辐射对血液流变效应的研究及动物全身照射后全血粘度的变化规律

本文结果表明经一次大剂量全身照射后的机体血液流变的主要特性为全血表观粘度先高粘后低粘的双向性变化,从照后第一天起即升高。随着放射病病程的发展,在早期有一个高粘峰,其峰均值比照前升高47.80％。但因不同动物、不同剂量、不同均速,不同血源而变化不同。     

Induction of immune tolerance with heart-thymus composite allotransplantation in rats

Objective To study on the role of thymus transplantation for heart allograft in rats. Methods Vascularized heart-thymus combined transplantation was performed with microsurgical technique. Graft survival, histopathology, level of IL-2, IL-4 and its mRNA expression in serum and cardiac grafts were investigated. Results Heart-thymus combined transplantation achieved effect in the prolongation of cardiac graft survival with short-term administration of cyclosporine. Conclusions Vascularized thymus transplantation induced immune tolerance in thymectomized rats.     

含锂霞石颗粒和硼酸铝晶须的铝基复合材料

为了制备具有低热膨胀系数和较高强度的复合材料，选用具有负体膨胀系数的β-锂霞石颗粒和高强度的硼酸铝晶须作为复合材料组分，用挤压铸造法制备了6061铝基复合材料，并对该复合材料的显微结构、拉伸性能和热膨胀性能进行了研究，结果表明，该复合材料能同时获得较低的热膨胀系数和较高的强度；通过改变复合材料中β-锂霞石和硼酸铝的体积分数，在较大的范围内可以对复合材料的强度和热膨胀系数进行设计和调节。     

A quantitative method for evaluating the performances of hyperspectral image fusion

Hyperspectral image fusion is a key technique of hyperspectral data processing. In recent years, many fusion methods have been proposed, but there is little work concerning evaluation of the performances of different image fusion methods. In this paper, a method called quantitative correlation analysis (QCA) is proposed, which provides a quantitative measure of the information transferred by an image fusion technique into the output image. Using the proposed method, the performances of different image fusion methods can be compared and analyzed directly based on the images of before and after performing the fusion. The correlation information entropy, based on the developed QCA, is also proposed and testified by numerical simulations. Typical hyperspectral data are applied to the proposed method. The results show that the method is effective, and its conclusions agree with the classification results in applications.     

Cramer-Rao bounds for parametric shape estimation in inverse problems

We address the problem of computing fundamental performance bounds for estimation of object boundaries from noisy measurements in inverse problems, when the boundaries are parameterized by a finite number of unknown variables. Our model applies to multiple unknown objects, each with its own unknown gray level, or color, and boundary parameterization, on an arbitrary known background. While such fundamental bounds on the performance of shape estimation algorithms can in principle be derived from the Cramer-Rao lower bounds, very few results have been reported due to the difficulty of computing the derivatives of a functional with respect to shape deformation. We provide a general formula for computing Cramer-Rao lower bounds in inverse problems where the observations are related to the object by a general linear transform, followed by a possibly nonlinear and noisy measurement system. As an illustration, we derive explicit formulas for computed tomography, Fourier imaging, and deconvolution problems. The bounds reveal that highly accurate parametric reconstructions are possible in these examples, using severely limited and noisy data.     

开展CAD／CAM／CAE工作提高矿用牙轮钻头设计研制水平

我国矿用牙轮钻头同世界先进水平相比有较大差距，大力开展矿用牙轮钻头CAD／CAM／CAE工作，促进学科交叉融合，是摆脱落后局面，参与全球性竞争的一项重要任务。     

低阶煤煤层气富集模式初探

通过对美国粉河盆地以及我国铁法盆地煤层气富集规律的解剖,总结出影响低阶煤煤层气富集的关键因素是封堵,而构造、岩性和水动力是形成煤层气封堵的主要因素。同时提出了5种不同的煤层气富集模式,即背斜模式、构造—水动力模式、构造—岩性模式、岩性—水动力模式和岩性模式。     

En/Decoder for Spectral Phase-Coded OCDMA System Based on Amplitude Sampled FBG

A novel en/decoder for spectral phase-coded optical code-division multiple-access system based on amplitude sampled fiber Bragg grating (FBG) is proposed. Both equivalent chirp and equivalent phase shift are achieved by amplitude sampling. Compared with previous en/decoder based on step chirped FBG, it is easier to fabricate. The performance of the proposed en/decoder is verified by both numerical simulation and experimental demonstration.