测量顺序对实验影响的研究

本文研究了双棱镜干涉测钠光波长、测液体粘滞系数(落球法)实验中物理量测量顺序对实验结果的影响,得出选择合理的测量顺序有利于节约实验时间、利于提高实验精度。指出在实验中对测量顺序的选择应该引起足够的重视。     

小商塬丹阳村滑坡影响因素及成因分析

在分析了丹阳村滑坡形成的地质环境。滑坡特征及成因的基础上。对滑坡进行了有限元数值分析及评价，揭示了影响该滑坡稳定的主要内在因素。据此提出了相应的建议。     

我国旅游经济增长对星级饭店规模的弹性系数分析——基于Panel—Data模型

文章选取2001～2010年全国31个省域的数据,基于panel—data模型,采用空间面板回归和聚类分析方法,研究中国省域星级饭店规模与旅游经济增长的关系。按照旅游经济增长对星级饭店规模的弹性系数,将全国分为四类地区。研究发现：各类区域星级饭店对旅游经济的影响程度有很大差异,且存在一定的空间相关性。对于部分星级饭店规模已趋于饱和的省域,应注重星级酒店的市场营销,发展经济型酒店和家庭旅馆;而对于弹性系数较大的区域,则应加强发展星级酒店,扩大星级酒店的规模,提高接待水平。     

一种测量鱼体积的简便方法

确定鱼体积是正确评价变动食物条件下鱼体组成变化的关键.提出了一种测定鱼体积的简便方法,并以鲫鱼为实验对象初步评价了该方法的可靠性.结果表明,利用排水法可方便地测量出体质量17～55 g的鲫鱼体积.为获得较为可靠的结果需进行至少3次测量,测量结果变异系数为2％～10％.     

高分三号SAR影像L1A级产品精处理方法

L1A级影像产品是中国高分三号SAR卫星产品发布的初级产品形式。为实现后续科学研究、增值应用,提出一套完整的L1A级产品处理流程,用以生成辐射纠正产品、几何纠正产品等高级产品形式。在辐射纠正过程中,为剔除L1A级产品量化过程中存在空值和零值像素对辐射纠正结果造成的统计偏差,基于高分三号等效噪声系数提出改进的辐射纠正方法。在几何纠正中,提出RPC参数反算算法确定影像角点坐标,基于xml元数据文件中提供的轨道方向、视向以及采样间隔参数保证反算方法的稳健性,在几何校正重采样部分引入SAR滤波算子实现等效视数的提升。对使用Envi5.5软件无法完成几何校正的部分高分三号影像,使用本文提出的处理流程可以顺利完成,其处理结果通过与同为C波段的Sentinel-1影像辐射精度,以及Sentinel-2光学影像几何精度的对比,表明本方法对L1A产品进行处理的精确性和可靠性。     

浅析我国死刑的存废

死刑是人类刑罚史上最为严厉的刑种 ,而死刑的存废也并不完全取决于所谓当前的国情。没有一个国家会对重罪轻罚的 ,作为法治国家 ,建立一个公正的犯罪惩罚机制以打击犯历时保护人民正常生活是毫无疑问的 ,然而一个国家的治理如果不以道德和基本人权为基本理念 ,则这个国家与其说是落后 ,不如说是不够文明开化。世界上大多数国家已经废除了死刑 ,但仍有不少国家以维护大多数人的利益为名义仍保留死刑 ,这篇文章尝试支持废除死刑的观点。     

高等数学对关联基础课的相关性影响

通过对学生成绩的抽样统计,采用数理统计分析方法得出高等数学对相关基础课--大学物理、线性代数、概率论与数理统计的成绩都有影响,从而肯定了高等数学在理工科学科中的基础性地位.     

Determination of Diffusion Coefficient and Analysis of Diffusion Factors of Cr(Ⅵ) Ion in Clay Soil

Some laboratory diffusion tests were conducted with diffusion device to determine the diffusion coefficient of Cr(Ⅵ) ion passing through Dalian red clay samples. The concentrations of Cr(Ⅵ) at different places of the samples were then measured spectrophotometrically after a standing time of 1 000 d. A one-dimensional solute transport equation was used to simulate the transport of Cr(Ⅵ) through clay samples. Back-calculation of diffusion coefficient of Cr(Ⅵ) was made with finite difference method. Parametric...     

Experimental performance of TJR02 as an alternative refrigerant to R22 in a small-scale cold storage

A refrigerant mixture TJR02 was developed and the comparison experiment was performed on a singlestage vapor compression refrigeration system originally designed for R22.Experimental results show that TJR02 can be directly used in the system without modifying the original system or changing lubricant.By replacing R22 with TJR02,cooling rate gets faster and at least 20% of energy is saved.The actual detection in the standard test-bed verifies the experimental results and indicates that the adoption of TJR02 leads to greater efficiency and wider application.And the lower the refrigeratory temperature is,the more obvious the energy saving effects will be.     

Damage identification in beam-type structures using pseudo strain energy density and grey relation coefficient

Based on pseudo strain energy density （PSED） and grey relation coefficient （GRC）, an index is proposed to locate the damage of beam-type structures in time-domain. The genetic algorithm （GA） is utilized to identify the structural damage severity of confirmed damaged locations. Furthermore, a systematic damage identification program based on GA is developed on MATLAB platform. ANSYS is employed to conduct the finite element analysis of com- plicated civil engineering structures, which is embedded with interface technique. The two-step damage identification is verified by a finite element model of Xinxingtang Highway Bridge and a laboratory beam model based on polyvi- nylidens fluoride （PVDF）. The bridge model was constructed with 57 girder segments, and simulated with 58 meas- urement points. The damaged segments were located accurately by GRC index regardless of damage extents and noise levels. With stiffness reduction factors of detected segments as variables, the GA program evolved for 150 generations in 6 h and identified the damage extent with the maximum errors of 1% and 3% corresponding to the noise to signal ratios of 0 and 5%, respectively. In contrast, the common GA-based method without using GRC index evolved for 600 generations in 24 h, but failed to obtain satisfactory results. In the laboratory test, PVDF patches were used as dynamic strain sensors, and the damage locations were identified due to the fact that GRC indexes of points near damaged ele- ments were smaller than 0.6 while those of others were larger than 0.6. The GA-based damage quantification was also consistent with the value of crack depth in the beam model.