This study aimed to identify the worst“bad actors”in mixtures of pollutants contributing to liver damage and shorter telomeres in the U.S.population,using weighted quantile sum(WQS)modeling with stratification by ra...This study aimed to identify the worst“bad actors”in mixtures of pollutants contributing to liver damage and shorter telomeres in the U.S.population,using weighted quantile sum(WQS)modeling with stratification by race/ethnicity.We conducted a comprehensive cross-sectional analysis of mixtures of pollutants in National Health and Nutrition Examination Survey datasets:(1)33,979 adults with blood levels of cadmium(Cd),lead(Pb),and mercury,including subsets with measurements of per-/polyfluoroalkyl substances(PFAS),and polychlorinated biphenyls(PCBs)/polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs);and(2)7360 adults with measurements of telomeres,Cd,and Pb.Multivariable-adjusted WQS regression examined associations between WQS mixture indices and liver injury(alanine aminotransferase(ALT)-elevation),advanced liverfibrosis(LF),and telomere length.WQSmetal indices were associated with advanced-LF in all racial/ethnic groups.The top contributor was Cd in the total population and in non-Hispanic Whites(NHW),while Pb was the top contributor in non-Hispanic Blacks(NHB).The WQSmetal-PCB-PCDD/F index was associated with ALT-elevation,with PCB126,Cd and Pb as main contributors;the odds ratio(OR)per decile was 1.50(95%CI,1.26–1.78),while the OR per decile of the WQSmetal-PFAS index was 1.03(95%CI,0.98–1.05),not significant.WQS_(metal indices)were associated with shorter telomeres.Cd was main contributor associated with advanced-LF in NHW,while Pb was the major bad actor in NHB,suggesting that NHB may be especially susceptible to Pb toxicity.Metals were associated with shorter telomeres.Metal and PCB/PCDD/F mixtures were associated with ALT-elevation.Heavy metals and organic chemicals may contribute to liver-related morbidity and healthcare disparities.展开更多
Nonlinear spectral mixture analysis (NSMA) is a widely used unmixing algorithm. It can fit the mixed spectra adequately, but collinearity effect among true and virtual endmembers will decrease the retrieval accuracies...Nonlinear spectral mixture analysis (NSMA) is a widely used unmixing algorithm. It can fit the mixed spectra adequately, but collinearity effect among true and virtual endmembers will decrease the retrieval accuracies of endmember fractions. Use of linear spectral mixture analysis (LSMA) can effectively reduce the degree of collinearity in the NSMA. However, the inadequate modeling of mixed spectra in the LSMA will also yield retrieval errors, especially for the cases where the multiple scattering is not ignorable. In this study, a generalized spectral unmixing scheme based on a spectral shape measure, i.e. spectral information divergence (SID), was applied to overcome the limitations of the conventional NSMA and LSMA. Two simulation experiments were undertaken to test the performances of the SID, LSMA and NSMA in the mixture cases of treesoil, tree-concrete and tree-grass. Results demonstrated that the SID yielded higher accuracies than the LSMA for almost all the mixture cases in this study. On the other hand, performances of the SID method were comparable with the NSMA for the tree-soil and tree-grass mixture cases, but significantly better than the NSMA for the tree-concrete mixture case. All the results indicate that the SID method is fairly effective to circumvent collinearity effect within the NSMA, and compensate the inadequate modeling of mixed spectra within the LSMA.展开更多
Impervious surface mapping is essential for urban environmental studies.Spectral Mixture Analysis(SMA)and its extensions are widely employed in impervious surface estimation from medium-resolution images.For SMA,inapp...Impervious surface mapping is essential for urban environmental studies.Spectral Mixture Analysis(SMA)and its extensions are widely employed in impervious surface estimation from medium-resolution images.For SMA,inappropriate endmember combinations and inadequate endmember classes have been recognized as the primary reasons for estimation errors.Meanwhile,the spectral-only SMA,without considering urban spatial distribution,fails to consider spectral variability in an adequate manner.The lack of endmember class diversity and their spatial variations lead to over/underestimation.To mitigate these issues,this study integrates a hierarchical strategy and spatially varied endmember spectra to map impervious surface abundance,taking Wuhan and Wuzhou as two study areas.Specifically,the piecewise convex multiple-model endmember detection algorithm is applied to automatically hierarch-ize images into three regions,and distinct endmember combinations are independently developed in each region.Then,spatially varied endmember spectra are synthesized through neighboring spectra using the distance-based weight.Comparative analysis indicates that the proposed method achieves better performance than Hierarchical SMA and Fixed Four-endmembers SMA in terms of MAE,SE,and RMSE.Further analysis suggests that the hierarch-ical strategy can expand endmember class types and considerably improve the performance for the study areas in general,specifically in less developed areas.Moreover,we find that spatially varied endmember spectra facilitate the reduction of heterogeneous surface material variations and achieve the improved performance in developed areas.展开更多
A new algorithm for unsupervised hyperspectral data unmixing is investigated, which includes a modified minimum noise fraction （MNF） transformation and independent component analysis （ICA）. The modified MNF transf...A new algorithm for unsupervised hyperspectral data unmixing is investigated, which includes a modified minimum noise fraction （MNF） transformation and independent component analysis （ICA）. The modified MNF transformation is used to reduce noise and remove correlation between neighboring bands. Then the ICA is applied to unmix hyperspectral images, and independent endmembers are obtained from unmixed images by using post-processing which includes image segmentation based on statistical histograms and morphological operations. The experimental results demonstrate that this algorithm can identify endmembers resident in mixed pixels. Meanwhile, the results show the high computational efficiency of the modified MNF transformation. The time consumed by the modified method is almost one fifth of the traditional MNF transformation.展开更多
An array composed of sixteen gas sensors was constructed to analyze gas mixtures quantitatively. The data of responses from the sensor array to ethane, propane and propylene were treated by three-layer ANN with BP alg...An array composed of sixteen gas sensors was constructed to analyze gas mixtures quantitatively. The data of responses from the sensor array to ethane, propane and propylene were treated by three-layer ANN with BP algorithms and PLS. The analytical results indicated that the concentration predicted with ANN is better than that with PLS. The average prediction errors for ethane, propane and propylene were 5.11%, 8.28%, 2.64%, respectively.展开更多
Ensuring water resource security and enhancing resilience to extreme hydrological events demand a comprehensive understanding of water dynamics across various scales.However,monitoring water bodies with highly seasona...Ensuring water resource security and enhancing resilience to extreme hydrological events demand a comprehensive understanding of water dynamics across various scales.However,monitoring water bodies with highly seasonal hydrological variability,particularly using medium-resolution satellite imagery such as Landsat 4-9,presents substantial challenges.This study introduces the Normalized Difference Water Fraction Index(NDWFI)based on spectral mixture analysis(SMA)to improve the detection of subtle and dynamically changing water bodies.First,the effectiveness of NDWFI is rigorously assessed across four challenging sites.The findings reveal that NDWFI achieves an average overall accuracy(OA)of 98.2%in water extraction across a range of water-covered scenarios,surpassing conventional water indices.Subsequently,using approximately 11,000 Landsat satellite images and NDWFI within the Google Earth Engine(GEE)platform,this study generates a high-resolution surface water(SW)map for Jiangsu Province,China,exhibiting an impressive OA of 95.91%±0.23%.We also investigate the stability of the NDWFI threshold for water extraction and its superior performance in comparison to existing thematic water maps.This research offers a promising avenue to address crucial challenges in remote sensing hydrology monitoring,contributing to the enhancement of water security and the strengthening of resilience against hydrological extremes.展开更多
The component analysis and structure characterization of complex mixtures of biomass conversion remain a challenging work.Hence,developing effective and easy to use techniques is necessary.Diffusion-ordered NMR spectr...The component analysis and structure characterization of complex mixtures of biomass conversion remain a challenging work.Hence,developing effective and easy to use techniques is necessary.Diffusion-ordered NMR spectroscopy(DOSY)is a non-selective and non-invasive method capable of achieving pseudo-separation and structure assignments of individual compounds from biomass mixtures by providing diffusion coefficients(D)of the components.However,the conventional 1H DOSY NMR is limited by crowded resonances when analyzing complex mixtures containing similar chemical structure resulting in similar coefficient.Herein we describe the application of an advanced diffusion NMR method,Pure Shift Yielded by CHirp Excitation DOSY(PSYCHE-iDOSY),which can record high-resolution signal diffusion spectra efficiently separating compounds in model and genuine mixture samples from cellulose,hemicellulose and lignin.Complicated sets of isomers(D-glucose/D-fructose/D-mannose and 1,2-/1,5-pentadiol),homologous compounds(ethylene glycol and 1,2-propylene glycol),model compounds of lignin,and a genuine reaction system(furfuryl alcohol hydrogenolysis with ring opening)were successfully separated in the diffusion dimension.The results show that the ultrahigh-resolution DOSY technique is capable of detecting and pseudo-separating the mixture components of C_(5)/C_(6) sugar conversion products and its derivative hydrogenation/hydrogenolysis from lignocellulose biomass.展开更多
A novel approach named aligned mixture probabilistic principal component analysis(AMPPCA) is proposed in this study for fault detection of multimode chemical processes. In order to exploit within-mode correlations,the...A novel approach named aligned mixture probabilistic principal component analysis(AMPPCA) is proposed in this study for fault detection of multimode chemical processes. In order to exploit within-mode correlations,the AMPPCA algorithm first estimates a statistical description for each operating mode by applying mixture probabilistic principal component analysis(MPPCA). As a comparison, the combined MPPCA is employed where monitoring results are softly integrated according to posterior probabilities of the test sample in each local model. For exploiting the cross-mode correlations, which may be useful but are inadvertently neglected due to separately held monitoring approaches, a global monitoring model is constructed by aligning all local models together. In this way, both within-mode and cross-mode correlations are preserved in this integrated space. Finally, the utility and feasibility of AMPPCA are demonstrated through a non-isothermal continuous stirred tank reactor and the TE benchmark process.展开更多
In this paper,a new method for simultaneous spectrophotometric analysis of multi- component with double-system was developed.The multivariate calibration method,principal component analysis-partial least squares(PCA-P...In this paper,a new method for simultaneous spectrophotometric analysis of multi- component with double-system was developed.The multivariate calibration method,principal component analysis-partial least squares(PCA-PLS),was described and applied to the processing of measurement data.A demonstration,simultaneous determination of cobalt,nickel,copper,zinc and iron with double-system(5-Br-PADAP and PAR as chromogenic chelate reagents,respectively) was given.The results showed that the method with douhle-system gave better precision than those with single system and MLR(in this paper,AKC method was selected)did not give satis- fied precision in any situation.展开更多
The UV absorption spectra of o-naphthol,α-naphthylamine,2,7-dihydroxy naphthalene,2,4-dimethoxy ben- zaldehyde and methyl salicylate,overlap severely;therefore it is impossible to determine them in mixtures by tradit...The UV absorption spectra of o-naphthol,α-naphthylamine,2,7-dihydroxy naphthalene,2,4-dimethoxy ben- zaldehyde and methyl salicylate,overlap severely;therefore it is impossible to determine them in mixtures by traditional spectrophotometric methods.In this paper,the partial least-squares(PLS)regression is applied to the simultaneous determination of these compounds in mixtures by UV spectrophtometry without any pretreatment of the samples.Ten synthetic mixture samples are analyzed by the proposed method.The mean recoveries are 99.4%,996%,100.2%,99.3% and 99.1%,and the relative standard deviations(RSD) are 1.87%,1.98%,1.94%,0.960% and 0.672%,respectively.展开更多
The health effects of traffic-derived pollutants have gathered increasing concerns.Our objectives were to evaluate the associations of traffic-related heavy metal exposure with serum uric acid(SUA)and hyperuricemia an...The health effects of traffic-derived pollutants have gathered increasing concerns.Our objectives were to evaluate the associations of traffic-related heavy metal exposure with serum uric acid(SUA)and hyperuricemia and to explore the underlying mechanism.Traffic-related heavy metals(including zinc,iron,manganese,copper,lead,cadmium,antimony,and barium)and SUA were determined among 3909 community-based adults from the Wuhan-Zhuhai cohort.Various regression methods were applied to assess the association of heavy metals with SUA and hyperuricemia.Furthermore,mediation analyses were employed to evaluate the potential role of systemic inflammation in these associations.In single metal analyses,positive dose-response relationships between urinary zinc,iron,manganese,and antimony and SUA were observed.Furthermore,each 1-unit increase of ln-transformed urinary zinc levels was related to a 37.9%(OR=1.379,95%CI:1.148 to 1.657)increase in the hyperuricemia risk.In multiple metal analyses,both Bayesian kernel machine regression(BKMR)and weighted quantile sum regression(WQS)models showed positive associations of heavy metals mixture with SUA and hyperuricemia risk,and WQS analyses further revealed that zinc was the dominant metal(component weight:0.611 and 0.594,respectively).Additionally,plasma C-reactive protein(CRP)mediated 4.919%and 8.417%of the association of urinary zinc with SUA and hyperuricemia,respectively.In conclusion,exposure to several traffic-related heavy metals or traffic-related heavy metal mixtures were positively associated with SUA and hyperuricemia risk in the general Chinese population,in which zinc played a dominating role.Plasma CRP might partly mediate the association of urinary zinc with SUA and hyperuricemia risk.展开更多
Previous studies have suggested that abnormal hepatobiliary system function may contribute to poor prognosis in patientswith acute coronary syndrome(ACS)and that abnormal hepatobiliary system function may be associate...Previous studies have suggested that abnormal hepatobiliary system function may contribute to poor prognosis in patientswith acute coronary syndrome(ACS)and that abnormal hepatobiliary system function may be associated with per-and polyfluoroalkyl substances(PFAS)exposure.However,there is limited evidence for this association in cardiovascular subpopulations,particularly in the ACS patients.Therefore,we performed this study to evaluate the association between plasma PFAS exposure and hepatobiliary system function biomarkers in patients with ACS.This study included 546 newly diagnosed ACS patients at the Second Hospital of Hebei Medical University,and data on 15 hepatobiliary system function biomarkers were obtained from medical records.Associations between single PFAS and hepatobiliary system function biomarkers were assessed using multiple linear regression models and restricted cubic spline model(RCS),and mixture effects were assessed using the Quantile g-computation model.The results showed that total bile acids(TBA)was negative associated with perfluorohexane sulfonic acid(PFHxS)(-7.69%,95%CI:-12.15%,-3.01%).According to the RCS model,linear associations were found between TBA and PFHxS(P for overall=0.003,P for non-linear=0.234).We also have observed the association between between PFAS congeners and liver enzyme such as aspartate aminotransferase(AST)and α-l-Fucosidase(AFU),but it was not statistically significant after correction.In addition,Our results also revealed an association between prealbumin(PA)and PFAS congeners as well as mixtures.Our findings have provided a piece of epidemiological evidence on associations between PFAS congeners or mixture,and serum hepatobiliary system function biomarkers in ACS patients,which could be a basis for subsequent mechanism studies.展开更多
In the present investigation,a new composite nanostructured photoanodes were prepared using TiO_2 nanotubes（TNTs） with TiO_2 nanoparticles（TNPs）.TNPs were synthesized by sol-gel method,and TNTs were prepared throu...In the present investigation,a new composite nanostructured photoanodes were prepared using TiO_2 nanotubes（TNTs） with TiO_2 nanoparticles（TNPs）.TNPs were synthesized by sol-gel method,and TNTs were prepared through alkali hydrothermal method.Dye-sensitized solar cells（DSSCs） were fabricated with different photoanodes comprising of various ratios of TNTs ＋ TNPs,synthetic indigo dye as photosensitizer,PMII（l-propyl-3-methylimidazolium iodide） as ionic liquid electrolyte and cobalt sulfide as counter electrode.The structures and morphologies of TNPs and TNTs were analyzed through X-ray diffractometer,transmission electron microscope and scanning electron microscopes.The results of the investigation showed that the DSSC-4 made with composite photoanode structure（TNTs/TNPs）（90% of TNPs ＋ 10% of TNTs） had improved photocurrent efficiency（2.11%） than pure TNPs（1.00%） and TNT film（0.78%）.Electrochemical impedance spectra revealed that the composite TNTs/TNPs film-based DSSCs possessed the lowest charge-transfer resistances and longest electron lifetime.Hence,it could be concluded that the composite TNTs/TNPs photoanode facilitates the charge transport rate and enhances the efficiencies of DSSCs.展开更多
Objective The study aimed to investigate the impact of rare earth elements(REEs)exposure on pregnancy outcomes of in vitro fertilization-embryo transfer(IVF-ET)by analyzing samples from spouses.Methods A total of 141 ...Objective The study aimed to investigate the impact of rare earth elements(REEs)exposure on pregnancy outcomes of in vitro fertilization-embryo transfer(IVF-ET)by analyzing samples from spouses.Methods A total of 141 couples were included.Blood and follicular fluid from the wives and semen plasma from the husbands,were analyzed for REEs using inductively coupled plasma mass spectrometry(ICP-MS).Spearman's correlation coefficients and the Mann–Whitney U test were used to assess correlations and compare REE concentrations among three types of samples,respectively.Logistic models were utilized to estimate the individual REE effect on IVF-ET outcomes,while BKMR and WQS models explored the mixture of REE interaction effects on IVF-ET outcomes.Results Higher La concentration in semen(median 0.089 ng/mL,P=0.03)was associated with a lower fertilization rate.However,this effect was not observed after artificial selection intervention through intracytoplasmic sperm injection(ICSI)(P=0.27).In semen,the REEs mixture did not exhibit any significant association with clinical pregnancy.Conclusion Our study revealed a potential association between high La exposure in semen and a decline in fertilization rate,but not clinical pregnancy rate.This is the first to report REEs concentrations in follicular fluid with La,Ce,Pr,and Nd found at significantly lower concentrations than in serum,suggesting that these four REEs may not accumulate in the female reproductive system.However,at the current exposure levels,mixed REEs exposure did not exhibit reproductive toxicity.展开更多
Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter...Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter） and the weak spectral features of salinized soil. Therefore, an index such as the salinity index （SI） that only uses soil spectra may not detect soil salinity effectively and quantitatively. The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance. The normalized difference vegetation index （NDVI）, as the most common vegetation index, was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas. Therefore, the arid fraction integrated index （AFⅡ） was created as supported by the spectral mixture analysis （SMA）, which is more appropriate for analyzing variations in vegetation cover （particularly halophytes） than NDVI in the study area. Using soil and vegetation separately for detecting salinity perhaps is not feasible. Then, we developed a new and operational model, the soil salinity detecting model （SDM） that combines AFⅡ and SI to quantitatively estimate the salt content in the surface soil. SDMs, including SDM1 and SDM2, were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFⅡ and SI using a scatterplot. The SDMs were then compared to the combined spectral response index （COSRI） from field measurements with respect to the soil salt content. The results indicate that the SDM values are highly correlated with soil salinity, in contrast to the performance of COSRI. Strong exponential relationships were observed between soil salinity and SDMs （R2〉0.86, RMSE〈6.86） compared to COSRI （R2=0.71, RMSE=16.21）. These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively provide information on soil salinity.展开更多
This paper provides a study of the changes in land use in urban environments in two cities,Wuhan,China and western Sydney in Australia.Since mixed pixels are a characteristic of medium resolution images such as Landsa...This paper provides a study of the changes in land use in urban environments in two cities,Wuhan,China and western Sydney in Australia.Since mixed pixels are a characteristic of medium resolution images such as Landsat,when used for the classification of urban areas,due to changes in urban ground cover within a pixel,Multiple Endmember Spectral Mixture Analysis(MESMA)together with Super-Resolution Mapping(SRM)are employed to derive class fractions to generate classification maps at a higher spatial resolution using an Artificial Neural Network(ANN)predicted Wavelet method.Landsat images over the two cities for a 30-year period,are classified in terms of vegetation,buildings,soil and water.The classifications are then processed using Indifrag software to assess the levels of fragmentation caused by changes in the areas of buildings,vegetation,water and soil over the 30 years.The extents of fragmentation of vegetation,buildings,water and soil for the two cities are compared,while the percentages of vegetation are compared with recommended percentages of green space for urban areas for the benefit of health and well-being of inhabitants.Changes in Ecosystem Service Values(ESVs)resulting from the urbanization have been assessed for Wuhan and Sydney.The UN Sustainable Development Goals(SDG)for urban areas are being assessed by researchers to better understand how to achieve the sustainability of cities.展开更多
This paper explores the potential to improve the impervious surface estimation accuracy using a multi-stage approach on the basis of vegetation-impervious surface-soil (V-I-S) model. In the first stage of Spectral Mix...This paper explores the potential to improve the impervious surface estimation accuracy using a multi-stage approach on the basis of vegetation-impervious surface-soil (V-I-S) model. In the first stage of Spectral Mixture Analysis (SMA) process, pixel purity index, a quantitative index for defining endmember quality, and a 3-dimensional endmember selection method were applied to refining endmembers. In the second stage, instead of obtaining impervious surface fraction by adding high and low albedo fractions directly, a linear regression model was built between impervious surface and high/low albedo using a random sampling method. The urban impervious surface distribution in the urban central area of Shanghai was predicted by the linear regression model. Estimation accuracy of spectral mixture analysis and impervious surface fraction were assessed using root mean square (RMS) and color aerial photography respectively. In comparison with three different research methods, this improved estimation method has a higher overall accuracy than traditional Linear Spectral Mixture Analysis (LSMA) method and the normalized SMA model both in root mean square error (RMSE) and standard error (SE). However, the model has a tendency to overestimate the impervious surface distribution.展开更多
Arid and semi-arid ecosystems exhibit a spatially complex biogeophysical structure. According to arid western special climate-vegetation characters, the fractional cover of photosynthetic vegetation （PV）, non-photos...Arid and semi-arid ecosystems exhibit a spatially complex biogeophysical structure. According to arid western special climate-vegetation characters, the fractional cover of photosynthetic vegetation （PV）, non-photosynthetic vegetation （NPV）, bare soil and water are unmixed, using the remote sensing spectral mixture analysis. We try the method to unmix the canopy funation structure of arid land cover in order to avoid the differentiation of regional vegetation system and the disturbance of environmental background. We developed a modified production efficiency model NPP-PEM appropriate for the arid area at regional scale based on the concept of radiation use efficiency. This model refer to the GLO-PEM and CASA model was driven with remotely sensed observations, and calculates not just the conversion efficiency of absorbed photosynthetically active radiation but also the carbon fluxes that determine net primary productivity （NPP）. We apply and validate the model in the Kaxger and Yarkant river basins in arid western China. The NPP of the study area in 1992 and 1998 was estimated based on the NPP-PEM model. The results show that the improved PEM model, considering the photosynthetical activation of heterogeneous functional vegetation, is in good agreement with field measurements and the existing literature. An accurate agreement （R2= 0.85, P〈0.001） between the estimates and the ground-based measurement was obtained. The spatial distribution of mountain-oasis-desert ecosystem shows an obvious heterogeneous carbon uptake. The results are applicable to arid ecosystem studies ranging from characterizing carbon cycle, carbon flux over arid areas to monitoring change in mountain-oasis-desert productivity, stress and management.展开更多
Initiatives on tackling food insecurity among global emerging economies are being focused on enriching native staple foods with locally available nutritious underutilized crops. The objective of this study was to opti...Initiatives on tackling food insecurity among global emerging economies are being focused on enriching native staple foods with locally available nutritious underutilized crops. The objective of this study was to optimize protein content and dietary fibre in rice (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oryza sativa</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">) flour using Sorghum (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Sorghum bicolor</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> L.) and Bamboo shoots (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Yushania alpine</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">). An extreme vertices design of mixture approach with 11 runs was employed in the study using MINITAB</span><span style="font-family:Verdana;">®</span><span style="font-family:Verdana;"> software. The 11 blends from 11 generated runs and individual ingredient samples were analyzed for nutritional composition. Energy value and energy-to-protein ratio for the samples was calculated. Bamboo shoots flour (BSF) had </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">highest content for all proximate components except total carbohydrates on dry weight basis. Rice had </span><span style="font-family:Verdana;">the</span><span style="font-family:Verdana;"> highest content of total carbohydrates at 77.71% and energy to protein ratio of 53.72 kcal/g. Sorghum had </span><span style="font-family:Verdana;">the</span><span style="font-family:Verdana;"> highest mean total phenolic and condensed tannins of 45.512 (mg GAE/kg) and 2.512 (mg CE/g) while rice the least with 0.042 (mg GAE/kg) and 0.102 (mg CE/g), respectively. Fresh bamboo shoots had </span><span style="font-family:Verdana;">the</span><span style="font-family:""><span style="font-family:Verdana;"> highest level content of HCN of 117.81 mg/kg. Other dried ingredients had a mean HCN content of 2.313, 1.584 and 0.066 mg/kg for dried BSF, sorghum and rice respectively. Increasing the quantity of BSF and sorghum flour in the blends consequentially increased the protein content, dietary fibre and total minerals. Optimum blend was established to be 50:27:23 for rice, sorghum and BSF, respectively. This blend had 13.4% protein, 6.2% dietary fibre and 3.9% total minerals. Regression analysis showed that apart from dry matter, all other constituents were significantly predictable during optimization with R</span><sup><span style="font-family:Verdana;">2</span></sup></span><span style="font-family:""> </span><span style="font-family:Verdana;">></span><span style="font-family:""> </span><span style="font-family:Verdana;">0.7530. Cluster analysis showed that the nutritional components analyzed are in four main clusters. Cluster 1: Dry matter and protein digestibility, cluster 2: Carbohydrates, energy value and energy ratio, cluster 3: Protein, fibre and ash while cluster 4: Crude fat only. These findings of the optimum composite ratio and other blends could contribute in addressing the food insecurity for low income countries.展开更多
The marine dynamic environment of the Bohai Sea and the Yellow Sea in the winter of 2006 is simulated by the Regional Ocean Modelling System（ROMS） marine numerical model. Using the simulated temperature and salinity...The marine dynamic environment of the Bohai Sea and the Yellow Sea in the winter of 2006 is simulated by the Regional Ocean Modelling System（ROMS） marine numerical model. Using the simulated temperature and salinity, the water exchange zone between the Bohai Sea and Yellow Sea is defined through the Spectral Mixture Model（SMM）. The influence of winter gales on the water exchange is also discussed. It is found that the Yellow Sea water masses in winter are distributed in a ＂tongue＂ shape in the Bohai Strait region, the water exchange zone presents a zonal distribution along the margin of the ＂tongue＂, with a tendency of running from northwest to southeast, and the water exchange is intensified at the tip of the ＂tongue＂. Besides, the coastal area in the northernmost Yellow Sea does not participate in the water exchange between the Bohai Sea and Yellow Sea. The result shows that the winter gale events play a role in enhancing the water exchange. It is specifically shown by the facts： the Yellow Sea warm current is enhanced to intrude the Bohai Sea by the gale process; the water exchange zone extends into the Bohai Sea; the water exchange belt in the southern part becomes wider; the mixture zone of river runoff with the Bohai Sea water upon its entry is enlarged and shifts northwards. Within two days after the gale process, the exchange zone retreats toward the Yellow Sea and the exchange zone resulted from the Huanghe River（Yellow River） runoff also shrinks back shoreward.展开更多
基金supported by U01OH012263,and U01 OH012622 from the National Institute for Occupational Safety and HealthPCF 604934 from Prevent Cancer Foundation+1 种基金National Institutes of Health(NIH)/National Cancer Institute(NCI)1U01CA288425–0P30 ES023515 from the National Institute of Environmental Health Sciences.
文摘This study aimed to identify the worst“bad actors”in mixtures of pollutants contributing to liver damage and shorter telomeres in the U.S.population,using weighted quantile sum(WQS)modeling with stratification by race/ethnicity.We conducted a comprehensive cross-sectional analysis of mixtures of pollutants in National Health and Nutrition Examination Survey datasets:(1)33,979 adults with blood levels of cadmium(Cd),lead(Pb),and mercury,including subsets with measurements of per-/polyfluoroalkyl substances(PFAS),and polychlorinated biphenyls(PCBs)/polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs);and(2)7360 adults with measurements of telomeres,Cd,and Pb.Multivariable-adjusted WQS regression examined associations between WQS mixture indices and liver injury(alanine aminotransferase(ALT)-elevation),advanced liverfibrosis(LF),and telomere length.WQSmetal indices were associated with advanced-LF in all racial/ethnic groups.The top contributor was Cd in the total population and in non-Hispanic Whites(NHW),while Pb was the top contributor in non-Hispanic Blacks(NHB).The WQSmetal-PCB-PCDD/F index was associated with ALT-elevation,with PCB126,Cd and Pb as main contributors;the odds ratio(OR)per decile was 1.50(95%CI,1.26–1.78),while the OR per decile of the WQSmetal-PFAS index was 1.03(95%CI,0.98–1.05),not significant.WQS_(metal indices)were associated with shorter telomeres.Cd was main contributor associated with advanced-LF in NHW,while Pb was the major bad actor in NHB,suggesting that NHB may be especially susceptible to Pb toxicity.Metals were associated with shorter telomeres.Metal and PCB/PCDD/F mixtures were associated with ALT-elevation.Heavy metals and organic chemicals may contribute to liver-related morbidity and healthcare disparities.
文摘Nonlinear spectral mixture analysis (NSMA) is a widely used unmixing algorithm. It can fit the mixed spectra adequately, but collinearity effect among true and virtual endmembers will decrease the retrieval accuracies of endmember fractions. Use of linear spectral mixture analysis (LSMA) can effectively reduce the degree of collinearity in the NSMA. However, the inadequate modeling of mixed spectra in the LSMA will also yield retrieval errors, especially for the cases where the multiple scattering is not ignorable. In this study, a generalized spectral unmixing scheme based on a spectral shape measure, i.e. spectral information divergence (SID), was applied to overcome the limitations of the conventional NSMA and LSMA. Two simulation experiments were undertaken to test the performances of the SID, LSMA and NSMA in the mixture cases of treesoil, tree-concrete and tree-grass. Results demonstrated that the SID yielded higher accuracies than the LSMA for almost all the mixture cases in this study. On the other hand, performances of the SID method were comparable with the NSMA for the tree-soil and tree-grass mixture cases, but significantly better than the NSMA for the tree-concrete mixture case. All the results indicate that the SID method is fairly effective to circumvent collinearity effect within the NSMA, and compensate the inadequate modeling of mixed spectra within the LSMA.
基金supported by the National Natural Science Foundation of China with grant numbers[41890820,42090012,41771452 and 41771454].
文摘Impervious surface mapping is essential for urban environmental studies.Spectral Mixture Analysis(SMA)and its extensions are widely employed in impervious surface estimation from medium-resolution images.For SMA,inappropriate endmember combinations and inadequate endmember classes have been recognized as the primary reasons for estimation errors.Meanwhile,the spectral-only SMA,without considering urban spatial distribution,fails to consider spectral variability in an adequate manner.The lack of endmember class diversity and their spatial variations lead to over/underestimation.To mitigate these issues,this study integrates a hierarchical strategy and spatially varied endmember spectra to map impervious surface abundance,taking Wuhan and Wuzhou as two study areas.Specifically,the piecewise convex multiple-model endmember detection algorithm is applied to automatically hierarch-ize images into three regions,and distinct endmember combinations are independently developed in each region.Then,spatially varied endmember spectra are synthesized through neighboring spectra using the distance-based weight.Comparative analysis indicates that the proposed method achieves better performance than Hierarchical SMA and Fixed Four-endmembers SMA in terms of MAE,SE,and RMSE.Further analysis suggests that the hierarch-ical strategy can expand endmember class types and considerably improve the performance for the study areas in general,specifically in less developed areas.Moreover,we find that spatially varied endmember spectra facilitate the reduction of heterogeneous surface material variations and achieve the improved performance in developed areas.
基金Sponsored by the National Natural Science Foundation of China(Grant No. 60272073).
文摘A new algorithm for unsupervised hyperspectral data unmixing is investigated, which includes a modified minimum noise fraction （MNF） transformation and independent component analysis （ICA）. The modified MNF transformation is used to reduce noise and remove correlation between neighboring bands. Then the ICA is applied to unmix hyperspectral images, and independent endmembers are obtained from unmixed images by using post-processing which includes image segmentation based on statistical histograms and morphological operations. The experimental results demonstrate that this algorithm can identify endmembers resident in mixed pixels. Meanwhile, the results show the high computational efficiency of the modified MNF transformation. The time consumed by the modified method is almost one fifth of the traditional MNF transformation.
文摘An array composed of sixteen gas sensors was constructed to analyze gas mixtures quantitatively. The data of responses from the sensor array to ethane, propane and propylene were treated by three-layer ANN with BP algorithms and PLS. The analytical results indicated that the concentration predicted with ANN is better than that with PLS. The average prediction errors for ethane, propane and propylene were 5.11%, 8.28%, 2.64%, respectively.
基金National Science Foundation for Distinguished Young Scholars of China under grant 42225107National Key Research and Development Program under grant 2022YFB3903402Natural Science Foundation of China under grants 61976234,42171409,and 42171410.
文摘Ensuring water resource security and enhancing resilience to extreme hydrological events demand a comprehensive understanding of water dynamics across various scales.However,monitoring water bodies with highly seasonal hydrological variability,particularly using medium-resolution satellite imagery such as Landsat 4-9,presents substantial challenges.This study introduces the Normalized Difference Water Fraction Index(NDWFI)based on spectral mixture analysis(SMA)to improve the detection of subtle and dynamically changing water bodies.First,the effectiveness of NDWFI is rigorously assessed across four challenging sites.The findings reveal that NDWFI achieves an average overall accuracy(OA)of 98.2%in water extraction across a range of water-covered scenarios,surpassing conventional water indices.Subsequently,using approximately 11,000 Landsat satellite images and NDWFI within the Google Earth Engine(GEE)platform,this study generates a high-resolution surface water(SW)map for Jiangsu Province,China,exhibiting an impressive OA of 95.91%±0.23%.We also investigate the stability of the NDWFI threshold for water extraction and its superior performance in comparison to existing thematic water maps.This research offers a promising avenue to address crucial challenges in remote sensing hydrology monitoring,contributing to the enhancement of water security and the strengthening of resilience against hydrological extremes.
基金The authors thank for National Natural Science Foundation of China(22075308)for financial support。
文摘The component analysis and structure characterization of complex mixtures of biomass conversion remain a challenging work.Hence,developing effective and easy to use techniques is necessary.Diffusion-ordered NMR spectroscopy(DOSY)is a non-selective and non-invasive method capable of achieving pseudo-separation and structure assignments of individual compounds from biomass mixtures by providing diffusion coefficients(D)of the components.However,the conventional 1H DOSY NMR is limited by crowded resonances when analyzing complex mixtures containing similar chemical structure resulting in similar coefficient.Herein we describe the application of an advanced diffusion NMR method,Pure Shift Yielded by CHirp Excitation DOSY(PSYCHE-iDOSY),which can record high-resolution signal diffusion spectra efficiently separating compounds in model and genuine mixture samples from cellulose,hemicellulose and lignin.Complicated sets of isomers(D-glucose/D-fructose/D-mannose and 1,2-/1,5-pentadiol),homologous compounds(ethylene glycol and 1,2-propylene glycol),model compounds of lignin,and a genuine reaction system(furfuryl alcohol hydrogenolysis with ring opening)were successfully separated in the diffusion dimension.The results show that the ultrahigh-resolution DOSY technique is capable of detecting and pseudo-separating the mixture components of C_(5)/C_(6) sugar conversion products and its derivative hydrogenation/hydrogenolysis from lignocellulose biomass.
基金Supported by the National Natural Science Foundation of China(61374140)Shanghai Pujiang Program(12PJ1402200)
文摘A novel approach named aligned mixture probabilistic principal component analysis(AMPPCA) is proposed in this study for fault detection of multimode chemical processes. In order to exploit within-mode correlations,the AMPPCA algorithm first estimates a statistical description for each operating mode by applying mixture probabilistic principal component analysis(MPPCA). As a comparison, the combined MPPCA is employed where monitoring results are softly integrated according to posterior probabilities of the test sample in each local model. For exploiting the cross-mode correlations, which may be useful but are inadvertently neglected due to separately held monitoring approaches, a global monitoring model is constructed by aligning all local models together. In this way, both within-mode and cross-mode correlations are preserved in this integrated space. Finally, the utility and feasibility of AMPPCA are demonstrated through a non-isothermal continuous stirred tank reactor and the TE benchmark process.
基金This project was supported by the Natural Science Foundation of Jiangxi Province
文摘In this paper,a new method for simultaneous spectrophotometric analysis of multi- component with double-system was developed.The multivariate calibration method,principal component analysis-partial least squares(PCA-PLS),was described and applied to the processing of measurement data.A demonstration,simultaneous determination of cobalt,nickel,copper,zinc and iron with double-system(5-Br-PADAP and PAR as chromogenic chelate reagents,respectively) was given.The results showed that the method with douhle-system gave better precision than those with single system and MLR(in this paper,AKC method was selected)did not give satis- fied precision in any situation.
文摘The UV absorption spectra of o-naphthol,α-naphthylamine,2,7-dihydroxy naphthalene,2,4-dimethoxy ben- zaldehyde and methyl salicylate,overlap severely;therefore it is impossible to determine them in mixtures by traditional spectrophotometric methods.In this paper,the partial least-squares(PLS)regression is applied to the simultaneous determination of these compounds in mixtures by UV spectrophtometry without any pretreatment of the samples.Ten synthetic mixture samples are analyzed by the proposed method.The mean recoveries are 99.4%,996%,100.2%,99.3% and 99.1%,and the relative standard deviations(RSD) are 1.87%,1.98%,1.94%,0.960% and 0.672%,respectively.
基金supported by the Key Program of the National Natural Science Foundation of China(No.82241088).
文摘The health effects of traffic-derived pollutants have gathered increasing concerns.Our objectives were to evaluate the associations of traffic-related heavy metal exposure with serum uric acid(SUA)and hyperuricemia and to explore the underlying mechanism.Traffic-related heavy metals(including zinc,iron,manganese,copper,lead,cadmium,antimony,and barium)and SUA were determined among 3909 community-based adults from the Wuhan-Zhuhai cohort.Various regression methods were applied to assess the association of heavy metals with SUA and hyperuricemia.Furthermore,mediation analyses were employed to evaluate the potential role of systemic inflammation in these associations.In single metal analyses,positive dose-response relationships between urinary zinc,iron,manganese,and antimony and SUA were observed.Furthermore,each 1-unit increase of ln-transformed urinary zinc levels was related to a 37.9%(OR=1.379,95%CI:1.148 to 1.657)increase in the hyperuricemia risk.In multiple metal analyses,both Bayesian kernel machine regression(BKMR)and weighted quantile sum regression(WQS)models showed positive associations of heavy metals mixture with SUA and hyperuricemia risk,and WQS analyses further revealed that zinc was the dominant metal(component weight:0.611 and 0.594,respectively).Additionally,plasma C-reactive protein(CRP)mediated 4.919%and 8.417%of the association of urinary zinc with SUA and hyperuricemia,respectively.In conclusion,exposure to several traffic-related heavy metals or traffic-related heavy metal mixtures were positively associated with SUA and hyperuricemia risk in the general Chinese population,in which zinc played a dominating role.Plasma CRP might partly mediate the association of urinary zinc with SUA and hyperuricemia risk.
基金supported by the National Natural Science Foundation of China(No.21976050)the Science and Technology Program of Hebei Province(No.21377779D)+3 种基金the Natural Science Foundation of Hebei Province(No.B2020206008)China Postdoctoral Science Foundation(Nos.2023M730317 and 2023T160066)the Fundamental Research Funds for the Central Universities(No.3332023042)the Open Project of Hebei Key Laboratory of Environment and Human Health(No.202301).
文摘Previous studies have suggested that abnormal hepatobiliary system function may contribute to poor prognosis in patientswith acute coronary syndrome(ACS)and that abnormal hepatobiliary system function may be associated with per-and polyfluoroalkyl substances(PFAS)exposure.However,there is limited evidence for this association in cardiovascular subpopulations,particularly in the ACS patients.Therefore,we performed this study to evaluate the association between plasma PFAS exposure and hepatobiliary system function biomarkers in patients with ACS.This study included 546 newly diagnosed ACS patients at the Second Hospital of Hebei Medical University,and data on 15 hepatobiliary system function biomarkers were obtained from medical records.Associations between single PFAS and hepatobiliary system function biomarkers were assessed using multiple linear regression models and restricted cubic spline model(RCS),and mixture effects were assessed using the Quantile g-computation model.The results showed that total bile acids(TBA)was negative associated with perfluorohexane sulfonic acid(PFHxS)(-7.69%,95%CI:-12.15%,-3.01%).According to the RCS model,linear associations were found between TBA and PFHxS(P for overall=0.003,P for non-linear=0.234).We also have observed the association between between PFAS congeners and liver enzyme such as aspartate aminotransferase(AST)and α-l-Fucosidase(AFU),but it was not statistically significant after correction.In addition,Our results also revealed an association between prealbumin(PA)and PFAS congeners as well as mixtures.Our findings have provided a piece of epidemiological evidence on associations between PFAS congeners or mixture,and serum hepatobiliary system function biomarkers in ACS patients,which could be a basis for subsequent mechanism studies.
文摘In the present investigation,a new composite nanostructured photoanodes were prepared using TiO_2 nanotubes（TNTs） with TiO_2 nanoparticles（TNPs）.TNPs were synthesized by sol-gel method,and TNTs were prepared through alkali hydrothermal method.Dye-sensitized solar cells（DSSCs） were fabricated with different photoanodes comprising of various ratios of TNTs ＋ TNPs,synthetic indigo dye as photosensitizer,PMII（l-propyl-3-methylimidazolium iodide） as ionic liquid electrolyte and cobalt sulfide as counter electrode.The structures and morphologies of TNPs and TNTs were analyzed through X-ray diffractometer,transmission electron microscope and scanning electron microscopes.The results of the investigation showed that the DSSC-4 made with composite photoanode structure（TNTs/TNPs）（90% of TNPs ＋ 10% of TNTs） had improved photocurrent efficiency（2.11%） than pure TNPs（1.00%） and TNT film（0.78%）.Electrochemical impedance spectra revealed that the composite TNTs/TNPs film-based DSSCs possessed the lowest charge-transfer resistances and longest electron lifetime.Hence,it could be concluded that the composite TNTs/TNPs photoanode facilitates the charge transport rate and enhances the efficiencies of DSSCs.
基金supported by the National Key Research and Development Program of China(2022YFC2702900 and 2021YFC2701103)National Natural Science Foundation of China(82171654)。
文摘Objective The study aimed to investigate the impact of rare earth elements(REEs)exposure on pregnancy outcomes of in vitro fertilization-embryo transfer(IVF-ET)by analyzing samples from spouses.Methods A total of 141 couples were included.Blood and follicular fluid from the wives and semen plasma from the husbands,were analyzed for REEs using inductively coupled plasma mass spectrometry(ICP-MS).Spearman's correlation coefficients and the Mann–Whitney U test were used to assess correlations and compare REE concentrations among three types of samples,respectively.Logistic models were utilized to estimate the individual REE effect on IVF-ET outcomes,while BKMR and WQS models explored the mixture of REE interaction effects on IVF-ET outcomes.Results Higher La concentration in semen(median 0.089 ng/mL,P=0.03)was associated with a lower fertilization rate.However,this effect was not observed after artificial selection intervention through intracytoplasmic sperm injection(ICSI)(P=0.27).In semen,the REEs mixture did not exhibit any significant association with clinical pregnancy.Conclusion Our study revealed a potential association between high La exposure in semen and a decline in fertilization rate,but not clinical pregnancy rate.This is the first to report REEs concentrations in follicular fluid with La,Ce,Pr,and Nd found at significantly lower concentrations than in serum,suggesting that these four REEs may not accumulate in the female reproductive system.However,at the current exposure levels,mixed REEs exposure did not exhibit reproductive toxicity.
基金financially supported by the National Basic Research Program of China (2009CB825105)the National Natural Science Foundation of China (41261090)
文摘Modeling soil salinity in an arid salt-affected ecosystem is a difficult task when using remote sensing data because of the complicated soil context （vegetation cover, moisture, surface roughness, and organic matter） and the weak spectral features of salinized soil. Therefore, an index such as the salinity index （SI） that only uses soil spectra may not detect soil salinity effectively and quantitatively. The use of vegetation reflectance as an indirect indicator can avoid limitations associated with the direct use of soil reflectance. The normalized difference vegetation index （NDVI）, as the most common vegetation index, was found to be responsive to salinity but may not be available for retrieving sparse vegetation due to its sensitivity to background soil in arid areas. Therefore, the arid fraction integrated index （AFⅡ） was created as supported by the spectral mixture analysis （SMA）, which is more appropriate for analyzing variations in vegetation cover （particularly halophytes） than NDVI in the study area. Using soil and vegetation separately for detecting salinity perhaps is not feasible. Then, we developed a new and operational model, the soil salinity detecting model （SDM） that combines AFⅡ and SI to quantitatively estimate the salt content in the surface soil. SDMs, including SDM1 and SDM2, were constructed through analyzing the spatial characteristics of soils with different salinization degree by integrating AFⅡ and SI using a scatterplot. The SDMs were then compared to the combined spectral response index （COSRI） from field measurements with respect to the soil salt content. The results indicate that the SDM values are highly correlated with soil salinity, in contrast to the performance of COSRI. Strong exponential relationships were observed between soil salinity and SDMs （R2〉0.86, RMSE〈6.86） compared to COSRI （R2=0.71, RMSE=16.21）. These results suggest that the feature space related to biophysical properties combined with AFII and SI can effectively provide information on soil salinity.
文摘This paper provides a study of the changes in land use in urban environments in two cities,Wuhan,China and western Sydney in Australia.Since mixed pixels are a characteristic of medium resolution images such as Landsat,when used for the classification of urban areas,due to changes in urban ground cover within a pixel,Multiple Endmember Spectral Mixture Analysis(MESMA)together with Super-Resolution Mapping(SRM)are employed to derive class fractions to generate classification maps at a higher spatial resolution using an Artificial Neural Network(ANN)predicted Wavelet method.Landsat images over the two cities for a 30-year period,are classified in terms of vegetation,buildings,soil and water.The classifications are then processed using Indifrag software to assess the levels of fragmentation caused by changes in the areas of buildings,vegetation,water and soil over the 30 years.The extents of fragmentation of vegetation,buildings,water and soil for the two cities are compared,while the percentages of vegetation are compared with recommended percentages of green space for urban areas for the benefit of health and well-being of inhabitants.Changes in Ecosystem Service Values(ESVs)resulting from the urbanization have been assessed for Wuhan and Sydney.The UN Sustainable Development Goals(SDG)for urban areas are being assessed by researchers to better understand how to achieve the sustainability of cities.
基金Under the auspices of National Natural Science Foundation of China (No. 40701177)
文摘This paper explores the potential to improve the impervious surface estimation accuracy using a multi-stage approach on the basis of vegetation-impervious surface-soil (V-I-S) model. In the first stage of Spectral Mixture Analysis (SMA) process, pixel purity index, a quantitative index for defining endmember quality, and a 3-dimensional endmember selection method were applied to refining endmembers. In the second stage, instead of obtaining impervious surface fraction by adding high and low albedo fractions directly, a linear regression model was built between impervious surface and high/low albedo using a random sampling method. The urban impervious surface distribution in the urban central area of Shanghai was predicted by the linear regression model. Estimation accuracy of spectral mixture analysis and impervious surface fraction were assessed using root mean square (RMS) and color aerial photography respectively. In comparison with three different research methods, this improved estimation method has a higher overall accuracy than traditional Linear Spectral Mixture Analysis (LSMA) method and the normalized SMA model both in root mean square error (RMSE) and standard error (SE). However, the model has a tendency to overestimate the impervious surface distribution.
基金National Project for Basic Research, No.2002CB412507 National key project of fundamental research, No.G1999043500 National Natural Science Foundation of China, No.90202002
文摘Arid and semi-arid ecosystems exhibit a spatially complex biogeophysical structure. According to arid western special climate-vegetation characters, the fractional cover of photosynthetic vegetation （PV）, non-photosynthetic vegetation （NPV）, bare soil and water are unmixed, using the remote sensing spectral mixture analysis. We try the method to unmix the canopy funation structure of arid land cover in order to avoid the differentiation of regional vegetation system and the disturbance of environmental background. We developed a modified production efficiency model NPP-PEM appropriate for the arid area at regional scale based on the concept of radiation use efficiency. This model refer to the GLO-PEM and CASA model was driven with remotely sensed observations, and calculates not just the conversion efficiency of absorbed photosynthetically active radiation but also the carbon fluxes that determine net primary productivity （NPP）. We apply and validate the model in the Kaxger and Yarkant river basins in arid western China. The NPP of the study area in 1992 and 1998 was estimated based on the NPP-PEM model. The results show that the improved PEM model, considering the photosynthetical activation of heterogeneous functional vegetation, is in good agreement with field measurements and the existing literature. An accurate agreement （R2= 0.85, P〈0.001） between the estimates and the ground-based measurement was obtained. The spatial distribution of mountain-oasis-desert ecosystem shows an obvious heterogeneous carbon uptake. The results are applicable to arid ecosystem studies ranging from characterizing carbon cycle, carbon flux over arid areas to monitoring change in mountain-oasis-desert productivity, stress and management.
文摘Initiatives on tackling food insecurity among global emerging economies are being focused on enriching native staple foods with locally available nutritious underutilized crops. The objective of this study was to optimize protein content and dietary fibre in rice (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oryza sativa</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">) flour using Sorghum (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Sorghum bicolor</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> L.) and Bamboo shoots (</span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Yushania alpine</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">). An extreme vertices design of mixture approach with 11 runs was employed in the study using MINITAB</span><span style="font-family:Verdana;">®</span><span style="font-family:Verdana;"> software. The 11 blends from 11 generated runs and individual ingredient samples were analyzed for nutritional composition. Energy value and energy-to-protein ratio for the samples was calculated. Bamboo shoots flour (BSF) had </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">highest content for all proximate components except total carbohydrates on dry weight basis. Rice had </span><span style="font-family:Verdana;">the</span><span style="font-family:Verdana;"> highest content of total carbohydrates at 77.71% and energy to protein ratio of 53.72 kcal/g. Sorghum had </span><span style="font-family:Verdana;">the</span><span style="font-family:Verdana;"> highest mean total phenolic and condensed tannins of 45.512 (mg GAE/kg) and 2.512 (mg CE/g) while rice the least with 0.042 (mg GAE/kg) and 0.102 (mg CE/g), respectively. Fresh bamboo shoots had </span><span style="font-family:Verdana;">the</span><span style="font-family:""><span style="font-family:Verdana;"> highest level content of HCN of 117.81 mg/kg. Other dried ingredients had a mean HCN content of 2.313, 1.584 and 0.066 mg/kg for dried BSF, sorghum and rice respectively. Increasing the quantity of BSF and sorghum flour in the blends consequentially increased the protein content, dietary fibre and total minerals. Optimum blend was established to be 50:27:23 for rice, sorghum and BSF, respectively. This blend had 13.4% protein, 6.2% dietary fibre and 3.9% total minerals. Regression analysis showed that apart from dry matter, all other constituents were significantly predictable during optimization with R</span><sup><span style="font-family:Verdana;">2</span></sup></span><span style="font-family:""> </span><span style="font-family:Verdana;">></span><span style="font-family:""> </span><span style="font-family:Verdana;">0.7530. Cluster analysis showed that the nutritional components analyzed are in four main clusters. Cluster 1: Dry matter and protein digestibility, cluster 2: Carbohydrates, energy value and energy ratio, cluster 3: Protein, fibre and ash while cluster 4: Crude fat only. These findings of the optimum composite ratio and other blends could contribute in addressing the food insecurity for low income countries.
基金The National Natural Science Foundation of China under contract Nos 41206013,41376014,41430963 and41106004the Key Marine Science Foundation of the State Oceanic Administration of China for Young Scholar under contract Nos2012202,2013203 and 2012223+2 种基金the Public Science and Technology Research Funds Projects of Ocean under contract No.201205018the National Science and Technology Support Program under contract No.2014BAB12B02the Tianjin Science and Technology Support Program under contract No.14ZCZDSF00012
文摘The marine dynamic environment of the Bohai Sea and the Yellow Sea in the winter of 2006 is simulated by the Regional Ocean Modelling System（ROMS） marine numerical model. Using the simulated temperature and salinity, the water exchange zone between the Bohai Sea and Yellow Sea is defined through the Spectral Mixture Model（SMM）. The influence of winter gales on the water exchange is also discussed. It is found that the Yellow Sea water masses in winter are distributed in a ＂tongue＂ shape in the Bohai Strait region, the water exchange zone presents a zonal distribution along the margin of the ＂tongue＂, with a tendency of running from northwest to southeast, and the water exchange is intensified at the tip of the ＂tongue＂. Besides, the coastal area in the northernmost Yellow Sea does not participate in the water exchange between the Bohai Sea and Yellow Sea. The result shows that the winter gale events play a role in enhancing the water exchange. It is specifically shown by the facts： the Yellow Sea warm current is enhanced to intrude the Bohai Sea by the gale process; the water exchange zone extends into the Bohai Sea; the water exchange belt in the southern part becomes wider; the mixture zone of river runoff with the Bohai Sea water upon its entry is enlarged and shifts northwards. Within two days after the gale process, the exchange zone retreats toward the Yellow Sea and the exchange zone resulted from the Huanghe River（Yellow River） runoff also shrinks back shoreward.
