The study was to investigate the changes of α-amylase inhibitor content in Pu-erh tea during pile-fermentation process. Pu-erh tea samples from two regions of Shuangjiang County and Jinggu Dai and Yi Autonomous Count...The study was to investigate the changes of α-amylase inhibitor content in Pu-erh tea during pile-fermentation process. Pu-erh tea samples from two regions of Shuangjiang County and Jinggu Dai and Yi Autonomous County of Yunnan Province at various fermentation stages were used as experimental materials to investigate the effect of different fermentation stages on the inhibitory effect to α-amylase; and the change law of the inhibitory effect of c-amylase inhibitor during processing was meanwhile studied by determining the contents of tea polyphenol and amino acid. The results showed that crude meterial of Pu-erh tea presented strong inhibitory effect to α-amylase; this inhibitory effect assumed a de： creasing trend to the minimum at the middle stage of fermentation, whereafter it increased to some extent. Made tea also showed a strong inhibitory effect to α-amylase. During whole processing period, contents of tea polyphenol and amino acid generally assumed a remarkably decreasing trend. Our results provided references for further isolating co-amylase inhibitor from Pu-erh tea and discussing the mechanism of its health care function.展开更多
Developing high-yielding rice(Oryza sativa L.)cultivars depends on having a better understanding of nitrogen(N) accumulation and translocation to the ear during the reproductive stage.Field experiments were carried ou...Developing high-yielding rice(Oryza sativa L.)cultivars depends on having a better understanding of nitrogen(N) accumulation and translocation to the ear during the reproductive stage.Field experiments were carried out to evaluate the genetic variation for N accumulation and translocation in different Japonica rice cultivars at different N rates and to identify any relationship to grain yield in southeast China.Four Japonica cultivars with similar agronomic characteristics were grown at two experimental sites in 2004 with three N rates of 0,60,and 180 kg N ha^(-1).Dry weights and N contents of rice plants were measured at tillering,initiation,anthesis,and maturity.Grain yields exhibited significant differences (P<0.05)among the cultivars and N application rates.Increasing N rates improved N uptake at anthesis and maturity in all four cultivars(P<0.05).N translocation from vegetative organs to the grains increased with enhanced N rates (P<0.05).N translocation to the grains ranged from 9 to 64 kg N ha^(-1)and N-translocation efficiency from 33% to 68%. Grain yield was linear to N uptake at anthesis(r^2=0.78^(**))and N translocation(r^2=0.67^(**)).Thus,cultivars with a high N uptake at anthesis,low residual N in the straw at maturity,and appropriate low N fertilizer supply in southeast China should efficiently increase N-recovery rate while maintaining grain yield and soil fertility.展开更多
To clarify the countercurrent flow in a PWR hot leg under reflux condensation, numerical simulations of countercurrent air-water flow for a 1/15th scale model of the PWR hot leg were conducted using the two-fluid mode...To clarify the countercurrent flow in a PWR hot leg under reflux condensation, numerical simulations of countercurrent air-water flow for a 1/15th scale model of the PWR hot leg were conducted using the two-fluid model implemented in CFD software. In this paper, the effect of expansion of the inclined pipe, which is the actual plant geometry, was evaluated. When increasing the air velocity, CCFL characteristics and the mechanism of flow pattern transition had significant differences between the case with and without expansion of the inclined pipe. CCFL characteristics were mitigated in the case with expansion. The effect of computational grid size was also discussed. When the supplied water velocity was small, the predicted flow pattern transition point agreed well with the measured data by increasing the number of cells. On the other hand, when the air velocity was decreasing, there were no significant differences in each case.展开更多
A one-dimensional sand-pile model (Manna model), which has a stochastic redistribution process, is studied both in discrete and continuous manners. The system evolves into a critical state after a transient period. A ...A one-dimensional sand-pile model (Manna model), which has a stochastic redistribution process, is studied both in discrete and continuous manners. The system evolves into a critical state after a transient period. A detailed analysis of the probability distribution of the avalanche size and duration is numerically investigated. Interestingly,contrary to the deterministic one-dimensional sand-pile model, where multifractal analysis works well, the analysis based on simple finite-size scaling is suited to fitting the data on the distribution of the avalanche size and duration. The exponents characterizing these probability distributions are measured. Scaling relations of these scaling exponents and their universality class are discussed.展开更多
Quality of soil humic substances and compost quality was assessed using different techniques of fluorescence spectroscopy. Emission, excitation, synchronous and emission-excitation matrix help us to characterize diffe...Quality of soil humic substances and compost quality was assessed using different techniques of fluorescence spectroscopy. Emission, excitation, synchronous and emission-excitation matrix help us to characterize different fluorophores in humic substances molecule. Content of stabile carbon forms in soil was assessed by humic substances fractionation. Content of labile water extractable carbon and nitrogen was determined by analyzer Shimadzu TOC-VCSH with chemo-luminescent detection in infrared spectral region. Results showed that compost amendment caused changes in both stabile （recalcitrant） and labile carbon content. Humic substances isolated from compost consist mainly of simple structural components of wide molecular heterogeneity and low molecular weight. Humification degree and content of conjugated fluorophores in compost was lower compared with stabile soil humic substances. The last contained more conjugated aromatic π-electron systems with electron-withdrawing functional groups, which are responsible for the fluorescence shift to lower energy levels or longer wavelengths.展开更多
Runaway electrons in tokamaks have been widely studied theoretically and experimentally. The runaway confinement time τ1 in ohmic and additionally heated tokamak plasmas presents an anomalous behavior when compared w...Runaway electrons in tokamaks have been widely studied theoretically and experimentally. The runaway confinement time τ1 in ohmic and additionally heated tokamak plasmas presents an anomalous behavior when compared with theoretical predictions based on neoclassical models. Runaway electrons have received lately a great attention due to several reasons： （a） the possibility to study electromagnetic turbulence by measuring the runaway flux fluctuations and its energy spectra, and （ b ） the runaway electrons are powerful diagnostics capable of yielding valuable information on the actual distribution function of fusion experiments.展开更多
Two are the critical factors in the commercial production of ornamental plants： the substrate and the fertilization method, since the ＂sustainable floriculture＂ discourages the use of synthetic chemical fertilizers...Two are the critical factors in the commercial production of ornamental plants： the substrate and the fertilization method, since the ＂sustainable floriculture＂ discourages the use of synthetic chemical fertilizers and peat-based substrates. The aim of this paper was to test a peat/compost based substrate and a guano ＋ mycorrhizal inoculum fertilizer mixture, in order to obtain a sustainable quality yield of geranium plants. Geranium cuttings （Pelargonium zonale cv. real polaris and Pelargonium grandiflorum cv. lotus） were grown for two months in a glasshouse. Peat, in the growing substrate, was replaced with high quality compost （20% and 40% as reduction percentages）. The fertilizer mixture was made up of guano （3 g/L） and mycorrhizal inoculum （7.5 L/m^3）. Plants of Pelargonium cv. Real polaris, grown on a substrate made up of peat and 20% of high quality compost, presented the better trade features, so to satisfy the ＂sustainable floriculture＂ need.展开更多
This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we ...This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we have used several different types of activation foils （Au, Sc, Ti, Ni, and plates） which have been irradiated in the central position of the reactor core （setting number 203） at a reactor power level （64.57±2.91 watts）. The activation foils were counted by solid-state detector HPGe （high pure germanium detector） （gamma spectrometry）. The experimental data of nuclear reaction rates （saturated activity per target nucleus） and a neutron spectrum estimated by a reactor physics computer code are the main input data to get the most suitable neutron spectrum in the irradiation position obtained through SANDBP （spectrum analysis neutron detection code-version Budapest University） code： a neutron spectra unfolding code that uses an iterative adjustment method. the integral neutron flux, （2.41 ± 0.01） × 10^9 n·cm^-2·s^-1 for the thermal The adjustment resulted in （3.85 ± 0.14） × 10^9 n·cm^-2·s^-1 for neutron flux, （1.09 ±0.02） × 10^9n·cm^-2·s^-1 for intermediate neutron flux and （3.41 ± 0.02） × 10^8 n·cm^-2·s^-1 for the fast neutrons flux. These results can be used to verify and validate the nuclear reactor codes and its associated nuclear data libraries, besides, show how much effective it can be that the use of a neutron flux trap in the nuclear reactor core to increase the thermal neutron flux without increase the operation reactor power level. The thermal neutral flux increased 4.04 ± 0.21 times compared with the standard configuration of the reactor core.展开更多
Post-irradiation examination of encapsulated INCONEL 600 coiled flux detectors that had failed after several years of service in a CANDU reactor showed that many of the detector wires inside the carrier rod were broke...Post-irradiation examination of encapsulated INCONEL 600 coiled flux detectors that had failed after several years of service in a CANDU reactor showed that many of the detector wires inside the carrier rod were broken. It was concluded that failure occurred because the He cover gas was lost and replaced by air. Because He is a better thermal conductor than air, and because nuclear heating is significant, the temperature of the assembly increased. The examination showed that those parts of the INCONEL 600 detector wires that had operated at the highest temperature were the most severely embrittled. Parts of the same detector wires that were operating at lower temperatures remained ductile. The temperature dependence for the embrittlement of INCONEL 600 material can be explained in terms of the transition from recombination-dominated to sink-dominated reaction-rate kinetics for point defect accumulation at sinks. Cavity formation and accumulation at grain boundaries could weaken the material and result in the observed brittle intergranular failure.展开更多
The paper describes the instrumentation for studying temperature and void reactivity effects that were developed at VR-I zero power reactor. Further are described its operational parameters, fields and ways of its uti...The paper describes the instrumentation for studying temperature and void reactivity effects that were developed at VR-I zero power reactor. Further are described its operational parameters, fields and ways of its utilization as well as issues connected to its implementation into the reactor core.展开更多
文摘The study was to investigate the changes of α-amylase inhibitor content in Pu-erh tea during pile-fermentation process. Pu-erh tea samples from two regions of Shuangjiang County and Jinggu Dai and Yi Autonomous County of Yunnan Province at various fermentation stages were used as experimental materials to investigate the effect of different fermentation stages on the inhibitory effect to α-amylase; and the change law of the inhibitory effect of c-amylase inhibitor during processing was meanwhile studied by determining the contents of tea polyphenol and amino acid. The results showed that crude meterial of Pu-erh tea presented strong inhibitory effect to α-amylase; this inhibitory effect assumed a de： creasing trend to the minimum at the middle stage of fermentation, whereafter it increased to some extent. Made tea also showed a strong inhibitory effect to α-amylase. During whole processing period, contents of tea polyphenol and amino acid generally assumed a remarkably decreasing trend. Our results provided references for further isolating co-amylase inhibitor from Pu-erh tea and discussing the mechanism of its health care function.
基金Project supported by the National Natural Science Foundation of China(Nos.30390082 and 3027079)the Science and Technology Committee of Jiangsu Province,China(No.BE2005369).
文摘Developing high-yielding rice(Oryza sativa L.)cultivars depends on having a better understanding of nitrogen(N) accumulation and translocation to the ear during the reproductive stage.Field experiments were carried out to evaluate the genetic variation for N accumulation and translocation in different Japonica rice cultivars at different N rates and to identify any relationship to grain yield in southeast China.Four Japonica cultivars with similar agronomic characteristics were grown at two experimental sites in 2004 with three N rates of 0,60,and 180 kg N ha^(-1).Dry weights and N contents of rice plants were measured at tillering,initiation,anthesis,and maturity.Grain yields exhibited significant differences (P<0.05)among the cultivars and N application rates.Increasing N rates improved N uptake at anthesis and maturity in all four cultivars(P<0.05).N translocation from vegetative organs to the grains increased with enhanced N rates (P<0.05).N translocation to the grains ranged from 9 to 64 kg N ha^(-1)and N-translocation efficiency from 33% to 68%. Grain yield was linear to N uptake at anthesis(r^2=0.78^(**))and N translocation(r^2=0.67^(**)).Thus,cultivars with a high N uptake at anthesis,low residual N in the straw at maturity,and appropriate low N fertilizer supply in southeast China should efficiently increase N-recovery rate while maintaining grain yield and soil fertility.
文摘To clarify the countercurrent flow in a PWR hot leg under reflux condensation, numerical simulations of countercurrent air-water flow for a 1/15th scale model of the PWR hot leg were conducted using the two-fluid model implemented in CFD software. In this paper, the effect of expansion of the inclined pipe, which is the actual plant geometry, was evaluated. When increasing the air velocity, CCFL characteristics and the mechanism of flow pattern transition had significant differences between the case with and without expansion of the inclined pipe. CCFL characteristics were mitigated in the case with expansion. The effect of computational grid size was also discussed. When the supplied water velocity was small, the predicted flow pattern transition point agreed well with the measured data by increasing the number of cells. On the other hand, when the air velocity was decreasing, there were no significant differences in each case.
文摘A one-dimensional sand-pile model (Manna model), which has a stochastic redistribution process, is studied both in discrete and continuous manners. The system evolves into a critical state after a transient period. A detailed analysis of the probability distribution of the avalanche size and duration is numerically investigated. Interestingly,contrary to the deterministic one-dimensional sand-pile model, where multifractal analysis works well, the analysis based on simple finite-size scaling is suited to fitting the data on the distribution of the avalanche size and duration. The exponents characterizing these probability distributions are measured. Scaling relations of these scaling exponents and their universality class are discussed.
文摘Quality of soil humic substances and compost quality was assessed using different techniques of fluorescence spectroscopy. Emission, excitation, synchronous and emission-excitation matrix help us to characterize different fluorophores in humic substances molecule. Content of stabile carbon forms in soil was assessed by humic substances fractionation. Content of labile water extractable carbon and nitrogen was determined by analyzer Shimadzu TOC-VCSH with chemo-luminescent detection in infrared spectral region. Results showed that compost amendment caused changes in both stabile （recalcitrant） and labile carbon content. Humic substances isolated from compost consist mainly of simple structural components of wide molecular heterogeneity and low molecular weight. Humification degree and content of conjugated fluorophores in compost was lower compared with stabile soil humic substances. The last contained more conjugated aromatic π-electron systems with electron-withdrawing functional groups, which are responsible for the fluorescence shift to lower energy levels or longer wavelengths.
文摘Runaway electrons in tokamaks have been widely studied theoretically and experimentally. The runaway confinement time τ1 in ohmic and additionally heated tokamak plasmas presents an anomalous behavior when compared with theoretical predictions based on neoclassical models. Runaway electrons have received lately a great attention due to several reasons： （a） the possibility to study electromagnetic turbulence by measuring the runaway flux fluctuations and its energy spectra, and （ b ） the runaway electrons are powerful diagnostics capable of yielding valuable information on the actual distribution function of fusion experiments.
文摘Two are the critical factors in the commercial production of ornamental plants： the substrate and the fertilization method, since the ＂sustainable floriculture＂ discourages the use of synthetic chemical fertilizers and peat-based substrates. The aim of this paper was to test a peat/compost based substrate and a guano ＋ mycorrhizal inoculum fertilizer mixture, in order to obtain a sustainable quality yield of geranium plants. Geranium cuttings （Pelargonium zonale cv. real polaris and Pelargonium grandiflorum cv. lotus） were grown for two months in a glasshouse. Peat, in the growing substrate, was replaced with high quality compost （20% and 40% as reduction percentages）. The fertilizer mixture was made up of guano （3 g/L） and mycorrhizal inoculum （7.5 L/m^3）. Plants of Pelargonium cv. Real polaris, grown on a substrate made up of peat and 20% of high quality compost, presented the better trade features, so to satisfy the ＂sustainable floriculture＂ need.
文摘This paper presents the neutron energy spectrum in the central position of a neutron flux trap assembled in the core center of the research nuclear reactor IPEN/MB-01, obtained by an unfolding method. To this end, we have used several different types of activation foils （Au, Sc, Ti, Ni, and plates） which have been irradiated in the central position of the reactor core （setting number 203） at a reactor power level （64.57±2.91 watts）. The activation foils were counted by solid-state detector HPGe （high pure germanium detector） （gamma spectrometry）. The experimental data of nuclear reaction rates （saturated activity per target nucleus） and a neutron spectrum estimated by a reactor physics computer code are the main input data to get the most suitable neutron spectrum in the irradiation position obtained through SANDBP （spectrum analysis neutron detection code-version Budapest University） code： a neutron spectra unfolding code that uses an iterative adjustment method. the integral neutron flux, （2.41 ± 0.01） × 10^9 n·cm^-2·s^-1 for the thermal The adjustment resulted in （3.85 ± 0.14） × 10^9 n·cm^-2·s^-1 for neutron flux, （1.09 ±0.02） × 10^9n·cm^-2·s^-1 for intermediate neutron flux and （3.41 ± 0.02） × 10^8 n·cm^-2·s^-1 for the fast neutrons flux. These results can be used to verify and validate the nuclear reactor codes and its associated nuclear data libraries, besides, show how much effective it can be that the use of a neutron flux trap in the nuclear reactor core to increase the thermal neutron flux without increase the operation reactor power level. The thermal neutral flux increased 4.04 ± 0.21 times compared with the standard configuration of the reactor core.
文摘Post-irradiation examination of encapsulated INCONEL 600 coiled flux detectors that had failed after several years of service in a CANDU reactor showed that many of the detector wires inside the carrier rod were broken. It was concluded that failure occurred because the He cover gas was lost and replaced by air. Because He is a better thermal conductor than air, and because nuclear heating is significant, the temperature of the assembly increased. The examination showed that those parts of the INCONEL 600 detector wires that had operated at the highest temperature were the most severely embrittled. Parts of the same detector wires that were operating at lower temperatures remained ductile. The temperature dependence for the embrittlement of INCONEL 600 material can be explained in terms of the transition from recombination-dominated to sink-dominated reaction-rate kinetics for point defect accumulation at sinks. Cavity formation and accumulation at grain boundaries could weaken the material and result in the observed brittle intergranular failure.
文摘The paper describes the instrumentation for studying temperature and void reactivity effects that were developed at VR-I zero power reactor. Further are described its operational parameters, fields and ways of its utilization as well as issues connected to its implementation into the reactor core.
