86 resultados para 3D CAD


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本文着重从仪器本身参数方面和样品方面讨论了由于各参数的不同,对电子结合能的影响。通过半导体CdS膜的研究,探讨了Cd 3d5/2,Cd 3d3/2特征峰结合能的变化规律,分析了这种变化在测试中带来的影响。

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3DMove software, based on the three-dimension structural model of geologic interpretation, can forecast reservoir cracks from the point of view of formation of the structural geology, and analyze the characteristics of the cracks. 3DMove software dominates in forecasting cracks. We forecast the developments and directions of the cracks in Chengbei buried hill with the application of forecasting technique in 3DMove software, and obtain the chart about strain distributing on top in buried hill and the chart about relative density and orientation and the chart about the analysis of crack unsealing. In Chengbei 30 buried hill zone, north-west and north-east and approximately east-west cracks in Cenozoic are very rich and the main directions in every fault block are different. Forecasting results that are also verified by those of drilling approximately accord with the data from well logging, the case of which shows that the technique has the better ability in forecasting cracks, and takes more effects on exploration and exploitation of crack reservoir beds in ancient buried hill reservoirs.

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A novel manganese superoxide dismutase (MnSOD) was cloned from bay scallop Argopecten irradians by 3' and 5' rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of MnSOD was of 1207 bp with a 678 bp open reading frame encoding 226 amino acids. The deduced amino acid sequence contained a putative signal peptide of 26 amino acids. Sequence comparison showed that the MnSOD of A. irradians shared high identity with MnSOD in invertebrates and vertebrates, such as MnSOD from abalone Haliotis discus discus (ABG88843) and frog Xenopus laevis (AAQ63483). Furthermore, the 3D structure of bay scallop MnSOD was predicted by SWISS-MODEL Protein Modelling Server and compared with those of other MnSODs. The overall structure of bay scallop MnSOD was similar to those of zebrafish Danio rerio, fruit fly Drosophila melanogaster, Chinese shrimp Fenneropenaeus chinensis, human Homo sapiens, and had the highest similarity to scallop Mizuhopecten yessoensis and abalone H. discus discus. A quantitative real-time PCR (qRT-PCR) assay was developed to detect the mRNA expression of MnSOD in different tissues and the temporal expression in haemocytes following challenge with the bacterium Vibrio anguillarum. A higher-level of mRNA expression of MnSOD was detected in gill and mantle. The expression of MnSOD reached the highest level at 3 h post-injection with V. anguillarum and then slightly recovered from 6 to 48 h. The results indicated that bay scallop MnSOD was a constitutive and inducible protein and thus could play an important role in the immune responses against V anguillarum infection. (c) 2008 Elsevier Ltd. All rights reserved.

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分析了当前 CAD和 RP系统间数据模型的各种转换方法,并指明了进一步的发展方向。 STL交换标准的局限和不足已日趋明显,由 CAD模型直接分层得到的 CLI格式将成为与 STL文件并存的一种接口格式。

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微观尺度下的观测与操作是进行微纳米科学技术研究与实现、微纳米特性发现与利用、加工制造的重要技术手段。因此微纳米操作的关键技术问题主要包括两个方面:微纳米操作的观测成像,通过成像微纳米尺度下的物体可以被观测者所感知和观测;利用感知与观测信息指导微纳米尺度下机械操作控制。深度信息在计算机视觉的研究中占有着重要的地位,它使我们更好地理解现实世界中物体的3D关系。因此,利用深度信息实现3D测量逐渐被应用于微纳米操作的观测成像领域。工作域显微图像是唯一能反映被控目标体运动和位置的反馈信息,自然对象的深度信息也只能从此中获得。虽然很难自动地从这个平面图像中获得,但根据显微镜点扩散模型的光学特点,可以构造合理的模糊度判据,实现对象深度信息恢复。本文作者以微观尺度下的3D视觉观测与可视化为应用背景,通过分析几何光学成像中的各种成像规律。建立图像的模糊度判据,并利用该判据完成了微观尺度下的3D视觉观测与可视化。主要工作包括:(1)分析光学成像的基本原理,了解光学成像过程中聚焦和离焦成像现象发生条件和描述方法;分析图像清晰/模糊程度与景物深度变化之间的关系规律,进而给出基于光学图像信息的微观景物深度测量理论依据;(2)结合序列图像的清晰/模糊程度变化规律,分析不同测度算子对于清晰/模糊程度响应的灵敏度与适应性;提出建立适宜的模糊测度算子方法。(3)基于模糊测度算子和模糊化测度分布模型,提出建立微观尺度下的显微视觉图像与实际景物的模糊度-深度关系模型的获取实验方法。设计实验系统与实验方法,完成微观3D视觉观测;(4)通过基于模糊化测度的微观景物深度信息获取研究,提出微观景物的3D重建方法,实现微观尺度下的3D重建及其可视化方法,完成实验验证。本文就微纳米技术研究中的显微成像离焦现象进行了分析,给出了建立基于模糊测度的微米尺度下离焦度与景物深度信息关系的方法;分析了不同梯度算子所具有的不同模糊测度响应;并以实验验证了利用这种模糊测度可以对微观尺度下的景物进行深度信息获取,并且利用深度信息进行3D重建。

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文章概要地介绍了CAD/CAM系统的结构、CAD/CAM一体化的工作流程,提出实现CAD/CAM一体化的几种可行方案,并以具体零件机床为例,给出从设计到数控编程和机床加工的全过程。

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Soil-rock mixture (S-RM) refers to one extremely uneven loose rock and soil materials system with certain stone content. Its formation has started since Quaternary and it is composed of block stone, fine grained soil and pore with certain project scale and high strength. S-RM has extensive distribution in nature, especially in southwest China where the geotectonic background is complicated, the fracture activity is developed and the geomorphological characteristics of high mountain and steep gorge area are protuberant. This kind of complicated geologic body has developed wider in these areas. S-RM has obvious difference with the general soil or rock (rock mass) in physical and mechanical properties because its two components-“soil” and “rock-block” has extreme differences in physical and mechanical properties. The proposition of S-RM and its deep research are needed in the modern engineering construction. It is also the necessity in the modern development of rock and soil mechanics. The dissertation starts from the meso-structural characteristics of soil-rock and takes a systematic research on its meso-structural mechanics, deformation and failure mechanism and the stability of S-RM slope. In summary, it achieves the following innovative results and conclusions. There are various views on the conception of S-RM and its classification system. Based on the large number of field tests, the dissertation makes the conception and classification of S-RM more systematic. It systematically proposed the conception of meso-structural mechanics of S-RM. Thus the dissertation has laid a foundation for its deep study. With the fast development of the computer technology and digital image processing theory, digital image processing technology has been successfully applied in many fields and provided reliable technology support for the quantitative description of the structural characteristics of S-RM. Based on the digital image processing technology, the dissertation systematically proposes and developed the quantitative analysis method and quantitative index for the meso-structure of S-RM. The results indicate that the meso-structure such as its internal soil-rock granularity composition, the soil-rock shape and the orientability has obvious self-organization in the macro statistical level. The dissertation makes a systematic research on the physical mechanical properties, deformation and failure mechanism of S-RM based on large field test. It proposes the field test for the underwater S-RM and deduces the 3D data analysis method of in-situ horizontal push-shear test. The result indicates that S-RM has significant phenomenon of shear dilatancy in the shearing process, and its dilatancy will be more obvious with the increased proportion of rock or the decreased confining pressure. The proportion of rock has great effect on the strength of S-RM and rock-block, especially the spatial position of particles with comparatively big size has great effect on the shape and spatial position of the sample shear zone. The dissertation makes some improvements in the single ring infiltration test equipment and its application on the permeability of S-RM. The results indicate that the increasing of rock-block would make it more difficult for the soil to fill in the vacuity between the rock-block and the proportion would increase which would result in the increased permeability coefficient. The dissertation builds the real meso-structural model of S-RM based on the digital image processing technology. By using geometric reconstruction technology, it transfers the structural mode represented by Binary image into CAD format, which makes it possible to introduce the present finite element analysis software to take research on numerical experimental investigation. It systematically realizes leaping research from the image,geometric mode, to meso-structural mechanics numerical experiment. By using this method, the dissertation takes large scale numerical direct-shear test on the section of S-RM. From the mesoscopic perspective, it reveals three extended modes about the shear failure plane of S-RM. Based on the real meso-structural model and by using the numerical simulation test, the character and mechanics of seepage failure of S-RM are studied. At the same time, it builds the real structural mode of the slope based on the analysis about the slope crosssection of S-RM. By using the strength reduction method, it takes the research on the stability of S-RM and gets great achievements. The three dimensional geometric reconstruction technology of rock block is proposed, which provides technical support for the reconstruction of the 3D meso-structural model of S-RM. For the first time, the dissertation builds the stochastic structure model of two-dimensional and three-dimensional polygons or polyhedron based on the stochastic simulation technique of monte carlo method. It breaks the traditional research which restricted to the random generation method of regular polygon and develops the relevant software system (R-SRM2D/3D) which has great effect on meso-structural mechanics of S-RM. Based on the R-SRM software system which randomly generates the meso-structural mode of S-RM according to the different meso-structural characteristics, the dissertation takes a series of research on numerical test of dual axis and real three-axis, systematically analyses the meso destroy system, the effects of meso-structural characteristics such as on the stone content, size composition and block directionality on the macro mechanical behavior and macro-permeability. Then it proposes the expression of the upper and lower limit for the macro-permeability coefficient of the inhomogeneous geomaterials, such as S-RM. By using the strength reduction FEM, the dissertation takes the research on the stability of the slope structural mode of the randomly formed S-RM. The results indicate that generally, the stability coefficient of S-RM slope increases with the increasing of stone content; on the condition of the same stone content, the stability coefficient of slope will be different with different size composition and the space position of large block at the internal slop has great effect on the stability. It suggests that meso-structural characteristics, especially the space position of large block should be considered when analyzing the stability of this kind of slope and strengthening design. Taking Xiazanri S-RM slope as an example, the dissertation proposes the fine modeling of complicated geologic body based on reverse engineering and the generation method of FLAC3D mode. It resolves the bottleneck problem about building the fine structural mode of three-dimensional geological body. By using FLAC3D, the dissertation takes research on the seepage field and the displacement field of Xiazanri S-RM slope in the process of reservoir water level rising and decreasing. By using strength reduction method, it analyses the three-dimension stability in the process of reservoir water level rising and decreasing. The results indicate that the slope stability firstly show downward trend in the process of reservoir water level rising and then rebound to increase; the sudden drawdown of reservoir water level has great effect on the slope stability and this effect will increase with the sudden drawdown amplitude rising. Based on the result of the rock block size analysis of S-RM, and using R-SRM2D the stochastic structure model of Xiazanri S-RM slope is built. By using strength reduction method, the stability of the stochastic structure model is analysis, the results shows that the stability factor increases significantly after considering the block.

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