Radiosity with Well Distributed Ray Sets

In this paper we present a new radiosity algorithm, based on the notion of a well distributed ray set (WDRS). A WDRS is a set of rays, connecting mutually visible points and patches, that forms an approximate representation of the radiosity operator and the radiosity distribution. We propose an algorithm that constructs an optimal WDRS for a given accuracy and mesh. The construction is based on discrete importance sampling as in previously proposed stochastic radiosity algorithms, and on quasi Monte Carlo sampling. Quasi Monte Carlo sampling leads to faster convergence rates and the fact that the sampling is deterministic makes it possible to represent the well distributed ray set very efficiently in computer memory. Like previously proposed stochastic radiosity algorithms, the new algorithm is well suited for computing the radiance distribution in very complex diffuse scenes, when it is not feasible to explicitly compute and store form factors as in classical radiosity algorithms. Experiments show that the new algorithm is often more efficient than previously proposed Monte Carlo radiosity algorithms by half an order of magnitude and more.     

N_2/Fe(100)相互作用的动力学研究

用准经典轨迹法对N2－Fe（100）系统进行了研究，分析了氮分子在Fe（100）面上的直接散射和离解性吸附等过程中的能量传递和重新分配，阐明了表面催化的机理。作为准经典轨迹法更为深入的应用，研究了主要LEPS势参数和势特性对初始离解吸附几率（S0）的影响，得出了S0随势特性变化的规律。     

Spectral approximations of the Stokes problem by divergence-free functions

The method of Moser, Moin, and Leonard (1983) for the approximation of the three-dimensional Navier-Stokes equations using divergence-free subspaces is revisited and analyzed. It is shown that the computed velocity field converges to the physical one with spectral accuracy. Moreover, a method for recovering the pressure field is proposed. This method is stable and provides a pressure that converges to the physical one with spectral accuracy.     

Excavation of Inlet Tunnels at Geheyan Power Station

1　ＯｖｅｒｖｉｅｗＴｈｅＧｅｈｅｙａｎＰｏｗｅｒＳｔａｔｉｏｎｈａｓｆｏｕｒｃｉｒｃｕｌａｒｉｎｌｅｔｔｕｎ ｎｅｌｓ，ｏｎｔｈｅｒｉｇｈｔｂａｎｋｏｆｄａｍｓｉｔｅ，ｗｉｔｈｔｈｅｉｒｅｘｃａｖａｔｉｏｎｄｉ ａｍｅｔｅｒｏｆ 11．3ｍｔｏ 12．5ｍ，ａｆｔｅｒ ｌｉｎｉｎｇｄｉａｍｅｔｅｒｏｆ 9．5ｍ，ａｘｉｓ ｔｏ ａｘｉｓｓｐａｃｉｎｇｏｆ2 4ｍ．Ｔｈｅｔｈｉｃｋｎｅｓｓｏｆｐｉｌｌａｒｓａｒｅｅｑｕａｌｔｏｔｈｅｔｕｎｎｅｌｄｉａｍｅｔｅｒ．Ｔｈｅｉｎｔａｋｅｃｅｎｔｅｒｉｓａｔｅｌｅｖａ ｔｉ…     

Drying of Chestnuts (Castanea sativa Mill.) after Osmotic Dehydration with Sucrose and Glucose Solutions

Chestnuts were dehydrated by using a combined method of osmotic dehydration followed by air drying. Samples were osmotically pretreated with sucrose (60% w/w) and glucose (56% w/w) for 8 h, air-dried at temperatures of 45, 55, and 65°C, at a relative humidity of 30% and at a velocity of 2.7 m·s^-1 and the experimental data of the drying kinetics were obtained. Whole samples were dried with different peelings: (a) removal of endocarp and pericarp (peeled) and (b) additionally the internal rough surface (cut). In all cases, cut chestnuts show greater drying rates than peeled samples, indicating that a significant mass transfer resistance in the layer nearest to the surface takes place. Peeled samples pretreated with sucrose solutions behave in a similar way to untreated samples. For the rest of the samples, the cut samples osmotically treated with sucrose solutions and all the samples treated with the glucose solution, the drying rates decrease during drying. Drying kinetics are successfully modeled by employing a diffusional model that takes the shrinkage into account. The effective coefficient of water diffusion was evaluated and correlated with temperature. The quality of the final product was monitored by color change. In spite of the fact that the total color difference is not modified by the osmotic treatment, the L*, a*, and b* color coordinates of cut samples treated with sucrose and glucose solutions do undergo changes; the L* and a* coordinates change less than the b*.     

基于ANSYS的闩体刚强度有限元分析

闩体的刚度和强度必须满足设计要求。用有限元法对复杂结构件进行力学性能分析是非常有效的方法。采用ANSYS软件对闩体进行了刚度和强度分析,得出了有用的结论,可供相关设计借鉴。     

用MONTECARLO方法研究分光光度法在比色分析中的精度

对使用分光光度法进行比色分析时的误差特性及工作曲线的计算做了讨论，给出了在测试数据不等时的拟合工作曲线的最小二乘算法，并使用ＭｏｎｔｅＣａｒｌｏ方法定量地分析了测试精度与试验条件间的具体关系。     

动载荷下应力强度因子的边界元计算

用Ｎａｒｄｉｎｉ－Ｂｒｅｂｂｉａ边界元法计算了动载荷下的应力强度因子，与解析解及有限元解相比较，效果较好。最后对计算结果进行了分析讨论。     

固定床吸附器透过曲线参数优化方法

开发了一种固定床吸附器透过曲线参数估值的优化方法，用Ｂａｓｉｃ语言编制了运算程序，并在普及型２８６微机上考核了该法的可靠性，相对误差在１％以下，运算机时７．５ｍｉｎ。