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This study theoretically and empirically analyzes the impact and mechanism of corporate green transformation on accrual earnings management using a sample of China's A-share listed companies from 2015 to 2021. The results indicate that the green transformation of enterprises helps restrain accrual-based earnings management, especially accrual-based earnings management, which increases profits, and that the inhibition effect of enterprise green transformation on earnings management is more significant in high-tech and growth-stage enterprises. The mechanism test shows that corporate green transformation can inhibit accrual-based earnings management by increasing analyst follow-up and easing financing constraints. Using China's environmental tax law, promulgated in 2018, as an exogenous shock to construct the PSM-DID, the conclusion still holds after alleviating endogeneity. Further research has found that green transformations can also help inhibit real earnings management. This study provides new empirical evidence for a comprehensive understanding and evaluation of the governance role of corporate green transformation and provides a reference value for further comprehensively promoting the green transformation of Chinese enterprises and improving the quality of accounting information.

As one of China's nine border provinces, Jilin Province is an important window for China's “Belt and Road” to open up to the north, and an important channel for China's foreign trade and foreign exchanges. Therefore, understanding hydrogeochemical characteristics is very important for effective water resources management in Jilin Province. A total of 64 groundwater samples were collected from 32 monitoring Wells in Jilin Province. Use of hydrogeochemical analysis techniques, WQI index and human health risk index methods to assess hydrogeochemical processes and groundwater quality, including the determination of hydrogeochemical parameters, conventional ions, trace elements and stable isotopes (δD and δ18O). The results show that the groundwater is slightly alkaline, the cations are mainly Na+, Ca2+, Mg2+, and K+, and the anions are mainly HCO3-, Cl−, and SO42-. Most of the groundwater samples belong to Ca-HCO3 and Na-HCO3 types, which are formed by the dissolution of calcite, dolomite, gypsum, silicates and carbonates. Stable isotope analysis shows that groundwater recharge in Jilin mainly comes from atmospheric precipitation at an altitude of 1,430~2,348 m. The strong correlation between trace elements indicates a common source. Most of the groundwater quality index (WQI) in the study area is Class I to Class III, and hazard quotient (HQ) and hazard index (HI) are both below 1. This indicates excellent water quality and minimal health risks associated with human consumption. It is worth noting that trace elements are enriched in the Tanlu fault zone. It provides scientific guidance for the utilization and allocation of groundwater resources in Jilin Province.

Trace elements in hot-spring waters are indicators for tracing hydrochemical processes, such as the deep circulation of geothermal water, the degree of water–rock interaction, redox reactions, the contamination of shallow water by thermal water, etc. In this study, 74 hot springs in the Xianshuihe–Xiaojiang Fault Zone (XSHF-XJF) were chosen for an investigation of the geochemical characteristics of trace elements using classic geochemical tools and multivariate statistical analysis. The results indicated (1) the hot-spring waters were mainly derived from atmospheric precipitation as indicated by δD and δ18O values that generally increased with decreasing elevations; (2) the high concentrations of B, As, Fe, and Mn in the waters, as well as the values of the Water Quality Index (WQI), indicated that the water quality was spatially heterogeneous and the hot-spring waters are not entirely suitable for drinking; and (3) B/Cl ratios showed that hot springs have different reservoir sources in the XSHF and XJF, respectively. The leaching of surrounding rock during water circulation contributed predominantly to the trace elements of the study’s waters. Diversity of lithology was the main factor affecting their concentrations. In addition, deep circulation controlled by the fault could influence trace-element enrichment. Our results offer a guide for the exploration and use of geothermal resources.

Introduction: Carbon dioxide emissions from non-volcanic areas are undervalued in the carbon cycle.Methods: First estimates of diffuse CO2 flux from the Anninghe—Zemuhe fault (AZF), Southeastern Tibetan Plateau, China, which suggests this could equal 15% emissions from all volcanoes in China. Following the accumulation chamber method, CO2 flux was investigated at 1,483 points, and along 67 profiles crossing the AZF. Results and discussion: Total CO2 emissions from the AZF were estimated 1.2 Mt yr-1. The relationship between soil gas CO2 fluxes, earthquakes, and fault activity was discussed. The intense fault activity in the southern part of the Zemuhe fault (ZMHF) and the northern part of the Anninghe fault (ANH) was inferred, which could have enhanced the porosity of the soil, and accelerated the water-rock interactions and soil gas emission within the fault zone. The chemical and isotopic data indicated that biogenic CO2 was the primary source of CO2 from the AZF. Produced by interactions between groundwaters and carbonates, soil gas CO2 could migrate to the near surface through cracks. Spatial variations of CO2 flux in soil gas indicate that seismic activity could be responsible for the jumpy variations of CO2 flux. The diffuse CO2 from deep faults may contribute considerably to the greenhouse gas cycles.

Significant anomalous hydrogeochemical changes in hot spring water are detected during strong seismic cycles. It is now necessary to clarify the relationship between tectonic movements, earthquakes and the evolution of hot springs. In this paper, laboratory analyses of major, trace elements, δD, δ18O and 87Sr/86Sr values of 28 hot spring waters in the Jinshajiang fault zone (JSJFZ) in the northwestern boundary of the Sichuan-Yunnan block were conducted. The results showed that the primary source of water for JSJFZ hot springs was atmospheric precipitation. The geothermal reservoir temperature variation based on the silicon enthalpy mixing model ranged from 73 to 272°C. And the circulation depth range was 1.2–5.4 km. The segmentation characteristics of the 87Sr/86Sr values were related to the influence of source rocks on groundwater cycle processes. A conceptual model of the hydrologic cycle of hot springs explained the spatial distribution of earthquakes associated with tectonic movements. The Batang segment had the strongest water-rock reaction, the highest reservoir temperature and the deepest circulation depth; meanwhile, it was also an earthquake prone area. The fluid circulation of the JSJFZ corresponds well with the seismicity, which indicates that the hydrological characteristics of the hot spring water in a fracture zone play a crucial role in receiving information on seismic activity.

Geochemical investigation on the origin and circulation of geothermal water is crucial for better understanding the interaction between hydrosphere and lithosphere. Previous studies on the Himalayan geothermal belt mainly distributed in the central and eastern Tibetan Plateau. In this study, water samples (8 hot springs and 1 cold spring) from the Karakorum fault (KKF) zone of western Tibetan Plateau were analyzed for the hydrogeochemical characteristics and isotopic compositions. Three types of spring water along the KKF were classified on basis of ionic concentration and Sr isotopic composition: type A water (HCO3–Mg or Ca), type B water (HCO3–Na) and type C water (Cl–Na). Type A water is originated from the infiltration of meteoric water and the dissolution of silicate/evaporite. Type B water is mainly leached from the metamorphic and granitoid rocks. Type C water is formed by the dissolution of chlorides and sulphates. δD and δ18O isotopes indicate that geothermal fluid along the fault zone was mainly recharged by local precipitation. Moreover, reservoir temperatures of 144.2–208.6°C were estimated by the silica–enthalpy mixing model, and the thermal waters have a relatively deep circulation depth (≥ 7.0 km). Meanwhile, the thermal waters are characterized by extremely high Li, B, Fe and As concentrations and earthquakes frequently happened in the vicinity, suggesting that the KKF is a deep and active fault, which also indicates that the thermal fluids are strongly associated with seismicity. Therefore, thermal fluid can potentially be used as continuous monitoring sites for earthquake forecasting.

Hydrogeochemical characterization studies are regarded as an important method for determining the origin of hot springs. The major elements, trace elements, and stable isotopes of four groups of hot spring water samples and two groups of gas samples collected from the intersection of the Altyn Tagh fault zone and the East Kunlun fault belt were investigated in this study. The hot spring water temperature ranged between 6 °C and 14 °C. The water chemistry types of the hot springs were Na·Mg-Cl, Mg·Na-Cl·HCO3, Na-Cl·SO4, and Na-Cl·HCO3. The δD values ranged from −50.00% to −68.60%, while the δ18O values ranged from −6.90% to −8.60%. The hot spring water was recharged mainly by infiltrating precipitation, with a recharge elevation of 3390~3676 m. The heat storage temperature ranged from 66.7 to 164.9 °C. The circulation depth was estimated to range between 1043 and 2679 m. The strontium isotopic composition of the water samples in response to the main weathering sources comprised carbonate and sulfate. CO2 was the main component in the hot spring gas in the study region, and its content was over 95%. The 3He/4He-R/Ra relationship diagram revealed that the mantle-sourced helium from the Yitunbulake spring was 3.06%. In comparison, that from the Aiken spring was 7.38%, which indicated an intrusion of mantle-source material mixed into the hot springs in the study region. The crustal marine limestone contributed significantly to the carbon inventory of the hot spring gas samples (>75%). The dissolution of the marl aquifer resulted in the release of CO2. Carbon was primarily obtained through metamorphism and hydrothermal reactions in the basement lithologies. The Yitunbulake and Aiken hot springs are found near the intersection of the Arjin and East Kunlun fractures, where the water–rock response is relatively strong and the depth of circulation and thermal storage temperature are both high. This causes relatively high ambient pressure to be released from the deep fluid, resulting in microseismic activity in this region. The continuous observation of Aiken spring water chemistry allows for the monitoring of fracture activity in the region. The results of the study could serve as a foundation for further exploration of the relationship between geothermal water and deep faults, shallow geological formations, hydrogeological conditions, and geothermal resource development in the region.

The coupling relationship between regional seismic activity and the hydrogeochemical field provides an important theoretical basis for regional earthquake precursor exploration. The intersection area of the Red River fault zone (RRF) and the Xiaojiang fault zone (XJF) in southeast Yunnan province has become the focus area of earthquake monitoring and prediction because of its special tectonic position in China. There were 20 hot springs that were sampled and analyzed in the laboratory for major elements, including trace elements, silica, stable isotopes (δ18O and δD), and strontium isotopes, from the years 2015 to 2019. (1) The meteoric water is the main source of recharge for thermal springs in the study area, and recharged elevations ranged from 1.1 to 2 km; (2) the geothermometer method was used to estimate the region of thermal storage temperature, and its temperature ranged between 64.3 to 162.7 °C, whereas the circulation depth ranged from 1.1 to 7.2 km. Hydrochemical types were mainly controlled by aquifer lithology, in which sodium bicarbonate and sulphuric acid water gathered mainly in the RRF, while calcium bicarbonate water gathered mainly in the XJF. According to the silicon–enthalpy equation method, the temperature range and cold water mixing ratio were 97–268 °C and 61–97%, respectively; (3) the circulation depth of the RRF was deeper than that of the XJF, and it was mainly concentrated in the second segment and the fourth segment on the RRF. Most of the hot spring water was immature with a weak water–rock reaction; (4) the hot water intersections of RRF and XJF were obviously controlled by the fault and the cutting depth of granite; (5) the relationship discussed between geothermal anomaly and earthquake activity had a good correspondence with regional seismicity. The intensity of the reaction between underground hot water and the surrounding rock may lead to the change of pore pressure, and the weakening effect of groundwater on fracture may change accordingly, followed by the change in the adjustment of tectonic stress. Eventually, the difference in seismic activity was shown, implying that deep fluid has an important control action on the regional seismicity.

Pt-based multimetallic nanorings with a hollow structure are attractive as advanced catalysts due to their fantastic structure feature. However, the general method for the synthesis of such unique nanostructures is still lack. Here we report the synthesis of Pd@PtM (M = Rh, Ni, Pd, Cu) multimetallic nanorings by selective epitaxial growth of Pt alloyed shells on the periphery of Pd nanoplates in combination with oxidative etching of partial Pd in the interior. In situ generation of CO and benzoic acid arising from interfacial catalytic reactions between Pd nanoplates and benzaldehyde are critical to achieve high-quality Pt-based multimetallic nanorings. Specifically, the in-situ generated CO promotes the formation of Pt alloyed shells and their epitaxial growth on Pd nanoplates. In addition, the as-formed benzoic acid and residual oxygen are responsible for selective oxidative etching of partial Pd in the interior. When evaluated as electrocatalysts, the Pd@PtRh nanorings exhibit remarkably enhanced activity and stability for ethanol oxidation reaction (EOR) compared to the Pd@PtRh nanoplates and commercial Pt/C due to their hollow nanostructures.

The Chuan–Dian region, situated in the middle part of the north-south seismic zone of mainland China in a highly deformed area of the eastern margin of the Tibetan Plateau, is one of the principal areas for monitoring earthquake activities in China. In this study, the geochemical characteristics of soil degassing (of CH4, H2, CO2, Rn, and Hg) and, the relationship between degassing and fault activity, were investigated in the Xianshuihe–Xiaojiang fault system (XXFS) at the eastern boundary of the Chuan–Dian rhombic block. The mean soil-gas concentrations of CH4, H2, CO2, Rn, and Hg in the XXFS were 8.1 ppm, 9.9 ppm, 0.5%, 15.1 kBq/m3 and 12.9 ng/m3, respectively. The δ13CCO2 and δ13CCH4 values of the hot-spring gases varied from −11.9‰ to −3.7‰ and −62.5‰ to 17‰, respectively. The He-C isotopic ratios indicate that the carbon in the northern and middle parts of the XXFS may have originated from deep fluids, whereas the carbon in the southern part of the XXFS is of organic origin. The high concentrations of soil gas were distributed near the faults, indicating that the faults could act as channels for gas migration. The distributions of the high soil-gas concentrations in the XXFS coincide with the highest stress and maximum strain rates, indicating that the fault activity enhanced permeability and increased the emission rates of the gases. The results of this study will be helpful for degassing in active fault zones and earthquake monitoring.

The gas compositions (He, H2, CO2, CH4, Ar and N2) and isotope ratios (3He/4He and δ13C) were yearly investigated from April 2010 to April 2019 at the Luojishan spring located in the proximity of the Zemuhe Fault, eastern Tibetan Plateau. The continuous automatic monitoring of hydrogen concentrations in Luojishan hot spring bubbling gas for the purpose of earthquake prediction requires the discrimination of seismic precursor anomalies. Helium isotope ratios (3He/4He) in the bubbling gas of hot springs varied from 0.05 to 0.18 Ra (Ra = 3He/4He = 1.39 × 10−6 in the air), with a maximum mantle-derived He up to 2.2% of the total He measured in the Luojishan hot spring (assuming R/Ra = 8.0 for mantle). This suggests that Zemuhe Fault might act as a conduit for crustal-derived fluid. N2 concentrations in the majority of the hot spring was ≥80 vol%, and δ13CCO2 values varied from −13.2 to −9.3‰ (vs.PDB). Hydrogen concentration time series display a complex temporal pattern reflecting a wide range of different physical processes. There were short-term (5–60 h) seismic precursor anomalies of hydrogen concentration before natural earthquake. The anthropogenically-induced earthquakes provoke only post-earthquake responses. The concentration of hydrogen in bubbling gas of the Luojishan hot spring is sensitive to increase of stress in the Xianshuihe-Xiaojiang fault system. Monitoring the hydrogen concentrations with automatic gas stations may be promising tool for unraveling earthquake mechanisms and for predicting earthquakes.

Based on the observation of the geochemical characteristics of 19 hot springs in the Litang Fault Zone (LFZ) from 2010 to 2019, the major elements, trace elements, and stable isotopes were investigated, and a conceptual model of ground fluid circulation in the LFZ was established. The main hydrochemical type of hot spring water samples is HCO3−-Na+. The δ2H values range from −157.6‰ to −123.4‰ and δ18O values range from −24.5‰ to −15.4‰. The hot spring water in the Litang fault zone is mainly recharged by infiltrating precipitation, with a recharge elevation of 4062~6018 m. Hydrochemical types of Litang hot springs are mainly controlled by the circulation of groundwater in a deep fault system, and are related to the rock lithology of thermal reservoir and water–rock reaction areas. Hot springs in the Litang fault zone attribute to three different heat sources, belonging to three geothermal systems. The flow direction of groundwater in the LFZ is roughly from northwest to southeast along the Litang fault. The deeper the circulation depth of hot spring water on the fault, the higher the thermal reservoir temperature and the stronger the seismic activity of the segment, which is closely related to the increase in pore fluid pressure, rock weakening, and deep fluid upwelling. This study is helpful for further study on regional hydrogeological environments and provides a scientific basis for revealing geothermal fluid movement in fault zones.

Hydrogeochemical changes in association with earthquakes are considered as a potential means of identifying earthquake precursors. The Xianshuihe fault zone (XSHF) is considered one of the most active seismic fault zones in China; 43 hot springs were sampled and analysed in the laboratory for major elements, silica, stable isotopes (δD and δ18O) and strontium isotopes were investigated from 2008 to 2021. The meteoric water acted as the primary water source of the hot spring in the XSHF, and recharged elevations ranged from 1.9 to 4.8 km. The geothermometers method was used to estimate the region of thermal storage temperature and its temperature between 8 and 142 °C. And the circulation depth ranged from 0.1 to 6.9 km. Most of the hot spring water was immature water with a weak degree of water-rock reaction. However, the degree of water-rock reaction and the depth of hot spring water circulation were high in part of the Kangding and Daufu segments, which also had the highest reservoir temperature and the most frequent strong earthquakes. Temporal variations of hydrogeochemical showed that Na+, Cl− and SO42− decreased obviously following the 12 May 2008 Wenchuan Ms8.0 and existed abnormal value fluctuations from the 20 April 2013 Lushan Ms7.0 to 22 November 2014 Kangding Ms6.3 occurred and after 20 July 2017 returned to the normal levels. And the ion concentrations in hot springs increased by 5% to 35% three months before 22 November 2014 Kangding Ms6.3 with the obvious precursor anomaly. Hydrogeochemical anomalies could be useful for predicting an earthquake in the study area.

The Weixi–Qiaohou Fault (WQF) is considered an important zone of the western boundary of the Sichuan–Yunnan block, and its seismicity has attracted much attention after a series of moderate–strong earthquakes, especially the Yangbi Ms6.4 earthquake that occurred on 21 May 2021. In the present research, we investigate major and trace elements, as well as hydrogen and oxygen isotopes, of 10 hot springs sites located along the WQF, which are recharged by infiltrated precipitation from 1.9 to 3.1 km. The hydrochemical types of most analyzed geothermal waters are HCO3SO4-Na, SO4Cl-NaCa, and SO4-Ca, proving that they are composed of immature water and thus are characterized by weak water–rock reactions. The heat storage temperature range was from 44.1 °C to 101.1 °C; the circulation depth was estimated to range between 1.4 and 4.3 km. The results of annual data analysis showed that Na+, Cl−, and SO42− in hot springs decreased by 11.20% to 23.80% north of the Yangbi Ms5.1 earthquake, which occurred on 27 March 2017, but increased by 5.0% to 28.45% to the south; this might be correlated with the difference in seismicity within the fault zone. The results of continuous measurements of NJ (H1) and EYXX (H2) showed irregular variation anomalies 20 days before the Yangbi Ms6.4 earthquake. In addition, Cl− concentration is more sensitive to near-field seismicity with respect to Na+ and SO42−. We finally obtained a conceptual model on the origin of groundwater and the hydrogeochemical cycling process in the WQF. The results suggest that anomalies in the water chemistry of hot spring water can be used as a valid indicator of earthquake precursors.

Abstract Developing an efficient Pt‐based electrocatalyst with well‐defined structures for the methanol oxidation reaction (MOR) is critical, however, still remains a challenge. Here, a one‐pot approach is reported for the synthesis of Pd3Pb/PtnPb nanocubes with tunable Pt composition varying from 3.50 to 2.37 and 2.07, serving as electrocatalysts toward MOR. Their MOR activities increase in a sequence of Pd3Pb/Pt3.50Pb << Pd3Pb/Pt2.07Pb < Pd3Pb/Pt2.37Pb, which are substantially higher than that of commercial Pt/C. Specifically, Pd3Pb/Pt2.37Pb electrocatalysts achieve the highest specific (13.68 mA cm−2) and mass (8.40 A mgPt−1) activities, which are ≈8.8 and 6.8 times higher than those of commercial Pt/C, respectively. Structure characterizations show that Pd3Pb/Pt2.37Pb and Pd3Pb/Pt2.07Pb are dominated by hexagonal‐structured PtPb intermetallic phase on the surface, while the surface of Pd3Pb/Pt3.50Pb is mainly composed of face‐centered cubic (fcc)‐structured PtxPb phase. As such, hexagonal‐structured PtPb phase is much more active than the fcc‐structured PtxPb one toward MOR. This demonstration is supported by density functional theory calculations, where the hexagonal‐structured PtPb phase shows the lowest adsorption energy of CO. The decrease in CO adsorption energy and structural stability also endows Pd3Pb/PtnPb electrocatalysts with superior durability relative to commercial Pt/C.

Understanding how catalysts corrode during use is crucial in developing new, durable devices. Here, the authors studied the real-time corrosion of core-shell palladium-platinum nanocubes by electron microscopy and found two competitive etching mechanisms to dominate catalyst degradation behavior.

Analyzing the hydrochemical composition in thermal springs is an advantageous method for studying the coupling mechanism of the deep and shallow fluids in active fault zones. Here we conducted sampling in 30 thermal springs near fault zones in Fujian Province, and the major elements, trace elements, silica, stable isotopes (δD and δ18O) and strontium isotopes were tested in the laboratory. The results show that (1) the thermal springs in the study area can be divided into six types according to the content of the major elements: HCO3-Na, HCO3·SO4-Na, Cl·HCO3-Na, Cl-Na, Cl-Na·Ca and HCO3·SO4-Ca; (2) hydrogen and oxygen isotopes indicate that precipitation is the main source of recharge for thermal springs in the study area, and the recharge height is between 258 m and 1859 m; (3) the content of SiO2 in the thermal spring varies from 18.1 mg/L to 59.3 mg/L. The geothermal reservoir temperature calculated is 90~226 °C, and the circulation depth is 2.9~5.4 km, except for the W10 thermal spring, whose circulation depth is 8.4 km; and (4) the 87Sr/86Sr of the thermal springs in southwestern Fujian and eastern Fujian has obviously different characteristics, indicating the influence of different rock formations on the groundwater cycle process. Additionally, a continuous measurement of the main anions and cations was performed in five thermal springs every three days since January 2020. There were obvious abnormal changes in the hydrochemical compositions, chlorine in four of the five springs, sodium at three springs, and four ions at one spring, which all showed abnormal high-value changes by 15% to 80%, and which occurred 85~168 days prior to the M6.1 earthquake in Hualien, Taiwan. An inspiration could be provided for obtaining effective earthquake precursor anomalies by monitoring the change in ion concentration in thermal springs.

Significant hydrogeochemical changes may occur prior- and post-earthquakes. The Xiaojiang fault zone (XJF), situated in a highly deformed area of the southeastern margin of the Tibetan Plateau, is one of the active seismic areas. In this study, major and trace elements, and hydrogen and oxygen isotopes of 28 sites in hot springs along the XJF were investigated from June 2015 to April 2019. The meteoric water acts as the primary water source of the hot spring in the XJF and recharged elevations ranged from 1.8 to 4.5 km. Most of the hot spring water in the study area was immature water and the water–rock reaction degree was weak. The temperature range was inferred from an equation based on the SiO2 concentration and chemical geothermal modeling: 24.3~96.0 °C. The circulation depth for the springs was estimated from 0.45 to 4.04 km. We speculated the meteoric water firstly infiltrated underground and became heated by heat sources, and later circulated to the earth’s surface along the fault and fracture and finally constituted hot spring recharge. Additionally, a continuous monitoring was conducted every three days in the Xundian hot spring since April 2019, and in Panxi and Qujiang hot springs since June 2019. There were short-term (4–35 d) seismic precursor anomalies of the hydrochemical compositions prior to the Xundian ML4.2, Dongchuan ML4.2, and Shuangbai ML5.1 earthquakes. The epicentral distance of anomalous sites ranged from 19.1 to 192.8 km. The anomalous amplitudes were all over 2 times the anomaly threshold. The concentrations of Na+, Cl−, and SO42− are sensitive to the increase of stress in the XJF. Modeling on hydrology cycles of hot springs can provide a plausible physicochemical basis to explain geochemical anomalies in water and the hydrogeochemical anomaly may be useful in future earthquake prediction research of the study area.

This paper reports a strategy for more reliably obtaining sputtered thin yttrium–iron–garnet (YIG) films possessing both low magnetic damping (α) and a highly spin transparent surface, which represent two of the most important properties for YIG films applied in spintronic devices. The two key points of this strategy, concluded from our systematical studies, are as follows: oxygen reactive sputtering of a slight Y-rich YIG target to avoid the over-stoichiometry of the Fe component and at the same time minimize oxygen vacancy density; and employing phosphoric acid wet etching to remove the inevitable thin magnetic dead layer formed on the surface. The feasibility of this strategy was proved by the achievement of a high quality 30 nm-thick YIG film. It possesses a ferromagnetic resonance linewidth of only 3.4 Oe at 8 GHz, α of only 4.6 × 10−4, and a very spin-transparent surface, as proved by the measured extremely large spin pumping voltage of 650.1 µV after depositing a 3 nm Pt layer.

Since the advent of germ cell transplantation (GCT), it has been widely used in shortening the fish breeding cycle, sex-controlled breeding and the protection of rare and endangered fish. In this study, the effectiveness of female sterile recipient preparation and donor stem cell isolation and purification were comprehensively evaluated for spermatogonial stem cell transplantation (SSCT) in Paralichthys olivaceus. The best way to prepare sterile recipients was found to be giving three-year-old fish four intraovarian injections of busulfan (20 mg/kg body weight) combined with exposure to a high temperature (28 °C) after the spawning season compared with the two other ways, which induced apoptosis of most of the endogenous germ cells, resulting in shrinkage of the spawning plate and enlargement of the ovarian lumen. Further analysis showed that both the gonadosomatic index and germ-cell-specific vasa expression were significantly lower than those of the natural-temperature group before treatment (p < 0.05). A high percentage (>60.00%) of spermatogonial stem cells (SSCs) were obtained after isolation and purification and were transplanted into the prepared recipients. After three weeks of SSCT, the numbers of PKH26-labeled SSCs were increased in the ovaries of the recipients. These findings provide a basis for the establishment of an ideal SSCT technique using P. olivaceus females as the recipients, ultimately contributing to the efficient conservation of male germplasm resources and effective breeding.