摘要：In the research of fractal cities, the fractal dimension is very important. It is used to describe the fractal character of the city. The authors have designed two approaches to calculate the fractal dimension by the box-counting method through an example of Beijing, which are called the vector method and the grid method, respectively. The former calculates the fractal dimension through an intersecting analysis in ArcView; and the latter is carried out by programming in Matlab. They are compared from three aspects： the calculating process, the limits in use, and the results. As a result, the conclusion is made that there are merits and faults on both methods, and they should be chosen to use properly in practical situation.

摘要：Land consolidation engineering is one of the very important ways to improve the quality of farmland and the level of agricultural productivity. Studies of land consolidation and crop cultivation still mainly focus on single land functional optimization or crop breeding and yields. However, whether the improved crop varieties were sown on healthy and fertile soils is still a question. This paper introduces new ideas and engineering measures for sandy land rehabilitation and modern agricultural development in the Mu Us Sandy Land, Shaanxi Province, Western China. The important roles of particles and aggregates in soil reconstruction were confirmed following three innovative microscopic theories, including micro-structure, micro-morphology and micro-mechanism. New soil was constructed based on the physical complementarity of sandy, clay and loess particles in the Yulin area, northern Shaanxi Province. Field experiments were carried out to study the appropriate mixture ratio of different soils and their suitability for different crops. The improved crop varieties were sown on healthy and fertile soils, which were chosen by coupling according to its soil ecological suitability and crop physiological adaptability. The fertility improvement practices in the new constructed soils with different crops integrated water and fertilizer management measures, which were also provided in the experiment. Overall, an integrated land optimization configuration with improved and optimized crop variety selection was suggested for engineering sandy land-oriented consolidation from the soil particles to the agricultural system.

摘要：This study chose major Chinese cities and used the creative model of Smart Low-carbon Strength Quo- tient （SLSQ） to investigate the level and state of urban smart low-carbon development. The results show that： （1） three main categories of smart low-carbon cities are found; namely, leaders with high SLSQ, steady ones with av- erage SLSQ and lagging ones with low SLSQ; （2） the SLSQ level shows a spatial change trend of diminishing from the southeast to the northwest and differing within regions; （3） the SLSQ level indicates an urban scale change trend of decreasing from the big to the small and differing within each scale; （4） the SLSQ level suggests an ad- ministrative hierarchy change trend of descending from the high to the low and differing within each class; （5） based on the SLSQ, three dynamic patterns were identified： leading mode, steady mode and preparing mode, among which the steady mode accounts for the vast majority of smart low-carbon development in major Chinese cities.

摘要：Knowledge Sharing and Service is one effective way to eliminate knowledge poverty and promote social *** knowledge sharing and service is mainly provided in some organizations or specific social ***,a knowledge sharing and service system about geography,natural resources and ecology has not been *** proposed a public welfare professional knowledge-sharing and service platform for all members of society in geography,natural resources and *** construction of a knowledge-sharing and service platform is based on five aspects of work：analysis of user requirements,setting standards and drafting policies,aggregating knowledge resources,the technical realization and the maintenance of *** resources can be aggregated by using a＂two-step＂strategy.A knowledge-sharing and service system can be implemented by using＂four-tier＂structures that are comprised of resources,resource access,application and service,based on the Hadoop-distributed cluster *** has been proven that adhering to the idea of co-building and co-sharing,and using the mechanism of＂payment is equal to benefit＂can effectively promote the gathering of knowledge resources,and arouse the enthusiasm of all members of society to participate in knowledge sharing and service,to achieve the objective of narrowing the knowledge gap between social groups.

摘要：Drought is a worldwide natural disaster that has long affected agricultural production as well as social and economic activities. Frequent droughts have been observed in the Belt and Road area, in which much of the agricultural land is concentrated in fragile ecological environment. Based on the Tropical Rainfall Measuring Mission Satellite（TRMM） 3 B43 precipitation data, we used the Precipitation Abnormity Percentage drought model to study the monthly spatio-temporal distribution of drought in south region of N50° of the Belt and Road area. It was observed that drought during winter was mainly distributed in Northeast Asia, Southeast Asia, and South Asia, while it was mainly distributed in Central Asia and West Asia during summer. The occurrence of historical droughts indicates an obvious seasonal cycle. The regional variations in drought were analyzed using the Breaks for Additive Season and Trend tool（BFAST） in six sub-regions according to the spatial distribution of six economic corridors in the Belt and Road area. The average drought conditions over the 18 years show a slight decreasing trend in Northeast Asia, West Asia, North Africa, South Asia, Central and Eastern Europe, and a slight increasing trend in Central Asia. However, it was a fluctuating pattern of first increasing and then decreasing in Southeast Asia. The results indicate that the total drought area in the Belt and Road region showed a general decreasing trend at a rate of 40,260 km^2 per year from 1998 to 2015.