T形短肢剪力墙静力性能有限元仿真分析

利用有限元分析软件ANSYS,首先采用其中三维实体单元SOLID65建立了T形短肢剪力墙有限元分析模型,从弹性到混凝土开裂直至破坏的全过程进行了仿真试验分析。分析了影响短肢剪力墙受力的几种因素:混凝土强度等级、配筋率、轴压比、墙肢截面高厚比对短肢剪力墙承载能力、变形能力及延性的影响,剖析了短肢剪力墙破坏过程及其原因。比较真实的反映了短肢剪力墙在轴压力和逐步加载侧向力共同作用下的响应。试验结果表明:增加混凝土等级和轴压比能提高试件的开裂、屈服和极限荷载,但应综合考虑其与变形能力、延性的关系。截面配筋率具有其特殊性,配筋率在1.4%1.6%之间时试件的承载能力、变形能力及延性较好。墙肢截面高厚比是不稳定因素但在高厚比为6.57.1时,延性及变形能力较强。     

Observed characteristics of atmospheric ducts over the South China Sea in autumn

The observed characteristics of lower atmospheric ducts over the South China Sea(SCS) were analyzed based on Global Position Systerm(GPS) radiosonde data collected four times daily during autumn open cruises from 2006 to 2012.Duct occurrence,thickness,and strength over the SCS were about 40%,150-m thick,and 8 M units,respectively,which were larger than during the summer monsoon period.Most ducts occurred at heights 1 500 m and these ducts easily trap electromagnetic wave clusters with wavelengths 2 m.Diurnal variation of the SCS ducts appeared evident.They occurred more often at midnight at higher altitudes(about 1 100 m),with a thickest layer of about 145 m and less frequently during the evening at lower altitudes(about 800 m),with a thinnest layer of about 125 m.Moreover,ducts during the daytime at a mean height of about 900 m,with the greatest strength of about 10 M units.Furthermore,all duct variables observed over the SCS in autumn decreased from north to south.These findings are useful not only in the design of radar and communication systems,but also for evaluating possible effects of anomalous propagation on meteorological radar and military applications.     

地震信息对薄砂岩储层特性的描述

近年来,以地震信息为主进行油气藏描述,这是当前对石油勘探的重点攻关课题.本文结合我国陆上和海域部分油田或含油气构造的实际资料,运用地震信息为主,结合测井、地质及钻井等资料,对储层进行综合解释。同时,提出了用多地震信息计算薄层厚度的基本公式,根据地区性岩性和地震资料的差异,使用了确定性地质统计和Coringing分析两种方法进行储层物性参数的预测,文中给出大量的实例说明各种储层参数描述方法和应用效果。     

Ensemble retrieval of atmospheric temperature profiles from AIRS

ABSTRACT Satellite-based observations provide great opportunities for improving weather forecasting. Physical retrieval of atmo spheric profiles from satellite observations is sensitive to the uncertainty of the first guess and other factors. In order to improve the accuracy of the physical retrieval, an ensemble methodology was developed with an emphasis on perturbing the first guess. In the methodology, a normal probability density function （PDF） is used to select the optimal profile from the ensemble retrievals. The ensemble retrieval algorithm contains four steps： （1） regression retrieval for original first guess; （2） perturbation of the original first guess to generate new first guesses （ensemble first guesses）; （3） using the ensemble first guesses and nonlinear iterative physical retrieval to generate ensemble physical results; and （4） the final optimal profile is selected from the ensemble physical results by using PDE Temperature eigenvectors （EVs） were used to generate the pertur- bation and generate the ensemble first guess. Compared with the regular temperature profile retrievals from the Atmospheric InfraRed Sounder （AIRS）, the ensemble retrievals RMSE of temperature profiles selected by the PDF was reduced between 150 and 320 hPa and below 400 hPa, with a maximum improvement of 0.3 K at 400 hPa. The bias was also reduced in many layers, with a maximum improvement of 0.69 K at 460 hPa. The combined optimal （CombOpt） profile and a mean optimal （MeanOpt） profile of all ensemble physical results were improved below 150 hPa. The MeanOpt profile was better than the CombOpt profile, and was regarded as the final optimal （FinOpt） profile. This study lays the foundation for improving temperature retrievals from hyper-spectral infrared radiance measurements.     

Preliminary Study of the Ability of Large-scale Deformation Observed by Lunar Based InSAR—Taking Vertical Displacement of Solid Earth Tide as an Example

Based on the principle of InSAR (Interferometirc Synthetic Aperture Radar) characterized by large-scale, continuity, permanency and dynamic, we took vertical displacement of solid Earth tide as an example to simulate the large-scale deformation observed by lunar based InSAR for the first time in the study and the observation ability was analyzed. Solid Earth tide has a feature of a large-space distribution range and the lunar based InSAR exhibits a feature of an ultra-wide swath imaging. According to these features, a simplified observation geometry model was established and a mid-low latitudes area with 50 degrees span in both longitude and latitude was selected as the simulation area. Then the revisit time intervals of the lunar based SAR for the selected area and the tidal vertical displacements at the points scanned by the radar were calculated. The time differentials were further computed to get the relative vertical deformation of the solid Earth tide. The simulation results show that the revisit period of the lunar based radar is about 24.8 hours and the maximum vertical displacement in 30 days is up to 30 cm. Since the designed accuracy of the lunar based InSAR reaches several centimeters, the observing of the vertical displacement of the solid Earth tide by using the lunar based InSAR is feasible in theory as the maximum magnitude of the vertical displacement is 1 order of magnitude larger than the designed accuracy. Theoretically ,solid Earth tide is observable by using lunar based InSAR in a sizable area.We can also use the observation data to study the temporal and spatial variation characteristics when observation time lasts two revisit periods or more. On the other hand,the result of the study also provides references for the parameter designing of other observations using the lunar based InSAR, especially for observing large-scale geodynamic phenomena.     

蒙古国植被对干旱响应的敏感性研究

本文分析了蒙古国不同区域、不同土地覆被类型区的植被生长状况对干旱响应的敏感性特征,并探讨了成因。研究表明：① 2001—2019年,蒙古国虽然发生了3次较为严重的干旱事件,但整体上干旱程度呈轻微降低趋势,SPEI出现轻微上升,总体增速为0.001%/a;植被生长状况出现了好转,植被指数也呈上升趋势,总体增速为0.15%/a。② 蒙古国大部分区域植被生长受干旱影响较强,各植被指数与干旱指数呈较明显的正相关关系,在NDVI与SPEI-12的相关性分析中,正相关面积占比达76.36%;而在杭爱山脉和肯特山脉以北降水量丰沛的区域和阿尔泰山脉以南荒漠化严重和植被极为稀少区域,植被生长受干旱影响较弱,植被指数与SPEI相关性较小。③ 不同类型植被对干旱响应的敏感性也有差异,其中草地敏感性最强（0.22）,而森林敏感性最弱（-0.04）。④ 干旱持续时间长短,对植被生长影响有较大差异,蒙古国大部分区域的植被对延续3个月至半年的干旱最为敏感,而年内以7月份干旱对植被影响最强。⑤ 植被对干旱响应的敏感性实质是区域水分平衡的植被影响,对同种植被而言多年平均气温越高或降水量越少,植被对干旱响应的敏感性越强,反之则越弱。本文的研究结果对蒙古国因地制宜开展荒漠化防治具有重要参考价值。     

Diffusion Characteristics of Swells in the North Indian Ocean

Research on the diffusion characteristics of swells contributes positively to wave energy forecasting, swell monitoring, and early warning. In this work, the South Indian Ocean westerly index(SIWI) and Indian Ocean swell diffusion effect index(IOSDEI) are defined on the basis of the 45-year(September 1957–August 2002) ERA-40 wave reanalysis data from the European Centre for Medium-Range Weather Forecasts(ECMWF) to analyze the impact of the South Indian Ocean westerlies on the propagation of swell acreage. The following results were obtained: 1) The South Indian Ocean swell mainly propagates from southwest to northeast. The swell also spreads to the Arabian Sea upon reaching low-latitude waters. The 2.0-meter contour of the swell can reach northward to Sri Lankan waters. 2) The size of the IOSDEI is determined by the SIWI strength. The IOSDEI requires approximately 2–3.5 days to fully respond to the SIWI. The correlations between SIWI and IOSDEI show obvious seasonal differences, with the highest correlations found in December–January–February(DJF) and the lowest correlations observed in June–July–August(JJA). 3) The SIWI and IOSDEI have a common period of approximately 1 week in JJA and DJF. The SIWI leads by approximately 2–3 days in this common period.     

测绘地理信息类本科专业“一干两轴三维”人才培养模式建设

为优化配置教学资源,提高教学效率,增强专业人才培养特色,提出测绘地理信息类本科专业“一干两轴三维”人才培养模式。该模式以掌握现代测绘地理信息科学技术理论为中心,培养创新研究能力和创新实践能力为主轴,设置工程测量、城市空间信息工程、摄影测量与遥感3个方向;从制订培养方案入手,围绕课程体系建设改革教学模式,针对专业方向强化实践教学;构建了校企合作开放型人才培养体系。该模式目前已经应用,取得了显著效果。     

台湾美浓MW6.4地震InSAR形变场初步分析

利用欧洲航天局最新发射的宽刈幅、高分辨率Sentinel-1A卫星,第一时间获取2016-02-06台湾美浓MW6.4地震干涉像对,使用D-InSAR技术获取美浓地区的同震形变场。利用震中附近39个同震GPS观测进行对比验证后显示,InSAR获取的同震形变场精度优于1 cm（3σ）。形变发生在宏观震中30 km×30 km范围内,主要表现为沿雷达视线向抬升,最大抬升约12 cm。从形变场空间分布特征可以看出,空间连续性较好,说明宏观震中附近地表未发生明显破裂。宏观震中并不与震中位置重合,而是位于震中西部约15 km处。     

德州市德城区地籍调查数据整理入库工作探讨

全国第二次土地调查是一项重大的国情国力调查,在此次调查中笔者负责德城区调查成果数据入库。该文基于在第二次土地调查中的工作经验,就扫描档案文件、宗地权属信息和宗地界址信息快速整理入库提出几点方法,供广大一线工作者参考。