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| 1 | Correlation analysis between the chemical contents and bioactivity for the quality control of Alismatis Rhizoma显示文摘In order to clarify regions of production and to discriminate processing methods, quantitative and qualitative analyses for saccharides and terpenes in 35 batches of Alismatis Rhizoma were performed.Methodologies included HPLC–PDA, HPLC–VWD and UHPLC–MSn, combined with principal component analysis(PCA) and partial least squares regression techniques(PLSR). The inhibitory effects of triterpenes and Alismatis Rhizoma extracts on lipase activity were evaluated in vitro. PLSR analysis revealed significant positive correlations(R2= 0.5795) between the contents of triterpenes 10, 14, 15, 18 and 22 and the inhibitory effects of Alismatis Rhizoma. The present study establishes an effective method for simultaneous determination of multiple components, and identifies key bioactive triterpenes. These results can be used for systematic and novel analytical strategies for the quality control of Alismatis Rhizoma production. | Xiaoxv Gao Chengpeng Sun Zhenglong Yu Jian Cang Xiangge Tian Xiaokui Huo Lei Feng Xinguang Liu Chao Wang Baojing Zhang Xiaochi Ma | 2018 | Acta Pharmaceutica Sinica B2018,8,2: | 4 |
| 2 | Introduction of porous structure:A feasible and promising method for improving thermoelectric performance of Bi_2Te_3 based bulks显示文摘The porous p-type Bi_(0.4)Sb_(1.6)Te_3 bulks containing irregularly and randomly oriented pores were obtained by artificially controlling the relative density of sintered samples during resistance pressing sintering process. It is demonstrated that the thermoelectric performances are significantly affected by the porous structure, especially for the electrical and thermal conductivity due to the enhanced carrier scattering and phonon scattering. The increasing porosity resulted in the obvious decrease in electrical and thermal conductivity, and little change in Seebeck coefficients. It is encouraging that the reduction of thermal conductivity can compensate for the deterioration of electrical performance, leading to the enhancement in thermoelectric figure of merit(ZT). The maximum ZT value of 1.0 was obtained for the sample with a relative density of 90% at 333 K. Unfortunately, the increase in porosity also brought in obvious degradations in Vickers hardness from 51.71 to 27.74 HV. It is worth mentioning that although the Vickers hardness of the sample with a relative density of 90% decreased to 40.12 HV, it was still about twice as high as that of the zone melting sample(21.25 HV). To summarize, introducing pores structure into bulks properly not only enhances the ZT value of Bi_2Te_3 based alloys, but also reduces the use of raw materials and saves production cost. | Jie Hu Xi’An Fan Chengpeng Jiang Bo Feng Qiusheng Xiang Guangqiang Li Zhu He Yawei Li | 2018 | Journal of Materials Science & Technology2018,34,12: | 1 |
| 3 | Electromechanical coupling properties of a self-powered vibration sensing device for near-surface observation tower monitoring显示文摘The wind-induced vibration of a remote sensing tower is the key factor affecting the stability of image sensing and structural reliability. Monitoring the vibration of a long-time unattended tower is critical to its proper operation. Currently, most monitoring devices are supplied with wired power or battery, significantly limiting their practical applications in remote areas. In this paper,a self-powered vibration sensing device based on hybrid electromechanical conversion mechanisms is proposed. The device depends on a cylindrical magnetic levitation structure sensitive to ambient vibration for transferring mechanical energy and is taken as a dual-functional heterogeneous integrated system comprising electromagnetic, piezoelectric, and triboelectric generators. When the device vibrates under environmental force driving, the suspension magnet reciprocates vertically and generates induced electromagnetic energy, which is used to power the device. Moreover, the triboelectric and piezoelectric voltages,respectively originating from magnet impact on two separation friction materials and magnetic field repulsion-induced strain deformation of a piezoelectric sheet, are used as the synergistic sensing signals. To improve the output energy, a set of dualsegmented annular coils is designed in an electromagnetic generator, which greatly avoids the obstructive effect of the suspended magnet on the magnetic flux change at its end. Compared with a whole isochoric coil, it increases the output voltage by 78.3%.For the triboelectric sensing module, a silicone film with a large specific surface area is fabricated via 3D modification, which improves the output voltage by 29.4%. Furthermore, a pair of piezoelectric sensing modules is set to improve the accuracy of comparative sensing data. The experimental measurement shows that the device maintains a high sensitivity of 6.711 V(m s;);and excellent linearity of 0.991 in the range of 0–14 m s;. This work provides a practical strategy for the vibration monitoring of remote sensing towers and exhibits attractive potential in early warning and data analysis. | MU JiLiang HE HuiCheng MU JinBiao HE Jian SONG JinSha HAN XiaoTao FENG ChengPeng ZOU Jie YU JunBin CHOU XiuJian | 2022 | Science China(Technological Sciences)2022,65,7: | 1 |
| 4 | Breeze-activated wind speed sensor with ultra-low friction resistance for self-powered gale disaster warning显示文摘The early warning and monitoring of gale disasters are very important for the safety of people’s lives and properties. Triboelectric nanogenerators(TENGs) are popular for wind speed sensors due to their self-powered property. However, a TENG cannot easily work at low wind speeds due to the limitation of the high frictional resistance structure. In this paper, a TENG-based breezeactivated wind speed sensor(BAWS) with an ultra-low frictional resistance is proposed. The key drive unit of the BAWS is a Savonius-like vertical axis wind turbine, which is fabricated by arrayed airfoil profile blades with excellent flow field characteristics. Here a wind turbine plays dual roles in driving the electromagnetic generator below it to supply energy and lead the TENG above it to sense the wind force. Compared to a classical turbine with a wind cup, the designed turbine has a low resistance torque. The synergistic effect of the drive unit with low-resistance and triboelectric materials with low viscosity allows the BAWS to be activated even at a wind speed of 2.9 m/s. The sensitivities of the voltage frequency and current amplitude of the TENG are used to reflect the electrical property of the BAWS. The measured values are 0.291 Hz/(m·s-1) and 0.221 μA/(m·s-1),which reflects the good sensitivity of the BAWS. Moreover, the linearity of the BAWS reaches up to 0.991, which shows an accurate output for the wind speed. In addition, the device is equipped with a combined electromagnetic-solar unit as the sole power source to meet the sensor’s all-weather operation requirements. This work expands the application prospects of selfpowered sensing technology in the field of disaster warning. | HE HuiCheng MU JiLiang MU JinBiao FENG ChengPeng ZHAO JuanHong WANG Yin ZHOU Hao ZHANG Le HE Jian CHOU XiuJian | 2023 | Science China(Technological Sciences)2023,66,1: | 0 |