直达列车取送车顺序的优化

本文根据组合最优化原理将直达列车最佳取送车顺序的绝对计算法简化为分析计算法,使之更便于实际应用.     

利用微机检验物理实验数据

本文研究了利用计算机检验各种仪表达数正确与否的方法，给出有效数字运算正确性的检验方法．可以用来检验实验数据处理过程和实验结果．     

介电量子阱中激子的Stark效应

在考虑像势影响的情况下，利用变分的方法计算了垂直电场下无限深介电势阱中激子的结合能，得到了像势对激子结合能的修正随阱宽、电场强度以及阱垒介电函数之比的变化曲线，我们发现：考虑像势影响对激子结合能及其Ｓｔａｒｋ效应的修正是很有意义的，而且自像势和互像势对Ｓｔａｒｋ效应的影响是相反的。     

关于城镇体系的区域与结构研究——以湖北省宜昌地域为例

城镇体系是我国近年来城市地理和城市规划研究的重要课题之一。城镇体系的研究应主要是在区域背景研究基础上对其职能、空间和规模等三大结构的研究。据此,本文具体地分析了湖北省宜昌地域的经济社会发展对城镇体系的影响,提出了该体系结构的发展设想:(1) 建立以区域型工、矿业城镇性质为核心的职能结构;(2) 建设东、中、西均衡分布、各具特色的空间结构;(3) 加强两宜城镇群建设,组成中小结合的规模结构。     

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.     

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.