A microscopic understanding of the complex solute-defect interaction is pivotal for optimizing the alloy’s macroscopic mechanical properties.Simulating solute segregation in a plastically deformed crystalline system ...A microscopic understanding of the complex solute-defect interaction is pivotal for optimizing the alloy’s macroscopic mechanical properties.Simulating solute segregation in a plastically deformed crystalline system at atomic resolution remains challenging.The objective is to efficiently model and predict a phys-ically informed segregated solute distribution rather than simulating a series of diffusion kinetics.To ad-dress this objective,we coupled molecular dynamics(MD)and Monte Carlo(MC)methods using a novel method based on virtual atoms technique.We applied our MD-MC coupling approach to model off-lattice carbon(C)solute segregation in nanoindented Fe-C samples containing complex dislocation networks.Our coupling framework yielded the final configuration through efficient parallelization and localized en-ergy computations,showing C Cottrell atmospheres near dislocations.Different initial C concentrations resulted in a consistent trend of C atoms migrating from less crystalline distortion to high crystalline distortion regions.Besides unraveling the strong spatial correlation between local C concentration and defect regions,our results revealed two crucial aspects of solute segregation preferences:(1)defect ener-getics hierarchy and(2)tensile strain fields near dislocations.The proposed approach is generic and can be applied to other material systems as well.展开更多
It is commonly recognized that the cooling rate has a substantial effect on solute partitioning and its resultant microsegregation during solidification.The classical dendrite tip undercooling theory clarifies the mit...It is commonly recognized that the cooling rate has a substantial effect on solute partitioning and its resultant microsegregation during solidification.The classical dendrite tip undercooling theory clarifies the mitigation of microsegregation by increasing the cooling rate.However,most of the studies focused on binary alloys,leaving an open question as to whether the microsegregation of different solutes in a multi-component alloy system exhibits a relieving degree similar to increasing cooling rate.Taking a widely used 6022-type Al alloy(Al-0.76Mg-0.93Si-0.2Fe)as a model alloy,the current study reveals that the microsegregation of Mg gets alleviated to the greatest extent,followed by those of Si and Fe when the cooling rate increases from 5 to 128 K/s.This phenomenon is attributed to the solute-based difference in response to partitioning to cooling rate(denoted as Rk).We propose a theoretical equation to quantify Rk,and the R_(k)values of solute Mg,Si,and Fe successfully explain the rank of solute partitioning in exper-iments.Furthermore,a broad range of R_(k)values of other commonly used alloying elements in Al alloys were calculated and ranked,delivering a handy tool to predict the microsegregation behavior and sol-ubility of different solute elements upon sub-rapid solidification,which is consistent with experimental observation.This framework can also be extended to other multi-component alloy systems.展开更多
The diffusion coefficients(Dapp) and the heterogeneous electron-transfer rate constants(ks)for ferrocene and its seven derivatives in MPEG/LiClO4 electrolyte were determined by using steadystate voltammetry. The two p...The diffusion coefficients(Dapp) and the heterogeneous electron-transfer rate constants(ks)for ferrocene and its seven derivatives in MPEG/LiClO4 electrolyte were determined by using steadystate voltammetry. The two parameters increase with increasing temperature, indicating Arrhenius behavior. The effects of the nature of electroactive solute molecules on Dapp, ks, and the half-wave potentials(E1/2) are discussed.展开更多
The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the t...The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the two parameters indicates Arrhenius behavior. The polymer solventeffects on diffusion and electron transfer dynamics of ferrocene were discussed展开更多
The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rat...The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rates, and also discusses the possibility that the microelectrode coated with poly(ethylene oxide)(PEO) film can be used as gas sensor.展开更多
Safflower is an important, traditional, multipurpose oil crop. This was to investigate the effect of different salinity levels on morphological, physiological, biochemical and antioxidant response of two safflower cul...Safflower is an important, traditional, multipurpose oil crop. This was to investigate the effect of different salinity levels on morphological, physiological, biochemical and antioxidant response of two safflower cultivars (Carthamus tinctorius L. cultivar TSF1 and cultivar SM) differing in salt tolerance. Salinity stress (0.0%, 1.0%, 1.5% and 2.0% of NaCl) was induced to safflower plants after 19 days of vegetative growth. After 12 days of stress impositions, plants were harvested and analysed for various parameters. The results revealed that cultivar TSF1 showed maximum growth, dry weight, cell membrane stability and more water content in both root and leaf tissues at higher salinity levels than cultivar SM. Salt stress resulted an accumulation of more soluble sugars, amino acids, proline and glycine betaine at high salinity level confers the tolerance potential of cultivar TSF1 over cultivar SM. Salt stress induces more increase in the enzyme activity of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase and catalase in tolerant cultivar than sensitive one. The results indicate that each cultivar adopt specific strategy at distinct salinity level for resistance against salinity. The possible conclusion is that improved tolerance in cultivar TSF1 to salinity may be accomplished by better management of growth, physiological attributes and antioxidative defence mechanisms.展开更多
How to determine accurately the association states of solutes in aqueous systems is of fundamental importance in a variety of chemical, physical, and biological processes, We apply four widely used criteria to analyze...How to determine accurately the association states of solutes in aqueous systems is of fundamental importance in a variety of chemical, physical, and biological processes, We apply four widely used criteria to analyze the dynamic association processes of solutes, e.g., amphiphilic molecules, and to find the inappropriate selections of representative sites on solutes in these criteria may bring about appreciable influence on the estimation of dynamic association behaviors such as unrealistic packing radii and even misleading packing structures. It would be better to select dynamically representative sites on solute molecules based on the characteristic of solute associations. Our detailed discussions give a guide on how to determine an appropriate criterion to accurately analyze the association behaviors of solute molecules in aqueous solutions.展开更多
Recent years have seen the development of a number of mathematical models for the description of the simultaneous transport of microorganisms and bioreactive solutes in porous media. Most models are based on the adve...Recent years have seen the development of a number of mathematical models for the description of the simultaneous transport of microorganisms and bioreactive solutes in porous media. Most models are based on the advection dispersion equation, with terms added to account for interactions with the surfaces of the solid matrix, transformations and microbial activities. Those models based on the advection dispersion equation have all been shown to represent laboratory experimental data adequately although various assumptions have been made concerning the pore scale distribution of bacteria. This paper provides an overview of the recent work on modelling the transport and fate of microorganisms and bioreactive solutes in porous media and examines the different assumptions regarding the pore scale distribution of microorganisms.展开更多
The ditheion coefficients(Dapp) and the heterogeneous electron-transfer rate constan(ks)for ferrocene in MPEG/salt electrolytes were determined by using Steady-stae voltammetry. The temperature dependence of the two p...The ditheion coefficients(Dapp) and the heterogeneous electron-transfer rate constan(ks)for ferrocene in MPEG/salt electrolytes were determined by using Steady-stae voltammetry. The temperature dependence of the two parameters obeys the Arrhenius equstion. The effect of the ionic size of sir supporting electrolytes on diffusion and electron transfer dynamics of fermcene was discussed展开更多
In order to study osmotic adjustment and accumulation of anions and cations in rice （Oryza sativa L.） seedlings under NaCl stress, a greenhouse experiment was conducted using two rice cultivars including IR651 （tol...In order to study osmotic adjustment and accumulation of anions and cations in rice （Oryza sativa L.） seedlings under NaCl stress, a greenhouse experiment was conducted using two rice cultivars including IR651 （tolerant） and IR29 （sensitive）. Seedlings were grown in Youshida nutrient solution. Salinity treatments were imposed 21 days after sowing with 0 and 100 mM NaCI and seedlings were harvested 0, 72, 120 and 240 hour after salinization. Water （ψw） and osmotic （ψs） potentials, total soluble sugars and inorganic ions （Na＋. K＋, Cl-, Ca2＋ and Mg2＋） concentrations and osmotic adjustment were determined in sixth （youngest） leaf. Salinity caused a substantial biomass reduction in rice seedlings, ψs reduction in IR29 was occurred more than IR651. Water potential decreased in both the cultivars under stress conditions, but IR651 was able to maintain higher ψw and kept better growth till the end of the experiment. Osmotic adjustment was observed in IR651 was about 10 times more than in IR29. K＋ accumulation decreased in both cultivars under stress condition while Na＋ accumulation increased in both the cultivars with higher increase in IR29 seedlings. CI concentration increased in youngest leaf of both IR29 and IR651. Our results showed that tolerant cultivar was able to make osmotic adjustment faster than the sensitive cultivar using high accumulation of solutes especially total soluble sugars.展开更多
We present a review of the principal developments in the evolution and synergism of solute and particle migration in a liquid melt in high-gradient magnetic fields and we also describe their effects on the solidificat...We present a review of the principal developments in the evolution and synergism of solute and particle migration in a liquid melt in high-gradient magnetic fields and we also describe their effects on the solidification microstructure of alloys.Diverse areas relevant to various aspects of theory and applications of high-gradient magnetic field-controlled migration of solutes and particles are surveyed.They include introduction,high-gradient magnetic field effects,migration behavior of solute and particles in high-gradient magnetic fields,microstructure evolution induced by high-gradient magnetic fieldcontrolled migrations of solute and particles,and properties of materials modified by high-gradient magnetic field-tailored microstructure.Selected examples of binary and multiphase alloy systems are presented and examined,with the main focus on the correlation between the high-gradient magnetic field-modified migration and the related solidification microstructure evolution.Particular attention is given to the mechanisms responsible for the microstructure evolution induced by highgradient magnetic fields.展开更多
The effect of solutes on grain formation has been studied over a century but is still under debating,simply because it is a very complex topic.This article focuses on the effect of dissolved solute on the growth,fragm...The effect of solutes on grain formation has been studied over a century but is still under debating,simply because it is a very complex topic.This article focuses on the effect of dissolved solute on the growth,fragmentation of a dendrite and the resultant grain size.Experimental data on grain size in magnesium and aluminum alloys with various solute concentrations are collected and analyzed using phase diagram variables including Q,P,andΔT.The physical meaning of each phase diagram variable is discussed.Curve fitting of the recently proposed two-parameter models with experimental data suggests that there is a clear correlation between the measured grain size and the solidification range of the alloy over the entire range of the hypoeutectic composition.Such a trend of grain size vs.ΔT is closely related to the grain refining mechanisms operating under relevant experimental conditions.A critical review of the grain refining mechanisms indicates that the mechanisms associated with the dendrite fragmentation are operating under the conditions where convection is substantial in the melt during its solidification.展开更多
Cold acclimation is associated with many metabolic changes that lead to an increase of freezing tolerance. In order to investigate the biochemical process of cold acclimation in Ammopiptanthus mongolicus, seedlings we...Cold acclimation is associated with many metabolic changes that lead to an increase of freezing tolerance. In order to investigate the biochemical process of cold acclimation in Ammopiptanthus mongolicus, seedlings were acclimated at 2℃ under 16-h photoperiod （150 μmol·m^-2·s^-1 photosynthetically active radiation） for 14 d. Freezing tolerance in seedlings increased after 14 d of cold-hardening. Contents of protein, proline and solute carbohydrate in cotyledon increased after cold acclimation. Patterns of isozymes of superoxide dismutase （SOD）, peroxidase, catalase and polyphenol oxidase （PPO） were investigated. The activities of SOD, peroxidase and PPO in cold acclimated plants were increased during cold-hardening. We deduced that compatible solutes and antioxidant enzymes play important roles in development of freezing tolerance during cold acclimation in this evergreen woody plant.展开更多
Forward osmosis(FO), as one of the emerging desalination technologies, has the potential to produce fresh water from a variety of water sources by utilizing the osmotic pressure gradient across a semi-permeable membra...Forward osmosis(FO), as one of the emerging desalination technologies, has the potential to produce fresh water from a variety of water sources by utilizing the osmotic pressure gradient across a semi-permeable membrane.Draw solution, as an essential component of any FO process, can extract water molecules from seawater or wastewater. An ideal draw solution should meet three essential requirements, namely high osmotic pressure, low reverse flux, and facile regeneration mechanism. The selection of proper draw solutes is especially critical for an energy-efficient FO process since the energy consumption mostly arises from the separation or regeneration of the draw solution. Recently, we developed a few multi-functional FO draw solutes, mainly aiming to enhance the FO water flux and to explore facile re-concentration methods. This review summarizes these draw solutes,including Na^+_- functionalized carbon quantum dots, thermoresponsive copolymers, hydrophilic magnetic nanoparticles, and thermoresponsive magnetic nanoparticles.展开更多
Novel magnetic nanoparticles(MNPs),Fe_(3)O_(4)@SiO_(2) and Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2),were prepared by loading different amounts of SiO_(2) or/and PEG-(COOH)_(2) onto Fe_(3)O_(4) nanoparticles,and their feasib...Novel magnetic nanoparticles(MNPs),Fe_(3)O_(4)@SiO_(2) and Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2),were prepared by loading different amounts of SiO_(2) or/and PEG-(COOH)_(2) onto Fe_(3)O_(4) nanoparticles,and their feasibility to be used as forward osmosis(FO)draw solutes was investigated.The characterization of the materials showed that,compared to normal Fe_(3)O_(4) nanoparticles,the modified MNPs exhibited enhanced dispersity and high osmotic pressure in aqueous solution.The FO experiment indicated that the synthesized draw solutes could obtain a water flux as high as 10 L·m^(-2)·h^(-1) with an aquaporin FO membrane.The optimal concentration of the added tetraethyl orthosilicate was 30%during the synthesis.The novel MNPs could be easily recovered from draw solutions by magnetic field,and the recovery rate of Fe_(3)O_(4)@SiO_(2) and Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2) was 83.95%and 63.37%,respectively.Moreover,after 5 recycles of reuse,the water flux of Fe_(3)O_(4)@SiO_(2) and Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2) as draw solutes still remained 64.36%and 85.26%,respectively.The experimental results demonstrated that the synthesized core–shell magnetic nanoparticles are promising draw solutes,and the Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2) was more suitable to be used as draw solute in FO process.展开更多
The detailed mechanisms that facilitate the heat tolerance of terrestrial cyanobacteria have not been completely elucidated, although several reports have revealed aspects of the heat tolerance mechanisms of several o...The detailed mechanisms that facilitate the heat tolerance of terrestrial cyanobacteria have not been completely elucidated, although several reports have revealed aspects of the heat tolerance mechanisms of several other organisms. The dormant cells, called akinetes, of the terrestrial cyanobacterium Nostoc sp. HK-01 can revive after dry heat exposure at 100℃ for more than 10 h. We investigated the compatible solutes that protect the biomolecules in Nostoc sp. HK-01 akinetes using colonies containing various proportions of akinetes. We extracted the intracellular substances from each colony with 80% ethanol, which we purified with a series of analytical columns and analyzed by high-performance liquid chromatography and liquid chromatography-electrospray ionization-mass spectrometry. The compatible solutes were screened for their ability to prevent protein aggregation upon heating using the model enzyme lactate dehydrogenase. We detected an accumulation of glucosylglycerol, betaine, and glycine in akinetes. In addition, we confirmed that betaine, glycine, sucrose, and trehalose contributed to the prevention of the protein aggregation. The levels of sucrose and glycine in the colonies were approximately 1000× higher than those of glucosylglycerol, betaine, or trehalose. Our results indicated that sucrose and glycine are the main compatible solutes in the hydrophilic fractions of the cell extracts of Nostoc sp. HK-01 akinetes.展开更多
The intensive and inappropriate use of water, fertilizers and phytosanitary products is sources of water and soil pollution. It is thus necessary to improve the management of irrigation water in order to optimize its ...The intensive and inappropriate use of water, fertilizers and phytosanitary products is sources of water and soil pollution. It is thus necessary to improve the management of irrigation water in order to optimize its use and productivity, especially in regions where water resources are becoming increasingly scarce. The water flow and non-reactive solutes’ transport simulation under drip irrigation were carried out in a 3-layered soil profile distributed from top to bottom<em> i.e</em>., sandy, sandy-silty, silty-sandy-clay. The aim of this study was thus, to provide a good practice of water management associated with solutes’ application, in order to retain as much solute as possible in the root zone, which will increase the residence time of the solutes. Three treatments of water flux corresponding to 100% <em>ET</em><sub><em>c</em></sub>, 75% <em>ET</em><sub><em>c</em></sub>, 50% <em>ET</em><sub><em>c</em></sub>, combined with 100 mmol /L/ m<sup>2</sup> of NPK and 246 mmol/L/m<sup>2</sup> of urea applicable in two doses, were carried out over a period of 110 days corresponding to the duration of the cropping cycle for the intermediate variety of maize. The 100%<em> ET</em><sub><em>c</em></sub> and 75% <em>ET</em><sub><em>c</em></sub> treatments cause more loss of water and solutes, because of the sandy texture of the soil. However, a 50% <em>ET</em><sub><em>c</em></sub> water flux would reduce more water loss through drainage, and solutes’ loss due to leaching beyond the root zone, which would increase the residence time of solutes in the soil profile. Application tests of the NPK solute on different days before the 15<sup>th</sup> day after sowing were also carried out according to the technical itinerary for maize production in Burkina Faso, in order to find a favorable day for application of the solute. For the different dates of solute’s application, there was more loss of the solute as we approach the 15<sup>th</sup> day after sowing. To limit this loss and increase the residence time of the NPK solute, one could apply the solute without first supplying water, the day before and the day after the date of solute’ injection. Or, one could amend the soil with organic matter to improve its retention capacity of water, and the solutes’ residence time in the soil.展开更多
The control of solute segregation at grain boundaries is of significance in engineering alloy properties.However,there is currently a lack of a physics-informed predictive model for estimating solute segre-gation ener...The control of solute segregation at grain boundaries is of significance in engineering alloy properties.However,there is currently a lack of a physics-informed predictive model for estimating solute segre-gation energies.Here we propose novel electronic descriptors for grain-boundary segregation based on the valence,electronegativity and size of solutes.By integrating the non-local coordination number of surfaces,we build a predictive analytic framework for evaluating the segregation energies across various solutes,grain-boundary structures,and segregation sites.This framework uncovers not only the coupling rule of solutes and matrices,but also the origin of solute-segregation determinants,which stems from the d-and sp-states hybridization in alloying.Our scheme establishes a novel picture for grain-boundary segregation and provides a useful tool for the design of advanced alloys.展开更多
BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD....BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.展开更多
基金the funding from the Ger-man Research Foundation(DFG)-BE 5360/1-1 and ThyssenKrupp Europe.
文摘A microscopic understanding of the complex solute-defect interaction is pivotal for optimizing the alloy’s macroscopic mechanical properties.Simulating solute segregation in a plastically deformed crystalline system at atomic resolution remains challenging.The objective is to efficiently model and predict a phys-ically informed segregated solute distribution rather than simulating a series of diffusion kinetics.To ad-dress this objective,we coupled molecular dynamics(MD)and Monte Carlo(MC)methods using a novel method based on virtual atoms technique.We applied our MD-MC coupling approach to model off-lattice carbon(C)solute segregation in nanoindented Fe-C samples containing complex dislocation networks.Our coupling framework yielded the final configuration through efficient parallelization and localized en-ergy computations,showing C Cottrell atmospheres near dislocations.Different initial C concentrations resulted in a consistent trend of C atoms migrating from less crystalline distortion to high crystalline distortion regions.Besides unraveling the strong spatial correlation between local C concentration and defect regions,our results revealed two crucial aspects of solute segregation preferences:(1)defect ener-getics hierarchy and(2)tensile strain fields near dislocations.The proposed approach is generic and can be applied to other material systems as well.
基金Financial support from the National Natural Science Foundation of China(Nos.52222409,52074132,U19A2084)the National Key Research and Development Program(No.2022YFE0122000)are greatly acknowledged.
文摘It is commonly recognized that the cooling rate has a substantial effect on solute partitioning and its resultant microsegregation during solidification.The classical dendrite tip undercooling theory clarifies the mitigation of microsegregation by increasing the cooling rate.However,most of the studies focused on binary alloys,leaving an open question as to whether the microsegregation of different solutes in a multi-component alloy system exhibits a relieving degree similar to increasing cooling rate.Taking a widely used 6022-type Al alloy(Al-0.76Mg-0.93Si-0.2Fe)as a model alloy,the current study reveals that the microsegregation of Mg gets alleviated to the greatest extent,followed by those of Si and Fe when the cooling rate increases from 5 to 128 K/s.This phenomenon is attributed to the solute-based difference in response to partitioning to cooling rate(denoted as Rk).We propose a theoretical equation to quantify Rk,and the R_(k)values of solute Mg,Si,and Fe successfully explain the rank of solute partitioning in exper-iments.Furthermore,a broad range of R_(k)values of other commonly used alloying elements in Al alloys were calculated and ranked,delivering a handy tool to predict the microsegregation behavior and sol-ubility of different solute elements upon sub-rapid solidification,which is consistent with experimental observation.This framework can also be extended to other multi-component alloy systems.
文摘The diffusion coefficients(Dapp) and the heterogeneous electron-transfer rate constants(ks)for ferrocene and its seven derivatives in MPEG/LiClO4 electrolyte were determined by using steadystate voltammetry. The two parameters increase with increasing temperature, indicating Arrhenius behavior. The effects of the nature of electroactive solute molecules on Dapp, ks, and the half-wave potentials(E1/2) are discussed.
文摘The diffusion coefficients(Dapp) and the heterogeneous electron transfer rate constants(ks)for ferrocene in several polymer solvents were determined by using steady-stae voltammetry. Thetemperature dependence of the two parameters indicates Arrhenius behavior. The polymer solventeffects on diffusion and electron transfer dynamics of ferrocene were discussed
文摘The present paper describes experiments aimed at delineating significant chemical characteristics of electrochemical reactions in polymeric solutions, including how rigid solvent environments affect mass transport rates, and also discusses the possibility that the microelectrode coated with poly(ethylene oxide)(PEO) film can be used as gas sensor.
文摘Safflower is an important, traditional, multipurpose oil crop. This was to investigate the effect of different salinity levels on morphological, physiological, biochemical and antioxidant response of two safflower cultivars (Carthamus tinctorius L. cultivar TSF1 and cultivar SM) differing in salt tolerance. Salinity stress (0.0%, 1.0%, 1.5% and 2.0% of NaCl) was induced to safflower plants after 19 days of vegetative growth. After 12 days of stress impositions, plants were harvested and analysed for various parameters. The results revealed that cultivar TSF1 showed maximum growth, dry weight, cell membrane stability and more water content in both root and leaf tissues at higher salinity levels than cultivar SM. Salt stress resulted an accumulation of more soluble sugars, amino acids, proline and glycine betaine at high salinity level confers the tolerance potential of cultivar TSF1 over cultivar SM. Salt stress induces more increase in the enzyme activity of superoxide dismutase, ascorbate peroxidase, guaiacol peroxidase and catalase in tolerant cultivar than sensitive one. The results indicate that each cultivar adopt specific strategy at distinct salinity level for resistance against salinity. The possible conclusion is that improved tolerance in cultivar TSF1 to salinity may be accomplished by better management of growth, physiological attributes and antioxidative defence mechanisms.
基金Supported by the National Science Fund for Outstanding Young Scholars under Grant No 11422542the Key Research Program of Chinese Academy of Sciences under Grant No KJZD-EW-M03,KIPCAS+1 种基金the Shanghai Supercomputer Center of Chinathe High Performance Computing Center of Shanghai University
文摘How to determine accurately the association states of solutes in aqueous systems is of fundamental importance in a variety of chemical, physical, and biological processes, We apply four widely used criteria to analyze the dynamic association processes of solutes, e.g., amphiphilic molecules, and to find the inappropriate selections of representative sites on solutes in these criteria may bring about appreciable influence on the estimation of dynamic association behaviors such as unrealistic packing radii and even misleading packing structures. It would be better to select dynamically representative sites on solute molecules based on the characteristic of solute associations. Our detailed discussions give a guide on how to determine an appropriate criterion to accurately analyze the association behaviors of solute molecules in aqueous solutions.
文摘Recent years have seen the development of a number of mathematical models for the description of the simultaneous transport of microorganisms and bioreactive solutes in porous media. Most models are based on the advection dispersion equation, with terms added to account for interactions with the surfaces of the solid matrix, transformations and microbial activities. Those models based on the advection dispersion equation have all been shown to represent laboratory experimental data adequately although various assumptions have been made concerning the pore scale distribution of bacteria. This paper provides an overview of the recent work on modelling the transport and fate of microorganisms and bioreactive solutes in porous media and examines the different assumptions regarding the pore scale distribution of microorganisms.
文摘The ditheion coefficients(Dapp) and the heterogeneous electron-transfer rate constan(ks)for ferrocene in MPEG/salt electrolytes were determined by using Steady-stae voltammetry. The temperature dependence of the two parameters obeys the Arrhenius equstion. The effect of the ionic size of sir supporting electrolytes on diffusion and electron transfer dynamics of fermcene was discussed
文摘In order to study osmotic adjustment and accumulation of anions and cations in rice （Oryza sativa L.） seedlings under NaCl stress, a greenhouse experiment was conducted using two rice cultivars including IR651 （tolerant） and IR29 （sensitive）. Seedlings were grown in Youshida nutrient solution. Salinity treatments were imposed 21 days after sowing with 0 and 100 mM NaCI and seedlings were harvested 0, 72, 120 and 240 hour after salinization. Water （ψw） and osmotic （ψs） potentials, total soluble sugars and inorganic ions （Na＋. K＋, Cl-, Ca2＋ and Mg2＋） concentrations and osmotic adjustment were determined in sixth （youngest） leaf. Salinity caused a substantial biomass reduction in rice seedlings, ψs reduction in IR29 was occurred more than IR651. Water potential decreased in both the cultivars under stress conditions, but IR651 was able to maintain higher ψw and kept better growth till the end of the experiment. Osmotic adjustment was observed in IR651 was about 10 times more than in IR29. K＋ accumulation decreased in both cultivars under stress condition while Na＋ accumulation increased in both the cultivars with higher increase in IR29 seedlings. CI concentration increased in youngest leaf of both IR29 and IR651. Our results showed that tolerant cultivar was able to make osmotic adjustment faster than the sensitive cultivar using high accumulation of solutes especially total soluble sugars.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51425401,51690161,51574073,and 51774086)Fundamental Research Funds for the Central Universities,China(Grant Nos.N170902002 and N170908001)Liaoning Innovative Research Team in University,China(Grant No.LT2017011)
文摘We present a review of the principal developments in the evolution and synergism of solute and particle migration in a liquid melt in high-gradient magnetic fields and we also describe their effects on the solidification microstructure of alloys.Diverse areas relevant to various aspects of theory and applications of high-gradient magnetic field-controlled migration of solutes and particles are surveyed.They include introduction,high-gradient magnetic field effects,migration behavior of solute and particles in high-gradient magnetic fields,microstructure evolution induced by high-gradient magnetic fieldcontrolled migrations of solute and particles,and properties of materials modified by high-gradient magnetic field-tailored microstructure.Selected examples of binary and multiphase alloy systems are presented and examined,with the main focus on the correlation between the high-gradient magnetic field-modified migration and the related solidification microstructure evolution.Particular attention is given to the mechanisms responsible for the microstructure evolution induced by highgradient magnetic fields.
文摘The effect of solutes on grain formation has been studied over a century but is still under debating,simply because it is a very complex topic.This article focuses on the effect of dissolved solute on the growth,fragmentation of a dendrite and the resultant grain size.Experimental data on grain size in magnesium and aluminum alloys with various solute concentrations are collected and analyzed using phase diagram variables including Q,P,andΔT.The physical meaning of each phase diagram variable is discussed.Curve fitting of the recently proposed two-parameter models with experimental data suggests that there is a clear correlation between the measured grain size and the solidification range of the alloy over the entire range of the hypoeutectic composition.Such a trend of grain size vs.ΔT is closely related to the grain refining mechanisms operating under relevant experimental conditions.A critical review of the grain refining mechanisms indicates that the mechanisms associated with the dendrite fragmentation are operating under the conditions where convection is substantial in the melt during its solidification.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.30671476 and 30271067).
文摘Cold acclimation is associated with many metabolic changes that lead to an increase of freezing tolerance. In order to investigate the biochemical process of cold acclimation in Ammopiptanthus mongolicus, seedlings were acclimated at 2℃ under 16-h photoperiod （150 μmol·m^-2·s^-1 photosynthetically active radiation） for 14 d. Freezing tolerance in seedlings increased after 14 d of cold-hardening. Contents of protein, proline and solute carbohydrate in cotyledon increased after cold acclimation. Patterns of isozymes of superoxide dismutase （SOD）, peroxidase, catalase and polyphenol oxidase （PPO） were investigated. The activities of SOD, peroxidase and PPO in cold acclimated plants were increased during cold-hardening. We deduced that compatible solutes and antioxidant enzymes play important roles in development of freezing tolerance during cold acclimation in this evergreen woody plant.
基金Supported by the National Research Foundation-Prime Minister's office,Republic of Singapore(Grant#R-279-000-337-281)
文摘Forward osmosis(FO), as one of the emerging desalination technologies, has the potential to produce fresh water from a variety of water sources by utilizing the osmotic pressure gradient across a semi-permeable membrane.Draw solution, as an essential component of any FO process, can extract water molecules from seawater or wastewater. An ideal draw solution should meet three essential requirements, namely high osmotic pressure, low reverse flux, and facile regeneration mechanism. The selection of proper draw solutes is especially critical for an energy-efficient FO process since the energy consumption mostly arises from the separation or regeneration of the draw solution. Recently, we developed a few multi-functional FO draw solutes, mainly aiming to enhance the FO water flux and to explore facile re-concentration methods. This review summarizes these draw solutes,including Na^+_- functionalized carbon quantum dots, thermoresponsive copolymers, hydrophilic magnetic nanoparticles, and thermoresponsive magnetic nanoparticles.
文摘Novel magnetic nanoparticles(MNPs),Fe_(3)O_(4)@SiO_(2) and Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2),were prepared by loading different amounts of SiO_(2) or/and PEG-(COOH)_(2) onto Fe_(3)O_(4) nanoparticles,and their feasibility to be used as forward osmosis(FO)draw solutes was investigated.The characterization of the materials showed that,compared to normal Fe_(3)O_(4) nanoparticles,the modified MNPs exhibited enhanced dispersity and high osmotic pressure in aqueous solution.The FO experiment indicated that the synthesized draw solutes could obtain a water flux as high as 10 L·m^(-2)·h^(-1) with an aquaporin FO membrane.The optimal concentration of the added tetraethyl orthosilicate was 30%during the synthesis.The novel MNPs could be easily recovered from draw solutions by magnetic field,and the recovery rate of Fe_(3)O_(4)@SiO_(2) and Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2) was 83.95%and 63.37%,respectively.Moreover,after 5 recycles of reuse,the water flux of Fe_(3)O_(4)@SiO_(2) and Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2) as draw solutes still remained 64.36%and 85.26%,respectively.The experimental results demonstrated that the synthesized core–shell magnetic nanoparticles are promising draw solutes,and the Fe_(3)O_(4)@SiO_(2)@PEG-(COOH)_(2) was more suitable to be used as draw solute in FO process.
文摘The detailed mechanisms that facilitate the heat tolerance of terrestrial cyanobacteria have not been completely elucidated, although several reports have revealed aspects of the heat tolerance mechanisms of several other organisms. The dormant cells, called akinetes, of the terrestrial cyanobacterium Nostoc sp. HK-01 can revive after dry heat exposure at 100℃ for more than 10 h. We investigated the compatible solutes that protect the biomolecules in Nostoc sp. HK-01 akinetes using colonies containing various proportions of akinetes. We extracted the intracellular substances from each colony with 80% ethanol, which we purified with a series of analytical columns and analyzed by high-performance liquid chromatography and liquid chromatography-electrospray ionization-mass spectrometry. The compatible solutes were screened for their ability to prevent protein aggregation upon heating using the model enzyme lactate dehydrogenase. We detected an accumulation of glucosylglycerol, betaine, and glycine in akinetes. In addition, we confirmed that betaine, glycine, sucrose, and trehalose contributed to the prevention of the protein aggregation. The levels of sucrose and glycine in the colonies were approximately 1000× higher than those of glucosylglycerol, betaine, or trehalose. Our results indicated that sucrose and glycine are the main compatible solutes in the hydrophilic fractions of the cell extracts of Nostoc sp. HK-01 akinetes.
文摘The intensive and inappropriate use of water, fertilizers and phytosanitary products is sources of water and soil pollution. It is thus necessary to improve the management of irrigation water in order to optimize its use and productivity, especially in regions where water resources are becoming increasingly scarce. The water flow and non-reactive solutes’ transport simulation under drip irrigation were carried out in a 3-layered soil profile distributed from top to bottom<em> i.e</em>., sandy, sandy-silty, silty-sandy-clay. The aim of this study was thus, to provide a good practice of water management associated with solutes’ application, in order to retain as much solute as possible in the root zone, which will increase the residence time of the solutes. Three treatments of water flux corresponding to 100% <em>ET</em><sub><em>c</em></sub>, 75% <em>ET</em><sub><em>c</em></sub>, 50% <em>ET</em><sub><em>c</em></sub>, combined with 100 mmol /L/ m<sup>2</sup> of NPK and 246 mmol/L/m<sup>2</sup> of urea applicable in two doses, were carried out over a period of 110 days corresponding to the duration of the cropping cycle for the intermediate variety of maize. The 100%<em> ET</em><sub><em>c</em></sub> and 75% <em>ET</em><sub><em>c</em></sub> treatments cause more loss of water and solutes, because of the sandy texture of the soil. However, a 50% <em>ET</em><sub><em>c</em></sub> water flux would reduce more water loss through drainage, and solutes’ loss due to leaching beyond the root zone, which would increase the residence time of solutes in the soil profile. Application tests of the NPK solute on different days before the 15<sup>th</sup> day after sowing were also carried out according to the technical itinerary for maize production in Burkina Faso, in order to find a favorable day for application of the solute. For the different dates of solute’s application, there was more loss of the solute as we approach the 15<sup>th</sup> day after sowing. To limit this loss and increase the residence time of the NPK solute, one could apply the solute without first supplying water, the day before and the day after the date of solute’ injection. Or, one could amend the soil with organic matter to improve its retention capacity of water, and the solutes’ residence time in the soil.
基金support from the National Natural Science Foundation of China(Nos.22173034,11974128,52130101)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure(No.SKL202206SIC)+2 种基金the Program of Innovative Research Team(in Science and Technology)in University of Jilin Province,the Program for JLU(Jilin University)Science and Technology Innovative Research Team(No.2017TD-09)the Fundamental Research Funds for the Central Universitiesthe computing resources of the High Performance Computing Center of Jilin University,China.
文摘The control of solute segregation at grain boundaries is of significance in engineering alloy properties.However,there is currently a lack of a physics-informed predictive model for estimating solute segre-gation energies.Here we propose novel electronic descriptors for grain-boundary segregation based on the valence,electronegativity and size of solutes.By integrating the non-local coordination number of surfaces,we build a predictive analytic framework for evaluating the segregation energies across various solutes,grain-boundary structures,and segregation sites.This framework uncovers not only the coupling rule of solutes and matrices,but also the origin of solute-segregation determinants,which stems from the d-and sp-states hybridization in alloying.Our scheme establishes a novel picture for grain-boundary segregation and provides a useful tool for the design of advanced alloys.
基金Supported by Science and Technology Department of Sichuan Province,No.2020YFS0376National Natural Science Foundation of China,No.81900599Science and Technology Program of Hospital of TCM,Southwest Medical University,No.2022-CXTD-01.
文摘BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.
