云南丽江旅游的发展与大研古镇的发展方向问题

一、发展过程与现状 (一)古城和雪山完美地结合,特点突出,古镇拉动效应明显 丽江有丰富的旅游资源,如独特的东巴文化、古城、雪山等等。经过一段时间发展,丽江旅游产品也形成几个比较突出的亮点,如古城-雪山产品,古城如此完整,雪山的风貌如此突出,而且古城和雪山在不大的地理范围内集中到一起,这在国内是很难得的。古城被评为世界文化遗产后还形成了一个显著的市场拉动效应。     

声光效应拉曼-内斯方程矩阵级数解法及声光调制器优化设计

提出一种求解正常声光相互作用拉曼 内斯 (Raman Nath)方程的矩阵级数解法 ,该解法直观方便且具有普遍性。计算结果表明 ,对Q =4 1π ,Bragg衍射的效率只有 97 5 % ;对非对称入射 ,以往的Raman Nath近似解误差较大 ;指出提高Bragg衍射效率的有效途径在于提高声光频率比并给出计算声光器件最优长度的计算公式。     

A Neural Network Approach for Signal Detection in Digital Communications

In this paper, we propose a new approach for signal detection in wireless digital communications based on the neural network with transient chaos and time-varying gain (NNTCTG), and give a concrete model of the signal detector after appropriate transformations and mappings. It is well known that the problem of the maximum likelihood signal detection can be described as a complex optimization problem that has so many local optima that conventional Hopfield-type neural networks fail to solve. By refraining from the serious local optima problem of Hopfield-type neural networks, the NNTCTG makes use of the time-varying parameters of the recurrent neural network to control the evolving behavior of the network so that the network undergoes the transition from chaotic behavior to gradient convergence. It has richer and more flexible dynamics rather than conventional neural networks only with point attractors, so that it can be expected to have much ability to search for globally optimal or near-optimal solutions. After going through a transiently inverse-bifurcation process, the NNTCTG can approach the global optimum or the neighborhood of global optimum of our problem. Simulation experiments have been performed to show the effectiveness and validation of the proposed neural network based method for the signal detection in digital communications.     

超高分子量聚乙烯的辐照效应

通过密度测定和ＤＳＣ热分析，观测了超高分子量聚乙烯的辐射效应。实验结果表明：在吸收剂量０—１．１３ＭＧｙ范围内，密度随吸收剂量的增加而增大，熔化热和熔点也有所增加，特别是在低剂量范围内增加十分明显。以上结果都说明，超高分子量聚乙烯在辐照过程中，结晶在完善或有新的结晶形成     

一种多晶硅高温压力传感器

制作压力传感器时，在二氧化硅层上淀积多晶硅膜，既可利用优良的机械特性，又可保证压敏电阻与衬底间具有良好的绝缘性，由此可大大提高器件的温度特性。介绍了一种多晶硅压力传感器的原理和设计。实验结果表明，这类传感器具有灵敏度好，精度高等特点，电路工作范围为０－２５０℃，且具有良好的温度稳定性。     

Scientific and artistic investigation of multi-dimensional fractals on the AT & T pixel machine

The pipelined architecture and parallel organization of the AT&T Pixel Machine image computer are described and demonstrated with applications for the visualization of multidimensional fractals, particularly linear fractals and quaternion/ stacked Julia sets. Techniques for pushing the Pixel Machine to its peak abilities are described and apply to more recent parallel image computers as well.     

高氧化态（Ⅱ─Ⅳ）三核金属簇合物构型的人工神经网络判别方法

本文运用一典型的人工神经网络模型─“反向传播”模型，对高氧化态（Ⅱ─Ⅳ）三核金属簇合物的构型分布进行了分析，得到了较好的分类、预报结果为化合物结构分析提供了新的工具。     

Bacteriophage lambda: transactivation, positive control and other odd findings

The purpose for this study was to evaluate the results of silicone oil use in patients who have undergone vitrectomy for proliferative vitreoretinopathy (PVR). The authors reviewed the 5-year results of 50 consecutive patients (52 eyes) with grade C1/D3 PVR operated on in 1987. Silicone oil has been removed in 42 eyes. The retina remained attached in 38 eyes. Visual acuities were finger counting in 12 eyes and 0.1 or greater in 19 eyes. Glaucoma was thought to be the major cause of loss of visual acuity after an initial improvement (9 eyes), as well as the most frequent complication of surgery (13 eyes). Silicone oil was deemed nonremovable in 10 operated eyes. A questionnaire was developed to determine the patients' perceptions of the use of silicone oil, and 46 patients responded to the questionnaire. Four patients indicated that they would not have elected to have surgery again. Six patients thought that surgery was not worthwhile, but would permit treatment again. Most patients thought that a modest amount of improvement had taken place and that vision was stable. Subjectively, most patients believed that surgery was worthwhile.