Orientation effects of deformed nuclei on the production of superheavy elements

Within the dinuclear system model, the effects of the relative orientations of interacting deformed nuclei on the interaction potential energy surfaces, the evaporation residue cross sections of some cold fusion reactions leading to superheavy elements are investigated. The competition between fusion and quasifission is studied to show the effect of the orientation. It turns out that the belly-belly orientation is in favor of the production of superheavy nuclei, because in the case a barrier has suppressed the quasifission and thus helped fusion.

The influence of nuclear orientation in fusion dynamics

Fusion barriers have been calculated for different orientations of the axial symmetry axis of deformed projectile-and target-nucleus. Using the concept of dinuclear system, considering the strong competition between fusion and quasifission processes, by solving the master equation numerically to calculate the fusion probability of superheavy nuclei, we have estimated the dependence of the fusion probabilities for Ge-76 + Pb-208 and Ca-48 + Pu-244 on the orientation angles of the symmetry axis of projectile-and target-nucleus, which shows that belly-belly is the most favorable orientation for synthesizing superheavy nuclei.

低能He~(2+)入射He原子转移电离实验中出射电子成像研究；Momentum image of emission electrons in transfer ionization process of slow He~(2+) colliding on He

利用反应显微谱仪对70keV He2+-He转移电离过程中的出射电子进行了成像,研究了出射电子的空间速度分布特征.结果表明:电子主要集中在散射平面内;在散射平面内,电子速度分布介于零与入射离子速度Vp之间(即前向出射)且在散射离子和靶核核间轴处有一极小值,呈现出典型的双峰结构.出射电子的上述分布特征可由出射电子波函数σ振幅和π振幅的干涉进行定性解释,σ振幅和π振幅对出射电子波函数的贡献与碰撞参数相关.在小碰撞参数下,π振幅的贡献更加明显;而在大碰撞参数下,σ振幅的贡献更加显著.

Controlled crystallinity and crystallographic orientation of Cu nanowires fabricated in ion-track templates

The hallmark of materials science is the ability to tailor the structures of a given material to provide a desired response. In this work, the structures involving crystallinity and crystallographic orientation of Cu nanowires electrochemically fabricated in ion-track templates have been investigated as a function of fabrication condition. Both single crystalline and polycrystalline nanowires were obtained by adjusting applied voltages and temperatures of electrochemical deposition. The anti-Hall-Petch effect was experimentally evidenced in the polycrystalline nanowires. The dominant crystallographic orientations of wires along [111], [100], or [110] directions were obtained by selecting electrochemical deposition conditions, i.e., H2SO4 concentration in electrolyte, applied voltage, and electrodeposition temperature.

Orientation and alignment of reagent molecules by two-photon excitation

The expressions used for describing the angular distribution of oriented and aligned reagent molecules are derived. The algebraic forms of orientation and alignment parameters of molecules in the excited states are obtained for two-photon excitation. The reagent molecules after absorbing two-photon may produce the higher order orientation and alignment than doing one-photon. (C) 2002 Elsevier Science B.V. All rights reserved.

Controlling the orientation and alignment of reagent molecules by a polarized laser

The expressions used for controlling the alignment and orientation of reagent molecules are derived. The problem to the control of the orientation and alignment of reagent molecules by the polarization direction and propagation direction of laser is discussed.

Partially Supervised Neighbor Embedding for Example-Based Image Super-Resolution

Neighbor embedding algorithm has been widely used in example-based super-resolution reconstruction from a single frame, which makes the assumption that neighbor patches embedded are contained in a single manifold. However, it is not always true for complicated texture structure. In this paper, we believe that textures may be contained in multiple manifolds, corresponding to classes. Under this assumption, we present a novel example-based image super-resolution reconstruction algorithm with clustering and supervised neighbor embedding (CSNE). First, a class predictor for low-resolution (LR) patches is learnt by an unsupervised Gaussian mixture model. Then by utilizing class label information of each patch, a supervised neighbor embedding is used to estimate high-resolution (HR) patches corresponding to LR patches. The experimental results show that the proposed method can achieve a better recovery of LR comparing with other simple schemes using neighbor embedding.

Image Ratio Features for Facial Expression Recognition Application

Video-based facial expression recognition is a challenging problem in computer vision and human-computer interaction. To target this problem, texture features have been extracted and widely used, because they can capture image intensity changes raised by skin deformation. However, existing texture features encounter problems with albedo and lighting variations. To solve both problems, we propose a new texture feature called image ratio features. Compared with previously proposed texture features, e. g., high gradient component features, image ratio features are more robust to albedo and lighting variations. In addition, to further improve facial expression recognition accuracy based on image ratio features, we combine image ratio features with facial animation parameters (FAPs), which describe the geometric motions of facial feature points. The performance evaluation is based on the Carnegie Mellon University Cohn-Kanade database, our own database, and the Japanese Female Facial Expression database. Experimental results show that the proposed image ratio feature is more robust to albedo and lighting variations, and the combination of image ratio features and FAPs outperforms each feature alone. In addition, we study asymmetric facial expressions based on our own facial expression database and demonstrate the superior performance of our combined expression recognition system.

Image reconstruction by an alternating minimisation

This paper focuses on the problem of incomplete data in the applications of the circular cone-beam computed tomography. This problem is frequently encountered in medical imaging sciences and some other industrial imaging systems. For example, it is crucial when the high density region of objects can only be penetrated by X-rays in a limited angular range. As the projection data are only available in an angular range, the above mentioned incomplete data problem can be attributed to the limited angle problem, which is an ill-posed inverse problem. This paper reports a modified total variation minimisation method to reduce the data insufficiency in tomographic imaging. This proposed method is robust and efficient in the task of reconstruction by showing the convergence of the alternating minimisation method. The results demonstrate that this new reconstruction method brings reasonable performance. (C) 2010 Elsevier B.V. All rights reserved.