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Collisions Between Lumps/Rogue Waves and Solitons for A(3+1)-Dimensional Generalized Variable-Coefficient Shallow Water Wave Equation
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作者 WU Xiao-yu DU Zhong 《China Ocean Engineering》 SCIE EI CSCD 2022年第5期808-813,共6页
In this paper,we investigate a(3+1)-dimensional generalized variable-coefficient shallow water wave equation,which can be used to describe the flow below a pressure surface in oceanography and atmospheric science.Empl... In this paper,we investigate a(3+1)-dimensional generalized variable-coefficient shallow water wave equation,which can be used to describe the flow below a pressure surface in oceanography and atmospheric science.Employing the Kadomtsev−Petviashvili hierarchy reduction,we obtain the semi-rational solutions which describe the lumps and rogue waves interacting with the kink solitons.We find that the lump appears from one kink soliton and fuses into the other on the x−y and x−t planes.However,on the x−z plane,the localized waves in the middle of the parallel kink solitons are in two forms:lumps and line rogue waves.The effects of the variable coefficients on the two forms are discussed.The dispersion coefficient influences the speed of solitons,while the background coefficient influences the background’s height. 展开更多
关键词 variable-coefficient shallow water wave equation lumps linear rogue waves Kadomtsev-Petviashvili hierarchy reduction
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Histopathological and Ultrasound Correlation in Women Presenting with Breast Lumps in Yaoundé, Cameroon
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作者 Yann Chris Mannel Eng Ambroise Merci Seme Engoumou +3 位作者 Armel Philippe Awana Sandrine Prisca Ndongo Onembele Junie Annick Metogo Ntsama Odile Fernande Zeh 《Open Journal of Radiology》 2023年第4期218-231,共14页
Context: Breast cancer is very deadly among women with higher rates in the developing world. Imaging tools such as ultrasound, can be used to differentiate between the types of breast lumps. This study aimed to determ... Context: Breast cancer is very deadly among women with higher rates in the developing world. Imaging tools such as ultrasound, can be used to differentiate between the types of breast lumps. This study aimed to determine the value of ultrasound as a first-line examination in the diagnosis of breast masses. Methods: This was a retrospective cross-sectional study of women presenting with breast lumps from November 2022 to June 2023 at the Yaounde General Hospital, which lasted seven months, from November 2022 to June 2023. The sampling was exhaustive and consecutive. Association between variables was studied using the x<sup>2</sup> test and concordance between ultrasound and histopathological findings was assessed using the Kappa correlation coefficient. Results: 234 women were included in the study. Their mean age was 46.3 ± 11.4 years. Overall, 15 (6.4%) lumps were benign while 219 (93.6%) were malignant. Triple negative (5.6%) was the most recurrent genomic classification. The correlation between the ultrasound and histopathological findings was significant, with an observed concordance rate at 85.1%, kappa = 0.322 and a p-value Conclusion: The performance of ultrasound in differentiating benign and malignant lesion was high. However, the discordant cases highlight the need for a diagnosis system which blends histopathological and radiological findings for an improved management of patients with breast lumps. 展开更多
关键词 ULTRASOUND Histopathological Diagnosis Breast lumps Yaoundé
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Analysis of High-Frequency Ultrasound in the differential Diagnosis of Lumps in Foot and Hand
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作者 Huitong Yan Heying Li +1 位作者 Jianmei Han Yingbo Tang 《Proceedings of Anticancer Research》 2020年第4期27-31,共5页
Objective:To investigate the ultrasonogram characteristics of common lumps in hand and foot,pursuing for greater understanding of hand and foot lumps.Methods:65 cases of ultrasonographic characteristics of lumps in ha... Objective:To investigate the ultrasonogram characteristics of common lumps in hand and foot,pursuing for greater understanding of hand and foot lumps.Methods:65 cases of ultrasonographic characteristics of lumps in hand and foot were retrospectively analyzed,including the location,size,shape,boundary,internal echo and posterior echo,surrounding relationship and blood flow.Results:Among 65 cases,there were 26 cases of tendon sheath cyst,16 cases of tenosynovitis giant cell tumor,10 cases of hemangioma,4 cases of tendon sheath fibroma,3 cases of epidermoid cyst,2 cases of Schwannoma,2 cases of fibrolipoma,1 case of angiolipoma and 1 case of neurofibroma.The preoperative and postoperative pathological diagnoses of 45 cases,accounting for 69.23%,were consistent,3 cases(4.62%)were misdiagnosed,which included that 2 cases of tenosynovitis giant cell tumor were misdiagnosed as tendon sheath cyst,1 case of neurofibroma as epidermoid cyst,and the preoperative diagnosis of the rest 17 cases(26.15%)were indefinite.Conclusion:The high-frequency ultrasound can diagnose properties of lumps in foot and hand well,providing diagnosis basis for further treatment in clinic. 展开更多
关键词 High-frequency ultrasound lumps Hand and foot Publication
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Antidiastole Value of Three-dimensional Ultrasonography and Power Doppler between Uterine Parenchyma Lumps and Endometrial Cancer:A Retrospective Study 被引量:14
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作者 Yan ZHANG Jing CHEN +1 位作者 Zeng ZHEN Xiao-yan XU 《Current Medical Science》 SCIE CAS 2019年第5期816-819,共4页
Sometimes endometrial polyps,submucosal myomas,and endometrial cancer show similar findings under ultrasonography.The aim of this study was to assess the antidiastole value of blood flow parameters using three-dimensi... Sometimes endometrial polyps,submucosal myomas,and endometrial cancer show similar findings under ultrasonography.The aim of this study was to assess the antidiastole value of blood flow parameters using three-dimensional(3D)power Doppler ultrasonography angiography(PDA)between endometrial cancer and uterine parenchyma lumps.The data of the blood flow indices in 3D-PDA including the vascularization index(VI),flow index(FI),and vascularization flow index(VFI)in 40 patients with endometrial cancer and 41 patients with uterine parenchyma lumps(endometrial polyps and submucosal myomas)were retrospectively analysed and compared utilizing Virtual Organ Computer-aided AnaLysis(VOCAL)software.The results showed that all the blood flow parameters(VI,FI,VFI)were significantly higher in women with endometrial cancer than in those with uterine parenchyma lumps(P<0.001).The area under the curve of ROC of VI,FI,and VFI was 0.98,0.84,and 0.97,respectively.Thus,the best predictor of endometrial carcinoma was VI with a sensitivity of 97.0% and a specificity of 91.0%.The optimal cutoff value of VI was 4.06%.Our data demonstrated that all of the blood flow signal parameters(including VI,FI,and VFI)in 3D power Doppler ultrasonography had significant antidiastole values between endometrial cancer and uterine parenchyma lumps to assist clinicians in properly diagnosing patients. 展开更多
关键词 power DOPPLER three-dimensional ultrasound UTERINE PARENCHYMA lump ENDOMETRIAL CARCINOMA BLOOD flow signal parameter
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Repeated lumps and infections: A case report on breast augmentation complications 被引量:2
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作者 Ming-Xuan Zhang Shi-Yan Li +3 位作者 Li-Long Xu Bo-Wen Zhao Xiao-Yan Cai Guang-Lan Wang 《World Journal of Clinical Cases》 SCIE 2019年第20期3322-3328,共7页
BACKGROUND Polyacrylamide hydrogel(PAAG)injections were once common in breast augmentation and have been prohibited for augmentation mammaplasty in China since a large number of patients who underwent breast augmentat... BACKGROUND Polyacrylamide hydrogel(PAAG)injections were once common in breast augmentation and have been prohibited for augmentation mammaplasty in China since a large number of patients who underwent breast augmentation with PAAG injections have continued to seek medical advice as a result of related complications.Among all these complications,distant migration is relatively rare.CASE SUMMARY A 49-year-old female presented at the hospital with a one-year history of a vulvar lump.The sonography of the lump showed several subcutaneous fluid-filled regions from the left vulva to the pubic symphysis,which suggested possible fat liquefaction.An enhanced magnetic resonance imaging(MRI)revealed a cystic area,which was considered a benign lesion.Intraoperative observations showed that the mass did not have an obvious capsule,the subcutaneous tissue presented as a cavity,and some yellow material came out of this cavity.A culture of the drainage did not show bacterial contamination.Histopathology revealed a foreign body granuloma.After resection and closed drainage,lumps were successively observed in the left lower abdomen and the bilateral hypochondriac region with infections.Sonography found that the hypoechoic areas in the bilateral hypochondriac region seemed continuous with deep in the breasts.The patient reported that she had undergone surgery with PAAG injections 20 years ago after she was repeatedly asked about her past history.Finally,a diagnosis of distant migration of PAAG was made.CONCLUSION PAAG gel can migrate after long periods of time.A diagnosis should not be limited to the area where the symptom develops. 展开更多
关键词 BREAST augmentation DISTANT MIGRATION Repeated lump Repeated INFECTION Case report
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General M-lumps, T-breathers, and hybrid solutions to (2+1)-dimensional generalized KDKK equation 被引量:1
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作者 Peisen Yuan Jiaxin Qi +1 位作者 Ziliang Li Hongli An 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第4期173-183,共11页
A special transformation is introduced and thereby leads to the N-soliton solution of the(2+1)-dimensional generalized Konopelchenko-Dubrovsky-Kaup-Kupershmidt(KDKK) equation.Then,by employing the long wave limit and ... A special transformation is introduced and thereby leads to the N-soliton solution of the(2+1)-dimensional generalized Konopelchenko-Dubrovsky-Kaup-Kupershmidt(KDKK) equation.Then,by employing the long wave limit and imposing complex conjugate constraints to the related solitons,various localized interaction solutions are constructed,including the general M-lumps,T-breathers,and hybrid wave solutions.Dynamical behaviors of these solutions are investigated analytically and graphically.The solutions obtained are very helpful in studying the interaction phenomena of nonlinear localized waves.Therefore,we hope these results can provide some theoretical guidance to the experts in oceanography,atmospheric science,and weather forecasting. 展开更多
关键词 KDKK equation Hirota bilinear method high-order lump solution T-breather solution hybrid solution
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Characteristics and genesis of microbial lumps in the Maozhuang Stage(Cambrian Series 2),Shandong Province,China 被引量:8
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作者 YANG RenChao FAN AiPing +2 位作者 HAN ZuoZhen CHI NaiJie HAN Yu 《Science China Earth Sciences》 SCIE EI CAS 2013年第3期494-503,共10页
Microbial lumps have been found in the Maozhuang Stage(Cambrian Series 2) in the Liangcheng section,Shandong Province,China.Their macro-and micro-scale features distinguish them from other carbonate particles such as ... Microbial lumps have been found in the Maozhuang Stage(Cambrian Series 2) in the Liangcheng section,Shandong Province,China.Their macro-and micro-scale features distinguish them from other carbonate particles such as intraclasts and oncoids.Most lumps have a coarse sand to pebble size.They were mostly rounded during sedimentation or combined to form irregular shapes.A distinct boundary is present between the lumps and the surrounding cement of sparry calcite.The lumps contain either no core at all or several irregular "cores",without a distinct inner texture.They are composed mainly of calcified(micritized) microbes,most likely cyanobacteria.The microbes drilled holes in carbonate grains,after which lumps formed by micritization,cementation,and agglutination by an extracellular polymeric substance(EPS) in a high-energy shallow-marine,subtidal environment.As the lumps are directly related to microbes,they should be considered as microbialites. 展开更多
关键词 CAMBRIAN Maozhuang Stage MICROBE microbial lump carbonate
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Preliminary study on CT perfusion imaging in guiding biopsy of pulmonary lumps 被引量:7
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作者 KANG Li-qing SONG Zhao-wei +4 位作者 LI Zhong-xin YU Shu-jing LIU Feng-hai CHEN Yue-feng XING Rong-ge 《Chinese Medical Journal》 SCIE CAS CSCD 2009年第7期807-812,共6页
Background CT perfusion imaging (CTP) has been proved to be a powerful functional imaging technique. This study aimed to evaluate the value of CTP in guiding biopsy of pulmonary lumps. Methods A total of 147 patient... Background CT perfusion imaging (CTP) has been proved to be a powerful functional imaging technique. This study aimed to evaluate the value of CTP in guiding biopsy of pulmonary lumps. Methods A total of 147 patients with pulmonary lumps who had CT guided biopsies were enrolled in this study from February 2005 to June 2007. The patients were assigned to 3 groups: 33 cases guided by CTP as group 1, 45 cases guided by contrast-enhanced scan of CT as group Ⅱ, and 69 cases guided by plain scan of CT as group Ⅲ. Each group was subdivided into central and peripheral types according to the location of the lumps. The achievement ratio of biopsy, the accuracy in grouping, and grading of lung cancer, and the incidence of complication were compared. Results The total achievement ratios of biopsy from group Ⅰ to Ⅲ were 100% (33/33), 91% (41/45), and 80% (55/69) respectively, and the difference was statistically significant between group Ⅰ and Ⅲ (P 〈0.05). For the central type, they were 100% (18/18), 88% (15/17), and 79% (11/14) respectively, and the difference was also statistically significant between group Ⅰand Ⅲ (P 〈0.05). For the peripheral type, they were 100% (15/15), 93% (26/28), and 80% (44/55) respectivelies, and the difference was not statistically significant among the three groups. The total accuracies in grouping and grading of lung cancer from group Ⅰ to Ⅲ were 100% (27/27), 91% (31/34), and 72% (33/46) respectively, and the difference was statistically significant between group Ⅰ and Ⅲ and between group Ⅱ and Ⅲ (P 〈0.05). For the central type, they were 100% (16/16), 94% (16/17), and 70% (8/12) respectively, and the difference was statistically significant between group Ⅰ and Ⅲ (P〈0.05). For the peripheral type, they were 100% (11/11), 88% (15/17), and 72% (26/36) respectively, and the difference was statistically significant between group Ⅰ and Ⅲ (P 〈0.05). The total incidence of complication from group Ⅰ to Ⅲ were 15% (5/33), 27% (12/45), and 43% (30/69) respectively, and the difference was statistically significant between group Ⅰ and Ⅲ (P 〈0.01). For the central type, they were 11% (2/18), 24% (4/17), and 57% (8/14) respectively, and the difference was statistically significant between group Ⅰ and Ⅲ (P 〈0.01). For the peripheral type, they were 20% (3/15), 29% (8/28), and 40% (22/55) respectively, and no statistically significant difference was found among the three groups. Conclusions CTP guided biopsy of pulmonary lumps using multi-detector row CT has the potential to improve the accuracy of histopathological diagnosis with a lower risk and higher achievement ratio. More research and technical improvements are needed before it is widelv used. 展开更多
关键词 pulmonary lump tomography X-ray computerized perfusion imaging BIOPSY
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(2+1)维Korteweg-de Vries-Sawada-Kotera-Ramani方程中lump波和其它非线波碰撞前后的轨迹方程
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作者 黄文杰 夏亚荣 +1 位作者 王璇 孙晓晴 《应用数学》 北大核心 2025年第1期263-275,共13页
本文首先基于Hirota双线性方法研究了(2+1)维Korteweg-de Vries-Sawada-Kotera-Ramani(KdVSKR)方程的多孤子解,接着利用长波极限法推导出KdVSKR方程的lump波与线波、呼吸波以及lump波的相互作用解.其次,根据lump波沿直线运动的特点,将Kd... 本文首先基于Hirota双线性方法研究了(2+1)维Korteweg-de Vries-Sawada-Kotera-Ramani(KdVSKR)方程的多孤子解,接着利用长波极限法推导出KdVSKR方程的lump波与线波、呼吸波以及lump波的相互作用解.其次,根据lump波沿直线运动的特点,将KdVSKR方程的精确解沿着某些平行直线,在无穷远处进行逼近,进而推导出lump波与线波、呼吸波及lump波撞前后的轨迹方程,并给出了波峰高度以及波的相移.更进一步地,将上述情形推广到lump波与任意多个线波、任意阶呼吸波及任意阶lump波碰撞的情形.最后验证了lump波与其它非线性波的碰撞是弹性碰撞,并绘制了碰撞过程的相关图像. 展开更多
关键词 HIROTA双线性方法 长波极限法 轨迹方程 Lump波
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城市不同下垫面的能量平衡及温度差异模拟 被引量:9
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作者 崔耀平 刘纪远 +2 位作者 张学珍 胡云锋 王军邦 《地理研究》 CSSCI CSCD 北大核心 2012年第7期1257-1268,共12页
城市能量平衡是研究城市热岛效应的物理基础。利用北京市教学植物园2010年的实测数据,设置不同类型下垫面(植被覆盖类型:林地、草地和不透水层覆盖类型:道路、房屋),利用局地尺度城市气象参数化方案模拟并分析了相同气象条件和净辐射通... 城市能量平衡是研究城市热岛效应的物理基础。利用北京市教学植物园2010年的实测数据,设置不同类型下垫面(植被覆盖类型:林地、草地和不透水层覆盖类型:道路、房屋),利用局地尺度城市气象参数化方案模拟并分析了相同气象条件和净辐射通量输入下,不同类型下垫面的显热、潜热通量及蒸散降温效应的差异。结果显示:(1)不同类型下垫面的各能量支出项有明显差异,植被覆盖区域和不透水层覆盖区域的波文比年均值分别为0.28和4.60,且在植被生长季差异较大;(2)城市扩展过程中道路、房屋替换林地、草地的过程,也是显热增加而潜热减少的过程。植被层向不透水层转换的过程中,显热通量年均增加32.74W/m2,潜热通量减少38.87W/m2,储热通量增加7.95W/m2;(3)理论上,植被蒸散的年降温效应使单位面积植被覆盖区域的气温比不透水层区域可低2.63℃。 展开更多
关键词 能量平衡 城市下垫面 lumps 蒸散 北京市
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Extracting fuzzy clusters from massive attributed graphs using Markov lumpability optimization
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作者 Kai-Yue Jiang Li-Heng Xu +3 位作者 Shi-Pei Lin Li-Yang Zhou Hui-Jia Li Ge Gao 《Chinese Physics B》 2025年第10期609-617,共9页
Attributed graph clustering plays a vital role in uncovering hidden network structures,but it presents significant challenges.In recent years,various models have been proposed to identify meaningful clusters by integr... Attributed graph clustering plays a vital role in uncovering hidden network structures,but it presents significant challenges.In recent years,various models have been proposed to identify meaningful clusters by integrating both structural and attribute-based information.However,these models often emphasize node proximities without adequately balancing the efficiency of clustering based on both structural and attribute data.Furthermore,they tend to neglect the critical fuzzy information inherent in attributed graph clusters.To address these issues,we introduce a new framework,Markov lumpability optimization,for efficient clustering of large-scale attributed graphs.Specifically,we define a lumped Markov chain on an attribute-augmented graph and introduce a new metric,Markov lumpability,to quantify the differences between the original and lumped Markov transition probability matrices.To minimize this measure,we propose a conjugate gradient projectionbased approach that ensures the partitioning closely aligns with the intrinsic structure of fuzzy clusters through conditional optimization.Extensive experiments on both synthetic and real-world datasets demonstrate the superior performance of the proposed framework compared to existing clustering algorithms.This framework has many potential applications,including dynamic community analysis of social networks,user profiling in recommendation systems,functional module identification in biological molecular networks,and financial risk control,offering a new paradigm for mining complex patterns in high-dimensional attributed graph data. 展开更多
关键词 attributed clustering Markov chain lumped random walk fuzzy clusters OPTIMIZATION
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Hybrid model of multimodal based on data enhancement and lumped reaction kinetics: Applying to industrial ebullated-bed residue hydrogenation unit
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作者 Jian Long Mengru Zhang +2 位作者 Anlan Li Cheng Huang Dong Xue 《Chinese Journal of Chemical Engineering》 2025年第2期284-302,共19页
Industrial ebullated-bed is an important device for promoting the cleaning and upgrading of oil products. The lumped kinetic model is a powerful tool for predicting the product yield of the ebullated-bed residue hydro... Industrial ebullated-bed is an important device for promoting the cleaning and upgrading of oil products. The lumped kinetic model is a powerful tool for predicting the product yield of the ebullated-bed residue hydrogenation (EBRH) unit, However, during the long-term operation of the device, there are phenomena such as low frequency of material property analysis leading to limited operating data and diverse operating modes at the same time scale, which poses a huge challenge to building an accurate product yield prediction model. To address these challenges, a data augmentation-based eleven lumped reaction kinetics mechanism model was constructed. This model combines generative adversarial networks, outlier elimination, and L2 norm data filtering to expand the dataset and utilizes kernel principal component analysis-fuzzy C-means for operating condition partitioning. Based on the hydrogenation reaction mechanism, a single and sub operating condition eleven lumped reaction kinetics model of an ebullated-bed residue hydrogenation unit, comprising 55 reaction paths and 110 parameters, was constructed before and after data augmentation. Compared to the single model before data enhancement, the average absolute error of the sub-models under data enhancement division was reduced by 23%. Thus, these findings can help guide the operation and optimization of the production process. 展开更多
关键词 Mixed modeling Generative adversarial network Lumped kinetic model Multi-modal learning Ebullated-bed residue hydrogenation
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Compact Integrated Lumped-Element Bandpass Filter Loaded with Defected Ground Structure Based on Multilayer Liquid Crystal Polymer Substrate
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作者 LIU Weihong CHEN Yuan +1 位作者 HUANG Qian LIU Qingran 《Journal of Shanghai Jiaotong university(Science)》 2025年第2期227-232,共6页
Design of a miniaturized lumped-element bandpass filter in multilayer liquid crystal polymer technology is proposed.Fractional bandwidth of the bandpass filter is 20%,operating at a center frequency of 500 MHz.In orde... Design of a miniaturized lumped-element bandpass filter in multilayer liquid crystal polymer technology is proposed.Fractional bandwidth of the bandpass filter is 20%,operating at a center frequency of 500 MHz.In order to further reduce the size and improve the performance of the proposed filter,defected ground structure(DGS)has been implemented in the filter.Based on this structure,the volume of the inductor is reduced by 60%eficiently compared with the inductor without DGS,and the Q-factor is increased up to 257%compared with the traditional multilayer spiral inductor.The measured results indicate that the designed filter has a very sharp stopband,an insertion loss of 2.3dB,and a return loss of 18.6dB in the passband.The whole volume of the fabricated filter is 0.032入_(g)×0.05入_(g)×0.00075入_(g),where Ag is the guided wavelength of the center frequency.The proposed filter is easily integrated into radio-frequency/microwave circuitry at a low manufacturing cost,especially wireless communication. 展开更多
关键词 multilayer liquid crystal polymer defected ground structure bandpass filter MINIATURIZATION lumped element
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一个(2+1)维非线性偏微分方程的精确解
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作者 毛辉 欧阳宇恒 孙睿 《南宁师范大学学报(自然科学版)》 2025年第2期90-96,共7页
该文研究一个由KP方程与(2+1)维Ito方程组合成的非线性偏微分方程的精确解。先对未知函数做变量变换并取恰当的积分常数,得到该方程的Hirota双线性形式。然后用同宿测试法给出该方程的孤子解和呼吸子解,并展示它们的动力学性质。再用正... 该文研究一个由KP方程与(2+1)维Ito方程组合成的非线性偏微分方程的精确解。先对未知函数做变量变换并取恰当的积分常数,得到该方程的Hirota双线性形式。然后用同宿测试法给出该方程的孤子解和呼吸子解,并展示它们的动力学性质。再用正二次函数法构造该方程的4组lump解,并分析这些解的振幅和波速等。最后由扩展的正二次函数法得到该方程的条纹孤子解与lump解的相互作用解,并展示解的吞噬现象。 展开更多
关键词 非线性偏微分方程 HIROTA双线性方法 呼吸子解 lump解 孤子解
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Periodic lump,soliton,and some mixed solutions of the(2+1)-dimensional generalized coupled nonlinear Schrödinger equations
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作者 Xiao-Min Wang Ji Li Xiao-Xiao Hu 《Chinese Physics B》 2025年第11期340-350,共11页
The(2+1)-dimensional generalized coupled nonlinear Schrödinger equations with a four-wave mixing term are studied in this paper,which describe optical solitons in birefringent fibers.Utilizing the Hirota bilinear... The(2+1)-dimensional generalized coupled nonlinear Schrödinger equations with a four-wave mixing term are studied in this paper,which describe optical solitons in birefringent fibers.Utilizing the Hirota bilinear method,we systematically construct single-and double-periodic lump solutions.To provide a detailed insight into the dynamic behavior of the nonlinear waves,we explore diverse mixed solutions,including bright-dark,W-shaped,multi-peak,and bright soliton solutions.Building upon single-periodic lump solutions,we analyze the dynamics of lump waves on both plane-wave and periodic backgrounds using the long-wave limit method.Moreover,we obtain the interaction solutions involving lumps,periodic lumps,and solitons.The interactions among two solitons,multiple lumps,and mixed waves are illustrated and analyzed.Comparative analysis reveals that these multi-lump solutions exhibit richer dynamical properties than conventional single-lump ones.These results contribute to a deeper understanding of nonlinear systems and may facilitate solving nonlinear problems in nature. 展开更多
关键词 nonlinear Schrödinger equations lump solutions mixed solutions Hirota bilinear method
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A variationally consistent nodal integration for cubic serendipity finite elements with optimal convergence in explicit transient heat conduction analysis
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作者 Songyang Hou Zhiwei Lin +1 位作者 Zhenyu Wu Dongdong Wang 《Theoretical & Applied Mechanics Letters》 2025年第6期597-609,共13页
The 13-node quadrilateral and 39-node hexahedral cubic serendipity elements produce nodally integrated positive-definite lumped heat capacity matrices in higher-order finite element analysis.However,these elements dis... The 13-node quadrilateral and 39-node hexahedral cubic serendipity elements produce nodally integrated positive-definite lumped heat capacity matrices in higher-order finite element analysis.However,these elements display severe convergence deterioration in explicit transient heat conduction analysis with lumped heat ca-pacity matrices.This convergence decay is due to the violation of variational integration consistency by the standard Galerkin formulation with lumped heat capacity matrices.This issue is resolved by introducing the boundary-enhanced Galerkin weak form that incorporates the elemental boundary contribution in the discrete finite element formulation.Subsequently,it is theoretically proven that a direct nodal integration identically fulfills the variational integration consistency in the context of the boundary-enhanced Galerkin weak form.The proposed variationally consistent nodal integration therefore enables optimal convergence for explicit transient heat conduction analysis with lumped heat capacity matrices.The efficacy of the proposed variationally con-sistent nodal integration formulation for the 13-node quadrilateral and 39-node hexahedral cubic elements is thoroughly demonstrated via numerical examples. 展开更多
关键词 Cubic serendipity element Heat conduction analysis Nodal integration Lumped heat capacity matrix Variational integration consistency Optimal convergence
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A methodology to simulate interior and intermediate ballistics with dynamic mesh technique and lumped parameter code
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作者 G.Guermonprez T.Gaillard +2 位作者 J.Dupays J.Anthoine R.Demarthon 《Defence Technology(防务技术)》 2025年第7期447-464,共18页
The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.F... The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.First,the methodology is introduced with the development of an interior ballistics(IB)lumped parameter code(LPC),integrating an original image processing method for calculating the specific regression of propellant grains that compose the gun propellant.The ONERA CFD code CEDRE,equipped with a Dynamic Mesh Technique(DMT),is then used in conjunction with the developed LPC to build a dedicated methodology to calculate IB.First results obtained on the AGARD gun and 40 mm gun test cases are in a good agreement with the existing literature.CEDRE is also used to calculate inter-mediate ballistics(first milliseconds of free flight of the projectile)with a multispecies and reactive approach either starting from the gun muzzle plane or directly following IB.In the latter case,an inverse problem involving a Latin hypercube sampling method is used to find a gun propellant configuration that allows the projectile to reach a given exit velocity and base pressure when IB ends.The methodology developed in this work makes it possible to study the flame front of the intermediate flash and depressurization that occurs in a base bleed(BB)channel at the gun muzzle.Average pressure variations in the BB channel during depressurization are in good agreement with literature. 展开更多
关键词 Intermediate ballistics Interior ballistics(IB) Lumped parameter code(LPC) Form function Dynamic mesh
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Non-Lumped Microwave Topolectrical Resonator Based on the Su–Schriefer–Heeger Model
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作者 Chengxin Yu Xiao Zhang 《Chinese Physics Letters》 2025年第7期235-250,共16页
Topological states realized in metamaterials have provided a versatile platform for exploring topological physics and enabling novel applications,with topolectrical circuits emerging as a prominent example.However,pre... Topological states realized in metamaterials have provided a versatile platform for exploring topological physics and enabling novel applications,with topolectrical circuits emerging as a prominent example.However,previous research in this feld has primarily focused on lumped-element implementations,while non-lumped microwave circuits remain relatively underexplored.In this work,we design and investigate a one-dimensional non-lumped Su–Schriefer–Heeger topolectrical circuit composed of copper parallel-plate transmission lines and inductors,ofering compatibility with integrated microwave applications.Full-wave microwave simulations in the 0–10 GHz range show excellent agreement with theoretical predictions.The impedance spectrum of a fveunit-cell system displays periodic resonant passbands and stopbands corresponding to bulk states,while distinct high-Q(on the order of 10^(2))topological boundary resonances(TBRs)emerge within the stopbands,indicating the presence of localized edge states.Furthermore,the TBRs vanish when the system is reconfgured into the trivial phase,providing direct evidence of its topological nature.These response characteristics make the proposed resonator a promising candidate for future microwave devices and topological circuit applications. 展开更多
关键词 METAMATERIALS non lumped microwave circuits topological states SU Schriefer Heeger model exploring topological physics topolectrical circuit topolectrical circuits
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(2 + 1)维BLMP方程Lump波与孤波的相互作用解
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作者 肖星奇 《理论数学》 2025年第4期22-30,共9页
本文应用Hirota双线性方法探讨了(2 + 1)维Boiti-Leon-Manna-Pempinelli (BLMP)方程的解及其相互作用。该方法的一个特点是使用对数变换将方程转化为双线性形式,且我们在对数变换中引入了非零常数。本文分析了1-lump波分别与1-kink孤波... 本文应用Hirota双线性方法探讨了(2 + 1)维Boiti-Leon-Manna-Pempinelli (BLMP)方程的解及其相互作用。该方法的一个特点是使用对数变换将方程转化为双线性形式,且我们在对数变换中引入了非零常数。本文分析了1-lump波分别与1-kink孤波和2-kink孤波之间的相互作用,揭示了它们的弹性和共振碰撞行为。为了进一步说明这些解的特征,我们利用Mathematica软件提供了详细的三维图示结果。In this study, we investigate the (2 + 1)-dimensional Boiti-Leon-Manna-Pempinelli equations using the Hirota bilinear method. A feature of our approach is the use of a logarithmic transformation to convert the equation into bilinear form with the introduction of a nonzero constant in the transformation. We analyze the interaction dynamics of lump solutions with one and two kink solitons, revealing their elastic and resonant collision behaviors. To further illustrate the characteristics of these solutions, we provide detailed 3D plots using the Mathematica software. 展开更多
关键词 (2 + 1)维BLMP方程 Lump解 共振相互作用 Hirota双线性法 长波极限法
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A Preliminary Study of the Dynamics of Eastward Shifting Cyclonic Vortices 被引量:5
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作者 陈联寿 罗哲贤 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2003年第3期323-332,共10页
The dynamics of eastward shifting cyclonic vortices are investigated in terms of a barotropic primitive equation model, and six experiments are performed. Both the interaction of a cyclonic vortex with vorticity lumps... The dynamics of eastward shifting cyclonic vortices are investigated in terms of a barotropic primitive equation model, and six experiments are performed. Both the interaction of a cyclonic vortex with vorticity lumps and the interaction of the vortex with the shearing basic flow may induce the strengthening of the vortex in a short period, however, the vortex intensity still shows a general decreasing tendency over the whole integration time period. The interaction among the shearing basic flow, cyclonic vortex, and multiple vorticity lumps can change the tendency. The merging of the cyclonic vortex with vorticity lumps in the shearing basic flow of positive vorticity is directly responsible for the maintenance and development of the cyclonic vortex. 展开更多
关键词 eastward shifting cyclonic vortex shearing basic flow vorticity lump merging of vortex with lumps intensification of vortex
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