期刊文献+
共找到6,813篇文章
< 1 2 250 >
每页显示 20 50 100
ON SELECTIONS OF SET-VALUED EULER-LAGRANGE INCLUSIONS WITH APPLICATIONS
1
作者 Hamid KHODAEI Iz-iddine EL-FASSI Bahman HAYAT 《Acta Mathematica Scientia》 SCIE CSCD 2020年第4期1105-1115,共11页
We discuss the set-valued dynamics related to the theory of functional equations.We look for selections of convex set-valued functions satisfying set-valued Euler-Lagrange inclusions.We improve and extend upon some of... We discuss the set-valued dynamics related to the theory of functional equations.We look for selections of convex set-valued functions satisfying set-valued Euler-Lagrange inclusions.We improve and extend upon some of the results in[13,20],but under weaker assumptions.Some applications of our results are also provided. 展开更多
关键词 set-valued dynamics Euler-Lagrange inclusion composite operator SELECTION
下载PDF
SET-VALUED EXTENSION OF OPERATORS VIA STEINER SELECTIONS (Ⅰ)-THEORETICAL RESULTS
2
作者 Tern, Pedro, L pez_Dían, Miguel (Facultad de Ciencias, Universidad de Oviedo, C/Calvo Sotelo, s/n 33007 Oviedo Spain) (Communicated by ZHANG Shi_sheng) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第5期568-579,共12页
A way to extend operators in spaces of continuous functions to spaces of continuous set_valued functions is proposed. This extension is developed through the Steiner selections of the set_valued functions. Their prope... A way to extend operators in spaces of continuous functions to spaces of continuous set_valued functions is proposed. This extension is developed through the Steiner selections of the set_valued functions. Their properties and characteristics of the convergence of sequences of operators of this class are studied. In Part Ⅱ of this series some applications to approximation theory will be shown. 展开更多
关键词 set_valued extension steiner selection operator
下载PDF
Continuous Selections and Fixed Points forφ-maps with Their Applications to Section Problems
3
作者 PIAO YONG-JIE JIN HAI-LAN PIAO GUANG-RI 《Communications in Mathematical Research》 CSCD 2012年第3期225-234,共10页
The concept of finitely continuous topological space is introduced and the basic properties of the space are given. Several continuous selection theorems and fixed point theorems for Ф-maps are established, and as ap... The concept of finitely continuous topological space is introduced and the basic properties of the space are given. Several continuous selection theorems and fixed point theorems for Ф-maps are established, and as applications of the above fixed point theorems, some section problems are discussed. The results generalize and improve many corresponding conclusions. 展开更多
关键词 FC-SPACE FC-subset Ф-map continuous selection fixed point section problem
下载PDF
SET-VALUED EXTENSION OF OPERATORS VIA STEINER SELECTIONS(Ⅱ)-APPLICATIONS TO APPROXIMATION
4
作者 Tern, Pedro, Lpez_Daz, Miguel(Facultad de Ciencias, Universidad de Oviedo, C/Calvo Sotelo, s/n. 33007 Oviedo. Spain) (Communicated by ZHANG Shi_sheng) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2002年第5期580-589,共10页
On the basis of Part (Ⅰ) of this series some applications to the approximation of set_valued functions are obtained: Korovkin type theorems, a method to extend classical approximation operators to the set_valued sett... On the basis of Part (Ⅰ) of this series some applications to the approximation of set_valued functions are obtained: Korovkin type theorems, a method to extend classical approximation operators to the set_valued setting and a Jackson type estimate. 展开更多
关键词 set_valued extension Steiner selection a Jackson type estimate
下载PDF
CONTINUOUS SELECTIONS OF THE SET-VALUED METRIC GENERALIZED INVERSE IN 2-STRICTLY CONVEX BANACH SPACES
5
作者 Shaoqiang SHANG 《Acta Mathematica Scientia》 SCIE CSCD 2022年第3期1225-1237,共13页
In this paper,we prove that if X is an almost convex and 2-strictly convex space,linear operator T:X→Y is bounded,N(T)is an approximative compact Chebyshev subspace of X and R(T)is a 3-Chebyshev hyperplane,then there... In this paper,we prove that if X is an almost convex and 2-strictly convex space,linear operator T:X→Y is bounded,N(T)is an approximative compact Chebyshev subspace of X and R(T)is a 3-Chebyshev hyperplane,then there exists a homogeneous selection T^(σ)of T^(■)such that continuous points of T^(σ)and T^(■)are dense on Y. 展开更多
关键词 Continuous selection 3-Chebyshev hyperplane set-valued metric generalized inverses 2-strictly convex space
下载PDF
1-TYPE LIPSCHITZ SELECTIONS IN GENERALIZED 2-NORMED SPACES
6
作者 Sh. Rezapour I. Kupka 《Analysis in Theory and Applications》 2008年第3期205-210,共6页
We shall introduce 1-type Lipschitz multifunctions from R into generalized 2-normed spaces, and give some results about their 1-type Lipschitz selections.
关键词 MULTIFUNCTION 2-normed space Lipschitz selection
下载PDF
Observation on fitting male selections of different kiwifruit varieties
7
作者 HuZhihui ZhongCaihong 《Hunan Agricultural Science & Technology Newsletter》 2003年第1期22-24,共3页
Five male kiwifruit selections Truwind M1, M2, M3, M4 and M5 bred by Hunan Horticultural Research Institute (HHRI)have been observed on the suitability,of which Truwind M1,M2 and M3 are Actinidia chinensis,Truwind M4 ... Five male kiwifruit selections Truwind M1, M2, M3, M4 and M5 bred by Hunan Horticultural Research Institute (HHRI)have been observed on the suitability,of which Truwind M1,M2 and M3 are Actinidia chinensis,Truwind M4 and M5 are Actinidia deliciosa. In terms of flower period Truwind M1 is early and 7 days, which is the suitable pollinator for‘Fengyue’;Truwind M2 is intermediate with 15 days,suitable for ‘Kuimi’and‘Lushanxiang’;Truwind M3 and M4 are 14 days and 13 days respectively,suitable for‘Cuiyu’and‘Miliang 1’;Truwind M5 is late and 8 days, suitable for‘Jinkui’,‘Qinxiang’and‘Hayward’. 展开更多
关键词 KIWIFRUIT male selection SUITABILITY
下载PDF
基于SELECT理念腹腔镜下保留脾脏的胰体尾切除
8
作者 李爽 张标 +5 位作者 刘航宇 祁冰 Thomas Juby 张桂信 张庆凯 尚东 《临床外科杂志》 2024年第7期776-779,共4页
腹腔镜下胰体尾切除术目前已经成为治疗胰腺体尾部肿瘤的标准术式。而腹腔镜下保留脾脏的胰体尾切除术由于可保留脾脏功能,减少脾切除术后并发症,越来越受到重视。然而,胰腺肿瘤发病隐匿、解剖位置复杂,这些对其诊断和保留脾脏的胰体尾... 腹腔镜下胰体尾切除术目前已经成为治疗胰腺体尾部肿瘤的标准术式。而腹腔镜下保留脾脏的胰体尾切除术由于可保留脾脏功能,减少脾切除术后并发症,越来越受到重视。然而,胰腺肿瘤发病隐匿、解剖位置复杂,这些对其诊断和保留脾脏的胰体尾切除术带来了挑战。近年来,我们团队积累了丰富的胰腺肿瘤诊疗经验,创新提出“SELECT”(S-Single-Operator Cholangiopancreatoscopy,E-ERCP,L-Laparoscopy,E-Endoscopic ultrasound,C-Choledochoscopy/Confocal laser endomicroscopy,T-Traditional Chinese medicine)多镜组合中西医微创诊治理念。根据胰腺肿瘤的类型及特点,应用多种内镜和腹腔镜技术,多种不同微创诊疗方法的优选组合,围手术期采用中医药,进行中西医结合加速康复。将SELECT理念充分应用于腹腔镜下保留脾脏的胰体尾切除术,有利于术前精准诊断、术中精准切除、术后并发症预判和治疗,一站式诊治胰腺肿瘤,使病人利益最大化。 展开更多
关键词 SELECT理念 多镜联合 胰腺肿瘤 保留脾脏 胰体尾切除术
下载PDF
基于DTA-FSAF的无人机小目标检测研究
9
作者 赵侃 汪慧兰 +1 位作者 郭娇娇 王桂丽 《计算机技术与发展》 2024年第4期101-108,共8页
随着无人机的应用越来越广泛,基于无人机下的交通场景目标检测的需求也越来越高。但是现有算法在无人机视角下检测精度不高,鲁棒性也不够稳定。为了解决交通场景下无人机视角的车辆和行人的目标检测问题,该文提出DTA-FSAF的目标检测网... 随着无人机的应用越来越广泛,基于无人机下的交通场景目标检测的需求也越来越高。但是现有算法在无人机视角下检测精度不高,鲁棒性也不够稳定。为了解决交通场景下无人机视角的车辆和行人的目标检测问题,该文提出DTA-FSAF的目标检测网络。首先,将可变形卷积融入骨干网络ResNet-50中提高FSAF网络(Feature Selective Anchor-Free)的特征学习能力,采用PAFPN(Path Aggregation Feature Pyramid Network)实现多尺度融合,从而提高小目标的检测精度与网络的拟合能力;其次,使用任务对齐检测头减小网络的分类与定位任务在检测小目标时出现的分类与定位任务的错位,从而进一步提高网络的鲁棒性;最后,通过调整IoU损失提高网络整体的检测效果。通过在无人机数据集VisDrone上进行实验和分析比较可知,相比于其他网络,在不同的交通场景下,DTA-FSAF网络在满足实时性需求的同时检测精度达到了41.3%。相比于FSAF网络提升了19.6%。通过实验证明改进算法能有效地在各种复杂交通场景下完成对行人和车辆的目标检测。 展开更多
关键词 目标检测 小目标检测 Feature Selective Anchor-Free 无人机 标签分配
下载PDF
Dealuminated Hβ zeolite for selective conversion of fructose to furfural and formic acid 被引量:1
10
作者 Rui Li Qixuan Lin +3 位作者 Junli Ren Xiaobao Yang Yingxiong Wang Lingzhao Kong 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第2期311-320,共10页
The fructose-to-furfural transformation is facing major challenges in the selectivity and high efficiency. Herein, we have developed a simple and effective approach for the selective conversion of fructose to furfural... The fructose-to-furfural transformation is facing major challenges in the selectivity and high efficiency. Herein, we have developed a simple and effective approach for the selective conversion of fructose to furfural using Hβ zeolite modified by organic acids for dealuminization to regulate its textural and acidic properties. It was found that citric acid-dealuminized Hβ zeolite possessed high specific surface areas, wide channels and high Brønsted acid amount, which facilitated the selective conversion of fructose to furfural with a maximum yield of 76.2% at433 K for 1 h in the γ-butyrolactone(GBL)-H_(2)O system, as well as the concomitant formation of 83.0% formic acid. The^(13)C-isotope labelling experiments and the mechanism revealed that the selective cleavage of C1–C2 or C5–C6 bond on fructose was firstly occurred to form pentose or C5 intermediate by weak Brønsted acid, which was then dehydrated to furfural by strong Brønsted acid. Also this dealuminized Hβ catalyst showed the great recycling performance and was active for the conversion of glucose and mannose. 展开更多
关键词 FRUCTOSE Dealuminated-Hb zeolite Selective conversion FURFURAL
下载PDF
Recent developments in selective laser processes for wearable devices 被引量:1
11
作者 Youngchan Kim Eunseung Hwang +3 位作者 Chang Kai Kaichen Xu Heng Pan Sukjoon Hong 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第4期517-547,共31页
Recently,the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication methods.Lasers have long been used to d... Recently,the increasing interest in wearable technology for personal healthcare and smart virtual/augmented reality applications has led to the development of facile fabrication methods.Lasers have long been used to develop original solutions to such challenging technological problems due to their remote,sterile,rapid,and site-selective processing of materials.In this review,recent developments in relevant laser processes are summarized under two separate categories.First,transformative approaches,such as for laser-induced graphene,are introduced.In addition to design optimization and the alteration of a native substrate,the latest advances under a transformative approach now enable more complex material compositions and multilayer device configurations through the simultaneous transformation of heterogeneous precursors,or the sequential addition of functional layers coupled with other electronic elements.In addition,the more conventional laser techniques,such as ablation,sintering,and synthesis,can still be used to enhance the functionality of an entire system through the expansion of applicable materials and the adoption of new mechanisms.Later,various wearable device components developed through the corresponding laser processes are discussed,with an emphasis on chemical/physical sensors and energy devices.In addition,special attention is given to applications that use multiple laser sources or processes,which lay the foundation for the all-laser fabrication of wearable devices. 展开更多
关键词 Selective laser process Wearable device Transformative approach Laser-induced graphene Ablation SINTERING Synthesis
下载PDF
Rice Heat Tolerance Breeding: A Comprehensive Review and Forward Gaze 被引量:1
12
作者 Ravindran Lalithambika VISAKH Sreekumar ANAND +4 位作者 Sukumaran Nair ARYA Behera SASMITA Uday Chand JHA Rameswar Prasad SAH Radha BEENA 《Rice science》 SCIE CSCD 2024年第4期375-400,I0022,共27页
The yield potential of rice is seriously affected by heat stress due to climate change. Since rice is a staple food globally, it is imperative to develop heat-resistant rice varieties. Thus, a thorough understanding o... The yield potential of rice is seriously affected by heat stress due to climate change. Since rice is a staple food globally, it is imperative to develop heat-resistant rice varieties. Thus, a thorough understanding of the complex molecular mechanisms underlying heat tolerance and the impact of high temperatures on various critical stages of the crop is needed. Adoption of both conventional and innovative breeding strategies offers a long-term advantage over other methods, such as agronomic practices, to counter heat stress. In this review, we summarize the effects of heat stress, regulatory pathways for heat tolerance, phenotyping strategies, and various breeding methods available for developing heat-tolerant rice. We offer perspectives and knowledge to guide future research endeavors aimed at enhancing the ability of rice to withstand heat stress and ultimately benefit humanity. 展开更多
关键词 genetic mechanism high-temperature stress molecular breeding genomics selection
下载PDF
Artificial intelligence-driven radiomics study in cancer:the role of feature engineering and modeling 被引量:1
13
作者 Yuan-Peng Zhang Xin-Yun Zhang +11 位作者 Yu-Ting Cheng Bing Li Xin-Zhi Teng Jiang Zhang Saikit Lam Ta Zhou Zong-Rui Ma Jia-Bao Sheng Victor CWTam Shara WYLee Hong Ge Jing Cai 《Military Medical Research》 SCIE CAS CSCD 2024年第1期115-147,共33页
Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’anatomy.However,the interpretation of medical images can be highly subjective and dependent on the expertise of... Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’anatomy.However,the interpretation of medical images can be highly subjective and dependent on the expertise of clinicians.Moreover,some potentially useful quantitative information in medical images,especially that which is not visible to the naked eye,is often ignored during clinical practice.In contrast,radiomics performs high-throughput feature extraction from medical images,which enables quantitative analysis of medical images and prediction of various clinical endpoints.Studies have reported that radiomics exhibits promising performance in diagnosis and predicting treatment responses and prognosis,demonstrating its potential to be a non-invasive auxiliary tool for personalized medicine.However,radiomics remains in a developmental phase as numerous technical challenges have yet to be solved,especially in feature engineering and statistical modeling.In this review,we introduce the current utility of radiomics by summarizing research on its application in the diagnosis,prognosis,and prediction of treatment responses in patients with cancer.We focus on machine learning approaches,for feature extraction and selection during feature engineering and for imbalanced datasets and multi-modality fusion during statistical modeling.Furthermore,we introduce the stability,reproducibility,and interpretability of features,and the generalizability and interpretability of models.Finally,we offer possible solutions to current challenges in radiomics research. 展开更多
关键词 Artificial intelligence Radiomics Feature extraction Feature selection Modeling INTERPRETABILITY Multimodalities Head and neck cancer
下载PDF
Liver transplantation as an alternative for the treatment of neuroendocrine liver metastasis: Appraisal of the current evidence 被引量:1
14
作者 Philip C.Muller Matthias Pfister +1 位作者 Dilmurodjon Eshmuminov Kuno Lehmann 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS CSCD 2024年第2期146-153,共8页
Background:Liver transplantation(LT)for neuroendocrine liver metastases(NELM)is still in debate.Studies comparing LT with liver resection(LR)for NELM are scarce,as patient selection is heterogeneous and experience is ... Background:Liver transplantation(LT)for neuroendocrine liver metastases(NELM)is still in debate.Studies comparing LT with liver resection(LR)for NELM are scarce,as patient selection is heterogeneous and experience is limited.The goal of this review was to provide a critical analysis of the evidence on LT versus LR in the treatment of NELM.Data sources:A scoping literature search on LT and LR for NELM was performed with PubMed,including English articles up to March 2023.Results:International guidelines recommend LR for NELM in resectable,well-differentiated tumors in the absence of extrahepatic metastatic disease with superior results of LR compared to systemic or liver-directed therapies.Advanced liver surgery has extended resectability criteria whilst entailing increased perioperative risk and short disease-free survival.In highly selected patients(based on the Milan criteria)with unresectable NELM,oncologic results of LT are promising.Prognostic factors include tumor biology(G1/G2)and burden,waiting time for LT,patient age and extrahepatic spread.Based on low-level evi-dence,LT for low-grade NELM within the Milan criteria resulted in improved disease-free survival and overall survival compared to LR.The benefits of LT were lost in patients beyond the Milan NELM-criteria.Conclusions:With adherence to strict selection criteria especially tumor biology,LT for NELM is becoming a valuable option providing oncologic benefits compared to LR.Recent evidence suggests even stricter selection criteria with regard to tumor biology. 展开更多
关键词 Liver transplantation Neuroendocrine liver metastases Liver resection Selection criteria Tumor biology
下载PDF
Step‑by‑Step Modulation of Crystalline Features and Exciton Kinetics for 19.2%Efficiency Ortho‑Xylene Processed Organic Solar Cells 被引量:1
15
作者 Bosen Zou Weiwei Wu +10 位作者 Top Archie Dela Pena Ruijie Ma Yongmin Luo Yulong Hai Xiyun Xie Mingjie Li Zhenghui Luo Jiaying Wu Chuluo Yang Gang Li He Yan 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期258-272,共15页
With plenty of popular and effective ternary organic solar cells(OSCs)construction strategies proposed and applied,its power conversion efficiencies(PCEs)have come to a new level of over 19%in single-junction devices.... With plenty of popular and effective ternary organic solar cells(OSCs)construction strategies proposed and applied,its power conversion efficiencies(PCEs)have come to a new level of over 19%in single-junction devices.However,previous studies are heavily based in chloroform(CF)leaving behind substantial knowledge deficiencies in understanding the influence of solvent choice when introducing a third component.Herein,we present a case where a newly designed asymmetric small molecular acceptor using fluoro-methoxylated end-group modification strategy,named BTP-BO-3FO with enlarged bandgap,brings different morphological evolution and performance improvement effect on host system PM6:BTP-eC9,processed by CF and ortho-xylene(o-XY).With detailed analyses supported by a series of experiments,the best PCE of 19.24%for green solvent-processed OSCs is found to be a fruit of finely tuned crystalline ordering and general aggregation motif,which furthermore nourishes a favorable charge generation and recombination behavior.Likewise,over 19%PCE can be achieved by replacing spin-coating with blade coating for active layer deposition.This work focuses on understanding the commonly met yet frequently ignored issues when building ternary blends to demonstrate cutting-edge device performance,hence,will be instructive to other ternary OSC works in the future. 展开更多
关键词 Organic solar cells Ternary design Solvent selection Flouro-methoxylated end group Morphological ordering
下载PDF
A robust & weak-nucleophilicity electrocatalyst with an inert response for chlorine ion oxidation in large-current seawater electrolysis 被引量:1
16
作者 Junting Dong Chang Yu +5 位作者 Hui Wang Lin Chen Hongling Huang Yingnan Han Qianbing Wei Jieshan Qiu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期486-495,I0011,共11页
Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and c... Seawater splitting into hydrogen,a promising technology,is seriously limited by the durability and tolerance of electrocatalysts for chlorine ions in seawater at large current densities due to chloride oxidation and corrosion.Here,we present a robust and weak-nucleophilicity nickel-iron hydroxide electrocatalyst with excellent selectivity for oxygen evolution and an inert response for chlorine ion oxidation which are key and highly desired for efficient seawater electrolysis.Such a weak-nucleophilicity electrocatalyst can well match with strong-nucleophilicity OH-compared with the weak-nucleophilicity Cl^(-),resultantly,the oxidation of OH-in electrolyte can be more easily achieved relative to chlorine ion oxidation,confirmed by ethylenediaminetetraacetic acid disodium probing test.Further,no strongly corrosive hypochlorite is produced when the operating voltage reaches about 2.1 V vs.RHE,a potential that is far beyond the thermodynamic potential of chlorine ion oxidatio n.This concept and approach to reasonably designing weaknucleophilicity electrocatalysts that can greatly avoid chlorine ion oxidation under alkaline seawater environments can push forward the seawater electrolysis technology and also accelerate the development of green hydrogen technique. 展开更多
关键词 Nickel-iron hydroxide electrocatalysts Highly selective seawater electrolysis Weak nucleophilicity Oxygen evolution reaction Hydrogen
下载PDF
Surface engineering of ZnO electrocatalyst by N doping towards electrochemical CO_(2) reduction 被引量:1
17
作者 Rohini Subhash Kanase Getasew Mulualem Zewdie +7 位作者 Maheswari Arunachalam Jyoti Badiger Suzan Abdelfattah Sayed Kwang-Soon Ahn Jun-Seok Ha Uk Sim Hyeyoung Shin Soon Hyung Kang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期71-81,I0002,共12页
The discovery of efficient,selective,and stable electrocatalysts can be a key point to produce the largescale chemical fuels via electrochemical CO_(2) reduction(ECR).In this study,an earth-abundant and nontoxic ZnO-b... The discovery of efficient,selective,and stable electrocatalysts can be a key point to produce the largescale chemical fuels via electrochemical CO_(2) reduction(ECR).In this study,an earth-abundant and nontoxic ZnO-based electrocatalyst was developed for use in gas-diffusion electrodes(GDE),and the effect of nitrogen(N)doping on the ECR activity of ZnO electrocatalysts was investigated.Initially,a ZnO nanosheet was prepared via the hydrothermal method,and nitridation was performed at different times to control the N-doping content.With an increase in the N-doping content,the morphological properties of the nanosheet changed significantly,namely,the 2D nanosheets transformed into irregularly shaped nanoparticles.Furthermore,the ECR performance of Zn O electrocatalysts with different N-doping content was assessed in 1.0 M KHCO_(3) electrolyte using a gas-diffusion electrode-based ECR cell.While the ECR activity increased after a small amount of N doping,it decreased for higher N doping content.Among them,the N:ZnO-1 h electrocatalysts showed the best CO selectivity,with a faradaic efficiency(FE_(CO))of 92.7%at-0.73 V vs.reversible hydrogen electrode(RHE),which was greater than that of an undoped Zn O electrocatalyst(FE_(CO)of 63.4%at-0.78 V_(RHE)).Also,the N:ZnO-1 h electrocatalyst exhibited outstanding durability for 16 h,with a partial current density of-92.1 mA cm^(-2).This improvement of N:ZnO-1 h electrocatalyst can be explained by density functional theory calculations,demonstrating that this improvement of N:ZnO-1 h electrocatalyst comes from(ⅰ)the optimized active sites lowering the free energy barrier for the rate-determining step(RDS),and(ⅱ)the modification of electronic structure enhancing the electron transfer rate by N doping. 展开更多
关键词 ZNO N-doped ZnO Gas-diffusion electrode CO Selectivity Electrochemical CO_(2)reduction
下载PDF
Interplay of laser power and pore characteristics in selective laser melting of ZK60 magnesium alloys:A study based on in-situ monitoring and image analysis 被引量:1
18
作者 Weijie Xie Hau-Chung Man Chi-Wai Chan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第4期1346-1366,共21页
This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)alloys.High-speed in-situ monitoring was employed to visualis... This study offers significant insights into the multi-physics phenomena of the SLM process and the subsequent porosity characteristics of ZK60 Magnesium(Mg)alloys.High-speed in-situ monitoring was employed to visualise process signals in real-time,elucidating the dynamics of melt pools and vapour plumes under varying laser power conditions specifically between 40 W and 60 W.Detailed morphological analysis was performed using Scanning-Electron Microscopy(SEM),demonstrating a critical correlation between laser power and pore formation.Lower laser power led to increased pore coverage,whereas a denser structure was observed at higher laser power.This laser power influence on porosity was further confirmed via Optical Microscopy(OM)conducted on both top and cross-sectional surfaces of the samples.An increase in laser power resulted in a decrease in pore coverage and pore size,potentially leading to a denser printed part of Mg alloy.X-ray Computed Tomography(XCT)augmented these findings by providing a 3D volumetric representation of the sample internal structure,revealing an inverse relationship between laser power and overall pore volume.Lower laser power appeared to favour the formation of interconnected pores,while a reduction in interconnected pores and an increase in isolated pores were observed at higher power.The interplay between melt pool size,vapour plume effects,and laser power was found to significantly influence the resulting porosity,indicating a need for effective management of these factors to optimise the SLM process of Mg alloys. 展开更多
关键词 Selective laser melting(SLM) Magnesium(Mg)alloys Biodegradable implants POROSITY In-situ monitoring
下载PDF
Selective internal radiation therapy segmentectomy:A new minimally invasive curative option for primary liver malignancies? 被引量:1
19
作者 Riccardo Inchingolo Francesco Cortese +5 位作者 Antonio Rosario Pisani Fabrizio Acquafredda Roberto Calbi Riccardo Memeo Fotis Anagnostopoulos Stavros Spiliopoulos 《World Journal of Gastroenterology》 SCIE CAS 2024年第18期2379-2386,共8页
Transarterial radioembolization or selective internal radiation therapy(SIRT)has emerged as a minimally invasive approach for the treatment of tumors.This percutaneous technique involves the local,intra-arterial deliv... Transarterial radioembolization or selective internal radiation therapy(SIRT)has emerged as a minimally invasive approach for the treatment of tumors.This percutaneous technique involves the local,intra-arterial delivery of radioactive microspheres directly into the tumor.Historically employed as a palliative measure for liver malignancies,SIRT has gained traction over the past decade as a potential curative option,mirroring the increasing role of radiation segmentectomy.The latest update of the BCLC hepatocellular carcinoma guidelines recognizes SIRT as an effective treatment modality comparable to other local ablative methods,particularly well-suited for patients where surgical resection or ablation is not feasible.Radiation segmentectomy is a more selective approach,aiming to deliver high-dose radiation to one to three specific hepatic segments,while minimizing damage to surrounding healthy tissue.Future research efforts in radiation segmentectomy should prioritize optimizing radiation dosimetry and refining the technique for super-selective administration of radiospheres within the designated hepatic segments. 展开更多
关键词 Transarterial radioembolization Selective internal radiation therapy Radiation segmentectomy Hepatocellular carcinoma Primary liver malignancies Personalised dosimetry
下载PDF
A phenology-based vegetation index for improving ratoon rice mapping using harmonized Landsat and Sentinel-2 data 被引量:1
20
作者 Yunping Chen Jie Hu +6 位作者 Zhiwen Cai Jingya Yang Wei Zhou Qiong Hu Cong Wang Liangzhi You Baodong Xu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1164-1178,共15页
Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while r... Ratoon rice,which refers to a second harvest of rice obtained from the regenerated tillers originating from the stubble of the first harvested crop,plays an important role in both food security and agroecology while requiring minimal agricultural inputs.However,accurately identifying ratoon rice crops is challenging due to the similarity of its spectral features with other rice cropping systems(e.g.,double rice).Moreover,images with a high spatiotemporal resolution are essential since ratoon rice is generally cultivated in fragmented croplands within regions that frequently exhibit cloudy and rainy weather.In this study,taking Qichun County in Hubei Province,China as an example,we developed a new phenology-based ratoon rice vegetation index(PRVI)for the purpose of ratoon rice mapping at a 30 m spatial resolution using a robust time series generated from Harmonized Landsat and Sentinel-2(HLS)images.The PRVI that incorporated the red,near-infrared,and shortwave infrared 1 bands was developed based on the analysis of spectro-phenological separability and feature selection.Based on actual field samples,the performance of the PRVI for ratoon rice mapping was carefully evaluated by comparing it to several vegetation indices,including normalized difference vegetation index(NDVI),enhanced vegetation index(EVI)and land surface water index(LSWI).The results suggested that the PRVI could sufficiently capture the specific characteristics of ratoon rice,leading to a favorable separability between ratoon rice and other land cover types.Furthermore,the PRVI showed the best performance for identifying ratoon rice in the phenological phases characterized by grain filling and harvesting to tillering of the ratoon crop(GHS-TS2),indicating that only several images are required to obtain an accurate ratoon rice map.Finally,the PRVI performed better than NDVI,EVI,LSWI and their combination at the GHS-TS2 stages,with producer's accuracy and user's accuracy of 92.22 and 89.30%,respectively.These results demonstrate that the proposed PRVI based on HLS data can effectively identify ratoon rice in fragmented croplands at crucial phenological stages,which is promising for identifying the earliest timing of ratoon rice planting and can provide a fundamental dataset for crop management activities. 展开更多
关键词 ratoon rice phenology-based ratoon rice vegetation index(PRVI) phenological phase feature selection Harmonized Landsat Sentinel-2 data
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部