Coupling Relationship Analysis of Gold Content Using Gaofen-5 (GF-5) Satellite Hyperspectral Remote Sensing Data: A Potential Method in Chahuazhai Gold Mining Area, Qiubei County, SW China

The gold (Au) geochemical anomaly is an important indicator of gold mineralization. While the traditional field geochemical exploration method is time-consuming and expensive, the hyperspectral remote sensing technique serves as a robust technique for the delineation and mapping of hydrothermally altered and weathered mineral deposits. Nonetheless, mineralization element anomaly detection was still seldomly used in previous hyperspectral remote sensing applications in mineralization. This study explored the coupling relationship between Gaofen-5 (GF-5) hyperspectral data and Au geochemical anomalies through several models. The Au geochemical anomalies in the Chahuazhai mining area, Qiubei County, Yunnan Province, SW China, was studied in detail. First, several noise reduction methods including radiometric calibration, Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH), Savitzky–Golay filter, and endmember choosing methods including Minimum Noise Fraction (MNF) transformation, matched filtering, and Fast Fourier Transform (FFT) transformation were applied to the Gaofen-5 (GF-5) hyperspectral data processing. The Spectrum-Area (S-A) method was introduced to build an FFT filter to highlight the spectral abnormal characteristics associated with Au geochemical anomaly information. Specifically, the Matched Filtering (MF) technique was applied to the dataset to find the Au geochemical anomaly abundances of endmembers with innovative large-sample learning. Then, Multiple Linear Regression (MLR), Partial Least Squares (PLS) regression, a Back Propagation (BP) network, and Geographically Weighted Regression (GWR) were used to reveal the coupling relationship between the spectra of the processed hyperspectral data and the Au geochemical anomalies. The results show that the GWR analysis has a much higher coefficient of determination, which implies that the Au geochemical anomalies and the spectral information are highly related to spatial locations. GWR works especially well for showing the regional Au geochemical anomaly trend and simulating the Au concentrated areas. The GWR model with application of the S-A method is applicable to the detection of Au geochemical anomalies, which could provide a potential method for Au deposit exploration using GF-5 hyperspectral data.

Ecological Land Protection or Carbon Emission Reduction? Comparing the Value Neutrality of Mainstream Policy Responses to Climate Change

Improving the quality of forest, water, farmland, and other types of land use with outstanding ecosystem optimization, restoration functions (ecological lands) and reducing anthropogenic carbon emissions are recognized as the two main approaches of current mainstream climate change policies. The paper aims to evaluate and compare the value neutrality within these two main types of policy responses to climate change. To do that, a case study was conducted at the Yangtze River Economic Belt, China. We first summarized the implementation status of all climate change policies in the study area and collected data related to climate and economy at the policy pilot sites. Next, the coupling relationship between climate and socio-economic conditions at policy pilot sites was calculated by the Tapio model. Finally, we constructed dummy variables that reflected the status of policy implementation, to estimate the value neutrality of mainstream climate change policies and their impact on the coupling relationship by DID models. The results showed that the proportion of policies related to ecological lands that significantly improved the coupling degree between climate and socio-economic conditions of the pilot sites is more than that of carbon emission-related ones. Moreover, the average coupling degree between climate and socio-economic conditions of the pilot sites of ecological land policies was significantly increased by 3.99 units after policy implementation, which is 27.8% higher than that of carbon emission reduction policies. Generally, the two main findings directly evidenced that the climate change policies aimed at improving the area and quality of ecological lands were more conducive to the coupling development of the climate–economy nexus than the policies focusing on restricting carbon emissions, which provides important enlightenment for the establishment of relevant environmental policies around the world.

Ultrasonic thalamic stimulation modulates neural activity of thalamus and motor cortex in the mouse

Objective. Previous studies have demonstrated that ultrasound thalamic stimulation (UTS) can treat disorders of consciousness. However, it is still unclear how UTS modulates neural activity in the thalamus and cortex. Approach. In this study, we performed UTS in mice and recorded the neural activities including spike and local field potential (LFP) of the thalamus and motor cortex. We analyzed the firing rate of spikes and the power spectrum of LFPs and evaluated the coupling relationship between LFPs from the thalamus and motor cortex with Granger causality. Main results. Our results clearly indicate that UTS can directly induce neural activity in the thalamus and indirectly induce neural activity in the motor cortex. We also found that there is a strong connection relationship of neural activity between thalamus and motor cortex under UTS. Significance. These results demonstrate that UTS can modulate the neural activity of the thalamus and motor cortex in mice. It has the potential to provide guidance for the ultrasound treatment of thalamus-related diseases.

Research on Multiphysics Coupling Relationship for the IPT System in Seawater Environment

Wireless charging in the marine environment has problems such as high loss and low efficiency. In order to solve these problems, based on the wireless power transmission technology in the seawater environment, this paper studies the multi-physical field coupling relationship of the underwater IPT system. Through researching on the law of mutual influence and interaction between the fields, the relationship between the physical fields is established. The software is used to establish a system simulation model, the dataset is solved and analyzed to get the distribution of electric field, magnetic field, thermal field, and flow field, which provides a theoretical basis for the model and optimization of the IPT system in the seawater.

Empirical Study of the Coupling Relationship Between Biodiversity and Environmental Geology Under Different Ecological Status: Evidence From Five Typical Areas in Guizhou, China

Analyzing the coupling relationship between biodiversity and environmental geology and exploring the factors affecting the coupling degree are of vital significance for the protection and restoration of the ecological environment. In this study, we selected five typical areas (i.e., Caohai, Chishui, Fanjingshan, Maolan, and Guanshanhu) to represent the whole Guizhou Province, China. Based on the coupling coordination degree model, we analyzed their coupling coordination trend. The results showed that the coordinated development stages of the Chishui and Fanjingshan areas both could be categorized as the synchronous development type of primary coordination because of their excellent nature conditions; the Maolan area was categorized as having restrained environmental geology because of its weak environmental geology condition; and the Guanshanhu and Weining areas were strongly affected by human activities, and both could be categorized as having restrained biodiversity. In combination with practical situation, Guizhou province can be categorized into the following three zones: an original ecological zone, a zone with fragile ecological environment, and a zone affected by human activities. Biodiversity conservation measures should be proposed according to the specific ecological situation of these different zones. In this way, the harmonious coexistence of economic development and the ecological environment can be realized.