Modified weak signal fault diagnosis method forbearing inner ring

In view of the shortcomings of mode mixing in EMD, the excess IMF component in the low frequency band, spectral kurtosis has no adaptive. The method of EMD and spectral kurtosis are proposed. Spectral kurtosis is very sensitive to the fault signal and it can enhance the fault pulse signal effectively. Then combine spectral kurtosis with EMD to overcome the shortcomings of EMD. Improved the efficiency and accuracy of EMD decomposition and the level of fault diagnosis. The method of EMD and spectral kurtosis are applied to the simulation signal and rolling bearing fault diagnosis. The experimental results show that the method of EMD and spectrum kurtosis can accurately judge the rolling bearing weak fault and have a good application prospect

Design and research of cutting load measuring device for coal and rock

Based on the analysis of the present situation of the research on the cutting process of the drum, the research method of the equipment capable of obtaining the cutting force in the drum cutting process is proposed by combining the finite element explicit dynamic analysis. Aiming at the complicated force of the shearer’s pick cutter in cutting the coal rock. In this paper, the finite element software is used to explicit dynamics simulate the picking of coal mining in the cutting process, and the strain distribution on the cutting is determined. Based on this, the use of strain gauge bridge design ideas to indirectly obtain the force on the cutter, and finally get the relevant experimental data. Compared with the finite element simulation analysis, the feasibility of the two schemes is explained, and the foundation of the follow-up experiment is laid

The relationship between daytime napping and glycemic control in people with type 2 diabetes

AimTo examine the association between napping characteristics and glycemic control in people with type 2 diabetes.DesignThis study used a cross-sectional design.MethodsA convenience sample of people with type 2 diabetes (N=226) were included. Glycemic control was indicated by HbA1c which was measured by A1C Now®+. Napping characteristics including napping frequency, duration, timing, and type were measured by validated questionnaires. Other variables, such as insomnia, cognitive impairment, and depression were measured by the Insomnia Severity Index, Montreal Cognitive Assessment, and Patient Health Questionnaire-9, respectively. Multivariate linear regression analyses were performed.ResultsThe sample consisted of 122 women (54.0%), with a median age of 67 years. Their median HbA1c was 6.8%. No significant relationship was found between napping frequency and HbA1c. Among nappers, after controlling for covariates, long napping duration (≥60 min) and morning napping were both associated with poorer glycemic control. Compared with appetitive napping, restorative napping was associated with better glycemic control.ConclusionDaytime napping (e.g., duration and type) is an important modifiable factor for glycemic control in people with type 2 diabetes. This study provides new insights into the relationship between napping and glucose management among people with diabetes

Roadmap on energy harvesting materials

Ambient energy harvesting has great potential to contribute to sustainable development and address growing environmental challenges. Converting waste energy from energy-intensive processes and systems (e.g. combustion engines and furnaces) is crucial to reducing their environmental impact and achieving net-zero emissions. Compact energy harvesters will also be key to powering the exponentially growing smart devices ecosystem that is part of the Internet of Things, thus enabling futuristic applications that can improve our quality of life (e.g. smart homes, smart cities, smart manufacturing, and smart healthcare). To achieve these goals, innovative materials are needed to efficiently convert ambient energy into electricity through various physical mechanisms, such as the photovoltaic effect, thermoelectricity, piezoelectricity, triboelectricity, and radiofrequency wireless power transfer. By bringing together the perspectives of experts in various types of energy harvesting materials, this Roadmap provides extensive insights into recent advances and present challenges in the field. Additionally, the Roadmap analyses the key performance metrics of these technologies in relation to their ultimate energy conversion limits. Building on these insights, the Roadmap outlines promising directions for future research to fully harness the potential of energy harvesting materials for green energy anytime, anywhere

Modification on phenolic profiles and enhancement of antioxidant activity of proso millets during germination

Changes in phenolic profiles and antioxidant activity of three varieties of proso millet during germination were investigated. Total phenolic content (TPC) and total flavonoid content (TFC) increased significantly with prolongation in germination period. After germination for 6 days, TPC of the free and bound fractions increased 6.30–8.66-fold and 77.65–116.18%, respectively. The free and bound phenolic compounds identified by UPLC-MS/MS, displayed significant variations. Feruloylquinic acid and N,N′-bis-(p-coumaroyl)-putrescine biosynthesized during germination, are reported for the first time in proso millets. Other phenolics including trans- and cis-ferulic, trans-p-coumaric, vanillic acid and ferulic acid dimers (DFAs) were increased significantly along with a new DFA (8,5′-DFA) seemingly produced during germination. The germinated proso milllets displayed superior antioxidant activity than the corresponding ungerminated samples indicating that germination could be one applicable method for improving phenolic profiles and antioxidant capacity of proso millets. Thus germinated proso millet could be exploited as a functional ingredient in several products

Enhanced Thermoelectric Performance of Bi2O2Se with Ag Addition

Polycrystalline Bi2O2Se/Ag nanocomposites were synthesized by spark plasma sintering process. Their thermoelectric properties were evaluated from 300 to 673 K. With the addition of silver, the conductive second phase Ag2Se and Ag can be observed, which results in a significant enhancement of electrical conductivity. The maximum conductivity is 691.8 S cm−1 for Bi2O2Se/20 vol.% Ag, which increased nearly 500 higher times than the pure Bi2O2Se bulk. ZT value can be enhanced greatly, ~0.07, for Bi2O2Se/5 vol.% Ag at 673 K, which is two times larger than the pure sample

Ion-regulating Hybrid Electrolyte Interface for Long-life and Low N/P Ratio Lithium Metal Batteries

Practical lithium metal batteries (LMBs) require full and reversible utilization of limited metallic Li anodes at a solid/quasi-solid electrolyte condition. This leads to a challenging issue, i.e., how to create compatible interphases to regulate interfacial ionic transport and protect the reactive metal. Herein, to address this issue, we report a robust cellulose-based composite gel electrolyte (r-CCE) capable of stabilizing ion deposition via compositing bacterial cellulose (BC) skeleton with Li6.4La3Zr1.4Ta0.6O12 (LLZTO) particles. Benefiting from the decoupled segment structure of cellulose and additional ionic channels of LLZTO, r-CCE not only achieves high ionic conductivity (1.68 × 10−3 S/cm) with a remarkable Li-ion transfer number (∼0.92) and a wide window of electrochemical stability (∼5.3 V), but also helps stabilize the Li anode. Utilizing ultrathin lithium metal anodes (15 μm), ultra-stable symmetric Li/Li cells that are armed with r-CCE demonstrate a highly stable plating/stripping process. Furthermore, a high areal capacity of ∼4.2 mAh/cm2, and 100 cycles with improved stability of the full Li metal batteries with n/p ratio of ∼0.74 are achieved