To evaluae small animal imaging with individual different high voltage, filter thickness and tube current, an animal X-ray micro-computed tomography （micro-CT） system based on panel detector is developed and a rat i...To evaluae small animal imaging with individual different high voltage, filter thickness and tube current, an animal X-ray micro-computed tomography （micro-CT） system based on panel detector is developed and a rat is scanned by using the system with individual high voltage, tube current, filter thickness, and exposure time. A model is presented based on the Monte Carlo code PENELOPE for generating the X-ray spectra of X-ray tube used in the micro-CT system. A platform developed based on Matlab allows for calculating beam quality parameters, including the average energy of X-ray beam, the change of transmition rate and the input X-ray fluence. The factors affecting the signal difference to noise ratio （SDNR） of micro-CT are investigated and the relationship between SDNR and scan combinations is analyzed. A series of tools and methods are developed for small animal imaging and imaging performance evaluation in the field of small animal imaging.展开更多
Gas emissions of workfaces in steeply inclined and extremely thick coal seams differ from those under normal geological conditions, which usually feature a high gas concentration and a large emission quantity. This st...Gas emissions of workfaces in steeply inclined and extremely thick coal seams differ from those under normal geological conditions, which usually feature a high gas concentration and a large emission quantity. This study took the Wudong coal mine in Xinjiang province of China as a typical case. The gas occurrence of the coal seam and the pressure-relief range of the surrounding rock(coal) were studied by experiments and numerical simulations. Then, a new method to calculate the gas emission quantity for this special geological condition was provided. Based on the calculated quantity, a further gas drainage plan, as well as the evaluation of it with field drainage data, was finally given. The results are important for engineers to reasonably plan the gas drainage boreholes of steeply inclined and extremely thick coal seams.展开更多
Eight single-low or double-low rapeseed cultivars were bred from 1980 to 2000 in Hunan Province. In this paper, characters and breeding method of these cultivars are introduced.
In the experimental study, AGE-782 thermal instrument was used to detect the infrared radiation variation of coal and sandstone (wave-length range 3.6～5.5 μm was used). It's discovered that coal and sandstone fa...In the experimental study, AGE-782 thermal instrument was used to detect the infrared radiation variation of coal and sandstone (wave-length range 3.6～5.5 μm was used). It's discovered that coal and sandstone failure under load have three kinds of infrared thermal features as well as infrared forewarning messages. That are: (1) temperature rises gradually but drops before failure ; (2) temperature rises gradually but quickly rises before failure; (3) first rises,then drops and lower temperature emerges before failure. The further researches and the prospect of micro-wave remote sensing detection .on ground pressure is also discussed.展开更多
With the continuous advancement of Intemet technology, Intemet is penetrating to various sectors of the society and every comer of life, which spawned a variety of needs. Therefore. the development of the Interact sho...With the continuous advancement of Intemet technology, Intemet is penetrating to various sectors of the society and every comer of life, which spawned a variety of needs. Therefore. the development of the Interact should ahvays meet the needs of customers. How the next generation of the lntemet will develop？ How the technology will get the breakthrough？ How to use MPLS technology to make the transition of the lntemet more practical and more scientific？ And so on. These questions need network technical staff give full play of the technical expertise to promote Interact technology＇ continues moving forward. This paper first introduces MPLS technology, and then analyzes the overall architecture of the next generation Interact and the service quality required by the next generation lntemet, and at last study how to make the MPLS-based transition technology of next-generation more perfect.展开更多
基金Supported by the National Natural Science Foundation of China (60672104,10527003)the Nation-al Basic Research Program of China ("973"Program)(2006CB705705)the Joint Research Foundation of Beijing Mu-nicipal Commission of Education (JD100010607)~~
文摘To evaluae small animal imaging with individual different high voltage, filter thickness and tube current, an animal X-ray micro-computed tomography （micro-CT） system based on panel detector is developed and a rat is scanned by using the system with individual high voltage, tube current, filter thickness, and exposure time. A model is presented based on the Monte Carlo code PENELOPE for generating the X-ray spectra of X-ray tube used in the micro-CT system. A platform developed based on Matlab allows for calculating beam quality parameters, including the average energy of X-ray beam, the change of transmition rate and the input X-ray fluence. The factors affecting the signal difference to noise ratio （SDNR） of micro-CT are investigated and the relationship between SDNR and scan combinations is analyzed. A series of tools and methods are developed for small animal imaging and imaging performance evaluation in the field of small animal imaging.
基金provided by the National Science and Technology Major Project (No. 2016ZX05043-005)
文摘Gas emissions of workfaces in steeply inclined and extremely thick coal seams differ from those under normal geological conditions, which usually feature a high gas concentration and a large emission quantity. This study took the Wudong coal mine in Xinjiang province of China as a typical case. The gas occurrence of the coal seam and the pressure-relief range of the surrounding rock(coal) were studied by experiments and numerical simulations. Then, a new method to calculate the gas emission quantity for this special geological condition was provided. Based on the calculated quantity, a further gas drainage plan, as well as the evaluation of it with field drainage data, was finally given. The results are important for engineers to reasonably plan the gas drainage boreholes of steeply inclined and extremely thick coal seams.
文摘Eight single-low or double-low rapeseed cultivars were bred from 1980 to 2000 in Hunan Province. In this paper, characters and breeding method of these cultivars are introduced.
文摘In the experimental study, AGE-782 thermal instrument was used to detect the infrared radiation variation of coal and sandstone (wave-length range 3.6～5.5 μm was used). It's discovered that coal and sandstone failure under load have three kinds of infrared thermal features as well as infrared forewarning messages. That are: (1) temperature rises gradually but drops before failure ; (2) temperature rises gradually but quickly rises before failure; (3) first rises,then drops and lower temperature emerges before failure. The further researches and the prospect of micro-wave remote sensing detection .on ground pressure is also discussed.
文摘With the continuous advancement of Intemet technology, Intemet is penetrating to various sectors of the society and every comer of life, which spawned a variety of needs. Therefore. the development of the Interact should ahvays meet the needs of customers. How the next generation of the lntemet will develop？ How the technology will get the breakthrough？ How to use MPLS technology to make the transition of the lntemet more practical and more scientific？ And so on. These questions need network technical staff give full play of the technical expertise to promote Interact technology＇ continues moving forward. This paper first introduces MPLS technology, and then analyzes the overall architecture of the next generation Interact and the service quality required by the next generation lntemet, and at last study how to make the MPLS-based transition technology of next-generation more perfect.
