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A review of linear friction welding of Ni -based superalloys

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1382-1391页

作者： Xiawei Yang Tingxi meng Qiang Chu Yu Su Zhenguo Guo Rui xu Wenlong fan Tiejun Ma Wenya Li State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding TechnologiesNorthwestern Polytechnical UniversityXi’an 710072China Xi’an Aerospace Engine Co.Ltd. Xi’an 710100China

Ni-based superalloys are one of the most important materials employed in high-temperature applications within the aerospace and nuclear energy industries and in gas turbines due to their excellent corrosion,radiation,fatigue resistance,and high-temperature *** friction welding(LFW)is a new joining technology with near-net-forming characteristics that can be used for the manu-facture and repair of a wide range of aerospace *** paper reviews published works on LFW of Ni-based superalloys with the aim of understanding the characteristics of frictional heat generation and extrusion deformation,microstructures,mechanical proper-ties,flash morphology,residual stresses,creep,and fatigue of Ni-based superalloy weldments produced with LFW to enable future optim-um utilization of the LFW process.

关键词： Ni-based superalloys linear friction welding microstructures mechanical properties flash morphology

Preoperative prediction of hepatocellular carcinoma microvascular invasion based on magnetic resonance imaging feature extraction artificial neural network

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World Journal of Gastrointestinal Surgery 2024年第8期16卷 2546-2554页

作者： Jing-Yi xu Yu-fan Yang Zhong-Yue Huang Xin-Ye Qian fan-Hua meng Center of Hepatobiliary Pancreatic Disease Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China Department of Surgical Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China Department of Anesthesiology Huashan HospitalFudan UniversityShanghai 200040China

BACKGROUND Hepatocellular carcinoma(HCC)recurrence is highly correlated with increased *** invasion(MVI)is indicative of aggressive tumor biology in *** To construct an artificial neural network(ANN)capable of accurately predicting MVI presence in HCC using magnetic resonance *** This study included 255 patients with HCC with tumors<3 *** annotated the tumors on the T1-weighted plain MR ***,a three-layer ANN was constructed using image features as inputs to predict MVI status in patients with *** pathological examination is considered the gold standard for determining *** operating characteristic analysis was used to evaluate the effectiveness of the *** Using the bagging strategy to vote for 50 classifier classification results,a prediction model yielded an area under the curve(AUC)of ***,correlation analysis revealed that alpha-fetoprotein values and tumor volume were not significantly correlated with the occurrence of MVI,whereas tumor sphericity was significantly correlated with MVI(P<0.01).CONCLUSION Analysis of variable correlations regarding MVI in tumors with diameters<3 cm should prioritize tumor *** ANN model demonstrated strong predictive MVI for patients with HCC(AUC=0.79).

关键词： Hepatocellular carcinoma Microvascular invasion Artificial neural network Magnetic resonance imaging Tumor sphericity Area under the curve

Screening and identification of functional bacterial attachment genes in aerobic granular sludge

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Journal of Environmental Sciences 2024年第7期141卷 205-214页

作者： Kai Qiao Tingting Zhao LeiWang Wei Zhang Weimeng fan Liu xu Gao Jianrong Zhu School of Environment Beijing Normal UniversityBeijing 100875China State Key Laboratory of Water Simulation Beijing 100875China R&D Centre of Aerobic Granule Technology Beijing 100875China

The screening and identification of attachment genes is important to exploring the formation mechanism of biofilms at the gene *** is helpful to the development of key culture technologies for aerobic granular sludge(AGS).In this study,genome-wide sequencing and gene editing were employed for the first time to investigate the effects and functions of attachment genes in *** the help of whole-genome analysis,ten attachment genes were screened from thirteen genes,and the efficiency of gene screening was greatly ***,two attachment genes were selected as examples to further confirm the gene functions by constructing gene-knockout recombinant mutants of Stenotrophomonas maltophilia;when the two attachment genes were knocked out,the attachment potential was reduced by 50.67%and 43.93%,*** results provide a new theoretical principle and efficient method for the development of AGS from the perspective of attachment genes.

关键词： Attachment gene Genome-wide sequence Gene-knockout Attachment potential Aerobic granular sludge biofilm

Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction:Efficient photodegradation of organic pollutant and toxicity evaluation

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Journal of Materials Science & Technology 2024年第3期170卷 200-211页

作者： Yanyan Zhao xu fan Hongxing Zheng Enzhou Liu Jun fan xuejun Wang College of Biology Pharmacy and Food Engineering Shangluo UniversityShangluo 726000China QinLing-Bashan Mountains Bioresources Comprehensive Development C.I.C. Shaanxi University of TechnologyHanzhong 723001China School of Chemical Engineering Northwest UniversityXi’an 710069China

Constructing of heterojunction was identified as a feasible way to improve photocatalytic activity of *** this work,a n-p type Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was successfully prepared for organic pollutants *** Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction exhibited much higher pho-tocatalytic activity towards Rhodamine B(92.24%,expose to visible light for 60 min),norfloxacin(81.73%,expose to visible light for 90 min)and levofloxacin(87.46%,expose to visible light for 90 min)than pure Bi_(2)WO_(6)and pure AgInS_(2).Toxicity analysis indicated the low environmental toxicity of Rhodamine B degradation intermediates for Rye seeds and Sudangrass seeds germination and *** study displayed that AgInS_(2)and Bi_(2)WO_(6)work as the primary photocatalyst to form·O_(2)−and ·OH,*** improved photocatalytic activity of the Bi_(2)WO_(6)/AgInS_(2)S-scheme heterojunction was due to the im-proved light response range and intensified carrier separation ***,a S-scheme charge transfer mechanism including multiple charge transfer channels was *** work could provide an effective strategy for organic pollutants degradation in wastewater.

关键词： Photocatalysis S-scheme heterojunction AgInS_(2) Bi_(2)WO_(6) Toxicity experiments

Multi-UAV cooperative maneuver decision-making for pursuitevasion using improved MADRL

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Defence Technology（防务技术） 2024年第5期35卷 187-197页

作者： Delin Luo Zihao fan Ziyi Yang Yang xu School of Aerospace Engineering Xiamen UniversityXiamen 361102China School of Civil Aviation Northwestern Polytechnical UniversityXi'an 710072China

Aiming at the problem of multi-UAV pursuit-evasion confrontation, a UAV cooperative maneuver method based on an improved multi-agent deep reinforcement learning(MADRL) is proposed. In this method, an improved Comm Net network based on a communication mechanism is introduced into a deep reinforcement learning algorithm to solve the multi-agent problem. A layer of gated recurrent unit(GRU) is added to the actor-network structure to remember historical environmental states. Subsequently,another GRU is designed as a communication channel in the Comm Net core network layer to refine communication information between UAVs. Finally, the simulation results of the algorithm in two sets of scenarios are given, and the results show that the method has good effectiveness and applicability.

关键词： Reinforcement learning UAV Maneuver decision GRU Cooperative control

Evolution of inner wall wrinkle defects in the sinking zone of a thick-walled steel tube during radial forging

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Advances in Manufacturing 2024年第2期12卷 396-408页

作者： Yu-Zhao Yang Cheng xu Li-Xia fan School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094People’s Republic of China

An axial wrinkle defect was observed in the inner wall of the sinking zone of a thick-wall steel tube processed by cold radial *** can evolve into *** present study focuses on the evolution of wrinkles and the effects of process parameters on them using a three-dimensional radial forging process finite element model,radial forging experiments,and surface morphology *** results indicated that the vertical section angle of the hammer die and the size of the tube blank significantly affect the evolution of *** height-to-width ratioλwas introduced to describe the morphology of *** had an approximately linear relationship with the radius reduction in the sinking *** was a linear correlation between the growth slope ofλand the axial to circumferential strain ratio|εr/εθ|,which can predict theλunder few process *** the 30SiMn2MoVA steel,at the junction of the forging and sinking zones,the threshold ofλof the wrinkle that can evolve into a fissure is approximately 1.123.

关键词： Radial forging Inner wall Wrinkle defects Evolution Sinking zone

Normalized and self-normalized Cramér-type moderate deviations for the Euler-Maruyama scheme for the SDE

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Science China Mathematics 2024年第8期67卷 1865-1880页

作者： Xiequan fan Haijuan Hu Lihu xu Center for Applied Mathematics Tianjin UniversityTianjin 300072China School of Mathematics and Statistics Northeastern University at QinhuangdaoQinhuangdao 066004China Department of Mathematics Faculty of Science and TechnologyUniversity of MacaoMacaoChina

In this paper,we establish normalized and self-normalized Cramér-type moderate deviations for the Euler-Maruyama scheme for *** to our results,Berry-Esseen's bounds and moderate deviation principles are also *** norm... 详细信息

关键词： Euler-Maruyama scheme Cramer-type moderate deviations self-normalized sequences Berry-Esseen’s bounds

Solubility determination and comparison ofβ-HMX and RDX in two binary mixed solvents(acetonitrile+water,nitric acid+water)

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Chinese Journal of Chemical Engineering 2024年第5期69卷 238-249页

作者： Yuehua Yao fan Wang Yinguang xu Zishuai xu Lizhen Chen Jianlong Wang School of Chemistry and Chemical Engineering North University of ChinaTaiyuan 030051China Gansu Yinguang Chemical Industry Group Co.Ltd. Baiyin 730900China

In order to remove hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX),the main impurity,in process of polymorphic transformation of octrahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),the solubility ofβ-HMX and RDX in acetonitrile(ACN)+water in the temperature range of 288.15-333.15 K and in nitric acid(HNO_(3))+water in the temperature range of 298.15-333.15 K were measured by laser dynamic *** results showed that the solubility of bothβ-HMX and RDX in binary mixed solvents increased monotonously as the temperature increase at a given solvent composition or with increasing of mole fraction of solvent(ACN and nitric acid).Solubility data were well correlated by the modified Apelblat equation,Jouyban-Acree model,Yaws equation and van't Hoff equation,and the Yaws equation achieved the best fitting results according to the relative error and the mean square error ***,the solubility ofβ-HMX and RDX in binary mixed solvent was compared,based on the solubility difference and the solvent's own properties,the best separation degree ofβ-HMX and RDX was found when the mole fraction of nitric acid was 0.22 at room temperature,which provided data support for HMX crystallization in mixed *** solubility differences between RDX andβ-HMX in mixed solvents were explained from the formation of intermolecular and intramolecular hydrogen bonds.

关键词： Solubility Octrahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine Hexahydro-1,3,5-trinitro-1,3,5-triazine Separation Model Hydrogen bond

Characteristics of the microbial communities regulate soil multi-functionality under different cover crop amendments in Ultisol

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Journal of Integrative Agriculture 2024年第6期23卷 2099-2111页

作者： Guilong Li Xiaofen Chen Wenjing Qin Jingrui Chen Ke Leng Luyuan Sun Ming Liu meng Wu Jianbo fan Changxu xu Jia Liu Soil and Fertilizer&Resources and Environment Institute Jiangxi Academy of Agricultural SciencesNanchang 330200China Key Laboratory of Acidified Soil Amelioration and Utilization Ministry of Agriculture and Rural AffairsNanchang 330200China Ecological Experimental Station of Red Soil Chinese Academy of SciencesYingtan 335211China

The use of cover crops is a promising strategy for influencing the soil microbial consortium,which is essential for the delivery of multiple soil functions(i.e.,soil multifunctionality).Nonetheless,relatively little is known about the role of the soil microbial consortium in mediating soil multifunctionality under different cover crop amendments in dryland ***,we assessed the multifunctionality of soils subjected to four cover crop amendments(control,non-amended treatment;RD,radish monoculture;HV,hairy vetch monoculture;and RDHV,radish-hairy vetch mixture),and we investigated the contributions of soil microbial richness,network complexity,and ecological clusters to soil *** results demonstrated that cover crops whose chemical composition differed from that of the main plant crop promoted higher multifunctionality,and the radish-hairy vetch mixture rendered the highest *** obtained evidence that changes in soil microbial richness and network complexity triggered by the cover crops were associated with higher soil ***,specialized microbes in a key ecological cluster(ecological cluster 2)of the soil microbial network were particularly important for maintaining soil *** results highlight the importance of cover crop-induced variations in functionally important taxa for promoting the soil multifunctionality of dryland Ultisols.

关键词： cover crops soil multifunctionality microbial richness network complexity ecological cluster