6 kinds of IPN's PVA were synthesized by using different monomers of HEMA, MAA and MMA. The effect of adding polysaccharide was also studied. The cell growth on them were determined and compared. The results showe...6 kinds of IPN's PVA were synthesized by using different monomers of HEMA, MAA and MMA. The effect of adding polysaccharide was also studied. The cell growth on them were determined and compared. The results showed that the cell growth property of the IPN's PVA with hydrophobic monomer of MMA is better, and it can be improved further by adding hyaluronic acid.展开更多
We report on the single crystal growth and superconducting properties of PbTaSe2 with the non-centrosymmetric crystal structure. By using the chemicM vapor transport technique, centimeter-size single crystals are succ...We report on the single crystal growth and superconducting properties of PbTaSe2 with the non-centrosymmetric crystal structure. By using the chemicM vapor transport technique, centimeter-size single crystals are success- fully obtained. The measurement of temperature dependence of electricaJ resistivity p(T) in both normal and superconducting states indicates a quasi-two-dimensional electronic state in contrast to that of polycrystalline samples. Specific heat C(T) measurement reveals a bulk superconductivity with Tc ≈ 3.75K and a specific heat jump ratio of 1.42. All these results are in agreement with a moderately electron-phonon coupled, type-g Bardeen-Cooper-Schrieffer superconductor.展开更多
In this paper, the spectral and luminescence properties of a series of KGd(WO4)2 powder samples codoped with different concentrations of Er^3+ and Yb^3+ were reported,and the best doping concentrations were found ...In this paper, the spectral and luminescence properties of a series of KGd(WO4)2 powder samples codoped with different concentrations of Er^3+ and Yb^3+ were reported,and the best doping concentrations were found to be lat% Er^3+ and 10at% Yb^3+ for attaining the strongest intensity. The Er^3+/yb^3+ codoped KGd(WO4)2 crystal with good optical quality was grown by the TSSG method and the growth conditions were presented. The unpolarized absorption and emission spectra of the crystal have been measured. The strong absorption peak is at 980 nm with a FWHM of 65 nm, and the emission peak is at 1536 nm when pumped by 976 rim. The fluorescence lifetime of manifold ^4I13/2 is estimated to be 4.5 ms at room temperature.Investigations of Er, Yb:KGW crystal have shown it to have necessary combination of properties to get an effective generation of - 1.54 μm eye-safe radiation with laser diode pumping.展开更多
Chinese herbal medicine additives can not only directly improve the growth performance of chickens,but also indirectly affect the growth of chickens by enhancing the antioxidant capacity,immunity and disease resistanc...Chinese herbal medicine additives can not only directly improve the growth performance of chickens,but also indirectly affect the growth of chickens by enhancing the antioxidant capacity,immunity and disease resistance of the body,and eliminating diseases and adverse factors,thereby improving the growth performance of chickens.In the context of the current national prohibition of adding antibiotics to feed,the research and application of Chinese herbal medicine additives are of practical significance to eliminate the long-term use of antibiotics as chicken feed additives and reduce the threat to the environment and human health.For this reason,the research related to the substitution of Chinese herbal medicine for antibiotics is made a brief introduction to provide a reference in research and production practice.展开更多
The InGaAs/InAIAs/InP high electron mobility transistor (HEM:F) structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and grow...The InGaAs/InAIAs/InP high electron mobility transistor (HEM:F) structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and growth interruption on the electrical properties are investigated by changing the Si-cell temperature, doping time and growth process. It is found that the optimal Si ^-doping concentration (Nd) is about 5.0 x 1012 cm-2 and the use of growth interruption has a dramatic effect on the improvement of electrical properties. The material structure and crystal interface are analyzed by secondary ion mass spectroscopy and high resolution transmission elec- tron microscopy. An InGaAs/InAiAs/InP HEMT device with a gate length of lOOnm is fabricated. The device presents good pinch-off characteristics and the kink-effect of the device is trifling. In addition, the device exhibits fT = 249 GHa and fmax 〉 400 GHz.展开更多
Soil amendment with fly ash(FA) and combined supplementation with N_2-fixing cyanobacteria masses as biofertilizer were done in field experiments with rice. Amendments with FA levels, 0, 0.5, 1.0, 2.0, 4.0, 8.0 and ...Soil amendment with fly ash(FA) and combined supplementation with N_2-fixing cyanobacteria masses as biofertilizer were done in field experiments with rice. Amendments with FA levels, 0, 0.5, 1.0, 2.0, 4.0, 8.0 and 10.0 kg/m2, caused increase in growth and yield of rice up to 8.0 kg/m2, monitored with several parameters. Pigment contents and enzyme activities of leaves were enhanced by FA, with the maximum level of FA at 10.0 kg/m2. Protein content of rice seeds was the highest in plants grown at FA level 4.0 kg/m2. Basic soil properties, p H value, percentage of silt, percentage of clay, water-holding capacity, electrical conductivity, cation exchange capacity, and organic carbon content increased due to the FA amendment. Parallel supplementation of FA amended plots with 1.0 kg/m2 N_2-fixing cyanobacteria mass caused further significant increments of the most soil properties, and rice growth and yield parameters. 1000-grain weight of rice plants grown at FA level 4.0 kg/m2 along with cyanobacteria supplementation was the maximum. Cyanobacteria supplementation caused increase of important basic properties of soil including the total N-content. Estimations of elemental content in soils and plant parts(root and seed) were done by the atomic absorption spectrophotometry. Accumulations of K, P, Fe and several plant micronutrients(Mn, Ni, Co, Zn and Cu) and toxic elements(Pb, Cr and Cd) increased in soils and plant parts as a function of the FA gradation, but Na content remained almost unchanged in soils and seeds. Supplementation of cyanobacteria had ameliorating effect on toxic metal contents of soils and plant parts. The FA level 4.0 kg/m2, with 1.0 kg/m2 cyanobacteria mass supplementation, could be taken ideal, since there would be recharging of the soil with essential micronutrients as well as toxic chemicals in comparative lesser proportions, and cyanobacteria mass would cause lessening toxic metal loads with usual N_2-fixation.展开更多
The titanium oxide (TiO2) nanotubes have attracted attention for their use in dye-sensitized solar cells as photoanode. In this study semiconducting cadmium sulfide (CdS) nanoparticles arc grown on top opened TiO2...The titanium oxide (TiO2) nanotubes have attracted attention for their use in dye-sensitized solar cells as photoanode. In this study semiconducting cadmium sulfide (CdS) nanoparticles arc grown on top opened TiO2 nanotubes arrays by radio-frequency magnetron sputtering. X-ray diffraction, scanning electron mieroscopy, transmission electron microscopy and diffuse reflection spectra are used to study structural, morphological and optical properties of the CdS/TiO2 bilayer.展开更多
The Be films were prepared by thermal evaporation at different sources to substrate distances(SSD) on glass substrates. The decrease of SSD from 90 mm to 50 mm caused the increase of substrate temperature and the ri...The Be films were prepared by thermal evaporation at different sources to substrate distances(SSD) on glass substrates. The decrease of SSD from 90 mm to 50 mm caused the increase of substrate temperature and the rising density of incident Be atoms, thus the properties of Be films greatly changed accordingly. The experimental results showed that the grain diameter in the Be films transited from below 100 nm to 300 nm, the film growth rate increased from 2.35 nm/min to 4.73 nm/min and the roughness increased from 7 nm to 49 nm. The performance study suggested that the friction coefficient of Be films increased from 0.13 to 0.27 and was related to the surface roughness and inner structure, the near-infrared reflectance of Be films increased from 40% to 85% with the increase of wavelength and concurrently decreased with the decrease of SSD, respectively. The performance study indicated that the Be film had the potential application in specific near-infrared reflectance optical system.展开更多
Al-doped ZnO(AZO) thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures(P_(O2)).The effect of P_(O2) on the crystal structure,preferred orientation as well a...Al-doped ZnO(AZO) thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures(P_(O2)).The effect of P_(O2) on the crystal structure,preferred orientation as well as the electrical and optical properties of the films was investigated.The structure characterizations indicated that the as-grown films were single-phased with a wurtzite ZnO structure,showing a significant c-axis orientation.The films were well crystallized and exhibited better crystallinity and denser texture when deposited at higher P_(O2).At the optimum oxygen partial pressures of 10- 15 Pa,the AZO thin films were epitaxially grown on c-sapphire substrates with the(0001) plane parallel to the substrate surface,i e,the epitaxial relationship was AZO(000 1) // A1_2O_3(000 1).With increasing P_(O2),the value of Hall carrier mobility was increased remarkably while that of carrier concentration was decreased slightly,which led to an enhancement in electrical conductivity of the AZO thin films.All the films were highly transparent with an optical transmittance higher than 85%.展开更多
Polysilicon films deposited by low-pressure chemical vapor deposition (LPCVD) exhibit large residual stress and stress gradient, depending on the deposition condition. An in situ growth method based on multilayer conc...Polysilicon films deposited by low-pressure chemical vapor deposition (LPCVD) exhibit large residual stress and stress gradient, depending on the deposition condition. An in situ growth method based on multilayer concept is presented to control the property for as-deposited polysilicon. A 3-μm thick polysilicon film with nine layers structure is demonstrated under the detailed analysis of multi-layer theory and material characteristic of polysilicon. The results show that a 3-μm-thick polysilicon film with 8-MPa overall residual tensile stress and 2.125-MPa/μm stress gradient through the film thickness is fabricated successfully.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
Acicular goethite(a-Fe OOH) and worm-like maghamite(γ-Fe2O3) nanostructures have been prepared adopting a novel route, using Na2[Fe(HL)2(H2O)2] chelate complex in alkaline medium. It is found that concentrati...Acicular goethite(a-Fe OOH) and worm-like maghamite(γ-Fe2O3) nanostructures have been prepared adopting a novel route, using Na2[Fe(HL)2(H2O)2] chelate complex in alkaline medium. It is found that concentration of hydrated Fe(III) ions increased with increasing temperature, which later play a key role in generation of different phases of iron oxide. Phase and morphology of the products are investigated using XRD, FTIR, SEM, and TEM analysis. Using UV–Vis spectra, various electronic transitions of goethite and maghamite particles are examined. Maghamite nanostructures exhibit superparamagnetic property at room temperature. On the basis of experimental observations and analytical data, growth mechanism of the nanostructures is discussed.展开更多
Additive manufacturing is believed to open up a new era in precise microfabrication,and the dynamic microstructure evolution during the process as well as the experiment-simulation correlated study is conducted on a p...Additive manufacturing is believed to open up a new era in precise microfabrication,and the dynamic microstructure evolution during the process as well as the experiment-simulation correlated study is conducted on a prototype multi-principal-element alloys FeCrNi fabricated using selective laser melting(SLM).Experimental results reveal that columnar crystals grow across the cladding layers and the dense cellular structures develop in the filled crystal.At the micron scale,all constituent elements are evenly distributed,while at the near-atomic scale,Cr element is obviously segregated.Simulation results at the atomic scale illustrate that i)the solid-liquid interface during the grain growth changes from horizontal to arc due to the radial temperature gradient;ii)the precipitates,microscale voids,and stacking faults also form dynamically as a result of the thermal gradient,leading to the residual stress in the SLMed structure.In addition,we established a microstructure-based physical model based on atomic simulation,which indicates that strong interface strengthening exists in the tensile deformation.The present work provides an atomic-scale understanding of the microstructural evolution in the SLM process through the combination of experiment and simulation.展开更多
With words as nodes,and a link exits between two neighboring words,the weighted directed English and Chinese written human language networks are constructed from one English novel and two Chinese ones.We hereby analyz...With words as nodes,and a link exits between two neighboring words,the weighted directed English and Chinese written human language networks are constructed from one English novel and two Chinese ones.We hereby analyze in detail the topological structure of them,in order to clarify their similar and different statistical properties.The empirical results show that the English and Chinese language networks all possess the shifted power law(SPL)degree distribution,the small-world property and the hierarchical structure,the connections among the words have positive assortativity coefficient and reciprocal characteristics.We also investigate the features of the strength and the centrality,which describe the importance of a specific word.Furthermore,considering the growth properties of the language networks and part of topological property,we find that the English written human language network grows slower than the Chinese one,which implies different mechanisms of the English and Chinese languages.展开更多
The microstructure, microsegregation, and mechanical properties of directional solidified Mg–3.0Nd–1.5Gd ternary alloys were experimentally studied. Experimental results showed that the solidification microstructure...The microstructure, microsegregation, and mechanical properties of directional solidified Mg–3.0Nd–1.5Gd ternary alloys were experimentally studied. Experimental results showed that the solidification microstructure was composed of dendrite primary a(Mg) phase and interdendritic a(Mg) · Mg12(Nd, Gd) eutectic and Mg5 Gd phase. The primary dendrite arm spacing k1 and secondary dendrite arm spacing k2 were found to be depended on the cooling rate R in the form k1= 8.0415 9 10-6R-0.279 and k2= 6.8883 9 10-6R-0.205, respectively, under the constant temperature gradient of40 K/mm and in the region of cooling rates from 0.4 to 4 K/s. The concentration profiles of Nd and Gd elements calculated by Scheil model were found to be deviated from the ones measured by EPMA to varying degrees, due to ignorance of the back diffusion of the solutes Nd and Gd within a(Mg) matrix. And microsegregation of Gd depended more on the growth rate, compared with Nd microsegregation. The directionally solidified experimental alloy exhibited higher strength than the non-directionally solidified alloy, and the tensile strength of the directionally solidified experimental alloy was improved,while the corresponding elongation decreased with the increase of growth rate.展开更多
Sn/carbon-fibers(CFs) nanocomposite has been prepared by chemical vapor deposition with in-situ catalytic growth of CFs.The nanocomposite has been characterized by X-ray diffraction(XRD),field emission scanning el...Sn/carbon-fibers(CFs) nanocomposite has been prepared by chemical vapor deposition with in-situ catalytic growth of CFs.The nanocomposite has been characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM) and Raman spectrum.The electrochemical performance of the nanocomposite has been investigated by galvanostatic cycling and cyclic voltammetry(CV).It has been found that a three-dimensional conductive network forms by the interconnected CFs,which offers conductive channels for the Sn nanoparticles.The nanocomposite gives a first charge capacity of 385 mAh.g-1 and exhibits an improved cycling stability than bare Sn.展开更多
文摘6 kinds of IPN's PVA were synthesized by using different monomers of HEMA, MAA and MMA. The effect of adding polysaccharide was also studied. The cell growth on them were determined and compared. The results showed that the cell growth property of the IPN's PVA with hydrophobic monomer of MMA is better, and it can be improved further by adding hyaluronic acid.
基金Supported by the National Basic Research Program of China under Grant Nos 2015CB921303,2011CBA00100 and 2012CB821404the Strategic Priority Research Program(B) of Chinese Academy of Sciences under Grant Nos XDB07020100and XDB07020200the National Natural Science Foundation of China under Grant No 11174350
文摘We report on the single crystal growth and superconducting properties of PbTaSe2 with the non-centrosymmetric crystal structure. By using the chemicM vapor transport technique, centimeter-size single crystals are success- fully obtained. The measurement of temperature dependence of electricaJ resistivity p(T) in both normal and superconducting states indicates a quasi-two-dimensional electronic state in contrast to that of polycrystalline samples. Specific heat C(T) measurement reveals a bulk superconductivity with Tc ≈ 3.75K and a specific heat jump ratio of 1.42. All these results are in agreement with a moderately electron-phonon coupled, type-g Bardeen-Cooper-Schrieffer superconductor.
基金This project was supported by the Natural Science Foundation of Fujian Province (No. E0310031) ② Corresponding author. E-mail: tcy@fjirsm.ac.cn
文摘In this paper, the spectral and luminescence properties of a series of KGd(WO4)2 powder samples codoped with different concentrations of Er^3+ and Yb^3+ were reported,and the best doping concentrations were found to be lat% Er^3+ and 10at% Yb^3+ for attaining the strongest intensity. The Er^3+/yb^3+ codoped KGd(WO4)2 crystal with good optical quality was grown by the TSSG method and the growth conditions were presented. The unpolarized absorption and emission spectra of the crystal have been measured. The strong absorption peak is at 980 nm with a FWHM of 65 nm, and the emission peak is at 1536 nm when pumped by 976 rim. The fluorescence lifetime of manifold ^4I13/2 is estimated to be 4.5 ms at room temperature.Investigations of Er, Yb:KGW crystal have shown it to have necessary combination of properties to get an effective generation of - 1.54 μm eye-safe radiation with laser diode pumping.
基金Supported by Guangxi Innovation Team Construction Project of National Modern Agricultural Industrial Technology System(nycytxgxcxtd-19)Guangxi Agricultural Science and Technology Self Financing Project(Z2022114)。
文摘Chinese herbal medicine additives can not only directly improve the growth performance of chickens,but also indirectly affect the growth of chickens by enhancing the antioxidant capacity,immunity and disease resistance of the body,and eliminating diseases and adverse factors,thereby improving the growth performance of chickens.In the context of the current national prohibition of adding antibiotics to feed,the research and application of Chinese herbal medicine additives are of practical significance to eliminate the long-term use of antibiotics as chicken feed additives and reduce the threat to the environment and human health.For this reason,the research related to the substitution of Chinese herbal medicine for antibiotics is made a brief introduction to provide a reference in research and production practice.
基金Supported by the National Natural Science Foundation of China under Grant No 61434006
文摘The InGaAs/InAIAs/InP high electron mobility transistor (HEM:F) structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and growth interruption on the electrical properties are investigated by changing the Si-cell temperature, doping time and growth process. It is found that the optimal Si ^-doping concentration (Nd) is about 5.0 x 1012 cm-2 and the use of growth interruption has a dramatic effect on the improvement of electrical properties. The material structure and crystal interface are analyzed by secondary ion mass spectroscopy and high resolution transmission elec- tron microscopy. An InGaAs/InAiAs/InP HEMT device with a gate length of lOOnm is fabricated. The device presents good pinch-off characteristics and the kink-effect of the device is trifling. In addition, the device exhibits fT = 249 GHa and fmax 〉 400 GHz.
基金supported by the project from Council of Scientific and Industrial Research,New Delhi,India (Grant No.21 (0859)/11/EMR-Ⅱ)
文摘Soil amendment with fly ash(FA) and combined supplementation with N_2-fixing cyanobacteria masses as biofertilizer were done in field experiments with rice. Amendments with FA levels, 0, 0.5, 1.0, 2.0, 4.0, 8.0 and 10.0 kg/m2, caused increase in growth and yield of rice up to 8.0 kg/m2, monitored with several parameters. Pigment contents and enzyme activities of leaves were enhanced by FA, with the maximum level of FA at 10.0 kg/m2. Protein content of rice seeds was the highest in plants grown at FA level 4.0 kg/m2. Basic soil properties, p H value, percentage of silt, percentage of clay, water-holding capacity, electrical conductivity, cation exchange capacity, and organic carbon content increased due to the FA amendment. Parallel supplementation of FA amended plots with 1.0 kg/m2 N_2-fixing cyanobacteria mass caused further significant increments of the most soil properties, and rice growth and yield parameters. 1000-grain weight of rice plants grown at FA level 4.0 kg/m2 along with cyanobacteria supplementation was the maximum. Cyanobacteria supplementation caused increase of important basic properties of soil including the total N-content. Estimations of elemental content in soils and plant parts(root and seed) were done by the atomic absorption spectrophotometry. Accumulations of K, P, Fe and several plant micronutrients(Mn, Ni, Co, Zn and Cu) and toxic elements(Pb, Cr and Cd) increased in soils and plant parts as a function of the FA gradation, but Na content remained almost unchanged in soils and seeds. Supplementation of cyanobacteria had ameliorating effect on toxic metal contents of soils and plant parts. The FA level 4.0 kg/m2, with 1.0 kg/m2 cyanobacteria mass supplementation, could be taken ideal, since there would be recharging of the soil with essential micronutrients as well as toxic chemicals in comparative lesser proportions, and cyanobacteria mass would cause lessening toxic metal loads with usual N_2-fixation.
文摘The titanium oxide (TiO2) nanotubes have attracted attention for their use in dye-sensitized solar cells as photoanode. In this study semiconducting cadmium sulfide (CdS) nanoparticles arc grown on top opened TiO2 nanotubes arrays by radio-frequency magnetron sputtering. X-ray diffraction, scanning electron mieroscopy, transmission electron microscopy and diffuse reflection spectra are used to study structural, morphological and optical properties of the CdS/TiO2 bilayer.
基金Funded by the Laboratory of Precision Manufacturing Technology,China Academy of Engineering Physics(No.ZZ15011)
文摘The Be films were prepared by thermal evaporation at different sources to substrate distances(SSD) on glass substrates. The decrease of SSD from 90 mm to 50 mm caused the increase of substrate temperature and the rising density of incident Be atoms, thus the properties of Be films greatly changed accordingly. The experimental results showed that the grain diameter in the Be films transited from below 100 nm to 300 nm, the film growth rate increased from 2.35 nm/min to 4.73 nm/min and the roughness increased from 7 nm to 49 nm. The performance study suggested that the friction coefficient of Be films increased from 0.13 to 0.27 and was related to the surface roughness and inner structure, the near-infrared reflectance of Be films increased from 40% to 85% with the increase of wavelength and concurrently decreased with the decrease of SSD, respectively. The performance study indicated that the Be film had the potential application in specific near-infrared reflectance optical system.
基金Funded by National Natural Science Foundation of China(Nos.51272195,51521001)111 project(No.B13035)+1 种基金Hubei Provincial National Natural Science Foundation(No.2015CFB724)Fundamental Research Funds for the Central Universities(Nos.2013-ZD-4,2014-KF-3)
文摘Al-doped ZnO(AZO) thin films were grown on c-sapphire substrates by laser ablation under different oxygen partial pressures(P_(O2)).The effect of P_(O2) on the crystal structure,preferred orientation as well as the electrical and optical properties of the films was investigated.The structure characterizations indicated that the as-grown films were single-phased with a wurtzite ZnO structure,showing a significant c-axis orientation.The films were well crystallized and exhibited better crystallinity and denser texture when deposited at higher P_(O2).At the optimum oxygen partial pressures of 10- 15 Pa,the AZO thin films were epitaxially grown on c-sapphire substrates with the(0001) plane parallel to the substrate surface,i e,the epitaxial relationship was AZO(000 1) // A1_2O_3(000 1).With increasing P_(O2),the value of Hall carrier mobility was increased remarkably while that of carrier concentration was decreased slightly,which led to an enhancement in electrical conductivity of the AZO thin films.All the films were highly transparent with an optical transmittance higher than 85%.
文摘Polysilicon films deposited by low-pressure chemical vapor deposition (LPCVD) exhibit large residual stress and stress gradient, depending on the deposition condition. An in situ growth method based on multilayer concept is presented to control the property for as-deposited polysilicon. A 3-μm thick polysilicon film with nine layers structure is demonstrated under the detailed analysis of multi-layer theory and material characteristic of polysilicon. The results show that a 3-μm-thick polysilicon film with 8-MPa overall residual tensile stress and 2.125-MPa/μm stress gradient through the film thickness is fabricated successfully.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 11271045, 11226093) and the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20100003110004).
文摘We give the growth properties of harmonic functions at infinity in a cone, which generalize the results obtained by Siegel-Talvila.
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.
文摘Acicular goethite(a-Fe OOH) and worm-like maghamite(γ-Fe2O3) nanostructures have been prepared adopting a novel route, using Na2[Fe(HL)2(H2O)2] chelate complex in alkaline medium. It is found that concentration of hydrated Fe(III) ions increased with increasing temperature, which later play a key role in generation of different phases of iron oxide. Phase and morphology of the products are investigated using XRD, FTIR, SEM, and TEM analysis. Using UV–Vis spectra, various electronic transitions of goethite and maghamite particles are examined. Maghamite nanostructures exhibit superparamagnetic property at room temperature. On the basis of experimental observations and analytical data, growth mechanism of the nanostructures is discussed.
基金supported by the National Natural Science Foundation of China(Nos.52020105013,51871092,and 11902113)the Natural Science Foundation of Hunan Province(Nos.2019JJ50068 and 2021JJ40032)+1 种基金the Changsha Municipal Natu-ral Science Foundation(No.kq2014126)support from the National Science Foundation(Nos.DMR-1611180 and 1809640).
文摘Additive manufacturing is believed to open up a new era in precise microfabrication,and the dynamic microstructure evolution during the process as well as the experiment-simulation correlated study is conducted on a prototype multi-principal-element alloys FeCrNi fabricated using selective laser melting(SLM).Experimental results reveal that columnar crystals grow across the cladding layers and the dense cellular structures develop in the filled crystal.At the micron scale,all constituent elements are evenly distributed,while at the near-atomic scale,Cr element is obviously segregated.Simulation results at the atomic scale illustrate that i)the solid-liquid interface during the grain growth changes from horizontal to arc due to the radial temperature gradient;ii)the precipitates,microscale voids,and stacking faults also form dynamically as a result of the thermal gradient,leading to the residual stress in the SLMed structure.In addition,we established a microstructure-based physical model based on atomic simulation,which indicates that strong interface strengthening exists in the tensile deformation.The present work provides an atomic-scale understanding of the microstructural evolution in the SLM process through the combination of experiment and simulation.
基金supported by the National Natural Science Foundation of China(Grant Nos.10647125,10635020,10975057 and 10975062)the Programme of Introducing Talents of Discipline to Universities under Grant No.B08033.
文摘With words as nodes,and a link exits between two neighboring words,the weighted directed English and Chinese written human language networks are constructed from one English novel and two Chinese ones.We hereby analyze in detail the topological structure of them,in order to clarify their similar and different statistical properties.The empirical results show that the English and Chinese language networks all possess the shifted power law(SPL)degree distribution,the small-world property and the hierarchical structure,the connections among the words have positive assortativity coefficient and reciprocal characteristics.We also investigate the features of the strength and the centrality,which describe the importance of a specific word.Furthermore,considering the growth properties of the language networks and part of topological property,we find that the English written human language network grows slower than the Chinese one,which implies different mechanisms of the English and Chinese languages.
基金financially supported by the National Natural Science Foundation of China (No. 51071129)the Special Funds of the National Natural Science Foundation of China (No. 51227001)
文摘The microstructure, microsegregation, and mechanical properties of directional solidified Mg–3.0Nd–1.5Gd ternary alloys were experimentally studied. Experimental results showed that the solidification microstructure was composed of dendrite primary a(Mg) phase and interdendritic a(Mg) · Mg12(Nd, Gd) eutectic and Mg5 Gd phase. The primary dendrite arm spacing k1 and secondary dendrite arm spacing k2 were found to be depended on the cooling rate R in the form k1= 8.0415 9 10-6R-0.279 and k2= 6.8883 9 10-6R-0.205, respectively, under the constant temperature gradient of40 K/mm and in the region of cooling rates from 0.4 to 4 K/s. The concentration profiles of Nd and Gd elements calculated by Scheil model were found to be deviated from the ones measured by EPMA to varying degrees, due to ignorance of the back diffusion of the solutes Nd and Gd within a(Mg) matrix. And microsegregation of Gd depended more on the growth rate, compared with Nd microsegregation. The directionally solidified experimental alloy exhibited higher strength than the non-directionally solidified alloy, and the tensile strength of the directionally solidified experimental alloy was improved,while the corresponding elongation decreased with the increase of growth rate.
基金supported by Zijin Program of Zhejiang University,Chinathe Fundamental Research Funds for the Central Universities (No. 2010QNA4003)+1 种基金the Ph.D.Programs Foundation of Ministry of Education of China(No. 20100101120024)the Foundation of Education Office of Zhejiang Province (No. Y201016484)
文摘Sn/carbon-fibers(CFs) nanocomposite has been prepared by chemical vapor deposition with in-situ catalytic growth of CFs.The nanocomposite has been characterized by X-ray diffraction(XRD),field emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM) and Raman spectrum.The electrochemical performance of the nanocomposite has been investigated by galvanostatic cycling and cyclic voltammetry(CV).It has been found that a three-dimensional conductive network forms by the interconnected CFs,which offers conductive channels for the Sn nanoparticles.The nanocomposite gives a first charge capacity of 385 mAh.g-1 and exhibits an improved cycling stability than bare Sn.