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Highlights • An evaluation system considering pressure and pressure-bearing was established. • Grid scale ecological security was evaluated using this system and entropy method. • County scale security level was evaluated based on entropy matter-element model. • Changes of ecological security situation between 2000 and 2015 were explored. Abstract Ecological security is important for social and economic sustainable development which needs stable resources and eco-environment support. In this study, we established an evaluation indicator system considering pressure and pressure-bearing to quantify the ecological security for Kunming city as it is a socioeconomic center in Southwest China with important ecological niche and rapid urbanization. According to the weights assigned by entropy method, we overlaid 13 indicators which were divided into 2 units, pressure indicators and pressure-bearing indicators, to evaluate the ecological security on grid scale. And then, ecological security level on district-county scale was evaluated based on the entropy matter-element model. On this basis, we explored their spatial distribution characteristics and the change trend from 2000 to 2015. Results showed that spatial distribution characteristic of ecological security evaluation was similar with the results of pressure evaluation, showing the scores and levels gradually increased from the urban area to the surrounding areas. Compared the ecological security levels in 2000 and in 2015, both of the highest value and the lowest value increased slightly. In general, the area with improved ecological security situation accounted for 89.10% of the total area. In terms of the change trend of ecological security levels, eight counties deteriorated while five counties remained unchanged which were driven by different deterioration reasons. The evaluation results of this study can provide comprehensive and targeted support for regional sustainable development. [ABSTRACT FROM AUTHOR]

• Plume infrared signatures were studied from the phenomenological point of view. • A methodology to characterize the rocket altitude from several spectral bands was proposed. • Effects of afterburning on the radiation phenomena were studied. • Effects of atmospheric attenuation and observation angles were discussed. Rocket exhaust plume treated as a significant radiation source has been widely used in space-based detection. In this paper, infrared radiation signatures of plumes were studied in the view of the phenomenon. The reacting plume flows were calculated by an axisymmetric computational fluid dynamics (CFD) solver. Radiative properties of gases were evaluated with the statistical narrow-band (SNB) model by relying on the NASA-3080 database. The line-of-sight (LOS) based on the single-line-group (SLG) approximation was employed for radiative transfer computations. The numerical model was validated against reference data. Based on this model, radiation characteristics of Atlas-II liquid rocket plumes were computed and analyzed in aspects of afterburning, atmospheric attenuation, spectral bands and observation angle. Results show that afterburning has a significant improvement in the wavelengths of 1.5–6.0 μm. Also, the atmospheric attenuation greatly decreases the plume radiance at low altitudes but it can be ignored above 40 km. Radiance is strongly dependent on the spectral bands. The altitude-varying spectral dependency can contribute to the rocket altitude estimation. The effect of the observation angle on the radiance distributions is varying with the spectra band and the flight altitude. These results are helpful for the design of the rocket motors and the application of the infrared detecting system. [ABSTRACT FROM AUTHOR]

Highlights • Infrared thermal radiation noise of the bow-shock layer was investigated. • A relationship between the radiation intensity and flight conditions was given. • Simulations results were discussed including the LOS, station and direction. • Effects of the dome radius and altitudes on the radiation noise were studied. Abstract To examine the effect of atmospheric trace species on the infrared thermal radiation of a supersonic dome, a series of radiation characteristics with different geometry sizes at near-ground altitudes were investigated numerically. The conjugate heat transfer method was applied to build the heat transfer model of the optical dome. Three major radiating species of H 2 O, CO 2 , and CO were taken into account in the shock layer. A line-by-line (LBL) method was used for evaluating the radiative properties of species. A line-of-sight (LOS) approach was applied to solve the radiative transfer equation (RTE). The simulated and measured results of the dome were also proposed to validate the numerical method. The effects of the dome geometry size, the dome material and the time-varying altitude on the infrared radiation noise were studied in detail. The results show that the altitude-varying radiation intensity along the LOS is related to the ambient density and velocity. The variation of the dome radius is proportional to the total radiation received on the dome surface. It is observed that the maximum radiation intensity along the LOS does not occur in the normal direction of the receiving point, but it is determined by both the flow field parameters and the path length. Also, the radiation increment corresponding to different dome sizes approximately obeys a Gaussian distribution related to the product of density and velocity. [ABSTRACT FROM AUTHOR]

Abstract In this study, a novel elliptical jet-stabilized combustor is developed; the combustion and emission characteristics are numerically investigated and compared with those of a circular jet-stabilized combustor. Five elliptical combustors with different semi-major/semi-minor axis ratios (1.00, 1.27, 1.56, 1.89, and 2.25) are considered, and an optimization method for adjustable stabilizer jet air supply is proposed. An Eulerian-Lagrangian approach is used for solving the liquid fuel spray. Employing the realizable k - ε turbulence model and the finite-rate/eddy-dissipation model simulates the turbulent combustion. The discrete ordinate method is used to model thermal radiation, and the thermal and prompt NO formations are to be predictive of NO emissions. The numerical models are validated against available experimental data. The results show that the semi-major/semi-minor axis ratio significantly affects the performance of elliptical jet-stabilized combustors. To improve the temperature uniformity and to reduce NO emissions, the proposed optimization method is successfully applied. Compared with the circular combustor, the optimized elliptical combustor achieves strong mixing performance, resulting in improved combustion and emission performance. By adjusting the major/minor axis jet mass flow rate ratio (m a / m b = 0.6) in the elliptical combustor with semi-major/semi-minor axis ratio of 1.56, NO emissions are reduced by 50% compared with the circular combustor. Graphical abstract Image 1 Highlights • A novel elliptical jet-stabilized combustor is designed and compared with a circular one. • The effect of semi-major/semi-minor axis ratio is investigated. • The optimization of adjustable stabilizer jet air supply is carried out. • NO emissions reduce in elliptical jet-stabilized combustors. [ABSTRACT FROM AUTHOR]

Abstract The continuously increasing concentration of atmospheric CO 2 has considerably altered ecosystem functioning. However, few studies have examined the long-term (i.e. over a decade) effect of elevated CO 2 on soil microbial communities. Using 16S rRNA gene amplicons and a GeoChip microarray, we investigated soil microbial communities from a Californian annual grassland after 14 years of experimentally elevated CO 2 (275 ppm higher than ambient). Both taxonomic and functional gene compositions of the soil microbial community were modified by elevated CO 2. There was decrease in relative abundance for taxa with higher ribosomal RNA operon (rrn) copy number under elevated CO 2 , which is a functional trait that responds positively to resource availability in culture. In contrast, taxa with lower rrn copy number were increased by elevated CO 2. As a consequence, the abundance-weighted average rrn copy number of significantly changed OTUs declined from 2.27 at ambient CO 2 to 2.01 at elevated CO 2. The nitrogen (N) fixation gene nifH and the ammonium-oxidizing gene amoA significantly decreased under elevated CO 2 by 12.6% and 6.1%, respectively. Concomitantly, nitrifying enzyme activity decreased by 48.3% under elevated CO 2 , albeit this change was not significant. There was also a substantial but insignificant decrease in available soil N, with both nitrate (NO 3 −) (−27.4%) and ammonium (NH 4 +) (−15.4%) declining. Further, a large number of microbial genes related to carbon (C) degradation were also affected by elevated CO 2 , whereas those related to C fixation remained largely unchanged. The overall changes in microbial communities and soil N pools induced by long-term elevated CO 2 suggest constrained microbial N decomposition, thereby slowing the potential maximum growth rate of the microbial community. Graphical abstract Unlabelled Image Highlights • Effects of 14 years of experimentally elevated CO 2 on soil microbes in a semi-arid grassland were examined. • The abundance-weighted average rrn copy number of significantly changed OTUs declined by elevated CO 2. • The nitrogen fixation gene nifH and the ammonium-oxidizing gene amoA significantly decreased by elevated CO 2. • Elevated CO 2 constrained microbial N decomposition, thereby slowing potential maximum growth rate of microbial community. [ABSTRACT FROM AUTHOR]

Abstract Spatially quantifying ecosystem services (ES) supply, demand and balance dynamics and exploring their relations with socio-economic factors are very significant for regional sustainability. In this study, land use/land cover (LULC) matrix model was used to quantify the relevant capacity of the ES supply, demand and balance in China. Also, we explored the spatial-temporal characteristics of ES at three scales (national, provincial and city scale). The results revealed that the ES supply, demand and balance in China had strong spatial heterogeneity and showed different time-varying characteristics on different scales. For the provinces with ES deficit, linear optimization model was then applied to achieve the theoretical ES balance through land cover conversion. For the provinces with negative regulating ES, farmland should be significantly reduced while desert and grassland should be converted to farmland and forest for the provinces with negative provisioning ES. In addition, the key driving factors of ES dynamics were selected through ordination analysis of 109 cities at city scale. The results showed that forest proportion was the most important influencing factor of ecosystem services supply while ES supply management can be carried out by adjusting the output values of agriculture, forestry and animal husbandry. On the other hand, ES demand can be adjusted by per capita GDP, energy consumption per unit of GDP and permanent population. The results can provide targeted information with ES management and this method can be applied at a smaller scale considering data availability. This study provides a convenient and propagable method for ES quantification and a quantitative support for regional ES management decisions. Graphical abstract Unlabelled Image Highlights • ES had strong spatiotemporal heterogeneity on national, provincial and city scales. • Forest proportion was the most important driving force of ES supply. • Different land cover conversion strategies should be implemented for ES balance. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • FQI is a suitable index for evaluating the vegetation restoration. • Cu content had the greatest promotional effect on FQI. • Cd and TK contents had a significantly inhibitory effect on FQI. • Excessive nutrients might produce 'toxicity' to the growth of vegetation. Abstract Open-pit mining activities cause great damage to the local ecosystems. It is therefore necessary to assess and recover the vegetation status to maintain ecological stability. In this study, the Floristic Quality Index (FQI) was used to assess the vegetation habitat and the structural equation model (SEM) was applied to quantify the influences of different environmental factors on FQI in the Kunyang open-pit phosphate rock mine in Yunnan Province, China. Non-metric multidimensional scaling analyses revealed that great differences of vegetation community composition existed in the sampled plots, even those at similar distances to mining areas, which indicates that disturbing distance was not the only factor to determine the vegetation community. SEM results showed that Cu promoted the FQI most obviously (0.84), followed by Co (0.75), while the inhibition of Cd content in soil to the FQI was the most significant (−0.88), followed by TK (−0.82), and C (−0.79). Soil fertility quality and soil pollution indexes were also established to analyze the effects of comprehensive soil parameters on FQI. The results showed that the soil fertility quality index had a strong negative effect on FQI, which revealed that higher levels of TP, TN, TK, and other nutrients in the soil would produce 'toxicity' to the growth of vegetation. Findings from our study could provide a scientific method for assessing the ecological restoration results in the mining area. [ABSTRACT FROM AUTHOR]

In this paper, we propose an idea of using asymmetric dielectric resonators to increase the number of perfect absorption bands. We break the symmetry of the dielectric resonators by reducing the length of one of the two silicon split strips. A quad-band MPA is achieved in the near-infrared band based on the asymmetric-dielectric–dielectric–metal (ASDDM) structure, which can excite two extra electric quadrupole (EQ) modes comparing with the symmetry structure exciting only two dipole modes. Operated as a refractive index sensor, those four narrow absorption bands have the figure of merit (FOM) as high as 338.6, 98.5, 38, and 60.6, respectively. This preliminary analysis shows that the resonators asymmetric method is feasible for designing multiple-band MPAs. To obtain more absorption bands, we propose another idea of stacking the dielectric resonators on metal resonators other than only stacking metal resonators. A single-band MPA is first designed based on the metal–dielectric–metal (MDM) structure. Next, we stack the asymmetric dielectric resonators of the quad-band MPA on the metal resonators of the single-band MPA. The absorption spectrum shows that five perfect absorption bands are achieved in the near-infrared band, which preliminary proves the feasibility of the modified resonators stacked method for designing multiple-band MPAs. [ABSTRACT FROM AUTHOR]

• The working medium studied is supercritical liquid hydrogen. • Different from the traditional circular U-tube structure, this paper adopts the triangular U-tube structure for research. • Five different structural types of U-tubes were compared and the one with the best heat transfer performance was selected. • This work provides a useful technical guidance for thermal design and thermal management of neutron source and target station, as well as novel ideas for flow and heat transfer of supercritical liquid hydrogen in U-tube. In this study, the heat transfer characteristics of supercritical hydrogen in triangular U-tubes with different radius were investigated. In order to compare the heat transfer capacity of triangular U-tubes, and to explore the heat transfer characteristics of supercritical liquid hydrogen inside them, a three-dimensional numerical simulation was carried out by Fluent. The unstructured grid and RNG k-ε turbulence model were used to encrypt the grid. Meanwhile, the grid independence and the effectiveness of the turbulence model are verified. The T w , T f and Nu along the triangular U-tube at different q and Re were compared. The result shows that T w , T f and Nu increase with the increase of q and Re. The change of Re was found to be largest for Nu. The effect of secondary flow on Nu was similar to the entrance effect of upstream straight pipe, and the effect of secondary flow on Nu was slightly larger than the entrance effect. This work provides a useful technical guidance for thermal design and thermal management of neutron source and target station, as well as novel ideas for flow and heat transfer of supercritical liquid hydrogen in U-tube. [ABSTRACT FROM AUTHOR]

Partitioning, a method considering environmental protection and development potential, is an effective way to provide regional management strategies to maintain ecological sustainability. In this study, we provide a large-scale regional division approach and present a strategy for Southwest China, which also has extremely high development potential because of the “Western development” policy. Based on the superposition of 15 factors, including species diversity, pattern restriction, agricultural potential, accessibility, urbanization potential, and topographical limitations, the environmental value and development benefit in the region were quantified spatially by weighting the sum of indicators within environmental and development categories. By comparing the scores with their respective median values, the study area was divided into four different strategy zones: Conserve zones (34.94%), Construction zones (32.95%), Conflict zones (16.96%), and Low-tension zones (15.16%). The Conflict zones in which environmental value and development benefit were both higher than the respective medians were separated further into the following 5 levels: Extreme conflict (36.20%), Serious conflict (28.07%), Moderate conflict (12.28%), Minor conflict (6.55%), and Slight conflict (16.91%). We found that 9.04% of nature reserves were in Conflict zones, and thus should be given more attention. This study provides a simple and feasible method for regional partitioning, as well as comprehensive support that weighs both the environmental value and development benefit for China's current Ecological Red Line and space planning and for regional management in similar situations. [ABSTRACT FROM AUTHOR]

Integrating biodiversity and ecosystem services (BES) has been viewed as an appropriate approach to identifying conservation priorities. Taking Xishuangbanna tropical region in Southwest China, different BESs (habitat quality [used as a proxy for biodiversity], carbon storage, and water yield) were quantified using the InVEST model and conservation hotspots from 1976, 1990, and 2010 were identified by overlapping and ranking the service layers. Results showed that BESs areas were unevenly distributed. High habitat quality and carbon storage areas located in the eastern part of the region were mainly occupied by broad-leaved forest, while high water yield areas were covered by grassland and tropical forests. Recognized hotspots were primarily composed of the broad-leaved forest and shrub grassland. However, these habitat types declined by nearly 50% from 1.25×105 ha to 0.63×105 ha and became more fragmented during the study period. We also found that the sub-watersheds which decreased in BES had fewer hotspots distributed and suffered greater landscape fragmentation. Our study further explored the impacts of land-use conversion on BES, and illustrated the necessity and feasibility of BESs in identifying potential conservation areas. [ABSTRACT FROM AUTHOR]

Rapid plantation expansion and its associated impacts on habitat fragmentation and landscape connectivity in many tropical areas has raised increasing concerns as to its impact on Ecosystem Services (ES). Using the InVEST modelling suite, we evaluated critical ES dynamics in four zones of varying plantation expansion intensity (high, medium, low and no plantation expansion) in Xishuangbanna prefecture in Southwest China from 1976 to 2012. Based on these results, we also exmained the relationship between ES and landscape pattern and connectivity derived by the “probability of connectivity” model. We found that during the study period, plantation area increased more than 20 times in Xishuangbanna prefecture as a whole, while broad-leaved forest cover decreased by nearly 30%. The impact of plantation on ES was substantial at both the regional and local scale. Carbon stocks and water yield services decreased by 15.48% and 10.85%, respectively, from 1976 to 2012 throughout the region as a whole. Within the selected study zones, carbon stock and water yeild decreased by 45% and 32%, respectively, from the no plantation to the high plantation zones in 2012 specifically. Plantation expansion has also resulted in a decrease in natural forest cover and a high level of habitat fragmentation. Landscape connectivity decreased by a range of 54.64–95.58% throughout the study area, with 134.58 km 2 of forest patches of high importance reduced to medium or low importance during the study period. Correlation analysis showed that carbon storage was more closely correlated to landscape connectivity than forest habitat percentage, large patch index or cohesion index. Together, these results highlight that habitat configuration with a high connectivity level between fragmented patches is important for maintaining critical Ecosystem Services. [ABSTRACT FROM AUTHOR]

Appropriate graft length within the joint and inside the osseous tunnel is essential for achieving posterior stability and adequate anchorage strength. Because of the curving path and thickness of the graft in double-bundle posterior cruciate ligament (PCL) reconstruction, especially in double-bundle PCL augmentation (with remnant preservation), the actual intra-articular length of PCL grafts, which remains unknown, may be longer than previously published values. The main purpose of the current study is to measure the actual intra-articular graft length required in sandwich-style PCL reconstruction (remnant-preserving double-bundle PCL augmentation) and Zhao-style non-remnant-preserving double-bundle PCL reconstruction (semi-anatomic double-bundle PCL reconstruction using double-double tunnel with tibial medial and lateral arrangement). Nine matched pairs of intact cadaveric knees were randomized between two groups and respectively received sandwich-style PCL reconstruction (remnant-preserving group) and Zhao-style non-remnant-preserving double-bundle PCL reconstruction (non-remnant-preserving group). The tunnel positions were exactly the same in two groups. The anterolateral (AL) bundle was reconstructed with four-stranded semitendinosus tendon, and the posteromedial (PM) bundle was reconstructed with four-stranded gracilis tendon. For each bundle, the length of the graft portion within the joint was measured. The current study indicated that in remnant-preserving group, the average intra-articular exposed portion was 42.0 mm (SD, 1.3 mm; range, 40.0 mm to 43.4 mm) for the AL bundle and 32.5 mm (SD, 2.9 mm; range, 27.8 mm to 35.8 mm) for the PM bundle. In non-remnant-preserving group, the intra-articular exposed portion was 34.5 mm (SD, 1.0 mm; range, 32.7 mm to 36.0 mm) for the AL bundle and 29.1 mm (SD, 2.1 mm; range, 25.2 mm to 31.9 mm) for the PM bundle. For both the AL and PM bundles, significant differences were found in average intra-articular graft length between the two groups. The current study, whose methodology is more rigorous and accurate by measuring the actual intra-articular graft length, has direct applications to clinical practice. When considering the total graft lengths during reconstruction, it is necessary to recognize that remnant PCL has a space occupation effect on graft and that remnant preservation requires longer intra-articular graft lengths than non-remnant preservation. [ABSTRACT FROM AUTHOR]

SOM is a crucial factor that indicates soil fertility and vegetation status and, to a considerable extent, influences the CO 2 concentration in the atmosphere and even the global carbon cycle. We collected 294 SOM data from the secondary soil survey of Yunnan province in 1979 and investigated 210 soil sample sites (0–20 cm depth) in 2011 to enhance the understanding of the spatial variability of SOM between two phase data and its dominant influencing factors in the mountainous region in southwestern China. We examined whether land use types (farmland, grassland, forestland and scrubland), topographic conditions (elevation, slope and CTI) and vegetation coverage (NDVI) affect the spatial distribution and content of SOM in a mountainous region in southwestern China. The results indicated that, SOM content decreased among different land use types in the following order: forestland > scrubland > grassland > farmland. An accurate spatial prediction of SOM content has great significance in the estimation of the SOC pool. This study exhibited that the combined use of vegetation index and terrain attributes would result in a suitable method of predicting SOM distribution even in complex terrain. The prediction of spatial variability in SOM contents was achieved establishing IDW and UK. The root mean square error RMSE and ME methods were selected as comparison criteria to indicate prediction accuracy. Owing to the heterogeneous natural environment, the application of the UK and IDW methods is limited. And it is still challenging that further work was necessary to accurately predict spatial distribution of SOM by choosing appropriate methods in these mountain areas. This study laid a foundation to estimate and evaluate SOM sequestration for regional land use management. [ABSTRACT FROM AUTHOR]

We detected the longitudinal variability of phosphorus speciations and its relation to metals and grain size distribution of sediments in three cascade canyon reservoirs (Xiaowan, Manwan and Dachaoshan) along Lancang River, China. Five phosphorus speciations including loosely bound P (ex-P), reductant soluble P (BD-P), metal oxide-bound P (NaOH-P) calcium-bound P (HCl-P) and residual-P were extracted and quantified. Results showed that in Manwan Reservoir HCl-P accounted for the largest part of total phosphorus (TP) (49.69%), while in Xiaowan and Dachaoshan reservoirs, NaOH-P was the most abundant speciation which accounted for 57.21% and 55.19% of total phosphorus respectively. Higher contents of bio-available phosphorus in Xiaowan and Dachaoshan reservoirs suggested a high rate of P releasing from sediments. Results also showed ex-P and HCl-P had positive correlation with Ca. Total phosphorus was positively correlated with Fe. The silt/clay contents of the sediments had close relationship with ex-P ( r = 0.413, p < 0.05), NaOH-P ( r = 0.428, p < 0.05) and BAP ( r = 0.458, p < 0.05). The concentration of Ca, Mn and silt/clay speciation in the sediments explained 40%, 10% and 4% of the spatial variation of phosphorus speciations, respectively. [ABSTRACT FROM AUTHOR]

• A laser radar cross-section (LRCS) approach for arbitrarily complex targets in the aero-optical environment is proposed and verified. • The effects of incoming density, incoming Mach number, and material bidirectional reflectance distribution function (BRDF) parameters on LRCS measurements are investigated. • The influence of the aero-optical environmental flow field on the LRCS is characterized by a directional and regional distribution. One of the concerns in the process of measuring laser radar cross-section (LRCS) using optical measurement methods is the aero-optical effect around a high-speed flow field. In this paper, a computational model for LRCS considering supersonic flow in a non-homogeneous medium is presented. First, by taking a typical 15° half-cone blunt cone as the research object, based on CFD calculation, the flow field distribution of the non-uniform medium around the high-speed vehicle is obtained. The ray-tracing method is used to calculate the light transmission in an aero-optical environment. An LRCS approach for arbitrarily complex targets in the aero-optical environment is then proposed, and the method is verified by analytical and numerical methods. Finally, the effects of incoming density, incoming Mach number, and material bidirectional reflectance distribution function (BRDF) parameters on LRCS measurements are investigated, and the errors caused by the steady aero-optical environment are analyzed. The results show that the maximum relative error of the measurement caused by the aero-optical environment in the direction of the shock-wave layer observation is significant when the Fresnel function approximation exponential function parameter is too large or when the root mean square (RMS) of the surface slope is too small in the BRDF parameters of the material. The influence of the aero-optical environmental flow field on the LRCS is characterized by a directional and regional distribution, determined by the incoming Mach number and shock-wave angle, with the influence of the incident flow density on the regional distribution being weakly correlated. The proposed method and calculation results are useful for the simulation, analysis, and calibration of LRCS measurements in complex aero-optical environments. [ABSTRACT FROM AUTHOR]

Abstract: This study was conducted to understand the impacts of dam-induced water-level fluctuations (WLFs) on soil properties. The redundancy analysis (RDA) and two soil degradation indices were used to analyse soil degradation under different land uses and at different soil depths. In addition, the relationships among soil degradation and topographical and geographical parameters were determined. The sampling sites were located in two zones along the Manwan Reservoir, which is a section of the Lancang River in Southwestern China. These zones included a water-level-fluctuation zone (WLFZ) and an infralittoral reference zone (IRZ), which included forestlands, scrublands, and farmlands. The results indicated that WLFs increased soil pH, total phosphorus (TP) concentrations, and total potassium (TK) concentrations, and decreased soil total carbon (TC) and total nitrogen (TN) concentrations. Meanwhile, the WLFs increased the soil C/N ratio, which indicated that the WLFs had a stronger effect on TN than on TC. The degree of soil degradation based on the soil degradation index and the changes in the soil quality index indicated that WLFs significantly affected topsoil quality (0–5cm), especially in the scrubland, which had the highest degradation level. The results from the RDA indicated that soil degradation significantly increased with decreasing distance along the river upstream of the dam (P<0.05; F =3.05). Our results identified soil degradation in the WLFZ along the Manwan Reservoir. However, further research is needed to determine the mechanisms of degradation in this zone. [Copyright &y& Elsevier]

Awareness of the adverse ecological effects of road and other large construction projects has resulted in a rapidly growing demand to quantitatively predict and evaluate the effects on gene flow among plants and animals in natural habitats. In this study, we evaluated the effects of different road construction scenarios on animal species movement by using the methods of ecological landscape connectivity in the typical regions of Yunnan Province, China. The results showed landscape connectivity levels (Probability of Connectivity (PC)) decreased after road construction and species with lower dispersal abilities were more affected to the subsequent habitat fragmentation. First level roads affected landscape connectivity most significantly. At a distance of 100 m, the PC index decreased more than 50%. Further analysis suggested that the use of landscape connectivity to assess landscape processes revealed the adverse effects on the species movement more effectively compared with the traditional landscape pattern analysis. In addition, we conducted a graph theory and a least-cost modeling discussion, it is obvious that they are powerful tools to represent and analyze landscape networks with respect to related species movement. Network analysis offers a quantitative and simple but effective tool for ecological process assessment and biological conservation on large scales. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fragmentation indexes changed greater than shape and aggregation indexes. [•] Sensitivity analysis of different species dispersal abilities was compared. [•] Landscape connectivity loss was significant greater than pattern change. [Copyright &y& Elsevier]

Dam construction causes the accumulation of phosphorus in the sediments of reservoirs and increases the release rate of internal phosphorus (P) loading. This study investigated the longitudinal variability of phosphorus fractions in sediments and the relationship between the contents of phosphorus fractions and its influencing factors of the Manwan Reservoir, Lancang River, Yunnan Province, China. Five sedimentary phosphorus fractions were quantified separately: loosely bound P (ex-P); reductant soluble P (BD-P); metal oxide-bound P (NaOH-P); calcium-bound P (HCl-P), and residual-P. The results showed that the total phosphorus contents ranged from 623 to 899 µg/g and were correlated positively with iron content in the sediments of the reservoir. The rank order of P fractions in sediments of the mainstream was HCl-P>NaOH-P>residual-P>BD-P>ex-P, while it was residual-P>HCl-P>NaOH-P>BD-P>ex-P in those of the tributaries. The contents of bio-available phosphorus in the tributaries, including ex-P, BD-P and NaOH-P, were significantly lower than those in the mainstream. The contents of ex-P, BD-P, NaOH-P showed a similar increasing trend from the tail to the head of the Manwan Reservoir, which contributed to the relatively higher content of bio-available phosphorus, and represents a high bio-available phosphorus releasing risk within a distance of 10 km from Manwan Dam. Correlation and redundancy analyses showed that distance to Manwan Dam and the silt/clay fraction of sediments were related closely to the spatial variation of bio-available phosphorus. [ABSTRACT FROM AUTHOR]

Regional ecological degradation induced by hydroelectric project construction (HPC) is of great concern in the field of landscape ecology research. Using GIS-based spatial analysis, we predicted and assessed the impacts of HPC on the ecological integrity of the Nuozhadu Nature Reserve (NNR). The results show that, after Nuozhadu HPC, the naturality of the NNR will be modified due to changes in the landscape composition such that larger areas covered by vegetation will be occupied by construction land and flooded by water areas. Meanwhile, landscape diversity will increase due to the additional landscape types of construction land and submerged areas, while landscape stability will decrease because of the splitting and contagion of the landscape after Nuozhadu HPC. The human disturbance index shows that the HPC will contribute to increasing the disturbance of the ecosystem. From buffer analyses, we conclude that the impacts of HPC will mainly occur in buffer zones over the distance of 800 m from the Lancang River in the NNR, and tend to be moderate in the 800-5,000 m buffer zone. Therefore, within the 800 m buffer zone, taking the naturality, diversity and stability of the ecosystem as well as anthropogenic interference as evaluation indicators, we calculated the ecological integrity index; the results indicate that the ecological integrity of the NNR will decrease by 7.6 % after project construction. [ABSTRACT FROM AUTHOR]

Energy, carbon, water and their interactions determine agricultural production efficiency and sustainability. On the Qinghai-Tibet Plateau (QTP), agricultural activities threaten the ecological security of the region, and agriculture itself is susceptible to climate change. In this study, we applied an energy-carbon-water nexus framework to assess the carbon emissions, water utilization, and energy flow, and their links with agricultural production on the QTP, using emergy analysis, footprint analysis (carbon footprint and water footprint) and a coupling model. The results showed that agricultural activities on the QTP released 2.17 × 1010 kgCO 2 -eq and absorbed 6.00 × 1010 kgCO 2 -eq, using 3.24 × 1022 sej of emergy and 8.19 × 109 m3 of water in 2018. Meanwhile, the energy-carbon-water nexus of agricultural production on the QTP was imbalanced, and the environmental footprint revealed large spatial heterogeneity at county scale. The coupling interaction among the energy-carbon-water nexus in agricultural production was investigated based on the coupling coordination model. Five categories of coupling interaction were identified by the degree of coordination. The largest emitter was agricultural input, especially electricity and nitrogen fertilizer, accounting for 24% and 7% of the total on average, respectively. With regard to emergy flows, renewable organic resources, accounted for 47%, making them the predominant in emergy inputs. The green water footprint (water from natural rainfall) at 51% was higher than the blue water footprint (water from irrigation) at 49%. More measurements to reduce carbon emission and improve the efficiency of energy usage and water usage are needed, such as optimizing planting patterns and structures, promoting cleaner energy, improving the efficiency of agrochemical use and proposing reasonable spatial planning for regional ecological development. Our findings provide a systematic reference for energy-carbon-water nexus analysis and sustainable agricultural development policy for decision-makers on the QTP. [Display omitted] • Footprints of agricultural activities at county scale were evaluated on the Qinghai-Tibet Plateau. • The imbalanced degree of energy-carbon-water nexus caused by agricultural activities was analyzed. • Key factors affecting energy-carbon-water nexus were identified on the Qinghai-Tibet Plateau. • Energy-carbon-water nexus framework of agricultural production was proposed. [ABSTRACT FROM AUTHOR]

Abstract: Based on Landsat MSS and TM images from 1974, 1988, and 2004, we conducted a case study of the Manwan Dam along the Lancang (Mekong) River to determine the influencing distance of dam construction and reservoir impoundment on land use. Spatio-temporal variation in land use was analyzed within 14 adjacent buffer zones around the dam site (concentric rings) and in upstream and downstream areas along the riverway (linear tract). Grassland increased with the greatest dynamic degree in the 1974–1988 period, whereas water area increased extensively in the 1988–2004 period. The integrated dynamic degrees of forestland were low in both periods. The integrated land use dynamics in the 14 concentric rings showed that the impact of dam construction extended to a threshold distance of 5000–6000m from the dam site during the 1974–1988 period and to 2000–3000m during the 1988–2004 period. The transformational patch density in the 14 linear buffer zones indicated that the impact of reservoir impoundment on land use conversion exhibited a threshold distance of 3000m from the riverway. The impact intensity of dam construction in the concentric rings and linear buffer zones tended to decline with increasing distance from the dam site or riverway. The impacts of dam construction and reservoir impoundment were larger in upstream locations than in downstream ones. Our results enhance our understanding of the threshold of dam construction and may guide the management of dam construction on a regional landscape level. [Copyright &y& Elsevier]

This paper presents an evaluation of the spatio-temporal patterns of hydrologic alteration induced by dam construction and precipitation variability in the Lancang River Basin of southwest China from 1957 to 2000. Analyses were conducted using the linear regression method, the Mann-Kendall test, and the Range of Variability Approach. The results indicate that there was considerable variation in the average monthly precipitation between the pre- and post-dam periods in the Lancang River Basin. Second, the magnitude of monthly runoff was strongly related to precipitation, which showed an up-down annual variation, and was significantly altered by dam construction and precipitation variability. In the modified series (hydrologic series with the precipitation impacts removed), runoff deviations between the pre- and post-dam periods became larger. Third, the extreme runoff cycles were influenced by dam construction and precipitation variability downstream from the dam, and the monthly maximum runoff increased from the pre-dam to post-dam period at all hydrologic stations. Fourth, the degree of hydrologic alteration (DHA) indicates that the precipitation variability not only affected the hydrologic regime of unregulated river reach but also modified the negative impacts of dam construction, which could provide a modest mitigation of the hydrologic alterations induced by dam construction, possibly decreasing the level of DHA. Last, the overall degree of hydrologic alteration in the observed series reached 25.2, 25.3, and 29.1 % for the upstream, midstream, and downstream areas, respectively. These results show that the hydrologic regimes of the Lancang River during the 1957-2000 period were affected by damming and precipitation variability, but the hydrologic alteration was relatively low in the upstream areas of the river without a dam. [ABSTRACT FROM AUTHOR]

Abstract: Characterizing the landscape changes and hydrologic alterations associated with dam construction is very important for watershed management. This paper presents a case study of the Lancang River in Yunnan Province following dam construction. The landscape patterns and dynamics indicate the fragmentation, shape, and diversity of the river in 1980, 1990, and 2000. The Range of Variability Approach (RVA) is used to evaluate the degree of hydrologic alteration (DHA) using 44 years (1957–2000) of hydrologic data. The results indicate that the midstream and downstream landscapes were affected by dam construction, becoming more complex and fragmented during the 1980–2000 period; the upstream area was not influenced by dam construction and the reservoir impoundment exhibited less change. The variability in maximum runoff occurrence in the post-dam period was less than that in the pre-dam period. The integrated DHAs of the Jiuzhou (upstream), Gajiu (midstream), and Yunjinghong (downstream) stations were relatively low, reaching 26.28%, 33.40%, and 37.14%, respectively. However, the alteration became obvious in the midstream area, and the situation worsened when the river was simultaneously influenced by dam construction and other human activities (downstream). The results of the regression analysis show strong relationships of landscape metric changes with DHA, and the forestland and water areas with DHA. The DHA increased along with the aggravation of landscape fragmentation, the complexity of the landscape shape, and the diversification of the landscape. [Copyright &y& Elsevier]

Abstract: The paper presents the results of a case study carried out in Xishuangbanna, Southwest China, to examine the relationship between vegetation dynamics and road network extension. We find that lower level roads had more effects on vegetation patches. Minor roads, including Class IV and Class V roads, contributed most to regional landscape fragmentation while high level roads had larger effect on vegetation dynamics in road effect zone. Further, road classes have close relationships with village distribution, topography fluctuation and landscape fragmentation. Topography, however had no direct relationship with vegetation pattern. [Copyright &y& Elsevier]

Pipe height in cylindrical neutron moderator is an important factor to flow pattern, temperature distribution and even the neutron characters. In this paper, the steady-state thermal analysis of cold neutron moderator is carrying out with different heights, conjugated heat transfer method and one-way coupled with a neutron transfer software. The different pipe heights, which is the jet-to-surface distances (H/D = 0.5~6), were compared using a 2D moderator model. The results show that vortex size and velocity gradient from container wall to vortex center vary with H/D, the center of recirculation zone nearly remain constant, and heat transfer effect is weakened on the target bottom surface. With H/D increasing, the velocity at bottom target surface is progressively decreased, and cooling effect is poor, leading to the rise in temperature. The optimal range cooling performance is (H/D) = 0.5~1 at Re = 1.7 × 105, and the enhancement of beam power further strengthens the thermal deposition difference between container and liquid hydrogen. The results can be applied to moderator component design and optimization in the future spallation neutron source. [ABSTRACT FROM AUTHOR]

The flow field distribution and thermal properties of supercritical hydrogen are crucial factors affecting the quality of neutrons output from spallation neutron source, which may contribute to the optimization design of the moderator. Several sensitivity studies on affecting heat transfer characteristics of liquid hydrogen inside a moderator were executed, and a choice was made to use a computational fluid dynamics method for numerical simulation. The sensitivity degree of factors affecting the heat transfer characteristics of liquid hydrogen are in sequence of inlet mass flow, beam power and operating pressure. Especially when the beam power is 500 kW (the temperature range of liquid hydrogen is about 20~30 K); where the effect of mass flow rate is remarkable, the cooling effect is best in the range of 60~90 g/s × 394 mm2. Meanwhile, the maximum temperature of liquid hydrogen is close to the bottom recirculation zone due to the influence of the flow field and the heat deposition distribution of the poisoned plate. The effect of variable pressure on the temperature of liquid hydrogen is not significant, whereas the sudden rise of wall temperature is observed near the large specific heat region of 15 bar. [ABSTRACT FROM AUTHOR]

Based on the land use (LU) (in 1985 and 2000) and road networks (RN) data in the Longitudinal Range- Gorge Region (LRGR), ecosystem services value (ESV) loss under the disturbance of road networks was estimated by using landscape degradation index (LDI) to clarify the effects of human activities on ecosystem service function (ESF). Results show that the ESV decreased more than 65×108 Yuan (RMB) due to the transformation of ecosystems in the study area during the past 16 years. The ecosystems influenced by road networks of different grades account for 5.4% of the total land in the study area. The ecosystems lost their ESV of 1900×108 Yuan (RMB) by the disturbance of RN. The effect of RN on the ESV decreased exponentially. The forecast shows that ESV will be decreased 1.2%/a on average in 2010 and 2020 due to RN projects. The effect of ecosystem structure change on ESV was complex and nonlinear. The disturbance of RN, one of the human activities influencing ESF is considered, further study and new method should be developed to accurately estimate the loss of ESV and the ecosystem function. [ABSTRACT FROM AUTHOR]

As an intrinsic disturbance factor of landscape, roads are conspicuous artificial components. Regional landscape pattern and change are influenced by the existence and extension of road networks. Study of the relationship between road features and its disturbance level is important for regional ecosystem management. Based on the spatial variation analysis of road corridor and network features in the LRGR, we examined the effect of road network on landscape pattern change using GIS. Further, the regularity between regional ecological disturbance and network features was discussed. The results showe that road density was significantly relative to topography, village number and the ecosystem patch number, and the significance varied greatly with road types. With the increase of road density and network extension, α (network circuitry), β (edge-nodes ratio) and γ (network connectivity) indexes increased. Also, total ecosystem patch number, patch density, landscape evenness and fractal index increased while regional minimum patch area, average patch area and contagion index decreased. The result exhibit that low-grade road had greater effect on regional landscape fragmentation. We used human disturbance indexes (Hd) of 1980 and 2000 to indicate the ecological disturbance level. The Hd indexes have a positive and significant relationship with α, β and γ indexes, which suggests the ecological disturbance increased with the network expanding. [ABSTRACT FROM AUTHOR]

This study considers aerosol optical properties and direct radiative forcing over Harbin (126.63° E, 45.75° N), the highest latitude city in Northeast China, during 2017. Observations based on the CE-318 sun-photometer show that the annual mean values of the aerosol optical depth (AOD) at 500 nm and the Angstrom exponent (AE) at 440–870 nm over Harbin are respectively 0.26   ±   0.20 and 1.36   ±   0.26 . Aerosol loading is the highest in the spring followed by winter, and the lowest loading is in autumn. AE 440 – 870 is the highest in summer, second highest in winter, and lowest in autumn. The Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model is used to estimate the shortwave aerosol radiative forcing at the top of the atmosphere, on the Earth's surface and in the atmosphere, and the annual mean values are − 16.36   ±   18.42   Wm − 2 , − 71.01   ±   27.37   Wm − 2 and 54.65   ±   30.62   Wm − 2 , respectively, which indicate that aerosols cause climate effects of cooling the earth-atmosphere system, cooling the earth's surface and heating the atmosphere. Four main aerosol types in Harbin are classified via AOD and AE. Specifically, clean continental, mixed type, biomass burning and urban industry, and desert dust aerosols accounted for 51%, 38%, 9%, and 2% of the total, respectively. Aerosol radiative forcing varies greatly in different seasons, and the aerosol load and type from different emission sources have an important influence on the seasonal variation of radiative forcing. [ABSTRACT FROM AUTHOR]

Tree species and afforestation age can affect soil carbon (C) and nitrogen (N) sequestration as well as soil properties through different litter input and microbial activities. However, uncertainty remains because the responses vary under different climates and prior land uses. A site-specific study was conducted to investigate the dissimilarities in plant litter, soil properties, and soil microbial biomass and their influencing factors of different aged (22, 32, and 44 years) larch (Larix principis-rupprechtii) plantations and different aged (19, 30, and 43 years) Mongolian pine (Pinus sylvestris var. mongolica) plantations. In general, afforestation increased soil organic carbon (SOC), soil total nitrogen (STN), soil microbial biomass carbon (MBC), and soil microbial biomass nitrogen (MBN) contents compared with those of sparse grassland. However, there was still room for improvement in these variables compared with local natural secondary forest, which was dominated by white birch (Betula platyphylla , a deciduous broad-leaved tree species). Changes in STN, SOC, MBC, and MBN contents with afforestation age were almost insignificant in larch plantations, while significant increase can be found in STN (only in 10–20 cm soil layer), MBC and MBN in Mongolian pine plantations. The results indicated that larch was superior to Mongolian pine in soil C and N sequestration and soil fertility improvement at an early afforestation stage probably because of the higher C and N inputs from litter and higher N supply in the soil. There is an upper limit of carbon and nitrogen sequestration and soil fertility in the coniferous plantation, and mix planting of broad-leaved trees in coniferous forests may make up for this disadvantage. This study provided a reference for the selection of afforestation tree species in northern China and other areas with similar climatic conditions. • Afforestation increased SOC, STN, MBC, and MBN contents compared with those of barren land. • Changes in STN, SOC, MBC, and MBN contents with afforestation age varied in larch and Mongolian pine. • Larch was superior to Mongolian pine in soil fertility improvement at an early afforestation stage. • The higher C and N inputs from litter and N supply form soil may cause the differences between larch and Mongolian pine. [ABSTRACT FROM AUTHOR]

• A meta-analysis on the degraded grasslands of the Qinghai-Tibetan Plateau. • More severe degradation for plant growth and soil quality than plant diversity. • Fertilisation improves plant growth and soil quality but limits plant diversity. • Optimal effect is found when jointly using phosphorus and nitrogen. • Climatic factors regulate degradation degree and fertilisers' effect. Climate warming and human disturbance are supposed to have severely affected the alpine grasslands on the Qinghai-Tibetan Plateau (QTP), a region where the extremely harsh and fragile ecological environment has attracted great attention because of its sensitivity to global change. However, there is still no unified understanding of the degree and magnitude of grassland degradation and the effectiveness of nutrient addition in this vast landscape, since most previous studies have focused on short-term observations at a single site. Here, we conducted a meta-analysis of 145 published studies on degraded alpine grassland along with 90 published studies, which concerning nutrient addition (nitrogen [N], phosphorus [P], and combined N and P [NP]) to quantitatively assess the responses of plant and soil characteristics to land degradation and restoration. Our results revealed that the response ratio (RR) of above-ground biomass (AGB), below-ground biomass (BGB), soil organic carbon (SOC), and soil total N (TN) decreased significantly (−47.23 %, −43.45 %, −32.35 %, and −37.97 %, respectively) in degraded grassland compared with non-degraded grassland. The RR of AGB was correlated with mean annual precipitation (MAP), while the RR of BGB was correlated with the interaction of MAP and mean annual temperature (MAT). Severely degraded grassland required additional nutrients to aid recovery. NP addition to severely degraded sites increased plant AGB (+32.44 %), TN (+10.99 %), soil total P (+32.25 %), and soil moisture (+9.21 %), but significantly decreased species richness (−45.46 %), diversity (−30.40 % for Shannon−Wiener index) and soil pH (−3.91 %). N addition increased the RR of AGB and grass biomass significantly by 28.77 % and 36.49 %, but had no significant effect on sedge and forb biomass. MAP influenced the RR of AGB, TN, TP under NP addition, the RR of BGB and the AGB of different function groups were significantly affected by MAT. We evidenced that the QTP has endured severe vegetation and soil degradation, which cannot be completely mitigated by supplementary fertilisation. Fertilisation could yield positive effects on plant performance and soil quality, but negative effects on biodiversity. Climate warming and associated precipitation change may regulate the effects of fertiliser on plant biomass and soil nutrients. [ABSTRACT FROM AUTHOR]

A swirl micro-combustor which has strong capability to stabilize the flame has been developed and is promising to be used in micro thermophotovoltaic power generators in this work. Heat recirculation plays a requisite role in flame stability and thermal performance of micro combustors. Thus, the effects of three parameters (center inlet radius w 1 , swirler width w 2 , and step height w 3) that determine the size and location of the recirculation zones in a premixed hydrogen/air flame are investigated numerically. The results show that inner recirculation zone and corner recirculation zone generated by a swirler are critical for stabilizing the flame. The parameter w 1 has an insignificant influence on the thermal performance. Enlarging the inner recirculation zone by decreasing w 2 provokes enhanced heat transfer, and increases the temperature level and temperature non-uniformity of combustor walls. The size of corner recirculation zone is increased by increasing w 3 , which raises the outer wall temperature uniformity. Based on the parametric analysis, the newly designed micro combustor possesses a high wall temperature level. Additionally, the energy output increment is between 9.1% and 14.2% at hydrogen mass flow rate of 0.0006 g/s when stoichiometric hydrogen/air ratio ranges from 0.6 to 1.4. Image 1025 • A novel swirl micro-combustor for micro TPV system is proposed. • Geometrical parameters that determine the recirculation zones are studied. • Inner and corner recirculation zones contributes to flame stabilization. • Small swirler width improves wall temperature. • Large step height increases wall temperature uniformity. [ABSTRACT FROM AUTHOR]

Simple Summary: Trophy hunting and mass tourism were introduced to Khunjerab National Park, northern Pakistan to generate income for the community and help conserve and sustain the ecosystem in the region. These initiatives have provided economic benefits, but only at the cost of other environmental problems, as both trophy hunting and mass tourism have resulted in various ecological issues. Trophy hunting has not been based on scientific population data and has thus not helped increase numbers of wild ungulates or wild carnivores. Although mass tourism has increased enormously in this region, it has damaged the ecosystem through pollution generation and negatively impacted wildlife. We suggest that trophy hunting should be stopped, and mass tourism should be shifted to ecotourism as a sustainable solution to help improve the ecosystem, while generating income for the local community. Further studies are required to investigate ecotourism as a potential mitigation measure for the conservation issues in this region. Trophy hunting and mass tourism are the two major interventions designed to provide various socioeconomic and ecological benefits at the local and regional levels. However, these interventions have raised some serious concerns that need to be addressed. This study was conducted in Khunjerab National Park (KNP) with an aim to analyze comparatively the socioeconomic and ecological impacts of trophy hunting and mass tourism over the last three decades within the context of sustainability. Focus Group Discussions (FGDs) with key stakeholders and household interviews were conducted to collect data on trophy hunting and mass tourism, and on local attitudes towards these two interventions in and around KNP. The results revealed that 170 Ibex (Capra sibirica) and 12 Blue sheep (Pseudois nayaur) were hunted in the study area over the past three decades, and trophy hunting was not based on a sustainable harvest level. Trophy hunting on average generated USD 16,272 annual revenue, which was invested in community development. However, trophy hunting has greatly changed the attitudes of local residents towards wildlife: a positive attitude towards the wild ungulates and strongly negative attitude towards wild carnivores. In addition, trophy hunting has reduced the availability of ungulate prey species for Snow leopards (Panthera uncia), and consequently, Snow leopards have increased their predation on domestic livestock. This has, in turn, increased human–snow leopard conflict, as negative attitudes towards carnivores result in retaliatory killing of Snow leopards. Furthermore, according to official record data, the number of tourists to KNP has increased tremendously by 10,437.8%, from 1382 in 1999 to 145,633 in 2018. Mass tourism on average generated USD 33,904 annually and provided opportunities for locals to earn high incomes, but it caused damages to the environment and ecosystem in KNP through pollution generation and negative impacts on wildlife. Considering the limited benefits and significant problems created by trophy hunting and mass tourism, we suggest trophy hunting should be stopped and mass tourism should be shifted to ecotourism in and around KNP. Ecotourism could mitigate human–Snow leopard conflicts and help conserve the fragile ecosystem, while generating enough revenue incentives for the community to protect biodiversity and compensate for livestock depredation losses to Snow leopards. Our results may have implications for management of trophy hunting and mass tourism in other similar regions that deserve further investigation. [ABSTRACT FROM AUTHOR]

Conservation of the snow leopard (Panthera uncia) is challenging because of its threatened status and increase in human-snow leopard conflict (HSC). The area of occupancy of the snow leopard comprises mountainous regions of Asia that are confronted with various environmental pressures including climate change. HSCs have increased with a burgeoning human population and economic activities that enhance competition between human and snow leopard or its preys. Here we systematically review the peer-reviewed literature from 1994 to 2018 in Web of Science, Google Scholar, Science Direct and PubMed (30 articles), to evaluate the current state of scholarship about HSCs and their management. We determine: 1) the spatio-temporal distribution of relevant researches; 2) the methodologies to assess HSCs; 3) and evaluate existing interventions for conflict management; and 4) the potential options for HSC management. The aim of the current study is thus to identify key research gaps and future research requirements. Of the articles in this review, 60% evaluated the mitigation of HSCs, while only 37% provided actionable and decisive results. Compensation programs and livestock management strategies had high success rates for mitigating HSCs through direct or community-managed interventions. Further research is required to evaluate the efficacy of existing HSC mitigation strategies, many of which, while recommended, lack proper support. In spite of the progress made in HSC studies, research is needed to examine ecological and socio-cultural context of HSCs. We suggest future work focus on rangeland management for HSC mitigation, thus ultimately fostering a co-existence between human and snow leopard. Unlabelled Image • This review of studies on human-snow leopard conflict (HSC) identifies key research gaps and future research requirements. • Despite prevalence of HSCs, most studies on HSCs have been conducted in India, China, Nepal and Pakistan after 2011. • Compensation program and livestock management strategy have high success ratio and are mostly recommended to mitigate HSCs. • Research is needed to assess efficacy of existing HSC mitigation means and ecological and socio-cultural context of HSCs. • Sound rangeland management has potential to mitigate HSCs, thereby fostering co-existence between human and snow leopard. [ABSTRACT FROM AUTHOR]

• Near-field-coupled lighting-rod effect is proposed and demonstrated. • Rotating square resonators array 45° to form tip-tip coupling structure. • Demonstrates 4.5 times emissivity enhancement of 2-D (1, 2) MP mode. • Near-field-coupled lighting-rod effect is strongly dependent on coupling distance. Comparing to the 1-D resonators like strips, the 2-D resonators, such as squares, can excite the higher-order 2-D magnetic plasmon (MP) modes in addition to the fundamental and higher-order 1-D MP modes. However, the low absorptivity of 2-D MP modes greatly limits its applications. We propose and demonstrate an idea utilizing the near-field coupling of electromagnetic fields accumulated around the tips of 2-D square resonators (near-field-coupled lighting-rod effect) to enhance the electromagnetic fields intensity and the emissivity or absorptivity of 2-D MP modes. The tip-tip coupling structure is formed by rotating the square resonators array 45°. The experiment demonstrates the 4.5 times absorptivity enhancement of higher-order 2-D (1, 2) MP mode from 12.5% to 55.8% in addition to the fundamental MP 10 and higher-order 1-D MP 30 modes with high absorptivity. Our proposed near-field-coupled lighting-rod effect is strongly dependent on the formation of tip-tip coupling structure and the coupling distance. [ABSTRACT FROM AUTHOR]

Exposure to air pollutants is a significant trigger of asthma in China. However, there is little evidence of which pollutants are associated most with asthma at the national level, and little research on pollutants' critical values based on concentration-response (C-R) curves. Further, the potential influential variables of air pollutants have not been identified clearly. In this study, logistic regression analyses were used to evaluate the associations between air pollutants and asthma based on 14176 samples across 12 provinces in China in 2015. We also fit a generalized additive model to evaluate the nonlinear C-R curves to identify the critical values. Our results showed that PM 10-2.5 (odds ratios, 95% confidence intervals: 0.95, 0.90–1.00) and NO X (odds ratios, 95% confidence intervals: 0.98, 0.96–1.00) were associated significantly with asthma's prevalence (p < 0.05) in China, in which the correlation between NO X pollution and asthma's prevalence was relatively more significant. The risk of asthma increased significantly when the average annual PM 10-2.5 and NO X concentrations exceeded approximately 40 μg/m3 and 67 μg/m3, respectively. The results of structural equation modelling confirmed that economic scale was the most important driving force for PM 10-2.5 and NO X pollution. Economic scale primarily had a direct influence on increased PM 10-2.5 concentrations, while it primarily had an indirect influence on increased NO X concentrations. Our findings contribute to the limited evidence on PM 10-2.5 and NO X pollution's effects on asthma's prevalence in China. • PM 10-2.5 and NO X were associated significantly with prevalence of asthma in China. • The critical value of PM 10-2.5 concentrations for asthma was 40 μg/m3 in China. • The critical value of NO X concentrations for asthma was 67 μg/m3 in China. • Economic scale had the strongest impact on PM 10-2.5 and NO X pollution. [ABSTRACT FROM AUTHOR]

• A radiative property database was established based on the NBK method. • Thermal effects of the MSL capsule along the reconstructed trajectory were simulated. • The contribution of the radiative heating to aero-heating was compared and analyzed. Radiative heating of a Mars entry capsule was evaluated along a reconstruction trajectory. Reactive flows were computed using a three-dimensional computational fluid dynamics (CFD) solver. Based on the narrow-band k-distribution (NBK) method, a new seven-point radiative property database was established relying on the line-by-line (LBL) approach. The CFD solver and the radiative model were verified by use of the experimental data. Some issues were numerically studied including flow field parameters, radiative heat fluxe (RHF) at forebody and afterbody, and contribution of radiative heating to aero-heating. The results reveal that the high RHF region is distributed in the windward side of the forebody and the leeward side of the afterbody. A comparison between the RHF and the convective heat flux (CHF) shows that the contribution of the RHF has a noticeable increase at low-altitude trajectory points. The maximum increase of the RHF reaches up to 45% of the total heat flux. In addition, the computational results without the angle-of-attack (AOA) indicate that the AOA has a less than 20% influence on the maximum RHF. These computational results provide a guide for the design of the thermal protection system (TPS) of Mars entry capsules. [ABSTRACT FROM AUTHOR]

Optical design parameters for a ground-based infrared sensor rely strongly on the target's optical radiation properties. Infrared (IR) optical observability and imaging simulations of an Earth entry vehicle were evaluated using a comprehensive numerical model. Based on a ground-based IR detection system, this model considered many physical mechanisms including thermochemical nonequilibrium reacting flow, radiative properties, optical propagation, detection range, atmospheric transmittance, and imaging processes. An orbital test vehicle (OTV) was selected as the research object for analysis of its observability using a ground-based infrared system. IR radiance contours, maximum detecting range (MDR), and thermal infrared (TIR) pixel arrangement were modeled. The results show that the distribution of IR radiance is strongly dependent on the angle of observation and the spectral band. Several special phenomena, including a strong receiving region (SRR), a characteristic attitude, a blind zone, and an equivalent zone, are all found in the varying altitude MDR distributions of mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) irradiances. In addition, the possible increase in detectivity can greatly improve the MDR at high altitudes, especially for the backward and forward views. The difference in the peak radiance of the LWIR images is within one order of magnitude, but the difference in that of the MWIR images varies greatly. Analyses and results indicate that this model can provide guidance in the design of remote ground-based detection systems. [ABSTRACT FROM AUTHOR]

Improving the flame stability and thermal behavior of the micro-combustor (MC) are major challenges in microscale combustion. In this paper, the micro combustions of an H2/air premixed flame in a swirl MC with various channel diameters (Din = 2, 3, 4 mm) were analyzed based on an established three-dimensional numerical model. The effects of hydrogen mass flow rate, thermal conductivity of walls, and the preferential transport of species were investigated. The results indicated that the flame type was characterized by the presence of two recirculation zones. The flame was anchored by the recirculation zones, and the anchoring location of the flame root was the starting position of the recirculation zones. The recirculation zones had a larger distribution of local equivalence ratio, especially in the proximity of the flame root, indicating the formation of a radical pool. The combustion efficiency increased with an increasing Din due to the longer residence time of the reactants. Furthermore, the MC with Din = 2 mm obtained the highest outer wall temperature distribution. However, the MC with Din = 4 mm had a better uniformity of outer wall temperature and large emitter efficiency due to the larger radiation surface. An increase in thermal conductivity boosts the thermal performance of combustion efficiency, emitter efficiency, and wall temperature uniformity. But there is a critical point of thermal conductivity that can increase the thermal performance. The above results can offer us significant guidance for designing MC with high thermal performance. [ABSTRACT FROM AUTHOR]