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Forming the transverse inner rib of a curved generatrix part through power spinning

Advances in Manufacturing 2019年第1期7卷 105-115页

作者： Hong-Rui Zhang Mei Zhan Jing Guo Xian-Xian Wang peng-fei gao fei Ma State Key Laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 People's Republic of China Shaanxi Key Laboratory of High-Performance Precision Forming Technology and Equipment School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 People's Republic of China Long March Machinery Factory China Aerospace Science and Technology Corporation Chengdu 610100 People's Republic of China

How to form high-quality transverse inner ribs through power spinning is a key issue for complicated integrated curved generatrix parts with transverse inner ribs. In this study, the forming characteristics and laws during the power spinning process were investigated using a finite element simulation based on the orthogonal design method. The results show that the transverse inner rib distributes homogeneously along the circumferential direction but inhomogeneously along the generatrix direction. Depressions occur easily in the middle zone of the rib (MZR). The roller nose radius is the most significant parameter of the MZR underfill degree. A larger roller nose radius is helpful to decrease the MZR underfill degree. Furthermore, the preformed billet thickness also plays a vital role in the underfill degree of the front zone of the rib and the back zone of the rib, as well as the depression degree of the outer surface of the rib. By combining the ribfilling characteristics and laws, the optimized forming process window for obtaining high-quality inner ribs was obtained by regression analysis, thus laying a basis for improving the forming quality of curved generatrix parts with transverse inner ribs in power spinning.

关键词： Power spinning Transverse inner rib Rib filling Process optimization

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Constitutive modeling of compression behavior of TC4 tube based on modified Arrhenius and artificial neural network models

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Rare Metals 2016年第2期35卷 162-171页

作者： Zhi-Jun Tao He Yang Heng Li Jun Ma peng-fei gao State Key Laboratory of Solidification Processing School of Materials Science and Engineering Northwestern Polytechnical University

Warm rotary draw bending provides a feasible method to form the large-diameter thin-walled（LDTW）TC4 bent tubes, which are widely used in the pneumatic system of aircrafts. An accurate prediction of flow behavior of TC4 tubes considering the couple effects of temperature,strain rate and strain is critical for understanding the deformation behavior of metals and optimizing the processing parameters in warm rotary draw bending of TC4 tubes. In this study, isothermal compression tests of TC4 tube alloy were performed from 573 to 873 K with an interval of 100 K and strain rates of 0.001, 0.010 and0.100 s^（-1）. The prediction of flow behavior was done using two constitutive models, namely modified Arrhenius model and artificial neural network（ANN） model. The predictions of these constitutive models were compared using statistical measures like correlation coefficient（R）, average absolute relative error（AARE） and its variation with the deformation parameters（temperature, strain rate and strain）. Analysis of statistical measures reveals that the two models show high predicted accuracy in terms of R and AARE. Comparatively speaking, the ANN model presents higher predicted accuracy than the modified Arrhenius model. In addition, the predicted accuracy of ANN model presents high stability at the whole deformation parameter ranges, whereas the predictability of the modified Arrhenius model has some fluctuation at different deformation conditions. It presents higher predicted accuracy at temperatures of 573-773 K, strain rates of 0.010-0.100 s^（-1）and strain of 0.04-0.32, while low accuracy at temperature of 873 K, strain rates of 0.001 s^（-1）and strain of ***, the application of modified Arrhenius model is limited by its relatively low predicted accuracy at some deformation conditions, while the ANN model presents very high predicted accuracy at all deformation conditions,which can be used to study the compression behavior of TC4 tube at the temperature range of 573-

关键词： TC4 tube Compression behavior Constitutive model Modified Arrhenius model Neural network model

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Effect of vanadium on hydrogen embrittlement susceptibility of high-strength hot-stamped steel

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Journal of Iron and Steel Research International 2021年第2期28卷 211-222页

作者： Wei-jian Chen peng-fei gao Shuai Wang Hong-zhou Lu Zheng-zhi Zhao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology University of Science and Technology BeijingBeijing 100083China CITIC Metal Co. Ltd.Beijing 100004China

Based on the chemical composition of traditional hot-stamped steel(e.g.,22MnB5 and 30MnB5),Nb and V microalloying elements are added into 30MnB5 steel to meet the requirements of ultra-high strength,excellent ductility and potent resistance to hydrogen embrittlement(HE)at the same *** influence of hot-stamped steel on HE was studied by conducting a hydrogen permeation method and pre-charged hydrogen slow strain rate ***,the experimental steel microstructures and corresponding fracture surfaces are observed and analyzed to characterize HE *** results show that a finer microstructure,a lower apparent diffusion coefficient of hydrogen and a smaller percentage of strength and plasticity reduction are obtained due to the addition of the vanadium element into hot-stamped *** to the V free experimental steel,the steel with 0.14 wt.% V has a large number of dispersive precipitates and more grain boundary areas,which makes hydrogen atoms dispersedly distribute.

关键词： Hot-stamped steel Vanadium Hydrogen embrittlement Hydrogen permeation test Slow strain rate test Microstructure

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Prediction and evaluation of optimum quenching temperature and microstructure in a 1300 MPa ultra-high-strength Q&P steel

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Journal of Iron and Steel Research International 2022年第2期29卷 307-315页

作者： peng-fei gao Ju-hua Liang Wei-jian Chen Feng Li Zheng-zhi Zhao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation Beijing100083China Key Laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of SciencesHefei230031AnhuiChina

The quenching and partitioning steel is the representative of the third generation of advanced high-strength *** effect of quenching temperature on the microstructure and mechanical property of ferrite-containing quenching and partitioning steel was studied by intercritical annealing quenching and partitioning *** preparing a test steel with a tensile strength of 1300 MPa and total elongation of 19%,it is found that the actual optimum quenching temperature was lower than that calculated according to the constrained carbon *** results indicate that the martensite start temperature of the austenite was overestimated when considering the diffusion of carbon *** grain size which is affected by low temperature and the existence of ferrite during intercritical annealing influenced the optimum quenching temperature.A scheme considering the diffusion of various alloying elements and austenite grain size was proposed and *** this scheme,the optimum quenching temperature of intercritically annealed quenching and partitioning steel with complex microstructures was well predicted.

关键词： Quenching and partitioning Constrained carbon equilibrium Retained austenite Martensite start temperature Plasticity Quenching temperature

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Phase fraction evolution in hot working of a two-phase titanium alloy： experiment and modeling

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Rare Metals 2017年第10期36卷 769-779页

作者： Xiao-Guang Fan Huo-Jun Zheng peng-fei gao Mei Zhan Wen-Jia Mei School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 China State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072 China

In the present work, the coupled effects of initial structure and processing parameters on microstructure of a two-phase titanium alloy were investigated to predict the microstructural evolution in multiple hot working. It is found that microstructure with different constituent phases can be obtained by regulating the initial structure and hot working conditions. The variation of deformation degree and cooling rate can change the morphology of the con- stituent phases, but do not alter the phase fraction. The phase transformation during heating and holding determi- nes the phase fraction for a certain initial structure. ^--at-~3 transformation occurs during heating and holding. [3 to ct transformation leads to a significant increase in content and size of lamellar ~. The ct to [3 transformation occurs simultaneously in equiaxed at and lamellar ct. The thickness of lamellar ~t increases with temperature, which is caused by the vanishing of fine a lamellae due to phase transformation and coarsening by termination migration. By assuming a quasi-equilibrium phase transformation in heating and holding, a modeling approach is proposed for predicting microstructural evolution. The three stages of phase transformation are modeled separately and combined to predict the variation of phase fraction with temperature. Model predictions agree well with the experimental results.

关键词： Titanium alloy Hot working Microstructure Modeling

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AuNPs/graphene Hybrids-Based Enzyme-Free Plasmonic Immunoassay for Respiratory Syncytial Virus Detection

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Journal of Analysis and Testing 2021年第3期5卷 203-209页

作者： Lei Zhan Chun-Mei Li peng-fei gao Cheng-Zhi Huang Key Laboratory of Luminescence Analysis and Molecular Sensing(Southwest University) Ministry of EducationCollege of Pharmaceutical SciencesSouthwest UniversityChongqing 400715China

Accurate diagnosis of early infections caused by the viral pathogen is a major challenge because patients usually have nonspecific *** development of sensitive,reliable,robust,and rapid laboratory tools is still in high ***,we developed an extremely sensitive and affordable plasmonic immunoassay for respiratory syncytial virus(RSV)detection with the naked eye based on gold nanoparticles(AuNPs)/graphene hybrids combined with metal enhancement *** limit of detection was found to be 1.7 fg/mL,which was 100 times higher than that of the AuNPs-based *** ultrahigh sensitivity could be attributed to the large number of well-dispersed AuNPs deposited on the graphene surface,which had an extremely high relative surface *** signal amplification was achieved by catalytic enlargement of AuNPs with HAuCl_(4)-NH_(2)OH redox ***,the plasmonic immunoassay was successfully used to detect RSV in artificial serum samples,showing great potential in practical applications.

关键词： AuNPs/graphene hybrids Plasmonic immunoassay Signal amplification Respiratory syncytial virus

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Plasmonic locator with sub-diffraction-limited resolution for continuously accurate positioning

Aggregate

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Aggregate 2022年第2期3卷 154-161页

作者： peng fei gao Hong Yan Zou Ming Xuan gao Yuan Fang Li Cheng Zhi Huang Key Laboratory of Luminescence Analysis and Molecular Sensing(Southwest University) Ministry of EducationCollege of Pharmaceutical SciencesSouthwest UniversityChongqing 400715China College of Chemistry and Chemical Engineering Southwest UniversityChongqing 400715China

Both the accurate distance measurement and positioning information at the nanoscale are important for the analysis of micro/nano *** ruler has been an indispensable optical tool to detect the chemical and biological dynamic processes via distance-dependent plasmon coupling in the nearly aggregated *** it cannot disclose the detailed and accurate information of positions and dynamic movements of its two plasmonic components owing to the inherent diffraction ***,a plasmonic locator is presented which consists of a heterotypic pair of red/blue plasmonic components with significant wavelength difference(∼150 nm).Attributed to the detuned energy(∼0.64 eV)of the two components,the plasmonic locator has the ability of sub-diffraction-limited resolution(center to center,30 nm)and accurate positioning under conventional dark-field microscopy,making the relative dynamic information of nearby red/blue components be recorded accurately at video *** an important complement to the current aggregate science and technology of plasmonics,this newly developed plasmonic locator presents a facile means to realize super-resolution imaging,accurate positioning,and continuous tracing in chemical and biological interactions at the single-molecule level.

关键词： accurate positioning dark-field microscopy image reconstruction plasmonic locator sub-diffractionlimited resolution

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Molecular Thermal Motion Modulated Room-Temperature Phosphorescence for Multilevel Encryption

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Research 2022年第4期2022卷 597-607页

作者： Jiaqiang Zhao Guojuan Yan Wei Wang Shishi Shao Binfang Yuan Yan Jie Li Xuepeng Zhang Cheng Zhi Huang peng fei gao Key Laboratory of Luminescence Analysis and Molecular Sensing(Southwest University) Ministry of EducationCollege of Pharmaceutical SciencesSouthwest UniversityChongqing 400715China Chongqing Key Laboratory of Inorganic Special Functional Materials Collge of Chemistry and Chemical EngineeringYangtze Normal UniversityFulingChongqing 408100China Hefei National Laboratory for Physical Science at the Microscale University of Science and Technology of China96 Jinzhai RdHefeiAnhui 230026China

The stimulus-responsive room-temperature phosphorescence(RTP)materials have become an increasingly significant topic in the fields of bioimaging,sensing,and ***,this kind of materials is scarce to date,especially for the ones with delicate stimulus-responsive ***,a universal strategy for multilevel thermal erasure of RTP via chromatographic separation of host-guest doping RTP systems is *** tunable host-guest systems,matrix materials,heating temperature,and time are demonstrated to allow precise six-level data encryption,QR code encryption,and thermochromic phosphorescence *** study reveals that the thermal-responsive property might be attributed to molecular thermal motion and the separation effect of the silica gel,which provides expanded applications of host-guest RTP materials such as cold chain break *** work offers a simple yet universal way to construct advanced responsive RTP materials.

关键词： RTP separation precise

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Effect of Cr and isothermal holding temperature on microstructure and properties of complex phase steel with high formability(CH steel)

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Journal of Iron and Steel Research International 2023年第2期30卷 328-337页

作者： Xiao-hong Chu peng-fei gao Wei-jian Chen Feng Li Tao Kang Yan Zhao Xian-dong Yin Zheng-zhi Zhao Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing100083China Beijing Laboratory for Modern Transportation Advanced Metal Materials and Processing Technology University of Science and Technology BeijingBeijing100083China Technical Center Shougang Jingtang United Iron and Steel Co.Ltd.Tangshan063200HebeiChina

The effects of Cr contents(0.3 and 1.0 wt.%)and isothermal holding temperatures(400,440,and 480℃)on the microstructure evolution and properties of complex phase steel with high formability(CH steel)were investigated using dilatometry,scanning electron microscopy,transmission electron microscopy(TEM),and X-ray *** results show that the microstructures of CH steel with 0.3 wt.%Cr are ferrite,granular bainite,martensite,and retained austenite,while no ferrite is observed in the microstructure of CH steel with 1.0 wt.%Cr in the same *** promotes the precipitation of(Nb,Ti)C in the high-temperature austenite region through theoretical calculations and TEM *** retards the bainite transformation and refines the grain size of CH ***,as isothermal holding temperature increases from 400 to 480℃,the bainite and retained austenite fractions of two CH steels decrease,while the martensite fraction increases in the steels after final ***,the strength has an increasing tendency and the total elongation has a decreasing tendency with increasing isothermal temperature.

关键词： Complex phase steel High formability steel CH steel Cr Isothermal holding temperature Microstructure Mechanical property

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Application of remimazolam transversus abdominis plane block in gastrointestinal tumor surgery

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World Journal of Gastrointestinal Oncology 2023年第12期15卷 2101-2110页

作者： Jun Liu Jian-Min Tian Guo-Ze Liu Jun-Na Sun peng-fei gao Yong-Qiang Zhang Xiu-Qin Yue Department of Anesthesiology and Perioperative Medicine The First Affiliated Hospital of Xinxiang Medical UniversityWeihui 453100Henan ProvinceChina

BACKGROUND Transversus abdominis plane block(TAPB)is a block of the abdominal afferent nerve fibers between the internal oblique muscle and the transverse abdominal muscle achieved with local *** can effectively block the conduction of the anterior nerve of the abdominal wall and exert a good analgesic ***,the effect of combining the block with remimazolam on anesthesia in patients undergoing gastrointestinal tumor surgery is still *** To examine the effects of combining TAPB with remimazolam on the stress response and postoperative recovery of gastrointestinal tumor surgery *** A retrospective analysis was conducted on the clinical data of 102 individuals diagnosed with gastrointestinal malignancies who underwent laparoscopic surgery under general anesthesia between April 2020 and June *** patients were categorized into a control group(n=51),receiving remimazolam for general anesthesia,and an observation group(n=51),receiving TAPB combined with remimazolam for general anesthesia.A comparison was made between both groups in terms of hemodynamic parameters,stress markers,pain levels,recovery quality,analgesic effects,and adverse reactions during the perioperative *** The observation group had significantly higher heart rates at time points 1 min after induction and upon leaving the operating room than the control group(P<0.05).The mean arterial pressure at time point T1 in the observation group was significantly higher than that in the control group(P<0.05).Five minutes after extubation,the levels of the hormones adrenaline and noradrenaline in the observation group were considerably lower than those in the control group(P<0.05).At 12 h,24 h,and 48 h following surgery,the visual analog scale scores of the observation group were considerably lower than those of the control group(P<0.05).The observation group had shorter awakening and extubation times and lower Riker sedation-agitation scale scores than the con

关键词： Transversus abdominis plane block Remimazolam General anesthesia Gastrointestinal tumor surgery Stress response

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