Recently, Chen and his team were active in the theoretical and practical study of a new heliostat for the use of solar energy. This work represents the first innovation in the area of heliostats after many years of li...Recently, Chen and his team were active in the theoretical and practical study of a new heliostat for the use of solar energy. This work represents the first innovation in the area of heliostats after many years of little progress. The mathematical development of the tracking and concentration optics principles, and the practical implementation and demonstration of the technology, are both very interesting advances in this field. Many applications are possible for this technology such as generation of solar electricity and solar industrial process heat.展开更多
The New Vacuum Solar Telescope （NVST） is a one meter vacuum solar telescope that aims to observe fine structures on the Sun. The main goals of NVST are high resolution imaging and spectral observations, including me...The New Vacuum Solar Telescope （NVST） is a one meter vacuum solar telescope that aims to observe fine structures on the Sun. The main goals of NVST are high resolution imaging and spectral observations, including measurements of the solar magnetic field. NVST is the primary ground-based facility used by the Chinese solar research community in this solar cycle. It is located by Fuxian Lake in southwest China, where the seeing is good enough to perform high resolution observations. We first introduce the general conditions at the Fuxian Solar Observatory and the primary science cases of NVST. Then, the basic structures of this telescope and instruments are described in detail. Finally, some typical high resolution data of the solar photosphere and chromosphere are also shown.展开更多
We investigate the wavelet transform of yearly mean relative sunspot number series from 1700 to 2002. The curve of the global wavelet power spectrum peaks at 11-yr, 53-yr and 101-yr periods. The evolution of the ampli...We investigate the wavelet transform of yearly mean relative sunspot number series from 1700 to 2002. The curve of the global wavelet power spectrum peaks at 11-yr, 53-yr and 101-yr periods. The evolution of the amplitudes of the three periods is studied. The results show that around 1750 and 1800, the amplitude of the 53-yr period was much higher than that of the the 11-yr period, that the ca. 53-yr period was apparent only for the interval from 1725 to 1850, and was very low after 1850, that around 1750, 1800 and 1900, the amplitude of the 101-yr period was higher than that of the 11-yr period and that, from 1940 to 2000, the 11-yr period greatly dominates over the other two periods.展开更多
About , there have been four views: windows, granaries, a name of sacrifice and sites. This paper offers new research on the shape and meaning of the inscription on bones, following the former researchers. The su...About , there have been four views: windows, granaries, a name of sacrifice and sites. This paper offers new research on the shape and meaning of the inscription on bones, following the former researchers. The suggestion is that the inscription should be shaped from the sun, and its original meaning is sacrificial sites.展开更多
Owing to the largely improved facilities and working conditions, solar physics research in China has recently shown marked development. This paper reports on the recent progress of solar physics research in China'...Owing to the largely improved facilities and working conditions, solar physics research in China has recently shown marked development. This paper reports on the recent progress of solar physics research in China's Mainland, mainly focusing on several hot issues, including instrumentations, magnetic field observations and research, solar flares, filaments and their eruptions, coronal mass ejections and related processes, as well as active regions and the corona, small-scale phenomena, solar activity and its predictions. A vision of the future is also described.展开更多
The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an L...The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an LCVR polarimeter,an image-stabilization system,a seven-stage tunable Lyot filter,a CMOS camera with 4096×4096 pixels and a pair of calibration/focus wheels.In this paper,we describe the design of the FMG instrument and provide a summary of test observations carried out with the FMG prototype.展开更多
A method combining the support vector machine （SVM） the K-Nearest Neighbors （KNN）, labelled the SVM-KNN method, is used to construct a solar flare forecasting model. Based on a proven relationship between SVM and ...A method combining the support vector machine （SVM） the K-Nearest Neighbors （KNN）, labelled the SVM-KNN method, is used to construct a solar flare forecasting model. Based on a proven relationship between SVM and KNN, the SVM-KNN method improves the SVM algorithm of classification by taking advantage of the KNN algorithm according to the distribution of test samples in a feature space. In our flare forecast study, sunspots and 10cm radio flux data observed during Solar Cycle 23 are taken as predictors, and whether an M class flare will occur for each active region within two days will be predicted. The SVM- KNN method is compared with the SVM and Neural networks-based method. The test results indicate that the rate of correct predictions from the SVM-KNN method is higher than that from the other two methods. This method shows promise as a practicable future forecasting model.展开更多
Paleoclimatic studies indicate four epochs of global cooling during the last 4 000 years, i.e. during the few centuries before and after 2000 BC, 800 BC, 400 AD, and 1 600 AD; the quasiperiodicity corresponds to cycli...Paleoclimatic studies indicate four epochs of global cooling during the last 4 000 years, i.e. during the few centuries before and after 2000 BC, 800 BC, 400 AD, and 1 600 AD; the quasiperiodicity corresponds to cyclic variation of solar activity. Global temperature changes influenced regional precipitation patterns: Northern Europe was wetter while the middle and low latitude lands were more arid during colder epochs. Both sets of cold climatical conditions were unfavorable for agricultural production. Historical records show that large demographic movements in history took place because of crop failures and mass starvation, rather than escaping from war zones. The "wandering" of the Germanic tribes during the first two or three centuries of the Christian Era is one example. Whereas the accelerated release of carbon dioxide from the burning of fossil fuels is ultimately to cause global warming, historical evidence indicates, however, that global warming has been on the whole a blessing to mankind. Global cooling, on the other hand, has curtailed agricultural production and has led to famines and mass migrations of people. Perhaps the most important task at the present is not so much computer modelling of greenhouse effect on global climate, but water management and agricultural researches to insure food supply for an everincreasing world population.展开更多
Urban stormwater runoff nearly discharges directly into bodies of water through gray infrastructure in China, such as sewers, impermeable ditches, and pump stations. As urban flooding, water shortage, and other enviro...Urban stormwater runoff nearly discharges directly into bodies of water through gray infrastructure in China, such as sewers, impermeable ditches, and pump stations. As urban flooding, water shortage, and other environment problems become serious, integrated water environment management is becoming increasingly complex and challenging. At more than 200 ha, the Oriental Sun City community is a large retirement community located in the eastern side of Beijing. During the beginning of its construction, the project faced a series of serious water environment crises such as eutrophication, flood risk, water shortage, and high maintenance costs. To address these issues, an integral storrnwater management master plan was developed based on the concept of low impact development （LID）. A large number of LID and green stormwater infrastructure （GSI） approaches were designed and applied in the community to replace traditional stormwater drainage systems completely. These approaches mainly included bioretention （which captured nearly 85th percentile volume of the annual runoff in the site, nearly 5.4 x 10^5 m3 annually）, swales （which functioned as a substitute for traditional stormwater pipes）, waterscapes, and stormwater wetlands. Finally, a stormwater system plan was proposed by integrating with the gray water system, landscape planning, an architectural master plan, and related consultations that supported the entire construction period. After more than 10 years of planning, designing, construction, and operation, Oriental Sun City has become one of the earliest modem large-scale LID communities in China. Moreover, the project not only addressed the crisis efficiently and effectively, but also yielded economic and ecological benefits.展开更多
We present a new method for automatically forecasting the occurrence of solar flares based on photospheric magnetic measurements. The method is a cascading combination of an ordinal logistic regression model and a sup...We present a new method for automatically forecasting the occurrence of solar flares based on photospheric magnetic measurements. The method is a cascading combination of an ordinal logistic regression model and a support vector machine classifier. The predictive variables are three photospheric magnetic parameters, i.e., the total unsigned magnetic flux, length of the strong-gradient magnetic polarity inversion line, and total magnetic energy dissipation. The output is true or false for the occurrence of a certain level of flares within 24 hours. Experimental results, from a sample of 230 active regions between 1996 and 2005, show the accuracies of a 24- hour flare forecast to be 0.86, 0.72, 0.65 and 0.84 respectively for the four different levels. Comparison shows an improvement in the accuracy of X-class flare forecasting.展开更多
Employing the Poincar6 index of isolated null-points in a vector field, we worked out a mathematical method of searching for 3D null-points in coronal magnetic fields. After introducing the relevant differential topol...Employing the Poincar6 index of isolated null-points in a vector field, we worked out a mathematical method of searching for 3D null-points in coronal magnetic fields. After introducing the relevant differential topology, we test the method by using the analytical model of Brown ＆ Priest. The location of nullpoint identified by our method coincides precisely with the analytical solution. Finally we apply the method to the 3D coronal magnetic fields reconstructed from an observed MDI magnetogram of a super-active region （NOAA 10488）. We find that the 3D null-point seems to be a key element in the magnetic topology associated with flare occurrence.展开更多
A new multi-wavelength solar telescope, the Optical and Near-infrared Solar Eruption Tracer （ONSET） of Nanjing University, has been constructed. It was fabricated at the Nanjing Institute of Astronomical Optics ＆ T...A new multi-wavelength solar telescope, the Optical and Near-infrared Solar Eruption Tracer （ONSET） of Nanjing University, has been constructed. It was fabricated at the Nanjing Institute of Astronomical Optics ＆ Technology, and the oper- ation is jointly administered with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows： He I 10830 A, Ha and white-light at 3600 A and 4250 A, which are selected in order to simultaneously record the dynam- ics of the corona, chromosphere and photosphere respectively. Full-disk or partial-disk solar images with a field of 10~ at three wavelengths can be obtained nearly simultane- ously. It is designed to trace solar eruptions with high spatial and temporal resolutions. This telescope was installed at a new solar observing site near Fuxian Lake in Yunnan Province, southwest China. The site is located at E102N24, with an altitude of 1722 m. The seeing is stable and has high quality. We give a brief description of the scientific objectives and the basic structure of ONSET. Some preliminary results are also pre- sented.展开更多
We present a brief review of predictions of solar cycle maximum amplitude with a lead time of 2 years or more. It is pointed out that a precise prediction of the maximum amplitude with such a lead-time is still an ope...We present a brief review of predictions of solar cycle maximum amplitude with a lead time of 2 years or more. It is pointed out that a precise prediction of the maximum amplitude with such a lead-time is still an open question despite progress made since the 1960s. A method of prediction using statistical characteristics of solar cycles is developed: the solar,cycles are divided into two groups, a high rising velocity (HRV) group and a low rising velocity (LRV) group, depending on the rising velocity in the ascending phase for a given duration of the ascending phase. The amplitude of Solar Cycle 24 can be predicted after the start of the cycle using the formula derived in this paper. Now, about 5 years before the start of the cycle, we can make a preliminary prediction of 83.2-119.4 for its maximum amplitude.展开更多
文摘Recently, Chen and his team were active in the theoretical and practical study of a new heliostat for the use of solar energy. This work represents the first innovation in the area of heliostats after many years of little progress. The mathematical development of the tracking and concentration optics principles, and the practical implementation and demonstration of the technology, are both very interesting advances in this field. Many applications are possible for this technology such as generation of solar electricity and solar industrial process heat.
基金Supported by the National Natural Science Foundation of China
文摘The New Vacuum Solar Telescope （NVST） is a one meter vacuum solar telescope that aims to observe fine structures on the Sun. The main goals of NVST are high resolution imaging and spectral observations, including measurements of the solar magnetic field. NVST is the primary ground-based facility used by the Chinese solar research community in this solar cycle. It is located by Fuxian Lake in southwest China, where the seeing is good enough to perform high resolution observations. We first introduce the general conditions at the Fuxian Solar Observatory and the primary science cases of NVST. Then, the basic structures of this telescope and instruments are described in detail. Finally, some typical high resolution data of the solar photosphere and chromosphere are also shown.
基金Supported by the National Natural Science Foundation of China
文摘We investigate the wavelet transform of yearly mean relative sunspot number series from 1700 to 2002. The curve of the global wavelet power spectrum peaks at 11-yr, 53-yr and 101-yr periods. The evolution of the amplitudes of the three periods is studied. The results show that around 1750 and 1800, the amplitude of the 53-yr period was much higher than that of the the 11-yr period, that the ca. 53-yr period was apparent only for the interval from 1725 to 1850, and was very low after 1850, that around 1750, 1800 and 1900, the amplitude of the 101-yr period was higher than that of the 11-yr period and that, from 1940 to 2000, the 11-yr period greatly dominates over the other two periods.
文摘About , there have been four views: windows, granaries, a name of sacrifice and sites. This paper offers new research on the shape and meaning of the inscription on bones, following the former researchers. The suggestion is that the inscription should be shaped from the sun, and its original meaning is sacrificial sites.
基金supported by the National Natural Science Foundation of China (NSFC, Grant Nos. 10878002, 10610099, 10933003 and 10673004)the National Basic Research Program of China (973 program, 2011CB811402)
文摘Owing to the largely improved facilities and working conditions, solar physics research in China has recently shown marked development. This paper reports on the recent progress of solar physics research in China's Mainland, mainly focusing on several hot issues, including instrumentations, magnetic field observations and research, solar flares, filaments and their eruptions, coronal mass ejections and related processes, as well as active regions and the corona, small-scale phenomena, solar activity and its predictions. A vision of the future is also described.
基金China Aerospace Science and Technology Corporation, the NO.771 InstituteChina Academy of Engineering Physics+4 种基金Changchun Institute of Optics, Fine Mechanics and Physics, CASNational Space Science Center, CASShanghai Engineering Center for Microsatellites, CASPurple Mountain Observatory, CASsupported by Grants:XDA15320102, 11427901 and XDA15052200
文摘The Full-disk Magneto Graph(FMG),a payload onboard the Advanced Space Solar Observatory(ASO-S),will measure the vector magnetic field in the photosphere.The instrument consists of a frontwindow filter,a telescope,an LCVR polarimeter,an image-stabilization system,a seven-stage tunable Lyot filter,a CMOS camera with 4096×4096 pixels and a pair of calibration/focus wheels.In this paper,we describe the design of the FMG instrument and provide a summary of test observations carried out with the FMG prototype.
基金the National Natural Science Foundation of China
文摘A method combining the support vector machine （SVM） the K-Nearest Neighbors （KNN）, labelled the SVM-KNN method, is used to construct a solar flare forecasting model. Based on a proven relationship between SVM and KNN, the SVM-KNN method improves the SVM algorithm of classification by taking advantage of the KNN algorithm according to the distribution of test samples in a feature space. In our flare forecast study, sunspots and 10cm radio flux data observed during Solar Cycle 23 are taken as predictors, and whether an M class flare will occur for each active region within two days will be predicted. The SVM- KNN method is compared with the SVM and Neural networks-based method. The test results indicate that the rate of correct predictions from the SVM-KNN method is higher than that from the other two methods. This method shows promise as a practicable future forecasting model.
文摘Paleoclimatic studies indicate four epochs of global cooling during the last 4 000 years, i.e. during the few centuries before and after 2000 BC, 800 BC, 400 AD, and 1 600 AD; the quasiperiodicity corresponds to cyclic variation of solar activity. Global temperature changes influenced regional precipitation patterns: Northern Europe was wetter while the middle and low latitude lands were more arid during colder epochs. Both sets of cold climatical conditions were unfavorable for agricultural production. Historical records show that large demographic movements in history took place because of crop failures and mass starvation, rather than escaping from war zones. The "wandering" of the Germanic tribes during the first two or three centuries of the Christian Era is one example. Whereas the accelerated release of carbon dioxide from the burning of fossil fuels is ultimately to cause global warming, historical evidence indicates, however, that global warming has been on the whole a blessing to mankind. Global cooling, on the other hand, has curtailed agricultural production and has led to famines and mass migrations of people. Perhaps the most important task at the present is not so much computer modelling of greenhouse effect on global climate, but water management and agricultural researches to insure food supply for an everincreasing world population.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment (No.2010ZX07320-002)the Project of Beijing Academic Innovation Group in Urban Stormwater System and Water Environmental Eco-technologies (No.PHR201106124)+1 种基金the Open Research Fund Program of the Key Laboratory of Urban Stormwater SystemWater Environment (Beijing University of Civil Engineering and Architecture),Ministry of Education
文摘Urban stormwater runoff nearly discharges directly into bodies of water through gray infrastructure in China, such as sewers, impermeable ditches, and pump stations. As urban flooding, water shortage, and other environment problems become serious, integrated water environment management is becoming increasingly complex and challenging. At more than 200 ha, the Oriental Sun City community is a large retirement community located in the eastern side of Beijing. During the beginning of its construction, the project faced a series of serious water environment crises such as eutrophication, flood risk, water shortage, and high maintenance costs. To address these issues, an integral storrnwater management master plan was developed based on the concept of low impact development （LID）. A large number of LID and green stormwater infrastructure （GSI） approaches were designed and applied in the community to replace traditional stormwater drainage systems completely. These approaches mainly included bioretention （which captured nearly 85th percentile volume of the annual runoff in the site, nearly 5.4 x 10^5 m3 annually）, swales （which functioned as a substitute for traditional stormwater pipes）, waterscapes, and stormwater wetlands. Finally, a stormwater system plan was proposed by integrating with the gray water system, landscape planning, an architectural master plan, and related consultations that supported the entire construction period. After more than 10 years of planning, designing, construction, and operation, Oriental Sun City has become one of the earliest modem large-scale LID communities in China. Moreover, the project not only addressed the crisis efficiently and effectively, but also yielded economic and ecological benefits.
基金supported by NSF under grants ATM-071 6950,ATM-0745744NASA under grant NNXO-8 AQ90G
文摘We present a new method for automatically forecasting the occurrence of solar flares based on photospheric magnetic measurements. The method is a cascading combination of an ordinal logistic regression model and a support vector machine classifier. The predictive variables are three photospheric magnetic parameters, i.e., the total unsigned magnetic flux, length of the strong-gradient magnetic polarity inversion line, and total magnetic energy dissipation. The output is true or false for the occurrence of a certain level of flares within 24 hours. Experimental results, from a sample of 230 active regions between 1996 and 2005, show the accuracies of a 24- hour flare forecast to be 0.86, 0.72, 0.65 and 0.84 respectively for the four different levels. Comparison shows an improvement in the accuracy of X-class flare forecasting.
基金Supported by the National Natural Science Foundation of China.
文摘Employing the Poincar6 index of isolated null-points in a vector field, we worked out a mathematical method of searching for 3D null-points in coronal magnetic fields. After introducing the relevant differential topology, we test the method by using the analytical model of Brown ＆ Priest. The location of nullpoint identified by our method coincides precisely with the analytical solution. Finally we apply the method to the 3D coronal magnetic fields reconstructed from an observed MDI magnetogram of a super-active region （NOAA 10488）. We find that the 3D null-point seems to be a key element in the magnetic topology associated with flare occurrence.
基金Supported by the National Natural Science Foundation of China
文摘A new multi-wavelength solar telescope, the Optical and Near-infrared Solar Eruption Tracer （ONSET） of Nanjing University, has been constructed. It was fabricated at the Nanjing Institute of Astronomical Optics ＆ Technology, and the oper- ation is jointly administered with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows： He I 10830 A, Ha and white-light at 3600 A and 4250 A, which are selected in order to simultaneously record the dynam- ics of the corona, chromosphere and photosphere respectively. Full-disk or partial-disk solar images with a field of 10~ at three wavelengths can be obtained nearly simultane- ously. It is designed to trace solar eruptions with high spatial and temporal resolutions. This telescope was installed at a new solar observing site near Fuxian Lake in Yunnan Province, southwest China. The site is located at E102N24, with an altitude of 1722 m. The seeing is stable and has high quality. We give a brief description of the scientific objectives and the basic structure of ONSET. Some preliminary results are also pre- sented.
基金This work is supported by National Nature Science Foundation Project No.4999-0451Space Environmental Prediction CenterCenter for Space Science and Applied Research, CAS, China.
文摘We present a brief review of predictions of solar cycle maximum amplitude with a lead time of 2 years or more. It is pointed out that a precise prediction of the maximum amplitude with such a lead-time is still an open question despite progress made since the 1960s. A method of prediction using statistical characteristics of solar cycles is developed: the solar,cycles are divided into two groups, a high rising velocity (HRV) group and a low rising velocity (LRV) group, depending on the rising velocity in the ascending phase for a given duration of the ascending phase. The amplitude of Solar Cycle 24 can be predicted after the start of the cycle using the formula derived in this paper. Now, about 5 years before the start of the cycle, we can make a preliminary prediction of 83.2-119.4 for its maximum amplitude.
