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In this paper, the digital management of scientific and technological innovation services in universities based on the background of artificial intelligence is studied in depth, aiming to create a comprehensive and efficient management platform. By constructing a platform with a multi-level architecture, it realizes the informatization management of the whole process of university science and technology projects. Specifically, this study designed a functional structure of 10 subsystems, covering all stages from project declaration to results management. To improve the management efficiency, principal component analysis and cluster analysis techniques were introduced, and the effectiveness and feasibility of the platform were verified by analyzing 270 questionnaires. The average score is 3.8293, showing that users highly recognize the platform. In addition, by qualitatively and quantitatively analyzing the factors affecting management, the key factors promoting and inhibiting the management efficiency were clarified, providing a new perspective for the management of scientific and technological innovation services in universities.

We develop a moving-mesh permafrost model that contains a ground subsidence computation module to estimate the effects of ground subsidence on permafrost simulation under different warming scenarios. Including the ground subsidence process in the permafrost simulation produces only a relatively small improvement in the simulation performance of the ground temperature field, as validated by observations from two sites on the Qinghai–Tibetan Plateau (QTP). It is shown that ignoring ground subsidence tends to achieve a larger active layer thickness (ALT) but a smaller original thickness of permafrost that has thawed when simulating permafrost changes in a warming climate. The heat consumed by permafrost changes will be underestimated in simulations that do not consider ground subsidence. The effects that ground subsidence exerts within the permafrost simulation are clearly demonstrated under a strong warming scenario, which will influence the global energy budget. Projections indicate that the permafrost in the continuous permafrost area of the QTP may be close to the phase transition temperature to become zero thermal gradients in 2030–2040 under the SSP5-8.5 scenario, and there will be a great risk of ground subsidence by that stage. For permafrost regions with rich ground ice, the downward propagating temperature signals caused by ground subsidence are more attenuated. However, the heat calculation error will be larger in a simulation that does not consider ground subsidence there. This study quantifies the effects of ground subsidence, which can provide a better understanding of the permafrost thaw and energy budget of the QTP. [ABSTRACT FROM AUTHOR]

The freeze–thaw (F-T) cycle of the active layer (AL) causes the "frost heave and thaw settlement" deformation of the terrain surface. Accurately identifying its amplitude and time characteristics is important for climate, hydrology, and ecology research in permafrost regions. We used Sentinel-1 SAR data and small baseline subset-interferometric synthetic aperture radar (SBAS-InSAR) technology to obtain the characteristics of F-T cycles in the Zonag Lake-Yanhu Lake permafrost-affected endorheic basin on the Qinghai-Tibet Plateau from 2017 to 2019. The results show that the seasonal deformation amplitude (SDA) in the study area mainly ranges from 0 to 60 mm, with an average value of 19 mm. The date of maximum frost heave (MFH) occurred between November 27th and March 21st of the following year, averaged in date of the year (DOY) 37. The maximum thaw settlement (MTS) occurred between July 25th and September 21st, averaged in DOY 225. The thawing duration is the thawing process lasting about 193 days. The spatial distribution differences in SDA, the date of MFH, and the date of MTS are relatively significant, but there is no apparent spatial difference in thawing duration. Although the SDA in the study area is mainly affected by the thermal state of permafrost, it still has the most apparent relationship with vegetation cover, the soil water content in AL, and active layer thickness. SDA has an apparent negative and positive correlation with the date of MFH and the date of MTS. In addition, due to the influence of soil texture and seasonal rivers, the seasonal deformation characteristics of the alluvial-diluvial area are different from those of the surrounding areas. This study provides a method for analyzing the F-T cycle of the AL using multi-temporal InSAR technology. [ABSTRACT FROM AUTHOR]

Thaw settlement caused by permafrost degradation has great impacts on engineering infrastructure, hydrological cycles and ecosystems in recent decades under climate warming. We combined the moving‐grid method (Lagrangian method) with the heat conduction equation to develop a new moving‐grid permafrost model. Our model takes into account not only the cryostratigraphy of permafrost, but also the thaw settlement. We used the model to simulate the thaw settlement and the permafrost changes at the three sites along the Qinghai‐Tibet Engineering Corridor from 1966 to 2018. The monitoring of the ground temperature and the geodetic leveling in situ were used for model validation. The results show that our model can accurately reproduce the observed interannual thaw settlement and ground temperature fields. The risk of thawing settlement in ice‐rich permafrost regions in the zero‐temperature‐gradient stage is high. Plain Language Summary: Under climate warming, the thawing of permafrost in Arctic and alpine mountain has induced ground surface settlement (thaw settlement). Thaw settlement may lead to geologic hazards damaging engineering foundation and changing local hydrological cycles and ecosystems. It is essential to accurately assess permafrost changes and thaw settlement by models. Few current permafrost simulations, however, take thaw settlement into account. We developed a new permafrost model based on the moving‐grid method. Our model can quantitatively assess not only permafrost changes but also associated thaw settlement. We used the new model to simulate the permafrost changes and the thaw settlement at three sites along the Qinghai‐Tibet Engineering Corridor (Qinghai‐Tibet Engineering Corridor) over a span of 50 recent years. The monitoring of the ground surface settlement and the ground temperatures in nearly a decade from the three sites were used to validate the simulated results. The simulated results were well consistent with the observations, which indicated that our model could capture thaw settlement processes and permafrost changes in a warming climate. The simulation results show that those permafrost regions with slowly rising ground temperature but quickly ground ice thawing may have a great risk of thawing settlement. Key Points: We develop a new moving‐grid permafrost model taking thaw settlement into account based on the Lagrangian moving‐grid methodThaw settlement and permafrost changes at the three sites along the Qinghai‐Tibetan Engineering Corridor from 1966 to 2018 are modeledHigh risk of thawing settlement in ice‐rich permafrost regions occurs in the zero‐temperature‐gradient stage [ABSTRACT FROM AUTHOR]

Permafrost distribution is of great significance for the study of climate, ecology, hydrology, and infrastructure construction in high-cold mountain regions with complex topography. Therefore, updated high-resolution permafrost distribution mapping is necessary and highly demanded in related fields. This case study conducted in a small catchment in the northeast of the Qinghai Tibet Plateau proposes a new method of using ground-penetrating radar (GPR) to detect the stratigraphic structure, interpret the characteristics of frozen ground, and extract the boundaries of permafrost patches in mountain areas. Thus, an empirical–statistical model of mountain frozen ground zonation, along with aspect (ASP) adjustment, is established based on the results of the GPR data interpretation. The spatial mapping of the frozen ground based on this model is compared with a field survey dataset and two existing permafrost distribution maps, and their consistencies are all higher than 80. In addition, the new map provides more details on the distribution of frozen ground. In this case, the influence of ASP on the distribution of permafrost in mountain areas is revealed: the adjustment of ASP on the lower limit of continuous and discontinuous permafrost is 180–200 m, the difference in the annual mean ground temperature between sunny and shady slopes is up to 1.4–1.6 °C, and the altitude-related temperature variation and uneven distribution of solar radiation in different ASPs comprehensively affect the zonation of mountain frozen ground. This work supplements the traditional theory of mountain permafrost zonation, the results of which are of value to relevant scientific studies and instructive to engineering construction in this region. [ABSTRACT FROM AUTHOR]

Relict permafrost presents an ideal opportunity to understand the impacts of climatic warming on the ground thermal regime since it is characterized by a mean annual ground temperature close to 0 ∘ C and relatively thin permafrost. The long-term and continuous observations of permafrost thermal state and climate background are of great importance to reveal the links between the energy balance on hourly to annual timescales, to evaluate the variations in permafrost thermal state over multiannual periods and to validate the remote sensing dataset. We present 11 years of meteorological and soil data from the Mahan Mountain relict permafrost site of northeastern Qinghai–Tibet Plateau. The meteorological data comprise air and land surface temperature, relative humidity, wind speed and direction, shortwave and longwave downwards and upwards radiation, water vapor pressure, and precipitation on a half-hour timescale. The active layer data include daily soil temperature and soil volumetric water content at five different depths. The permafrost data consist of the ground temperature at 20 different depths up to 28.4 m. The high-quality and long-term datasets are expected to serve as accurate forcing data in land surface models and evaluate remote-sensing products for a broader geoscientific community. The datasets are available from the National Tibetan Plateau/Third Pole Environment Data Center (10.11888/Cryos.tpdc.271838, Wu and Xie, 2021). [ABSTRACT FROM AUTHOR]

The permafrost degradation can cause long‐term ground surface subsidence, and the surface undergoes frost heave and thaw settlement due to the ice‐water phase change in the active layer. The multi‐year surveys by leveling observations and Interferometric Synthetic Aperture Radar monitoring (InSAR) are helpful to understand the characteristics of seasonal deformation and to model the permafrost terrain surface deformation. In this paper, we studied the characteristics of seasonal deformation over permafrost terrain in Xidatan, obtained by leveling measurements from 2010 to 2018, Sentinel‐1 data from 2014 to 2020, and hydrothermal‐data‐based simulation. The results consistently showed a four‐stage pattern of seasonal deformation characteristics: Summer thaw subsiding, warm‐season stable‐standing, winter freeze heaving and stable‐standing. The leveling measurements proved that spatial heterogeneity also exists on a small spatial scale (400 m2). The deformation amplitude obtained by leveling data is the largest, and the InSAR data is the smallest. Plain Language Summary: The active layer plays a key role in land surface processes in permafrost areas. Due to the volume change associated with the ice‐water phase transition, this causes periodic deformation of the ground surface. Surface deformation in permafrost areas has a great negative impact on cold‐region infrastructures, and it is also an indicator of permafrost changes in a warming climate. Since 2010, we have been conducting a large number of observations along the Qinghai‐Tibet Highway. The meteorological observation field provides data for simulation and the analysis of deformation. And Interferometric Synthetic Aperture Radar (InSAR) has significant advantages in providing high time‐resolved deformation results. Here, the characteristics of permafrost surface intra‐annual deformation are firstly investigated in detail by using a multi‐data source. The applicability of InSAR and simulation results in the permafrost region was evaluated using leveling measured data, and the reasons for the difference were analyzed. Key Points: Seasonal deformation was studied in detail by leveling measurement, InSAR monitoring and hydrothermal‐data‐based simulationThe leveling observations of surface deformation in the permafrost site of Xidatan from 2010 to 2018 were first presentedA four‐stage intra‐annual deformation pattern: summer thaw subsiding, warm‐season stable‐standing, winter freeze heaving and stable‐standing [ABSTRACT FROM AUTHOR]

Relict permafrost presents an ideal opportunity to understand the impacts of climatic warming on the ground thermal regime since it is characterized by mean annual ground temperature close to 0 °C and relatively thin permafrost. The long-term and continuous observations of permafrost thermal state and climate background are of great importance to reveal the links between the energy balance on hourly to annual timescales, to evaluate the variations of permafrost thermal state over multi-annual periods and to validate the remote sensing dataset. Until now there are few data available in relict permafrost regions although those data are important to understand the impacts of climate changes on permafrost especially in the boundary regions between permafrost and seasonally frozen ground regions. In this study, we present 11 years of meteorological and soil data in a relict permafrost site of the Mahan Mountain on the northeast of the Qinghai-Tibet Plateau. The meteorological data are comprised of air and ground surface temperature, relative humidity, wind speed and direction, shortwave and longwave downward and upward radiation, water vapor pressure, and precipitation on half-an-hour timescale. The active layer data include daily soil temperature and soil moisture at five different depths. The permafrost data consist of ground temperature at twenty different depths up to 28.4 m. The high-quality and long-term datasets are expected to serve as accurate forcing data in land surface models and evaluate remote-sensing products for a broader geoscientific community. The datasets are available from the National Tibetan Plateau/Third Pole Environment Data Center (https://doi.org/10.11888/Cryos.tpdc.271838, Wu and Xie, 2021). [ABSTRACT FROM AUTHOR]

Combretastatin A‐4 (CA4), a tubulin inhibitor, binds to the colchicine site of tubulin, inhibits tubulin polymerization, and leads to the apoptosis of tumor cells. However, the poor hydrophilicity and blood–brain barrier (BBB) penetration ability of CA4 hampers its application in the treatment of glioma. In this study, a novel combretastatin A‐4 derivative (CA4D) was designed and developed, which was further conjugated with glucose via disulfide‐bond‐bridged (CA4D‐SS‐Glu) to enhance the BBB penetration capacity. The obtained CA4D‐SS‐Glu conjugate displayed a suitable water partition coefficient and the superior ability across BBB in vitro and in vivo. In addition, the CA4D‐SS‐Glu exhibited rapid redox‐responsive drug release in the presence of glutathione, enhanced in vitro cytotoxicity, and cell apoptosis. Our data further confirmed that CA4D‐SS‐Glu inhibited proliferation, and restrained migration via affecting microtubule stabilization. Additionally, the conjugate also showed the highest antiproliferative and antitumor action on glioma in vivo as compared to CA4D and CA4. Taken together, the novel CA4D‐SS‐Glu conjugate possess improved physicochemical property and BBB penetration ability, reduction triggered release of CA4D, and efficient antiproliferative activity. These results provided a novel and effective entry to the treatment of glioma. [ABSTRACT FROM AUTHOR]

Permafrost has great influences on the climatic, hydrological, and ecological systems on the Qinghai–Tibet Plateau (QTP). The changing permafrost and its impact have been attracting great attention worldwide like never before. More observational and modeling approaches are needed to promote an understanding of permafrost thermal state and climatic conditions on the QTP. However, limited data on the permafrost thermal state and climate background have been sporadically reported in different pieces of literature due to the difficulties of accessing and working in this region where the weather is severe, environmental conditions are harsh, and the topographic and morphological features are complex. From the 1990s, we began to establish a permafrost monitoring network on the QTP. Meteorological variables were measured by automatic meteorological systems. The soil temperature and moisture data were collected from an integrated observation system in the active layer. Deep ground temperature (GT) was observed from boreholes. In this study, a comprehensive dataset consisting of long-term meteorological, GT, soil moisture, and soil temperature data was compiled after quality control from an integrated, distributed, and multiscale observation network in the permafrost regions of QTP. The dataset is helpful for scientists with multiple study fields (i.e., climate, cryospheric, ecology and hydrology, meteorology science), which will significantly promote the verification, development, and improvement of hydrological models, land surface process models, and climate models on the QTP. The datasets are available from the National Tibetan Plateau/Third Pole Environment Data Center (https://data.tpdc.ac.cn/en/disallow/789e838e-16ac-4539-bb7e-906217305a1d/ , last access: 24 August 2021, 10.11888/Geocry.tpdc.271107, Lin et al., 2021). [ABSTRACT FROM AUTHOR]

Permafrost that exists near the boundary of the permafrost zone is generally more sensitive to climate change. By analyzing ground temperatures observed from two 30‐m‐deep boreholes, a case study was conducted to present some characteristics of recent permafrost warming in the Xidatan area, near the northern limit of the permafrost zone on the Qinghai–Tibetan Plateau. The rate of permafrost degradation from top to bottom in the area was far less than that from bottom to top. Local conditions produced spatial differences in permafrost characteristics, and thus the site covered by alpine meadow had a thinner active layer and lower rate of change than the site with desert steppe. With permafrost warming, the depths of zero annual amplitude at the two sites showed significant decreasing trends, suggesting that the warming could change the proportion of unfrozen water and ice in permafrost, and then lead to a decrease in the mean thermal diffusivity of formation. Mean annual permafrost temperatures at depth of zero annual amplitude of the two boreholes were respectively −0.4°C and −0.7°C, indicating that high‐temperature permafrost is widely distributed in the study area. The lower temperature permafrost had a higher warming rate and a higher upward shift rate of the permafrost base. The pattern of permafrost degradation near the limit of permafrost was characterized by nonuniform speed and staged development. [ABSTRACT FROM AUTHOR]

The comprehensive understanding of the occurred changes of permafrost, including the changes of mean annual ground temperature (MAGT) and active layer thickness (ALT), on the Qinghai‐Tibet Plateau (QTP) is critical to project permafrost changes due to climate change. Here, we use statistical and machine learning (ML) modeling approaches to simulate the present and future changes of MAGT and ALT in the permafrost regions of the QTP. The results show that the combination of statistical and ML method is reliable to simulate the MAGT and ALT, with the root‐mean‐square error of 0.53°C and 0.69 m for the MAGT and ALT, respectively. The results show that the present (2000–2015) permafrost area on the QTP is 1.04 × 106 km2 (0.80–1.28 × 106 km2), and the average MAGT and ALT are −1.35 ± 0.42°C and 2.3 ± 0.60 m, respectively. According to the classification system of permafrost stability, 37.3% of the QTP permafrost is suffering from the risk of disappearance. In the future (2061–2080), the near‐surface permafrost area will shrink significantly under different Representative Concentration Pathway scenarios (RCPs). It is predicted that the permafrost area will be reduced to 42% of the present area under RCP8.5. Overall, the future changes of MAGT and ALT are pronounced and region‐specific. As a result, the combined statistical method with ML requires less parameters and input variables for simulation permafrost thermal regimes and could present an efficient way to figure out the response of permafrost to climatic changes on the QTP. Key Points: The combined statistical method with machine learning is efficient to obtain the thermal regime of permafrost on the Qinghai‐Tibet Plateau (QTP)The present permafrost area on the QTP is ∼1.04 × 106 km2, and the average mean annual ground temperature and active layer thickness are −1.35 ± 0.42°C and 2.3 ± 0.60 m, respectivelyThe future changes of permafrost are projected to be pronounced due to climate change, but region‐specific [ABSTRACT FROM AUTHOR]

Warming permafrost on a global scale is projected to have significant impacts on engineering, hydrology and environmental quality. Greater warming trends are predicted on the Qinghai–Tibetan Plateau (QTP), but most models for mountain permafrost have not considered the effects of water phase change and the state of deep permafrost due to a lack of detailed information. To better understand historical and future permafrost change based on in situ monitoring and field investigations, a numerical heat conduction permafrost model was introduced which differentiated the frozen and thawed state of soil, and considered unfrozen water content in frozen soil, distribution of ground ice and geothermal heat flow. Simulations were conducted at two sites with validation by long‐term monitoring of ground temperature data. After forcing with reconstructed historical ground surface temperature series starting from 1966, the model predicted permafrost changes until 2100 under different RCP scenarios. The results indicate a slow thermal response of permafrost to climate warming at the two investigated sites. Even under the most radical warming scenario (RCP8.5), deepening of the permafrost table is not obvious before 2040. At both sites, the model indicates that shallow permafrost may disappear but deep permafrost may persist by 2100. Moreover, the simulation shows that the degradation modes may differ between zones of discontinuous and continuous permafrost. The main degradation mode of the site in the discontinuous zone appears to be upward thawing from the permafrost base, while that of the site in the continuous zone is downward thawing at the permafrost table with little change at the permafrost base. [ABSTRACT FROM AUTHOR]

The long-term and large-scale soil moisture (SM) record is important for understanding land atmosphere interactions and their impacts on the weather, climate, and regional ecosystem. SM products are one of the parameters used in some Earth system models, but these records require evaluation before use. The water resources on the Qinghai-Tibet Plateau (QTP) are important to the water security of billions of people in Asia. Therefore, it is necessary to know the SM conditions on the QTP. In this study, the evaluation metrics of multilayer (0-10, 10-40, and 40-100 cm) SM in different reanalysis datasets of the European Centre for Medium-Range Weather Forecasts interim reanalysis (ERA-Interim [ERA]), National Centers for Environmental Prediction Climate Forecast System and the Climate Forecast System version 2 (CFSv2), and China Meteorological Administration Land Data Assimilation System (CLDAS) are compared with in situ observations at 5 observation sites, which represent alpine meadow, alpine swamp meadow, alpine grassy meadow, alpine desert steppe, and alpine steppe environments during the thawing season from January 1, 2011, to December 31, 2013, on the QTP. The ERA SM remains constant at approximately 0.2 m3⋅m−3 at all observation sites during the entire thawing season. The CLDAS and CFSv2 SM products show similar patterns with those of the in situ SM observations during the thawing season. The CLDAS SM product performs better than the CFSv2 and ERA for all vegetation types except the alpine swamp meadow. The results indicate that the soil texture and land cover types play a more important role than the precipitation to increase the biases of the CLDAS SM product on the QTP. [ABSTRACT FROM AUTHOR]

The dynamics of permafrost (including the permafrost thermal state and active layer thicknesses (ALT)) across the Qinghai-Tibetan Plateau (QTP) have not been well understood on a large scale. Here we simulate the ALT and permafrost thermal state using the Geophysical Institute Permafrost Lab version 2 (GIPL2) model across the QTP. Based on the single-point simulations, the model is upscaled to the entire QTP. The upscaled model is validated with five investigated regions (IRs), including Wenquan (WQIR), Gaize (GZIR), Aerjin (AEJIR), Xikunlun (XKLIR), and Qinghai-Tibetan Highway (G109IR). The results show that the modified GIPL2 model improves the accuracy of the permafrost thermal state simulations. Due to our simulated results on the QTP, the average ALT is of 2.30 m (2.21-2.40 m). The ALT decreases with an increase in the altitude and decreases from the southeast to the northwest. The ALT is thin in the central QTP, but it is thick in the high-elevation mountain areas and some areas surrounding glaciers and lakes. The largest ALT is found in the border areas between permafrost and seasonally frozen ground regions. The simulated results of the MAGT (the mean annual ground temperature) indicate that most of the permafrost is substable, which is sensitive to climate warming. The simulated results would be of great significance on assessing the impacts of permafrost dynamics on local hydrology, ecology, and engineering construction. [ABSTRACT FROM AUTHOR]

The characteristics of long-term variation for extreme precipitation events were analyzed at the Tanggula site in the continuous permafrost regions of the Qinghai-Tibetan Plateau (QTP). In addition, the impacts of extreme precipitation events in summer on soil thermal-moisture dynamics were also investigated. The results showed that local extreme precipitation indices fluctuated significantly and that the trend magnitudes of local very wet days (R95p), annual total wet-day precipitation (PRCPTOT), number of heavy precipitation days (R10mm), maximum length of dry spell (CDD), and simple daily intensity index (SDII) were larger than those of the western QTP, other regions of China, and even the global average. The freeze-thaw cycling in the local active layer occurred from October to the next September during 2006 to 2014. The influence of extreme precipitation event in summer on local soil hydrothermal conditions could reach soil depths up to 105 cm or so, and these were more pronounced than with light or moderate precipitation events. Soil temperature reacted more promptly to local extreme precipitation events than did soil moisture. The rate at which local soil temperature fell after an extreme precipitation event was greater than the rate of increasing temperature on nonprecipitation days. Moreover, the amount of precipitation received during extreme precipitation events had a greater effect on local soil moisture and temperature than duration time for these events. Consecutive extreme precipitation events with a longer duration time did not necessarily to have a greater effect than a single precipitation event with a shorter duration. Finally, the thawing process of active layer and local water migration modes could also affect the response of soil hydrothermal conditions to an extreme precipitation event to a large extent. [ABSTRACT FROM AUTHOR]

ABSTRACT Mahan Mountain is the only region in the Loess Plateau (China) where permafrost persists. The permafrost is typical warm permafrost and remains in a very fragile and sensitive state. Remnants of permafrost (approximately 0.134 km2 in area) remain in a low-lying swamp where the top 70 cm of soil contains abundant organic material (peat). The lowest temperature of the permafrost was -0.2°C between depths of 10 and 16 m, with temperature increasing upwards and downwards along a gradient of ± 0.01°C/m, and the permafrost thickness exceeded 30 m in this region. The distribution and thermal state of permafrost on Mahan Mountain closely relate to the surface conditions and soil type. In this study, the important protective effects of the peat layer and ground ice are illustrated using a one-dimensional finite difference model of heat flow. The simulation results indicate that active-layer thickness of permafrost on Mahan Mountain would increase by approximately 83 per cent under current climate conditions without the protection of the peat layer and ground ice. Based on the temperature projections of general circulation models, this study projects that permafrost will likely remain on Mahan Mountain for the next 40 to 50 years. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this study, the ground surface temperature (GST) records from 16 meteorological stations, which are located in or adjacent to permafrost regions on the central Qinghai-Tibet Plateau (QTP), are analysed using Mann-Kendal test and Sen's slope estimate methods. We revealed that the GSTs have shown statistically significant warming. On average, mean annual ground surface temperature has increased at a rate of 0.60 °C decade−1 over the period of 1980-2007, which is more pronounced than the increase of mean annual air temperature on the plateau. The winter ground surface warming is especially prominent, which is similar to the seasonal trends in changes of air temperature. As important parameters to assess the changes of ground thermal regime in cold regions, surface freezing and thawing indices were also studied. The nonparametric statistic test and estimate indicate that surface freezing and thawing indices both show significant variations (−111.2 and 125.0 °C d decade−1, respectively) on the central QTP. The intensive ground surface warming is responsible for the concurrent increase in permafrost temperatures at the long-term observation sites on the plateau. The close correlations between ground surface and permafrost temperatures indicate that the dramatic ground surface warming could have significant influence on the change of permafrost thermal regime in the study region. Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

• Lakes in the endorheic basin exhibited a rapid expansion since 2000. • The significant lake expansion was observed in the Hoh Xil region. • Lake expansion was closely related to precipitation and permafrost degradation. • Meltwater from permafrost thawing contributes to 21% of lake volume change. • Glacier retreat contributed to expansion of several large lakes. The QTP (Qinghai-Tibet Plateau) holds the greatest concentration of high-elevation inland lakes in the world, and most of these lakes are located in the QTP endorheic basin. Accelerated lake expansion in the endorheic basin since 2000 has been confirmed by many studies, but there is disagreement as to which components of the water balance explain most of the lake expansion. In this paper, based on Landsat images, meteorological data, glacier data and permafrost monitoring data, we analyzed the spatial–temporal changes in lake area and further explored the driving factors behind rapid lake expansion in different zones in the endorheic basin. The results suggested that the spatial pattern of trends in lake area in the endorheic basin from 2000 to 2017 showed a southwest-northeast transition from contracting to slightly expanding to rapidly expanding. More importantly, the dramatic lake expansion observed in most regions was statistically significant (0.01 ~ 26.29 km2/yr). Although retreating glaciers may have contributed to lake growth, this can not fully explain the recent lake expansion. We find that increasing precipitation was the primary driver behind lake expansion, and that permafrost degradation accelerated lake expansion. Lakes on the northern slope of the Gangdise Mountains, fed by the most rapidly retreating glaciers, were relatively stable or even contracted. In contrast, most of the non-glacier-fed lakes in the Hoh Xil region and the central endorheic basin nevertheless experienced significant expansion and slight expansion, respectively, which were mainly attributed to the greatest increase in AP (annual precipitation). Remarkable lake expansion was found in the continuous permafrost zone. The increasing ALT (active layer thickness) and soil temperature of permafrost resulted in an increase in meltwater from ground ice, the partial release of soil moisture and an amount of unfrozen water content, which has contributed to supply lakes and accelerated lake expansion. [ABSTRACT FROM AUTHOR]

Lakes on the Qinghai–Tibetan Plateau (QTP) have experienced significant changes, especially the prevailing lake expansion since 2000 in the endorheic basin. The influence of permafrost thawing on lake expansion is significant but rarely considered in previous studies. In this study, based on Landsat images and permafrost field data, the spatial-temporal area changes of lakes of more than 5 km2 in the endorheic basin on the QTP during 2000–2017 is examined and the impact of permafrost degradation on lake expansion is discussed. The main results are that permafrost characteristics and its degradation trend have close relationships with lake changes. Lake expansion in the endorheic basin showed a southwest–northeast transition from shrinking to stable to rapidly expanding, which corresponded well with the permafrost distribution from island-discontinuous to seasonally frozen ground to continuous permafrost. A dramatic lake expansion in continuous permafrost showed significant spatial differences; lakes expanded significantly in northern and eastern continuous permafrost with a higher ground ice content but slightly in southern continuous permafrost with a lower ground ice content. This spatial pattern was mainly attributed to the melting of ground ice in shallow permafrost associated with accelerating permafrost degradation. Whereas, some lakes in the southern zones of island-discontinuous permafrost were shrinking, which was mainly because the extended taliks arising from the intensified permafrost degradation have facilitated surface water and suprapermafrost groundwater discharge to subpermafrost groundwater and thereby drained the lakes. Based on observation and simulated data, the melting of ground ice at shallow depths below the permafrost table accounted for 21.2% of the increase in lake volume from 2000 to 2016. [ABSTRACT FROM AUTHOR]

The ground surface soil heat flux (G0) is very important to simulate the changes of frozen ground and the active layer thickness; in addition, the freeze-thaw cycle will also affect G0 on the Tibetan Plateau (TP). As G0 could not be measured directly and soil heat flux is difficult to be observed on the TP in situ due to its high altitude and cold environment, most of previous studies have directly applied existing remote sensing-based models to estimate G0 without assessing whether the selected model is the best one of those models for those study regions. We use in-situ observation data collected at 12 sites combined with Moderate Resolution Imaging Spectroradiometer (MODIS) data (MOD13Q1, MODLT1D, MOD09CMG, and MCD15A2H) and the China meteorological forcing dataset (CMFD-SRad and CMFD-LRad) to validate the main models during the freeze-thaw process. The results show that during the three stages (complete freezing (CF), daily freeze-thaw cycle (DFT), and complete thawing (CT)) of the freeze-thaw cycle, the root mean square error (RMSE) between the models' G0 simulated value and the corresponding G0 "measured value" is the largest in the CT phase and smallest in the CF phase. The simulated results of the second group schemes (SEBAL, Ma, SEBALadj, and Maadj) were slightly underestimated, more stable, and closer to the measured values than the first group schemes (Choudhury, Clawson, SEBS, Choudhuryadj, Clawsonadj, and SEBSadj). The Maadj scheme is the one with the smallest RMSE among all the schemes and could be directly applied across the entire TP. Then, four possible reasons leading to the errors of the main schemes were analyzed. The soil moisture affecting the ratio G0/Rn and the phase shift between G0 and net radiation Rn are not considered in the schemes directly; the scheme cannot completely and correctly capture the direction of G0; and the input data of the schemes to estimate the regional G0 maybe bring some errors into the simulated results. The results are expected to provide a basis for selecting remote sensing-based models to simulate G0 in frozen ground dynamics and to calculate evapotranspiration on the TP during the freeze-thaw process. The scheme Maadj suitable for the TP was also offered in the study. We proposed several improvement directions of remote sensing-based models in order to enhance understanding of the energy exchange between the ground surface and the atmosphere. [ABSTRACT FROM AUTHOR]

Landslides are one of the major geohazards in the Qinghai-Tibet Plateau, and have recently increased in both frequency and size. SAR interferometry (InSAR) has been widely applied in landslide research, but studies on monitoring small-scale landslides are rare. In this study, we investigated the performance of Small Baseline Subsets method (SBAS) in monitoring small-scale landslide and further developed a new deformation model to obtain the absolute deformation time series. The results showed that SBAS could well capture the small-scale landslide characteristics including spatiotemporal abnormal displacement and progressive failure processes. The newly developed absolute deformation model further detected the process of landslide details, such as instances of noticeable creeps induced by rainfall and snowmelt. Finally, a conceptual model of the kinematics-based failure mechanism for small-scale landslide was proposed. This study extended the monitoring capability of InSAR and improved our knowledge on the deformation in the frozen ground regions. [ABSTRACT FROM AUTHOR]

The ground surface soil heat flux (G0) quantifies the energy transfer between the atmosphere and the ground through the land surface. However; it is difficult to obtain the spatial distribution of G0 in permafrost regions because of the limitation of in situ observation and complication of ground surface conditions. This study aims at developing an improved G0 parameterization scheme applicable to permafrost regions of the Qinghai-Tibet Plateau under clear-sky conditions. We validated several existing remote sensing-based models to estimate G0 by analyzing in situ measurement data. Based on the validation of previous models on G0; we added the solar time angle to the G0 parameterization scheme; which considered the phase difference problem. The maximum values of RMSE and MAE between "measured G0" and simulated G0 using the improved parameterization scheme and in situ data were calculated to be 6.102 W/m2 and 5.382 W/m2; respectively. When the error of the remotely sensed land surface temperature is less than 1 K and the surface albedo measured is less than 0.02; the accuracy of estimates based on remote sensing data for G0 will be less than 5%. MODIS data (surface reflectance; land surface temperature; and emissivity) were used to calculate G0 in a 10 x 10 km region around Tanggula site; which is located in the continuous permafrost region with long-term records of meteorological and permafrost parameters. The results obtained by the improved scheme and MODIS data were consistent with the observation. This study enhances our understanding of the impacts of climate change on the ground thermal regime of permafrost and the land surface processes between atmosphere and ground surface in cold regions. [ABSTRACT FROM AUTHOR]

• A novel bone-targeted glutamic hexapeptide-folic acid (Glu 6 -FA) derivative was designed and synthesized as liposome ligand. • The preliminary evaluation in vivo demonstrated that ligand Glu 6 -FA-coated liposome had an improved targeting ability. • Glu 6 -FAcould act as a vector to enhance the delivery of drugs bone metastasis. Bone is the most common organ affected by metastatic breast cancer. Targeting delivery of drugs to bone may not only enhance the treatment efficacy, but also reduce the quantity of drug administered. In order to increase the distribution of paclitaxel (PTX) in bone, herein, a novel bone metastasis-targeted glutamic hexapeptide-folic acid (Glu 6 -FA) derivative was designed and synthesized as liposome ligand to deliver PTX to bone metastasis effectively. The liposomes were prepared by thin film hydration method and its particle size, zeta potential, encapsulation efficiency, release profile, stability, hemolysis were also characterized. What's more, the anti-tumor effects of PTX-Glu 6 -FA-Lip were confirmed by the detection of cell cycle, migration, and further measurement of microtubule stabilization. In addition, the PTX-Glu 6 -FA-Lip showed superior targeting ability in vitro and in vivo evaluation as compared to naked PTX, non-coated, singly-modified and co-modified by physical blending liposomes. All the results suggested that Glu 6 -FA-modified liposome showed excellent targeting activity to metastatic bone cancer. These findings suggested that Glu 6 -FA-Lip was a promising bone metastasis-targeting carrier for the delivery of PTX. This study may therefore be conducive to the field of bone-targeting drugs delivery. [ABSTRACT FROM AUTHOR]

• A series of novel dendritic aspartic acid derivatives were designed and synthesized as liposome ligands. • The preliminary evaluation in vivo demonstrated that ligand Asp 8 -coated liposome had an improved bone-targeting ability. • The quantity of Asp residues will increase the affinity for bone. Bone diseases are notoriously difficult diseases to treat due to the comparatively low blood flows in bone tissue. Therefore, targeting delivery of drugs to bone may not only enhance the treatment efficacy, but also reduce the quantity of drug administered. In order to increase the distribution of paclitaxel (PTX) in bone, in this study, a series of novel dendritic aspartic acid derivatives were designed and synthesized as liposome ligands to deliver PTX to bone effectively. The liposomes were prepared by thin film hydration method and its particle size, zeta potential, encapsulation efficiency, release profile, stability, hemolysis were also characterized. All the aspartic acid-coated liposomes showed more than 60% binding rates to hydroxyapatite (HAP), especially the PTX-Asp 8 -Lip exhibited dramatic binding rates (> 97%) after 24 h. Moreover, the bone-targeting study in vivo indicated that all liposomes could improve the accumulation of PTX in bone, among which, the PTX-Asp 8 -Lip showed the best affinity due to the increase of aspartic acid residues exposed on the liposome surface. These results provided a novel and effective entry to the development of bone-targeting drugs. [ABSTRACT FROM AUTHOR]