一种液晶显示系统的单片机接口设计     

郭燕  李焕信 《时间频率学报》1997,(1)

液晶显示器（LCD）工作电压低、功耗小、能与CMOS电路匹配；且显示柔和、字迹清晰、重量轻、可靠性高、寿命长，自问世以来其发展速度之快，用途之广远远超过了其它发光器件。在自动化仪表及自动控制系统中，越来越多的设计者采用液晶显示与仪器对接，尽管其接口电路较传统的LED显示器复杂，由于其独特的优点，正得到广泛地应用。现介绍一种单片机LCD显示器接口的设计。在使用步进电机进行精密自动控制的系统中，利用8031单片机作为控制器，加之使用8255并行接口，可实现移位显示，也可适时显示转角信息和检测信息。该设计自动化程度高、可控性强，可用于天文仪器的精密定位、扫描以及其它自控监示系统。  相似文献   

Potential of turbidity monitoring for measuring the transport of suspended solids in streams     

Christopher James Gippel 《水文研究》1995,9(1):83-97

Investigating the transport of suspended solids by water sampling usually leads to an underestimation of loads and an unrealistically high sampling frequency is required to properly characterize temporal trends. An alternative method is to use in situ optical turbidimeters to estimate the suspended solids concentration; however, the relationship between turbidity and suspended solids concentration is potentially confounded by variations in particle size, particle composition and water colour. Field measurements, and laboratory measurements using the type of natural material suspended in streamwater, were made to quantify the influences of these factors on nephelometric turbidity (Hach 2100A) and attenuance turbidity (Partech 7000 3RP MKII). The attenuance turbidity was approximately 2.5 times higher than nephelometric turbidity. The turbidity instruments were most sensitive to dispersions with a median diameter of 1.2-1.4γm. Particle size variation can cause the turbidity to vary by a factor of four for the same concentration of suspended solids. However, the numerous close correlations between turbidity and suspended solids concentration reported previously suggests that either the particle size variations are not usually great, or that particle size variations are often associated with variations in suspended solids concentration. For the same concentration and particle size, organic particles gave attenuance turbidity values two to three times higher than mineral particles. However, shortterm temporal variations from purely organic to purely mineral particle loads are rare in nature, so variations in the percentage of organic matter in the paniculate load will not confound turbidity to this extent. Coloured dissolved organic matter is unlikely to alter the turbidity reading by more than 10%. An adequate relationship between turbidity measured in the field and suspended solids concentration should be expected in most situations. Some variance can be tolerated because a continuous estimate of suspended solids concentration overcomes the problem of infrequent sampling, which is the greatest source of error in the estimation of stream sediment loads.  相似文献   

11~＃住宅楼沉降监测及其变形规律分析     

徐惠莲  郭新成 《地球科学与环境学报》1997,(Z1)

建筑物沉降观测，是高层建筑变形测量重要项目之一。本文以实测１１＃住宅楼为例，介绍了其沉降监测的实施方法和观测成果的分析；并得出施工阶段沉降变化规律。其结果对验证地基与基础的可靠性，工程结构的设计方案具有一定的参考价值。  相似文献   

A survey to determine levels of chlorinated pesticides and PCBs in mussels and seawater from the Mid-Black Sea Coast of Turkey     

Kurt PB  Ozkoc HB 《Marine pollution bulletin》2004,48(11-12):1076-1083

A mussel and seawater monitoring survey was conducted at six sampling points between Yalikoy (Ordu) and Sinop in 1999-2000 along the Mid-Black Sea Coast of Turkey in order to assess concentrations of organochlorine pesticides (OCs) and polychlorinated biphenyls (PCBs). Chlorinated pesticides and PCBs were measured in the mussel Mytilus Galloprovincialis and in seawater. In the mussel samples, the most common pollutants in terms of average concentration per g of wet weight (ww), were DDT (max. 1800 pg/gww, min. 240 pg/gww) and its metabolites DDD (max. 5400 pg/gww, min. 240 pg/gww) and DDE (max. 2800 pg/gww, min. 70 pg/gww). Also, dieldrin, heptachlor and HCB were notable contaminants in the mussel samples. PCBs were determined in none of the biota or seawater samples. The concentrations of the OCs and PCBs in mussels were higher in coastal areas receiving river discharges and close to the largest city of the region, Samsun (especially in sampling points in the harbour area). The well-known long persistence of DDTs and other chlorinated compounds was confirmed by residues of these pollutants measured in mussels. On the other hand, even though the usage of such kind of persistent compounds in Turkey was banned, there may still be illegal usage and it is not certain whether the application of these compounds did end in the region.  相似文献   

 GIS在矿产资源开发状况遥感动态监测中的应用   总被引：9，自引：0，他引：9  

刘琼  聂洪峰  吕杰堂  洪顺英  周英杰 《国土资源遥感》2005,16(1):61-65

为建立全国性的矿产资源开发状况数据库系统，以山西省晋城市和江西省崇义县矿产资源开发状况遥感动态监测成果为基础 ，通过GIS 强大的空间数据管理功能，对所收集的数据进行管理，建立了具有浏览编辑、查询检索、统计分析及动态监测等特点的空 间数据库系统。本文就建立这一数据库系统的技术方法、设计思路、系统组成和GIS的应用等方面进行了阐述。  相似文献   

基于ASP.NET的滑坡实时监测数据网上发布系统设计与实现   总被引：5，自引：0，他引：5  

张像源 《中国地质灾害与防治学报》2005,16(4):120-123

基于Asp．Net是目前数据库开发应用的新趋势。文章分析了Asp．Net特点的条件下，提出利用．net技术，采用Ado．Net数据访问组件，建立基于用户层、数据库服务层、业务逻辑层的3层结构框架的地质灾害实时数据发布系统。并从数据库表设计、功能设计等方面进行了系统构建的分析，结合身份验证、监测数据的发布、监测曲线的发布等方面说明了系统实现过程，最后给出了一个基于此设计建立的实例，说明了通过Internet采用最新的．net技术，可以便利地建立耦合最新的、实时的、多类滑坡动态监测数据、滑坡基础灾害资料、实时气象数据等于一体的图文并茂的滑坡灾害网上实时发布系统。  相似文献   

Monitoring land subsidence in Semarang,Indonesia   总被引：1，自引：0，他引：1  

Muh Aris Marfai  Lorenz King 《Environmental Geology》2007,53(3):651-659

Semarang is one of the biggest cities in Indonesia and nowadays suffering from extended land subsidence, which is due to groundwater withdrawal, to natural consolidation of alluvium soil and to the load of constructions. Land subsidence causes damages to infrastructure, buildings, and results in tides moving into low-lying areas. Up to the present, there has been no comprehensive information about the land subsidence and its monitoring in Semarang. This paper examines digital elevation model (DEM) and benchmark data in Geographic Information System (GIS) raster operation for the monitoring of the land subsidence in Semarang. This method will predict and quantify the extent of subsidence in future years. The future land subsidence prediction is generated from the expected future DEM in GIS environment using ILWIS package. The procedure is useful especially in areas with scarce data. The resulting maps designate the area of land subsidence that increases rapidly and it is predicted that in 2020, an area of 27.5 ha will be situated 1.5–2.0 m below sea level. This calculation is based on the assumption that the rate of land subsidence is linear and no action is taken to protect the area from subsidence.  相似文献   

泰州市地面沉降问题的探讨     

薛小平 《现代测绘》2006,29(2):26-27

通过两次测定的水准点高程数据的比较,评估出泰州市海陵区的地面沉降量,并由此进行了分析。对今后如何展开工作,重视地面沉降问题提出了重要的建议。  相似文献   

Failure mechanism in an extremely slow rock slide at Bitchu-Matsuyama castle site (Japan)   总被引：1，自引：1，他引：1  

Vladimir Greif  Kyoji Sassa  Hiroshi Fukuoka 《Landslides》2006,3(1):22-38

One of the specific problems related to historical structures is the fact that they are prone to damage caused by even very small deformations acting over a long period of time, such as creep or extremely small rock displacements. If any damage has already occurred, the determination of the rock slope failure mechanism is one of the prerequisites for successful mitigation technique selection. In this study a medieval castle in central Japan, suffering damage caused by deformation of the rock mass in the subgrade of the castle, was investigated using a combination of field investigation, high-precision monitoring and physical modeling experiments. Using these techniques an attempt to determine the failure mechanism of the rock slope was made. Based on the field investigation a toe-slope failure seemed to be the main triggering factor activating the deformations in the upper slope area, right below the defense walls of the castle. The displacement monitoring of the surface rock blocks revealed a slumping failure with the backward rotational component prevailing over the sliding in the immediate vicinity of the castle wall. This was in accordance with the expectations obtained from the structural analysis of the rock mass carried out during the field investigation. The displacements obtained during the rock block monitoring, especially from the crack gauges, were not sufficient for drawing a satisfactory conclusions about the failure mechanism of the blocks located in the central part of the slope. Therefore, the failure mechanisms of rock blocks inferred from their displacements obtained from the monitoring were correlated with the results of modeling experiments carried out on the scaled slope model. The physical modeling revealed a possibility of toppling failure of rock blocks in the central area of the slope caused mainly by block interlocking, which was supported by the data from surface tilt meters installed additionally in the field. Furthermore, the possibility of the occurrence of forward and backward rock block rotations in the same sliding body at given conditions was supported by the physical modeling experiments.  相似文献   

Application of multi-temporal differential interferometry to slope instability detection in urban/peri-urban areas     

F. Bovenga  R. Nutricato  A. Refice  J. Wasowski   《Engineering Geology》2006,88(3-4):218-239

We present two case studies regarding the application of Synthetic Aperture Radar (SAR) Persistent Scatterers Interferometry (PSI) techniques to landslide-prone slopes situated in the municipal territories of Caramanico Terme and Volturino (Italy). The analysis of satellite SAR data with PSI techniques poses often problems on sites where, due to the scarcity of human artefacts and the presence of vegetation cover, density of coherent points (PS) is low (< 10 per km²). Moreover, the steep and rough topography typical of landslide-prone areas hamper the interferometric pre-processing, making more difficult the joint estimation of displacements and of DEM errors. Under these conditions the significance of temporal interferometric phase trends can be uncertain and conservative assumptions, necessary to ensure low false detection probabilities, need to be coupled with innovative processing strategies to increase the detection efficiency of PS objects. Here, the SPINUA (Stable Point Interferometry over Un-urbanised Areas) processing technique is applied together with an alternative PS Candidate (PSC) selection procedure based on the use of pixels classified as urban.

The cases of Caramanico and Volturino are representative, respectively, of harsh and favourable conditions for PSI applications. The results from Caramanico show clusters of PS exhibiting similar line-of-sight (LOS) deformation behaviour in the period 1995–2000. The locations of moving PS often coincide with distressed buildings and appear consistent with the areal distribution of recent and past landslide activity. The temporal displacement trends, however, are characterised by very low annual average velocities (from 3 to 7 mm/y) and it is uncertain to what extent the PS data reflect true slope movements, local deformations (e.g. settlement of engineering structures) or both.

Thanks to the more favourable conditions, the application of the standard SPINUA approach in the Volturino area was sufficient to obtain suitable densities of PS, as well as spatially and temporally consistent displacement results for a period 1992–2000. In particular, a group of moving PS was identified in a peri-urban area, known for the past and recent slope stability problems. The slowly moving PS (from 3 to 5 mm/y) fall in a location that, unlike the remaining part of the town, is characterised by the presence of many distressed buildings and structures. Although the site information confirms the reliability of PS data, in the absence of ground monitoring and detailed records of landslide movements, it is difficult to identify the main mechanism of the detected deformations. In general, in geologically and topographically complex urban/peri-urban settings, the significance of very low-velocity PSI surface displacements should always be considered together with in situ geotechnical controls and ground monitoring data.  相似文献