Base on the principle and method of B-P neural network,the prediction model of SO2 concentration in urban atmosphere was established by using the statistical data of a city in southwest China from 1991 to 2009,so as t...Base on the principle and method of B-P neural network,the prediction model of SO2 concentration in urban atmosphere was established by using the statistical data of a city in southwest China from 1991 to 2009,so as to forecast atmospheric SO2 concentration in a city of southwest China.The results showed that B-P neural network applied in the prediction of SO2 concentration in urban atmosphere was reasonable and efficient with high accuracy and wide adaptability,so it was worthy to be popularized.展开更多
Current shipping,tourism,and resource development requirements call for more accurate predictions of the Arctic sea-ice concentration(SIC).However,due to the complex physical processes involved,predicting the spatiote...Current shipping,tourism,and resource development requirements call for more accurate predictions of the Arctic sea-ice concentration(SIC).However,due to the complex physical processes involved,predicting the spatiotemporal distribution of Arctic SIC is more challenging than predicting its total extent.In this study,spatiotemporal prediction models for monthly Arctic SIC at 1-to 3-month leads are developed based on U-Net-an effective convolutional deep-learning approach.Based on explicit Arctic sea-ice-atmosphere interactions,11 variables associated with Arctic sea-ice variations are selected as predictors,including observed Arctic SIC,atmospheric,oceanic,and heat flux variables at 1-to 3-month leads.The prediction skills for the monthly Arctic SIC of the test set(from January 2018 to December 2022)are evaluated by examining the mean absolute error(MAE)and binary accuracy(BA).Results showed that the U-Net model had lower MAE and higher BA for Arctic SIC compared to two dynamic climate prediction systems(CFSv2 and NorCPM).By analyzing the relative importance of each predictor,the prediction accuracy relies more on the SIC at the 1-month lead,but on the surface net solar radiation flux at 2-to 3-month leads.However,dynamic models show limited prediction skills for surface net solar radiation flux and other physical processes,especially in autumn.Therefore,the U-Net model can be used to capture the connections among these key physical processes associated with Arctic sea ice and thus offers a significant advantage in predicting Arctic SIC.展开更多
The global rise in CO_(2)concentration is having a profound impact on the structure and function of aquatic ecosystems.However,little information is available on the responses of odorproducing cyanobacteria to the inc...The global rise in CO_(2)concentration is having a profound impact on the structure and function of aquatic ecosystems.However,little information is available on the responses of odorproducing cyanobacteria to the increase in CO_(2)concentration.In this study,the effects of different CO_(2)concentrations on 2-methylisoborneol(MIB)-producing Pseudanabaena and non-2-MIB-producing Pseudanabaena under monoculture and co-culture conditions were investigated.Results show that the specific growth rate of Pseudanabaena gradually increased with the rise in CO_(2)concentration,and for the 2-MIB-producing strain,this increase was significantly higher than the non-2-MIB-producing strain.Under co-culture conditions,the proportion of non-2-MIB-producing Pseudanabaena was significantly higher than that of 2-MIB-producing Pseudanabaena,suggesting a superior competitive ability of non-2-MIB-producing Pseudanabaena over 2-MIB-producing Pseudanabaena.Under monoculture conditions,the total 2-MIB production at the 300-μg/g CO_(2)concentration was significantly higher than that at 600-and 1200-μg/g CO_(2)concentrations.The 2-MIB concentration produced by Pseudanabaena decreased with the increasing in CO_(2)concentration.Therefore,we believe that with the future increase in CO_(2)concentration,2-MIB concentration would be decreased and so would the risk of 2-MIB outbreaks.展开更多
Electrochemical nitrate(NO_(3)^(-))reduction reaction(eNO_(3)RR)to ammonia(NH3)provides a promising route for both water conservation and green ammonia synthesis.Although various catalysts were designed for the eNO_(3...Electrochemical nitrate(NO_(3)^(-))reduction reaction(eNO_(3)RR)to ammonia(NH3)provides a promising route for both water conservation and green ammonia synthesis.Although various catalysts were designed for the eNO_(3)RR and great achievements have been achieved,it is still a challenge to realize selective eNO_(3)RR to NH3at low concentration for the competing hydrogen evolution reaction(HER)and poor mass transfer of NO_(3)^(-).Herein,we designed a tandem catalyst of Pd nanoparticle loaded Cu_(2)O hierarchical nanofiber(Pd-Cu_(2)O)to improve eNO_(3)RR performance at low nitrate concentration.The Pd-Cu_(2)O shows a faraday efficiency(FE)of 95.80%and an ammonia selectivity of 97.34%at a comparatively low applied potential of-0.15 V versus RHE with low concentration.Besides,it exhibits excellent nitrate removal effects,the residual concentration of nitrate-N was only 7.22 ppm at-0.15 V.Electrochemical characterizations indicate that the abundant secondary heterojunction structures and the tandem effects of Pd-Cu_(2)O synergistic ally accelerate the transfer and conversion of NO_(3)^(-)and improve the dynamic of eNO_(3)RR at low concentration.Furthermore,the operando electrochemical impedance spectroscopy(EIS)and density functional theory(DFT)calculations suggested the tandem effects of Pd-Cu_(2)O improved the adsorption of NO_(3)^(-)and*H and thus promoted the dynamics of eNO_(3)RR at low concentration.The findings highlight the tandem effects of Pd-Cu_(2)O and provide an effective strategy for designing electrocatalysts that can be applied to low concentration and low applied potential conditions.展开更多
The removal and recovery of low-concentration phosphates from water have become crucial due to the dual challenges of eutrophication and the phosphorus crisis.Herein,we engineered a highly efficient and recyclable pho...The removal and recovery of low-concentration phosphates from water have become crucial due to the dual challenges of eutrophication and the phosphorus crisis.Herein,we engineered a highly efficient and recyclable phosphate trapping agent of La_(2-x)CexO_(2)CO_(3) solid solution.The incorporation of Ce enhances the surface area and surface potential of La_(2-x)CexO_(2)CO_(3),providing abundant adsorption sites for phosphate.Surprisingly,we found that adjusting the Ce proportion affects the carbonate content,thereby influencing the anion-exchange capacity between carbonate and phosphate.Specifically,at 3% Ce content(3%-CeL),the carbonate ratio is maximized,resulting in an optimal sorption capacity(196.4mg P/g)and a rapid removal rate(under 40min)for phosphate,unaffected by interfering ions.Remarkably,3%-CeL achieved nearly 100%phosphate removal efficiency in diverse water samples from sewage treatment plants,rivers,reservoirs,and groundwater.After five adsorption-desorption cycles,the phosphate removal and recovery efficiency of 3%-CeL remained above 90%.Mechanistic studies revealed that 3%Ce content yielded the highest proportion of Ce^(4+)/Ce^(3+),enabling greater carbonate binding for anion-exchange.This study proposes a high-performance phosphate trapping agentwith broad applicability for treating actual waters and provides a new perspective on enhancing low-concentration phosphate removal in La-based materials through manipulating Ce ratio and valence.展开更多
Rapid increases in Carbon dioxide(CO_(2))levels could trigger unpredictable climate change.The assessment of spatiotempor-al variation and influencing factors of CO_(2) concentration are helpful in understanding the s...Rapid increases in Carbon dioxide(CO_(2))levels could trigger unpredictable climate change.The assessment of spatiotempor-al variation and influencing factors of CO_(2) concentration are helpful in understanding the source/sink balance and supporting the formu-lation of climate policy.In this study,Greenhouse Gases Observing Satellite(GOSAT)data were used to explore the variability of CO_(2) concentrations in China from 2009 to 2020.Meteorological parameters,vegetation cover,and anthropogenic activities were combined to explain the increase in CO_(2) concentration,using pixel-based correlations and Covariance Based Structural Equation Modeling(CB-SEM)analysis.The results showed that the influence of vertical CO_(2) transport diminished with altitude,with a distinct inter-annual in-crease in CO_(2) concentrations at 17 vertical levels.Spatially,the highest values were observed in East China,whereas the lowest were observed in Northwest China.There were significant seasonal variations in CO_(2) concentration,with maximum and minimum values in spring(April)and summer(August),respectively.According to the pixel-based correlation analysis,the near-surface CO_(2) concentration was positively correlated with population(r=0.99,P<0.001),Leaf Area Index(LAI,r=0.95,P<0.001),emissions(r=0.91,P<0.001),temperature(r=0.60,P<0.05),precipitation(r=0.34,P>0.05),soil water(r=0.29,P>0.05),nightlight(r=0.28,P>0.05);and negatively correlated with wind speed(r=−0.58,P<0.05).CB-SEM analysis revealed that LAI was the most important con-trolling factor explaining CO_(2) concentration variation(total effect of 0.66),followed by emissions(0.58),temperature(0.45),precipita-tion(0.30),wind speed(−0.28),and soil water(−0.07).The model explained 93% of the increase in CO_(2) concentration.Our results provide crucial information on the patterns of CO_(2) concentrations and their driving mechanisms,which are particularly significant in the context of climate change.展开更多
Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) +...Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively.展开更多
The effects of CO 2 concentration on the morphological and anatomical characters of soybean (Glycine max) leaf were investigated by means of light microscopy and SEM.It was noticed that exomorphology did not show dra...The effects of CO 2 concentration on the morphological and anatomical characters of soybean (Glycine max) leaf were investigated by means of light microscopy and SEM.It was noticed that exomorphology did not show dramatic change,while stomatal density decreased with increasing CO 2 concentration.Under SEM,no epicuticular wax was observed on both abaxial and adaxial sides of the control group as well as on adaxial side of the treatment group.However,leaf surface of abaxial side was noticed to be densely covered with microasterisk epicuticular wax when they were exposed to CO 2 enriched environment.The epicuticular wax deposition was present in equal abundance on both stomatal and nonstomatal areas.Furthermore,leaf thickness increased significantly due largely to the origin of an extra layer of palisade in the treatment group.The results confirmed that CO 2 enrichment might enhance cell division and induce greater quantity of epicuticular wax.展开更多
The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii wer...The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii were studied under controlled conditions. The types ofHoagland nutrient solution with three Ca^(2+) concentrations levels (200, 400 and 600 μg·g^(-1))and a control (without Ca^(2+)) were designed to culture Pteroceltis tatarinowii. After 6 months,contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and barkwere analyzed. The results indicated that Ca accumulations content in the root, leaf and bark hadpositively relation with Ca^(2+) concentrations (200, 400, 600 μg · g^(-1)), and the order of theCa content in the three components was root>leaf>bark. Ca content in the root treated with 600 μg·g^(-1) Ca^(2+) concentrations was 5.5 times as high as that of the control, and about 1.4 times ashigh as that of the root treated in 200 and 400 μg/g Ca^(2+) concentrations respectively. On thecontrary, K and Mg contents in the root, leaf and bark were negatively related to Ca^(2+)concentrations, especially in the bark, and their accumulation trend followed the order ofleaf>root>bark. K content in the bark treated with 600 μg ·g^(-1) Ca^(2+) concentrations was 39.3%of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 μg ·g^(-1)and 400 μg ·g^(-1) Ca^(2+) concentrations respectively; Mg content in the bark treated with 600μg ·g^(-1) Ca^(2+) concentrations was 23.4% of that of the control, and was 27.1% and 35.4% ofthat of the bark treated with 200 and 400 μg·g^(-1) Ca^(2+) concentrations respectively. Comparedwith the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca^(2+)concentrations and their contents were in the order: root>leaf>bark. Based on the results of thisstudy, the experiment has been useful for providing academic bases in improving the bark quality ofPteroceltis tatarinowii on non-limestone soil.展开更多
Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architect...Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.展开更多
The bark of Pteroceltis tatarinowii is a raw material for manufacturing Xuan Paper. The effects of Ca2+ concentrations on the accumulation of mineral elements in the bark, leaf and root of Pteroceltis tatarinowii were...The bark of Pteroceltis tatarinowii is a raw material for manufacturing Xuan Paper. The effects of Ca2+ concentrations on the accumulation of mineral elements in the bark, leaf and root of Pteroceltis tatarinowii were studied under controlled condi-tions. The types of Hoagland nutrient solution with three Ca2+ concentrations levels (200, 400 and 600 靏g-1) and a control (without Ca2+) were designed to culture Pteroceltis tatarinowii. After 6 months, contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and bark were analyzed. The results indicated that Ca accumulations content in the root, leaf and bark had positively relation with Ca2+ concentrations (200, 400, 600 靏g-1), and the order of the Ca content in the three components was root】leaf】bark. Ca content in the root treated with 600 靏g-1 Ca2+ concentrations was 5.5 times as high as that of the control, and about 1.4 times as high as that of the root treated in 200 and 400 靏/g Ca2+ concentrations respectively. On the contrary, K and Mg contents in the root, leaf and bark were negatively related to Ca2+ concentrations, especially in the bark, and their accumulation trend followed the order of leaf】root】bark. K content in the bark treated with 600 靏g-1 Ca2+ con-centrations was 39.3% of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 靏g-1 and 400靏g-1 Ca2+ concentrations respectively; Mg content in the bark treated with 600 靏g-1 Ca2+ concentrations was 23.4% of that of the control, and was 27.1% and 35.4% of that of the bark treated with 200 and 400 靏g-1 Ca2+ concentrations respectively. Com-pared with the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca2+ concentrations and their contents were in the order: root】leaf】bark. Based on the results of this study, the experiment has been useful for providing academic bases in improving the bark quality of Pteroceltis tatarinowii on non-limestone soil.展开更多
针对燃煤电厂参与调峰负荷波动较大,出口SO_(2)浓度控制效果不佳的问题,建立了一种基于捕鱼优化算法(catch fish optimization algorithm,CFOA)优化融合神经网络的出口SO_(2)浓度预测模型。首先使用互信息算法筛选由机理分析得到的特征...针对燃煤电厂参与调峰负荷波动较大,出口SO_(2)浓度控制效果不佳的问题,建立了一种基于捕鱼优化算法(catch fish optimization algorithm,CFOA)优化融合神经网络的出口SO_(2)浓度预测模型。首先使用互信息算法筛选由机理分析得到的特征变量,并通过逐次变分模态分解对筛选后的辅助变量进行分解重构,保留相关性较大的重构分量作为输入变量。随后采用双向时间卷积网络、双向门控循环单元与多头自注意力机制构建融合神经网络模型,通过CFOA对模型超参数寻优以进一步提高精度。最后使用某660 MW燃煤电厂历史运行数据进行对比实验,实验结果表明,该模型在出口SO_(2)浓度剧烈波动的工况下仍能实现较好的预测效果。同多种模型对比,该模型具有更小的误差和更高的预测精度,体现出其在复杂变化环境中的鲁棒性和可靠性。展开更多
A retrieval algorithm of arctic sea ice concentration （SIC） based on the brightness temperature data of “HY-2” scanning microwave radiometer has been constructed. The tie points of the brightness temperature were ...A retrieval algorithm of arctic sea ice concentration （SIC） based on the brightness temperature data of “HY-2” scanning microwave radiometer has been constructed. The tie points of the brightness temperature were selected based on the statistical analysis of a polarization gradient ratio and a spectral gradient ratio over open water （OW）, first-year ice （FYI）, and multiyear ice （MYI） in arctic. The thresholds from two weather filters were used to reduce atmospheric effects over the open ocean. SIC retrievals from the “HY-2” radiom-eter data for idealized OW, FYI, and MYI agreed well with theoretical values. The 2012 annual SIC was calcu-lated and compared with two reference operational products from the National Snow and Ice Data Center （NSIDC） and the University of Bremen. The total ice-covered area yielded by the “HY-2” SIC was consistent with the results from the reference products. The assessment of SIC with the aerial photography from the fifth Chinese national arctic research expedition （CHINARE） and six synthetic aperture radar （SAR） images from the National Ice Service was carried out. The “HY-2” SIC product was 16% higher than the values de-rived from the aerial photography in the central arctic. The root-mean-square （RMS） values of SIC between “HY-2” and SAR were comparable with those between the reference products and SAR, varying from 8.57% to 12.34%. The “HY-2” SIC is a promising product that can be used for operational services.展开更多
An experiments were carried out with treatments differing in nitrogen supply （0, 5 and 15 g N/m^2） and CO2 levels （350 and 700 μmol/mol） using OTC （open top chamber） equipment to investigate the biomass of Cala...An experiments were carried out with treatments differing in nitrogen supply （0, 5 and 15 g N/m^2） and CO2 levels （350 and 700 μmol/mol） using OTC （open top chamber） equipment to investigate the biomass of Calamagrostis angustifolia and soil active carbon contents after two years. The results showed that elevated CO2 concentration increased the biomass of C. angustifolia and the magnitude of response varied with each growth period. Elevated CO2 concentration has increased aboveground biomass by 16.7% and 17.6% during the jointing and heading periods and only 3.5% and 9.4% during dough and maturity periods. The increases in belowground biomass due to CO2 elevation was 26.5%, 34.0% and 28.7% during the heading, dough and maturity periods, respectively. The responses of biomass to enhanced CO2 concentrations are differed in N levels. Both the increase of aboveground biomass and belowground biomass were greater under high level of N supply （15 g N/m^2）. Elevated CO2 concentration also increased the allocation of biomass and carbon in root. Under elevated CO2 concentration, the average values of active carbon tended to increase. The increases of soil active soil contents followed the sequence of microbial biomass carbon （10.6%） 〉 dissolved organic carbon （7.5%） 〉 labile oxidable carbon （6.6%） 〉 carbohydrate carbon （4.1%）. Stepwise regressions indicated there were significant correlations between the soil active carbon contents and plant biomass. Particularly, microbial biomass carbon, labile oxidable carbon and carbohydrate carbon were found to be correlated with belowground biomass, while dissolved organic carbon has correlation with aboveground biomass. Therefore, increased biomass was regarded as the main driving force for the increase in soil active organic carbon under elevated CO2 concentration.展开更多
Metal-organic chemical vapor deposition was applied to fabricate YBa2Cu3OT-a （YBCO） films on singlecrystal LaA103 （001） substrates for its high deposition rate, easy adjustment on film composition, and low require...Metal-organic chemical vapor deposition was applied to fabricate YBa2Cu3OT-a （YBCO） films on singlecrystal LaA103 （001） substrates for its high deposition rate, easy adjustment on film composition, and low requirement on vacuum apparatus. The effects of Cu（tmhd）2 concentra- tion in the precursor on the properties of YBCO films were systematically investigated. X-ray diffraction （XRD） reveals that the mole ratio of Cu/Ba in the precursor from 0.77 to 0.97 is helpful to improve the crystallization and out-of-plane orientation of YBCO films; however, it hardly affects the inplane texture. Scanning electron microscope （SEM） shows the dense, crack-free but rough surface, on which there are Cu-O and Ba-Cu-O outgrowths identified by energy-dispersive spectrometer （EDS）. As the mole ratio of Cu/Ba increasing, the average size of Ba-Cu-O precipitates keeps increasing and the film composition becomes inhomoge- neous at the mole ratio of Cu/Ba of 0.97. The 250 nm thick YBCO film prepared at the mole ratio of Cu/Ba of 0.91 shows the critical current density （Jc） of 4.0 MA.cm-2 （77 K, 0 T）.展开更多
To investigate the relationship between intracellular free Ca^2＋ concentration （[Ca^2＋ ]i ） and calcium-activated chloride （Clca） channels of pulmonary artery smooth muscle cells （PASMCs） in rats under acute a...To investigate the relationship between intracellular free Ca^2＋ concentration （[Ca^2＋ ]i ） and calcium-activated chloride （Clca） channels of pulmonary artery smooth muscle cells （PASMCs） in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2＋ indicator Fura-2/AM was used to observe [Ca^2＋ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid （NFA） and indaryloxyacetic acid （IAA-94） exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2＋ ]i was increased. Under normoxic condition, [Ca^2＋ If was （123.634-18.98） nmol/ L, and in hypoxic condition, [Ca^2＋]i wag （281. 754-16.48） nmol/L （P〈0. 01）. Under normoxic condition, [Ca^2＋ ]i showed no significant change and no effect on Clca channels was observed （P〉 0. 05）. Chronic hypoxia increased [Ca^2＋ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2＋ ]i from （281.75± 16.48） nmot/L to （117.66 ±15.36） nmol/L （P〈0.01）. MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency （A value） from 0. 459±0. 058 to 0. 224±0. 025 （P〈0. 01）. Hypoxia increased [Ca^2＋ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2＋ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.展开更多
The influence of high concentration Zn^(2+) on the floatability of sphalerite in an acidic system was investigated via flotation experiments,zeta potential measurements,contact angle measurements,and X-ray photoelectr...The influence of high concentration Zn^(2+) on the floatability of sphalerite in an acidic system was investigated via flotation experiments,zeta potential measurements,contact angle measurements,and X-ray photoelectron spectroscopy.The results indicated that Zn^(2+) was adsorbed on the sphalerite surface and a Zn-hydroxyl complex was formed at a pH of 4 and a Zn^(2+) concentration of 4×10^(-2) mol/L.The zeta potential increased and the contact angle decreased from 84.80°to 36.48°,strongly inhibiting the floatability of sphalerite.When S^(2−) or Cu^(2+) activator was used alone,sphalerite was not activated after Zn^(2+) was adsorbed,and its contact angle did not change significantly.However,by using a combination of S^(2−) and Cu^(2+) activators,its floatability was realized after Zn^(2+) adsorption.This result was attributed to the removal of the Zn-hydroxyl complex on the surface of sphalerite by S^(2-).After this removal,Cu^(2+) was adsorbed on the sphalerite surface to form a Cu_(2)S·S^(0) hydrophobic film.展开更多
文摘Base on the principle and method of B-P neural network,the prediction model of SO2 concentration in urban atmosphere was established by using the statistical data of a city in southwest China from 1991 to 2009,so as to forecast atmospheric SO2 concentration in a city of southwest China.The results showed that B-P neural network applied in the prediction of SO2 concentration in urban atmosphere was reasonable and efficient with high accuracy and wide adaptability,so it was worthy to be popularized.
基金supported by the National Key Research and Development Program of China[grant number 2022YFE0106800]an Innovation Group Project of the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)[grant number 311024001]+3 种基金a project supported by the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)[grant number SML2023SP209]a Research Council of Norway funded project(MAPARC)[grant number 328943]a Nansen Center´s basic institutional funding[grant number 342624]the high-performance computing support from the School of Atmospheric Science at Sun Yat-sen University。
文摘Current shipping,tourism,and resource development requirements call for more accurate predictions of the Arctic sea-ice concentration(SIC).However,due to the complex physical processes involved,predicting the spatiotemporal distribution of Arctic SIC is more challenging than predicting its total extent.In this study,spatiotemporal prediction models for monthly Arctic SIC at 1-to 3-month leads are developed based on U-Net-an effective convolutional deep-learning approach.Based on explicit Arctic sea-ice-atmosphere interactions,11 variables associated with Arctic sea-ice variations are selected as predictors,including observed Arctic SIC,atmospheric,oceanic,and heat flux variables at 1-to 3-month leads.The prediction skills for the monthly Arctic SIC of the test set(from January 2018 to December 2022)are evaluated by examining the mean absolute error(MAE)and binary accuracy(BA).Results showed that the U-Net model had lower MAE and higher BA for Arctic SIC compared to two dynamic climate prediction systems(CFSv2 and NorCPM).By analyzing the relative importance of each predictor,the prediction accuracy relies more on the SIC at the 1-month lead,but on the surface net solar radiation flux at 2-to 3-month leads.However,dynamic models show limited prediction skills for surface net solar radiation flux and other physical processes,especially in autumn.Therefore,the U-Net model can be used to capture the connections among these key physical processes associated with Arctic sea ice and thus offers a significant advantage in predicting Arctic SIC.
基金Supported by the National Key R&D Program of China(No.2021YFC3200900)the National Natural Science Foundation of China(No.31971477)。
文摘The global rise in CO_(2)concentration is having a profound impact on the structure and function of aquatic ecosystems.However,little information is available on the responses of odorproducing cyanobacteria to the increase in CO_(2)concentration.In this study,the effects of different CO_(2)concentrations on 2-methylisoborneol(MIB)-producing Pseudanabaena and non-2-MIB-producing Pseudanabaena under monoculture and co-culture conditions were investigated.Results show that the specific growth rate of Pseudanabaena gradually increased with the rise in CO_(2)concentration,and for the 2-MIB-producing strain,this increase was significantly higher than the non-2-MIB-producing strain.Under co-culture conditions,the proportion of non-2-MIB-producing Pseudanabaena was significantly higher than that of 2-MIB-producing Pseudanabaena,suggesting a superior competitive ability of non-2-MIB-producing Pseudanabaena over 2-MIB-producing Pseudanabaena.Under monoculture conditions,the total 2-MIB production at the 300-μg/g CO_(2)concentration was significantly higher than that at 600-and 1200-μg/g CO_(2)concentrations.The 2-MIB concentration produced by Pseudanabaena decreased with the increasing in CO_(2)concentration.Therefore,we believe that with the future increase in CO_(2)concentration,2-MIB concentration would be decreased and so would the risk of 2-MIB outbreaks.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB4000604)National Natural Science Foundation of China(No.52271220)+2 种基金The Program of the Ministry of Education of China for Introducing Talents of Discipline to Universities(No.B12015)the Fundamental Research Funds for the Central UniversitiesHaihe Laboratory of Sustainable Chemical Transformations,Guangxi Collaborative Innovation Centre of Structure and Property for New Energy and Materials,Science Research and Technology Development Project of Guilin(No.20210102-4)
文摘Electrochemical nitrate(NO_(3)^(-))reduction reaction(eNO_(3)RR)to ammonia(NH3)provides a promising route for both water conservation and green ammonia synthesis.Although various catalysts were designed for the eNO_(3)RR and great achievements have been achieved,it is still a challenge to realize selective eNO_(3)RR to NH3at low concentration for the competing hydrogen evolution reaction(HER)and poor mass transfer of NO_(3)^(-).Herein,we designed a tandem catalyst of Pd nanoparticle loaded Cu_(2)O hierarchical nanofiber(Pd-Cu_(2)O)to improve eNO_(3)RR performance at low nitrate concentration.The Pd-Cu_(2)O shows a faraday efficiency(FE)of 95.80%and an ammonia selectivity of 97.34%at a comparatively low applied potential of-0.15 V versus RHE with low concentration.Besides,it exhibits excellent nitrate removal effects,the residual concentration of nitrate-N was only 7.22 ppm at-0.15 V.Electrochemical characterizations indicate that the abundant secondary heterojunction structures and the tandem effects of Pd-Cu_(2)O synergistic ally accelerate the transfer and conversion of NO_(3)^(-)and improve the dynamic of eNO_(3)RR at low concentration.Furthermore,the operando electrochemical impedance spectroscopy(EIS)and density functional theory(DFT)calculations suggested the tandem effects of Pd-Cu_(2)O improved the adsorption of NO_(3)^(-)and*H and thus promoted the dynamics of eNO_(3)RR at low concentration.The findings highlight the tandem effects of Pd-Cu_(2)O and provide an effective strategy for designing electrocatalysts that can be applied to low concentration and low applied potential conditions.
基金supported by the National Key Research and Development Program of China(Nos.2022YFC3703700,2021YFA0910300,and 2021YFC3200902)the National Natural Science Foundation of China(No.22125606)+1 种基金the Special Project of Ecological Environmental Technology for Carbon Dioxide Emissions Peak and Carbon Neutrality(No.RCEESTDZ-2021-21)China South-to-North Water Diversion Corporation Limited Research Project(No.NSBDZX/SH/KY/2022-001).
文摘The removal and recovery of low-concentration phosphates from water have become crucial due to the dual challenges of eutrophication and the phosphorus crisis.Herein,we engineered a highly efficient and recyclable phosphate trapping agent of La_(2-x)CexO_(2)CO_(3) solid solution.The incorporation of Ce enhances the surface area and surface potential of La_(2-x)CexO_(2)CO_(3),providing abundant adsorption sites for phosphate.Surprisingly,we found that adjusting the Ce proportion affects the carbonate content,thereby influencing the anion-exchange capacity between carbonate and phosphate.Specifically,at 3% Ce content(3%-CeL),the carbonate ratio is maximized,resulting in an optimal sorption capacity(196.4mg P/g)and a rapid removal rate(under 40min)for phosphate,unaffected by interfering ions.Remarkably,3%-CeL achieved nearly 100%phosphate removal efficiency in diverse water samples from sewage treatment plants,rivers,reservoirs,and groundwater.After five adsorption-desorption cycles,the phosphate removal and recovery efficiency of 3%-CeL remained above 90%.Mechanistic studies revealed that 3%Ce content yielded the highest proportion of Ce^(4+)/Ce^(3+),enabling greater carbonate binding for anion-exchange.This study proposes a high-performance phosphate trapping agentwith broad applicability for treating actual waters and provides a new perspective on enhancing low-concentration phosphate removal in La-based materials through manipulating Ce ratio and valence.
基金Under the auspices of National Natural Science Foundation of China(No.41871193,U1910207)Program for the Philosophy and Social Science of Shanxi Province(No.2023YJ107)。
文摘Rapid increases in Carbon dioxide(CO_(2))levels could trigger unpredictable climate change.The assessment of spatiotempor-al variation and influencing factors of CO_(2) concentration are helpful in understanding the source/sink balance and supporting the formu-lation of climate policy.In this study,Greenhouse Gases Observing Satellite(GOSAT)data were used to explore the variability of CO_(2) concentrations in China from 2009 to 2020.Meteorological parameters,vegetation cover,and anthropogenic activities were combined to explain the increase in CO_(2) concentration,using pixel-based correlations and Covariance Based Structural Equation Modeling(CB-SEM)analysis.The results showed that the influence of vertical CO_(2) transport diminished with altitude,with a distinct inter-annual in-crease in CO_(2) concentrations at 17 vertical levels.Spatially,the highest values were observed in East China,whereas the lowest were observed in Northwest China.There were significant seasonal variations in CO_(2) concentration,with maximum and minimum values in spring(April)and summer(August),respectively.According to the pixel-based correlation analysis,the near-surface CO_(2) concentration was positively correlated with population(r=0.99,P<0.001),Leaf Area Index(LAI,r=0.95,P<0.001),emissions(r=0.91,P<0.001),temperature(r=0.60,P<0.05),precipitation(r=0.34,P>0.05),soil water(r=0.29,P>0.05),nightlight(r=0.28,P>0.05);and negatively correlated with wind speed(r=−0.58,P<0.05).CB-SEM analysis revealed that LAI was the most important con-trolling factor explaining CO_(2) concentration variation(total effect of 0.66),followed by emissions(0.58),temperature(0.45),precipita-tion(0.30),wind speed(−0.28),and soil water(−0.07).The model explained 93% of the increase in CO_(2) concentration.Our results provide crucial information on the patterns of CO_(2) concentrations and their driving mechanisms,which are particularly significant in the context of climate change.
文摘Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively.
文摘The effects of CO 2 concentration on the morphological and anatomical characters of soybean (Glycine max) leaf were investigated by means of light microscopy and SEM.It was noticed that exomorphology did not show dramatic change,while stomatal density decreased with increasing CO 2 concentration.Under SEM,no epicuticular wax was observed on both abaxial and adaxial sides of the control group as well as on adaxial side of the treatment group.However,leaf surface of abaxial side was noticed to be densely covered with microasterisk epicuticular wax when they were exposed to CO 2 enriched environment.The epicuticular wax deposition was present in equal abundance on both stomatal and nonstomatal areas.Furthermore,leaf thickness increased significantly due largely to the origin of an extra layer of palisade in the treatment group.The results confirmed that CO 2 enrichment might enhance cell division and induce greater quantity of epicuticular wax.
基金This paper is supported by National Natural Science Foundation of China (No. 39970608).
文摘The bark of Pteroce/tis tatarinowii is a raw material for manufacturing XuanPaper. The effects of Ca^(2+) concentrations on the accumulation of mineral elements in the bark,leaf and root of Pteroceltis tatarinowii were studied under controlled conditions. The types ofHoagland nutrient solution with three Ca^(2+) concentrations levels (200, 400 and 600 μg·g^(-1))and a control (without Ca^(2+)) were designed to culture Pteroceltis tatarinowii. After 6 months,contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and barkwere analyzed. The results indicated that Ca accumulations content in the root, leaf and bark hadpositively relation with Ca^(2+) concentrations (200, 400, 600 μg · g^(-1)), and the order of theCa content in the three components was root>leaf>bark. Ca content in the root treated with 600 μg·g^(-1) Ca^(2+) concentrations was 5.5 times as high as that of the control, and about 1.4 times ashigh as that of the root treated in 200 and 400 μg/g Ca^(2+) concentrations respectively. On thecontrary, K and Mg contents in the root, leaf and bark were negatively related to Ca^(2+)concentrations, especially in the bark, and their accumulation trend followed the order ofleaf>root>bark. K content in the bark treated with 600 μg ·g^(-1) Ca^(2+) concentrations was 39.3%of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 μg ·g^(-1)and 400 μg ·g^(-1) Ca^(2+) concentrations respectively; Mg content in the bark treated with 600μg ·g^(-1) Ca^(2+) concentrations was 23.4% of that of the control, and was 27.1% and 35.4% ofthat of the bark treated with 200 and 400 μg·g^(-1) Ca^(2+) concentrations respectively. Comparedwith the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca^(2+)concentrations and their contents were in the order: root>leaf>bark. Based on the results of thisstudy, the experiment has been useful for providing academic bases in improving the bark quality ofPteroceltis tatarinowii on non-limestone soil.
文摘Wheat ( Triticum aestivum L.) plants were grown under ambient and doubled_CO 2(plus 350 μL/L) concentration in cylindrical open_top chamber to examine their effects on the ultrastructure, supramolecular architecture, absorption spectrum and low temperature (77 K) fluorescence emission spectrum of the chloroplasts from wheat leaves. The results were briefly summarized as follows: (1) The wheat leaves possessed normally developed chloroplasts with intact grana and stroma thylakoid membranes; The grana intertwined with stroma thylakoid membranes and increased slightly in stacking degree and the width of granum, in spite of more accumulated starch grains within the chloroplasts than those in control; (2) The particle density in the stacked region of the endoplasmic fracture face (EFs) and protoplasmic fracture face (PFs) and in the unstacked region the endoplasmic fracture face (EFu) and the protoplasmic fracture face (PFu) was significantly higher than that of control. Furthermore, in some cases many more particles on EFs faces of thylakoid membranes appeared as a paracrystalline particle array; (3) The variations in the structure of chloroplasts were consistent with the absorption spectra and the low temperature (77 K) fluorescence emission spectra of the chloroplasts developed under the doubled_CO 2 concentration. Results indicate that the capability of light energy absorption of chloroplasts and regulative capability of excitation energy distribution between PSⅡ and PSⅠ were raised by doubled_CO 2 concentration. This is very favorable for final productivity of wheat.
基金This paper is supported by National Natural Science Foundation of China (No. 39970608).
文摘The bark of Pteroceltis tatarinowii is a raw material for manufacturing Xuan Paper. The effects of Ca2+ concentrations on the accumulation of mineral elements in the bark, leaf and root of Pteroceltis tatarinowii were studied under controlled condi-tions. The types of Hoagland nutrient solution with three Ca2+ concentrations levels (200, 400 and 600 靏g-1) and a control (without Ca2+) were designed to culture Pteroceltis tatarinowii. After 6 months, contents of seven mineral elements including Ca, K, Mg, Mn, Zn, Cu and Na in the root, leaf and bark were analyzed. The results indicated that Ca accumulations content in the root, leaf and bark had positively relation with Ca2+ concentrations (200, 400, 600 靏g-1), and the order of the Ca content in the three components was root】leaf】bark. Ca content in the root treated with 600 靏g-1 Ca2+ concentrations was 5.5 times as high as that of the control, and about 1.4 times as high as that of the root treated in 200 and 400 靏/g Ca2+ concentrations respectively. On the contrary, K and Mg contents in the root, leaf and bark were negatively related to Ca2+ concentrations, especially in the bark, and their accumulation trend followed the order of leaf】root】bark. K content in the bark treated with 600 靏g-1 Ca2+ con-centrations was 39.3% of that of the control, and was 79.0% and 91.8% of that of the bark treated with 200 靏g-1 and 400靏g-1 Ca2+ concentrations respectively; Mg content in the bark treated with 600 靏g-1 Ca2+ concentrations was 23.4% of that of the control, and was 27.1% and 35.4% of that of the bark treated with 200 and 400 靏g-1 Ca2+ concentrations respectively. Com-pared with the control, the general tendency of Mn, Zn and Cu content decreased with increasing of Ca2+ concentrations and their contents were in the order: root】leaf】bark. Based on the results of this study, the experiment has been useful for providing academic bases in improving the bark quality of Pteroceltis tatarinowii on non-limestone soil.
文摘针对燃煤电厂参与调峰负荷波动较大,出口SO_(2)浓度控制效果不佳的问题,建立了一种基于捕鱼优化算法(catch fish optimization algorithm,CFOA)优化融合神经网络的出口SO_(2)浓度预测模型。首先使用互信息算法筛选由机理分析得到的特征变量,并通过逐次变分模态分解对筛选后的辅助变量进行分解重构,保留相关性较大的重构分量作为输入变量。随后采用双向时间卷积网络、双向门控循环单元与多头自注意力机制构建融合神经网络模型,通过CFOA对模型超参数寻优以进一步提高精度。最后使用某660 MW燃煤电厂历史运行数据进行对比实验,实验结果表明,该模型在出口SO_(2)浓度剧烈波动的工况下仍能实现较好的预测效果。同多种模型对比,该模型具有更小的误差和更高的预测精度,体现出其在复杂变化环境中的鲁棒性和可靠性。
基金The International Science and Technology Cooperation Project of China under contract No.2011DFA22260the National Natural Science Foundation of China under contract No.41276191+1 种基金the Public Science and Technology Research Funds Projects of Ocean by the State Oceanic Administration under contract No.201205007-05the Chinese Polar Environment Comprehensive Investigation & Assessment Program by the State Oceanic Administration under contract Nos 2013-02-04 and 2012-04-03-02
文摘A retrieval algorithm of arctic sea ice concentration （SIC） based on the brightness temperature data of “HY-2” scanning microwave radiometer has been constructed. The tie points of the brightness temperature were selected based on the statistical analysis of a polarization gradient ratio and a spectral gradient ratio over open water （OW）, first-year ice （FYI）, and multiyear ice （MYI） in arctic. The thresholds from two weather filters were used to reduce atmospheric effects over the open ocean. SIC retrievals from the “HY-2” radiom-eter data for idealized OW, FYI, and MYI agreed well with theoretical values. The 2012 annual SIC was calcu-lated and compared with two reference operational products from the National Snow and Ice Data Center （NSIDC） and the University of Bremen. The total ice-covered area yielded by the “HY-2” SIC was consistent with the results from the reference products. The assessment of SIC with the aerial photography from the fifth Chinese national arctic research expedition （CHINARE） and six synthetic aperture radar （SAR） images from the National Ice Service was carried out. The “HY-2” SIC product was 16% higher than the values de-rived from the aerial photography in the central arctic. The root-mean-square （RMS） values of SIC between “HY-2” and SAR were comparable with those between the reference products and SAR, varying from 8.57% to 12.34%. The “HY-2” SIC is a promising product that can be used for operational services.
基金supported by the Chinese Academy of Sciences (No KZCX2-YW-309)the National Basic Research Program (973) of China (No 2004CB418507)
文摘An experiments were carried out with treatments differing in nitrogen supply （0, 5 and 15 g N/m^2） and CO2 levels （350 and 700 μmol/mol） using OTC （open top chamber） equipment to investigate the biomass of Calamagrostis angustifolia and soil active carbon contents after two years. The results showed that elevated CO2 concentration increased the biomass of C. angustifolia and the magnitude of response varied with each growth period. Elevated CO2 concentration has increased aboveground biomass by 16.7% and 17.6% during the jointing and heading periods and only 3.5% and 9.4% during dough and maturity periods. The increases in belowground biomass due to CO2 elevation was 26.5%, 34.0% and 28.7% during the heading, dough and maturity periods, respectively. The responses of biomass to enhanced CO2 concentrations are differed in N levels. Both the increase of aboveground biomass and belowground biomass were greater under high level of N supply （15 g N/m^2）. Elevated CO2 concentration also increased the allocation of biomass and carbon in root. Under elevated CO2 concentration, the average values of active carbon tended to increase. The increases of soil active soil contents followed the sequence of microbial biomass carbon （10.6%） 〉 dissolved organic carbon （7.5%） 〉 labile oxidable carbon （6.6%） 〉 carbohydrate carbon （4.1%）. Stepwise regressions indicated there were significant correlations between the soil active carbon contents and plant biomass. Particularly, microbial biomass carbon, labile oxidable carbon and carbohydrate carbon were found to be correlated with belowground biomass, while dissolved organic carbon has correlation with aboveground biomass. Therefore, increased biomass was regarded as the main driving force for the increase in soil active organic carbon under elevated CO2 concentration.
基金financially supported by the Sichuan Youth Science and Technology Innovation Research Team(No.2011JTD0006)the Fundamental Research Funds for the Central Universities(Nos.ZYGX2012J039 and ZYGX2011Z002)
文摘Metal-organic chemical vapor deposition was applied to fabricate YBa2Cu3OT-a （YBCO） films on singlecrystal LaA103 （001） substrates for its high deposition rate, easy adjustment on film composition, and low requirement on vacuum apparatus. The effects of Cu（tmhd）2 concentra- tion in the precursor on the properties of YBCO films were systematically investigated. X-ray diffraction （XRD） reveals that the mole ratio of Cu/Ba in the precursor from 0.77 to 0.97 is helpful to improve the crystallization and out-of-plane orientation of YBCO films; however, it hardly affects the inplane texture. Scanning electron microscope （SEM） shows the dense, crack-free but rough surface, on which there are Cu-O and Ba-Cu-O outgrowths identified by energy-dispersive spectrometer （EDS）. As the mole ratio of Cu/Ba increasing, the average size of Ba-Cu-O precipitates keeps increasing and the film composition becomes inhomoge- neous at the mole ratio of Cu/Ba of 0.97. The 250 nm thick YBCO film prepared at the mole ratio of Cu/Ba of 0.91 shows the critical current density （Jc） of 4.0 MA.cm-2 （77 K, 0 T）.
文摘To investigate the relationship between intracellular free Ca^2＋ concentration （[Ca^2＋ ]i ） and calcium-activated chloride （Clca） channels of pulmonary artery smooth muscle cells （PASMCs） in rats under acute and chronic hypoxic conditions, acute hypoxia-induced contraction was observed in rat pulmonary artery by using routine blood vascular perfusion in vitro. The fluorescence Ca^2＋ indicator Fura-2/AM was used to observe [Ca^2＋ ]i of rat PASMCs under normal and chronic hypoxic condition. The effect of Clca channels on PASMCs proliferation was assessed by MTT assay. The Clca channel blockers niflumic acid （NFA） and indaryloxyacetic acid （IAA-94） exerted inhibitory effects on acute hypoxia-evoked contractions in the pulmonary artery. Under chronic hypoxic condition, [Ca^2＋ ]i was increased. Under normoxic condition, [Ca^2＋ If was （123.634-18.98） nmol/ L, and in hypoxic condition, [Ca^2＋]i wag （281. 754-16.48） nmol/L （P〈0. 01）. Under normoxic condition, [Ca^2＋ ]i showed no significant change and no effect on Clca channels was observed （P〉 0. 05）. Chronic hypoxia increased [Ca^2＋ ]i which opened Clca channels. The NFA and IAA-94 blocked the channels and decreased [Ca^2＋ ]i from （281.75± 16.48） nmot/L to （117.66 ±15.36） nmol/L （P〈0.01）. MTT assay showed that under chronic hypoxic condition NFA and IAA-94 decreased the value of absorbency （A value） from 0. 459±0. 058 to 0. 224±0. 025 （P〈0. 01）. Hypoxia increased [Ca^2＋ ]i which opened Cl~ channels and had a positive-feedback in [Ca^2＋ ]i. This may play an important role in hypoxic pulmonary hypertension. Under chronic hypoxic condition, Clca channel may play a part in the regulation of proliferation of PASMCs.
基金the financial supports from the National Key R&D Program of China(Nos.2018YFC0903404,2018YFC1903400)the National Natural Science Foundation of China(No.51974138)+1 种基金the Natural Science Foundation of Jiangxi Province,China(No.20202BABL214022)the Research Startup Fund Project of JXUST,China(Nos.jxxjbs17032,jxxjbs19019).
文摘The influence of high concentration Zn^(2+) on the floatability of sphalerite in an acidic system was investigated via flotation experiments,zeta potential measurements,contact angle measurements,and X-ray photoelectron spectroscopy.The results indicated that Zn^(2+) was adsorbed on the sphalerite surface and a Zn-hydroxyl complex was formed at a pH of 4 and a Zn^(2+) concentration of 4×10^(-2) mol/L.The zeta potential increased and the contact angle decreased from 84.80°to 36.48°,strongly inhibiting the floatability of sphalerite.When S^(2−) or Cu^(2+) activator was used alone,sphalerite was not activated after Zn^(2+) was adsorbed,and its contact angle did not change significantly.However,by using a combination of S^(2−) and Cu^(2+) activators,its floatability was realized after Zn^(2+) adsorption.This result was attributed to the removal of the Zn-hydroxyl complex on the surface of sphalerite by S^(2-).After this removal,Cu^(2+) was adsorbed on the sphalerite surface to form a Cu_(2)S·S^(0) hydrophobic film.
