Hedysarum laeve Maxim. (Leguminosae) is one of the major species used frequently in revegetation of dune_field in the sandlands of the northern part of China by means of aerial sowing. Seedlings of the species after e...Hedysarum laeve Maxim. (Leguminosae) is one of the major species used frequently in revegetation of dune_field in the sandlands of the northern part of China by means of aerial sowing. Seedlings of the species after emergence above the sand surface may be buried in sand to various depths during its establishment in late spring and early summer. A study was made to examine the effects of sand burial at different levels of 0 (control), 33%, 67%, 100% and 133% of their shoot height, on the survivorship, growth, and biomass allocation pattern of H. laeve seedlings (one and two weeks old after emergence). When burial depth was up to 100% of their shoot height, about 70% seedlings died; and the burial at depth of 133% of their shoot height led to death of all seedlings. When seedlings was buried at depth of 33% and 67% of their shoot height, respectively, after six_week growth, their biomass of whole plant, blade, and root and relative growth rate were higher than the unburied counterparts. The seedlings in both 33% and 67% sand burial treatments did not significantly change their biomass allocation pattern comparing with the unburied ones. Furthermore, the number of leaves and shoot height of the seedlings in both 33% and 67% sand burial treatments were not significantly different from those of unburied individuals, respectively. The newly born leaves of the surviving seedlings, in 33%, 67%, and 100% burial treatments, during the period of experiment, were significantly more than those in control.展开更多
This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to ne...This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60 d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.展开更多
Enantioselective liquid–liquid extraction has attracted considerable attention for its potential use in largescale production. Kinetic data are needed for the reliable scale-up of the process. This paper reports the ...Enantioselective liquid–liquid extraction has attracted considerable attention for its potential use in largescale production. Kinetic data are needed for the reliable scale-up of the process. This paper reports the kinetic study of reactive extraction of phenylalanine(Phe) enantiomers with BINAP–copper complex(BINAP–Cu) as a chiral selector. The theory of extraction accompanied by a chemical reaction was applied.The effects of agitation speed, interfacial area, p H value of aqueous phase, initial concentration of Phe enantiomers and initial concentration of BINAP–Cu on the specific rate of extraction were investigated. The forward rate constants of the reactions in the reactive extraction process are 7.93 × 10-5m5/2·mol-1/2·s-1for D-Phe and 1.29 × 10-4m5/2·mol-1/2·s-1for L-Phe.展开更多
The study of ultracold Fermi gases has exploded a variety of experimental and theoretical research since the achievement of degenerate quantum gases in the lab,which expands the research range over atomic physics,cond...The study of ultracold Fermi gases has exploded a variety of experimental and theoretical research since the achievement of degenerate quantum gases in the lab,which expands the research range over atomic physics,condensed matter physics,astrophysics and particle physics.Using the Feshbach resonance,one can tune the attractive two-body interaction from weak to strong and thereby make a smooth crossover from the BCS superfluid of cooper pairs to the Bose Einstein condensate of bound molecules.In this crossover regime,the pairing effect plays a significant role in interpreting the interaction mechanism.Whenever the localized or delocalized pairing occurs at sufficiently low temperature,the single-particle energy will shift with respect to free atoms,due to the two-body or many-body interaction.Measuring the pairing gap can improve the understanding of the thermodynamics and hydrodynamics of the phase transition from the pseudogap to the superfluid,which will make an analogue to the high-temperature superconductivity in condensed matter.In this work,we will give a brief introduction to a novel radio-frequency(RF) spectroscopic measurement for pairing gap in an ultracold Fermi gas,which is currently widely used on the ultracold atomic table in the lab.In different interaction regimes of the BEC-BCS crossover,ultracold atoms are excited with a RF pulse and the characteristic behavior can be extracted from the spectrum.展开更多
文摘Hedysarum laeve Maxim. (Leguminosae) is one of the major species used frequently in revegetation of dune_field in the sandlands of the northern part of China by means of aerial sowing. Seedlings of the species after emergence above the sand surface may be buried in sand to various depths during its establishment in late spring and early summer. A study was made to examine the effects of sand burial at different levels of 0 (control), 33%, 67%, 100% and 133% of their shoot height, on the survivorship, growth, and biomass allocation pattern of H. laeve seedlings (one and two weeks old after emergence). When burial depth was up to 100% of their shoot height, about 70% seedlings died; and the burial at depth of 133% of their shoot height led to death of all seedlings. When seedlings was buried at depth of 33% and 67% of their shoot height, respectively, after six_week growth, their biomass of whole plant, blade, and root and relative growth rate were higher than the unburied counterparts. The seedlings in both 33% and 67% sand burial treatments did not significantly change their biomass allocation pattern comparing with the unburied ones. Furthermore, the number of leaves and shoot height of the seedlings in both 33% and 67% sand burial treatments were not significantly different from those of unburied individuals, respectively. The newly born leaves of the surviving seedlings, in 33%, 67%, and 100% burial treatments, during the period of experiment, were significantly more than those in control.
基金financial support by grant No. 30871928 from the National Natural Science Foun-dation of China (NSFC)
文摘This feeding trial was conducted to evaluate the potential of poultry by-product meal (PBM) as a protein source in the culture of Litopenaeus vannamei. Seven isonitrogenous and isoenergetic diets were formulated to near to commercial diet with about 40% protein and 7.5% lipid. Fish meal was replaced by 0, 30%, 40%, 50%, 60%, 70% and 100% of PBM (diets 1-7). The diet with 100% fish meal was used as a control (diet 1). Post-larvae were reared in an indoor semi-closed re-circulating system. Each dietary treatment was tested in 4 replicate tanks (260 L) of 40 shrimp, arranged in a completely randomized design. The shrimps were hand-fed for three times a day to near-satiation (0700, 1200 and 1800) for 60 d. Percentage weight gain, survival, feed conversion ratio (FCR), protein efficiency ratio (PER) and body composition of shrimps were measured. There were no significant differences (P>0.05) in growth performance among shrimps fed diets 1-5 (0-60% fish meal replacement). However, shrimps fed diet 7 (100% fish meal replacement) had significantly lower (P<0.05) growth than those fed diets 1-5 (0-60% fish meal replacement). Shrimp fed diets 2-4 (30%-50% fish meal replacement) showed significantly higher growth than those fed diets 6 and 7 (70% and 100% fish meal replacement, respectively). Survival ranged from 94.7% to 100.0% and did not differ significantly (P>0.05) among different experimental diets. No differences in body composition were found among shrimps fed different diets. These results showed that up to 70% of fish meal protein can be replaced by PBM without adversely affecting the growth, survival, FCR, PER and body composition of Litopenaeus vannamei.
基金Supported by the National Natural Science Foundation of China(21171054)the Open Fund Project of Key Laboratory in Hunan University(11K029)the Key Laboratory of Hunan Province and Aid program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
文摘Enantioselective liquid–liquid extraction has attracted considerable attention for its potential use in largescale production. Kinetic data are needed for the reliable scale-up of the process. This paper reports the kinetic study of reactive extraction of phenylalanine(Phe) enantiomers with BINAP–copper complex(BINAP–Cu) as a chiral selector. The theory of extraction accompanied by a chemical reaction was applied.The effects of agitation speed, interfacial area, p H value of aqueous phase, initial concentration of Phe enantiomers and initial concentration of BINAP–Cu on the specific rate of extraction were investigated. The forward rate constants of the reactions in the reactive extraction process are 7.93 × 10-5m5/2·mol-1/2·s-1for D-Phe and 1.29 × 10-4m5/2·mol-1/2·s-1for L-Phe.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11004224 and 11204355)the National Basic Research Program of China (Grant No. 2011CB921601)the Program of "OneHundred Talented People" of the Chinese Academy of Sciences
文摘The study of ultracold Fermi gases has exploded a variety of experimental and theoretical research since the achievement of degenerate quantum gases in the lab,which expands the research range over atomic physics,condensed matter physics,astrophysics and particle physics.Using the Feshbach resonance,one can tune the attractive two-body interaction from weak to strong and thereby make a smooth crossover from the BCS superfluid of cooper pairs to the Bose Einstein condensate of bound molecules.In this crossover regime,the pairing effect plays a significant role in interpreting the interaction mechanism.Whenever the localized or delocalized pairing occurs at sufficiently low temperature,the single-particle energy will shift with respect to free atoms,due to the two-body or many-body interaction.Measuring the pairing gap can improve the understanding of the thermodynamics and hydrodynamics of the phase transition from the pseudogap to the superfluid,which will make an analogue to the high-temperature superconductivity in condensed matter.In this work,we will give a brief introduction to a novel radio-frequency(RF) spectroscopic measurement for pairing gap in an ultracold Fermi gas,which is currently widely used on the ultracold atomic table in the lab.In different interaction regimes of the BEC-BCS crossover,ultracold atoms are excited with a RF pulse and the characteristic behavior can be extracted from the spectrum.
