New urbanization, industrialization, and agricultural modernization are the engine of coordinating urban and rural development. Urbanization is the leading driving force for the transformation of urban and rural development, and it increasingly highlights its leading role in coordinating urban-rural relations. Urbanization research has always been a hot topic in the field of geography, especially the mode selection of urbanization development is the core issue of academic research and debate. It not only focuses on the development of small towns and big cities, but also advocates diversified urbanization. . In recent years, we have focused on the level of urbanization development at the national or provincial level, the urbanization regional pattern, the relationship between urbanization and economic development, the resource and environmental basis of urbanization, the dynamic stage of urbanization, urbanization and rural hollowing. The research has made new progress, and some scholars have focused on the typical case studies of urbanization development mechanisms and models. From the perspective of the urbanization process of the countries in the world, the general countries have experienced the transformation process of urban-rural differentiation, isolation, opposition to urban-rural integration, and integrated development. Among them, the urbanization rate in the urban-rural integration stage is generally 50%~70%, and the industrialization rate is transforming in urban and rural development. It is a comprehensive humanistic process of the factor transfer, strategic transformation and mechanism transformation of the urban-rural relationship regional system. In 2011, China's urbanization rate exceeded 50%, and urban-rural relations have entered an important stage of urban-rural integration and even integrated development. Since the Fifth Plenary Session of the 16th Central Committee of the Communist Party of China put forward the strategy of "building a new socialist countryside", urbanization and new rural construction have become "two-wheel drive" for China's urban and rural development. The development of county economy, the urbanization of migrant workers and the development of small and medium-sized cities have also become an important part of the national economic development strategy. Adapting to the urban-rural development transformation and healthy urbanization strategy transformation fund project: National Natural Science Foundation of China (41130748); National Natural Science Fund Youth Science Fund Project (41101162); Chinese Academy of Sciences Knowledge Innovation Project (KZCX2-EW-304) Member of China Geography Society (S110005331M). Mainly engaged in land use and agricultural and rural development research. He has published more than 200 papers and published the development of county-level urbanization, which has become a frontier field of academic research. At present, the systematic research on the development trend, spatial pattern and formation mechanism of county urbanization is still insufficient. This paper focuses on the quantitative analysis of the spatial and temporal characteristics of urbanization in China and its formation mechanism, in order to deepen the theoretical research of rural geography, science. Establish a development strategy for county urbanization and provide a basis for improving the regional model of urbanization.
2 Data Sources and Research Methods 2.1 Data Sources This paper analyzes the urbanization of China's counties since 1990 using the population and non-agricultural population data provided by the county population statistics (1991, 2001, 2009). Spatial characteristics and their formation mechanism. Among them, the total population refers to the permanent population data of counties in 1990, 2000 and 2008; the non-agricultural population refers to the population engaged in the second and third industries and the part of the population they support. The urbanization rate statistics after 2000 adopted the resident population statistics method, and the statistical results included a large number of floating population who did not really realize the settlement in the city. This paper takes non-agricultural population as the main data source for urbanization rate calculation, aiming to reveal the level of urbanization and its difference pattern in China's county from the perspective of farmers realizing the settlement and living in the city. The socio-economic data of each period mainly comes from the China Regional Economic Statistical Yearbook, the China County (City) Social and Economic Statistics Yearbook, and the statistical yearbooks of various provinces and cities. Vector graphics, DEM data from the National Geographic Information Center.
2.2 Research methods This paper mainly uses the research methods such as coefficient of variation, geostatistics, sample strips and geographic detectors. Among them, the coefficient of variation of the urbanization rate and the annual rate of change of urbanization rate in each period is used to describe the regional difference; the geostatistical research method is used for the spatial distribution analysis of urbanization level, and the urbanization of each typical sample zone is obtained. Distribution trend; using the sample method, focusing on determining the distribution characteristics of urbanization and its dominant influencing factors in representative regions; geo-detectors are used to extract the dominant influencing factors, and quantitatively evaluate each influencing factors.
The coefficient of variation is used to measure the degree of urbanization in the county, and the spatial and temporal dynamics of urbanization development in the county are described. This coefficient has been widely used in the study of spatial differences in geographic data. The calculation formula is as follows: Transect is a linear research area with a regular change in the gradient along a dominant driving factor or a linear regional type with distinct differences. Driven by the international IGBP research program, the sample band research method has been successfully applied in global change research. In order to better reveal the internal mechanism of urbanization development in China's counties, this paper selects three counties along the Yangtze River, along the Bohai New Railway, along the northern border, along the 106 National Highway, and within 100km of the eastern coast. Two north-south transects, the sample band analysis can help reveal the spatial differences in the urbanization level of China's counties and the regional differences in their formation mechanisms.
Geostatistical trend analysis method The urbanization regional difference simulation analysis is an important part of GIS geostatistical analysis. Using GIS as a platform, through the perspective analysis of the orthogonal projection of the urbanization rate of the sample zone, it is helpful for the deep people to reveal the differentiation law of the urbanized sample zone. Each vertical bar in the trend analysis graph represents the value (height) and position of a data point. These points are projected onto an east-west, north-south orthogonal plane, and a best-fit line is drawn from the projected points to simulate trends in a particular direction. See the specific mathematical model of geostatistical trend analysis.
Thiocyanate (also known as rhodanide) is the anion [SCN]−. It is the conjugate base of thiocyanic acid. Common derivatives include the colourless salts Potassium Thiocyanate and Sodium Thiocyanate. Organic compounds containing the functional group SCN are also called thiocyanates. Mercury(II) thiocyanate was formerly used in pyrotechnics.
Thiocyanate is analogous to the cyanate ion, [OCN]−, wherein oxygen is replaced by sulfur. [SCN]− is one of the pseudohalides, due to the similarity of its reactions to that of halide ions. Thiocyanate used to be known as rhodanide (from a Greek word for rose) because of the red colour of its complexes with iron. Thiocyanate is produced by the reaction of elemental sulfur or thiosulfate with cyanide
Thiocyanate[4] is known to be an important part in the biosynthesis of hypothiocyanite by a lactoperoxidase.[5][6][7] Thus the complete absence of thiocyanate[8] or reduced thiocyanate[9] in the human body, (e.g., cystic fibrosis) is damaging to the human host defense system.[10][11]
Thiocyanate is a potent competitive inhibitor of the thyroid sodium-iodide symporter.[12] Iodine is an essential component of thyroxine. Since thiocyanates will decrease iodide transport into the thyroid follicular cell, they will decrease the amount of thyroxine produced by the thyroid gland. As such, foodstuffs containing thiocyanate are best avoided by Iodide deficient hypothyroid patients.[13]
In the early 20th century, thiocyanate was used in the treatment of hypertension, but it is no longer used because of associated toxicity.[14] Sodium nitroprusside, a metabolite of which is thiocyanate, is however still used for the treatment of a hypertensive emergency. Rhodanese catalyzes the reaction of sodium nitroprusside with thiosulfate to form the metabolite thiocyanate
Our main Thiocyanates are Sodium Thiocyanate, Potassium Thiocyanate, ammonium thiocyanate.
Thiocyanate
Sodium Thiocyanate, Potassium Thiocyanate,ammonium thiocyanate
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