Review of Thermal Design of SiC Power Module for Motor Drive in Electrical Vehicle Application

In the current vehicle electric propulsion systems,the thermal design of power modules heavily relies on empirical knowledge,making it challenging to effectively optimize irregularly arranged Pinfin structures,thereby limiting their performance.This paper aims to review the underlying mechanisms of how irregularly arranged Pinfins influence the thermal characteristics of power modules and introduce collaborative thermal design with DC bus capacitor and motor.Literature considers chip size,placement,coolant flow direction with the goal of reducing thermal resistance of power modules,minimizing chip junction temperature differentials,and optimizing Pinfin layouts.In the first step,algorithms should efficiently generating numerous unique irregular Pinfin layouts to enhance optimization quality.The second step is to efficiently evaluate Pinfin layouts.Simulation accuracy and speed should be ensured to improve computational efficiency.Finally,to improve overall heat dissipation effectiveness,papers establish models for capacitors,motors,to aid collaborative Pinfin optimization.These research outcomes will provide essential support for future developments in high power density motor drive for vehicles.

A Noise Reduction Method for Multiple Signals Combining Computed Order Tracking Based on Chirplet Path Pursuit and Distributed Compressed Sensing

With the development of multi-signal monitoring technology,the research on multiple signal analysis and processing has become a hot subject.Mechanical equipment often works under variable working conditions,and the acquired vibration signals are often non-stationary and nonlinear,which are difficult to be processed by traditional analysis methods.In order to solve the noise reduction problem of multiple signals under variable speed,a COT-DCS method combining the Computed Order Tracking(COT)based on Chirplet Path Pursuit(CPP)and Distributed Compressed Sensing(DCS)is proposed.Firstly,the instantaneous frequency(IF)is extracted by CPP,and the speed is obtained by fitting.Then,the speed is used for equal angle sampling of time-domain signals,and angle-domain signals are obtained by COT without a tachometer to eliminate the nonstationarity,and the angledomain signals are compressed and reconstructed by DCS to achieve noise reduction of multiple signals.The accuracy of the CPP method is verified by simulated,experimental signals and compared with some existing IF extraction methods.The COT method also shows good signal stabilization ability through simulation and experiment.Finally,combined with the comparative test of the other two algorithms and four noise reduction effect indicators,the COT-DCS based on the CPP method combines the advantages of the two algorithms and has better noise reduction effect and stability.It is shown that this method is an effective multi-signal noise reduction method.

Spatiotemporal simulation and predication of heavy metal(loid) concentrations in coal chemical industrial areas with a soil environmental capacity model

Heavy metal (loid)(HM) accumulation in the soil and the HM spatiotemporal distribution have important implication for soil pollution prevention and remediation. The present study investigated the concentrations and spatiotemporal distributions of lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr) and arsenic (As) in the topsoil of a coal chemical plant in Ningxia Aulonomous region (Ningxia), China. Topsoil samples (/?= 153) were obtained using the checkerboard method, and the HM concentrations were determined. The soil residual rates of the five HMs were measured with leaching experinients and were applied in a soil environmental capacity model to predict the quarHitiHive variation of the HM concentrations. The predicted results were employed to estimate the HM spatiotemporal distribution within 2() years with the Kriging technique. The number of sampling sites, where all five HM concentratio ns exceed their corresponding background values in Ningxia, would be increased from 0 to 90% within 1() years of the plant operation. In addition, Pb and Cd were distributed along the traffic routes. Mercury and As were distributed near fuel gas emission vents. Chromium was mainly accumulated in slag dumps. The study may provide the theoretical and practical foun d at ion for future HM pollution control in coal chemical plants.

Sodium butyrate activates HMGCS2 to promote ketone body production through SIRT5-mediated desuccinylation

Ketone bodies have beneficial metabolic activities,and the induction of plasma ketone bodies is a health promotion strategy.Dietary supplementation of sodium butyrate(SB)is an effective approach in the induction of plasma ketone bodies.However,the cellular and molecular mechanisms are unknown.In this study,SB was found to enhance the catalytic activity of 3-hydroxy-3-methylglutaryl-CoA synthase 2(HMGCS2),a rate-limiting enzyme in ketogenesis,to promote ketone body production in hepatocytes.SB administrated by gavage or intraperitoneal injection significantly induced bloodβ-hydroxybutyrate(BHB)in mice.BHB production was induced in the primary hepatocytes by SB.Protein succinylation was altered by SB in the liver tissues with down-regulation in 58 proteins and up-regulation in 26 proteins in the proteomics analysis.However,the alteration was mostly observed in mitochondrial proteins with 41%down-and 65%up-regulation,respectively.Succinylation status of HMGCS2 protein was altered by a reduction at two sites(K221 and K358)without a change in the protein level.The SB effect was significantly reduced by a SIRT5 inhibitor and in Sirt5-KO mice.The data suggests that SB activated HMGCS2 through SIRT5-mediated desuccinylation for ketone body production by the liver.The effect was not associated with an elevation in NAD+/NADH ratio according to our metabolomics analysis.The data provide a novel molecular mechanism for SB activity in the induction of ketone body production.

Whole-brain patterns of the presynaptic inputs and axonal projections of BDNF neurons in the paraventricular nucleus

Brain-derived neurotrophic factor (BDNF) plays a crucial role in human obesity. Yet, the neural circuitry supporting the BDNF-mediated control of energy homeostasis remains largely undefined. To map key regions that might provide inputs to or receive inputs from the paraventricular nucleus (PVN) BDNF neurons, a key type of cells in regulating feeding and thermogenesis, we used rabies virus-based transsynaptic labeling and adeno-associated virus based anterograde tracing techniques to reveal their whole-brain distributions. We found that dozens of brain regions provide dense inputs to or receive dense inputs from PVN BDNF neurons, including several known weight control regions and several novel regions that might be functionally important for the BDNF-mediated regulation of energy homeostasis.Interestingly, several regions show very dense reciprocal connections with PVN BDNF neurons, including the lateral septum, the preoptic area, the ventromedial hypothalamic nucleus, the paraventricular thalamic nucleus, the zona incerta, the lateral parabrachial nucleus, the subiculum, the raphe magnus nucleus, and the raphe pallidus nucleus. These strong anatomical connections might be indicative of important functional connections. Therefore, we provide an outline of potential neural circuitry mediated by PVN BDNF neurons, which might be helpful to resolve the complex obesity network.

NF-κB regulates brown adipocyte function through suppression of ANT2

The transcription factor nuclear factor of kappa-light-chain-enhancer of activated B cells(NF-κB)is expressed in brown adipocytes,but its role remains largely unknown in the cells.This issue was addressed in current study by examining NF-κB in brown adipocytes in vitro and in vivo.NF-κB activity was increased by differentiation of brown adipocytes through elevation of p65(RelA)expression.The transcriptional activity of NF-κB was induced by the cold stimulation with an elevation in S276 phosphorylation of p65 protein.Inactivation of NF-κB in brown adipocytes made the knockout mice[uncoupling protein 1(Ucp1)-CreER-p65^(f/f),U-p65-KO]intolerant to the cold environment.The brown adipocytes exhibited an increase in apoptosis,a decrease in cristae density and uncoupling activity in the interscapular brown adipose tissue(iBAT)of p65-KO mice.The alterations became severer after cold exposure of the KO mice.The brown adipocytes of mice with NF-κB activation(p65 overexpression,p65-OE)exhibited a set of opposite alterations with a reduction in apoptosis,an increase in cristae density and uncoupling activity.In mechanism,NF-κB inhibited expression of the adenine nucleotide translocase 2(ANT2)in the control of apoptosis.Data suggest that NF-κB activity is increased in brown adipocytes by differentiation and cold stimulation to protect the cells from apoptosis through down-regulation of ANT2 expression.

Mechanism regulating the inhibition of lung cancer A549 cell proliferation and structural analysis of the polysaccharide Lycium barbarum

The water-soluble polysaccharide LBP-1 was isolated and characterized from Lycium barbarum L.LBP-1 was mainly composed of arabinose,galactose,glucose,xylose,mannose at a molar ratio of 37.53:28.08:14.72:7.83:4.50,respectively.Based on nuclear magnetic resonance(NMR)and methylation analysis,the backbone of LBP-1 was speculated in theα-L-Ara(1→[5-α-L-Ara(1→3)-β-D-Galp-(1→]n→4)-α-D-Galp-(1[→5-α-L-Ara(1]n[→6)-β-D-Galp-(1→4)-β-D-Galp-(1→]n,and the side chains of LBP-1 were in theα-L-Ara(1→3)-β-D-Galp-(1→6 position.These results showed that LBP-1 inhibited the growth of cancer A549 cells through cell cycle arrest and apoptosis,with an IC50 value of 42.5μg/mL.In addition,LBP-1 altered the expression of Cyclin D1,Cyclin D3,and CDK 2,thus blocking the cell cycle in G0/G1 phase,reducing cell migration,and regulating the PI3K/Akt/mTOR signaling pathway to induce apoptosis.

A photocalibrated NO donor based on N-nitrosorhodamine 6G upon UV irradiation

A photocalibrated NO donor, N-nitrosated rhodamine 6 G acid (NOG) was designed for monitoring the kinetics or the dose of NO release in a real-time fashion with spectroscopic methods Upon irradiation, a drastic fluorescence turn-on was observed, and the NO release from NOG was not interfered by biothiols.Furthermore, this NO donor enabled time-and site-controlled NO release in living cells. With these merits, NOG can be a useful molecular tool in NO biology.