Seed germination with selenium(Se)is promising for producing Se-biofortified foods.Mungbean(Vigna radiata(L.)Wilczek)sprout is freshly eaten as a salad dressed with sauce,making it superior for Se biofortification.Since...Seed germination with selenium(Se)is promising for producing Se-biofortified foods.Mungbean(Vigna radiata(L.)Wilczek)sprout is freshly eaten as a salad dressed with sauce,making it superior for Se biofortification.Since the Se safety range for the human body is extremely narrow,it is imperative to evaluate the genotypic responses of mungbean sprouts to Se.This study evaluated the Se enrichment capacity and interaction withflavonoids and antioxidant systems in sprouts of 20 mungbean germplasms.Selenium treatment was done by immersing mung-bean seeds in 20μM sodium selenite solution for 8 h.Afterward,the biomass,Se amounts,flavonoid(particularly vitexin and isovitexin)contents,antioxidant capacity,and key biosynthetic gene expressions were measured.Sprout Se content was 2.0-7.0μg g^(-1) DW among the 20 mungbean germplasms.Selenium treatment differentially affected the biomass,totalflavonoid,vitexin,isovitexin,antioxidant enzyme activities,and antioxidant capacities of the mungbean germplasms.Eight germplasms showed increased biomass(p<0.05),the highest increasing by 127%,but 13 did not phenotypically respond to Se treatment.Seven and six germplasms showed varied levels of vitexin and isovitexin increment after Se treatment,the highest measuring 2.67-and 2.87-folds for vitexin and isovitexin,respectively.Two mungbeanflavonoid biosynthesis genes,chalcone synthase(VrCHS)and chalcone isomerase(VrCHI)were significantly up-regulated in the germplasms with increased vitexin and isovitexin levels(p<0.05).Moreover,Se enrichment capacity was significantly correlated with the vitexin,isovitexin,and antiox-idant capacities.In conclusion,mungbean sprouts could be a useful Se-biofortified food,but the Se enrichment capacity and nutritional response must be determined for each germplasm before commercialization.展开更多
Due to the uneven seabed and heaving of soil during pumping,incomplete soil plugs may occur during the installation of bucket foundations,and the impacts on the bearing capacities of bucket foundations need to be eval...Due to the uneven seabed and heaving of soil during pumping,incomplete soil plugs may occur during the installation of bucket foundations,and the impacts on the bearing capacities of bucket foundations need to be evaluated.In this paper,the contact ratio(the ratio of the top diameter of the soil plug to the diameter of the bucket)and the soil plug ratio(the ratio of the soil heave height to the skirt height)are defined to describe the shape and size of the incomplete soil plug.Then,finite element models are established to investigate the bearing capacities of bucket foundations with incomplete soil plugs and the influences of the contact ratios,and the soil plug ratios on the bearing capacities are analyzed.The results show that the vertical bearing capacity of bucket foundations in homogeneous soil continuously improves with the increase of the contact ratio.However,in normally consolidated soil,the vertical bearing capacity barely changes when the contact ratio is smaller than 0.75,while the bearing capacity suddenly increases when the contact ratio increases to 1 due to the change of failure mode.The contact ratio hardly affects the horizontal bearing capacity of bucket foundations.Moreover,the moment bearing capacity improves with the increase of the contact ratio for small aspect ratios,but hardly varies with increasing contact ratio for aspect ratios larger than 0.5.Consequently,the reduction coefficient method is proposed based on this analysis to calculate the bearing capacities of bucket foundations considering the influence of incomplete soil plugs.The comparison results show that the proposed reduction coefficient method can be used to evaluate the influences of incomplete soil plug on the bearing capacities of bucket foundations.展开更多
The transformation of LPSO type in Mg-4Y-2Er-2Zn-0.6Zr during heat treatment and its influence on damping and mechanical properties are reported in this work.Prior to heat treatment,the alloy consisted of a-Mg matrix ...The transformation of LPSO type in Mg-4Y-2Er-2Zn-0.6Zr during heat treatment and its influence on damping and mechanical properties are reported in this work.Prior to heat treatment,the alloy consisted of a-Mg matrix and lamellar 14H LPSO phases.After 510℃heat treatment,lamellae shortened,and their content decreased.Upon 8h heat treatment,block 18R LPSO phases formed at the grain boundaries while 14H LPSO lamellae disappeared.Presence of block 18R LPSO phases improved mechanical and damping properties of the alloy.The corresponding mechanisms of the influence of LPSO type and morphology on mechanical and damping capacities are discussed.展开更多
Magnesium(Mg)alloys,as the lightest metal structural material with good damping capacities,have im-portant application prospects in realizing structural lightweight and vibration reduction.However,their engineering ap...Magnesium(Mg)alloys,as the lightest metal structural material with good damping capacities,have im-portant application prospects in realizing structural lightweight and vibration reduction.However,their engineering application is greatly limited by poor plastic formability.Wire and arc additive manufactur-ing(WAAM)provides a potential approach for fabricating large-scale Mg alloy components with high manufacturing flexibility.In this study,the evolution of the solidification microstructure of a WAAM-processed Mg-Al-based alloy was quantitatively analyzed based on the analytical models;then,the cor-relations between the solidification microstructure and mechanical properties/damping capacities were investigated.The results revealed that the WAAM-processed Mg-Al-based alloy with an equiaxed-grain-dominated microstructure displayed a simultaneous enhancement in mechanical properties and damping capacities compared to those of the cast Mg-Al-based alloy.The good combination of mechanical prop-erties and damping capacities are mainly attributed to the weakened basal texture with a relatively high Schmid factor for basalslip,the twinning-induced plasticity(TWIP)effect associated with the profuse{10-12}tensile twinning,and the relatively high dislocation density caused by the thermal stress during the WAAM process.展开更多
Three cooking methods,namely boiling,steaming,and stir-frying for 5 to 10 min,were used to evaluate the effect on nutrient components,free amino acids,L-ascorbic acid,total phenolic contents,and antioxidant capacities...Three cooking methods,namely boiling,steaming,and stir-frying for 5 to 10 min,were used to evaluate the effect on nutrient components,free amino acids,L-ascorbic acid,total phenolic contents,and antioxidant capacities of bamboo shoots(Phyllostachys praecox).Results showed that boiling and stir-frying had a great effect on the nutrient components and they decreased the contents of protein,soluble sugar,and ash,and caused a great loss in the total free amino acids(decreased by 38.35% and 34.86%,respectively).Significant differences(P<0.05) in free amino acids were observed in the samples cooked by different methods.Stir-fried bamboo shoots had a high fat content which increased by 528.57% because of the addition of edible oil.After boiling,the L-ascorbic acid and total phenolic contents were significantly reduced,while steaming increased total phenolic content by 3.98% and stir-frying well-preserved L-ascorbic acid(78.87% of its previous content).Results of the antioxidative property study showed that stir-frying could increase antioxidant capacities of bamboo shoots.It is concluded that stir-frying is more suitable for bamboo shoots because it could obtain the maximum retention of antioxidant capacities.展开更多
Equal channel angular extrusion (ECAE) was applied to commercial pure magnesium and AZ91D alloy. Microstructures of these magnesium alloys before and after ECAE process were observed by optical microscopy (OM). The ul...Equal channel angular extrusion (ECAE) was applied to commercial pure magnesium and AZ91D alloy. Microstructures of these magnesium alloys before and after ECAE process were observed by optical microscopy (OM). The ultimate tensile strength of pure magnesium and AZ91D alloy processed by ECAE is about 130 and 260MPa, respectively, and it is much higher than that of the as cast alloys. The elongation of them is increased from about 2% to 8%. The strain amplitude dependence damping capacities of these magnesium alloys were investigated by dynamic mechanical analyzer (DMA). ECAE process largely decreases the damping capacities of pure magnesium from 0.033 to about 0.012 (ε=1×10 -4), but does not show obvious influence on that of AZ91D alloy, which is about 0.0015.展开更多
An overview of a long-gap peripheral nerve therapy： A long- gap peripheral nerve transection injury is an irreparable injury to the living body, and mostly leads to permanent loss of re- lated motor and sensory funct...An overview of a long-gap peripheral nerve therapy： A long- gap peripheral nerve transection injury is an irreparable injury to the living body, and mostly leads to permanent loss of re- lated motor and sensory functions. In such long gap injuries, nerve end-to-end suture is physically impossible. Therefore, bridging a long nerve-gap is critical to re-establish adequate mechanical support for separated nerve ends, and prevent the diffusion of neurotrophic and neurotropic factors secreted by transected stumps （Deumens et al., 2010）.展开更多
In order to investigate the chemical-biological relationship caused by the special processing technology,the constituent＇s content and antioxidant capacity in vivo of Euphorbia fischeriana Steud processing Terminalia...In order to investigate the chemical-biological relationship caused by the special processing technology,the constituent＇s content and antioxidant capacity in vivo of Euphorbia fischeriana Steud processing Terminalia chebula Retz. have been tested. Taking T. chebula Retz. as control,the content of gallic acid is analyzed with high performance liquid chromatography（HPLC） method. The results show that the increase of gallic acid concentration from 4.54% to 7.46% leads to enhancement of the antioxidant capacities in vivo of the E. fischeriana Steud processing T. chebula Retz. The significant antioxidant capacity in vivo（p〈0.05） of the processed product possesses is better than the unprocessed herb. Its superoxide dismutase（SOD）and malondia-ldehyde（MDA） contents in serum,the MDA content in liver can match the effects of vitamine E when administered at high dosage.展开更多
For the development process in the rapidly growing economies, knowledge transfer and technology cooperation are becoming important issues. Research and technological competences are key indicators for the absorptive c...For the development process in the rapidly growing economies, knowledge transfer and technology cooperation are becoming important issues. Research and technological competences are key indicators for the absorptive capacity of sustainability technologies and for the ability to export them. These issues are analyzed empirically for Brazil, Russia, India, China and South Africa (BRICS). Sustainability related research in BRICS is mostly carried out within broader, more sector oriented programmes. Specialization patterns of international patents and in foreign trade indicate various strengths and weaknesses of the BRICS countries. The differences within the countries imply that the analysis must proceed at a technology specific level. China has considerable capabilities in technologies such as photovoltaics, solar thermal or buildings. There is a strong need for strategic positioning of the countries and for coordination of the various policy fields involved.展开更多
The amplitude-dependent and temperature-dependent low frequency damping capacities of magnesium with 99.96% purity were studied by a dynamic mechanical analyzer. The pure magnesium alloys include CPM1 and CPM2 casting...The amplitude-dependent and temperature-dependent low frequency damping capacities of magnesium with 99.96% purity were studied by a dynamic mechanical analyzer. The pure magnesium alloys include CPM1 and CPM2 castings having textures of columnar grains which extraordinarily influence the damping behaviours. The commercial pure magnesium alloy CPM was re-melted to obtain equiaxed grains, which could remove the effect of texture orientation on the damping behaviours of these pure magnesium alloys. The results of strain amplitude-dependent damping spectrums of these pure magnesium alloys show that the pure magnesium with equiaxed grains possesses the highest damping capacity. In temperature-dependent damping plot for all these three pure magnesium alloys, there are two damping peaks P1 and P2 located at 80 and 230 °C, respectively. These two damping peaks are considered to be caused by the interaction between dislocation and point defects, and the movement of grain boundaries, respectively.展开更多
Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temper...Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temperature range,the heat capacities increased in a smooth and continuous manner and no phase transition or thermal anomaly occurred.Therefore,the sample was stable in the above temperature range.The values of experimental heat capacities were fitted to a polynomial equation with least square method and ...展开更多
The changes of capacities of positive and negative electrodes, reserve capacities of charging and discharging, and the weight of batteries during cycling have been determined. The increase of the discharging reserve c...The changes of capacities of positive and negative electrodes, reserve capacities of charging and discharging, and the weight of batteries during cycling have been determined. The increase of the discharging reserve capacity due to the conjugated electrochemical reactions of the oxidation of hydrogen storage alloy is estimated. The results show that the failure mode of Ni/MH batteries developed is as follows: during the increase of cycles, the hydrogen storage alloy is oxidized continuously and the charging reserve capacity is decreased rapidly while the discharging reserve capacity is increased gradually, thus the internal pressure is increasing, first H 2 leaks out from the battery, then the mixture of H 2 and O 2. The leakage of gases and the total reaction of oxidation of the alloy consume H 2O, and the surface oxides on the alloy increase, so that the internal resistance of the battery increases.展开更多
Based on the analysis of completeness and finiteness of HF molecular vibrational levels, HF systemic vibrational heat capacity is studied with quantum statistical and full set of vibrational energy level determined AM...Based on the analysis of completeness and finiteness of HF molecular vibrational levels, HF systemic vibrational heat capacity is studied with quantum statistical and full set of vibrational energy level determined AM (algebraic method). The results show that correct vibrational description and vibrational energy level set of HF system are key factors in calculating heat capacity, HF heat capacity data determined by AM energy spectra {Eυ} are much superior to the ones of harmonic oscillator model, AM results are agreement with experiment data.展开更多
A 56-day feeding trial was performed to evaluate the effects of dietary probiotic Clostridium butyricum(CB) on intestine digestive and metabolic capacities, intestine short-chain fatty acids(SCFA) content and body com...A 56-day feeding trial was performed to evaluate the effects of dietary probiotic Clostridium butyricum(CB) on intestine digestive and metabolic capacities, intestine short-chain fatty acids(SCFA) content and body composition of kuruma shrimp Marsupenaeus japonicus. Shrimp s were randomly allocated into 9 tanks, 30 each, and f ed with diets containing different levels of C. butyricum(1×10~9 cfug^(-1)): 0 mgg^(-1) feed(Control), 100 mgg^(-1) feed(CB-100), 200 mgg^(-1) feed(CB-200), while each level was triplicated. The results indicated that compared with the control group, the intestine pepsin(Pep) activity and 5-hydroxytryptamine(5-HT) concentration of two C. butyricum group s were both increased. Amylase(AM Y) and lipase(LPS) activities wer e only induced in CB-200 group. Alanine aminotransferase(ALT) and aspartate aminotransferase(A ST) activities of two C. butyricum group s showed no significant change. The α-amylase(AM Y) gene expression was induced in CB-200 group, and tryp sin gene expression of two C. butyricum treated group s were both induced. Intestine SCFA content and body composition analysis showed that the contents of propionic acid, butyric acid and the crude protein of two C. butyricum group s were all higher than those of control. These results revealed that C. butyricum can modulate intestine digestive and metabolic capacities, improve intestine SCFA content and body crude protein content in M. japonicus.展开更多
We investigated the structural behavior and bearing capacity of system scaffolds.The research showed that the critical load of a system scaffold structure without diagonal braces is similar to that of a door-shaped st...We investigated the structural behavior and bearing capacity of system scaffolds.The research showed that the critical load of a system scaffold structure without diagonal braces is similar to that of a door-shaped steel scaffold structure.Joint stiffness between vertical props in system scaffolds can be defined based on a comparison between analytical and experimental results.When the number of scaffold stories increases,the critical loads of system scaffolds decrease.Diagonal braces markedly enhance the critical load of system scaffolds.The coupling joint position between vertical props should be kept away from story-to-story joints to prevent a reduction in critical loads.The critical load of a system scaffold decreases as the quantity of extended vertical props at the bottom of the structure increases.A large Christmas tree set up by system scaffolds under various loads was used as an example for analysis and to check the design of system scaffolds.展开更多
CeO2-ZrO2-Al2O3 ternary oxides were successfully prepared by a green route of supercritical anti-solvent precipitation with supercritical CO2 as anti-solvent and methanol as solvent. The structures and oxygen storage ...CeO2-ZrO2-Al2O3 ternary oxides were successfully prepared by a green route of supercritical anti-solvent precipitation with supercritical CO2 as anti-solvent and methanol as solvent. The structures and oxygen storage capacities of these ternary oxides were characterized by XRD, Raman spectra and oxygen storage capacity measurements. It was found that Al3＋ and Zr4＋ inserted into CeO2 lattice, forming CeO2-ZrO2-Al2O3 solid solution. The concentration of aluminium isopropoxide in the solution affected the concentration of oxygen vacancy and the distortion of oxygen sublattice which were responsible for the oxygen storage capacity. The rapidest oxygen uptake/release rate and maximum total oxygen storage capacity （122.0 mmolO2/molCeO2） were obtained with the aluminitun isopropoxide concentration at 0.2 wt.% in the solution.展开更多
To study the influence of B4C particle size on the microstructure and damping capacities of(B_(4)C+Ti)/Mg composites,in situ reactive infiltration technique was utilized to prepare Mg-matrix composites.The microstruct...To study the influence of B4C particle size on the microstructure and damping capacities of(B_(4)C+Ti)/Mg composites,in situ reactive infiltration technique was utilized to prepare Mg-matrix composites.The microstructure,produced phases and damping capacities of the composites prepared with different particle size of B4C were characterized and analyzed.The results show that the reaction between B4C and Ti tends to be more complete when finer B_(4)C particle was used to prepare the composites.But the microstructure of the as-prepared composites is more homogenous when B4C and Ti have similar particle size.The strain-dependent damping capacities of(B_(4)C+Ti)/Mg composites improve gradually with the increase of strain amplitude,and composites prepared with coarser B4C particles tend to have higher damping capacities.The temperature-dependent damping capacities improve with increasing the measuring temperatures,and the kind of damping capacities of the composites prepared with 5mm B4C are inferior to those of coarser particles.The dominant damping mechanism for the strain-damping capacity is dislocation damping and plastic zone damping,while that for the temperature-damping capacity is interface damping or grain boundary damping.展开更多
Suspensions of a latosol with a clay concentration of 30 g kg^(-1) wereprepared from electrodialyzed clay fractions, less than 2 μm in diameter, five nitrate solutionswith a concentration of 1 X 10^(04)/z mol L^(-1),...Suspensions of a latosol with a clay concentration of 30 g kg^(-1) wereprepared from electrodialyzed clay fractions, less than 2 μm in diameter, five nitrate solutionswith a concentration of 1 X 10^(04)/z mol L^(-1), where z is the valence, and five sodium saltsolutions with a concentration of 3.3 X 10^(-5)/2 mol L^(-1). The direct current (DC) electricalconductivities (ECs) of the colloidal suspensions were measured at a constant temperature of 25 ℃,using a newly established method of measuring the Wien effect in soil suspensions at field strengthsranging from 13.5 to 150 kV cm^(-1), to determine their electrical conductivity-field strengthrelationships and to infer the order of the bonding strength (retaining force) between soilparticles and various ions. The measurements with the latosol suspensions in NaNO_3, KNO_3,Ca(NO_3)_2, Mg(NO_3)_2 and Zn(NO_3)_2 solutions resulted in increments of the suspension ECs, ΔECs,of 7.9, 5.0, 7.1, 7.0 and 5.8 μS cm^(-1), respectively, when the applied field strength increasedfrom 14.5 to 142 kV cm^(-1). As for the suspensions in NaNO_3, NaCl, Na_2SO_4, Na_3PO_4 andNa_3AsO_4 solutions, the ΔECs were 6.2, 5.3, 4.1, 4.0 and 3.7μS cm^(-1), respectively, when theapplied field strength increased from 13.5 to 90 kV cm^(-1). Thus, it can be deduced that theretaining forces of the clay fraction of the latosol for the cations were in the descending orderK^+ > Zn^(2+) > Mg^(2+) ≥ Ca^(2+) > Na^+, and for the anions in the descending order H_2AsO_4^- >H_2PO_4^-≥ SO_4^(2-) > Cl^- > NO_3~ -.展开更多
Suction bucket foundations can be divided into four compartments by cruciform internal bulkheads,thereby yielding better capacity in certain conditions than those without internal bulkheads.As yet,no systematic study ...Suction bucket foundations can be divided into four compartments by cruciform internal bulkheads,thereby yielding better capacity in certain conditions than those without internal bulkheads.As yet,no systematic study has been conducted regarding the effects of cruciform internal bulkheads on the capacities of suction bucket foundations.In this study,we established a large number of finite element models of suction bucket foundations with and without cruciform internal bulkheads and of solid embedded circular foundations.We found the uniaxial capacities and failure modes of suction bucket foundations with various depth ratios to remain basically unaffected by internal bulkheads in uniform clays.However,in inhomogeneous clay with high strength heterogeneity,we observed the uniaxial moment and horizontal capacities and corresponding failure modes of suction bucket foundations with a low depth ratio to be obviously affected by internal bulkheads.In this case,the uniaxial moment capacities,in particular,as well as the horizontal capacities of suction bucket foundations with cruciform internal bulkheads become obviously greater than those without internal bulkheads.Under combined loading,we found the failure envelopes of suction bucket foundations with and without cruciform internal bulkheads and of solid circular foundation to also be basically consistent in uniform clays.However,in inhomogeneous clay with high strength heterogeneity,cruciform internal bulkheads can obviously change the shapes of the failure envelopes of bucket foundations with a small depth ratio.We conclude that when the acting vertical load or foundation depth is relatively small,suction bucket foundations with cruciform internal bulkheads can be subjected to larger moment and horizontal loads in soft clays with high strength heterogeneity.展开更多
The empirical models of sulfide capacity calculated by traditional optical basicity do not consider the charge compensation of alkaline metal ions to AP＋ in the molten slags, so that the deviations between the calcul...The empirical models of sulfide capacity calculated by traditional optical basicity do not consider the charge compensation of alkaline metal ions to AP＋ in the molten slags, so that the deviations between the calculated values and measured ones of sulfide capacity are inevitable. The relation between sulfide capacity and the corrected optical basicity put forward by Mills considering the charge compensation was investigated. Combined with the relation be- tween sulfide capacity and temperatures, a novel and accurate calculation model of sulfide capacity was proposed, which was applied to calculate the sulfide capacities of CaO-Al2 O3-SiO2-MgO and CaO-Al2 03-SiO2-MgO-TiO2 sys-tems, where the sum of the CaO and MgO concentrations in the slags must be not lower than the Al2O3 concentra tion. It was also found that the calculated values were in a good agreement with the measured values, and the mean deviations were 2.57% and 2.65%, respectively.展开更多
基金This study was supported by the Key Project of Natural Science Research for Colleges and Universities in Anhui Province(KJ2021A0533,2023AH050345)the Excellent Scientific Research and Innovation Team of Universities in Anhui Province(2022AH010029).
文摘Seed germination with selenium(Se)is promising for producing Se-biofortified foods.Mungbean(Vigna radiata(L.)Wilczek)sprout is freshly eaten as a salad dressed with sauce,making it superior for Se biofortification.Since the Se safety range for the human body is extremely narrow,it is imperative to evaluate the genotypic responses of mungbean sprouts to Se.This study evaluated the Se enrichment capacity and interaction withflavonoids and antioxidant systems in sprouts of 20 mungbean germplasms.Selenium treatment was done by immersing mung-bean seeds in 20μM sodium selenite solution for 8 h.Afterward,the biomass,Se amounts,flavonoid(particularly vitexin and isovitexin)contents,antioxidant capacity,and key biosynthetic gene expressions were measured.Sprout Se content was 2.0-7.0μg g^(-1) DW among the 20 mungbean germplasms.Selenium treatment differentially affected the biomass,totalflavonoid,vitexin,isovitexin,antioxidant enzyme activities,and antioxidant capacities of the mungbean germplasms.Eight germplasms showed increased biomass(p<0.05),the highest increasing by 127%,but 13 did not phenotypically respond to Se treatment.Seven and six germplasms showed varied levels of vitexin and isovitexin increment after Se treatment,the highest measuring 2.67-and 2.87-folds for vitexin and isovitexin,respectively.Two mungbeanflavonoid biosynthesis genes,chalcone synthase(VrCHS)and chalcone isomerase(VrCHI)were significantly up-regulated in the germplasms with increased vitexin and isovitexin levels(p<0.05).Moreover,Se enrichment capacity was significantly correlated with the vitexin,isovitexin,and antiox-idant capacities.In conclusion,mungbean sprouts could be a useful Se-biofortified food,but the Se enrichment capacity and nutritional response must be determined for each germplasm before commercialization.
基金financially supported by the National Science Fund for Distinguished Young Scholars of China(Grant No.51825904)the Research on the Form,Design Method and Weathering Resistance of Key Components of Novel Floating Support Structures for Offshore Photovoltaics(Grant No.2022YFB4200701).
文摘Due to the uneven seabed and heaving of soil during pumping,incomplete soil plugs may occur during the installation of bucket foundations,and the impacts on the bearing capacities of bucket foundations need to be evaluated.In this paper,the contact ratio(the ratio of the top diameter of the soil plug to the diameter of the bucket)and the soil plug ratio(the ratio of the soil heave height to the skirt height)are defined to describe the shape and size of the incomplete soil plug.Then,finite element models are established to investigate the bearing capacities of bucket foundations with incomplete soil plugs and the influences of the contact ratios,and the soil plug ratios on the bearing capacities are analyzed.The results show that the vertical bearing capacity of bucket foundations in homogeneous soil continuously improves with the increase of the contact ratio.However,in normally consolidated soil,the vertical bearing capacity barely changes when the contact ratio is smaller than 0.75,while the bearing capacity suddenly increases when the contact ratio increases to 1 due to the change of failure mode.The contact ratio hardly affects the horizontal bearing capacity of bucket foundations.Moreover,the moment bearing capacity improves with the increase of the contact ratio for small aspect ratios,but hardly varies with increasing contact ratio for aspect ratios larger than 0.5.Consequently,the reduction coefficient method is proposed based on this analysis to calculate the bearing capacities of bucket foundations considering the influence of incomplete soil plugs.The comparison results show that the proposed reduction coefficient method can be used to evaluate the influences of incomplete soil plug on the bearing capacities of bucket foundations.
基金This paper was supported by National Natural Science Foundation of China(51671063,51771060,51871068,51971071)Domain Foundation of Equipment Advance Research of 13th Five-year Plan(61409220118)+3 种基金Heilongjiang Province Natural Science Foundation(LH2019E081,E2017030)the Fundamental Research Funds for the Central Universities(HEUCFG201834)Harbin City Application Technology Research and Development Project(2017RAQXJ032)Project of Mudanjiang normal university(GP2020004).
文摘The transformation of LPSO type in Mg-4Y-2Er-2Zn-0.6Zr during heat treatment and its influence on damping and mechanical properties are reported in this work.Prior to heat treatment,the alloy consisted of a-Mg matrix and lamellar 14H LPSO phases.After 510℃heat treatment,lamellae shortened,and their content decreased.Upon 8h heat treatment,block 18R LPSO phases formed at the grain boundaries while 14H LPSO lamellae disappeared.Presence of block 18R LPSO phases improved mechanical and damping properties of the alloy.The corresponding mechanisms of the influence of LPSO type and morphology on mechanical and damping capacities are discussed.
基金supported by the National Key Research and Development Program of China (No.2021YFB3701100)the National Natural Science Foundation of China (Nos.U20A20234,51874062)+1 种基金the Postdoctoral Science Foundation of China (No.2022M710503)the Chongqing Foundation and Advanced Research Project (No.cstc2019jcyj-zdxmX0010).
文摘Magnesium(Mg)alloys,as the lightest metal structural material with good damping capacities,have im-portant application prospects in realizing structural lightweight and vibration reduction.However,their engineering application is greatly limited by poor plastic formability.Wire and arc additive manufactur-ing(WAAM)provides a potential approach for fabricating large-scale Mg alloy components with high manufacturing flexibility.In this study,the evolution of the solidification microstructure of a WAAM-processed Mg-Al-based alloy was quantitatively analyzed based on the analytical models;then,the cor-relations between the solidification microstructure and mechanical properties/damping capacities were investigated.The results revealed that the WAAM-processed Mg-Al-based alloy with an equiaxed-grain-dominated microstructure displayed a simultaneous enhancement in mechanical properties and damping capacities compared to those of the cast Mg-Al-based alloy.The good combination of mechanical prop-erties and damping capacities are mainly attributed to the weakened basal texture with a relatively high Schmid factor for basalslip,the twinning-induced plasticity(TWIP)effect associated with the profuse{10-12}tensile twinning,and the relatively high dislocation density caused by the thermal stress during the WAAM process.
基金Project supported by the Fundamental Research Funds for the Central Universities (No. KYJD09033)the National Key Technology R & DProgram of China (No. 2008BAD91B04)the Science and Technology Department of Zhejiang Province (Nos. 2010C12012 and 2008C02015),China
文摘Three cooking methods,namely boiling,steaming,and stir-frying for 5 to 10 min,were used to evaluate the effect on nutrient components,free amino acids,L-ascorbic acid,total phenolic contents,and antioxidant capacities of bamboo shoots(Phyllostachys praecox).Results showed that boiling and stir-frying had a great effect on the nutrient components and they decreased the contents of protein,soluble sugar,and ash,and caused a great loss in the total free amino acids(decreased by 38.35% and 34.86%,respectively).Significant differences(P<0.05) in free amino acids were observed in the samples cooked by different methods.Stir-fried bamboo shoots had a high fat content which increased by 528.57% because of the addition of edible oil.After boiling,the L-ascorbic acid and total phenolic contents were significantly reduced,while steaming increased total phenolic content by 3.98% and stir-frying well-preserved L-ascorbic acid(78.87% of its previous content).Results of the antioxidative property study showed that stir-frying could increase antioxidant capacities of bamboo shoots.It is concluded that stir-frying is more suitable for bamboo shoots because it could obtain the maximum retention of antioxidant capacities.
文摘Equal channel angular extrusion (ECAE) was applied to commercial pure magnesium and AZ91D alloy. Microstructures of these magnesium alloys before and after ECAE process were observed by optical microscopy (OM). The ultimate tensile strength of pure magnesium and AZ91D alloy processed by ECAE is about 130 and 260MPa, respectively, and it is much higher than that of the as cast alloys. The elongation of them is increased from about 2% to 8%. The strain amplitude dependence damping capacities of these magnesium alloys were investigated by dynamic mechanical analyzer (DMA). ECAE process largely decreases the damping capacities of pure magnesium from 0.033 to about 0.012 (ε=1×10 -4), but does not show obvious influence on that of AZ91D alloy, which is about 0.0015.
文摘An overview of a long-gap peripheral nerve therapy： A long- gap peripheral nerve transection injury is an irreparable injury to the living body, and mostly leads to permanent loss of re- lated motor and sensory functions. In such long gap injuries, nerve end-to-end suture is physically impossible. Therefore, bridging a long nerve-gap is critical to re-establish adequate mechanical support for separated nerve ends, and prevent the diffusion of neurotrophic and neurotropic factors secreted by transected stumps （Deumens et al., 2010）.
基金Suppported by the Research Platform for the Project of the Application Basic Plan in Sichuan Province(2014JY0113)the Project of Department of science in Sichuan Province(14ZA0003)
文摘In order to investigate the chemical-biological relationship caused by the special processing technology,the constituent＇s content and antioxidant capacity in vivo of Euphorbia fischeriana Steud processing Terminalia chebula Retz. have been tested. Taking T. chebula Retz. as control,the content of gallic acid is analyzed with high performance liquid chromatography（HPLC） method. The results show that the increase of gallic acid concentration from 4.54% to 7.46% leads to enhancement of the antioxidant capacities in vivo of the E. fischeriana Steud processing T. chebula Retz. The significant antioxidant capacity in vivo（p〈0.05） of the processed product possesses is better than the unprocessed herb. Its superoxide dismutase（SOD）and malondia-ldehyde（MDA） contents in serum,the MDA content in liver can match the effects of vitamine E when administered at high dosage.
文摘For the development process in the rapidly growing economies, knowledge transfer and technology cooperation are becoming important issues. Research and technological competences are key indicators for the absorptive capacity of sustainability technologies and for the ability to export them. These issues are analyzed empirically for Brazil, Russia, India, China and South Africa (BRICS). Sustainability related research in BRICS is mostly carried out within broader, more sector oriented programmes. Specialization patterns of international patents and in foreign trade indicate various strengths and weaknesses of the BRICS countries. The differences within the countries imply that the analysis must proceed at a technology specific level. China has considerable capabilities in technologies such as photovoltaics, solar thermal or buildings. There is a strong need for strategic positioning of the countries and for coordination of the various policy fields involved.
基金Project (50801017) supported by the National Natural Science Foundation of Chinaproject (20080440843) supported by Postdoctoral Science Foundation, ChinaProject (HIT.NSRIF.2009028) supported by the Natural Scientific Research Innovation Foundation of Harbin Institute of Technology, China
文摘The amplitude-dependent and temperature-dependent low frequency damping capacities of magnesium with 99.96% purity were studied by a dynamic mechanical analyzer. The pure magnesium alloys include CPM1 and CPM2 castings having textures of columnar grains which extraordinarily influence the damping behaviours. The commercial pure magnesium alloy CPM was re-melted to obtain equiaxed grains, which could remove the effect of texture orientation on the damping behaviours of these pure magnesium alloys. The results of strain amplitude-dependent damping spectrums of these pure magnesium alloys show that the pure magnesium with equiaxed grains possesses the highest damping capacity. In temperature-dependent damping plot for all these three pure magnesium alloys, there are two damping peaks P1 and P2 located at 80 and 230 °C, respectively. These two damping peaks are considered to be caused by the interaction between dislocation and point defects, and the movement of grain boundaries, respectively.
基金supported by the National Natural Science Foundation of China(20373072,20753002)
文摘Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temperature range,the heat capacities increased in a smooth and continuous manner and no phase transition or thermal anomaly occurred.Therefore,the sample was stable in the above temperature range.The values of experimental heat capacities were fitted to a polynomial equation with least square method and ...
文摘The changes of capacities of positive and negative electrodes, reserve capacities of charging and discharging, and the weight of batteries during cycling have been determined. The increase of the discharging reserve capacity due to the conjugated electrochemical reactions of the oxidation of hydrogen storage alloy is estimated. The results show that the failure mode of Ni/MH batteries developed is as follows: during the increase of cycles, the hydrogen storage alloy is oxidized continuously and the charging reserve capacity is decreased rapidly while the discharging reserve capacity is increased gradually, thus the internal pressure is increasing, first H 2 leaks out from the battery, then the mixture of H 2 and O 2. The leakage of gases and the total reaction of oxidation of the alloy consume H 2O, and the surface oxides on the alloy increase, so that the internal resistance of the battery increases.
文摘Based on the analysis of completeness and finiteness of HF molecular vibrational levels, HF systemic vibrational heat capacity is studied with quantum statistical and full set of vibrational energy level determined AM (algebraic method). The results show that correct vibrational description and vibrational energy level set of HF system are key factors in calculating heat capacity, HF heat capacity data determined by AM energy spectra {Eυ} are much superior to the ones of harmonic oscillator model, AM results are agreement with experiment data.
基金supported by Guangdong Provincial Special Fund for Marine Fisheries Technology (No. A 201701B09)Fund of Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture, P. R. China (No. FREU2017-01)+4 种基金Guangdong Natural Science Foundation (No. 2017A 030 313147)Special Scientific Research Funds for Central Public-interest Scientific Institution Basal Research Fund, South China Sea Fisheries Research Institute, CAFS (Nos. 2016TS07, 2017YB12)Guangdong Provincial Key Laboratory of Fishery Ecology and Environment (No. LFE2016-12)the National Natural Science Foundation of China (Nos. 31502183, 31702352)Shenzhen Science and Technology Planning Project (No. JCYJ201704 12110605075)
文摘A 56-day feeding trial was performed to evaluate the effects of dietary probiotic Clostridium butyricum(CB) on intestine digestive and metabolic capacities, intestine short-chain fatty acids(SCFA) content and body composition of kuruma shrimp Marsupenaeus japonicus. Shrimp s were randomly allocated into 9 tanks, 30 each, and f ed with diets containing different levels of C. butyricum(1×10~9 cfug^(-1)): 0 mgg^(-1) feed(Control), 100 mgg^(-1) feed(CB-100), 200 mgg^(-1) feed(CB-200), while each level was triplicated. The results indicated that compared with the control group, the intestine pepsin(Pep) activity and 5-hydroxytryptamine(5-HT) concentration of two C. butyricum group s were both increased. Amylase(AM Y) and lipase(LPS) activities wer e only induced in CB-200 group. Alanine aminotransferase(ALT) and aspartate aminotransferase(A ST) activities of two C. butyricum group s showed no significant change. The α-amylase(AM Y) gene expression was induced in CB-200 group, and tryp sin gene expression of two C. butyricum treated group s were both induced. Intestine SCFA content and body composition analysis showed that the contents of propionic acid, butyric acid and the crude protein of two C. butyricum group s were all higher than those of control. These results revealed that C. butyricum can modulate intestine digestive and metabolic capacities, improve intestine SCFA content and body crude protein content in M. japonicus.
基金Project supported by the National Science Council,Taiwan(No. NSC 93-2211-E-224-002)the Service Center of Construction Tech-nology and Materials,National Yunlin University of Science and Technology,Taiwan(No.95-215)the Hong Kong Polytechnic University(Nos.PolyU 5115/07E and PolyU 5117/06E),Hong Kong,China
文摘We investigated the structural behavior and bearing capacity of system scaffolds.The research showed that the critical load of a system scaffold structure without diagonal braces is similar to that of a door-shaped steel scaffold structure.Joint stiffness between vertical props in system scaffolds can be defined based on a comparison between analytical and experimental results.When the number of scaffold stories increases,the critical loads of system scaffolds decrease.Diagonal braces markedly enhance the critical load of system scaffolds.The coupling joint position between vertical props should be kept away from story-to-story joints to prevent a reduction in critical loads.The critical load of a system scaffold decreases as the quantity of extended vertical props at the bottom of the structure increases.A large Christmas tree set up by system scaffolds under various loads was used as an example for analysis and to check the design of system scaffolds.
基金National Natural Science Foundation of China(20976120)the Natural Science Foundation of Tianjin(09JCYBJC06200)
文摘CeO2-ZrO2-Al2O3 ternary oxides were successfully prepared by a green route of supercritical anti-solvent precipitation with supercritical CO2 as anti-solvent and methanol as solvent. The structures and oxygen storage capacities of these ternary oxides were characterized by XRD, Raman spectra and oxygen storage capacity measurements. It was found that Al3＋ and Zr4＋ inserted into CeO2 lattice, forming CeO2-ZrO2-Al2O3 solid solution. The concentration of aluminium isopropoxide in the solution affected the concentration of oxygen vacancy and the distortion of oxygen sublattice which were responsible for the oxygen storage capacity. The rapidest oxygen uptake/release rate and maximum total oxygen storage capacity （122.0 mmolO2/molCeO2） were obtained with the aluminitun isopropoxide concentration at 0.2 wt.% in the solution.
基金Project(51901095)supported by the National Natural Science Foundation of China。
文摘To study the influence of B4C particle size on the microstructure and damping capacities of(B_(4)C+Ti)/Mg composites,in situ reactive infiltration technique was utilized to prepare Mg-matrix composites.The microstructure,produced phases and damping capacities of the composites prepared with different particle size of B4C were characterized and analyzed.The results show that the reaction between B4C and Ti tends to be more complete when finer B_(4)C particle was used to prepare the composites.But the microstructure of the as-prepared composites is more homogenous when B4C and Ti have similar particle size.The strain-dependent damping capacities of(B_(4)C+Ti)/Mg composites improve gradually with the increase of strain amplitude,and composites prepared with coarser B4C particles tend to have higher damping capacities.The temperature-dependent damping capacities improve with increasing the measuring temperatures,and the kind of damping capacities of the composites prepared with 5mm B4C are inferior to those of coarser particles.The dominant damping mechanism for the strain-damping capacity is dislocation damping and plastic zone damping,while that for the temperature-damping capacity is interface damping or grain boundary damping.
基金Project supported by the National Natural Science Foundation of China (Nos. 49771046 and 49831005) the Center for International Cooperation, Ministry of Foreign Affairs, State of Israel.
文摘Suspensions of a latosol with a clay concentration of 30 g kg^(-1) wereprepared from electrodialyzed clay fractions, less than 2 μm in diameter, five nitrate solutionswith a concentration of 1 X 10^(04)/z mol L^(-1), where z is the valence, and five sodium saltsolutions with a concentration of 3.3 X 10^(-5)/2 mol L^(-1). The direct current (DC) electricalconductivities (ECs) of the colloidal suspensions were measured at a constant temperature of 25 ℃,using a newly established method of measuring the Wien effect in soil suspensions at field strengthsranging from 13.5 to 150 kV cm^(-1), to determine their electrical conductivity-field strengthrelationships and to infer the order of the bonding strength (retaining force) between soilparticles and various ions. The measurements with the latosol suspensions in NaNO_3, KNO_3,Ca(NO_3)_2, Mg(NO_3)_2 and Zn(NO_3)_2 solutions resulted in increments of the suspension ECs, ΔECs,of 7.9, 5.0, 7.1, 7.0 and 5.8 μS cm^(-1), respectively, when the applied field strength increasedfrom 14.5 to 142 kV cm^(-1). As for the suspensions in NaNO_3, NaCl, Na_2SO_4, Na_3PO_4 andNa_3AsO_4 solutions, the ΔECs were 6.2, 5.3, 4.1, 4.0 and 3.7μS cm^(-1), respectively, when theapplied field strength increased from 13.5 to 90 kV cm^(-1). Thus, it can be deduced that theretaining forces of the clay fraction of the latosol for the cations were in the descending orderK^+ > Zn^(2+) > Mg^(2+) ≥ Ca^(2+) > Na^+, and for the anions in the descending order H_2AsO_4^- >H_2PO_4^-≥ SO_4^(2-) > Cl^- > NO_3~ -.
基金supported by the National Natural Science Foundation of China(Nos.51479133,51109157)the Elite Scholar Program of Tianjin University(2017XRG0040)
文摘Suction bucket foundations can be divided into four compartments by cruciform internal bulkheads,thereby yielding better capacity in certain conditions than those without internal bulkheads.As yet,no systematic study has been conducted regarding the effects of cruciform internal bulkheads on the capacities of suction bucket foundations.In this study,we established a large number of finite element models of suction bucket foundations with and without cruciform internal bulkheads and of solid embedded circular foundations.We found the uniaxial capacities and failure modes of suction bucket foundations with various depth ratios to remain basically unaffected by internal bulkheads in uniform clays.However,in inhomogeneous clay with high strength heterogeneity,we observed the uniaxial moment and horizontal capacities and corresponding failure modes of suction bucket foundations with a low depth ratio to be obviously affected by internal bulkheads.In this case,the uniaxial moment capacities,in particular,as well as the horizontal capacities of suction bucket foundations with cruciform internal bulkheads become obviously greater than those without internal bulkheads.Under combined loading,we found the failure envelopes of suction bucket foundations with and without cruciform internal bulkheads and of solid circular foundation to also be basically consistent in uniform clays.However,in inhomogeneous clay with high strength heterogeneity,cruciform internal bulkheads can obviously change the shapes of the failure envelopes of bucket foundations with a small depth ratio.We conclude that when the acting vertical load or foundation depth is relatively small,suction bucket foundations with cruciform internal bulkheads can be subjected to larger moment and horizontal loads in soft clays with high strength heterogeneity.
基金Sponsored by National Natural Science Foundation of China(51090384)
文摘The empirical models of sulfide capacity calculated by traditional optical basicity do not consider the charge compensation of alkaline metal ions to AP＋ in the molten slags, so that the deviations between the calculated values and measured ones of sulfide capacity are inevitable. The relation between sulfide capacity and the corrected optical basicity put forward by Mills considering the charge compensation was investigated. Combined with the relation be- tween sulfide capacity and temperatures, a novel and accurate calculation model of sulfide capacity was proposed, which was applied to calculate the sulfide capacities of CaO-Al2 O3-SiO2-MgO and CaO-Al2 03-SiO2-MgO-TiO2 sys-tems, where the sum of the CaO and MgO concentrations in the slags must be not lower than the Al2O3 concentra tion. It was also found that the calculated values were in a good agreement with the measured values, and the mean deviations were 2.57% and 2.65%, respectively.
