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It is difficult for traditional cooling liquids to meet equipment requirements due to the high power and high integration they demand. Nanofluids are nanoparticle dispersions with high thermal conductivities, thus they have been proposed for heat transfer applications. Boron nitride nanosheets (BNNSs) possess high thermal conductivities and excellent insulation properties. Here, we fabricated BNNS nanofluids and investigated their effects on thermal conductivity enhancements. We find that BNNSs can effectively enhance the thermal conductivity of water. The thermal conductivity of the BNNS nanofluids reached 2.39 W mK-1 at 24 vol% loading. The surface temperature changes of the nanofluids and water were observed during the heating process using an infrared camera. The results show that the nanofluids transfer heat much faster than water, indicating that the fabricated BNNS nanofluids have excellent thermal transfer properties.

Herein, a cigarette filter-templated graphene/epoxy composite was prepared with enhanced thermal conductive properties. The through-plane thermal conductivity of the epoxy composite was up to 1.2 W mK−1, which was 4 times that of it in the in-plane (0.298 W mK−1) after only 5 filtration cycles. The thermal conductive anisotropy and improvement in the through-plane thermal conductivity of the epoxy composite were attributed to the particular structure of cigarette filter-templated graphene in the epoxy matrix. The unique structure formed effective conductive pathways in the composite to improve the thermal transportation properties. The excellent thermal transportation properties allow the epoxy composite to be used as an efficient heat dissipation material for thermal management applications.

During the fieldwork of hydraulic engineering, practical engineers normally document geological information manually. Although there are some GIS-based digital tools for geology, they are not perfectly applicable to hydraulic engineering. As a result, the current work mode is ineffective, unmanageable, error-prone, and not conducive to subsequent analysis. To address this problem, we developed a digital tool which enables geological recording and quick modeling based on 3D real scenes in the field of hydropower projects. There are three modules in the surface tool: object recording, image interpretation, and field analysis. The object recording module is to mark geological points (e.g., drills and shafts), lines (e.g., faults, stratigraphic boundaries), and surfaces (e.g., slope and stocking yard) on a 3D scene and then store them in the database. The image interpretation is to interpret the 2D information in images to 3D models loaded in 3D software for further studies, such as GOCAD. The field analysis includes surface fitting, stability analysis of blocks, occurrences calculating, rock recognition, and 69/sketching. The tool is helpful for recording data, drawing geological boundaries, and building a preliminary model in the geological survey.

In recent years, the pursuit of high electrochemical stability and safety are considered as the newly growing and leading trend of next-generation lithium-ion batteries (LIB). The gelation of polymer electrolytes(GPEs) is the most direct and effective way to improve electrochemical performance. Herein, a novel composited polyethylene glycol (PEG) electrolyte is reported with a dual acceleration conduction effect of Li+ by the nano-TiO2 and triethyl phosphate (TEP). The negative ZETA potential of nano-TiO2/PEG internal interface promoted the dissociation of lithium salt by the unstable adsorption in diffusion layer, which enhanced the lithium ion migration and promoted the uniformity of lithium deposition. The flame retardant TEP improved safety performance, adjusted the affinity between EO and Li+, which bestowed it a high discharge 125.7mAh/g at 0.2C, with a low average capacity decay rate of 0.08% per cycle. The well-designed PEG-TEP-TiO2 GPEs showed wide electrochemical window, stable Li+ stripping/plating, smaller voltage polarizations and excellent cycling performance. The new understanding of composite electrolytes provides a powerful avenue for facilitating the gelation-solid-state lithium ion batteries.

For the first time, conductive starch/poly(ionic liquid) hydrogels from a polymerizable deep eutectic solvent (DES) by frontal polymerization (FP) were reported. The solubility and dispersibility for starch granules in the polymerizable DES was investigated. The effects of starch content on FP behaviors, mechanical properties and electrical conductivity of composite hydrogels were studied. Results showed that starch could be partially dissolved and dispersed in the DES. Comparing with the pure poly(ionic liquid) hydrogel from DES (the tensile strength was 41 K Pa), the tensile strength of composite hydrogel could increased by 3.07 times and reached 126 K Pa. When the fixed strain was 80 %, its compressive strength could increase by 6 times and reaches 16.8 MPa. The main reason was that there was a strong interfacial interaction between starch and the polymer hydrogel network. The starch/poly(ionic liquid) composite hydrogels also had good electrical conductivity. Absorption of water could increase the conductivity of the composite hydrogel significantly.

Studying the water use processes of desert riparian vegetation in arid regions and analyzing the response and adaptation strategies of plants to drought stress are of great significance for developing ecological restoration measures. Based on field monitoring and test analyses of physiological ecological indicators of dominant species (Populus euphratica and Tamarix chinensis) in the desert riparian forest in the lower reaches of the Tarim River, the water relations of P. euphratica and T. chinensis under drought stress are discussed and some water use strategies put forward. The results show that (1) concerning plant water uptake, desert riparian forests depend mainly on groundwater to survive under long-term water stress. (2) Concerning plant water distribution, the survival of P. euphratica and nearby shallow root plants is mainly due to the hydraulic lift and water redistribution of P. euphratica under drought stress. (3) Concerning plant water transport, P. euphratica sustains the survival of competitive and advantageous branches by improving their ability to acquire water while restraining the growth of inferior branches. (4) Concerning plant transpiration, the sap flow curves of daily variations of P. euphratica and T. chinensis were wide-peak sin and narrower-peak respectively. T. chinensis has better environmental adaptability.

With the development of electronic devices such as integrated circuits toward the continual increase in power density and consumption, the efficient heat dissipation and low thermal expansion of materials become one of the most important issue. However, conventional polymers have the problem of poor thermal dissipation performance, which hinder application for electronic devices. In this work, the two-dimensional material, MXene (Ti3C2), is used as the reinforcement additive to optimize the thermal properties of polymers. We reported the preparation of multilayer Ti3C2 MXene by HF etching method and obtained few-layer Ti3C2 MXene by simple ultrasonication. Meanwhile, Ti3C2/epoxy composites were prepared by a solution blending method. The results show that the thermal properties of the composites are improved in comparison with the neat epoxy. Thermal conductivity value (0.587 W/mK) of epoxy composite with only 1.0 wt% Ti3C2 MXene fillers, is increased by 141.3% compared with that of neat epoxy. In addition, the composite presents an increased glass transition temperature, high thermal stability and lower coefficient of thermal expansion. This work is of great significance for the research of high-performance composite materials.

Defect reactions and reaction parameters of SrTiO3 and BaTiO3, published in literatures, over the doping range from acceptor to donor, temperature range from room temperature to >1500 K and oxygen partial pressure range of 10 - 25 to 1 bar are summarized in this work, and a Windows® based DefectChemCal program is developed. With the program, one can calculate the defect concentrations and the electrical properties of acceptor and donor-doped SrTiO3 and BaTiO3, and the validity of the program is demonstrated by comparing the calculation and experimental results.

Different groundwater conditions affect leaf hydraulic conductance and leaf pressure–volume parameters in Populus euphratica at the extremely arid zone in the northwest of China. Efficient water transport inside leaves constitutes a major determinant of plant function, especially in drought-stressed plants. The previous researches have reported the correlation between leaf hydraulic properties and water availability. In this study, we tested the hypothesis that water relation parameters of Populus euphratica in an extremely arid zone of China are sensitive and acclimated to groundwater depth. We measured leaf hydraulic conductance (K leaf) using rehydration kinetics methods (RKM), pressure–volume (P–V) curves, and leaf vulnerability curves of P. euphratica growing at four groundwater depth gradients. We also assessed the hydraulic safety margins across groundwater depth gradients. We found that K leaf–max shows an increasing trend as the groundwater depth increases, while osmotic potential at full turgor (πft) and turgor loss point (Ψtlp) exhibits a decreasing trend, suggesting that increased tolerance to drought is formed as the groundwater depth increases. Furthermore, safety margins showed positive and negative variations under different groundwater depths, indicating that P. euphratica has formed special drought survival strategies, which can be summarized as a “conservative” strategy in favorable water conditions or a “risk” strategy in severe drought stress.

In thermal management systems, it is quite meaningful to achieve high thermal conductivity enhancement efficiency for polymer-based thermally conductive materials with low content filler. In this work, a novel 2D all-carbon allotrope, graphdiyne (GDY) was attempted as a filler to improve the thermal conductivity of the polymer matrix. The poly(vinylidene fluoride) (PVDF) composite films, with ultralow mass fraction (≤ 1 wt%) GDY, were fabricated by solution blend and hot pressing. As a consequence, the obtained composite film, at only 1 wt% GDY content, exhibited a high in-plane thermal conductivity of 3.86 W/mK, which revealed a 2249% thermal conductivity enhancement compared with neat PVDF. This excellent heat transport performance makes GDY an attractive filler for high-performance composite for electronic cooling applications.

Constructing a three-dimensional thermal transport framework is an effective strategy for enhancing thermal conductivity of polymer composites. Vacuum-assisted filtration has been utilized as an effective method to prepare heat spreader films, which always exhibit poor heat dissipation performance in the axial direction. Herein, with the incorporation of spherical alumina, a pea-pod-like binary alumina-graphene architecture has been fabricated via vacuum filtration and impregnated with epoxy to obtain alumina-graphene/epoxy composite. The thermal conductivity of epoxy composite in axial direction has risen to 13.3 W m−1 K−1 with the assistance of pea-pod-like binary alumina-graphene foam with 12.1 wt% graphene and 42.4 wt% alumina loading. Thermal conductivity of the composite in radial direction reached 33.4 W m−1 K−1, which exhibits about 166 times enhancement than that of pure epoxy. The test result of the thermal conductivity of the composite under various conditions and heat transport applications confirmed the excellent thermal transport performance of the composite. Our work provides a new idea to significantly enhance the thermal conductivity of thermal management materials.

Investigation of the water sources used by trees of different ages is essential to formulate a conservation strategy for the riparian tree, P. euphratica. This study addressed the contributions of different potential water sources to P. euphratica based on levels of stable oxygen and hydrogen isotopes (δ18O, δ2H) in the xylem of different aged P. euphratica, as well as in soil water and groundwater along the lower Heihe River. We found significant differences in δ18O values in the xylem of different aged P. euphratica. Specifically, the δ18O values of young, mature and over-mature forests were −5.368(±0.252) ‰, −6.033(± 0.185) ‰ and −6.924 (± 0.166) ‰, respectively, reflecting the reliance of older trees on deeper sources of water with a δ18O value closer to that of groundwater. Different aged P. euphratica used different water sources, with young forests rarely using groundwater (mean 45 %), and mature and over-mature forests using water from deeper than 100 cm derived primarily from groundwater.

Based on the data of five observed meteorological elements (temperature, precipitation, wind speed, sunshine duration, and relative humidity) from 22 stations, the paper investigated the climate variations in northern Xinjiang over the past 50 years. The analytical results showed that both the temperature and the precipitation have increased significantly (0.35 °C/10 y, 11.2 mm/10 y) during the period of 1960–2011. An abrupt change was detected to have occurred in 1986 for temperature and in 1987 for precipitation. Autumn was the season when the temperature increased most dramatically, and winter and autumn were the seasons when the precipitation increased most dramatically. The twenty years after 1990 were the warmest and wettest two decades of the past ∼50 years, but the warming and wetting paces have slowed down during the same period. The results also showed that the mean annual minimum temperature increased more dramatically than the mean annual maximum temperature, resulting in a greatly reduced diurnal range. The reasons or mechanisms for rising trend of temperature during the past 50 years and also for the faster rising rate of the temperature in northern Xinjiang and the adjacent areas have been reasonably explored in published literature. However, the reasons or mechanisms for the rising trend of the past 50-year precipitation in northern Xinjiang and the adjacent areas have not been reasonably explored. This wetting trend has not extended further to the surrounding areas including Republic of Mongolia, major part of North China, and five republics of the former Soviet Union, and the need is thus pressing to explore the reasons or mechanisms behind this relatively “localized” wetting trend.

Based on the long-term trends analysis of five meteorological parameters (temperature, precipitation, wind speed, sunshine duration and relative humidity) in the four chosen stations of different settings, this paper attempts to reveal the characteristics of climate change in Urumqi City during 1960–2013. Our analytical results showed that both the temperature and precipitation in the Urumqi City have increased significantly since the middle 1980s. Autumn was the season when the temperature increased most drastically, and winter was the season when the precipitation increased most drastically. The average minimum temperature increased faster than the average maximum temperature, thus resulting in greatly reduced diurnal and annual temperature ranges. The wind speed was weakening significantly since the middle 1980s. The sunshine duration did not display any geographic coherence or consistency among different stations. The relative humidity has maintained more or less a constant, meaning that the absolute amount of water vapor has been increased under warming conditions. Comparatively, the Urumqi station (i.e., the urbanized area) had the most pronounced changes in temperature, precipitation and sunshine duration and the most pronounced changes were possibly due to the combined effects of natural and anthropogenic factors. Climate change in the mountainous area was synchronous with that in the plain area and the underlying surfaces and topographies, together with degrees of human activities, distinguished the regional climatic responses to global warming.

In the background of clothing products online shopping, data of 276 service failure experienced consumers had been collected through online survey. The aim of this study was to investigate the influence mechanism of service recovery strategies (compensation, recovery speed, apology and recovery initiation) on recovery satisfaction (RS) and behavior intentions (BI) (Word-of-Mouth (WOM) and Repurchase Intention (RI)). Hierarchical regression and bootstrapping had been used to examine the mediation effect of WOM and RS. The findings indicated that all of the four strategies had positive effects on RS; Positive WOM had the mediation effect between RS and RI; RS had the mediation effects between recovery strategies and BI. Also, theoretical and practical contributions had been discussed to give some new perspectives or advices. Limitations and suggestions for future research had been mentioned in the end.

A strategy was reported to prepare boron nitride nanosheets (BNNSs) by a molten hydroxide assisted liquid exfoliation from hexagonal boron nitride (h-BN) powder. BNNSs with an average thickness of 3 nm were obtained by a facile, low-cost, and scalable exfoliation method. Highly thermally conductive polyimide (PI) composite films with BNNSs filler were prepared by solution-casting process. The in-plane thermal conductivity of PI composite films with 7 wt% BNNSs is up to 2.95 W/mK, which increased by 1,080% compared to the neat PI. In contrast, the out-of plane thermal conductivity of the composites is 0.44 W/mK, with an increase by only 76%. The high anisotropy of thermal conductivity was verified to be due to the high alignment of the BNNSs. The PI/BNNSs composite films are attractive for the thermal management applications in the field of next-generation electronic devices.

The Green Corridor in the lower reaches of Tarim River in northwestern China has an extreme hot and dry climate. Vegetation here, consisting of arbor, shrub and grass, relies on groundwater exceedingly. However, the increasing anthropogenic activities of large-scale agricultural reclamation and unreasonable water utilization in the upper and middle reaches caused the 321-km riverway in the lower reaches to dry up completely in 1972 and resulted in the sharp decline of groundwater, followed by the ruin of desert riparian vegetation on a large scale. The Green Corridor is on the verge of shrinking. Water has a key role in maintaining ecological balance and socioeconomic development. This paper, focused on the relationship between vegetation and groundwater, discusses (1) the change of groundwater table caused by the ecological water delivery carried out in the lower reaches of Tarim River; (2) the appropriate groundwater depth meeting the vegetation’s survival; (3) the minimum ecological flux and ecological water requirement for the growth of natural vegetation. It was shown that (1) based on the analysis of the monitoring data from the groundwater level of ten times water delivery, such an extensive artificial watering takes positive effect on raising the groundwater level along the two sides of the river; (2) a groundwater table depth of 2–4 m is probably the appropriate ecological water table level for the lower reaches of the Tarim River, and 6 m is the threshold for the local vegetation; (3) at the lower Tarim River, 1.157 × 108 m3 of water flow is needed for itself. The longer the duration of water releases, the greater would be the groundwater rise and the larger the range of vegetation influenced. It was found that the duration and volume of water delivery was closely related to restoration of vegetation in the lower reaches of the Tarim River. The goal of this paper is to offer scientific evidences for water delivery in the rigorous areas to maintain an ecological balance.

The high integration and high power devices cause serious local heat accumulation, which will damage the reliability and service life of devices. Efficient heat dissipation has become priority issues for electronic devices. As a one-dimension thermal conductive fillers, carbon fibers (CFs) exhibits ultra-high thermal conductive performance. However, the superiority is not fully utilized by traditional approaches especially for short CFs. In this work, a micro-phragmites communis structure was constructed for enhance thermal transfer property of composites. And the composites were obtained by immersed in polydimethylsiloxane (PDMS) with vacuum-assisted. Owing to vertical CFs structure, the through-plane thermal conductivity of polymer composites achieving 6.04 W m−1 K−1 at low CFs loading. Further, the surface temperature variation of composites in heating and cooling process was observed by infrared camera, and it exhibits excellent heat transfer performance. The applicability of the high thermal conductive composite was investigated by applied in CPU heat dissipation. This work reveals promising approaches for fully utilize the ultra-high axes thermal conductivity of CFs to prepared high thermal conductive composites.

Corn is one of most important agricultural products in China. Understanding impacts of regional climate change, as well as agricultural management practices, on corn yields is critical for maintaining stable corn production. Using the DayCent model and observed climatic data in Sichuan province (a humid and hot environment) and Hebei province (a cold and dry environment) in China, corn yields in 1948-2010 were simulated. The spatial variations of simulated corn yields and the relationship between regional climate variability and warming with corn yields in these two environments were analyzed. The results demonstrated that: (1) corn yields in Zhangjiakou of Hebei and most regions of Sichuan decreased significantly after 2000 compared to other regions; (2) relative humidity and precipitation exhibit a significant negative correlation with observed crop yields in the growing season in Hebei province; (3) air temperature from 23.33 °C to 29 °C constitutes the ideal range influencing the increase of corn yields in Sichuan; (4) the planting of the large amount of silage maize in Sichuan compensated the negative impact of the rising air temperature on corn yields; (5) sensitivity tests for different fertilization levels and OMAD suggest that an increasing fertilization level significantly affects corn yields in Hebei province, a cold and dry environment, while a decreasing fertilization level has a significant negative effect in Sichuan province, a hot and humid environment. The overarching goal of these analyses is to provide the theoretical basic for maintaining stable corn production under regional climate warming and different agricultural management practices.

In this paper, we discuss the adaptation mechanisms of desert riparian forest vegetation's responses to drought stress. Ecological and physiological parameters are presented, including coverage, density and species diversity. Also investigated are the photosynthesis, fluorescent parameters, leaf water potential, leaf proline (PRO), soluble sugar, malondialdehyde, superoxide dismutase (SOD), peroxidase (POD) and abscisic acid (ABA) of the main constructive species at various buried groundwater depths of the Tarim River's lower reaches. The results reveal a close relationship between vegetation and groundwater depth and show that the most appropriate groundwater depths for the optimal composition and structure of plant communities is 2–6 m. For the main constructive species, Populus euphratica and Tamarix spp., the most appropriate groundwater depths and the critical depths are 4 and 8 m for P. euphratica and 6 and 10 m for Tamarix spp., respectively. However, when groundwater depths exceed 4 m for P. euphratica or 6 m for Tamarix spp., the plants suffer drought stress. During moderate or extreme drought stress, P. euphratica and Tamarix spp. rapidly accumulate PRO, soluble sugar, SOD and ABA in their leaves, thereby reducing leaf water potential and stomatal conductance, enhancing osmoregulation and alleviating the esterification of cell membranes. Such a response decreases the yield as well as the photosynthetic and electron transport rate, thus improving the efficiency of water utilization. Complementary actions in resisting drought stress likewise occurred between SOD activity and POD activity, and between the contents of PRO and soluble sugar in P. euphratica and Tamarix spp. leaf cells. In the main, P. euphratica accumulated a large amount of soluble sugar for osmoregulation to counter drought stress, whereas Tamarix spp. accumulated a large volume of PRO. When suffering extreme drought stress, Tamarix spp. enhanced its POD activity. Copyright © 2013 John Wiley & Sons, Ltd.

Based on hydrological and climatic data and land use/cover change data covering the period from 1957 to 2009, this paper investigates the hydrological responses to climate change and to human activities in the arid Tarim River basin (TRB). The results show that the surface runoff of three headstreams (Aksu River, Yarkant River and Hotan River) of the Tarim River exhibited a significant increasing trend since 1960s and entered an even higher-runoff stage in 1994. In the contrary, the surface runoff of Tarim mainstream displayed a persistent decreasing trend since 1960s. The increasing trend of surface runoff in the headstreams can be attributed to the combined effects of both temperature and precipitation changes during the past five decades. But, the decreasing trend of surface runoff in the mainstream and the observed alterations of the temporal and spatial distribution patterns were mainly due to the adverse impacts of human activities. Specifically, increasingly intensified water consumption for irrigation and the associated massive constructions of water conservancy projects were responsible for the decreasing trend of runoff in the mainstream. And, the decreasing trend has been severely jeopardizing the ecological security in the lower reaches. It is now unequivocally clear that water-use conflicts among different sectors and water-use competitions between upper and lower reaches are approaching to dangerous levels in TRB that is thus crying for implementing an integrated river basin management scheme.

Taking the group of IT RD 2) Work-family promotion positively affects psychological contract, and negatively affects turnover intention; 3) Psychological contract partly mediates the effect of work-family conflict and promotion on turnover intention. This study filled the gaps of theoretical research, and provided realistic suggestions to the enterprise how to reduce turnover rate.

Based on the hydro-meteorological data over the past 50 years (1961–2010), the runoff change of the Kaidu River was predicted for the future 30 years (2011–2040). Two statistical downscaling models, the Statistical DownScaling Model (SDSM) and the Statistical Analog Resampling Scheme (STARS), were used to downscale the HadCM3 outputs for projecting the future climate scenarios of the basin. The Soil and Water Assessment Tool (SWAT) hydrological model was driven by the projected climate scenarios to generate the future runoff. Modeling results suggested that the SWAT model can well duplicate the recorded runoff changes in the basin and thus can be applied to simulation of future runoff changes. Both the SDSM and the STARS models performed well in simulating the temperature but relatively poorly in simulating the precipitation. Under the A2 and B2 scenarios the basin will experience a significant increasing trend in temperature and an indistinctive change trend in precipitation during the entire forecast period. Under the S1–S3 scenarios, both temperature and precipitation do not exhibit distinctive changes. In terms of river runoff, the predicted average annual runoff will be relatively abundant during the period from 2010s to 2020s but obviously short after 2020s under A2 scenario and will be kept relatively steady under B2 scenario. The predicted runoff will fluctuate drastically with no any significant trend under S1–S3 scenarios. The relatively high runoffs under S2–S3 scenarios seem to indicate the importance of temperature increasing in generating runoff. The scenario-based predictions suggest that moderate emission (e.g., B2) or moderate warming (e.g., S2) is beneficial to maintaining the expected level of runoff in the future.

Eco-hydrological research in arid inland river basins has been a focus of geologists and ecologists as it is crucial for maintaining the sustainable development of socio-economy, particularly in ecologically vulnerable areas. Based on the research work carried out in the Tarim River basin of Xinjiang, northwestern China, this paper summarizes synthetically the climate change and associated responses of water resources in the mountainous area, land use and land cover in the oasis, and plants responding to environmental stresses in the desert area of the river basin. Research gaps, challenges, and future perspectives in the eco-hydrological studies of the Tarim River basin are also discussed.

In this case study, the diurnal courses of gas exchange in Populus euphratica at different groundwater depths in the lower reaches of Tarim River were investigated to understand the effects of soil hydrology on photosynthesis and water use efficiency (WUE) of vegetation in arid desert area. It was found that the photosynthetic rate (PN) was not sensitive to the change of groundwater depth (GD) within the range of 4.2–6.8 m. Compared to stomatal conductance (gs) and transpiration rate (E) of P. euphratica grown at GD 4.2, 5.6 and 5.8 m, gs and E at GD 6.8 m both markedly declined in June, suggesting that P. euphratica at deeper GD can avoid overall water loss by stomatal adjustment. The intrinsic water use efficiency of P. euphratica first decreases with the increasing GD, but when GD increased to 6.8 m, intrinsic WUE increased by 1.2–2.2 fold, compared with the WUE of P. euphratica at GD 4.2–5.8 m, indicating that intrinsic WUE of P. euphratica will increase when the plant suffers from moderate drought stress.

We studied the dominant environmental factors that affect the gas-exchange characteristics and water potential (ψ) of broad-ovate leaves of Populus euphratica Oliv. in extreme arid area of Tarim River, China, and their correlation to water status of P. euphratica by analyzing on-field monitored meteorological data, soil moisture and salinity, P. euphratica leaf gas exchange and ψ, and revealed the indicative threshold of environmental factors for P. euphratica leaf water changes and growth. The results indicated that meteorological factors such as air relative humidity (RH), air temperature (Tair), etc. are the dominant factors. The threshold value of RH is (48.19 ± 1.06)% for P. euphratica growth, i.e. RH from 10.69% to 48.19% is suitable for P. euphratica growth in extremely arid region of Tarim River. This study provides a theoretical basis for reducing drought damage to P. euphratica and maintaining normal growth of P. euphratica by in-time watering.

The Ili River Valley is located in western Xinjiang as a ‘wet island’ in an arid region, and is rich with unique plant species. In this paper, TWINSPAN (two-way indicator species analysis) and DCCA (detrended canonical correspondence analysis) were performed to analyze the vegetation patterns and influential factors based on data from a field investigation in the mountainous region of the valley. 259 species were recorded in the 85 plots, up to 235 species all appeared in the herb layer, and species of woody plants were very limited. The species composition varied widely between the northern slope and the southern slope. 35 plots on the northern slope were clustered into 10 groups, and 50 plots on the southern slope were clustered into 11 groupes. The DCCA ordination indicated that elevation as a compound factor was the critical driver of species composition on both the slopes. The vegetation patterns were also related to slope gradient, aspect, soil water, soil pH, organic matter and total nitrogen. Available phosphorus and available potassium were important factors on the southern slope only, maybe because of the appearance of shrubs there. The proportion of variation explained was 49.54% on the northern slope and 41.08% on the southern slope. Edaphic variables were more important than topographical variables on the northern slope, while topographical variables seemed to be more influential on the southern slope.

Taking Tamarix hispida as test materials, a group of different concentrations of NaCl were then added to the pots and the salinity was maintained at 3.0(CK), 5.0, 10.0, 15.0 and 20.0 g/L. Na+ content and K+ content of different samples were analyzed by ICP-AES. This paper has studied the influence of salt stress on the content and the distribution of Na+ and K+ in Tamarix hispida and discussed the ion transport and selective absorption mechanism of plants under the salt stress. The result shows that Na+ content of Tamarix hispida were increasing prominently with increased salinity and K+ content was rising at first and then decreasing. In the same level of salt concentration, the order of Na+ content and K+ content in Tamarix hispida is leaf>root>stem, leaf is the main part of Na+ accumulation and K+ accumulation. And the stem is just a transmission channel for Na+ where does not exist the cumulative process. In different growth areas, Na+ content is always greater than K+ content. That is because Tamarix hispida is a salt secretion plant. It has expelled the excess salt in leaves outside the body through the salt glands, which will relieve the damage of Na+ on roots to a certain extent. K+/ Na+ in leaves are greater than the one in roots, which explains the salt resistance of leaf is greater than the root.

Based on the glacial flood events and climate change in the Yarkant River basin during the past 50 years, the study investigated the long-term change of temperature and precipitation, the characteristics of glacial floods, the origin of sudden flood release, the suggested flood mechanism of glacial lakes and the relationship between glacial floods and climate change. Results showed that there was an obvious increase in the temperature of the basin since 1987. Specifically in the mountainous area, the significantly increasing temperature in the summer and autumn seasons accelerated the melting rate of glaciers and caused glacial-lake burst. Sudden flood release occurred frequently. The frequency of glacial-lake outburst floods was 0.4 times/a during the period 1959-1986 and increased to 0.7 times/a during 1997-2006. Peak discharge also increased. There were seven floods with peak discharge over 4000 m(3)/s from 1959-2006, and three occurred after 1997. The increasing frequency and magnitude of glacial outburst floods mirrored the effect of climate warming on glaciers. (C) 2010 Elsevier Ltd and INQUA. All rights reserved.

In this paper, detrended canonical correspondence analysis was performed to analyze the relationships between diversity indices and environmental gradients, generalized additive model was employed to modal the response curves of diversity indices to the elevation, based on data from field investigation in the mountainous region of the Ili River Valley and a survey of 94 sample plots. Two hundred fifty-nine plant species were recorded in the 94 sample plots investigated, up to 235 species all appeared in the herb layer, and the species of woody plants were very limited. The communities with a complicated vertical structure presented higher values of indices. The distribution pattern of plant species diversity on the northern slope was affected by such factors as elevation, slope aspect, slope gradient, total nitrogen, total potassium, soil water content, organic matter, and that on the southern slope was mainly affected by such factors as slope gradient, elevation, available phosphorus, and soil water content. On the northern slope, Patrick index and Shannon-Wiener index of the plant communities presented a bimodality pattern along altitude; Simpson index and Pielou index showed a partially unimodal pattern. On the southern slope all the distribution pattern of species diversity indices showed two peaks, though Patrick index's bimodality pattern was not an obvious one. These altitudinal patterns were formed by the synthetic action of a variety of environmental factors with elevation playing an important role.

We analyzed and estimated the distribution and reserves of soil organic carbon under nine different vegetation conditions including alpine meadow, meadow steppe, typical steppe, desert steppe, and temperate coniferous forest and so on, in the Ili River valley, Xinjiang according to data from field investigations and laboratory analyses in 2008 and 2009. The study results show that the soil organic carbon content in the Ili River valley varies with the type of vegetation. In the 0-50 cm soil horizon, the soil organic carbon content is the highest under the vegetation types of alpine meadow and meadow steppe, slightly lower under temperate coniferous forest and typical steppe, and the lowest under the intrazonal vegetation and desert vegetation types. The soil organic carbon content shows basically a tendency to decrease as soil depth increases under various vegetation types except in the case of the intrazonal vegetation. Similarly, the soil organic carbon density is the highest and varies little under the vegetation types of alpine meadow, meadow steppe and temperate coniferous forest, and is the lowest under the desert vegetation type. Both the soil organic carbon content and density in the topsoil of meadows in the Ili River valley are high, so protecting meadows in the Ili River valley, and especially their topsoil, should be a priority so that the potential of change in soil organic carbon in the shallow soil horizon is reduced, and this means maintenance of the stability of the soil carbon pool.

Mobile edge computing (MEC) is an emerging technology that leverages computing, storage, and network resources deployed at the proximity of users to offload their delay-sensitive tasks. Various existing facilities including mobile devices with idle resources, vehicles, and MEC servers deployed at base stations or road side units, could act as edges in the network. Since task offloading incurs extra transmission energy consumption and transmission latency, two key questions to be addressed in such an environment are (i) should the workload be offloaded to the edge or computed in terminals? (ii) Which edge, among the available ones, should the task be offloaded to? In this paper, we formulate the task assignment problem as a one-to-many matching game which is a powerful tool for studying the formation of a mutual beneficial relationship between two sets of agents. The main goal of our task assignment mechanism design is to reduce overall energy consumption, while satisfying task owners&rsquo, heterogeneous delay requirements and supporting good scalability. An intensive simulation is conducted to evaluate the efficiency of our proposed mechanism.

Heterogeneous networks provide an effective solution to bridge the gap between enormous global traffic demands and limited spectrum resources. In this paper, we investigate the resource al...

The characteristic of change in value of Tarim River ecosystem service function and its causes are discussed by combining the remote-sensing images with social statistical data related to the change in land utilization of Tarim River Main stream area during 1973–2005 and applying correlation analysis, regressional analysis and principal component analysis methods. The results show a right ascension state in the value of Tarim River ecosystem service function over the past 30 years. Of which, the Cropland ecosystem service function is of the largest increment in the economic value, which is far in excess of other ecosystem systems; the capacity of forest, grassland and wetland in service supply and value attribution show a downward tendency relatively; the area of Cropland and unused land ecosystems increase while that of forest, grassland and wetland ecosystems decrease, which indicates that the integral capacity and balance of the ecosystem in the region investigated has been affected severely and the ecosystem deteriorated; the economic activity of human is the key factor to regulate the change in economic value of Tarim River ecosystem service function and its trend in development.

Changes of stomatal conductance (g s), net photosynthetic rates (P N) and water use efficiency (WUE) were investigated in Populus euphratica grown on sites with different groundwater depths (GDs) under two CO2 concentrations in the lower reaches of Tarim River, Xinjiang, northwestern China. P N in P. euphratica only slightly decreased when the groundwater depth increased from 4.12 to 7.74 m below the ground surface. P N values significantly increased in response to an elevated CO2 concentration at all GDs except at GD of 4.12 m for its good availability of groundwater. WUE values decreased with an initial increase in the groundwater depth, but increased when the groundwater depth reached 7.74 m especially under the elevated CO2 concentration. The g s values measured at 4.12 and 4.74 m both decreased indistinctively by only 3% due to CO2 enrichment; however, when GDs increased to 5.54 and 7.74 m, the g s values decreased significantly by about 10%. It shows that the response of g s in P. euphratica to elevated CO2 is weaker under lower groundwater depth (mild drought stress) but stronger under deeper groundwater depth (moderate drought stress). Results from this study suggest that groundwater depth could determine the response of photosynthesis to future CO2 enrichment in P. euphratica in arid desert areas.

Spatio-temporal variation of snow depth in the Tarim River basin has been studied by the empirical orthogonal function (EOF) based on the data collected by special sensor microwave/imager (SSM/I) and scanning multichannel microwave radiometer (SMMR) during the period from 1979 to 2005. The long-term trend of snow depth and runoff was presented using the Mann-Kendall non-parametric test, and the effects of the variations of snow depth and climatic factors on runoff were analysed and discussed by means of the regression analysis. The results suggested that the snow depth variation on the entire basin was characterised by four patterns: all consistency, north–south contrast, north-middle-south contrast and complex. The first pattern accounting 39·13% of the total variance was dominant. The entire basin was mainly affected by one large-scale weather system. However, the spatial and temporal differences also existed among the different regions in the basin. The significant snow depth changes occurred mainly in the Aksu River basin with the below-normal snow depth anomalies in the 1980s and the above-normal snow depth anomalies in the 1990s. The long-term trend of snow depth was significant in the northwestern, western and southern parts of the basin, whereas the long-term trend of runoff was significant in the northwestern and northeastern parts. The regression analysis revealed that the runoff of the rivers replenished by snow melt water and rainfall was related primarily to the summer precipitation, followed by the summer temperature or the maximum snow depth in the cold season. Our results suggest that snow is not the principal factor that contributes to the runoff increase in headstreams, although there was a slow increase in snow depth. It is the climatic factors that are responsible for the steady and continuous water increase in the headstreams. Copyright © 2009 John Wiley & Sons, Ltd.

The photosynthetic characterization of Populus euphratica and its response to the elevated carbon dioxide concentration ([CO 2 ]) were analyzed based on its net photosynthetic rate ( P n ), stomatal conductance ( g s ), intercellular CO 2 concentration ( C i ), transpiration rate ( T r ), and water use efficiency (WUE) at different groundwater depths measured by a portable gas exchange system (LI-6400) in the lower reaches of the Tarim River. The results showed that the elevation of [CO 2 ] decreased the g s , and increased the P n , C i and WUE of P. euphratica. However, the effects of the elevated [CO 2 ] on g s , P n , C i and WUE varied considerably with groundwater depth. The response of photosynthesis to rising [CO 2 ] was stronger at the greater groundwater depth (more than 6 m) than that at the shallower groundwater depth (less than 6 m). The critical groundwater depth required to maintain the normal survival of P. euphratica was less than 6 m. When the groundwater depth increased to more than 6 m, P. euphratica encountered moderate water stress, and the plant suffered severe water stress when the groundwater depth increased to more than 7 m.

Innovation Project of the Chinese Academy of Sciences 'Water resources in Xinjiang: formation, transformation and control[KZCX2-YW-127]; Water Resources Utilization and Integrated Management Demonstration in Tarim River Basin[90502004]; National Natural Science Foundation of China[30500081, 40672171]

The lower reaches of Tarim River in the Xinjiang Uygur region of western China had been dried out for more than 30 years before water began to be diverted from Konqi (Peacock) River via a 927-km-long channel in year 2000, aimed at improving the riparian ecological systems. Since then, eight intermittent water deliveries have been carried out. To evaluate the response of riparian vegetation to these operations, the groundwater regime and vegetation changes have been monitored along the 350-km-long stem of the river using a network of 40 dug wells at nine transects across the river and 30 vegetation plots at key sites. Results show that the water table rose remarkably, i.e. from a depth of 9.87 m before the water delivery to 3.16 m after the third water delivery. The lateral distance of affected water table extended to 1,050 m from the riverbank after the fourth water delivery. The riparian vegetation has changed in composition, type, distribution, and growing behavior. This shows that the water deliveries have had significant effects on restoration of riparian ecosystems.

A case study on the responses of streamflow to climate change in the Toutun River basin was carried out based on data analysis of streamflow, precipitation, and temperatures during the past 50 years. Temporal series of the streamflow change in the Toutun River basin was analyzed and tested using the Mann-Kendall nonparametric test. Results revealed that the annual runoff of the Toutun River had been in a monotonic decreasing trend for the past 50 years. Compared with the 1950s and 1960s, the annual runoff in the 1990s decreased by 4.0×105 m3 and 7.2×105 m3. The precipitation did not show monotonic trend during the past 50 years, but the annual temperature increased by 1.12°C since the 1950s. Further data analysis indicated that the monthly runoff of the Toutun River decreased significantly from August to October, with precipitation displaying the similar pattern of seasonal change. Analysis suggests that the reduction of streamflow in the Toutun River basin is possibly caused by the seasonal change of precipitation, especially the precipitation reduction in summer, and temperature increases.

This research explored the effect of different presentation orders on processing time and time estimation, from the perspective of verbal working memory dual-task mode task. 108 participants took part in memorizing order or disorder French word, it showed that the presentation order significantly shortens the processing time and estimation time, thus it proved that the orderly presentation can enhance the work efficiency compared with the disorderly presentation. This research highlights the impact of presentation upon the verbal working memory, which had important theoretical and practical implications.

The purpose of this article is to explore the impact of different plan form of circulation systems on spatial information processing and orientation abilities of newcomers in unfamiliar large-scale commercial environments. Two shopping malls in Beijing were chosen to apply the same field experiments, which were in the same conditions except different types of circulation systems— one with multi-atriums and linear serial type of circulation system and the other with single-atrium centric radiation type of circulation system. Space transition nodes from horizontal route to vertical route in each circulation system were various as well. A total of 69 participants were divided randomly into two groups and complete 4 separate tasks to explore the correlation between different types of circulation systems and space orientation performance. Personal difference in cognitive styles and spatial abilities were examined as well to explore the correlation with space orientation behavior. The main conclusion was that performance of space cognition tasks of space users in multi-atriums and linear serial type of circulation system is superior to single-atrium centric radiation type of circulation system. Cognitive style of space users was correlated with performance in space cognitive sketch-map tasks and the answers to a questionnaire.

Net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE), and stomatal limitation (Ls) of Populus euphratica grown at different groundwater depths in the arid region were measured. gs of the trees with groundwater depth at 4.74 m (D4) and 5.82 m (D5) were lower and a little higher than that at 3.82 m (D3), respectively. Compared with Ci and Ls of the D3 trees, Ci decreased and Ls increased at 4.74 m, however, Ci increased and Ls decreased at D5. Hence photosynthetic reduction of P. euphratica was attributed to either stomatal closure or non-stomatal factors depending on the groundwater depths in the plant locations. PN of the D3 trees was significantly higher than those at D4 or D5. The trees of D4 and D5 did not show a significant difference in their PN, indicating that there are mechanisms of P. euphratica tolerance to mild and moderate drought stress.

The eco-physiological response and adaptation of Populus euphratica Oliv and Tamarix ramosissima Ldb during water release period were investigated. Nine typical areas and forty-five tran-sects were selected along the lower reaches of Tarim River. The groundwater table as well as plant performance and the contents of proline, soluble sugars, and plant endogenous hormone (ABA, CTK) in leaves were monitored and analyzed. The groundwater table was raised in different areas and tran-sects by water release program. The physiological stress to P. euphratica and T. ramosissima had been reduced after water release. Our results suggested that the groundwater table in the studied region remained at −3.15 to −4.12 m, the proline content from 9.28 to 11.06 (mmol/L), the soluble sugar content from 224.71 to 252.16 (mmol/L), the ABA content from 3.59 to 5.01 (ng/g FW), and the CK content from 4.01 to 4.56 (ng/g FW), for the optimum growth and restoration of P. euphratica indicated by the plant performance parameters and the efficiency of water application was the highest. The groundwater table in the studied region remained at −2.16 to −3.38 m, the proline content from 12.15 to 14.17 (mmol/L), the soluble sugar content from 154.71 to 183.16 (mmol/L), the ABA content from 2.78 to 4.86 (ng/g FW), and the CK content from 3.78 to 4.22 (ng/g FW), for the optimum growth and restoration of T. ramosissima indicated by the plant performance parameters and the efficiency of water application was the highest. The rational groundwater table for the restoration of vegetation in the studied region was at −3.15 to −3.38 m.

The hydrological response to climate change in the Tarim River Basin was investigated by analysing the hydrological, temperature and precipitation data of the past 50 years. The long-term trend of the hydrological time-series, including air temperature, precipitation, and streamflow, was examined by using both parametric and non-parametric techniques and the plausible association between streamflow and climate change by the method of grey correlation analysis. The results show that the study area became warmer in the last few decades. The air temperature experienced a significant monotonic increase by 5%; the precipitation showed a significant decrease in the 1970s and then a major increase in the1980s and 1990s, with average annual precipitation up by 6·8 mm per decade. A step change occurred in both temperature and precipitation around 1986, with mean temperature and precipitation increasing from 6·7 °C and 146 mm before 1986 to 7·3 °C and 180 mm respectively after 1986. The temperature has risen by nearly 1 °C over the past 50 years, possibly resulting from the impact of global climate change. Streamflows in the Aksu River and the Yarkant River have shown a significant (P < 0·05) tendency of increase. This is particularly the case for the Aksu River. The coefficients of streamflow increase in the Aksu and Yarkant Rivers are 0·41 and 0·13 respectively. The results of grey correlation analysis show that in the Aksu River, which is located in the northwest of the basin, the impact of precipitation on streamflow is much greater than that of temperature. However, in the Hotan River, which is located in the southwest of the basin, the impact of temperature on streamflow is much greater than that of precipitation. This is likely to be related to the geographic distribution of the headstreams of the rivers. Copyright © 2006 John Wiley & Sons, Ltd.

Based on the analysis of the three-year (2000–2002) monitoring data of the four times intermittent stream water conveyance to the lower reaches of Tarim River where the stream flow was dried up for more than 30 years and the measurement of PRO, SOD and POD in plants collected from 24 vegetation plots, it is concluded that the stream water conveyance plays an important role in lifting groundwater level. The groundwater nearby the watercourse was raised from 5–8 m in depth before the stream water conveyance to 2.5–5 m after stream water conveyance. The physiological response of Phragmites communis, Tamarix spp. and Populus euphratica to the change of groundwater is sensitive and represents a grads change obviously. The growth of the plants in the lower reaches of Tarim River is stressed by drought to various degrees. Lengthways, the drought stress exposed to the plants increases with groundwater depth from the upper sections to the lower sections; and breadthwise, the drought stress exposed to the ...