悬挂式水准尺在高铁桥梁沉降观测中的应用

分析了斜尺测量和倒尺测量在高铁桥梁沉降观测中存在的缺陷,提出一种悬挂式水准尺。介绍了其外观设计和采用悬挂式水准尺进行桥梁沉降观测的方法。通过实例进行对比分析,验证了悬挂式水准尺应用于高铁沉降观测的可行性。     

水准尺倾斜对沉降变形量的影响研究

在分析了水准尺倾斜对高差影响的基础上，提出了减弱水准尺倾斜对沉降变形量影响的具体措施及改正计算公式，结合武汉市鑫汉花园的沉降监测的工程实践，对其影响作了分析，得出了一些有用的结论和建议。     

经纬仪横轴误差对竖直角观测的影响

通过对经纬仪横轴本身不水平和由于竖轴不竖直导致横轴不水平2方面分析横轴倾斜对竖直角观测的影响,推出相应的公式.并通过实验数据得出,通过水准管安置经纬仪,由于横轴倾斜角非常小,不必考虑横轴倾斜对竖直角观测的影响.     

两种特殊情况下的建筑物沉降观测方法

在对建筑物进行沉降观测的过程中,由于建筑物自身构造特点和周边环境条件的限制,有时会使监测点布设在特殊的位置,正常的观测方法不易观测。探讨了建筑物沉降观测中水准标尺不能立直和监测点位置偏高的两种特殊情况以及进行测量的具体解决方法。     

某电站压力钢管镇墩永久变形监测网建立及分析

本文介绍了青藏高原某抽水蓄能电站压力钢管镇墩永久变形观测网的设计方案,着重分析了铟钢水准尺温度改正、分划面弯曲改正及水准尺圆水准气泡倾斜改正等系统误差的影响规律,得出了一些有益的结论。     

水平角观测时竖轴倾斜引起误差的改正方法探讨

对于水平角观测时垂直轴倾斜带来的影响,一是采用测回间重新整平的方法来削弱;二是在有竖盘指标水准管的情况下,读取格值施加改正数的方法来削弱。但这两种方法的精度有限,且对于无竖盘指标水准管的仪器目前没有提出相应的解决方法,＂虚拟目标法＂可以有效地解决这个问题。     

差异沉降法中倾斜量的正算与反演

针对差异沉降法倾斜观测数据的处理,及与其他方法所得成果的比对需要等问题,本文理论推导了任意两方向沉降差正算监测体最大倾斜角、倾斜方向的可靠公式,并用算例验算其正确性;由于差异沉降法一般不能反映0期监测时的倾斜量,本文提出将当前倾斜量作基础沉降差反演,导出通式,求得"原始高程",使后期沉降差完整反映监测体倾斜状态成为可能;最后通过试验验证本文方法。     

基于分区回归模型确定建筑物倾斜状态

针对高层建筑物外部结构复杂、仪器设站困难的问题,提出了分区回归模型,拟合基础沉降面,确定建筑物倾斜状态。在建筑物内部基础上均匀布设沉降监测点,测量出各周期累积沉降量,对基础沉降进行分块拟合,获得基础沉降的局部变形特征,以此进行区域划分,最后利用基础沉降面的法线向量确定建筑物倾斜度和倾斜方向。对比传统倾斜测量结果可以看出,利用分区回归模型能满足实际工程需求,比回归平面模型具有更高的精度和适用性。     

基于全站仪的圆形建筑物倾斜观测的方法和精度

随着建筑物的不断增高、增大,其稳定性和可靠性成为人们关注的焦点.其中建筑物的倾斜度是衡量施工技术质量的重要指标之一.而传统的观测方法如经纬仪测小角法、经纬仪投点法,由于受仪器精度和观测条件的限制,观测精度较低.拓普康全站仪独具推出的圆柱偏心测量功能为快速、准确测定圆形建筑物的倾斜量开辟了一条新途径,本文阐述了基于全站仪的圆形建筑物倾斜观测的原理和方法,并对其精度进行分析.     

钻孔桩斜距简便测定方法

本文介绍了土建工程桩基础施工中,桩孔倾斜的测定方法。这种方法采用经纬仪一次架设,一次观测读数,用水准仪测两点高差,配合5米水准尺,再通过计算就可以准确的测定桩孔的倾斜度和斜距。此法勿需搬动仪器就可一次获得成果。此法适用于各种孔径的干成孔钻孔桩。     

Pinpointing the sources and measuring the lengths of the principal rivers of the world

Abstract

Cultures throughout the world are associating with the rivers. People depend upon the rivers and their tributaries for food, water, transport, and many other aspects of their daily lives. Unfortunately, human beings have not calculated the accurate lengths for the great rivers even today. The lengths of the rivers are very different in popular textbooks, magazines, atlases and encyclopedias, etc. To accurately determine the lengths of the principal rivers of the world, the combination of satellite image analysis and field investigations to the source regions is proposed in this paper. The lengths of the Nile, Amazon, Yangtze, Mississippi, Yellow, Ob, Yenisey, Amur, Congo and Mekong, with lengths over or close to 5000 km, were calculated using the proposed method. The results may represent the most reliable and accurate lengths of the principal rivers of the world that are currently achievable.     

世纪之交的沉思--论21世纪软科学的发展

软科学这一术语是70年代在国外提出的.然而30多年以来,它在国外不仅未得到普遍的承认,而且对软科学的定义也还未能达成大体上一致的共识.而在改革开放后的中国,出于决策科学化和民主化的需要,经过一些领导人的提倡和支持,特别是通过1986年召开的软科学座谈会及1994年召开的全国软科学工作会议,软科学事业得到了蓬勃的发展.据初步统计,截止1998年底全国共有软科学研究机构1224个,研究人员32655人,初步形成了一支较为强大的研究队伍,并取得了数百项覆盖多个领域的研究成果,为支持各级各类的决策发挥了一定的作用.     

Improving the modeling of the atmospheric delay in the data analysis of the Intensive VLBI sessions and the impact on the UT1 estimates

The very long baseline interferometry (VLBI) Intensive sessions are typically 1-h and single-baseline VLBI sessions, specifically designed to yield low-latency estimates of UT1-UTC. In this work, we investigate what accuracy is obtained from these sessions and how it can be improved. In particular, we study the modeling of the troposphere in the data analysis. The impact of including external information on the zenith wet delays (ZWD) and tropospheric gradients from GPS or numerical weather prediction models is studied. Additionally, we test estimating tropospheric gradients in the data analysis, which is normally not done. To evaluate the results, we compared the UT1-UTC values from the Intensives to those from simultaneous 24-h VLBI session. Furthermore, we calculated length of day (LOD) estimates using the UT1-UTC values from consecutive Intensives and compared these to the LOD estimated by GPS. We find that there is not much benefit in using external ZWD; however, including external information on the gradients improves the agreement with the reference data. If gradients are estimated in the data analysis, and appropriate constraints are applied, the WRMS difference w.r.t. UT1-UTC from 24-h sessions is reduced by 5% and the WRMS difference w.r.t. the LOD from GPS by up to 12%. The best agreement between Intensives and the reference time series is obtained when using both external gradients from GPS and additionally estimating gradients in the data analysis.     

Movements of the protoplanetary superconducting particles in the magnetic field of the Saturn lead to the origin of the rings

In this letter, we are trying to resolve the electromagnetic problem for the movements of the superconducting particles of the protoplanetary cloud in the magnetic field of Saturn. The force of levitation (Meissner-Ochsenfeld phenomenon) is introduced to the field of planetary science for the first time. It is shown from our theoretical analysis that rings of Saturn might have a superconducting origin, and rings might levitate within magnetic equator plane of the planet.     

省直管市（县）体制下建设用地监管技术研究

面向解决省直体制下市（县）建设用地管理业务监管难度大问题,研究建设用地全过程监管关键技术,设计该模式下的监管模式、技术架构、业务模型和数据模型,实现省直管市（县）模式下的建设用地批前、批中、批后＂批-供-用-补-查-登＂全过程监管。     

国家一等水准网复测高程变化分析及其成果使用

分析国家一等水准网点复测高程的变化量值与分布特征以及导致高程变化的原因，对现有国家水准网点高程的使用提出建议。     

跟踪世界发展动态 致力地球重力场研究

比较系统、扼要地叙述了笔者所在单位40余年来坚持跟踪世界发展动态，致力于地球重力场理论和方法的研究，并从教学和生产需要出发，在地球重力场研究方面所获得的一些有理论意义和实用价值的成果。