International trade intensifies the process of globalization which has extended to the entire planet and extends to the entire planet. In view of the difficulties of installing these documentary systems in developing ...International trade intensifies the process of globalization which has extended to the entire planet and extends to the entire planet. In view of the difficulties of installing these documentary systems in developing countries, in particularly the countries of sub-Saharan Africa, the new strategies of traceability emerge. Among the new tools of tracing the products of vegetable origin, a ＂biological code bar＂ based on the analysis of the DNA of micro-organisms present on the fruits is an interesting tool. A molecular technique employing 26S rDNA profiles generated by PCR-DGGE was used to detect the variation in yeast community structures of Shea tree fruits （Vitellaria paradoxa） from Senegal, Ghana and Mali. When the 26S rDNA profiles were analyzed by image analysis and multivariate analysis, distinct microbial communities were detected on Shea tree fruits. The band profiles of yeasts from different countries were specific for each location and could be used as a bar code to discriminate the origin of the fruits. This method is a new traceability tool which provides fruit products with an unique biological bar code and makes it possible to trace back the fruits to their original location.展开更多
The data of modified isochronal testing of gas well is just used to calculate gas well deliverability. Fully utilizing well test data make it possible to obtain formation parameters, such as gas well deliverability, e...The data of modified isochronal testing of gas well is just used to calculate gas well deliverability. Fully utilizing well test data make it possible to obtain formation parameters, such as gas well deliverability, effective permeability and skin factor at the same time. Based on transient flow theory, the pressure drawdown equation of gas unsteady seepage can be deducted. One simulated case is used to illustrate the applicability of the proposed method. The result of analyzed case shows that the proposed method can provide accurate estimate of formation permeability and skin factor compared with the method of Homer curves.展开更多
It is well known that aboveground productivity usually increases with precipitation.However,how belowground carbon(C)processes respond to changes in precipitation remains elusive,although belowground net primary produ...It is well known that aboveground productivity usually increases with precipitation.However,how belowground carbon(C)processes respond to changes in precipitation remains elusive,although belowground net primary productivity(BNPP)represents more than one-half of NPP and soil stores the largest terrestrial C in the biosphere.This paper reviews the patterns of belowground C processes(BNPP and soil C)in response to changes in precipitation from transect studies,manipulative experiments,modeling and data integration and synthesis.The results suggest the possible existence of nonlinear patterns of BNPP and soil C in response to changes in precipitation,which is largely different from linear response for aboveground productivity.C allocation,root turnover time and species composition may be three key processes underlying mechanisms of the nonlinear responses to changes in precipitation for belowground C processes.In addition,microbial community structure and long-term ecosystem processes(e.g.mineral assemblage,soil texture,aggregate stability)may also affect patterns of belowground C processes in response to changes in precipitation.At last,we discuss implications and future perspectives for potential nonlinear responses of belowground C processes to changes in precipitation.展开更多
Let A and B be two factor von Neumann algebras. For A, B ∈ A, define by [A, B]_*= AB-BA~*the skew Lie product of A and B. In this article, it is proved that a bijective map Φ : A → B satisfies Φ([[A, B]_*, C]_*) =...Let A and B be two factor von Neumann algebras. For A, B ∈ A, define by [A, B]_*= AB-BA~*the skew Lie product of A and B. In this article, it is proved that a bijective map Φ : A → B satisfies Φ([[A, B]_*, C]_*) = [[Φ(A), Φ(B)]_*, Φ(C)]_*for all A, B, C ∈ A if and only if Φ is a linear *-isomorphism, or a conjugate linear *-isomorphism, or the negative of a linear *-isomorphism, or the negative of a conjugate linear *-isomorphism.展开更多
文摘International trade intensifies the process of globalization which has extended to the entire planet and extends to the entire planet. In view of the difficulties of installing these documentary systems in developing countries, in particularly the countries of sub-Saharan Africa, the new strategies of traceability emerge. Among the new tools of tracing the products of vegetable origin, a ＂biological code bar＂ based on the analysis of the DNA of micro-organisms present on the fruits is an interesting tool. A molecular technique employing 26S rDNA profiles generated by PCR-DGGE was used to detect the variation in yeast community structures of Shea tree fruits （Vitellaria paradoxa） from Senegal, Ghana and Mali. When the 26S rDNA profiles were analyzed by image analysis and multivariate analysis, distinct microbial communities were detected on Shea tree fruits. The band profiles of yeasts from different countries were specific for each location and could be used as a bar code to discriminate the origin of the fruits. This method is a new traceability tool which provides fruit products with an unique biological bar code and makes it possible to trace back the fruits to their original location.
文摘The data of modified isochronal testing of gas well is just used to calculate gas well deliverability. Fully utilizing well test data make it possible to obtain formation parameters, such as gas well deliverability, effective permeability and skin factor at the same time. Based on transient flow theory, the pressure drawdown equation of gas unsteady seepage can be deducted. One simulated case is used to illustrate the applicability of the proposed method. The result of analyzed case shows that the proposed method can provide accurate estimate of formation permeability and skin factor compared with the method of Homer curves.
基金supported by the National Key Research and Development Program of China(2023YFF0806900)the National Natural Science Foundation of China(31930072,32241032,42203076)the Natural Science Foundation of Heilongjiang Province of China(ZD2021C002).
文摘It is well known that aboveground productivity usually increases with precipitation.However,how belowground carbon(C)processes respond to changes in precipitation remains elusive,although belowground net primary productivity(BNPP)represents more than one-half of NPP and soil stores the largest terrestrial C in the biosphere.This paper reviews the patterns of belowground C processes(BNPP and soil C)in response to changes in precipitation from transect studies,manipulative experiments,modeling and data integration and synthesis.The results suggest the possible existence of nonlinear patterns of BNPP and soil C in response to changes in precipitation,which is largely different from linear response for aboveground productivity.C allocation,root turnover time and species composition may be three key processes underlying mechanisms of the nonlinear responses to changes in precipitation for belowground C processes.In addition,microbial community structure and long-term ecosystem processes(e.g.mineral assemblage,soil texture,aggregate stability)may also affect patterns of belowground C processes in response to changes in precipitation.At last,we discuss implications and future perspectives for potential nonlinear responses of belowground C processes to changes in precipitation.
基金supported by the National Natural Science Foundation of China(No.11526123,No.11401273)the Natural Science Foundation of Shandong Province of China(No.ZR2015PA010)
文摘Let A and B be two factor von Neumann algebras. For A, B ∈ A, define by [A, B]_*= AB-BA~*the skew Lie product of A and B. In this article, it is proved that a bijective map Φ : A → B satisfies Φ([[A, B]_*, C]_*) = [[Φ(A), Φ(B)]_*, Φ(C)]_*for all A, B, C ∈ A if and only if Φ is a linear *-isomorphism, or a conjugate linear *-isomorphism, or the negative of a linear *-isomorphism, or the negative of a conjugate linear *-isomorphism.
