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Strong winds have evident impacts on the environment and the society. It can affect the dispersion of air pollutants, land erosion, and damage buildings, representing a severe hazard to people and properties. However, the changes and variabilities of extreme winds are still largely unknown, especially in global high-elevation regions, e.g., the Tibetan Plateau. This study analyses for the first-time changes in extreme wind speed over the Tibetan Plateau using homogenized near-surface daily maximum wind speed observations for 1973–2020. Results show that the daily maximum wind speed has significantly decreased in most stations during 1973–2020, with the largest decline in magnitude observed in spring. The frequency of daily maximum wind speed exceeding the 95% percentile shows a similar slowdown pattern. The detected decline is linked to large-scale atmospheric circulation, particularly to changes in the patterns of westerly and monsoon, which explain 35%~57% of daily maximum wind speed anomaly variations. Furthermore, this study reveals that changes in (a) geostrophic wind, (b) the instability of atmospheric thermal stratification, (c) vertical wind shear, and (d) Tibetan Plateau low vortex also contributes to the observed decreasing trends of daily maximum wind speed. [ABSTRACT FROM AUTHOR]

The Jishishan Ms 6.2 earthquake occurred at 23:59 on December 18, 2023 in Gansu Province, China. We conducted a field survey to assess the hazards and damages caused by the earthquake and its associated geo-activities. Subsequently, we organized a seminar to discuss the possible causes of the destruction of a prehistoric site—Lajia Settlement—dated back to four thousand years B.P. and located only several kilometers away from the epicenter of the Jishishan earthquake. The Jishishan earthquake was unique for its hazard and disaster process, which featured ground shaking and a series of complex geological and geomorphological activities: sediment and soil spray piles, liquefaction, collapse, landslide, and mudflow along water channels. We define this phenomenon as the Jishishan earthquake ripple hazard (JERH). The most recent evidence from the JERH suggests that a prehistoric earthquake similar to the JERH, instead of riverine floods or earthquake-induced landslide dam outburst flood, as previously hypothesized, destroyed the Lajia Settlement. [ABSTRACT FROM AUTHOR]

The extreme precipitation in China is greatly influenced by the East Asian summer monsoon, which can be divided into two components: the southeast monsoon (SEM) and the southwest monsoon (SWM). The Hanjiang River basin (HJB), a representative monsoon‐influenced basin in China, is alternately influenced by the southwest monsoon and southeast monsoon throughout the year. However, the specific relationship between rainstorms and monsoons, and the relative contribution of different monsoons, remains unclear in the HJB. Using multiple datasets, this study analysed the variability of various rainstorm types in the HJB during 1985–2020, investigated their relationships with different monsoon indicators and assessed the contribution of monsoons on the rainstorm variance. The results reveal a nonsignificant increasing trend in rainstorms within the basin, the severe convective rainstorm days accounted for a high proportion of the total rainstorm days, and the spatiotemporal characteristics of different rainstorm types are different. The rainstorm indicators are significantly correlated with the monsoon within the HJB and are positively correlated with the SWM, particularly its intensity. The SEM exhibits a weak correlation with rainstorms and has limited explanation for the variance in rainstorms. The intensity of SWM within the HJB shows a significant positive correlation with all rainstorm indicators. It is also detected as the most important indicator for explaining the interannual variation in rainstorms, explaining 41.97% and 39.45% of the variance in daily rainstorm frequency and totals, which comprises more than half of the total explanatory portion. The explanation of circulation factors for the variance in daily rainstorms is higher than that for severe convective rainstorms. In addition to monsoons, the Pacific Decadal Oscillation and the Southern Oscillation Index also have a great contribution to the rainstorm variability in the HJB. [ABSTRACT FROM AUTHOR]

A decline in atmospheric oxygen concentration is projected in the 21st century given the background of global warming. The Qinghai-Tibetan Plateau is located at a high altitude, and thus, it faces a hypoxia challenge; however, knowledge of the factors contributing to its atmospheric oxygen concentration is still lacking. Here, we conducted joint observations of ecosystem oxygen production and carbon sinks and near-surface atmospheric oxygen concentrations on the Qinghai-Tibetan Plateau and meteorological elements at Beijing Fangshan Station. Using seasonal differences and statistical methods, we calculated the relative contribution rates of vegetation to changes in atmospheric oxygen concentration. Our results indicate that solar radiation, atmospheric humidity, and ecosystem oxygen consumption and production have a significant impact on the atmospheric oxygen concentration, and the impact shows temporal and spatial differences. Vegetation significantly impacts the oxygen concentration, with a contribution rate of 16.7%–24.5%, which is underestimated in existing research. Our findings provide important insights into the factors that influence atmospheric oxygen concentration and highlight the contribution of vegetation. To better understand the oxygen dynamics of the Qinghai-Tibetan Plateau, we recommend further field observations of soil respiration and vegetation photosynthesis to clarify the contributions of carbon storage, carbon sinks and other factors to the near-surface atmospheric oxygen concentration. [ABSTRACT FROM AUTHOR]

Based on historical land use for eight periods from 1980 to 2020 and the projected land use under seven Shared Socioeconomic Pathways (SSPs: SSP1-1.9, SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP4-3.4, SSP4-6.0, and SSP5-8.5) from 2021 to 2100, we conducted a study on past and future land use changes in the Qinghai-Tibet Plateau (QTP). This work aims to reveal the land use changes during the carbon peak (2021–2040) and carbon neutrality (2051–2070) periods and at the end of the 21st century (2081–2100). The results show that: (1) in the historical period (1980–2020), the land use types in the QTP were grassland (1475×103 km2, 58.2%), barren land (685×103 km2, 27.0%), forest land (243×103 km2, 9.6%), water (114×103 km2, 4.5%), cropland (18.6×103 km2, 0.7%) and urban land (0.3×103 km2, 0.01%). (2) Relative to the baseline period (1995–2014), the area of grassland is projected to decrease by 0.7% (SSP4-6.0)–5.4% (SSP2-4.5) (0.5–3.9% of the total area of the QTP), 2.8% (SSP4-6.0)–12.5% (SSP3-7.0) (2.1–9.4% of the total area of the QTP) and 6.1% (SSP4-6.0)–21.7% (SSP4-3.4) (4.6–16.4% of the total area of the QTP) in the future three periods. In contrast, the forest land area is projected to increase, by approximately 2.5% (SSP4-6.0) to 30.1% (SSP3-7.0) (0.3–4.3% of the total area of the QTP), 9.2% (SSP4-6.0) to 56.5% (SSP2-4.5) (1.3–8.0% of the total area of the QTP), and 21.2% (SSP4-6.0) to 72.8% (SSP2-4.5) (3.0–10.2% of the total area of the QTP) in the future three periods, respectively. (3) Approximately 0.4 (SSP4-6.0) to 6.9% (SSP5-8.5), 0.9 (SSP4-6.0) to 2.7% (SSP4-3.4), and 0.04 (SSP5-8.5) to 3.5% (SSP1-1.9) of land is expected to convert from grassland to forest land in the future three periods, respectively. The shift from grassland to forest land area is likely to enhance the carbon sink potential of the QTP in the future period. [ABSTRACT FROM AUTHOR]

Precise embolism control in immature brains can facilitate mechanistic studies of brain damage and repair after perinatal arterial ischemic stroke (PAIS), but it remains a technical challenge. Microhemorrhagic transformation is observed in one-third of infant patients who have suffered PAIS, but the underlying mechanism remains elusive. Building on an established approach that uses magnetic nanoparticles to induce PAIS, we develop a more advanced approach that utilizes magnetized erythrocytes to precisely manipulate de novo and in situ embolus formation and reperfusion in perinatal rodent brains. This approach grants spatiotemporal control of embolic stroke without any transarterial delivery of pre-formed emboli. Transmission electron microscopy revealed that erythrocytes rather than nanoparticles are the main material obstructing the vessels. Both approaches can induce microbleeds as an age-dependent complication; this complication can be prevented by microglia and macrophage depletion. Thus, this study provides an animal model mimicking perinatal embolic stroke and implies a potential therapeutic strategy for the treatment of perinatal stroke. SIMPLE and SIMPLeR are proposed as models for embolism, the latter reversibly manipulating magnetized red blood cells to occlude cerebral vessels. Both methods induce age-dependent micro-hemorrhage transformation, with microglia/macrophage depletion preventing hemorrhage transformation. [ABSTRACT FROM AUTHOR]

Climate change is often described as the average changes in temperature and precipitation; however, it is the change in climate extremes determines the levels of socioeconomic impacts related to climate change. It is generally believed that global warming drives increase in frequency, intensity and duration of precipitation extremes, but these changes vary regionally. Focusing on the relationships between evolution of extreme events and long‐term climate change, here we propose a novel classification scheme based on Kӧppen's system and changes in mean and variability of precipitation, divide the global climate into 20 different changing types and reveal the regional evolution of precipitation extremes. We find that precipitation extremes ascend significantly in wetting regions, especially in tropical and temperate zones, independent with changed variability. As for drying regions, the evolution of extremes is related to precipitation variability. An increase of extremes can still be detected in fluctuant‐drying areas, while a slight decrease can be seen in stabilized‐drying areas. It is surprising to find increase in both wetness and dryness extremes which implies higher intensity of meteorological hazards in densely populated areas. Based on the current and projected growth of population exposure to precipitation extremes, we identify some hotspots with high potential risk in the future. [ABSTRACT FROM AUTHOR]

Climate change is often described as the average changes in temperature and precipitation; however, it is the change in climate extremes determines the levels of socioeconomic impacts related to climate change. It is generally believed that global warming drives increase in frequency, intensity and duration of precipitation extremes, but these changes vary regionally. Focusing on the relationships between evolution of extreme events and long-term climate change, here we propose a novel classification scheme based on Köppen's system and changes in mean and variability of precipitation, divide the global climate into 20 different changing types and reveal the regional evolution of precipitation extremes. We find that precipitation extremes ascend significantly in wetting regions, especially in tropical and temperate zones, independent with changed variability. As for drying regions, the evolution of extremes is related to precipitation variability. An increase of extremes can still be detected in fluctuant-drying areas, while a slight decrease can be seen in stabilized-drying areas. It is surprising to find increase in both wetness and dryness extremes which implies higher intensity of meteorological hazards in densely populated areas. Based on the current and projected growth of population exposure to precipitation extremes, we identify some hotspots with high potential risk in the future. [ABSTRACT FROM AUTHOR]

Oxygen (O2) is the most abundant molecule in the atmosphere after nitrogen. Previous studies have documented that oxygen concentration remains nearly constant (20.946%) at all altitudes. Here we show for the first time that oxygen concentration varies significantly from earlier consensus and shows strong spatial and seasonal differences. Field observations on the Qinghai-Tibetan Plateau (QTP) indicate oxygen concentration of 19.94–20.66% (2018, n = 80), 19.98–20.78% (2019, n = 166) and 19.97–20.73% (2020, n = 176), all statistically different from earlier reports (p < 0.001) and are lower than the nearly constant. The mean oxygen concentration in summer (20.47%) is 0.31% higher than that of winter (20.16%) (n = 53) at identical locations in 2019, sampled in the Qilian Mountains, northwest QTP. We used LMG (The Lindeman, Merenda and Gold) method to estimate the relative contributions of altitude, air temperature and vegetation index (Fractional Vegetation Cover, FVC and Leaf Area Index, LAI) to oxygen concentration, which are 47%, 32% and 3% (FVC, R2 = 82%); 45%, 30% and 7% (LAI, R2 = 82%), respectively. These findings provide a new perspective for in-depth understanding on population risk in high altitude regions in the context of global climate change, to ensure the health and safety of residents and tourists in high altitude regions and promoting the stability, prosperity and sustainable development of high-altitude regions worldwide. [ABSTRACT FROM AUTHOR]

Exploring the components of evapotranspiration (ET) is essential but challenging because of the difficulties in ET partitioning. This study aims to improve the accuracy in partitioning ET under farmland and apple orchards by the hydrological model HYDRUS-1D constrained with isotopes, and further identify the effects of land use change on soil water balance (SWB). In particular, the long-term average SWB was first decoupled by combining multiple isotopes (δ2H, δ18O, and δ3H), and then used to constrain HYDRUS-1D to improve model performance. With the isotope-based partitioned SWB, some hydrological model parameters difficult to be obtained experimentally were inversely optimized. Consequently, the performance of HYDRUS-1D in ET partitioning was greatly improved. Specifically, with the isotope method as a reference, the HYDRUS-1D with optimized parameters had errors of 20%±2.1, 4%±2.0, and 6%±0.8 for evaporation (E), transpiration (T), and ratio of transpiration to evapotranspiration (T/ET), which were much smaller than those from the model with default parameter (171%±34.5, 57%±5.8, and 58%±5.8). The apple orchards increased T by decreasing other SWB components. The framework of optimizing hydrological model by isotope-based SWB decoupling is promising in improving model accuracy, and the partitioned SWB components can be used to promote our understanding of ecohydrological processes. [Display omitted] • Combination of multiple isotopes for SWB partitioning is effective. • HYDRUS-1D was constrained by isotope-based water balance decoupling. • Optimized hydrological model is promising in accurately partitioning ET. • Other SWB components decreased to satisfy the increased transpiration. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A material shows turn-on type mechanochromic luminescence (MCL). • An information carrier is developed based on this MCL material. • Binary data can be written by mechanical encoding and erased by heating. Abstract We report a turn-on type mechanochromic luminescent (MCL) material in this work. The molecular design, including the electron donor-acceptor (D-A) pairs and single-bond rotation, endows the material with both intramolecular charge transfer (ICT) and aggregation-enhanced emission (AEE) nature. It shows remarkable emission enhancement with large blue-shift upon grinding and is able to convert back to the initial state after thermal treatment, suggesting high sensitivity and fatigue resistance. An information carrier based on mechanochromic material is developed, by which the binary data can be written by mechanical encoding and erased by heating. [ABSTRACT FROM AUTHOR]

Abstract We report the synthesis and photoluminescence of a new molecular system designed based on diaminomaleonitrile derivatives. They are endowed with both aggregation-induced emission (AIE) and intramolecular charge transfer (ICT) natures. More importantly, one of them, i.e. , 2-amino-3-((E)-(4-(diethylamino) benzylidene) amino)maleonitrile (C4), exhibits unique vapochromism, namely a turn-on fluorescence in response to organic vapour. Based on spectral analysis, DFT calculation, SEM observation and crystallographic data, a mechanism for the vapochromic fluorescence was proposed: Donor-acceptor (D-A) coupling, which caused by the combined effect of π-π interaction and electrostatic force, is mainly responsible for the initial weak fluorescence of C4 ; Its fluorescence will be spontaneously restored when D-A coupling is destructed by organic vapour. Such vapochromism of C4 motivated us to develop a new optical data storage (ODS) capable of data encryption-decryption. Encrypted information in binary form can be stored on the device fabricated by C4 film, which cannot be read unless it is treated by solvent fumigaition. After this decryption process, the fluorescent signals are remarkably enhanced, showing 3∼6-fold higher than false signals, which makes the former easy to be identified by both naked eyes and instruments. This study presents a successful archetype of security data storage, which only displays data at a specific condition. Otherwise, the data are concealed to avoid illegal reading or copying. Graphical abstract Image 1 Highlights • An AIE compound shows remarkable vapochromism. • The fluorescence will be turned on by a solvent-assistant self-assembly process. • A new encryption-decryption technique is developed based on these AIE compounds. • Binary data stored on the data storage cannot be decoded unless treated by fumigation. [ABSTRACT FROM AUTHOR]

Abstract Desalinating sea ice to obtain fresh water is a new way to solve the water shortage. Centrifugal desalination (CD) is an important method for desalination of sea ice, and it is of great significance to improve desalination efficiency. Microwave heating has a significant effect on improving salt-water separation efficiency, but the effect on centrifugal desalination is still unclear. In this paper, sea ice centrifugal desalination by microwave heating (CDBMH) was designed. The four factors of the particle size of ice, initial ice temperature, relative centrifugal force and centrifugation time were selected from the key parameters of centrifugal technology and sea ice material properties, and the impact of each factor on the salinity of the melted water, the desalination rate, and the water yield rate was explored. The results showed that with the decrease of the particle size of ice, the increase of initial ice temperature, relative centrifugal force and centrifugation time, the desalination rate showed an upward trend, while the water yield rate and the salinity of the melted water gradually decreased. As a result of the CDBMH process, the desalination rate was 93.3%, and the water yield rate was 72.4%, and the salinity of the melted water was 0.4‰. Highlights • A sea ice desalination method combined with centrifugal and microwave heating technology is introduced. • Multiple experimental factors are designed. • The large particle size of sea ice also achieves acceptable salinity of yield water. • Increasing the ice temperature is beneficial to improve the desalination effect. [ABSTRACT FROM AUTHOR]

Abstract This study analyzes the variability of winter haze days and visibility in the Beijing-Tianjin-Hebei (BTH) region, in relation to the regional average wind speed changes in the lower troposphere and emissions for 1961–2014. Winter mean surface meteorological data, NCEP/NCAR atmospheric reanalysis data, and fossil fuel emission data are used. The results reveal a significant increase in the haze days of +0.8 days decade−1 (p <.01), and a subsequent decline in visibility of −1.56 km decade−1 (p <.01). Most interestingly, an accelerated increase in the number of haze days was observed for the last 11-year period (+8.3 days decade−1, p <.01) of the study period (2004–2014). Regression analysis indicates that the increase of haze occurrence and decrease in visibility are partly due to the significant (p <.01) declining trend of the mean wind speed in the lower troposphere (−0.19 m s−1 decade−1 at 10 m, (−0.23 m s−1 decade−1 at 925 hPa), and − 0.21 m s−1 decade−1 at 850 hPa), and partly due to the declining (dust storm frequency as a proxy, −0.41 days dec−1) surrounding particulate sources and increasing fossil fuel emissions (total carbon emission as a proxy, +48,206.8 thousand metric tons dec−1). Specifically, wind speed changes in the lower troposphere explain 41.3% of the interannual varation of the winter haze days and 71.2% of the visibility variance. These are extended to 51.7% and 81.6% respectively when combined with information about the natural (dust storm frequency) and anthropogenic (fossil fuel emissions) particulate sources. Therefore, the analyses show that wind speed changes in the lower troposphere, together with the varied natural and anthropogenic sources of particulates, play a key role in modulating winter haze and visibility conditions in the BTH area. Highlights • A significant increase in winter haze days and a decline in visibility in the Beijing-Tianjin-Hebei region was observed. • Weakened wind speed in the lower troposphere was adverse to the ventilation and long distance transport of haze particles. • The varied particles source from natural and human activity caused the increase of winter haze occurrence. [ABSTRACT FROM AUTHOR]

Separating out the influence of climatic trend, fluctuations and extreme events on crop yield is of paramount importance to climate change adaptation, resilience, and mitigation. Previous studies lack systematic and explicit assessment of these three fundamental aspects of climate change on crop yield. This research attempts to separate out the impacts on rice yields of climatic trend (linear trend change related to mean value), fluctuations (variability surpassing the "fluctuation threshold" which defined as one standard deviation (1 SD) of the residual between the original data series and the linear trend value for each climatic variable), and extreme events (identified by absolute criterion for each kind of extreme events related to crop yield). The main idea of the research method was to construct climate scenarios combined with crop system simulation model. Comparable climate scenarios were designed to express the impact of each climate change component and, were input to the crop system model (CERES-Rice), which calculated the related simulated yield gap to quantify the percentage impacts of climatic trend, fluctuations, and extreme events. Six Agro-Meteorological Stations (AMS) in Hunan province were selected to study the quantitatively impact of climatic trend, fluctuations and extreme events involving climatic variables (air temperature, precipitation, and sunshine duration) on early rice yield during 1981-2012. The results showed that extreme events were found to have the greatest impact on early rice yield (−2.59 to −15.89%). Followed by climatic fluctuations with a range of −2.60 to −4.46%, and then the climatic trend (4.91-2.12%). Furthermore, the influence of climatic trend on early rice yield presented "trade-offs" among various climate variables and AMS. Climatic trend and extreme events associated with air temperature showed larger effects on early rice yield than other climatic variables, particularly for high-temperature events (−2.11 to −12.99%). Finally, the methodology use to separate out the influences of the climatic trend, fluctuations, and extreme events on crop yield was proved to be feasible and robust. Designing different climate scenarios and feeding them into a crop system model is a potential way to evaluate the quantitative impact of each climate variable. [ABSTRACT FROM AUTHOR]

As a recently reported network property, consilience degree (CSD) indicates how well a network system integrates its topology and node activities together to serve a specific systemic goal. As is well known, many natural and man-made systems are complex networks where, besides network topology, node activity states also play an important role in determining system performance. For example, a collaborative project involving friends is more likely to succeed than one involving enemies, even though the topology of network organization is the same. The concept of CSD can quantitatively distinguish the difference between the involvement of friends and the involvement of enemies. This article reports a simulation study on the adaptive behaviors of nodes based on the selfish rule and the following-others rule, and the simulation results show that based on such adaptive behaviors of nodes, a network system will automatically evolve to a high level of system consilience. The simulation study also demonstrates that a high level of system consilience resulting from adaptive behaviors will contribute to increased system resistance to external disturbances. The generality of adaptive behaviors in reality implies that CSD is an inherent attribute of real-world network systems, and therefore, the concept of CSD has significant application potential in the study of adaptive behaviors in network systems. [ABSTRACT FROM AUTHOR]

Two solid emitters DMA and HBA were synthetized, showing aggregation-induced emission (AIE) phenomenon. Incorporation of electron donor-acceptor (D-A) pairs endows the solid emitters with both charge transfer (CT) state emission and distinct solvatochromic effect. The compounds undergo a rapid interaction with amines followed by the resulting weakened electron withdrawing ability to yield florescent products with either hypochromatic shift or decrease in the emission intensity. DFT calculations on HOMO and LUMO electronic cloud distribution and energy levels have demonstrated that the transition from CT state to locally excited (LE) state is mainly responsible for the spectral changes. The AIE compounds were thus developed into solid-supported amine sensor and show nice linear relationship. The detection limits of DMA- and HBA-based sensing film to ammonia gas are 2.61 Pa and 2.63 Pa, respectively. Time-dependent emission spectra upon treating with a variety of amines exhibited differential responses, in which two factors were defined accordingly, including maximum emission wavelength and quenching efficiency. Two-dimensional coordinate system was then built on the basis of the two factors, creating a fingerprint data base for the involved amines. The fingerprint map shows a clear differentiation of the tested amines, making DMA and HBA synergistic twain probes for identification of diverse amines. [ABSTRACT FROM AUTHOR]

• Trees shift water sources from shallow to deep soils over the growing season. • Water uptake proportions from soils are not correlated to soil water contents. • Root water uptake is influenced by precipitation and soil water residence time. Understanding how trees absorb water is important for the sustainable management of water resources and vegetation restoration. However, the water uptake strategy of apple trees and its link with precipitation and soil water dynamics (i.e., contents, recharge proportion and residence time) remains poorly understood. In this study, we determined the source water of apple trees, the recharge proportion and mean residence time (MRT) of soil water through collecting precipitation, soil water and xylem water samples with a high frequency. Results indicated that apple trees mainly absorbed water from shallow soil layers of 0–2 m (>64%) in the early growing season (May to July), but deep soil water below 2 m (∼60%) in the late growing season (August to October). As such, apple trees had seasonal variations in water uptake strategies by shifting water sources from shallow to deep soils. In addition, the proportions of water uptake from the same soil layer varied with tree ages. The proportions of water uptake from different soil layers were not significantly correlated to the corresponding soil water contents (p > 0.05), which may be attributed to the long residence time of soil water (14–99 days). Therefore, the water uptake strategies of apple trees were likely to be influenced by precipitation and MRT of soil water, as well as stand ages. The indicated relationship between water uptake strategies and precipitation and soil water dynamics can improve insights into the interaction between soil and vegetation. [ABSTRACT FROM AUTHOR]

ABSTRACT Station-based observed precipitation data are available in a limited way and only at low spatial resolution. High-resolution satellite rainfall products can help to monitor precipitation changes over large areas. The Tropical Rainfall Measuring Mission 3B43 ( TRMM 3B43) precipitation data with coarse spatial resolution and low data accuracy are capable of depicting the spatial variability of precipitation, but fail to estimate the accurate magnitude. These data available in Xinjiang, China, need to be evaluated, especially because Xinjiang has a complex terrain and application of such data becomes a challenging task. Based on the relation between precipitation and normalized difference vegetation index ( NDVI), a proxy for vegetation, a new statistical downscaling algorithm is proposed in this study. The calibration was based on geographical difference analysis ( GDA) and the monthly fractions derived from the un-calibrated TRMM data can be used to disaggregate high-resolution annual precipitation to high-resolution monthly precipitation. The accuracy of downscaled TRMM precipitation was evaluated based on station-based observed precipitation for a period of 1998-2010. Results indicated that: (1) optimal relations shown by R2 between TRMM precipitation and NDVI at different temporal and spatial scales were different: the largest R2 value was 0.69 for the period of 1998-2010 at a spatial resolution of 1.00° × 1.00°, was 0.70 for the dry year (2001 in this study) at a spatial resolution of 0.75° × 0.75°, and was 0.67 for the wet year (2010 in this study) at a spatial resolution of 1.25° × 1.25°; (2) the downscaled TRMM precipitation data obtained using NDVI described spatial patterns of precipitation reasonably well at a spatial resolution of 8 km × 8 km with more detailed information when compared to the raw TRMM precipitation at a spatial resolution of 0.25° × 0.25°; (3) the downscaled TRMM precipitation with GDA calibration, PDSGDA, can exclude the regions with irrigation- and/or ground water-induced vegetation coverage. Therefore, PDSGDA obtained in this study can be regarded as estimated alternative precipitation data across Xinjiang for management of water resources and agricultural irrigation activities. [ABSTRACT FROM AUTHOR]

Global warming has caused changes in the area and thickness of permafrost on the Qinghai-Tibet Plateau and prompted the transition from permafrost to seasonally frozen soil, which has affected the soil moisture, soil temperature, and distribution of plant roots. This, in turn, affects grassland vegetation productivity and aboveground/belowground biomass. In this study, we took Qinghai Province in the northeastern Qinghai-Tibet Plateau as the research area to model the spatial pattern of grassland biomass and then evaluated the potential influence of frozen soil type information on aboveground and belowground biomass. Our research shows that there are significantly more biomass observations in seasonally frozen soil regions than in permafrost regions. However, when we ignore the type of frozen soil, the model does not show more accurate simulation in seasonally frozen soil regions, mainly because the stronger correlation between permafrost biomass and environmental factors, such as precipitation, compensates for the lack of observational data. In addition, we found that the biomass estimation error can be reduced significantly by building different models for each type of frozen soil, which implies that the type of frozen soil has an important impact on grassland biomass. Therefore, in considering the effects of future climate warming, more attention should be given to the impact of changes in frozen soil type on regional vegetation productivity. In addition, our investigation contributes a benchmark dataset of above- and belowground vegetation carbon storage in different frozen soil types, which provides the research community with useful information for optimizing process-based carbon cycle models. [ABSTRACT FROM AUTHOR]

ABSTRACT Drought is a major natural hazard that can have devastating impacts on regional agriculture, water resources and the environment. To assess the variability and pattern of drought characteristics in the Huang-Huai-Hai ( HHH) Plain, the daily Standardized Precipitation Evapotranspiration Index ( SPEI) is developed based on daily meteorological data in this study. The daily SPEI data are used, including Annual Total Drought Severity ( ATDS), Annual Total Drought Duration ( ATDD) and Annual Drought Frequency ( ADF), which were calculated from 1981 to 2010 at 28 meteorological stations. We used the indices ( ATDS, ATDD and ADF), Hovmöller diagrams and the reliable no parameter statistical methods of the Mann-Kendall test to assess the variability and pattern of drought characteristics for the period from 1981 to 2010 in the HHH plain. The results suggested that severe drought occurred in the 1980s, the late 1990s and the early 2000s, severe drought events occurred in 1981, 1986, 1997 and 2002. Decreasing trends for both ATDS and ATDD were found, and the drought situation did not worsen under global warming during the past 30 years, and the drought situation is alleviating in the entire HHH plain. The northeast and southwest regions of the HHH plain have suffered from more severe drought, and the north region is prone to drought. The results of the study can provide a scientific understanding for the adoption of countermeasures of regional defence against drought and also may serve as a reference point for drought hazard vulnerability analysis. [ABSTRACT FROM AUTHOR]

Since climatic condition is the important foundation for human subsistence and development and the key factor in sustainable development of economy and society, climate change has been a global issue attracting great attentions of politicians, scientists, governments, and the public alike throughout the world. Existing climate regionalization in China aims to characterize the regional differences in climate based on years of the mean value of different climate indexes. However, with the accelerating climate change nowadays, existing climate regionalization cannot represent the regional difference of climate change, nor can it reflect the disasters and environmental risks incurred from climate changes. This paper utilizes the tendency value and fluctuation value of temperature and precipitation from 1961 to 2010 to identify the climate change quantitatively, and completes the climate change regionalization in China (1961-2010) with county administrative regionalization as the unit in combination with China's terrain feature. Level-I regionalization divides China's climate change (1961-2010) into five tendency zones based on the tendency of temperature and precipitation, which are respectively Northeast China-North China warm-dry trend zone, East China-Central China wet-warm trend zone, Southwest China-South China dry-warm trend zone, Southeast Tibet-Southwest China wet-warm trend zone, and Northwest China-Qinghai-Tibet Plateau warm-wet trend zone; level-II regionalization refers to fourteen fluctuation regions based on level-I regionalization according to the fluctuation of temperature and precipitation. [ABSTRACT FROM AUTHOR]

Abstract: Urbanization increases impervious area, generates pollution and transforms the configuration, composition and context of land covers and thus has direct or indirect impacts on aquatic systems. Detecting land use-water quality relationships is of significance for both urban sustainable development and environmental risk management. We first selected suitable landscape metrics at landscape and class levels as well as productivity as land use indicators; second, we integrated ten water quality indicators into a comprehensive pollution index (CPI) that serves as the primary water quality indicator for measuring the effects of diffusive pollution in an urban area; finally, taking water quality indicators as dependent variables and land use indicators as independent variables, we detected land use-water quality relationships using both ordinary least squares (OLS) and geographically weighted regression (GWR) models. The main findings are (1) the CPI is a good water quality indicator for detecting land use-water quality relationships and the performance of the GWR model is superior to that of the OLS model and (2) landscape metrics have potential for predicting water quality; however, improving the productivity of natural vegetation is a more tangible and reliable way to promote water resources restoration than rearranging the configuration of land use types. [Copyright &y& Elsevier]

This descriptive case study examines the linkage between rapid urbanization and alterations of river networks. It is intended to address ecological services changes in a highly urbanized catchment of Shenzhen, China. Using remote sensing and GIS, urban development and the river network between 1980 and 2005 were analyzed. Furthermore, an analysis of vegetation coverage, biological resources value, ecosystems service value, and ecological capital in the highly urbanized Guanlan River subbasin was performed to indicate the ecological consequences of urban sprawl. Results show that rapid urbanization has resulted in a clear decline of drainage density and an obvious ecological degradation in river ecosystems. Geographically, there is a shifting of urban land, and the extent of drainage density decreases from the core of towns to the outskirts. The outward expansion of the urban land and the decrease/disappearance of wetland and water bodies are found to be among the most important driving forces explaining the ecological degradation in river ecosystems in this region of China. Human activities driven by socioeconomic factors should be considered responsible for the degradation of river ecological services. It is irrational to encourage encroachment of river lands in the process of urbanization, and it is also urgent to effectively restore the natural rivers to build healthy cities. [ABSTRACT FROM AUTHOR]

By using a land cover map, normalized difference vegetation index (NDVI) data sets, monthly meteorological data and observed net primary productivity (NPP) data, we have improved the method of estimating light use efficiency (LUE) for different biomes and soil moisture coefficients in the Carnegie-Ames-Stanford Approach (CASA) ecosystem model. Based on this improved model we produced an annual NPP map (in 1999) for the East Asia region located at 10-70° N, 70-170° E (about 19.66% of the terrestrial surface of the Earth). The results show that the mean NPP for the study area in 1999 was 374.12 g carbon (C) m-2 year-1 and the total NPP was 1.096 × 1014 kg C year-1, making up 17.51-18.39% of the global NPP. Comparison between the estimated NPP obtained from this improved CASA ecosystem model and the observed NPP obtained from two NPP databases indicates that the estimated NPP is close to the observed NPP, with an average error of 5.15% for the study region. We used two different land cover maps of China to drive the improved CASA model by keeping other inputs unchanged to determine how the classification accuracy of the land cover map affects the estimated NPP, and the results indicate that an accurate land cover map is important for obtaining an accurate and reliable estimate of NPP for some regions, especially for a particular biome. [ABSTRACT FROM AUTHOR]

• Understanding groundwater recharge is important in arid region with thick vadose zone. • Piston flow recharges groundwater accounting for < 7% of mean annual precipitation. • Deep-rooted plants prevent connectivity between unsaturated and saturated zones. • Multiple tracers and methods enhance the understanding of groundwater recharge. Accurate estimation of groundwater recharge in regions with limited water and thick unsaturated zones is challenging because of the limited water flux. This study aims to employ multiple tracers and methods to investigate the mechanism of groundwater recharge in the thick loess deposits of China. We collected soil samples under different vegetation, unconfined groundwater, and precipitation to determine the water isotopes (δ2H, δ18O, and 3H), chloride (Cl-), nitrate (NO 3 –). Then, these tracers were employed to estimate recharge rates with methods considering the differences in shallow- and deep-rooted vegetation, as well as those in unsaturated and saturated zones. Results indicated that local precipitation predominantly recharges groundwater through matrix flow at a velocity of 14.5 cm year−1 with the residence time of > 200 years. The recharge rates range from 0 to 37 mm year−1, equivalent to 0–7% of annual average precipitation. However, the deep-rooted vegetation greatly reduced deep drainage compared with shallow-rooted vegetation, which will perturb the current hydraulic connectivity between unsaturated and saturated zones. The multiple tracers and methods can complement each other to enhance the understanding of groundwater recharge mechanisms. The indicated relationship between recharge form and land use suggests the urgency in developing strategies to balance the agroforestry system and water resource sustainability. [ABSTRACT FROM AUTHOR]

Nedd4-2 has been proposed to play a critical role in regulating epithelial Na+ channel (ENaC) activity. Biochemical and overexpression experiments suggest that Nedd4-2 binds to the PY motifs of ENaC subunits via its WW domains, ubiquitinates them, and decreases their expression on the apical membrane. Phosphorylation of Nedd4-2 (for example by Sgk1) may regulate its binding to ENaC, and thus ENaC ubiquitination. These results suggest that the interaction between Nedd4-2 and ENaC may play a crucial role in Na+ homeostasis and blood pressure (BP) regulation. To test these predictions in vivo, we generated Nedd4-2 null mice. The knockout mice had higher BP on a normal diet and a further increase in BP when on a high-salt diet. The hypertension was probably mediated by ENaC overactivity because 1) Nedd4-2 null mice had higher expression levels of all three ENaC subunits in kidney, but not of other Na+ transporters; 2) the downregulation of ENaC function in colon was impaired; and 3) NaCI- sensitive hypertension was substantially reduced in the presence of amiloridé, a specific inhibitor of ENaC. Nedd4-2 null mice on a chronic high-salt diet showed cardiac hypertrophy and markedly depressed cardiac function. Overall, our results demonstrate that in vivo Nedd4-2 is a critical regulator of ENaC activity and BP. The absence of this gene is sufficient to produce salt-sensitive hypertension. This model provides an opportunity to further investigate mechanisms and consequences of this common disorder. [ABSTRACT FROM AUTHOR]

In mammals, the hormonal regulation of water homeostasis is mediated by the aquaporin-2 water channel (Aqp2) of the collecting duct (CD). Vasopressin induces redistribution of Aqp2 from intracellular vesicles to the apical membrane of CD principal cells, accompanied by increased water permeability. Mutations of AQP2 gene in humans cause both recessive and dominant nephrogenic diabetes insipidus (NDI), a disease in which the kidney is unable to concentrate urine in response to vasopressin. In this study, we generated a line of mice with the distal COOH-terminal tail of the Aqp2 deleted (Aqp2Δ230), including the protein kinase A phosphorylation site (S256), but still retaining the putative apical localization signal (221-229) at the COOH-terminal. Mice heterozygous for the truncation appear normal. Homozygotes are viable to adulthood, with reduced urine concentrating capacity, increased urine output, decreased urine osmolality, and increased daily water consumption. Desmopressin increased urine osmolality in wild-type mice but had no effect on Aqp2Δ230/Δ230 mice. Kidneys from affected mice showed CD and pelvis dilatation and papillary atrophy. By immunohistochemical and immunoblot analyses using antibody against the NH2-terminal region of the protein Aqp2Δ230/Δ230 mice had a markedly reduced protein abundance. Expression of the truncated protein in MDCK cells was consistent with a small amount of functional expression but no stimulation. Thus we have generated a mouse model of NDI that may be useful in studying the physiology and potential therapy of this disease. [ABSTRACT FROM AUTHOR]

Since current administrative unit-based urban land area statistical data in China lack enough spatial information, the urbanization process research at large scale cannot be effectively supported. Based on the current administrative unit-based urban land area statistical data in China, a new approach to quickly and cheaply derive urban land information from the non-radiance-calibrated Defense Meteorological Satellite Program/ Operational Linescan System (DMSP/OLS) nighttime light imagery is presented in this paper. With the new approach, the urban pattern information in China in 1992, 1996 and 1998 was derived with the urbanization processes in China in the 1990s restored by using the non-radiance-calibrated DMSP/OLS nighttime imagery. The accuracy assessment based on the statistical data showed that the relative error between the derived total urban land area and the statistical data at national scale was less than 2% in 1992, and less than 1% in 1996 and 1998, and the maximum relative error at province scale do not exceed 10% with most of the provinces less than 3%. In addition, the urban patterns derived from the high-resolution Landsat TM imagery were compared with those from the DMSP/OLS data. The results showed that the urban pattern characteristics derived from DMSP/OLS were basically coincident with those from TM imagery with the total accuracy of about 80%. Thus it can be seen that our restored urbanization process in China in the 1990s by using the non-radiance DMSP/OLS night-time imagery can be accepted and can represent the actual urban development in China at that time on the whole. [ABSTRACT FROM AUTHOR]

Abstract: Reducing soil evaporation (E) is an important way to increase water use efficiency for agriculture and sustainable water use. To achieve this goal, an accurate estimate of soil evaporation at the macro-scale level is necessary. By including the surface temperature of dry soil, the three temperatures model (3T model) was proposed as an estimate of E, and its temperature term was defined as the soil evaporation transfer coefficient (h a). Although it has been primarily shown that h a determines the boundaries of E, further studies of its properties are necessary because h a has the application potential for remote sensing. The objectives of this study are to (1) investigate the relationships between h a and those parameters that are important for E estimation but are not able to be remotely measured (aerodynamic resistance, soil surface resistance (r s), and cumulative evaporation (E c)); and (2) discuss the possibility for remote sensing application. Two experiments were carried out for these purposes: one in an open field and the other one in a closed growth chamber at constant temperature, humidity, and radiation. The following results were obtained: (1) Given the boundaries of 0≤ h a ≤1, E was determined between its maximum value (potential evaporation rate) and minimum value (zero); (2) During the period when evaporation is controlled by r s, a linear relation between h a and log (r s) is observed with a coefficient of determination r 2 =0.76. Because h a and r s are independent variables with significant differences in properties and magnitudes, these results indicate that h a and r s are well related to each other; (3) During stage 1 of evaporation, cumulative evaporation (E c ) increased with time while h a remained constant. Afterwards, h a linearly increased with E c. The relationships among h a, E c, r a, and r s would be useful for estimation of evapotranspiration by remote sensing. [Copyright &y& Elsevier]

A review of flood disasters in China during the past five decades has shown a steady increase in the disaster toll due to rapid urbanization, especially through landscape urbanization in metropolitan areas. This paper illustrates the relationship and the interactions between urbanization in the metropolis and the process of flood disaster changes. Furthermore, a solution is proposed to alleviate fluctuations in flood disasters through the adjustment of the land use structure and pattern in metropolitan areas. Based on the solution, the authors conclude that the proportion of ‘ecological land’ in metropolitan areas should not be lower than 40%. The proportion of water and wetlands in ecological land should not be lower than their area in the years of average precipitation and water level. This means that in the Pearl River Metropolitan Area and the Yangtze River Delta Metropolitan Area, the proportion of water and wetlands in ecological land should be more than 25%. Moreover, the authors propose constituting a regional management mode which combines government, society, and insurance companies for controlling flood risk in metropolitan areas. [ABSTRACT FROM AUTHOR]

Analyzes palynological records of environmental changes in the middle part of Inner Mongolia, China. Arboreal genera revealed through high-resolution pollen analysis; Stage changes underwent by the vegetation.

Living organisms can produce corresponding functions by responding to external and internal stimuli, and this irritability plays a pivotal role in nature. Inspired by such natural temporal responses, the development and design of nanodevices with the ability to process time-related information could facilitate the development of molecular information processing systems. Here, we proposed a DNA finite-state machine that can dynamically respond to sequential stimuli signals. To build this state machine, a programmable allosteric strategy of DNAzyme was developed. This strategy performs the programmable control of DNAzyme conformation using a reconfigurable DNA hairpin. Based on this strategy, we first implemented a finite-state machine with two states. Through the modular design of the strategy, we further realized the finite-state machine with five states. The DNA finite-state machine endows molecular information systems with the ability of reversible logic control and order detection, which can be extended to more complex DNA computing and nanomachines to promote the development of dynamic nanotechnology. [ABSTRACT FROM AUTHOR]

• Stable and radioactive isotopes were combined for sources and ages of soil water. • Each component of soil water balance was partitioned. • Soil water above 8 m originated from precipitation over the past ~55 years. • Fruit trees increased transpiration but decreased evaporation relative to farmland. Deep-rooted fruit trees mine more water from deep soils than their shallow-rooted counterparts. Understanding how deep soil water (DSW) is replenished and subsequently depleted by deep-rooted fruit trees, therefore, are important for informing sustainable water resources management particularly in arid regions. In this study, we collected soil samples from the surface down to 20 m under four land use types (farmland, 8-year apple orchard, 12-year peach orchard, and 25-year apple orchard) in China's Loess Plateau. We then measured the soil water content, stable (δ2H and δ18O) and radioactive (3H) isotopic compositions. The radioactive isotope was used to constrain the age of soil water while the stable isotopes were used to determine the types of storms that would have contributed to recharging the DSW. We then implemented a soil water balance model to identify the mechanisms underlying the changes in DSW. Mechanistically, our results show that water movement in these soils was predominantly via piston flow. The age of DSW below 8 m was determined to be older than 55 years. Altogether, these results support an interpretation that DSW may have only been recharged by high-intensity, low-frequency rainfall events during the wet season (July to September), but that the magnitude of DSW recharge was likely to be influenced by subsequent water mining by deep-rooted fruit trees. The deep-rooted fruit trees consumed more DSW than farmland vegetation, substantially limiting the magnitude of DSW recharge under the orchards. Our simple soil water balance model, informed by water stable isotopes and supplemented with information from tritium, provides a technique for partitioning soil water balance (SWB) and insights into the long-term effects of land use change on water resources in arid regions. [ABSTRACT FROM AUTHOR]

• A material shows multi-stimuli-responsive luminescence. • The emission can be reversibly switched among three states. • A prototype of thermal-printing and mechanical-erasing system is developed. We present the synthesis and luminescence behaviour of a new aggregation-induced emission (AIE) compound, DBNA. The twisted molecular conformation with electron donor-acceptor (D-A) pairs, endows the new compound with multi-stimuli-responsive emission, manifesting as reversible mechanochromism-vapochromism-thermochromism. The main advantage of such multi-stimuli-responsive material stems from the three-state emission switching with high contrast-ratio and fatigue-resistance. The mechanism is ascribed to the coupling-decoupling-recoupling of the intermolecular D-A units. Based on DBNA , an archetype of the thermal-printing and mechanical-erasing system is developed, where data and pattern can be written and erased repeatedly. [ABSTRACT FROM AUTHOR]

In this work, we report the synthesis and emission behavior of two analogue compounds, 2-((E)-((9H-fluoren-2-yl)methylene)amino)-3-aminomaleonitrile (C1) and 2-amino-3-((E)-(4-(diphenylamino)benzylidene)amino)maleonitrile (C2). The two compounds exert both aggregation-induced emission (AIE) nature and intramolecular charge transfer (ICT) character. They show mechanochromic luminescence (MCL) in different ways: The C1 solid powder has strong green emission but would be quenched without color change after grinding. While C2 shows strong green emission in powder form but turns orange-red with a 30% loss in the quantum efficiency after grinding. The force-induced emission of both C1 and C2 can be changed back to the starting state by a simple immersion treatment in organic solvents, suggesting high fatigue resistance. Their MCL mechanisms were studied base on spectroscopic analysis combined with quantum chemical calculation. Powder x-ray diffraction (PXRD) diffractograms suggest a decrease in crystallinity rather than a full amorphization, excluding the phase transition mechanism that has been widely accepted for most of the MCL materials in prior reports. The photophysical process has been modeled according to the quantum chemical calculation using DFT-PBE0/6-311g (d,p), two stable isomers of C1 were detected, which exhibit structural relaxation with a conical intersection seam. The conical intersection of C1 can be accessed by mechanical stimuli but is unable to reach in the starting crystalline phase due to conformation rigidity. In contrast, such structural relaxation is less possible with C2 due to high emission in solution state. And the MCL mechanism mainly involves conformation planarizartion, which leads to bathochromic-shift with its emission. The new working mechanism with C1 is superior to other counterparts on account of its sensitivity and practicability. A new type of pressure sensor based on C1 film was developed, showing remarkable quenching effect with the pressure. A linear relation between pressure and emission intensity was obtained, offering a low detection limit down to 22.92 Mpa. This mechanochromic system succeeds in mechanical printing using MCL: Pressure up to 30 Mpa clearly imprints the cartoon patterns in detail with high contrast using the MCL materials, demonstrating a feasible prototype of printing technology. Image 1 • Structural relaxation with a conical intersection seam is used to explain mechanochromic luminescence. • A film sensor for pressure measuring is developed, showing high sensitivity. • This mechanochromic system succeeds in mechanical printing. [ABSTRACT FROM AUTHOR]

Background: Quantifying the stock of soil organic carbon (SOC) and evaluating its potential impact factors is important to evaluating global climate change. Human disturbances and past climate are known to influence the rates of carbon fixation, soil physiochemical properties, soil microbial diversity and plant functional traits, which ultimately affect the current SOC storage. However, whether and how the paleoclimate and human disturbances affect the distribution of SOC storage on the high-altitude Tibetan Plateau remain largely unknown. Here, we took the Qinghai Plateau, the main component of the Tibetan Plateau, as our study region and applied three machine learning models (random forest, gradient boosting machine and support vector machine) to estimate the spatial and vertical distributions of the SOC stock and then evaluated the effects of the paleoclimate during the Last Glacial Maximum and the mid-Holocene periods as well as the human footprint on SOC stock at 0 to 200 cm depth by synthesizing 827 soil observations and 71 environmental factors. Results: Our results indicate that the vegetation and modern climate are the determinant factors of SOC stocks, while paleoclimate (i.e., paleotemperature and paleoprecipitation) is more important than modern temperature, modern precipitation and the human footprint in shaping current SOC stock distributions. Specifically, the SOC stock was deeply underestimated in near natural ecosystems and overestimated in the strongly human disturbance ecosystems if the model did not consider the paleoclimate. Overall, the total SOC stock of the Qinghai Plateau was underestimated by 4.69%, 12.25% and 6.67% at depths of 0 to 100 cm, 100 to 200 cm and 0 to 200 cm, respectively. In addition, the human footprint had a weak influence on the distributions of the SOC stock. We finally estimated that the total and mean SOC stock at 200 cm depth by including the paleoclimate effects was 11.36 Pg C and 16.31 kg C m−2, respectively, and nearly 40% SOC was distributed in the top 30 cm. Conclusion: The paleoclimate is relatively important for the accurate modeling of current SOC stocks. Overall, our study provides a benchmark for predicting SOC stock patterns at depth and emphasizes that terrestrial carbon cycle models should incorporate information on how the paleoclimate has influenced SOC stocks. [ABSTRACT FROM AUTHOR]

Diversified molecular information‐processing methods have significant implications for nanoscale manipulation and control, monitoring and disease diagnosis of organisms, and direct intervention in biological activities. However, as an effective approach for implementing multifunctional molecular information processing, DNA reaction networks (DRNs) with numerous functionally specialized molecular structures have challenged them on scale design, leading to increased network complexity, further causing problems such as signal leakage, attenuation, and cross‐talk in network reactions. Our study developed a strategy for performing various signal‐processing tasks through engineering modular DRNs. This strategy is based on a universal core unit with signal selection capability, and a time‐adjustable signal self‐resetting module is achieved by combing the core unit and self‐resetting unit, which improves the time controllability of modular DRNs. In addition, multi‐input and ‐output signal cross‐catalytic and continuously adjustable signal delay modules were realized by combining core and threshold units, providing a flexible, precise method for modular DRNs to process the signal. The strategy simplifies the design of DRNs, helps generate design ideas for large‐scale integrated DRNs with multiple functions, and provides prospects in biocomputing, gene regulation, and biosensing. [ABSTRACT FROM AUTHOR]

There has been increasing interest in understanding climate change impacts on crop yield stability, including interannual yield variability and lower yield extremes, in addition to mean yield. In this study, we evaluated these impacts on wheat yield and investigated the contribution of changes in climate mean and variability, and their interaction, on the North China Plain (NCP). Wheat yield simulation experiments with control groups were conducted using the Crop Environment Resource Synthesis (CERES) model, with multiple general circulation model ensembles under two representative concentration pathways (RCPs), namely 4.5 and 8.5. Climate change was projected to reduce mean yield by 15 and 17%, increase yield interannual variability by 5 and 11%, and reduce 10‐year return period lower yield extremes by 31 and 34% under RCPs 4.5 and 8.5, respectively. When analysed, changes in climate mean proved the main cause for changes in mean yield (62–71%), followed by the interactive changes in climate mean and variability (26–33%). As for the impact on yield variability, the interaction of the changes in climate mean and variability proved the main cause (48–54%), followed by changes in climate mean (33–41%). Surprisingly, climate change in variability contributed the least in both cases. Our results pertaining to the decrease in both availability and stability of wheat yield on the NCP presents a greater challenge for building a resilient food system for local areas than before. They also highlighted the importance of separating the impacts of changes in climate mean and variability on crop yield stability in a holistic framework, with particular attention paid to the tangible and interactive effects. [ABSTRACT FROM AUTHOR]

• Impacts of climate change on global terrestrial ecoregions were assessed. • Climate change may lead to habitat modifications in most scenarios. • Both gain and losses in biodiversity and ecosystem services are to be expected. • Fire and habitat transformation should be considered in conserving biodiversity. • Current ecoregion scheme should be updated under changing climate. Terrestrial ecoregions, including critical ecoregions (CEs), vulnerable ecoregions (VEs), and intact ecoregions (IEs) have been used by the World Wildlife Fund (WWF) to classify global biodiversity and are being affected by climate change, which was considered as one of the main threats to biodiversity conservation. However, the impacts of future climate change in shifted means and extremes of temperature, precipitation, and cloud cover under the representative concentration pathways (RCP 2.6, 4.5, and 8.5) on the characteristics of these ecoregions have yet to be fully understood. The present study was designed using a dynamic global vegetation model and both current and future climate scenarios, to investigate the impacts of shifted means and extremes of temperature, precipitation, and cloud cover on five ecological indicators including net primary productivity (NPP), carbon storage, runoff, wildfire risk, and habitat transformation at the ecoregional scale. The analysis was performed for the terrestrial ecoregions as a whole, as well as for specific subsets of CEs, VEs, and IEs. The results showed that future climate scenarios (whether RCP 2.6, 4.5, or 8.5) were estimated to increase the mean NPP, runoff, wildfire risk, and habitat transformation for all ecoregion types, when comparing values for 2071–2100 to the baseline (1971–2000) period. In contrast, the mean carbon storage in the TEWs, VEs, and CEs was estimated to decrease from the baseline to the values under RCP 2.6 and RCP 4.5 and then increase to their largest values under RCP 8.5. The mean carbon storage in the IEs under RCP 8.5 was estimated to remain lower than the baseline period values. Climate change in shifted means and extremes of temperature, precipitation, and cloud cover are generally significant drivers of the variances of NPP, carbon storage, runoff, wildfire risk, and habitat transformation under RCP 2.6, RCP 4.5, and RCP 8.5. The dynamics of the climate change metrics and the five ecological indicators have significant implications for biodiversity conservation in changing climates. [ABSTRACT FROM AUTHOR]

• RWEQ model simulated a significant decrease in wind erosion from 1982 to 2016. • Wind stilling has a significant influence on the decline of soil wind erosion. • Wind stilling might minimize soil degradation in other regions of the world. Wind erosion in arid and semi-arid areas is an important global environmental issue, and changes in wind speed trends over time play a key role in wind erosion dynamics. In a warming climate, scientists have recently observed a widespread decline in wind speed, termed "stilling". Here, we apply the Revised Wind Erosion Equation Model (RWEQ) to simulate the variability of wind erosion and quantify the impact of wind speed changes on soil degradation dynamics over the eastern agro-pastoral transitional zone of Northern China from 1982 to 2016. Our results show that a significant (i.e., p < 0.05) decrease (-0.007 m s−1 year−1) of near-surface wind speed was observed annually, with significant declining trends in spring (-0.010 m s−1 year−1)and autumn (-0.009 m s−1 year−1). At the same time, wind erosion simulations reveal a negative trend for the annual soil loss from wind erosion (-6.20 t hectare-2 year -1, p < 0.05; affecting 99.8% of the study region), with significant declining trends in all seasons, particularly in spring (-3.49 t hectare-2 year−1) and autumn (-1.26 ha-2 year−1). Further, we isolate the effects of wind variability on wind erosion from 1982 to 2016 by the model variable control method. This shows that wind speed variability strongly weakens wind erosion at -8.14 t hectare-2 year -1 (p < 0.05) annually, with the strongest stilling recorded in spring leading to major decreases of wind erosion in spring (-4.77 t hectare-2 year−1, p < 0.05). Meanwhile, the weakest stilling in summer had the opposite influence on wind erosion (+0.40 t hectare-2 year -1, p < 0.10). To summarize, our findings have shown a significant impact of wind stilling on the decline of soil erosion rates in Northern China. [ABSTRACT FROM AUTHOR]

Abstract Impacts of floods on human society have been drawing increasing human concerns in recent years. In this study, flood observations from EM-DAT (Emergency Events Database) and DFO (Dartmouth Flood Observatory) datasets were analyzed to investigate frequency and intensity of floods, and flood-induced mortality, flood-affected population as well during 1975–2016 across the globe. Results indicated that: (1) occurrence rate of floods, flood-induced mortality and flood-affected population were generally increasing globally. However, flood-induced mortality and flood-affected people per flood event were in slight decrease, indicating that flood-induced mortality and flood-affected people due to increased floods exceeded those by individual flood event; (2) annual variation of mortality per flood event is highly related to floods with higher intensity. Specifically, the flood frequency and flood-induced mortality are the largest in Asia, specifically in China, India, Indonesia and Philippine; while significantly increased flood-affected population and mean annual mortality was detected in China, USA and Australia; (3) tropical cyclones (TC) are closely related to flood-induced mortality in parts of the countries along the western coast of the oceans. The frequency of channel floods in these regions is the largest and large proportion of flood-induced deaths and the highest flood-induced mortality can be attributed to TC-induced flash floods; (4) Population density and GDP per unit area are in significantly positive correlation with the number of flood-related victims per unit area, number of deaths and economic losses with exception of low-income countries. However, the flood-affected population and flood-induced mortality increase with decrease of per capita GDP; while the per capita economic loss increases with the increase of per capita GDP, indicating that the higher the population density and GDP per unit for a region, the higher sensitivity of this area to flood hazards. Graphical abstract Unlabelled Image Highlights • New findings about increased mortality due to increased flood frequency but not enhanced flood intensity • New light on linkages between topography and occurrences of floods • Novel viewpoints pertaining impacts of TCs on floods along the coastal regions of the globe [ABSTRACT FROM AUTHOR]

The article focuses on China's program to clean up the Huai River basin that was begun in the mid-1990s. The author discusses a widely-publicized environmental catastrophe in July 2004, when authorities were forced to open water gates in the upper stream of the river, which released a 500 million-ton torrent of polluted water. The result of this discharge was hundreds of kilometers of contaminated water and dead fish, ducks and other birds. The article discusses the huge environmental challenges that China faces as the nation develops. INSETS: The xuzhou experience;Figure 1-6;The xuzhou experience.

The forest ecohydrological processes change with time of tree plantation; however, it remains challenging to estimate tree ages at the regional scale. The objective of this study is to estimate the regional-scale apple tree distribution and ages, and further use it as a bridge to quantify the impacts of apple orchards on hydrological processes. Taking the Changwu County on the Loess Plateau of China as example, we first identified the spatial distribution and age structure of apple trees from 1995 to 2020 based on field investigation, remote sensing data and machine learning procedure, and then explored the spatiotemporally varied impacts of apple orchards on water balance through extrapolating the point-scale observation to the whole study area. The area and tree age of apple orchards were satisfactorily identified, with R2 values of 0.94 and 0.68, respectively. The area of apple orchards kept increasing, and its value in 2020 (17117 ha) was 2.5 times of that in 1995 (6842 ha). Young apple trees dominated the apple orchards during 1995–2000, while trees over 15 years old accounted for 72 % of the apple orchards in 2020. With the point-scale relations of tree ages to soil water balance, the regional-scale cumulative soil water consumed by the increasing apple orchards and old trees reached 129 GL by 2020, and the ratio of actual evapotranspiration to precipitation was 109 % when the apple tree was 22 years old. This study proposes a framework to estimate the regional-scale temporal changes in ecohydrological effects of vegetation using tree age as a bridge. The methods in this study can be referred by other studies, and the results can be used for sustainable management of water resources and agricultural production. • Age-NDVI relationship was established to estimate the regional-scale age structure. • Age is used as bridge to quantify impacts of orchards on hydrological processes. • Increasing apple orchards and old trees have caused severe soil water deficit. • Regional scale soil water consumption exceeds annual mean precipitation. [ABSTRACT FROM AUTHOR]

Hydrological and statistical models are playing an increasing role in hydrological forecasting, particularly for river basins with data of different temporal scales. In this study, statistical models, e.g. artificial neural networks, adaptive network-based fuzzy inference system, genetic programming, least squares support vector machine, multiple linear regression, were developed, based on parametric optimization methods such as particle swarm optimization (PSO), genetic algorithm (GA), and data-preprocessing techniques such as wavelet decomposition (WD) for river flow modelling using daily streamflow data from four hydrological stations for a period of 1954-2009. These models were used for 1-, 3- and 5-day streamflow forecasting and the better model was used for uncertainty evaluation using bootstrap resampling method. Meanwhile, a simple conceptual hydrological model GR4J was used to evaluate parametric uncertainty based on generalized likelihood uncertainty estimation method. Results indicated that: (1) GA and PSO did not help improve the forecast performance of the model. However, the hybrid model with WD significantly improved the forecast performance; (2) the hybrid model with WD as a data preprocessing procedure can clarify hydrological effects of water reservoirs and can capture peak high/low flow changes; (3) Forecast accuracy of data-driven models is significantly influenced by the availability of streamflow data. More human interferences from the upper to the lower East River basin can help to introduce greater uncertainty in streamflow forecasts; (4) The structure of GR4J may introduce larger parametric uncertainty at the Longchuan station than at the Boluo station in the East river basin. This study provides a theoretical background for data-driven model-based streamflow forecasting and a comprehensive view about data and parametric uncertainty in data-scarce river basins. [ABSTRACT FROM AUTHOR]

Using NDVI3g vegetation index, we defined 18 phenology metrics to investigate phenological change on the Tibetan Plateau (TP). Considering the heterogeneity of vegetation phenology, we divided TP into 8 vegetation clusters according to a 1:1000000 vegetation cluster map. For regions where phenology is highly sensitive to climate, we investigated the impact of climate variables, such as temperature, precipitation, and solar radiation on phenology using the partial least squares regression (PLS) method. Results indicated (1) that turning points of the starting date of the growing season (SOS) metrics were in 1997–2000, before which SOS metrics advanced 2–3d/10a. The ending date of the growing season (EOS) and the length of growing season metrics (LOS) turning points were 2005 and 2004–2007, respectively. Before the turning points, the EOS metrics had a delayed tendency of 1–2d/10a, and the LOS metrics also had a prolonging tendency of 1–2d/10a. After the turning points, the significant levels of SOS and EOS metrics’ tendency only reached 0.1, and LOS’s tendency was insignificant at the 0.1 level. (2) Alpine meadows and alpine shrub meadows changed most intensely on TP. Advanced SOS and delayed EOS were the main reasons of the alpine meadow LOS extension. Advance SOS mainly contributed to the alpine shrub meadow LOS extension. (3) We used meteorological variables, such as temperature, precipitation and solar radiation, to analyze the drastic change of the phenology of alpine meadows and alpine shrub meadows through the PLS method. Temperature was found to be the dominant meteorological variable impacting phenology. In those regions, the previous year autumn and early winter temperature had a positive effect on the SOS phenology. The high temperature in this period would postpone previous year EOS, indirectly delaying SOS in the current year. On the other hand, warming autumn and early winter may slow the fulfilment of chilling requirements and lead to later SOS, which would have a delayed effect on SOS. Except summer, the minimum temperature had a similar effect on vegetation phenology, as average and maximum temperature. Furthermore, the effect of precipitation on phenology fluctuated widely across different months. The previous year autumn and winter precipitation had a negative effect on the SOS phenology, and early spring precipitation had a positive effect. The main factor limiting vegetation development in August was precipitation, and during this month precipitation had a positive impact on the EOS phenology. The influence of solar radiation was mainly during summer and early fall. This study will contribute toward vegetation phenology model improvement. [ABSTRACT FROM AUTHOR]

The Yellow River is the second largest river in China and is the important source for water supply in the northwestern and northern China. It is often regarded as the mother river of China. Owing to climatic change and intensifying human activities, such as increasing withdrawal of water for meeting growing agricultural irrigation needs since 1986, the flow of Yellow River has decreased, with serious impacts on the ecological environment. Using multiple hydrological indicators and Flow Duration Curve (DFC)-based ecodeficit and ecosurplus, this study investigates the impact of hydrological alterations, such as the impact of water reservoirs or dams, on downstream ecological instream flow. Results indicate that: (1) due to the impoundment and hydrological regulations of water reservoirs, occurrence rates and magnitudes of high flow regimes have decreased and the decrease is also found in the magnitudes of low flow events. These changes tend to be more evident from the upper to the lower Yellow River basin; (2) human activities tend to enhance the instream flow variability, particularly after the 1980s;(3) the ecological environment in different parts of the Yellow River basin is under different degrees of ecological risk. In general, lower to higher ecological risk can be detected due to hydrological alterations from the upper to the lower Yellow River basin. This shows that conservation of ecological environment and river health is facing a serious challenge in the lower Yellow River basin; (4) ecological instream flow indices, such as ecodeficit and ecosurplus, and IHA32 hydrological indicators are in strong relationships, suggesting that ecodeficit and ecosurplus can be regarded as appropriate ecological indicators for developing measures for mitigating the adverse impact of human activities on the conservation of ecological environment in the Yellow River basin. [ABSTRACT FROM AUTHOR]

In this work we studied the photoluminescence (PL) behaviour of a new intramolecular charge transfer (ICT) compound, DHAIA. It shows ICT solvent effect in common organic solvents and specific solvent effect in aqueous medium as confirmed by its spectra characterization. The specific solvent effect can be ascribed to the transition from charge-transfer (CT) state to locally excited (LE) state, which is activated by intermolecular hydrogen bonding. The proposed mechanism was confirmed by DFT calculations. The compound can serve as a reliable sensor for identifying the brand of liquors and confirming their authenticity, based on such unique solvent effect intrinsic to this fluorogen. The sensor aimed to fingerprint different liquors via plotting their characteristic factors recorded by spectroscopic analysis. It succeeded in identifying an adulterated liquor sample, once commercially available, provided by Municipal Public Security Bureau, showing great potential in liquor differentiation and identification. [ABSTRACT FROM AUTHOR]

Using flood peaks data from 62 hydrological stations covering a period of 1951–2014 and tropical cyclone (TC) tracks, floods due to TCs were differentiated and relations between occurrences of floods and TCs were investigated. Then, the impact of TCs on the flood magnitude and frequency was evaluated. Results indicated that there was more than one external influencing factor for flood occurrences, i.e. convective precipitation and TC-related heavy precipitation. In general, the landed TC events have a crucial influence on the occurrence of floods in eastern and western parts of Guangdong province. The mountainous topography limits the northward propagation of TC events and hence limits their impact on the occurrence of floods in the northern part. More than 60% of the largest 10 hazardous floods in the northern and eastern parts were attributed to TCs and hence they significantly modified the probability distributions of flood peaks, increasing the location and scale parameters of the generalized extreme value (GEV) probability distribution model. Therefore, development of measures for mitigation of coastal flooding would need to consider the occurrences of TCs. [ABSTRACT FROM AUTHOR]

The construction of DNA reaction networks with complex functions using various methods has been an important research topic in recent years. Whether the DNA reaction network can perform complex tasks and be recycled directly affects the performance of the reaction network. Therefore, it is very important to design and implement a DNA reaction network capable of multiple tasks and reversible regulation. In this paper, the hairpin allosteric method was used to complete the assembly task of different functional nucleic acids. In addition, information conversion of the network was realized. In this network, multiple hairpins were assembled into nucleic acid structures with different functions to achieve different output information through the cyclic use of trigger strands. A method of single-input dual-output information conversion was proposed. Finally, the network with signal amplification and reversible regulation was constructed. In this study, the reversible regulation of different functional nucleic acids in the same network was realized, which shows the potential of this network in terms of programmability and provides new ideas for constructing complex and multifunctional DNA reaction networks. [ABSTRACT FROM AUTHOR]