Search

The southern Junggar Basin, Xinjiang, has abundant coalbed methane (CBM) resources. Currently, the Baiyang River development pilot test area (BYR block for short) in the Fukang east block has achieved large-scale CBM development, but the productivity characteristics and its controlling factor are still unclear. Based on the field production data of the BYR block and experimental tests, this paper summarizes the gas and water production characteristics and presents the analysis results of the geological and geochemical responses to the productivity of CBM wells. The productivity of CBM wells in the BYR block was generally characterized as medium-to-low yield. The productivity was jointly controlled by the burial depth, structure condition, thickness and number of co-production coal seams, and hydrogeological conditions. The gas production first increased and then decreased with the increase in the burial depth of the coal seam, and a burial depth between 750 and 1000 m was the most beneficial to increasing the gas production due to the good gas preservation conditions and suitable permeability and stress conditions. The total thickness of the co-production coal seams had a positive effect on the productivity of gas wells, but the productivity was also affected by the number of co-production coal seams and interlayer interference. In the BYR block, the co-production of the nos. 41 and 42 coal seams was the most favorable combination form for CBM drainage. The productivity of CBM wells had a good response to the Na+, K+ and HCO3− concentrations but a poor response to δD-H2O and δ18O-H2O. Based on the concentrations of the main ions and TDSs of the coal seam water, a productivity response index δ* was established, and there was a good positive correlation between the productivity and δ*. [ABSTRACT FROM AUTHOR]

The new development pattern is a strategic choice to reshape China's new advantages in international cooperation and competition. It is based on China's current development stage, changes in the environment, and other factors. Located deep within China's interior, Xinjiang is a crucial region for the development of the western region and the Belt and Road Initiative. Its agricultural resources are exported to numerous foreign nations. In the context of the new development pattern, this paper first examines the foreign trade issues in Xinjiang. Second, this paper analyzes the current state of Sino-Kazakhstani trade, in particular the current state of trade in agricultural products. In addition, the growth potential of Xinjiang's agricultural international trade is analyzed utilizing the gravity model and fuzzy algorithm. Finally, countermeasures for the mode of development of Xinjiang's international trade are proposed. [ABSTRACT FROM AUTHOR]

Hydrogen is receiving unprecedented momentum and is projected to meet a sizable share of the final energy demand in the future. The coupling between the hydrogen and power systems can help integrate volatile renewable energy, reduce curtailment, and realize long-term energy storage. Different coupling modes are being proposed, yet quantitative comparisons are absent. To fill this gap, this paper firstly summarizes the system composition of potential power–hydrogen coupling modes and analyzes their advantages and disadvantages. Then, a model for power–hydrogen coordinated planning optimization is proposed for quantitative analysis. Southern Xinjiang is chosen as a representative of the northwestern area in China, which has plentiful renewable resources and a relatively small local load at present, for a case study. Through result analysis, it is found that the mode of power–hydrogen coupling at the source side, either for in situ utilization or for long-distance transport via pipelines, shows better economic competitiveness. The discussion provides suggestions and a reference to policymakers for formulating infrastructure or industry plans in advance to better accommodate the rapidly developing renewable energy. [ABSTRACT FROM AUTHOR]

Groundwater is a primary freshwater resource for human consumption and an essential source for industry and agriculture. Therefore, understanding its spatial and temporal trends and drivers is crucial for governments to take appropriate measures to manage water resources. This paper uses Gravity Recovery and Climate Experiment (GRACE) satellite data and the Global Land Data Assimilation System (GLDAS) to derive groundwater storage anomalies (GWSAs) and to analyze the spatial and temporal trends of GWSA in different regions of China (Xinjiang, Tibet, Inner Mongolia, North China Plain, South China, and Northeast China). It used groundwater-level observation data to verify the accuracy of GWSA estimates and analyzed the drivers of regional GWSA changes. The results showed that: (1) GWSA in South China increased at a rate of 4.79 mm/a from 2003 to 2016, and GWSA in other regions in China showed a decreasing trend. Among them, the decline rates of GWSA in Xinjiang, Tibet, Inner Mongolia, North China Plain, and Northeast China were −6.24 mm/a, −3.33 mm/a, −3.17 mm/a, −7.35 mm/a, and −0.75 mm/a, respectively. (2) The accuracy of the annual-scale GWSA estimates was improved after deducting gravity losses due to raw coal quality, and the correlation coefficient between GWSA and groundwater levels monitored by observation wells increased. (3) In Xinjiang, the annual water consumed by raw coal mining, industrial, and agricultural activities had a greater impact on GWSA than rainfall and temperature, so these human activities might be the main drivers of the continued GWSA decline in Xinjiang. Water consumption by raw coal mining and industry might be the main drivers of the continued decline in GWSA in Inner Mongolia and the North China Plain. The increase in groundwater storage in South China was mainly due to the recharge of rainfall. [ABSTRACT FROM AUTHOR]

There are large, heavy oil reserves in Block X of the Xinjiang oilfields, China. Due to its large burial depth (1300 m) and low permeability (26.0 mD), the traditional steam-injection technology cannot be used to obtain effective development benefits. This paper conducts experimental and simulation research on the feasibility and mechanism of CO 2 -energized fracturing of horizontal wells and N 2 foam huff-n-puff in deep heavy oil reservoirs with low permeability in order to further explore the appropriate production technology. The foaming volume of the foaming agent at different concentrations and the oil displacement effect of N 2 foam at different gas/liquid ratios were compared by the experiments. The results show that a high concentration of foaming agent mixed with crude oil is more conducive to increasing the foaming volume and extending the half-life, and the best foaming agent concentration is 3.0∼4.0%. The 2D micro-scale visualization experiment results show that N 2 foam has a good selective blocking effect, which increases the sweep area. The number of bubbles per unit area increases as the gas/liquid ratio increases, with 3.0∼5.0 being the optimal gas/liquid ratio. Numerical simulation results show that, when CO 2 -energized fracturing technology takes into account the advantages of fracturing and crude oil viscosity reduction by CO 2 dissolution, the phased oil recovery factor in the primary production period can reach approximately 13.7%. A solvent pre-slug with N 2 foam huff-n-puff technology is applied to improve oil recovery factor following primary production for 5∼6 years, and the final oil recovery factor can reach approximately 35.0%. The methodology formulated in this study is particularly significant for the effective development of this oil reservoir with deeply buried depth and low permeability, and would also guide the recovery of similar oil deposits. [ABSTRACT FROM AUTHOR]

GM crops, as a widely researched and applied biotechnology, hold significant strategic and practical implications for promoting the commercialization of GM crops in China, driving agricultural industry upgrading, and fostering economic and social development. However, despite their potential benefits, the commercialization of GM crops in China has been consistently delayed. Therefore, this study aims to explore the trust relationship between the government and the public in the field of genetically modified organisms and the heterogeneous impacts generated at the production and consumption ends. We primarily focus on insect-resistant cotton and genetically modified papaya as representatives and base our research on survey data from Xinjiang and Guangdong. By employing factor analysis and establishing multiple Probit models with government trust, crop purposes, and farmer expectations as independent variables, and the commercialization of GM crops as the dependent variable, we conduct two sets of empirical analyses. The study finds that government trust has a more significant impact on consumer concerns about whether to consume GM products than on producers, who prioritize farmers' desire for agricultural product profitability. Age and education levels also influence the public's acceptance of planting GM crops, but the effects are not as significant as the core variables mentioned earlier. Based on this, we conclude that consumers and farmers have different positions and contradictions in the specific scenario of delayed GM commercialization in China. In this context, this paper argues that diversified strategies should be adopted to address the issue of commercialization of GM crops in China. [ABSTRACT FROM AUTHOR]

In northwest China, underground mining is frequently conducted in weakly cemented rock environments, including the aquiclude that protects the aquifer from dewatering. In this context, understanding the aquiclude responses to longwall mining is significant for assessing the reliability of water-conserved mining in the weakly cemented rock environment. Taking the Jurassic and Paleogene coal measure geology in Yili Mine in Xinjiang Province, China, as a case study, the paper conducted a laboratorial three-dimensional simulation by configuring a longwall operation and induced groundwater migration. The study analysed the aquiclude depressurisation and revealed the aquiclude stability in response to longwall mining. The results indicated that the aquiclude had a significant plastic strain and self-healing ability in the ground depressurisation condition. The aquiclude experienced tension and then compression, and, accordingly, fracture initiation, propagation, and convergence, during which the aquiclude had significant bending deformation. On the aquiclude horizon, tensile fracturing dominated above the set-up and longwall stop positions. The self-healing behaviour was correlated to the high content of clay minerals and disintegration proneness. The simulation results had a good agreement with field measurements, suggesting that the aquiclude had a satisfactory water-resisting ability and that the simulation results were practically reliable. [ABSTRACT FROM AUTHOR]

The understanding of formation has always been a challenge for field development. In this paper, we evaluate the reservoir parameters and gas well productivity based on production data. The model of nonuniform conductivity of fractures in multistage fracturing horizontal wells (MFHW) is used to interpret the transient pressure data. Binomial and exponential deliverability equations and pressure dimensionless productivity formula are combined to evaluate the gas well productivity. After that, the key factors that influence gas well production are analyzed, and the gas rate vs. oil nozzle is presented. Results show that the fracture half-length and conductivity for high- and low-conductivity fractures, respectively, are obtained, apart from the reservoir pressure, permeability, skin factor, etc. The test time in each oil nozzle is recommended to extend to achieve stability and to obtain a more accurate absolute open flow potential. The findings of this study provides a guidance for the production data analysis of nonuniform conductivity of fractures in MFHW in the future work. And it can help for the better understanding of predicting gas production rates in MFHW. [ABSTRACT FROM AUTHOR]

The supply of coins and their metal materials is important for state governance. Many details about the monetary supply network in ancient China still need to be verified. In this paper, 15 early Tang dynasty Kaiyuan Tongbao 開元通寶 coins excavated from the Lafu Queke 拉甫却克 cemetery, Hami 哈密 city, were studied by combining scientific analyses (PXRF and MC-ICP-MS etc.) with the archaeological context and historical texts. The results show that all of these coins are made of Cu-Sn–Pb ternary alloy. The lead isotopes match with the isotopic signatures of some southwest China lead mines consistent with historical records, 14 coins are located in the range of Southern China geochemical province, and the lead of 5 coins could be considered as highly radiogenic lead (HRL). Combining these results with the archaeological context and historical texts, it can be inferred that the coins minted in southwest China were made from locally exploited raw metal, and supplied to the northwest borderland of the Tang dynasty in the seventh century CE. [ABSTRACT FROM AUTHOR]

Run-of-mine fragmentation is an important aspect of mine productivity optimization, as it affects all mine-to-mill processes. The current blasting fragmentation calculation methods do not consider the 3D geometric information. Therefore, their calculation results are imprecise. 3D laser scanning is a technique for extracting the 3D geometric information of an object by constructing a 3D point cloud model, with which extra information on the geometrical characteristics of an object could be captured than with the technique of 2D image processing. In this paper, 3D laser scanning technology was utilized for the calculation of the rock blocks on the surface of a muck pile, and the information about the surface blocks was utilized as the samples for the statistical estimation of blasting fragmentation of muck pile (BFMP). Monte Carlo simulation was utilized as the statistical estimation method for the BFMP. In the lab experiment, results from 2D image processing technique and from 3D laser scanning technique combined with statistical estimate were compared with the physical measurements utilizing a water tank, which show that results with 3D laser scanning are more similar to the physical measurement. Finally, the applicability of 3D laser scanning technology combined with statistical methods to the calculation of blast fragmentation was estimated through field tests in Biesikuduke and Santanghu mine, two open-pit coal mines in Xinjiang Province of western China. Results show that the accuracy of the statistical estimation results of BFMP has a particle size deviation of 1–3 cm. [ABSTRACT FROM AUTHOR]

The arid region of northwest China (ARNC) is one of the most sensitive areas to global warming. However, the performance of new Global Climate Models (GCMs) from phase 6 of the Coupled Model Intercomparison Project (CMIP6) in simulating climate in this region, especially in the subregions, is not clear yet. Based on the temperature dataset from historical runs of CMIP6, this paper analyzed and evaluated the simulation ability of 29 GCMs in reproducing the annual mean temperature (tas), annual mean maximum temperature (tasmax) and annual mean minimum temperature (tasmin) in the ARNC and subregions from 1961 to 2014. The results show that (1) the correlation coefficients (CCs) between simulation and observation time series for the mean of two model ensembles (MME for equal-weight multi-model ensemble and PME for preferred-model ensemble) are generally better than those of 29 individual GCMs, with CCs ranging from 0.38 to 0.87 (p < 0.01). (2) All the models can simulate the significant warming trend of the three temperature elements in the study area well. However, the warming magnitude simulated by most of the models (41%) is smaller than the observations except for tasmax, which is also shown in the MME. (3) The spatial pattern of the three temperature elements can be better reflected by most models. Model simulation ability for the ARNC is better compared to that of the four subregions, with a spatial CC greater than 0.7 (p < 0.01). Among the subregions, the simulation performance of the north of Xinjiang for spatial pattern is superior to that of the other regions. (4) The preferred models for each subregion are various and should be treated differently when used. Overall, the PME outperforms both the MME and the individual models; it can not only simulate the linear trend accurately but also reduce the deviation effectively. [ABSTRACT FROM AUTHOR]

As one of the pioneer palaeontologists, Professor Zhuoting Liao has contributed his lifetime to promoting palaeontological and stratigraphical research in China for 60 years, and he passed away in the field excursion in South China on June 20, 2020. In his palaeontological career, Liao has worked on Late Palaeozoic to Mesozoic palaeontology and stratigraphy of almost all regions across China, and his interests have also extended to the Permian–Triassic (P‐Tr) boundary and mass extinction. He has worked on palaeontology, palaeobiogeography, biostratigraphy, tectonostratigraphy, and their implications in mineral and oil‐gas industries. Liao has established 22 new genera and 172 new species of brachiopods, and, together with his colleagues, proposed 11 new genera and 25 new species of echinoderms. He dedicated his lifetime to work on Late Palaeozoic palaeontology and stratigraphy of the previously remote and tectonically complex Xinjiang and adjacent regions, north‐west China, and established integrated stratigraphical frameworks for the Carboniferous to Permian strata, providing fundamental basis for mineral and hydrocarbon exploration in the poorly understood Central Asian terranes. In addition, he has mentored many young palaeontologists and stratigraphers in various ways. This volume assembles 30 papers addressing the Late Palaeozoic to Mesozoic palaeontology and stratigraphy of China and adjacent regions, which pays tribute to the achievement of Professor Zhuoting Liao. [ABSTRACT FROM AUTHOR]

Hand, foot and mouth (HFM) disease is a common childhood illness. The paper aims to capture the spatiotemporal characters, and investigate the influence factors of the HFM epidemic in 15 regions of Xinjiang province from 2008 to 2017, China. Descriptive statistical analysis shows that the children aged 0-5 years have a higher HFM incidence, mostly boys. The male-female ratio is 1.5:1. Through the scanning method, we obtain the first cluster high-risk areas. The cluster time is usually from May to August every year. A spatiotemporal model is proposed to analyze the impact of meteorological factors on HFM disease. Comparing with the spatial model, the model is more effective in terms of R2, AIC, deviation, and mean-square error. Among meteorological factors, the number of HFM cases generally increases with the intensity of rainfall. As the temperature increases, there are more HFM patients. Some regions are mostly influenced by wind speed. Further, another spatiotemporal model is introduced to investigate the relationship between HFM disease and socioeconomic factors. The results show that socioeconomic factors have significant influence on the disease. In most areas, the risk of HFM disease tends to rise with the increase of the gross domestic product, the ratios of urban population and tertiary industry. The incidence is closely related to the number of beds and population density in some regions. The higher the ratio of primary school, the lower the number of HFM cases. Based on the above analysis, it is the key measure to prevent and control the spread of the HFM epidemic in high-risk areas, and influence factors should not be ignored. [ABSTRACT FROM AUTHOR]

The effects of global climate change and human activities are anticipated to significantly impact ecosystem services (ESs), particularly in urban agglomerations of arid regions. This paper proposes a framework integrating the dynamic Bayesian network (DBN), system dynamics (SD) model, patch generation land use simulation (PLUS) model, and the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model for predicting land use change and optimizing ESs spatial patterns that is built upon the SSP-RCP scenarios from CMIP6. This framework is applied to the oasis urban agglomeration on the northern slope of the Tianshan Mountains in Xinjiang (UANSTM), China. The findings indicate that both the SD model and PLUS model can accurately forecast the distribution of future land use. The SD model shows a relative error of less than 2.32%, while the PLUS model demonstrates a Kappa coefficient of 0.89. The land use pattern displays obvious spatial heterogeneity under different climate scenarios. The expansion of cultivated land and construction land is the main form of land use change in UANSTM in the future. The DBN model proficiently simulates the interactive relationships between ESs and diverse factors. The classification error rates for net primary productivity (NPP), habitat quality (HQ), water yield (WY), and soil retention (SR) are 20.04%, 3.47%, 4.45%, and 13.42%, respectively. The prediction and diagnosis of DBN determine the optimal ESs development scenario and the optimal ESs region in the study area. It is found that the majority of ESs in UANSTM are predominantly influenced by natural factors with the exception of HQ. The socio-economic development plays a minor role in such urban agglomerations. This study offers significant insights that can contribute to the fields of ecological protection and land use planning in arid urban agglomerations worldwide. • An integrated framework combining DBN, SD, PLUS and InVEST models was proposed. • Impact of natural and socioeconomic factors on ESs was determined under climate scenarios. • The spatial pattern of ESs was optimized and partitioned using DBNs. • ESs in arid oasis urban agglomerations are mainly affected by natural factors. [ABSTRACT FROM AUTHOR]

• Synergistic effects of surface and groundwater on desert riparian vegetation were analyzed. • The cautionary depth to groundwater for vegetation expansion in the lower Tarim River is 4.0–5.0 m. • Flooding by surface water (lateral water transfer coverage) acts as the main driver for the expansion of vegetation in arid areas. • A zonal ecological water transfer strategy helps to promote effective ecosystem restoration in the region. Restoring degraded ecosystems in drylands is challenging because of low precipitation and high evapotranspiration. Water availability determines the existence and spatiotemporal distribution patterns of key endangered species struggling to survive in the severely damaged desert riparian ecosystem of the lower Tarim River (LTR) in NW China. Ecological water flow restoration measures with high costs and uncertainties have been implemented since 2000. The key task for scientists is to assess the success and drawbacks of this restoration project and propose specific recommendations for stakeholders to optimize the ecological benefits of the project in a cost-effective manner. In this study, Landsat time-series data from 1990 to 2020 were used to extract vegetation index values from river corridors along the LTR and explore the spatiotemporal patterns of desert riparian forest (DRF) vegetation. Based on land use and surface water data, we extracted the interannual spatial distribution range of vegetation and surface water, and selected several sample plots to demonstrate the influence of surface water and groundwater on vegetation change trends. The study results showed the following. 1) From 1990 to 1999, the vegetation slowly degraded; from 2000 to 2012, the extent of vegetation restoration was approximately 1 km from the river; and from 2013 to 2020, the extent of vegetation restoration at the Yingsu and Karday sections increased to 4.5–6.0 km, while that at the Arghan and Yiganbujima sections remained within 1 km from the river. 2) The vegetation growth rate increased substantially and was spatially heterogeneous when the groundwater level reached 4.0–5.0 m and was influenced by surface water divergence; the average vegetation expansion rates per square km for P 1 –P 4 were 0.017 km2/a, 0.011 km2/a, 0.005 km2/a, and 0.002 km2/a, respectively. 3) Flooding by surface water was the main driver of vegetation expansion when groundwater was stable and elevations in surface vegetation area were often accompanied by the spreading of surface water. Surface water was significantly correlated with vegetation cover and normalized difference vegetation index (NDVI) (Water pixels–Vegetation cover [P 1 : R2 = 0.57, P < 0.001; P 2 : R2 = 0.45, P < 0.01]; Water pixels–NDVI [P 1 : R2 = 0.22, P < 0.05; P 2 : R2 = 0.40, P < 0.01]). The increase in surface vegetation has alleviated the desertification process in the LTR, and the survival of the poplar has been mitigated. The results of this paper can help decision makers to formulate reasonable ecological water conveyance strategies and realize sustainable management of DRF ecosystems in arid zones. [ABSTRACT FROM AUTHOR]

At present, there is insufficient research on the refinement of the vertical structure of winter snowstorm systems in arid areas, and, compared with the central and eastern China, the observation sites in arid areas of northwestern China are scarce. To deepen the understanding of dynamics and microphysical processes and improve the level of forecasting and warning of snowstorms in northwestern China, the Institute of Desert Meteorology, China Meteorological Administration, Urumqi, carried out the Central Asia Extreme Precipitation Observation Test (CAEPOT) in Yili, Xinjiang, a typical arid region in China in February 2020. This paper uses multiple fine detection datasets obtained from the CAEPOT, including radar wind profiler, ground-based microwave radiometer, and millimeter-wave cloud radar to analyze macroscopic characteristics and microphysical changes of snowstorm system in Xinjiang. Studies have shown that the low trough with sufficient moisture, heat, power conditions, and weakening banded cloud system, which moved eastward from the Aral Sea to the west of Xinjiang during the snowstorm, were the key influencing system of this snowstorm. Before the snowstorm, the vertical shear of the horizontal wind field was severe, which aggravated the instability of the atmosphere, and there was upward motion in the lower atmosphere. A variety of physical quantities related to moisture showed a tendency to increase at the lower level and could be used as an early warning signal for snowstorm about 8 hours in advance, and the cloud and snow particles observed by millimeter-wave cloud radar were simultaneously developing upward and downward from 4 km, providing snowstorm warning 12 hours in advance. During the snowstorm, the horizontal wind speed and vertical speed were obviously enhanced, and the physical quantities related to moisture further increased, and, with the blocking and uplifting of the Tianshan Mountains, the snowstorm increased. The particles collided and grew while falling, resulting in a decrease in particle concentration and an increase in particle radius from high altitude to the ground, eventually resulting in near-ground reflectivity factor up to 30 dBz. In addition, reflectivity factor, physical quantities related to moisture, wind field, particle concentration, and particle radius all had a good correspondence with the beginning, end, and intensity of snowstorm, so when the physical quantities mentioned above weakened and stopped, snowstorm also weakened and stopped. In a word, this research is an important and meaningful work that provides more backgrounds and references for the forecast and warning of snowstorm in northwestern China. [ABSTRACT FROM AUTHOR]

There was presently a lack of multidimensional investigation on the impact of virtual water flow (VWF) on regional water use and scarcity. A framework for impact analysis of VWF in consideration of blue, green and grey water differentiation, taking the crop-water relationship estimation in 31 provinces of China as case study, was established in current paper. Results showed that, VWF, which mainly from northern to eastern plain and southeast, reduced agricultural water footprints by 8.3 (blue), 322.0 (green) and 52.5 (grey) G m3. National water stress index reduced from 1.20 (severe water stress) to 0.92 (high water stress), comparing crop consumption to production perspectives. VWF alleviated the resource-based water scarcity attributed to green water stress in south of the Yangtze River, and transformed the resource-based to systematic water scarcity in Xinjiang (XJ). Clarifying the influences of VWF on blue, green and grey water is the innovation of the analytical framework proposed in current paper. • Influences of virtual water flow (VWF) on blue, green and grey water footprint scarcity were quantified. • Green and grey VWFs and their effects on water resources were more impressive than blue water. • VWF alleviated water stress and changed water scarcity type in crop production of China. • Crop production improvement and optimization are proposed to increase the benefits of VWF. [ABSTRACT FROM AUTHOR]

• The addition of nano-silica can significantly improve oil production after fracturing. • Nano-silica improved in the anti-swelling performance of the gel-breaking fluid. • Nano-silica had an excellent oil-washing effect. • Field tests showed the cumulative oil production of the test wells was significantly enhanced. Nanomaterials have the characteristics of reducing water molecular clusters and improving surface properties. Therefore, it can effectively enhance the oil displacement (or imbibition) effect while developing low permeability and unconventional reservoirs. Volume fracturing based on horizontal wells has become the primary technology in developing unconventional reservoirs. In this paper, we investigated the effect of nano-SiO 2 on the rheology, flowback, and subsequent oil displacement performance of fracturing fluid. Results showed that nano-SiO 2 had little impact on the swelling and dispersion properties of the two thickeners (i.e., guar gum and emulsion polymer). The apparent viscosity of these two thickener solutions decreased by less than 15% after aging for 24 h. Nevertheless, nano-SiO 2 particularly influenced the rheological properties of guar gum based fracturing fluid. That is to say, the increase in the amount of nano-SiO 2 gradually reduced the temperature and shear resistance of the fracturing fluid. When the concentration of nano-SiO 2 reached 5%, the temperature and shear resistance of fracturing fluid decreased by 40%–60% in the temperature range of 80 to 100 °C. However, nano-SiO 2 had little effect on the fracturing fluid's breaking time and the solution's viscosity after breaking, and the surface tension of the solution slightly increased after breaking. The fracturing fluid added with nano-SiO 2 improved the performance of inhibiting clay swelling after the gel was broken. In addition, the solution after gel breaking had an excellent demulsification effect on emulsified crude oil when the concentration of nano-SiO 2 was less than 0.2%. While the concentration of nano-SiO 2 was greater than 0.5%, the increase in nano-SiO 2 concentration gradually strengthened the emulsification between crude oil and gel-breaking fluid. Nano-SiO 2 also had an excellent oil displacement effect, and it increased the recovery efficiency of primary water flooding by 9.99–13.34 percentage points. IThe field test of nanoparticle flooding and fracturing integrated technology was carried out for two wells in the Mahu tight oil reservoir of Xinjiang Oilfield, NW China. The pilot tests of the two wells were very successful, and the cumulative oil production on the 180th day after the fracturing operation was 20–50% higher than that of the comparison well. [ABSTRACT FROM AUTHOR]

Sexual segregation has been found among many vertebrate species. Argali, like other sexually dimorphic Capridae, form sexually segregated groups outside the breeding season. The degree of sexual segregation and its seasonal changes have never been examined and quantified in Asiatic species of wild sheep. In this paper we are considering seasonal fluctuation in the degree of sexual segregation and check the activity budget hypothesis to explain this phenomenon in the Darwin's wild sheep (Ovis ammon darwini), a subspecies of argali sheep (Ovis ammon). The activity budget hypothesis states that sexually size-dimorphic males and females segregate into different groups due to incompatibilities in activity budgets and movement rates. We collected data on activity budgets in the argali sheep from 2015 to 2016, in the Mengluoke Mountains of Xinjiang Province, and used Conradt's segregation coefficient (SC) to measure the degree of sexual segregation outside and during the rutting seasons. Our results showed that the SC value was highest outside the rutting season (0.98), when argalis were almost completely segregated. During the rutting period, the segregation coefficient dropped more than twofold (0.43) compared to the non-rutting season. In addition, our data supported the activity budget hypothesis: female and male argali had different behavioural activity patterns during the non-rutting season. Female argali spent more time feeding, followed by resting, standing, moving, and other behaviours, while males spent most of their time resting, followed by feeding, standing, other behaviours, and moving. Female argali spent significantly more time feeding than males, while males spent significantly more time resting and in other behaviours than females. Activity synchronization indices for both female groups and male groups were significantly higher than in mixed-sex groups. Sexual segregation is the best behavioural strategy for sexually dimorphic ungulates and the activity budget hypothesis explained this phenomenon well in Darwin's wild sheep. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via the original article. [ABSTRACT FROM AUTHOR]

The western Tianshan Mountains region in China has a complex topography where basins, mountains and glaciers co-exist. It is of great significance to study the sensitivity of meteorological factors in this region to different parameterization schemes of climate models. In this paper, the regional climate model RegCM4.5 is used to simulate the meteorological factor (mean temperature, maximum temperature, minimum temperature, precipitation and wind speed) occurring in the western Tianshan Mountains region from 2012 to 2016, so as to investigate the effects of different cumulus convective schemes (Grell, Tiedtke and Emanuel), including land cumulus convective schemes (LCCs) and ocean convective schemes (OCCs) on annual and seasonal simulations of meteorological factor by using the schemes of RUN1 (Grell for LCC and Tiedtke for OCC), RUN2 (Tiedtke for LCC and Emanuel for OCC), RUN3 (Grell for LCC and Emanuel for OCC) and ENS (the ensemble of RUN1, RUN2 and RUN3). The results show that the simulations of annual and seasonal meteorological factors are not significantly sensitive to the combination of LCCs and OCCs. In the annual simulations, RUN2 scheme has the best simulation performance for the maximum, average and minimum temperatures. However, other schemes of precipitation simulation outperform RUN2 scheme, and there is no difference among the four schemes for wind speed simulation. In the seasonal simulations, RUN2 scheme still performs well in the simulation of the average, maximum and minimum temperatures for four seasons, except for the simulation of the average temperature in spring and summer. For the simulation of the maximum temperature in summer, RUN2 scheme performs the same as ENS. For the simulation of other seasons, different meteorological factors have different performances in four seasons. Overall, the results show that different combinations of cumulus convection schemes can improve the simulation performance of meteorological factors in the western Tianshan Mountains of Xinjiang. [ABSTRACT FROM AUTHOR]

Xinjiang, the most northwest provincial administrative area of China, was the area where the oriental people met the occidental. The populations in Xinjiang exhibit very high genetic diversity. Previous study revealed that the eastern Xinjiang populations of the Bronze Age were mixed by the Eastern and the Western Eurasians. However, few studies have been performed to reveal when the population admixture started and how far to the west it reached. In this paper, we studied 148 craniofacial traits of 18 skulls from the Bronze Age Liushui graveyard in Khotan (Keriya County) in the southwest of Xinjiang. Seventeen craniometrical parameters of the Khotan samples were then compared with those of other ancient samples from around Xinjiang using dendrogram cluster analysis, principal components analysis, and multidimensional scaling. The results indicated that population sample of Liushui graveyard was mixed by the Western and Eastern Eurasians with about 79% contribution from the east. Therefore, we demonstrated that population admixture between east and west Eurasia can be traced back to as early as 1000 BC in southwest Xinjiang. [ABSTRACT FROM AUTHOR]

This paper investigates how a regional identity can be maintained in a nonmodern context, focusing on the case of southern Xinjiang in the late nineteenth and early twentieth centuries. The argument focuses on one aspect of this identity system, the popular historical tradition, arguing that its deployment through both manuscript technology and regional shrine pilgrimage contributed to the maintenance of Xinjiang's settled Turki identity group before the construction of the “Uyghur” identity. In the absence of a national history, separate histories of local heroes were linked together through custom anthology production and networked travel to shrines, yielding a modular historical tradition that accommodated local interests in regional narratives. Central to the operation of this system were community authorship in the manuscript tradition, the creation of a new genre for local history, and the publicly recorded circulation of pilgrims who heard performances of historical texts. This constellation of phenomena underpinned an alternative type of imagined community: a reasonably homogeneous, regional, writing-facilitated identity system flourishing in a nonmodern context. [ABSTRACT FROM PUBLISHER]

The implementation of systemic modeling methods to understand the variation of natural capital and ecosystem services in response to economic activities has huge significance for sound decision-making also at local scale. This paper reports the results of an investigation performed on the grassland ecosystem in North Xinjiang. The Emergy Synthesis method introduced by H.T. Odum in the 1980s was used to dynamically simulate the trend of grassland natural capital and its related ecosystem services. The simulation of natural capital was based on indexes of standing biomass, soil organic matter, soil nitrogen and soil water storages; ecosystem services were assessed by means of indexes of annual CO2 uptake, O2 release, forage supply as animal feed, food supply for human nutrition, and finally soil conservation. Results indicate that an upper limit of livestock carrying capacity in the region was reached in the year 1994; after that year the natural capital and main ecosystem services of the grassland ecosystem declined steadily. The emergy based currency equivalent value of the grassland ecosystem in terms of ecosystem services was higher than 87.3 billion Yuan RMB/yr in 1990. Such a value declined to 62.3 billion Yuan RMB/yr in 2010. Similarly, the total emergy based value of natural capital was about 331.7 billion Yuan RMB in 1990 and dropped to 155.6 billion Yuan RMB in 2010. According to the simulation model, the natural capital components such as biomass and soil stocks, the ecosystem services and the replacement value declined due to intensive herding and disturbance from human activities. Such trend is not sustainable because it exceeds the renewable carrying capacity of the area, but it is likely to continue until fundamental changes in human behavior and management of the grassland and animal husbandry occur or until the whole area is fully degraded. Social reasons prevent from simply decreasing the intensity of the livestock activities that provide living means to a large number of local farmers. As a consequence, the traditional low-productivity and environmental unfriendly grazing farming system should gradually be converted into a human-managed pasture based on farming higher productivity pasture crops in a small part of the local land, in order to decrease the grazing pressure on natural grassland of North Xinjiang. [Copyright &y& Elsevier]

Since the 1990s, the idea that water should be treated as an economic good has become a widely acclaimed but also disputed principle. In Xinjiang, a dry region in north-west China, the idea has been translated into government water management policies and practices. Based on investigations in the Kaidu-Kongque River Basin, this paper describes how the idea is interpreted in concrete water fee policies and practices in local water management in irrigation agriculture, and discusses what problems exist in current water fee collection practices and expenditure, as well as in water management in irrigation agriculture. The main argument is that water management is deeply tied to the political, social and economic conditions of the state, and water pricing is part of the complex, diverse and changing social reality. In the study area, the interpretation of treating water as an economic good has not contributed to a fairer and more efficient use of scarce water resources, but rather it has been applied to achieve other political and economic goals as well as to strengthen a powerful and rapidly growing bureaucracy. [ABSTRACT FROM AUTHOR]

In the context of carbon neutrality, the paper uses Super Efficiency Data Envelopment Analysis (DEA) to evaluate the level of regional energy efficiency in China, then selects Theil index to analyze the difference and change of regional energy efficiency. The results are as follows: (1) The overall level of energy efficiency in China is relatively low, and the average efficiency level from 2007 to 2019 is 0.568. Among them, Beijing is the highest, at 1.261, and Xinjiang is the lowest, at only 0.205. The energy efficiency of the eastern region is the highest in China: the average is 0.812. The central region is lower than the national average, with the value of 0.534. The lowest energy efficiency is in the western region, which is only 0.349. It can be seen that there are significant differences in regional energy efficiency, and from west to east has increased. (2) The Theil coefficient increased before 2012 and began to show a downward trend in 2013. The difference in the eastern region maintained the smallest downward trend among the three regions. The difference in the central region fluctuated and increased before 2011, and dropped sharply after 2012. In the western region, the coefficient is relatively stable and has not changed significantly. (3) Differences within and between regions in China show an overall downward trend. From the perspective of contribution rate, the difference between regions contributes the most to the overall difference. • We use super-efficiency DEA to measure China's regional energy efficiency. • We use Theil Index to illustrate regional differences in energy efficiency. • We have reached a conclusion that can provide a theoretical reference for policy making. • We compared the magnitude and trend of energy efficiency in various regions. [ABSTRACT FROM AUTHOR]

Monitoring and estimating potential snow disasters in pastoral areas of northern Xinjiang Province are important for decision-making in hazard reduction and prevention. In this paper, four scenes of NOAA/AVHHR (Advanced Very high Resolution Radiometer) images were combined with ground observation data in the north of Xinjiang Province to establish a model for monitoring snow depth. Using a linear spectral decomposition method, the pixel-based snow coverage and snow classification were studied. The spatial characteristics of snow, grassland, animal and climate factors were used to develop two new quantified indices for estimating the potential snow hazard grade and for integrated evaluation of snow disasters to grassland animal husbandry. The criteria for snow hazard grade and snow disaster evaluation were established. Results indicated that: (i) a pixel-based index K1, based on grassland yield, animal capacity, utilisable grassland area coefficient and seasonal grazing utilisation scenarios, can be quantitatively integrated to reflect the grassland capability of resisting snow disasters; (ii) the snow hazard index (K) systematically expresses the spatial and temporal changes of grassland and snow cover, and analyses, and predicts and evaluates the snow hazard grade under conditions where climatic and animal husbandry information may be unavailable during snow disasters. This index plays an important role in studies on early warning of snow hazard in pastoral areas; (iii) the integrated snow disaster evaluation index (E) and related classification criteria reflect the details of snow disaster magnitude in temporal and spatial scales, which provide the basic information for dynamic monitoring and integrated evaluation on snow disasters in pastoral areas. [ABSTRACT FROM AUTHOR]

The recent development in remote sensing imagery and the use of remote sensing detection feature spectrum information together with the geochemical data is very useful for the surface element quantitative remote sensing inversion study. This aim of this article is to select appropriate methods that would make it possible to have rapid economic prospecting. The Qishitan gold polymetallic deposit in the Xinjiang Uygur Autonomous Region, Northwest China has been selected for this study. This paper establishes inversion maps based on the contents of metallic elements by integrating geochemical exploration data with ASTER and WorldView-2 remote sensing data. Inversion modelling maps for As, Cu, Hg, Mo, Pb, and Zn are consistent with the corresponding geochemical anomaly maps, which provide a reference for metallic ore prospecting in the study area. ASTER spectrum covers short-wave infrared and has better accuracy than WorldView-2 data for the inversion of some elements (e.g., Au, Hg, Pb, and As). However, the high spatial resolution of WorldView-2 drives the final content inversion map to be more precise and to better localize the anomaly centers of the inversion results. After scale conversion by re-sampling and kriging interpolation, the modeled and predicted accuracy of the models with square interpolation is much closer compare with the ground resolution of the used remote sensing data. This means our results are much satisfactory as compared to other interpolation methods. This study proves that quantitative remote sensing has great potential in ore prospecting and can be applied to replace traditional geochemical exploration to some extent. [ABSTRACT FROM AUTHOR]

• Landscape fragmentation and connectivity of the Bogda forest, China, were assessed. • Connectivity was high for long but low for short/medium distance dispersal species. • Out of 196 habitat patches, two identified as integral for overall connectivity. • Integral patches and small patches (dispersal 'stepping-stones') to be prioritized. Habitat fragmentation hinders the dispersal of species and reduces the range of suitable habitat, thereby threatening the conservation of biodiversity. Even in protected areas, an assessment of the landscape connectivity of suitable habitat for species is still essential. In this paper, we investigated the overall forest connectivity, and determined patch characteristics and their role in species dispersion for species with different dispersal abilities in the World Natural Heritage Site of Bogda, Xinjiang, China. In our study site, the overall landscape connectivity was low for species with short- and medium-distance (≤500 m) dispersal, but high for species with long-distance (>500 m) dispersal abilities. We ranked the importance of patches according to their role in maintaining overall connectivity. Two patches were identified as being the most important: one mainly provided habitat area and fluxes (i.e., the flow of species into and out of the area) for species, while the other acted as a 'stepping-stone' for dispersal and provided fluxes. All species could use smaller patches (≤50 ha) as stepping-stones, and some of these patches could provide special environmental conditions for endemic species with short- and medium-distance dispersal abilities. Our study offers a way to prioritize the conservation of patches in a forest network for biodiversity and ecosystem health. [ABSTRACT FROM AUTHOR]

[Display omitted] • The construction land and farmland in Jinghe County has changed dramatically. • The farmland increased significantly and expanded along with a "triangle" three sides. • The biodiversity of farmland decreased, while the fragmentation degree of forest land increased. • Human factors are the main driving force of landscape pattern change in Jinghe County. The eco-environment of the arid area is constantly fragile global-wide. The study on the spatial and temporal variation of its landscape pattern can quickly identify the driving factors, which is an effective analysis method of ecological conservation in the arid area. In this study, Jinghe County, Xinjiang, in Northwestern China, is chosen as a case study of understanding the major driving force of the oasis landscape. Landsat satellite images of 1994, 2007, and 2017 are used as the basic data sources for analysis. The moving window method, transition matrix, and factor analysis are selected as the main technical means for this paper to reveal the temporal and spatial variation of landscape pattern in Jinghe County, and to quantitatively describe its driving factors. The results of the analysis show that: (1) The landscape pattern of Jinghe County has changed dramatically, especially the construction land and farmland. Both show an increase of 351.29% and 269.01% respectively between 1994 and 2017. Farmland increased the most, with the proportion of 6.45% in Jinghe County, and expanded along with the "triangle" three sides. The area of forest land increased slightly, the area of grassland and unused land decreased, and the area of water did not change significantly. (2) The dominant obvious regional differences of landscape types in Jinghe County are mainly manifested in farmland and forest land. Taking the unused land as the boundary, the biodiversity of farmland decreased, and the aggregation degree deepened, while the fragmentation degree of forest land increased. (3) The spatial–temporal variation of landscape patterns in Jinghe County is the result of the combination of natural and human factors, but the correlation between human factors and the change of landscape area is significantly greater than that of natural factors. Thus, human factors are the main driving force of landscape pattern change in Jinghe County. The scientific management and planning of the intensity of human activities in Jinghe County should be the focus of ecological environment restoration and protection. [ABSTRACT FROM AUTHOR]

Xinjiang is located in an arid and semi-arid climate region in China, but Xinjiang Ili river valley is more humid, with higher precipitation intensity and precipitation, which is closely related to the role of the Tianshan Mountains. In this paper, through the NCRP 1° × 1° reanalysis data and the conventional observation data of the Ili River Valley in Xinjiang, the terrain sensitivity experiment conducted by the WRF model is used to analyze the short-term extreme precipitation event of the Ili River Valley from 18–19 of May 2017, to reveal the influence of Tianshan Mountains on the extreme precipitation event of the Ili River Valley. The results show that: (1) The reduction or removal of the terrain will cause a wide range of wind field changes, weaken the vertical upward movement of the windward slope, and the accumulation of water vapor before the windward slope will also be reduced; a large-scale change of the terrain will also affect the direction of water vapor transportation. These effects together lead to a decrease or increase in regional precipitation. (2) "Fuzzy" (smooth) terrain will affect the precipitation simulated by changing the local vertical movement and water vapor transport, which shows that the WRF model's accurate description of the terrain structure characteristics of mountainous areas is beneficial to accurately simulate the precipitation process on the windward slope area. [ABSTRACT FROM AUTHOR]

In this paper, we comprehensively evaluated the utility of integrated long-term satellite-based precipitation and evapotranspiration products for drought monitoring over mainland China. The latest Integrated Multi-satelliteE Retrievals for Global Precipitation Measurement V06 three Runs precipitation products, i.e., the near real-time Early Run (IMERG-E) and Late Run (IMERG-L) and the post-real time Final Run (IMERG-F), and the Global Land Evaporation Amsterdam Model V3.3a (GLEAM) potential evapotranspiration (PET) products from 2001 to 2017 were considered. The accuracy of IMERG precipitation and GLEAM PET products was first evaluated against observed precipitation and Penman-Monteith method estimated PET, respectively, based on dense meteorological station network. The Standard Precipitation Evapotranspiration Index (SPEI) calculated based on IMERG precipitation and GLEAM PET products (SPEIs, including SPEI E , SPEI L and SPEI F corresponding to IMERG-E, IMERG-L and IMERG-F, respectively) were then validated by using SPEI calculated based on meteorological data (SPEIm) at multiple temporal-spatial scales. Finally, four typical drought events were selected to analyse the ability of SPEIs to characterize the temporal-spatial evolution of drought situations. The results showed that the IMERG-F presents much better performance than IMERG-E and IMERG-L in terms of higher CC and smaller BIAS and RMSE values over mainland China. The GLEAM PET well simulated the change trend of reference PET, but generally underestimated reference PET in Northwest China (NW), Xinjiang (XJ) and Qinghai–Tibet plateau (TP). In general, the performances of SPEIs over eastern China and Southwest China (SW) were significantly superior to their performances in the NW, XJ, and TP regions. Even though the SPEI F performed the best, the SPEI E and SPEI L also performed reasonably well in some specific regions. SPEIs can well capture the temporal process and reasonably reflect the spatial characteristics for four typical drought events. It is thus highlighted that the latest IMERG precipitation (especially for IMERG-F) and GLEAM PET products could be used as alternative data sources for comprehensive drought monitoring, on account of the water balance principle over mainland China, particularly in eastern China and SW China. The outcomes of this study will provide valuable references for drought monitoring by integration of multi-source remote-sensing datasets in the GPM era. • The utility of integrated IMERG precipitation and GLEAM PET for drought monitoring was evaluated over mainland China. • SPEIs based on IMERG precipitation and GLEAM PET were validated at multiple spatial and temporal scales over mainland China. • IMERG precipitation and GLEAM PET show great potential for drought monitoring over eastern China and Southwest China. • SPEIs can well capture the temporal process and reasonably reflect the spatial characteristics for typical drought events. [ABSTRACT FROM AUTHOR]

Remote sensing image segmentation with samples imbalance is always one of the most important issues. Typically, a high-resolution remote sensing image has the characteristics of high spatial resolution and low spectral resolution, complex large-scale land covers, small class differences for some land covers, vague foreground, and imbalanced distribution of samples. However, traditional machine learning algorithms have limitations in deep image feature extraction and dealing with sample imbalance issue. In the paper, we proposed an improved full-convolution neural network, called DeepLab V3+, with loss function based solution of samples imbalance. In addition, we select Sentinel-2 remote sensing images covering the Yuli County, Bayingolin Mongol Autonomous Prefecture, Xinjiang Uygur Autonomous Region, China as data sources, then a typical region image dataset is built by data augmentation. The experimental results show that the improved DeepLab V3+ model can not only utilize the spectral information of high-resolution remote sensing images, but also consider its rich spatial information. The classification accuracy of the proposed method on the test dataset reaches 97.97%. The mean Intersection-over-Union reaches 87.74%, and the Kappa coefficient 0.9587. The work provides methodological guidance to sample imbalance correction, and the established data resource can be a reference to further study in the future. [ABSTRACT FROM AUTHOR]