The Qinghai-Tibet Plateau (QTP) is an area with highly distinctive natural and socio-cultural characteristics. In recent years, the pastoral areas of northern Tibet have undergone a phase transition ...from nomadic to settled grazing, and the settlement system is in a stage of formation and evolution. Against the backdrop of China’s new strategy of rural revitalization, conducting associated research on the evolution of the settlement system and the prospect of rural revitalization is of great significance for improving the living and working conditions of herdsmen in alpine pastoral areas and promoting sustainable development on the QTP. Using settlement patch data obtained by visual interpretation of high-definition remote sensing images, combined with field investigations, this paper explores the temporal and spatial evolution characteristics of the settlement system in Nagqu County, northern Tibet, summarizing its development status and existing problems from the perspective of factor-structure-function, and details the paths for rural revitalization on this basis. The results show the following: (1) Since 2005, the settlement system of Nagqu County has undergone a phase transition from concentrated settlement to functional expansion, with the continuous enrichment of development elements and the enhancement of functions. The density distribution of settlements shows strong adaptability to the natural geographical environment. The pattern of settlement has gradually changed from resource-dependent to facility-dependent. Transportation and public service facilities play an important role in guiding the speed and direction of settlement evolution. (2) There are still various problems in the settlement system of Nagqu County, including a weak industrial foundation; some occupation of important ecological spaces and ecologically fragile areas by settlements; insufficient attention to the cultural aspect of the Tibetan settlement system; a scattered settlement layout, which makes grassroots governance difficult; a large talent gap; and weak spatial support system of settlements. (3) From the perspective of enriching and integrating the development factors of rural settlements, reorganizing the diversified structure of rural settlements, and improving and expanding the functions of rural settlements, this paper explains the correlation mechanism between optimization of the rural settlement system and rural revitalization, and puts forward the implementation paths for rural revitalization in alpine pastoral areas of the QTP. The study expands our understanding of the characteristics of settlements in sparsely populated alpine pastoral areas, and provides valuable, up-to-date policy guidance for the promotion of rural revitalization in alpine pastoral areas on the QTP.
The people of China and its (widely differing) regions have not all benefited equally from the country’s rapid increase in prosperity, and the speed and timing of increases have varied across time ...and space. However, China has managed to help those left behind to catch up. These outcomes reflect a specific social model embedded in China’s cultural and political milieu. Exploring the Chinese Social Model presents new analysis and fresh research on how China deals with unequal development and inequality in the context of its surging economic growth. The book sheds new light on the workings of China’s social model, going beyond binary notions of market and state, and considers the new facets of its socialist market economy. In exploring these questions, the authors consider what is special about China and what the Chinese model is all about.
This research aimed to understand supply and demand in the global nickel market from a product chain perspective. Accordingly, we established an extensive time-series database for the nickel trade ...network and employed network analysis methods to explore the dynamics and shifts in the global nickel trade network. The results are as follows: first, refined nickel and nickel semis dominated global nickel trade; second, the interaction between different nickel product networks profoundly affected the global nickel supply chain; third, the global nickel trade network consisted of core-periphery structures exhibiting different degrees of spatial heterogeneity; and fourth, the most connected global backbone structure was in nickel semis, followed by refined nickel, nickel ore, and nickel scrap. Together, trade in these four products constituted an overall network topology characterized by complex forms, a clear hierarchy, and uneven development. We conclude the paper by making several recommendations to secure global nickel supply chains and promote nickel circular economy.
The purpose of a rock bolt is to improve the strength capacity of a jointed rock mass. The strengthened arch controlling area can be formed based on the superposition of the controlling influence ...range of the bolt with the controlling influence angle of rock bolt playing an important role. However, quantitative research on the influence angle is still rare. In this study, numerical simulations and mathematical analysis are used to study the law of stress field distribution and the controlling influence angle through a single bolt, and the following conclusions can be obtained. (1) The compressive stress field is roughly distributed in an "Apple shape" and in a "conical" spatial distribution. (2) The bolt controlling angle is not a constant 45°, and it is influenced by the rock mass strength and bolt parameters. It decreases with the increasing elastic modulus of the bolt, bolt diameter and bolt length. It also increases with the increasing pretension and rock mass strength. The length has less influence on the supporting range. (3) Based on the experimental results, an optimal analytical model to predict the bolt’s controlling influence angle was developed. The analytical model includes the influences of the rock mass strength and bolt parameters. (4) A comparison between the model predictions with the results from the Dabei Mining 103 face transportation tunnel and the existing results shows the rationale behind the original support design scheme and an improvement over the existing results.
Rice straw is a common agricultural waste. In order to increase the added value of rice straw and improve the performance of rice straw biochar. MgO-modified biochar (MRBC) was prepared from rice ...straw at different temperatures, pyrolysis time and MgCl
concentrations. The microstructure, chemical and crystal structure were studied using X-ray diffraction (XRD), a Scanning Electron Microscope (SEM), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption desorption isotherms and Elementary Analysis (EA). The results showed that the pyrolysis temperature had significant influence on the structure and physicochemical property of MRBCs. MRBC-2 h has the richest microporous structure while MRBC-2 m has the richest mesoporous structure. The specific surface area (from 9.663 to 250.66 m
/g) and pore volume (from 0.042 to 0.158 cm
/g) of MRBCs increased as temperature rose from 300 to 600 °C. However, it was observed MgCl
concentrations and pyrolysis time had no significant influence on pore structure of MRBCs. As pyrolysis temperature increased, pH increased and more oxygen-containing functional groups and mineral salts were formed, while MgO-modified yield, volatile matter, total content of hydrogen, oxygen, nitrogen, porosity and average pore diameter decreased. In addition, MRBCs formed at high temperature showed high C content with a low O/C and H/C ratios.
Biochar is important for soil improvement, fertilizer innovation, and greenhouse gas reduction. In this paper, Mg-modified biochar was prepared from rice and corn straw and mixed with soil at a 1% (
.../
) addition in an indoor soil simulation experiment to study the effect of Mg-modified biochar on the chemical properties of acidic soil. The results showed that the addition of Mg-modified biochar reduced soil acidity and improved soil fertility. Compared with the control group, the Mg-modified biochar treatment significantly increased the concentrations of available potassium, available phosphorus, total phosphorus, organic carbon and exchangeable calcium and magnesium in the soil, and effectively increased the concentration of total nitrogen. Rice straw Mg-modified biochar treatment was more effective in increasing the soil-available potassium, available phosphorus, total phosphorus and exchangeable magnesium concentration, while corn straw Mg-modified biochar was more effective in increasing the soil organic carbon and exchangeable calcium concentration. In addition, the high pyrolysis temperature of Mg-modified biochar was more effective in promoting the soil-available potassium, available phosphorus and total nitrogen concentration, while the low pyrolysis temperature of Mg-modified biochar was more effective in promoting soil alkaline nitrogen, exchangeable calcium and magnesium.
Trade facilitation is one of the five main agendas of the Belt and Road Initiative (BRI). Social network analysis has helped understand the complexity of trade networks, but existing studies tend to ...overlook the fact that not all bilateral trade relations are equally important to a country. To fill this gap in the literature, this paper focuses on the top 2 trade relations networks to illuminate the structure and evolution of B&R trade relations, the relative positions of different countries, and changes in the composition of trade communities (e.g., the community leaders) and the changing patterns of trade between them. We find rich dynamics over time both inter- and intra-communities. The overall international trade networks of B&R countries experienced a leadership change from Russia to China on one hand, some temporary communities experienced emergence, disappearance (e.g. the Kuwait- and Thailand-led communities) or reemergence (e.g. Poland-led community), and a community membership was generally consistent on the other hand. Since the future impacts of China’s BRI will depend on the degree of integration of the connected regions, some countries with stable and high centrality indices (e.g. Russia, Singapore, Serbia, Greece, Turkey, Iran, Poland, Hungary and Romania) could be selected by China as strategic regional partners, and countries with a strategically important geographical position but weak trade links (e.g. Myanmar, Pakistan, and Belarus) should be prioritized.
Dust pollution is one of the most severe environmental issues in open pit mines, hindering green mining development. Open pit mine dust has characteristics of multiple dust-generating points, is ...irregular, influenced by climatic conditions, and has a high degree of distribution with a wide dispersion range in three dimensions. Consequently, evaluating the quantity of dust dispersion and controlling environmental pollution are crucial for supporting green mining. In this paper, dust monitoring above the open pit mine was carried out with an unmanned aerial vehicle (UAV) on board. The dust distribution patterns above the open pit mine were studied in different vertical and horizontal directions at different heights. The results show that the temperature changes less in the morning and more at noon in winter. At the same time, the isothermal layer becomes thinner and thinner as the temperature rises, which makes it easy for dust to spread. The horizontal dust is mainly concentrated at 1300 and 1550 elevations. The dust concentration is polarized at 1350-1450 elevation. The most serious exceedance is at 1400 elevation, with TSP (the concentration of total suspended particulate), PM10 (particulates with aerodynamic diameter < 10 μm), and PM2.5 (particulates with aerodynamic diameter < 2.5 μm) accounting for 188.8%, 139.5%, and 113.8%, respectively. The height is 1350-1450 elevation. Dust monitoring technology carried out by UAV can be applied to the study of dust distribution in the mining field, and the research results can provide reference for other open pit mines. It can also provide a basis for law enforcement part to carry out law enforcement, which has expanded and wide practical application value.
Soil biochar is a kind of organic matter rich in carbon, which is of great significance in soil fertility improvement, fertilizer type innovation and greenhouse gas emission reduction. In this paper, ...Mg-modified biochar was prepared by thermal cracking using rice straw and corn straw as raw materials. The Mg-modified biochar and unmodified biochar were fully mixed with prepared soil samples at the addition amounts of 0.5% (w/w), 1% (w/w) and 2% (w/w), respectively, and then simulated indoor soil cultivation experiments were carried out. The effects of magnesium ion-modified biochar and non-modified biochar on soil chemical properties and the effects of different amounts of biochar on soil properties were studied. The results showed that the yield of Mg-modified biochar from rice straw and corn straw, prepared by pyrolysis, was 65%, and the ash content was large. The pH of MG-modified corn stalk biochar (MCBC) is weakly basic (8.55), while the pH of MG-modified rice stalk biochar (MRBC) is basic (10.1), and their internal structures are slightly different. After the application of biochar prepared from rice straw and maize stover, soil indicators were determined. Compared to the control, the chemical properties of the treated soil samples were significantly improved, with an increase in soil pH, an increase in the content of effective nutrients, such as fast-acting potassium, fast-acting phosphorus and alkaline dissolved nitrogen, and an increase in the content of the total phosphorus and total nitrogen, as well as an increase in the content of organic matter. The Mg-modified biochar was generally superior to the unmodified biochar in improving soil fertility, at the same addition level. It was also found that the rice-straw biochar performed better than the corn-stover biochar and had a more obvious effect on soil improvement in terms of fast-acting potassium, ammonium nitrogen, nitrate nitrogen, total phosphorus and total nitrogen contents.
Especially since 2012 Chinese companies have acquired stakes as investors and constructors of overseas ports in both high-income and emerging economies. These initiatives play an important role in ...the construction of a Maritime Silk Road and China’s Belt and Road Initiative (BRI). Although a result of many factors, of which Chinese port investments are only one, macro-geographical gravity methods show that distance impedance and increases in the export market potential, export supply capacity and access to imports of these countries drove increases in income per capita. Export supply capacity rose particularly in Southeast Asia and more recently in Sub-Saharan Africa. In difficult times for the world economy, countries in which China invested in overseas port infrastructure saw increases in national export market potential and income per capita, due to reduction in the impedance of distance, while in the case of developing economies export market supply capacity and access to imported capital equipment and intermediate goods improved.
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