A Ni layer with a thickness of about 100 nm was sputtered on Cu substrates,followed by an ultrasonic seeding with nanodiamond suspension.High-quality diamond film with its crystalline grains close to thermal equilibri...A Ni layer with a thickness of about 100 nm was sputtered on Cu substrates,followed by an ultrasonic seeding with nanodiamond suspension.High-quality diamond film with its crystalline grains close to thermal equilibrium shape was deposited on Cu substrates by hot-filament chemical vapor deposition(HF-CVD),and the sp2 carbon content was less than 5.56%.The nucleation and growth of diamond film were investigated by micro-Raman spectroscopy,scanning electron microscopy,and X-ray diffraction.The results show that the nucleation density of diamond on the Ni-modified Cu substrates is 10 times higher than that on blank Cu substrates.The enhancement mechanism of the nucleation kinetics by Ni modification layer results from two effects:namely,the nanometer rough Ni-modified surface shows an improved absorption of nanodiamond particles that act as starting points for the diamond nucleation during HF-CVD process;the strong catalytic effect of the Ni-modified surface causes the formation of graphite layer that acts as an intermediate to facilitate diamond nucleation quickly.展开更多
Using an optical microscope and scanning electron microscope (SEM), the variation of eutectic Si morphology of Al-Si alloy in solution treatment was observed to study its influence on mechanical properties and fractur...Using an optical microscope and scanning electron microscope (SEM), the variation of eutectic Si morphology of Al-Si alloy in solution treatment was observed to study its influence on mechanical properties and fracture behavior. The results show that eutectic Si undergoes stubbing, necking, fragmentation, and growth in the initial stage (250 min); in the middle solution stage (250 to 400 min), the eutectic Si morphology has no significant change, only the degree of spheroidizing becomes higher; after 600 min, the growth of eutectic Si is a coarsening process controlled by diffusion and follows the Liftshitz-Slyozov-Wangner (LSW) model, and the eutectic Si morphology deteriorates due to the occurrence of facets and lap. Based on the quantitative measure and regression analysis, the eutectic Si morphology has a remarkable influence on mechanical properties and fracture behavior.展开更多
The comparative morphology of the lips and associated structures is studied among Parasinilabeo and its taxonomically related groups. On the basis of the morphological features of the lips and associated structure...The comparative morphology of the lips and associated structures is studied among Parasinilabeo and its taxonomically related groups. On the basis of the morphological features of the lips and associated structures, Parasinilabeo is proposed to be closely associated with Pseudogyrinocheilus and Semilabeo ;and four typical mouth patterns are identifled among Parasinilabeo and its taxonomically related groups.展开更多
A procedure of low temperature solid-phase sintering(LTSS) was carried out to fabricate sintered metal fibrous media(SMFM) with high specific surface area.Stainless steel fibers which were produced by cutting proc...A procedure of low temperature solid-phase sintering(LTSS) was carried out to fabricate sintered metal fibrous media(SMFM) with high specific surface area.Stainless steel fibers which were produced by cutting process were first plated with a coarse copper coating layer by electroless plating process.A low-temperature sintering process was then completed at about 800 °C for 1 h under the protection of hydrogen atmosphere.The results show that a novel SMFM with complex surface morphology and high specific surface area(0.2 m2/g) can be obtained in this way.The effect of sintering temperature on the surface morphology and specific surface area of SMFM was studied by means of scanning electron microscopy and Brunauer-Emmett-Teller.The damage of micro-structure during the sintering process mainly contributed to the loss of specific surface area of SMFM and the optimal sintering temperature was 800 °C.展开更多
[Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media. [Method] 32 strains of endophytic fungi were identified form the inner bark of T. media,and their fermentation prod...[Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media. [Method] 32 strains of endophytic fungi were identified form the inner bark of T. media,and their fermentation products were detected by high performance liquid chromatography (HPLC). [Result] Through the screening,a strain of taxol-producing endophytic fungi M57 was obtained,which could produce 45-50 μg/L of taxol,and M57 was defined as Rhizopus sp. through morphological observation and 18S rDNA sequence analysis. [Conclusion] The finding of Rhizopus sp. M57 provided a promising strain for producing taxol with taxol-producing fungi fermentation process.展开更多
Hot compression tests in the temperature range of 340-450 ℃ and strain rate range of 0.001-1 s^-1 of spray-formed 7055 aluminum alloy were carried out to study its hot deformation behavior. Three phenomenological mod...Hot compression tests in the temperature range of 340-450 ℃ and strain rate range of 0.001-1 s^-1 of spray-formed 7055 aluminum alloy were carried out to study its hot deformation behavior. Three phenomenological models including Johnson-Cook, modified Fields-Backofen and Arrhenius-type were introduced to predict the flow stresses during the compression process. And then, a comparative predictability of the phenomenological models was estimated in terms of the relative errors, correlation coefficient(R), and average absolute relative error(AARE). The results indicate that Johnson-Cook model and modified Fields-Backofen model cannot well predict the hot deformation behavior due to the large deviation in the process of line regression fitting. Arrhenius-type model obtains the best fit through combining the effect of strain rate and temperature.展开更多
Twenty one joints were made with Brazilian tests and each surface was scanned by the Talysurf CLI 2000. Morphological characteristics of joint surface were quantified by statistical and textural parameters. By the con...Twenty one joints were made with Brazilian tests and each surface was scanned by the Talysurf CLI 2000. Morphological characteristics of joint surface were quantified by statistical and textural parameters. By the contrast of these parameters between both sides of each coupled joint, the following conclusions are drawn. The upper and lower surfaces of coupled joints have approximately equal values of Sp(maximum height of joint surface), Sa(arithmetic mean height of joint surface) and Sq(root mean square height of joint surface), but the Ssk(skewness of the height distribution of joint surface) values of the two surfaces of a coupled joint are different, one is positive while the other is negative. The Saj(auto-correlation length) parameter values of both surfaces of each coupled joint are quite close, and the S^(texture aspect ratio) values have the same situation to the Sal parameter, but the same parameters of different surfaces have big differences which illustrates its own characteristics of each joint. The two surfaces of each coupled joint have similar values of θp (mean profile angle) which can be used to deduce the value of θp each other.展开更多
This paper presents a weakly nonlinear water wave model using a mild slope equation and a new explicit formulation which takes into account dispersion of wave phase velocity, approximates Hedges’ (1987) nonlinear dis...This paper presents a weakly nonlinear water wave model using a mild slope equation and a new explicit formulation which takes into account dispersion of wave phase velocity, approximates Hedges’ (1987) nonlinear dispersion relationship, and accords well with the original empirical formula. Comparison of the calculating results with those obtained from the experimental data and those obtained from linear wave theory showed that the present water wave model considering the dispersion of phase velocity is rational and in good agreement with experiment data.展开更多
Marine active fault exploration and paleoearthquake research are still a gap in China. The paper gives a review on major research methods and new progress made abroad, including submarine survey boat, seismic reflecti...Marine active fault exploration and paleoearthquake research are still a gap in China. The paper gives a review on major research methods and new progress made abroad, including submarine survey boat, seismic reflection and acoustic reflection. Through detailed studies of offset history of 10 ka to 30 ka, it is possible to determine paleoearthquake recurrent intervals and elapsed time since last major earthquake. It is suggested that active fault exploration can be carried out by acoustic exploring method in large earthquake region of Bohai Sea. Paleoearthquake activity history can be revealed and earthquake risk in the future can be predicted.展开更多
Cold-rolled Ti/Al laminated composites were annealed at 525−625℃for 0−128 h,and the interfacial microstructure evolution was investigated.The results indicate that only the TiAl_(3) phase was formed at the Ti/Al inte...Cold-rolled Ti/Al laminated composites were annealed at 525−625℃for 0−128 h,and the interfacial microstructure evolution was investigated.The results indicate that only the TiAl_(3) phase was formed at the Ti/Al interface;most of TiAl_(3) grains were fine equiaxed with average sizes ranging from hundreds of nanometers to several microns and the TiAl_(3) grain size increased with increasing annealing time and/or temperature,but the effect of annealing temperature on the TiAl_(3) grain size was far greater than that of annealing time.The growth of the TiAl_(3) phase consisted of two stages.The initial stage was governed by chemical reaction with a reaction activation energy of 195.75 kJ/mol,and the reaction rate constant of the TiAl_(3) phase was larger as the Ti/Al interface was bonded with fresh surfaces.At the second stage,the growth was governed by diffusion,the diffusion activation energy was 33.69 kJ/mol,and the diffusion growth rate constant of the TiAl_(3) phase was mainly determined by the grain boundary diffusion owing to the smaller TiAl_(3) grain size.展开更多
Huangguogan, an obvious Citrus hybrid, is suitable for transportation and export and ripens in March or April. Because of late season, it may playa significant role in fruit market. However, its origin is still unconf...Huangguogan, an obvious Citrus hybrid, is suitable for transportation and export and ripens in March or April. Because of late season, it may playa significant role in fruit market. However, its origin is still unconfirmed. The aim of this study was to clarify the possible parentage of Huangguogan via the combination of morphological and molecular markers including simple sequence repeat (SSR) and chloroplast simple sequence repeat (cpSSR). Analysis of morphological traits including leaf stalk length, phylliform index and fruit shape index indicated that Huangguogan had similarities in morphology with Sweet orange. The SSR Cluster Analysis showed that Huangguogan was clustered together with Hongju tangerine and revealed -80% genetic similarity. They illustrated a close genetic distance between Huangguogan and Hongju tangerine. In addition, the bands of2 polymorphic cpSSR were identical in Huangguoggan and Sweet orange. Consequently, it is likely that its female parentage was the sweet orange (Citrus sinensis (L.) Osbeck) and its male parentage was the tangerine (Citrus reticulata Blanco).展开更多
TiC nanoparticle-reinforced Mg−4Zn−0.5Ca matrix nanocomposites were processed by combining multidirectional forging(MDF)and extrusion(EX).The grain size of the nanocomposite after MDF+EX multi-step deformation was sig...TiC nanoparticle-reinforced Mg−4Zn−0.5Ca matrix nanocomposites were processed by combining multidirectional forging(MDF)and extrusion(EX).The grain size of the nanocomposite after MDF+EX multi-step deformation was significantly decreased compared with that processed only by MDF.The average size of the recrystallized grains gradually increased after EX with increasing the number of MDF passes at 270℃.However,the grain size significantly decreased by MDF processing at 310℃.Both fine and coarse MgZn2 phases appeared in the(MDF+EX)-processed nanocomposites,and their volume fractions gradually increased with increasing the number of MDF passes before EX.Ultrahigh tensile properties(yield strength of^404 MPa,ultimate tensile strength of^450.3 MPa and elongation of^5.2%)were obtained in the nanocomposite after three MDF passes at 310℃ followed by EX.This was attributed to the refinement of the recrystallized grains,together with the improved Orowan strengthening provided by the precipitated MgZn2 particles that were generated by MDF+EX multi-step deformation.展开更多
Amorphous silicon films are prepared at lower temperature of 350 ℃ by new catalytic chemical vapor deposition method.In the method,material gases (SiH 4 and H 2) are decomposed by catalytic reaction at given temper...Amorphous silicon films are prepared at lower temperature of 350 ℃ by new catalytic chemical vapor deposition method.In the method,material gases (SiH 4 and H 2) are decomposed by catalytic reaction at given temperature,so a-Si films are deposited on substrates.It is found that a-Si films with high quality can be obtain,such as high photosensitivity of 10 6,low spin density of 2.5×10 16 cm -3 .展开更多
The influence of high pressure and manganese addition on Fe-rich phases(FRPs)and mechanical properties of Al-14Si-2Fe alloy with rheo-squeeze casting(RSC)was investigated.The semi-solid alloy melt was treated by ultra...The influence of high pressure and manganese addition on Fe-rich phases(FRPs)and mechanical properties of Al-14Si-2Fe alloy with rheo-squeeze casting(RSC)was investigated.The semi-solid alloy melt was treated by ultrasonic vibration(UV)firstly,and then formed by squeeze casting(SC).Results show that the FRPs in as-cast SC alloys are composed of coarseβ-Al5(Fe,Mn)Si,δ-Al4(Fe,Mn)Si2 and bone-shapedα-Al15(Fe,Mn)3Si2 phases when the pressure is 0 MPa.With RSC process,the FRPs are first refined by UV,and then the solidification under pressure further causes the grains to become smaller.The peritectic transformation occurs during the formation ofαphase.For the alloy with the same composition,the ultimate tensile strength(UTS)of RSC sample is higher than that of the SC sample.With the same forming process,the UTS of Al-14Si-2Fe-0.8Mn alloy is higher than that of Al-14Si-2Fe-0.4Mn alloy.展开更多
The effects of partial substitution of Fe element for Ni element on the structure,martensitic transformation and mechanicalproperties of Ni50-xFexMn38Sn12(x=0and3%,molar fraction)ferromagnetic shape memory alloys were...The effects of partial substitution of Fe element for Ni element on the structure,martensitic transformation and mechanicalproperties of Ni50-xFexMn38Sn12(x=0and3%,molar fraction)ferromagnetic shape memory alloys were investigated.Experimentalresults indicate that by substitution of Fe for Ni,the microstructure and crystal structure of the alloys change at room temperature.Compared with Ni50Mn38Sn12alloy,the martensitic transformation starting temperature of Ni47Fe3Mn38Sn12alloy is decreased by32.5K.It is also found that martensitic transformation occurs over a broad temperature window from288.9to352.2K.It is found that themechanical properties of Ni-Mn-Sn alloy can be significantly improved by Fe addition.The Ni47Fe3Mn38Sn12alloy achieves amaximum compressive strength of855MPa with a fracture strain of11%.Moreover,the mechanism of the mechanical propertyimprovement is clarified.Fe doping changes the fracture type from intergranular fracture of Ni50Mn38Sn12alloy to transgranularcleavage fracture of Ni47Fe3Mn38Sn12alloys.展开更多
Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was ...Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was verifi ed by monitoring larvae and juveniles of knownage.The results revealed that lapilli and sagittae developed before hatching,and the first otolith increment was identified at 2 days post hatching in both.The shape of lapilli was relatively stable during development compared with that of sagittae;however,growth of four sagittae and lapilli areas was consistent,but the posterior area grew faster than the anterior area and the ventral surface grew faster than the dorsal surface.Similarly,the sum length of the radius of the anterior and posterior areas on sagittae and lapilli were linearly and binomially related to total fish length,respectively.Moreover,daily deposition rates were validated by monitoring knownage larvae and juveniles.The increase in lapilli width was 1.88±0.080 0μm at the ninth increment,which reached a maximum and the decreased gradually toward the otolith edge,whereas that of sagittae increased more slowly.These results illustrate the developmental biology of S.davidi,which will aid in population conservation and fish stock management.展开更多
The dynamics of changes in body shape of fast-growing and slow-growing strains of turbot Scophthalmus maximus, and of the differences in body shape between the two strains, were evaluated from 3 to 27 months of age. T...The dynamics of changes in body shape of fast-growing and slow-growing strains of turbot Scophthalmus maximus, and of the differences in body shape between the two strains, were evaluated from 3 to 27 months of age. The ratios of total length/body length, body width/body length and total length/body width were used as morphometric indices. The two strains exhibited different temporal trends in total length/body length but similar trends in body width/body length and total length/body width. Generally, body width/body length of the two strains increased with time and total length/body width decreased. Thus, the bodies of both fast-growing and slow-growing strains of turbot changed from a narrow to a more rounded shape. However, the ratio total length/body length was generally lower, body width/body length was mostly higher and total length/body width was consistently lower in the fast-growing strain than in the slowgrowing strain. Correlation analysis of the three shape ratios with body weight showed that total length/body length and total length/body width were unsuitable, and that width/body length was suitable, for use as a phenotypic marker for selective breeding of turbot for growth in weight.展开更多
The purpose of this paper is looking for associations between environmental factors and morphological parameters in tambaqui (Piaractus brachypomus) individuals to differentiate this species in lentic environments ...The purpose of this paper is looking for associations between environmental factors and morphological parameters in tambaqui (Piaractus brachypomus) individuals to differentiate this species in lentic environments (lake) and lotic (river). In this, regard studied 30 specimens, 15 from lentic environment (lake) and 15 from lotic (river). Also, on right profile of these 25 morphometric variables were measured. On data matrix a PCA (principal components analysis) based on morphometric correlations matrix, which was defined in the new morphologic space of these specimens (3 principal components) which explain 73.23% of variability. Fish projection in first two principal components showed a morphological differentiation between two environments (lentic and lotic), with variables as, horizontal eye diameter, length maxilla, suggesting greater response of these fish in lotic environment by their adaptation to light conditions, predators threat and food distribution. Finally, in lotic environment these fish have thinner caudal peduncle, indicating greater plasticity, namely stylized fish.展开更多
Multiphase emulsions could be used as templates in considerable fields such as coating, optical materials, stan- dard particles and biomedicine. Among various emulsion forming methods, microfluidic technology, with go...Multiphase emulsions could be used as templates in considerable fields such as coating, optical materials, stan- dard particles and biomedicine. Among various emulsion forming methods, microfluidic technology, with good monodispersity, high controllability and operation simplicity, has been widely used in the preparation of multi- phase emulsions with different systems. This review would focus on the basic principles of forming multiphase emulsions, the recent progress in controlling multiphase flow in microfluidics, and preparation of functional ma- terials with microfluidics mainly by the authors' research group. We believe that the review will contribute to the readers in this prospective area very well. ~ 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.展开更多
基金Project(20110933K) supported by the State Key Laboratory of Powder Metallurgy,ChinaProject(2012QNZT002) supported by the Freedom Explore Program of Central South University,ChinaProject(CSUZC2012024) supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘A Ni layer with a thickness of about 100 nm was sputtered on Cu substrates,followed by an ultrasonic seeding with nanodiamond suspension.High-quality diamond film with its crystalline grains close to thermal equilibrium shape was deposited on Cu substrates by hot-filament chemical vapor deposition(HF-CVD),and the sp2 carbon content was less than 5.56%.The nucleation and growth of diamond film were investigated by micro-Raman spectroscopy,scanning electron microscopy,and X-ray diffraction.The results show that the nucleation density of diamond on the Ni-modified Cu substrates is 10 times higher than that on blank Cu substrates.The enhancement mechanism of the nucleation kinetics by Ni modification layer results from two effects:namely,the nanometer rough Ni-modified surface shows an improved absorption of nanodiamond particles that act as starting points for the diamond nucleation during HF-CVD process;the strong catalytic effect of the Ni-modified surface causes the formation of graphite layer that acts as an intermediate to facilitate diamond nucleation quickly.
文摘Using an optical microscope and scanning electron microscope (SEM), the variation of eutectic Si morphology of Al-Si alloy in solution treatment was observed to study its influence on mechanical properties and fracture behavior. The results show that eutectic Si undergoes stubbing, necking, fragmentation, and growth in the initial stage (250 min); in the middle solution stage (250 to 400 min), the eutectic Si morphology has no significant change, only the degree of spheroidizing becomes higher; after 600 min, the growth of eutectic Si is a coarsening process controlled by diffusion and follows the Liftshitz-Slyozov-Wangner (LSW) model, and the eutectic Si morphology deteriorates due to the occurrence of facets and lap. Based on the quantitative measure and regression analysis, the eutectic Si morphology has a remarkable influence on mechanical properties and fracture behavior.
文摘The comparative morphology of the lips and associated structures is studied among Parasinilabeo and its taxonomically related groups. On the basis of the morphological features of the lips and associated structures, Parasinilabeo is proposed to be closely associated with Pseudogyrinocheilus and Semilabeo ;and four typical mouth patterns are identifled among Parasinilabeo and its taxonomically related groups.
基金Project (50930005) supported by the National Natural Science Foundation of ChinaProject (U0834002) supported by the Key Programof NSFC-Guangdong Joint Funds of China+1 种基金Project (LYM09024) supported by Training Program for Excellent Young Teachers withInnovation of Guangdong University, ChinaProject (2009ZM0121) supported by the Fundamental Research Funds for the CentralUniversities of South China University of Technology,China
文摘A procedure of low temperature solid-phase sintering(LTSS) was carried out to fabricate sintered metal fibrous media(SMFM) with high specific surface area.Stainless steel fibers which were produced by cutting process were first plated with a coarse copper coating layer by electroless plating process.A low-temperature sintering process was then completed at about 800 °C for 1 h under the protection of hydrogen atmosphere.The results show that a novel SMFM with complex surface morphology and high specific surface area(0.2 m2/g) can be obtained in this way.The effect of sintering temperature on the surface morphology and specific surface area of SMFM was studied by means of scanning electron microscopy and Brunauer-Emmett-Teller.The damage of micro-structure during the sintering process mainly contributed to the loss of specific surface area of SMFM and the optimal sintering temperature was 800 °C.
基金Supported by National Natural Science Foundation of China(20776058)New Century Training Programme Foundation for the Talents by the State Education Commission (NCET-06-0646)~~
文摘[Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media. [Method] 32 strains of endophytic fungi were identified form the inner bark of T. media,and their fermentation products were detected by high performance liquid chromatography (HPLC). [Result] Through the screening,a strain of taxol-producing endophytic fungi M57 was obtained,which could produce 45-50 μg/L of taxol,and M57 was defined as Rhizopus sp. through morphological observation and 18S rDNA sequence analysis. [Conclusion] The finding of Rhizopus sp. M57 provided a promising strain for producing taxol with taxol-producing fungi fermentation process.
基金Project(2013HH100055) supported by the Basic Research and Science and Technology Innovation Fund of Foshan City,China
文摘Hot compression tests in the temperature range of 340-450 ℃ and strain rate range of 0.001-1 s^-1 of spray-formed 7055 aluminum alloy were carried out to study its hot deformation behavior. Three phenomenological models including Johnson-Cook, modified Fields-Backofen and Arrhenius-type were introduced to predict the flow stresses during the compression process. And then, a comparative predictability of the phenomenological models was estimated in terms of the relative errors, correlation coefficient(R), and average absolute relative error(AARE). The results indicate that Johnson-Cook model and modified Fields-Backofen model cannot well predict the hot deformation behavior due to the large deviation in the process of line regression fitting. Arrhenius-type model obtains the best fit through combining the effect of strain rate and temperature.
基金Project(51174228) supported by the National Natural Science Foundation of ChinaProject(2011ssxt275) supported by the Graduate Students’Thesis Innovation Foundation of Central South University,ChinaProject(11MX22) supported by the Central South University Students’ Innovation Foundation of the Mittal Company,China
文摘Twenty one joints were made with Brazilian tests and each surface was scanned by the Talysurf CLI 2000. Morphological characteristics of joint surface were quantified by statistical and textural parameters. By the contrast of these parameters between both sides of each coupled joint, the following conclusions are drawn. The upper and lower surfaces of coupled joints have approximately equal values of Sp(maximum height of joint surface), Sa(arithmetic mean height of joint surface) and Sq(root mean square height of joint surface), but the Ssk(skewness of the height distribution of joint surface) values of the two surfaces of a coupled joint are different, one is positive while the other is negative. The Saj(auto-correlation length) parameter values of both surfaces of each coupled joint are quite close, and the S^(texture aspect ratio) values have the same situation to the Sal parameter, but the same parameters of different surfaces have big differences which illustrates its own characteristics of each joint. The two surfaces of each coupled joint have similar values of θp (mean profile angle) which can be used to deduce the value of θp each other.
文摘This paper presents a weakly nonlinear water wave model using a mild slope equation and a new explicit formulation which takes into account dispersion of wave phase velocity, approximates Hedges’ (1987) nonlinear dispersion relationship, and accords well with the original empirical formula. Comparison of the calculating results with those obtained from the experimental data and those obtained from linear wave theory showed that the present water wave model considering the dispersion of phase velocity is rational and in good agreement with experiment data.
文摘Marine active fault exploration and paleoearthquake research are still a gap in China. The paper gives a review on major research methods and new progress made abroad, including submarine survey boat, seismic reflection and acoustic reflection. Through detailed studies of offset history of 10 ka to 30 ka, it is possible to determine paleoearthquake recurrent intervals and elapsed time since last major earthquake. It is suggested that active fault exploration can be carried out by acoustic exploring method in large earthquake region of Bohai Sea. Paleoearthquake activity history can be revealed and earthquake risk in the future can be predicted.
基金the financial supports from the S&T Program of Hebei Province,China(No.20373901D)the National Natural Science Foundation of China(Nos.51807047,51804095)+2 种基金the National Science Foundation of Hebei Province,China(No.E2019402433)the Youth Top Talents Science and Technology Research Project of Hebei Province University,China(No.BJ2019003)the Research and Development Project of Science and Technology of Handan City,China(No.19422111008-19).
文摘Cold-rolled Ti/Al laminated composites were annealed at 525−625℃for 0−128 h,and the interfacial microstructure evolution was investigated.The results indicate that only the TiAl_(3) phase was formed at the Ti/Al interface;most of TiAl_(3) grains were fine equiaxed with average sizes ranging from hundreds of nanometers to several microns and the TiAl_(3) grain size increased with increasing annealing time and/or temperature,but the effect of annealing temperature on the TiAl_(3) grain size was far greater than that of annealing time.The growth of the TiAl_(3) phase consisted of two stages.The initial stage was governed by chemical reaction with a reaction activation energy of 195.75 kJ/mol,and the reaction rate constant of the TiAl_(3) phase was larger as the Ti/Al interface was bonded with fresh surfaces.At the second stage,the growth was governed by diffusion,the diffusion activation energy was 33.69 kJ/mol,and the diffusion growth rate constant of the TiAl_(3) phase was mainly determined by the grain boundary diffusion owing to the smaller TiAl_(3) grain size.
文摘Huangguogan, an obvious Citrus hybrid, is suitable for transportation and export and ripens in March or April. Because of late season, it may playa significant role in fruit market. However, its origin is still unconfirmed. The aim of this study was to clarify the possible parentage of Huangguogan via the combination of morphological and molecular markers including simple sequence repeat (SSR) and chloroplast simple sequence repeat (cpSSR). Analysis of morphological traits including leaf stalk length, phylliform index and fruit shape index indicated that Huangguogan had similarities in morphology with Sweet orange. The SSR Cluster Analysis showed that Huangguogan was clustered together with Hongju tangerine and revealed -80% genetic similarity. They illustrated a close genetic distance between Huangguogan and Hongju tangerine. In addition, the bands of2 polymorphic cpSSR were identical in Huangguoggan and Sweet orange. Consequently, it is likely that its female parentage was the sweet orange (Citrus sinensis (L.) Osbeck) and its male parentage was the tangerine (Citrus reticulata Blanco).
基金Projects(51771129,51401144,51771128)supported by the National Natural Science Foundation of China,Project supported by the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi,ChinaProjects(2015021067,201601D011034)supported by the Natural Science Foundation of Shanxi Province,China+1 种基金Project(201703D421039)supported by the International Cooperation in Shanxi,ChinaProject supported by the China Scholarship Council。
文摘TiC nanoparticle-reinforced Mg−4Zn−0.5Ca matrix nanocomposites were processed by combining multidirectional forging(MDF)and extrusion(EX).The grain size of the nanocomposite after MDF+EX multi-step deformation was significantly decreased compared with that processed only by MDF.The average size of the recrystallized grains gradually increased after EX with increasing the number of MDF passes at 270℃.However,the grain size significantly decreased by MDF processing at 310℃.Both fine and coarse MgZn2 phases appeared in the(MDF+EX)-processed nanocomposites,and their volume fractions gradually increased with increasing the number of MDF passes before EX.Ultrahigh tensile properties(yield strength of^404 MPa,ultimate tensile strength of^450.3 MPa and elongation of^5.2%)were obtained in the nanocomposite after three MDF passes at 310℃ followed by EX.This was attributed to the refinement of the recrystallized grains,together with the improved Orowan strengthening provided by the precipitated MgZn2 particles that were generated by MDF+EX multi-step deformation.
文摘Amorphous silicon films are prepared at lower temperature of 350 ℃ by new catalytic chemical vapor deposition method.In the method,material gases (SiH 4 and H 2) are decomposed by catalytic reaction at given temperature,so a-Si films are deposited on substrates.It is found that a-Si films with high quality can be obtain,such as high photosensitivity of 10 6,low spin density of 2.5×10 16 cm -3 .
基金Project(51605342) supported by the National Natural Science Foundation of ChinaProject(2015CFB431) supported by the Natural Science Foundation of Hubei Province,China+1 种基金Project(K201520) supported by the Science Research Foundation of Wuhan Institute of Technology,ChinaProject(2016KA01) supported by the Open Research Fund Program of Hubei Provincial Key Laboratory of Chemical Equipment Intensification and Intrinsic Safety,China
文摘The influence of high pressure and manganese addition on Fe-rich phases(FRPs)and mechanical properties of Al-14Si-2Fe alloy with rheo-squeeze casting(RSC)was investigated.The semi-solid alloy melt was treated by ultrasonic vibration(UV)firstly,and then formed by squeeze casting(SC).Results show that the FRPs in as-cast SC alloys are composed of coarseβ-Al5(Fe,Mn)Si,δ-Al4(Fe,Mn)Si2 and bone-shapedα-Al15(Fe,Mn)3Si2 phases when the pressure is 0 MPa.With RSC process,the FRPs are first refined by UV,and then the solidification under pressure further causes the grains to become smaller.The peritectic transformation occurs during the formation ofαphase.For the alloy with the same composition,the ultimate tensile strength(UTS)of RSC sample is higher than that of the SC sample.With the same forming process,the UTS of Al-14Si-2Fe-0.8Mn alloy is higher than that of Al-14Si-2Fe-0.4Mn alloy.
基金Projects(51471064,51301054)supported of the National Natural Science Foundation of ChinaProject(1253-NCET-009)supported by the Program for New Century Excellent Talents,China+1 种基金Project(1251G022)supported by Program for Youth Academic Backbone in Heilongjiang Provincial University,ChinaProject(12541138)supported by Scientific Research Fund of Heilongjiang Provincial Education Department,China
文摘The effects of partial substitution of Fe element for Ni element on the structure,martensitic transformation and mechanicalproperties of Ni50-xFexMn38Sn12(x=0and3%,molar fraction)ferromagnetic shape memory alloys were investigated.Experimentalresults indicate that by substitution of Fe for Ni,the microstructure and crystal structure of the alloys change at room temperature.Compared with Ni50Mn38Sn12alloy,the martensitic transformation starting temperature of Ni47Fe3Mn38Sn12alloy is decreased by32.5K.It is also found that martensitic transformation occurs over a broad temperature window from288.9to352.2K.It is found that themechanical properties of Ni-Mn-Sn alloy can be significantly improved by Fe addition.The Ni47Fe3Mn38Sn12alloy achieves amaximum compressive strength of855MPa with a fracture strain of11%.Moreover,the mechanism of the mechanical propertyimprovement is clarified.Fe doping changes the fracture type from intergranular fracture of Ni50Mn38Sn12alloy to transgranularcleavage fracture of Ni47Fe3Mn38Sn12alloys.
基金Supported by the Double Branch Plan of Sichuan Agricultural University(Nos.03571421,03571779)
文摘Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths.Otolith development was observed and their formation period was verifi ed by monitoring larvae and juveniles of knownage.The results revealed that lapilli and sagittae developed before hatching,and the first otolith increment was identified at 2 days post hatching in both.The shape of lapilli was relatively stable during development compared with that of sagittae;however,growth of four sagittae and lapilli areas was consistent,but the posterior area grew faster than the anterior area and the ventral surface grew faster than the dorsal surface.Similarly,the sum length of the radius of the anterior and posterior areas on sagittae and lapilli were linearly and binomially related to total fish length,respectively.Moreover,daily deposition rates were validated by monitoring knownage larvae and juveniles.The increase in lapilli width was 1.88±0.080 0μm at the ninth increment,which reached a maximum and the decreased gradually toward the otolith edge,whereas that of sagittae increased more slowly.These results illustrate the developmental biology of S.davidi,which will aid in population conservation and fish stock management.
基金Supported by the Earmarked Fund for Modern Agro-Industry Technology Research System(No.CARS-50-G01)the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A408-8)
文摘The dynamics of changes in body shape of fast-growing and slow-growing strains of turbot Scophthalmus maximus, and of the differences in body shape between the two strains, were evaluated from 3 to 27 months of age. The ratios of total length/body length, body width/body length and total length/body width were used as morphometric indices. The two strains exhibited different temporal trends in total length/body length but similar trends in body width/body length and total length/body width. Generally, body width/body length of the two strains increased with time and total length/body width decreased. Thus, the bodies of both fast-growing and slow-growing strains of turbot changed from a narrow to a more rounded shape. However, the ratio total length/body length was generally lower, body width/body length was mostly higher and total length/body width was consistently lower in the fast-growing strain than in the slowgrowing strain. Correlation analysis of the three shape ratios with body weight showed that total length/body length and total length/body width were unsuitable, and that width/body length was suitable, for use as a phenotypic marker for selective breeding of turbot for growth in weight.
文摘The purpose of this paper is looking for associations between environmental factors and morphological parameters in tambaqui (Piaractus brachypomus) individuals to differentiate this species in lentic environments (lake) and lotic (river). In this, regard studied 30 specimens, 15 from lentic environment (lake) and 15 from lotic (river). Also, on right profile of these 25 morphometric variables were measured. On data matrix a PCA (principal components analysis) based on morphometric correlations matrix, which was defined in the new morphologic space of these specimens (3 principal components) which explain 73.23% of variability. Fish projection in first two principal components showed a morphological differentiation between two environments (lentic and lotic), with variables as, horizontal eye diameter, length maxilla, suggesting greater response of these fish in lotic environment by their adaptation to light conditions, predators threat and food distribution. Finally, in lotic environment these fish have thinner caudal peduncle, indicating greater plasticity, namely stylized fish.
基金Supported by the National Natural Science Foundation of China(21322604,21476121,21136006)NSAF(U1530107)+1 种基金the National Basic Research Programof China(2012CBA01203)and Tsinghua University Initiative Scientific Research Program(2014z21026)
文摘Multiphase emulsions could be used as templates in considerable fields such as coating, optical materials, stan- dard particles and biomedicine. Among various emulsion forming methods, microfluidic technology, with good monodispersity, high controllability and operation simplicity, has been widely used in the preparation of multi- phase emulsions with different systems. This review would focus on the basic principles of forming multiphase emulsions, the recent progress in controlling multiphase flow in microfluidics, and preparation of functional ma- terials with microfluidics mainly by the authors' research group. We believe that the review will contribute to the readers in this prospective area very well. ~ 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.