期刊文献+
共找到819篇文章
< 1 2 41 >
每页显示 20 50 100
Disruption prediction based on fusion feature extractor on J-TEXT
1
作者 郑玮 薛凤鸣 +9 位作者 陈忠勇 沈呈硕 艾鑫坤 钟昱 王能超 张明 丁永华 陈志鹏 杨州军 潘垣 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第7期12-23,共12页
Predicting disruptions across different tokamaks is necessary for next generation device.Future large-scale tokamaks can hardly tolerate disruptions at high performance discharge,which makes it difficult for current d... Predicting disruptions across different tokamaks is necessary for next generation device.Future large-scale tokamaks can hardly tolerate disruptions at high performance discharge,which makes it difficult for current data-driven methods to obtain an acceptable result.A machine learning method capable of transferring a disruption prediction model trained on one tokamak to another is required to solve the problem.The key is a feature extractor which is able to extract common disruption precursor traces in tokamak diagnostic data,and can be easily transferred to other tokamaks.Based on the concerns above,this paper presents a deep feature extractor,namely,the fusion feature extractor(FFE),which is designed specifically for extracting disruption precursor features from common diagnostics on tokamaks.Furthermore,an FFE-based disruption predictor on J-TEXT is demonstrated.The feature extractor is aimed to extracting disruption-related precursors and is designed according to the precursors of disruption and their representations in common tokamak diagnostics.Strong inductive bias on tokamak diagnostics data is introduced.The paper presents the evolution of the neural network feature extractor and its comparison against general deep neural networks,as well as a physics-based feature extraction with a traditional machine learning method.Results demonstrate that the FFE may reach a similar effect with physics-guided manual feature extraction,and obtain a better result compared with other deep learning methods. 展开更多
关键词 feature extractor disruption prediction deep learning tokamak diagnostics
下载PDF
Robust and Reusable Fuzzy Extractors from Non-Uniform Learning with Errors Problem
2
作者 Joo Woo Jonghyun Kim Jong Hwan Park 《Computers, Materials & Continua》 SCIE EI 2023年第1期1985-2003,共19页
Afuzzy extractor can extract an almost uniformrandom string from a noisy source with enough entropy such as biometric data.To reproduce an identical key from repeated readings of biometric data,the fuzzy extractor gen... Afuzzy extractor can extract an almost uniformrandom string from a noisy source with enough entropy such as biometric data.To reproduce an identical key from repeated readings of biometric data,the fuzzy extractor generates a helper data and a random string from biometric data and uses the helper data to reproduce the random string from the second reading.In 2013,Fuller et al.proposed a computational fuzzy extractor based on the learning with errors problem.Their construction,however,can tolerate a sub-linear fraction of errors and has an inefficient decoding algorithm,which causes the reproducing time to increase significantly.In 2016,Canetti et al.proposed a fuzzy extractor with inputs from low-entropy distributions based on a strong primitive,which is called digital locker.However,their construction necessitates an excessive amount of storage space for the helper data,which is stored in authentication server.Based on these observations,we propose a new efficient computational fuzzy extractorwith small size of helper data.Our scheme supports reusability and robustness,which are security notions that must be satisfied in order to use a fuzzy extractor as a secure authentication method in real life.Also,it conceals no information about the biometric data and thanks to the new decoding algorithm can tolerate linear errors.Based on the non-uniform learning with errors problem,we present a formal security proof for the proposed fuzzy extractor.Furthermore,we analyze the performance of our fuzzy extractor scheme and provide parameter sets that meet the security requirements.As a result of our implementation and analysis,we show that our scheme outperforms previous fuzzy extractor schemes in terms of the efficiency of the generation and reproduction algorithms,as well as the size of helper data. 展开更多
关键词 Fuzzy extractor REUSABILITY robustness biometric authentication non-uniform learning with errors
下载PDF
PP-GAN:Style Transfer from Korean Portraits to ID Photos Using Landmark Extractor with GAN
3
作者 Jongwook Si Sungyoung Kim 《Computers, Materials & Continua》 SCIE EI 2023年第12期3119-3138,共20页
The objective of style transfer is to maintain the content of an image while transferring the style of another image.However,conventional methods face challenges in preserving facial features,especially in Korean port... The objective of style transfer is to maintain the content of an image while transferring the style of another image.However,conventional methods face challenges in preserving facial features,especially in Korean portraits where elements like the“Gat”(a traditional Korean hat)are prevalent.This paper proposes a deep learning network designed to perform style transfer that includes the“Gat”while preserving the identity of the face.Unlike traditional style transfer techniques,the proposed method aims to preserve the texture,attire,and the“Gat”in the style image by employing image sharpening and face landmark,with the GAN.The color,texture,and intensity were extracted differently based on the characteristics of each block and layer of the pre-trained VGG-16,and only the necessary elements during training were preserved using a facial landmark mask.The head area was presented using the eyebrow area to transfer the“Gat”.Furthermore,the identity of the face was retained,and style correlation was considered based on the Gram matrix.To evaluate performance,we introduced a metric using PSNR and SSIM,with an emphasis on median values through new weightings for style transfer in Korean portraits.Additionally,we have conducted a survey that evaluated the content,style,and naturalness of the transferred results,and based on the assessment,we can confidently conclude that our method to maintain the integrity of content surpasses the previous research.Our approach,enriched by landmarks preservation and diverse loss functions,including those related to“Gat”,outperformed previous researches in facial identity preservation. 展开更多
关键词 Style transfer style synthesis generative adversarial network(GAN) landmark extractor ID photos Korean portrait
下载PDF
Study on extraction phenol from coal tar with high flux centrifugal extractor 被引量:6
4
作者 Yuan Zhao Xuefeng Mao +2 位作者 Weilin Li Xiaohui Gu Guangyao Wang 《International Journal of Coal Science & Technology》 EI 2017年第4期333-341,共9页
Solvent extraction phenol from coal tar were carried out with novel composite YH-3 as extraction agent, and the high flux centrifugal extractor was used as extraction device. Under the premise of high phenol extractio... Solvent extraction phenol from coal tar were carried out with novel composite YH-3 as extraction agent, and the high flux centrifugal extractor was used as extraction device. Under the premise of high phenol extraction rate, composite YH-3 extraction agent reduces n-n interaction between phenolic compounds and aromatic hydrocarbons, thus decreasing the entrainment of neutral oil. The optimization of operation conditions, such as the diameter of heavy phase weir HWD, the flow ratio, the total flow rate and the rotation speed, are necessary. For single stage extraction experiment, the mass transfer efficiency was up to 84% while the rate of extraction agent loss was lower than 0.28% with the operation conditions of 29 mm of the heavy phase weir diameter (HWD), 1:1-1.4:1 of the flow ratio range, 160-200 mL/min of the total flow rate and the rotation speed varied from 2200 to 2600 r/min. For three stage counter-current test, the mass transfer efficiency reached up to 92.6% with the optimum operation condition of 29 mm of the HWD, 1:1 of the flow ratio, 200 rnL/min of the total flow rate and 2400 r/rain of the rotation speed. The results indicated that phenol could be extracted effectively from coal tar in the process of multistage continuous count current centrifugal extraction. 展开更多
关键词 High flux centrifugal extractor Coal tar PHENOL Mass transfer efficiency Loss rate
下载PDF
An industrial-scale annular centrifugal extractor for the TRPO process 被引量:2
5
作者 Wu-Hua Duan Tiao-Xiang Sun Jian-Chen Wang 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第4期137-145,共9页
Annular centrifugal extractors(ACEs) offer advantages including excellent hydraulic and mass-transfer performance, small hold-up volume, short residence time,and thus low solvent degradation, high nuclear criticality,... Annular centrifugal extractors(ACEs) offer advantages including excellent hydraulic and mass-transfer performance, small hold-up volume, short residence time,and thus low solvent degradation, high nuclear criticality,easy start-up and shut-down, high compact structure.Therefore, ACEs have attracted increasing interest for future nuclear processing schemes, including the partitioning of high-level liquid waste(HLLW). Laboratoryscale and pilot-scale ACEs have been applied in demonstration tests of the trialkyl phosphine oxide(TRPO) process for HLLW partitioning. In this study, an industrialscale ACE(260 mm in rotor diameter) with magnetic coupling and a ‘‘hanging'' rotor structure was developed for the TRPO process. Moreover, a series of hydraulic and mass-transfer tests were carried out in the industrial-scale ACE. The maximum throughput can reach 10 m^3/h under suitable operation parameters when kerosene is used as the organic phase, and water is used as the aqueous phase. The influence of the total flowrate, the flow ratio(aqueous/organic, A/O), and the rotor speed on the liquid hold-up volume was determined. The extraction stage efficiency is higher than 98% under test parameters for extraction of Nd^(3+) and HNO_3, using 30% TRPO kerosene as theextractant from an HNO_3 solution containing Nd. All results show good performance of the industrial-scale ACE for the TRPO process. 展开更多
关键词 ANNULAR CENTRIFUGAL extractor TRPO PROCESS MASS-TRANSFER efficiency Hydraulic performance Industrial-scale
下载PDF
Gas-liquid-liquid extraction in a novel rotating microchannel extractor 被引量:2
6
作者 Rui Ma Chunxin Fan +3 位作者 Yubin Wang Jianhong Luo Jun Li Sridhar Komarneni 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第10期2523-2532,共10页
In this work,a novel rotating microchannel extractor(RME)is designed and further used for the extraction of chromium(Ⅲ)from water.Unexpectedly,the micro-extraction had the same effect as carrying out 2.9-stage cross-... In this work,a novel rotating microchannel extractor(RME)is designed and further used for the extraction of chromium(Ⅲ)from water.Unexpectedly,the micro-extraction had the same effect as carrying out 2.9-stage cross-flow extractions.Various factors,including the gas intake methods,gas intake quantity(Qg),distance between inner rotor and outer wall(D),rotational inner rotor speed(R)and volumetric flow rate(Qa,Qo),were selected to investigate their effect on the extraction efficiency(η)thoroughly.The relation map ofηwith Weaand We(o-g)for RME provides a comprehension for the gas–liquid–liquid extraction process in this RME system. 展开更多
关键词 MICROEXTRACTION Gas–liquid–liquid Rotating microchannel extractor Mass transfer Extraction efficiency
下载PDF
Experimental and Simulation Study on the Extraction of p-Cresol Using Centrifugal Extractors 被引量:1
7
作者 周嘉贞 段五华 +1 位作者 许金全 杨义燕 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第2期209-214,共6页
In this study,extraction of p-cresol from the simulated wastewater has been studied using centrifugal extractors and QH-1 extractant.The distribution ratio of p-cresol was approximately 308.5 in the QH-1-p-cresol(pH=2... In this study,extraction of p-cresol from the simulated wastewater has been studied using centrifugal extractors and QH-1 extractant.The distribution ratio of p-cresol was approximately 308.5 in the QH-1-p-cresol(pH=2.0)system.The extraction stage efficiency of the single-stage centrifugal extractor was higher than 92%,and the extraction rate of the three-stage cascade was higher than 99%.When 15% NaOH was used for the stripping of p-cresol in QH-1 solution,the stripping rate of the three-stage cascade reached 100%.A mathematical model of multistage countercurrent extraction process that considers the phase volume change,extraction stage efficiency,and phase entrainment was used to simulate the extraction of p-cresol using centrifugal extractors.The calculated results using this model were in good agreement with the experimental results. 展开更多
关键词 P-CRESOL EXTRACTION QH-1 extractant centrifugal extractor mathematical model
下载PDF
Extraction kinetics of phenol with N, N-di (1-methyl-heptyl)acetamide-kerosene using hollow fiber membrane extractor
8
作者 YANG Zhu xian, DU Hui fang, SUN Xian bo, XIA Ye, ZHOU Zu ming(Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, China. 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2001年第3期380-384,共5页
Extraction kinetics of phenol with N,N-di(1-methyl-heptyl) acetamide-kerosene using hollow fiber membrane extractor has been studied. The rate regularities and kinetic types of forward and backward extraction were obt... Extraction kinetics of phenol with N,N-di(1-methyl-heptyl) acetamide-kerosene using hollow fiber membrane extractor has been studied. The rate regularities and kinetic types of forward and backward extraction were obtained respectively by determining the forward and backward extraction rate under various experimental conditions. The mass transfer mechanism was discussed. Both the forward and backward extraction of phenol might be controlled by diffusion processes, and the diffusion resistance for both forward and backward extraction mainly exists in aqueous phase. In addition, ways to optimize the extraction process of phenol were discussed as well. 展开更多
关键词 extraction kinetics PHENOL hollow fiber membrane extractor
下载PDF
亚像素图像ContourExtractor2DimageFilter算法研究
9
作者 孙彪 张赛男 《通讯世界(下半月)》 2015年第4期231-231,共1页
随着实时图像、超大图像处理的需求增加,图像的轮廓提取已成为计算机视觉处理中的重要环节。本文研究了一种亚象素轮廓高速提取算法,对其算法总则进行了概括,对算法方法进行了描述,并基于该算法进行了实验,对其算法效率进行了分析,取得... 随着实时图像、超大图像处理的需求增加,图像的轮廓提取已成为计算机视觉处理中的重要环节。本文研究了一种亚象素轮廓高速提取算法,对其算法总则进行了概括,对算法方法进行了描述,并基于该算法进行了实验,对其算法效率进行了分析,取得良好的效果。 展开更多
关键词 亚象素 轮廓提取 CONTOUR extractor2Dimage Filter算法
下载PDF
Cubic Root Extractors of Gaussian Integers and Their Application in Fast Encryption for Time-Constrained Secure Communication
10
作者 Boris Verkhovsky 《International Journal of Communications, Network and System Sciences》 2011年第4期197-204,共8页
There are settings where encryption must be performed by a sender under a time constraint. This paper de-scribes an encryption/decryption algorithm based on modular arithmetic of complex integers called Gaus-sians. It... There are settings where encryption must be performed by a sender under a time constraint. This paper de-scribes an encryption/decryption algorithm based on modular arithmetic of complex integers called Gaus-sians. It is shown how cubic extractors operate and how to find all cubic roots of the Gaussian. All validations (proofs) are provided in the Appendix. Detailed numeric illustrations explain how to use the method of digital isotopes to avoid ambiguity in recovery of the original plaintext by the receiver. 展开更多
关键词 Cryptographic Protocol Secure Communication Time-Constrained ENCRYPTION CUBIC ROOT extractor GAUSSIAN INTEGERS Modular Arithmetic Prefix/Suffix Positioning Digital Isotope Quadratic Residue Jacoby Symbol
下载PDF
Lightweight Key Management Scheme Using Fuzzy Extractor for Wireless Mobile Sensor Network
11
作者 Eid Rehman Ibrahima Kalil Toure +5 位作者 Kashif Sultan Muhammad Asif Muhammad Habib Najam Ul Hasan Oh-Young Song Aaqif Afzaal Abbasi 《Computers, Materials & Continua》 SCIE EI 2022年第4期1695-1712,共18页
The mature design of wireless mobile sensor network makes it to be used in vast verities of applications including from home used to the security surveillance.All such types of applications based on wireless mobile se... The mature design of wireless mobile sensor network makes it to be used in vast verities of applications including from home used to the security surveillance.All such types of applications based on wireless mobile sensor network are generally using real time data,most of them are interested in real time communication directly from cluster head of cluster instead of a base station in cluster network.This would be possible if an external user allows to directly access real time data from the cluster head in cluster wireless mobile sensor network instead of accessing data from base station.But this leads to a serious security breach and degrades the performance of any security protocol available in this domain.Most existing schemes for authentication and cluster key management for external users,exchange a number of messages between cluster head and base station to allow external to access real time data from the base station instead of cluster head.This increase communication cost and delay in such real time access information.To handle this critical issue in cluster wireless mobile sensor network,we propose a lightweight authentication and key management scheme using a fuzzy extractor.In this scheme,any external user can access data directly from the cluster head of any cluster without the involvement of the base station.The proposed scheme only uses the one-way hash functions and bitwise XOR operations,apart from the fuzzy extractor method for the user biometric verification at the login phase.The presented scheme supports scalability for an increasing number of nodes using polynomials.The proposed scheme increases the life-time of the network by decreasing the key pool size. 展开更多
关键词 Fuzzy extractor user authentication key management cluster session key wireless mobile sensor network
下载PDF
Natural Ventilation by Air Captors and Extractors Sheds in Hospitals in Brazil: Wind Tunnel Measurements
12
作者 Marieli Azoia Lukiantchuki Rosana Caram +1 位作者 Edson Matsumoto Lucila Chebel Labaki 《Journal of Civil Engineering and Architecture》 2014年第10期1293-1303,共11页
Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures c... Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures consist of roof openings that work as air captors or extractors depending on their location in relation to the prevailing wind directions. The hospitals of the Sarah Network, designed by the Brazilian architect Joao Filgueiras Lima, Lele, are worldwide known for using these elements to improve natural ventilation. This paper analyses the natural ventilation performance of sheds for air collecting and extracting in two Sarah hospitals located in the cities of Salvador and Rio de Janeiro. In each building, the sheds were analyzed for air extracting and collecting. The analyses were carried out by reduced physical models in an atmospheric boundary layer wind tunnel. The wind velocity was measured at external and internal points of the buildings, using hot-wire anemometers. The results show that the wards in Rio de Janeiro hospital are 17% more ventilated than the ones in the Salvador hospital. However, this difference occurs not only because of the collecting sheds but also because of set of openings and the configuration of the covering in hospitals in Rio de Janeiro. 展开更多
关键词 Natural ventilation air captors and extractors sheds wind tunnel Joao Filgueiras Lima.
下载PDF
Sinomenine Purification by Continuous Liquid-Liquid Extraction Process with Centrifugal Extractors
13
作者 Zuren Peng Wanying Wang +7 位作者 Xianjun Long Ping Qiu Qiaoqiao Liu Yuanxiang Yang Xuechun Yang Meili Wang Songmao Yin Xingchu Gong 《Advances in Chemical Engineering and Science》 2020年第3期171-180,共10页
Continuous manufacturing is considered as one of the future trends of pharmaceutical engineering. In this work, continuous liquid-liquid extraction for sinomenine purification was realized with the usage of centrifuga... Continuous manufacturing is considered as one of the future trends of pharmaceutical engineering. In this work, continuous liquid-liquid extraction for sinomenine purification was realized with the usage of centrifugal extractors. Chloroform was used as the extractant because of the high distribution coefficient (>100). Higher extraction ratio can be obtained when using the centrifugal extractor of Model CWL50-N. The extraction ratio of the second-stage extraction was higher than that of the first-stage extraction. The extraction ratio of the second-stage countercurrent extraction was higher than that of second-stage cross-flow extraction. When chloroform phase was recycled for liquid-liquid extraction, the extraction ratio was also higher than 95%. This work can also be an example of continuous liquid-liquid extraction for the separation of other Chinese medicine components. 展开更多
关键词 SINOMENINE Continuous Manufacturing Liquid-Liquid Extraction Centrifugal extractor
下载PDF
Swift Extractor——Flash资源提取者
14
作者 斌子 《网络与信息》 2004年第7期89-89,共1页
关键词 SWIFT extractor FLASH文件 动作脚本 图像 声音
下载PDF
Recent advances of annular centrifugal extractor for hot test of nuclear waste partitioning process 被引量:3
15
作者 HeXiang-Ming YanYu-Shun 《Nuclear Science and Techniques》 SCIE CAS CSCD 1998年第3期157-162,共6页
1IntroductionSolventextractionequipmenthasevolvedconsiderablyfornedofseparationofnuclearelementsoverthelast5... 1IntroductionSolventextractionequipmenthasevolvedconsiderablyfornedofseparationofnuclearelementsoverthelast50years.Mixerset... 展开更多
关键词 核废料处理 隔离处理 离心分离器
下载PDF
Stage-efficiency of centrifugal extractor used in nuclear industry
16
作者 吴秋林 景山 +1 位作者 王兴海 宋崇立 《中国有色金属学会会刊:英文版》 CSCD 2003年第4期982-987,共6页
The stage efficiency of a single stage prototype ( d 70) centrifugal extractor and the cascade is tested by HNO 3 Nd 3+ and 30%TRPO kerosene system. The experimental results of the single stage centrifugal extractor s... The stage efficiency of a single stage prototype ( d 70) centrifugal extractor and the cascade is tested by HNO 3 Nd 3+ and 30%TRPO kerosene system. The experimental results of the single stage centrifugal extractor show that the carryover of the two phases decreases with increasing ratio of the two flow rate and rotation rate and the stage efficiency increases with not only decreasing total flow rate but also increasing rotor speed. However, the experimental results of the cascade show that the average stage efficiency of the cascade increases with not only decreasing total flow rate but also increasing rotor speed in both three stage mode and two stage mode. 展开更多
关键词 核工业 离心分离器 效率 分离工艺
下载PDF
不同核酸提取方法对HBV-DNA检测性能验证情况分析 被引量:1
17
作者 周文娟 林真 徐建萍 《现代医药卫生》 2024年第4期575-580,共6页
目的评估2种乙型肝炎病毒(HBV)-DNA提取方法及2家检测试剂的性能,有助于选择优化提取试剂和检测试剂。方法2023年4月采用达安全自动核酸提取仪提取法(磁珠法)和手工提取法(一步法),并用达安和圣湘2种HBV-DNA试剂检测,对其进行精密度、... 目的评估2种乙型肝炎病毒(HBV)-DNA提取方法及2家检测试剂的性能,有助于选择优化提取试剂和检测试剂。方法2023年4月采用达安全自动核酸提取仪提取法(磁珠法)和手工提取法(一步法),并用达安和圣湘2种HBV-DNA试剂检测,对其进行精密度、正确度、线性范围、检出限及抗干扰能力等性能进行验证和评价。结果达安全自动核酸提取仪提取达安试剂检测、手工提取达安试剂检测和手工提取圣湘试剂检测在精密度、正确度、线性范围、检出限方面验证结果均达标;达安全自动核酸提取仪提取圣湘试剂检测在低值检测中变异系数大于5%,最低检测限验证不合格;抗干扰能力方面,全自动核酸提取仪提取的2.0 g/dL血红蛋白浓度的样本用达安和圣湘试剂检测结果均不受影响。手工提取甘油三酯浓度达3000 mg/dL的样本用达安和圣湘试剂检测的结果均不受影响。结论不同厂家的提取和检测试剂避免混用,达安和圣湘试剂对HBV-DNA定量检测的结果均符合要求。 展开更多
关键词 乙型肝炎病毒-DNA定量检测 全自动核酸提取仪法 手工提取法 性能验证
下载PDF
履带浮筒式挖藕机滑橇支承装置设计与试验
18
作者 王洪昌 陈龙 +6 位作者 李正博 唐楠锐 刘婉茹 裴蕾 丁凯权 黄海东 张国忠 《农业工程学报》 EI CAS CSCD 北大核心 2024年第10期44-54,共11页
针对履带挖藕机行驶阻力大和下陷深的问题,该研究设计了一种滑橇支承装置,该装置安装于底盘两侧,由液压驱动其上下运动调节所在位置,可辅助支撑底盘,从而降低履带接地压力和下陷深度以改善通过性。为明确增加滑橇支承装置后底盘行驶性... 针对履带挖藕机行驶阻力大和下陷深的问题,该研究设计了一种滑橇支承装置,该装置安装于底盘两侧,由液压驱动其上下运动调节所在位置,可辅助支撑底盘,从而降低履带接地压力和下陷深度以改善通过性。为明确增加滑橇支承装置后底盘行驶性能的变化,以履带浮筒式挖藕机底盘为对象,建立底盘行驶阻力和牵引力模型,对土壤与滑橇前端破土面间的挤压受力进行理论分析。以前进阻力为指标,建立原尺寸三分之一的滑撬比例模型,利用EDEM软件开展单因素仿真试验,获得滑切角、斜切角、行进速度和下陷深度对前进阻力的影响规律。以滑切角、斜切角、行进速度为影响因素开展Box-Behnken中心组合试验,结果表明,滑切角40°、斜切角70°、行进速度0.1 m/s时前进阻力最小,仿真模拟与台架试验结果分别为66.09和82.28 N。开展采用滑撬支承装置前后的履带浮筒式挖藕机田间行驶性能对比试验,结果显示,采用滑撬支承装置前后行驶马达阻力矩降低6.51%,底盘下陷深度降低7.64%,整机通过性得到提高。研究结果可为水田地面机器系统行走装置设计及其工作机理研究提供参考。 展开更多
关键词 底盘 阻力 滑橇 莲藕 挖藕机 通过性
下载PDF
取石球囊在内镜逆行胰胆管造影术治疗肝移植术后胆管吻合口狭窄中的特殊应用
19
作者 王旋 陈雪雯 +6 位作者 黄金鑫 陈佳骏 曲岩 高浩 龚彪 张晞文 李甫 《中国内镜杂志》 2024年第3期7-13,共7页
目的探讨在内镜逆行胆胰管造影术(ERCP)治疗肝移植术后胆管吻合口狭窄中,应用取石球囊协助导丝跨越胆管吻合口狭窄的效果。方法收集在原位肝移植术后发生胆管吻合口狭窄,行ERCP治疗的48例患者的临床资料。常规使用切开刀插管跨越狭窄段... 目的探讨在内镜逆行胆胰管造影术(ERCP)治疗肝移植术后胆管吻合口狭窄中,应用取石球囊协助导丝跨越胆管吻合口狭窄的效果。方法收集在原位肝移植术后发生胆管吻合口狭窄,行ERCP治疗的48例患者的临床资料。常规使用切开刀插管跨越狭窄段失败后,使用取石球囊尝试跨越吻合口狭窄,统计手术成功率,观察术中情况,分析治疗转归和并发症发生情况。结果48例患者入院体征主要包括:32例腹部不适,7例发热,4例皮肤瘙痒,3例黄疸,2例无明显症状;术前胆道磁共振胆胰管成像(MRCP)检查显示,胆管吻合口单纯狭窄35例,狭窄合并结石13例。在取石球囊引导下,导丝成功跨越吻合口狭窄26例,成功率为54.17%(26/48);通过对成功组和失败组的统计分析,两组患者中胆总管远端是否扩张存在明显差异,差异有统计学意义(χ2=8.39,P=0.004)。26例经取石球囊治疗成功者,术后48 h的丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、血清γ-谷氨酰转移酶(γ-GT)、碱性磷酸酶(ALP)和总胆红素(TBiL)水平较术前下降,差异均有统计学意义(P<0.05)。26例成功手术患者,均未出现严重并发症。结论取石球囊在肝移植术后胆管吻合口狭窄治疗中,能够提高操作成功率,特别是对于胆总管远端扩张者优势明显,且安全性较高,值得临床推广应用。 展开更多
关键词 取石球囊 胆管吻合口狭窄 肝移植 内镜逆行胰胆管造影术(ERCP) 胆总管扩张
下载PDF
基于隐式神经表示的模型隐写方案
20
作者 董炜娜 刘佳 +3 位作者 孙文权 陈立峰 潘晓中 柯彦 《科学技术与工程》 北大核心 2024年第25期10857-10865,共9页
可视数据(图像、视频、3D模型)的隐式表达已经成为当前计算机视觉研究的热点,提出了一种新的基于隐式神经表示的模型隐写方案,消息发送方利用神经辐射场(neural radiance fields,NeRF)新视角合成的特性,通过引入一个视角作为密钥,由NeR... 可视数据(图像、视频、3D模型)的隐式表达已经成为当前计算机视觉研究的热点,提出了一种新的基于隐式神经表示的模型隐写方案,消息发送方利用神经辐射场(neural radiance fields,NeRF)新视角合成的特性,通过引入一个视角作为密钥,由NeRF模型生成秘密视角图像作为后门,然后利用过拟合的方法训练一个消息提取器,以建立秘密消息和秘密视角图像的一一映射。发送方将训练好的NeRF模型和消息提取器通过公开信道传递给接收方,接收方利用双方共享的密钥,由NeRF模型获得秘密视角下的渲染图像,再通过消息提取器获得秘密消息。而攻击方因无法准确掌握该视角信息,从而无法窃取秘密消息。实验结果证明:所训练的消息提取器实现大容量快速隐写,消息嵌入量达100%,同时NeRF巨大的视角密钥空间保证了该方案的隐蔽性。 展开更多
关键词 信息隐藏 隐式神经表示 神经辐射场 模型隐写 消息提取器
下载PDF
上一页 1 2 41 下一页 到第
使用帮助 返回顶部