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A comprehensive research on wear resistance of GH4169 superalloy in longitudinal-torsional ultrasonic vibration side milling with tool wear and surface quality

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Chinese Journal of Aeronautics 2024年第4期37卷 556-573页

作者： Baoqi chang Zhaoxi yi Fen ZHANG Lian DUAN Ji-an DUAN School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China State Key Laboratory of High Performance and Complex Manufacturing Central South UniversityChangsha 410083China School of Physics and Electronics Central South UniversityChangsha 410083China

To improve the service and machining performance of the workpiece, the tool wear mechanisms, surface machining quality, and wear resistance in conventional side milling(CSM)and longitudinal-torsional ultrasonic vibration side milling(LTUVSM) of GH4169 superalloy at different cutting lengths are investigated systematically. Tool wear mechanisms are revealed and the correlation between machined surface quality with tool wear is analyzed correspondingly. Tool wear patterns mainly include adhesive wear, diffusion wear, abrasive wear, and chipping *** surface quality is achieved in LTUVSM due to a maximum reduction of flank wear bandwidth and wear rate by 71.9% and 71.5%, respectively, compared to CSM. The friction coefficient,initial wear stage time, and wear volume of dry sliding wear were measured to evaluate the workpiece wear resistance. The maximum reductions in friction coefficient and wear volume in LTUVSM are 18.2% and 15.8% compared to CSM. The regular ultrasonic vibration textures suppress the friction and the growth of contact nodes in the contact area, decreasing the degree of surface wear, which is demonstrated by a 38.8% increase in initial wear stage time compared to *** conclusion, the workpiece in LTUVSM exhibits higher wear resistance because of the improvement of tool wear and the guarantee of surface quality.

关键词： Dry sliding wear Surface quality Tool wear Ultrasonic vibration Wear resistance

Mathematical Model,Numerical Simulation and Convergence Analysis of a Semiconductor Device Problem with Heat and Magnetic Influences

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 302-319页

作者： chang-feng LI yi-rang YUAN Huai-ling SONG School of Economics Shandong UniversityJinan 250100China Institute of Mathematics Shandong UniversityJinan 250100China College of Mathematics and Econometrics Hunan UniversityChangsha 410082China

In this paper,the authors discuss a three-dimensional problem of the semiconductor device type involved its mathematical description,numerical simulation and theoretical *** important factors,heat and magnetic influences are *** mathematical model is formulated by four nonlinear partial differential equations(PDEs),determining four major physical *** influences of magnetic fields are supposed to be weak,and the strength is parallel to the *** elliptic equation is treated by a block-centered method,and the law of conservation is *** computational accuracy is improved one *** equations are convection-dominated,thus are approximated by upwind block-centered *** difference can eliminate numerical dispersion and nonphysical *** diffusion is approximated by the block-centered difference,while the convection term is treated by upwind ***,the unknowns and adjoint functions are computed at the same *** characters play important roles in numerical computations of conductor device *** the theories of priori analysis such as energy estimates,the principle of duality and mathematical inductions,an optimal estimates result is *** a composite numerical method is shown for solving this problem.

关键词： three-dimensional conductor device problem with heat and magnetic influences upwind blockcentered differences elemental conservation of mass numerical analysis

Enhancement of low-temperature toughness of Fe-Mn-C-Al alloy by rare earth Ce-modified inclusions

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Journal of Iron and Steel Research(International) 2024年第1期31卷 157-173页

作者： Guang-kai Yang chang-ling Zhuang yi-zhuang Li Chen Hu Shao-bo Li College of Materials and Metallurgy Guizhou UniversityGuiyang550025GuizhouChina Department of Mechanical Engineering University of Hong KongHong Kong999077China The State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025GuizhouChina

Fe-Mn-C-Al alloys have been recognized as promising materials for certain low-temperature applications due to their exceptional mechanical properties and ***,their limited low-temperature toughness restricts their large-scale applications in specific *** influence of trace amounts of rare earth cerium(Ce)on the low-temperature toughness of Fe-18Mn-0.6C-1.8Al alloys was *** addition of Ce effectively alters the inclu-sions in the alloy,transforming large-sized irregular inclusions into fine ellipsoidal rare earth *** leads to a significant reduction in both the proportion and average size of the inclusions,resulting in their effective dispersion throughout the matrix and improved cryogenic *** presence of Ce-containing inclusions within the matrix reduces stress concentration,thereby inhibiting microcrack formation and improving impact absorption ***-cally,the addition of rare earth Ce alters the fracture behavior of the material at room temperature and low temperature,changing from brittle cleavage fracture to a more ductile failure *** impact toughness of the Fe-Mn-C-Al alloy is significantly improved by the addition of 0.0048 wt.%Ce,particularly at-196℃where the impact toughness reaches 103.6 J/cm^(2),representing an impressive improvement of 87.3%.

关键词： Fe-Mn-C-Al alloy Rare earth Low-temperature toughness Inclusion Fracture

Host-induced silencing of MpPar6 confers Myzus persicae resistance in transgenic rape plants

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Journal of Integrative Agriculture 2024年第1期23卷 187-194页

作者： Qi Zhang Wenqin Zhan Chao Li Ling chang yi Dong Jiang Zhang State Key Laboratory of Biocatalysis and Enzyme Engineering School of Life SciencesHubei UniversityWuhan 430062China Oil Crops Research Institute Chinese Academy of Agricultural SciencesWuhan 430062China Agricultural Genomics Institute at Shenzhen Chinese Academy of Agricultural SciencesShenzhen 518000China

Plant-mediated RNA interference(RNAi)has emerged as a promising technology for insect *** green peach aphid,Myzus persicae,feeds on over 400 species of host *** napus(rape)is the second most important oilseed crop *** persicae is highly reproductive and causes severe damage to the rape plants due to its quite flexible life *** this study,we tested the RNAi effects of transgenic rape plants on *** in vitro feeding *** with artificial diets containing double-stranded RNAs(dsRNAs)targeting seven aphid genes,we identified a new gene encoding the partitioning-defective protein 6(Par6)as the most potent RNAi ***-and stage-expression analysis of Par6 suggested this gene is highly expressed in the embryo and adult stage of *** next generated transgenic rape plants expressing ds Par6 by Agrobacteriummediated transformation and obtained nine independent transgenic *** to wild-type control plants,transgenic rape lines expressing ds Par6 showed strong resistance to *** assays revealed that feeding transgenic rape plants to *** significantly decreased MpPar6 expression and survival rate and impaired ***,we showed that the resistance levels to *** are positively correlated with ds Par6 expression levels in transgenic rape *** study demonstrates that transgenic rape plants expressing ds Par6 are efficiently protected from *** with the genes involved in embryo development could be the effective RNAi targets for controlling aphids and potentially other insect pests.

关键词： oilseed rape pest control aphid double-stranded RNA RNA interference

Assessment of the triglyceride glucose index in adult patients with chronic diarrhea and constipation

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World Journal of Clinical Cases 2024年第6期12卷 1094-1103页

作者： Jing-yi Zhu Mu-Yun Liu chang Sun Department of Gastroenterology The First Affiliated Hospital of Naval Medical UniversityShanghai 200433China Department of Gastroenterology Navy No.905 HospitalNaval Medical UniversityShanghai 200433China

BACKGROUND Accumulating evidence suggests that the gut microbiome is involved in the pathogenesis of insulin resistance(IR).However,the link between two of the most prevalent bowel disorders,chronic diarrhea and constipation,and the triglyceride glucose(TyG)index,a marker of IR,has not yet been *** To investigate the potential association between TyG and the incidence of chronic diarrhea and *** This cross-sectional study enrolled 2400 participants from the National Health and Nutrition Examination Survey database from *** was used as an exposure variable,with chronic diarrhea and constipation as determined by the Bristol Stool Form Scale used as the outcome variables.A demographic investigation based on TyG quartile subgroups was *** application of multivariate logistic regression models and weighted generalized additive models revealed potential correlations between TyG,chronic diarrhea,and *** analyses were performed to examine the stability of any potential *** In the chosen sample,chronic diarrhea had a prevalence of 8.00%,while chronic constipation had a prevalence of 8.04%.In multiple logistic regression,a more prominent positive association was found between TyG and chronic diarrhea,particularly in model 1(OR=1.45;95%CI:1.17-1.79,P=0.0007)and model 2(OR=1.40;95%CI:1.12-1.76,P=0.0033).No definite association was observed between the TyG levels and chronic *** weighted generalized additive model findings suggested a more substantial positive association with chronic diarrhea when TyG was less than 9.63(OR=1.89;95%CI:1.05-3.41,P=0.0344),and another positive association with chronic constipation when it was greater than 8.2(OR=1.74;95%CI:1.02-2.95,P=0.0415).The results of the subgroup analyses further strengthen the extrapolation of these results to a wide range of *** Higher TyG levels were positively associated with abnormal bowel health.

关键词： Triglyceride glucose index National Health and Nutrition Examination Survey Chronic diarrhea Chronic constipation Cross-sectional study Bowel health

Self-Driven Photo-Polarized Water Molecule-Triggered Graphene-Based Photodetector

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Research 2024年第2期2023卷 273-283页

作者： Shisheng Lin chang Liu Xin Chen yi Zhang Hongtao Lin Xutao Yu Yujiao Bo Yanghua Lu College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310027P.R.China Hangzhou Gelanfeng Technology Co.Ltd Hangzhou 310051P.R.China State Key Laboratory of Modern Optical Instrumentation Zhejang UniversityHangzhou 310027P.R.China Key Laboratory of Wide Bandgap Semiconductor Materials and Devices HCSemitek CorporationYiwu 322009P.R.China Smart Materials for Architecture Research Lab Innovation Center of Yangtze River DeltaZhejiang UniversityJiaxing 314100P.R.China

Flowing water can be used as an energy source for generators,providing a major part of the energy for daily ***,water is rarely used for information or electronic ***,we present the feasibility of a polarized liquid-triggered photodetector in which polarized water is sandwiched between graphene and a *** to the polarization and depolarization processes of water molecules driven by photogenerated carriers,a photo-sensitive current can be repeatedly produced,resulting in a high-performance *** response wavelength of the photodetector can be fine-tuned as a result of the free choice of semiconductors as there is no requirement of lattice match between graphene and the *** zero voltage bias,the responsivity and specific detectivity of Gr/NaCl(0.5 M)W/N-GaN reach values of 130.7 mA/W and 2.3×10^(9)Jones under 350 nm illumination,***,using a polar liquid photodetector can successfully read the photoplethysmography signals to produce accurate oxygen blood saturation and heart *** with the commercial pulse oximetry sensor,the average errors of oxygen saturation and heart rate in the designed photoplethysmography sensor are~1.9%and~2.1%,*** study reveals that water can be used as a high-performance photodetector in informative industries.

关键词： polarization polarized saturation

Recent landscape and trends for industry-sponsored pediatric clinical trials in China from 2013 to 2022

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Pediatric Investigation 2024年第1期8卷 12-20页

作者： chang Liu yi Liu Ling Ou Yuenan Qi Jianmin Zhang Drug Clinical Trial Institution Children’s HospitalCapital Institute of PediatricsBeijingChina

Importance:Pediatric medication is a challenging issue *** trials of medications for children and implementing measures to encourage innovation for addressing unmet medical and health needs are ***:To explore the recent landscape of pediatric clinical trials of new investigational drugs conducted by pharmaceutical enterprises in China from 2013 to 2022 to provide insight into pediatric drug development in the pharmaceutical industry and regulatory policy ***:We performed a cross-sectional observational investigation of pediatric clinical trials registered from January 1,2013,to December 31,2022,on the Registration and Information Disclosure Platform for Drug Clinical Trials,the official registration platform established in 2013 for trials of new investigational drugs initiated by biopharmaceutical *** that included pediatric participants(under 18 years old)were retrieved,and their relevant characteristics were extracted and ***:In total,895 pediatric clinical trials were collected,accounting for 5.1%of the total registered clinical trials initiated prior to January 1,*** overall average annual growth rate for the number of pediatric clinical trials was 12%(P<0.001).Phase III trials accounted for the highest proportion(49.1%,439).Of the 895 trials included,736(82.2%)were domestic trials,and 159(17.8%)were international multicenter *** terms of tested drugs,investigations of biological products accounted for the largest proportion of trials(67.4%,603).Among pediatric clinical trials,studies of vaccines accounted for the largest proportion of trials(41.0%,367),followed by trials for rare diseases(17.2%,154).Furthermore,geographical distribution analysis revealed that the largest and smallest numbers of trials were conducted in North China(35.7%,320)and Northeast China(0.8%,7),***:The growth trends for industry-sponsored clinical trials involving children illust

关键词： Geographic distribution Pediatric clinical trials Pediatric medication Rare disease

High glucose reduces Nrf2-dependent cRAGE release and enhances inflammasome-dependent IL-1βproduction in monocytes:the modulatory effects of EGCG

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Food Science and Human Wellness 2024年第3期13卷 1531-1542页

作者： Chi-Hao Wu yin-Hsuan chang Chin-Lin Hsu Sheng-yi Chen Gow-Chin Yen Graduate Programs of Nutrition Science School of Life ScienceTaiwan Normal UniversityTaipei 106209TaiwanChina Department of Food Science and Biotechnology Chung Hsing UniversityTaichung 40227TaiwanChina School of Nutrition Chung Shan Medical UniversityTaichung 40201TaiwanChina

Soluble receptor for advanced glycation end products(sRAGE)acts as a decoy sequestering of RAGE ligands,thus preventing the activation of the ligand-RAGE axis linking human ***,the molecular mechanisms underlying sRAGE remain *** this study,THP-1 monocytes were cultured in normal glucose(NG,5.5 mmol/L)and high glucose(HG,15 mmol/L)to investigate the effects of diabetesrelevant glucose concentrations on sRAGE and interleukin-1β(IL-1β)*** modulatory effects of epigallocatechin gallate(EGCG)in response to HG challenge were also *** enhanced intracellular reactive oxygen species(ROS)generation and RAGE *** secretion of sRAGE,including esRAGE and cRAGE,was reduced under HG conditions,together with the downregulation of a disintegrin and metallopeptidase 10(ADAM10)and nuclear factor erythroid 2-related factor 2(Nrf2)nuclear ***,the HG effects were counteracted by siRAGE and exacerbated by *** immunoprecipitation results showed that Nrf2 binding to the ADAM10 promoter and HG interfered with this *** data reinforce the notion that RAGE and Nrf2 might be sRAGE-regulating *** HG conditions,the treatment of EGCG reduced ROS generation and RAGE ***-stimulated cRAGE release was likely caused by the upregulation of the Nrf2-ADAM10 *** inhibited HG-mediated NLRP3 inflammasome activation at least partly by stimulating sRAGE,thereby reducing IL-1βrelease.

关键词： Epigallocatechin gallate(EGCG) Inflammasome Nuclear factor erythroid 2-related factor 2(Nrf2) Receptor for advanced glycation end products(RAGE) Soluble RAGE(sRAGE)

Tuning interface mechanism of FeCo alloy embedded N,S-codoped carbon substrate for rechargeable Zn-air battery

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Journal of Energy Chemistry 2024年第6期93卷 400-410,I0010页

作者： Hui chang Lulu Zhao Shan Zhao Zong-Lin Liu Peng-Fei Wang ying Xie Ting-Feng yi School of Materials Science and Engineering Northeastern UniversityShenyang 110819LiaoningChina Key Laboratory of Functional Inorganic Material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080HeilongjiangChina Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province School of Resources and MaterialsNortheastern University at QinhuangdaoQinhuangdao 066004HebeiChina

The interface mechanism between catalyst and carbon substrate has been the focus of *** this paper,the FeCo alloy embedded N,S co-doped carbon substrate bifunctional catalyst(FeCo/S-NC)is obtained by a simple one-step pyrolysis *** experimental results and density functional theory(DFT)calculation show that the formation of FeCo alloy is conducive to promoting electron transfer,and the introduction of S atom can enhance the interaction between FeCo alloy and carbon substrate,thus inhibiting the migration and agglomeration of particles on the surface of carbon *** FeCo/SNC catalysts show outstanding performance for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER).FeCo/S-NC shows a high half-wave potential(E_(1/2)=0.8823 V)for ORR and a low overpotential at 10 mA cm^(-2)(E_(j=10)=299 mV)for *** addition,compared with Pt/C+RuO_(2) assembled Zn-air battery(ZAB),the FeCo/S-NC assembled ZAB exhibits a larger power density(198.8 mW cm^(-2)),a higher specific capacity(786.1 mA h g_(zn)~(-1)),and ultra-stable cycle *** results confirm that the optimized composition and the interfacial interaction between catalyst and carbon substrate synergistically enhance the electrochemical performance.

关键词： FeCo alloy N S co-doped carbon DFT calculation Zn-air batteries Interfacial interaction