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1.
Atmospheric CO(2) monitoring from space   总被引:2,自引:0,他引:2  
Park JH 《Applied optics》1997,36(12):2701-2712
A spectroscopic method of monitoring the atmospheric CO(2) mixing ratio vertical profile from space is described. An experimental design is presented for a solar occultation mode with the O(2)A band in the visible region to retrieve pressure and temperature profiles first, and then several CO(2) bands in the infrared region at 4.3, 2.7, and 2.0 mum to obtain CO(2) mixing ratio profiles. Instrument techniques considered are low resolution Fourier transform spectrometry and radiometry of various bandwidths. Simulations indicate that the precision of the pressure, temperature, and CO(2) mixing ratio measurements for an altitude region 30-10 km are less than 1%, 1 K, and 1%, respectively, for the case of the Fourier transform spectrometer and approximately 1%, 1 K, and 2% for the case of the radiometer. With careful experimental design, measurements can be made with better precision and also can extend below 10 km. This inferred precision of CO(2) may be considered to be good enough for investigating atmospheric dynamics when CO(2) is used as a tracer and also for measuring spatial and temporal variations of CO(2) mixing ratios in the range of 0.5-6.5% of 350 parts per million by volume in the troposphere and the lower stratosphere.  相似文献   

2.
Roadside checkpoints were used to determine the percentage of motorists driving while suspended (DWS) during various times of the day. These data showed that the percentage of motorists DWS was 57% of the expected value relative to their representation among all drivers. Data also showed that suspended drivers make up a higher percentage of drivers on the road after midnight. Results also indicated that 90% of suspended drivers stopped in this study produced a driving permit even though they are required to surrender it when suspended. In order to compare data collected at roadside checkpoints with self-report data. a questionnaire was administered to 456 persons taking a re-education course for first offenders and 68 participants taking a re-education course for second offenders. The results indicated that participants under-represented their own incidence of DWS. However, when asked about the driving behavior of other suspended drivers, their estimates were much closer to the data obtained with the roadside survey.  相似文献   

3.
Body area network for wireless patient monitoring   总被引:1,自引:0,他引:1  
Patient data monitoring is a key issue for health and disease management. The use of wireless sensors within a body area network (BAN) makes this task seamless and easy. A BAN system is presented, which allows the connectivity of a wide range of heterogeneous body sensors to a portable hub device that is connectable to external networks (IEEE 802.11, GPRS). This BAN is based on the use of Zigbee/IEEE 802.15.4 standard technology and off-the-shelf modules. It is currently being used at the European level for the detection and the prediction of the human physiological state in relation to wakefulness, fatigue, and stress applications in which users carrying out daily activities are monitored in an unobtrusive and comfortable way. Characterised by its low power consumption, low cost, and ability to connect a wide range of heterogeneous sensors, this system can substantially improve the performance of different services, especially those that are health related.  相似文献   

4.
The Pierre Auger Observatory, completed in September 2008, detects cosmic rays by observing and studying the development of extensive air showers in atmosphere. The atmosphere itself, with its unpredictable changes of conditions, directly influences the estimation of the air shower characteristics. In this paper, all the instruments and techniques adopted by the Auger Observatory are explained, and the impact of their results on the most important shower parameters are shown.  相似文献   

5.
《中国测试》2015,(8):83-87
针对因建模的三维数据量巨大导致传统Open GL固定管线对三维地形渲染难以满足实时性需求这一问题,提出利用GPU可编程图形管线来进行渲染,实现区域的可视化实时显示。建模过程中首先使用基于分形理论的随机中点位移法产生地形高程数据,然后利用三角面元连接地形高程散点生成三维曲面,最后通过GLSL着色语言对GPU进行编程实现对地形的渲染。该方法建模过程与Open GL固定管线渲染效率进行对比,结果表明:利用GPU可编程图形管线对400万的三维地形网格数据进行渲染仅用时82.92 ms,效率远高于Open GL固定管线的渲染,能够满足实时渲染的需要。  相似文献   

6.
研究了甲醛与尿素的配比[n(F)/n(U)比值]、缩聚温度、时间与pH值,以及改性剂对以尿素、甲醛为主要原料制备脲醛(UF)树脂胶粘剂游离甲醛含量的影响,获得了确保其粘接强度不致下降,而游离甲醛含量只有0.25%的最佳制备工艺条件。  相似文献   

7.
8.
Selecting the instruments to determine the operational quantities in the neutron fields produced by particle accelerators involves a combination of aspects, which is peculiar to these environments: the energy distribution of the neutron field, the continuous or pulsed time structure of the beam, the presence of other radiations to which the neutron instruments could have significant response and the large variability in the dose rate, which can be observed when moving from areas near the beam line to free-access areas. The use of spectrometric techniques in support of traditional instruments is highly recommended to improve the accuracy of dosimetric evaluations. The multi-sphere or Bonner Sphere Spectrometer (BSS) is certainly the most used device, due to characteristics such as the wide energy range, large variety of active and passive detectors suited for different workplaces, good photon discrimination and the simple signal management. Disadvantages are the poor energy resolution, weight and need to sequentially irradiate the spheres, leading to usually long measurement sessions. Moreover, complex unfolding analyses are needed to obtain the neutron spectra. This work is an overview of the BSS for area monitoring in particle accelerators.  相似文献   

9.
A neutron radiation area monitoring system has been developed for proton accelerator facilities dedicated to cancer therapy. The system comprises commercial measurement equipment, computer hardware and a suite of software applications that were developed specifically for use in a medical accelerator environment. The system is designed to record and display the neutron dose-equivalent readings from 16 to 24 locations (depending on the size of the proton therapy centre) throughout the facility. Additional software applications provide for convenient data analysis, plotting, radiation protection reporting, and system maintenance and administration tasks. The system performs with a mean time between failures of >6 months. Required data storage capabilities and application execution times are met with inexpensive off-the-shelf computer hardware.  相似文献   

10.
11.
Existing solar radiative codes such as lowtran allow us to model the radiative properties of the atmosphere and its constituents for standard atmospheric conditions. The increase in urbanization and air pollution has led to changes in the distribution, type, and concentration of the atmospheric constituents, affecting spectral atmospheric transmission and modifying weather and climate. This requires knowledge of the real optical properties of atmospheric transmission. We have developed a model for the radiative properties of atmospheric transmission, with ground-based multispectral measurements of direct solar radiation in the 310-830-nm range. An application of this model to Athens' urban atmosphere is described. The radiative properties of a U.S. Standard Atmosphere are also simulated by use of the lowtran 7 code; simulations and calculations are compared. The total ozone retrieval scheme and the algorithm for retrieving the spectral transmission function and optical thickness, considering multiple scattering, are given. Results for the spectral atmospheric transmission and aerosol and gas transmission functions as well as optical-thickness measurements for the Athens area are also presented as an application of the proposed methodology.  相似文献   

12.
为了更好的贯彻实施发展高产、优质、高效农业,建立健全农业标准和监测体系,水资源严重缺乏的安徽省已确定在实施优化水源配置,节水与开源两手抓的战略方针指导下,实行节水型农村、节水型农业、节水型社会的基本政策,“3181”节水灌溉工程计划(‘九五’期间增加节水农田207万公顷,选择八个重点县,建设十个高标准节水灌溉示范片)已进行,并取得了阶段性成效,但节水农业工作中的综合标准化与监测工作尚待加强。一进一步进行水稻节水灌溉技术研究水稻技术灌溉是按作物生长发育需水机制,即按水稻不同生长阶段的生理、生态…  相似文献   

13.
The response of a TLD-600/TLD-700 area dosemeter has been characterized in neutron fields around the 590 MeV cyclotron ring at the Paul Scherrer Institute (PSI). The dosemeter is based on a cylindrical paraffin moderator with three of each type of TLD chip at the centre, and is intended to use for area monitoring around accelerator facilities. The dosemeter is calibrated in terms of ambient dose equivalent using a non-moderated 252Cf neutron source. The ambient dose equivalent response has been tested in five locations where the neutron fields and dose rates have been well characterized by Bonner sphere spectrometer and active neutron monitor measurements. The different spectrum shapes and dose rates in the five locations permit the comparison of the behavior of the active and passive dosemeters in these neutron fields.  相似文献   

14.
15.
In December 2000 the International Atomic Energy Agency sponsored an intercomparison of radiation protection area monitoring instruments which was held at the Instituto de Radioprote??o e Dosimetria--IRD/CNEN, Rio de Janeiro. Brazil. This intercomparison exercise was aimed at evaluating the ability of some Latin American and Caribbean countries to perform calibrations or such instruments, or have them properly performed by a third party. Nine countries participated in the exercise with 13 portable gamma dose rate monitors. The quantity of interest for the intercomparison was the ambient dose equivalent, H*(10), although some instruments were not designed or calibrated in this quantity. Results were converted to H*(10), whenever necessary. according to the information supplied by each participant. All results for the quantity of interest agree well within 10% of the reference values and the quoted uncertainties.  相似文献   

16.
1.Introduction Coordinated regional development is one of the national strategies in the new era[1].The fifth plenary session of the 19th Central Committee of t...  相似文献   

17.
Atmospheric modulation transfer function in the infrared   总被引:2,自引:0,他引:2  
In high-resolution ultranarrow field-of-view thermal imagers, image quality over relatively long path lengths is typically limited by atmospheric degradation, especially atmospheric blur. We report our results and analyses of infrared images from two sites, Fort A. P. Hill and Aberdeen Proving Ground. The images are influenced by the various atmospheric phenomena: scattering, absorption, and turbulence. A series of experiments with high-resolution equipment in both the 3-5- and 8-13-microm regions at the two locations indicate that, as in the visible, image quality is limited much more by atmosphere than by the instrumentation for ranges even of the order of only a few kilometers. For paths close to the ground, turbulence is more dominant, whereas for paths involving higher average elevation, aerosol modulation transfer function (MTF) is dominant. As wavelength increases, turbulence MTF also increases, thus permitting aerosol MTF to become more dominant. A critical role in aerosol MTF in the thermal infrared is attributed to absorption, which noticeably decreases atmospheric transmission much more than in the visible, thereby reducing high-spatial-frequency aerosol MTF. These measurements indicate that atmospheric MTF should be a basic component in imaging system design and analysis even in the infrared, especially as higher-resolution hardware becomes available.  相似文献   

18.
Automated fluorometric determination of formaldehyde in air   总被引:3,自引:0,他引:3  
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19.
20.
Smirnov  B. M. 《High Temperature》2021,59(2-6):207-218
High Temperature - Changes in the Earth’s atmosphere that affect its energetics are analyzed. The results of NASA programs on carbon dioxide monitoring in the atmosphere and the evolution of...  相似文献   

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