[Objective] This study was conducted to establish a near-infrared diffuse reflectance spectroscopy of Guizhou Aspidistra plants. [Method] Twenty three batch- es of Guizhou Aspidistra plants including A. chishuiensis, ...[Objective] This study was conducted to establish a near-infrared diffuse reflectance spectroscopy of Guizhou Aspidistra plants. [Method] Twenty three batch- es of Guizhou Aspidistra plants including A. chishuiensis, A. spinula, A. Caespitosa, A. sichuanensis, A. ebianensis, A. retusa, A. guizhouensis and A. liboensis were subjected to drying, pulverization and sieving and then directly determined for near- infrared reflectance spectrums; and the plants in this genus were classified by clus- ter analysis and principal component analysis （PCA）. [Result] The near-infrared re- flectance spectrums of the 23 batches of Guizhou Aspidistra plants showed very high similarity. The spectrums were processed by first derivative method, and the spectral range of 4 000-7 500 cm-1 was selected as the analytical range. Cluster analysis and PCA were employed to mass spectrum variables of plants in Aspidis- tra, fewer new variables became the linear combination of primary variables, and small differences between different varieties were enlarged, thereby facilitating intu- itive classification of plants in this genus. [Conclusion] Near-infrared diffuse re- flectance spectroscopy is nondestructive and rapid for determination of solid sam- pies, and provides a new method for the classification of Guizhou Aspidistra plants combined by information processing techniques.展开更多
Aim To investigate the chemical constituents of Ixeris sonchifolia Hance. Methods The chemical constituents were isolated by various column chromatographic methods and the structures were elucidated and characterized ...Aim To investigate the chemical constituents of Ixeris sonchifolia Hance. Methods The chemical constituents were isolated by various column chromatographic methods and the structures were elucidated and characterized by spectral evidences. Result Thirteen compounds were obtained and identified as 3β-acetoxy-20-taraxasten-22-one （1）, bauerenyl acetate （2）, 3β-acetoxy- 11-oxours-12-ene （3）, oleanic acid （4）, oleanane （5）, 8-desoxyartelin （6）, aesculetin （7）, ferulic acid （8）, vanillic acid （9）, sonchifolinin （10）, hexacosanol （11）, β-sitosterol （12）, and daucosterol （13）. Conclusion Compounds 1, 5, and 8 were isolated from this genus for the first time; compound 7 was obtained firstly from this plant.展开更多
The control problem of trajectory based path following for passenger vehicles is studied. Comprehensive nonlinear vehicle model is utilized for simulation vehicle response during various maneuvers in MATLAB/Simulink. ...The control problem of trajectory based path following for passenger vehicles is studied. Comprehensive nonlinear vehicle model is utilized for simulation vehicle response during various maneuvers in MATLAB/Simulink. In order to follow desired path, a driver model is developed to enhance closed loop driver/vehicle model. Then, linear quadratic regulator(LQR) controller is developed which regulates direct yaw moment and corrective steering angle on wheels. Particle swam optimization(PSO) method is utilized to optimize the LQR controller for various dynamic conditions. Simulation results indicate that, over various maneuvers, side slip angle and lateral acceleration can be reduced by 10% and 15%, respectively, which sustain the vehicle stable. Also, anti-lock brake system is designed for longitudinal dynamics of vehicle to achieve desired slip during braking and accelerating. Proposed comprehensive controller demonstrates that vehicle steerability can increase by about 15% during severe braking by preventing wheel from locking and reducing stopping distance.展开更多
The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity...The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity sensors. The disadvantage is successive overshoot, i. e. successive transition from wheels locking mode to wheels rolling mode. So braking mechanism can’ t realize the maximum possible torque in the current road conditions. The idea of increasing the braking effectiveness is the intensity of rising pressure depends on the road conditions. The problem is the torque produced by braking mechanism, current road conditions and the value of traction coefficient is unknown For evaluation of these parameters built and training three neural networks. A simulator of random road condition＇s variation was built to test adequacy of the control unites operation in close to real conditions.展开更多
This paper aims to make a contrastive study on complaining strategies between American and Chinese university students, based on the descriptive study of the collected data, with reference to the social variables of s...This paper aims to make a contrastive study on complaining strategies between American and Chinese university students, based on the descriptive study of the collected data, with reference to the social variables of social status and social distance. It is found that Chinese and American university students are significantly different in the choice of complaining strategies produced to professors, intimates, friends and strangers. The Chinese show greater respect to professors than Americans do. Generally, as to interlocutors with equal social status, Americans＇ complaining degree displays a gradually descending tendency along a social distance continuum, while the Chinese have intimates and strangers at the both ends, with friends in the middle. No significant difference has been revealed in the choice of complaining strategies to parents, but Americans tend to be more polite than the Chinese. This challenges Brown and Levinson＇s formula, Wx = D （S, H） ＋ P （H, S） ＋Rx, which implies the same weight for each of these three factors. The study proves that in private conversations, the variable of social distance carries more importance than the variable of social status.展开更多
A novel homoisoflavone typicalvone A （1）, together with two known compounds, n-heneicosane and p-hydroxy benzoic acid, were isolated from Aspidistra typica Baill. The structure of the new compound was elucidated by ...A novel homoisoflavone typicalvone A （1）, together with two known compounds, n-heneicosane and p-hydroxy benzoic acid, were isolated from Aspidistra typica Baill. The structure of the new compound was elucidated by sepctral techniques, viz. 1D, 2D NMR spectra and HR-ESI-MS. Compared with berberine hydrochloride, typicalvone A showed moderate anti-bacterial activities, especially against the Gram-negative Paeudomonas aeruginosa ATCC-9027 and Escherichia coli ATCC-25922, with MBC values of 1000 and 500 μg/mL, respectively. In addition, it exhibited weak inhibitory activities against the tumour cells.展开更多
The BRICS basic infrastructure suffers from a huge financing gap, but their massive foreign exchange reserves lack profitable outlets and member states＇ self-contained management costs are extremely high. The coincid...The BRICS basic infrastructure suffers from a huge financing gap, but their massive foreign exchange reserves lack profitable outlets and member states＇ self-contained management costs are extremely high. The coincidence of the need for basic infrastructure investment and the need for profitable foreign exchange reserves are the immediate reasons for setting up the BRICS Development Bank. Comparative advantage and the co-movement of fluctuations in the BRICS member states optimize their cooperative interests. A co- movement game model analysis enables us to deduce the logical necessity for cooperation among the BRICS. Compared with other patterns of cooperation, virtual networks enable this financial cooperation to yield benefits in a short timeframe. The mutually supportive relationship between development and stability in the BRICS economies provides a solid rationale for the establishment of the New Development Bank.展开更多
基金Supported by National Natural Science Foundation of China(81360623)~~
文摘[Objective] This study was conducted to establish a near-infrared diffuse reflectance spectroscopy of Guizhou Aspidistra plants. [Method] Twenty three batch- es of Guizhou Aspidistra plants including A. chishuiensis, A. spinula, A. Caespitosa, A. sichuanensis, A. ebianensis, A. retusa, A. guizhouensis and A. liboensis were subjected to drying, pulverization and sieving and then directly determined for near- infrared reflectance spectrums; and the plants in this genus were classified by clus- ter analysis and principal component analysis （PCA）. [Result] The near-infrared re- flectance spectrums of the 23 batches of Guizhou Aspidistra plants showed very high similarity. The spectrums were processed by first derivative method, and the spectral range of 4 000-7 500 cm-1 was selected as the analytical range. Cluster analysis and PCA were employed to mass spectrum variables of plants in Aspidis- tra, fewer new variables became the linear combination of primary variables, and small differences between different varieties were enlarged, thereby facilitating intu- itive classification of plants in this genus. [Conclusion] Near-infrared diffuse re- flectance spectroscopy is nondestructive and rapid for determination of solid sam- pies, and provides a new method for the classification of Guizhou Aspidistra plants combined by information processing techniques.
文摘Aim To investigate the chemical constituents of Ixeris sonchifolia Hance. Methods The chemical constituents were isolated by various column chromatographic methods and the structures were elucidated and characterized by spectral evidences. Result Thirteen compounds were obtained and identified as 3β-acetoxy-20-taraxasten-22-one （1）, bauerenyl acetate （2）, 3β-acetoxy- 11-oxours-12-ene （3）, oleanic acid （4）, oleanane （5）, 8-desoxyartelin （6）, aesculetin （7）, ferulic acid （8）, vanillic acid （9）, sonchifolinin （10）, hexacosanol （11）, β-sitosterol （12）, and daucosterol （13）. Conclusion Compounds 1, 5, and 8 were isolated from this genus for the first time; compound 7 was obtained firstly from this plant.
文摘The control problem of trajectory based path following for passenger vehicles is studied. Comprehensive nonlinear vehicle model is utilized for simulation vehicle response during various maneuvers in MATLAB/Simulink. In order to follow desired path, a driver model is developed to enhance closed loop driver/vehicle model. Then, linear quadratic regulator(LQR) controller is developed which regulates direct yaw moment and corrective steering angle on wheels. Particle swam optimization(PSO) method is utilized to optimize the LQR controller for various dynamic conditions. Simulation results indicate that, over various maneuvers, side slip angle and lateral acceleration can be reduced by 10% and 15%, respectively, which sustain the vehicle stable. Also, anti-lock brake system is designed for longitudinal dynamics of vehicle to achieve desired slip during braking and accelerating. Proposed comprehensive controller demonstrates that vehicle steerability can increase by about 15% during severe braking by preventing wheel from locking and reducing stopping distance.
文摘The operating principle of an antilock braking system （ABS） is it compares current value of angular acceleration with the threshold value. The advantage of such system is that enough it has only the angular velocity sensors. The disadvantage is successive overshoot, i. e. successive transition from wheels locking mode to wheels rolling mode. So braking mechanism can’ t realize the maximum possible torque in the current road conditions. The idea of increasing the braking effectiveness is the intensity of rising pressure depends on the road conditions. The problem is the torque produced by braking mechanism, current road conditions and the value of traction coefficient is unknown For evaluation of these parameters built and training three neural networks. A simulator of random road condition＇s variation was built to test adequacy of the control unites operation in close to real conditions.
基金supported by the Teaching Reform Grant from Nanjing University of Posts and Telecommunications.Grant No.:JG00910JX32sponsored by Qing Lan Project of Education Department of Jiangsu Province
文摘This paper aims to make a contrastive study on complaining strategies between American and Chinese university students, based on the descriptive study of the collected data, with reference to the social variables of social status and social distance. It is found that Chinese and American university students are significantly different in the choice of complaining strategies produced to professors, intimates, friends and strangers. The Chinese show greater respect to professors than Americans do. Generally, as to interlocutors with equal social status, Americans＇ complaining degree displays a gradually descending tendency along a social distance continuum, while the Chinese have intimates and strangers at the both ends, with friends in the middle. No significant difference has been revealed in the choice of complaining strategies to parents, but Americans tend to be more polite than the Chinese. This challenges Brown and Levinson＇s formula, Wx = D （S, H） ＋ P （H, S） ＋Rx, which implies the same weight for each of these three factors. The study proves that in private conversations, the variable of social distance carries more importance than the variable of social status.
基金The Project of Department of Science in Sichuan Province(Grant No.14ZA0003)
文摘A novel homoisoflavone typicalvone A （1）, together with two known compounds, n-heneicosane and p-hydroxy benzoic acid, were isolated from Aspidistra typica Baill. The structure of the new compound was elucidated by sepctral techniques, viz. 1D, 2D NMR spectra and HR-ESI-MS. Compared with berberine hydrochloride, typicalvone A showed moderate anti-bacterial activities, especially against the Gram-negative Paeudomonas aeruginosa ATCC-9027 and Escherichia coli ATCC-25922, with MBC values of 1000 and 500 μg/mL, respectively. In addition, it exhibited weak inhibitory activities against the tumour cells.
基金the initial results of the SSFC-funded project "Assessment of the desired scale of foreign exchange reserves of the BRICS countries:multiple motives,big country models,cooperative adjustment"(No.13BGJ039)the National Soft Science Research Program-funded major project "Study on key issues of BRICS'Multi-level Strategic Cooperation"(No.GXS3D043)sponsored by the Center for Collaborative innovation between Modern Service Industry Developmentand New Urbanization in Hunan
文摘The BRICS basic infrastructure suffers from a huge financing gap, but their massive foreign exchange reserves lack profitable outlets and member states＇ self-contained management costs are extremely high. The coincidence of the need for basic infrastructure investment and the need for profitable foreign exchange reserves are the immediate reasons for setting up the BRICS Development Bank. Comparative advantage and the co-movement of fluctuations in the BRICS member states optimize their cooperative interests. A co- movement game model analysis enables us to deduce the logical necessity for cooperation among the BRICS. Compared with other patterns of cooperation, virtual networks enable this financial cooperation to yield benefits in a short timeframe. The mutually supportive relationship between development and stability in the BRICS economies provides a solid rationale for the establishment of the New Development Bank.
