闸控感潮河网H-ADCP测流系统建设及应用

为准确把握不同调度模型下水量动态变化情况,中顺大围建设H-ADCP闸控感潮河网测流系统。系统造价低,维护简便,提供的水量数据可指导工程调度方案编制,为调度模型演算提供基础数据,也可作为闸泵自动控制系统配套设备,提供工程运行实时水量数据。从设备选型、站点选址、设备安装、数据处理等方面对系统进行介绍。系统在闸泵调度和水库联合调度中具有较好的应用价值。

Outlining a stepwise,multi-parameter debris flow monitoring and warning system:an example of application in Aizi Valley,China

In recent years, the increasing frequency of debris flow demands enhanced effectiveness and efficiency of warning systems. Effective warning systems are essential not only from an economic point of view but are also considered as a frontline approach to alleviate hazards. Currently, the key issues are the imbalance between the limited lifespan of equipment, the relatively long period between the recurrences of such hazards, and the wide range of critical rainfall that trigger these disasters. This paper attempts to provide a stepwise multi-parameter debris flow warning system after taking into account the shortcomings observed in other warning systems. The whole system is divided into five stages. Differentwarning levels can be issued based on the critical rainfall thresholds. Monitoring starts when early warning is issued and it continues with debris flow near warning, triggering warning, movement warning and hazard warning stages. For early warning, historical archives of earthquake and drought are used to choose a debris flow-susceptible site for further monitoring. Secondly, weather forecasts provide an alert of possible near warning. Hazardous precipitation, model calculation and debris flow initiation tests, pore pressure sensors and water content sensors are combined to check the critical rainfall and to publically announce a triggering warning. In the final two stages, equipment such as rainfall gauges, flow stage sensors, vibration sensors, low sound sensors and infrasound meters are used to assess movement processes and issue hazardwarnings. In addition to these warnings, communitybased knowledge and information is also obtained and discussed in detail. The proposed stepwise, multiparameter debris flow monitoring and warning system has been applied in Aizi valley China which continuously monitors the debris flow activities.

Design and Implementation of Computer Network Traffic Monitoring

This paper focuses on the key technologies of P2P and network traffic monitoring, research and analyze the traditional P2P flow control technology and the working principle of deployment, discuss on the straight loss and bypass interference control technology, and the reasonable combination of two kinds of technology to design straight bypass joint deployment. On basis of it, we design a new P2P traffic monitoring system. Through the design and implementation of computer network traffic monitoring system based on C/S mode to achieve automatic control, maintenance, and monitor network traffic, which is suitable for the current engineering software to monitor a network application environment. From the network users and network operator＇ s perspective, monitoring of network traffic is scientific, reasonable that improve network management and it has important research value.

数字缆道在淮滨水文站的应用

流量是反映江河、湖泊、水库等水体水量变化的基本资料,也是河道治理、防洪抗旱、水利工程规划设计和管理的依据。数字缆道测流系统是目前较为先进的获取流量资料的设施之一,以下结合淮滨水文站使用情况对该缆道系统作一介绍。

Automatic detection of oceanic eddies in reanalyzed SST images and its application in the East China Sea

Oceanic eddies may cause local sea surface temperature （SST）, height, and salinity anomalies in remote sensing （RS） images. Remote sensed SST imagery has proven to be an effective technique in oceanic eddy detection, because of its high temporal and spatial resolution. Various techniques have been used to identify eddies from SST images. However, mainly owing to the strong morphological variation of oceanic eddies, there is arguably no uniquely correct eddy detection method. A scheme of algorithm based on quasi-contour tracing and clustering of eddy detection from SST dataset is presented. The method does not impose fixed restrictions or limitations during the course of ＂suspected＂ eddy detection, and any eddy-like structures can be detected as ＂suspected＂ eddies. Then, ＂true＂ eddies can be identified based on the combination of intensity and spatial/temporal scale criteria. This approach has been applied to detect eddies in the East China Sea by using Operational SST ＆ Sea Ice Analysis （OSTIA） dataset. Experiments proved that oceanic eddies ranging in diameter from tens to hundreds of kilometers can be detected. Through investigation of the 2007-2011 OSTIA daily SST dataset from the Kuroshio region in the East China Sea, we found that the most active regions for oceanic eddies are those along the Kuroshio path, northeast of Taiwan Island, the Yangtze Estuary and the Ryukyu Islands. About 86% of the cyclonic eddies and 87% of the anticyclonic eddies have the size of 50-100 km in diameter. Only 25% of the anticyclonic eddy and 26% of the cyclonic eddy have the strength more than 0.4℃ in the sea surface layer.

A single camera volumetric particle image velocimetry and its application

Volumetric particle image velocimetry(VPIV) refers to a PIV-based technique which can obtain full velocity components in a three-dimensional measurement volume.A new VPIV method with a single lens was developed.A three-vision prism was used to make viewing from different angles using one camera.The technique was tested and successfully applied to a three-dimensional three-component(3D3C) measurement of a zero-net-mass-flux jet flow.The accuracy of the measurement was investigated,specifically in steps of calibration,self-calibration and particle triangulation.Time sequence of a vortex ring development was presented.It was shown that the measurement has high accuracy with validation rate of velocity vector reaching about 95%.The flow with vortex ring passing the measurement volume was studied using both swirl strength and vorticity magnitude criteria.Through comparison,the swirl criterion was found to be superior to the criterion of vorticity in differentiating the rotation motion and the free shear.

Electrical conductivity of hydrous silicate melts and aqueous fluids: Measurement and applications

The combination of magnetotelluric survey and laboratory measurements of electrical conductivity is a powerful approach for exploring the conditions of Earth's deep interior. Electrical conductivity of hydrous silicate melts and aqueous fluids is sensitive to composition, temperature, and pressure, making it useful for understanding partial melting and fluid activity at great depths. This study presents a review on the experimental studies of electrical conductivity of silicate melts and aqueous fluids, and introduces some important applications of experimental results. For silicate melts, electrical conductivity increases with increasing temperature but decreases with pressure. With a similar Na^+ concentration, along the calc-alkaline series electrical conductivity generally increases from basaltic to rhyolitic melt, accompanied by a decreasing activation enthalpy. Electrical conductivity of silicate melts is strongly enhanced with the incorporation of water due to promoted cation mobility. For aqueous fluids, research is focused on dilute electrolyte solutions. Electrical conductivity typically first increases and then decreases with increasing temperature, and increases with pressure before approaching a plateau value. The dissociation constant of electrolyte can be derived from conductivity data. To develop generally applicable quantitative models of electrical conductivity of melt/fluid addressing the dependences on temperature, pressure, and composition, it requires more electrical conductivity measurements of representative systems to be implemented in an extensive P-T range using up-to-date methods.

Development of a toy column model and its application in testing cumulus convection parameterizations

A single-column model is constructed based on parameterizations inherited from the Finite-volume/Spectral Atmospheric Model F/SAMIL and tested in simulations of tropical convective systems. Two representative convection schemes are compared in terms of their performances on precipitation types, individual physical tendencies, and temperature and moisture fields. The main difference between the two selected schemes is in their representation of entraining/detraining process. The Tiedtke scheme assumes bulk entrainment, while the Zhang–Mc Farlane scheme parameterizes entrainment/detrainment rates under the spectrum concept. Large-scale forcing and verification data are taken from the GATE phase III field campaign, during which abundant convective events were observed. Given the same triggering function and closure assumption, results show that entrainment/detrainment representation remains the dominant factor on the simulation of cumulus mass flux and of temperature and moisture fields. By analyzing sources and sinks of heat and moisture, this study reveals how parameterization components compensate for each other and make model results insensitive to parameterization changes in certain fields, thus suggesting the need to treat parameterizations as systems rather than individual components.

Experimental and Theoretical Analysis of an Optical Current Sensor for High Power Systems

A magneto-optical sensor, using a dual quadrature polarimetfic processing scheme, was evaluated for current metering and protection applications in high voltage lines. Sensor calibration and resolution were obtained in different operational conditions using illumination in the 1550-nm band. Results obtained indicated the feasibility of interrogating such sensor via the optical ground wire （OPGW） link installed in standard high power grids. The polarimetric bulk optical current sensor also was theoretically studied, and the effects of different sources of error considering practical deployment were evaluated. In particular, the interference from external magnetic fields in a tree-phase system was analyzed.

Applications and challenges for single-bacteria analysis by flow cytometry

Flow cytometry(FCM)is a powerful technique for single-bacteria analysis via simultaneous light-scattering and fluorescence measurements.By offering high-throughput,quantitative,and multiparameter analysis at the single-cell level,FCM has gained an increased popularity in microbiological research,food safety monitoring,water quality control,and clinical diagnosis.Here we will review the recent applications of flow cytometry in areas such as(1)total bacterial cell count,(2)bacterial viability analysis,(3)specific bacterial detection and identification,(4)characterization of physiological changes under environmental perturbations,and(5)biological function studies.Nevertheless,despite these widespread applications,challenges still remain for the detection of small sizes of bacteria and biochemical features that cannot be brightly stained via fluorescence.Recent improvement in FCM instrumentation will be discussed,and particularly the development of high sensitivity flow cytometry for advanced analysis of single bacterial cells will be highlighted.