Two new triterpenoid glycosides, hederagenin-3-O-b-D-xylopyranoside (1), dodecandral 3-O-b-D-xylopyranoside(2), were isolated from Elsholtzia bodinieri Vant. The structures of 1 and 2 were established by spectroscopi...Two new triterpenoid glycosides, hederagenin-3-O-b-D-xylopyranoside (1), dodecandral 3-O-b-D-xylopyranoside(2), were isolated from Elsholtzia bodinieri Vant. The structures of 1 and 2 were established by spectroscopic and chemical methods.展开更多
Two new monoterpene diglycosides, wincaloside A (1) and wincaloside B (2), along with loganin (3) were isolated from the stem barks of Winchia calophylla A. DC. The structures of 1 and 2 were established by spectrosco...Two new monoterpene diglycosides, wincaloside A (1) and wincaloside B (2), along with loganin (3) were isolated from the stem barks of Winchia calophylla A. DC. The structures of 1 and 2 were established by spectroscopic and chemical methods.展开更多
AIM: To explore the role of bile liquid crystal in the process of gallbladder stone formation and to provide bases for preventing and treating cholelithiasis.METHODS: 46 guinea pigs, half males and half females,were r...AIM: To explore the role of bile liquid crystal in the process of gallbladder stone formation and to provide bases for preventing and treating cholelithiasis.METHODS: 46 guinea pigs, half males and half females,were randomly divided into control group and stone-causing group. Normal feed and stoneleading feed were used respectively to raise guinea pigs in the control group and stone-causing group. The guinea pigs were killed in three batches during the raising period. Under polarizing microscope, the pattern changes of bile liquid crystal in the gallbladder biles of the guinea pigs in the control group and stone-causing group were dynamicly observed respectively in single-blind trial.RESULTS: It was found that there were few crystals in the guinea pigs′biles of the control group, and their Malta cross was small and scattered, and existed in single form. With the increase of the feeding days, bile liquid crystals grew and Malta cross became bigger with their distribution densified, denser somewhere, but always existed in single form. While those of the stone-causing group had more bile liquid crystals, Malta cross was big and merged in strings.With the increase of the feeding days, bile liquid crystals grew in amount and strings of Malta cross increased and became bigger. The crosses in strings were arranged more and more regularly and they gradually changed into stone crystals.CONCLUSION: Formation of gallbladder stone is a process of nucleation from different substances, and the causing-stone gallbladder bile is a constantly supersaturated solution, and bile liquid crystal is a nucleation factor in the formation of gallbladder stones. The process of nucleation includes gathering, merging and phase-changing of bile liquid crystals.The process of gathering, merging of bile liquid crystal is the key to nucleation.展开更多
Solitary waves in relativistic electromagnetic plasmas are obtained numerically. The longitudinal momentum of electrons has been taken into account in the problem. It is found that in the moving frame with electromagn...Solitary waves in relativistic electromagnetic plasmas are obtained numerically. The longitudinal momentum of electrons has been taken into account in the problem. It is found that in the moving frame with electromagnetic field propagating the solitary waves can exist in both cases, where the vector potential frequency is larger or smaller than the plasma characteristic frequency.展开更多
A novel horizontal push-pull multi-substrate epitaxy boat with three separate cells is introduced in this article, with which multi-substrate LPE processing is feasible in horizontal LPE furnace. The processes of LPE ...A novel horizontal push-pull multi-substrate epitaxy boat with three separate cells is introduced in this article, with which multi-substrate LPE processing is feasible in horizontal LPE furnace. The processes of LPE AlxGa1-x)As/ GaAs solar cells are studied and the efficiency of the solar cells achieved 19.8% （AMO, 25℃, 120 mW/cm2）.展开更多
Shunt resistance of solar cell must be monitored for large area solar cell manufactured with conventional process.A measuring method for the shunt resistance is derived from direct-current model.The shunt resistance o...Shunt resistance of solar cell must be monitored for large area solar cell manufactured with conventional process.A measuring method for the shunt resistance is derived from direct-current model.The shunt resistance of solar cell is obtained only by treating a part of I-V data.展开更多
Theoretical dependence of the quantum yields on the size of Agnano-particle distribution from 0.8 nm to 37 nm embedded in BaOsemiconductor is discussed. The calculation results show that theincrease in Ag nano-particl...Theoretical dependence of the quantum yields on the size of Agnano-particle distribution from 0.8 nm to 37 nm embedded in BaOsemiconductor is discussed. The calculation results show that theincrease in Ag nano-particle diameter leads to the increase of thequantum yield threshold and the emergence of the rough Gaussian form,the results also shown that the greater increase in Ag nano-particlediameter causes the emergence of the exact Gaussian form and makesthe peaks rise up.展开更多
The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline si...The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline silicon thin film solar cells are compared. The future development trends are pointed out. It is found that polycrystalline silicon thin film solar cells will be more promising for application with great potential.展开更多
Let x be an m-dimensional umbilic-free hypersurface in an （m＋1）-dimensional unit sphere Sm＋l （m≥3）. In this paper, we classify and explicitly express the hypersurfaces with two distinct princi- pal curvatures a...Let x be an m-dimensional umbilic-free hypersurface in an （m＋1）-dimensional unit sphere Sm＋l （m≥3）. In this paper, we classify and explicitly express the hypersurfaces with two distinct princi- pal curvatures and closed MSbius form, and then we characterize and classify conformally flat hypersurfaces of dimension larger than 3.展开更多
With the research of the relationship between culture and language teaching deepening, people have realized the necessity of introducing culture into language teaching. This article aims at illustrating the importance...With the research of the relationship between culture and language teaching deepening, people have realized the necessity of introducing culture into language teaching. This article aims at illustrating the importance of culture introduction from two perspectives, namely the relationship between culture and language, and the learners' motivation.展开更多
In this paper a stochastic volatility model is considered. That is, a log price process Y whichis given in terms of a volatility process V is studied. The latter is defined such that the logprice possesses some of the...In this paper a stochastic volatility model is considered. That is, a log price process Y whichis given in terms of a volatility process V is studied. The latter is defined such that the logprice possesses some of the properties empirically observed by Barndorff-Nielsen & Jiang[6]. Inthe model there are two sets of unknown parameters, one set corresponding to the marginaldistribution of V and one to autocorrelation of V. Based on discrete time observations ofthe log price the authors discuss how to estimate the parameters appearing in the marginaldistribution and find the asymptotic properties.展开更多
This Paper gives a Fan’s type minimax theorem, a nearest point theorem and two existence theorems of solutions for a kind of generalized quasi-variational inequalities in H-spaces without any linear structure.
New transmission line equations are deduced applying Maxwell's equations in this paper. The conditions of the classical transmission line equations have been discussed, which is important to solve the EM problems ...New transmission line equations are deduced applying Maxwell's equations in this paper. The conditions of the classical transmission line equations have been discussed, which is important to solve the EM problems in high frequency case.展开更多
Pragmatics plays an important role in correctly understanding sentences. Much useful information will be lost if the context in which a sentence is asserted is ignored. There are some approaches in logic to pragmatics...Pragmatics plays an important role in correctly understanding sentences. Much useful information will be lost if the context in which a sentence is asserted is ignored. There are some approaches in logic to pragmatics, such as situation theories and context logics. Although these methods associate a sentence with a context or a situation, they consider only the truth value of the sentence. However, a sentence should have more meanings than its truth value, and people care more about what a sentence conveys. For the affection of contexts, the meaning of a sentence is not always its semantic meaning and a sentence may have different pragmatical implications in different contexts. In this paper, a context is considered as some structure in the real world. A sentence from some logical language is conceptualized as a concept, whose intent is a set of sentences implied semantically by the sentence, and whose extent is a set of contexts in which the sentence describes a part of the contexts. In terms of tools and theories of concepts, a strictly defined theory is given to study the pragmatics of sentences in contexts in information systems, which cannot be derived from the sentences by using logical reasoning methods.展开更多
文摘Two new triterpenoid glycosides, hederagenin-3-O-b-D-xylopyranoside (1), dodecandral 3-O-b-D-xylopyranoside(2), were isolated from Elsholtzia bodinieri Vant. The structures of 1 and 2 were established by spectroscopic and chemical methods.
基金supported by the National Natural Science Foundation for Outstanding Young Scientists to Prof.Xiao Jiang Hao(No.39525025).
文摘Two new monoterpene diglycosides, wincaloside A (1) and wincaloside B (2), along with loganin (3) were isolated from the stem barks of Winchia calophylla A. DC. The structures of 1 and 2 were established by spectroscopic and chemical methods.
基金the National Natural Sciencce Foundation of China,No.39960024Applied Basic Research Fund of Yunnan Provincial Science and Technology Committee,No.1999C 0064MScience Foundation of Yunnan Education Committee,No.9912073
文摘AIM: To explore the role of bile liquid crystal in the process of gallbladder stone formation and to provide bases for preventing and treating cholelithiasis.METHODS: 46 guinea pigs, half males and half females,were randomly divided into control group and stone-causing group. Normal feed and stoneleading feed were used respectively to raise guinea pigs in the control group and stone-causing group. The guinea pigs were killed in three batches during the raising period. Under polarizing microscope, the pattern changes of bile liquid crystal in the gallbladder biles of the guinea pigs in the control group and stone-causing group were dynamicly observed respectively in single-blind trial.RESULTS: It was found that there were few crystals in the guinea pigs′biles of the control group, and their Malta cross was small and scattered, and existed in single form. With the increase of the feeding days, bile liquid crystals grew and Malta cross became bigger with their distribution densified, denser somewhere, but always existed in single form. While those of the stone-causing group had more bile liquid crystals, Malta cross was big and merged in strings.With the increase of the feeding days, bile liquid crystals grew in amount and strings of Malta cross increased and became bigger. The crosses in strings were arranged more and more regularly and they gradually changed into stone crystals.CONCLUSION: Formation of gallbladder stone is a process of nucleation from different substances, and the causing-stone gallbladder bile is a constantly supersaturated solution, and bile liquid crystal is a nucleation factor in the formation of gallbladder stones. The process of nucleation includes gathering, merging and phase-changing of bile liquid crystals.The process of gathering, merging of bile liquid crystal is the key to nucleation.
文摘Solitary waves in relativistic electromagnetic plasmas are obtained numerically. The longitudinal momentum of electrons has been taken into account in the problem. It is found that in the moving frame with electromagnetic field propagating the solitary waves can exist in both cases, where the vector potential frequency is larger or smaller than the plasma characteristic frequency.
文摘A novel horizontal push-pull multi-substrate epitaxy boat with three separate cells is introduced in this article, with which multi-substrate LPE processing is feasible in horizontal LPE furnace. The processes of LPE AlxGa1-x)As/ GaAs solar cells are studied and the efficiency of the solar cells achieved 19.8% （AMO, 25℃, 120 mW/cm2）.
文摘Shunt resistance of solar cell must be monitored for large area solar cell manufactured with conventional process.A measuring method for the shunt resistance is derived from direct-current model.The shunt resistance of solar cell is obtained only by treating a part of I-V data.
文摘Theoretical dependence of the quantum yields on the size of Agnano-particle distribution from 0.8 nm to 37 nm embedded in BaOsemiconductor is discussed. The calculation results show that theincrease in Ag nano-particle diameter leads to the increase of thequantum yield threshold and the emergence of the rough Gaussian form,the results also shown that the greater increase in Ag nano-particlediameter causes the emergence of the exact Gaussian form and makesthe peaks rise up.
文摘The preparation, current status and trends are investigated for silicon thin film solar cells. The advantages and disadvantages of amorphous silicon thin film, polycrystalline silicon thin film and mono-crystalline silicon thin film solar cells are compared. The future development trends are pointed out. It is found that polycrystalline silicon thin film solar cells will be more promising for application with great potential.
基金supported by National Natural Science Foundation of China (Grant Nos.10561010, 10861013)
文摘Let x be an m-dimensional umbilic-free hypersurface in an （m＋1）-dimensional unit sphere Sm＋l （m≥3）. In this paper, we classify and explicitly express the hypersurfaces with two distinct princi- pal curvatures and closed MSbius form, and then we characterize and classify conformally flat hypersurfaces of dimension larger than 3.
文摘With the research of the relationship between culture and language teaching deepening, people have realized the necessity of introducing culture into language teaching. This article aims at illustrating the importance of culture introduction from two perspectives, namely the relationship between culture and language, and the learners' motivation.
基金Project supported by the Yunnan Provincial Natural Science Foundation of China(No.00A0006R).
文摘In this paper a stochastic volatility model is considered. That is, a log price process Y whichis given in terms of a volatility process V is studied. The latter is defined such that the logprice possesses some of the properties empirically observed by Barndorff-Nielsen & Jiang[6]. Inthe model there are two sets of unknown parameters, one set corresponding to the marginaldistribution of V and one to autocorrelation of V. Based on discrete time observations ofthe log price the authors discuss how to estimate the parameters appearing in the marginaldistribution and find the asymptotic properties.
基金the Foundation of the Technology Commission of Zhejiang Province, China.(No.19990500), the National Natural Science Foundation
文摘This Paper gives a Fan’s type minimax theorem, a nearest point theorem and two existence theorems of solutions for a kind of generalized quasi-variational inequalities in H-spaces without any linear structure.
文摘New transmission line equations are deduced applying Maxwell's equations in this paper. The conditions of the classical transmission line equations have been discussed, which is important to solve the EM problems in high frequency case.
文摘Pragmatics plays an important role in correctly understanding sentences. Much useful information will be lost if the context in which a sentence is asserted is ignored. There are some approaches in logic to pragmatics, such as situation theories and context logics. Although these methods associate a sentence with a context or a situation, they consider only the truth value of the sentence. However, a sentence should have more meanings than its truth value, and people care more about what a sentence conveys. For the affection of contexts, the meaning of a sentence is not always its semantic meaning and a sentence may have different pragmatical implications in different contexts. In this paper, a context is considered as some structure in the real world. A sentence from some logical language is conceptualized as a concept, whose intent is a set of sentences implied semantically by the sentence, and whose extent is a set of contexts in which the sentence describes a part of the contexts. In terms of tools and theories of concepts, a strictly defined theory is given to study the pragmatics of sentences in contexts in information systems, which cannot be derived from the sentences by using logical reasoning methods.
