Trend in the atmospheric heat source over the central and eastern Tibetan Plateau during recent decades: Comparison of observations and reanalysis data

The trend in the atmospheric heat source over the central and eastern Tibetan Plateau (CE-TP) is quantitatively estimated using historical observations at 71 meteorological stations, three reanalysis datasets from 1980-2008, and two satellite radiation datasets from 1984-2007. Results show that a weakening of sensible heat (SH) flux over the CE-TP continues. The most significant trend occurs in spring, induced mainly by decelerated surface wind speeds. The ground-air temperature difference shows a notable increasing trend over the last 5 years. Trends in net radiation flux of the atmospheric column over the CE-TP, evaluated by two satellite radiation datasets, are clearly different. Trends in the atmospheric heat source calculated by the three reanalysis datasets are not completely consistent, and even show opposite signals. Results from the two datasets both show a weakening of the heat source but the magnitude of one is significantly stronger, whereas an increase is indicated by the other data. Therefore, it is challenging to accurately calculate the trend in the atmospheric heat source over the CE-TP, particularly from the estimates of the reanalysis datasets.     

Thermal behavior of zirconia-dop ed mullite gel fibers

The zirconia-doped mullite gel fibers were prepared via a sol-gel method.The thermal behaviors of the gel fibers during pyrolysis were investigated by means of thermal gravitydifferential scanning calo...     

基于细胞自动机的断控岩溶过程数值模拟方法

断溶体作为一种特殊的碳酸盐岩储集体类型,其形成过程尚缺乏一种定量的模拟方法.根据断溶体地质研究认识,断控岩溶以断裂破碎带为核心发生溶蚀扩大,其溶蚀程度的差异受断裂分布、裂缝密度、地层岩性差异、大气淡水或底部热液接触时间等综合因素影响.提出一种基于细胞自动机模拟断控岩溶过程的方法,以走滑断裂形成的裂缝网络为初始条件,以一定酸浓度的大气水注入为边界条件,综合考虑地层岩性差异、裂缝发育密度、重力作用,建立了基于酸扩散、连通性和传导率共同控制的模拟规则,并最终形成由累积酸溶蚀定量表征溶蚀演化程度的模拟方法.通过塔河10区典型断溶体单元实例模拟,验证了该方法的可行性.     

基于山地环境的尾流分布特征的风洞试验

针对复杂山地环境开展缩尺模型风洞试验,研究气流越过山体后背风面尾流的分布特征.分析不同坡度下山体背风面平均风剖面以及脉动风速功率谱随测点位置的变化规律,研究山体的山顶加速效应和遮挡效应影响以及背风面涡旋发展情况.当背风面坡度为25°时,山顶出现加速效应,山体遮挡效应不明显,尾流中涡旋不充分;当背风面坡度为50°时,山体遮挡效应明显,尾流中涡旋发展充分.山体高度为H,其背风面至少1.7H(高度)×6H(长度)范围内存在涡旋并影响风场频域分布,且离山脚6H范围外遮挡效应仍未消失.比较了中美规范中关于山顶加速比的计算差异,结果表明规范计算值较风洞试验值偏大.     

Maturation of Osteoblast-Like Saos-2 on Hydroxyapatite Ceramics

Hydroxyapatite ceramics (.HA) has been proved to be excellent in biocompatibility and bioactivity.However, limited information is available concerning how HA ceramics affects the maturation of es-tcoblasts in molecular biological level /n v/tro. This study examines the mRNA expression and protein production of hone-related genes in estcoblast-like cell line(Saos-2) cultured on HA disks. Saos-2 cells are seeded onto the substrates and cultured for 18 days. Harvested cells are tested for the cell growth rate, expression of mRNAs for esteocalcin and alkaline phosphatase, and protein production of bone sialo-protein and esteocalcin. MTS assay shows that cell proliferates well on HA ceramic substrate. After 9d,bone sialoprotein and esteocalcin protein production in SAPS-2 increases more on HA surfaces than on control material. As bone sialoprotein and esteocalcin are the genes to be highly expressed at the late stage of estcoblast differentiation, this study reveals that after long time culture in HA, HA can induce Saos-2 maturation. The behavior of Saos-2 on HA surfaces revealed in this study provides valuable infor-mation for the understanding of the biocompatibility and bioactivity of HA ceramics.     

纳米改性氢氧化铝与包覆红磷协效阻燃尼龙66的研究

文中分别研究了纳米改性氢氧化铝 (CG-ATH)单独使用以及与包覆红磷协效阻燃尼龙66(PA66 )复合体系的阻燃性能和力学性能。将纳米CG-ATH和包覆红磷以不同比例添加到PA6-6中,制得复合材料。用氧指数法测定了复合体系的阻燃性能,此外还进行了拉伸和冲击性能测试。结果表明,包覆红磷与纳米CG-ATH具有一定的协同效应,当复合材料中PA66、包覆红磷和纳米CG-ATH的质量比为100∶13∶20时,该复合体系的氧指数为33,而只PA66和纳米CG-ATH的质量比为100∶40的 PA66复合体系的氧指数29.5,但是100g PA6 6中,只添加15g包覆红磷时,该复合体系的氧指数只有27,该协效阻燃体系的拉伸强度为79.3MPa,拉伸弹性模量为2182.3MPa,断裂伸长率为5.9% ,冲击强度为4.5kJ/m² 。因此,纳米改性氢氧化铝与包覆红磷的协同效应,实现了在无机阻燃剂添加量相对较少且保证 PA66本身力学性能的前提下,大幅度改善材料阻燃性能的要求。     

地形起伏变化下的边界层参数化台风风场模型

对于登陆台风来说,采用平坦下垫面和单一的地表粗糙长度假设并不能与实际情况相吻合.为了更准确地模拟台风近地面风场,基于现有参数化台风风场模型,采用随地形变化的坐标系建模方法和高精度地形与土地覆盖资料,考虑了台风登陆过程中地形起伏和土地覆盖变化的影响.针对历史上影响广东省的3个台风案例,利用大量观测数据对比和验证了改进后的台风风场模型.对比结果表明:改进后的参数化台风风场模型对风速的模拟并没有表现出明显的系统偏差,并且能较好地模拟出台风登陆过程中风速风向的时程变化.     

Kinect骨骼信息下的动态手势识别研究

针对复杂环境中存在的手势识别问题,提出一种利用Kinect传感器获取深度信息并进行动态手势识别的方法。该方法通过对Kinect传感器获取的深度信息进行分析,获取人体主要骨骼点的3D坐标,从中选取六个点作为手部运动的特征参照;为提高手势识别系统的识别速度,提出了一种基于查表的DTW算法对得到的特征数据进行模板训练并实现动态手势识别。实验结果表明:该方法具有较高的识别速度和识别率,对复杂背景及光照强度变化具有较强的鲁棒性。     

“T”型杂种小麦花药培养研究

本项研究表明,C_(17)培养基诱导小麦三系材料花药出愈,均好于其它五种培养基的诱导效果;而杂种F_1代材料花药出愈均极显著地高于不育系、保持系和恢复系材料花药的出愈频率。杂种F_1代花药在培养过程中产生愈伤组织同它们的母本不育系和父本恢复系花药出愈频率没有相关关系,杂种F_1代材料花药出愈频率同检查它们在田间套袋自交结实表现有逆相关的趋势;杂种F_1代材料花药的出愈同测得材料起身至拔节期过氧化物同工酶谱带变化也存在相关的趋势。     

1—苯基—3—甲基—4—氯代苯氧乙酰基—5—吡唑啉酮的合成

合成了三种新的β-二酮化合物——1-苯基-3-甲基-4-氯代苯氧乙酰基-5-吡唑啉酮,并通过红外、核磁共振、质谱和元素分析确定了它们的结构,初步考察了其对(UO_2)~(++)离子的萃取性能。