[Objective] The aim of the research was to study the effect of the ice bath time after heat shock and the incubation time on the transformation efficacy,and to establish a simple and quick transformation method.[Metho...[Objective] The aim of the research was to study the effect of the ice bath time after heat shock and the incubation time on the transformation efficacy,and to establish a simple and quick transformation method.[Method]Competent cells were prepared with two buffer solutions;with the ice bath time after heat shock and the recovery time as the variables,the relationship between these two factors and transformation efficacy was studied.[Result]The transformation efficacy was the best when the ice bath time was 2 min and the recovery time was 30 or 40 min;when the ice bath time and the recovery time was 0 min,a certain amount of transformants still could be obtained.[Conclusion]The ice bath time after heat shock and the recovery time had certain impact on transformation efficacy,but they were not the decisive factors.Therefore,in the general transformation experiment,these two steps could be omitted.展开更多
A mathematical formulation is developed to represent the magneticfield intensity, the current density, the velocity field, the temperature field in the DC arc furnace bath.The governing equations are solved numericall...A mathematical formulation is developed to represent the magneticfield intensity, the current density, the velocity field, the temperature field in the DC arc furnace bath.The governing equations are solved numerically to describe the magnetic field intensity profiles, the current density profiles, Lorentz force profiles, streamline profiles, the velocity profiles and temperature profiles in the 30t DC-EAF bath. The theoretical predictions of temperature field are in good agreement with measurement in the 30t DC-EAF bath, and the recirculation rate of flow is also in good agreement with published estimation.展开更多
Vibrio vulnificus can cause rotten-skin disease in marine fish aquaculture, resulting in a large number of deaths. The occurrence of rotten-skin disease is becoming severer and severer, leading to serious economic los...Vibrio vulnificus can cause rotten-skin disease in marine fish aquaculture, resulting in a large number of deaths. The occurrence of rotten-skin disease is becoming severer and severer, leading to serious economic losses. In this study, the sensitivities of V. vulnificus to the 18 kinds of herbs, such as stone calamus and Chinese rhubarb, were determined using the agar diffusion method （susceptibility paper）. The results showed that Chinese gall, dark plum, sea buckthorn and eucalyptus leaves have bacteriostatic and bactericidal effects, while sappan wood, Chi- nese rhubarb, pomegranate bark, mentha and clove have strong bacteriostatic ef- fects. The Chinese medicinal herb bath showed good control effect on V. vulnificus.展开更多
Objective To investigate the effects of short-term forest bathing on human health. Methods Twenty healthy male university students participated as subjects and were randomly divided into two groups of 10. One group wa...Objective To investigate the effects of short-term forest bathing on human health. Methods Twenty healthy male university students participated as subjects and were randomly divided into two groups of 10. One group was sent on a two-night trip to a broad-leaved evergreen forest, and the other was sent to a city area. Serum cytokine levels reflecting inflammatory and stress response, indicators reflecting oxidative stress, the distribution of leukocyte subsets, and plasma endothelin-1 （ET-1） concentrations were measured before and after the experiment to evaluate the positive health effects of forest environments. A profile of mood states （POMS） evaluation was used to assess changes in mood states. Results No significant differences in the baseline values of the indicators were observed between the two groups before the experiment. Subjects exposed to the forest environment showed reduced oxidative stress and pro-inflammatory level, as evidenced by decreased malondialdehyde, interleukin-6, and tumor necrosis factor a levels compared with the urban group. Serum cortisol levels were also lower than in the urban group. Notably, the concentration of plasma ET-1 was much lower in subjects exposed to the forest environment. The POMS evaluation showed that after exposure to the forest environment, subjects had lower scores in the negative subscales, and the score for vigor was increased. Conclusion Forest bathing is beneficial to human health, perhaps through preventive effects related to several pathological factors.展开更多
A mathematical model was developed to describe the interaction of multiple physical fields in a slag bath during electroslag remelting （ESR） process with a current-conductive mould. The distributions of current dens...A mathematical model was developed to describe the interaction of multiple physical fields in a slag bath during electroslag remelting （ESR） process with a current-conductive mould. The distributions of current density, magnetic induction intensity, electromagnetic force, Joule heating, fluid flow and temperature were simulated. The model was verified by temperature measurements during remelting 12CrMoVG steel with a slag of 50wt%-70wt% CaF2, 20wt%-30wt% CaO, 10wt%-20wt% A1203, and 〈10wt% SiO2 in a 600 mm diameter current-conductive mould. There is a good agreement between the calculated temperature results and the measured data in the slag bath. The calculated results show that the maximum values of current density, electromagnetic force and Joule heating are in the region between the comer electrodes and the conductivity element. The characteristics of current density distribution, magnetic induction intensity, electromagnetic force, Joule heating, velocity patterns and temperature profiles in the slag bath during ESR process with current-conductive mould were analyzed.展开更多
A mathematical model describing the flow field, heat transfer and the electromagnetic phenomenon in a DC electric arc furnace has been developed. First the governing equations in the arc plasma region are solved and t...A mathematical model describing the flow field, heat transfer and the electromagnetic phenomenon in a DC electric arc furnace has been developed. First the governing equations in the arc plasma region are solved and the calculated results of heat transfer, current density and shear stresses on the anode surface are used as boundary conditions in a model of molten bath. Then a two-dimensional time-dependent model is used to describe the flow field and electromagnetic phenomenon in the molten bath. Moreover, the effect of bottom electrode diameter on the circulation of molten bath is studied.展开更多
In this article, the growth process of chemical bath deposited CdS films was systematically investigated. The structural, optical, and morphological properties were investigated by X-ray diffraction （XRD）, transmiss...In this article, the growth process of chemical bath deposited CdS films was systematically investigated. The structural, optical, and morphological properties were investigated by X-ray diffraction （XRD）, transmission electron microscope （TEM）, UV-Vis spectrophotometer, scanning electron microscope （SEM）, respectively. CdS nanocubes with size of less than 500 nm and nanocrystal-lites with diameter of less than 5 nm forming in reaction solution are observed. According to the TEM results and the SEM morphological evolution of CdS films, a crystal-lite-by-crystallite growth mechanism is proposed to eluci-date the growth process of chemical bath deposited CdS films based on the present growth mechanism.展开更多
SnS and SnS：In films were deposited onto glass substrates by chemical bath technique. The structure and surface morphology of the SnS：In films were studied by X-ray diffraction （XRD） and scanning electron microsco...SnS and SnS：In films were deposited onto glass substrates by chemical bath technique. The structure and surface morphology of the SnS：In films were studied by X-ray diffraction （XRD） and scanning electron microscope （SEM） respectively. Energy dispersive spectroscopy （EDS） showed the existence of In in the films. The undoped SnS film exhibited a rather high resistivity and InCl3 could reduce the resistivity of these films by two orders approximately. The band gaps of the SnS and SnS：In films were evaluated from the optical transmission spectra.展开更多
The molten slag in smelting reduction with iron bath has peculiar behaviour for its high FeO concentration. Slag foaming is effected by the concentration and reduction rate of FeO, basicity of slag and temperature. Ad...The molten slag in smelting reduction with iron bath has peculiar behaviour for its high FeO concentration. Slag foaming is effected by the concentration and reduction rate of FeO, basicity of slag and temperature. Addition of granulated coke can greatly decrease slag foaming extent in the process of smelting reduction with iron bath. The anti-foaming capacity of granulated coke is the best when the ratio of coke used for coke layer to total coke used in smelting reduction is controlled at about 20%.展开更多
Effect of bath composition （[Co^2＋]/[-Pt^Ⅳ ] and [-WO4^2- ], [cit^-]） and pH on the magnetic properties of electrodeposited Co-Pt-W thin films has been investigated. Electrodeposited Co-Pt-W thin films exhibited s...Effect of bath composition （[Co^2＋]/[-Pt^Ⅳ ] and [-WO4^2- ], [cit^-]） and pH on the magnetic properties of electrodeposited Co-Pt-W thin films has been investigated. Electrodeposited Co-Pt-W thin films exhibited strong perpendicular magnetic anisotropy when the ratio of [-Co^2＋ ] to [-Pt^Ⅳ ] was 10 ; cathode current efficiency and perpendicular magnetic anisotropy showed little variations when [WO4^2- ] was lower than 0. 1 mol/L, but perpendicular magnetic anisotropy had strengthened when [WO4^2-] was over 0. 1 mol/L, which could be explained by the fact that the hydrogen evolution could produce pores as magnetic domain pinnings; citrate as complexing reagent can promote the polarization of [Co^2＋] and [Pt^Ⅳ]. As a result, the equilibrium electrode potentials of cobalt and platinum moved to negative direction, which led to the co-deposition of Co, Pt, and W. It was also found out that the as-deposited Co- Pt-W hard magnetic thin films were very homogeneous, smooth, and had the maximum coercivity for the bath pH 8. 5 and the concentration of citrate 0. 26 mol/L.展开更多
The electrochemical method was used to remove nickel ion from spent electroless nickel plating bath (pH=5 3). An electrolytic cell was composed of a porous nickel foam cathode and an inert RuO 2/Ti anode. Nickel ions ...The electrochemical method was used to remove nickel ion from spent electroless nickel plating bath (pH=5 3). An electrolytic cell was composed of a porous nickel foam cathode and an inert RuO 2/Ti anode. Nickel ions were reduced and deposited on the surface of the nickel foam cathode. The effect of current density (i), linear velocity of wastewater(v), gap between cathode and anode(d C/A) and reaction time(t) on nickel removal rate and current efficiency were studied. As reaction time prolonged, nickel removal rate increased while current efficiency decreased. And larger v and smaller d C/A can enhance nickel removal rate and increase current efficiency by promoting mass transfer and dropping concentration polarization. The effect of current density on nickel removal by electrochemistry was related to other parameters. After three hours’ electrolysis with i=1 0 A/dm2, v=18 5 cm/min and d C/A=0 5 cm, nickel removal rate and current efficiency reached 85 6% and 29 1%, respectively.展开更多
基金Supported by Foundation for Returned Scholars of Hebei Province(2010)Research Fund for the Doctoral Program of Hebei Normal University(L2009B13)~~
文摘[Objective] The aim of the research was to study the effect of the ice bath time after heat shock and the incubation time on the transformation efficacy,and to establish a simple and quick transformation method.[Method]Competent cells were prepared with two buffer solutions;with the ice bath time after heat shock and the recovery time as the variables,the relationship between these two factors and transformation efficacy was studied.[Result]The transformation efficacy was the best when the ice bath time was 2 min and the recovery time was 30 or 40 min;when the ice bath time and the recovery time was 0 min,a certain amount of transformants still could be obtained.[Conclusion]The ice bath time after heat shock and the recovery time had certain impact on transformation efficacy,but they were not the decisive factors.Therefore,in the general transformation experiment,these two steps could be omitted.
文摘A mathematical formulation is developed to represent the magneticfield intensity, the current density, the velocity field, the temperature field in the DC arc furnace bath.The governing equations are solved numerically to describe the magnetic field intensity profiles, the current density profiles, Lorentz force profiles, streamline profiles, the velocity profiles and temperature profiles in the 30t DC-EAF bath. The theoretical predictions of temperature field are in good agreement with measurement in the 30t DC-EAF bath, and the recirculation rate of flow is also in good agreement with published estimation.
基金Supported by Incentive Program Subsidized by Department of Science and Technology of Hebei Province(15926620H)Key Technology Research and Development Program of Science and Technology Bureau of Qinhuangdao City(201401A067,201402B043)~~
文摘Vibrio vulnificus can cause rotten-skin disease in marine fish aquaculture, resulting in a large number of deaths. The occurrence of rotten-skin disease is becoming severer and severer, leading to serious economic losses. In this study, the sensitivities of V. vulnificus to the 18 kinds of herbs, such as stone calamus and Chinese rhubarb, were determined using the agar diffusion method （susceptibility paper）. The results showed that Chinese gall, dark plum, sea buckthorn and eucalyptus leaves have bacteriostatic and bactericidal effects, while sappan wood, Chi- nese rhubarb, pomegranate bark, mentha and clove have strong bacteriostatic ef- fects. The Chinese medicinal herb bath showed good control effect on V. vulnificus.
基金supported by the project "Modern forestry-exploitation and utilization of therapeutic forest" commissioned by the Forestry Department of Zhejiang Provincefunds from the Ministry of Health of P.R.China (WKJ2011-2-014)+1 种基金the Science and Technology Department of Zhejiang Province Program (2008C33046)Zhejiang Provincial key disciplinary fields of Geriatrics Program (2007ZB006 and 2008ZJ004)
文摘Objective To investigate the effects of short-term forest bathing on human health. Methods Twenty healthy male university students participated as subjects and were randomly divided into two groups of 10. One group was sent on a two-night trip to a broad-leaved evergreen forest, and the other was sent to a city area. Serum cytokine levels reflecting inflammatory and stress response, indicators reflecting oxidative stress, the distribution of leukocyte subsets, and plasma endothelin-1 （ET-1） concentrations were measured before and after the experiment to evaluate the positive health effects of forest environments. A profile of mood states （POMS） evaluation was used to assess changes in mood states. Results No significant differences in the baseline values of the indicators were observed between the two groups before the experiment. Subjects exposed to the forest environment showed reduced oxidative stress and pro-inflammatory level, as evidenced by decreased malondialdehyde, interleukin-6, and tumor necrosis factor a levels compared with the urban group. Serum cortisol levels were also lower than in the urban group. Notably, the concentration of plasma ET-1 was much lower in subjects exposed to the forest environment. The POMS evaluation showed that after exposure to the forest environment, subjects had lower scores in the negative subscales, and the score for vigor was increased. Conclusion Forest bathing is beneficial to human health, perhaps through preventive effects related to several pathological factors.
基金supported by China Postdoctoral Science Foundation (No.20100471452)
文摘A mathematical model was developed to describe the interaction of multiple physical fields in a slag bath during electroslag remelting （ESR） process with a current-conductive mould. The distributions of current density, magnetic induction intensity, electromagnetic force, Joule heating, fluid flow and temperature were simulated. The model was verified by temperature measurements during remelting 12CrMoVG steel with a slag of 50wt%-70wt% CaF2, 20wt%-30wt% CaO, 10wt%-20wt% A1203, and 〈10wt% SiO2 in a 600 mm diameter current-conductive mould. There is a good agreement between the calculated temperature results and the measured data in the slag bath. The calculated results show that the maximum values of current density, electromagnetic force and Joule heating are in the region between the comer electrodes and the conductivity element. The characteristics of current density distribution, magnetic induction intensity, electromagnetic force, Joule heating, velocity patterns and temperature profiles in the slag bath during ESR process with current-conductive mould were analyzed.
文摘A mathematical model describing the flow field, heat transfer and the electromagnetic phenomenon in a DC electric arc furnace has been developed. First the governing equations in the arc plasma region are solved and the calculated results of heat transfer, current density and shear stresses on the anode surface are used as boundary conditions in a model of molten bath. Then a two-dimensional time-dependent model is used to describe the flow field and electromagnetic phenomenon in the molten bath. Moreover, the effect of bottom electrode diameter on the circulation of molten bath is studied.
基金financially supported by the National Natural Science Foundation of China(No.21101151)the Innovative Talent Program of Institute of Electrical Engineering(No.O940171C41)
文摘In this article, the growth process of chemical bath deposited CdS films was systematically investigated. The structural, optical, and morphological properties were investigated by X-ray diffraction （XRD）, transmission electron microscope （TEM）, UV-Vis spectrophotometer, scanning electron microscope （SEM）, respectively. CdS nanocubes with size of less than 500 nm and nanocrystal-lites with diameter of less than 5 nm forming in reaction solution are observed. According to the TEM results and the SEM morphological evolution of CdS films, a crystal-lite-by-crystallite growth mechanism is proposed to eluci-date the growth process of chemical bath deposited CdS films based on the present growth mechanism.
基金supported by the Science Foundation of Shanghai Municipal Commission of Science and Technology （Grant No.03DZ12033）, and the Shanghai Leading Academic Discipline （Grant No.T0101）
文摘SnS and SnS：In films were deposited onto glass substrates by chemical bath technique. The structure and surface morphology of the SnS：In films were studied by X-ray diffraction （XRD） and scanning electron microscope （SEM） respectively. Energy dispersive spectroscopy （EDS） showed the existence of In in the films. The undoped SnS film exhibited a rather high resistivity and InCl3 could reduce the resistivity of these films by two orders approximately. The band gaps of the SnS and SnS：In films were evaluated from the optical transmission spectra.
文摘The molten slag in smelting reduction with iron bath has peculiar behaviour for its high FeO concentration. Slag foaming is effected by the concentration and reduction rate of FeO, basicity of slag and temperature. Addition of granulated coke can greatly decrease slag foaming extent in the process of smelting reduction with iron bath. The anti-foaming capacity of granulated coke is the best when the ratio of coke used for coke layer to total coke used in smelting reduction is controlled at about 20%.
基金Item Sponsored by National Natural Science Foundation of China(20571067)
文摘Effect of bath composition （[Co^2＋]/[-Pt^Ⅳ ] and [-WO4^2- ], [cit^-]） and pH on the magnetic properties of electrodeposited Co-Pt-W thin films has been investigated. Electrodeposited Co-Pt-W thin films exhibited strong perpendicular magnetic anisotropy when the ratio of [-Co^2＋ ] to [-Pt^Ⅳ ] was 10 ; cathode current efficiency and perpendicular magnetic anisotropy showed little variations when [WO4^2- ] was lower than 0. 1 mol/L, but perpendicular magnetic anisotropy had strengthened when [WO4^2-] was over 0. 1 mol/L, which could be explained by the fact that the hydrogen evolution could produce pores as magnetic domain pinnings; citrate as complexing reagent can promote the polarization of [Co^2＋] and [Pt^Ⅳ]. As a result, the equilibrium electrode potentials of cobalt and platinum moved to negative direction, which led to the co-deposition of Co, Pt, and W. It was also found out that the as-deposited Co- Pt-W hard magnetic thin films were very homogeneous, smooth, and had the maximum coercivity for the bath pH 8. 5 and the concentration of citrate 0. 26 mol/L.
文摘The electrochemical method was used to remove nickel ion from spent electroless nickel plating bath (pH=5 3). An electrolytic cell was composed of a porous nickel foam cathode and an inert RuO 2/Ti anode. Nickel ions were reduced and deposited on the surface of the nickel foam cathode. The effect of current density (i), linear velocity of wastewater(v), gap between cathode and anode(d C/A) and reaction time(t) on nickel removal rate and current efficiency were studied. As reaction time prolonged, nickel removal rate increased while current efficiency decreased. And larger v and smaller d C/A can enhance nickel removal rate and increase current efficiency by promoting mass transfer and dropping concentration polarization. The effect of current density on nickel removal by electrochemistry was related to other parameters. After three hours’ electrolysis with i=1 0 A/dm2, v=18 5 cm/min and d C/A=0 5 cm, nickel removal rate and current efficiency reached 85 6% and 29 1%, respectively.
