73 resultados para Ultrasonographie 3D


Relevância:

20.00% 20.00%

Publicador:

Resumo:

By using a correction factor of d electron effects on bond, PV theory is applied to the calculation of chemical bond;parameters of d transition-metal compounds. Racah parameters and Mossbauer isomer shifts are calculated, and the results are agreement with the experimental values.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

用比较力场分析研究了 3 ,4 二甲基 4 ( 3 羟基苯基 )哌啶及其衍生物类吗啡拮抗物的结构与抑食活性的关系 ,考察了网格结构和探针原子的影响 .结果表明 ,立体效应和静电作用场是描述其抑食活性和进行结构性能关系研究的最重要的结构参数

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文利用 PV理论通过考虑 3 d电子对晶体化学键的影响,计算了若干 3 d过渡金属化合物的化学键参数并运用于Racah参数和穆斯堡尔谱同质异能位移的研究,计算得到的结果与实验值符合的很好。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

研究了甾族化合物的结构与抗炎活性相关性的三维构效关系,采用比较分子力场分析法(CoMFA)寻找结构与活性的关系,建立了一个可靠的构效关系模型,为活性分子的进一步修饰和改造提供了信息。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

With XRD, R-T, and ac chi measurements a comparative study on the doping effects of 3d elements in Bi(1.5)Pb(0.2)Sr(2)Ca(2)Cu(2.8)M(0.2)O(y) (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, or Zn) has been carried out. The effects of the former five members are significantly different, both on phase formed and on T-c, from the latter four. It seems that the effect on phase stabilization correlates with the valency of the doped cation. In connection with the instability of the 2223 phase, the correlation has been discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

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。

Relevância:

20.00% 20.00%

Publicador: