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Remote sensing has become an important means and method of geographical research. Water conservation is one of the most critical functions of terrestrial ecosystems. Research on water conservation in these areas is essential for water resource utilization and ensuring food security. This study focuses on the Ningxia Hui Autonomous Region, utilizing the concept of the water balance method. By collecting, obtaining, and processing various data sources, including precipitation, evapotranspiration, and land use, the study quantitatively analyses changes in land use in the research area. Based on this analysis, the water conservation status in the region from 2000 to 2020 is assessed. The research findings reveal the following key points: (1) The spatial distribution of water conservation in the Ningxia Hui Autonomous Region is highly uneven, with a pattern of more water conservation in the north and less in the south. There are significant differences in water conservation functions among various administrative units. (2) From 2000 to 2020, in the southern region of the Ningxia Hui Autonomous Region, the water conservation quantity has consistently increased and expanded northward. In the northern region, the water conservation quantity initially increased and then decreased. There was no significant change in water conservation quantity in the eastern and western regions. From 2000 to 2010, the water conservation function of all prefecture-level cities in Ningxia Hui Autonomous Region was improved However, from 2010 to 2020, Guyuan City experienced a substantial increase in water conservation quantity, while other prefecture-level cities showed varying degrees of decrease.

Debris flow accumulation has the characteristics of loose and broken, low strength, poor stability and so on. When the tunnel passes through the debris flow accumulation area, it is easy to bring major safety hazards to the construction site. Based on the engineering background of Gangou tunnel crossing debris flow accumulation area in the fourth bid of Jiumian expressway, this paper establishes a numerical calculation model, studies the large deformation characteristics of tunnel surrounding rock in debris flow area, determines the reasonable reinforcement range of tunnel surrounding rock, and puts forward the comprehensive control technology of tunnel passing through debris flow accumulation body combining surface stability and underground reinforcement based on simulation results and field experience. The numerical results show that the deformation of surrounding rock and ground surface can be effectively controlled. The rationality of the proposed control measures is verified by field monitoring, which provides a reference for surrounding rock control of tunnel under type conditions.

Subgrade filling of high-speed railway will cause additional settlement and deformation of existing lines.In this paper,using the finite element analysis platform (Taxis 2D) and considering the settlement of the existing line itself, This paper analyzes the impact of the new and old subgrade lap type and the layer filled this lesson of the new subgrade on the implementation of the existing subgrade. The results illustrate the following points:(1) Compared with different overlapping surface types, different filling those points have a greater impact on the settlement of the existing line; (2) The height of the steps is 0.6m and the width is 1.0m.In the subsequent layered filling construction process, each level The loading capacity of 30cm is more reasonable, which can effectively control the influence of the existing line on the additional settlement of the existing railway. The research results can provide a reference for the optimization of similar roadbed width construction.

In the power system, live workers need to complete various tasks such as heat treatment of the draft plate in a strong electric field. The inaccurate estimation of the wire load increases the labor load of the operators and can cause safety accidents such as wire disconnection and grounding short-circuit. This paper proposes a set of simple and easy-to-use live working mechanics calculation software to assist the dynamic analysis of the live working load of transmission lines, rationally select working tools, and improve the safety of live working.

The work load of the traditional calculation method of safety distance check and circuit mechanics calculation is huge inefficiency, this paper presents a set of software of safety analysis and mechanics calculation for live working, the electrical and mechanical parameters of live working transmission lines are obtained, the feasibility of operation is analyzed, working tools are reasonably selected to improve the safety and efficiency of live working, it is of great significance to reduce the emergency response time, the electric safety distance check and the line mechanics calculation methods.

The effect of different aging times (1 day, 3 days, 5 days and 7 days) on the combustion performance and mechanical properties of nitroguanidine propellants was studied.Through the mechanical properties test of impact and compression and closed bomb test of the prepared propellants, it was found that the relative steepness of the propellants aged for 3 days under normal and low temperature conditions was all less than 1;Under normal and low temperature conditions, the impact strength of propellants aged for 5 days was the largest;Propellants aged for 7 days had the highest compressive strength at low temperatures and propellants aged for 1 day had the highest compression rate at low temperatures.Comprehensive research results show that aging time of three days has a better improvement in the combustion performance and mechanical properties of the propellants.

With the application of the live working method of the zero phase potential of the working phase more and more widely, the safety of the live working operators is urgently needed for research. Considering the influence of electric shock time and frequency on the allowable current of the human body, the safe current is analyzed during live operation, and it is concluded that in the frequency range of 50~60Hz, the current below 50mA can basically guarantee that it will not die after electric shock. In the three scenarios where the insulator maintenance personnel accidentally touch the ground, the grounding wire shocks the electric shock and the charged electric shock of the tower, the human body electric shock is further analyzed. Finally, based on the CDEGS, the model of the human body contacting the grounding conductor is established. The simulation verifies the influence of the allowable current on the time and frequency of the human body withstand current under the zero potential state through the contact voltage diagram and the danger degree diagram.

When the live working is carried out in the distribution network, the zero-potential charging operation is often used. The safety of zero-potential live working is closely related to the measurement distance error. The influence of the measurement error of the zero-potential live working point on the operating phase voltage needs to be studied. Based on the Floyd algorithm, a method for calculating the shortest electrical distance from the operating point to the substation is proposed. The sub-station is centered on the branch nodes of the line to form the distance matrix, and the Floyd algorithm is used to calculate the shortest electrical distance from the working point to the substation. The working phase injection voltage is further calculated based on the zero phase potential characteristics of the operating phase. Finally, based on the PSCAD, the system model is established. The simulation concludes that the distance between the substation and the working point is less than 20m, and the operating point voltage can still be below the safe voltage.

With the economic development in Shanghai, a lot of energy has been consumed in the building industry, and is accompanied by a great amount of carbon emissions. Based on the data of energy consumption in the two stages of the building materials production and construction process in Shanghai, a calculation model of CO2 emissions was created, total CO2 emissions have been evaluated during recent ten years, and CO2 emissions influencing factors was identified in each stage. The research results show that CO2 emissions in the stage of building materials production, account for more than 90% of total CO2 emissions, mainly traced from cement, iron and steel industry, and have greater potential for energy conservation and emissions reduction.

For the nonlinear structures such as traverse and mesh spanning structure, it is very difficult to analyze the traditional calculation method. The initial shape of the structure is determined by the finite element method and the accuracy of the model is verified. Based on this model, the natural frequencies and vibration modes of the structure are analyzed and determined, which can provide reference for transient dynamic analysis.

The development of electric vehicles (EV) is constrained by factors such as the spatial distribution and planning volume of charging infrastructure. In order to determine the planning volume of charging piles in charging stations and the spatial layout of charging infrastructure service area within the service radius of Tianjin, this paper firstly determines the service area demand based on the service radius, combined with the demand prediction function and the EV ownership, and secondly forms the charging infrastructure service area with the central place theory large spatial layout, and finally determine the planning volume of charging infrastructure through queuing service system. The research results can provide a new theoretical basis for the layout planning of charging infrastructure, and finally put forward the relevant factors and development trends for the optimal layout of charging facilities.

Microgravity combustion has always been one of the key and frontier research fields in the international combustion community. Why has microgravity combustion attracted so much attention? First of all, fire safety and combustion reliability are imminent to spacecraft. Secondly, the convection effect is weakened in the microgravity environment, and the basic combustion phenomena are more prominent, which is greatly helpful to study the fundamental laws of combustion and develop reliable combustion models for fuels. This article systematically summarized and analyzed the research focuses, namely fire safety of spacecraft, droplet combustion, soot formation and flame structures, and current research status in the field of microgravity combustion during the past decades of years. In this paper, motivations, methods, and achievements of fire safety in spacecraft and fundamental combustion characteristics in microgravity were analyzed, which provide a comprehensive review for the microgravity combustion research. Suggestions for the development direction of microgravity combustion science were also made. Improving the application of efficient and clean combustion and optimizing fire safety strategies of new generation spacecraft materials should still be regarded as two critical targets in the future.

The non-circulating DC speed adjusting system is widely used. DLC is the core controller of the non-circulating DC speed adjusting system. The working principle of DLC was analyzed. A simulation model of the DLC controller was built. The parameters of the DLC were set. The reversible system obtained forward and reverse waveforms was obtained. And the simulation results surface: the method is correct and feasible.

Enhancement of system resilience of microgrid is important when the system is operated in the islanded mode. The commonly used clean energy in microgrid is the intermittent renewable energy which would deteriorate the system resilience of microgrid. To solve this problem, the residual energy pre-served in the energy storage system is introduced in this paper to extend the time duration of fundamental load demand when the power outage is present. The experiment is implemented in the demo system in the campus of National Central University to verify the performance of proposed management strategy.