This article presents a new well test model for two-zone linear composite reservoirs, where the rock and fluid properties as well as the formation thicknesses on both sides of the discontinuity are distinctly differen...This article presents a new well test model for two-zone linear composite reservoirs, where the rock and fluid properties as well as the formation thicknesses on both sides of the discontinuity are distinctly different. An analytical solution of pressure-transient behavior for a line-source, constant-rate well in this type of reservoir configuration is obtained with Fourier space transformation and Laplace transformation. By applying Duhamel principle, the wellbore storage and skins effects can easily be included. A set of type curves are generated and the sensitivities of the relevant parameters are discussed. A new correlating parameter MhDl√ηD is proposed to identify the pressure response in the pressure derivative curve. The model as well as the corresponding type curves are quite general that they are useful in predicting the production performance or analyzing the production data from this type of well-reservoir systems.展开更多
Walking robots use leg structures to overcome obstacles or move on complicated terrains. Most robots of current researches are equipped with legs of simple structure. The specific design method of walking robot legs i...Walking robots use leg structures to overcome obstacles or move on complicated terrains. Most robots of current researches are equipped with legs of simple structure. The specific design method of walking robot legs is seldom studied. Based on the generalized-function(GF) set theory, a systematic type synthesis process of designing robot legs is introduced. The specific mobility of robot legs is analyzed to obtain two main leg types as the goal of design.Number synthesis problem is decomposed into two stages, actuation and constraint synthesis by name,corresponding to the combinatorics results of linear Diophantine equations. Additional restrictions are discussed to narrow the search range to propose practical limb expressions and kinematic-pair designs. Finally, all the fifty-one leg structures of four subtypes are carried out, some of which are chosen to make up robot prototypes, demonstrating the validity of the method. This paper proposed a novel type synthesis methodology, which could be used to systematically design various practical robot legs and the derived robots.展开更多
The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic belt of the most famous Au-Ag ...The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic belt of the most famous Au-Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension-shear fault-fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K-Ar), Yanshanian granite-porphyry (105±6 Ma, Rb-Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow-seated thick and big ones, which are short-lenticular in plan and wedge-shaped in cross section, shallow buried, large in size and high-grade; the other is lean orebodies, which occur as parallel veins at depths. The ores are mainly of Au-Ag polymetallic sulphide-rich breccia type. Pyrite (limonite) is the dominant metallic mineral, with subordinate chal-copyrite, galena, sphalerite, tenantite, native gold, electrum, native silver and argentite. The gangue minerals consist mainly of quartz and plagioclase, with subordinate carbonate minerals, alunite chalcedony and kaolin. Kaolinization is the characteristic alteration type. Sulphide minerals contain abundant trace minerals such as Cu, Pb, Ag, Sb and Hg, while in the ores Ag, Cu, Pb, Zn, As and Sb are the best indicator element assemblage of Au. The δ34S(%o) values of the ores rane from ?3.2%o to 5.3%o, with average ?0.102%o. The δO H2O(%o) and δ(%o) values are in the ranges from ?3.1%o to 7.73%o and from ?64%o to ?90%o respectively. The Pb isotopic compositions of the rocks and ores in this region indicate that Pb comes from three tectonic sources—upper mantle, lower crust and orogenic展开更多
In this study,we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular byproduct.The vitrimer samples thus pr...In this study,we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular byproduct.The vitrimer samples thus prepared exhibit linear viscoelasticity dependent on the length of A moiety as well as the content of the crosslinks.When the average number of A monomers per end moiety m=1.1,the crosslinker can only extend the chain but not crosslink the chain.When m becomes 2.8 or higher,introducing a crosslinker first leads to the gelation,whereas excess in crosslinker molecules leads opening of the crosslinking sites and accordingly reentry into the sol regime.Surprisingly,a further increase in the length of the A moieties increases the relaxation time much weaker than the exponential increase seen for the physically crosslinked ABAtype ionomers.We attribute this difference to the distinct relaxation mechanisms:the relaxation of the vitrimer samples is based on relatively independent exchange reactions,which contrasts with the ABA-type ionomers that relax through the collective hopping of connected ionic groups from one ion aggregate to another.展开更多
In this paper, the MacWilliams type identity for the m-ply Lee weight enumerator for linear codes over F2 ＋uF2 is determined. As an application of this identity, the authors obtain a MacWilliams type identity on Lee ...In this paper, the MacWilliams type identity for the m-ply Lee weight enumerator for linear codes over F2 ＋uF2 is determined. As an application of this identity, the authors obtain a MacWilliams type identity on Lee weight for linear codes over F2m ＋ uF2m. Furthermore, the authors prove a duality for the m-ply Lee weight distributions by taking advantage of the Krawtchouk polynomials.展开更多
基金Project supported by the National Key Basic Research Program of China (973 Program,Grant No.2006CB705808)the State Major Science and Technology Special Project during the 11th Five-year Plan (Grant No.2008ZX05054)
文摘This article presents a new well test model for two-zone linear composite reservoirs, where the rock and fluid properties as well as the formation thicknesses on both sides of the discontinuity are distinctly different. An analytical solution of pressure-transient behavior for a line-source, constant-rate well in this type of reservoir configuration is obtained with Fourier space transformation and Laplace transformation. By applying Duhamel principle, the wellbore storage and skins effects can easily be included. A set of type curves are generated and the sensitivities of the relevant parameters are discussed. A new correlating parameter MhDl√ηD is proposed to identify the pressure response in the pressure derivative curve. The model as well as the corresponding type curves are quite general that they are useful in predicting the production performance or analyzing the production data from this type of well-reservoir systems.
基金Supported by National Natural Science Foundation of China(Grant Nos.U1613208,51335007)National Basic Research Program of China(973 Program,Grant No.2013CB035501)+1 种基金Science Fund for Creative Research Groups of the National Natural Science Foundation of China(Grant No.51421092)Science and Technology Commission of Shanghai-based "Innovation Action Plan" Project(Grant No.16DZ1201001)
文摘Walking robots use leg structures to overcome obstacles or move on complicated terrains. Most robots of current researches are equipped with legs of simple structure. The specific design method of walking robot legs is seldom studied. Based on the generalized-function(GF) set theory, a systematic type synthesis process of designing robot legs is introduced. The specific mobility of robot legs is analyzed to obtain two main leg types as the goal of design.Number synthesis problem is decomposed into two stages, actuation and constraint synthesis by name,corresponding to the combinatorics results of linear Diophantine equations. Additional restrictions are discussed to narrow the search range to propose practical limb expressions and kinematic-pair designs. Finally, all the fifty-one leg structures of four subtypes are carried out, some of which are chosen to make up robot prototypes, demonstrating the validity of the method. This paper proposed a novel type synthesis methodology, which could be used to systematically design various practical robot legs and the derived robots.
文摘The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic belt of the most famous Au-Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension-shear fault-fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K-Ar), Yanshanian granite-porphyry (105±6 Ma, Rb-Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow-seated thick and big ones, which are short-lenticular in plan and wedge-shaped in cross section, shallow buried, large in size and high-grade; the other is lean orebodies, which occur as parallel veins at depths. The ores are mainly of Au-Ag polymetallic sulphide-rich breccia type. Pyrite (limonite) is the dominant metallic mineral, with subordinate chal-copyrite, galena, sphalerite, tenantite, native gold, electrum, native silver and argentite. The gangue minerals consist mainly of quartz and plagioclase, with subordinate carbonate minerals, alunite chalcedony and kaolin. Kaolinization is the characteristic alteration type. Sulphide minerals contain abundant trace minerals such as Cu, Pb, Ag, Sb and Hg, while in the ores Ag, Cu, Pb, Zn, As and Sb are the best indicator element assemblage of Au. The δ34S(%o) values of the ores rane from ?3.2%o to 5.3%o, with average ?0.102%o. The δO H2O(%o) and δ(%o) values are in the ranges from ?3.1%o to 7.73%o and from ?64%o to ?90%o respectively. The Pb isotopic compositions of the rocks and ores in this region indicate that Pb comes from three tectonic sources—upper mantle, lower crust and orogenic
基金financially supported by the National Natural Science Foundation of China(Nos.22173095 and 52103021)。
文摘In this study,we synthesized a series of ABA-type vitrimers by crosslinking the short A moieties of precursors with a bifunctional crosslinker and evaporating the small molecular byproduct.The vitrimer samples thus prepared exhibit linear viscoelasticity dependent on the length of A moiety as well as the content of the crosslinks.When the average number of A monomers per end moiety m=1.1,the crosslinker can only extend the chain but not crosslink the chain.When m becomes 2.8 or higher,introducing a crosslinker first leads to the gelation,whereas excess in crosslinker molecules leads opening of the crosslinking sites and accordingly reentry into the sol regime.Surprisingly,a further increase in the length of the A moieties increases the relaxation time much weaker than the exponential increase seen for the physically crosslinked ABAtype ionomers.We attribute this difference to the distinct relaxation mechanisms:the relaxation of the vitrimer samples is based on relatively independent exchange reactions,which contrasts with the ABA-type ionomers that relax through the collective hopping of connected ionic groups from one ion aggregate to another.
基金supported by National Natural Science Funds of China under Grant No.60973125College Doctoral Funds of China under Grant No.20080359003+1 种基金Anhui College Natural Science Research Project under Grant No.KJ2010B171Research Project of Hefei Normal University under Grant No.2012kj10
文摘In this paper, the MacWilliams type identity for the m-ply Lee weight enumerator for linear codes over F2 ＋uF2 is determined. As an application of this identity, the authors obtain a MacWilliams type identity on Lee weight for linear codes over F2m ＋ uF2m. Furthermore, the authors prove a duality for the m-ply Lee weight distributions by taking advantage of the Krawtchouk polynomials.
