Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the poten...Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the potential rangeρ=14 and the number of atoms N up to 400.All the putative global minima reported in the literature have been successfully reproduced with relatively high success ratios.Compared to the available results for N≤240 and several larger Morse clusters,new global minima(and local minima)with lower energies have been found out for N=164,175,188,193,194,197,239,246,260,318,and 389.Clusters with magic numbers are figured out through fitting the size-dependent global minimum energies.The cluster structures tend to be close-packed for short-range potential with large N.展开更多
Five fundamental judgments on oil security situation With the revival of world economy and acceleration of globalization, and with China＇s rapid growth in national economy and improved market accessibility, both glo...Five fundamental judgments on oil security situation With the revival of world economy and acceleration of globalization, and with China＇s rapid growth in national economy and improved market accessibility, both global and domestic macro situations are undergoing profound changes.展开更多
Sinopec led the Chinese firms in the list, with its ranking up to 31 from 52 of last year. China National Petroleum Corporation （CNPC） also witnessed a major ranking boost, climbing to 46 from 73 in 2004. The rise f...Sinopec led the Chinese firms in the list, with its ranking up to 31 from 52 of last year. China National Petroleum Corporation （CNPC） also witnessed a major ranking boost, climbing to 46 from 73 in 2004. The rise for these two oil firms is related to the oil prices jump in the global market, according to some experts.展开更多
There are many business needs for implementing delegation in IT （Information Technology） systems. However, existing approaches to delegation in IT systems are limited in their usability, flexibility, and capability ...There are many business needs for implementing delegation in IT （Information Technology） systems. However, existing approaches to delegation in IT systems are limited in their usability, flexibility, and capability to implement least privilege. The result is that delegation is either not implemented or is implemented informally （e.g., by sharing credentials [passwords or hardware tokens] between users）, resulting in serious security concerns and a lack of accountability. This paper describes a methodology for delegation based on the persona concept. A persona is a special category of user that embodies only delegated privileges, and which is explicitly assumed only after the ＂real＂ human user taking on that persona explicitly chooses it, This paper describes the persona delegation framework in the context of a large enclave-based architecture currently being implemented by a major enterprise. The creation of a persona solves a lot of downstream problems by allowing the persona to be treated like any other entity in the system. That is, identity, authentication, authorization, and other security processes already know how to handle an entity of this type. Benefits of the framework include increased flexibility to handle a number of different delegation business scenarios, decreased complexity of the solution, and greater accountability with only a modest amount of additional infrastructure required.展开更多
Abstract： Tillage practice has received much attention due to its effects on greenhouse gas emissions from agricultural fields. The understanding of carbon mineralization associated with soil aggregates helps to expl...Abstract： Tillage practice has received much attention due to its effects on greenhouse gas emissions from agricultural fields. The understanding of carbon mineralization associated with soil aggregates helps to explore the influence mechanisms of tillage practice on soil carbon dynamics. Total carbon and carbon mineralization rates associated with various sizes of soil aggregates under no-tillage and tillage treatments were studied with a volcanic ash soil. Total carbon content in microaggregates （〈0.25 mm） was higher than that in macroaggregates （〉0.25 mm） for both the no-tillage and tillage treatments, since microaggregates of the volcanic ash soil include more fine silts and clay particles absorbing more organic agents. The carbon mineralization rate and total carbon were highly correlated （R2 = 0.6552, P= 0.002） for both treatments, suggesting that soil aggregate size is an important factor to influence the carbon mineralization rate. The no-tillage system showed the advantage of improving soil structure for volcanic ash soil. A larger proportion of microaggregates with relatively high carbon mineralization might contribute to the greater carbon loss from tilled soils. Unlike aggregate size, short-term tillage showed no significant effects on carbon mineralization rates associated with aggregates in a specific size class.展开更多
基金supported by the National Natural Science Foundation of China(No.21803053)the Natural Science Foundation of Zhejiang Province,China(No.LY20B030005)the Open Project Fund of Key Laboratory of Excited-State Materials of Zhejiang Province。
文摘Global optimization of Morse clusters with shortrange potential is a great challenge.Here,we apply our recently developed unbiased fuzzy global optimization method to systematically study Morse clusters with the potential rangeρ=14 and the number of atoms N up to 400.All the putative global minima reported in the literature have been successfully reproduced with relatively high success ratios.Compared to the available results for N≤240 and several larger Morse clusters,new global minima(and local minima)with lower energies have been found out for N=164,175,188,193,194,197,239,246,260,318,and 389.Clusters with magic numbers are figured out through fitting the size-dependent global minimum energies.The cluster structures tend to be close-packed for short-range potential with large N.
文摘Five fundamental judgments on oil security situation With the revival of world economy and acceleration of globalization, and with China＇s rapid growth in national economy and improved market accessibility, both global and domestic macro situations are undergoing profound changes.
文摘Sinopec led the Chinese firms in the list, with its ranking up to 31 from 52 of last year. China National Petroleum Corporation （CNPC） also witnessed a major ranking boost, climbing to 46 from 73 in 2004. The rise for these two oil firms is related to the oil prices jump in the global market, according to some experts.
文摘There are many business needs for implementing delegation in IT （Information Technology） systems. However, existing approaches to delegation in IT systems are limited in their usability, flexibility, and capability to implement least privilege. The result is that delegation is either not implemented or is implemented informally （e.g., by sharing credentials [passwords or hardware tokens] between users）, resulting in serious security concerns and a lack of accountability. This paper describes a methodology for delegation based on the persona concept. A persona is a special category of user that embodies only delegated privileges, and which is explicitly assumed only after the ＂real＂ human user taking on that persona explicitly chooses it, This paper describes the persona delegation framework in the context of a large enclave-based architecture currently being implemented by a major enterprise. The creation of a persona solves a lot of downstream problems by allowing the persona to be treated like any other entity in the system. That is, identity, authentication, authorization, and other security processes already know how to handle an entity of this type. Benefits of the framework include increased flexibility to handle a number of different delegation business scenarios, decreased complexity of the solution, and greater accountability with only a modest amount of additional infrastructure required.
基金supported by the 100 Talents Program of the Chinese Academy of SciencesNational Natural Science Foundation of China(31570472)the Science and Technology Service Network Initiative of the Chinese Academy of Sciences(KFJ-EW-STS-054)
文摘Abstract： Tillage practice has received much attention due to its effects on greenhouse gas emissions from agricultural fields. The understanding of carbon mineralization associated with soil aggregates helps to explore the influence mechanisms of tillage practice on soil carbon dynamics. Total carbon and carbon mineralization rates associated with various sizes of soil aggregates under no-tillage and tillage treatments were studied with a volcanic ash soil. Total carbon content in microaggregates （〈0.25 mm） was higher than that in macroaggregates （〉0.25 mm） for both the no-tillage and tillage treatments, since microaggregates of the volcanic ash soil include more fine silts and clay particles absorbing more organic agents. The carbon mineralization rate and total carbon were highly correlated （R2 = 0.6552, P= 0.002） for both treatments, suggesting that soil aggregate size is an important factor to influence the carbon mineralization rate. The no-tillage system showed the advantage of improving soil structure for volcanic ash soil. A larger proportion of microaggregates with relatively high carbon mineralization might contribute to the greater carbon loss from tilled soils. Unlike aggregate size, short-term tillage showed no significant effects on carbon mineralization rates associated with aggregates in a specific size class.
