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In the present paper, we investigate the existence of solutions to second order nonlinear boundary value problems (BVPs) involving the distributional Henstock-Kurzweil integral. The present results in this article are generalizations of previous results in the literature.

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To achieve the green backfill of an abandoned open pit mine with a large difference chute process system, Fushun West open pit mine is used as the research subject. Based on the theory of gas-solid two-phase flow and the characteristics of large difference chutes, FLUENT numerical simulation software was used to carry out the numerical simulation of the trajectories of dust particles in the chute. The influence factors of the dust movement and the relationship between the factors were explored. The numerical simulation results showed that, the greater the material flow rate, the more serious the resulting dust pollution. The larger the chute angle, the greater the acceleration of the backfill material, and the greater the dust concentration. Therefore, as far as possible, to control the flow rate of the material, a suitable chute angle and U-shaped section of the chute should be selected to control powder or moisture content; these are effective measures by which to reduce dust precipitation. An applied in open pit mine backfill chute, the elevation difference can reach at least hundreds of meters. The large elevation difference chute process system transports rock; in this process, it produce large amounts of dust pollution, leads to the deterioration of the production environment, and causes a variety of occupational diseases [1]. Open pit mine large difference chutes have a certain degree of particularity [2]. First, the controlled space of the large difference chute and the mine fully mechanized coal mining face and tape transport system are different. The chute itself is a semi-enclosed space structure, and the chute is exposed to the pit. Dust movement in the space was relatively large, and is more greatly impacted by external environmental factors. Second, the large difference of the chute transported traffic up to several tens of cubic meters per second. Third, the material flows fast and the impact is considerable. Abroad, the chute transport dust movement law research has focused on the chute transfer point, where the mine fully mechanized coal mining face, roadway belt conveyor, transfer point of the dust, and the big difference between the chute dusts movements are all areas of gas-solid two-phase flow. However, the mechanism and regularity of dust generation and migration in large differential chutes were not comprehensive and thorough, and there is a lack of numerical simulation model construction [3-6]. There are a variety of factors that affect the movement of dust [7]: the Fushun West Open-pit Mine was the research background, and the factors affecting the dust movement of the large differential chute system and the relationship between the influencing factors were explored; this was in an attempt to clarify the mechanism and the movement law of dust in the process of large difference chute system transportation. This has a positive effect on the environmental management of dozens of abandoned open pit mines, and open pit mines in China, which promotes the development of chute technology. Mathema...

IntroductionGlobal climate change, which is characterized by climate warming, has become one of the most prominent risk problems in society at present. Climate migration brings many accompanying problems to the environment, economy, politics, society, and culture. It is of great theoretical and practical significance to study the internal relationship between climate change and population migration.MethodsThe data were extracted from the Web of Science core collection database (WOS) and China Knowledge Network database (CNKI). A total of 785 documents and 157 documents in the field of climate migration from 2008 to 2021 were selected as analysis samples. Word frequency analysis, clustering analysis, sudden word detection analysis, and other methods were extensively used to build the evolution trend map of climate migration using CiteSpace visual bibliometric software.ResultsIt is concluded that climate migration research has experienced three stages of development: initial exploration stage (2008-2011), development enrichment stage (2012-2017), and system deepening stage (2018).The hot topics of climate migration include: (1) different types of climate migration research; (2) Quantitative model research on climate migration; (3) Climate justice research. Different types of climate migration include 7 main types: (1) migration caused by sea level rise; (2) Resettlement caused by flood disaster; (3) Migration due to worsening drought; (4) Migration caused by extreme climate events; (5) Voluntary migration due to climate change discomfort; (6) Project resettlement caused by climate change response engineering measures; (7) Migrants whose livelihoods are broken due to climate change.DiscussionThe study points out that climate migration research is an interdisciplinary research field, which needs joint research by scholars from different academic backgrounds. In the future climate migration research, 1) strengthen the prediction ability of climate change population migration model; 2) Make use of China’s beneficial exploration in the migration fields such as engineering resettlement, ecological resettlement and poverty alleviation resettlement to formulate climate migration policies, regulations and strategic planning; 3) Establish a database cloud platform related to climate change and population migration; 4) Strengthen the exchange and cooperation between Chinese researchers in the field of climate migration and international scientific research institutions.