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Progress in clustering algorithms for astronomical spectra over a decade
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作者 Jianing Tian Haifeng Yang +4 位作者 Jianghui Cai Yuqing Yang Xiangru Li Zhenping Yi Lili Wang 《Astronomical Techniques and Instruments》 2026年第1期10-25,共16页
As large-scale astronomical surveys,such as the Sloan Digital Sky Survey(SDSS)and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST),generate increasingly complex datasets,clustering algorithms have... As large-scale astronomical surveys,such as the Sloan Digital Sky Survey(SDSS)and the Large Sky Area Multi-Object Fiber Spectroscopic Telescope(LAMOST),generate increasingly complex datasets,clustering algorithms have become vital for identifying patterns and classifying celestial objects.This paper systematically investigates the application of five main categories of clustering techniques-partition-based,density-based,model-based,hierarchical,and“others”-across a range of astronomical research over the past decade.This review focuses on the six key application areas of stellar classification,galaxy structure analysis,detection of galactic and interstellar features,highenergy astrophysics,exoplanet studies,and anomaly detection.This paper provides an in-depth analysis of the performance and results of each method,considering their respective suitabilities for different data types.Additionally,it presents clustering algorithm selection strategies based on the characteristics of the spectroscopic data being analyzed.We highlight challenges such as handling large datasets,the need for more efficient computational tools,and the lack of labeled data.We also underscore the potential of unsupervised and semi-supervised clustering approaches to overcome these challenges,offering insight into their practical applications,performance,and results in astronomical research. 展开更多
关键词 CLUSTERING Stellar types astronomical techniques CLASSIFICATION GALAXIES
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Key Techniques for High-yield and High-efficiency Cultivation of‘Zhouhua 5’Peanut under Film Mulching
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作者 Chaoyang JIA Yake LEI +3 位作者 Jianhang ZHANG Shijie ZHAN Chenwei DENG Jingbin CUI 《Agricultural Biotechnology》 2026年第1期13-15,25,共4页
With the expansion of peanut planting area year by year,film mulching cultivation has become increasingly important in peanut production due to its unique advantages in enhancing both yield per unit area and overall e... With the expansion of peanut planting area year by year,film mulching cultivation has become increasingly important in peanut production due to its unique advantages in enhancing both yield per unit area and overall economic benefits.Based on the varietal characteristics of‘Zhouhua 5’and addressing practical issues in peanut production,this paper summarized key techniques for high-yield and high-efficiency film mulching cultivation of this variety.These techniques cover all critical stages,including land preparation and fertilization,seed preparation,sowing methods,field management,and timely harvesting,providing technical guidance for varietal promotion and peanut production. 展开更多
关键词 PEANUT Zhouhua 5 Film mulching Key technique
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Prospects and potential mechanism of appropriate traditional Chinese medicine techniques for myopia treatment
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作者 Hui-Min Guo Hong-Mei Li Shu-Li Man 《Traditional Medicine Research》 2026年第1期100-114,共15页
Currently,the number of patients with myopia is increasing rapidly across the globe.Traditional Chinese medicine(TCM),with its long history and rich experience,has shown promise in effectively managing and treating th... Currently,the number of patients with myopia is increasing rapidly across the globe.Traditional Chinese medicine(TCM),with its long history and rich experience,has shown promise in effectively managing and treating this condition.Nevertheless,considering the vast amount of research that is currently being conducted,focusing on the utilization of TCM in the management of myopia,there is an urgent requirement for a thorough and comprehensive review.The review would serve to clarify the practical applications of TCM within this specific field,and it would also aim to elucidate the underlying mechanisms that are at play,providing a deeper understanding of how TCM principles can be effectively integrated into modern medical practices.Here,some modern medical pathogenesis of myopia and appropriate TCM techniques studies are summarized in the prevention and treatment of myopia.Further,we discussed the potential mechanisms and the future research directions of TCM against myopia.Identifying these mechanisms is crucial for understanding how TCM can be effectively utilized in this context.The combination of various TCM methods or the combination of traditional Chinese and Western medicine is of great significance for the prevention and control of myopia in the future. 展开更多
关键词 traditional Chinese medicine MYOPIA PATHOGENESIS appropriate TCM techniques
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Enhancing Heat Exchanger Performance through Passive Techniques:A Comprehensive Review
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作者 Muhammad Waheed Azam Uzair Sajjad +1 位作者 Faisal Maqbool Giovani Sempirini 《Frontiers in Heat and Mass Transfer》 2026年第1期25-53,共29页
Heat exchangers play a crucial role in thermal energy systems,with their performance directly impacting efficiency,cost,and environmental impact.Apowerful technique for performance improvement can be given by passive ... Heat exchangers play a crucial role in thermal energy systems,with their performance directly impacting efficiency,cost,and environmental impact.Apowerful technique for performance improvement can be given by passive enhancement strategies,which are characterized by their dependability and minimal external power requirements.This comprehensive review critically assesses recent advancements in such passive methods to evaluate their heat transfer mechanisms,performance characteristics,and practical implementation challenges.Our methodology involves a systematic and comprehensive analysis of various heat transfer enhancement techniques,including surface modifications,extended surfaces,swirl flow devices,and tube inserts.This approach synthesizes and integrates findings from a broad spectrum of experimental investigations and numerical simulations to establish a cohesive understanding of their performance characteristics and underlyingmechanisms.Based on the findings,passive heat transfer techniques result in significant improvements in thermal performance;for instance,corrugated and roughened surfaces increase the heat transfer coefficient by 50%–200%,and advanced insert geometries,such as modified twisted tapes,can increase it by more than 300%,typically accompanied by significant pressure-drop penalties.However,an important finding is the general trade-off between enhanced heat transfer and higher frictional loss,which requires optimization depending on the applications.Finally,this review also provides recommendations that will document the gaps of various passive techniques in heat exchangers to future address. 展开更多
关键词 Heat transfer enhancement passive techniques pressure drop heat exchangers
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Impact of Data Processing Techniques on AI Models for Attack-Based Imbalanced and Encrypted Traffic within IoT Environments
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作者 Yeasul Kim Chaeeun Won Hwankuk Kim 《Computers, Materials & Continua》 2026年第1期247-274,共28页
With the increasing emphasis on personal information protection,encryption through security protocols has emerged as a critical requirement in data transmission and reception processes.Nevertheless,IoT ecosystems comp... With the increasing emphasis on personal information protection,encryption through security protocols has emerged as a critical requirement in data transmission and reception processes.Nevertheless,IoT ecosystems comprise heterogeneous networks where outdated systems coexist with the latest devices,spanning a range of devices from non-encrypted ones to fully encrypted ones.Given the limited visibility into payloads in this context,this study investigates AI-based attack detection methods that leverage encrypted traffic metadata,eliminating the need for decryption and minimizing system performance degradation—especially in light of these heterogeneous devices.Using the UNSW-NB15 and CICIoT-2023 dataset,encrypted and unencrypted traffic were categorized according to security protocol,and AI-based intrusion detection experiments were conducted for each traffic type based on metadata.To mitigate the problem of class imbalance,eight different data sampling techniques were applied.The effectiveness of these sampling techniques was then comparatively analyzed using two ensemble models and three Deep Learning(DL)models from various perspectives.The experimental results confirmed that metadata-based attack detection is feasible using only encrypted traffic.In the UNSW-NB15 dataset,the f1-score of encrypted traffic was approximately 0.98,which is 4.3%higher than that of unencrypted traffic(approximately 0.94).In addition,analysis of the encrypted traffic in the CICIoT-2023 dataset using the same method showed a significantly lower f1-score of roughly 0.43,indicating that the quality of the dataset and the preprocessing approach have a substantial impact on detection performance.Furthermore,when data sampling techniques were applied to encrypted traffic,the recall in the UNSWNB15(Encrypted)dataset improved by up to 23.0%,and in the CICIoT-2023(Encrypted)dataset by 20.26%,showing a similar level of improvement.Notably,in CICIoT-2023,f1-score and Receiver Operation Characteristic-Area Under the Curve(ROC-AUC)increased by 59.0%and 55.94%,respectively.These results suggest that data sampling can have a positive effect even in encrypted environments.However,the extent of the improvement may vary depending on data quality,model architecture,and sampling strategy. 展开更多
关键词 Encrypted traffic attack detection data sampling technique AI-based detection IoT environment
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Research Advances in Modern Analytical Techniques for Quality Control and Clinical Application of Ganmai Dazao Decoction
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作者 Zihan Zhu 《Journal of Clinical and Nursing Research》 2026年第1期338-344,共7页
Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao)... Ganmai Dazao Decoction,originating from“Jin Gui Yao Lue”(Synopsis of the Golden Chamber),is a classical prescription for treating visceral agitation.Composed of three medicinal and edible substances-licorice(Gancao),wheat(Xiaomai),and jujube(Dazao),it functions to nourish the heart and calm the mind,harmonize the middle burner and regulate Qi,and alleviate urgency and restlessness.As its clinical application has expanded from traditional emotional disorders to neurological,endocrine,and various psychosomatic diseases,establishing a scientifically precise quality control system and deeply elucidating its pharmacodynamic material basis and mechanism of action have become critical tasks.Modern analytical methods,typified by chromatography,spectroscopy,and their hyphenated techniques,with their high sensitivity,high resolution,and powerful substance characterization capabilities,have become the core driving force for standardizing the quality control and modernizing the clinical application research of this formula.This paper systematically reviews the progress of the aforementioned analytical techniques and chemometrics in interpreting the chemical composition,establishing fingerprint profiles,controlling process quality,and researching the pharmacodynamic material basis of Ganmai Dazao Decoction.Furthermore,it discusses integrated approaches combining analytical techniques with pharmacology and clinical medicine to reveal mechanisms of action and explore therapeutic biomarkers.Finally,it provides an outlook on future directions and challenges,including technological integration and innovation,standardization of whole-process quality control systems,and evidence-based research aimed at internationalization. 展开更多
关键词 Ganmai Dazao Decoction Quality control Modern analytical techniques FINGERPRINT Pharmacodynamic material basis Clinical application
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Synaptic pruning mechanisms and application of emerging imaging techniques in neurological disorders
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作者 Yakang Xing Yi Mo +1 位作者 Qihui Chen Xiao Li 《Neural Regeneration Research》 2026年第5期1698-1714,共17页
Synaptic pruning is a crucial process in synaptic refinement,eliminating unstable synaptic connections in neural circuits.This process is triggered and regulated primarily by spontaneous neural activity and experience... Synaptic pruning is a crucial process in synaptic refinement,eliminating unstable synaptic connections in neural circuits.This process is triggered and regulated primarily by spontaneous neural activity and experience-dependent mechanisms.The pruning process involves multiple molecular signals and a series of regulatory activities governing the“eat me”and“don't eat me”states.Under physiological conditions,the interaction between glial cells and neurons results in the clearance of unnecessary synapses,maintaining normal neural circuit functionality via synaptic pruning.Alterations in genetic and environmental factors can lead to imbalanced synaptic pruning,thus promoting the occurrence and development of autism spectrum disorder,schizophrenia,Alzheimer's disease,and other neurological disorders.In this review,we investigated the molecular mechanisms responsible for synaptic pruning during neural development.We focus on how synaptic pruning can regulate neural circuits and its association with neurological disorders.Furthermore,we discuss the application of emerging optical and imaging technologies to observe synaptic structure and function,as well as their potential for clinical translation.Our aim was to enhance our understanding of synaptic pruning during neural development,including the molecular basis underlying the regulation of synaptic function and the dynamic changes in synaptic density,and to investigate the potential role of these mechanisms in the pathophysiology of neurological diseases,thus providing a theoretical foundation for the treatment of neurological disorders. 展开更多
关键词 CHEMOKINE COMPLEMENT experience-dependent driven synaptic pruning imaging techniques NEUROGLIA signaling pathways synapse elimination synaptic pruning
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Smart Techniques Promoting Sustainability in Construction Engineering and Management 被引量:2
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作者 Song-Shun Lin Shui-Long Shen +1 位作者 Annan Zhou Xiang-Sheng Chen 《Engineering》 2025年第2期262-282,共21页
Construction engineering and management(CEM)has become increasingly complicated with the increasing size of engineering projects under different construction environments,motivating the digital transformation of CEM.T... Construction engineering and management(CEM)has become increasingly complicated with the increasing size of engineering projects under different construction environments,motivating the digital transformation of CEM.To contribute to a better understanding of the state of the art of smart techniques for engineering projects,this paper provides a comprehensive review of multi-criteria decision-making(MCDM)techniques,intelligent techniques,and their applications in CEM.First,a comprehensive framework detailing smart technologies for construction projects is developed.Next,the characteristics of CEM are summarized.A bibliometric review is then conducted to investigate the keywords,journals,and clusters related to the application of smart techniques in CEM during 2000-2022.Recent advancements in intelligent techniques are also discussed under the following six topics:①big data technology;②computer vision;③speech recognition;④natural language processing;⑤machine learning;and⑥knowledge representation,understanding,and reasoning.The applications of smart techniques are then illustrated via underground space exploitation.Finally,future research directions for the sustainable development of smart construction are highlighted. 展开更多
关键词 Construction engineering and management Multi-criteria decision-making techniques Intelligent techniques Digital transformation SUSTAINABILITY
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Design and analysis of a direct-drive motor for astronomical telescopes in extreme Antarctic environments 被引量:1
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作者 Yao Zhang Qingshan Li +3 位作者 Zhengyang Li Xiaoyan Li Zhenshuai Yan Jia’nan Cong 《Astronomical Techniques and Instruments》 2025年第6期339-347,共9页
Effective motors are crucial for driving astronomical telescopes,especially for those operating in Antarctica,where the harsh environment and operating conditions,including extreme low temperature,ice/snow accumulatio... Effective motors are crucial for driving astronomical telescopes,especially for those operating in Antarctica,where the harsh environment and operating conditions,including extreme low temperature,ice/snow accumulation,low power consumption,and unattended operation,introduce challenges to the design and development of motor drives.We present the design of a permanent magnet synchronous motor suitable for this environment,conducting a quantitative analysis on the impacts of cryogenic conditions on lubricant performance,differential thermal contraction of metallic components,and remanent flux density of neodymium iron boron(N52)permanent magnets.We also implement a labyrinth seal structure,combined with silicone sealing rings,to mitigate ice crystal intrusion risks.Finite element analysis and laboratory tests demonstrate a maximum torque output of 25 Nm.This kind of motor is used in the Antarctic 15 cm Near Infrared Telescope at Dome A,Antarctica.Operation data shows a total encoder feedback error of 0.0678"for the telescope control system with 15"s^(−1)tracking speed at−56.79°C.These results comprehensively validate the high reliability and precision of the motor under the extreme conditions of the polar environment. 展开更多
关键词 Axial flux motor Low temperature 3D finite element analysis Antarctic astronomical telescope Dome A
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Improvement and correction for transverse emittance diagnosis based on Q-scanning techniques 被引量:1
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作者 Yi-Feng Zeng Hao Hu Tong-Ning Hu 《Nuclear Science and Techniques》 2025年第3期1-11,共11页
Precise transverse emittance assessment in electron beams is crucial for advancing high-brightness beam injectors.As opposed to intricate methodologies that use specialized devices,quadrupole focusing strength scannin... Precise transverse emittance assessment in electron beams is crucial for advancing high-brightness beam injectors.As opposed to intricate methodologies that use specialized devices,quadrupole focusing strength scanning(Q-scanning)techniques offer notable advantages for various injectors owing to their inherent convenience and cost-effectiveness.However,their stringent approximation conditions lead to inevitable errors in practical operation,thereby limiting their widespread application.This study addressed these challenges by revisiting the analytical derivation procedure and investigating the effects of the underlying approximation conditions.Preliminary corrections were explored through a combination of data processing analysis and numerical simulations.Furthermore,based on theoretical derivations,virtual measurements using beam dynamics calculations were employed to evaluate the correction reliability.Subsequent experimental validations were performed at the Huazhong University of Science and Technology injector to verify the effectiveness of the proposed compensation method.Both the virtual and experimental results confirm the feasibility and reliability of the enhanced Q-scanning-based diagnosis for transverse emittance in typical beam injectors operating under common conditions.Through the integration of these corrections and compensations,enhanced Q-scanning-based techniques emerge as promising alternatives to traditional emittance diagnosis methods. 展开更多
关键词 Beam diagnostics Transverse emittance Q-scanning technique Beam injector
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High-fidelity Lumped-parameter Thermal Models for Assessing Cooling Techniques of PMSMs in EV Applications 被引量:2
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作者 Dawei Liang Zi Qiang Zhu Ankan Dey 《CES Transactions on Electrical Machines and Systems》 2025年第1期1-14,共14页
This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,includin... This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,including frame forced air/liquid cooling,oil jet cooling for endwinding,and rotor shaft cooling.To address the temperature misestimation in the LP thermal modelling due to assumptions of concentrated loss input and uniform heat flows,the developed HF-LPTM introduces two compensation thermal resistances for the winding and PM components,which are analytically derived from the multi-dimensional heat transfer equations and are robust against different load/thermal conditions.As validated by the finite element analysis method and experiments,the conventional LPTMs exhibit significant winding temperature deviations,while the proposed HF-LPTM can accurately predict both the midpoint and average temperatures.The developed HFLPTM is further used to assess the effectiveness of various cooling techniques under different scenarios,i.e.,steady-state thermal states under the rated load condition,and transient temperature profiles under city,freeway,and hybrid(city+freeway)driving cycles.Results indicate that no single cooling technique can maintain both winding and PM temperatures within safety limits.The combination of frame liquid cooling and oil jet cooling for end winding can sufficiently mitigate PMSM thermal stress in EV applications. 展开更多
关键词 Cooling techniques Electric vehicle Lumpedparameter thermal model Permanent magnet synchronous machines Thermal analysis Thermal management
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Enhancing Deepfake Detection:Proactive Forensics Techniques Using Digital Watermarking
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作者 Zhimao Lai Saad Arif +2 位作者 Cong Feng Guangjun Liao Chuntao Wang 《Computers, Materials & Continua》 SCIE EI 2025年第1期73-102,共30页
With the rapid advancement of visual generative models such as Generative Adversarial Networks(GANs)and stable Diffusion,the creation of highly realistic Deepfake through automated forgery has significantly progressed... With the rapid advancement of visual generative models such as Generative Adversarial Networks(GANs)and stable Diffusion,the creation of highly realistic Deepfake through automated forgery has significantly progressed.This paper examines the advancements inDeepfake detection and defense technologies,emphasizing the shift from passive detection methods to proactive digital watermarking techniques.Passive detection methods,which involve extracting features from images or videos to identify forgeries,encounter challenges such as poor performance against unknown manipulation techniques and susceptibility to counter-forensic tactics.In contrast,proactive digital watermarking techniques embed specificmarkers into images or videos,facilitating real-time detection and traceability,thereby providing a preemptive defense againstDeepfake content.We offer a comprehensive analysis of digitalwatermarking-based forensic techniques,discussing their advantages over passivemethods and highlighting four key benefits:real-time detection,embedded defense,resistance to tampering,and provision of legal evidence.Additionally,the paper identifies gaps in the literature concerning proactive forensic techniques and suggests future research directions,including cross-domain watermarking and adaptive watermarking strategies.By systematically classifying and comparing existing techniques,this review aims to contribute valuable insights for the development of more effective proactive defense strategies in Deepfake forensics. 展开更多
关键词 Deepfake proactive forensics digital watermarking TRACEABILITY detection techniques
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Elastic properties of Cu–6wt% Ag alloy wires for pulsed magnets investigated by ultrasonic techniques 被引量:1
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作者 Ziyu Li Tianyi Gu +12 位作者 Wenqi Wei Yang Yuan Zhuo Wang Kangjian Luo Yupeng Pan Jianfeng Xie Shaozhe Zhang Tao Peng Lin Liu Qi Chen Xiaotao Han Yongkang Luo Liang Li 《Chinese Physics B》 2025年第2期90-95,共6页
Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we... Conductor materials with good mechanical performance as well as high electrical and thermal conductivities are particularly important to break through the current bottle-neck limit(~ 100 T) of pulsed magnets. Here, we perform systematic studies on the elastic properties of the Cu–6wt% Ag alloy wire, which is a promising candidate material for the new-generation pulsed magnets, by employing two independent ultrasonic techniques, i.e., resonant ultrasound spectroscopy(RUS) and ultrasound pulse-echo experiments. Our RUS measurements manifest that the elastic properties of the Cu–6wt% Ag alloy wires can be improved by an electroplastic drawing procedure as compared with the conventional cold drawing. We also take this opportunity to test the availability of our newly-built ultrasound pulse-echo facility at the Wuhan National High Magnetic Field Center(WHMFC, China), and the results suggest that the elastic performance of the electroplastically-drawn Cu–6wt% Ag alloy wire remains excellent without anomalous softening under extreme conditions,e.g., in ultra-high magnetic field up to 50 T and nitrogen or helium cryogenic liquids. 展开更多
关键词 high-field magnet Cu–Ag alloy ultrasonic techniques elastic constants
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Sphincter-preserving surgical techniques in low rectal cancer management:A systematic review of contemporary evidence 被引量:1
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作者 Song Wang A-Jian Li +2 位作者 Hui-Hong Jiang Yin Lin Hai-Bo Ding 《World Journal of Gastrointestinal Surgery》 2025年第7期41-52,共12页
Rectal cancer ranks as the third most prevalent malignancy globally,with an estimated 1.9 million incident cases reported in 2020.The management of low rectal cancer presents significant therapeutic challenges due to ... Rectal cancer ranks as the third most prevalent malignancy globally,with an estimated 1.9 million incident cases reported in 2020.The management of low rectal cancer presents significant therapeutic challenges due to its anatomical complexity,and substantially impacts patients'quality of life.While abdominoperineal resection(Miles procedure)ensures oncological radicality,the morbidity associated with permanent colostomy has driven innovations in sphincter-preserving surgical techniques.This review synthesizes current evidence on sphincter-preserving surgical approaches for low rectal cancer.The implementation of total mesorectal excision(TME)principles and enhanced understanding of circumferential resection margin have facilitated the evolution of diverse sphincter-preserving surgical modalities.These include local excision,low anterior resection(Dixon procedure),intersphincteric resection,pull-through procedures,transanal TME,and conventional sphincter-preserving operation.Minimally invasive approaches,particularly laparoscopic and robotic platforms,alongside natural orifice transluminal endoscopic surgery,have demonstrated improved surgical precision and enhanced postoperative recovery outcomes.Novel functional perineal reconstruction techniques offer promising alternatives for patients requiring posterior pelvic exenteration.Nevertheless,the high incidence of low anterior resection syndrome(LARS)and its chronic sequelae remain clinically notable.Evidence indicates that long-course neoadjuvant radiotherapy and TME constitute significant risk factors for LARS development.Contemporary sphincter-preserving surgery for low rectal cancer is advancing toward minimally invasive,personalized,and precision-based approaches.The increasing incidence of early-onset rectal cancer necessitates individualized treatment strategies that balance oncological efficacy with functional preservation.Future directions should focus on standardizing surgical indications,optimizing postoperative rehabilitation protocols,and enhancing treatment outcomes through multidisciplinary integration and technological innovation. 展开更多
关键词 Low rectal cancer Sphincter-preserving surgery Minimally invasive techniques Functional reconstruction Quality of life
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Methodology Study for Planning On-site Monitoring for Radio Astronomical Site Selection from Unmanned Aspects
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作者 Yongwei Guo Chao Hu +2 位作者 Xiaoyun Ma Gang Xu Jianbin Li 《Research in Astronomy and Astrophysics》 2025年第7期88-94,共7页
Astronomical site selection work is very hard.Unmanned technologies are important trends and solutions.We present a relatively easy method to plan a high reliability site selection which can extend the time from site ... Astronomical site selection work is very hard.Unmanned technologies are important trends and solutions.We present a relatively easy method to plan a high reliability site selection which can extend the time from site deployment to returning for maintaining by unmanned confirming the site.First,we redefine the reliability of a site selection deployment with the parameter of the trusty time,which means when we must return,and which can be relatively easy for estimating.The redefinition makes the reliability parameter as a Bayesian probability,and can be obtained by estimating besides testing,which makes the evaluation of each device's reliability much easier.Then we use block diagram tools in the Matlab Simulink software to construct structure diagram,and to link each component with relations of parallel,serial,protection,and so on.This makes the whole reliability value can be calculated at the time when we design or plan a site selection.We applied this concept and method in an actual site selection in Lenghu,Qinghai Province,China.The survey practice reveals its effectiveness and simpleness. 展开更多
关键词 astronomical Instrumentation Methods and techniques site testing methods:analytical
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Enhanced Ion Sampling Techniques for In-situ Neutral Gas and Low-energy Ions Exploration of Main-belt Comet
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作者 WANG Xinyue ZHANG Aibing +4 位作者 SU Bin DU Dan KONG Linggao TIAN Zheng ZHENG Xiangzhi 《空间科学学报》 北大核心 2025年第3期749-760,共12页
One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific object... One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water. 展开更多
关键词 neutral gas low energy ions sampling techniques ion sampling techniques investigate space environment main belt comet gas ion analyzer gia situ measurement
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The Special Issue on Antarctic Astronomy:Techniques and Instruments
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《Astronomical Techniques and Instruments》 2025年第6期I0001-I0001,共1页
Dear Readers:Antarctica,with its unparalleled atmospheric transparency,extended polar nights,and unique geographical position,has become a premier site for modern astronomical observation.Two decades ago,the Chinese A... Dear Readers:Antarctica,with its unparalleled atmospheric transparency,extended polar nights,and unique geographical position,has become a premier site for modern astronomical observation.Two decades ago,the Chinese Antarctic Research Expedition(CHINARE)team reached Dome A,the highest point of the Antarctic ice sheet,marking the beginning of a new era for astro-nomical research from the Antarctic plateau. 展开更多
关键词 geographical position atmospheric transparency modern astronomical observationtwo chinese antarctic research expedition polar nights astronomical observation antarctic research antarctic astronomy
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Advancements and challenges in neuroimaging for the diagnosis of intracranial aneurysms:Addressing false positive diagnoses and emerging techniques
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作者 Nanthida Arora Sombat Muengtaweepongsa 《World Journal of Clinical Cases》 SCIE 2025年第6期48-50,共3页
Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We dis... Despite advancements in neuroimaging,false positive diagnoses of intracranial aneurysms remain a significant concern.This article examines the causes,prevalence,and implications of such false-positive diagnoses.We discuss how conditions like arterial occlusion with vascular stump formation and infundibular widening can mimic aneurysms,particularly in the anterior circulation.The article compares various imaging modalities,including computer tomography angiogram,magnetic resonance imaging/angiography,and digital subtraction angiogram,highlighting their strengths and limitations.We emphasize the im-portance of accurate differentiation to avoid unnecessary surgical interventions.The potential of emerging technologies,such as high-resolution vessel wall ima-ging and deep neural networks for automated detection,is explored as promising avenues for improving diagnostic accuracy.This manuscript underscores the need for continued research and clinical vigilance in the diagnosis of intracranial aneurysms. 展开更多
关键词 Intracranial aneurysms Neuroimaging techniques Computed tomographic angiography Magnetic resonance angiography Digital subtraction angiography False positive diagnoses
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Astronomical time scale-based analysis of Miocene sedimentation rates and their controlling factors in the Zhujiang River Mouth Basin
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作者 Bianqing Guo Di Gao +4 位作者 Guangrong Peng Meng Li Yanshu Yin Guangxu Wang Wei Wu 《Acta Oceanologica Sinica》 2025年第12期139-152,共14页
The Zhujiang River Mouth Basin,a primary depocenter for terrigenous sediments in the western Pacific,presents a semienclosed tectonic setting with limited exchange with the open ocean.This unique feature enables syste... The Zhujiang River Mouth Basin,a primary depocenter for terrigenous sediments in the western Pacific,presents a semienclosed tectonic setting with limited exchange with the open ocean.This unique feature enables systematic linkages among sedimentary processes,climate change,regional sea-level fluctuations,and tectonic events.To explore these linkages,this study focuses on Well PY35 in the Baiyun Sag of the Zhujiang River Mouth Basin.By integrating microfossil analysis with Milankovitch cycle analysis of well log data,an astronomical time scale(ATS)(17.54-7.80 Ma)and a high-resolution stratigraphic framework were established,allowing for the calculation of sedimentation rates across different hierarchical sequences and time intervals.The results indicate that between 17.54 Ma and 7.80 Ma,the sedimentation rate initially increased and then decreased,ranging from 6.1 cm/ka to 45.7 cm/ka,with an average rate of 22.2 cm/ka.During the Middle Miocene Climatic Optimum(MMCO),sedimentation rates were moderate and exhibited an increasing trend,largely driven by increased sediment input due to enhanced weathering from rising temperatures and by expanded accommodation space resulting from tectonic subsidence.Meanwhile,the Middle Miocene Climate Transition(MMCT)was marked by a notable rise in sedimentation rates,consistent with a major sea-level fall due to global cooling,which promoted the direct seaward progradation of marginal sediments.The Late Middle Miocene to Late Miocene had the lowest sedimentation rates,which can be attributed to reduced weathering under cold and arid conditions,along with a sea-level rise induced by regional tectonics.The short-term increase in the sedimentation rate observed at 10.4 Ma may have been driven by sea-level fluctuations.This study provides both theoretical and empirical support for understanding the influence of abrupt climate changes on sedimentary processes. 展开更多
关键词 MIOCENE astronomical time scale sedimentation rate Milankovitch cycle stratigraphic framework
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Research Status of Short Process Forming Techniques for Brazing and Soldering Materials
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作者 Dong Bowen Shi Guangyuan +4 位作者 Zhong Sujuan Dong Xian Cheng Yafang Long Weimin Zhang Guanxing 《稀有金属材料与工程》 北大核心 2025年第2期377-384,共8页
Short process forming techniques for brazing and soldering materials can shorten the process,improve product quality,and increase production efficiency,which has received much attention from welding researchers.This r... Short process forming techniques for brazing and soldering materials can shorten the process,improve product quality,and increase production efficiency,which has received much attention from welding researchers.This review mainly summarized the research reports on short process forming techniques for brazing and soldering materials.Firstly,the traditional process and its shortcomings were presented.Secondly,the latest research of short process forming technologies,such as continuous casting technique,atomization powder technique,solder ball forming technique,and rapid solidification technique,was summarized,and the traditional forming performance of several brazing and soldering materials was introduced.Finally,the current restrictions and research trends of short process forming technique for brazing and solder materials were put forward,providing theoretical guidance and reference for related research and technique development in brazing and soldering field. 展开更多
关键词 short process forming technique continuous casting atomization powder soldering ball rapid solidification amorphous filler metals
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