深层前馈网络的单调同伦学习算法

本文研究前馈神经网络的结构以及快速二阶学习算法，首先提出一种能和适应分布网络结构的深层前馈网络模型，并利用构造性方法证明了该网络的通有逼近性质，为改进网络学习效率及大范围收敛性，提出了网络权值学习的单调同伦方法，该方法具有与牛顿法相同的二阶收敛性，数值实例显示了该方法的高效性与大范围收敛性，深层前馈网络模型具有自适应分布网络结构，高度非线性逼近性以及可实现快速学习算法等特点。     

Interaction between poly（amidoamine） dendrimers and DNA studied by spectroscopic methods

The interaction between amino-terminated, and ethylenedtamine core poly（amtdoamine） （PAMAM） dendrimers and herring sperm DNA was investigated by various spectroscopic methods including UV spectroscopy, fluorescence spectroscopy, microscopic FTIR- and circular dichroism （CD-） spectroscopy. Ethidium bromide （EB） is used as a nucleic acid probe for this study. Experimental results show that PAMAM dendrimers can form stable complexes with DNA and the dendrimers bind to DNA sufficiently strong which cannot be displaced by EB, and we also found that the formation of the complexes can cause the conformation change of the DNA secondary structure. According to the Scatchard analysis, the association constant of PAMAM to DNA is calculated to be 2.53×10^4 mol/L^-1.     

pH-responsive poly（2-diethylaminoethyl methacrylate）-functionalized multiwalled carbon nanotubes

Poly（2-diethylaminoethyl methacrylate） （PDEAEMA）-coated multiwalled carbon nanotubes （MWNT-PDEAEMA） were successfully prepared by MWNT-surface initiated atom transfer radical polymerization （ATRP）. The obtained MWNT-PDEAEMA nanocylinders have a core of MWNT and a shell of PDEAEMA and this core-shell structure was confirmed by TEM observations. The UV-Vis and AFM measurements showed that the MWNT-PDEAEMA exhibited obvious pH sensitivity. The solubility of PDEAEMA-coated MWNT dramatically decreased when pH increased to ca. 7.0. Because of the giant molecular weight of the molecular hybrids and local high density of polymeric grafts linked onto MWNTs, the resulting MWNT-PDEAEMA nanocomposites are easier to aggregate, or more sensitive to pH, as compared with the neat PDEAEMA.     

Behavior of MC3T3-E1 Osteoblast Cultured on Chitosan Modified with Polyvinylpyrrolidone

The physical and chemical properties of four kinds of modified chitosan materials made by blending chitosan with polyvinylpyrrolidone （PVP） were investigated. All four of these modified chitosan materials were hydrophilic with water contact angles ranging from 59°to 69°. Fourier transform-infrared spectra of the modified materials showed a new band at 1288 cm^-1, implying formation of a surface physical interpenetrating network structure. Enzyme linked immunosorbent assay results indicated that much less fibronectin was adsorbed on the modified materials than on only chitosan. The viability of MC3T3-E1 osteoblasts cultured on the materials was assessed by 3-（4,5-dimethyl-2-thiazolyl）-2,5-diphenyl- 2H-tetrazolium bromide assay. The results show that adding PVP10000 into the chitosan promotes adhesion of MC3T3-E1 osteoblasts on the modified materials, but has no effect on cell growth and proliferation; while adding PVP40000 reduces cell adhesion, growth, and proliferation. The results suggest that the increased hydrophilicity of the material surface does not always improve its biocompatibility, which will influence the selection and design of biomaterials.     

High resolution stalagmite δ18O records over the past 1000 years from Dongge Cave in Guizhou

Based on MC-ICP-MS U-series dating andstable O-isotope analysis results, a 4-5 years resolution monsoon record over the past 1000 years has been established for two stalagmites from Dongge Cave, Guizhou. The high resolution oxygen isotope record serves as a proxy for variations in rainfall of Asian southwest monsoon over the Yunnan-Guizhou Plateau. A close relation of the δ18O record with the A^14C record from tree rings largely reflects impact of centennial-scale solar activity on the monsoon climate changes. The conspicuous decrease in the δ18O value at AD 1720 indicates an abrupt increase in monsoon rainfall, suggesting that an atmospheric-oceanic couple over the tropical Indian Ocean plays an important role in rapid increase of the Northern Hemisphere temperature over the last century.     

系统辩证学视阈下的宇宙与人——乌杰《系统辩证学》解读之一

系统辩证学，是在马克思主义哲学基础上结合现代科学的研究成果和新的理论成就发展形成的哲学的科学，是一种新的世界观和方法论。在当今宇宙论的诸多论题中，时空有限还是无限、世界完美还是残缺以及人在宇宙中的位置是最重要也最困难的。以系统辩证学为思想和方法，尝试对以上三大宇宙论问题进行初步的系统辩证观的解读。     

Criterions and Measures of Route Selection of Shallowly Embedded Long.Distance Oil and Gas Pipeline in Mountain Areas

According to the engineering investigation of long-distance oil and gas pipelines, the criterions and measures of route selection are drawn as follows： the flat landform is the first choice in route alignment. The foot of mountain is the first choice when the route passes by the valley. The route should pass by but the shady and deposited slope and not in sunny and erosive slope as possible as it can. The pipeline should be vertical to contour climbing and descending the mountain except steep slope. Tunnel can be used in crossing foothill. Perpendicularly traversing the river is better than beveling; the worst choice is to put the pipeline along the river. Bypass is the best choice in karsts area. The order of route selection should be pre-choosing, investigation, optimization and adjustment.     

Deformation and Development Tendency of Shiliushubao Landslide by Numerical Modeling

On the basis of analysing basic features of Shiliushubao landslide, the landslide＇s deformation and development tendency are quantitatively studied by using FLA^3D program. The results accord with monitoring results. The results are indicated that resevoir impounding accelerates the landslide＇s deformation, and the variation of reservoir water level is key factor of affecting the deformation; The landslide has the characters of pull-behind move ment according to the displacement of the landslide body gradually reducing from leading edge to trailing edge; Excavating and deloading slow down the landslide＇s deformation in the certain degree. On the basis, the deformation developmental tendency of Shiliushubao landslide is predicted by the established simulating model.     

基于字符图像质量评价的打印机取证

为了认定打印文件的来源，提出一种基于字符图像质量评价的打印机取证方法，在分析字符打印区域“条带”噪声的基础上，通过高斯滤波对字符图像提取噪声，并借助图像质量评价方法提取噪声图像的统计特征，来描述每台打印机的个体特征，并采用支持向量机作为分类器，对比目前国外已有文献的方法，所提出的方法不仅10台打印机都判决正确，而且字符分类正确率有很大提高，字符图像质量特征抓住了打印机的个体特性，使取证结果有效且具有说服力。     

汽车主动悬架的约束预测控制

约束预测控制的最大优点之一是能优化被控系统的性能指标，并显式地处理被控系统的约束条件，使之动态满足。以某二自由度四分之一车为例，讨论了汽车主动悬架的约束预测控制(CMPC)问题：依次给出了状态反馈方法和输出反馈方法，并基于预测控制的滚动实施策略，提出了一种自适应约束预测控制方法。仿真结果表明，CMPC主动悬架能在确保操纵稳定性和保持较小作动力的情况下，满足悬架系统的输出约束，同时控制输出得以优化，明显提高了悬架系统的乘坐舒适性。