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Influence of the Multi-segment Micro-crack and Groups of Kinked Micro-cracks on the Plastic Behavior of a Macro-crack 认领 引用
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作者 Hongda Yang Jiding Zhang +1 位作者 Wentao Ma Xiaoyu Jiang 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2025年第6期970-979,共10页
Combining the continuously distributed dislocation technique(DDT)and the von Mises yield criterion,new double-crack and multi-crack models were established.The influences of multi-segment kinked micro-cracks and group... Combining the continuously distributed dislocation technique(DDT)and the von Mises yield criterion,new double-crack and multi-crack models were established.The influences of multi-segment kinked micro-cracks and groups of kinked micro-cracks on the plastic behavior of the macro-crack were investigated.The results show that a smaller kinking angle of the micro-crack enhances its influence on the plastic deformation of the macro-crack,potentially leading to plastic zone fusion.Meanwhile,micro-cracks with smaller kinking angles exert a stronger attracting force on macro-crack growth,facilitating convergence between them.Furthermore,annularly distributed micro-crack groups demonstrate a more pronounced attraction on macro-crack propagation compared to linearly distributed micro-crack groups.The double-crack and multi-crack models established in this paper offer a theoretical framework for analyzing the plastic fracture behavior of metallic materials containing complex kinked cracks. 展开更多
关键词 Distributed dislocation technique Multi-segment micro-crack Groups of kinked micro-cracks Plastic zone
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Three-dimensional numerical analysis on combustion performance and flow of hybrid rocket motor with multi-segmented grain 认领 引用 被引量：6
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作者 Hui TIAN Yu DUAN Hao ZHU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第4期1181-1191,共11页
This paper presents the combustion characteristics in hybrid rocket motors with multisegmented grain through three-dimensional numerical simulations.Multi-segmented grain is composed of several thin grains with two or... This paper presents the combustion characteristics in hybrid rocket motors with multisegmented grain through three-dimensional numerical simulations.Multi-segmented grain is composed of several thin grains with two or more ports.The numerical model consists of Navier-Stokes equations with turbulence,solid fuel pyrolysis,chemical reactions,a fluid–solid coupling model and a regression rate model.The simulations adopt 90%Hydrogen Peroxide(HP)and PolyEthylene(PE)as the propellant combination.The effects of the rotation,port number,fuel grain segment number and mid-chamber length on the flow field and combustion performances are analyzed.The results indicate that the multi-segmented grain configuration can strengthen the flow field,and the regression rate and combustion efficiency are enhanced.Take the cases with two grain segments and three ports for example,the regression rate is increased by 32.4%-45.1%and the combustion efficiency increases by 6%-8.6%in different rotation angles. 展开更多
关键词 Combustion efficiency Hybrid rocket motor Multi-segmented grain Regression rate Rotation angle
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Multi-segment and Multi-ply Overlapping Process of Multi Coupled Activities Based on Valid Information Evolution 认领 引用 被引量：1
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作者 WANG Zhiliang WANG Yunxia QIU Shenghai 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第1期176-188,共13页
Complex product development will inevitably face the design planning of the multi-coupled activities, and overlapping these activities could potentially reduce product development time, but there is a risk of the addi... Complex product development will inevitably face the design planning of the multi-coupled activities, and overlapping these activities could potentially reduce product development time, but there is a risk of the additional cost. Although the downstream task information dependence to the upstream task is already considered in the current researches, but the design process overall iteration caused by the information interdependence between activities is hardly discussed; especially the impact on the design process＇ overall iteration from the valid information accumulation process. Secondly, most studies only focus on the single overlapping process of two activities, rarely take multi-segment and multi-ply overlapping process of multi coupled activities into account; especially the inherent link between product development time and cost which originates from the overlapping process of multi coupled activities. For the purpose of solving the above problems, as to the insufficiency of the accumulated valid information in overlapping process, the function of the valid information evolution （VIE） degree is constructed. Stochastic process theory is used to describe the design information exchange and the valid information accumulation in the overlapping segment, and then the planning models of the single overlapping segment are built. On these bases, by analyzing overlapping processes and overlapping features of multi-coupling activities, multi-segment and multi-ply overlapping planning models are built; by sorting overlapping processes and analyzing the construction of these planning models, two conclusions are obtained： （1） As to multi-segment and multi-ply overlapping of multi coupled activities, the total decrement of the task set development time is the sum of the time decrement caused by basic overlapping segments, and minus the sum of the time increment caused by multiple overlapping segments; （2） the total increment of development cost is the sum of the cost increment caused by all overlapping process. And then, based on overlapping degree analysis of these planning models, by the V1E degree function, the four lemmas theory proofs are represented, and two propositions are finally proved： （1） The multi-ply overlapping of the multi coupled activities will weaken the basic overlapping effect on the development cycle time reduction （2） Overlapping the multi coupled activities will decrease product development cycle, but increase product development cost. And there is trade-off between development time and cost. And so, two methods are given to slacken and eliminate multi-ply overlapping effects. At last, an example about a vehicle upper subsystem design illustrates the application of the proposed models; compared with a sequential execution pattern, the decreasing of development cycle （22%） and the increasing of development cost （3%） show the validity of the method in the example The proposed research not only lays a theoretical foundation for correctly planning complex product development process, but also provides specific and effective operation methods for overlapping multi coupled activities. 展开更多
关键词 multi coupled activities valid information evolution multi-segment ＆ multi-ply overlapping development time and cost,trade-ofl iteration
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DDoS Defense Algorithm Based on Multi-Segment Timeout Technology 认领 引用 被引量：1
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作者 DU Ruizhong YANG Xiaohui MA Xiaoxue HE Xinfeng 《Wuhan University Journal of Natural Sciences》 EI CAS 2006年第6期1823-1826,共4页
Through the analysis to the DDoS（distributed denial of service） attack, it will conclude that at different time segments, the arrive rate of normal SYN （Synchronization） package are similar, while the abnormal pac... Through the analysis to the DDoS（distributed denial of service） attack, it will conclude that at different time segments, the arrive rate of normal SYN （Synchronization） package are similar, while the abnormal packages are different with the normal ones. Toward this situation a DDoS defense algorithm based on multi-segment timeout technology is presented, more than one timeout segment are set to control the net flow. Experiment results show that in the case of little flow, multi-segment timeout has the ability dynamic defense, so the system performance is improved and the system has high response rate. 展开更多
关键词 DDoS（distributed denial of service） multi-segments timeout dynamic defense net flow analysis
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High-power and high optical conversion efficiency diode-end-pumped laser with multi-segmented Nd:YAG/Nd:YVO-4 认领 引用
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作者 Meng-Yao Wu Peng-Fei Qu +3 位作者 Shi-Yu Wang SEl Zhen Guo De-Fang Cai Bing-Bin Li 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第9期306-310,共5页
A novel flat-flat resonator consisting of two crystals（Nd：YAG ＋ Nd：YVO4） is established for power scaling in a diode-end-pumped solid-state laser. We systematically compare laser characteristics between multi-seg... A novel flat-flat resonator consisting of two crystals（Nd：YAG ＋ Nd：YVO4） is established for power scaling in a diode-end-pumped solid-state laser. We systematically compare laser characteristics between multi-segmented（Nd：YAG ＋ Nd：YVO4） and conventional composite（Nd：YAG ＋ Nd：YAG） crystals to demonstrate the feasibility of spectral line matching for output power scale-up in end-pumped lasers. A maximum continuous-wave output power of 79.2 W is reported at 1064 nm, with Mx2= 4.82, My2= 5.48, and a pumping power of 136 W in the multi-segmented crystals（Nd：YAG ＋ Nd：YVO4）. Compared to conventional composite crystals（Nd：YAG ＋ Nd：YAG）, the optical-optical conversion efficiency of multi-segmented crystals（Nd：YAG ＋ Nd：YVO4） from 808 nm to 1064 nm is enhanced from 30% to 58.8%,while the laser output sensitivity as affected by the diode-laser temperature is reduced from 55% to 9%. 展开更多
关键词 diode-pumped solid-state laser multi-segmented crystals（Nd：YAG ＋ Nd：YVO4） spectral line matching diode-laser temperature
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Enhancement of thermal rectification by asymmetry engineering of thermal conductivity and geometric structure for multi-segment thermal rectifier 认领 引用 被引量：2
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作者 杜甫烨 张望 +1 位作者 王惠琼 郑金成 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期34-43,共10页
Thermal rectification is an exotic thermal transport phenomenon,an analog to electrical rectification,in which heat flux along one direction is larger than that in the other direction and is of significant interest in... Thermal rectification is an exotic thermal transport phenomenon,an analog to electrical rectification,in which heat flux along one direction is larger than that in the other direction and is of significant interest in electronic device applications.However,achieving high thermal rectification efficiency or rectification ratio is still a scientific challenge.In this work,we performed a systematic simulation of thermal rectification by considering both efforts of thermal conductivity asymmetry and geometrical asymmetry in a multi-segment thermal rectifier.It is found that the high asymmetry of thermal conductivity and the asymmetry of the geometric structure of multi-segment thermal rectifiers can significantly enhance the thermal rectification,and the combination of both thermal conductivity asymmetry and geometrical asymmetry can further improve thermal rectification efficiency.This work suggests a possible way for improving thermal rectification devices by asymmetry engineering. 展开更多
关键词 thermal conductivity simulation thermal rectification multi-segment thermal rectifier
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Multi-segmented nanowires for vortex magnetic domain wall racetrack memory 认领 引用
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作者 M Al Bahri M Al Hinaai T Al Harthy 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第12期582-588,共7页
A vortex domain wall's(VW) magnetic racetrack memory's high performance depends on VW structural stability,high speed, low power consumption and high storage density. In this study, these critical parameters w... A vortex domain wall's(VW) magnetic racetrack memory's high performance depends on VW structural stability,high speed, low power consumption and high storage density. In this study, these critical parameters were investigated in magnetic multi-segmented nanowires using micromagnetic simulation. Thus, an offset magnetic nanowire with a junction at the center was proposed for this purpose. This junction was implemented by shifting one portion of the magnetic nanowire horizontally in the x-direction(l) and vertically(d) in the y-direction. The VW structure became stable by manipulating magnetic properties, such as magnetic saturation(M4) and magnetic anisotropy energy(Ku). In this case, increasing the values of M4 ≥ 800 kA/m keeps the VW structure stable during its dynamics and pinning and depinning in offset nanowires,which contributes to maintenance of the storage memory's lifetime for a longer period. It was also found that the VW moved with a speed of 500 m/s, which is desirable for VW racetrack memory devices. Moreover, it was revealed that the VW velocity could be controlled by adjusting the offset area dimensions(l and d), which helps to drive the VW by using low current densities and reducing the thermal-magnetic spin fluctuations. Further, the depinning current density of the VW(Jd) over the offset area increases as d increases and l decreases. In addition, magnetic properties, such as the M4 and Ku,can affect the depinning process of the VW through the offset area. For high storage density, magnetic nanowires(multisegmented) with four junctions were designed. In total, six states were found with high VW stability, which means three bits per cell. Herein, we observed that the depinning current density(Jd) for moving the VW from one state to another was highly influenced by the offset area geometry(l and d) and the material's magnetic properties, such as the M4 and Ku. 展开更多
关键词 micromagnetic simulation vortex domain wall racetrack memory multi-segmented magnetic nanowire spin transfer torque
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A two-parameter multiple shooting method and its application to the natural vibrations of non-prismatic multi-segment beams 认领 引用
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作者 R.HOŁUBOWSKI K.JARCZEWSKA 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第12期2243-2252,共10页
This paper presents an enhanced version of the standard shooting method that enables problems with two unknown parameters to be solved.A novel approach is applied to the analysis of the natural vibrations of Euler-Ber... This paper presents an enhanced version of the standard shooting method that enables problems with two unknown parameters to be solved.A novel approach is applied to the analysis of the natural vibrations of Euler-Bernoulli beams.The proposed algorithm,named as two-parameter multiple shooting method,is a new powerful numerical tool for calculating the natural frequencies and modes of multi-segment prismatic and non-prismatic beams with different boundary conditions.The impact of the axial force and additional point masses is also taken into account.Due to the fact that the method is based directly on the fourth-order ordinary differential equation,the structures do not have to be divided into many small elements to obtain an accurate enough solution,even though the geometry is very complex.To verify the proposed method,three different examples are considered,i.e.,a three-segment non-prismatic beam,a prismatic column subject to non-uniformly distributed compressive loads,and a two-segment beam with an additional point mass.Numerical analyses are carried out with the software MATHEMATICA.The results are compared with the solutions computed by the commercial finite element program SOFiSTiK.Good agreement is achieved,which confirms the correctness and high effectiveness of the formulated algorithm. 展开更多
关键词 two-parameter multiple shooting method two-point boundary value problem natural vibration non-prismatic beam multi-segment beam
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Double tractors swing microendoscopic discectomy technique for multi-segmental lumbar disc herniation 认领 引用
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作者 张春霖 《外科研究与新技术（中英文）》 2011年第2期104-104,共1页
Objective To evaluate the effect of double tractors swing microendoscopic discectomy technique in multisegmental lumbar disc herniation.Methods From December 2006 to November 2009,153 patients with multisegmental lumb... Objective To evaluate the effect of double tractors swing microendoscopic discectomy technique in multisegmental lumbar disc herniation.Methods From December 2006 to November 2009,153 patients with multisegmental lumbar disc herniation 展开更多
关键词 Double tractors swing microendoscopic discectomy technique for multi-segmental lumbar disc herniation
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A 14-bit wide temperature range differential SAR ADC with an on-chip multi-segment BGR 认领 引用 被引量：2
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作者 乔宁 高见头 +3 位作者 赵凯 杨波 刘忠立 于芳 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2011年第8期80-86,共7页
A 14-bit low power self-timed differential successive approximation（SAR） ADC with an on-chip multisegment bandgap reference（BGR） is described.An on-chip multi-segment BGR,which has a temperature coefficient of 1.3... A 14-bit low power self-timed differential successive approximation（SAR） ADC with an on-chip multisegment bandgap reference（BGR） is described.An on-chip multi-segment BGR,which has a temperature coefficient of 1.3 ppm/℃and a thermal drift of about 100μV over the temperature range of -40 to 120℃is implemented to provide a high precision reference voltage for the SAR ADC.The Gray code form is utilized instead of binary form mode control to reduce substrate noise and enhance the linearity of the whole system.Self-timed bit-cycling is adopted to enhance the time efficiency.The 14-bit ADC was fabricated in a TSMC 0.13μm CMOS process. With the on-chip BGR,the SAR ADC achieves an SNDR of 81.2 dB（13.2 ENOB） and an SFDR of 85.2 dB with a conversion rate of 2 MS/s at room temperature and can keep an ENOB of more than 12 bits at a conversion rate of 2 MS/s over the temperature range from -40 to 120℃. 展开更多
关键词 differential successive approximation ADC self-timed bit-cycling gray code on-chip multi-segment BGR
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Optimizing the cleanliness in multi-segment disk amplifiers based on vector flow schemes 认领 引用 被引量：1
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作者 Zhiyuan Ren Jianqiang Zhu +1 位作者 Zhigang Liu Xiaowei Yang 《High Power Laser Science and Engineering》 SCIE EI CAS CSCD 2018年第1期1-6,共6页
The objective of maintaining the cleanliness of the multi-segment disk amplifier in Shenguang-II(SG-II) is to reduce laser-induced damage for optics. The flow field of clean gas, which is used for the transportation o... The objective of maintaining the cleanliness of the multi-segment disk amplifier in Shenguang-II(SG-II) is to reduce laser-induced damage for optics. The flow field of clean gas, which is used for the transportation of contaminant particles,is a key factor affecting the cleanliness level in the multi-segment disk amplifier. We developed a gas–solid coupling and three-dimensional flow numerical simulation model. The three-dimensional and two-phase flow model is verified by the flow-field smog experiment and the particle concentration measurement experiment with the 130-disk amplifier in SG-II. By optimizing the boundary conditions with the same flow rate, the multi-inlet vector flow scheme can not only effectively reduce the purging time, but also prevent the reverse diffusion of contaminant particles in the multi-segment disk amplifier and the deposition of contaminant particles on the surface of the Nd:glass. 展开更多
关键词 cleanliness computational fluid dynamics flow field multi-segment disk amplifier vector flow
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Multi-segment linear gradient optimization strategy based on resolution map in HPLC 认领 引用
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作者 Andreas Seidel-Morgenstern 《Science China Chemistry》 CAS 2006年第4期315-325,共11页
Based on the mechanism of chromatographic retention (the relationship between the retention of solute and the mobile phase conditions) and method of resolution map, several methods of optimizing multi-segment linear g... Based on the mechanism of chromatographic retention (the relationship between the retention of solute and the mobile phase conditions) and method of resolution map, several methods of optimizing multi-segment linear gradient elution conditions were proposed according to the different separation requirements of various samples. These methods were verified using literature data. Moreover, the advantages and disadvantages of these methods were compared. It was proved that the third method is a fast optimization method which is capable of separating all the components with relatively high resolution. 展开更多
关键词 optimization, multi-segment, linear gradient, resolution map, liquid chromatography.
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页岩储层限流射孔高效起裂机理 认领 引用 被引量：1
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作者 朱柏宇 王大江 +3 位作者 李奎东 肖佳林 朱志芳 张凡 《断块油气田》 CAS CSCD 北大核心 2026年第1期170-176,共7页
水平井分段多簇压裂是目前非常规储层开发的有效手段,但往往面临着非均衡起裂扩展的问题。限流射孔通过限制段内射孔数,进而提高射孔摩阻,已经被光纤监测、示踪剂监测等手段验证能够提高多簇裂缝起裂均衡程度。然而,限流射孔裂缝几何形... 水平井分段多簇压裂是目前非常规储层开发的有效手段,但往往面临着非均衡起裂扩展的问题。限流射孔通过限制段内射孔数,进而提高射孔摩阻,已经被光纤监测、示踪剂监测等手段验证能够提高多簇裂缝起裂均衡程度。然而,限流射孔裂缝几何形态与控制因素仍不明确。以涪陵气田JY-A为例,采用三维离散格子法对射孔簇尺度三维水力裂缝起裂行为、规律及模式进行了研究,并进一步分析了裂缝起裂的影响因素。结果显示:1)不同孔眼水力裂缝扩展的呼吸效应与光纤监测结果一致;2)由于射孔簇多点起裂,存在单孔多缝模式;3)射孔数为3~4时水力裂缝起裂较为均衡,180°水平射孔起裂最为均匀。在该结果基础上摒弃传统“分段分簇”射孔模式,提出“全段均衡限流射孔”压裂工艺思路。该研究为非常规油气分段多簇裂缝扩展提供了不同尺度的视角,有助于现场极限限流射孔方法的设计。 展开更多
关键词 水力压裂 限流射孔 三维格子法 呼吸效应 多点起裂 分段分簇
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电流变液驱动多节分控式采摘手爪设计与试验 认领 引用
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作者 赵云伟 刘政 +2 位作者 李进州 卫恒 刘晓敏 《农业机械学报》 EI CAS CSCD 北大核心 2026年第7期251-263,共13页
为实现多类型果蔬采摘,仿人指设计了一种电流变液驱动多节分控式柔性采摘手爪,该手爪采用模块化集成式设计,柔性手爪由微泵驱动。分控式手指内包含3个多腔室的柔指关节,利用内置电流变液微阀通断实现类人指的各关节独立弯曲变形。研究... 为实现多类型果蔬采摘,仿人指设计了一种电流变液驱动多节分控式柔性采摘手爪,该手爪采用模块化集成式设计,柔性手爪由微泵驱动。分控式手指内包含3个多腔室的柔指关节,利用内置电流变液微阀通断实现类人指的各关节独立弯曲变形。研究了手指多节分控原理,建立了电流变微阀阈值模型、柔指关节变形模型和手指运动学模型,并进行了相关试验验证,获得了微阀阈值、关节变形规律、手指正压力、手指运动位姿和工作空间。试制了两指采摘手样机,搭建试验平台进行了多种果蔬抓持测试和采摘试验。结果表明,柔性手指动作灵活、柔顺多样,可实现单输入多模态变形,共包含7种动作模式,指关节弯曲角度为121°,手指最大正压力为2.3 N。两指采摘手具有包、捏、夹等多种取物模式,物形适应性好,适用于小而轻质果蔬采摘。 展开更多
关键词 果蔬采摘手爪 电流变液驱动 多节分控 电流变液微阀
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结合多尺度特征融合和改进ViT的细胞计数方法 认领 引用 被引量：1
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作者 田辉 段鑫龙 +5 位作者 郝琪雅 隋文灏 马裕莹 虞祖华 徐杨 曹仰杰 《计算机工程》 CAS CSCD 北大核心 2026年第5期203-215,共13页
细胞计数是临床医学研究中的常见任务之一,在生物学和临床医学领域发挥着十分重要的作用。细胞计数任务中存在细胞重叠等情况,导致很多计数方法将多个细胞统计为单个,从而造成细胞计数精度降低的问题。为此,引入U-Net医学图像分割模型... 细胞计数是临床医学研究中的常见任务之一,在生物学和临床医学领域发挥着十分重要的作用。细胞计数任务中存在细胞重叠等情况,导致很多计数方法将多个细胞统计为单个,从而造成细胞计数精度降低的问题。为此,引入U-Net医学图像分割模型并对其进行改进,提出一种结合改进ViT(Vision Transformer)模块和多尺度特征融合的细胞计数方法,该计数方法包括4个部分,分别为提取深层特征的编码器、用于拼接编码器特征和解码器特征的多尺度特征融合模块、捕获全局上下文信息的改进ViT模块和用于恢复特征尺寸并输出分割结果的解码器。其中,改进ViT模块利用新颖的空间注意力模块和通道注意力模块,解决了传统ViT在提取特定空间和通道维度信息时能力不足的问题。多尺度特征融合模块将不同尺度的特征图进行融合,提高模型分割不同尺寸细胞的边界的能力,降低细胞重叠对计数精度造成的影响。此外,为了进一步提高模型分割重叠细胞的能力,提出一种数据增强策略,通过将原始细胞标注转换为一定半径的圆形标注,调整细胞标注之间的距离,从而指导模型更好地将存在重叠的细胞进行分离。在LiveCell、MBM cells和DCC数据集上进行实验,结果表明,所提计数方法取得了较好的结果,有效解决了由细胞重叠引起的计数精度降低的问题。 展开更多
关键词 细胞计数 医学图像分割 多尺度特征融合 Vision Transformer 通道注意力模块 空间注意力模块
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自动驾驶汽车路径跟随间歇式预瞄方法研究 认领 引用
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作者 管欣 李思深 贾鑫 《汽车工程》 EI CSCD 北大核心 2026年第3期542-552,共11页
路径跟随是自动驾驶汽车重要功能之一,当前自动驾驶汽车在路径跟随时侧向加速度波动较大。为了解决这一问题,本文提出一种自动驾驶汽车路径跟随间歇式预瞄方法。首先建立事件触发预瞄方法,以事件是否触发作为判断条件,确定是否重新预瞄... 路径跟随是自动驾驶汽车重要功能之一,当前自动驾驶汽车在路径跟随时侧向加速度波动较大。为了解决这一问题,本文提出一种自动驾驶汽车路径跟随间歇式预瞄方法。首先建立事件触发预瞄方法,以事件是否触发作为判断条件,确定是否重新预瞄,事件触发机制主要考虑路径跟随偏差和最大执行里程。然后,建立基于运动基元的多段预瞄方法。根据误差确定分段点,动态调整每段的距离,保证预瞄误差处于容许误差范围内。最后,在仿真环境下,验证本文提出的方法的有效性,并与多种方法进行对比。试验结果表明,本文提出的预瞄方法,能够保证路径跟随误差小于设定的容差范围且预期侧向加速度相比其它方法更加平稳。 展开更多
关键词 间歇式预瞄 事件触发 多段预瞄 路径跟随 自动驾驶汽车
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基于多任务分割与自适应压缩的黄花菜采摘点三维定位 认领 引用 被引量：1
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作者 张睿 王骞 +1 位作者 张延军 白峭峰 《农业工程学报》 EI CAS CSCD 北大核心 2026年第4期66-77,共12页
针对田间黄花菜采摘存在类间差异小、类内差异大、密集重叠导致定位难的问题,该研究提出一种融合多任务分割与自适应压缩的采摘点三维定位方法。首先,构建DaylilyPick-Net多任务分割网络,集成密集信息估计、多维信息增强融合、任务协同... 针对田间黄花菜采摘存在类间差异小、类内差异大、密集重叠导致定位难的问题,该研究提出一种融合多任务分割与自适应压缩的采摘点三维定位方法。首先,构建DaylilyPick-Net多任务分割网络,集成密集信息估计、多维信息增强融合、任务协同动态分割头等模块及动态损失权重策略,提升密集场景下的分割性能;其次,提出自适应调控剪枝策略(adaptive collabora-tive self-optimizing pruning,ACSP),融合层级动态自适应剪枝与全局增强蛇鹭优化算法,压缩模型同时维持精度;最后,进一步提出黄花菜三维采摘点定位及裁剪角度确定方法,融合分割掩码与深度信息实现采摘点三维定位与裁剪角度计算。结果表明,DaylilyPick-Net在田间密集黄花菜数据集上平均精度均值(m AP@50)、参数量、浮点计算量和平均帧率分别为59.62%、13.01 M、71.7 G和57帧/s,优于YOLO系列等主流模型;ACSP在剪枝率为40%时mAP@50达60.31%;采摘点定位误差保持在0.30 cm以内。该研究可为密集场景下的农业采摘机器人提供一定的视觉感知技术支持。 展开更多
关键词 卷积神经网络 图像处理 采摘 密集场景 多任务图像分割 模型自适应压缩 采摘点三维定位
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基于双边滤波的自适应多波束角度响应改正算法 认领 引用
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作者 王胜平 张俊 +3 位作者 欧阳永忠 董超 曾毅 刘娉婷 《哈尔滨工程大学学报》 EI CAS CSCD 北大核心 2026年第4期829-837,共9页
针对现有角度响应曲线改正方法存在精度不足或残留误差的问题,本文提出了一种融合双边滤波与改进角度响应模型的多区段自适应改正算法。利用双边滤波保边去噪特性,精准提取角度响应曲线的关键参数,并基于改进模型计算改正值。试验结果表... 针对现有角度响应曲线改正方法存在精度不足或残留误差的问题,本文提出了一种融合双边滤波与改进角度响应模型的多区段自适应改正算法。利用双边滤波保边去噪特性,精准提取角度响应曲线的关键参数,并基于改进模型计算改正值。试验结果表明,本文方法将相邻条带重叠区反向散射强度差值标准差降至2.34 dB以下、交叉区域降至1.23 dB,同时保持影像结构相似性高达0.9938,在改正精度与纹理效果上均有显著提升,为后续高精度海底底质分类奠定了坚实基础。 展开更多
关键词 反向散射强度 双边滤波 改进角度响应模型 多区段自适应改正 角度响应 高亮区域异常校正 纹理效果 海底底质分类
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大豆蛋白多级分段干燥过程仿真研究 认领 引用
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作者 李庚 林凤岩 +7 位作者 孙连强 申燕 陈永军 陈龙 朱辰阳 曹栋 赵树超 刘宝友 《中国油脂》 CAS CSCD 北大核心 2026年第3期38-45,共8页
为解决喷雾干燥法制备大豆蛋白粉常用单级干燥工艺干燥效果不理想、生产工艺参数难控制的问题,研发压力式喷雾干燥塔搭配流化床的多级分段干燥工艺,并基于计算流体力学(CFD)方法,建立相关结构模型及设备内液滴离散相、气体连续相等数值... 为解决喷雾干燥法制备大豆蛋白粉常用单级干燥工艺干燥效果不理想、生产工艺参数难控制的问题,研发压力式喷雾干燥塔搭配流化床的多级分段干燥工艺,并基于计算流体力学(CFD)方法,建立相关结构模型及设备内液滴离散相、气体连续相等数值计算模型。基于设备三维物理模型,建立流体域模型,通过ANSYS Fluent 2020R2软件分别对传统单个压力式喷雾干燥塔干燥(单级干燥)和多级分段干燥过程进行仿真,对比分析单级干燥和多级分段干燥的效果,并以流化床出风温度、平均水蒸气含量为考察指标,采用响应面法优化多级分段干燥工艺参数。结果表明:相较于单级干燥,多级分段干燥可以更有效地去除物料中的水分,同时又缩短了总干燥时间,可以降低物料内部的水分梯度,实现更均匀的水分含量,更高效地利用热能,减少了整个干燥过程的能耗和运行成本;大豆蛋白多级分段最佳喷雾干燥工艺参数为干燥塔进风温度179.92℃、进料压力19.89 MPa(进料流速190.32 m/s)、流化床进风温度101.58℃,在此条件下流化床出风温度为68.63℃,平均水蒸气含量为1.503%。实际工程应用中,调整干燥塔进风温度为172℃、进料压力为20 MPa、流化床进风温度为105℃,所对应干燥系统出风温度为72℃,产品干基含水率在7%左右,干燥效果较好,这与仿真结果基本吻合。综上,基于CFD方法的多级分段干燥过程仿真研究,具有较高的可行性和有效性。 展开更多
关键词 大豆蛋白 喷雾干燥 多级分段 数值模拟 响应面法
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基于可形变VMamba与特征对齐的无人机多模态图像语义分割(特邀) 认领 引用
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作者 张涛 卢瑞涛 +3 位作者 李垚辰 谢学立 范继伟 杨小冈 《红外与激光工程》 EI CAS CSCD 北大核心 2026年第4期322-336,共15页
针对无人机低空城市场景感知中可见光-红外多模态图像存在视角偏差导致的弱对齐问题,以及现有语义分割方法全局建模能力有限、标准Mamba固定扫描路径易丢失二维空间结构信息的不足,提出一种基于可形变VMamba与特征对齐的无人机多模态语... 针对无人机低空城市场景感知中可见光-红外多模态图像存在视角偏差导致的弱对齐问题,以及现有语义分割方法全局建模能力有限、标准Mamba固定扫描路径易丢失二维空间结构信息的不足,提出一种基于可形变VMamba与特征对齐的无人机多模态语义分割方法UAV-Mamba,旨在提升弱对齐场景下的分割精度与复杂环境鲁棒性。首先,构建了可形变扫描视觉Mamba主干网络,通过生成动态偏移量自适应调整特征参考点与扫描顺序,形成结构感知特征序列,使模型能够匹配与目标形态一致的扫描路径,从而突破固定扫描策略对二维空间结构信息的限制,增强对小目标与细节特征的感知能力。其次,设计了跨模态特征空间对齐模块,以红外特征为基准生成从可见光到红外的动态偏移场,实现双模态特征的像素级自适应配准,有效缓解模态弱对齐带来的特征融合误差。最后提出了Cross-Mamba交互自适应融合模块,通过交叉选择性扫描机制实现双模态特征的双向信息补偿,结合冲突感知机制完成特征自适应加权融合,充分挖掘多模态数据的互补特性。在典型无人机RGB-T语义分割数据集Kust4K上的实验结果表明,所提方法平均交并比mIoU达到73.4%,较基准模型Sigma-T提升1.9个百分点,在低光照、目标遮挡等复杂场景下表现出良好的分割性能。 展开更多
关键词 无人机 多模态语义分割 视觉Mamba 可形变扫描
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