Riparian habitat quality as an indicator of land use/land cover effects on riverine water quality

Riparian land use/land cover(LULC)plays a crucial role in maintaining riverine water quality by altering the transport of pollutants and nutrients.Nevertheless,establishing a direct relationship between water quality and LULC is challenging due to the multi-indicator nature of both factors.Water quality encompasses a multitude of physical,chemical,and biological parameters,while LULC represents a diverse array of land use types.Riparian habitat quality(RHQ)serves as an indicator of LULC.Yet,it remains to be seen whether RHQ can act as a proxy of LULC for assessing the impact of LULC on riverine water quality.This study examines the interplay between RHQ,LULC and water quality,and develops a comprehensive indicator to predict water quality.We measured several water quality parameters,including pH(potential of hydrogen),TN(total nitrogen),TP(total phosphorus),T_(water)(water temperature),DO(dissolved oxygen),and EC(electrical conductivity)of the Yue and Jinshui Rivers draining to the Han River during 2016,2017 and 2018.The water quality index(WQI)was further calculated.RHQ is assessed by the InVEST(Integrated Valuation of Ecosystem Services and Tradeoffs)model.Our study found noticeable seasonal differences in water quality,with a higher WQI observed in the dry season.The RHQ was strongly correlated with LULC compositions.RHQ positively correlated with WQI,and DO concentration and vegetation land were negatively correlated with T_(water),TN,TP,EC,cropland,and construction land.These correlations were stronger in the rainy season.Human-dominated land,such as construction land and cropland,significantly contributed to water quality degradation,whereas vegetation promoted water quality.Regression models showed that the RHQ explained variations in WQI better than LULC types.Our study concludes that RHQ is a new and comprehensive indicator for predicting the dynamics of riverine water quality.

Preparation of Ta-Doped TiO2 Using Ta2O5 as the Doping Source

A novel method for preparing Ta-doped Ti02 via using Ta2 05 as the doping source is proposed. The preparation process combines the hydrothernlal fluorination of Ta2O5 and the subsequent formation of Ta-doped TiO2 sol. The results show that the doped sample annealed at 393 K generates an unstable intermediate NH4 TiOF3, which converts into anatase TiO2 with the increase of temperature. After annealing at ≥673K, the Ta-doped TiO2 nanocrystals with the grain size 〈20nm are obtained. Both the XRD and TG-DSC results confirm that Ta doping prevents the anatase-rutile crystal transition of TiO2. The band gap values of the doped samples, as obtained by UV-vis diffuse reflectance spectra, are smaller than that of pure anatase TiO2. The first-principle pseudopotential method calculations indicate that Ta5＋ lies in the TiO2 lattice at the interstitial position.

Determination of CeO_2 , Dy_2O_3, CuO and PbO in Yttrium Oxide Reference Material by Isotope Dilution Spark Source Mass Spectrometry

This paper describes the quantitative determination of rare-earth elements cerium, dysprosium and non-rare-earth element copper, lead and the homogeneity examination of these four elements in yttrium oxide reference material by isotope dilution spark source mass spectrometry (ID-SSMS). The sensitivity of the meth- od is l0^(-5)～10^(-7%). The precision is better than 6%. The accuracy is better than 5%. The interferences of the spectra and the optimum amount of the spike added to the sample are discussed. The choice of the conducting material for the sample electrodes is studied.

Preparation of Strontium Bismuth Tantalum (SBT) Fine Powder by Sol-Gel Process Using Bismuth Subnitrate as Bismuth Source

Strontium bismuth tantalum (SBT) fine power was prepared by Sol-Gel method. Pentaethoxy tantalum, strontium acetate and bismuth subnitrate were used as raw materials, and were dissolved in proper order in ethylene glycol to form transparent sol. The mixed precursor was dried at 80℃ and annealed at 800℃ for 1 h. Crystallized nanometer sized SBT fine powder was obtained and characterized by XRD.

A NEW FACILE METHOD FOR THE SYNTHESIS OF AZACROWN ETHERS BY USING BENZYLSULFONAMIDE AS A SOURCE OF NITROGEN

Benzylsulfonamide was used as a source of nitrogen in the syn- thesis of azacrown ethers,and the cyclic intermediates were easily deben- zylsulfonylated by treating with CaF_2/H_2SO_4 to afford the azacrown ethers.

Spatiotemporal characteristics of cultivated land use eco-efficiency and its influencing factors in China from 2000 to 2020

Improving cultivated land use eco-efficiency(CLUE)can effectively promote agricultural sustainability,particularly in developing countries where CLUE is generally low.This study used provincial-level data from China to evaluate the spatiotemporal evolution of CLUE from 2000 to 2020 and identified the influencing factors of CLUE by using a panel Tobit model.In addition,given the undesirable outputs of agricultural production,we incorporated carbon emissions and nonpoint source pollution into the global benchmark-undesirable output-super efficiency-slacks-based measure(GB-US-SBM)model,which combines global benchmark technology,undesirable output,super efficiency,and slacks-based measure.The results indicated that there was an upward trend in CLUE in China from 2000 to 2020,with an increase rate of 2.62%.The temporal evolution of CLUE in China could be classified into three distinct stages:a period of fluctuating decrease(2000-2007),a phase of gradual increase(2008-2014),and a period of rapid growth(2015-2020).The major grain-producing areas(MPAs)had a lower CLUE than their counterparts,namely,non-major grain-production areas(non-MPAs).The spatial agglomeration effect followed a northeast-southwest strip distribution;and the movement path of barycentre revealed a"P"shape,with Luoyang City,Henan Province,as the centre.In terms of influencing factors of CLUE,investment in science and technology played the most vital role in improving CLUE,while irrigation index had the most negative effect.It should be noted that these two influencing factors had different impacts on MPAs and non-MPAs.Therefore,relevant departments should formulate policies to enhance the level of science and technology,improve irrigation condition,and promote sustainable utilization of cultivated land.

Phase-matching quantum key distribution with imperfect sources

The huge discrepancies between actual devices and theoretical assumptions severely threaten the security of quantum key distribution.Recently,a general new framework called the reference technique has attracted wide attention in defending against the imperfect sources of quantum key distribution.Here,the state preparation flaws,the side channels of mode dependencies,the Trojan horse attacks,and the pulse classical correlations are studied by using the reference technique on the phase-matching protocol.Our simulation results highlight the importance of the actual secure parameters choice for transmitters,which is necessary to achieve secure communication.Increasing the single actual secure parameter will reduce the secure key rate.However,as long as the parameters are set properly,the secure key rate is still high.Considering the influences of multiple actual secure parameters will significantly reduce the secure key rate.These actual secure parameters must be considered when scientists calibrate transmitters.This work is an important step towards the practical and secure implementation of phase-matching protocol.In the future,it is essential to study the main parameters,find out their maximum and general values,classify the multiple parameters as the same parameter,and give countermeasures.

Sensitivity of Medium-Range Weather Forecasts to the Use of Reference Atmosphere

In this paper, the authors develop the earlier work of Chen Jiabin et al. (1986). In order to reduce spectral truncation errors, the reference atmosphere has been introduced in ECMWF model, and the spectrally-represented variables, temperature, geopotential height and orography, are replaced by their deviations from the reference atmosphere. Two modified semi- implicit schemes have been proposed to alleviate the computational instability due to the introduction of reference atmosphere. Concerning the deviation of surface geopotential height from reference atmosphere, an exact computational formulation has been used instead of the approximate one in the earlier work. To re duce aliasing errors in the computations of the deviation of the surface geopotential height, a spectral fit has been used slightly to modify the original Gaussian grid-point values of orography.A series of experiments has been performed in order to assess the impact of the reference atmosphere on ECMWF medium- range forecasts at the resolution T21, T42 and T63. The results we have obtained reveal that the reference atmosphere introduced in ECMWF spectral model is generally beneficial to the mean statistical scores of 1000-200 hPa height 10-day forecasts over the globe. In the Southern Hemisphere, it is a clear improvement for T21, T42 and T63 throughout the 10-day forecast period. In the Northern Hemisphere, the impact of the reference atmos phere on anomaly correlation is positive for resolution T21, a very slightly damaging at T42 and almost neutral at T63 in the range of day 1 to day 4. Beyond the day 4 there is a clear improvement at all resolutions.

Research on the Influence of Land Use Changing on Non-point Source Pollution in Heihe River Basin

Based on the exploring of SWAT model suitability in Hei River Basin, this paper analyze quantitatively and compare non-point source pollution loads occurred under different land use scene. At last, the following conclusion can be attained： （1） Land use change exerts tremendous influence on non-point source pollution. Since forest land can save water and reduce soil loss, which decreases greatly the source of non-point source pollution; （2） Strengthening land management and promoting reasonable land use, especially the over 15 degree slope farmland, will be the effective measure to control non-point source pollution and protect the quality of water in the Hei River basin; （3） The best land use situation in Hei River basin should be like the following modes： complying with national water source protection policy, gradual evacuation of river basin population, returning all the sloping farmland which is above 15 degree to forest land, allowing the existence of few farming land below 15 slope degree on the premise that the drinking water quality standard is reached, no unused land, good vegetation covering situation. At then, total nitrogen load is 13.25 kg, total phosphate load is 3.29 kg, which means it will not contaminate

Ghost Imaging with High Visibility Using Classical Light Source

We experimentally demonstrate a novel ghost imaging experiment utilizing a classical light source, capable of resolving objects with a high visibility. The experimental results show that our scheme can indeed realize ghost imaging with high visibility for a relatively complicated object composed of three near-ellipse-shaped holes with different dimensions. In our experiment, the largest hole is -36 times of the smMlest one in area. Each of the three holes exhibits high-visibility in excess of 80%. The high visibility and high spatial-resolution advantages of this technique could have applications in remote sensing.

Phase Imaging Using Laser-produced X-ray Sources

A possible novel application of hard x-ray emitted during laser-plasma interaction was discussed. We established an Optical Transform Function to study the joint effect of the spectral distribution and temporal profile of the laser-produced x-ray on x-ray phase imaging. Though the laser-produced x-ray pulse duration is short and incoherent, the analysis confirms that the current x-ray phase imaging theory still holds for laser-produced x-ray phase imaging.

Spatial and Temporal Distribution Characteristics of Agricultural Non-point Source Pollution in Xixi Watershed of Jinjiang Basin

The SWAT model was applied to analyze the temporal-spatial distribution patterns of non-point source pollution loads and the difference of pollution loads of different land use types in Xixi Watershed of Jinjiang Basin. The results showed that both yearly nitrogen and phosphorus pollution loads were evenly distributed during 1973 to 1979,the annual TN pollution from non-point source was 1530 t,or 6. 3 kg / ha,and the annual TP pollution from non-point source was 270 t,or 1. 1 kg / ha during 1973 to 1979 in the watershed. Considerable differences were identified on both monthly nitrogen and phosphorus pollution loads. The TN and TP pollution loads during the flood season( from April to September) accounted for 76. 2% and 75. 8% of the annual load respectively. There were great differences in both TN and TP pollution loads of different land use types in the study area,and the pollution load of both farmland and orchard was higher than that of the other land use types. TN and TP pollution loads of farmland accounted for 66% and 83% of total watershed. There was a great spatial difference in the nonpoint source pollution load of the study area. The critical source areas of non-point source pollution are mainly located at Guanqiao Town,Longmen Town,Changkeng Town,Shangqing Town and Dapu Town,where the efforts of controlling pollution should be made.

Development of A Reference Dose for BDE-47,99,and 209 Using Benchmark Dose Methods

Eleven recently completed toxicological studies were critically reviewed to identify toxicologically significant endpoints and dose-response information. Dose-response data were compiled and entered into the USEPA＇s benchmark dose software （BMDS） for calculation of a benchmark dose （BMD） and a benchmark dose low （BMDL）. After assessing 91 endpoints across the nine studies, a total of 23 of these endpoints were identified for BMD modeling, and BMDL estimates corresponding to various dose-response models were compiled for these separate endpoints. Thyroid, neurobehavior and reproductive endpoints for BDE-47, -99, -209 were quantitatively evaluated. According to methods and feature of each study, different uncertainty factor （UF） value was decided and subsequently reference doses （RfDs） were proposed. Consistent with USEPA, the lowest BMDLs of 2.10, 81.77, and 1698 I^g/kg were used to develop RfDs for BDE-47, -99, and -209, respectively. RfDs for BDE-99 and BDE-209 were comparable to EPA results, and however, RfD of BDE-47 was much lower than that of EPA, which may result from that reproductive/developmental proves to be more sensitive than neurobehavior for BDE-47 and the principal study uses very-low-dose exposure.

Integrated Water Resource Assessment of Irrigation System of Haryana

Agriculture is the major activity in the state of Haryana and large volume of water is required to meet the irrigation demands of the crops grown. But, there is limited water availability in the state. Haryana receives water from Yamuna River and Bhakra system. Sowmelt, rainfall and groundwater are main sources of water in the catchment. It is essential to integrate the manmade canal system with hydrological system. This paper focuses on integrated hydrological modeling framework to conceptualize the system and to assess the Water Resources of the state. Snowmelt and Rainfall runoff modeling using GR4JSG model were combined to model the inflows to the irrigation system of Haryana. Irrigator canal model of eWater Source has been used to generate water demands from crops grown. The water balance and water use efficiency have been worked out for each district of Haryana. The hydro climate input data, stream flows, crop data and soil data have been used in the study. The flows modeled at Tuini (P), Yashwant Nagar, Bausan, Haripur, Poanta and HKB sites were compared with the observed flows. The objective function of NSE Daily and log Flow duration was used for model calibration and validation at various locations up to Mathura, the outlet of the study area. The value of the objective function at Mathura was 0.54, a fairly good value. The results of the Irrigator canal model have shown that all the Inflows, Outflows and the Utilizations of water have been properly balanced for each district. The water use efficiency of districts varies from 27% to 59%. The overall water use efficiency for Haryana canal system has been calculated as 39%. This is low value indicating excess water is being extracted to meet the water demands.

A Cascade Multilevel Inverter Using a Single DC Source

3.SWITCHING ANGLES If the nominal capacitor voltage is chosen as Vdc/2, then one can compute the switching anglesθ1,θ2,andθ3.Following the development,the Fourier series expan- sion of the(staircase)output voltage waveform of the multilevel inverter as shown in Fig.2(a)

Seasonal variation of nitrogen-concentration in the surface water and its relationship with land use in a catchment of northern China

Surface waters can be contaminated by human activities in two ways: (1) by point sources, such as sewage treatment discharge and storm-water runoff; and (2) by non-point sources, such as runoff from urban and agricultural areas. With point-source pollution effectively controlled, non-point source pollution has become the most important environmental concern in the world. The formation of non-point source pollution is related to both the sources such as soil nutrient, the amount of fertilizer and pesticide applied, the amount of refuse, and the spatial complex combination of land uses within a heterogeneous landscape. Land-use change, dominated by human activities, has a significant impact on water resources and quality. In this study, fifteen surface water monitoring points in the Yuqiao Reservoir Basin, Zunhua, Hebei Province, northern China, were chosen to study the seasonal variation of nitrogen concentration in the surface water. Water samples were collected in low-flow period(June), high-flow period(July) and mean-flow period(October) from 1999 to 2000. The results indicated that the seasonal variation of nitrogen concentration in the surface water among the fifteen monitoring points in the rainfall-rich year is more complex than that in the rainfall-deficit year. It was found that the land use, the characteristics of the surface river system, rainfall, and human activities play an important role in the seasonal variation of N-concentration in surface water.

Stable isotope analysis of water sources for Tamarix laxa in the mega-dunes of the Badain Jaran Desert, China

The complex interactions in desert ecosystems between functional types and environmental conditions could be reflected by plant water use patterns. However, the mechanisms underlying the water use patterns as well as the water sources of Tamarix laxa in the mega-dunes of the Badain Jaran Desert, China, remain unclear. This study investigated the water sources and water use patterns of T. laxa using the stable oxygen isotope method. The δ18O values of xylem water, soil water in different layers(0–200 cm), rainwater, snow water, lake water, atmospheric water vapor, condensate water, and groundwater were measured. The sources of water used by T. laxa were determined using the IsoSource model. The results indicate that T. laxa mainly relies on soil water. At the beginning of the growing season(in May), the species is primarily dependent on water from the middle soil layer(60–120 cm) and deep soil layer(120–200 cm). However, it mainly absorbs water from the shallow soil layer(0–60 cm) as the rainy season commences. In September, water use of T. laxa reverts to the deep soil layer(120–200 cm). The water use patterns of T. laxa are closely linked with heavy precipitation events and soil water content. These findings reveal the drought resistance mechanisms of T. laxa and are of significance for screening species for ecological restoration.

Sediment sources and their impacts on a check dam-controlled watershed, Loess Plateau, China

Soil erosion is a major issue in Loess Plateau,China,and quantitative analyses of sediment sources are crucial for soil erosion control.In this study,a combination of flood couplet analysis and composite fingerprint identification was used for historical reconstructions of soil erosion in sediment source areas in Loess Plateau.Each flood couplet was constructed based on sediment 137Cs activity,and past soil erosion was calculated using soil bulk density and storage capacity curves.The contribution rates of the sediment sources were calculated using the fingerprinting method,and the amount of erosion in the sediment source areas was estimated.The best fingerprint combination(Cr,Ni,V,and TOC)enabled a 97.2%recognition of sediment sources from 29 flood events(1956–1990)in the Loess Plateau.The contribution rates of gullies,farmland,grassland,and shrubland were 44.89%,26.38%,10.49%,and 18.24%,respectively.These four land use types contributed 1,227,751,512,and 279 tons of sediments,respectively.Re-vegetation decreased soil erosion(1966–1983),whereas deforestation increased soil erosion(1956–1965 and 1984–1990).Rational soil and water conservation measures on slopes and check dam construction in gullies are therefore suggested to mitigate erosion.

Combining CLUE-S and SWAT Models to Forecast Land Use Change and Non-point Source Pollution Impact at a Watershed Scale in Liaoning Province, China

Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.