河道施工降水对邻近建筑物的影响

通过对地基进行沉降计算,对基础沉降进行实际观测,分析了河道施工降水对邻近建筑物的影响。结果表明:施工降水是导致邻近建筑物沉降、开裂的原因;利用规范法计算有效应力增加引起的地基沉降量,是一种切实可行、简单有效的方法;采用设止水帷幕和回灌井联合控制地下水位下降是一种有效的措施。     

Measurement properties as a possible cause of digital device effects on a standardized assessment of learning

Recent research found a substantial effect of digital device type on a computerized, standardized assessment of learning. Findings were consistent across grade and content domain. To investigate the source of these differences, the current research probed whether measurement differences or, equivalently, test bias due to device type could explain achievement or proficiency differences. We used 2018–2019 results on the Indiana Learning Evaluation Assessment Readiness Network (ILEARN). The data are census-based and cover grades 3 and 8 in the content domains of mathematics and English language arts (ELA). For our analysis, we use the root mean-squared deviation (RMSD) for detecting measurement differences across students that took ILEARN on different digital devices. Our findings suggest that few, if any, achievement differences that depend on the type of digital device can be explained by test bias. We discuss our findings in the context of multiple-group versus multiple indicator, multiple cause measurement models. Our findings suggest that digital device operates directly on the construct (math or ELA) rather than on the indicators that measure the construct. Finally, we conclude that a competing hypothesis – that differences are due to a digital device familiarity effect – remains plausible.     

End Stage Renal Disease,Differential Diagnosis,A Rare Genetic Disorder: Bardet–Biedl Syndrome: Case Report and Review

End stage renal disease (ESRD) represents a clinical condition in which there is an irreversible loss of endogenous renal function. Both structural and functional abnormalities of the kidney are associated with increased morbidity, mortality. Bardet–Biedel syndrome (BBS) is one of the rare genetic disorders with prevalence of 1 in 1, 40,000–1 in 1,60,000 worldwide. ESRD in BBS patients is the final stage of the disease, increasing mortality in youth.     

GPS手持机在土地利用更新调查中的应用

全国土地第二次调查是目前国土部门的一项重大任务。在对手持GPS机性能和定位精度研究的基础上,总结了一些实际工作中数据采集的方法,详细说明了GPS手持机中地方坐标系和国家坐标系的转换问题,并对其定位误差的处理措施和提高定位精度的方法做了说明。     

一类含参变量的广义积分的计算

本文讨论一类舍参变量的广义积分计算问题,利用Fourier变换和Laplace变换的定义和性质,总结出计算该问题的一般方法,并举出了例子说明。     

LDPC based differential unitary space-frequency coding for MIMO-OFDM systems

INTRODUCTION Unitary space-time modulation (USTM) (Hochwald and Marzetta, 2000) has been shown to be ideally suited for Rayleigh flat fading channels when there is no CSI. And for continuously changing fading channels, differential unitary space-time modulation (DUSTM) was proposed in Hochwald and Sweldens (2000). However, the performance of DUSTM de-grades considerably in frequency-selective fading channels often encountered in broadband wireless communications. Hence concatena…     

Unusual differential erosion related to the presence of endolithic microorganisms (Martvili,Georgia)

The presence of a diffuse biodeterioration phenomena can be observed across large areas of the outer surface of the limestone walls of the Church of the Virgin in Martvili. A differential erosion phenomenon was detected, suggesting a possible association with biological colonization. The erosion phenomenon is characterized by a circular discoloration leading progressively to the detachment of flakes of limestone at its center. Since the aforementioned process has not been described in the literature until now, the present study was focused on the interpretation of its origin and evolution. Three sides of the Church are affected by a variety of occurrences of circular differential erosion which display different stages of the process, whereas the western side is affected by epilithic growths across its entire surface. Surveys of the petrographic, mineralogical and physical features of the stone were made, and parameters such as density and porosity were recorded. Samples were analyzed by optical microscopy and SEM analysis in order to detected the presence of microorganisms whose species were then identified by means of morphological and molecular examinations. The study of cross-sections stained using the PAS method has confirmed the causal connection between microorganisms and the deterioration phenomena, providing information about their spread of penetration into the substrate and their substantial potential for causing damage. Dryness appears to be the main ecological condition favoring endolithic rather than epilithic growth. The most common isolated microorganisms were cyanobacteria (Chroococcales) and, to a lesser extent, meristematic fungi. The characteristics of the stone, and especially some endogenous discontinuities related to the accumulation of sedimentary layers and to the action of stone carving tools, might explain why the same differential erosion phenomenon occurs in specific areas of the block stones. The development of the differential erosion phenomenon shows a variety of stages of biological colonization. The progressive evolution of the deterioration process has been observed in detail: (a) firstly, white circular discolorations appear on the stone, which darken over time eventually becoming almost black; (b) circular perforations appear around the perimeter; (c) and finally a flake detaches from the center, leaving a deep depression in the stone.     

对满足特定解的复微分方程的系数的估计

讨论复线性微分方程f（n）＋An-1（z）f（n-1）＋…＋A1（z）f＇＋A0（z）f=0的解满足一定条件时,系数函数Aj需要满足的条件。     

车道被占用对城市道路通行能力影响的传统交通流模型

以2013年全国大学生数学建模竞赛A题为背景,利用传统交通流模型研究车道被占用对城市道路通行能力影响.首先进行模型假设;其次建立模型和求解模型,以车流波动理论建立传统交通流模型,分析车流排队与消散的过程以及集结波与消散波的传播方式,得到车辆排队长度x以及事故消散时间T＊的表达式;最后通过模型检验,说明模型具有一定的稳定性和鲁棒性.     

Construction of a hepatic stellate cells subtracted cDNA library of differentially expressed genes in normal mice and mice with Schistosomiasis japonica

To construct a hepatic stellate cells (HSCs) subtracted cDNA library to find differentially expressed genes in normal mice and mice infected with Schistosomajaponicum (S. japonicum). Suppression subtractive hybridization (SSH) was used. The cDNA fragments of normal mouse were compared to those of schistosoma-infected mice to find differentially expressed genes. Then differentially expressed cDNA fragments were directly inserted into T/A cloning vector to set up the subtractive library. Amplification of the library was carried out with transformation of DH5α. The amplified library contained more than 400 positive bacterial clones, which were then hybridized with forward and backward subtracted probes for differential screening, One hundred positive bacterial clones were randomly selected for sequencing and BLAST analysis, Finally, virtual Northern Blot confirmed such differential expression. The subtracted cDNA library of differentially expressed genes of HSCs was constructed successfully, the library is efficient and lays foundation for screening and cloning new and specific genes of schistosomiasis.