基于三坐标测量的复杂曲面边界线的获取与构建

提出了利用三坐标测量机测量曲面边界线、获取曲面边界点数据和构建曲面边界线的方法。     

广义塑性力学在边坡稳定性分析中的应用

有限元法进行边坡稳定性分析时。常采用传统塑性力学的本构关系得到应力应变值。但大量土工实验证明传统塑性力学理论不适于分析土体变形．广义塑性力学理论对于解决土体变形有很好的优越性，将此理论应用到边坡稳定性分析中，计算结果更能符合实际．     

应用响应面法优化PEG引发甜玉米种子的条件

将响应面分析法(RSA)应用于提高种子活力条件的筛选。以聚乙二醇(PEG)浓度、引发时间2个因素5个水平的组合对甜玉米种子进行处理,观察种子活力变化,经过SAS软件分析,发现在因素范围内,发芽势、发芽率、发芽指数、平均发芽时间、获利指数均能找到最佳处理组合。进一步进行主成分分析(PCA),发现当PEG浓度13.33%,引发时间24.57 h时,发芽势、发芽率、发芽指数分别为65.21%,74.29%,9.82。     

Effects of roller burnishing process parameters on surface roughness of A356/5%SIC composite using response surface methodology

In this study, a simple roller burnishing tool was made to operate burnishing processes on A356/5%SIC metal matrix composite fabricated by electromagnetic stir casting under different parameters. The effects of burnishing speed, burnishing force and number of burnishing passes on the surface roughness and tribological properties were measured. Scanning electron microscopy （SEM） graphs of the machined surface with PCD （insert-10） tool and roller burnished surface with tungsten carbide （WC） roller were taken into consider- ation to observe the surface finish of metal matrix composites. The mechanical properties （tensile strength, hardness, duc- tility） of A356/5%SIC metal matrix composites were studied for both unburnished samples and burnished samples. The results revealed that the roller burnished samples of A356/ 5%SIC led to the improvement in tensile strength, hardness and ductility. In order to find out the effects of roller bur- nishing process parameters on the surface roughness of A356/ 5%SIC metal matrix composite, response surface methodol- ogy （RSM） （Box-Behnken design） was used and a prediction model was developed relevant to average surface roughness using experimental data. In the range of process parameters, the result shows that roller burnishing speed increases, and surface roughness decreases, but on the other hand roller burnishing force and number of passes increase, and surface roughness increases. Optimum values of burnishing speed （1.5 m/s）, burnishing force （50 N） and number of passes （2） during roller burnishing of A356/5%SIC metal matrix com- posite to minimize the surface roughness （predicted 1.232 μm） have been found out. There was only 5.03% error in the experimental and modeled results of surface roughness.     

超细矿物粉体增强材料的研究与开发

本文在实验测试和统计的基础上,从微粉粒径、粒型等结构特点出发,研究超细微粉经过表面活性处理,与基体材料复合后,表现出独特的物理、化学性质的机理,继而依据此机理开发出各种超细矿物粉体增强材料.     

横向延展,“场”“面”横生——中国古代诗歌语言的空间特性试论

中国古代诗歌在语言构成上的一个重要特点是横向延展,而不同于散文和西方诗歌常见的纵向线性延伸。这使得诗歌语言成为一种＂面＂型语言,这种特点之所以在中国古代诗歌中表现得最为典型,根本的原因在于汉语是最不重视句子的关系框架的＂流块语言＂;同时也与古代诗歌的题材有一定关系——模山范水客观上要求语言的横向延展,近体诗与山水诗实乃异名同体。＂面＂型语言的进一步发展,就形成为一种气化的语义场,成为＂场＂型语言。     

基于光谱混合分析的城市植被覆盖度与地表温度关系的研究

分别选择NDVI和光谱混合分析植被组分(VF)作为城市植被覆盖度指示因子,研究植被覆盖度与地表温度(LST)的相关关系.选择了一定数量的样本点,通过线性拟合的方法研究了NDVI及VF与LST的相关关系.研究结果表明,VF与LST之间的相关性比NDVI与LST之间相关性更好.研究表明,在城市LST研究中VF可以作为表征植被性质的参数.     

极小旋转曲面的生成曲线

用分析的方法导出了极小旋转曲面的生成曲线的方程。     

Reclaiming America: the quest for home in Shawn Wong’s Homebase

ABSTRACT

With its dynamic narrative, Shawn Wong's Homebase recounts the story of four generations of a Chinese family searching for a homebase on the land of the United States. Personal experiences, family chronicles, and Chinese American history are portrayed through various forms, including short stories, correspondences, student essays, memories, and dreams. A major theme of the novel is geographically and spiritually “reclaiming America,” or attempts by Chinese Americans to make the United States their “real” home. The protagonist's way to reclaim America involves revisiting landmarks and other places in the United States where his father and grandfather had traveled, through which he tries to discover the meaning of his own life in the United States and thereby to find his personal identity and home in this country. In drawing the topography of Chinese American history, Shawn Wong not only inscribed Chinese American presence on those places where the protagonist's forefathers had lived and worked, but also used legends to implant their heritage into those soils. Shawn Wong hopes that through his writing he can build for Chinese Americans a history, a cultural foundation with myths and legends of their own. Only when a people's myths spread over the land they inhabit can the land truly be considered theirs. The Chinese American identity shaped in Homebase is heroism, rooted in the ethnic identity of the male Chinese American in the American West, and this is the “home” that the protagonist as well as many other Chinese Americans ever quest for.     

西北干旱区地表水与地下水资源转换的几个问题探讨

从山区至平原，地表水与地下水之间在不同地质地貌单元相互转换，是我国西北干旱区山前平原水资源的主要特点，直接影响到水资源开发利用模式的变化。随着和水利用率不断提高，减少了地下水补给来源，引起地下水位下降，泉水量削减，甚至枯竭，迫使泉灌区边城井灌。这在水资源西藏高原、森林资源、持续发展