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Dynamics and genetic regulation of macronutrient concentrations during grain development in maize 被引量:1
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作者 Pengcheng Li Shuangyi Yin +7 位作者 Yunyun Wang Tianze Zhu Xinjie Zhu Minggang Ji Wenye Rui Houmiao Wang Chenwu Xu Zefeng Yang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第3期781-794,共14页
Nitrogen(N), phosphorus(P), and potassium(K) are essential macronutrients that are crucial not only for maize growth and development, but also for crop yield and quality. The genetic basis of macronutrient dynamics an... Nitrogen(N), phosphorus(P), and potassium(K) are essential macronutrients that are crucial not only for maize growth and development, but also for crop yield and quality. The genetic basis of macronutrient dynamics and accumulation during grain filling in maize remains largely unknown. In this study, we evaluated grain N, P, and K concentrations in 206 recombinant inbred lines generated from a cross of DH1M and T877 at six time points after pollination. We then calculated conditional phenotypic values at different time intervals to explore the dynamic characteristics of the N, P, and K concentrations. Abundant phenotypic variations were observed in the concentrations and net changes of these nutrients. Unconditional quantitative trait locus(QTL) mapping revealed 41 non-redundant QTLs, including 17, 16, and 14 for the N, P, and K concentrations, respectively. Conditional QTL mapping uncovered 39 non-redundant QTLs related to net changes in the N, P, and K concentrations. By combining QTL, gene expression, co-expression analysis, and comparative genomic data, we identified 44, 36, and 44 candidate genes for the N, P, and K concentrations, respectively, including GRMZM2G371058 encoding a Doftype zinc finger DNA-binding family protein, which was associated with the N concentration, and GRMZM2G113967encoding a CBL-interacting protein kinase, which was related to the K concentration. The results deepen our understanding of the genetic factors controlling N, P, and K accumulation during maize grain development and provide valuable genes for the genetic improvement of nutrient concentrations in maize. 展开更多
关键词 MAIZE nutrient concentration unconditional QTL mapping conditional QTL mapping dynamic trait
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Rheological properties and concentration evolution of thickened tailings under the coupling effect of compression and shear 被引量:1
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作者 Aixiang Wu Zhenqi Wang +3 位作者 Zhuen Ruan Raimund Bürger Shaoyong Wang Yi Mo 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第5期862-876,共15页
Cemented paste backfill(CPB)is a key technology for green mining in metal mines,in which tailings thickening comprises the primary link of CPB technology.However,difficult flocculation and substandard concentrations o... Cemented paste backfill(CPB)is a key technology for green mining in metal mines,in which tailings thickening comprises the primary link of CPB technology.However,difficult flocculation and substandard concentrations of thickened tailings often occur.The rheological properties and concentration evolution in the thickened tailings remain unclear.Moreover,traditional indoor thickening experiments have yet to quantitatively characterize their rheological properties.An experiment of flocculation condition optimization based on the Box-Behnken design(BBD)was performed in the study,and the two response values were investigated:concentration and the mean weighted chord length(MWCL)of flocs.Thus,optimal flocculation conditions were obtained.In addition,the rheological properties and concentration evolution of different flocculant dosages and ultrafine tailing contents under shear,compression,and compression-shear coupling experimental conditions were tested and compared.The results show that the shear yield stress under compression and compression-shear coupling increases with the growth of compressive yield stress,while the shear yield stress increases slightly under shear.The order of shear yield stress from low to high under different thickening conditions is shear,compression,and compression-shear coupling.Under compression and compression-shear coupling,the concentration first rapidly increases with the growth of compressive yield stress and then slowly increases,while concentration increases slightly under shear.The order of concentration from low to high under different thickening conditions is shear,compression,and compression-shear coupling.Finally,the evolution mechanism of the flocs and drainage channels during the thickening of the thickened tailings under different experimental conditions was revealed. 展开更多
关键词 thickened tailings compression-shear coupling compressive yield stress shear yield stress concentration
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Different concentrations of hyaluronic acid eye drops for dry eye syndrome: a systematic review and Meta-analysis
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作者 Xiao-Wei Ouyang Sheng Fang +5 位作者 Yun-Min Yi Shi-Peng Zou Qi-Yu Hu Zi-Xuan Huang Qing-Xia Li Jin-Yan Luo 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第6期1110-1119,共10页
AIM:To compare high or low concentration of hyaluronic acid eye drops(HY)for dry eye syndromes(DES).METHODS:Randomized controlled trials(RCTs)comparing various concentrations of HY were searched in PubMed,Embase,Web o... AIM:To compare high or low concentration of hyaluronic acid eye drops(HY)for dry eye syndromes(DES).METHODS:Randomized controlled trials(RCTs)comparing various concentrations of HY were searched in PubMed,Embase,Web of Science,Cochrane,SinoMed,CNKI,Wanfang Database,CQVIP,and Chinese journals databases between inception and July 2023.Pooled standardized mean differences(SMD)or weighted mean difference(WMD)with 95%confidence intervals(CI)from RCTs evaluating Schirmer’s I test(SIT),corneal fluorescein staining score(CFS),tear breakup time(TBUT),DES score(DESS),and Ocular Surface Disease Index(OSDI)were calculated.Sensitivity analysis,Egger’s test and Meta-regression analysis were performed for all indicators.RESULTS:We conducted a Meta-analysis of 10 RCTs that met the inclusion criteria,involving 1796 cases.High-concentrations group significantly improved the outcome of CFS according to random effects modelling(SMD,-3.37;95%CI,-5.25 to-1.48;P=0.0005).The rest of the results were not statistically significant,including indicators such as SIT,TBUT,DESS and OSDI.CONCLUSION:For dry eyes with positive corneal staining,a high concentration of HY is recommended,whereas in other cases,a high concentration of HY does not offer a more pronounced advantage over a low concentration of HY in the treatment of dry eyes. 展开更多
关键词 dry eye hyaluronic acid concentration META-ANALYSIS
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Achievable hole concentration at room temperature as a function of Mg concentration for MOCVD-grown p-GaN after sufficient annealing
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作者 Siyi Huang Masao Ikeda +4 位作者 Feng Zhang Minglong Zhang Jianjun Zhu Shuming Zhang Jianping Liu 《Journal of Semiconductors》 EI CAS CSCD 2024年第8期67-73,共7页
Relationship between the hole concentration at room temperature and the Mg doping concentration in p-GaN grown by MOCVD after sufficient annealing was studied in this paper.Different annealing conditions were applied ... Relationship between the hole concentration at room temperature and the Mg doping concentration in p-GaN grown by MOCVD after sufficient annealing was studied in this paper.Different annealing conditions were applied to obtain sufficient activation for p-GaN samples with different Mg doping ranges.Hole concentration,resistivity and mobility were characterized by room-temperature Hall measurements.The Mg doping concentration and the residual impurities such as H,C,O and Si were measured by secondary ion mass spectroscopy,confirming negligible compensations by the impurities.The hole concentration,resistivity and mobility data are presented as a function of Mg concentration,and are compared with literature data.The appropriate curve relating the Mg doping concentration to the hole concentration is derived using a charge neutrality equation and the ionized-acceptor-density[N-(A)^(-)](cm^(−3))dependent ionization energy of Mg acceptor was determined asE_(A)^(Mg)=184−2.66×10^(−5)×[N_(A)^(-)]1/3 meV. 展开更多
关键词 P-GAN hole concentration electrical properties ANNEALING ionization energy
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Study on the spatial and temporal evolutionary characteristics of ozone concentration and the impact of human activities in China in 2019
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作者 Yongchun Wang Wang Zhang +4 位作者 Yu’an Liu Yazhu Wang Yuting Fu Zhaohui Feng Lingqing Wang 《Acta Geochimica》 EI CAS CSCD 2024年第5期985-995,共11页
Ozone(O_(3))pollution has a profound impact on human health,vegetation development,and the ecological environment,making it a critical focus of global academic research.In recent years,O_(3)pollution in China has been... Ozone(O_(3))pollution has a profound impact on human health,vegetation development,and the ecological environment,making it a critical focus of global academic research.In recent years,O_(3)pollution in China has been on a steady rise,with ozone emerging as the sole conventional pollutant to consistently increase in concentration without any decline.This study conducted a quantitative analysis of O_(3)concentrations across 367 Chinese cities in 2019,examining spatial autocorrelation and local clustering of O_(3)levels,and investigated the diverse relationships between human activity factors and O_(3)concentration.The seasonal fluctuation of O_(3)exhibited the“M-type”pattern,with peak concentrations in winter and the lowest levels in summer.The center of O_(3)pollution migrated southeastward,with the area of highest concentration progressively shifting south along the eastern coast.Moreover,O_(3)concentration showed a strong positive correlation with population density,road freight volume,and industrial emissions,suggesting that human activities,vehicle emissions,and industrial operations are significant contributors to O_(3)production.The results provide comprehensive information on the characteristics,causes,and occurrence mechanism of O_(3)in Chinese cities that can be utilized by global government departments to formulate strategies to prevent and control O_(3)pollution. 展开更多
关键词 Ozone concentration Urban agglomerations Human activities Spatial heterogeneity
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Effects of Different Concentrations of Sulfate Ions on Carbonate Crude Oil Desorption:Experimental Analysis and Molecular Simulation
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作者 Nannan Liu Hengchen Qi +1 位作者 Hui Xu Yanfeng He 《Fluid Dynamics & Materials Processing》 EI 2024年第8期1731-1741,共11页
Low salinity water containing sulfate ions can significantly alter the surface wettability of carbonate rocks.Nevertheless,the impact of sulfate concentration on the desorption of oil film on the surface of carbonate ... Low salinity water containing sulfate ions can significantly alter the surface wettability of carbonate rocks.Nevertheless,the impact of sulfate concentration on the desorption of oil film on the surface of carbonate rock is still unknown.This study examines the variations in the wettability of the surface of carbonate rocks in solutions containing varying amounts of sodium sulfate and pure water.The problem is addressed in the framework of molecular dynamics simulation(Material Studio software)and experiments.The experiment’s findings demonstrate that sodium sulfate can increase the rate at which oil moisture is turned into water moisture.The final contact angle is smaller than that of pure water.The results of the simulations show that many water molecules travel down the water channel under the influence of several powerful forces,including the electrostatic force,the van der Waals force and hydrogen bond,crowding out the oil molecules on the calcite’s surface and causing the oil film to separate.The relative concentration curve of water and oil molecules indicates that the separation rate of the oil film on the surface of calcite increases with the number of sulfate ions. 展开更多
关键词 Carbonate rocks WETTABILITY sulfate ions concentration molecular simulation DESORPTION
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Effects of Serum Concentration, Synchronization Time and Confluence on the Cell-Cycle Synchronization Efficiency of Goat Fibroblasts
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作者 Van Khanh Nguyen Huong Thu Thi Vu +4 位作者 Au Thi Hoang Yen Kim Thi Pham Giang Thi Thanh Nhan Hung Phu Lai Lan Doan Pham 《Open Journal of Animal Sciences》 2024年第3期194-203,共10页
This study aims to evaluate the effect of serum concentration, synchronization time, and confluence degree on the synchronisation efficiency of goat fibroblast cycle. The results indicated that there was no difference... This study aims to evaluate the effect of serum concentration, synchronization time, and confluence degree on the synchronisation efficiency of goat fibroblast cycle. The results indicated that there was no difference in the percentage of nucleated fibroblasts in the G0/G1 stage between serum concentrations of 0.3% and 0.4% (83.89% and 82.69%, respectively, P > 0.05) as well as between serum concentrations of 0.2% and 0.5% (76.95% and 75.46%, respectively, P > 0.05). The percentage of nucleated fibroblasts in the G0/G1 stage was highest at the concentration of 0.3% and lowest in the control group (83.89% vs. 62.67%, P 0.05). The beneficial effect of high confluence was confirmed by the large percentage of nucleated fibroblasts at the G0/G1 stage. The 60% confluency was significantly lower than the 80% and 100% confluency (73.44%, 86.63%, and 87.17%, respectively, P < 0.05). The results indicate that the goat fibroblast cycle synchronization is the most effective at the serum concentration of 0.3%, 72 hours of synchronization and 100% confluency. 展开更多
关键词 Goat Fibroblast Cycle Synchronisation Serum concentration Synchronization Time CONFLUENCE
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Effects of different concentrations of nicotinamide on hematopoietic stem cells cultured in vitro
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作者 Yan Ren Yan-Ni Cui Hong-Wei Wang 《World Journal of Stem Cells》 SCIE 2024年第2期163-175,共13页
BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital resource.Nicotinamide(NAM)can promote HSC expansion ex vivo,but its effect... BACKGROUND In vitro expansion to increase numbers of hematopoietic stem cells(HSCs)in cord blood could improve clinical efficacy of this vital resource.Nicotinamide(NAM)can promote HSC expansion ex vivo,but its effect on hematopoietic stem and progenitor cells(HSPCs,CD34^(+)CD38)and functional subtypes of HSCs-shortterm repopulating HSCs(ST-HSCs,CD34^(+)CD38CD45RACD49f^(+))and long-term repopulating HSCs(LT-HSCs,CD34^(+)CD38CD45RACD49f^(+)CD90^(+))is not yet known.As a sirtuin 1(SIRT1)inhibitor,NAM participates in regulating cell adhesion,polarity,migration,proliferation,and differentiation.However,SIRT1 exhibits dual effects by promoting or inhibiting differentiation in different tissues or cells.We propose that the concentration of NAM may influence proliferation,differentiation,and SIRT1 signaling of HSCs.AIM To evaluate the effects and underlying mechanisms of action of different concentrations of NAM on HSC proliferation and differentiation.METHODS CD34^(+)cells were purified from umbilical cord blood using MacsCD34 beads,and cultured for 10-12 d in a serum-free medium supplemented with cytokines,with different concentrations of NAM added according to experimental requirements.Flow cytometry was used to detect phenotype,cell cycle distribution,and apoptosis of the cultured cells.Real-time polymerase chain reaction was used to detect the transcription levels of target genes encoding stemness-related factors,che mokines,components of hypoxia pathways,and antioxidant enzymes.Dichloro-dihydro-fluorescein diacetate probes were used to evaluate intracellular production of reactive oxygen species(ROS).Determination of the effect of different culture conditions on the balance of cytokine by cytometric bead array.RESULTS Compared with the control group,the proportion and expansion folds of HSPCs(CD34^(+)CD38)incubated with 5 mmol/L or 10 mmol/L NAM were significantly increased(all P<0.05).The ST-HSCs ratio and fold expansion of the 5 mmol/L NAM group were significantly higher than those of the control and 10 mmol/L NAM groups(all P<0.001),whereas the LT-HSCs ratio and fold expansion of the 10 mmol/L NAM group were significantly higher than those of the other two groups(all P<0.05).When the NAM concentration was>10 mmol/L,cell viability significantly decreased.In addition,compared with the 5 mmol/L NAM group,the proportion of apoptotic cells in the 10 mmol/L NAM group increased and the proportion of cells in S and G2 phase decreased.Compared with the 5 mmol/L NAM group,the HSCs incubated with 10 mmol/L NAM exhibited significantly inhibited SIRT1 expression,increased intracellular ROS content,and downregulated expression of genes encoding antioxidant enzymes(superoxide dismutase 1,peroxiredoxin 1).CONCLUSION Low concentrations(5 mmol/L)of NAM can better regulate the balance between proliferation and differentiation,thereby promoting expansion of HSCs.These findings allow adjustment of NAM concentrations according to expansion needs. 展开更多
关键词 Hematopoietic stem cells NICOTINAMIDE concentration PROLIFERATION DIFFERENTIATION Sirtuin 1
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A Facile Li_(2)TiO_(3) Surface Modification to Improve the Structure Stability and Electrochemical Performance of Full Concentration Gradient Li-Rich Oxides
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作者 Naifang Hu Yuan Yang +5 位作者 Lin Li Yuhan Zhang Zhiwei Hu Lan Zhang Jun Ma Guanglei Cui 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第3期41-48,共8页
Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rat... Full concentration gradient lithium-rich layered oxides are catching lots of interest as the next generation cathode for lithium-ion batteries due to their high discharge voltage,reduced voltage decay and enhanced rate performance,whereas the high lithium residues on its surface impairs the structure stability and long-term cycle performance.Herein,a facile multifunctional surface modification method is implemented to eliminate surface lithium residues of full concentration gradient lithium-rich layered oxides by a wet chemistry reaction with tetrabutyl titanate and the post-annealing process.It realizes not only a stable Li_(2)TiO_(3)coating layer with 3D diffusion channels for fast Li^(+)ions transfer,but also dopes partial Ti^(4+)ions into the sub-surface region of full concentration gradient lithium-rich layered oxides to further strengthen its crystal structure.Consequently,the modified full concentration gradient lithium-rich layered oxides exhibit improved structure stability,elevated thermal stability with decomposition temperature from 289.57℃to 321.72℃,and enhanced cycle performance(205.1 mAh g^(-1)after 150 cycles)with slowed voltage drop(1.67 mV per cycle).This work proposes a facile and integrated modification method to enhance the comprehensive performance of full concentration gradient lithium-rich layered oxides,which can facilitate its practical application for developing higher energy density lithium-ion batteries. 展开更多
关键词 full concentration gradient lithium-rich layered oxides structure stability surface modification
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Experimental Study on the Chloride Ion Concentration of Cement Pastes Prepared with Limestone Powder
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作者 ZHANG Kaijian HUANG Zeping +1 位作者 JIA Xuxiu WANG Dehui 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第6期1474-1483,共10页
To investigate the impact of limestone powder on the chloride ion concentration coefficient of cement pastes,various techniques such as scanning electron microscopy(SEM),X-ray diffraction(XRD),thermogravimetric analys... To investigate the impact of limestone powder on the chloride ion concentration coefficient of cement pastes,various techniques such as scanning electron microscopy(SEM),X-ray diffraction(XRD),thermogravimetric analysis(TGA),and mercury-porosimetry(MIP)were employed in this paper.The findings demonstrate that the creation of Friedel's salt is inversely associated with the addition of limestone powder,that is,Friedel's salt production is lessened by adding more limestone powder,however,the coefficient of chloride ion concentration initially decreased and then increased again,as does the porosity,and most likely the pore size as well.The specific surface area of limestone powder has increased,and the content of Friedel’s salt increased first and then decreased.However,the shifting trend of Friedel's salt and chloride ion concentration coefficient is in direct opposition,and the pore structure was therefore significantly enhanced.The results of this study offer robust theoretical backing for the inclusion of limestone powder in concrete and provide a positive assessment of its potential applications. 展开更多
关键词 limestone powder specific surface area CONTENT friedel's salt chloride ion concentration coefficient
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Effect of low concentration electrolytes on the formation and corrosion resistance of PEO coatings on AM50 magnesium alloy
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作者 Peng Xie Carsten Blawert +4 位作者 Maria Serdechnova Natalia Konchakova Tatsiana Shulha Ting Wu Mikhail L.Zheludkevich 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第4期1386-1405,共20页
In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were system... In this paper,the formation process,morphology,and electrochemical performance of PEO coatings on AM50 magnesium alloy prepared in low concentration phosphate,aluminate,and phosphate-aluminate electrolytes were systematically studied.The results show that the coatings prepared from the phosphate electrolytes have a higher thickness and better corrosion resistance properties compared to the other electrolytes.The coatings prepared from low concentration phosphate-aluminate mixed electrolytes have slightly thinner thickness,a similar coating structure and an order of magnitude lower value of electrochemical impedance compared with phosphate electrolyte coatings.The Coatings prepared from low concentration aluminate electrolytes have the lowest thickness and the worst corrosion resistance properties which gets close to corrosion behavior of the bare AM50 under the same test conditions.Considering application,coatings prepared from single low concentration phosphate electrolytes and low concentration phosphate-aluminate electrolytes have greater potential than single low concentration aluminate coatings.However,reducing the electrolyte concentrations of coating forming ions too much has negative influence on the coating growth rate. 展开更多
关键词 Plasma electrolytic oxidation Low concentration electrolytes Corrosion resistance AM50 magnesium alloy
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Efficient concentration of trace analyte with ordered hotspot construction for a robust and sensitive SERS platform
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作者 Youdi Hu Yanlei Hu +4 位作者 Zhenyu Wang Jiale Yong Wei Xiong Dong Wu Shixiang Xu 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第3期532-542,共11页
Surface-enhanced Raman scattering(SERS)platform,which enables trace analyte detection,has important application prospects.By structuring/modifying the surface of the SERSsubstrate,analyte in highly diluted solutions c... Surface-enhanced Raman scattering(SERS)platform,which enables trace analyte detection,has important application prospects.By structuring/modifying the surface of the SERSsubstrate,analyte in highly diluted solutions can be concentrated into localized active areas for highly sensitive detection.However,subject to the difficulty of the fabrication process,itremains challenging to balance hot-spot construction and the concentration capacity of analyte simultaneously.Therefore,preparing SERS substrates with densely ordered hot spots andefficient concentration capacity is of great significance for highly sensitive detection.Herein,we propose an Ag and fluoroalkyl-modified hierarchical armour substrate(Ag/F-HA),which has a double-layer stacking design to combine analyte concentration with hotspot construction.The microarmour structure is fabricated by femtosecond-laser processing to serve as asuperhydrophobic and low-adhesive surface to concentrate analyte,while the anodic aluminium oxide(AAO)template creates a nanopillar array serving as dense and ordered hot spots.Under the synergistic action of hot spots and analyte concentration,Ag/F-HA achieves a detectionlimit down to 10^(-7)M doxorubicin(DOX)molecules with a RSD of 7.69%.Additionally,Ag/F-HA exhibits excellent robustness to resist external disturbances such as liquid splash or abrasion.Based on our strategy,SERS substrates with directional analyte concentrations are further explored by patterning microcone arrays with defects.This work opens a way to the realistic implementation of SERS in diverse scenarios. 展开更多
关键词 surface-enhanced Raman scattering anodic aluminium oxide femtosecond laser processing concentration of trace analytes mechanical robustness
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Effects of Controlled Atmospheres with High_O_2 or High_CO_2 Concentrations on Postharvest Physiology and Storability of "Napoleon" Sweet Cherry 被引量:27
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作者 姜爱丽 田世平 徐勇 《Acta Botanica Sinica》 CSCD 2002年第8期925-930,共6页
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
关键词 sweet cherry physiological properties quality STORABILITY high O(2) concentrations high CO(2) concentrations
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Corrosion behavior of micro-arc oxidation coating on AZ91D magnesium alloy in NaCl solutions with different concentrations 被引量:13
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作者 郭惠霞 马颖 +3 位作者 王劲松 王宇顺 董海荣 郝远 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第7期1786-1793,共8页
Ceramic oxide coatings were prepared on AZ91D magnesium alloys in alkaline silicate solution using micro-arc oxidation(MAO) technique.The corrosion behavior of MAO coating on AZ91D magnesium alloys in NaCl solutions... Ceramic oxide coatings were prepared on AZ91D magnesium alloys in alkaline silicate solution using micro-arc oxidation(MAO) technique.The corrosion behavior of MAO coating on AZ91D magnesium alloys in NaCl solutions with different concentrations(0.1%,0.5%,1.0%,3.5% and 5.0% in mass fraction) was evaluated by electrochemical measurements and immersion tests.The results showed that the corrosion rate of the MAO coated AZ91D increased with increasing chloride ion concentration.The main form of corrosion failure was localized corrosion for the MAO coated AZ91D immersed in higher concentration NaCl solutions(1.0%,3.5% and 5.0%),while it was general corrosion in dilute NaCl solutions(0.1% and 0.5%).Two different stages of the failure process of the MAO coated AZ91D could be identified:1) occurrence of the metastable pits and 2) growth of the pits.Different equivalent circuits were also proposed based on the results of electrochemical impedance spectroscopy(EIS) for the MAO coated AZ91D immersed in different concentrations of NaCl solutions for 120 h. 展开更多
关键词 micro-arc oxidation coating AZ91D magnesium alloy corrosion behavior chloride ion concentration electrochemical techniques
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Effects of mechanical activation and oxidation-reduction on hydrochloric acid leaching of Panxi ilmenite concentration 被引量:6
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作者 谭平 胡慧萍 张黎 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第6期1414-1421,共8页
The effects of oxidation-reduction treatment and mechanical activation on the hydrochloric acid leaching performance of Panxi ilmenite concentration were investigated.The results show that both of oxidation-reduction ... The effects of oxidation-reduction treatment and mechanical activation on the hydrochloric acid leaching performance of Panxi ilmenite concentration were investigated.The results show that both of oxidation-reduction treatment and mechanical activation significantly accelerate the extraction of Fe,Ca and Mg from Panxi ilmenite concentration;however,the CaO and MgO contents of the calcined residues obtained from oxidized-reduced ilmenite concentration are higher than the standard values required by chlorination process.The Ca and Mg in oxidized-reduced ilmenite concentration can be leached much faster after mechanical activation,yielding a synthetic rutile which meets the requirements of chlorination process containing 90.50% TiO2 and 1.37% total iron as well as combined CaO and MgO of 1.00%.The optimum oxidation and reduction conditions are as follows:oxidization at 900 ℃ in the presence of oxygen for 15 min and reduction at 750 ℃ by hydrogen for 30 min. 展开更多
关键词 ilmenite concentration mechanical activation OXIDATION REDUCTION hydrochloric acid leaching
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Effect of chloride salt concentration on unconfined compression strength of cement-treated Lianyungang soft marine clay 被引量:4
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作者 章定文 曹智国 +1 位作者 范礼彬 邓永锋 《Journal of Southeast University(English Edition)》 EI CAS 2013年第1期79-83,共5页
This study aims to quantify the influence of the amount of cement and chloride salt on the unconfined compression strength (UCS) of Lianyungang marine clay. The clays with various sodium chloride salt concentrations... This study aims to quantify the influence of the amount of cement and chloride salt on the unconfined compression strength (UCS) of Lianyungang marine clay. The clays with various sodium chloride salt concentrations were prepared artificially and stabilized by ordinary Portland cement with various contents. A series of UCS tests of cement stabilized clay specimen after 28 d curing were carried out. The results indicate that the increase of salt concentration results in the decrease in the UCS of cement-treated soil. The negative effect of salt concentration on the strength of cement stabilized clay directly relates to the cement content and salt concentration. The porosity-salt concentration/cement content ratio is a fundamental parameter for assessing the UCS of cement-treated salt-rich clay. An empirical prediction model of UCS is also proposed to take into account the effect of salt concentration. The findings of this study can be referenced for the stabilization improvement of chloride slat- rich soft clay. 展开更多
关键词 soft marine clay salt concentration CEMENTATION unconfined compression strength
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STRUCTURAL RESPONSE OF SOYBEAN LEAF TO ELEVATED CO_2 CONCENTRATION 被引量:26
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作者 林金星 胡玉熹 《Acta Botanica Sinica》 CSCD 1996年第1期31-34,共4页
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
关键词 SOYBEAN Foliar structure CO 2 concentration
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Concentrations of foliar and surface soil in nutrients Pinus spp. plantations in relation to species and stand age in Zhanggutai sandy land, northeast China 被引量:5
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作者 陈广生 曾德慧 陈伏生 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第1期11-18,J001,共9页
The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, ... The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, total P and C: N ratio of the soil inP. sylvestris var.mongolica stands were significantly higher in comparison with those inP. tabulaeformis andP. densiflora stands. ForP. sylvestris var.mongolica, the foliar P concentration appeared to decrease with age, and the foliar N and K concentrations did not show a consistent change with age. As for the different tree species of the similar age, the foliar N and P concentrations were significantly different (p<0.05), being withP. sylvestris var.mongolica>P. densiflora>P. tabulaeformis. The foliar N: P ratio ofP. densiflora significantly was higher thanP. sylvestris var.mongolica andP. tabulaeformis, while the foliar K was no obvious difference between the three tree species. There were significant correlation (p<0.05) between soil total N and P, soil organic matter and total P, foliar N and P, but it did not show significant correlations between soil and foliar nutrient concentrations, which might attribute to the excessive litter raking, overgrazing and low soil moisture in this area. Based on the foliar N: P ratio, we introduced a combination threshold index of N: P ratio with their absolute foliar nutrient concentrations to determine the possible limiting nutrient. According to the critical N: P ratio and their absolute foliar N, P concentrations, theP. sylvestris var.mongolica stands showed a decreased N limitation degree with age, theP. densiflora stands showed unlimited by N and P in the whole, and theP. tabulaeformis stands showed co-limited by N and P. No significant difference in soil nutrient concentrations of the surface soils was found between 45, 29, 20-yr-oldPinus sylvestris var.mongolica plantation stands. Keywords coniferous trees - foliar nutrient concentration - limiting nutrients - N - P ratio - Zhanggutai sandy land CLC number S718.55 Document code A Article ID 1007-662X(2004)01-0011-08 Foundation item: This research was supported by Key Knowledge Innovation Project (KZCX3-SW-418) of Chinese Academy of Sciences.Biography: CHEN Guang-sheng (1978-), male, master candidate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. ChinaResponsible editor: Song Funan 展开更多
关键词 coniferous trees foliar nutrient concentration limiting nutrients N P ratio Zhanggutai sandy land
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Effects of Temperature on Determination of Protein Concentration with Coomassie Brilliant Blue Method 被引量:4
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作者 赵卓 孙文斌 +1 位作者 嵇雅茹 郝锡联 《Agricultural Science & Technology》 CAS 2015年第2期209-213,共5页
[Objective] This study aimed to investigate the effects of temperature on determination of protein concentration with Coomassie Brilliant Blue method,thus proving advice and guidance for accurate determination of prot... [Objective] This study aimed to investigate the effects of temperature on determination of protein concentration with Coomassie Brilliant Blue method,thus proving advice and guidance for accurate determination of protein concentration.[Method] With Coomassie Brilliant Blue method,the concentrations of different bovine serum albumin samples were determined under different temperatures and incubation time.[Result] According to the standard curve,when the determination range of protein concentration was 0-100 mg/ml,the determined protein concentration was relatively stable after incubation at 20 ℃ for 20-30 min.Furthermore,the determination result of higher protein concentration with Coomassie Brilliant Blue method was less affected by various factors.[Conclusion] In determination of protein concentration with Coomassie Brilliant Blue method,temperature,sample concentration and incubation time were important factors affecting the accuracy of experimental results. 展开更多
关键词 Coomassie Brilliant Blue method PROTEIN TEMPERATURE concentration Incubation time
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A study of impact of the reclamation and artificial island projects on tidal currents and sediment concentration in radial sand ridge field of the South Yellow Sea 被引量:3
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作者 赵强 何琴燕 +1 位作者 杨耀芳 黄秀清 《Marine Science Bulletin》 CAS 2015年第1期71-85,共15页
The two-dimensional hydrodynamic model, MIKE21, is applied to simulate the tidal currents and sediment concentration in the radial sand ridges of the South Yellow Sea. Results are in accordance with in situ observatio... The two-dimensional hydrodynamic model, MIKE21, is applied to simulate the tidal currents and sediment concentration in the radial sand ridges of the South Yellow Sea. Results are in accordance with in situ observations. Then the variations of tidal currents and suspended sediment concentration caused by reclamation and artificial islands projects are simulated. The results show that the impacts are limited around the project areas. After the projects, the fan-shaped, Jianggang centered tidal current pattern would be replaced by a pattern which is formed by two tidal paths. One locates at the Xiyang channel in north-south direction, and the other locates at the Huangshayang channel in east-west direction. The reclamation of Tiaozini separates the waters into south portion and north portion. The changes of sediment concentrations coincide with those of currents. Both the sediment concentrations and tidal currents increase at the northwest of Dongsha and the south of Gaoni, while both decrease at the north and south of Tiaozini, and the east and southwest of Dongsha. 展开更多
关键词 radial sand ridges RECLAMATION artificial island tidal currents suspended sediment concentration numerical modeling
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