28 resultados para information technology research


Relevância:

90.00% 90.00%

Publicador:

Resumo:

银纳米晶体掺杂的高非线性石英光纤的全光转换应用

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Tb/Yb共掺的石英光纤的上转换绿光发光研究,研究了最佳浓度配比和发光机理。

Relevância:

90.00% 90.00%

Publicador:

Resumo:

University of Twente; Centre for Telematics and Information Technology; Netherlands Organisation for Scientific Research; Jacquard; Capgemini

Relevância:

90.00% 90.00%

Publicador:

Resumo:

We report development of a new fiber doped with PbSe quantum dots for nonlinear optical applications. PbSe quantum dots related absorption peaks were obtained at 1021, 1093 and 1351 nm. The resonant optical nonlinearity and attenuation at 1500 nm were measured to be 9.4 × 10−16 m2/W and 0.01 dB/m, respectively. The emission around 1540 nm was observed upon near resonant pumping at 1064 nm.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This paper gives definitions of urban forest and describes the research contents about this comprehensive subject.It provides an overview of the past and current research on urban forest from three aspects:the analysis about the structure of urban forest,the ecological values,and the planning and management of urban forest.This paper also holds a discussion about the development on this important subject.It includes urban forest and hydrology,urban forest and global climate change,analysis of urban rural ecotone interface,and the application of modern information technology in urban forest.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

With long-term marine surveys and research, and especially with the development of new marine environment monitoring technologies, prodigious amounts of complex marine environmental data are generated, and continuously increase rapidly. Features of these data include massive volume, widespread distribution, multiple-sources, heterogeneous, multi-dimensional and dynamic in structure and time. The present study recommends an integrative visualization solution for these data, to enhance the visual display of data and data archives, and to develop a joint use of these data distributed among different organizations or communities. This study also analyses the web services technologies and defines the concept of the marine information gird, then focuses on the spatiotemporal visualization method and proposes a process-oriented spatiotemporal visualization method. We discuss how marine environmental data can be organized based on the spatiotemporal visualization method, and how organized data are represented for use with web services and stored in a reusable fashion. In addition, we provide an original visualization architecture that is integrative and based on the explored technologies. In the end, we propose a prototype system of marine environmental data of the South China Sea for visualizations of Argo floats, sea surface temperature fields, sea current fields, salinity, in-situ investigation data, and ocean stations. An integration visualization architecture is illustrated on the prototype system, which highlights the process-oriented temporal visualization method and demonstrates the benefit of the architecture and the methods described in this study.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Collision detection is an important component in simulation applications which are based on virtual geographic information system (VGIS). In this paper, an effective collision detection algorithm for multiple objects in VGIS, VGIS-COLLIDE, is presented. The algorithm firstly integrates existing quadtree, which is the global hierarchical structure of VGIS, with axis-aligned bounding box of object to perform the broad-phase of collision detection. After that, exact collision detection between two objects which have passed the broad-phase of collision detection is performed. The algorithm makes no assumption about input primitives or object's motion and is directly applicable to all triangulated models. It can be applicable to both rigid and deformable objects without preprocessing. The performance of the algorithm has been demonstrated in several environments consisting of a high number of objects with hundreds of thousands of triangles.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Based on the RS and GIS methods, Siping city is selected as a study case with four remote sensing images in 25 years. Indices of urban morphology such as fractal dimension and compactness are employed to research the characteristics of urban expansion. Through digital processing and interpreting of the images, the process and characteristics of urban expansion are analysed using urban area change, fractal dimension and compactness. The results showed that there are three terms in this period. It expended fastest in the period of 1979~1991, and in the period of 1992~2001, the emphases on urban redevelopment made it expended slower. And this is in agreement with the Siping Statistical Yearbook. This indicates that the united of metrics of urban morphology and statistical data can be used to satisfactorily describe the process and characteristics of urban expansion. © 2008 IEEE.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Static correction is one of the indispensable steps in the conventional onshore seismic data processing, particularly in the western part of China; it is theoretically and practically significant to resolve the issue of static correction. Conventional refraction static correction is put forward under the assumption that layered medium is horizontal and evenly distributed. The complicated nature of the near surface from western part of China is far from the assumption. Therefore, the essential way to resolve the static correction problem from the complex area is to develop a new theory. In this paper, a high-precision non-linear first arrival tomography is applied to solve the problem, it moved beyond the conventional refraction algorithm based on the layered medium and can be used to modeling the complex near surface. Some of the new and creative work done is as follows: One. In the process of first arrival tomographic image modeling, a fast high-order step algorithm is used to calculate the travel time for first arrival and ray path and various factors concerning the fast step ray tracing algorithm is analyzed. Then the second-order and third-order differential format is applied to the step algorithm which greatly increased the calculation precision of the ray tracing and there is no constraint to the velocity distribution from the complex areas. This method has very strong adaptability and it can meet the needs of great velocity variation from the complicated areas. Based on the numerical calculation, a fast high-order step is a fast, non-conditional and stable high-precision tomographic modeling algorithm. Two, in the tomographic inversion, due to the uneven fold coverage and insufficient information, the inversion result is unstable and less reliable. In the paper, wavelet transform is applied to the tomographic inversion which has achieved a good result. Based on the result of the inversion from the real data, wavelet tomographic inversion has increased the reliability and stability of the inversion. Three. Apply the constrained high-precision wavelet tomographic image to the static correction processing from the complex area. During tomographic imaging, by using uphole survey, refraction shooting or other weathering layer method, weathering layer can be identified before the image. Because the group interval for the shot first arrival is relatively big, there is a lack of precision for the near surface inversion. In this paper, an inversion method of the layer constraint and well constraint is put forward, which can be used to compensate the shallow velocity of the inversion for the shot first arrival and increase the precision of the tomographic inversion. Key words: Tomography ,Fast marching method,Wavelet transform, Static corrections, First break

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Now low porosity and low permeability reservoir is one of the main targets of exploration for the onshore oilfields of China. Most of the reservoirs are none flowing because of bad formation percolation condition, poor gas oil ratio , low formation pressure coefficient and other factors. In the recent years, a number of domestic oilfields have carried out some research work and achieved some success on oil testing and production technology in such formation. But by now, there is still no systematic and mature technology, particularly testing technology in none flowing formation is still needed further study. Based on study the key problem of well testing and interpretation technology in none flowing formation, solve the important problems in well testing technology, continuously improve and innovate geological information acquisition technology for none flowing reservoir, accurately acquire boundary information and evaluate reservoir flow characteristics. Its wide application remarkable result has shown. The main results and cognitions obtained from research are as follows: 1. This new technology research results help solve the occurrent problems in well testing process for none flowing formations, such as small investigation radius, poor representative of interpretation results from the poor data, low level application of interpretation results. This new technology helps create favorable conditions for early precise reservoir evaluation and reduction of the risk of exploration. 2. The technological difficulties for none flowing well testing are successfully solved by using none flowing formation combined mechanical tool string .This method has been proved by its applications to be able to improve the efficiency of the testing and the quantity of the acquired test data ,and so as to enhance the application of the interpretation results of the test in development of oil fields. 3. The application of the rotary formation tester, selective test valve, well testing string and their allier tools help to resolve problems such as the operation of opening and shutting-in the well under different well conditions, to broaden the scope of well test technology for none flowing formations. 4. Refined Testing Technique for production Wells has greatly shortened the testing dwration and improved the efficiency and accuracy of operation, enriched test results, and at the same time created conditions for conducting multi-well interference well testing.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In order to carry out high-precision three-dimensional "integration" for the characteristics of the secondary seismic exploration for Biyang Depression, in the implementation process, through a combination of scientific research and production, summed up high-precision seismic acquisition, processing and interpretation technologies suitable for the eastern part of the old liberated areas, achieved the following results: 1. high-precision complex three-dimensional seismic exploration technology series suitable for shallow depression Biyang block group. To highlight the shallow seismic signal, apply goal-based observing system design, trail from the small panel to receive and protect the shallow treatment of a range of technologies; to explain the use of three-dimensional visualization and coherent combination of full-body three-dimensional fine interpretation identification of the 50-100 m below the unconformity surface and its formation of about 10 meters of the distribution of small faults and improve the small block and stratigraphic unconformity traps recognition. 2. high-precision series of three-dimensional seismic exploration technology suitable for deep depression Biyang low signal to noise ratio of information. Binding model using forward and lighting technology, wide-angle observation system covering the design, multiple suppression and raise the energy of deep seismic reflection processing and interpretation of detailed, comprehensive reservoir description, such as research and technology, identified a number of different types of traps. 3. high-precision seismic exploration technology series for the southern Biyang Depression high steep three-dimensional structure. The use of new technology of seismic wave scattering theory and high-precision velocity model based on pre-stack time migration and depth migration imaging of seismic data and other high-precision processing technology, in order to identify the southern steep slope of the local structure prediction and analysis of sandstone bedrock surface patterns provide a wealth of information.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Through years of practice, reservoir management has already become the basic mode of foreign oil companies to realize the high-efficient development of the oil field. From the view of reservoir development and technological economy, reservoir management regards the study of the reservoir engineering, designs of reservoir projects and the dynamic analysis of the reservoir's performance as a system. In the fields of reservoir description, the establishment of the geological models and development models, the dynamic simulations of reservoir exploitation and the design of the oil engineering, reservoir management emphasizes the cooperation of the geology and the engineering, the combination of the engineering technology and the economic evaluation. In order to provide the means and basis for the reservoir geology study, reservoir evaluation, reserves calculation, numerical simulation, development plan and risk analysis, it adopts the reservoir management activities(team work) to make and implement the optimized oil field development management strategies so that secientific and democratic decision making can be achieved. Under the planned economic system for a long time, the purpose of Chinese reservoir development has been to fulfill the" mandatory" production task. With the deepening of the reform, the management organization of Chinese petroleum enterprises has been gradually going through the transition and reforms to the operational entity and the establishment of the mode of oil companies under the socialist market economy system. This research aims at introducing the advanced reservoir management technique from foreign countries to further improve the reservoir development results and wholly raise the economic benefits of Chinese mature land facieses sandstone reservoirs in the later stage of the water flooding. We are going to set up a set of modern reservoir management modes according to the reservoir features, current situation and existing problems of GangXi oil field of DaGang oil company. Through the study and implementation of the reservoir description and numerical simulation technology effectively, we plan to work out integrated adjustment projects, to study the related technology of oil recovery; to set up the effective confirmable data procedure and data management system of the reservoir management, to establish the coordinated model and workbench related to geology, engineering and economy in order to realize the real time supervision and evaluation on the process of reservoir development. We hope to stipulate modernization management tools for GangXi oil fields to rationally utilize various kinds of existing technological methods and to realize the economic exploitation and achieve the maximum benefits from the reservoir. The project of the modem reservoir management will be carried out on the GangXi oil field of DaGang oil company for this oil field is typical and has integrated foundamental materials and perfect networks. Besides, it is located in the good geographical position enjoying very convenient traffic. Implementing modern reservoir management will raise the recovery ratio, reduce the production cost and improve the working efficiency. Moreover, the popularization of modern reservoir management will improve the comprehensive benefits of DaGang oil company and even the whole Petro China. Through the reserch of this project, the following technical indicators can be reached: Establishing the concept of modern reservoir management. Establishing a set of integrated data information management system adapt to the features of GangXi reservoir. 3. Forming technical research modes of modern reservoir management suitable for mature reservoirs in the later developing stage. 4. Advancing projects of GangXi reservoir which are maxium optimized in engineering technique and economic benefits of oil exploitation. Besides, this set of technology, research principle and method can guide the mature reservoir of DaGang oil field and even the whole PetroChina to develop the further research of reservoir adjustment and improve the reservoir recovery factor and developing level constantly.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Study of 3D visualization technology of engineering geology and its application to engineering is a cross subject which includes geosciences, computer, software and information technology. Being an important part of the secondary theme of National Basic Research Program of China (973 Program) whose name is Study of Multi-Scale Structure and Occurrence Environment of Complicated Geological Engineering Mass(No.2002CB412701), the dissertation involves the studies of key problems of 3D geological modeling, integrated applications of multi-format geological data, effective modeling methods of complex approximately layered geological mass as well as applications of 3D virtual reality information management technology.The main research findings are listed below:Integrated application method of multi-format geological data is proposed,which has solved the integrated application of drill holes, engineering geology plandrawings, sectional drawings and cutting drawings as well as exploratory trenchsketch. Its application can provide as more as possible fundamental data for 3Dgeological modeling.A 3D surface construction method combined Laplace interpolation points withoriginal points is proposed, so the deformation of 3D model and the crossing error ofupper and lower surface of model resulted from lack of data when constructing alaminated stratum can be eliminated.3D modeling method of approximately layered geological mass is proposed,which has solved the problems of general modeling method based on the sections or points and faces when constructing terrain and concordant strata.The 3D geological model of VII dam site of Xiangjiaba hydropower stationhas been constructed. The applications of 3D geological model to the auto-plotting ofsectional drawing and the converting of numerical analysis model are also discussed.3D virtual reality information integrated platform is developed, whose mostimportant character is that it is a software platform having the functions of 3D virtualreality flying and multi-format data management simultaneously. Therefore, theplatform can load different 3D model so as to satisfy the different engineeringdemands.The relics of Aigong Cave of Longyou Stone Caves are recovered. Thereinforcement plans of 1# and 2# cave in phoenix hill also be expressed. The intuitiveexpression provided decision makers and designers a very good environment.The basic framework and specific functions of 3D geological informationsystem are proposed.The main research findings in the dissertation have been successfully applied to some important engineering such as Xiangjiaba hydropower station, a military airport and Longyou Stone Caves etc.