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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by the friction ***,with higher and higher speed requirements,the commonly used model of friction coefficient is no longer applicable and accurate.A novel approach is suggested to calculate the speed-dependent friction coefficient,in which the viscosity-pressure-temperature effects of the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-dependent friction coefficient-Slip:Chatter

Effect of graphite powder as a forming filler on the mechanical properties of SiCp/Al composites by pressure infiltration

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International Journal of Minerals,Metallurgy and Materials 2016年第5期23卷 601-607页

作者： Wei Cui Hui Xu Jian-hao Chen Shu-bin Ren xin-bo he Xuan-hui Qu Institute for Advanced Materials and Technology University of Science and Technology Beijing The State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing

（38vo1% SiCp ＋ 2vo1% A1203f）/2024 A1 composites were fabricated by pressure infiltration. Graphite powder was introduced as a forming filler in preform preparation, and the effects of the powder size on the microstructures and mechanical properties of the final com- posites were investigated. The results showed that the composite with 15 μm graphite powder as a forming filler had the maximum tensile strength of 506 MPa, maximum yield strength of 489 MPa, and maximum elongation of 1.2%, which decreased to 490 MPa, 430 MPa, and 0.4%, respectively, on increasing the graphite powder size from 15 to 60 μm. The composite with 60 μm graphite powder showed the highest elastic modulus, and the value decreased from 129 to 113 GPa on decreasing the graphite powder size from 60 to 15 μm. The differences between these properties are related to the different microstructures of the corresponding composites, which determine their failure modes.

关键词： metal matrix composites aluminum silicon carbide graphite preparation pressure infiltration mechanical properties

Graphite addition for SiC formation in diamond/SiC/Si composite preparation

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1166-1176页

作者： Wei Zheng xin-bo he Mao Wu Xuan-hui Qu Rong-jun Liu Dan-dan Guan Insititute for Advanced Material and Technology University of Science & Technology BeijingBeijing 100083China College of Aerospace and Materials Engineering National University of Defence TechnologyChangsha 410073China

herein, graphite was used in the Si-vapor reactive infiltration of diamond/SiC/Si composites to produce composites with various Si C contents. X-ray diffraction was used to determine the phases of the composite, whereas scanning electron microscopy was used to confirm the Si–C reaction between the silicon, graphite, and diamond and to observe the SiC morphology. Various SiC contents in the composite were observed with graphite addition. Furthermore, the reaction between silicon and graphite(diamond) produced coarse(fine) SiC particles. The generation of a 10-μm-diameter Si–C area on the surface of the diamond was observed. The thermal conductivity(TC) and coefficient of thermal expansion(CTE) of the composite was investigated, where the TC varied from 317–426 W·m^-1·K^-1 with the increase of the SiC volume fraction from 38% to 76% and the corresponding CTE increased from 1.7 × 10^-6 to 3.7 × 10^-6 K^-1, respectively. Furthermore, a critical point for the CTE was found to exist at approximately 250℃, where the composite was under a hydrostatic condition. Finally, the bending strength was found to range from 241 to 341 MPa.

关键词： diamond SiC graphite diffusion composite

Effect of sintering on the relative density of Cr-coated diamond/Cu composites prepared by spark plasma sintering

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International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 716-722页

作者： Wei Cui Hui Xu Jian-hao Chen Shu-bin Ren xin-bo he Xuan-hui Qu Institute for Advanced Materials and Technology University of Science and Technology Beijing State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing

Cr-coated diamond/Cu composites were prepared by spark plasma sintering. The effects of sintering pressure, sintering temperature, sintering duration, and Cu powder particle size on the relative density and thermal conductivity of the composites were investigated in this paper. The influence of these parameters on the properties and microstructures of the composites was also discussed. The results show that the relative density of Cr-coated diamond/Cu reaches ~100% when the composite is gradually compressed to 30 MPa during the heating process. The densification temperature increases from 880 to 915℃ when the diamond content is increased from 45vol% to 60vol%. The densification temperature does not increase further when the content reaches 65vol%. Cu powder particles in larger size are beneficial for increasing the relative density of the composite.

关键词： metal matrix composites copper diamond relative density spark plasma sintering

A Dietary Supplement Jinghuosu Ameliorates Reproductive Damage Induced by Tripterygium Glycosides

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Chinese Journal of Integrative Medicine 2024年第4期30卷 330-338页

作者： MA Jing SUN bo TE Li-ger HUANG xin ZUO xin HAN Xiao-ke WANG Shu-song hebei Key Laboratory of Reproductive Medicine Hebei Institute of Reproductive HealthHebei Reproductive Health HospitalShijiazhuang(050071)China Graduate School of hebei Medical University Shijiazhuang(050017)China School of Chemistry and Materials Science Hebei Normal UniversityShijiazhuang(050024)China xingtai Infertility Specialist Hospital XingtaiHebei Province(054000)China

Objective To determine the possible protective effects of Jinghuosu,a dietary supplement(DS),on tripterygium glycosides(TG)-induced reproductive system injury in rats and its underlying *** A reproductive damage model was established in rats by feeding of ***-eight male Sprague Dawley rats were randomly divided into 4 groups using a random number table(n=7 in each):control(C)group,model(M)group,DS group and L-carnitine(LC)*** in M,DS and LC groups received 40 mg/kg TGs *** from the 5th week,after administration of TGs for 4 h every day,rats in DS and LC groups were administered with 2.7 g/kg DS and 0.21 g/kg LC,respectively,for protective treatment over the next 4 *** in Group C continued to receive the control ***-eosin staining was used for histopathological analysis of rat testicular ***-linked immunosorbent assay was performed to measure alkaline phosphatase(ALP),lactate dehydrogenase,alcohol dehydrogenase,total antioxidant capacity(T-AOC),superoxide dismutase,glutathione peroxidase(GSH-Px),and malondialdehyde(MDA)*** assay was used to determine the serum testosterone *** real-time PCR and Western blotting were conducted to analyze the expression of genes and proteins related to the testosterone synthesis pathway and the nuclear factor erythroid 2-related factor 2/heme oxygenase 1 antioxidant *** Oral administration of TGs induced significant increases in the testicular levels of zinc transporter 1 and MDA(Phe other hand,sperm concentration,sperm motility,and serum testosterone,serum zinc,testicular zinc,Zrt-,Irt-like protein 1,ALP,luteinizing hormone(LH)receptor,steroidogenic acute regulatory protein,Cytochrome P450 family 11 subfamily A member 1,3β-hydroxysteroid dehydrogenase 1 T-AOC,GSH-Px,nuclear factor erythroid 2-related factor 2,heme oxygenase-1 and NAD(P)H:quinone oxidoreductase 1 levels decreased following TG

关键词： dietary supplement Jinghuosu tripterygium glycosides reproductive damage infertility

Identification and effective regulation of scarb1 gene involved in pigmentation change in autotetraploid Carassius auratus

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Zoological Research 2024年第2期45卷 381-397页

作者： Xi-Dan Xu Yue Zhou Chong-Qing Wang Xu Huang Kun Zhang Xiao-Wei Xu Li-Wen he xin-Yue Zhang xin-Zhu Fu Ming Ma Qin-bo Qin Shao-Jun Liu State Key Laboratory of Developmental Biology of Freshwater Fish Engineering Research Center of Polyploid Fish Reproduction and Breeding of the State Education MinistryCollege of Life SciencesHunan Normal UniversityChangshaHunan 410081China Nansha-South China Agricultural University Fishery Research Institute GuangzhouGuangdong 511458China Hunan Yuelu Mountain Science and Technology Co.Ltd.for Aquatic Breeding ChangshaHunan 410081China College of Chemistry and Chemical Engineering Hunan Normal UniversityChangshaHunan 410081China

The autotetraploid Carassius auratus(4nRR,4n=200,RRRR)is derived from whole-genome duplication of Carassius auratus red var.(RCC,2n=100,RR).In the current study,we demonstrated that chromatophores and pigment changes directly caused the coloration and variation of 4nRR skin(red in RCC,brownish-yellow in4nRR).To further explore the molecular mechanisms underlying coloration formation and variation in 4nRR,we performed transcriptome profiling and molecular functional verification in RCC and *** revealed that scarb1,associated with carotenoid metabolism,underwent significant down-regulation in *** editing of this candidate pigment gene provided clear evidence of its significant role in RCC ***,we identified four divergent scarb1 homeologs in 4nRR:two original scarb1 homeologs from RCC and two duplicated ***,three of these homeologs possessed two highly conserved alleles,exhibiting biased and allelespecific expression in the ***,after precise editing of both the original and duplicated scarb1homeologs and/or alleles,4nRR individuals,whether singly or multiply mutated,displayed a transition from brownishyellow skin to a cyan-gray ***,the proportional areas of the cyan-gray regions displayed a gene-dose *** findings illustrate the subfunctionalization of duplicated scarb1,with all scarb1genes synergistically and equally contributing to the pigmentation of *** is the first report concerning the functional differentiation of duplicated homeologs in an autopolyploidfish,substantiallyenrichingour understanding of coloration formation and change within this group of organisms.

关键词： Autopolyploidization Coloration change scarb1 Functional differentiation Genetic changes

An adaptive physics-informed deep learning method for pore pressure prediction using seismic data

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Petroleum Science 2024年第2期21卷 885-902页

作者： xin Zhang Yun-Hu Lu Yan Jin Mian Chen bo Zhou State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum(Beijing)Beijing102249China College of Petroleum Engineering China University of Petroleum(Beijing)Beijing102249China College of Artificial Intelligence China University of Petroleum(Beijing)Beijing102249China PetroChina Tarim Oilfield Company KorlaXinjiang841000China

Accurate prediction of formation pore pressure is essential to predict fluid flow and manage hydrocarbon production in petroleum *** deep learning technique has been receiving more interest due to the great potential to deal with pore pressure ***,most of the traditional deep learning models are less efficient to address generalization *** fill this technical gap,in this work,we developed a new adaptive physics-informed deep learning model with high generalization capability to predict pore pressure values directly from seismic ***,the new model,named CGP-NN,consists of a novel parametric features extraction approach(1DCPP),a stacked multilayer gated recurrent model(multilayer GRU),and an adaptive physics-informed loss *** machine training,the developed model can automatically select the optimal physical model to constrain the results for each pore pressure *** CGP-NN model has the best generalization when the physicsrelated metricλ=0.5.A hybrid approach combining Eaton and bowers methods is also proposed to build machine-learnable labels for solving the problem of few *** validate the developed model and methodology,a case study on a complex reservoir in Tarim Basin was further performed to demonstrate the high accuracy on the pore pressure prediction of new wells along with the strong generalization *** adaptive physics-informed deep learning approach presented here has potential application in the prediction of pore pressures coupled with multiple genesis mechanisms using seismic data.

关键词： Pore pressure prediction Seismic data 1D convolution pyramid pooling Adaptive physics-informed loss function High generalization capability

Controllable Ring-opening Polymerization ofδ-Valerolactone Catalyzed by Quinolinyl-Urea/MTBD Systems

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Chinese Journal of Polymer Science 2024年第8期42卷 1103-1110页

作者： xin-Yu Liu Liang Zhu Su-Yun Jie bo-Geng Li State Key Laboratory of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058China

Due to their excellent biocompatibility and biodegradability,aliphatic polyesters are widely used in the biomedical,packaging and agricultural fields,which are usually accessed by the ring-opening polymerization(ROP)of lactones and the catalysts particularly play an important *** a series of quinolinyl-urea catalysts have been synthesized via the reaction between isocyanate and aminoquinoline with an amino group at different substitution positions and *** combination with 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene(MTBD)as a cocatalyst and benzyl alcohol(BnOH)as an initiator,1-(3,5-bis(trifluoromethyl)phenyl)-3-(quinolin-3-yl)urea(3-QU)was observed to be most active for the ROP ofδ-valerolactone(δ-VL).The polymerization conditions were optimized by varying the type of organic base,catalyst concentration and reaction *** changing the ratio of[M]_0/[I],linear polyvalerolactones(PVLs)with different molecular weights and narrow molecular weight distribution were *** kinetic and chain extension experiments were carried out to prove the"living"/controllable *** the NMR experiments were used to support the proposal of possible mechanism.

关键词： Quinolinyl-urea Ring-opening polymerization PVL

Effect of oxygen content and heat treatment on carbide precipitation behavior in PM Ni-base superalloys

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International Journal of Minerals,Metallurgy and Materials 2012年第9期19卷 827-835页

作者： heng-san Liu Lin Zhang xin-bo he Xuan-hui Qu Hong-min Zhu Guo-qing Zhang State Key Laboratory for Advanced Metals and Materials Beijing Key Laboratory for Powder Metallurgy and Particulate Materials University of Science and Tech-nology Beijing Beijing 100083 China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China National Key Lab of High Temperature Structural Materials Beijing Institute of Aeronautical Materials Beijing 100095 China

The influence of oxygen content and heat treatment on the evolution of carbides in a powder metallurgy （PM） Ni-base superalloy was characterized. The results reveal that oxygen content has little influence on the precipitation of carbides inside the particles. However, under the consolidated state, stable Ti oxides on the particle surface act as nuclei for the precipitation of prior particle boundaries （PPB）. Also, oxygen can diffuse internally along grain boundaries under compressive stress, which favors the precipitation of carbides inside the particles. Therefore, a higher amount of carbides will appear with more oxygen content in the case of consolidated alloys. It is also observed that PPB can be disrupted into discontinuous particles at 1200℃, but this carbide network is hard to be eliminated completely. The combined MC-M23C6 morphology approves the nucleation and growth mechanism of carbide evolution.

关键词： powder metallurgy nickel alloys superalloys oxygen heat treatment carbides precipitation