基于遥感的城市边缘区土地利用动态监测

城市边缘区在城市地域结构体系中处于城市与乡村的过渡地带,从而既属于生态环境脆弱带,又属于城市区域人文因素高度复合带,其时空特征表现出十分迅速和不稳定的特征。及时了解和掌握城市边缘区土地利用变化的状况,对于合理进行城市规划,调整用地结构,实现区域可持续发展具有十分重要的意义。本文以LandsatTM为基本信息源,以Coreldraw和ARC/INFO为主要支撑软件,完成了实验区从1987年到1996年的城市边缘区土地利用动态监测与分析。此技术路线能够有效地提取城市边缘区土地利用动态信息,工作周期短,误差积累少,定性定位准确率高     

Dome Strengthening By Encircling Ties: A Monitored Experiment

This study describes a new strategy of conservation of historical monuments based on the combined use of monitoring analysis and empiric reappraisal. Over time, the mechanical behavior of domes—their lack of stability due to the horizontal thrusts generated by their self-weight—has been analyzed by architects and engineers, starting from the observation of damage. This process, which was mathematically demonstrated for the first time by the famous Viviani’s analysis of Santa Maria del Fiore in Florence, has provided over the centuries a number of enhancements in dome structural conception, thus leading to the final solution, referred to as encircling tie rod intervention. Based on these premises, the experimental case of Santa Maria del Quartiere dome in Parma, Italy, is discussed herein. Indeed, it has been considered a good opportunity to present the method used in its strengthening-intervention assessment, further validated by the monitoring system installed. In this monitored in-scale experiment, the empiric classical solution to the primeval dome’s thrust finds its confirmation and offers further possibilities of recalibration during time, thus indicating structural monitoring that may be described as a possible and desirable “alternative to intervention”, in step with “minimum intervention” and “reversibility” principles.     

Real‐time mud gas logging and sampling during drilling

Continuous mud gas loggings during drilling as well as offline mud gas sampling are standard procedures in oil and gas operations, where they are used to test reservoir rocks for hydrocarbons while drilling. Our research group has developed real‐time mud gas monitoring techniques for scientific drilling in non‐hydrocarbon formations mainly to sample and study the composition of crustal gases. We describe in detail this technique and provide examples for the evaluation of the continuous gas logs, which are not always easy to interpret. Hydrocarbons, helium, radon and with limitations carbon dioxide and hydrogen are the most suitable gases for the detection of fluid‐bearing horizons, shear zones, open fractures, sections of enhanced permeability and permafrost methane hydrate occurrences. Off‐site isotope studies on mud gas samples helped reveal the origin and evolution of deep‐seated crustal fluids.     

基于物联网技术的博物馆室内环境监测

物联网是传感器技术、无线通信技术、网络和嵌入式计算机技术交叉渗透的产物,随着物联网概念的提出,其技术得到了飞速发展,并且在社会多个领域取得了成功应用。针对当前博物馆环境监测存在的问题与难点,提出了基于物联网技术的博物馆室内环境监测系统的总体设计方案,在此基础上,分别给出了传感器节点、汇聚节点的软硬件设计方案,该设计具有低功耗、低成本、扩展灵活等优点。构建的测试平台验证了该系统良好的可行性与稳定性。     

Stress‐induced temperature variations in groundwater of the Monferrato area (north‐western Italy)

Although characterized by low seismicity, the Monferrato area of north‐western Italy was affected by earthquakes, of magnitude M5.1 and M4.8, in 2000 and 2001. At the same time, marked changes were recorded in water temperature and chemistry in several wells within the epicentral area. In May 2004, an automatic network for the continuous monitoring of groundwater was installed in selected wells to study the phenomenon. Here, we report on data collected during a 3‐year period of groundwater monitoring. During the first year, episodes of water heating (by up to 20°C) were observed in one monitored well. The temporal analysis of the seismic activity recorded in the area revealed as almost all seismic events occurred during the period of elevated water temperatures. The similar timing of earthquakes and groundwater‐temperature anomalies suggests that both may be triggered by the same processes acting in the crust.     

HYSTERESIS AND PARAMETER ESTIMATION OF MDOF SYSTEMS BY A CONTINUOUS-TIME LEAST SQUARES METHOD

Civil structures could undergo hysteresis cycles due to cracking or yielding, when subjected to severe earthquake motions. Seismic instrumentation, structural monitoring and system identification techniques have been used in the past years to assess civil structures under lateral loads. The present research makes use of a continuous-time Least Squares Method, modified herein to consider the nonlinear behaviour of the structure. The proposed on-line algorithm simultaneously estimates the hysteretic component and structural parameters such as damping and stiffness of a shear building structure. Simulations are carried out using the El Centro and the Mexico City seismic records. Fair convergence speed is obtained for the identification of the parameters and the estimation of the hysteretic component.     

Multiple Degrees of Freedom Positioning Correction for Hybrid Simulation

This study proposes a high-precision positioning correction method for multiple degree-of-freedom loading units in hybrid simulation. These loading units can impose inaccurate displacements to the specimens due to the elastic deformation at the reaction wall or connections. To compensate for these displacement errors, an online correction method adjusts the displacement command by the difference between the target and achieved displacement. This correction method also accompanies an accurate 6DOF monitoring system to detect the displacement errors. Two examples of hybrid simulation tests are provided to demonstrate the precise displacements attained on the specimens through this control method.     

Geodynamic processes in the NW Bohemian swarm earthquake region,Czech Republic,identified by continuous gas monitoring

The time series of two continuously operating gas monitoring stations at Oldřišská and Nový Kostel located along seismoactive faults in the epicentral area of the NW Bohemian swarm earthquakes (Czech Republic) are compared with water level fluctuations in two boreholes positioned along these faults and with gas flux variations of a mofette at the Soos mofette field at 9 km distance. The seasonal trend of the monitored CO₂ concentration with a maximum in November and a minimum in March/April is governed by groundwater temperatures, superimposed in spring by soil temperatures. CO₂ concentration variations identified at Oldřišská are also reflected in gas flux variations in the Soos mofette and/or water level fluctuations of two boreholes. Variations in the gas monitoring recordings of station at Nový Kostel are also linked with variations at Oldřišská. In all data sets, diurnal variations generated by earth tides occur, reflecting a daily stress – fault permeability cycle. Additional stress interferes with this cycle. Significant, abrupt changes are attributed to geodynamic processes linked with seismic events, as revealed by local seismicity or by the transient of waves of a strong remote earthquake. Simultaneous variations of the gas concentrations in the Nový Kostel area and in the gas flux in the Soos point to an interconnected hydraulic conductive fault systems present in the northern part of the Cheb Basin. Sharp falls in gas concentration, during or subsequent to, earthquake swarms may reflect fault compression associated with impeded gas migration. However, gas variations also occur in periods without seismic activity, indicating changes in fault permeability were caused by local aseismic fault movements, as revealed by events with opposite trends in the gas recordings at Oldřišská, Nový Kostel and the Soos. Therefore, a mathematical approach to establish a correlation between seismicity and gas geochemical variations is not possible.     

The countryside (Scotland) act of 1967 revisited

The recent opening‐up of the policy and precedent files relating to the promotion of the Countryside (Scotland) Act of 1967 provides opportunity for re‐assessing the significance and character of the debates leading up to the first explicit provision for what the Preamble to the Act described as ‘the better enjoyment of the Scottish countryside’. More generally, insight may be gained into the procedures and preoccupations of the ‘core executive’ of government, as they effect the ‘networking’ required for securing the support of the relevant user‐interests during the consultative and drafting stages of such legislation.     

Lake Dwellings in Baden-Württemberg. Conservation Projects In Situ at Lake Constance and the Federsee Moor

The Baden-Württemberg shoreline of Lake Constance and the lakes and moors of Upper Swabia contain important prehistoric wetland sites. From 1979, new research has brought up not only important finds and scientific results but also increasing information about bank erosion in the lakes and desiccation in the moorlands. At Lake Constance, early attempts were made in the 1980s to protect sites threatened by erosion by covering them with geo-textile and gravel. With further protective projects the know-how improved, but crucial questions still remained: What are the best practical solutions? How about ecological compatibility? Do we have other options? The INTERREG IV 2008–2011 international project ‘Erosion and Archaeological Heritage Protection in Lake Constance and Lake Zurich’ brought deeper insights and opened the field for new experiments with protective measures. At the Federsee Moor a long-term project started in 1980 with close collaboration between nature conservation and archaeological heritage management. With archaeological stocktaking, acquisition of land, establishment of new nature reserves, exchange of landholding and hydrographic engineering, the project was completed with the help of European Union funding by LIFE+in 2013.