170 results on '"Guo, Si"'
Search Results
2. On-state performance enhancement of AlGaN/GaN Fin-HEMTs by using arcuate sidewalls.
- Author
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Chen, Yi-Lin, Zhu, Qing, Zhang, Meng, Mi, Min-Han, Zhu, Jie-Jie, Guo, Si-Yin, Zhou, Yu-Wei, Wang, Peng-Fei, Gong, Can, Zhao, Zi-Yue, and Ma, Xiao-Hua
- Subjects
ELECTRIC capacity ,VOLTAGE - Abstract
In this study, AlGaN/GaN Fin-HEMTs with different nanochannel geometric parameters were fabricated and comprehensively characterized. In the arcuate Fin-HEMTs, where the sidewalls arcuate from the source to the drain side, enhancements in the drain current density and transconductance were observed. By extracting and analyzing parameters obtained from small-signal measurements and conducting an analysis of gate capacitance, it was demonstrated that the enhancement can be attributed to the modulation of gate capacitance. This enhances the control capability of the gate over channel carriers, resulting in increased transconductance of the device. Due to the enhanced transconductance, the f
T and fmax of the arcuate Fin-HEMTs are both enhanced. Notably, the arcuate Fin-HEMTs achieved a power-added efficiency of 71.4% at a frequency of 3.6 GHz and a drain voltage of 20 V. Meanwhile, the linearity of the arcuate Fin-HEMTs is improved compared with the conventional Fin-HEMTs. [ABSTRACT FROM AUTHOR]- Published
- 2024
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3. Surface Lattice Modulation Enables Stable Cycling of High‐Loading All‐solid‐state Batteries at High Voltages.
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Zhang, Hong‐Shen, Lei, Xin‐Cheng, Su, Dong, Guo, Si‐Jie, Zhu, Jia‐Cheng, Wang, Xue‐Feng, Zhang, Xing, Wu, Ting‐Ting, Lu, Si‐Qi, Li, Yu‐Tao, and Cao, An‐Min
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HIGH voltages ,SOLID electrolytes ,INTERFACIAL resistance ,IONIC conductivity ,NANOSATELLITES ,LITHIUM-ion batteries - Abstract
Halide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all–solid–state Li–ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+–doped, cation–disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium–deficient layer featuring a rock–salt–like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5 V. The ASSBs with the halide electrolyte Li3InCl6 and a high–loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5 V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide–based ASSBs at high voltages. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
4. Surface Lattice Modulation Enables Stable Cycling of High‐Loading All‐solid‐state Batteries at High Voltages.
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Zhang, Hong‐Shen, Lei, Xin‐Cheng, Su, Dong, Guo, Si‐Jie, Zhu, Jia‐Cheng, Wang, Xue‐Feng, Zhang, Xing, Wu, Ting‐Ting, Lu, Si‐Qi, Li, Yu‐Tao, and Cao, An‐Min
- Subjects
HIGH voltages ,SOLID electrolytes ,INTERFACIAL resistance ,IONIC conductivity ,NANOSATELLITES ,LITHIUM-ion batteries - Abstract
Halide solid electrolytes, known for their high ionic conductivity at room temperature and good oxidative stability, face notable challenges in all–solid–state Li–ion batteries (ASSBs), especially with unstable cathode/solid electrolyte (SE) interface and increasing interfacial resistance during cycling. In this work, we have developed an Al3+–doped, cation–disordered epitaxial nanolayer on the LiCoO2 surface by reacting it with an artificially constructed AlPO4 nanoshell; this lithium–deficient layer featuring a rock–salt–like phase effectively suppresses oxidative decomposition of Li3InCl6 electrolyte and stabilizes the cathode/SE interface at 4.5 V. The ASSBs with the halide electrolyte Li3InCl6 and a high–loading LiCoO2 cathode demonstrated high discharge capacity and long cycling life from 3 to 4.5 V. Our findings emphasize the importance of specialized cathode surface modification in preventing SE degradation and achieving stable cycling of halide–based ASSBs at high voltages. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Molecular dynamics study of hydrogen-induced cracking behavior of ferrite–pearlite gas transmission pipeline steel.
- Author
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Xu, Tao-long, Guo, Si-han, He, Gong-zhen, and Han, Hao-yu
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- 2024
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6. Mo-doping heterojunction: interfacial engineering in an efficient electrocatalyst for superior simulated seawater hydrogen evolution.
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He, Zuo-Ming, Zhang, Chun-Xiao, Guo, Si-Qi, Xu, Peng, Ji, Yuan, Luo, Si-Wei, Qi, Xiang, Liu, Yun-Dan, Cheng, Ning-Yan, Dou, Shi-Xue, Wang, Yun-Xiao, and Zhang, Bin-Wei
- Published
- 2024
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7. Stabilizing Undercoordinated Zn Active Sites through Confinement in CeO2 Nanotubes for Efficient Electrochemical CO2 Reduction.
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Guo, Si‐Tong, Du, Yu‐Wei, Luo, Huihua, Zhu, Ziyin, Ouyang, Ting, and Liu, Zhao‐Qing
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ELECTROLYTIC reduction ,CATALYST structure ,DYNAMIC stability ,REDUCTION potential ,BINDING energy - Abstract
Zn‐based catalysts hold great potential to replace the noble metal‐based ones for CO2 reduction reaction (CO2RR). Undercoordinated Zn (Znδ+) sites may serve as the active sites for enhanced CO production by optimizing the binding energy of *COOH intermediates. However, there is relatively less exploration into the dynamic evolution and stability of Znδ+ sites during CO2 reduction process. Herein, we present ZnO, Znδ+/ZnO and Zn as catalysts by varying the applied reduction potential. Theoretical studies reveal that Znδ+ sites could suppress HER and HCOOH production to induce CO generation. And Znδ+/ZnO presents the highest CO selectivity (FECO 70.9 % at −1.48 V vs. RHE) compared to Zn and ZnO. Furthermore, we propose a CeO2 nanotube with confinement effect and Ce3+/Ce4+ redox to stabilize Znδ+ species. The hollow core–shell structure of the Znδ+/ZnO/CeO2 catalyst enables to extremely expose electrochemically active area while maintaining the Znδ+ sites with long‐time stability. Certainly, the target catalyst affords a FECO of 76.9 % at −1.08 V vs. RHE and no significant decay of CO selectivity in excess of 18 h. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
8. Stabilizing Undercoordinated Zn Active Sites through Confinement in CeO2 Nanotubes for Efficient Electrochemical CO2 Reduction.
- Author
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Guo, Si‐Tong, Du, Yu‐Wei, Luo, Huihua, Zhu, Ziyin, Ouyang, Ting, and Liu, Zhao‐Qing
- Subjects
ELECTROLYTIC reduction ,CATALYST structure ,DYNAMIC stability ,REDUCTION potential ,BINDING energy - Abstract
Zn‐based catalysts hold great potential to replace the noble metal‐based ones for CO2 reduction reaction (CO2RR). Undercoordinated Zn (Znδ+) sites may serve as the active sites for enhanced CO production by optimizing the binding energy of *COOH intermediates. However, there is relatively less exploration into the dynamic evolution and stability of Znδ+ sites during CO2 reduction process. Herein, we present ZnO, Znδ+/ZnO and Zn as catalysts by varying the applied reduction potential. Theoretical studies reveal that Znδ+ sites could suppress HER and HCOOH production to induce CO generation. And Znδ+/ZnO presents the highest CO selectivity (FECO 70.9 % at −1.48 V vs. RHE) compared to Zn and ZnO. Furthermore, we propose a CeO2 nanotube with confinement effect and Ce3+/Ce4+ redox to stabilize Znδ+ species. The hollow core–shell structure of the Znδ+/ZnO/CeO2 catalyst enables to extremely expose electrochemically active area while maintaining the Znδ+ sites with long‐time stability. Certainly, the target catalyst affords a FECO of 76.9 % at −1.08 V vs. RHE and no significant decay of CO selectivity in excess of 18 h. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Individualized Delivery of Vancomycin by Model-Informed Bayesian Dosing Approach to Maintain an AUC24 Target in Critically Ill Patients.
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Rao, Zhi, Guo, Si-ming, and Wei, Yan-ming
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CRITICALLY ill ,VANCOMYCIN ,DRUG monitoring ,HIGH performance liquid chromatography - Abstract
Introduction: Monitoring of AUC
24 was updated recommendation in the guideline for the therapeutic drug monitoring (TDM) of vancomycin in Chinese pharmacological society published in 2020. Vancomycin pharmacokinetic profiles are diverse and unique in critically ill patients because of the drastic variability of the patients' physiological parameters, while the study for population pharmacokinetic (PPK) models in Chinese critically ill patients has been rarely reported. The objectives of this study were to construct a PPK model to describe the pharmacokinetic characteristics of vancomycin in critically ill patients and to individualize vancomycin dosing by model-informed Bayesian estimation for maintenance of AUC24 target at 400–650 mg h/L recommended by the 2020 guideline. Methods: Vancomycin with different dosing was administered intravenously over 1 h for critically ill patients, TDM was started at 48 h or 72 h since initiation of vancomycin therapy for patients. Blood samples were collected from patients for trough concentrations or Cmax . Vancomycin concentrations were determined by high-performance liquid chromatography method with ultraviolet detection. PPK model was performed using the nonlinear mixed-effect model (NONMEM® ). Individual PK parameters for critically ill patients treated with vancomycin were estimated using a post hoc empirical Bayesian method based on the final PPK model. AUC24 was calculated as the total daily dose divided by the clearance (L/h). Results: The PPK of vancomycin was determined by a one-compartment model with creatinine clearance as fixed effects. The PK estimates in the final model generally agreed with the median estimates and were contained within the 95% CI generated from the bootstrap results, indicating good precision and stability in the final model. The visual predictive check plots showed the adequate predictive performance of the final PK model and supported a good model fit. The model-informed Bayesian estimation was used to predict the AUC24 of critically ill patient by the acquired TDM results, and the dosing adjustment by maintenance of AUC24 at 400–650 mg h/L had made a great therapeutic effect for the case. Conclusion: This study established a PPK model of vancomycin in Chinese critically ill patients, and individualized dosing of vancomycin by model-informed Bayesian estimation to maintain an AUC24 target at 400–650 mg h/L has been successfully applied in clinic. This result supports the continued use of model-informed Bayesian estimation to vancomycin treatment in critically ill patients. [ABSTRACT FROM AUTHOR]- Published
- 2024
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10. A Chiral Emissive Conjugated Corral for High‐Affinity and Highly Enantioselective Recognition in Water.
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Fu, Rong, Zhao, Qing‐Yu, Han, Han, Li, Wen‐Li, Chen, Fang‐Yuan, Tang, Chun, Zhang, Wei, Guo, Si‐Dan, Li, Dai‐Yuan, Geng, Wen‐Chao, Guo, Dong‐Sheng, and Cai, Kang
- Subjects
BINAPHTHOL ,AQUEOUS solutions ,CHIRAL recognition - Abstract
Accurately distinguishing between enantiomeric molecules is a fundamental challenge in the field of chemistry. However, there is still significant room for improvement in both the enantiomeric selectivity (KR(S)/KS(R)) and binding strength of most reported macrocyclic chiral receptors to meet the demands of practical application scenarios. Herein, we synthesized a water‐soluble conjugated tubular host—namely, corral[4]BINOL—using a chiral 1,1′‐bi‐2‐naphthol (BINOL) derivative as the repeating unit. The conjugated chiral backbone endows corral[4]BINOL with good fluorescent emission (QY=34 %) and circularly polarized luminescence (|glum| up to 1.4×10−3) in water. Notably, corral[4]BINOL exhibits high recognition affinity up to 8.6×1010 M−1 towards achiral guests in water, and manifested excellent enantioselectivity up to 18.7 towards chiral substrates, both of which represent the highest values observed among chiral macrocycles in aqueous solution. The ultrastrong binding strength, outstanding enantioselectivity, and facile accessibility, together with the superior fluorescent and chiroptical properties, endow corral[4]BINOL with great potential for a wide range of applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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- View/download PDF
11. A Chiral Emissive Conjugated Corral for High‐Affinity and Highly Enantioselective Recognition in Water.
- Author
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Fu, Rong, Zhao, Qing‐Yu, Han, Han, Li, Wen‐Li, Chen, Fang‐Yuan, Tang, Chun, Zhang, Wei, Guo, Si‐Dan, Li, Dai‐Yuan, Geng, Wen‐Chao, Guo, Dong‐Sheng, and Cai, Kang
- Subjects
BINAPHTHOL ,AQUEOUS solutions ,CHIRAL recognition - Abstract
Accurately distinguishing between enantiomeric molecules is a fundamental challenge in the field of chemistry. However, there is still significant room for improvement in both the enantiomeric selectivity (KR(S)/KS(R)) and binding strength of most reported macrocyclic chiral receptors to meet the demands of practical application scenarios. Herein, we synthesized a water‐soluble conjugated tubular host—namely, corral[4]BINOL—using a chiral 1,1′‐bi‐2‐naphthol (BINOL) derivative as the repeating unit. The conjugated chiral backbone endows corral[4]BINOL with good fluorescent emission (QY=34 %) and circularly polarized luminescence (|glum| up to 1.4×10−3) in water. Notably, corral[4]BINOL exhibits high recognition affinity up to 8.6×1010 M−1 towards achiral guests in water, and manifested excellent enantioselectivity up to 18.7 towards chiral substrates, both of which represent the highest values observed among chiral macrocycles in aqueous solution. The ultrastrong binding strength, outstanding enantioselectivity, and facile accessibility, together with the superior fluorescent and chiroptical properties, endow corral[4]BINOL with great potential for a wide range of applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
12. A theoretical proposal of photonic crystals with gradient superconducting thicknesses for sensing applications.
- Author
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Hu, Cai-Xing, Guo, Si-Jia, and Zhang, Hai-Feng
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PHOTONIC crystals ,TRANSFER matrix ,REFRACTIVE index ,TERAHERTZ materials ,KEY performance indicators (Management) ,PHOTONIC crystal fibers ,RESONANCE - Abstract
In this paper, a refractive index (RI) sensor with superconducting photonic crystal in the terahertz regime is theoretically analyzed by the transfer matrix method. An asymmetric resonance cavity containing gradient thicknesses of the superconducting layer is employed to suppress the resonance absorption linewidth. We present the coupled wave theoretical model to give an optimization scheme for excellent sensing performance. The proposed sensing models can achieve an excellent single resonant peak when the temperature is over 80 K. When the incident angle varies between 50° and 70° in TE mode, the shift of a single resonant peak has a linear relationship with the incident angle. The simulation results report that the sensitivity and figure of merit in the optimal model can reach over 22.2 μm RIU
−1 (RIU represents RI unit) and 265 at the ultralow temperature (85 K), respectively. Its performance indicators are dozens of times those of the traditional photonic crystal RI sensor. Our study provides theoretical guidance for the design of a low-temperature RI sensor with a high-performance indicator. [ABSTRACT FROM AUTHOR]- Published
- 2021
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13. Polygonatum cyrtonema Hua Polysaccharides with Antiaging and Stress Resistance Efficacies in Caenorhabditis elegans.
- Author
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Wang, Wei, Yang, Ying, Hou, Ting-ting, Yi, Shan-yong, Chen, Yan-jun, Li, Guo-si, Chen, Cun-wu, Han, Bang-xing, Ke, Jia-ping, Liu, Dong, and Gao, Lei-lei
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CAENORHABDITIS elegans ,CAENORHABDITIS ,POLYSACCHARIDES ,REACTIVE oxygen species ,TRANSCRIPTION factors ,OXIDATIVE stress - Abstract
Polygonatum cyrtonema Hua, a source of Polygonati rhizoma, possesses multiple health-promoting properties and is widely used in food and medicine. This study aimed to elucidate the lifespan promotion abilities and potential mechanism of action of P. cyrtonema Hua polysaccharides (PCHPs) on Caenorhabditis elegans. The results revealed that PCHP had a molecular weight distribution of 8.77×10
3 −1.84 × 106 Da and comprised Man, GalA, Glu, Gal, Xyl, and Ara in a molar ratio of 13.8 : 3.5 : 22.7 : 2.7 : 1:1.3. PCHP (5.0 mg/mL) markedly increased the lifespan of C. elegans by 15.78% (p < 0.001), improved motility, and increased the resistance to heat stress, UV irradiation, and oxidative stress. PCHP also promoted healthy aging by attenuating the accumulation of reactive oxygen species (ROS) and lipofuscin. Furthermore, PCHP upregulated the expression of oxidative stress- and aging-related genes, promoted the migration of DAF-16 into the nucleus, and exerted no effect on the lifespan of daf-2, daf-16, age-1, skn-1, and sir-2.1 mutants. These results indicate that the transcription factors DAF-16, SIR-2.1, and SKN-1 are required for PCHP-mediated lifespan extension in C. elegans. In conclusion, PCHP has the potential to attenuate the effects of aging, which can lay the foundation for aging treatment research with P. cyrtonema. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
14. Establishment and study of a polarized X-ray radiation facility.
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Zhou, Xing, Qie, Xiao-Yu, Guo, Si-Ming, Huang, Yong-Bo, Shu, Zi-Yao, Huang, Shi-Kui, Fan, Li-Peng, Guo, Kai-Yue, Yu, Tao, and Wu, Jin-Jie
- Published
- 2023
- Full Text
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15. Research on Dissipation Dilution Mechanism and Boundary Dissipation Suppression Technique for High-Stress Graphene Nanoelectromechanical Resonator.
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Liu, Ying, Zhen, Jia Peng, Yang, Wen Xiang, Zheng, Xian De, Guo, Si Lin, Zhang, Yong, Yang, Peng, Lv, Ke Hong, Qiu, Jing, and Liu, Guan Jun
- Published
- 2023
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16. The asymmetric optical bistability based on the one-dimensional photonic crystals composed of the defect layers containing the magnetized ferrite and nonlinear Kerr dielectric under the transverse electric polarization.
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Guo, Si-Jia, Li, Zhi-Jian, Li, Fen-Ying, Xu, Yi, and Zhang, Hai-Feng
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OPTICAL bistability ,CRYSTAL defects ,PHOTONIC crystals ,KERR electro-optical effect ,MAGNETOOPTICS ,VOIGT effect ,PLASTIC optical fibers - Abstract
Utilizing the modified transfer matrix method, under transverse electric polarization, asymmetric optical bistability is achieved by designing one-dimensional photonic crystals (PCs) with two Bragg reflector segments containing traditional dielectrics and asymmetric defect multilayers consisting of a magnetized ferrite and nonlinear Kerr dielectric. When the incident wave frequency equals the resonance frequency, owing to the breaking of symmetry in the defect layers and the Voigt magneto-optical effect generating in the magnetized ferrite layers together with the Kerr effect existing in the Kerr dielectric layers, the asymmetric optical modulations are presented as the bistable state in the forward propagation and the multistable state in the backward propagation. Also, the diverse energy localization distributions of the electric field in the proposed PCs from the two incident directions are graphically illustrated. Furthermore, the optical bistable switch-up and switch-down thresholds of the proposed resonator can be tailored flexibly by the external magnetic field, the incident angle, the thicknesses of different dielectrics, and the nonlinear coefficient of Kerr dielectric. This work provides a constructive proposal for the design of light modulators, such as the optical isolator, the optical triode, the all-optical diode, and the sensor. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
17. The Vertical Distributions of Aerosol Optical Characteristics Based on Lidar in Nanyang City from 2021 to 2022.
- Author
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Zhang, Miao, Guo, Si, Wang, Yunuo, Chen, Shiyong, Chen, Jinhan, Chen, Mingchun, and Bilal, Muhammad
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AIR pollution control ,REMOTE sensing ,AEROSOLS ,ATMOSPHERIC aerosols ,LIDAR ,TROPOSPHERIC aerosols - Abstract
To investigate the vertical distribution of aerosol optical characteristics in Nanyang City, a ground-based dual-wavelength (532 nm and 355 nm) lidar system was developed for aerosol observation at the Nanyang Normal University Station (NYNU) from November 2021 to December 2022. Spatio-temporal dynamics information on vertical distributions of aerosol optical properties during polluted and non-polluted days was obtained. Aerosols were characterized by low altitudes (up to 2 km), thinner layers, and high-altitude (up to 4 km) thick layers during non-polluted and polluted days, with extinction coefficient values of ~0.03 km
−1 and ~0.2 km−1 , respectively. The mean values of the extinction coefficient at different altitudes (0~5 km) were all about ten-times higher on polluted days (0.04~0.19 km−1 ) than on non-polluted days (0.004~0.02 km−1 ). These results indicate that aerosol loadings and variations at different altitudes (0~5 km) were much higher and more prominent on polluted days than non-polluted days. The results show ten-times larger aerosol optical depth (AOD) values (0.4~0.6) on polluted days than on non-polluted days (0.05~0.08). At the same time, AOD values on both polluted and non-polluted days slightly decreased from 19:00 to 05:00, possibly due to dry depositions at nighttime. For the first time, this study established a ground-based lidar remote sensing system to investigate the vertical distribution of atmospheric aerosol optical characteristics in Henan Province. The experimental results can provide scientific dataset support for the local government to prevent and control air pollution. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
18. Effects of Light Intensity on Seedling Emergence and Early Growth of Liquidambar formosana Hance.
- Author
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Chen, Hang, Wang, Lei, Guo, Si, Li, Mengqi, Tian, Zhifang, Han, Biao, Tang, Xinghao, and Liu, Bo
- Subjects
LIGHT intensity ,LIQUIDAMBAR ,DECIDUOUS plants ,PHOTON flux ,ACTINIC flux ,SEEDLINGS - Abstract
Liquidambar formosana Hance is a common deciduous broad-leaved tree known for its fast growth rate and adaptability. However, excessive logging has substantially reduced the area of natural forest patches of L. formosana, and seedling regeneration is essential for the long-term continuation of L. formosana populations. To explore the effects of light intensity on the seedling emergence and early growth of L. formosana, a controlled experiment was conducted under three light-intensity treatments (20%, 60%, and 100% of full sunlight, i.e., the photosynthetic photon flux densities (PPFDs) were 223.93 ± 7.54, 670.94 ± 30.14, and 1119.61 ± 23.19 μmol·m
−2 ·s−1 , respectively). The seedling emergence percentage, mean germination time, germination synchrony, vitality index, survival percentage, emergence index, morphological characteristics, and biomass allocation under different light intensities were analyzed. The seedling vitality index and survival percentage significantly differed among the treatments and were the lowest under 20% light intensity. With increased light intensity, the seedling mean germination time and germination synchrony increased and then decreased, and the opposite was true for the emergence index. With the increased light intensity, the seedling height, stem diameter, and root length significantly increased. The total, root, stem, and leaf biomasses reached maximum values under full sunlight. With the increased light intensity, the leaf biomass ratio increased, whereas the root biomass, stem biomass, and root–shoot ratios decreased. Our results indicated that the poor light environment under the canopy is not conducive to the survival and growth of L. formosana seedlings and may be among the primary reasons for low seedling establishment. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
19. Selective Electrochemical Hydrogenation of Phenol with Earth‐abundant Ni−MoO2 Heterostructured Catalysts: Effect of Oxygen Vacancy on Product Selectivity.
- Author
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Zhou, Peng, Guo, Si‐Xuan, Li, Linbo, Ueda, Tadaharu, Nishiwaki, Yoshinori, Huang, Liang, Zhang, Zehui, and Zhang, Jie
- Subjects
PHENOL ,HYDROGENATION ,PHENOLS ,CATALYSTS ,DENSITY functional theory - Abstract
Herein, we report highly efficient carbon supported Ni−MoO2 heterostructured catalysts for the electrochemical hydrogenation (ECH) of phenol in 0.10 M aqueous sulfuric acid (pH 0.7) at 60 °C. Highest yields for cyclohexanol and cyclohexanone of 95 % and 86 % with faradaic efficiencies of ∼50 % are obtained with catalysts bearing high and low densities of oxygen vacancy (Ov) sites, respectively. In situ diffuse reflectance infrared spectroscopy and density functional theory calculations reveal that the enhanced phenol adsorption strength is responsible for the superior catalytic efficiency. Furthermore, 1‐cyclohexene‐1‐ol is an important intermediate. Its hydrogenation route and hence the final product are affected by the Ov density. This work opens a promising avenue to the rational design of advanced electrocatalysts for the upgrading of phenolic compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
20. Selective Electrochemical Hydrogenation of Phenol with Earth‐abundant Ni−MoO2 Heterostructured Catalysts: Effect of Oxygen Vacancy on Product Selectivity.
- Author
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Zhou, Peng, Guo, Si‐Xuan, Li, Linbo, Ueda, Tadaharu, Nishiwaki, Yoshinori, Huang, Liang, Zhang, Zehui, and Zhang, Jie
- Subjects
PHENOL ,HYDROGENATION ,PHENOLS ,CATALYSTS ,DENSITY functional theory - Abstract
Herein, we report highly efficient carbon supported Ni−MoO2 heterostructured catalysts for the electrochemical hydrogenation (ECH) of phenol in 0.10 M aqueous sulfuric acid (pH 0.7) at 60 °C. Highest yields for cyclohexanol and cyclohexanone of 95 % and 86 % with faradaic efficiencies of ∼50 % are obtained with catalysts bearing high and low densities of oxygen vacancy (Ov) sites, respectively. In situ diffuse reflectance infrared spectroscopy and density functional theory calculations reveal that the enhanced phenol adsorption strength is responsible for the superior catalytic efficiency. Furthermore, 1‐cyclohexene‐1‐ol is an important intermediate. Its hydrogenation route and hence the final product are affected by the Ov density. This work opens a promising avenue to the rational design of advanced electrocatalysts for the upgrading of phenolic compounds. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
21. Stable 4.5 V LiCoO2 cathode material enabled by surface manganese oxides nanoshell.
- Author
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Wang, Jun, Zhang, Si-Dong, Guo, Si-Jie, Lu, Si-Qi, Xu, Yan-Song, Li, Jin-Yang, Cao, An-Min, and Wan, Li-Jun
- Subjects
MANGANESE oxides ,CATHODES ,ELECTROLYTES ,NANOPARTICLES ,SURFACE coatings - Abstract
Charging the LiCoO
2 (LCO) cathode to a higher voltage, for example 4.5 V compared to the commonly used 4.2 V, is now intensively pursued so as to achieve a higher specific capacity. However, it suffers severe surface structural degradation and detrimental interfacial side reactions between cathode and electrolyte, which lead to the fast capacity fading during long-term cycling. Here, a surface coating strategy was developed for the protection of 4.5 V LCO by constructing a manganese oxides (MOs) nanoshell around LCO particles, which was achieved through a solution-based coating process with success in controlling the growth kinetics of the coating species. We found that the introduction of the MOs nanoshell is highly effective in alleviating the organic electrolyte decomposition at the cathode surface, thus ensuring a much more stable LiF-rich cathode-electrolyte interface and an obvious lower interfacial resistance during electrochemical cycling. Meanwhile, this protection layer can effectively improve the structural stability of the cathode by hindering the cracks formation and structural degradation of LCO particles. Therefore, the MOs modified LCO exhibited excellent rate performance and a high discharge capacity retention of 81.5% after 100 cycles at 1 C compared with the untreated LCO (55.2%), as well as the improved thermal stability and cyclability at the elevated temperature. It is expected that this discovery and fundamental understanding of the surface chemistry regulation strategy provide promising insights into improving the reversibility and stability of LCO cathode at the cut-off voltage of 4.5 V. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
22. Characters of Particulate Matter and Their Relationship with Meteorological Factors during Winter Nanyang 2021–2022.
- Author
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Zhang, Miao, Chen, Shiyong, Zhang, Xingang, Guo, Si, Wang, Yunuo, Zhao, Feifei, Chen, Jinhan, Qi, Pengcheng, Lu, Fengxian, Chen, Mingchun, and Bilal, Muhammad
- Subjects
PARTICULATE matter ,AIR pollution control ,AIR pollution prevention ,AIR pollution ,AIR quality ,WINTER ,AIR quality standards ,CESIUM isotopes - Abstract
The purpose of this study is to investigate the air quality levels of Nanyang city according to Chinese air quality standards. Therefore, in this study, fine particulate matter (PM
2.5 ), coarse particulate matter (PM10 ), and total suspended particulate (TSP) were analyzed from 19 November 2021 to 19 March 2022 in Nanyang city. The results show that the average concentrations of PM2.5 , PM10, and TSP were 106.47 µg/m3 , 137.32 µg/m3 , and 283.40 µg/m3 , respectively. The numbers of days that meet the national secondary air quality standard of 24-h average concentrations were 29.75% for PM2.5 , 63.64% for PM10 , and 63.64% for TSP, indicating that most of the time, the air quality of Nanyang city remains polluted in winter, especially with more contributions of PM2.5 compared to PM10 and TSP. The higher concentrations were observed between 07:00 and 08:00, suggesting that vehicular emissions can be a major cause of air pollution in Nanyang city. The results also show a significant positive correlation between particulate matter and relative humidity, and a weak correlation with temperature and wind speed, which suggests that higher relative humidity increases the formation of particulate matter. This study can provide theoretical support for the local government to formulate air pollution prevention and control policies for Nanyang city. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
23. Fault-Tolerant Current Control of Six-Phase Permanent Magnet Motor With Multifrequency Quasi-Proportional-Resonant Control and Feedforward Compensation for Aerospace Drives.
- Author
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Xu, Jinquan, Guo, Si, Guo, Hong, and Tian, Xinlei
- Abstract
To improve the current tracking performance, this article proposes a new fault-tolerant current control for the six-phase fault-tolerant permanent magnet synchronous motor (FTPMSM) system with multifrequency quasi-proportional-resonant (QPR) control and back electromotive force (EMF) feedforward compensation, which can track the time-varying sinusoidal and nonsinusoidal reference currents in the stationary reference frame (SRF) under normal and fault conditions. First, the multifrequency QPR current controller with shunt topology is proposed to track the time-varying reference current in SRF, which can guarantee the current control performance regardless of the motor speed variation and the load torque change. Second, the optimized feedforward compensation method for the back EMF is proposed to further reduce the steady-state current tracking error, which takes the time delay of the digital implementation into consideration. Finally, the effectiveness of the proposed approach is verified on a 3 kW six-phase FTPMSM platform. The resulting six-phase FTPMSM system with the proposed current control has great current tracking performance, strong robustness to various external/internal disturbance, as well as low computational burden, which can guarantee the multiphase FTPMSM system performance in normal and fault conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. Pyrotinib combined with trastuzumab and chemotherapy for the treatment of human epidermal growth factor receptor 2-positive metastatic breast cancer: a single-arm exploratory phase II trial.
- Author
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Xie, Xiao-Feng, Zhang, Qiu-Yi, Huang, Jia-Yi, Chen, Li-Ping, Lan, Xiao-Feng, Bai, Xue, Song, Lin, Xiong, Shui-Ling, Guo, Si-Jia, and Du, Cai-Wen
- Abstract
Purpose: A substantial need for effective and safe treatment options is still unmet for patients with heavily pre-treated human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (MBC). Herein, we assessed the efficacy and safety of pyrotinib plus trastuzumab and chemotherapy in patients with heavily treated HER2-positive MBC. Methods: In this single-arm exploratory phase II trial, patients with HER2-positive MBC previously treated with trastuzumab plus lapatinib or pertuzumab, received pyrotinib plus trastuzumab and chemotherapy. The primary end point was progression-free survival (PFS) in the total population (TP). Secondary end points included PFS in the subgroup with brain metastases (Sub-BrM), confirmed objective response rate (ORR), clinical benefit rate (CBR), disease control rate (DCR), exploration of predictive factors of PFS, and safety. Results: Between November 1, 2018, and March 31, 2021, 40 patients were eligible for this study. The median PFS reached 7.5 months (95% confidence interval [CI] 4.7 to 9.9 months) and 9.4 months (95% CI 6.6 to 12.1 months) in the TP and Sub-BrM, respectively. ORR was 50.5% (20/40). CBR was 75.5% (30/40) and DCR reached 97.5% (39/40). Cox univariate and multivariate analyses demonstrated that liver or/and lung metastases was the significant adverse prognostic factor for PFS (p = 0.018; p = 0.026; respectively). The most frequent grade 3 or 4 treatment-related adverse events were diarrhea, neutropenia and leukopenia. No new safety signals were observed. Conclusion: Pyrotinib plus trastuzumab and chemotherapy offered a promising option with manageable safety profile for heavily pre-treated HER2-positive MBC, especially for those without liver or/and lung metastases. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
25. The impact of sovereign defaults on lending countries.
- Author
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Guo, Si and Pei, Yun
- Subjects
LOANS ,FOREIGN banking industry ,COUNTERPARTY risk ,BANK loans ,GOVERNMENT securities ,DEFAULT (Finance) ,SOVEREIGN risk - Abstract
This paper explores the impact of sovereign defaults on lending countries and evaluates government intervention policies in a dynamic infinite-horizon model. When banks in the lending country hold risky foreign bonds, the default risk in the foreign country has a spillover effect on the output volatility of the lending country. A macroprudential tax on the purchase of foreign bonds reduces the lending country's exposure to foreign sovereign risk and output volatility. Households gain in welfare as a result, but bankers lose because taxes lower banks' profitability. The effect on overall welfare is mixed, depending on which group dominates. It is beneficial ex post to implement bailout policies when the government redistributes resources from households to banks after default, but bailouts encourage banks to take on risk by holding more sovereign bonds ex ante, leading to greater output fluctuations in the lending country. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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- View/download PDF
26. Risk of Monochamus saltuarius spreading in China.
- Author
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ZOU Ya, GE Xue-Zhen, ZHOU Yu-Ting, GUO Si-Wei, WANG Tao, and ZONG Shi-Xiang
- Subjects
HOST plants ,SPECIES distribution ,ECONOMIC impact ,PHYTOSANITATION - Abstract
[Objectives] To estimate the risk of Monochamus saltuarius Gebler spreading in China. [Methods] Three species distribution models within the BIOMOD2 modeling platform were used to predict the future distribution of M. saltuarius. In addition, we analyzed five potential consequences of the spread of this pest: its future distribution, its potential economic impact, the economic importance of its host plants, the possibility of transmission and the difficulty of control and management. [Results] The synthetic risk index, R, is 2.05 indicating that M. saltuarius has the potential to become widely distributed. [Conclusion] M. saltuarius has the potential to become a widespread, economically significant, pest in China. Quarantine management and removal measures need to be formulated to reduce the risk posed by this pest. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. Validation of the Lightning Fractal Model Based on the Attachment Probability Experiments Using Rod-Rod Air Gaps.
- Author
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Guo, Jun, Yang, Tian-Yi, Guo, Si-Yu, Zhang, Xu-Dong, Wang, Bang-Yong, Xie, Yan-Zhao, Wu, Jian, and Jing, Yan
- Subjects
LIGHTNING protection ,FRACTAL dimensions ,ELECTRIC lines ,LIGHTNING ,SYSTEM safety ,ELECTRIC discharges ,ELECTRIC fault location - Abstract
Direct lightning poses a serious threat to the safety of power systems. In recent years, the lightning fractal model, which can reflect the fractal characteristics and randomness of lightning leaders, has been gradually applied to direct lightning protection for substations, transmission lines, etc. However, since few studies have linked simulations with experiments, the reliability of the lightning fractal model in terms of attachment probability prediction lacks experimental verification. In this paper, a series of attachment tests are carried out under a rod-rod gap. The equivalence between simulation tests and natural lightning is discussed, and the influencing factors of the attachment results are investigated. The attachment probability is simulated and compared to the test value under each test configuration. The test results show that the fractal dimension of discharge channel is consistent with the observation results of natural lightning. Under different configurations, the test value of attachment probability basically conforms to the simulation value. In general, the dispersion of the test results is slightly greater than the simulation results, but the average probability differences are all within 10%. The test results strongly indicate that the lightning fractal model is of good reliability in the prediction of strike probability. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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- View/download PDF
28. Identification of Prognostic Markers and Potential Therapeutic Targets in Gastric Adenocarcinoma by Machine Learning Based on mRNAsi Index.
- Author
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Guo, Si Hong, Ma, Li, and Chen, Jie
- Subjects
STOMACH tumors ,ADENOCARCINOMA ,BIOCHEMISTRY ,PHENOMENOLOGICAL biology ,MACHINE learning ,GENE expression ,STEM cells ,MESSENGER RNA ,SURVIVAL analysis (Biometry) ,DRUG interactions ,GENOMICS ,GENES - Abstract
Background. Cancer stem cells (CSCs), characterized by self-renewal and therapeutic resistance, play important roles in stomach adenocarcinoma (STAD). However, the molecular mechanism of STAD stem cells is still unclear. In this study, our purpose is to explore the expression of stem cell-related genes in STAD. Methods. The stemness index based on mRNA expression (mRNAsi) was used to analyze STAD cases in The Cancer Genome Atlas (TCGA). Firstly, mRNAsi was used and analyzed by differential expression, survival analysis, clinical stage, and gender in STAD. Then, weighted gene coexpression network analysis (WGCNA) was used to discover the fascinating modules and key genes. Enrichment analysis was carried out to annotate the functions and pathways of key genes. The gene expression comprehensive database (GEO) in STAD was used to verify the expression levels of key genes in all cancers. Protein-protein interaction networks is used to determine the relationships between key genes. Results. The mRNAsi was obviously upregulated in tumor cases. With the increase of tumor stage and T stage, the mRNAsi score decreased, and the overall survival rate of high score group patients was better. According to the degree of association with mRNAsi, different modules and key genes were screened out. A total of 6,740 differential genes were found, of which 1,147 genes were downregulated and 5,593 genes were upregulated. 19 key genes (BUB1, BUB1B, KIF14, NCAPH, RACGAP, KIF15, CENPF, TPX2, RAD54L, KIF18B, KIF4A, TTK, SGO2, PLK4, ARHGAP11A, XRCC2, Clorf112, NCAPG, and ORC6) were screened due to significant upregulation in STAD. And they had been proven that enriched from the cell cycle Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, relating to cell proliferation Gene Ontology (GO) terms, as well. Among them, 9 genes have been extensively associated to OS, and 3 genes had been associated to receive chemotherapy resistance. PPI protein network suggests that there is a sturdy correlation between these key genes. Conclusion. A total of 19 key genes were found to play an essential position in retaining the traits of STAD stem cells. These genes can be used to evaluate the prognosis of STAD patients or become specific therapeutic targets. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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29. Development of an Escherichia coli whole cell biocatalyst for the production of hyperoside.
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Li, Guo-Si, Zhu, Fu-Cheng, Wei, Pei-Pei, Gu, Fang-Li, Xu, Qi-Ling, and Ma, Meng-Hua
- Subjects
ESCHERICHIA coli ,ENZYMES ,MOLECULAR chaperones ,SOYBEAN ,QUERCETIN ,SUCROSE ,GALACTOSE - Abstract
Objective: To produce high concentrations of hyperoside from quercetin using recombinant Escherichia coli with in situ regeneration of UDP-galactose. Results: Sucrose synthase from Glycine max (GmSUS) was co-expressed with UDP-glucose epimerase from E. coli (GalE) in E. coli for regenerating UDP-galactose from UDP and sucrose. Glycosyltransferase from Petunia hybrida (PhUGT) was introduced to synthesize hyperoside from quercetin through the regeneration system of UDP-galactose. Co-expressing with molecular chaperones GroEL/ES successfully enhanced the catalytic efficiency of the recombinant strain, which assisted the soluble expression of PhUGT. By using a fed-batch approach, the production of hyperoside reached 863.7 mg L
−1 with a corresponding molar conversion of 93.6% and a specific productivity of 72.5 mg L−1 h−1 . Conclusion: The method described herein for hyperoside production can be widely applied for the synthesis of isorhamnetin-3-O-galactoside, kaempferol-3-O-galactoside and other flavonoids. [ABSTRACT FROM AUTHOR]- Published
- 2022
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- View/download PDF
30. Human Activity Played a Key Role in Rice Stripe Disease Epidemics: From an Empirical Evaluation of over a 10-Year Period.
- Author
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Ma, Yan-Li, Lin, Wen-Wu, Guo, Si-Si, Xie, Lian-Hui, He, Dun-Chun, and Cheng, Zhao-Bang
- Subjects
LAODELPHAX striatellus ,EPIDEMICS ,RICE ,VIRUS diseases ,WHEAT harvesting ,DISEASE management - Abstract
Paddy is an artificial ecosystem driven by human activities, such as adjustment of cropping systems, deployment of resistant varieties and pesticides use. Inappropriate human intervention aggravated the disruption of ecosystems, which resulted in rice viral disease epidemics characterized by fulminant, migrating and intermittent outbreaks. Rice stripe disease (RSD), lasting for over 10 years from 2000, was modeled for exploring better management strategies of plant viral disease transmitted by insect vectors. In eight counties of Jiangsu province, China, the biotic, abiotic and human factors between 2000 and 2012 were monitored to determine key factors of human activities related to RSD epidemics. RSD severity was significantly related to resistance, the interval of wheat harvest and rice sowing (WHRS) and inconsecutive interval of wheat sowing and rice harvest (WSRH). The relationship between human activities and the small brown planthopper (SBPH) showed that the resistance was more significantly associated with SBPH viruliferous rate in the preceding year than that of the current year but not correlated with SBPH density. Resistance could impact the SBPH viruliferous rate in the preceding year indirectly through transmission probability and, thereafter, the continuing disease epidemics. The insignificant interactive effects among resistance, WHRS and WSRH on disease severity meant that these three factors could be taken into consideration separately in agricultural practice according to rice chronological order. The quantitative field study conducted in Jiangsu province presented a good example of plant viral disease management, guided by which could not only avoid pointless actions but, most importantly, generate more efficient and economic returns. Therefore, in order to improve the management of RSD, it should focus on the adjustment of these human factors independently and sequentially in combination with the forecast of RSD. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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31. Does Monitoring Total and Free Polymyxin B1 Plasma Concentrations Predict Polymyxin B-Induced Nephrotoxicity? A Retrospective Study in Critically Ill Patients.
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Deng, Yang, Gu, Jun-Yuan, Li, Xin, Tong, Huan, Guo, Si-Wei, Xu, Bing, Li, You, Zhang, Bi-Kui, Li, Ying, Huang, Hai-Ying, and Xiao, Gui-Ying
- Subjects
POLYMYXIN B ,CRITICALLY ill ,LIQUID chromatography-mass spectrometry ,POLYMYXIN ,DRUG monitoring ,NEPHROTOXICOLOGY - Abstract
Introduction: The correlation between total and free polymyxin B (PMB including PMB1 and PMB2) exposure in vivo and acute kidney injury (AKI) remains obscure. This study explores the relationships between plasma exposure of PMB1 and PMB2 and nephrotoxicity, and investigates the risk factors for PMB-induced acute kidney injury (AKI) in critically ill patients. Methods: Critically ill patients who used PMB and met the criteria were enrolled. The total plasma concentration and plasma binding of PMB1 and PMB2 were analysed by liquid chromatography–tandem mass spectrometry and equilibrium dialysis. Results: A total of 89 patients were finally included, and AKI developed in 28.1% of them. The peak concentration of PMB1 (C
max (B1)) (adjusted odds ratio (AOR) = 1.68, 95% CI 1.08–2.62, p = 0.023), baseline BUN level (AOR = 1.08, 95% CI 1.01–1.16, p = 0.039) and hypertension (AOR = 3.73, 95% CI 1.21–11.54, p = 0.022) were independent risk factors for PMB-induced AKI. The area under the ROC curve of the model was 0.799. When Cmax (B1) was 5.23 μg/ml or more, the probability of AKI was higher than 50%. The ratio of PMB1/PMB2 decreased after PMB preparation entered into the body. The protein binding rate in critically ill patients indicated significant individual differences. Free Cmax (B) and free Cmax (B1) levels in the AKI group were significantly (p < 0.05) higher than those in the non-AKI group. Total and free concentrations of PMB in patients showed a positive correlation. Conclusions: Both the ROC curve and logistic regression model showed that Cmax (B1) was a good predictor for the probability of PMB-induced AKI. Early therapeutic drug monitoring (TDM) of PMB should be considered in critically ill patients. Compared with Cmin (B), Cmax (B) and Cmax (B1) may be helpful for the early prediction of PMB-induced AKI in critically ill patients. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
32. A Novel Diagnostic Method for Single and Dual Power Switch Open-Circuit Faults of Six-Phase FTPMSM System Even in Fault Tolerant Operation.
- Author
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Xu, Jinquan, Guo, Si, Guo, Hong, and Tian, Xinlei
- Subjects
FAULT diagnosis ,PERMANENT magnet motors ,FAULT tolerance (Engineering) ,FAULT location (Engineering) ,FAULT-tolerant computing - Abstract
This article proposes a new diagnostic method based on average current Park vector (ACPV) for single and dual power switch open-circuit faults of six-phase fault-tolerant permanent magnet synchronous motor (FTPMSM) system, which can be applied for the system both in nonfault and fault tolerant operation conditions. The fault diagnosis structure is composed of two parts: the ACPV moduli-based fault detection and the ACPV polarity-based fault location. By analyzing the ACPV before and after the fault, the normalized ACPV moduli-based fault detection is proposed by using the ACPV components in three orthogonal subspaces, which has good robustness to the speed and load changes. The ACPV polarity-based fault location is then proposed to locate the faulted power switches of the FTPMSM system. Finally, the effectiveness of the proposed fault diagnosis method is validated by a six-phase FTPMSM experimental platform. The fault diagnosis approach has the advantageous features of simple implementation, good robustness to various disturbances, no requirement of the extra sensors, and low computational burden, which can achieve single and dual power switch open-circuit fault diagnosis for the FTPMSM system both in normal and fault tolerant operation conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
33. Effects of Soundscape on Flow State during Diabolo Exercise.
- Author
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Li, Tong-Yu, Guo, Si-Yuan, Xue, Bin-Xia, Meng, Qi, Jiang, Bo, Xu, Xin-Xin, and Chang, Chein-Chi
- Published
- 2022
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34. Advancing to 4.6 V Review and Prospect in Developing High‐Energy‐Density LiCoO2 Cathode for Lithium‐Ion Batteries.
- Author
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Zhang, Si‐Dong, Qi, Mu‐Yao, Guo, Si‐Jie, Sun, Yong‐Gang, Tan, Xin‐Xin, Ma, Pei‐Zhong, Li, Jin‐Yang, Yuan, Rong‐Zhong, Cao, An‐Min, and Wan, Li‐Jun
- Subjects
LITHIUM-ion batteries ,CATHODES ,SURFACE properties ,SURFACE structure ,PHASE transitions - Abstract
Layered LiCoO2 (LCO) is one of the most important cathodes for portable electronic products at present and in the foreseeable future. It becomes a continuous push to increase the cutoff voltage of LCO so that a higher capacity can be achieved, for example, a capacity of 220 mAh g–1 at 4.6 V compared to 175 mAh g–1 at 4.45 V, which is unfortunately accompanied by severe capacity degradation due to the much‐aggravated side reactions and irreversible phase transitions. Accordingly, strict control on the LCO becomes essential to combat the inherent instability related to the high voltage challenge for their future applications. This review begins with a discussion on the relationship between the crystal structures and electrochemical properties of LCO as well as the failure mechanisms at 4.6 V. Then, recent advances in control strategies for 4.6 V LCO are summarized with focus on both bulk structure and surface properties. One closes this review by presenting the outlook for future efforts on LCO‐based lithium ion batteries (LIBs). It is hoped that this work can draw a clear map on the research status of 4.6 V LCO, and also shed light on the future directions of materials design for high energy LIBs. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. The Use of Oral Anticoagulation Is Not Associated With a Reduced Risk of Mortality in Patients With COVID-19: A Systematic Review and Meta-Analysis of Cohort Studies.
- Author
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Dai, Meng-Fei, Guo, Si-Tong, Ke, Yi-Jun, Wang, Bao-Yan, Yu, Feng, Xu, Hang, Gu, Zhi-Chun, and Ge, Wei-Hong
- Subjects
COVID-19 ,ANTICOAGULANTS ,ORAL medication ,COHORT analysis ,MORTALITY ,INTENSIVE care units - Abstract
Background: Hypercoagulability and thromboembolic events are associated with poor prognosis in coronavirus disease 2019 (COVID-19) patients. Whether chronic oral anticoagulation (OAC) improve the prognosis is yet controversial. The present study aimed to investigate the association between the chronic OAC and clinical outcomes in COVID-19 patients. Methods: PubMed, Embase, Web of Science, and the Cochrane Library were comprehensively searched to identify studies that evaluated OAC for COVID-19 until 24 July 2021. Random-effects model meta-analyses were performed to pool the relative risk (RR) and 95% confidence interval (CI) of all-cause mortality and intensive care unit (ICU) admission as primary and secondary outcomes, respectively. According to the type of oral anticoagulants [direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs)], subgroup and interaction analyses were performed to compare DOACs and VKAs. Meta-regression was performed to explore the potential confounders on all-cause mortality. Results: A total of 12 studies involving 30,646 patients met the inclusion criteria. The results confirmed that chronic OAC did not reduce the risk of all-cause mortality (RR: 0.92; 95% CI 0.82–1.03; p = 0.165) or ICU admission (RR: 0.65; 95% CI 0.40–1.04; p = 0.073) in patients with COVID-19 compared to those without OAC. The chronic use of DOACs did not reduce the risk of all-cause mortality compared to VKAs (P
interaction = 0.497) in subgroup and interaction analyses. The meta-regression failed to detect any potential confounding on all-cause mortality. Conclusion: COVID-19 patients with chronic OAC were not associated with a lower risk of all-cause mortality and ICU admission compared to those without OAC, and the results were consistent across DOACs and VKA subgroups. Systematic Review Registration: clinicaltrials.gov, identifier CRD42021269764. [ABSTRACT FROM AUTHOR]- Published
- 2022
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- View/download PDF
36. Large self-assembled clathrin lattices spontaneously disassemble without sufficient adaptor proteins.
- Author
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Guo, Si-Kao, Sodt, Alexander J., and Johnson, Margaret E.
- Subjects
CLATHRIN ,CELL receptors ,ADAPTOR proteins ,DISCONTINUOUS precipitation ,CELL membranes - Abstract
Clathrin-coated structures must assemble on cell membranes to internalize receptors, with the clathrin protein only linked to the membrane via adaptor proteins. These structures can grow surprisingly large, containing over 20 clathrin, yet they often fail to form productive vesicles, instead aborting and disassembling. We show that clathrin structures of this size can both form and disassemble spontaneously when adaptor protein availability is low, despite high abundance of clathrin. Here, we combine recent in vitro kinetic measurements with microscopic reaction-diffusion simulations and theory to differentiate mechanisms of stable vs unstable clathrin assembly on membranes. While in vitro conditions drive assembly of robust, stable lattices, we show that concentrations, geometry, and dimensional reduction in physiologic-like conditions do not support nucleation if only the key adaptor AP-2 is included, due to its insufficient abundance. Nucleation requires a stoichiometry of adaptor to clathrin that exceeds 1:1, meaning additional adaptor types are necessary to form lattices successfully and efficiently. We show that the critical nucleus contains ~25 clathrin, remarkably similar to sizes of the transient and abortive structures observed in vivo. Lastly, we quantify the cost of bending the membrane under our curved clathrin lattices using a continuum membrane model. We find that the cost of bending the membrane could be largely offset by the energetic benefit of forming curved rather than flat structures, with numbers comparable to experiments. Our model predicts how adaptor density can tune clathrin-coated structures from the transient to the stable, showing that active energy consumption is therefore not required for lattice disassembly or remodeling during growth, which is a critical advance towards predicting productive vesicle formation. Author summary: Stochastic self-assembly of clathrin-coated structures on the plasma membrane is essential for transport into cells. We show here that even with abundant clathrin available, robust nucleation and growth into stable structures on membranes is not possible without sufficient adaptor proteins. Our results thus provide quantitative justification for why structures observed to form in vivo can still spontaneously disassemble over many seconds. Although clathrin disassembly after productive vesicle formation requires the work of ATPases, our study shows that active energy input is not necessary to control remodeling during growth. With parameterization against in vitro kinetics of assembly on membranes, our reaction-diffusion model provides a powerful and extensible tool for establishing determinants of productive assembly in cells. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
37. Precise surface control of cathode materials for stable lithium-ion batteries.
- Author
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Lu, Si-Qi, Guo, Si-Jie, Qi, Mu-Yao, Li, Jin-Yang, Cao, An-Min, and Wan, Li-Jun
- Subjects
LITHIUM-ion batteries ,SURFACE coatings ,SURFACE reactions ,NANOCOATINGS ,SURFACES (Technology) - Abstract
The increasing demand for high-energy Li-ion batteries (LIBs) continues to push the development of electrode materials, particularly cathode materials, towards their capacity limits. Despite the enormous success, the stability and reliability of LIBs are becoming a serious concern due to the much-aggravated side reactions between electrode materials and organic electrolytes. How to stabilize the cathode/electrolyte interface is therefore an imperative and urgent task drawing considerable attention from both academia and industry. An active treatment on the surface of cathode materials, usually by introducing an inert protection layer, to diminish their side reaction with electrolytes turns out to be a reasonable and effective strategy. This Feature Article firstly outlines our synthesis efforts for the construction of a uniform surface nanocoating on various cathode materials. Different wet chemical routes have been designed to facilitate the control of growth kinetics of targeted coating species so that a precise surface coating could be achieved with nanometer accuracy. Furthermore, we showed the possibility to transform the outer coating layer into a surface doping effect through surface solid reaction at high temperature. A detailed discussion on the structure–performance relationship of these surface-controlled cathode materials is introduced to probe the stabilization mechanism. Finally, perspectives on the development tendency of high-energy cathodes for stable LIBs are provided. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
38. Cross Correction and Chaotic Shape-Forming Filter Based Quadrature Multi-Carrier Differential Chaos Shift Keying Communication.
- Author
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Ren, Hai-Peng, Guo, Si-Long, Bai, Chao, and Zhao, Xiao-Hui
- Subjects
BIT error rate ,SIGNAL-to-noise ratio ,BIT rate ,CHAOTIC communication ,SHIFT registers - Abstract
In this paper, an improved Quadrature Multi-carrier Differential Chaos Shift Keying (QMC-DCSK) based on Chaotic Shape-forming Filter (CSF) and Cross Correction (CC) is proposed. The chaotic signal generated by CSF is used as reference spreading sequence in QMC-DCSK. Quadrature multi-carriers are used to carry the reference and multiple information bearing signals simultaneously in order to improve the Bit Transmission Rate (BTR). By this way, the proposed system is able to transmit $2M-1$ bits Traditional Data Stream (TDS) during one traditional DCSK bit duration, where $M$ is the number of carrier frequencies. Meanwhile, the reference signal transmits Additional Data Stream (ADS) encoded by CSF together with $2M-1$ identical or inverse data stream carried by the rest $2M-1$ channels (information bearing signals). By this system configuration, the channel redundance can be used to improved bit error rate (BER) performance of ADS, after decoding TDS. In turn, the TDS reliability can also be improved by checking most ADS polarity of the corresponding carrier. This process is referred to as CC. The contribution of this work lies in the CC operation, by which the reliability of both TDS and ADS is improved significantly. It is the CSF and multi-carrier that make CC possible. The analytical BER is derived for the proposed method. The merits of the proposed system include, first, it improves the BTR as compared to that of QMC-DCSK, because ADS conveys more information bits; second, the ADS reliability is improved dramatically because the $\text{2}\,M$ duplication can be used to improve the signal to noise ratio; third, the TDS reliability is improved as well because the information bits conveyed by each carrier frequency is enhanced and corrected by the $\text{2}\,M$ repetitions. By this way, not only TDS and ADS are transmitted (i.e., the higher BTR is achieved), but also both reliability are improved (i.e. the lower BER is achieved). In order to testify the feasibility and superiority of the proposed method, simulation and wireless open-access research platform (WARP) experiment are conducted. The simulation and experiment results show that the proposed method is superior to other comparison methods. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
39. Long-range migration of H-atoms from electron-induced dissociation of HS on Si(111).
- Author
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MacLean, Oliver, Guo, Si Yue, Timm, Matthew, and Polanyi, John C
- Published
- 2021
- Full Text
- View/download PDF
40. The Functions and Applications of Fluorinated Interface Engineering in Li‐Based Secondary Batteries.
- Author
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Qi, Mu-Yao, Xu, Yan-Song, Guo, Si-Jie, Zhang, Si-Dong, Li, Jin-Yang, Sun, Yong-Gang, Jiang, Ke-Cheng, Cao, An-Min, and Wan, Li-Jun
- Subjects
LITHIUM cells ,ENERGY storage ,ENERGY density ,ELECTROCHEMICAL analysis ,CATHODES - Abstract
Li‐based secondary batteries are now attracting soaring research attention as a promising energy storage system with high energy density for commercial applications. However, the high‐energy systems meanwhile are causing serious concerns on safety issues due to unstable interfaces on both cathodes and anodes. To improve interphase stability upon extended cycles, surface fluorinated treatment becomes highly desirable due to its unique capability in modulating the chemistry of electrode/electrolyte interface to ensure a stable electrochemical performance. Accordingly, it is essential that a deeper understanding on the solid electrolyte interphase (SEI), especially the role of fluorine‐containing components, is demanded to guide the interface design. This review begins with an introduction to the fundamental knowledge on the structure of SEI with focus on the unique physiochemical properties of fluorides. Detailed discussions are then taken on the control strategies for a reliable construction of fluoride‐based interfaces, which typically includes the surface coating of metal fluorides on cathodes and ex situ/in situ fluorination on lithium, based on which the structure–performance relationship is elaborated to inspire a rational interface engineering. Finally, perspectives are provided to give insights into the possible research directions of fluorinated SEI for further development of rechargeable Li batteries. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
41. High‐Performance Cathode Materials for Potassium‐Ion Batteries: Structural Design and Electrochemical Properties.
- Author
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Xu, Yan‐Song, Guo, Si‐Jie, Tao, Xian‐Sen, Sun, Yong‐Gang, Ma, Jianmin, Liu, Chuntai, and Cao, An‐Min
- Published
- 2021
- Full Text
- View/download PDF
42. Transcriptome-based identification and expression characterization of RgABCC transporters in Rehmannia glutinosa.
- Author
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Yang, Yan Hui, Wang, Chao Jie, Li, Rui Fang, Yi, Yan Jie, Zeng, Lei, Yang, Heng, Zhang, Chang Fu, Song, Kai Yi, and Guo, Si Jiao
- Subjects
MULTIDRUG resistance-associated proteins ,ATP-binding cassette transporters ,MULTIDRUG resistance ,ROOT development ,CELL membranes ,SEQUENCE alignment - Abstract
ABCC multidrug resistance-associated proteins (ABCCs/MRPs), a subfamily of ABC transporters, are involved in multiple physiological processes. Although these proteins have been characterized in some plants, limited efforts have been made to address their possible roles in Rehmannia glutinosa, a medicinal plant. Here, we scanned R. glutinosa transcriptome sequences and identified 18 RgABCC genes by in silico analysis. Sequence alignment revealed that the RgABCCs were closely phylogenetically related and highly conserved with other plant ABCCs/MRPs. Subcellular localization revealed that most of the RgABCCs were deposited in vacuoles and a few in plasma membranes. Tissue-specific expression of the RgABCCs indicated significant specific accumulation patterns, implicating their roles in the respective tissues. Differential temporal expression patterns of the RgABCCs exhibited their potential roles during root development. Various abiotic stress and hormone treatment experiments indicated that some RgABCCs could be transcriptionally regulated in roots. Furthermore, the transcription of several RgABCCs in roots was strongly activated by cadmium (Cd), suggesting possible roles under heavy metal stresses. Functional analysis of RgABCC1 heterologous expression revealed that it may increase the tolerance to Cd in yeast, implying its Cd transport activity. Our study provides a detailed inventory and molecular characterization of the RgABCCs and valuable information for exploring their functions in R. glutinosa. [ABSTRACT FROM AUTHOR]
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- 2021
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43. Bone marrow cells are differentiated into MDSCs by BCC‐Ex through down‐regulating the expression of CXCR4 and activating STAT3 signalling pathway.
- Author
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Liu, Quan‐Wen, Chen, Yong, Li, Jing‐Yuan, Xiao, Ling, Zhang, Wen‐Jie, Zhao, Jia‐Le, Gu, Hao‐Cheng, Wu, Han‐You, Zuo, Guo‐Si‐Lang, Deng, Ke‐Yu, and Xin, Hong‐Bo
- Subjects
BONE marrow cells ,MYELOID-derived suppressor cells ,B cells ,CHEMOKINE receptors ,T cells - Abstract
Studies showed that the increase of myeloid‐derived suppressor cells (MDSCs) in tumour microenvironment is closely related to the resistant treatment and poor prognosis of metastatic breast cancer. However, the effect of tumour‐derived exosomes on MDSCs and its mechanism are not clear. Here, we reported that breast cancer cells (4T1)‐secreted exosomes (BCC‐Ex) were able to differentiate bone marrow cells into MDSCs and significantly inhibited the proliferation of T lymphocytes to provide an immunosuppressive microenvironment for cancer cells in vivo and in vitro. The number of MDSCs in bone marrow and spleen of 4T1 tumour‐bearing mice and BCC‐Ex infused mice was significantly higher than that of normal mice, whereas the number of T lymphocytes in spleen was significantly decreased. In addition, BCC‐Ex markedly promoted the differentiation of MDSCs from bone marrow cells or bone marrow cells derived macrophages, seen as the increased expressions of MDSCs‐related functional proteins Arginase‐1 (Arg‐1) and inducible nitric oxide synthase (iNOS). Furthermore, BCC‐Ex significantly down‐regulated the expressions of chemokine receptor CXCR4 and markedly up‐regulated the levels of inflammatory cytokines IL‐6 and IL‐10 in bone marrow cells and macrophages and remarkably inhibited the division and proliferation of T cells. Importantly, CXCR4 agonist, CXCL12, could reverse the function of BCC‐Ex, indicating that BCC‐Ex‐induced MDSCs might be dependent on the down‐regulation of CXCR4. Western blot showed that BCC‐Ex significantly promoted the phosphorylation of STAT3 in bone marrow cells, resulting in the inhibitions of the proliferation and apoptosis of bone marrow cells, and the aggravation of the differentiation of bone marrow cells into MDSCs. [ABSTRACT FROM AUTHOR]
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- 2021
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- View/download PDF
44. Engineering a heterologous synthetic pathway in Escherichia coli for efficient production of biotin.
- Author
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Wei, Pei-Pei, Zhu, Fu-Cheng, Chen, Cun-Wu, and Li, Guo-Si
- Subjects
PSEUDOMONAS putida ,BIOTIN ,ESCHERICHIA coli ,BIOCHEMICAL engineering ,BACILLUS subtilis ,SACCHAROMYCES cerevisiae ,OPERONS - Abstract
Objective: To enhance biotin production in Escherichia coli by engineering a heterologous biotin synthetic pathway. Results: Biotin operon genes from Pseudomonas putida, which consisted of a bioBFHCD cluster and a bioA gene, was engineered into Escherichia coli for biotin production. The introduction of bioW gene from Bacillus subtilis, encoding pimeloyl-CoA synthetase and sam2 gene from Saccharomyces cerevisiae, encoding S-adenosyl-L-methionine (SAM) synthetase contributed to the heterologous production of biotin in recombinant E. coli. Furthermore, biotin production was efficiently enhanced by optimization of the fermentation compositions, especially pimelic acid and L-methionine, the precursor related to the pimeloyl-CoA and SAM synthesis, respectively. The combination of overexpression of the heterologous biotin operon genes and enhanced supply of key intermediate pimeloyl-CoA and SAM increased biotin production in E. coli by more than 121-fold. With bioprocess engineering efforts, biotin was produced at a final titer of 92.6 mg/L in a shake flask and 208.7 mg/L in a fed-batch fermenter. Conclusion: Through introduction of heterologous biotin synthetic pathway, increasing the supply of precursor pimeloyl-CoA and cofactor SAM can significantly enhance biotin production in E. coli. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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45. The development, performances and applications of the monochromatic X-rays facilities in (0.218–301) keV at NIM, China.
- Author
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Guo, Si-Ming, Wu, Jin-Jie, and Hou, Dong-Jie
- Published
- 2021
- Full Text
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46. Selective electrochemical hydrogenation of furfural to 2-methylfuran over a single atom Cu catalyst under mild pH conditions.
- Author
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Zhou, Peng, Chen, Yu, Luan, Peng, Zhang, Xiaolong, Yuan, Ziliang, Guo, Si-Xuan, Gu, Qinfen, Johannessen, Bernt, Mollah, Mamun, Chaffee, Alan L., Turner, David R., and Zhang, Jie
- Subjects
FURFURAL ,HYDROGENATION ,STANDARD hydrogen electrode ,ATOMS ,FURFURYL alcohol ,HYDROGEN evolution reactions - Abstract
Furfural is regarded as one of the most promising bio-based feedstocks in the bio-refinery industry. Selective hydrogenation of the carbonyl bond in furfural plays a vital role in its conversion to downstream products. Electrochemical hydrogenation (ECH) method provides a green and sustainable way for this reaction. Yet, it still suffers from harsh pH conditions and low selectivity for highly reduced products, such as 2-methylfuran. In this study, high faradaic efficiencies of over 90% for furfuryl alcohol and 60% for 2-methylfuran were obtained in a near-neutral environment (pH = 5) at −0.75 V and −0.90 V vs. the reversible hydrogen electrode, respectively. The key to this success is the integration of single atom copper active sites and the oxophilic phosphorus dopants in a single catalyst. Single atom Cu sites are found to be the active centers for this reaction and decreasing the size of Cu sites to a single atom enhances the efficiencies of the ECH reactions by suppressing the competing hydrogen evolution reaction. Phosphorus doping facilitates furfural hydrogenation to 2-methylfuran via a sequential two-step reduction process. This study opens up possibilities for the selective electrochemical hydrogenation of furfural to 2-methylfuran under mild conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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47. A cycloartenol synthase from the steroidal saponin biosynthesis pathway of Paris polyphylla.
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Guo, Si-Yuan, Yin, Yan, Lei, Tao, Shi, Ying-Hui, Gao, Wei, Zhang, Xia-Nan, and Li, Jia
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REVERSE transcriptase polymerase chain reaction ,MEDICINAL plants ,TERPENES ,GLYCOSIDES ,GENE expression ,PLANT roots ,LEAVES ,ENZYMES ,PLANT extracts ,PHYTOSTEROLS ,POLYMERASE chain reaction ,CHINESE medicine - Abstract
Steroidal saponins named polyphyllin are the major active components of Paris polyphylla. Cycloartenol synthase (CAS) is a key enzyme that catalyzes the formation of the sterol scaffold. In this study, we cloned a putative CAS gene from Paris polyphylla. Heterologous expression in yeast indicated that PpCAS can convert 2,3-oxidosqualene into cycloartenol. qRT-PCR analysis showed that the expression of PpCAS was highest in leaves and lowest in roots. To our best knowledge, this is the first report of the functional characterization of cycloartenol synthase from Paris polyphylla, which lays the foundation for further analysis of the biosynthesis pathway of polyphyllins. [ABSTRACT FROM AUTHOR]
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- 2021
- Full Text
- View/download PDF
48. Seismic data denoising under the morphological component analysis framework by dictionary learning.
- Author
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Guo, Yangqin, Guo, Si, Guo, Ke, and Zhou, Huailai
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MICROSEISMS ,DISCRETE cosine transforms ,IMAGE denoising ,DISCRETE wavelet transforms ,CURVELET transforms ,SIGNAL-to-noise ratio ,NOISE control - Abstract
Traditional denoising methods based on fixed transforms are not suited for exploiting their complicated characteristics and attenuating noise due to their lack of adaptability. Recently, a novel method called morphological component analysis (MCA) was proposed to separate different geometrical components by amalgamating several irrelevance transforms. For studying the local singular and smooth linear components characteristics of seismic data, we propose a novel method that excels particularly in attenuating random and coherent noise while preserving effective signals. The proposed method, which combines MCA, dictionary learning (DL), and deep noise reduction consists of three steps: first, we separate the local singular and smooth linear components from the seismic signal using MCA. Second, we apply a DL method on these two components to suppress noise and obtain the denoised signal and noise. In the final step, we apply the DL method to the noise to obtain a little of the seismic signal. Afterwards, we integrate the two seismic signals to obtain the final denoised seismic signal. Numerical results indicate that the proposed method can effectively suppress the undesired noise, maximally preserve the information of geologic bodies and structures, and improve the signal-to-noise ratio (S/N) of the data. We also demonstrate the superior performance of this approach by comparing with other novel dictionaries such as discrete cosine transforms (DCTs), undecimated discrete wavelet transforms (UDWTs), or curvelet transforms. This algorithm provides new ideas for data processing to advance quality and S/N of seismic data. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
49. Application of enzyme-assisted extraction of baicalin from Scutellaria baicalensis Georgi.
- Author
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Ma, Xiao-Di, Zhang, Xin-Guo, Guo, Si-Jia, Ma, Guo-Yan, Liu, Wen-Jie, Wang, Nan, Feng, Ming, and Su, Yu
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CHINESE skullcap ,SCUTELLARIA ,CELLULASE ,PLANT cell walls ,MEDICINAL plants ,SCANNING electron microscopy - Abstract
Endophytes may depend on degrading the plant cell wall with cellulases for their survival. Therefore, cellulase produced by endophytes may be useful in releasing the active ingredient of medicinal plants. Scutellaria baicalensis Georgi is a traditional Chinese medicinal plant widely used in China and baicalin is one of its main active ingredients. In this study, fresh S. baicalensis Georgi was used to isolate endophytes, Congo red staining was used to screen cellulase-producing strains, and HPLC was used to determine the content of baicalin in S. baicalensis Georgi. As a result, a highly active strain of endophyte capable of the extraction of high levels of baicalin was obtained. The strain was named HG-5 and identified as Bacillus sp. Scanning electron microscopy analysis confirmed that the enzyme better promotes the dissolution of plant active ingredients. After optimizing the enzyme production and extraction processes, we found that when compared with the traditional extraction method, the baicalin yield was increased 79.31% after extraction with the HG-5 enzyme. The current study provides a novel approach and method for the use of endophyte cellulase to improve the extraction of compounds from medicinal plants. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
50. Power Switch Open-Circuit Fault Diagnosis of Six-Phase Fault Tolerant Permanent Magnet Synchronous Motor System Under Normal and Fault-Tolerant Operation Conditions Using the Average Current Park's Vector Approach.
- Author
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Guo, Hong, Guo, Si, Xu, Jinquan, and Tian, Xinlei
- Subjects
PERMANENT magnet motors ,FAULT diagnosis ,FAULT-tolerant computing ,INTEGRATED circuit fault tolerance ,FAULT location (Engineering) ,SIGNS & symbols - Abstract
In this article, a new power switch open-circuit fault diagnosis approach is proposed for the six-phase fault-tolerant permanent magnet synchronous motor (FTPMSM) system based on average current Park's vector (ACPV), which can detect the fault power switch for the FTPMSM system in both normal and phase open-circuit/short-circuit fault-tolerant operation conditions. To detect the power switch open-circuit fault, the fault detection approach based on the moduli of the ACPV in two orthogonal subspaces is first proposed for the six-phase FTPMSM system even in phase open-circuit and short-circuit fault-tolerant operation. Then, the ACPV-based fault location approach is proposed, which can identify the fault power switch according to the sign symbol of the ACPV. The resulting fault diagnosis approach has a simple structure and low computation burden, which can detect the power switch open-circuit fault online for the FTPMSM system in both normal and fault-tolerant operation conditions. Finally, the effectiveness of the proposed fault diagnosis approach is demonstrated by a six-phase FTPMSM system experimental platform. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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