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Three-Stage Transfer Learning with AlexNet50 for MRI Image Multi-Class Classification with Optimal Learning Rate
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作者 Suganya Athisayamani A.Robert Singh +1 位作者 Gyanendra Prasad Joshi Woong Cho 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期155-183,共29页
In radiology,magnetic resonance imaging(MRI)is an essential diagnostic tool that provides detailed images of a patient’s anatomical and physiological structures.MRI is particularly effective for detecting soft tissue... In radiology,magnetic resonance imaging(MRI)is an essential diagnostic tool that provides detailed images of a patient’s anatomical and physiological structures.MRI is particularly effective for detecting soft tissue anomalies.Traditionally,radiologists manually interpret these images,which can be labor-intensive and time-consuming due to the vast amount of data.To address this challenge,machine learning,and deep learning approaches can be utilized to improve the accuracy and efficiency of anomaly detection in MRI scans.This manuscript presents the use of the Deep AlexNet50 model for MRI classification with discriminative learning methods.There are three stages for learning;in the first stage,the whole dataset is used to learn the features.In the second stage,some layers of AlexNet50 are frozen with an augmented dataset,and in the third stage,AlexNet50 with an augmented dataset with the augmented dataset.This method used three publicly available MRI classification datasets:Harvard whole brain atlas(HWBA-dataset),the School of Biomedical Engineering of Southern Medical University(SMU-dataset),and The National Institute of Neuroscience and Hospitals brain MRI dataset(NINS-dataset)for analysis.Various hyperparameter optimizers like Adam,stochastic gradient descent(SGD),Root mean square propagation(RMS prop),Adamax,and AdamW have been used to compare the performance of the learning process.HWBA-dataset registers maximum classification performance.We evaluated the performance of the proposed classification model using several quantitative metrics,achieving an average accuracy of 98%. 展开更多
关键词 MRI tUMORs CLAssIFICAtION AlexNet50 transfer learning hyperparameter tuning OPtIMIZER
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Transfer RNA-derived small RNA serves as potential non-invasive diagnostic marker and a novel therapeutic target for acute pancreatitis
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作者 Jing Zhang Chun-Lin Ou 《World Journal of Gastroenterology》 SCIE CAS 2025年第1期152-156,共5页
Transfer RNA(tRNA)-derived fragments,a new type of tRNA-derived small RNA(tsRNA),can be cleaved from tRNA by enzymes to regulate target gene expression at the transcriptional and translational levels.tsRNAs are not on... Transfer RNA(tRNA)-derived fragments,a new type of tRNA-derived small RNA(tsRNA),can be cleaved from tRNA by enzymes to regulate target gene expression at the transcriptional and translational levels.tsRNAs are not only degradation fragments but also have biological functions,including those in immune inflammation,metabolic disorders,and cell death.tsRNA dysregulation is closely associated with multiple diseases,including various cancers and acute pancreatitis(AP).AP is a common gastrointestinal disease,and its incidence increases annually.AP development is associated with tsRNAs,which regulate cell injury and induce inflammation,especially pyroptosis and ferroptosis.Notably,serum tRF36 has the potential to serve as a non-invasive diagnostic biomarker and leads to pancreatic acinar cell ferroptosis causing inflammation to promote AP.We show the characteristics of tsRNAs and their diagnostic value and function in AP,and discuss the potential opportunities and challenges of using tsRNAs in clinical applications and research. 展开更多
关键词 transfer RNA derived small RNAs Acute pancreatitis Liquid biopsy BIOMARKER Cell pyroptosis Ferroptosis
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Flow and heat transfer characteristics of regenerative cooling parallel channel
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作者 JU Yinchao LIU Xiaoyong +1 位作者 XU Guoqiang DONG Bensi 《推进技术》 北大核心 2025年第1期163-171,共9页
Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass rat... Due to the complex high-temperature characteristics of hydrocarbon fuel,the research on the long-term working process of parallel channel structure under variable working conditions,especially under high heat-mass ratio,has not been systematically carried out.In this paper,the heat transfer and flow characteristics of related high temperature fuels are studied by using typical engine parallel channel structure.Through numeri⁃cal simulation and systematic experimental verification,the flow and heat transfer characteristics of parallel chan⁃nels under typical working conditions are obtained,and the effectiveness of high-precision calculation method is preliminarily established.It is known that the stable time required for hot start of regenerative cooling engine is about 50 s,and the flow resistance of parallel channel structure first increases and then decreases with the in⁃crease of equivalence ratio(The following equivalence ratio is expressed byΦ),and there is a flow resistance peak in the range ofΦ=0.5~0.8.This is mainly caused by the coupling effect of high temperature physical proper⁃ties,flow rate and pressure of fuel in parallel channels.At the same time,the cooling and heat transfer character⁃istics of parallel channels under some conditions of high heat-mass ratio are obtained,and the main factors affect⁃ing the heat transfer of parallel channels such as improving surface roughness and strengthening heat transfer are mastered.In the experiment,whenΦis less than 0.9,the phenomenon of local heat transfer enhancement and deterioration can be obviously observed,and the temperature rise of local structures exceeds 200℃,which is the risk of structural damage.Therefore,the reliability of long-term parallel channel structure under the condition of high heat-mass ratio should be fully considered in structural design. 展开更多
关键词 Regenerative cooling Heat transfer Flow resistance ENGINE Parallel channel
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Brachioradialis tendon transfer and palmaris longus tendon graft for thumb avulsion:A case report and review of literature
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作者 Pierre Curings Sonia Ramos-Pascual +4 位作者 Kinga Michalewska Nicolas Gibert Lionel Erhard Mo Saffarini AlexisNogier 《World Journal of Clinical Cases》 SCIE 2025年第4期48-55,共8页
BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of t... BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of the flexor pollicis longus(FPL)at the musculotendinous junction.Possible treatments include direct tendon suture or tendon transfer,most commonly from the ring finger.To optimize function and avoid donor finger complications,we performed thumb replantation with flexion restoration using brachioradialis(BR)tendon transfer with palmaris longus(PL)tendon graft.CASE SUMMARY A 20-year-old left-handed male was admitted for a complete traumatic left thumb amputation following an accident while sliding from the top of a handrail.The patient presented with skin and bone avulsion at the MCP I,avulsion of the FPL tendon at the musculotendinous junction(zone 5),avulsion of the extensor pollicis longus tendon(zone T3),and avulsion of the thumb’s collateral arteries and nerves.The patient was treated with two stage thumb repair.The first intervention consisted of thumb replantation with MCP I arthrodesis,resection of avulsed FPL tendon and implantation of a silicone tendon prosthesis.The second intervention consisted of PL tendon graft and BR tendon transfer.Follow-up at 10 months showed good outcomes with active interphalangeal flexion of 70°,grip strength of 45 kg,key pinch strength of 15 kg and two-point discrimination threshold of 4 mm.CONCLUSION Flexion restoration after complete thumb amputation with FPL avulsion at the musculotendinous junction can be achieved using BR tendon transfer with PL tendon graft. 展开更多
关键词 Brachioradialis tendon transfer Flexor pollicis longus Palmaris longus tendon graft REPLANtAtION thumb amputation thumb avulsion Case report
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An Energy Management System with Mobile Energy Station Based Wireless Energy Transfer:System Design and Prototype Implementation
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作者 Yan Kang Li Jinhui +3 位作者 Fan Xinyu Hu Jie Yu Qin Yang Kun 《China Communications》 2025年第1期89-101,共13页
In indoor environments,various batterypowered Internet of Things(IoT)devices,such as remote controllers and electronic tags on high-level shelves,require efficient energy management.However,manually monitoring remaini... In indoor environments,various batterypowered Internet of Things(IoT)devices,such as remote controllers and electronic tags on high-level shelves,require efficient energy management.However,manually monitoring remaining energy levels and battery replacement is both inadequate and costly.This paper introduces an energy management system for indoor IoT,which includes a mobile energy station(ES)for enabling on-demand wireless energy transfer(WET)in radio frequency(RF),some energy receivers(ERs),and a cloud server.By implementing a two-stage positioning system and embedding energy receivers into traditional IoT devices,we robustly manage their energy storage.The experimental results demonstrate that the energy receiver can harvest a minimum power of 58 mW. 展开更多
关键词 angle of arrival(AOA) Internet of things(Iot) mobile station PROtOtYPE wireless energy transfer(WEt)
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基于改进Res2Net与迁移学习的水果图像分类
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作者 吴迪 肖衍 +2 位作者 沈学军 万琴 陈子涵 《电子科技大学学报》 北大核心 2025年第1期62-71,共10页
针对传统水果图像分类算法特征学习能力弱和细粒度特征信息表示不强的缺点,提出一种基于改进Res2Net与迁移学习的水果图像分类算法。首先,针对网络结构,在Res2Net的残差单元中引入动态多尺度融合注意力模块,对各种尺寸的图像动态地生成... 针对传统水果图像分类算法特征学习能力弱和细粒度特征信息表示不强的缺点,提出一种基于改进Res2Net与迁移学习的水果图像分类算法。首先,针对网络结构,在Res2Net的残差单元中引入动态多尺度融合注意力模块,对各种尺寸的图像动态地生成卷积核,利用meta-ACON激活函数优化ReLU激活函数,动态学习激活函数的线性和非线性,自适应选择是否激活神经元;其次,采用基于模型迁移的训练方式进一步提升分类的效率与鲁棒性。实验结果表明,该算法在Fruit-Dataset和Fruits-360数据集上的测试准确率相比Res2Net提升了1.2%和1.0%,召回率相比Res2Net提升了1.13%和0.89%,有效提升了水果图像分类性能。 展开更多
关键词 图像分类 Res2Net 动态多尺度融合注意力 激活函数 迁移学习
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Resting-state brain network remodeling after different nerve reconstruction surgeries:a functional magnetic resonance imaging study in brachial plexus injury rats
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作者 Yunting Xiang Xiangxin Xing +6 位作者 Xuyun Hua Yuwen Zhang Xin Xue Jiajia Wu Mouxiong Zheng He Wang Jianguang Xu 《Neural Regeneration Research》 SCIE CAS 2025年第5期1495-1504,共10页
Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network lev... Distinct brain remodeling has been found after different nerve reconstruction strategies,including motor representation of the affected limb.However,differences among reconstruction strategies at the brain network level have not been elucidated.This study aimed to explore intranetwork changes related to altered peripheral neural pathways after different nerve reconstruction surgeries,including nerve repair,endto-end nerve transfer,and end-to-side nerve transfer.Sprague–Dawley rats underwent complete left brachial plexus transection and were divided into four equal groups of eight:no nerve repair,grafted nerve repair,phrenic nerve end-to-end transfer,and end-to-side transfer with a graft sutured to the anterior upper trunk.Resting-state brain functional magnetic resonance imaging was obtained 7 months after surgery.The independent component analysis algorithm was utilized to identify group-level network components of interest and extract resting-state functional connectivity values of each voxel within the component.Alterations in intra-network resting-state functional connectivity were compared among the groups.Target muscle reinnervation was assessed by behavioral observation(elbow flexion)and electromyography.The results showed that alterations in the sensorimotor and interoception networks were mostly related to changes in the peripheral neural pathway.Nerve repair was related to enhanced connectivity within the sensorimotor network,while end-to-side nerve transfer might be more beneficial for restoring control over the affected limb by the original motor representation.The thalamic-cortical pathway was enhanced within the interoception network after nerve repair and end-to-end nerve transfer.Brain areas related to cognition and emotion were enhanced after end-to-side nerve transfer.Our study revealed important brain networks related to different nerve reconstructions.These networks may be potential targets for enhancing motor recovery. 展开更多
关键词 brain functional networks end-to-end nerve transfer end-to-side nerve transfer independent component analysis nerve repair peripheral plexus injury resting-state functional connectivity
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IDS-INT:Intrusion detection system using transformer-based transfer learning for imbalanced network traffic 被引量:4
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作者 Farhan Ullah Shamsher Ullah +1 位作者 Gautam Srivastava Jerry Chun-Wei Lin 《Digital Communications and Networks》 SCIE CSCD 2024年第1期190-204,共15页
A network intrusion detection system is critical for cyber security against llegitimate attacks.In terms of feature perspectives,network traffic may include a variety of elements such as attack reference,attack type,a... A network intrusion detection system is critical for cyber security against llegitimate attacks.In terms of feature perspectives,network traffic may include a variety of elements such as attack reference,attack type,a subcategory of attack,host information,malicious scripts,etc.In terms of network perspectives,network traffic may contain an imbalanced number of harmful attacks when compared to normal traffic.It is challenging to identify a specific attack due to complex features and data imbalance issues.To address these issues,this paper proposes an Intrusion Detection System using transformer-based transfer learning for Imbalanced Network Traffic(IDS-INT).IDS-INT uses transformer-based transfer learning to learn feature interactions in both network feature representation and imbalanced data.First,detailed information about each type of attack is gathered from network interaction descriptions,which include network nodes,attack type,reference,host information,etc.Second,the transformer-based transfer learning approach is developed to learn detailed feature representation using their semantic anchors.Third,the Synthetic Minority Oversampling Technique(SMOTE)is implemented to balance abnormal traffic and detect minority attacks.Fourth,the Convolution Neural Network(CNN)model is designed to extract deep features from the balanced network traffic.Finally,the hybrid approach of the CNN-Long Short-Term Memory(CNN-LSTM)model is developed to detect different types of attacks from the deep features.Detailed experiments are conducted to test the proposed approach using three standard datasets,i.e.,UNsWNB15,CIC-IDS2017,and NSL-KDD.An explainable AI approach is implemented to interpret the proposed method and develop a trustable model. 展开更多
关键词 Network intrusion detection transfer learning Features extraction Imbalance data Explainable AI CYBERsECURItY
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肺腺癌相关tsRNA的筛选和验证
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作者 陆春利 单亦凡 +6 位作者 谢薇佳 夏婷婷 向颖 邬娜 吴龙 白莉 李亚斐 《陆军军医大学学报》 北大核心 2025年第2期122-131,共10页
目的通过分析tsRNA在肺腺癌中的差异表达情况及其表达水平与患者预后的关系,进一步筛选并验证肺腺癌相关tsRNA,以了解其在肺腺癌发生和进展中的相关机制。方法基于计算医学中心数据库筛选出在肺腺癌组织和正常组织中差异表达的tsRNA;基... 目的通过分析tsRNA在肺腺癌中的差异表达情况及其表达水平与患者预后的关系,进一步筛选并验证肺腺癌相关tsRNA,以了解其在肺腺癌发生和进展中的相关机制。方法基于计算医学中心数据库筛选出在肺腺癌组织和正常组织中差异表达的tsRNA;基于癌症基因组图谱(The Cancer Genome Atlas,TCGA)数据库分析tsRNA表达水平对肺腺癌患者预后的影响;基于TRFtarget2.0和tRFTar数据库预测靶基因;基于DAVID、KOBA KEGG在线网站进行基因本体论(Gene Ontology,GO)富集分析和京都基因和基因组百科全书(Kyoto Encyclopedia of Genes and Genomes,KEGG)通路分析;基于阿拉巴马大学伯明翰分校癌症数据分析门户(the University of Alabama at Birmingham CANcer data analysis Portal,UALCAN)分析靶基因在肺腺癌组织和正常组织中的表达水平。采用增殖实验、迁移实验、侵袭实验验证tRF-19-69M8LOJX在肺腺癌细胞中的生物学功能。结果与正常组织相比,tRF-19-69M8LOJX在肺腺癌组织中表达上调(log2FC=4.28,FDR<0.05)。高表达水平的tRF-19-69M8LOJX预示着更短的无进展生存期(HR=1.565,95%CI=1.142~2.145,P=0.005);过表达tRF-19-69M8LOJX促进A549细胞的增殖、迁移(P<0.001)和侵袭(P=0.009);COL1A1(P=0.002)和VCAN(P=0.022)在tRF-19-69M8LOJX过表达细胞模型中显著上调。结论tRF-19-69M8LOJX在肺腺癌组织的表达水平上调,与患者不良预后密切相关,可能在肺腺癌的发生发展中起着重要作用。 展开更多
关键词 转移RNA衍生的小RNA 肺腺癌 预后
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Causal Analysis Between Rice Growth and Cadmium Accumulation and Transfer under Arbuscular Mycorrhizal Inoculation 被引量:2
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作者 ZHAO Ting WANG Li +1 位作者 YANG Jixian MA Fang 《Rice science》 SCIE CSCD 2024年第2期226-236,共11页
Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The r... Cadmium(Cd)contamination in rice has been a serious threat to human health.To investigate the effects of arbuscular mycorrhizal fungi(AMF)on the Cd translocation in rice,a controlled pot experiment was conducted.The results indicated that AMF significantly increased rice biomass,with an increase of up to 40.0%,particularly in root biomass by up to 68.4%.Notably,the number of prominent rice individuals also increased,and their plasticity was enhanced following AMF inoculation.AMF led to an increase in the net photosynthetic rate and antioxidant enzyme activity of rice.In the AMF treatment group,the Cd concentration in the rice roots was significantly higher(19.1%‒68.0%)compared with that in the control group.Conversely,the Cd concentration in the rice seeds was lower in the AMF treatment group,indicating that AMF facilitated the sequestration of Cd in rice roots and reduced Cd accumulation in the seeds.Path coefficients varied across different treatments,suggesting that AMF inoculation reduced the direct impact of soil Cd concentration on the total Cd accumulation in seeds.The translocation of Cd was consistently associated with simultaneous growth dilution and compensatory accumulation as a result of mycorrhizal effects.Our study quantitatively analyzed this process through path analysis and clarified the causal relationship between rice growth and Cd transfer under the influence of AMF. 展开更多
关键词 cadmium transfer dilution effect heavy metal immobilization mycorrhizal effect path analysis phenotypic plasticity
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Robust Information Hiding Based on Neural Style Transfer with Artificial Intelligence 被引量:1
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作者 Xiong Zhang Minqing Zhang +3 位作者 Xu AnWang Wen Jiang Chao Jiang Pan Yang 《Computers, Materials & Continua》 SCIE EI 2024年第5期1925-1938,共14页
This paper proposes an artificial intelligence-based robust information hiding algorithm to address the issue of confidential information being susceptible to noise attacks during transmission.The algorithm we designe... This paper proposes an artificial intelligence-based robust information hiding algorithm to address the issue of confidential information being susceptible to noise attacks during transmission.The algorithm we designed aims to mitigate the impact of various noise attacks on the integrity of secret information during transmission.The method we propose involves encoding secret images into stylized encrypted images and applies adversarial transfer to both the style and content features of the original and embedded data.This process effectively enhances the concealment and imperceptibility of confidential information,thereby improving the security of such information during transmission and reducing security risks.Furthermore,we have designed a specialized attack layer to simulate real-world attacks and common noise scenarios encountered in practical environments.Through adversarial training,the algorithm is strengthened to enhance its resilience against attacks and overall robustness,ensuring better protection against potential threats.Experimental results demonstrate that our proposed algorithm successfully enhances the concealment and unknowability of secret information while maintaining embedding capacity.Additionally,it ensures the quality and fidelity of the stego image.The method we propose not only improves the security and robustness of information hiding technology but also holds practical application value in protecting sensitive data and ensuring the invisibility of confidential information. 展开更多
关键词 Information hiding neural style transfer ROBUstNEss
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CoTCPP integrates with BiOBr microspheres for improved solar-driven CO_(2)reduction performance
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作者 Lina Li Yi Zhang +7 位作者 Gaopeng Liu Tiange Wei Junze Zhao Bin Wang Mengxia Ji Yuanbin She Jiexiang Xia Huaming Li 《Green Energy & Environment》 SCIE EI CAS 2025年第1期193-202,共10页
CO_(2) photoreduction into carbon-based chemicals has been considered as an appropriate way to alleviate the energy issue and greenhouse effect.Herein,the 5,10,15,20-tetra(4-carboxyphenyl)porphyrin cobalt(II)(CoTCPP)h... CO_(2) photoreduction into carbon-based chemicals has been considered as an appropriate way to alleviate the energy issue and greenhouse effect.Herein,the 5,10,15,20-tetra(4-carboxyphenyl)porphyrin cobalt(II)(CoTCPP)has been integrated with BiOBr microspheres and formed the CoTCPP/BiOBr composite.The as-prepared CoTCPP/BiOBr-2 composite shows optimized photocatalytic performance for CO_(2) conversion into CO and CH_(4) upon irradiation with 300 W Xe lamp,which is 2.03 and 2.58 times compared to that of BiOBr,respectively.The introduced CoTCPP significantly enhanced light absorption properties,promoted rapid separation of photogenerated carriers and boosted the chemisorption of CO_(2) molecules.The metal Co^(2+) at the center of the porphyrin molecules also acts as adsorption center for CO_(2) molecules,accelerating the CO_(2) conversion into CO and CH_(4).The possible mechanism of CO_(2) photoreduction was explored by in-situ FT-IR spectra.This work offers a new possibility for the preparation of advanced photocatalysts. 展开更多
关键词 BiOBr CotCPP CO_(2)photoreduction Carriers transfer CO_(2)adsorption-activation
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Effects of projectile parameters on the momentum transfer and projectile melting during hypervelocity impact 被引量:1
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作者 Wenjin Liu Qingming Zhang +6 位作者 Renrong Long Zizheng Gong Ren Jiankang Xin Hu Siyuan Ren Qiang Wu Guangming Song 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期89-103,共15页
The effects of projectile/target impedance matching and projectile shape on energy,momentum transfer and projectile melting during collisions are investigated by numerical simulation.By comparing the computation resul... The effects of projectile/target impedance matching and projectile shape on energy,momentum transfer and projectile melting during collisions are investigated by numerical simulation.By comparing the computation results with the experimental results,the correctness of the calculation and the statistical method of momentum transfer coefficient is verified.Different shapes of aluminum,copper and heavy tungsten alloy projectiles striking aluminum,basalt,and pumice target for impacts up to 10 km/s are simulated.The influence mechanism of the shape of the projectile and projectile/target density on the momentum transfer was obtained.With an increase in projectile density and length-diameter ratio,the energy transfer time between the projectile and targets is prolonged.The projectile decelerates slowly,resulting in a larger cratering depth.The energy consumed by the projectile in the excavation stage increased,resulting in lower mass-velocity of ejecta and momentum transfer coefficient.The numerical simulation results demonstrated that for different projectile/target combinations,the higher the wave impedance of the projectile,the higher the initial phase transition velocity and the smaller the mass of phase transition.The results can provide theoretical guidance for kinetic impactor design and material selection. 展开更多
关键词 Hypervelocity impact Energy partitioning Impact melting Momentum transfer
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Generation of mitochondrial replacement monkeys by female pronucleus transfer 被引量:1
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作者 Chun-Yang Li Xing-Chen Liu +6 位作者 Yu-Zhuo Li Yan Wang Yan-Hong Nie Yu-Ting Xu Xiao-Tong Zhang Yong Lu Qiang Sun 《Zoological Research》 SCIE CSCD 2024年第2期292-298,共7页
Mutations in mitochondrial DNA(mtDNA)are maternally inherited and have the potential to cause severe disorders.Mitochondrial replacement therapies,including spindle,polar body,and pronuclear transfers,are promising st... Mutations in mitochondrial DNA(mtDNA)are maternally inherited and have the potential to cause severe disorders.Mitochondrial replacement therapies,including spindle,polar body,and pronuclear transfers,are promising strategies for preventing the hereditary transmission of mtDNA diseases.While pronuclear transfer has been used to generate mitochondrial replacement mouse models and human embryos,its application in non-human primates has not been previously reported.In this study,we successfully generated four healthy cynomolgus monkeys(Macaca fascicularis)via female pronuclear transfer.These individuals all survived for more than two years and exhibited minimal mtDNA carryover(3.8%–6.7%),as well as relatively stable mtDNA heteroplasmy dynamics during development.The successful establishment of this nonhuman primate model highlights the considerable potential of pronuclear transfer in reducing the risk of inherited mtDNA diseases and provides a valuable preclinical research model for advancing mitochondrial replacement therapies in humans. 展开更多
关键词 Non-human primates Mitochondrial replacement Female pronuclear transfer
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Coherent optical frequency transfer via 972-km fiber link 被引量:1
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作者 邓雪 张翔 +8 位作者 臧琦 焦东东 王丹 刘杰 高静 许冠军 董瑞芳 刘涛 张首刚 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期277-282,共6页
We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for.Instead of employing a phase discriminator and a phase lockin... We demonstrate coherent optical frequency dissemination over a distance of 972 km by cascading two spans where the phase noise is passively compensated for.Instead of employing a phase discriminator and a phase locking loop in the conventional active phase control scheme,the passive phase noise cancellation is realized by feeding double-trip beat-note frequency to the driver of the acoustic optical modulator at the local site.This passive scheme exhibits fine robustness and reliability,making it suitable for long-distance and noisy fiber links.An optical regeneration station is used in the link for signal amplification and cascaded transmission.The phase noise cancellation and transfer instability of the 972-km link is investigated,and transfer instability of 1.1×10^(-19)at 10^(4)s is achieved.This work provides a promising method for realizing optical frequency distribution over thousands of kilometers by using fiber links. 展开更多
关键词 optical frequency transfer fiber link phase noise cancellation
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脂质转移蛋白SiLTP1基因参与谷子耐盐响应初探
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作者 孟凡花 刘敏 +1 位作者 沈傲 刘炜 《作物学报》 CAS 北大核心 2025年第1期58-67,共10页
土壤盐渍化严重制约农业生产发展,通过提高植物耐盐性进行盐碱地综合利用,对于保障粮食安全,提升农业生产效率具有重要意义。脂质转移蛋白是一类在高等植物中广泛存在的小分子蛋白质,能够参与植株生长、信号转导以及多种生物和非生物胁... 土壤盐渍化严重制约农业生产发展,通过提高植物耐盐性进行盐碱地综合利用,对于保障粮食安全,提升农业生产效率具有重要意义。脂质转移蛋白是一类在高等植物中广泛存在的小分子蛋白质,能够参与植株生长、信号转导以及多种生物和非生物胁迫过程。前期本课题组克隆到一个谷子中编码脂质转移蛋白的基因SiLTP1,本研究通过构建其原核表达载体和植物双元过表达载体,获得了该基因的原核表达蛋白及同源转化过表达阳性植株,经进一步筛选获得4个纯合株系。体外耐盐性试验显示, SiLTP1的原核表达蛋白具有一定耐盐性;转基因植株苗期耐盐生理指标测定显示,SiLTP1过表达植株在遭受盐胁迫时,植株体内MDA积累减少,抗氧化酶含量升高,可积累更少的过氧化氢,从而降低胁迫对植株的氧化损伤,显示基因过表达植株具有更好的耐盐性。本研究结果初步揭示, SiLTP1可正向调控谷子的耐盐性,其在谷子耐盐抗逆方面具有潜在功能,为耐盐谷子品种改良及新品种培育提供了理论基础和候选基因资源。 展开更多
关键词 脂质转移蛋白 siLtP1 盐胁迫 谷子 耐盐响应
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Processing,microstructure,and mechanical properties of wire arc additively-manufactured AZ91 magnesium alloy using cold arc process
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作者 Bai-hao CAI Ji-kang FAN +3 位作者 Jie LI Dong-qing YANG Yong PENG Ke-hong WANG 《中国有色金属学报》 北大核心 2025年第1期91-104,共14页
Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties... Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties were investigated.The results showed that the cold arc process reduced splashing at the moment of liquid bridge breakage and effectively shortened the droplet transfer period.The microstructures of the deposited samples exhibited layered characteristics with alternating distributions of coarse and fine grains.During layer-by-layer deposition,the β-phase precipitated and grew preferentially along grain boundaries,while the fineη-Al_(8)Mn_(5)phase was dispersed in the α-Mg matrix.The mechanical properties of the CA-WAAM deposited sample showed isotropic characteristics.The ultimate tensile strength and elongation in the building direction(BD)were 282.7 MPa and 14.2%,respectively.The microhardness values of the deposited parts were relatively uniform,with an average value of HV 69.6. 展开更多
关键词 AZ91 magnesium alloy droplet transfer MICROstRUCtURE mechanical properties cold arc process
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Label Recovery and Trajectory Designable Network for Transfer Fault Diagnosis of Machines With Incorrect Annotation 被引量:1
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作者 Bin Yang Yaguo Lei +2 位作者 Xiang Li Naipeng Li Asoke K.Nandi 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第4期932-945,共14页
The success of deep transfer learning in fault diagnosis is attributed to the collection of high-quality labeled data from the source domain.However,in engineering scenarios,achieving such high-quality label annotatio... The success of deep transfer learning in fault diagnosis is attributed to the collection of high-quality labeled data from the source domain.However,in engineering scenarios,achieving such high-quality label annotation is difficult and expensive.The incorrect label annotation produces two negative effects:1)the complex decision boundary of diagnosis models lowers the generalization performance on the target domain,and2)the distribution of target domain samples becomes misaligned with the false-labeled samples.To overcome these negative effects,this article proposes a solution called the label recovery and trajectory designable network(LRTDN).LRTDN consists of three parts.First,a residual network with dual classifiers is to learn features from cross-domain samples.Second,an annotation check module is constructed to generate a label anomaly indicator that could modify the abnormal labels of false-labeled samples in the source domain.With the training of relabeled samples,the complexity of diagnosis model is reduced via semi-supervised learning.Third,the adaptation trajectories are designed for sample distributions across domains.This ensures that the target domain samples are only adapted with the pure-labeled samples.The LRTDN is verified by two case studies,in which the diagnosis knowledge of bearings is transferred across different working conditions as well as different yet related machines.The results show that LRTDN offers a high diagnosis accuracy even in the presence of incorrect annotation. 展开更多
关键词 Deep transfer learning domain adaptation incorrect label annotation intelligent fault diagnosis rotating machines
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The regulation of ferrocene-based catalysts on heat transfer in highpressure combustion of ammonium perchlorate/hydroxyl-terminated polybutadiene/aluminum composite propellants 被引量:1
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作者 Jinchao Han Songqi Hu Linlin Liu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第5期174-186,共13页
The regulation of the burning rate pressure exponent for the ammonium perchlorate/hydroxylterminated polybutadiene/aluminum(AP/HTPB/Al)composite propellants under high pressures is a crucial step for its application i... The regulation of the burning rate pressure exponent for the ammonium perchlorate/hydroxylterminated polybutadiene/aluminum(AP/HTPB/Al)composite propellants under high pressures is a crucial step for its application in high-pressure solid rocket motors.In this work,the combustion characteristics of AP/HTPB/Al composite propellants containing ferrocene-based catalysts were investigated,including the burning rate,thermal behavior,the local heat transfer,and temperature profile in the range of 7-28 MPa.The results showed that the exponent breaks were still observed in the propellants after the addition of positive catalysts(Ce-Fc-MOF),the burning rate inhibitor((Ferrocenylmethyl)trimethylammonium bromide,Fc Br)and the mixture of Fc Br/catocene(GFP).However,the characteristic pressure has increased,and the exponent decreased from 1.14 to 0.66,0.55,and 0.48 when the addition of Ce-FcMOF,Fc Br and Fc Br/GFP in the propellants.In addition,the temperature in the first decomposition stage was increased by 7.50℃ and 11.40℃ for the AP/Fc Br mixture and the AP/Fc Br/GFP mixture,respectively,compared to the pure AP.On the other hand,the temperature in the second decomposition stage decreased by 48.30℃ and 81.70℃ for AP/Fc Br and AP/Fc Br/GFP mixtures,respectively.It was also found that Fc Br might generate ammonia to cover the AP surface.In this case,a reaction between the methyl in Fc Br and perchloric acid caused more ammonia to appear at the AP surface,resulting in the suppression of ammonia desorption.In addition,the coarse AP particles on the quenched surface were of a concave shape relative to the binder matrix under low and high pressures when the catalysts were added.In the process,the decline at the AP/HTPB interface was only exhibited in the propellant with the addition of Ce-Fc-MOF.The ratio of the gas-phase temperature gradient of the propellants containing catalysts was reduced significantly below and above the characteristic pressure,rather than 3.6 times of the difference in the blank propellant.Overall,the obtained results demonstrated that the pressure exponent could be effectively regulated and controlled by adjusting the propellant local heat and mass transfer under high and low pressures. 展开更多
关键词 AP/HtPB/Al propellants Heat transfer High-pressure combustion Ferrocene-based catalysts Pressure exponent
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Reliability analysis of slope stability by neural network,principal component analysis,and transfer learning techniques 被引量:1
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作者 Sheng Zhang Li Ding +3 位作者 Menglong Xie Xuzhen He Rui Yang Chenxi Tong 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期4034-4045,共12页
The prediction of slope stability is considered as one of the critical concerns in geotechnical engineering.Conventional stochastic analysis with spatially variable slopes is time-consuming and highly computation-dema... The prediction of slope stability is considered as one of the critical concerns in geotechnical engineering.Conventional stochastic analysis with spatially variable slopes is time-consuming and highly computation-demanding.To assess the slope stability problems with a more desirable computational effort,many machine learning(ML)algorithms have been proposed.However,most ML-based techniques require that the training data must be in the same feature space and have the same distribution,and the model may need to be rebuilt when the spatial distribution changes.This paper presents a new ML-based algorithm,which combines the principal component analysis(PCA)-based neural network(NN)and transfer learning(TL)techniques(i.e.PCAeNNeTL)to conduct the stability analysis of slopes with different spatial distributions.The Monte Carlo coupled with finite element simulation is first conducted for data acquisition considering the spatial variability of cohesive strength or friction angle of soils from eight slopes with the same geometry.The PCA method is incorporated into the neural network algorithm(i.e.PCA-NN)to increase the computational efficiency by reducing the input variables.It is found that the PCA-NN algorithm performs well in improving the prediction of slope stability for a given slope in terms of the computational accuracy and computational effort when compared with the other two algorithms(i.e.NN and decision trees,DT).Furthermore,the PCAeNNeTL algorithm shows great potential in assessing the stability of slope even with fewer training data. 展开更多
关键词 slope stability analysis Monte Carlo simulation Neural network(NN) transfer learning(tL)
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