Grice's maxims,which define the conditions for efficient spoken communication,can be adapted to the teaching of writing by providing both teachers and writers with a way of understanding successful and unsuccessfu...Grice's maxims,which define the conditions for efficient spoken communication,can be adapted to the teaching of writing by providing both teachers and writers with a way of understanding successful and unsuccessful written correspondence in mono-and cross-cultural settings.A survey of lay readers' responses to a sample letter which show that,while there are individual differences in the way these maxims are interpreted,readers expect clarity,brevity,and sincerity,and writing which fails to meet these expectations will be unfavorably received.Also discussed are the issues of contrastive rhetoric,and ways of helping writers to position themselves in relation to their real or imagined reader.展开更多
Neo-przewaquinone A was isolated from the root of Salvia przewalskii Maxim. The structure elucidation and 1H, 13C NMR assignments were achieved by spectroscopic method.
Two new ionone derivatives, rhododendrone A and rhododendronside, have been isolated from the alcoholic extract of the aerial parts of Rhododendron Przewalskii Maxim . The structures of the two compounds, (3R,6S)...Two new ionone derivatives, rhododendrone A and rhododendronside, have been isolated from the alcoholic extract of the aerial parts of Rhododendron Przewalskii Maxim . The structures of the two compounds, (3R,6S) -3-hydroxy- α -ionone 1 and 1,1,5-trimethyl-6-(3-hydroxyl)cyclohexene-5-yl-1- β-D -pyranoglucoside 2, have been elucidated on the basis of the spectroscopic analyses.展开更多
Two new ionone derivatives, named rhododendrone and rhododendronside, were isolated from the alcoholic extract of the aerial parts of Rhododendron przwalskii Maxim. Their structures were elucidated on the basis of spe...Two new ionone derivatives, named rhododendrone and rhododendronside, were isolated from the alcoholic extract of the aerial parts of Rhododendron przwalskii Maxim. Their structures were elucidated on the basis of spectroscopic analysis展开更多
From the root of Salvia przewalskii Maxim.a new phenolic acid, przewalskinic acid A was isolated and the structure was established by the analysis of^(13)C-NMR,~1H-NMR and two-dimensional COSY experiments.
Large-scale epidemiological studies have found that hyperhomocysteinemia is a powerful, independent risk factor for Alzheimer＇s disease. Trillium tschonoskii maxim is a traditional Chinese medicine that is used to pr...Large-scale epidemiological studies have found that hyperhomocysteinemia is a powerful, independent risk factor for Alzheimer＇s disease. Trillium tschonoskii maxim is a traditional Chinese medicine that is used to promote memory. However, scientific understanding of its mechanism of action is limited. This report studied the potential neuroprotective effects of Trillium tschonoskii maxim extract against homocysteine-induced cognitive deficits. Rats were intravenously injected with homocysteine（400 μg/kg） for 14 days to induce a model of Alzheimer＇s disease. These rats were then intragastrically treated with Trillium tschonoskii maxim extract（0.125 or 0.25 g/kg） for 7 consecutive days. Open field test and Morris water maze test were conducted to measure spontaneous activity and learning and memory abilities. Western blot assay was used to detect the levels of Tau protein and other factors involved in Tau phosphorylation in the hippocampus. Immunohistochemical staining was used to examine Tau protein in the hippocampus. Golgi staining was applied to measure hippocampal dendritic spines. Our results demonstrated that homocysteine produced learning and memory deficits and increased levels of Tau phosphorylation, and diminished the activity of catalytic protein phosphatase 2A. The total number of hippocampal dendritic spines was also decreased. Trillium tschonoskii maxim extract treatment reversed the homocysteine-induced changes. The above results suggest that Trillium tschonoskii maxim extract can lessen homocysteine-induced abnormal Tau phosphorylation and improve cognitive deterioration such as that present in Alzheimer＇s disease.展开更多
Given a maximal subgroup M of a group G, a θ*-completion C of M is called an s*-completion if either C = G or there exists a subgroup D of G which is not a θ*-completion of M such that D contains C as a maximal subg...Given a maximal subgroup M of a group G, a θ*-completion C of M is called an s*-completion if either C = G or there exists a subgroup D of G which is not a θ*-completion of M such that D contains C as a maximal subgroup. In this paper, we obtain several results on s*-completions which imply G to be solvable or supersolvable.展开更多
The antibacierial (staphylococcus aureus) activities of 23 diterpene quinones from the Salvia przewalskii Maxim, the artificial synthesis ones and that of the metabolism in pigs were examined in an effort to study the...The antibacierial (staphylococcus aureus) activities of 23 diterpene quinones from the Salvia przewalskii Maxim, the artificial synthesis ones and that of the metabolism in pigs were examined in an effort to study the quantitative structure activity relationship with the Free-Wilson method. With the application of the multipiy regression, the Free-Wilson pattern was established by the dummy (indicator) variable of the structural fragments or substituents. The results showed: (1) The diketone moiety played the fundamental role in antibacterial activities, ortho-quinones was higher active than para-quinones. (2) The single bond existed between the C15 and the C16 at D-ring led to higher activity. (3) The saturation at the A-ring led to higher activity. (4) The components adjacent to nitrogen substituents at C15 led to higher activity. (5)The hydroxylation or dehydrogenation at A-ring led to less activity. The research results can provide the theoretical basis for developing a new antibacterial drug from the Salvia diterpene quinones.展开更多
Based on single-factor experiment and L9 （34 ） orthogonal experiment, a stable ISSR-PCR reaction system of Salvia przewalskii Maxim. was established and optimized. The resuhs indicated that the optimal concentration...Based on single-factor experiment and L9 （34 ） orthogonal experiment, a stable ISSR-PCR reaction system of Salvia przewalskii Maxim. was established and optimized. The resuhs indicated that the optimal concentrations of various components in a 20 ill ISSR-PCR reaction system of S. przewalskii Maxim. were ： 2 ul of 10 x buffer （ Mg2＋）, 0.4 mmol/L dNTPs, 1.0 U of Taq DNA polymerase, 0.3 umol/L ISSR primers and 30 ng of DNA template. This study laid the foun- dation for the utilization of S. przewalskii Maxim. germplasm resources.展开更多
In this paper we deal with the martingales in variable Lebesgue space over a probability space.We first prove several basic inequalities for conditional expectation operators and give several norm convergence conditio...In this paper we deal with the martingales in variable Lebesgue space over a probability space.We first prove several basic inequalities for conditional expectation operators and give several norm convergence conditions for martingales in variable Lebesgue space.The main aim of this paper is to investigate the boundedness of weak-type and strong-type Doob’s maximal operators in martingale Lebesgue space with a variable exponent.In particular,we present two kinds of weak-type Doob’s maximal inequalities and some necessary and sufficient conditions for strong-type Doob’s maximal inequalities.Finally,we provide two counterexamples to show that the strong-type inequality does not hold in general variable Lebesgue spaces with p>1.展开更多
In this paper, we introduce the concept of weakly reducible maxi mal triangular algebras S*!which form a large class of maximal t riangular algebras. Let B be a weakly closed algebra containing S, we prove that the co...In this paper, we introduce the concept of weakly reducible maxi mal triangular algebras S*!which form a large class of maximal t riangular algebras. Let B be a weakly closed algebra containing S, we prove that the cohomology spaces Hn(S , B) ( n≥1) are trivial.展开更多
The research project'Development and application of FCC additive for maximization of propylene and isobutylene'jointly undertaken by RIPP,the Baling Petrochemical Company(BPC)and the SINOPEC
By adopting a complex formulation of Ohm’s law, we arrive at combined equations connecting the conductivities of conductors. The horizontal resistivity is equal to the inverse of Drude’s conductivity δo( ), and the...By adopting a complex formulation of Ohm’s law, we arrive at combined equations connecting the conductivities of conductors. The horizontal resistivity is equal to the inverse of Drude’s conductivity δo( ), and the vertical resistivity (ρy) is equal to the Hall’s conductivity ( δH). At high magnetic field, the horizontal conductivity becomes exceedingly small, whereas the vertical conductivity equals to Hall’s conductivity. The Hall’s conductivity is shown to represent the maximal conductivity of conductors. Drude’s and Hall’s conductivities are related by δo =δHωC , where ωC is the cyclotron frequency, and is the relaxation time. The quantization of Hall’s conductivity is attributed to the fact that the magnetic flux enclosed by the conductor is carried by electrons each with h/e, where h is the Planck’s constant and e is the electron’s charge. The Drude’s conductance is found to be equal to Hall's conductance provided the magnetic flux enclosed by the conductor is a multiple of h/e.展开更多
The problems of stability and stabilization for the discrete Takagi-Sugeno（T-S） fuzzy time-delay system are investigated.By constructing a discrete piecewise Lyapunov-Krasovskii function（PLKF） in each maximal over...The problems of stability and stabilization for the discrete Takagi-Sugeno（T-S） fuzzy time-delay system are investigated.By constructing a discrete piecewise Lyapunov-Krasovskii function（PLKF） in each maximal overlapped-rules group（MORG）,a new sufficient stability condition for the open-loop discrete T-S fuzzy time-delay system is proposed and proved.Then the systematic design of the fuzzy controller is investigated via the parallel distributed compensation control scheme,and a new stabilization condition for the closed-loop discrete T-S fuzzy time-delay system is proposed.The above two sufficient conditions only require finding common matrices in each MORG.Compared with the common Lyapunov-Krasovskii function（CLKF） approach and the fuzzy Lyapunov-Krasovskii function（FLKF） approach,these proposed sufficient conditions can not only overcome the defect of finding common matrices in the whole feasible region but also largely reduce the number of linear matrix inequalities to be solved.Finally,simulation examples show that the proposed PLKF approach is effective.展开更多
文摘Grice's maxims,which define the conditions for efficient spoken communication,can be adapted to the teaching of writing by providing both teachers and writers with a way of understanding successful and unsuccessful written correspondence in mono-and cross-cultural settings.A survey of lay readers' responses to a sample letter which show that,while there are individual differences in the way these maxims are interpreted,readers expect clarity,brevity,and sincerity,and writing which fails to meet these expectations will be unfavorably received.Also discussed are the issues of contrastive rhetoric,and ways of helping writers to position themselves in relation to their real or imagined reader.
文摘Neo-przewaquinone A was isolated from the root of Salvia przewalskii Maxim. The structure elucidation and 1H, 13C NMR assignments were achieved by spectroscopic method.
基金Supported by the National Natural Science Foundation of China( No.2 0 2 75 0 2 0 ) and the Natural Science Foundation ofShandong Province( No.Z2 0 0 2 B0 2 )
文摘Two new ionone derivatives, rhododendrone A and rhododendronside, have been isolated from the alcoholic extract of the aerial parts of Rhododendron Przewalskii Maxim . The structures of the two compounds, (3R,6S) -3-hydroxy- α -ionone 1 and 1,1,5-trimethyl-6-(3-hydroxyl)cyclohexene-5-yl-1- β-D -pyranoglucoside 2, have been elucidated on the basis of the spectroscopic analyses.
文摘Two new ionone derivatives, named rhododendrone and rhododendronside, were isolated from the alcoholic extract of the aerial parts of Rhododendron przwalskii Maxim. Their structures were elucidated on the basis of spectroscopic analysis
文摘From the root of Salvia przewalskii Maxim.a new phenolic acid, przewalskinic acid A was isolated and the structure was established by the analysis of^(13)C-NMR,~1H-NMR and two-dimensional COSY experiments.
基金supported in part by grants from the National Natural Science Foundation of China,No.81260172,81660223the Opening Foundation of Hubei Key Laboratory of Biological Resource Protection and Utilization of China,No.PKLHB1318+2 种基金the Science and Technology Innovation Team Project of Hubei University for Nationalities of China,No.MY2011T005the Doctoral Fund of Hubei University for Nationalities of China,No.MY2012B015the Natural Science Foundation of Hubei Province of China,No.2017CFB451
文摘Large-scale epidemiological studies have found that hyperhomocysteinemia is a powerful, independent risk factor for Alzheimer＇s disease. Trillium tschonoskii maxim is a traditional Chinese medicine that is used to promote memory. However, scientific understanding of its mechanism of action is limited. This report studied the potential neuroprotective effects of Trillium tschonoskii maxim extract against homocysteine-induced cognitive deficits. Rats were intravenously injected with homocysteine（400 μg/kg） for 14 days to induce a model of Alzheimer＇s disease. These rats were then intragastrically treated with Trillium tschonoskii maxim extract（0.125 or 0.25 g/kg） for 7 consecutive days. Open field test and Morris water maze test were conducted to measure spontaneous activity and learning and memory abilities. Western blot assay was used to detect the levels of Tau protein and other factors involved in Tau phosphorylation in the hippocampus. Immunohistochemical staining was used to examine Tau protein in the hippocampus. Golgi staining was applied to measure hippocampal dendritic spines. Our results demonstrated that homocysteine produced learning and memory deficits and increased levels of Tau phosphorylation, and diminished the activity of catalytic protein phosphatase 2A. The total number of hippocampal dendritic spines was also decreased. Trillium tschonoskii maxim extract treatment reversed the homocysteine-induced changes. The above results suggest that Trillium tschonoskii maxim extract can lessen homocysteine-induced abnormal Tau phosphorylation and improve cognitive deterioration such as that present in Alzheimer＇s disease.
文摘Given a maximal subgroup M of a group G, a θ*-completion C of M is called an s*-completion if either C = G or there exists a subgroup D of G which is not a θ*-completion of M such that D contains C as a maximal subgroup. In this paper, we obtain several results on s*-completions which imply G to be solvable or supersolvable.
文摘The antibacierial (staphylococcus aureus) activities of 23 diterpene quinones from the Salvia przewalskii Maxim, the artificial synthesis ones and that of the metabolism in pigs were examined in an effort to study the quantitative structure activity relationship with the Free-Wilson method. With the application of the multipiy regression, the Free-Wilson pattern was established by the dummy (indicator) variable of the structural fragments or substituents. The results showed: (1) The diketone moiety played the fundamental role in antibacterial activities, ortho-quinones was higher active than para-quinones. (2) The single bond existed between the C15 and the C16 at D-ring led to higher activity. (3) The saturation at the A-ring led to higher activity. (4) The components adjacent to nitrogen substituents at C15 led to higher activity. (5)The hydroxylation or dehydrogenation at A-ring led to less activity. The research results can provide the theoretical basis for developing a new antibacterial drug from the Salvia diterpene quinones.
基金Supported by Project of Qinghai Science and Technology Department(2011-NF19)Fund for Middle-aged and Young Scientists of Qinghai University(2012-QYT-1)
文摘Based on single-factor experiment and L9 （34 ） orthogonal experiment, a stable ISSR-PCR reaction system of Salvia przewalskii Maxim. was established and optimized. The resuhs indicated that the optimal concentrations of various components in a 20 ill ISSR-PCR reaction system of S. przewalskii Maxim. were ： 2 ul of 10 x buffer （ Mg2＋）, 0.4 mmol/L dNTPs, 1.0 U of Taq DNA polymerase, 0.3 umol/L ISSR primers and 30 ng of DNA template. This study laid the foun- dation for the utilization of S. przewalskii Maxim. germplasm resources.
文摘In this paper we deal with the martingales in variable Lebesgue space over a probability space.We first prove several basic inequalities for conditional expectation operators and give several norm convergence conditions for martingales in variable Lebesgue space.The main aim of this paper is to investigate the boundedness of weak-type and strong-type Doob’s maximal operators in martingale Lebesgue space with a variable exponent.In particular,we present two kinds of weak-type Doob’s maximal inequalities and some necessary and sufficient conditions for strong-type Doob’s maximal inequalities.Finally,we provide two counterexamples to show that the strong-type inequality does not hold in general variable Lebesgue spaces with p>1.
文摘In this paper, we introduce the concept of weakly reducible maxi mal triangular algebras S*!which form a large class of maximal t riangular algebras. Let B be a weakly closed algebra containing S, we prove that the cohomology spaces Hn(S , B) ( n≥1) are trivial.
文摘The research project'Development and application of FCC additive for maximization of propylene and isobutylene'jointly undertaken by RIPP,the Baling Petrochemical Company(BPC)and the SINOPEC
文摘By adopting a complex formulation of Ohm’s law, we arrive at combined equations connecting the conductivities of conductors. The horizontal resistivity is equal to the inverse of Drude’s conductivity δo( ), and the vertical resistivity (ρy) is equal to the Hall’s conductivity ( δH). At high magnetic field, the horizontal conductivity becomes exceedingly small, whereas the vertical conductivity equals to Hall’s conductivity. The Hall’s conductivity is shown to represent the maximal conductivity of conductors. Drude’s and Hall’s conductivities are related by δo =δHωC , where ωC is the cyclotron frequency, and is the relaxation time. The quantization of Hall’s conductivity is attributed to the fact that the magnetic flux enclosed by the conductor is carried by electrons each with h/e, where h is the Planck’s constant and e is the electron’s charge. The Drude’s conductance is found to be equal to Hall's conductance provided the magnetic flux enclosed by the conductor is a multiple of h/e.
基金supported in part by the Scientific Research Project of Heilongjiang Province Education Bureau(12541200)
文摘The problems of stability and stabilization for the discrete Takagi-Sugeno（T-S） fuzzy time-delay system are investigated.By constructing a discrete piecewise Lyapunov-Krasovskii function（PLKF） in each maximal overlapped-rules group（MORG）,a new sufficient stability condition for the open-loop discrete T-S fuzzy time-delay system is proposed and proved.Then the systematic design of the fuzzy controller is investigated via the parallel distributed compensation control scheme,and a new stabilization condition for the closed-loop discrete T-S fuzzy time-delay system is proposed.The above two sufficient conditions only require finding common matrices in each MORG.Compared with the common Lyapunov-Krasovskii function（CLKF） approach and the fuzzy Lyapunov-Krasovskii function（FLKF） approach,these proposed sufficient conditions can not only overcome the defect of finding common matrices in the whole feasible region but also largely reduce the number of linear matrix inequalities to be solved.Finally,simulation examples show that the proposed PLKF approach is effective.
