Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,t...Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,thermal management,displays,and camouflage.However,typical inorganic EC materials,such as tungsten oxides(WO_(3)),of⁃ten suffer from slow ion diffusion kinetics and limited optical contrast within the aqueous Zn^(2+)electrolyte because of the large size and strong Coulombic interactions of the Zn^(2+),which limits their wide applicability.Here,ordered WO_(3)nanowire films,constructed by a one-step grazing angle deposition method,is demonstrated to boost the response speed and optical contrast during EC phenomena.Compared with dense films,the ordered WO_(3)nanowire films with a porosity of 44.6%demonstrate anti-reflective property and excellent comprehensive EC performance,including fast response time(3.6 s and 1.2 s for coloring and bleaching,respectively),large optical contrast(66.6%at 700 nm)and high col⁃oration efficiency(64.3 cm^(2)·C^(-1)).A large-area prototype EC device(17 cm×12 cm)with fast color-switching is also successfully achieved.Mechanistic studies show that the improved performance is mainly due to the ordered porous nanowire structures,which provides direct electron transfer paths and sufficient interfacial contacts,thus simultaneously enhancing the electrochemical activity and fast redox kinetics.This study provides a simple and effective strategy to im⁃prove the performance of tungsten oxide-based aqueous zinc ion EC materials and devices.展开更多
Frequent drought events severely restrict global crop productivity,especially those occurring in the reproductive stages.Moderate drought priming during the earlier growth stages is a promising strategy for allowing p...Frequent drought events severely restrict global crop productivity,especially those occurring in the reproductive stages.Moderate drought priming during the earlier growth stages is a promising strategy for allowing plants to resist recurrent severe drought stress.However,the underlying mechanisms remain unclear.Here,we subjected wheat plants to drought priming during the vegetative growth stage and to severe drought stress at 10 days after anthesis.We then collected leaf samples at the ends of the drought priming and recovery periods,and at the end of drought stress for transcriptome sequencing in combination with phenotypic and physiological analyses.The drought-primed wheat plants maintained a lower plant temperature,with higher stomatal openness and photosynthesis,thereby resulting in much lower 1,000-grain weight and grain yield losses under the later drought stress than the non-primed plants.Interestingly,416 genes,including 27 transcription factors(e.g.,MYB,NAC,HSF),seemed to be closely related to the improved drought tolerance as indicated by the dynamic transcriptome analysis.Moreover,the candidate genes showed six temporal expression patterns and were significantly enriched in several stress response related pathways,such as plant hormone signal transduction,starch and sucrose metabolism,arginine and proline metabolism,inositol phosphate metabolism,and wax synthesis.These findings provide new insights into the physiological and molecular mechanisms of the long-term effects of early drought priming that can effectively improve drought tolerance in wheat,and may provide potential approaches for addressing the challenges of increasing abiotic stresses and securing food safety under global warming scenarios.展开更多
The impacts of drought stress on crop yield and quality are substantial. Drought priming during the early growth stage of plants has been shown to improve tolerance to drought stress during the reproductive stage, alt...The impacts of drought stress on crop yield and quality are substantial. Drought priming during the early growth stage of plants has been shown to improve tolerance to drought stress during the reproductive stage, although its effects on grain quality remain elusive. This study investigated the influence of drought priming on starch and protein levels in grains under drought stress during grain filling. Our results revealed that drought stress leads to a reduction in the contents of starch and its constituents, while simultaneously increasing glutenin macropolymers and protein fractions. Notably, drought primed plants under drought stress(PD) exhibited mitigated declines in the contents of starch and its components, leading to improvements in starch swelling power and pasting properties. In addition, PD resulted in a slight increase in the protein fractions, limiting the overall rise in total protein content compared to drought stress alone. The results of our study underscore the efficacy of drought priming as a strategy to counteract the negative effects of drought stress on grain quality, particularly by minimizing starch losses and restraining protein content elevation.展开更多
With the continued expansion of oil and gas exploration,both in the eastern and western regions,the quality of seismic acquisition has become a key factor in oil and gas exploration in complex areas.However,convention...With the continued expansion of oil and gas exploration,both in the eastern and western regions,the quality of seismic acquisition has become a key factor in oil and gas exploration in complex areas.However,conventional seismic acquisition methods cannot efficiently avoid challenging acquisition locations and produce high-quality seismic data.In this regard,based on the curvelet transform,this paper proposes an irregular seismic acquisition method,which utilizes the high-precision characteristics of the curvelet transform and simulated annealing algorithm to establish a method for the evaluation of the coherence of irregular sampling matrices and design of observation systems.The method was verified using forward simulation and actual acquisition data.The results suggest the superior quality of seismic data gathered in complicated areas through this method over those acquired using traditional methods,which can provide technical guidance for the design of observation systems in complex areas.展开更多
Staple crops such as rice,wheat,and maize are crucial for global food security;however,improving their quality remains a significant challenge.This review summarizes recent advances in enhancing crop quality,focusing ...Staple crops such as rice,wheat,and maize are crucial for global food security;however,improving their quality remains a significant challenge.This review summarizes recent advances in enhancing crop quality,focusing on key areas such as the molecular mechanisms underlying endosperm filling initiation,starch granule synthesis,protein body formation,and the interactions between carbon and nitrogen metabolism.It also highlights ten unresolved questions related to starch-protein spatial distribution,epigenetic regulation,and the environmental impacts on quality traits.The integration of multi-omics approaches and rational design strategies presents opportunities to develop high-yield“super-crop”varieties with enhanced nutritional value,better processing characteristics,and attributes preferred by consumers.Addressing these challenges is crucial to promote sustainable agriculture and achieve the dual objectives of food security and environmental conservation.展开更多
Due to the NP-hardness of the two-sided assembly line balancing (TALB) problem, multiple constraints existing in real applications are less studied, especially when one task is involved with several constraints. In ...Due to the NP-hardness of the two-sided assembly line balancing (TALB) problem, multiple constraints existing in real applications are less studied, especially when one task is involved with several constraints. In this paper, an effective hybrid algorithm is proposed to address the TALB problem with multiple constraints (TALB-MC). Considering the discrete attribute of TALB-MC and the continuous attribute of the standard teaching-learning-based optimization (TLBO) algorithm, the random-keys method is hired in task permutation representation, for the purpose of bridging the gap between them. Subsequently, a special mechanism for handling multiple constraints is developed. In the mechanism, the directions constraint of each task is ensured by the direction check and adjustment. The zoning constraints and the synchronism constraints are satisfied by teasing out the hidden correlations among constraints. The positional constraint is allowed to be violated to some extent in decoding and punished in cost fimction. Finally, with the TLBO seeking for the global optimum, the variable neighborhood search (VNS) is further hybridized to extend the local search space. The experimental results show that the proposed hybrid algorithm outperforms the late acceptance hill-climbing algorithm (LAHC) for TALB-MC in most cases, especially for large-size problems with multiple constraints, and demonstrates well balance between the exploration and the exploitation. This research proposes an effective and efficient algorithm for solving TALB-MC problem by hybridizing the TLBO and VNS.展开更多
Rice is one of the most important grain crops in Northeast China (NEC) and its cultivation is sensitive to climate change. This study aimed to explore the spatio-temporal changes in the NEC rice planting area over t...Rice is one of the most important grain crops in Northeast China (NEC) and its cultivation is sensitive to climate change. This study aimed to explore the spatio-temporal changes in the NEC rice planting area over the period of 1980-2010 and to analyze their relationship to climate change. To do so, the CLUE-S (conversion of land use and its effects at small region extent) model was ifrst updated and used to simulate dynamic changes in the rice planting area in NEC to understand spatio-temporal change trends during three periods: 1980-1990, 1990-2000 and 2000-2010. The changing results in individual periods were then linked to climatic variables to investigate the climatic drivers of these changes. Results showed that the NEC rice planting area expanded quickly and increased by nearly 4.5 times during 1980-2010. The concentration of newly planted rice areas in NEC constantly moved northward and the changes were strongly dependent on latitude. This conifrmed that climate change, increases in temperature in particular, greatly inlfuenced the shift in the rice planting area. The shift in the north limit of the NEC rice planting area generally followed a 1°C isoline migration pattern, but with an obvious time-lag effect. These ifndings can help policy makers and crop producers take proper adaptation measures even when exposed to the global warming situation in NEC.展开更多
Testing-effort(TE) and imperfect debugging(ID) in the reliability modeling process may further improve the fitting and prediction results of software reliability growth models(SRGMs). For describing the S-shaped...Testing-effort(TE) and imperfect debugging(ID) in the reliability modeling process may further improve the fitting and prediction results of software reliability growth models(SRGMs). For describing the S-shaped varying trend of TE increasing rate more accurately, first, two S-shaped testing-effort functions(TEFs), i.e.,delayed S-shaped TEF(DS-TEF) and inflected S-shaped TEF(IS-TEF), are proposed. Then these two TEFs are incorporated into various types(exponential-type, delayed S-shaped and inflected S-shaped) of non-homogeneous Poisson process(NHPP)SRGMs with two forms of ID respectively for obtaining a series of new NHPP SRGMs which consider S-shaped TEFs as well as ID. Finally these new SRGMs and several comparison NHPP SRGMs are applied into four real failure data-sets respectively for investigating the fitting and prediction power of these new SRGMs.The experimental results show that:(i) the proposed IS-TEF is more suitable and flexible for describing the consumption of TE than the previous TEFs;(ii) incorporating TEFs into the inflected S-shaped NHPP SRGM may be more effective and appropriate compared with the exponential-type and the delayed S-shaped NHPP SRGMs;(iii) the inflected S-shaped NHPP SRGM considering both IS-TEF and ID yields the most accurate fitting and prediction results than the other comparison NHPP SRGMs.展开更多
A new type of transformation induced plasticity (TRIP) steel with not only high strength and high ductility but also superior welding and galvanizing properties was designed and developed recently. Low carbon and lo...A new type of transformation induced plasticity (TRIP) steel with not only high strength and high ductility but also superior welding and galvanizing properties was designed and developed recently. Low carbon and low silicon content were preliminarily selected with the aim of meeting the requirements of superior quality in both welding and galvanizing. Phosphorus was chosen as one of the alloying elements, because it could reduce carbon activity in cementite and increase the stability of austenite. In addition, the possibility of phosphorus segregating at grain boundary was also discussed by thermodynamics as well as kinetics. Phase diagram was estimated at high temperature and the composition of the steel was then selected in the hyperperitectic range to avoid problems, which might occur in sheet steel continuous casting. Phase diagram in the inter.critical temperature was estimated for the steel to obtain the starting temperature of fast cooling. For understanding the minimum rate of fast cooling, pearlite growth kinetics was calculated with self-developed diffusion coefficients of elements in grain boundary. Overaging temperature was determined through the calculation of To temperature by both equilibrium and para-equilibrium assumptions, which was different from the current determination, which is only based on an equilibrium estimation.展开更多
The mechanism of mine water inrushes in coal mines in China differs considerably from that in other countries.In China, most water inrushes occur from floor strata, where the water-inrush sources are karstic limestone...The mechanism of mine water inrushes in coal mines in China differs considerably from that in other countries.In China, most water inrushes occur from floor strata, where the water-inrush sources are karstic limestone aquifers.Our study describes the mechanism of mine water inrushes through a fault in the mine floor using principles of strata mechanics and the path of water inrush from an aquifer to the working face.A criterion to judge whether a ground water inrush will occur through a fault or not is also described, together with a case history of water inflow in the Feicheng coalfield, China.展开更多
Although climate change impacts and agricultural adaptations have been studied extensively, how smallholder farmers perceive climate change and adapt their agricultural activities is poorly understood. Survey-based da...Although climate change impacts and agricultural adaptations have been studied extensively, how smallholder farmers perceive climate change and adapt their agricultural activities is poorly understood. Survey-based data (presents farmers' personal perceptions and adaptations to climate change) associated with external biophysical-socioeconomic data (presents real-world climate change) were used to develop a farmer-centered framework to explore climate change impacts and agricultural adaptations at a local level. A case study at Bin County (1980s-2010s), Northeast China, suggested that increased annual average temperature (0.6°C per decade) and decreased annual precipitation (46 mm per decade, both from meteorological datasets) were correctly perceived by 76 and 66.9%, respectively, of farmers from the survey, and that a longer growing season was conifrmed by 70%of them. These reasonably correct perceptions enabled local farmers to make appropriate adaptations to cope with climate change:Longer season alternative varieties were found for maize and rice, which led to a signiifcant yield increase for both crops. The longer season also affected crop choice:More farmers selected maize instead of soybean, as implicated from survey results by a large increase in the maize growing area. Comparing warming-related factors, we found that precipitation and agricultural disasters were the least likely causes for farmers' agricultural decisions. As a result, crop and variety selection, rather than disaster prevention and infrastructure improvement, was the most common ways for farmers to adapt to the notable warming trend in the study region.展开更多
Drought stress is a limiting factor for wheat production and food security.Drought priming has been shown to increase drought tolerance in wheat.However,the underlying mechanisms are unknown.In the present study,the g...Drought stress is a limiting factor for wheat production and food security.Drought priming has been shown to increase drought tolerance in wheat.However,the underlying mechanisms are unknown.In the present study,the genes encoding the biosynthesis and metabolism of abscisic acid(ABA)and jasmonic acid(JA),as well as genes involved in the ABA and JA signaling pathways were up-regulated by drought priming.Endogenous concentrations of JA and ABA increased following drought priming.The interplay between JA and ABA in plant responses to drought priming was further investigated using inhibitors of ABA and JA biosynthesis.Application of fluridone(FLU)or nordihydroguaiaretic acid(NDGA)to primed plants resulted in lower chlorophyll-fluorescence parameters and activities of superoxide dismutase and glutathione reductase,and higher cell membrane damage,compared to primed plants(PD)under drought stress.NDGA+ABA,but not FLU+JA,restored priming-induced tolerance,as indicated by a finding of no significant difference from PD under drought stress.Under drought priming,NDGA induced the suppression of ABA accumulation,while FLU did not affect JA accumulation.These results were consistent with the expression of genes involved in the biosynthesis of ABA and JA.They suggest that ABA and JA are required for priming-induced drought tolerance in wheat,with JA acting upstream of ABA.展开更多
Quercetin(QUE)has many beneficial biological activities and pharmacological actions in vitro.However,its oral bioavailability in vivo was very poor due to poor solubility,and severely restricted its clinical applicati...Quercetin(QUE)has many beneficial biological activities and pharmacological actions in vitro.However,its oral bioavailability in vivo was very poor due to poor solubility,and severely restricted its clinical applications.In this study,we prepared quercetin solid dispersion(QUE-SD)and quercetin phospholipids complex solid dispersion(QUE-PC-SD)by a solvent evaporation method to improve the absorption of QUE in vivo.The results of XRD of QUE-SD and QUE-PC-SD showed that QUE was dispersed homogeneously in an amorphous or molecular state in QUE-SD and QUE-PC-SD,which could contribute to improve the solubility and dissolution of QUE.The solubility of QUE-SD and QUE-PC-SD was enhanced from(4.03±0.02)μg/mL to(26.91=1=0.06)μg/mL and(30.65±0.06)μg/mL,respectively.The solubility of QUE-PC-SD was higher than that of QUE-SD.In vitro dissolution study,it was showed that the maximum dissolution of QUE(9.57%)from the QUE-SD and QUE-PC-SD was enhanced to 93.81%and 94.16%,respectively.The results of pharmacokinetic experiment indicated that the QUE-SD and QUE-PC-SD exhibited considerable enhancement in the oral bioavailability.The relative bioavailability of QUE-SD and QUE-PC-SD compared with QUE were 149.49%and 198.32%,respectively.In addition,the relative bioavailability of QUE-PC-SD was also higher than that of QUE-SD.Therefore,in regard to drugs with poor solubility and low permeation,an active constituent-PC-SD system could result to a better absorption and higher bioavailability.展开更多
Since the beginning of the 20th century, many researches on the sealing characteristic of mechanical seals were carried out broadly and in depth by various methods and some leakage models were built. But due to the la...Since the beginning of the 20th century, many researches on the sealing characteristic of mechanical seals were carried out broadly and in depth by various methods and some leakage models were built. But due to the lack of the way to characterize the main factors of influence on the leakage, most of the early researches were based on the assumptions that the seal faces topography and the frictional conditions were invariant. In the early built models, the effect of the surface topography change of the seal face on the leakage rate was neglected. Based on the fractal theory, the contact of end faces of the rotary and stationary rings was simplified to be the contact of a rough surface and an ideal rigid smooth surface, and the contact interface's cavity size-distribution function as well as the fractal characteristic of the cavity profile curve was discussed. By analyzing the influence of abrasion on the seal face topography and the leakage channel, the time-correlation leakage prediction model of mechanical seals based on the fractal theory was established and the method for predicting the leakage rate of mechanical seals with parallel plane was proposed. The values of the leakage rate predicted theoretically are similar to the measured values of the leakage rate in the model test and in situ test. The experimental results indicate that the leakage rate of mechanical seals is a transient value. The surface topography of the end faces of the seal tings and its change during the frictional wear of mechanical seals can be accurately characterized by the fractal parameters. Under the work conditions of changeless frictional mechanism, the fractal parameters measured or calculated based on the accelerated testing equation can be used to predict the leakage rate of mechanical seal in service. The proposed research provides the basis for determining the leakage state and predicting working life of mechanical seal.展开更多
Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has bee...Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has been widely accepted as the most potentially useful method for seagrass restoration over large areas. We examined the influence of key environmental factors on seed germination to help promote eelgrass bed restoration. Under anoxic conditions, the influence of temperature and salinity on the germination rate of eelgrass (Zostera marina L.) seeds was examined at different combinations of four temperatures (4, 9, 14, and 24℃) and nine salinities (5 to 45, increment of 5). The effect of significant interaction of temperature and salinity on germination rate was observed (ANOVA) (P<0.001). The highest germination rate (83.3 ± 3.5)% was reached in 8 weeks at 14℃ and salinity 5. Higher temperature significantly increased the germination rate at salinity 5 (P<0.001) during the whole observation period except for 24℃, while lower salinity significantly increased the germination rate at 14℃ (P<0.001). Although significant interaction was found between temperature and salinity (P<0.001), the influence of salinity was stronger than that of temperature for the germination of eelgrass seeds. These results provide useful information for the propagation of artificial seedlings for seagrass restoration in China.展开更多
Mitogen activated protein kinases (MAPK) cascades based on protein phosphorylation play an important role in plant growth and development. In this study, we have identified 15 putative members of the wheat MAPK gene...Mitogen activated protein kinases (MAPK) cascades based on protein phosphorylation play an important role in plant growth and development. In this study, we have identified 15 putative members of the wheat MAPK gene (TaMPK) family through an in silico search of wheat expressed sequence tags (EST) databases based on the presence of amino acid sequence of Arabidopsis and rice MAPKs. Phylogenetic analyses of MAPKs from wheat, rice and Arabidopsis genomes have classified them into seven subgroups (A, B, C, D, E, F, and G). Using the available EST information as a source of expression data, the MAPK family genes from Triticum aestivum were detected in diverse tissues. Further expression analysis of the MAPKs in NCBI EST database revealed that their transcripts were most abundant in callus (20%), followed by leaf (12%) and inflorescence (12%). Most MAPK family genes showed some tissue specificity.展开更多
Effects of dietary supplementation with fructooligosaccharides on the excretion of nitrogen and phosphorus in Miichthys miiuy fries were investigated. Nine hundred Miichthys miiuy fries were divided into 3 groups, eac...Effects of dietary supplementation with fructooligosaccharides on the excretion of nitrogen and phosphorus in Miichthys miiuy fries were investigated. Nine hundred Miichthys miiuy fries were divided into 3 groups, each with triplicates. The basal diet and the basal diet supplemented with carnitine groups were considered as the negative and positive controls respectively. Results showed that the nitrogen concentration in excreted feces decreased significantly in fries fed the diet supplementation with 1000×10?6 fructooligosaccharides and 200×10?6 carnitine (P<0.05). The ammonic-nitrogen concentration decreased significantly in the carnitine group only (P<0.05), indicating the decreasing tendency caused by the supplementation with fructooligosaccha-rides. Supplementation with both did not have significant effects on the concentration of phosphorus in feces of Miichthys miiuy fries.展开更多
The effects of acetylsalicylic acid (ASA), CaCl2, and ASA + CaCl2 on the photosynthetic apparatus and antioxidant enzyme activities were investigated in chrysanthemum Jinba (a cut flower cultivar) under low tempe...The effects of acetylsalicylic acid (ASA), CaCl2, and ASA + CaCl2 on the photosynthetic apparatus and antioxidant enzyme activities were investigated in chrysanthemum Jinba (a cut flower cultivar) under low temperature stress with low light (TL stress) (16/12℃, day/night, PFD 100 μmol m^-2 s-1). The results showed that under TL stress, the net photosynthesis rate (Pn), carboxylation efficiency (CE), apparent quantum yield (AQY), maximal photochemical efficiency (Fv/Fm) of PSII, quantum yield of PSII electron transport (ФPSII), and photochemical quenching (qP) of the chrysanthemum leaves in all treatments were significantly decreased, but the decreases were alleviated by ASA, CaCl2, and ASA + CaCl2 treatments compared with the controls. The alleviating effect of ASA + CaCI2 was better than either ASA or CaCl2 single treatment. Moreover, the ASA + CaCl2 treatment highly improved the chlorophyll content, relatively improved the number and size of chloroplast and starch grain in the leaves of chrysanthemum plants compared with ASA and CaCl2 treatments. It was indicated that ASA and/or CaCI2 could regulate the photosynthetic functions in the leaves of chrysanthemum plants to enhance the resistance against TL stress. On the other hand, reduction in relative conductance rate implied that ASA and/ or CaCl2 could protect from membrane injury in leaves of chrysanthemum plants. The activities of SOD, POD, and CAT in the treated leaves of chrysanthemum were increased as compared with the controls. It was suggested that ASA and/or CaCl2 had positive regulation effects on the defence enzyme activities in chrysanthemum leaves which could protect the photosynthetic apparatus to a certain degree under the TL stress. In brief, the treatment of ASA together with CaCl2 was better for chrysanthemum plants to adapt TL stress than single ASA or CaCl2 treatments.展开更多
In this essay, we studied how heat input affected the microstructure, hardness, grain size and heat-affected zone(HAZ) dimension of WCX355 ultra-fine grain steel which was welded respectively by the ultra narrow-gap w...In this essay, we studied how heat input affected the microstructure, hardness, grain size and heat-affected zone(HAZ) dimension of WCX355 ultra-fine grain steel which was welded respectively by the ultra narrow-gap welding (UNGW) process and the overlaying process with CO 2 as protective atmosphere and laser welding process. The experimental results show when the heat input changed from 1.65 kJ/cm to 5.93 kJ/cm, the width of its HAZ ranged from 0.6 mm to 2.1 mm.The average grain size grew up from 2~5 μm of base metal to 20~70 μm and found no obvious soften phenomenon in overheated zone. The width of normalized zone was generally wide as 2/3 as that of the whole HAZ, and the grain size in this zone is smaller than that in base metal. Under the circumstance of equal heat input, the HAZ width of UNGW is narrower than that of the laser welding.展开更多
Effect of impurity phase(α-Fe phase and La-rich phase) on corrosion resistance and magnetic entropy change of LaFe_(11.3)Co_(0.4)Si_(1.3)C_(0.15) compound was studied using scanning electron microscopy, pot...Effect of impurity phase(α-Fe phase and La-rich phase) on corrosion resistance and magnetic entropy change of LaFe_(11.3)Co_(0.4)Si_(1.3)C_(0.15) compound was studied using scanning electron microscopy, potentiodynamic polarization, electrochemical impedance spectroscopy techniques and magnetism testing. With the decrease of impurity phase, the corrosion resistance of LaFe_(11.3)Co_(0.4)Si_(1.3)C_(0.15) compound was first enhanced and then slightly impaired. Corrosion resistance could be significantly improved by the decrease of α-Fe phase. However, the matrix phase was corroded if the La-rich phase as anode was too few. This caused the corrosion resistance to decrease slightly. After immersing the sample in distilled water for 15 d, -?S_(max) of the samples annealed for 3, 12 h, 3 and 7 d decreased about 50%, 41%, 16% and 17%, respectively.展开更多
基金Supported by Jilin Provincial Scientific and Technological Development Program(20230508109RC,20230201051GX,20220201091GX)National Natural Science Foundation of China(62035013,61275235)。
文摘Aqueous zinc-ion electrochromic(EC)technology,boasting the capability to fulfill both safety and cost-ef⁃fectiveness requirements,is garnering extensive attention in various application areas including smart windows,thermal management,displays,and camouflage.However,typical inorganic EC materials,such as tungsten oxides(WO_(3)),of⁃ten suffer from slow ion diffusion kinetics and limited optical contrast within the aqueous Zn^(2+)electrolyte because of the large size and strong Coulombic interactions of the Zn^(2+),which limits their wide applicability.Here,ordered WO_(3)nanowire films,constructed by a one-step grazing angle deposition method,is demonstrated to boost the response speed and optical contrast during EC phenomena.Compared with dense films,the ordered WO_(3)nanowire films with a porosity of 44.6%demonstrate anti-reflective property and excellent comprehensive EC performance,including fast response time(3.6 s and 1.2 s for coloring and bleaching,respectively),large optical contrast(66.6%at 700 nm)and high col⁃oration efficiency(64.3 cm^(2)·C^(-1)).A large-area prototype EC device(17 cm×12 cm)with fast color-switching is also successfully achieved.Mechanistic studies show that the improved performance is mainly due to the ordered porous nanowire structures,which provides direct electron transfer paths and sufficient interfacial contacts,thus simultaneously enhancing the electrochemical activity and fast redox kinetics.This study provides a simple and effective strategy to im⁃prove the performance of tungsten oxide-based aqueous zinc ion EC materials and devices.
基金supported by the projects of the National Key Research and Development Program of China(2023YFD2300202)the Natural Science Foundation of Jiangsu Province,China(BK20241543)+5 种基金the National Natural Science Foundation of China(32272213,32030076,U1803235,and 32021004)the Fundamental Research Funds for the Central Universities,China(XUEKEN2023013)the Jiangsu Innovation Support Program for International Science and Technology Cooperation Project,China(BZ2023049)the Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(22)1006)the China Agriculture Research System(CARS-03)the Jiangsu Collaborative Innovation Center for Modern Crop Production,China(JCIC-MCP)。
文摘Frequent drought events severely restrict global crop productivity,especially those occurring in the reproductive stages.Moderate drought priming during the earlier growth stages is a promising strategy for allowing plants to resist recurrent severe drought stress.However,the underlying mechanisms remain unclear.Here,we subjected wheat plants to drought priming during the vegetative growth stage and to severe drought stress at 10 days after anthesis.We then collected leaf samples at the ends of the drought priming and recovery periods,and at the end of drought stress for transcriptome sequencing in combination with phenotypic and physiological analyses.The drought-primed wheat plants maintained a lower plant temperature,with higher stomatal openness and photosynthesis,thereby resulting in much lower 1,000-grain weight and grain yield losses under the later drought stress than the non-primed plants.Interestingly,416 genes,including 27 transcription factors(e.g.,MYB,NAC,HSF),seemed to be closely related to the improved drought tolerance as indicated by the dynamic transcriptome analysis.Moreover,the candidate genes showed six temporal expression patterns and were significantly enriched in several stress response related pathways,such as plant hormone signal transduction,starch and sucrose metabolism,arginine and proline metabolism,inositol phosphate metabolism,and wax synthesis.These findings provide new insights into the physiological and molecular mechanisms of the long-term effects of early drought priming that can effectively improve drought tolerance in wheat,and may provide potential approaches for addressing the challenges of increasing abiotic stresses and securing food safety under global warming scenarios.
基金supported by the projects of the National Key Research and Development Program of China (2023YFD2300202)the National Natural Science Foundation of China (32272213 and 31771693)+1 种基金the China Agriculture Research System (CARS-03)the Jiangsu Collaborative Innovation Center for Modern Crop Production, China (JCIC-MCP)。
文摘The impacts of drought stress on crop yield and quality are substantial. Drought priming during the early growth stage of plants has been shown to improve tolerance to drought stress during the reproductive stage, although its effects on grain quality remain elusive. This study investigated the influence of drought priming on starch and protein levels in grains under drought stress during grain filling. Our results revealed that drought stress leads to a reduction in the contents of starch and its constituents, while simultaneously increasing glutenin macropolymers and protein fractions. Notably, drought primed plants under drought stress(PD) exhibited mitigated declines in the contents of starch and its components, leading to improvements in starch swelling power and pasting properties. In addition, PD resulted in a slight increase in the protein fractions, limiting the overall rise in total protein content compared to drought stress alone. The results of our study underscore the efficacy of drought priming as a strategy to counteract the negative effects of drought stress on grain quality, particularly by minimizing starch losses and restraining protein content elevation.
基金innovation consortium project of China Petroleum and Southwest Petroleum University(No.2020CX010201)Sichuan Science and Technology Program(No.2024NSFSC0081)。
文摘With the continued expansion of oil and gas exploration,both in the eastern and western regions,the quality of seismic acquisition has become a key factor in oil and gas exploration in complex areas.However,conventional seismic acquisition methods cannot efficiently avoid challenging acquisition locations and produce high-quality seismic data.In this regard,based on the curvelet transform,this paper proposes an irregular seismic acquisition method,which utilizes the high-precision characteristics of the curvelet transform and simulated annealing algorithm to establish a method for the evaluation of the coherence of irregular sampling matrices and design of observation systems.The method was verified using forward simulation and actual acquisition data.The results suggest the superior quality of seismic data gathered in complicated areas through this method over those acquired using traditional methods,which can provide technical guidance for the design of observation systems in complex areas.
基金supported by the National Natural Science Foundation of China(32230074,32125030,32161143004)the Pinduoduo-China Agricultural University Research Fund(PC2023A01003)the Natural Science Foundation of Jiangsu Province(BK20220567).
文摘Staple crops such as rice,wheat,and maize are crucial for global food security;however,improving their quality remains a significant challenge.This review summarizes recent advances in enhancing crop quality,focusing on key areas such as the molecular mechanisms underlying endosperm filling initiation,starch granule synthesis,protein body formation,and the interactions between carbon and nitrogen metabolism.It also highlights ten unresolved questions related to starch-protein spatial distribution,epigenetic regulation,and the environmental impacts on quality traits.The integration of multi-omics approaches and rational design strategies presents opportunities to develop high-yield“super-crop”varieties with enhanced nutritional value,better processing characteristics,and attributes preferred by consumers.Addressing these challenges is crucial to promote sustainable agriculture and achieve the dual objectives of food security and environmental conservation.
基金Supported by National Natural Science Foundation of China(Grant Nos.51275366,50875190,51305311)Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20134219110002)
文摘Due to the NP-hardness of the two-sided assembly line balancing (TALB) problem, multiple constraints existing in real applications are less studied, especially when one task is involved with several constraints. In this paper, an effective hybrid algorithm is proposed to address the TALB problem with multiple constraints (TALB-MC). Considering the discrete attribute of TALB-MC and the continuous attribute of the standard teaching-learning-based optimization (TLBO) algorithm, the random-keys method is hired in task permutation representation, for the purpose of bridging the gap between them. Subsequently, a special mechanism for handling multiple constraints is developed. In the mechanism, the directions constraint of each task is ensured by the direction check and adjustment. The zoning constraints and the synchronism constraints are satisfied by teasing out the hidden correlations among constraints. The positional constraint is allowed to be violated to some extent in decoding and punished in cost fimction. Finally, with the TLBO seeking for the global optimum, the variable neighborhood search (VNS) is further hybridized to extend the local search space. The experimental results show that the proposed hybrid algorithm outperforms the late acceptance hill-climbing algorithm (LAHC) for TALB-MC in most cases, especially for large-size problems with multiple constraints, and demonstrates well balance between the exploration and the exploitation. This research proposes an effective and efficient algorithm for solving TALB-MC problem by hybridizing the TLBO and VNS.
基金supported and financed by the National Basic Research Program of China(973 Program,2010CB951504)the National Natural Science Foundation of China(41201089 and 41271112)
文摘Rice is one of the most important grain crops in Northeast China (NEC) and its cultivation is sensitive to climate change. This study aimed to explore the spatio-temporal changes in the NEC rice planting area over the period of 1980-2010 and to analyze their relationship to climate change. To do so, the CLUE-S (conversion of land use and its effects at small region extent) model was ifrst updated and used to simulate dynamic changes in the rice planting area in NEC to understand spatio-temporal change trends during three periods: 1980-1990, 1990-2000 and 2000-2010. The changing results in individual periods were then linked to climatic variables to investigate the climatic drivers of these changes. Results showed that the NEC rice planting area expanded quickly and increased by nearly 4.5 times during 1980-2010. The concentration of newly planted rice areas in NEC constantly moved northward and the changes were strongly dependent on latitude. This conifrmed that climate change, increases in temperature in particular, greatly inlfuenced the shift in the rice planting area. The shift in the north limit of the NEC rice planting area generally followed a 1&#176;C isoline migration pattern, but with an obvious time-lag effect. These ifndings can help policy makers and crop producers take proper adaptation measures even when exposed to the global warming situation in NEC.
基金supported by the Pre-research Foundation of CPLA General Equipment Department
文摘Testing-effort(TE) and imperfect debugging(ID) in the reliability modeling process may further improve the fitting and prediction results of software reliability growth models(SRGMs). For describing the S-shaped varying trend of TE increasing rate more accurately, first, two S-shaped testing-effort functions(TEFs), i.e.,delayed S-shaped TEF(DS-TEF) and inflected S-shaped TEF(IS-TEF), are proposed. Then these two TEFs are incorporated into various types(exponential-type, delayed S-shaped and inflected S-shaped) of non-homogeneous Poisson process(NHPP)SRGMs with two forms of ID respectively for obtaining a series of new NHPP SRGMs which consider S-shaped TEFs as well as ID. Finally these new SRGMs and several comparison NHPP SRGMs are applied into four real failure data-sets respectively for investigating the fitting and prediction power of these new SRGMs.The experimental results show that:(i) the proposed IS-TEF is more suitable and flexible for describing the consumption of TE than the previous TEFs;(ii) incorporating TEFs into the inflected S-shaped NHPP SRGM may be more effective and appropriate compared with the exponential-type and the delayed S-shaped NHPP SRGMs;(iii) the inflected S-shaped NHPP SRGM considering both IS-TEF and ID yields the most accurate fitting and prediction results than the other comparison NHPP SRGMs.
基金Item Sponsored by National Natural Science Foundation of China (50671061) National Engineering and Research Center of Advanced Steel Technology , Ansteel Company and China-Belgium Bilateral Project (2001-242)
文摘A new type of transformation induced plasticity (TRIP) steel with not only high strength and high ductility but also superior welding and galvanizing properties was designed and developed recently. Low carbon and low silicon content were preliminarily selected with the aim of meeting the requirements of superior quality in both welding and galvanizing. Phosphorus was chosen as one of the alloying elements, because it could reduce carbon activity in cementite and increase the stability of austenite. In addition, the possibility of phosphorus segregating at grain boundary was also discussed by thermodynamics as well as kinetics. Phase diagram was estimated at high temperature and the composition of the steel was then selected in the hyperperitectic range to avoid problems, which might occur in sheet steel continuous casting. Phase diagram in the inter.critical temperature was estimated for the steel to obtain the starting temperature of fast cooling. For understanding the minimum rate of fast cooling, pearlite growth kinetics was calculated with self-developed diffusion coefficients of elements in grain boundary. Overaging temperature was determined through the calculation of To temperature by both equilibrium and para-equilibrium assumptions, which was different from the current determination, which is only based on an equilibrium estimation.
基金Projects Y2007F46 supported by the Natural Science Foundation of Shandong Province20070424005 by the Doctor Disciplines Special Scientific Researc Foundation of the Ministry of Education+1 种基金108158 by the Key Project of the Ministry of Education of China50539080 by the National Natural Scienc Foundation of China
文摘The mechanism of mine water inrushes in coal mines in China differs considerably from that in other countries.In China, most water inrushes occur from floor strata, where the water-inrush sources are karstic limestone aquifers.Our study describes the mechanism of mine water inrushes through a fault in the mine floor using principles of strata mechanics and the path of water inrush from an aquifer to the working face.A criterion to judge whether a ground water inrush will occur through a fault or not is also described, together with a case history of water inflow in the Feicheng coalfield, China.
基金financed by the National Basic Research Program of China(2010CB951504)the National Natural Science Foundation of China(41271112 and 40930101)the National Nonprofit Institute Research Grant of CAAS(IARRP-2014-16)
文摘Although climate change impacts and agricultural adaptations have been studied extensively, how smallholder farmers perceive climate change and adapt their agricultural activities is poorly understood. Survey-based data (presents farmers' personal perceptions and adaptations to climate change) associated with external biophysical-socioeconomic data (presents real-world climate change) were used to develop a farmer-centered framework to explore climate change impacts and agricultural adaptations at a local level. A case study at Bin County (1980s-2010s), Northeast China, suggested that increased annual average temperature (0.6&#176;C per decade) and decreased annual precipitation (46 mm per decade, both from meteorological datasets) were correctly perceived by 76 and 66.9%, respectively, of farmers from the survey, and that a longer growing season was conifrmed by 70%of them. These reasonably correct perceptions enabled local farmers to make appropriate adaptations to cope with climate change:Longer season alternative varieties were found for maize and rice, which led to a signiifcant yield increase for both crops. The longer season also affected crop choice:More farmers selected maize instead of soybean, as implicated from survey results by a large increase in the maize growing area. Comparing warming-related factors, we found that precipitation and agricultural disasters were the least likely causes for farmers' agricultural decisions. As a result, crop and variety selection, rather than disaster prevention and infrastructure improvement, was the most common ways for farmers to adapt to the notable warming trend in the study region.
基金supported by the National Key Research and Development Program of China(2016YFD0300107)the National Natural Science Foundation of China(31771693,U1803235)+3 种基金the Fundamental Research Funds for the Central Universities(KYZ201807)the China Agricultural Research System(CARS-03)the Jiangsu Collaborative Innovation Center for Modern Crop Production(JCIC-MCP)the 111 Project(B16026)。
文摘Drought stress is a limiting factor for wheat production and food security.Drought priming has been shown to increase drought tolerance in wheat.However,the underlying mechanisms are unknown.In the present study,the genes encoding the biosynthesis and metabolism of abscisic acid(ABA)and jasmonic acid(JA),as well as genes involved in the ABA and JA signaling pathways were up-regulated by drought priming.Endogenous concentrations of JA and ABA increased following drought priming.The interplay between JA and ABA in plant responses to drought priming was further investigated using inhibitors of ABA and JA biosynthesis.Application of fluridone(FLU)or nordihydroguaiaretic acid(NDGA)to primed plants resulted in lower chlorophyll-fluorescence parameters and activities of superoxide dismutase and glutathione reductase,and higher cell membrane damage,compared to primed plants(PD)under drought stress.NDGA+ABA,but not FLU+JA,restored priming-induced tolerance,as indicated by a finding of no significant difference from PD under drought stress.Under drought priming,NDGA induced the suppression of ABA accumulation,while FLU did not affect JA accumulation.These results were consistent with the expression of genes involved in the biosynthesis of ABA and JA.They suggest that ABA and JA are required for priming-induced drought tolerance in wheat,with JA acting upstream of ABA.
基金National Science and Technology Major Projects “Major New Drugs Innovation and Development”(Grant No.2018ZX09201019-002-009)
文摘Quercetin(QUE)has many beneficial biological activities and pharmacological actions in vitro.However,its oral bioavailability in vivo was very poor due to poor solubility,and severely restricted its clinical applications.In this study,we prepared quercetin solid dispersion(QUE-SD)and quercetin phospholipids complex solid dispersion(QUE-PC-SD)by a solvent evaporation method to improve the absorption of QUE in vivo.The results of XRD of QUE-SD and QUE-PC-SD showed that QUE was dispersed homogeneously in an amorphous or molecular state in QUE-SD and QUE-PC-SD,which could contribute to improve the solubility and dissolution of QUE.The solubility of QUE-SD and QUE-PC-SD was enhanced from(4.03±0.02)μg/mL to(26.91=1=0.06)μg/mL and(30.65±0.06)μg/mL,respectively.The solubility of QUE-PC-SD was higher than that of QUE-SD.In vitro dissolution study,it was showed that the maximum dissolution of QUE(9.57%)from the QUE-SD and QUE-PC-SD was enhanced to 93.81%and 94.16%,respectively.The results of pharmacokinetic experiment indicated that the QUE-SD and QUE-PC-SD exhibited considerable enhancement in the oral bioavailability.The relative bioavailability of QUE-SD and QUE-PC-SD compared with QUE were 149.49%and 198.32%,respectively.In addition,the relative bioavailability of QUE-PC-SD was also higher than that of QUE-SD.Therefore,in regard to drugs with poor solubility and low permeation,an active constituent-PC-SD system could result to a better absorption and higher bioavailability.
基金supported by China Postdoctoral Science Foundation (Grant No. 20070410323)Jiangsu Provincial Planned Projects for Postdoctoral Research Funds of China (Grant No. 0701001C)Jiangsu Provincial Planned Projects for Fostering Talents of Six Scientific Fields of China (Grant No. 07-D-027)
文摘Since the beginning of the 20th century, many researches on the sealing characteristic of mechanical seals were carried out broadly and in depth by various methods and some leakage models were built. But due to the lack of the way to characterize the main factors of influence on the leakage, most of the early researches were based on the assumptions that the seal faces topography and the frictional conditions were invariant. In the early built models, the effect of the surface topography change of the seal face on the leakage rate was neglected. Based on the fractal theory, the contact of end faces of the rotary and stationary rings was simplified to be the contact of a rough surface and an ideal rigid smooth surface, and the contact interface's cavity size-distribution function as well as the fractal characteristic of the cavity profile curve was discussed. By analyzing the influence of abrasion on the seal face topography and the leakage channel, the time-correlation leakage prediction model of mechanical seals based on the fractal theory was established and the method for predicting the leakage rate of mechanical seals with parallel plane was proposed. The values of the leakage rate predicted theoretically are similar to the measured values of the leakage rate in the model test and in situ test. The experimental results indicate that the leakage rate of mechanical seals is a transient value. The surface topography of the end faces of the seal tings and its change during the frictional wear of mechanical seals can be accurately characterized by the fractal parameters. Under the work conditions of changeless frictional mechanism, the fractal parameters measured or calculated based on the accelerated testing equation can be used to predict the leakage rate of mechanical seal in service. The proposed research provides the basis for determining the leakage state and predicting working life of mechanical seal.
基金supported by a Municipal Research and Developmental Program of Science and Technology of Yantai, Shandong Province, China (Grant No. 2009211)an Open Foundation of the State Oce-anic Administration of China (Grant No. 200905020-12)
文摘Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has been widely accepted as the most potentially useful method for seagrass restoration over large areas. We examined the influence of key environmental factors on seed germination to help promote eelgrass bed restoration. Under anoxic conditions, the influence of temperature and salinity on the germination rate of eelgrass (Zostera marina L.) seeds was examined at different combinations of four temperatures (4, 9, 14, and 24℃) and nine salinities (5 to 45, increment of 5). The effect of significant interaction of temperature and salinity on germination rate was observed (ANOVA) (P<0.001). The highest germination rate (83.3 ± 3.5)% was reached in 8 weeks at 14℃ and salinity 5. Higher temperature significantly increased the germination rate at salinity 5 (P<0.001) during the whole observation period except for 24℃, while lower salinity significantly increased the germination rate at 14℃ (P<0.001). Although significant interaction was found between temperature and salinity (P<0.001), the influence of salinity was stronger than that of temperature for the germination of eelgrass seeds. These results provide useful information for the propagation of artificial seedlings for seagrass restoration in China.
基金supported by the Genetically Modified Organisms Breeding Major Projects, China (2008ZX08002-002, 2008ZX08002-003, 2008ZX08002-004)the Beijing Technical Nova Project, China (2007B056, 2008B035)+2 种基金the Excellence Scholar Fostered Program of Beijing Government,China (20081D0200500050)the Beijing Natural Science Foundation of China (5102016)Young Foundation Project of Beijing Academy of Agriculture and Forestry Scientific Research, China
文摘Mitogen activated protein kinases (MAPK) cascades based on protein phosphorylation play an important role in plant growth and development. In this study, we have identified 15 putative members of the wheat MAPK gene (TaMPK) family through an in silico search of wheat expressed sequence tags (EST) databases based on the presence of amino acid sequence of Arabidopsis and rice MAPKs. Phylogenetic analyses of MAPKs from wheat, rice and Arabidopsis genomes have classified them into seven subgroups (A, B, C, D, E, F, and G). Using the available EST information as a source of expression data, the MAPK family genes from Triticum aestivum were detected in diverse tissues. Further expression analysis of the MAPKs in NCBI EST database revealed that their transcripts were most abundant in callus (20%), followed by leaf (12%) and inflorescence (12%). Most MAPK family genes showed some tissue specificity.
基金Project supported by Public Bidding Item in Key Research of ZhejiangProvince (No. 02110281-2)Ningbo Tackle Key Problem forAgricultural Development (No. 2004C-100030), China
文摘Effects of dietary supplementation with fructooligosaccharides on the excretion of nitrogen and phosphorus in Miichthys miiuy fries were investigated. Nine hundred Miichthys miiuy fries were divided into 3 groups, each with triplicates. The basal diet and the basal diet supplemented with carnitine groups were considered as the negative and positive controls respectively. Results showed that the nitrogen concentration in excreted feces decreased significantly in fries fed the diet supplementation with 1000×10?6 fructooligosaccharides and 200×10?6 carnitine (P<0.05). The ammonic-nitrogen concentration decreased significantly in the carnitine group only (P<0.05), indicating the decreasing tendency caused by the supplementation with fructooligosaccha-rides. Supplementation with both did not have significant effects on the concentration of phosphorus in feces of Miichthys miiuy fries.
基金supported by the National Key Tech-nologies R&D Program of China during the 11th Five-Year-Plan period (2006BAD10B07)the Project for Returned Overseas Atudents to Start Research from Ministry of Education,China (33206)
文摘The effects of acetylsalicylic acid (ASA), CaCl2, and ASA + CaCl2 on the photosynthetic apparatus and antioxidant enzyme activities were investigated in chrysanthemum Jinba (a cut flower cultivar) under low temperature stress with low light (TL stress) (16/12℃, day/night, PFD 100 μmol m^-2 s-1). The results showed that under TL stress, the net photosynthesis rate (Pn), carboxylation efficiency (CE), apparent quantum yield (AQY), maximal photochemical efficiency (Fv/Fm) of PSII, quantum yield of PSII electron transport (ФPSII), and photochemical quenching (qP) of the chrysanthemum leaves in all treatments were significantly decreased, but the decreases were alleviated by ASA, CaCl2, and ASA + CaCl2 treatments compared with the controls. The alleviating effect of ASA + CaCI2 was better than either ASA or CaCl2 single treatment. Moreover, the ASA + CaCl2 treatment highly improved the chlorophyll content, relatively improved the number and size of chloroplast and starch grain in the leaves of chrysanthemum plants compared with ASA and CaCl2 treatments. It was indicated that ASA and/or CaCI2 could regulate the photosynthetic functions in the leaves of chrysanthemum plants to enhance the resistance against TL stress. On the other hand, reduction in relative conductance rate implied that ASA and/ or CaCl2 could protect from membrane injury in leaves of chrysanthemum plants. The activities of SOD, POD, and CAT in the treated leaves of chrysanthemum were increased as compared with the controls. It was suggested that ASA and/or CaCl2 had positive regulation effects on the defence enzyme activities in chrysanthemum leaves which could protect the photosynthetic apparatus to a certain degree under the TL stress. In brief, the treatment of ASA together with CaCl2 was better for chrysanthemum plants to adapt TL stress than single ASA or CaCl2 treatments.
文摘In this essay, we studied how heat input affected the microstructure, hardness, grain size and heat-affected zone(HAZ) dimension of WCX355 ultra-fine grain steel which was welded respectively by the ultra narrow-gap welding (UNGW) process and the overlaying process with CO 2 as protective atmosphere and laser welding process. The experimental results show when the heat input changed from 1.65 kJ/cm to 5.93 kJ/cm, the width of its HAZ ranged from 0.6 mm to 2.1 mm.The average grain size grew up from 2~5 μm of base metal to 20~70 μm and found no obvious soften phenomenon in overheated zone. The width of normalized zone was generally wide as 2/3 as that of the whole HAZ, and the grain size in this zone is smaller than that in base metal. Under the circumstance of equal heat input, the HAZ width of UNGW is narrower than that of the laser welding.
基金supported by the National Natural Science Foundation of China(51571018,51371026)the National High Technology Research and Development Program of China(2011AA03A404)
文摘Effect of impurity phase(α-Fe phase and La-rich phase) on corrosion resistance and magnetic entropy change of LaFe_(11.3)Co_(0.4)Si_(1.3)C_(0.15) compound was studied using scanning electron microscopy, potentiodynamic polarization, electrochemical impedance spectroscopy techniques and magnetism testing. With the decrease of impurity phase, the corrosion resistance of LaFe_(11.3)Co_(0.4)Si_(1.3)C_(0.15) compound was first enhanced and then slightly impaired. Corrosion resistance could be significantly improved by the decrease of α-Fe phase. However, the matrix phase was corroded if the La-rich phase as anode was too few. This caused the corrosion resistance to decrease slightly. After immersing the sample in distilled water for 15 d, -?S_(max) of the samples annealed for 3, 12 h, 3 and 7 d decreased about 50%, 41%, 16% and 17%, respectively.