《奉使图》与《东游集》及郑玙等问题的考辨

《奉使图》是从《东游集》而来的。《东游集》中的诗都是阿克敦从前三次出使朝鲜的诗稿中选出来的,本来只是供蒋衡书法,但后来它的影响进一步扩大,于是阿克敦在第四次出使朝鲜时充分准备了作画的素材,并于雍正三年请当时在京城很活跃的海宁画家郑玙作了20幅画。     

Study on optimization of agent initial positions in land combat simulation

The use of computational-intelligence-based techniques in the optimization of agent initial positions in land combat simulations is studied. A novel method for the reduction of support vectors in the support vector machine (SVM) is presented. The optimization on the width of the Gaussian kernel function and the combination of the SVM with the radial basis function neural network are performed in the proposed method. Simulation results show that the proposed method can improve the running efficiency drastically compared with that using the traditional SVM with the same precision. We also summarize and present some experiences and trends in the study on the optimization problem in land combat simulation.     

Estimate of error bounds in the improved support vector regression

An estimate of a generalization error bound of the improved support vector regression(SVR)is provided based on our previous work.The boundedness of the error of the improved SVR is proved when the algorithm is applied to the function approximation.     

A two-stage algorithm of adaptive model-based parameter estimation and its application in the fast calculation of Green''s function in multi-layer soils

A two-stage algorithm is presented to determine an analytical model-based rational function by adaptively selecting sampling points. At the first stage, the rational interpolation function is created by using Stoer-Bulirsch algorithm and comparing the fitted model with the different ranks. At the second stage, the fitted model is validated by comparing with the first-principle model at a set of checking points. Some checking points will be added to the sampling series determined in the first stage to improve the fitted model. The new proposed algorithm is more accurate and effective than that using Stoer-Bulirsch interpolation only due to the fact that it appends the validation approach. When a highly oscillating curve is approximated, the validation ensures the fitting precision. With the two-stage MBPE algorithm, some time-consuming electromagnetic computations can be replaced by the interpolation from the fitting functions, which can increase the computational efficiency greatly. This method is used to calculate the samplings of the Green's functions in a multi-layer horizontal soil to demonstrate its effectiveness. The number of samples used to accurately model such Green's functions is less than 20 for the typical soil parameters. The computational time can be reduced by more than two orders of magnitude compared with that using the conventional uniform sampling technology.     

Study on Injection Moulding of High Precision Aspheric Plastic Lens

With the rapid development of information and multi me dia technologies, the demand for the optical plastic aspheric elements used in o pto-electronic devices, camera, optical disc and projector lens etc. has been i ncreased rapidly in the recent years. The key technologies of fabrication of asp heric plastic lens are the design and manufacturing moulds, selection of proper injection moulding equipment, and optimization of injection moulding parameters etc. In this paper, the effect of injection pressure,...     

广州市住宅室内PM2 . 5 排放源的定量计算

对广州市部分采样住宅室内、室外PM2.5的浓度进行了15 min平均的实时监测.室内浓度系列与室外浓度系列相比,出现多个明显的浓度峰,定性判断住宅室内存在一定的排放源.结合物质平衡模型、线性回归模型及室内外实时监测浓度线性拟合情况,定量计算住宅室内PM2.5排放源源强,结果表明3个采样住宅的PM2.5室内排放源的平均排放强度为6 417-9 779μg.h-1.     

不排水条件下全风化花岗岩残积土工程特性与本构模型

通过土工试验对不排水剪切条件下的饱和松散砂质土的工程特性进行了探讨 ,发现其在剪切时的应力 -应变关系呈现出加工软化特性 ,土体超过峰值强度后最终达到了变形的稳定状态 .基于稳定状态概念 ,将临界土力学理论与非线性应力 -应变关系相结合 ,建立了非线性应力 -应变 -临界状态本构模型 .采用香港钻石山地区全风化花岗岩残积土的不排水三轴试验结果 ,确定了有关模型参数 ,验证了所建议本构模型的合理性     

溅射气压对ZnO薄膜的影响

采用射频磁控溅射的方法,通过改变溅射气压,在玻璃衬底上沉积出具有C轴择优取向的ZnO薄膜。用X射线衍射仪（xRD）、扫描电子显微镜（SEM）和原子力显微镜（AFM）对不同溅射气压下ZnO薄膜的结构、断面和表面形貌进行研究分析。结果表明,随着溅射气压的降低,ZnO薄膜的（002）取向增强,薄膜的厚度增加,沉积速率加快,氧化锌薄膜的沉积速率从4nm／min升高到21nm／min。在溅射压强为2．5Pa时制备的ZnO薄膜粗糙度最小,大小为5．45nm。     

土工织物加筋土坡变形和破坏过程的离心模型试验

为了评价土工织物加筋土坡的稳定性,研究了土工织物对土坡变形和破坏过程的影响。在清华大学离心机上进行了自重加载条件下离心模型试验。采用离心场图像采集和非接触位移测量系统,测量了加载过程中土坡的位移场及其发展变化过程,对比了素土坡与土工织物加筋土坡的破坏模式和变形发展过程。试验结果表明:土工织物明显改变了土坡的破坏形态,滑裂面位置明显前移;土工织物的约束作用使得土体的变形趋向均匀,增强了土体的整体稳定性。