Refined Composite Multiscale Fluctuation Dispersion Entropy and Supervised Manifold Mapping for Planetary Gearbox Fault Diagnosis

A novel fault diagnosis scheme was developed to address the difficulty of feature extraction for planetary gearboxes using refined composite multiscale fluctuation dispersion entropy (RCMFDE) and supervised manifold mapping. The RCMFDE was first utilized in this scheme to fully mine fault features from planetary gearbox signals under multiple scales. Subsequently, as a supervised manifold mapping method, supervised isometric mapping (S-Iso) was applied to decrease the dimensions of the original features and remove redundant information. Lastly, the marine predator algorithm-based support vector machine (MPA-SVM) classifier was employed to achieve intelligent fault diagnosis of planetary gearboxes. The suggested RCMFDE combines the composite coarse-grained construction and refined computing technology, overcoming unstable and invalid entropy in the traditional multiscale fluctuation dispersion entropy. Simulation experiments and fault diagnosis experiments from a real planetary gearbox drive system show that the complexity measure capability and feature extraction effectiveness of the proposed RCMFDE outperform the multiscale fluctuation dispersion entropy (MFDE) and multi-scale permutation entropy (MPE). The S-Iso’s visualization results and dimensionality reduction performance are better than principal components analysis (PCA), linear discriminant analysis (LDA), and isometric mapping (Isomap). Moreover, the suggested fault diagnosis scheme has an accuracy rate of 100% in identifying bearing and gear defects in planetary gearboxes

A multifunctional hydrogel fabricated via ultra-fast polymerization by graphene oxide-adsorbed liquid metal nanodroplets

Graphene structures have never been found to play a role in accelerating fabrication of functional hydrogels. In this work, it is initially discovered that multifunctional hydrogels are fabricated via ultra-fast polymerization (∼minutes) by graphene oxide-adsorbed liquid metal nanodroplets (LMNPs@GO) vs. by conventional approaches (∼hours/days). LMNPs@GO are used to rapidly initiate and further cross-link polyacrylic acid (PAA) chains into a three-dimensional (3D) network without any extra molecular initiators, cross-linkers, heat source, and/or protective gas. The polymerization process with LMNPs@GO is extremely faster than that without GO involved (20 s vs. 4 h of prepolymer formation, and then 10 min vs. 3 days of crosslinking) for free radical polymerization of PAA hydrogels. The resulting hydrogel with 2 wt% reduced graphene oxide (rGO) exhibits 600% increase in tensile strength and 950% enhancement in conductivity, as well as excellent self-healing capabilities, in comparison with that of the pure PAA. The sensitivity studies show its great potential for the application of flexible sensors. Furthermore, the hydrogel possesses good dissolving properties, which is greatly beneficial for recyclability of the LM. This creative study not only broadens a novel application of graphene for making advanced multifunctional polymer materials, but also provides a brand-new route to realization of ultra-fast manufacturing technology that is significantly promising for industrial production in wearable devices

Co‐insertion of Water with Protons into Organic Electrodes Enables High‐Rate and High‐Capacity Proton Batteries

The inherent short‐term transience of renewable energy sources causes significant challenges for the electricity grids. Energy storage systems that can simultaneously provide high power and high energy efficiency are required to accommodate the intermittent renewables. Herein, an ultrafast and high‐capacity aqueous proton battery is developed based on the organic pyrene‐4,5,9,10‐tetraone (PTO) anode. The co‐insertion of H2O molecules and proton into the PTO organic anode effectively reduces the interfacial resistance between the anode and electrolytes, and achieves an unprecedented rate capability up to 250 C and as short as 7 s per charge/discharge. A PTO‐based full cell exhibits an outstanding power density (>104 W kg−1) comparable to supercapacitors. The full utilization of the four C=O groups in PTO molecule during cycling enables the highest capacity (85 mAh g−1) reported for proton batteries to date. This study represents a significant leap forward in the exploitation of ultrafast electrochemical energy storage and accelerates the development of intermittent grid‐scale energy storage technologies

Evaluation of droplet digital PCR rapid detection method and precise diagnosis and treatment for suspected sepsis (PROGRESS): a study protocol for a multi-center pragmatic randomized controlled trial

Abstract Background Sepsis is still a major public health concern and a medical emergency due to its high morbidity and mortality. Accurate and timely etiology diagnosis is crucial for sepsis management. As an emerging rapid and sensitive pathogen detection tool, digital droplet PCR (ddPCR) has shown promising potential in rapid identification of pathogens and antimicrobial resistance genes. However, the diagnostic value and clinical impact of ddPCR tests remains to be studied in patients with suspected sepsis. PROGRESS trial is aimed to evaluate the clinical effectiveness of a novel ddPCR assay compared with standard practice. Methods PROGRESS is a multicenter, open-label, pragmatic randomized controlled trial (pRCT) set in ten hospitals, including departments of infectious disease and intensive care units. In this study, a total of 2292 patients with suspected sepsis will be randomly assigned to two arms: the ddPCR group and the control group with a ratio of 3:1. The primary outcome is the diagnostic efficacy, that is, the sensitivity and specificity of the ddPCR assay compared with the synchronous blood culture. Secondary outcomes include the mortality rates and the mean Sequential Organ Failure Assessment (SOFA) score at follow-up time points, the length of stay in the hospital, the time to directed antimicrobial therapy, duration of broad-spectrum antibiotic use, and the EQ-5D-5L score on day 90. Discussion It is the first multicenter pragmatic RCT to explore the diagnostic efficacy and clinical impact of the ddPCR assay in patients with suspected sepsis, taking advantage of both RCT’s ability to establish causality and the feasibility of pragmatic approaches in real-world studies (RWS). This trial will help us to get a comprehensive view of the assay’s capacity for precise diagnosis and treatment of sepsis. It has the potential to monitor the pathogen load change and to guide the antimicrobial therapy, making a beneficial impact on the prognosis of sepsis patients. Trial registration: ClinicalTrial.gov, NCT05190861. Registered January 13, 2022—‘Retrospectively registered’, https://clinicaltrials.gov/ct2/show/NCT05190861