A METHOD EXTRACTING TRANSIENT SIGNAL OF ROLLING BEARING BASED ON AUDITORY MODEL AND PROBABILITY OF EXTREME POINTS

One of the most important characteristics of rolling bearing fault is that the fault components will induce the shock response of vibration. Aiming at the modulation characteristics of roller bearing fault vibration signals and the complex of traditional analysis method,the paper puts forward a rolling bearing fault feature extraction method based on extreme point probability density and auditory model. The method firstly conduct band-pass filtering with Gammatone filters,phase adjustment and extreme points extraction for signals,and then calculate the amplitude probabilitydensity of extreme points,Judging whether there is a transient impact composition by its derivation in filtered signals,then extractrelated extreme points to get the transient componentsat last. Considering the modulation characteristic of the vibration signal. The amplitude of impact is different over time. Sectional processing of the signal can extract the impact component that may be ignored because the amplitude is small.The method is applied to analysis the vibration signal of a certain type of wire cutting machine ’s rolling bearing. The experimental results show that this method can effectively extract the transient components from the rolling bearing fault signal

Synthesis of High Specific Surface Lithium-Ion Sieve Templated by Bacterial Cellulose for Selective Adsorption of Li⁺

In recent years, with the development of batteries, ceramics, glass and other industries, the demand for lithium has increased rapidly. Due to the rich lithium resources in seawater and salt-lake brine, the question of how to selectively adsorb and separate lithium ions from such brine has attracted the attention and research of many scholars. The Li-ion sieve stands out from other methods thanks to its excellent special adsorption and separation performance. In this paper, mesoporous titanium dioxide and lithium hydroxide were prepared by hydrothermal reaction using bacterial cellulose as a biological template. After calcination at 600 °C, spinel lithium titanium oxide Li2TiO3 was formed. The precursor was eluted with HCl eluent to obtain H2TiO3. The lithium titanate were characterized by IR, SEM and X-ray diffraction. The adsorption properties of H2TiO3 were studied by adsorption pH, adsorption kinetics, adsorption isotherm and competitive adsorption. The results show that H2TiO3 has a single-layer chemical adsorption process, and has a good adsorption effect on lithium ions at pH 11.0, with a maximum adsorption capacity of 35.45 mg g−1. The lithium-ion sieve can selectively adsorb Li+, and its partition coefficient is 2242.548 mL g−1. It can be predicted that the lithium-ion sieve prepared by biological template will have broad application prospects

Antioxidant Activity and Anti-Apoptotic Effect of the Small Molecule Procyanidin B1 in Early Mouse Embryonic Development Produced by Somatic Cell Nuclear Transfer

As an antioxidant, procyanidin B1(PB1) can improve the development of somatic cell nuclear transfer (SCNT) embryos; PB1 reduces the level of oxidative stress (OS) during the in vitro development of SCNT embryos by decreasing the level of reactive oxygen species (ROS) and increasing the level of glutathione (GSH) and mitochondrial membrane potential (MMP). Metabolite hydrogen peroxide (H2O2) produces OS. Catalase (CAT) can degrade hydrogen peroxide so that it produces less toxic water (H2O) and oxygen (O2) in order to reduce the harm caused by H2O2. Therefore, we tested the CAT level in the in vitro development of SCNT embryos; it was found that PB1 can increase the expression of CAT, indicating that PB1 can offset the harm caused by oxidative stress by increasing the level of CAT. Moreover, if H2O2 accumulates excessively, it produces radical-(HO-) through Fe2+/3+ and damage to DNA. The damage caused to the DNA is mainly repaired by the protein encoded by the DNA damage repair gene. Therefore, we tested the expression of the DNA damage repair gene, OGG1. It was found that PB1 can increase the expression of OGG1 and increase the expression of protein. Through the above test, we proved that PB1 can improve the repairability of DNA damage. DNA damage can lead to cell apoptosis; therefore, we also tested the level of apoptosis of blastocysts, and we found that PB1 reduced the level of apoptosis. In summary, our results show that PB1 reduces the accumulation of H2O2 by decreasing the level of OS during the in vitro development of SCNT embryos and improves the repairability of DNA damage to reduce cell apoptosis. Our results have important significance for the improvement of the development of SCNT embryos in vitro and provide important reference significance for diseases that can be treated using SCNT technology

Very High Efficiency Orange-Red Light-Emitting Devices with Low Roll-Off at High Luminance Based on an Ideal Host-Guest System Consisting of Two Novel Phosphorescent Iridium Complexes with Bipolar Transport

Two phosphorescent iridium complexes with bipolar transporting ability, namely FPPCA (500 nm) and BZQPG (600 nm), are synthesized and employed as an ideal host-guest system for phosphorescent organic light emitting diodes (PHOLEDs).The devices give very high-efficiency orange-red emission from BZQPG with maximum external quantum efficiency (EQE or ηext) of >27% and maximum power efficiency (PE or ηp) of >75 lm/W, and maintain high levels of 26% and 55 lm/W, 25% and 40 lm/W at high luminance of 1000 and 5000 cd m−2, respectively, within a range of 8–15 wt% of BZQPG. The realization of such high and stable EL performance results from the coexistence of two parallel paths: i) effective energy transfer from host (FPPCA) to guest (BZQPG) and ii) direct exciton formation on the BZQPG emitter, which can alternately dominate the electrophosphorescent emission. This all-phosphor doping system removes the charge-injection barrier from the charge-transport process to the emissive layer (EML) due to the inherent narrow Eg of both phosphors. Therefore, this ideal host–guest system represents a new design to produce PHOLEDs with high efficiency and low efficiency roll-off using a simple device configuration

Expression of Pinellia pedatisecta Agglutinin PPA Gene in Transgenic Sugarcane Led to Stomata Patterning Change and Resistance to Sugarcane Woolly Aphid, Ceratovacuna lanigera Zehntner

The sugarcane woolly aphid is one of the main pests of sugarcane worldwide. The Pinellia pedatisecta agglutinin (PPA) gene has been demonstrated to function towards aphid resistance in other crops. In our study, in order to investigate the PPA function towards aphid control in sugarcane and its underlying mechanism, the PPA gene was overexpressed in a sugarcane Zhongzhe 1 (ZZ1) cultivar in independent transgenic sugarcane lines. It was confirmed in this study that PPA transgenic sugarcane can resist aphids via detecting the aphids’ development and tracing the survival number on PPA−transgenic sugarcane lines as well as PPA negative control lines. The mechanism of PPA lectin−associated defense against aphids was preliminarily explored. Stomatal patterning differences of sugarcane leaves between PPA−transgenic sugarcane lines and negative control lines were found. PPA overexpression led to an increase in stomata number and a decrease in stomata size that might have changed the transpiration status, which is critical for aphids’ passive feeding. Moreover, the antioxidant enzyme, sugar, tannin and chlorophyll content in sugarcane leaves before and after aphid infestation was determined. The results indicated that PPA overexpression in sugarcane resulted in an increase in antioxidant enzyme activity and tannin content, as well as a reduction in the decline of certain sugars. These together may improve sugarcane resistance against the sugarcane woolly aphid

Mineralogical and isotopic characterization of graphite deposits in the western part of the North Qaidam Orogen and East Kunlun Orogen, northeast Tibetan Plateau, China

Medium to high-grade metamorphic rocks comprising numerous graphite deposits are widely distributed in the periphery of the Qaidam Basin, Northern Tibetan Plateau, China. We present textural, XRD, and Raman spectroscopy characteristics of graphite, δ¹³C results of graphite and cogenetic calcite, and δ¹⁸O results of calcite in three graphite occurrences located at the periphery of Qaidam Basin. Graphite displays hexagonal platy, flaky, irregular polygonal, ovate morphologies with occasional spherulitic textures. Graphite morphologies, combined with XRD and Raman spectroscopy, indicate that graphite has relatively high crystallinity. Raman microspectroscopy of graphite shows that peak metamorphic temperatures vary between 690 and 801 ◦C. Graphite δ¹³CV-PDB values range between –26.3 and –21.6‰, indicating organic carbon as the major carbon source for graphite. Calcite δ¹³CV-PDB and calcite δ¹⁸OV-SMOW values range between –10.8 and +3.9‰, and between +6.6 and +29.5‰, respectively. Calcite δ¹³CV-PDB results show that organic carbon was mixed with inorganic carbon, which resulted in an increase of δ¹³CV-PDB. Calcite δ¹⁸OV-SMOW values indicate that the graphite deposits experienced late-stage water–rock interaction. The positive and negative anomalies of calcite δ¹³CV-PDB indicate that organic matter oxidation and recycling locally occurred during the final stage of the Great Oxidation Event. The wide distribution of regional metamorphic organogenic graphite deposits provides evidence for large-scale Paleoproterozoic biological activity in the periphery of the Qaidam Basin

Boosting the Efficiency and Stability of Blue TADF Emitters by Deuteration

Deep-blue organic light-emitting diodes (OLEDs) with both high efficiency and stability remain exclusive in scientific literatures after decades of research. A key reason is the chemical bond dissociation through conical intersections between potential energy surfaces (PESs) of energetically-hot excited states and dissociative states. Here, we report a deuteration strategy to stabilize blue thermally activated delayed fluorescence (TADF) emitters. It is unveiled that deuteration would lower high-frequency vibrations to create shallower PESs in both ground and excited states, energetically retarding the cross of the conical intersection point in dissociative process and alleviate vibrational coupling to eliminate nonradiative decay. With a deuterated blue TADF compound, namely 2,3,4,5,6-pentakis(9H-carbazol-9-yl-d8) benzonitrile, as the sensitizer, a deep-blue OLED simultaneously achieves a peak external quantum efficiency of 30.3%, a Commission Internationale de L’Eclairage coordinate y value (CIEy) of 0.17, and a superb LT80 (time to 80% of initial luminance) of 227 h at 1000 cd/m2. And a blue OLED with a CIEy~0.19 shows an even longer LT80 of 456 h at 1000 cd/m2

Beating the Limitation of Energy Gap Law Utilizing Deep Red MR-TADF Emitter with Narrow Energy-Bandwidth

The development of high-performance deep red/near-infrared organic light-emitting diodes is hindered by strong non-radiative processes as governed by the energy gap law. Herein, a novel BN-containing skeleton featuring linear N-π-N and B-π-B structure is developed, establishing partial bonding/antibonding character on phenyl core for enhanced electronics coupling of para-positioned B atoms as well as N atoms to narrow energy gaps. Also, the remained MR effect on the peripheral skeleton to maintain the MR effect to minimize the bonding/ antibonding character and suppress vibrational coupling between S0 and S1, thereby fundamentally overcoming the luminescent boundary set by the energy gap law. The target molecules R-BN and R-TBN exhibited extremely high PLQYs of 100% with emission wavelengths at 666 and 686 nm, respectively. The narrow FWMHs of 38 nm observed also testify the effectiveness of vibronic suppression. The corresponding OLEDs afford record-high EQEs over 28% with emission wavelength over 664 nm. </p