Edge-preserving wavelet thresholding for image denoising

In this paper we consider a general setting for wavelet based image denoising methods. In fact, in both deterministic regularization methods and stochastic maximum a posteriori estimations, the denoised image is obtained by minimizing a functional, which is the sum of a data fidelity term and a regularization term that enforces a roughness penalty on the solution. The latter is usually defined as a sum of potentials, which are functions of a derivative of the image. By considering particular families of dyadic wavelets, we propose the use of new potential functions, which allows us to preserve and restore important image features, such as edges and smooth regions, during the wavelet denoising process. Numerical results are presented, showing the optimal performance of the denoising algorithm obtained.     

MAB,a generally applicable molecular force field for structure modelling in medicinal chemistry

Summary The mathematical formulation, parametrization scheme, and structural results of a new, generally applicable molecular force field are presented. The central features are a scheme for automatic parameter assignments, the consistent united-atom approximation, the absence of atom types other than elements, the replacement of electrostatic terms by geometrical hydrogen-bonding terms, the concomitant lack of a need for partial atomic charge assignment and the strict adherence to a finite-range design. As a consequence of omitting all hydrogen atoms, optimal hydrogen-bond patterns are computed dynamically by appropriate network analyses. For a test set of 1589 structures, selected from the Cambridge Structural Database solely on the grounds of a given element list and criteria for high structure refinement, the agreements are on average 2 pm for bonds, 2° for valence angles and 10 to 20 pm for the root-mean-square deviation of atom positions, depending somewhat on size and flexibility of the structures. More qualitative testing of large-scale structural properties of the force field on proteins and DNA oligomers revealed satisfactory performance.     

Formulation of the Fourier transform in the spectral domain technique

A way to formulate the transform in spectral domain technique is presented.     

uu→ss过程的胶子交换势与pp→ΛΛ过程的反应截面

本文给出了夸克－反夸克对　湮没和夸克－反夸克对　产生过程的单胶子和双胶子交换势准至Ｐ２／ｍ２级近似的形式，据此推出了ｕｕ→ｓｓ过程的等效位势．应用这个位势在平面波玻恩近似（ＰＷＢＡ）下计算　→　反应的微分截面和总截面，得到了与实验符合得较好的结果．     

酸度对亚甲基蓝电极电位影响的电化学研究

本文报导了用玻碳电极,自制多孔玻碳切片光透电极,对亚甲基蓝(MB)在不同酸度条件下进行循环伏安法及光谱电化学研究,根据实验解释了酸度对亚甲基蓝电极电位的影响。     

A boundary element method for a non-linear free surface problem

In this paper a numerical method to compute the wave resistance of a body submerged in a free stream of finite and infinite depth is presented. Non-linear effects on the free surface are taken into account by an iterative procedure; the solution is in the form of a single-layer potential. For the 2D problem, results are shown for both the cases of finite and infinite depth of the fluid domain, with special emphasis on the supercritical flow in which the consistency of the scheme is pointed out. The method is also extended to the 3D case of a spheroid submerged in deep water. All the results presented are compared with experimental data and analytical solutions available in the literature.     

Optimal control of dams

Assume that a dam has a capacity V. Its water input I={I_t, t ? [0, ∞)}], is assumed to be a diffusion process. The water is released at one of two rates 0 and M units of water per unit of time. The release rate is 0 until the water reaches level λ(0 < λ < V), when the water is released at rate M until it reaches level λ, (0 ≤ τ < λ). Once the level λ is reached, the release rate remains at zero until level λ is reached again, and the cycle is repeated. Under general cost structure, we discuss and review some of the most recent work in the area of optimal control of dams with release policies of the above type; we also discuss some new results and corrections to some existing results.     

均匀性度量的势函数模型

分析了均匀性度量应满足的基本条件，根据物理学的势和力的模型，提出了均匀性度量的势函数模型，该模型较好地解决了均匀性度量的可计算性、布点的均匀性调整方法等问题；而且具有均匀性度量所应该具有的所有优良性质，如旋转对称性、平移对称性、中心对称性等。最后给出了应用实例，并就低维投影的均匀性问题和势函数模型的改进作了讨论。      

金刚石（111）附H表面分子簇模型的边缘效应对势能计算的影响

通过计算甲基吸附于金刚石（１１１）附Ｈ表面及金刚石（１１１）附Ｈ表面脱Ｈ过程的势能及其它物理参量的变化，讨论了边缘效应对势能计算的影响，给出了这一影响的数量级及进一步修正边缘效频的方法。     

高温下H_2─Ar、H_2O─CO_2混合气体中H_2O分子谱线的半宽度

本文用ＩＯＳ方法和我们改进的Ｂｕｃｋｉｎｇｈａｍ势计算了Ｈ２Ｏ—Ａｒ、Ｈ２Ｏ—ＣＯ２混合气体中Ｈ２Ｏ分子谱线在高温下（６００Ｋ、９００Ｋ、１２００Ｋ、１５００Ｋ）的压力展宽半宽度。分析了谱线半宽度随温度变化的规律，同时也讨论了半宽度和被加宽分子大小的关系。