This study attempted to establish a broad regional phenological pattern for Northeast Asia using time-series data of the satellite measured index of terrestrial chlorophyll content (MERIS Terrestrial Chlorophyll Index) from 2003 to 2007. A suite of phenological variables were extracted from 4 integral seasons of time-series Medium Resolution Imaging Spectrometer (MERIS) Terrestrial Chlorophyll Index (MTCI) of World Wildlife Fund (WWF) ecoregions smoothed by an asymmetric Gaussian model. In this study, spatial variation with latitude was observed for the chlorophyll content and phenological variables for natural vegetation across north-south transect of northeast Asia (NSTNEA). The onset of greenness for most ecoregions followed a latitudinal pattern with an earlier onset of greenness at lower latitudes. In general, the length of growing season was higher at lower latitudes. For forests in NSTNEA, the average maximum MTCI value and range of MTCI value at lower latitudes were significantly larger than that at higher latitudes during the study period. In addition, the cumulative CV showed a declining trend with an increase in latitude overall. Our findings suggest that although precipitation plays a promoting role, temperature is still the dominant factor in vegetation phenological period at high latitudes.
Field observations made with unmanned aerial vehicles of the particulate matter (PM) concentration from the ground to a height of 500 m were conducted at Xiaotang and Tazhong in the Taklimakan Desert (TD), China, from 7 to 15 November 2019. The vertical structures of the PM concentrations were studied. Pulsed lidar observations showed that dust aerosols in the TD can reach heights of 4 km. Within 500 m above the ground, the PM1.0, PM2.5, and PM10 concentrations were <100, <201, and <764 µg∙m−3, respectively, in the TD. On days containing sand-blowing periods (e.g., at 18:00 on 11 November), the PM1.0, PM2.5, and PM10 concentrations were 10–17.7 times higher than on clear days. The northern margin of the TD (Xiaotang) was dominated by fine particles, while the hinterland (Tazhong) was dominated by coarse particles, because there was sparse vegetation around Xiaotang and the surface was sand and clay, while there was no vegetation around Tazhong and the surface was sand. During floating dust periods, the boundary layer was dominated by fine particles. The average PM1.0/PM2.5 ratios were 0.25–0.65 and 0.40–0.80 at Tazhong and Xiaotang, respectively, while, during sand blowing periods, these ratios were 0.40–0.55 and 0.40–0.45, respectively. The critical condition in the atmospheric boundary layer for PM concentration was revealed with the enhanced momentum flux and sensible heat flux up to 0.52 kg∙m−1∙s−2, 0.69 m∙s−1, and 6.7 W∙m2, respectively, and the low mixed layer was high in the lower atmosphere.
Ultrasound imaging, as one of the four most important medical imaging technologies (ultrasound, CT, MRI, and isotope scanning), has become an indispensable important part of the clinical medicine after the development of more than half a century. Medical ultrasound imaging, by relying on its advantages such as real-time, nondestructive, no radiation, and cheap price, has constantly received attention from people. More accurate diagnosis and treatment, and more authoritative protection are continuously provided by the medical ultrasound imaging technology for clinical diseases. In this paper, starting from the basic ultrasonic wave, the application of ultrasound in medicine, medical ultrasonic imaging technology and classification, and the current ultrasonic equipments applied in medical imaging are introduced. The medical equipment use units and personnel can provide better health service for human beings as long as the equipments are better known and utilized.Ultrasonic and its application in medicine
Digital Elevation Models (DEM) implies numbers of geomorphologic spatial information. It not only includes the three-dimensional coordinate but also has unique texture information, which can describe the ‘true’ land surface adequately at relation of neighbors (plan) and relative (amplitude). We will use a method to study the wavelength characters by data mining and distribution of slope and local relief on the altitude steps through a local window. The Shuttle Radar Topography Mission (SRTM) collect detailed Digital Elevation Models(DEM) data between 60°N and 57°S, 80 percent for all land masses, and it provides reliable, high precision surface elevation data for us, suits to analyze efficiently landscape pattern. SRTM-DEM data simulate three-dimensional land surface with regular gridded matrix, and these discrete points are fit for spatial neighbors’ analysis and statistics, and convenient to geomorphologic pattern computation and analysis in digital computer. Geomorphologic pattern is influenced by Physical properties and human activities in a most direct way, but whilst it record numbers of geological evolution evidence, and these records provide some important information for climate change, geological and geographical processes and ecological environment researches in science. In this study, making the whole Jilin province as study object, we propose a fourth-order equation to approximate land as a continuous curved surface, association neighbors’ analysis method, utilize digital elevation matrix to validate an optimal statistic window, and subsequent study the area spatial distribution by parameterization and classification, get a satisfactory effect.
In this paper, the advantages and disadvantages of the existing ultrasonic image management system are analyzed, and also a multi-functional color Doppler ultrasound image-text management system is researched and developed in combination with the experience of color Doppler ultrasound doctors. With this system, the related operations such as color Doppler ultrasound images acquisition, processing, preservation, and medical records are implemented. In the design of the system, a professional acquisition card is used for implementing the acquisition of ordinary video signals. In the meantime, DICOM interface is designed using DICOM3.0 protocol for implementing multi-mode acquisition.
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