Quantifying and Analyzing the Responses of Habitat Quality to Land Use Change in Guangdong Province, China over the Past 40 Years

Guangdong Province is an important ecological barrier and the primary pillar of economic development in China. Driven by high-speed urbanization and industrialization, unreasonable land use change in Guangdong Province has exacerbated habitat degradation and loss, seriously affecting habitat quality. Thus, taking Guangdong Province as the study area, this paper quantifies the response of habitat quality on land use change using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and constructs a contribution index (CI). The following conclusions can be drawn from the results: (1) The habitat quality exhibits a spatial distribution pattern of low quality in plain areas and high quality in hilly and mountainous areas. (2) The annual average habitat quality gradually decreases from 1980 to 2020, with a total decrease of 0.0351 and a reduction rate of 4.83%; (3) The impact of land use change on habitat quality is mainly negative, and the habitat quality mainly decreases by the conversion of forest land to orchards, paddy field to urban land, and forest land to dry land, with CI values of −24.09, −11.67, and −8.04, respectively. Preventing the destruction of natural forests, increasing the diversity of plantation orchards, and rationalizing and mitigating the growth rate of construction land are key to maintaining and improving the habitat quality

Research on technology of key steps of intelligent ventilation in mines

The process steps of intelligent ventilation in mines were proposed, which could make the ventilation system more orderly and controllable. The process of intelligent ventilation in mines was divided into six process sections according to the production process, namely perception monitoring, analysis and diagnosis, intelligent decision-making, scheme approval, remote centralized control and joint control, and execution feedback, which included a total of 24 specific process steps. The input and output elements of each process step and the functional logical relationship between the process steps were clarified. According to the concept of “overall plan of the mine ventilation system+key refinement of the mining air area”, the scheme for implementing the intelligent ventilation process of the entire mine system and two refined intelligent ventilation process application scenarios for the coal mining and excavation working faces were proposed. The intelligent ventilation process steps of the mine were integrated into specific application scenarios. In order to achieve intelligent ventilation application scenarios, the overall architecture of the mine intelligent ventilation system was optimized based on the logical layering concept. The mine intelligent ventilation control platform consisting of hardware driver layer, functional module layer, computing processing layer, data storage layer, and data acquisition layer was planned and designed. The four key process sections of intelligent ventilation involved ten key process sections,which were ventilation perception monitoring, analysis and diagnosis, intelligent decision-making, remote centralized control and joint control. The ten key process steps included monitoring and perception of air volume and wind speed, online monitoring of ventilation resistance, analysis of air volume and pressure in the entire air network, identification and identification of disaster sources, calculation of dynamic air demand in mines, diagnosis of ventilation system faults, decision-making of on-demand air volume control plans, decision-making of emergency air control plans, unmanned remote air control, and unmanned emergency air control. The current technological status of the ten key process steps were summarized and analyzed, and the technical implementation paths for the ten key process steps were proposed. Through iterative upgrades of various intelligent ventilation key technologies, the mine ventilation system was ultimately achieved to be in the stable, reliable, safe, controllable, efficient, energy-saving, and emergency disaster reduction operation state throughout its entire lifecycle

Trade-off Analysis of Ecosystem Services in a Mountainous Karst Area, China

Diversity in ecosystem services and variation in land use by humans leads to reciprocal trade-offs or synergistic relationships between different ecosystem services. To achieve the dual goals of improving human welfare and developing sustainable ecosystems, understanding and clarifying these relationships is an important step. This study selected a mountainous karst area of China as a study area and used the InVEST (Integrate Valuation of Ecosystem Services and Trade-offs) model and the production possibility frontier analysis method to evaluate the spatio-temporal variations in ecosystem services and analyze the trade-off or synergic relationship between different services. The results showed that from 1990 to 2010, the percentage variations in annual mean water yield, soil conservation, carbon storage, and nutrient retention in the mountainous karst area were 2.47, 39.43, −0.34, and −1.16%, respectively. Water yield had trade-off relationships with soil conservation, nutrient retention, and carbon storage, increasing water yields were correlated with decreases in soil conservation, nutrient retention, and carbon storage. Soil conservation and nutrient retention also showed a trade-off relationship, decreasing soil conservation was correlated with gradually increasing nutrient retention. Carbon storage had synergic relationships with nutrient retention and soil conservation, continuous increases in carbon storage were correlated with incremental increases in nutrient retention and gradual decreases in soil conservation

Spatial Patterns and Driving Forces of Greenhouse Land Change in Shouguang City, China

As an important facet of modern agricultural development, greenhouses satisfy ever-increasing demands for agricultural production and, therefore, constitute a growing proportion of global agriculture. However, just a handful of countries regularly collect statistics on the land cover of greenhouse infrastructure. Even when collected, these data cannot provide the detailed spatial information required for environmental risk assessment. It is, therefore, important to map spatial changes in greenhouse land cover using remote sensing (RS) approaches to determine the underlying factors driving these changes. In this paper, we apply a support vector machine (SVM) algorithm to identify greenhouse land cover in Shouguang City, China. Enhanced thematic mapper (ETM) images were selected as the data source for land use classification in this study as they can be freely acquired and offer the necessary spatial resolution. We then used a binary logistic regression model to quantitatively discern the mechanisms underlying changes in greenhouse land cover. The results of this study show that greenhouse land cover in Shouguang increased by 50.51% between 2000 and 2015, and that 90.39% of this expansion took place between 2010 and 2015. Elevation, slope, precipitation, and the distance to the nearest rural settlements and coastline are all significant factors driving expansion in greenhouse land cover, while distance to the nearest urban areas, rivers, roads, railways, and coastline have contributed to contractions in this land use type. Our research provided a practical approach to allow the detection of changes in greenhouse land cover in the countries with using free or low-cost satellite images

High-Sensitivity Temperature Sensor Based on the Perfect Metamaterial Absorber in the Terahertz Band

In this study, a perfect metamaterial absorber (PMMA) based on an indium antimonide temperature-sensitive material is designed and investigated in the terahertz region. We demonstrate that it is an ideal perfect narrow-band absorber with polarization-insensitive and wide-angle absorption properties. Numerical simulation results show that the proposed PMMA can be operated as a temperature sensor with a sensitivity of 21.9 GHz/K. A graphene layer was added to the PMMA structure to improve the sensitivity, and the temperature sensitivity was increased to 24.4 GHz/K. Owing to its excellent performance, the proposed PMMA can be applied in thermal sensing, detection, and switching

Development and application of automatic on-line measuring device for roadway air volume

In order to realize the on-line and accurate measurement of roadway air volume, taking the return air roadway and auxiliary transportation roadway in Shangsitou north wing of Wangpo Coal Mine as the research object, the wind speed structure field of rectangular roadway and semi-circular arch roadway section was simulated by CFD method, and the regional distribution of average wind speed in roadway section under different air volume conditions of the same roadway section was compared. The air volume basically had no effect on the regional range and location of the average wind speed distribution of the roadway section and the dimensionless wind velocity structure field of roadway section was further obtained, which was the theoretical foundation for arranging multiple wind speed collection points in the roadway section average wind speed distribution area to accurately calculate the roadway average wind speed. Based on the dimensionless wind speed structure field of roadway section, the position of data acquisition point of roadway average wind speed was determined according to the distribution area of roadway section average wind speed, and the nine point acquisition method of roadway section average wind speed was constructed, which could accurately obtain the roadway average wind speed and check whether there was data distortion in the wind speed sensor. Combined with the nine point acquisition method of roadway section average wind speed, the gantry and folding fully automatic on-line test device for roadway air volume suitable for rectangular roadway and arch roadway were designed respectively. The structural size of the test device and the motion track of wind speed sensor were customized according to the position of roadway average wind speed data acquisition point. The fully automatic on-line test device for roadway air volume was deployed at 10 wind measuring stations in Wangpo Coal Mine. The relative error between manual wind measurement and device wind measurement data was less than 8%. The research showed that the wind measurement accuracy of the fully automatic on-line test device for roadway air volume could meet the mine requirements, and could realize the synchronous on-line measurement of the air volume of multiple roadways in the mine

On demand dynamic linkage control system for air volume of multiple coal working faces

When multiple coal working faces are mined at the same time in the coal mine, the change of branch air volume of any roadway will cause the change of branch air volume of other roadway. The air volume control of any coal working face in the mine will affect the air volume change of other coal working faces in the mine. Therefore, it is necessary to intelligently control the air volume of multiple coal working faces. However, the current research on intelligent control of air volume in coal working face is mainly based on automatic control algorithm of mine air volume or mine air volume control equipment. It lacks the research on the on demand dynamic linkage control system for air volume of multiple coal working faces. In order to solve the above problems, this paper puts forward a design scheme of on demand dynamic linkage control system for air volume of multiple coal working faces. Taking the louvered remote automatic regulating air window deployed in the return air crossheading of 3308 working face in Shanxi Tiandi Wangpo Coal Industry as the research object, the computational fluid dynamics (CFD) method is used to simulate the flow field distribution of the regulating air window. The Origin software is applied to fit the non-linear relationship between the wind area of the regulating air window and the wind resistance, and obtain the functional relationship between them. The relative error between the wind resistance of the regulating air window measured on site and that calculated by fitting is less than 6%. Based on the functional relationship between the wind area and the air resistance of the regulating air window and a joint calculation method of wind resistance regulation of multiple coal working faces, the upper computer calculation software is developed. And based on the upper computer calculation software, the underground explosion-proof and intrinsically safe control substation and the louvered remote automatic regulating air window, the on demand dynamic linkage control system for air volume of multiple coal working faces is constructed. The on demand dynamic linkage control of air volume on demand is carried out on 3308 and 3203 coal working faces in Wangpo Coal Industry. The field application shows that the relative error between the target air volume and the actual air volume after control is less than 7%. This result indicates that the on-demand dynamic linkage control system for air volume of multiple coal working faces has certain use effect

Nipple Discharge of CA15-3, CA125, CEA and TSGF as a New Biomarker Panel for Breast Cancer

Breast cancer is the second leading cause of cancer death in women. Serum biomarkers such as cancer antigen 15-3 (CA15-3), cancer antigen 125 (CA125), and carcinoembryonic antigen (CEA) can be used as diagnostic and prognostic factors and can also provide valuable information during follow-up. However, serum protein biomarkers show limited diagnostic sensitivity and specificity in stand-alone assays because their levels reflect tumor burden. To validate whether biomarkers in nipple discharge may serve as novel biomarkers for breast cancer, we composed a panel of potential cancer biomarkers, including CA15-3, CA125, CEA, and malignant tumor-specific growth factor (TSGF), and evaluated their expression in both serum and nipple discharge in order to explore the expression and significance of estrogen receptor (ER), progestrone receptor (PR), epidermal growth factor receptor type 2 (HER2/neu), CA15-3, CA125, CEA, and TSGF expression for their combined predictive value for breast cancer and in judging the prognosis of breast cancer. Univariate analysis revealed that combined detection of CA15-3, CA125, CEA, and TSGF in nipple discharge served as novel biomarkers for the diagnosis and prognosis of breast cancer, but in the multivariate analyses the adverse effects of the four biomarkers combination in nipple discharge positivity on overall survival were lost. Multivariate analysis revealed that the positivity of the combined detection of the four biomarkers in both nipple discharge and serum was significantly higher than that of other detection methods. Thus, the combined detection of these four biomarkers both in serum and nipple discharge was retained as an independent prognostic variable in breast cancer patients. Our results indicate that CA15-3, CA125, CEA, and TSGF in nipple discharge can serve as novel biomarkers in the diagnosis and prognosis of breast cancer