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The epikarst zone is widely distributed in the karst area of Southwest China, and it is the intersection zone of four circles (lithosphere, atmosphere, biosphere and hydrosphere). It is sensitive to environmental changes, in which rapid chemical reactions and strong karst actions are likely to take place. It records much information on short-term environmental change. It also has the function of regulating and storing karst water, and thus can effectively provide water resources for residents in karst mountainous areas. Therefore, the exploration and interpretation of the structure of epikarst zone is of great significance to the study of water cycle and the storage function of epikarst zone. In this study, comprehensive geophysical methods such as high-density resistivity method, spontaneous potential method and ground penetrating radar method have been used to explore and interpret the spatial structure characteristics of epikarst zone in slope runoff field of Guohua town ecological experiment base in Pingguo City. The high-density resistivity method can obtain the electrical structure section of slope runoff field by data inversion, and divide karst development areas by electrical structure. As an important method to interpret the development position of strong runoff belt, the spontaneous potential method can obtain the spatial position of polarization source through data inversion, and the generation of polarization source is closely related to water flow and electrochemical reaction between water and surrounding rock. With high resolution, the ground penetrating radar method is effective to interpret the development thickness of epikarst zone. The high-density resistivity method and the spontaneous potential method can be used to detect and comprehensively interpret the spatial position of the strong runoff belt in slope runoff field, and the ground penetrating radar method can be used to detect the thickness of the epikarst zone in the slope runoff field. In this study, according to the resistivity inversion cross-section and polarization source inversion results, the spatial positions of three strong runoff zones have been comprehensively explained, and their development depths vary between 5 m and 10 m. The development depth of the epikarst zone has been interpretated by the ground penetrating radar image. According to the development characteristics of epikarst zone in this area, the antenna frequency of the ground penetrating radar has been set as 400 MHz, and the radar wave reflection time has been converted into depth with the combination of the relevant geotechnical dielectric parameters of rock and soil. The development depth of epikarst zone in the slope runoff field is about 2.5 m (about 50 ns, with the speed of 10 cm·ns-1) The lateral variation of development thickness is significant. The accurate depth needs to be calibrated by the results of velocity measurement through drilling. In addition, there are deep karst fractures in the northwest of the slope runoff field, which gradually descend to the southeast and gradually expand to the surface. The research results show that the location of polarization source obtained by the inversion of spontaneous potential data can directly indicate the location of groundwater; therefore, the spontaneous potential method is effective to detect karst water-bearing structures. Combined with the results of high-density resistivity inversion section, the development location and spatial characteristics of strong runoff belt can be accurately interpreted, and the ground penetrating radar can detect the development thickness of epikarst zone and the development of shallow karst fracture structure with high resolution. In short, the integration of ground penetrating radar method, high-density resistivity method and spontaneous potential method can effectively detect the structural characteristics of epikarst zone, address the multi-solution problem, and hence an effective means to interpret the thickness of epikarst zone and to detect the spatial distribution of strong runoff belt. [ABSTRACT FROM AUTHOR]

The inherent ecological environment of mountainous regions is highly fragile, and the degree of sustainable development is low. There has not yet been a multi-phase ecological vulnerability evaluation (EVE) study based on remote sensing (RS) and GIS for mountainous provinces, for which there is an urgent need to establish a system that is appropriate, practicable and easily operated and applied. In this study, an integrated "RS and GIS + multi-phase land use/cover change (LUCC) + practically quantitative theory and methods of EVE" approach was adopted for analysis based on the interpretation results of five phases of the land use/land cover (LULC) RS images of Yunnan, with 129 counties being considered as the evaluation units. The organic combination of quantitative multi-index comprehensive evaluation (QMCE) and qualitative comprehensive analysis (QCA) methods was adopted to perform quantitative calculations of a system of county-level evaluation indicators which includes "innate" natural ecological vulnerability (INEV), land use ecological vulnerability (LUEV) and land cover ecological vulnerability (LCEV); the degree of ecological vulnerability (DEV) was assessed for the 129 counties within the province during the five study phases (1980, 1990, 2000, 2010 and 2020). The spatiotemporal variation characteristics and laws of DEV from 1980 to 2020 in the whole province and 129 counties were revealed, aiming to provide a basis for meeting the SDGs for mountainous provinces. The results are as follows: (1) Overall, INEV is high because of the high mountains and steep slopes, and the entire province is classified as "highly vulnerable" on average. In terms of counties, more than 79.07% are classified as "moderately vulnerable", "highly vulnerable" and "very highly vulnerable". (2) The degree of LUEV and LCEV caused by acquired human socioeconomic activities was higher in 1980. However, after a series of ecological measures in the past 40 years, the values of DEVLU and DEVLC in the whole province and counties in 2020 have decreased to different degrees. Accordingly, the degree of overall ecological vulnerability of Yunnan province and counties decreased significantly from 1980 to 2020. The basic law of change is that the number of counties with high DEV decreases significantly, while the number of counties with low DEV increases significantly. (3) The regional difference in the DEV of Yunnan province is large. In general, the degree of ecological vulnerability is lower in the southern, southwestern, western and central areas of Yunnan and higher in the northwest high mountain canyon, northeast mountain areas and east and southeast karst areas. (4) Overall, the DEV in Yunnan province is currently still high. There is an urgent need to enhance the construction of ecological civilization across the whole province and take effective measures to protect the ecological environment according to local conditions, so as to steadily reduce the DEV. [ABSTRACT FROM AUTHOR]

In this paper, the effect of atomic layer deposition (ALD)-derived Al2O3 passivation layers and annealing temperatures on the interfacial chemistry and transport properties of sputtering-deposited Er2O3 high-k gate dielectrics on Si substrate has been investigated. X-ray photoelectron spectroscopy (XPS) analyses have showed that the ALD-derived Al2O3 passivation layer remarkably prevents the formation of the low-k hydroxides generated by moisture absorption of the gate oxide and greatly optimizes the gate dielectric properties. Electrical performance measurements of metal oxide semiconductor (MOS) capacitors with different gate stack order have revealed that the lowest leakage current density of 4.57 × 10−9 A/cm2 and the smallest interfacial density of states (Dit) of 2.38 × 1012 cm−2 eV−1 have been achieved in the Al2O3/Er2O3/Si MOS capacitor, which can be attributed to the optimized interface chemistry. Further electrical measurements of annealed Al2O3/Er2O3/Si gate stacks at 450 °C have demonstrated superior dielectric properties with a leakage current density of 1.38 × 10−9 A/cm2. At the same, the leakage current conduction mechanism of MOS devices under various stack structures is systematically investigated. [ABSTRACT FROM AUTHOR]

Background. Becker's nevus (BN) severely affects a patient's appearance and can lead to depression, especially when it involves the face or neck. Currently, there is no effective treatment. Laser therapy has become popular, but its efficacy has not been confirmed. We evaluated the efficacy and safety of lasers in treating BN. Methods. This retrospective study involved 49 patients exposed to different laser treatments who completed at least one treatment session and follow-up. Results. The patients treated with the 755-nm alexandrite picosecond laser and Q-switched 694-nm ruby laser gained relatively good results: 3.07 ± 1.09 and 2.87 ± 1.14 on the five-point scale and 3.47 ± 0.73 and 3.40 ± 0.85 on the GAIS, respectively. However, the results of the 755-nm alexandrite picosecond laser with a diffractive focus lens array and the fractionated 1064-nm neodymium-doped: yttrium aluminum garnet picosecond laser were poor. Furthermore, there were marked differences between the number of treatment sessions and treatment effects, both for the five-point grading score for pigment clearance (F = 15.246, p < 0.001) and GAIS (F = 15.469, p < 0.001). Concerning different lasers and efficacy, there were no marked differences between the five-point grading scale and the GAIS (p > 0.05). Conclusions. Although the efficacy of various lasers for BN is not satisfactory and there are no marked differences between picosecond and Q-switched lasers, they can help in selecting an appropriate laser for slight-to -moderate pigment removal. The 755-nm alexandrite picosecond laser is a new option, whereas nonablative fractional picosecond lasers for BN are not recommended. Increasing the number of treatment sessions can improve the curative effect slightly. [ABSTRACT FROM AUTHOR]

Comparison of the efficacy and safety of a picosecond frequency-doubled 532-nm Nd:YAG Laser and a Q-switched frequency-doubled 532-nm Nd:YAG Laser for the treatment of ephelides: A randomized, split-lesion, double-center, controlled trial Keywords: efficacy; ephelides; picosecond frequency-doubled 532-nm Nd:YAG laser (PSNYL); Q-switched frequency-doubled 532-nm Nd:YAG laser (QSNYL); safety EN efficacy ephelides picosecond frequency-doubled 532-nm Nd:YAG laser (PSNYL) Q-switched frequency-doubled 532-nm Nd:YAG laser (QSNYL) safety 712 714 3 02/14/23 20230201 NES 230201 Abbreviations PSNYL Picosecond frequency-doubled 532-nm Nd:YAG laser QSNYL Q-switched frequency-doubled 532-nm Nd:YAG laser Ephelides are brown, dotted pigmentation spots that commonly appear on the face. Efficacy, ephelides, Q-switched frequency-doubled 532-nm Nd:YAG laser (QSNYL), picosecond frequency-doubled 532-nm Nd:YAG laser (PSNYL), safety. [Extracted from the article]