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Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

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Journal of Iron and Steel Research International 2024年第4期31卷 894-908页

作者： Yan-li Xin zhi-ying Gao Bo Tian Qing-dong Zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China

In the high-speed cold tandem rolling process of thin plate,chatter or slip instability gives rise to the deterioration of equipment and product *** instability behavior is closely related to interfacial friction-lubrication con-dition which is generally characterized by the friction ***,with higher and higher speed requirements,the commonly used model of friction coefficient is no longer applicable and accurate.A novel approach is suggested to calculate the speed-depen.ent friction coefficient,in which the viscosity-pressure-temperature effects of the lubricant,surface roughness states of work rolls and rolled piece are comprehensively involved and the mixed flm lubrication theory is ***,the influences of friction coefficient on the instability of slip and chatter are investigated for a five-stand cold tandem rolling *** one side,the critical friction coefficient for each stand is determined by calculating the corresponding slip factor;on the other hand,the friction coefficient varying with rolling speed is combined with the model of theoretical critical rolling speed presented under constant friction coefficient,so that the speed threshold is ***,the stable and unstable regions corresponding to the rear three stands are individually discussed,and the technical strategies are proposed to suppress both slip and chatter frequently occurring in the actual rolling process.

关键词： Cold tandem rolling:Oil film thickness Speed-depen.ent friction coefficient-Slip:Chatter

Effect of Mo and cold forging deformation on strength and ductility of cobalt-based alloy L605

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Journal of Iron and Steel Research International 2024年第7期31卷 1811-1823页

作者： Zhong-lin Wang zhi-hua Gong Quan li Han-sheng Bao School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014017Inner MongoliaChina Institute of Special Steels Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

Mo element was added to cobalt-based alloy L605,and cold forging deformation was *** effects of the addition and cold forging deformation on the microstructure and mechanical properties of the alloy were studied by thermodynamic calculation,electron backscatter diffraction,transmission electron microscopy,and X-ray *** stacking fault energy(SFE)of the alloy decreased after the addition,and the formation of stacking faults and intersections were promoted to improve the strength and *** tensile strength of the alloy with Mo increased from 1190 to 1702 MPa after 24%cold deformation,producing significant work *** strengthening mechanism is strain-induced martensitic transformation(SIMT)and deformation *** alloy,combined with Mo and after 24%deformation,had both high strength and ductility in comparison with the original cobalt-based alloy *** is attributed to the lower SFE which caused the increase in stacking fault *** the tensile process,theε-hcp phase was easily generated at the stacking fault to reduce the stress concentration and increase the *** SIMT by adjusting the density of stacking faults can improve the mechanical properties of cobalt-based ***ε-hcp phase,the interaction between deformation twins and dislocations,and the interaction between e-hcp phases during cold forging deformation caused local stress concentration,lowering ductility and toughness.

关键词： Cobalt-based alloy-Stacking fault energy Strain-induced martensitic transformation Deformation twin Cold forging deformation

Interpretation and characterization of rate of pen.tration intelligent prediction model

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Petroleum Science 2024年第1期21卷 582-596页

作者： zhi-Jun Pei Xian-zhi Song Hai-Tao Wang Yi-Qi Shi Shou-Ceng Tian Gen-Sheng li College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China State Key Laboratory of Petroleum Resources and Prospecting Beijing102249China Kunlun Digital Technology Co. Ltd.Beijing102206China

Accurate prediction of the rate of pen.tration(ROP)is significant for drilling *** the intelligent ROP prediction model based on fully connected neural networks(FNN)outperforms traditional ROP equations and machine learning algorithms,its lack of interpretability undermines its *** study proposes a novel interpretation and characterization method for the FNN ROP prediction model using the Rectified linear Unit(ReLU)activation *** leveraging the derivative of the ReLU function,the FNN function calculation process is transformed into vector *** FNN model is linearly characterized through further simplification,enabling its interpretation and *** proposed method is applied in ROP prediction scenarios using drilling data from three vertical wells in the Tarim *** results demonstrate that the FNN ROP prediction model with ReLU as the activation function performs exceptionally *** relative activation frequency curve of hidden layer neurons aids in analyzing the overfitting of the FNN ROP model and determining drilling data *** the well sections with similar drilling data,averaging the weight parameters enables linear characterization of the FNN ROP prediction model,leading to the establishment of a corresponding linear representation ***,the quantitative analysis of each feature's influence on ROP facilitates the proposal of drilling parameter optimization schemes for the current well *** established linear characterization equation exhibits high precision,strong stability,and adaptability through the application and validation across multiple well sections.

关键词： Fully connected neural network Explainable artificial intelligence Rate of pen.tration ReLU active function Deep learning Machine learning

Endoscopic band ligation or endoscopic tissue adhesive injection in the treatment of gastric varices:Which is better?

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World Journal of Gastroenterology 2024年第21期30卷 2827-2828页

作者： li-zhi Yi Sheng-Bing Zhao Department of Gastroenterology The People’s Hospital of LeshanLeshan 614000Sichuan ProvinceChina Department of Gastroenterology Changhai HospitalThe Second Military Medical University/Naval Medical UniversityShanghai 200433China

The combination of endoscopic ultrasound with endoscopic treatment of type 1 gastric variceal hemorrhage may improve the robustness and generalizability of the findings in future ***,the esophageal varices should also... 详细信息

关键词： Gastric varices Esophageal varices Endoscopic band ligation Endoscopic tissue adhesive injection Endoscopic ultrasound

Asymmetric alkenylation reaction of benzoxazinones with diarylethylenes catalyzed by B(C_(6)F_(5))_(3)/chiral phosphoric acid

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Chinese Chemical Letters 2024年第5期35卷 135-140页

作者： Zhen liu zhi-Yuan Ren Chen Yang Xiangyi Shao li Chen Xin li State Key Laboratory of Elemento-Organic Chemistry Frontiers Science Center for New Organic MatterCollege of ChemistryNankai UniversityTianjin 300071China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Zhenhai High School of Zhejiang Ningbo 315299China

Catalytic enantioselective alkenylation is an efficient method to construct chiral alkene molecules,but the asymmetric alkenylation of simple alkenes catalyzed by metal-free catalysts remains an elusive ***,we reported an asymmetric alkenylation of benzoxazinones with diarylethylenes by utilizing a B(C_(6)F_(5))_(3)/chiral phosphoric acid catalyst.A broad of benzoxazinones and diarylethylenes with electron-withdrawing and electron-donating groups were tolerated(up to 95%yield and 97.5:2.5 e.r.)in the methodology under mild reaction ***,the synthetic utility was confirmed by the scaled-up reaction and transformations of the *** mechanism was preliminarily explored by control reactions,nonlinear effect experiment and DFT calculations.

关键词： Asymmetric alkenylation Simple alkenes Benzoxazinones B(C_(6)F_(5))_(3)/chiral phosphoric acid Theoretical calculations

Paroxysmal Kinesigenic Dyskinesia:Genetics and Pathophysiological Mechanisms

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Neuroscience Bulletin 2024年第7期40卷 952-962页

作者： Jiao-Jiao Xu Hong-Fu li zhi-Ying Wu Department of Medical Genetics and Center for Rare Diseases The Second Affiliated HospitalZhejiang University School of MedicineHangzhou 310009China Department of Neurology in the Second Affiliated Hospital Key Laboratory of Medical Neurobiology of Zhejiang ProvinceZhejiang University School of MedicineHangzhou 310009China

Paroxysmal kinesigenic dyskinesia(PKD),the most common type of paroxysmal movement disorder,is characterized by sudden and brief attacks of choreoathetosis or dystonia triggered by sudden voluntary *** is mainly caused by mutations in the PRRT2 or TMEM151A *** exact pathophysiological mechanisms of PKD remain unclear,although the function of PRRT2 protein has been well characterized in the last *** on abnormal ion channels and disturbed synaptic transmission in the absence of PRRT2,PKD may be channelopathy or synaptopathy,or *** addition,the cerebellum is regarded as the key pathogenic *** depolarization in the cerebellum is tightly associated with dyskinetic ***,in PKD,other than the cerebellum,the role of the cerebrum including the cortex and thalamus needs to be further investigated.

关键词： Paroxysmal kinesigenic dyskinesia PRRT2 TMEM151A Genetics Pathophysiological mechanisms

Special Issue:Dynamic Polymer Networks

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Chinese Journal of Polymer Science 2024年第10期42卷 1401-1402页

作者： Jun-Qi Sun zhi-Bo li Tao Xie 不详

The ease of processing and light weight have made polymeric materials uniquely suited for numerous general ***,realization of their switchable chain configuration/mobility and molecular design versatility has pushed p... 详细信息

关键词： uniquely realization polymeric

Managing immune checkpoint inhibitor-associated gastritis: Insights and strategies

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World Journal of Gastroenterology 2024年第24期30卷 3120-3122页

作者： li-li Yu zhi-lin He Xin-Lai Qian Department of Pathology The Third Affiliated Hospital of Xinxiang Medical UniversityXinxiang Medical UniversityXinxiang 453003Henan ProvinceChina Department of Basic Medical Sciences Xinxiang Medical UniversityXinxiang 453003Henan ProvinceChina

Immune checkpoint inhibitors(ICIs)are widely used due to their effectiveness in treating various ***-related adverse events(irAEs)are defined as adverse effects resulting from ICI *** irAEs are a common type of irAEs characterized by intestinal side effects,such as diarrhea and colitis,which may lead to the discontinuation of ICIs.

关键词： Immunotherapy Immune checkpoint inhibitor Immune checkpoint inhibitor-related gastritis Immune-related adverse events Autoimmune responses

Metabolomic-based analysis reveals bile acid-mediated ovarian failure induced by low temperature in zebrafish

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Zoological Research 2024年第4期45卷 791-804页

作者： Wen-Hao li zhi-Qiang li Meng-Di Bu Jia-Zhen li liang-Biao Chen Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Ministry of EducationCollege of Fisheries and Life SciencesShanghai Ocean UniversityShanghai 201306China Laboratory for Marine Biology and Biotechnology Qingdao National Laboratory for Marine Science and TechnologyQingdaoShandong 266237China International Research Center for Marine Biosciences Ministry of Science and TechnologyCollege of Fisheries and Life SciencesShanghai Ocean UniversityShanghai 201306China

As ectotherms, fish are highly sensitive to temperature fluctuations, which can profoundly impact their reproductive cycles. In this study, we investigated the fertility and histological characteristics of zebrafish(Danio rerio) ovaries exposed to a temperature gradient ranging from the thermopreferendum temperature of the species,27℃, to lower temperatures of 22℃, 20℃, and 13℃ over a period of two weeks. Comparative metabolomic(six biological replicates for each temperature) and transcriptomic(four biological replicates for each temperature) analyses were conducted under the four temperature conditions. Results indicated that lower temperatures inhibited oocyte development and differential metabolites were involved in steroid hormone production,antioxidant function, and lipid and protein *** reproductive hormones, increased proteolysis,and lipid degradation significantly impeded oocyte development and egg maturation. Notably, a significant increase in bile acid content was noted in the ovaries of the cold-treated fish, indicating that bile acids play a critical role in ovarian failure. Overall, these findings provide valuable insights into the mechanisms governing the reproductive response of fish to cold stress.

关键词： old stress Ovarian failure Metabolome Zebrafish