In this study, through vitro culturing anthers of 7 F1 progenies of early Japonica rice in cold region on medium with different Fe2+ contents, it was found that Fe2+ content generated greater impacts on the induction ...In this study, through vitro culturing anthers of 7 F1 progenies of early Japonica rice in cold region on medium with different Fe2+ contents, it was found that Fe2+ content generated greater impacts on the induction rate and green plantlet differentiation. The result demonstrated that if Fe2+ increased from 32 to 40 mg/kg, the induction rate of early Japonica rice anther culture in N6 culture media was more then 1.4 times higher than that in N6 culture media containing 5.6 mg/kg Fe2+. In this concentration range, the induction rate increased with the increase of Fe2+ content, while if the concentration was over this concentration range, the induction rate decreased with the increase of Fe2+, showing single peak distribution. When the Fe2+ was 40 mg/kg in differentiation medium, the differentiation rate decreased dramatically. The green plantlet differentiations of callus which were induced on culture media containing 32-40 mg/kg Fe2+ were different, when they were cultured on MS culture media, and 85.7% materials could increase green plantlet productivity to about 7.8%. Therefore, increasing Fe2+in induction media properly could increase anther culture efficiency of early Japonica rice in cold region.展开更多
A new dsungaripterid pterosaur,Ordosipterus planignathus gen.et sp.nov.,is established on the incomplete articulated lower jaws from the Lower Cretaceous Luohandong Formation in Otog Qi,Ordos Region,Inner Mongolia,Chi...A new dsungaripterid pterosaur,Ordosipterus planignathus gen.et sp.nov.,is established on the incomplete articulated lower jaws from the Lower Cretaceous Luohandong Formation in Otog Qi,Ordos Region,Inner Mongolia,China.It differs from other dsungaripterids mainly by having broad and low dentary at and just behind the mandibular symphysis,flat dentary dorsal plane forming the distinct lateral ridge with the curved dentary lateral side,and lower alveoli arranged along the dentary dorsolateral margin with wide spacing that increases from rostral to caudal.It represents the first diagnostic pterosaur from the Ordos Region in Inner Mongolia,and further enlarges the geographical distribution of the family Dsungaripteridae from northwestern China(together with western Mongolia)to central North China.展开更多
Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain ...Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain temporal-spatial distribution characteristics. Volcanic fragments were probably derived from two different volcanic sources north and south of the North China Platform, while the magma of the two volcanic sources was probably derived from the lower crust. A new stratigraphic correlation scheme is put forward for the Benxi and Taiyuan Formations in this region on the basis of previous biostratigraphic work with the regionally widespread volcanic event layers as the marker bed for the isochronous stratigraphic correlation on a super-regional scale and in conjunction with the maximum transgressive event layers.展开更多
With the aim to improve the level of monitoring and warning as well as the comprehensive control of rice blast disease, and to feasibly reduce the disease threat in Nanchong City, the methods of GPS and GIS, systemati...With the aim to improve the level of monitoring and warning as well as the comprehensive control of rice blast disease, and to feasibly reduce the disease threat in Nanchong City, the methods of GPS and GIS, systematical monitoring and field survey, rice blast resistance identification, physiologic races of rice blast monitoring, and meteorological data analysis were performed to study the occurrence and epidemic region division, precise demarcation and occurrence and epidemic regularity of rice blast in Nanchong City. This study first completed the epidemic region division and precise demarcation; first clarified the initial affection(beginning period) locations, occurrence characteristics, epidemic trends and characteristics; explicated the existence of four epidemic peak periods of rice blast in the field, where the damage areas of first peak period played a decisive role during the blast epidemic years; in late May, the cumulative occurrence areas and annual occurrence areas presented higher positive correlation with the correlation coefficient of 0.817;and established a prediction model of occurrence areas per year based on the disease field rate at the end of boot stages and the diseased plant rate at dough stages. The results of investigation on the impact factors investigation of blast disease in Nanchong in recent years suggested that the internal causes were the decrease or loss of blast resistance of the rice cultivars, as well as the increase of physiological races with strong resistance to rice blast and the emergence of new virulent physiologic varieties; the external causes were suitable temperature, too much rainy, and sunlight shortage. Between 2010 and 2015, the short-term forecast accuracy for rice blast in Nanchong was up to 100%, and medium-and long-term forecast accuracy was also up to 98% and 95%, respectively, which increased by 5-15% than that before 1997, thereby making the control effect of rice blast in Nanchong increased by 15-30%.展开更多
Early Miocene stratigraphy,major structural systems,magmatic emplacement,volcanic eruption,vegetation change and paleo-elevation were analyzed for the Tibetan Plateau after regional geological mapping at a scale of 1...Early Miocene stratigraphy,major structural systems,magmatic emplacement,volcanic eruption,vegetation change and paleo-elevation were analyzed for the Tibetan Plateau after regional geological mapping at a scale of 1:250,000 and related researches,revealing much more information for tectonic evolution and topographic change of the high plateau caused by Indian-Asian continental collision.Lacustrine deposits of dolostone,dolomite limestone,limestone,marl,sandstone and conglomerate of weak deformation formed extensively in the central Tibetan Plateau,indicating that vast lake complexes as large as 100,000-120,000 km2 existed in the central plateau during Early Miocene.Sporopoilen assemblages contained in the lacustrine strata indicate the disappearance of most tropical-subtropical broad-leaved trees since Early Miocene and the flourishing of dark needle-leaved trees during Early Miocene.Such vegetation changes adjusted for latitude and global climate variations demonstrate that the central Tibetan Plateau rose to ca.4,000-4,500 m and the northeastern plateau uplifted to ca.3,500-4,000 m before the Early Miocene.Intensive thrust and crustal thickening occurred in the areas surrounding central Tibetan Plateau in Early Miocene,formed Gangdise Thrust System (GTS) in the southern Lhasa block,Zedong-Renbu Thrust (ZRT) in the northern Himalaya block,Main Central Thrust (MCT) and Main Boundary Thrust (MBT) in the southern Himalaya block,and regional thrust systems in the Qaidam,Qilian,West Kunlun and Songpan-Ganzi blocks.Foreland basins formed in Early Miocene along major thrust systems,e.g.the Siwalik basin along MCT,Yalung-Zangbu Basin along GTS and ZRT,southwestern Tarim depression along West Kunlun Thrust,and large foreland basins along major thrust systems in the northeastern margin of the plateau.Intensive volcanic eruptions formed in the Qiangtang,Hoh-Xil and Kunlun blocks,porphyry granites and volcanic eruptions formed in the Nainqentanglha and Gangdise Mts.,and leucogranites and granites formed in the Himalaya and Longmenshan Mts.in Early Miocene.The K2O weight percentages of Early Miocene magmatic rocks in the Gangdise and Himlayan Mts.are found to increase with distance from the MBT,indicating the genetic relationship between regional magmatism and subduction of Indian continental plate in Early Miocene.展开更多
Based on daily observation data in the Three Gorges Region(TGR)of the Yangtze River Basin and global reanalysis data,the authors analyzed the climate characteristics and associated temporal variations in the main mete...Based on daily observation data in the Three Gorges Region(TGR)of the Yangtze River Basin and global reanalysis data,the authors analyzed the climate characteristics and associated temporal variations in the main meteorological factors in 2021,as well as the year’s climatic events and meteorological disasters.The 2021 average temperature was 0.2℃above the 1991-2020 average and the 13 th-warmest year since 1961.Seasonally,winter and autumn were both warmer than usual.The annual mean precipitation was 12.8%above normal,and most regions experienced abundant rainfall throughout the year.The seasonal variation in precipitation was significant and the TGR had a wetter-than-normal spring and summer.The number of rainstorm days was higher than normal;the wind speed was above normal;and the relative humidity was higher than normal.In terms of rain acidity,2021 was tied with 2020 as the lowest since 1999.From mid-September to early October 2021,the TGR experienced exceptional high-temperature weather,which was driven by abnormal activity of mid-and high-latitude atmospheric circulation over the Eurasian continent and the western Pacific subtropical high(WPSH).In addition,a strong blocking high over the Ural Mountains accompanied by intense mid-latitude westerly winds prevented cyclonic disturbances from extending to the subtropical region.As a result,under the combined effect of the weaker-than-normal cold-air activities and the anomalous WPSH,the TGR experienced extreme high-temperature weather during early autumn 2021.展开更多
Earthquake early warning (EEW) systems are a new and effective way to mitigate the damage associated with earthquakes. A prototype EEW system is currently being constructed in the Fujian Province, a region along the...Earthquake early warning (EEW) systems are a new and effective way to mitigate the damage associated with earthquakes. A prototype EEW system is currently being constructed in the Fujian Province, a region along the Southeast coast of China. It is anticipated that the system will be completed in time to be tested at the end of this year (2013). In order to evaluate how much advanced warning the EEW system will be able to provide different cities in Fujian, we established an EEW information release scheme based on the seismic monitoring stations distributed in the region. Based on this scheme, we selected 71 historical earthquakes. We then obtained the delineation of the region's potential seismic source data in order to estimate the highest potential seismic intensities for each city as well as the EEW system warning times. For most of the Fujian Province, EEW alarms would sound several seconds prior to the arrival of the destructive wave. This window of time gives city inhabitants the opportunity to take protective measures before the full intensity of the earthquake strikes.展开更多
Ring-in-ring structures in Australian Early Precambrian banded iron formation (BIF) were identified as bubbling mud wavelets, which lithified during temporary exposure, contradicting the alleged BIF deep ocean origin....Ring-in-ring structures in Australian Early Precambrian banded iron formation (BIF) were identified as bubbling mud wavelets, which lithified during temporary exposure, contradicting the alleged BIF deep ocean origin. Least altered BIFs consist of alternating chert laminae with, and without iron oxides (or carbonates). They were precipitated during on-and-off periods of ferrous iron oxidation controlled by microbial oxygenic photosynthetic activity during solar illumination, which stopped during darkness as characterizing the Polar Regions, thus forming genuine annual varves. This polar environment is further corroborated by the magnetite-hematite-magnetite microcrystal layers in the iron-rich laminae reflecting mid-spring-summer-autumn changes in solar radiation, and by diamictite at the end of the sequence deposited from melting glaciers when the continental plate shifted to lower latitudes. BIF sequences in various countries comprise evaporates. They attest to intensive evaporation of the warm hydrothermal solution in restricted shallow lakes under the freezing dry climate up to silica (geyserite) precipitation referred to chert. The existence of oceans, mid-ocean-ridges and island arcs during the Early Precambrian results from the misinterpreted oceanic origin of BIFs and the Phanerozoic occurrences of the associated mafic-ultramafic basalt flows (Greenstone Belt).展开更多
The features of all fossil assemblage from Jiaonan region are equal to those of the plant in the forth stage or the fifth stage. The time of samples association of Dasycladaceae algae in Jiaonan area should be in earl...The features of all fossil assemblage from Jiaonan region are equal to those of the plant in the forth stage or the fifth stage. The time of samples association of Dasycladaceae algae in Jiaonan area should be in early Cretaceous period. The group of Dasycladaceae algae in Jiaonan region is marine plant, and belongs to the Tethys paleobotanic province. They began to distribute westward and eastward from Triassic period in a radiating way. And the geographical position was in tropical or subtropical zoneat that time.展开更多
随着分布式电源(distributed generation,DG)的容量变化,微电网原有的供电结构发生改变,使得潮流大小、方向和功率结构发生变化,对快速检测和定位微电网中的短路故障区域提出了挑战。在MATLAB/Simulink中搭建低压交流微电网模型;通过高...随着分布式电源(distributed generation,DG)的容量变化,微电网原有的供电结构发生改变,使得潮流大小、方向和功率结构发生变化,对快速检测和定位微电网中的短路故障区域提出了挑战。在MATLAB/Simulink中搭建低压交流微电网模型;通过高尺度小波能量谱算法对微电网与大电网公共连接点(point of common coupling,PCC)处检测到的电流进行分解,提取适应不同容量情况的短路故障特征值,实现了不同容量下微电网短路故障的早期检测;利用小波能量谱特征结合基于正交最小二乘法(orthogonal least square,OLS)的径向基函数(radial basis function,RBF)神经网络算法提出一种适用于不同容量微电网的短路故障区域定位方法,并进行仿真验证;在此基础上设计并网模式微电网短路故障保护硬件系统,并进行实验验证。结果表明,所设计的保护系统能够快速、准确地同时实现并网模式下交流微电网短路故障的早期检测与区域定位。展开更多
基金Supported by National Key Technology R&D Program(2006BAD01A01-6)~~
文摘In this study, through vitro culturing anthers of 7 F1 progenies of early Japonica rice in cold region on medium with different Fe2+ contents, it was found that Fe2+ content generated greater impacts on the induction rate and green plantlet differentiation. The result demonstrated that if Fe2+ increased from 32 to 40 mg/kg, the induction rate of early Japonica rice anther culture in N6 culture media was more then 1.4 times higher than that in N6 culture media containing 5.6 mg/kg Fe2+. In this concentration range, the induction rate increased with the increase of Fe2+ content, while if the concentration was over this concentration range, the induction rate decreased with the increase of Fe2+, showing single peak distribution. When the Fe2+ was 40 mg/kg in differentiation medium, the differentiation rate decreased dramatically. The green plantlet differentiations of callus which were induced on culture media containing 32-40 mg/kg Fe2+ were different, when they were cultured on MS culture media, and 85.7% materials could increase green plantlet productivity to about 7.8%. Therefore, increasing Fe2+in induction media properly could increase anther culture efficiency of early Japonica rice in cold region.
基金This study was funded by the National Natural Science Foundation of China(41872026,41688103)the China Geological Survey(DD20190008,DD20190602).
文摘A new dsungaripterid pterosaur,Ordosipterus planignathus gen.et sp.nov.,is established on the incomplete articulated lower jaws from the Lower Cretaceous Luohandong Formation in Otog Qi,Ordos Region,Inner Mongolia,China.It differs from other dsungaripterids mainly by having broad and low dentary at and just behind the mandibular symphysis,flat dentary dorsal plane forming the distinct lateral ridge with the curved dentary lateral side,and lower alveoli arranged along the dentary dorsolateral margin with wide spacing that increases from rostral to caudal.It represents the first diagnostic pterosaur from the Ordos Region in Inner Mongolia,and further enlarges the geographical distribution of the family Dsungaripteridae from northwestern China(together with western Mongolia)to central North China.
基金This study was supported by the National Natural Science Foundation of China Grant No. 4880102
文摘Deposits of 10 volcanic events of 6 stages have been discovered by the authors after detailed field and lab studies of the Benxi and Taiyuan Formations in Shandong Province and its adjacent regions. They show certain temporal-spatial distribution characteristics. Volcanic fragments were probably derived from two different volcanic sources north and south of the North China Platform, while the magma of the two volcanic sources was probably derived from the lower crust. A new stratigraphic correlation scheme is put forward for the Benxi and Taiyuan Formations in this region on the basis of previous biostratigraphic work with the regionally widespread volcanic event layers as the marker bed for the isochronous stratigraphic correlation on a super-regional scale and in conjunction with the maximum transgressive event layers.
基金Supported by Notice on the First Batch of National Modern Agricultural Demonstration Zone by the Ministry of Agriculture([2010]22)the Research and Application Project for the Early Warning and Comprehensive Control of the Major Pests and Diseases for Main Grain and Oil Crops(N1997-ZC002)the Fundamental Research Funds for the Central Universities(XDJK2015C060,SWU114046,2362015xk04)~~
文摘With the aim to improve the level of monitoring and warning as well as the comprehensive control of rice blast disease, and to feasibly reduce the disease threat in Nanchong City, the methods of GPS and GIS, systematical monitoring and field survey, rice blast resistance identification, physiologic races of rice blast monitoring, and meteorological data analysis were performed to study the occurrence and epidemic region division, precise demarcation and occurrence and epidemic regularity of rice blast in Nanchong City. This study first completed the epidemic region division and precise demarcation; first clarified the initial affection(beginning period) locations, occurrence characteristics, epidemic trends and characteristics; explicated the existence of four epidemic peak periods of rice blast in the field, where the damage areas of first peak period played a decisive role during the blast epidemic years; in late May, the cumulative occurrence areas and annual occurrence areas presented higher positive correlation with the correlation coefficient of 0.817;and established a prediction model of occurrence areas per year based on the disease field rate at the end of boot stages and the diseased plant rate at dough stages. The results of investigation on the impact factors investigation of blast disease in Nanchong in recent years suggested that the internal causes were the decrease or loss of blast resistance of the rice cultivars, as well as the increase of physiological races with strong resistance to rice blast and the emergence of new virulent physiologic varieties; the external causes were suitable temperature, too much rainy, and sunlight shortage. Between 2010 and 2015, the short-term forecast accuracy for rice blast in Nanchong was up to 100%, and medium-and long-term forecast accuracy was also up to 98% and 95%, respectively, which increased by 5-15% than that before 1997, thereby making the control effect of rice blast in Nanchong increased by 15-30%.
基金supported by the China Geological Survey under grants Nos.1212011120185 and 1212011221111the Ministry of Science and Technology of China under grant 2006DFB21330
文摘Early Miocene stratigraphy,major structural systems,magmatic emplacement,volcanic eruption,vegetation change and paleo-elevation were analyzed for the Tibetan Plateau after regional geological mapping at a scale of 1:250,000 and related researches,revealing much more information for tectonic evolution and topographic change of the high plateau caused by Indian-Asian continental collision.Lacustrine deposits of dolostone,dolomite limestone,limestone,marl,sandstone and conglomerate of weak deformation formed extensively in the central Tibetan Plateau,indicating that vast lake complexes as large as 100,000-120,000 km2 existed in the central plateau during Early Miocene.Sporopoilen assemblages contained in the lacustrine strata indicate the disappearance of most tropical-subtropical broad-leaved trees since Early Miocene and the flourishing of dark needle-leaved trees during Early Miocene.Such vegetation changes adjusted for latitude and global climate variations demonstrate that the central Tibetan Plateau rose to ca.4,000-4,500 m and the northeastern plateau uplifted to ca.3,500-4,000 m before the Early Miocene.Intensive thrust and crustal thickening occurred in the areas surrounding central Tibetan Plateau in Early Miocene,formed Gangdise Thrust System (GTS) in the southern Lhasa block,Zedong-Renbu Thrust (ZRT) in the northern Himalaya block,Main Central Thrust (MCT) and Main Boundary Thrust (MBT) in the southern Himalaya block,and regional thrust systems in the Qaidam,Qilian,West Kunlun and Songpan-Ganzi blocks.Foreland basins formed in Early Miocene along major thrust systems,e.g.the Siwalik basin along MCT,Yalung-Zangbu Basin along GTS and ZRT,southwestern Tarim depression along West Kunlun Thrust,and large foreland basins along major thrust systems in the northeastern margin of the plateau.Intensive volcanic eruptions formed in the Qiangtang,Hoh-Xil and Kunlun blocks,porphyry granites and volcanic eruptions formed in the Nainqentanglha and Gangdise Mts.,and leucogranites and granites formed in the Himalaya and Longmenshan Mts.in Early Miocene.The K2O weight percentages of Early Miocene magmatic rocks in the Gangdise and Himlayan Mts.are found to increase with distance from the MBT,indicating the genetic relationship between regional magmatism and subduction of Indian continental plate in Early Miocene.
基金jointly supported by the funds of the Strategic Cooperation Agreement Project between the China Meteorological Administration and the Three Gorges Corporation[Grant No.0704182]the Comprehensive Monitoring Program for Operational Safety of the Three Gorges Project[Grant No.SK2021015]financed by the Ministry of Water Resources of China.
文摘Based on daily observation data in the Three Gorges Region(TGR)of the Yangtze River Basin and global reanalysis data,the authors analyzed the climate characteristics and associated temporal variations in the main meteorological factors in 2021,as well as the year’s climatic events and meteorological disasters.The 2021 average temperature was 0.2℃above the 1991-2020 average and the 13 th-warmest year since 1961.Seasonally,winter and autumn were both warmer than usual.The annual mean precipitation was 12.8%above normal,and most regions experienced abundant rainfall throughout the year.The seasonal variation in precipitation was significant and the TGR had a wetter-than-normal spring and summer.The number of rainstorm days was higher than normal;the wind speed was above normal;and the relative humidity was higher than normal.In terms of rain acidity,2021 was tied with 2020 as the lowest since 1999.From mid-September to early October 2021,the TGR experienced exceptional high-temperature weather,which was driven by abnormal activity of mid-and high-latitude atmospheric circulation over the Eurasian continent and the western Pacific subtropical high(WPSH).In addition,a strong blocking high over the Ural Mountains accompanied by intense mid-latitude westerly winds prevented cyclonic disturbances from extending to the subtropical region.As a result,under the combined effect of the weaker-than-normal cold-air activities and the anomalous WPSH,the TGR experienced extreme high-temperature weather during early autumn 2021.
基金National Key Technology R&D Program (2009BAK55B03)
文摘Earthquake early warning (EEW) systems are a new and effective way to mitigate the damage associated with earthquakes. A prototype EEW system is currently being constructed in the Fujian Province, a region along the Southeast coast of China. It is anticipated that the system will be completed in time to be tested at the end of this year (2013). In order to evaluate how much advanced warning the EEW system will be able to provide different cities in Fujian, we established an EEW information release scheme based on the seismic monitoring stations distributed in the region. Based on this scheme, we selected 71 historical earthquakes. We then obtained the delineation of the region's potential seismic source data in order to estimate the highest potential seismic intensities for each city as well as the EEW system warning times. For most of the Fujian Province, EEW alarms would sound several seconds prior to the arrival of the destructive wave. This window of time gives city inhabitants the opportunity to take protective measures before the full intensity of the earthquake strikes.
文摘Ring-in-ring structures in Australian Early Precambrian banded iron formation (BIF) were identified as bubbling mud wavelets, which lithified during temporary exposure, contradicting the alleged BIF deep ocean origin. Least altered BIFs consist of alternating chert laminae with, and without iron oxides (or carbonates). They were precipitated during on-and-off periods of ferrous iron oxidation controlled by microbial oxygenic photosynthetic activity during solar illumination, which stopped during darkness as characterizing the Polar Regions, thus forming genuine annual varves. This polar environment is further corroborated by the magnetite-hematite-magnetite microcrystal layers in the iron-rich laminae reflecting mid-spring-summer-autumn changes in solar radiation, and by diamictite at the end of the sequence deposited from melting glaciers when the continental plate shifted to lower latitudes. BIF sequences in various countries comprise evaporates. They attest to intensive evaporation of the warm hydrothermal solution in restricted shallow lakes under the freezing dry climate up to silica (geyserite) precipitation referred to chert. The existence of oceans, mid-ocean-ridges and island arcs during the Early Precambrian results from the misinterpreted oceanic origin of BIFs and the Phanerozoic occurrences of the associated mafic-ultramafic basalt flows (Greenstone Belt).
文摘The features of all fossil assemblage from Jiaonan region are equal to those of the plant in the forth stage or the fifth stage. The time of samples association of Dasycladaceae algae in Jiaonan area should be in early Cretaceous period. The group of Dasycladaceae algae in Jiaonan region is marine plant, and belongs to the Tethys paleobotanic province. They began to distribute westward and eastward from Triassic period in a radiating way. And the geographical position was in tropical or subtropical zoneat that time.
文摘随着分布式电源(distributed generation,DG)的容量变化,微电网原有的供电结构发生改变,使得潮流大小、方向和功率结构发生变化,对快速检测和定位微电网中的短路故障区域提出了挑战。在MATLAB/Simulink中搭建低压交流微电网模型;通过高尺度小波能量谱算法对微电网与大电网公共连接点(point of common coupling,PCC)处检测到的电流进行分解,提取适应不同容量情况的短路故障特征值,实现了不同容量下微电网短路故障的早期检测;利用小波能量谱特征结合基于正交最小二乘法(orthogonal least square,OLS)的径向基函数(radial basis function,RBF)神经网络算法提出一种适用于不同容量微电网的短路故障区域定位方法,并进行仿真验证;在此基础上设计并网模式微电网短路故障保护硬件系统,并进行实验验证。结果表明,所设计的保护系统能够快速、准确地同时实现并网模式下交流微电网短路故障的早期检测与区域定位。