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Two new species of nemourid stonefly, Amphinemura bicoloratasp. n. and A. yadongasp. n., are described from Xizang Autonomous Region of south-western China. The relationships between the new species and similar species in the genus are discussed. [ABSTRACT FROM AUTHOR]

Objective To explore the current situation and development trend of coupling coordination between medical and health resource allocation and service utilization in eastern, central, and western regions and provinces of China, and to provide suggestions for promoting the coordinated development of medical and health resource allocation and service utilization. Methods The related index data of medical and health resource allocation and service utilization from 2018 to 2022 were selected, and the comprehensive development level index and relative development degree were used to evaluate the medical and health resource allocation and service utilization. The coupled coordination degree model was used to analyze the coupling coordination relationship and development trend of the two systems. Results There were significant differences in the comprehensive development level of medical and health resource allocation among provinces, and the overall structure of relative development degree in 2021 was "9-11-11". From 2017 to 2021, the coupling coordination degree of medical and health resource allocation and service utilization decreased, showing a decreasing trend from east to west as a whole. The overall coordination between the allocation of medical and health resources and the utilization of services in China was poor. Only 12 provinces achieved coordinated development in 2021. Xizang was still in the dilemma of serious imbalance. Conclusion It is suggested to improve the accuracy of medical and health resources allocation, reduce the differences in the develop-ment level of resource allocation between provinces, and build a multi-party co-governance pattern. The improvement strategy of coordination level should be accurately formulated according to the relative development of medical and health resource allocation and service utilization in each province. [ABSTRACT FROM AUTHOR]

Elevation has been a cornerstone of biodiversity research, and changes in the environmental factors behind it influence biodiversity and community patterns. Exploring the potential reasons behind liverwort community patterns has been a matter of multiplied interest for ecologists. In the present study, we recorded the liverwort taxa of Sygera Mountain growing on decaying wood, trees, soil, and rocks along an elevational gradient from 3100 m to 4500 m using complex field surveys in 2017 and 2019; we investigated the effects of elevation and various climatic factors on the liverworts' diversity and community composition. Furthermore, we used mixed effect modeling, NMDS, ANOSIM, and CCA to help us critically assess liverwort diversity with respect to environmental variables. The results of the study showed a bimodal variation in the richness of liverwort communities according to elevation, with peaks occurring at 3500 m and 4100 m, respectively. The variation in elevation was significant, with communities at 4300 m being associated with high mean diurnal range environments and those at 3100 m and 3300 m favoring areas of higher solar radiation and the precipitation of the wettest month. Among the climatic factors, the variation in the mean diurnal range was found to be the determinant of liverwort communities. The results suggest that the mean diurnal range plays a crucial role in the distribution and community structure formation of mountain liverwort. This study deepens our understanding of liverwort ecology and emphasizes the importance of climatic variables in determining liverwort community composition. [ABSTRACT FROM AUTHOR]

The Reshui area, located to the northeast of the Qinghai–Tibet Plateau, exhibits complex geological conditions, well-developed structures, and strong hydrothermal activities. The distribution of hot springs within this area is mainly controlled by faults. In this paper, five hot springs from the area were taken as the research object. We comprehensively studied the geochemical characteristics and genetic mechanism of the geothermal water by conducting a field investigation, hydrogeochemistry and environmental isotopic analysis (87Sr/86Sr, δ2H, δ18O, 3H). The surface temperature of the geothermal water ranges from 84 to 91 °C. The geothermal water in the area exhibits a pH value ranging between 8.26 and 8.45, with a total dissolved solids' (TDS) concentration falling between 2924 and 3140 mg/L, indicating a weakly alkaline saline nature. It falls into the hydrochemical type CI-Na and contains a relatively high content of trace components such as Li, Sr, B, Br, etc., which are of certain developmental value. Ion ratio analysis and strontium isotope characteristics show that the dissolution of evaporite minerals and carbonate minerals serves as a hot spring for the main source of solutes. Hydrogen and oxygen stable isotope characteristics findings indicate that the geothermal water is primarily recharged via atmospheric precipitation. Moreover, the tritium isotopic data suggest that the geothermal water is a mixture of both recent water and ancient water. Moreover, the recharge elevation is estimated to be between 6151 and 6255 m. and the recharge area is located in the Kunlun Mountains around the study area. The mixing ratio of cold water, calculated using the silicon enthalpy equation, is approximately 65% to 70%. Based on the heat storage temperature calculated using the silicon enthalpy equation and the corrected quartz geothermal temperature scale, we infer that the heat storage temperature of geothermal water in the area ranges from 234.4 to 247.8 °C, with a circulation depth between 7385 and 7816 m. The research results are highly valuable in improving the research level concerning the genesis of high-temperature geothermal water in Reshui areas and provide essential theoretical support for the rational development and protection of geothermal resources in the area. [ABSTRACT FROM AUTHOR]

The Qushenla Formation volcanic rocks are widely exposed in the northern margin of the Bangong-Nujiang suture zone (BNSZ). Research on these rocks is of great significance for understanding the tectonic evolution of the Bangong-Nujiang Tethys Ocean (BNTO). In this study, a systematic geological survey was conducted on the Qushenla Formation volcanic rocks that are widely exposed in the Nawucuo area, in the northern margin of the western segment along the BNSZ. The whole-rock geochemistry, zircon U-Pb dating, and in situ zircon Lu-Hf isotopes were carried out in this study, aiming to constrain the formation age, rock genesis, magma source and tectonic setting of the volcanic rocks. The zircon U-Pb dating shows that the Qushenla Formation volcanic rocks in the western BNSZ erupted during the period of 120–108 Ma, i.e., Early Cretaceous. The Qushenla Formation volcanic rocks are a suite of intermediate-basic volcanic and pyroclastic rocks belonging to the medium-K calc-alkaline series. They are relatively enriched in light rare earth elements (LREEs) and incompatible elements such as Rb, K, La, Th, Sm, and Hf, whereas depleted in heavy REEs (HREEs) and high field strength elements (HFSEs) such as Nb, P, Zr, and Ti. The in situ zircon εHf(t) values of the volcanic rocks range from 8.95 to 12.57, with an average of 10.40. The Mg#, Th/La and Th/Ce values are between those of the mantle-derived magma and the continental crust. The formation of the Qushenla Formation volcanic rocks can be explained through the following process: (1) As the nospheric materials that upwelled during the rollback of the subducting Tethys Ocean slab induced the large-scale partial melting of the mantle wedge and the formation of the initial basaltic magma. (2) These mantle-derived magmas ascended and induced the partial melting of the lower crust to generate peraluminous melts. (3) The mixing of the peraluminous melts and mantle-derived melts generated the initial magma with homogeneous Sr-Nd isotope compositions. (4) Last, the eruption of the magma produced the widespread Qushenla Formation volcanic rocks at the surface. When combining this information with the regional geological background, it is believed that the Qushenla Formation volcanic rocks, the Meiriqicuo Formation volcanic rocks and the Late Jurassic–Early Cretaceous intrusive rocks together constitute the tectonic magmatic arc of the active continental margin on the southern margin of Qiangtang, which was formed in the tectonic setting of the northward subduction of the Bangong-Nujiang oceanic crust beneath the Qiangtang Block. [ABSTRACT FROM AUTHOR]

As a frequent geological disaster, landslides cause serious casualties and economic losses every year. When landslides occur, rapid access to disaster information is the premise of implementing disaster relief and reduction. Traditional satellite remote sensing may not be able to timely obtain the image data from the disaster areas due to orbital cycle and weather impacts. Visual interpretation of remote sensing data and machine learning methods need to be improved the detection efficiency. This paper studies landslide recognition based on the UAV remote sensing image. The affected area of the Zhangmu Port region in Tibet by the Nepal earthquake occurred on 25 April 2015 was selected to carry out the landslide investigation. Aiming at the problem of insufficient training sample data of landslides, we adopt the transfer learning method. The evaluation indexes show that the proposed method can automatically identify landslide disasters. Comparing with the SSD model, our new approach has better detection performance, providing thus accurate data support for scientific decision-making of disaster rescue. [ABSTRACT FROM AUTHOR]

The continuing impact between the Eurasia Plate and India results in the thickening and shortening of the N-S Tibetan Plateau. There has been strong tectonic movement along the boundary of the zones of deformation of the NE corner of the Tibetan plateau (NET) since the new tectonic period, with its dynamic mechanisms remaining controversial. Here, we use observations of 39 Continuous Global Positioning System (CGPS) gauges and 451 Crustal Movement Observation Network of China (CMONOC) campaign-mode stations to detect the three-dimensional deformation of the crust in the NET. Improved processing procedures are implemented to strengthen the patterns of strain throughout the NET. The principal component analysis (PCA) technique is introduced to decompose the time series into spatial eigenvectors and principal components (PCs), and the first three PCs are used to estimate and rectify common mode errors (CMEs). In addition, GRACE observations are used to detect deformation changes that account for non-tidal oceanic mass loading, hydrological loading, and surface pressure. The rectified deformation of the crust indicates the anisotropic nature of both the subsidence and uplift, and that the highest uplift rate of the Longmen Shan fault uplift reaches 7.13 ± 0.53 mm/yr. Finally, the horizontal velocity is further used to enumerate the strain rates throughout the NET. The results show that the shear band retained property in line with the strike-slip fault along the Altyn Tagh fault, the Qilian Shan faults, the Haiyuan fault, the West Qinling fault, the East Kunlun fault, and the Longmen Shan fault. In addition, the results further indicate that the whole NET shows a strong relationship with the mean principal rates of horizontal shortening strain. Extension and compression of the crust reasonably describe its sinking and uplifting. [ABSTRACT FROM AUTHOR]

The Xiazha Formation recently identified in the Yarlung-Zangbo suture zone of southern Tibet has been considered as crucial evidence for early (pre-Cretaceous) subduction of Neo-Tethyan oceanic lithosphere. In this study, we carried out an integrated stratigraphic, petrographic, and geochemical study of the Xiazha Formation, which consists of abyssal chert, siliceous mudrocks, and calcareous turbidites deposited onto basaltic basement. Basalt geochemistry indicates alkali to tholeiitic magmas generated in a within-plate oceanic setting. The siliciclastic fraction contained in calcareous turbidites consists of plagioclase and mafic-rock fragments derived from the underlying basalts, and includes Cr-spinel grains with relatively high TiO 2 and moderate Al 2 O 3 concentrations pointing to an OIB source. Based on these data, and virtual lack of detritus of continental origin, we infer that the Xiazha Formation was deposited in oceanic island/plateau within the Neo-Tethyan domain. Its stratigraphy records an evolution from basaltic eruptions to the development of a carbonate platform surrounding the basaltic island, and finally to drowning of the atoll. The Xiazha Formation was not deposited in a subduction-related basin and, therefore, cannot be used as evidence for pre-Cretaceous initiation of the Yarlung subduction zone. • Earliest Cretaceous oceanic island developed in the Neo-Tethys Ocean. • The Xiazha Formation in the Yarlung suture shows intact stratigraphic continuity. • It was deposited on an oceanic island rather than in a subduction setting. • The Xiazha Formation records the evolution of the oceanic island through time. • The Xiazha Formation cannot be used as evidence for pre-130 Ma subduction. [ABSTRACT FROM AUTHOR]

• Explored the variation law of fracture gas-steam pressure with heat flow. • The stress intensity factors under the action of fracture gas-steam pressure and heat flow stress is established. • The influence of heat flow incidence angle and heat flow density on crack initiation is analyzed. • Provided certain theoretical guidance for engineering fractures with geothermal flow. The construction of tunnel projects in the Sichuan-Tibet region has led to the occurrence of rock fractures caused by high temperature and high humidity, which are inevitable challenges. When there is fracture water in rock fractures and it encounters a heat flow, the water vaporizes into fracture steam, which undergoes thermal expansion to generate fracture gas-steam pressure. The heat flow direction is at an angle to the crack, causing heat flow stress in the rock. To understand the mechanism of crack initiation and propagation in rocks under the joint action of uniform heat flow-induced fracture gas-steam pressure and heat flow stress, the control equation for fracture gas-steam pressure is derived and expressions for stress intensity factor, crack temperature field, stress field, and crack initiation strength criterion are established based on the theory of complex variable functions. The key parameters are analyzed and discussed, finding that under low heat flux density, small incidence angles, and large crack inclination angles, K I values are higher, and the crack initiation is mainly in tension. Under high heat flow density, large incidence angles, and crack inclination angles near 45°, K II values are higher, and the crack initiation is mainly in shear. The coupling effect of K I and K II is more sensitive to heat flow density and inclination angle. The critical initiation angle and initiation strength increase with the increase of heat flow density and incidence angle, with heat flow density being the determining factor. [ABSTRACT FROM AUTHOR]

• Based on the modified MTS criterion, the rock crack initiation criterion under the combined action of thermal stress and fracture air-vapor pressure is established by the superposition method. • The expansion pressure of the fracture gas in the crack is controlled by the temperature and the gas saturation, and the temperature is the dominant effect. • K I , K II are controlled by thermal stress and fracture gas-vapor pressure, in which thermal stress is the dominant factor. • With the increase of temperature, the crack initiation form tends to be tensioned from shearing, and the gas expansion pressure promotes the tensioned part. Near the surface of the Sichuan-Tibet line tunnel surrounding rock under construction is in a sub-hot and humid environment, and long-term accumulation will produce damp-heat diseases. The significant temperature difference leads to the thermal stress of the surrounding rock, and the surrounding rock fracture water vaporizes to create fracture air-vapor pressure, which induces crack initiation. The state equation of gases, thermoelastic mechanics, and the theory of linear elastic fracture mechanics are used to study the crack initiation law of rock under the joint action of sub-elevated temperature stress and fracture air-vapor pressure. The stress intensity factor's expression under the two joint actions is derived from the superposition principle. Then the initiation criterion considering both internal influencing factors (rock properties, crack geometry parameters (inclination angle)) and external influencing factors (far-field stress, temperature, humidity factors) is derived. The theory is used to quantitatively analyze the distribution law of tangential stress at the crack tip and the crack initiation form. The effects of each parameter on critical crack initiation angle and crack initiation strength are discussed. The theoretical results are further verified by numerical simulation. The results show that in the sub-elevated temperature range, the thermal stress and the fracture air-vapor pressure jointly affect the crack initiation law, and thermal stress is the dominant factor. With the temperature increase, K I > K II , the critical crack initiation angle increases gradually, the crack initiation form changes from shear to compression-shear, and finally tends to tension. The fracture air-vapor pressure promotes the tension part. The maximum tangential stress increases linearly with temperature. The maximum tangential stress and critical crack initiation angle increase first and then decrease with the rise of crack inclination angle and reach the maximum at 45°. The research results supply a theoretical basis for preventing and treating the rock crack propagation surrounding the tunnel under sub-elevated temperatures and high humidity. [ABSTRACT FROM AUTHOR]

Podocarpium is an extinct genus in Fabaceae with rich fossil records in Eurasia dating back to the Eocene. However, the diversification and biogeographic histories of Podocarpium are poorly known due to a lack of fossils in some key regions, such as the Tibetan Plateau, an area recently shown to be crucial for floristic exchanges worldwide in the geological past. Here, we describe well-preserved fossil pods of Podocarpium from the late Eocene (~ 35 Ma) of the Lunpola Basin, central Tibetan Plateau, China. Together with detailed morphological observation and geometric morphology analysis, these fossil pods are named Podocarpium tibeticum W.-C. Li, J. Huang et T. Su sp. nov., characterized by asymmetrical elliptical valves, olecranon fruit beak, and a clearly oblique base. This material comprises the oldest fossil record of Podocarpium from the Tibetan Plateau and adjacent regions. The discovery of P. tibeticum shows Podocarpium was present in central Tibet by the late Eocene. Together with previous fossil records, it indicates that Podocarpium may have originated in East Asia, migrated into the central valley of Tibet in the late Eocene, and then spread westward to Europe through a low-latitude path of island chains along the Neotethys. Results of paleoecological niche modeling demonstrate that Podocarpium had an almost worldwide potential distribution range in the Eocene, but this sharply contracted thereafter until by the Pliocene it was restricted to a small area of East Asia. Generally, this finding further supports the idea that what is now the central Tibetan Plateau was a globally significant hub for Paleogene floristic exchange. • First report of Podocarpium in central Tibetan Plateau. • Shows a new fossil pod species of Podocarpium. • Enhances understanding of its historic distribution globally. • Podocarpium is sensitive for dry and cool climates. [ABSTRACT FROM AUTHOR]

• The back-arc and arc-type magmatisms (ca. 838–748 Ma) were newly identified in the Rutong and Shiquanhe region, west of Tibet. • The North Lhasa terrane may separat from the Indian continent, finally constituted the northern segment of the East African Orogen during the Neoproterozoic. • The BNSZ retains geological records of the evolution of the Mozambique Ocean in the Neoproterozoic. Due to limited exposure of the Precambrian rocks in the Tibetan Plateau, their affinities and evolutions are inadequately studied. Here we report the newly identified Neoproterozoic metabasites (including metagabbros and metadolerites) at the western end of the Bangong-Nujiang suture zone (BNSZ) and the west part of the North Lhasa terrane. The Rutong Dong (RTD) metagabbros and Shiquanhe Nan (SQN) metadolerites yield zircon U-Pb ages of 838 Ma and 748 Ma, respectively. The RTD metagabbros are tholeiitic and exhibit both MORB- and arc-like geochemical characteristics, and we consider these to have formed in a back-arc basin setting. Combined with positive zircon ε Hf (t) (+6.3 to +13.8) and whole-rock ε Nd (t) (+4.4 to +5.3) values, the geochemical features of the RTD metagabbros indicate that they originated from a depleted mantle source enriched by subduction-related components (e.g., Th and U). The SQN metadolerites are mainly of transitional character (between tholeiitic and calc-alkaline), as well as representing typical calc-alkaline basalts. Their arc-like geochemical characteristics, as well as low positive whole-rock ε Nd (t) (+1.7 to +3.4), and positive zircon ε Hf (t) (+4.3 to +5.9) values, indicate generation by partial melting of an enriched subduction components modified mantle in an arc-type setting. Based on previous research, we propose that the North Lhasa terrane likely separated from India at ca. 925–860 Ma by the opening of the Mozambique Ocean. As the subduction zones were active at ca. 838–730 Ma in this ocean, a series of subduction-related magmatic events occurred, that is recorded in this study of the Rutong-Shiquanhe region, and other parts of the BNSZ and North Lhasa terrane. Consequently, we suggest that the BNSZ not only preserves information of the Meso-Tethys but also retains geological records of the Neoproterozoic Mozambique Ocean. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Shiquanhe-Yarlun Zangbo geothermal field enriched in rare alkali metal resources. • Himalayan leucogranite are typical of S-type granites. • Partial melting of metasediments and intense water–rock interaction promote RAMs enrichment. • Strong adsorption controls the hyper enrichment of rare metals during silica precipitation. Geothermal waters in the Shiquanhe-Yarlun Zangbo geothermal field of southern Tibet are highly enriched in rare alkali metals (RAMs), which form a globally unique geyserite Cs-deposit. Boron isotopes, together with the geochemistry of a local leucogranite, geothermal springs and geyserite were investigated to constrain the migration and accumulation of RAMs in the geyserite cesium deposit. The δ11B values of −9.7‰ to −8.4‰ in tourmalines from the Himalayan leucogranite have shown typical S-type granites. A mass balance calculation indicates that the magma of the S-type granite contained < 10 % dehydrated fluid, which resulted in an enrichment of RAMs by 4–5 times during the partial melting of crustal materials, compared to that in the UCC. The linear relationships of ΣRAMs vs. B and Na + K vs. soluble Si, indicate that further enrichment of RAMs in the geothermal fluids was promoted by intense water–rock interaction at temperatures of 210 to 250 °C in the geothermal system reservoir. A strong adsorption process controlled the hyper enrichment of RAMs (especially Cs) during silica precipitation from the upwelling geothermal water, with the sharp decreases in temperature and pressure leading to the enrichment of Cs in fresh geyserites. Despite loss of RAMs during dehydration of the geyserite during phase transformation from opal-A, opal-CT, and chalcedony to quartz, freshly deposited geyserites have great potential for exploration of RAMs resources in this area. [ABSTRACT FROM AUTHOR]