武则天的家世与生年新探

学术界对于武则天的家世生平多有研究 ,但仍有许多问题悬而未决。史实证明 ,武则天并非出于胡族 ;其母亲杨氏亦非出身寒微 ,以往有关她的年龄记载亦有误。据此 ,杨氏的年龄不足以成为武则天出生地的判断依据。而她出生于广元 。

Seismicity of the San Francisco Volcanic Field of Northern Arizona

Seismicity in northern Arizona is concentrated in a northwest-southeast trending belt that stretches from the Utah border south to the edge of the Colorado Plateau. Located within this NASB （Northern Arizona Seismic Belt） is the San Francisco volcanic field, classified by the United States Geological Survey as potentially active. The last volcanic event in the field was located at Sunset Crater and occurred less than 1,000 years ago. Eruption intervals in the volcanic field are of the same order of length of time. Seismic monitoring of the volcanic field area has improved greatly since 1985 with the establishment of new network seismic stations. This has allowed for a lowered threshold of detection of seismic events and improved location capabilities. As an example of the result of this improved ability to locate smaller tremors, two swarms have been identified in the field, the 2009 Halloween swarm near Sunset Crater volcano and the 2011 swarm near Flagstaff, the largest urban community in northern Arizona.

The Evolution Pattern and Simulation of Land Use in the Beijing Municipal Administrative Center(Tongzhou District)

Beijing Municipal Administrative Center(Beijing MC)in Tongzhou District has inherited the non-capital core functions of Beijing’s central urban area,and its rapid construction and development urgently require a scientific understanding of the pattern of land use evolution in the region.This paper analyzes the pattern of land use evolution in Tongzhou District over the past 40 years,from 1980 to 2020.According to the historical evolutionary characteristics of land use and urban development planning goals,combined with the driving factors of cultural tourism development,the Future Land-use Simulation(FLUS)model is used to simulate the spatial distribution of land use in Beijing MC(Tongzhou District)in 2035 under three scenarios of urbanization acceleration,deceleration and sustainable development.The results show three major trends.(1)Beijing MC(Tongzhou District)is dominated by urban development and construction.During the high-speed urbanization stage from 1980 to 2010,the urban expansion pattern of“along the Sixth Ring Road and along the Grand Canal”was formed.During the low-speed urbanization stage from 2010 to 2020,the land distribution was stable,and Tongzhou District formed a pattern of urban-rural differentiation and land intensification from northwest to southeast.As a typical area of Tongzhou District’s urbanization,Beijing MC has the same characteristics of the temporal and spatial evolution as Tongzhou as a whole.(2)By 2035,there are significant differences in land use among the three scenarios with respect to the magnitude of change and spatial distribution.The area and distribution of ecological land under the urban sustainable development scenario are optimal,which is conducive to the realization of sustainable urban development.In analyzing the degree of conformity with the three Beijing MC zoning plans,the prediction simulation under the sustainable development scenario is highly consistent with the land use of the“Beijing Municipal Administrative Center Regulatory Detailed Planning(Block Level)(2016–2035)”(hereinafter referred to as“Planning”)issued by the municipal government.However,there are certain deviations between the simulation predictions in the cultural tourism function area and the livable living scenery area and the corresponding“Planning”expectations.During the urban construction process,the internal ecological land area still needs to be increased.(3)Tongzhou District may lack a close connection between the urban and rural areas in the southeast.Potential risks such as the imbalance in the development of northern and southern townships require further attention in the development process.The prediction and simulation results of the model can provide certain data and methodological support for the construction of a harmonious and livable city in Beijing MC(Tongzhou District).