbon Neutrality Future Technology Sichuan UniversityChengdu 610065China National Engineering Research Center on Flue Gas Desulfurization Chengdu 610065China

The chemical composition of acid rain and its impact on lake water chemistry in Chongqing,china,from 2000 to 2020 were studied in this *** regional acid rain intensity is affected jointly by the acid gas emissions and the neutralization of alkaline *** pH of precipitation experienced three stages of fluctuating decline,continuous improvement,and a slight *** pH showed inflection points in 2010,mainly due to the total control actions of SO_(2)and NO_(x)implemented in *** total ion concentrations in rural areas and urban areas were 489.08μeq/L and 618.57μeq/L,*** top four ions were SO_(4)^(2-),Ca^(2+),NH_(4)^(+)and NO_(3.^(-),which accounted for more than 90%of the total ion concentration,indicating the anthropogenic *** 2010,SO_(4)^(2-)fluctuated greatly while NO_(3.^(-)continued to rise;however,after 2010,both SO_(4)^(2-)and NO_(3.^(-)began to decline rapidly,with the rates of-12.03.eq/(L·year)and-4.11μeq/(L·year).Because the decline rate of SO_(4)^(2-)was 2.91 times that of NO_(3.^(-),the regional acid rain has changed from sulfuric acid rain to mixed sulfuric and nitric acid *** lake water is weakly acidic,with an average pH of 5.86,and the acidification frequency is 3..00%.Acidification of lake water is jointly affected by acid deposition and acid neutralization capacity of lake *** deposition has a profound impact on water acidification,and nitrogen(N)deposition,especially reduced N deposition,should be the focus of future research.

关键词： Acid rain Chemical composition Neutralization Nitrogen deposition Water acidification

A skarn-type lead-zinc deposit related to low ^(18)O magma

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第19期42卷 1636-1640页

作者： MU Baolei, SHAO Jian, WANG Guanyu, YAN Guohan and Al YongfuDepartment of Geology , Peking university, beijing 100871, china Department of Geology Peking University Beijing China

THE Baiyinnuo skarn-type lead-zinc deposit occurs within the Da Hinggan Mountains, in theBalinzuo County 3.0 km north of the Chifeng City, the Inner Mongolia Autonomous *** minerals and relevant igneous rocks in the deposits are extremely depleted in 18O. Thephenomena are also found in other skarn-type lead-zinc deposits in the Baiyinnuo region andshould be further studied.

关键词： low 18O magma skarn melasomatic fluid.