Enhancement effect of cumulative second-harmonic generation by closed propagation feature of circumferential guided waves

On the basis of second-order perturbation approximate and modal expansion approach,we investigate the enhancement effect of cumulative second-harmonic generation(SHG)of circumferential guided waves(CGWs)in a circular tube,which is inherently induced by the closed propagation feature of CGWs.An appropriate mode pair of primary-and double-frequency CGWs satisfying the phase velocity matching and nonzero energy flux is selected to ensure that the second harmonic generated by primary CGW propagation can accumulate along the circumference.Using a coherent superposition of multi-waves,a model of unidirectional CGW propagation is established for analyzing the enhancement effect of cumulative SHG of primary CGW mode selected.The theoretical analyses and numerical simulations performed directly demonstrate that the second harmonic generated does have a cumulative effect along the circumferential direction and the closed propagation feature of CGWs does enhance the magnitude of cumulative second harmonic generated.Potential applications of the enhancement effect of cumulative SHG of CGWs are considered and discussed.The theoretical analysis and numerical simulation perspective presented here yield an insight previously unavailable into the physical mechanism of the enhancement effect of cumulative SHG by closed propagation feature of CGWs in a circular tube.

Structural features of crust-mantle assemblage in the lithosphere along the Longitudinal Seismic Belt of China and their tectonic effect

The 1°×1° distribution map of crustmantle structural ratio R for the lithosphere along the Longitudinal Seismic Belt of China has been compiled using computer based on the results of geophysical prospecting by previous researchers, and the latest results by the present authors. Based on this map, an insight into the structural features of the crustmantle assemblage along the Longitudinal Seismic Belt has been gained, while their relation to seismic activity and the distributions of geothermal flux and intracrustal high conductivitylow velocity layers, as well as their tectonic effect to seismicity have been discussed.

Relationship between biological features and the SMVS's inhibitory effect on mating behavior of Nilaparvata lugens (Stal)

Our previous studies revealed that second malevibration signal (SMVS) restrained the matingbehavior of N. lugens, the influences of threebiological features (density, age, and wingform) on SMVS’s inhibitory effect were hereinstudied by playing back its record. The dura-tion of playback was 4 h. Except otherwisestatement, N. lugens tested were virginmacropterous males and females aged 4-6 d af-ter emergence, and the density was 5 pairs (5females and 5 males) of N. lugens per cage (4cm in diameter and 8 cm in height). The in-hibitory effect of SMVS was evaluated usingmating rate (i. e. the rate of females withspermatophore). The results were as follows:

Nonlinear Feature of the Abrupt Transitions between Multiple Equilibria States of an Ecosystem Model

Based on a five-variable theoretical ecosystem model, the stability of equilibrium state and the nonlinear feature of the transition between a grassland state and a desert state are investigated. The approach of the conditional nonlinear optimal perturbations （CNOPs）, which are the nonlinear generalization of the linear singular vectors （LSVs）, is adopted. The numerical results indicate that the linearly stable grassland and desert states are nonlinearly unstable to large enough initial perturbations on the condition that the moisture index # satisfies 0.3126 〈 μ 〈 0.3504. The perturbations represent some kind of anthropogenic influence and natural factors. The results obtained by CNOPs, LSVs and Lyapunov vectors （LVs） are compared to analyze the nonlinear feature of the transition between the grassland state and the desert state. Besides this, it is shown that the five-variable model is superior to the three-variable model in providing more visible signals when the transitions occur.

A Study of Rhetorical Features of English News Headlines

As is known to all,headlines serve as a summary and advertisement for the main idea of the news so as to make the reader have a better understanding.Therefore,to some degree,we can say that the headline is the soul of a news report.Rhetoric,in all kinds of writing in all kinds of languages,can be applied and make an efficient effect.As for an English news headline,it is usually formed with certain rhetorical device to embody its soul and to appeal to more readers.This paper is to introduce and discuss the rhetorical features of the news headlines with examples and analysis.

Clinical features and prognostic factors in 49 patients with follicular lymphoma at a single center:A retrospective analysis

BACKGROUND Follicular lymphoma(FL)is a type of B-cell lymphoma that originates at the germinal center and has a low malignancy rate.FL has become the most common inert lymphoma in Europe and America but has a relatively low incidence in Asia.AIM To explore the clinical features,curative effects,and prognostic factors of FL.METHODS Completed medical records of 49 patients with FL who were admitted to the Ningbo First Hospital from June 2010 to June 2021 were examined.These patients were definitively diagnosed by pathological biopsy or immunohistochemical staining.The diagnostic criteria were based on the 2008 World Health Organization classification of lymphomas.Ann Arbor staging was performed according to the imaging and bone marrow examination results.Risk stratification of all patients was performed based on the International Prognostic Index(IPI),age-adjusted IPI,Follicular Lymphoma International Prognosis Index(FLIPI),and FLIPI2 to compare the efficacy of different treatment regimens and analyze the related prognostic factors.RESULTS The age of onset in patients ranged from 24 to 76 years,with a median age of 51 years.Most patients developed the disease at 40–59 years of age,and the male:female ratio was 1.6:1.No significant difference was noted in the curative effect between the non-chemotherapy,combined chemotherapy,and other chemotherapy regimens(P>0.05).Hemoglobin(Hb)level<120 g/L,Ki-67 value>50%,bone marrow involvement,and clinical stagesⅢ–IV were associated with a poor prognosis of FL(P<0.05).However,the influence of other indicators was not statistically significant.Risk grouping was performed using the FLIPI,and the results showed that 24.5%,40.8%,and 34.7%of patients were in the low-,moderate-,and high-risk groups,respectively.According to the survival analysis results,the survival rate of patients was lower in the high-risk group than in the other low-risk and moderate-risk groups(P<0.05).CONCLUSION FL mainly occurs in middle-aged and elderly men,primarily affecting lymph nodes and bone marrow.Hb level,Ki-67 value,bone marrow involvement,and clinical staging were used to evaluate prognosis.

Improved preprocessed Yaroslavsky filter based on shearlet features

An improved preprocessed Yaroslavsky filter（IPYF）is proposed to avoid the nick effects and obtain a better denoising result when the noise variance is unknown.Different from its predecessors,the similarity between two pixels is calculated by shearlet features.The feature vector consists of initial denoised results by the non-subsampled shearlet transform hard thresholding（NSST-HT）and NSST coefficients,which can help allocate the averaging weights more reasonably.With the correct estimated noise variance,the NSST-HT can provide good denoised results as the initial estimation and high-frequency coefficients contribute large weights to preserve textures.In case of the incorrect estimated noise variance,the low-frequency coefficients will mitigate the nick effect in cartoon regions greatly,making the IPYF more robust than the original PYF.Detailed experimental results show that the IPYF is a very competitive method based on a comprehensive consideration involving peak signal to noise ratio（PSNR）,computing time,visual quality and method noise.

The Study on the Clinical Features and Prognosis of Pregnancy-related Breast Cancer

Objective: To explore the clinical features ofpregnancy-related breast cancer and the related factorsaffecting the prognosis. Methods: The research workwas carried out in our hospital from January 2018 toJanuary 2019. In this study, 50 patients were selectedas related breast cancer patients and 50 non-pregnancyrelated breast cancer patients were selected as controlgroup. The clinical characteristics and prognosis ofthe two groups were compared and analyzed. Results:According to the incidence of pregnancy-related breastcancer, the onset of breast cancer is in pregnancy andlactation, with more than half of the total number ofpatients having two or more pregnancies and 74.0%of the patients having breast feeding history. In thetwo groups, most of the patients went to see a doctorbecause of palpable breast masses, and the averagemaximum diameter of tumors in PBC group was (5.13± 3.22)cm, including 5 cases accompanied by dimplesign, 7 cases accompanied by nipple depression, 8cases accompanied by inflammatory changes of skin,3 cases with pathological changes involving wholemilk, and 27 cases (54.00%) with palpable axillaryenlarged lymph nodes on the same side. The averagemaximum value of tumor in Non-PABC group was(3.94 ± 2.11) cm, with 5 cases accompanied by dimplesign, 4 cases accompanied by nipple depression, and 9cases (18.00%) with palpable axillary lymph nodes onthe same side. Conclusion: As far as pregnancy-relatedbreast cancer is concerned, the clinical misdiagnosisrate is relatively high and the prognosis is poor.Prenatal examination and breast-feeding breast cancerexamination are needed to ensure early detection anddiagnosis. This is the key factor to ensure the survivalrate of pregnancy-related breast cancer patients and haspositive significance for clinical development.

A trial study of vibration-induced effects on the spontaneous potential

Vibrator excitation generates not only reflections and refractions of wave fields on the subsurface interfaces but also electromagnetic waves with different frequencies. In this paper, we address the vibration-induced effects on the spontaneous potential field. The effects of controllable vibration on the spontaneous potential field were studied under real field geologic conditions. Experimental data confirmed that the vibration-induced effects on the spontaneous potential field do exist under field conditions. Monitoring records over a long time interval showed that there exist three information zones in the vibration-induced effects on the spontaneous potential field. These are the signal-varying zone, the extremestable zone, and the relaxation-recovery zone. Combined with different well-site data, it was concluded that the time-varying features of the anomalies in the information zones was closely related to the properties of the subsurface liquid （oil and water）.

The effects of Trichoderma on preventing cucumber fusarium wilt and regulating cucumber physiology

In our previous studies, we identified 3 Trichoderma strains with anti-Fusarium oxysporum activity, including T. asperellum 525, T. harzianum 610, and T. pseudokoningii 886. Here, we evaluated the effects of these 3 Trichoderma strains on preventing cucumber fusarium wilt through pot culture and greenhouse culture experiments. All 3 Trichoderma strains demonstrated higher control effects toward cucumber fusarium wilt than previous studies, with efficacies over 78%. Additionally, inoculation with the 3 Trichoderma strains significantly promoted the quality and yield of cucumbers. Among the 3 strains, Trichoderma 866 was the most effective, with disease control efficacy of 78.64% and a cucumber yield increase of 33%. Furthermore, seedlings inoculated with Trichoderma exhibited significantly increased measures of plant height, stem diameter, leaf area, aboveground fresh weight, underground fresh weight, chlorophyll content, and nitric nitrogen content, as well as the activities of several stress-resistance enzymes, including superoxide dismutase(SOD), peroxidase(POD), catalase(CAT), polyphenol oxidase(PPO), and ascorbate oxidase(AAO). In addition, the plants inoculated with Trichoderma showed decreased cell membrane permeability and malondialdehyde(MDA) content in the leaves. Together, our results suggest that T. asperellum 525, T. harzianum 610, and T. pseudokoningii 886 inoculations inhibit F. oxysporum infection, stimulate the metabolism in cucumbers, and enhance the activities of stress-resistance enzymes, which consequently promote the growth of cucumber plants, prevent cucumber fusarium wilt, and improve the yield and quality of cucumbers. T. harzianum is a commonly used biocontrol fungus, while few studies have focused on T. asperellum or T. koningense. In this study, strains of T. asperellum and T. pseudokoningii showed excellent plant disease prevention and growth promoting effects on cucumber, indicating that they also have great potential as biocontrol fungi.

NONLINEAR EFFECT OF THE DUALFREQUENCY IP SPECTRUM

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Temperature effects on the mechanical properties of slates in triaxial compression test

High geothermal temperatures appear to be unfavorable for the construction of tunnels in slate rocks with high overburden. To investigate the mechanical characteristics of slates at various levels of geothermal temperature, conventional triaxial compression tests at different levels of confining stress were carried out at 4 different temperatures from 20℃ to 120℃. The obtained results show high confining pressures weaken the thermal effects on rock mechanical characteristics while higher temperatures enhance the effect of confining pressure.At higher levels of confining stress the thermal effects on the rock strength characteristics decrease. The higher the temperature, the larger is the effect of confining pressure on the mechanical characteristics of the slate. Increase of temperature leads to a decrease of the peak strength but increases the deformability and ductility of the slate, the thermo effect on the peak strength and Poisson's ratio is larger than on the elastic modulus. Higher temperatures reduce the shear strength of slate, the decrease is mainly caused by a decrease of the cohesion. In general, the slate samples fail in shear failure.

脉冲涡流缺陷检测理论与技术研究综述

由于具有非接触、效率高、检测信号的信息含量丰富等诸多优点,脉冲涡流技术被广泛应用工业产品的缺陷检测,尤其是带包覆层、异质、以及多层导电结构等检测难度极大的工业产品。脉冲涡流探头结构的设计和优化是提高检测灵敏度和准确度的关键,目前大量的研究工作围绕探头结构的设计和优化开展;不同材质、结构、以及缺陷类型或形状需要选用合适特征量表征,特征量的选取与分析也是脉冲涡流技术研究的关键;另外,由于脉冲涡流检测信号受提离高度影响极大,未知提离高度的缺陷准确检测面临极大的挑战,因此提离效应的抑制也是研究的重点之一。本文从探头的设计与开发、特征量的选取与分析、提离效应的抑制等方面,对脉冲涡流检测技术的研究进展进行综述。同时,为更好的推动脉冲涡流检测技术发展,论文在现有的研究基础上,对脉冲涡流探头设计、特征量分析、以及提离效应抑制等进行了展望。

基于镇咳祛痰作用的“形”与药材品质关联的桔梗“辨状论质”研究

目的:通过桔梗宏观性状(长、宽、厚、质量)、微观形状(乳汁管面积)以及桔梗总皂苷和镇咳祛痰作用的关联分析,探究基于桔梗“形”的“辨状论质”实质。方法:本研究对桔梗“状”中的“形”、桔梗总皂苷和镇咳祛痰的药效结果进行定量测定,分别进行“状-量-效”和“状-效”关联分析,讨论“形”与桔梗品质的关系。结果:不同来源桔梗“形”的量化值、总皂苷含量和镇咳祛痰量化结果均有一定差异。“状-量-效”关联结果显示桔梗质量可体现药材品质,“状-效”关联结果显示宽度、厚度和乳汁管面积均与咳嗽次数呈显著相关,桔梗质量与酚红排泄量呈显著相关。结论:桔梗总皂苷可体现桔梗药材品质。“状-效”和“状-量-效”关联分析均可体现“辨状论质”的实质,其中“状-效”分析更明确、针对性更强。

基于高阶空间交互网络的光伏组件热斑故障检测

针对传统红外热斑故障检测算法由于特征表达能力不佳造成算法易受复杂背景干扰以及对密集目标、小目标故障检测精度低的问题,提出一种基于高阶空间交互的光伏组件热斑故障检测网络。首先,设计高阶空间交互模块,并将其引入YOLOv5主干网络进行全局交互建模,提升网络对密集目标的检测精度;其次,为突出复杂背景下故障目标的关键特征,设计基于协同注意力的特征提取模块重构颈部网络;然后,在颈部网络设计多尺度特征增强融合模块以提高检测网络对不同尺度特征的充分利用;最后,设计自适应特征融合检测头以提高模型对小目标的感知能力。实验结果表明,相较于7种经典检测算法,所提出的算法检测精度最高,精度可达84.3%。

融合动态特征与注意力的敦煌壁画修复模型

敦煌壁画图像含有丰富的纹理和结构信息,在破损壁画修复过程中,容易忽略受损特征信息与完整特征信息之间的区别,从而误导修复过程生成不合理的壁画内容。针对该问题,提出一种融合动态特征选择和像素级通道注意力的壁画修复模型。设计基于U-Net的网络生成器,实现对破损图像的编码与解码操作;采用有效可迁移卷积模块,通过动态选择采样空间位置,实现对有效特征信息的灵活提取,采用区域综合归一化模块减少修复区域与完整区域的期望和方差的偏移,从而加强对有效特征信息的选择和利用;在解码层设计像素级通道注意力模块,在增强有效特征权重的同时使模型可从相隔较远的空间位置学习有效特征。在敦煌壁画数据集上的实验结果表明,该算法能够利用有效信息修复掩膜区域比例不一的不规则破损壁画图像,相比PConv、PRVS、DSNet算法,在峰值信噪比(PSNR)指标上平均提升0.502 d B,在结构相似性(SSIM)指标上平均提升1.384%。

基于因果正则化极限学习机的风电功率短期预测方法

随着风电并网比例的逐年提高,电力系统对风电功率预测的准确性和稳定性提出了更高要求。对于同一风电场而言,为了避免不同特征选择方法所选择的风电场特征子集不同,从因果关系的角度出发,提出了一种基于因果正则化极限学习机(causal regularized extreme learning machine, CRELM)的风电功率短期预测方法。首先将极限学习机(extreme learning machine, ELM)建模为结构因果模型(structural causal model, SCM),在此基础上计算隐藏层神经元与输出层神经元之间的平均因果效应向量。然后将该平均因果效应向量与输出层权重相结合构成因果正则化项,在最小化训练误差的同时最大化网络的因果关系,以进一步提升模型的预测准确性和预测稳定性。最后,以国内蒙西某风电场数据为例,与采用特征选择或不采用特征选择的预测模型相对比,验证了所提方法的有效性和适用性。

基于敦煌飞天伎乐神艺术美的珠宝设计研究

敦煌壁画艺术作为敦煌艺术的主要组成部分,独一无二的着色与构图体现了敦煌艺术的壮丽[1]。在唐代敦煌壁画中,伎乐天神形象是敦煌壁画本土文化的重要展现于世人的方式之一,其中以飞天伎乐神最具有代表性,是多元中国美学文化融合的艺术形象,同时神女又是最为广为人知的部分,美学效果使其成为佛教文化的体现。设计以敦煌壁画中的飞天伎乐神造型为载体,对其进行基本的造型艺术特色分析,以其作为立点原型设计,用叙述型珠宝设计探讨其在珠宝设计中的应用,衍生出《熠熠煌玺》珠宝首饰设计。

复杂特征全景图像视觉传达效果优化仿真

由于全景拍摄中不同相机镜头的焦点距离不固定,因此在拼接之前相邻两个局部图像间就会产生视差,且距离越近的物体产生视差会越大。全景图像效果的优化是提升视觉质量的关键。提出一种复杂特征全景图像视觉传达效果优化方法。利用两种色彩空间模型与二维经验小波变换法,提取出图像的光谱特征与纹理特征。采用马拉特算法完成小波变换与小波分解,得到复杂特征融合后的全景图像重构结果。基于能量函数及负相关性,界定视觉传达效果的降噪优化目标,设计四阶偏微分方程的降噪模型,完成图像降噪处理。基于此,融合冲击滤波器与直方图均衡化,根据各连通分量对应的子图像,拉伸图像灰度级分布形式,增强细节信息,实现视觉传达效果优化。选取一幅具有复杂特征的全景图像,从感官与数据量化两方面评价不同方法下全景图像的优化效果。实验结果验证了上述方法提高了图像的对比度、清晰度、丰富度,且处理时间更短,具备良好的实践性与实时性。

基于“目的论”的旅游口号英译研究和翻译效果优化建议——以国内省级行政区中英文版旅游口号为例

根据旅游口号的文本特点,旅游口号的翻译最适用“目的论”翻译理论。以此理论为指导依据,选取国内旅游口号的英译案例进行分析,并对部分已有译文尝试改译并提出建议,如翻译时可针对口号内容、修辞、文化及受众等方面对传递的信息进行筛选和调整,以实现国内旅游口号英译效果的优化,使得译文能够达到在译语受众中的宣传目的,促进译语受众产生旅游消费欲望和旅游行为。