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Numerical simulation of fluid flow and free surface fluctuations during wheel and belt casting process

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Journal of Iron and Steel Research(International) 2024年第5期31卷 1117-1126页

作者： kun Gao Yan peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao066004HebeiChina

The unstable fluid flow and severe free surface fluctuations in the wheel and belt caster can affect the quality of the cast bar.The lower level height tends to entrap inclusions in the molten metal.On the other hand,the higher level height makes the production process more dangerous due to the overflow of high temperature fluid from the mold.A computational model of the molten metal pouring process was established.The transient fluid flow and free surface fluctuations behavior were calculated using the three-dimensional large eddy simulation model and the volume of fluid model.The results show that the flow velocity of the main jet gradually decreases under the influence of the low kinetic energy fluid in the mold.There is an obvious oscillation in the tail of the jet,while the flow field is asymmetric in space.The jet is closer to the inside radius side due to the Coanda effect,and there is a recirculation zone on the inside radius and the outside radius respectively,according to the 10 s time-averaged results.Compared with the industrial observation and simulation results,the shape of the free surface is a wave that varies with time.In addition,the free surface height is lowest and the flow velocity is highest in the region near the jet.

关键词： Fluid flow Free surface Wheel and belt caster Large eddy simulation Volume of fluid method

WSN Mobile Target Tracking Based on Improved Snake-Extended Kalman Filtering Algorithm

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Journal of Beijing Institute of Technology 2024年第1期33卷 28-40页

作者： Duo peng kun Xie Mingshuo Liu School of Computer and Communication of Lanzhou University of Technology Lanzhou Gansu 730050China

A wireless sensor network mobile target tracking algorithm(ISO-EKF)based on improved snake optimization algorithm(ISO)is proposed to address the difficulty of estimating initial values when using extended Kalman filtering to solve the state of nonlinear mobile target tracking.First,the steps of extended Kalman filtering(EKF)are introduced.Second,the ISO is used to adjust the parameters of the EKF in real time to adapt to the current motion state of the mobile target.Finally,the effectiveness of the algorithm is demonstrated through filtering and tracking using the constant velocity circular motion model(CM).Under the specified conditions,the position and velocity mean square error curves are compared among the snake optimizer(SO)-EKF algorithm,EKF algorithm,and the proposed algorithm.The comparison shows that the proposed algorithm reduces the root mean square error of position by 52%and 41%compared to the SOEKF algorithm and EKF algorithm,respectively.

关键词： wireless sensor network(WSN)target tracking snake optimization algorithm extended Kalman filter maneuvering target

Blockchain-Based Key Management Scheme Using Rational Secret Sharing

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Computers, Materials & Continua 2024年第4期79卷 307-328页

作者： Xingfan Zhao Changgen peng Weijie Tan kun Niu State Key Laboratory of Public Big Data College of Computer Science and TechnologyGuizhou UniversityGuiyang550025China Guizhou Big Data Academy Guizhou UniversityGuiyang550025China

Traditional blockchain key management schemes store private keys in the same location,which can easily lead to security issues such as a single point of failure.Therefore,decentralized threshold key management schemes have become a research focus for blockchain private key protection.The security of private keys for blockchain user wallet is highly related to user identity authentication and digital asset security.The threshold blockchain private key management schemes based on verifiable secret sharing have made some progress,but these schemes do not consider participants’self-interested behavior,and require trusted nodes to keep private key fragments,resulting in a narrow application scope and low deployment efficiency,which cannot meet the needs of personal wallet private key escrow and recovery in public blockchains.We design a private key management scheme based on rational secret sharing that considers the self-interest of participants in secret sharing protocols,and constrains the behavior of rational participants through reasonable mechanism design,making it more suitable in distributed scenarios such as the public blockchain.The proposed scheme achieves the escrow and recovery of personal wallet private keys without the participation of trusted nodes,and simulate its implementation on smart contracts.Compared to other existing threshold wallet solutions and keymanagement schemes based on password-protected secret sharing(PPSS),the proposed scheme has a wide range of applications,verifiable private key recovery,low communication overhead,higher computational efficiency when users perform one-time multi-key escrow,no need for trusted nodes,and personal rational constraints and anti-collusion attack capabilities.

关键词： Blockchain smart contract rational secret sharing key management

Efficacy and predictive factors of transarterial chemoembolization combined with lenvatinib plus programmed cell death protein-1 inhibition for unresectable hepatocellular carcinoma

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1236-1247页

作者： kun-peng Ma Jin-Xin Fu Feng Duan Mao-Qiang Wang Department of Interventional Radiology The Fifth Medical Center of Chinese People's Liberation Army General HospitalBeijing 100853China Chinese People's Liberation Army Medical School Beijing 100853China

BACKGROUND The efficacy and safety of transarterial chemoembolization(TACE)combined with lenvatinib plus programmed cell death protein-1(PD-1)for unresectable hepato-cellular carcinoma(HCC)have rarely been evaluated and it is unknown which factors are related to efficacy.AIM To evaluate the efficacy and independent predictive factors of TACE combined with lenvatinib plus PD-1 inhibitors for unresectable HCC.METHODS This study retrospectively enrolled patients with unresectable HCC who received TACE/lenvatinib/PD-1 treatment between March 2019 and April 2022.Overall survival(OS)and progression-free survival(PFS)were determined.The objective response rate(ORR)and disease control rate(DCR)were evaluated in accordance with the modified Response Evaluation Criteria in Solid Tumors.Additionally,the prognostic factors affecting the clinical outcome were assessed.RESULTS One hundred and two patients were enrolled with a median follow-up duration of 12.63 months.The median OS was 26.43 months(95%CI:17.00-35.87),and the median PFS was 10.07 months(95%CI:8.50-11.65).The ORR and DCR were 61.76%and 81.37%,respectively.The patients with Barcelona Clinic Liver Cancer Classification(BCLC)B stage,early neutrophil-to-lymphocyte ratio(NLR)response(decrease),or early alpha-fetoprotein(AFP)response(decrease>20%)had superior OS and PFS than their counterparts.CONCLUSION This study showed that TACE/lenvatinib/PD-1 treatment was well tolerated with encouraging efficacy in patients with unresectable HCC.The patients with BCLC B-stage disease with early NLR response(decrease)and early AFP response(decrease>20%)may achieve better clinical outcomes with this triple therapy.

关键词： Transarterial chemoembolization Efficacy Lenvatinib Programmed cell death protein-1 inhibitors Unresectable hepatocellular carcinoma

PHLDA2 reshapes the immune microenvironment and induces drug resistance in hepatocellular carcinoma

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Oncology Research 2024年第6期32卷 1063-1078页

作者： kun FENG HAO peng QINGpeng LV YEWEI ZHANG Hepatopancreatobiliary Center The Second Affiliated Hospital of Nanjing Medical UniversityNanjing210000China Medical School Southeast UniversityNanjing210000China

Hepatocellular carcinoma(HCC)is a malignancy known for its unfavorable prognosis.The dysregulation of the tumor microenvironment(TME)can affect the sensitivity to immunotherapy or chemotherapy,leading to treatment failure.The elucidation of PHLDA2’s involvement in HCC is imperative,and the clinical value of PHLDA2 is also underestimated.Here,bioinformatics analysis was performed in multiple cohorts to explore the phenotype and mechanism through which PHLDA2 may affect the progression of HCC.Then,the expression and function of PHLDA2 were examined via the qRT-PCR,Western Blot,and MTT assays.Our findings indicate a substantial upregulation of PHLDA2 in HCC,correlated with a poorer prognosis.The methylation levels of PHLDA2 were found to be lower in HCC tissues compared to normal liver tissues.Besides,noteworthy associations were observed between PHLDA2 expression and immune infiltration in HCC.In addition,PHLDA2 upregulation is closely associated with stemness features and immunotherapy or chemotherapy resistance in HCC.In vitro experiments showed that sorafenib or cisplatin significantly up-regulated PHLDA2 mRNA levels,and PHLDA2 knockdown markedly decreased the sensitivity of HCC cells to chemotherapy drugs.Meanwhile,we found that TGF-βinduced the expression of PHLDA2 in vitro.The GSEA and in vitro experiment indicated that PHLDA2 may promote the HCC progression via activating the AKT signaling pathway.Our study revealed the novel role of PHLDA2 as an independent prognostic factor,which plays an essential role in TME remodeling and treatment resistance in HCC.

关键词： HCC Immune infiltration Drug resistance TME PHLDA2

Overlapping infections of Mycobacterium canariasense and Nocardia farcinica in an immunocompetent patient:A case report

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World Journal of Clinical Cases 2024年第12期12卷 2079-2085页

作者： Hai-Yan Huang kun-peng Bu Jin-Wei Liu Jing Wei Department of Comprehensive Internal Medicine The Affiliated Cancer Hospital of Guangxi Medical UniversityNanning 530021Guangxi Zhuang Autonomous RegionChina Department of Doppler Ultrasound The Second Nanning People's HospitalNanning 530021Guangxi Zhuang Autonomous RegionChina

BACKGROUND Infections by non-tuberculous mycobacteria(NTM)have become more common in recent years.Mycobacterium canariasense(M.canariasense)was first reported as an opportunistic pathogen in 2004,but there have been very few case reports since then.Nocardia is a genus of aerobic and Gram-positive bacilli,and these species are also opportunistic pathogens and in the Mycobacteriales order.Conventional methods for diagnosis of NTM are inefficient.Metagenomic next-generation sequencing(mNGS)can rapidly detect many pathogenic microorganisms,even rare species.Most NTM and Nocardia infections occur in immunocompromised patients with atypical clinical symptoms.There are no previous reports of infection by M.canariasense and Nocardia farcinica(N.farcinica),especially in immunocompetent patients.This case report describes an immunocompetent 52-year-old woman who had overlapping infections of M.canariasense,N.farcinica,and Candida parapsilosis(C.parapsilosis)based on mNGS.CASE SUMMARY A 52-year-old woman presented with a productive cough and chest pain for 2 wk,and recurrent episodes of moderate-grade fever for 1 wk.She received antibiotics for 1 wk at a local hospital,and experienced defervescence,but the productive cough and chest pain persisted.We collected samples of a lung lesion and alveolar lavage fluid for mNGS.The lung tissue was positive for M.canariasense,N.farcinica,and C.parapsilosis,and the alveolar lavage fluid was positive for M.canariasense.The diagnosis was pneumonia,and application of appropriate antibiotic therapy cured the patient.CONCLUSION Etiological diagnosis is critical for patients with infectious diseases.mNGS can identify rare and novel pathogens,and does not require a priori knowledge.

关键词： Overlapping infection Mycobacterium canariasense Nocardia farcinica Metagenomic next-generation sequencing technology Case report

Understand the Temperature Sensing Behavior of Solid-state Polymerized PEDOT Hybrid Based on X-ray Scattering Studies

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Chinese Journal of Polymer Science 2024年第1期42卷 105-112,I0010页

作者： Zhen-Hang He Guang-Feng Liu Ze-kun Zhou Zhen Liu Yi-Shu Zeng peng Zhang School of Materials Science and Engineering Key Laboratory for Polymeric Composite and Functional Materials of Ministry of EducationSun Yat-sen UniversityGuangzhou 510275China Shanghai Advanced Research Institute(Zhangjiang Laboratory) Chinese Academy of SciencesShanghai 201204China

Poly(3,4-ethylenedioxythiophene)(PEDOT) is one of the most successful conductive polymers that recently has been used in wearable sensors for human health monitoring. In this work, we prepared a series of PEDOT hybrids consisting of PEDOT, sodium poly(styrene sulfonate)(PSSNa) and polyethylene oxide(PEO), and their preparation could be scaled-up via an adapted solid-state polymerization process. The resistance of the as-prepared PEDOT:PSS/PEO hybrid shows clear temperature response, i.e., it decreases almost linearly with the temperature increase. To understand this phenomenon, the in situ synchrotron radiation wide-and small-angle X-ray scattering(WAXS/SAXS) characterizations were undertaken to study the temperature-dependent microstructure change of the PEDOT:PSS/PEO hybrid. It demonstrated that PEDOT formed conductive paths in the hybrids, which were not destroyed by the PEO crystallization. As temperature increased, the PEO crystals' melting and the accompanying reorganization of PEDOT chains endowed the hybrid sample temperature responsiveness. Based on these fundamental knowledges, the hybrid materials were used to fabricate flexible wearable sensor that showing temperature sensing performance with an accuracy of 1 ℃. These findings shed lights on the scalable manufacturing of wearable sensors for body temperature monitoring.

关键词： Solid-state polymerization PEDOT hybrid Structure-property correlation X-ray scattering

Effects of rare earth elements on inclusions, microstructure and impact toughness of spring steel

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Journal of Iron and Steel Research(International) 2024年第4期31卷 933-944页

作者： Chun-lei Hao Chao-yun Yang peng Liu Yi-kun Luan Bao-guang Sang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016LiaoningChina School of Mechanical Engineering and Automation Dalian Polytechnic UniversityDalian 116034LiaoningChina

Spring steel is an indispensable basic part manufacturing material in mechanical equipment,which is widely used in transportation tools such as automobiles,railways,construction machinery and other industries.The effects of rare earth(RE)on inclusions,microstructure,carbides and impact toughness of 50CrV spring steel were studied by means of optical microscope,scanning electron microscope,transmission electron microscope and impact tester.The results show that the addition of rare earth can modify the main MnS and Al_(2)O_(3) inclusions in steel to form spherical or near-spherical rare earth inclusions,and the size of inclusions is significantly reduced.In the quenched structure,the size of martensite slab becomes smaller and the structure is refined.After tempering,the carbide changes from sheet to ellipse,which makes it easier for spring steel to form stress concentration cracks under stress.VC becomes finer and more dispersed,which leads to better pinning of grain boundaries and smaller grain sizes.The impact toughness of 50CrV-RE spring steel increased from 21 to 41 J by 95%due to the improvement of inclusions,microstructure and carbides by rare earth.It is possible to improve the strength and toughness of spring steel for the improvement of railway running speed and the development of vehicle lightweight in China.

关键词： Rare earth-Spring steel Inclusion Microstructure Impact toughness

A continuous and long-term in-situ stress measuring method based on fiber optic. Part I: Theory of inverse differential strain analysis

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Petroleum Science 2024年第2期21卷 1171-1189页

作者： kun-peng Zhang Mian Chen Chang-Jun Zhao Su Wang Yong-Dong Fan State Key Laboratory of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China MOE Key Laboratory of Petroleum Engineering in China University of Petroleum Beijing102249China Beijing International Center for Gas Hydrate School of Earth and Space SciencesPeking UniversityBeijing100871China

A method for in-situ stress measurement via fiber optics was proposed. The method utilizes the relationship between rock mass elastic parameters and in-situ stress. The approach offers the advantage of long-term stress measurements with high spatial resolution and frequency, significantly enhancing the ability to measure in-situ stress. The sensing casing, spirally wrapped with fiber optic, is cemented into the formation to establish a formation sensing nerve. Injecting fluid into the casing generates strain disturbance, establishing the relationship between rock mass properties and treatment pressure.Moreover, an optimization algorithm is established to invert the elastic parameters of formation via fiber optic strains. In the first part of this paper series, we established the theoretical basis for the inverse differential strain analysis method for in-situ stress measurement, which was subsequently verified using an analytical model. This paper is the fundamental basis for the inverse differential strain analysis method.

关键词： In-situ stress Fiber optic Orthotropic elastic Differential evolution ABAQUS