We present a study on the magnetocaloric properties of a CaBaCo_(4)O_(7) polycrystalline cobaltite along with research on the nature of magnetic phase transition.The magnetization as a function of temperature identifi...We present a study on the magnetocaloric properties of a CaBaCo_(4)O_(7) polycrystalline cobaltite along with research on the nature of magnetic phase transition.The magnetization as a function of temperature identifies the ferrimagnetic to paramagnetic transition at a Curie temperature of 60 K.Moreover,a Griffiths-like phase is confirmed in a temperature range above T_(C).The compound undergoes a crossover from the first to second-order ferrimagnetic transformation,as evidenced by the Arrott plots,scaling of the universal entropy curve,and field-dependent magnetic entropy change.The maximum of entropy change is 3 J/kg⋅K for ΔH=7 T at T_(C),and a broadening of the entropy peak with increasing magnetic field indicates a field-induced transition above T_(C).The analysis of the magnetic entropy change using the Landau theory reveals the second-order phase transition and indicates that the magnetocaloric properties of CaBaCo_(4)O_(7) are dominated by the magnetoelastic coupling and electron interaction.The corresponding values of refrigerant capacity and relative cooling power are estimated to be 33 J/kg and 42 J/kg,respectively.展开更多
The mechanical properties of fresh lotus seeds are still poorly understood,which complicates the design of mechanical shelling machinery.Therefore,this work carried out four-factor orthogonal tests to determine the ma...The mechanical properties of fresh lotus seeds are still poorly understood,which complicates the design of mechanical shelling machinery.Therefore,this work carried out four-factor orthogonal tests to determine the maximum permitted compressive force and minimum necessary shearing force to shell fresh lotus seeds without rupturing the kernel.It was found that the mean compression force that cracked the fresh lotus seed and led to kernel rupture was 213.03 N.Both the compressive force and the seed deformation upon kernel rupture were affected,in descending order of significance,by loading mode,seed grade,loading rate,and seed standing time.On the other hand,the shearing force needed to shell the seeds had a mean value of 7.84 N,far less than the compressive force that cracked the seed shell.The shearing force was affected,in descending order of significance,by seed standing time,tip angle of cutter blade,and loading rate,but not significantly affected by seed grade.The results suggested that mechanical shelling of fresh lotus seeds should ideally be carried out for fresh lotus seeds with a standing time of no more than 6 h using a cutter blade with an angle of about 40°at a loading rate of 30-90 mm/min.展开更多
Refined management is an inevitable trend in the development of livestock husbandry.Accurate acquisition of breeding environment parameters is beneficial to improve breeding efficiency while reducing environmental pol...Refined management is an inevitable trend in the development of livestock husbandry.Accurate acquisition of breeding environment parameters is beneficial to improve breeding efficiency while reducing environmental pollution.Light is an important breeding environmental factor during broiler breeding.In this study,a short-term broiler breeding experiment was conducted with different light color illumination environments in a digital breeding chamber under lab conditions.According to experimental results,the Red Light(RL)group was conducive to the growth of broilers at 30 d of age with low NH3 emission concentration;the Green Light(GL)group inhibited the broiler growth;the Yellow Light(YL)group showed the highest average emission concentration of NH3 and lowest daily average emission concentration of CO_(2).According to the analysis of moisture content,pH value,and C/N in the broiler manure,it can be concluded that the physical and chemical properties of broiler defecation quantities were different under various light color illuminations,resulting in the difference in broiler growth conditions and harmful gas emissions.The study results could provide a research basis and ideas of reference to establish a relationship between LED illumination information,broiler growth performance,and harmful gas emission.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No.51725104)Beijing Natural Science Foundation (Grant No.Z180009)。
文摘We present a study on the magnetocaloric properties of a CaBaCo_(4)O_(7) polycrystalline cobaltite along with research on the nature of magnetic phase transition.The magnetization as a function of temperature identifies the ferrimagnetic to paramagnetic transition at a Curie temperature of 60 K.Moreover,a Griffiths-like phase is confirmed in a temperature range above T_(C).The compound undergoes a crossover from the first to second-order ferrimagnetic transformation,as evidenced by the Arrott plots,scaling of the universal entropy curve,and field-dependent magnetic entropy change.The maximum of entropy change is 3 J/kg⋅K for ΔH=7 T at T_(C),and a broadening of the entropy peak with increasing magnetic field indicates a field-induced transition above T_(C).The analysis of the magnetic entropy change using the Landau theory reveals the second-order phase transition and indicates that the magnetocaloric properties of CaBaCo_(4)O_(7) are dominated by the magnetoelastic coupling and electron interaction.The corresponding values of refrigerant capacity and relative cooling power are estimated to be 33 J/kg and 42 J/kg,respectively.
基金This work was financially supported by the National Natural Science Foundation(Grant No.31772039)and the Special Fund for Key Program of Science and Technology of Fujian(Grant No.2018NZ003).
文摘The mechanical properties of fresh lotus seeds are still poorly understood,which complicates the design of mechanical shelling machinery.Therefore,this work carried out four-factor orthogonal tests to determine the maximum permitted compressive force and minimum necessary shearing force to shell fresh lotus seeds without rupturing the kernel.It was found that the mean compression force that cracked the fresh lotus seed and led to kernel rupture was 213.03 N.Both the compressive force and the seed deformation upon kernel rupture were affected,in descending order of significance,by loading mode,seed grade,loading rate,and seed standing time.On the other hand,the shearing force needed to shell the seeds had a mean value of 7.84 N,far less than the compressive force that cracked the seed shell.The shearing force was affected,in descending order of significance,by seed standing time,tip angle of cutter blade,and loading rate,but not significantly affected by seed grade.The results suggested that mechanical shelling of fresh lotus seeds should ideally be carried out for fresh lotus seeds with a standing time of no more than 6 h using a cutter blade with an angle of about 40°at a loading rate of 30-90 mm/min.
基金The authors acknowledge that this work was financially supported by the Fujian Provincial Natural Science Foundation Project(Grant No.2020J01577)the Fujian Key Laboratory of Agricultural Information Sensoring Technology(Grant No.2021ZDSYS0101).
文摘Refined management is an inevitable trend in the development of livestock husbandry.Accurate acquisition of breeding environment parameters is beneficial to improve breeding efficiency while reducing environmental pollution.Light is an important breeding environmental factor during broiler breeding.In this study,a short-term broiler breeding experiment was conducted with different light color illumination environments in a digital breeding chamber under lab conditions.According to experimental results,the Red Light(RL)group was conducive to the growth of broilers at 30 d of age with low NH3 emission concentration;the Green Light(GL)group inhibited the broiler growth;the Yellow Light(YL)group showed the highest average emission concentration of NH3 and lowest daily average emission concentration of CO_(2).According to the analysis of moisture content,pH value,and C/N in the broiler manure,it can be concluded that the physical and chemical properties of broiler defecation quantities were different under various light color illuminations,resulting in the difference in broiler growth conditions and harmful gas emissions.The study results could provide a research basis and ideas of reference to establish a relationship between LED illumination information,broiler growth performance,and harmful gas emission.
