In this paper we use the high speed multi channel meridian scanning photometer data and all sky TV camera images to analyze the intensity variations of the postnoon auroral bright sports of 557.7 nm and 630.0 nm em...In this paper we use the high speed multi channel meridian scanning photometer data and all sky TV camera images to analyze the intensity variations of the postnoon auroral bright sports of 557.7 nm and 630.0 nm emissions. Several results can be obtained from this paper. (1) Bright spots are rather transient features lasting typically for only a few minutes. (2) The intensity of the postnoon bright spots of 557.7 nm emissions can surpass 11 kR. The occurrence of the bright spots seems rather frequent. (3) The ratios of I(427.8)/I(630.0) and I(427.8)/I(557.7) during the bright spots occurring time show a positive peak and negative peak respectively. It qualitatively indicates that the average precipitating electron energies along the meridianal scan above Zhongshan Station increased as the bright spot appeared. And the intensification of the spot mainly was caused by the increasing of high energy (3 10 keV) flux. (4) Usually the bright spots are accompanied with the magnetic pulsation and the occurrence of multi band arcs.展开更多
"bright spot" on reflection seismic profile has been regarded as one of the important indications of oil and gas,and it has been widely used in the oil and gas exploration. Moreover,with the development of n..."bright spot" on reflection seismic profile has been regarded as one of the important indications of oil and gas,and it has been widely used in the oil and gas exploration. Moreover,with the development of new technologies,"bright spot" technique has been gradually applied to the exploration of coal,underground water and other fields,and also in the research of deep structure of the earth. Based on the reviewing of published literatures,the authors described the structural features and generation of "bright spot" on seismic profile for energy resources exploration and crustal-scale deep seismic reflection profiles,and further summarized the applications of the "bright spot"technique in energy resource exploration and deep structure research.展开更多
On the morning of August 17, 2002, colorful flags and slogan streamers were fluttering over the sports ground of the Dongsi Shisantiao Primary School in Dongcheng District of Beijing. A huge red streamer "Direct ...On the morning of August 17, 2002, colorful flags and slogan streamers were fluttering over the sports ground of the Dongsi Shisantiao Primary School in Dongcheng District of Beijing. A huge red streamer "Direct Election of the Jiudaowan Community of Beixinqiao Neighborhood Community Office of Dongcheng District" over a platform told that a direct election of the community was to be held there.展开更多
In 2009, China’s growth of national textile and apparel sales reached 20 percent, so that by 2010, domestic consumption has already become the bright spot in
Prospectors usually recognize the event with strong amplitude in seismic sections as bright spots. However, such a simple and rough method can’t distinguish whether these bright spots are related to favorable gas lay...Prospectors usually recognize the event with strong amplitude in seismic sections as bright spots. However, such a simple and rough method can’t distinguish whether these bright spots are related to favorable gas layer or water layer directly. In this paper, for the high correlation between reservoir gascontent and amplitude anomaly in research area, based on rock physical analysis of the wells drilled, using forward modeling technique respectively simulates and analyzes the seismic amplitude of gas layer and water layer. Then, combining the simulation result with corresponding statistics amplitude obtains the numerical relationship between each layer amplitude. At last, using the display technique directly recognizes the bright spots of gas layer in seismic profile and gets rid of those false bright spots caused by water layer, which improved the robustness in the bright spots interpretation and provided reliable basis for reducing exploration risks. Moreover, applying the method to the target zone, we obtain huge success.展开更多
This paper studies the properties of a kind of portable ultra-bright microfocus x-ray source with the Monte-Carlo method in detail. The new x-ray source consists of an electron-emission system, an electrostatic focusi...This paper studies the properties of a kind of portable ultra-bright microfocus x-ray source with the Monte-Carlo method in detail. The new x-ray source consists of an electron-emission system, an electrostatic focusing system and a metal target. A crystal Lanthanum Hexaboride cathode, a Wehnelt grid and an extracted electrode compose the triode electrode electron-gun system. Two equal radius cylinder electrodes form the focusing system. The key factors determining the focus properties of the electron beam such as the ratio Dw/H, grid bias Vg, and the properties of the extracted electrode arc numerically studied. The calculated results reveal that when Dw/H, Vg, the length of the extracted electrode, and the distance between the grid and the extracted electrode equals 5, q）.6 kV, 10 mm, and 8 mm respectively, the electron beam focal spot can be concentrated down to 9 μm in radius and a reasonable focal length about 72.5 mm can be achieved, at the same time, the cathode emission currents can be as high as 30 mA.展开更多
双曲调频(Hyperbolic Frequency Modulation,HFM)波形是传统主动声呐常用的信号波形,具有多普勒不变性。HFM信号虽然便于匹配,但无法进行准确的测速、测距。升降HFM组合的V型双曲调频(V-Hyperbolic Frequency Modulation,V-HFM)脉冲信号...双曲调频(Hyperbolic Frequency Modulation,HFM)波形是传统主动声呐常用的信号波形,具有多普勒不变性。HFM信号虽然便于匹配,但无法进行准确的测速、测距。升降HFM组合的V型双曲调频(V-Hyperbolic Frequency Modulation,V-HFM)脉冲信号,可以解决HFM的距离-速度耦合模糊问题,但在多目标情况下会有虚假亮点干扰问题。受V-HFM组合方式启发,文章提出一种新的HFM组合方法:N型双曲调频(N-Hyperbolic Frequency Modulation,N-HFM)组合信号。该信号形式可以降低虚假亮点出现的概率。水池实验表明:在多目标情况下,N-HFM脉冲信号可以实现距离和速度二维检测的较高分辨力,以及较强的抑制虚假目标的能力。展开更多
文摘In this paper we use the high speed multi channel meridian scanning photometer data and all sky TV camera images to analyze the intensity variations of the postnoon auroral bright sports of 557.7 nm and 630.0 nm emissions. Several results can be obtained from this paper. (1) Bright spots are rather transient features lasting typically for only a few minutes. (2) The intensity of the postnoon bright spots of 557.7 nm emissions can surpass 11 kR. The occurrence of the bright spots seems rather frequent. (3) The ratios of I(427.8)/I(630.0) and I(427.8)/I(557.7) during the bright spots occurring time show a positive peak and negative peak respectively. It qualitatively indicates that the average precipitating electron energies along the meridianal scan above Zhongshan Station increased as the bright spot appeared. And the intensification of the spot mainly was caused by the increasing of high energy (3 10 keV) flux. (4) Usually the bright spots are accompanied with the magnetic pulsation and the occurrence of multi band arcs.
基金Supported by projects of National Key Research and Development of China(No.2016YFC0600301)National Natural Science Foundation of China(No.41674124)
文摘"bright spot" on reflection seismic profile has been regarded as one of the important indications of oil and gas,and it has been widely used in the oil and gas exploration. Moreover,with the development of new technologies,"bright spot" technique has been gradually applied to the exploration of coal,underground water and other fields,and also in the research of deep structure of the earth. Based on the reviewing of published literatures,the authors described the structural features and generation of "bright spot" on seismic profile for energy resources exploration and crustal-scale deep seismic reflection profiles,and further summarized the applications of the "bright spot"technique in energy resource exploration and deep structure research.
文摘On the morning of August 17, 2002, colorful flags and slogan streamers were fluttering over the sports ground of the Dongsi Shisantiao Primary School in Dongcheng District of Beijing. A huge red streamer "Direct Election of the Jiudaowan Community of Beixinqiao Neighborhood Community Office of Dongcheng District" over a platform told that a direct election of the community was to be held there.
文摘In 2009, China’s growth of national textile and apparel sales reached 20 percent, so that by 2010, domestic consumption has already become the bright spot in
文摘Prospectors usually recognize the event with strong amplitude in seismic sections as bright spots. However, such a simple and rough method can’t distinguish whether these bright spots are related to favorable gas layer or water layer directly. In this paper, for the high correlation between reservoir gascontent and amplitude anomaly in research area, based on rock physical analysis of the wells drilled, using forward modeling technique respectively simulates and analyzes the seismic amplitude of gas layer and water layer. Then, combining the simulation result with corresponding statistics amplitude obtains the numerical relationship between each layer amplitude. At last, using the display technique directly recognizes the bright spots of gas layer in seismic profile and gets rid of those false bright spots caused by water layer, which improved the robustness in the bright spots interpretation and provided reliable basis for reducing exploration risks. Moreover, applying the method to the target zone, we obtain huge success.
基金supported by the Major Program of the National Natural Science Foundation of China(Grant No 60532090)the National Natural Science Foundation of China(Grant No 60771048)
文摘This paper studies the properties of a kind of portable ultra-bright microfocus x-ray source with the Monte-Carlo method in detail. The new x-ray source consists of an electron-emission system, an electrostatic focusing system and a metal target. A crystal Lanthanum Hexaboride cathode, a Wehnelt grid and an extracted electrode compose the triode electrode electron-gun system. Two equal radius cylinder electrodes form the focusing system. The key factors determining the focus properties of the electron beam such as the ratio Dw/H, grid bias Vg, and the properties of the extracted electrode arc numerically studied. The calculated results reveal that when Dw/H, Vg, the length of the extracted electrode, and the distance between the grid and the extracted electrode equals 5, q）.6 kV, 10 mm, and 8 mm respectively, the electron beam focal spot can be concentrated down to 9 μm in radius and a reasonable focal length about 72.5 mm can be achieved, at the same time, the cathode emission currents can be as high as 30 mA.
文摘双曲调频(Hyperbolic Frequency Modulation,HFM)波形是传统主动声呐常用的信号波形,具有多普勒不变性。HFM信号虽然便于匹配,但无法进行准确的测速、测距。升降HFM组合的V型双曲调频(V-Hyperbolic Frequency Modulation,V-HFM)脉冲信号,可以解决HFM的距离-速度耦合模糊问题,但在多目标情况下会有虚假亮点干扰问题。受V-HFM组合方式启发,文章提出一种新的HFM组合方法:N型双曲调频(N-Hyperbolic Frequency Modulation,N-HFM)组合信号。该信号形式可以降低虚假亮点出现的概率。水池实验表明:在多目标情况下,N-HFM脉冲信号可以实现距离和速度二维检测的较高分辨力,以及较强的抑制虚假目标的能力。
