| 1. |
- Zecheng, Li, et al.
(författare)
-
Fecal microbiota transplantation in obesity metabolism : A meta analysis and systematic review
- 2023
-
Ingår i: Diabetes Research and Clinical Practice. - 0168-8227. ; 202
-
Forskningsöversikt (refereegranskat)abstract
- Objective: The effect of fecal microbiota transplantation (FMT) on microbiota engraftment in patients with metabolic syndrome remains unclear. This systematic review employed a meta-analysis of RCTs for assessment on the role of FMT in treating obesity and metabolic syndrome, and its impact on clinically relevant parameters. Method: Major databases and grey literatures were searched identifying RCTs comparing FMT of lean donors with placebo in obese/metabolic syndrome patients. Studies using any form of placebo were included. Variations in the parameters before and after treatment were calculated followed by meta-analyses. Result: Ten studies met the inclusion criteria and a total of 334 patients were included for further analysis. Clinically significant parameters associated with obesity and metabolic syndrome were explored and FMT was identified significantly and negatively associated with most indices of abdominal adiposity including caloric intake, fasting glucose, HOMA-IR, systolic blood pressure, diastolic blood pressure, total cholesterol, HDL, LDL, triglycerides and CRP, Obesity parameters including fasting glucose and acetic acid were increased following FMT. Conclusion: FMT is more advantageous for obese patients with elevated blood pressure, disordered glucose and insulin metabolism, and elevated blood lipids. The study of metabolic factors in obese patients will be our starting point in the future.
|
|
| 2. |
- Li, Xiaojian, 1991, et al.
(författare)
-
A New Method for Impeller Inlet Design of Supercritical CO2 Centrifugal Compressors in Brayton Cycles
- 2020
-
Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 13:19
-
Tidskriftsartikel (refereegranskat)abstract
- Supercritical Carbon Dioxide (SCO2) is considered as a potential working fluid in next generation power and energy systems. The SCO2 Brayton cycle is advantaged with higher cycle efficiency, smaller compression work, and more compact layout, as compared with traditional cycles. When the inlet total condition of the compressor approaches the critical point of the working fluid, the cycle efficiency is further enhanced. However, the flow acceleration near the impeller inducer causes the fluid to enter two-phase region, which may lead to additional aerodynamic losses and flow instability. In this study, a new impeller inlet design method is proposed to achieve a better balance among the cycle efficiency, compressor compactness, and inducer condensation. This approach couples a concept of the maximum swallowing capacity of real gas and a new principle for condensation design. Firstly, the mass flow function of real gas centrifugal compressors is analytically expressed by non-dimensional parameters. An optimal inlet flow angle is derived to achieve the maximum swallowing capacity under a certain inlet relative Mach number, which leads to the minimum energy loss and a more compact geometry for the compressor. Secondly, a new condensation design principle is developed by proposing a novel concept of the two-zone inlet total condition for SCO2 compressors. In this new principle, the acceptable acceleration margin (AAM) is derived as a criterion to limit the impeller inlet condensation. The present inlet design method is validated in the design and simulation of a low-flow-coefficient compressor stage based on the real gas model. The mechanisms of flow accelerations in the impeller inducer, which form low-pressure regions and further produce condensation, are analyzed and clarified under different operating conditions. It is found that the proposed method is efficient to limit the condensation in the impeller inducer, keep the compactness of the compressor, and maintain a high cycle efficiency.
|
|
| 3. |
- Li, Xiaojian, 1991, et al.
(författare)
-
A new method for performance map prediction of automotive turbocharger compressors with both vaneless and vaned diffusers
- 2021
-
Ingår i: Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering. - : SAGE Publications. - 2041-2991 .- 0954-4070. ; 235:6, s. 1734-1747
-
Tidskriftsartikel (refereegranskat)abstract
- A new approach to predict the performance maps of automotive turbocharger compressors is presented. Firstly, a polynomial equation is applied to fit the experimental data of flow coefficient ratios for the centrifugal compressors with both vaneless and vaned diffusers. Based on this equation, the choke and surge flow coefficients under different machine Mach numbers can be quickly predicted. Secondly, a physically based piecewise elliptic equation is used to define compressors’ characteristic curves in terms of efficiency ratio. By introducing the flow coefficient ratio into the efficiency correlation, the empirical coefficients in the piecewise elliptic equation are uniquely calibrated by the experimental data, forming a unified algebraic equation to match the efficiency maps of the compressors with both vaneless and vaned diffusers. Then, a new universal equation, which connects the work coefficient, the impeller outlet flow coefficient and the non-dimensional equivalent impeller outlet width, is derived by using classical aerothermodynamic method. The off-design pressure ratio is predicted based on the equivalent impeller outlet width with less knowledge of the compressor geometry and no empirical coefficients. Finally, three state-of-the-art turbocharger compressors (one with vaneless diffuser, two with vaned diffusers) are chosen to validate the proposed method, and the results show a satisfactory accuracy for the performance map prediction. This method can be used for the preliminary design of turbocharger compressors with both vaneless and vaned diffusers, or to assess the design feasibility and challenges of the given design specifications.
|
|
| 4. |
- Liu, Yijia, et al.
(författare)
-
Metasurface-Based Modulation With Enhanced Interference Resilience
- 2023
-
Ingår i: IEEE Communications Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1089-7798 .- 1558-2558. ; 27:5, s. 1447-1451
-
Tidskriftsartikel (refereegranskat)abstract
- Reconfigurable Intelligent Surfaces (RISs) have great potential for Internet of Things (IoT) applications due to their cost-effectiveness and energy-efficiency. However, under the application of RIS, current RIS systems cannot actively predict and avoid interference, as evolving interference signals can dynamically change their frequency bands. To address this issue, we develop a learning-based dynamic RIS spectrum access scheme to avoid interference and enhance wireless transmission reliability. An intelligent metasurface-based modulation (MM) is designed for generating and reflecting anti-interference radio-frequency signals. Specifically, a Dyna-Q algorithm is employed at the RIS controller to learn the frequency of interference signals, which is used to determine the frequency of the carrier signals. Experiments are conducted on the proposed RIS demo system to evaluate its anti-interference capability, and the results show that our scheme leads to an increase of at least 50% in the system throughput. These numerical results demonstrate the effectiveness of proposed scheme.
|
|
| 5. |
- Wu, Zhenrui, et al.
(författare)
-
Unveiling the Mysteries: Acetonitrile's Dance with Weakly-Solvating Electrolytes in Shaping Gas Evolution and Electrochemical Performance of Zinc-ion Batteries
- 2024
-
Ingår i: Angewandte Chemie. - 1521-3773 .- 1433-7851. ; 63:19
-
Tidskriftsartikel (refereegranskat)abstract
- Aqueous Zn-metal battery (AZMB) is a promising candidate for future large-scale energy storage with commendable capacity, exceptional safety characteristics, and low cost. Acetonitrile (AN) has been widely used as an effective electrolyte constituent to improve AZMBs’ performance. However, its functioning mechanisms remain unclear. In this study, we unveiled the critical roles of AN in AZMBs via comparative in situ electrochemical, gaseous, and morphological analyses. Despite its limited ability to solvate Zn ions, AN-modulated Zn-ion solvation sheath with increased anions and decreased water achieves a weakly-solvating electrolyte. As a result, the Zn||Zn cell with AN addition exhibited 63 times longer cycle life than cell without AN and achieved a 4 Ah cm−2 accumulated capacity with no H2 generation. In V2O5||Zn cells, for the first time, AN suppressing CO2 generation, elevating CO2-initiation voltage from 2→2.44 V (H2: 2.43→2.55 V) was discovered. AN-impeded transit and Zn-side deposition of dissolved vanadium ions, known as “crosstalk,” ameliorated inhomogeneous Zn deposition and dendritic Zn growth. At last, we demonstrated an AN-enabled high-areal-capacity AZMB (3.3 mAh cm−2) using high-mass-loading V2O5 cathode (26 mg cm−2). This study shed light on the strategy of constructing fast-desolvation electrolytes and offered insights for future electrolyte accommodation for high-voltage AZMB cathodes.
|
|
| 6. |
- Ye, Tao, et al.
(författare)
-
Reducing livestock snow disaster risk in the Qinghai–Tibetan Plateau due to warming and socioeconomic development
- 2022
-
Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 813
-
Tidskriftsartikel (refereegranskat)abstract
- Global warming can have positive or negative impacts on society depending on sectors and changes in climate impact drivers, resulting in opportunities or risks. The same holds true for social-economic changes. However, past research has mostly focused on assessing risks, leaving potential opportunities under-addressed. Here, we simulated the impact of climate change and socioeconomic development on livestock snow disasters over the Qinghai–Tibetan Plateau during 1986–2100, by integrating the drivers of climate and socioeconomic changes via an event-based disaster risk assessment model. Model results show climate change and socioeconomic development contributes about equally to reducing livestock loss in snow disasters by 4% yr−1 up to 2100 under representative concentration pathway 8.5 and shared-socioeconomic pathway 5. The marginal benefit from climate change was projected to be a 43.2% reduction in annual average loss per degree kelvin warming, and that from socioeconomic development was a 12.4% reduction per 100% increase in gross domestic production. In a 2 °C warmer world, the annual average loss could be 91% smaller compared with the baseline period (1986–2005). Limiting global warming to 1.5 °C instead of 2 °C would reduce the benefit by 5%, requiring a 135% increase in the marginal benefits of prevention capacity to offset the reduction.
|
|
