大气湿沉降是流域生态系统水体中碳氮的重要来源,对生态系统的健康及稳定性有很大的影响。通过对江西千烟洲典型亚热带流域降雨过程的碳、氮湿沉降和径流过程的季节性动态特征进行监测分析,探讨流域沉降、径流输出的C、N耦合及平衡关系...大气湿沉降是流域生态系统水体中碳氮的重要来源,对生态系统的健康及稳定性有很大的影响。通过对江西千烟洲典型亚热带流域降雨过程的碳、氮湿沉降和径流过程的季节性动态特征进行监测分析,探讨流域沉降、径流输出的C、N耦合及平衡关系。结果表明:千烟洲香溪流域降雨径流中碳氮浓度明显低于雨水,流域大气降水中DOC浓度和TN浓度呈极显著正相关关系。香溪河流域常规水体C∶N均值为2.81,远低于根据Redfield比率得出的适宜浮游生物生长的C∶N(6.6左右),说明外源性N输入导致该流域水体环境处于N过量的状态,长期输出会提高下游鄱阳湖水系的营养化程度。降雨过程对流域碳输入输出平衡影响较小,对氮输入输出平衡的影响较大。流域湿沉降DOC年输入量为69.41 kg hm^(-2)a^(-1),TN湿沉降通量为77.23 kg hm^(-2)a^(-1),碳氮沉降水平受区域降雨量及空气污染情况控制。香溪流域生态系统截留的沉降TN占当地氮肥年均使用量的33.13%,大气降水对亚热带流域生态系统的大量营养物质输入不容忽视。展开更多
Miamiensis avidus Thompson & Moewus,1964,is a cosmopolitan and well-known marine pathogenic ciliated protist.However,the taxonomy of this species up to now has remained controversial,especially with respect to the...Miamiensis avidus Thompson & Moewus,1964,is a cosmopolitan and well-known marine pathogenic ciliated protist.However,the taxonomy of this species up to now has remained controversial,especially with respect to the validity of the morphologically similar species,Philasterides dicentrarchi,which was considered as a junior synonym of M.avidus.In this study,a population of M.avidus was collected from the skin of pharaoh cuttlefish(Sepia pharaonis) cultured near the East China Sea,Ningbo,China and its morphology and phylogeny were investigated in detail based on living characters,infraciliature,small subunit(SSU) r DNA and ITS1-5.8 S-ITS2 region sequences.In addition,the morphometrics of a previously reported free-living population,collected from the Bohai Sea,were rechecked and analyzed.We compared the present two isolates with all historic populations of M.avidus and P.dicentrarchi,and found that their morphological characters were either highly similar or exactly identical,indicating that they are the same morphospecies.However,the phylogenetic analyses based on SSU r DNA or ITS1-5.8 S-ITS2 region sequences revealed that most M.avidus and P.dicentrarchi populations formed one clade,and the two isolates of M.avidus from Weifang and American Type Culture Collection clustered in another clade,which indicated that there might be cryptic species in Miamiensis avidus.展开更多
AA6061-10 vol.% SiC composite was successfully prepared by spark plasma sintering. The deformation behaviour of this composite was studied using the uniaxial compression test, which was conducted at temperatures betwe...AA6061-10 vol.% SiC composite was successfully prepared by spark plasma sintering. The deformation behaviour of this composite was studied using the uniaxial compression test, which was conducted at temperatures between 300 and 500°C and strain rates between 0.001 and 1 s-1. Results indicate that the stress-strain curves of the AA6061-10 vol.% SiC composite typically feature dynamic recrystallization. The steady stress can be described by a hyperbolic sine constitutive equation, and the activation energy of the composite is 230.88 k J/mol. The processing map was established according to the dynamic materials model. The optimum hot deformation temperature is 450–500°C and the strain rate is 1–0.1 s-1. The instability zones of flow behaviour can also be identified using the processing map.展开更多
The fluidity and filling ability of glass-forming Zr-based alloy melt in copper mould were investigated both theoretically and experimentally. The major factors which affected the flowing behavior of the metallic melt...The fluidity and filling ability of glass-forming Zr-based alloy melt in copper mould were investigated both theoretically and experimentally. The major factors which affected the flowing behavior of the metallic melt in the mold were determined,which provides the foundation for overcoming the contradiction between the filling and formation of amorphous alloy during the rapid cooling process of the metallic melts. The casting factors to prepare a metallic ring were discussed and selected. As a result,a Zr-based bulk metallic glass ring was prepared successfully.展开更多
Electrochemical corrosion and oxidation resistances of Zr 60 Ni 21 Al 19 amorphous alloy were studied. The ternary amorphous alloy exhibits greater positive potential than its crystalline counterpart and 0Cr19Ni9Ti st...Electrochemical corrosion and oxidation resistances of Zr 60 Ni 21 Al 19 amorphous alloy were studied. The ternary amorphous alloy exhibits greater positive potential than its crystalline counterpart and 0Cr19Ni9Ti stainless steel. Its weight loss result measured in 2 mol/L HCl solution is in agreement with the potentiodynamic curve. But there is no obvious difference in the oxidation resistances between Zr 60 Ni 21 Al 19 amorphous and its crystalline alloys. They both exhibit high oxidation resistance.展开更多
Deformation of the bulk metallic glasses (BMGs) and the creation and propagation of the shear bands are closely interconnected.Shearing force was loaded on Zr 41.2 Ti 13.8 Cu 12.5 Ni 10.0 Be 22.5 (Vit.1) BMGs by cutti...Deformation of the bulk metallic glasses (BMGs) and the creation and propagation of the shear bands are closely interconnected.Shearing force was loaded on Zr 41.2 Ti 13.8 Cu 12.5 Ni 10.0 Be 22.5 (Vit.1) BMGs by cutting during the turning of the BMG rod.The temperature rise of alloy on the shear bands was calculated and the result showed that it could reach the temperature of the super-cooled liquid zone or exceed the melting point.The temperature rise caused viscous fluid flow and brought about the deformation of BMGs.This suggested that the deformation of BMGs was derived,at least to some extent,from the adiabatic shear temperature rise.展开更多
Over the last five years,accumulative roll bonding(ARB)has been used to produce aluminum-based metal matrix composites(AMMCs)with ultrafine-grained(UFG)structure.Al/Al2O3[1–3],Al/Si C[4],Al/B4C[5,6],and Al/WC[7]are c...Over the last five years,accumulative roll bonding(ARB)has been used to produce aluminum-based metal matrix composites(AMMCs)with ultrafine-grained(UFG)structure.Al/Al2O3[1–3],Al/Si C[4],Al/B4C[5,6],and Al/WC[7]are currently fabricated using ARB because of the resulting highly uniform reinforced particle distribution.展开更多
The compression behavior of Ni77P23 amorphous alloy is investigated at room temperature in a diamond-anvil cell instrument using insitu high pressure energy dispersive X-ray diffraction with a syn- chrotron radiation ...The compression behavior of Ni77P23 amorphous alloy is investigated at room temperature in a diamond-anvil cell instrument using insitu high pressure energy dispersive X-ray diffraction with a syn- chrotron radiation source. The equation of state is determined by fitting the experimental data accord- ing to Birch-Murnaghan equation: -ΔV/V0=0.08606P-3.2×10-4P2+5.7×10-6P3. It is found that the structure of Ni77P23 amorphous alloy is stable under pressures up to 30.5 GPa.展开更多
文摘大气湿沉降是流域生态系统水体中碳氮的重要来源,对生态系统的健康及稳定性有很大的影响。通过对江西千烟洲典型亚热带流域降雨过程的碳、氮湿沉降和径流过程的季节性动态特征进行监测分析,探讨流域沉降、径流输出的C、N耦合及平衡关系。结果表明:千烟洲香溪流域降雨径流中碳氮浓度明显低于雨水,流域大气降水中DOC浓度和TN浓度呈极显著正相关关系。香溪河流域常规水体C∶N均值为2.81,远低于根据Redfield比率得出的适宜浮游生物生长的C∶N(6.6左右),说明外源性N输入导致该流域水体环境处于N过量的状态,长期输出会提高下游鄱阳湖水系的营养化程度。降雨过程对流域碳输入输出平衡影响较小,对氮输入输出平衡的影响较大。流域湿沉降DOC年输入量为69.41 kg hm^(-2)a^(-1),TN湿沉降通量为77.23 kg hm^(-2)a^(-1),碳氮沉降水平受区域降雨量及空气污染情况控制。香溪流域生态系统截留的沉降TN占当地氮肥年均使用量的33.13%,大气降水对亚热带流域生态系统的大量营养物质输入不容忽视。
基金supported by the National Natural Science Foundation of China(No.31572230)the Open Fund of Zhejiang Provincial Top Key Discipline of Aqua-culture in Ningbo University(No.xkzsc1417)+1 种基金the K.C.Wong Magna Fund in Ningbo Universitythe Scientific Research Foundation of Graduate School of Ningbo University
文摘Miamiensis avidus Thompson & Moewus,1964,is a cosmopolitan and well-known marine pathogenic ciliated protist.However,the taxonomy of this species up to now has remained controversial,especially with respect to the validity of the morphologically similar species,Philasterides dicentrarchi,which was considered as a junior synonym of M.avidus.In this study,a population of M.avidus was collected from the skin of pharaoh cuttlefish(Sepia pharaonis) cultured near the East China Sea,Ningbo,China and its morphology and phylogeny were investigated in detail based on living characters,infraciliature,small subunit(SSU) r DNA and ITS1-5.8 S-ITS2 region sequences.In addition,the morphometrics of a previously reported free-living population,collected from the Bohai Sea,were rechecked and analyzed.We compared the present two isolates with all historic populations of M.avidus and P.dicentrarchi,and found that their morphological characters were either highly similar or exactly identical,indicating that they are the same morphospecies.However,the phylogenetic analyses based on SSU r DNA or ITS1-5.8 S-ITS2 region sequences revealed that most M.avidus and P.dicentrarchi populations formed one clade,and the two isolates of M.avidus from Weifang and American Type Culture Collection clustered in another clade,which indicated that there might be cryptic species in Miamiensis avidus.
基金supported by the National Basic Research Program of China(“973”Project)(Grant No.2013CB733000)
文摘AA6061-10 vol.% SiC composite was successfully prepared by spark plasma sintering. The deformation behaviour of this composite was studied using the uniaxial compression test, which was conducted at temperatures between 300 and 500°C and strain rates between 0.001 and 1 s-1. Results indicate that the stress-strain curves of the AA6061-10 vol.% SiC composite typically feature dynamic recrystallization. The steady stress can be described by a hyperbolic sine constitutive equation, and the activation energy of the composite is 230.88 k J/mol. The processing map was established according to the dynamic materials model. The optimum hot deformation temperature is 450–500°C and the strain rate is 1–0.1 s-1. The instability zones of flow behaviour can also be identified using the processing map.
基金the National Natural Science Foundation of China (Grant No. 50731005)SKPBRC (Grant No. 2006CB605201/2007CB616915)+3 种基金PCSIRT (Grant No. IRT0650)the Natural Science Foundation of Hebei Province of China (Grant No. E2004000209)the Scientific Research Foundation of Education Department of Hebei Province of China (Grant No. 2004464)the Experts and Scholars Fund of Personnel Department of Hebei Province,China (Grant No. 2003)
文摘The fluidity and filling ability of glass-forming Zr-based alloy melt in copper mould were investigated both theoretically and experimentally. The major factors which affected the flowing behavior of the metallic melt in the mold were determined,which provides the foundation for overcoming the contradiction between the filling and formation of amorphous alloy during the rapid cooling process of the metallic melts. The casting factors to prepare a metallic ring were discussed and selected. As a result,a Zr-based bulk metallic glass ring was prepared successfully.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50731005, 50821001 and 50774006)the National Basic Research Program of China (Grant No. 2010CB731600)
文摘Electrochemical corrosion and oxidation resistances of Zr 60 Ni 21 Al 19 amorphous alloy were studied. The ternary amorphous alloy exhibits greater positive potential than its crystalline counterpart and 0Cr19Ni9Ti stainless steel. Its weight loss result measured in 2 mol/L HCl solution is in agreement with the potentiodynamic curve. But there is no obvious difference in the oxidation resistances between Zr 60 Ni 21 Al 19 amorphous and its crystalline alloys. They both exhibit high oxidation resistance.
基金supported by the National Basic Research Program of China (Grant No. 2010CB731600)the National Natural Science Foundation of China (Grant Nos. 50731005,50821001 and 51171163)+1 种基金the Doctoral Fund of Ministry of Education of China (Grant No. 20101333110004)the Nature Science Foundation of Hebei (Grant No. E2010001176)
文摘Deformation of the bulk metallic glasses (BMGs) and the creation and propagation of the shear bands are closely interconnected.Shearing force was loaded on Zr 41.2 Ti 13.8 Cu 12.5 Ni 10.0 Be 22.5 (Vit.1) BMGs by cutting during the turning of the BMG rod.The temperature rise of alloy on the shear bands was calculated and the result showed that it could reach the temperature of the super-cooled liquid zone or exceed the melting point.The temperature rise caused viscous fluid flow and brought about the deformation of BMGs.This suggested that the deformation of BMGs was derived,at least to some extent,from the adiabatic shear temperature rise.
基金supported by the National Basic Research Program of China(Grant No.2013CB733000)the National Natural Science Foundation of China(Grant No.51465014)the Guangxi"Bagui"Teams for Innovation and Researches
文摘Over the last five years,accumulative roll bonding(ARB)has been used to produce aluminum-based metal matrix composites(AMMCs)with ultrafine-grained(UFG)structure.Al/Al2O3[1–3],Al/Si C[4],Al/B4C[5,6],and Al/WC[7]are currently fabricated using ARB because of the resulting highly uniform reinforced particle distribution.
基金Supported by the National Natural Science Foundation of China (Grant No. 50325103)Hebei Natural Science Foundation (Grant No. 503278)the Scien-tific Research Foundation for the Returned Overseas Chinese Scholars, State Educa-tion Ministry and SKPBRC (Grant No. 2006CB605201)
文摘The compression behavior of Ni77P23 amorphous alloy is investigated at room temperature in a diamond-anvil cell instrument using insitu high pressure energy dispersive X-ray diffraction with a syn- chrotron radiation source. The equation of state is determined by fitting the experimental data accord- ing to Birch-Murnaghan equation: -ΔV/V0=0.08606P-3.2×10-4P2+5.7×10-6P3. It is found that the structure of Ni77P23 amorphous alloy is stable under pressures up to 30.5 GPa.
