Nonlinear Flap-Wise Vibration Characteristics ofWind Turbine Blades Based onMulti-Scale AnalysisMethod

This work presents a novel approach to achieve nonlinear vibration response based on the Hamilton principle.We chose the 5-MW reference wind turbine which was established by the National Renewable Energy Laboratory(NREL),to research the effects of the nonlinear flap-wise vibration characteristics.The turbine wheel is simplified by treating the blade of a wind turbine as an Euler-Bernoulli beam,and the nonlinear flap-wise vibration characteristics of the wind turbine blades are discussed based on the simplification first.Then,the blade’s large-deflection flap-wise vibration governing equation is established by considering the nonlinear term involving the centrifugal force.Lastly,it is truncated by the Galerkin method and analyzed semi-analytically using the multi-scale analysis method,and numerical simulations are carried out to compare the simulation results of finite elements with the numerical simulation results using Campbell diagram analysis of blade vibration.The results indicated that the rotational speed of the impeller has a significant impact on blade vibration.When the wheel speed of 12.1 rpm and excitation amplitude of 1.23 the maximum displacement amplitude of the blade has increased from 0.72 to 3.16.From the amplitude-frequency curve,it can be seen that the multi-peak characteristic of blade amplitude frequency is under centrifugal nonlinearity.Closed phase trajectories in blade nonlinear vibration,exhibiting periodic motion characteristics,are found through phase diagrams and Poincare section diagrams.

Multiparameter Numerical Investigation of Two Types of Moving Interactions Between the Deep-Sea Mining Vehicle Track Plate and Seabed Soil:Digging and Rotating Motions

To ensure the safe performance of deep-sea mining vehicles(DSMVs),it is necessary to study the mechanical characteristics of the interaction between the seabed soil and the track plate.The rotation and digging motions of the track plate are important links in the contact between the driving mechanism of the DSMV and seabed soil.In this study,a numerical simulation is conducted using the coupled Eulerian–Lagrangian(CEL)large deformation numerical method to investigate the interaction between the track plate of the DSMV and the seabed soil under two working conditions:rotating condition and digging condition.First,a soil numerical model is established based on the elastoplastic mechanical characterization using the basic physical and mechanical properties of the seabed soil obtained by in situ sampling.Subsequently,the soil disturbance mechanism and the dynamic mechanical response of the track plate under rotating and digging conditions are obtained through the analysis of the sensitivity of the motion parameters,the grouser structure,the layered soil features and the soil heterogeneity.The results indicate that the above parameters remarkably influence the interaction between the DSMV and the seabed soil.Therefore,it is important to consider the rotating and digging motion of the DSMV in practical engineering to develop a detailed optimization design of the track plate.

Coupled-generalized nonlinear Schr¨odinger equations solved by adaptive step-size methods in interaction picture

We extend two adaptive step-size methods for solving two-dimensional or multi-dimensional generalized nonlinear Schr ¨odinger equation(GNLSE): one is the conservation quantity error adaptive step-control method(RK4IP-CQE), and the other is the local error adaptive step-control method(RK4IP-LEM). The methods are developed in the vector form of fourthorder Runge–Kutta iterative scheme in the interaction picture by converting a vector equation in frequency domain. By simulating the supercontinuum generated from the high birefringence photonic crystal fiber, the calculation accuracies and the efficiencies of the two adaptive step-size methods are discussed. The simulation results show that the two methods have the same global average error, while RK4IP-LEM spends more time than RK4IP-CQE. The decrease of huge calculation time is due to the differences in the convergences of the relative photon number error and the approximated local error between these two adaptive step-size algorithms.

基于截断p-shrinkage范数的航空发动机数据重构

针对航空发动机传感器的数据缺失问题,提出基于张量奇异值阈值(TSVT)的张量重构模型LRTC-PTNN,对航空发动机的传感器数据进行重构。LRTC-PTNN模型运用截断pshrinkage范数的方式代替原始张量迹范数作为张量秩的凸包络,并根据TSVT的特性,计算了传感器之间的相关性,选取传感器截面作为重构精度最佳的数据输入方向,使用交替乘子法实现LRTCPTNN算法。选取NASA提供的PHM2008数据集进行实验,对数据集进行标准化,并在重构后进行恢复,将多个时间序列个数相近的发动机传感器数据构建为高维张量的形式,设置2种传感器的数据缺失场景进行实验,结果表明:重构后数据的均方根误差和平均绝对百分比误差范围分别为2.10~13.13和0.32~1.49,LRTC-PTNN模型优于现有的基线模型,且在极端情况下有较强的鲁棒性。

血清CCL3、P-selectin联合检测对急性肺栓塞的诊断价值

目的探讨血清趋化因子配体3(CCL3)、P选择素(P-selectin)联合检测对急性肺栓塞(APE)的诊断价值。方法选取2020年6月~2022年6月期间本院接诊的90例APE患者作为研究组。另取90例同期在本院体检,且一般资料与APE患者相匹配的健康者作为对照组。采用Pearson法分析APE患者血清CCL3、P-selectin表达水平的相关性;采用Logistic回归分析影响APE发生的相关因素;受试者工作特征(ROC)曲线分析血清CCL3、P-selectin水平对APE的诊断价值。结果研究组血清CCL3、P-selectin水平均显著高于对照组(P<0.05);APE患者血清CCL3、P-selectin表达水平呈正相关(r=0.808,P<0.05);收集所有指标数据的中位数对影响APE发生的相关因素进行单因素分析,结果显示,研究组心率≥90次/min、SBP<120 mmHg和DBP<80 mmHg的患者所占比例显著高于对照组(P<0.05);心率、CCL3及P-selectin均为发生APE的危险因素(P<0.05),SBP、DBP为保护因素(P<0.05);血清CCL3、P-selectin及二者联合诊断APE的曲线下面积(AUC)分别为0.888、0.854和0.951,二者联合优于血清CCL3、P-selectin各自单独诊断(Z_(二者联合-CCL3)=2.146,Z_(二者联合-P-selectin)=2.315,P=0.022、0.039)。结论血清CCL3、P-selectin水平与APE的发生密切相关,二者联合检测对APE具有较好的诊断价值。

血清IL-33、sP-SLT与心房颤动患者认知功能改变的关系

目的探究血清白细胞介素(interleukin,IL)-33、P-选择素(sP-SLT)表达水平与持续性心房颤动(atrial fibrillation,AF)患者认知功能障碍(cognitive impairment,CI)的关系。方法选取笔者医院2020年10月~2021年2月收治的160例AF患者,并采用蒙特利尔认知评估量表(Montreal Cognitive Assessment,MoCA)评估其认知功能,将MoCA评分<26分者作为CI组(n=52)以及MoCA评分≥26分者作为NCI组(n=108),另选取同一时期体检健康者100例为对照组。所有受试者均于入院24h内采用双抗体夹心酶联免疫吸附法(enzyme-linked immunosorbent assay,ELISA)测定其血清中IL-33、sP-SLT表达水平,并分析两者与MoCA总分及各分项评分的关系。结果CI组IL-33、sP-SLT水平较NCI组以及对照组均明显更高(P<0.01),且NCI组IL-33、sP-SLT水平亦较对照组明显更高(P<0.01);CI组I语言、记忆、抽象思维、执行功能、视结构技能、注意与集中、计算和定向力以及MoCA总分较NCI组以及对照组均明显更低(P<0.05);Pearson检验发现,认知功能障碍组患者血清IL-33、sP-SLT水平与语言、记忆、执行功能、视结构技能、注意与集中、计算和定向力以及MoCA总分均呈正相关(r分别为0.813、0.805、0.815、0.786、0.723、0.685、0.517;r分别为0.846、0.798、0.814、0.826、0.801、0.652、0.543,P均<0.001)。结论血清IL-33、sP-SLT水平与AF患者CI密切相关,有助于临床评估AF患者的认知功能。

The anti-correlation method for removing harmonic distortion in vibroseis slip-sweep data

The slip-sweep technique is one of the high-efficiency, high-fidelity, and environmental vibroseis seismic prospecting techniques which consists of a vibrator group sweeping without waiting for the previous group＇s sweep to terminate. The cycle time can be reduced drastically and hence the production efficiency can be increased significantly but harmonic distortion of one sweep will leak into the record of the other sweep. In this paper, we propose an anti-correlation method for removing harmonic distortion in vibroseis data. This method is based on decomposition of the ground force signal into fundamental and harmonic components. Then the corresponding anti-correlation operator can be computed to estimate the energy of each harmonic after correlating the vibroseis data with the corresponding harmonic component. Finally, the vibroseis harmonic noise to be removed can be obtained by subtracting the extracted harmonic noise from the traces of the previous group＇s sweep. The advantage of the proposed method is that it can process both uncorrelated and correlated vibroseis seismic data. Moreover, the algorithm is simple, stable, and computationally fast. Especially, the significant contribution of this method is a considerable reduction in the harmonic without any alteration of the desired signals. The method was tested on both synthetic and field data sets to validate the good harmonic noise suppression results.

完全匹配层在矩阵式波动方程SBP-SAT方法应用

数值离散方法和截断边界效果是地震动模拟实现的关键。基于分部求和(summation-by-parts,SBP)和一致逼近(simultaneous approximation term,SAT)的SBP-SAT方法具有较高的稳定性,这使得该方法具备了较高的应用前景和价值。此外,完全匹配层(perfect matching layer,PML)是一种应用广泛用于模拟截断边界的技术,但引入匹配层可能会破坏原始方程的稳定性,特别是在各向异性介质或曲线域模型中。首先基于数理推导,给出弹性波动方程系数矩阵的对称形式。在此基础上,引入多轴完全匹配层(multi-axis perfect matching layer,MPML),并建立相应的匹配层方程。通过本征值分析,我们可以判断阻尼函数对原方程特征根实部的走向和取值范围的影响。然后,我们采用SBP-SAT方法对矩阵对称形式匹配层方程进行离散,并在频域中采用能量法进行稳定性评估。通过对不同模型的数值仿真,表明所提出的离散框架具有整合度高、稳定性好和拓展性强等特点。此外,多轴匹配层可以与SBP-SAT方法结合,可以稳定地模拟曲线域中的波传播。

基于P-犹豫模糊集与VIKOR的绿色产品设计多属性决策方法

针对绿色产品设计属性不确定及其关联关系的复杂性问题,提出一种基于P-犹豫模糊集与多准则妥协解排序(VIKOR)法的绿色产品设计多属性决策方法。利用Pythagorean犹豫模糊数度量产品属性及其特征值得到专家初始权重;考虑绿色设计决策者及属性关联,运用λ-模糊测度、Shapley值和交叉熵得到决策者及属性关联权重;以综合最大化整体效用和最小化个体遗憾为目标,基于VIKOR法对绿色产品设计方案进行排序选择;最后通过实例分析验证方法的合理性和有效性。研究结果显示,该方法既可以综合绿色设计决策者心理,有效区分不同绿色设计方案之间的差别,又可以描述绿色设计决策者和属性间的关联关系,为绿色产品设计多属性决策提供了一种可行的方法。

TI介质中P-SV波传播的SBP-SAT模拟

基于速度-应力形式的弹性波动方程,采用分部求和和同时逼近项技术建立的SBP-SAT方法,推导了横向各向同性(transversely isotropy,TI)介质的矩阵对称型(symmetric matrix form,SMF)弹性波动方程离散形式,并通过能量法进行了稳定性分析。将该方法应用于倾斜横向各向同性(tilted transverse isotropic,TTI)介质模型、垂直横向各向同性(transverse isotropy with a vertical axis of symmetry,VTI)介质和含裂缝及曲线域的复杂介质模型,对所得的速度幅值和单炮记录分析并总结规律;对不同时间步长、单元网格数的结果进行对比,得出计算效率并验证该方法在求解P-SV波传播问题上的正确性。数值模拟结果表明,该方法模拟精度高,适用性好,在地震数值模拟领域有很好的应用价值和前景。

血清HMGA2、P-gp与老年进展性脑梗死患者预后相关研究

目的探讨血清高迁移率族蛋白A2(HMGA2)、P-糖蛋白(P-gp)在老年进展性脑梗死患者中的表达水平及其与预后的关系。方法收集2020年2月—2023年2月大连市中心医院神经内科收治老年进展性脑梗死患者67例为进展组,老年非进展性脑梗死患者79例为非进展组;进展组根据治疗后3个月神经功能恢复情况分为预后良好亚组(n=39,mRS评分0~2分)和预后不良亚组(n=28,mRS评分3~6分)。采用酶联免疫吸附法检测血清HMGA2、P-gp水平,Pearson积矩相关分析血清HMGA2、P-gp与NIHSS评分的关系,Logistic回归分析进展性脑梗死患者预后不良的影响因素,受试者工作特征曲线(ROC)评估血清HMGA2、P-gp对预后不良的预测价值。结果进展组血清HMGA2、P-gp水平及NIHSS评分高于非进展组(t/P=13.672/<0.001,8.095/<0.001,8.226/<0.001)。进展性脑梗死患者血清HMGA2、P-gp与NIHSS评分均呈正相关(r/P=0.732/<0.001、0.708/<0.001);预后不良亚组患者年龄大于预后良好亚组,血清HMGA2、P-gp水平及NIHSS评分高于预后良好亚组(t/P=5.092/<0.001、5.103/<0.001、4.449/<0.001、2.357/0.021)。多因素Logistic回归结果显示,高龄和血清HMGA2、P-gp水平及NIHSS评分升高是进展性脑梗死患者预后不良独立危险因素[OR(95%CI)=1.429(1.093~1.869),1.288(1.082~1.533),1.586(1.161~2.165),1.483(1.120~1.963)];血清HMGA2、P-gp及二者联合预测进展性脑梗死患者预后不良的AUC分别为0.738、0.740、0.895,二者联合优于各自单独预测效能(Z/P=2.031/0.002、2.006/0.003)。结论血清HMGA2、P-gp在老年进展性脑梗死患者中异常升高,并与病情严重程度以及预后不良有关,早期联合检测两项指标可预测患者预后不良风险发生。

基于改进p-有效点法的多风电场共享储能联合参与一次调频的容量优化

以大规模多风电场接入电力系统的一次调频备用容量为研究对象,首先通过引入风电出力预测误差的概率分布描述系统的不确定性因素,考虑风储一次调频备用总成本最小为目标;然后建立基于机会约束规划的多风电场联合共享储能参与一次调频的容量优化模型;最后提出基于快速傅里叶变换快速求解联合变量概率分布的改进p-有效点法通过数学解析将机会约束规划从形式上转化为确定性规划,再通过Yalmip调用Cplex实现模型的快速求解。算例结果表明,所提模型和方法可有效提高风储调频效果和收益,且具有更高的求解效率。

健脾化瘀解毒法对结肠癌裸鼠模型癌及癌旁组织中AKT、mTOR、p-4EBP1表达的影响研究

目的研究健脾化瘀解毒法对结肠癌原位种植瘤癌及癌旁组织中蛋白激酶B(AKT)、哺乳动物雷帕霉素靶蛋白(mTOR)、磷酸化真核细胞起始因子4E结合蛋白1(p-4EBP1)表达的影响。方法建立裸鼠结肠癌模型,随机分为空白组、模型组、健脾益气组、化瘀解毒组、健脾化瘀解毒组、雷帕霉素组及5-氟尿嘧啶组,每组5只。干预各组4周后,检测各组癌组织与癌旁组织中AKT、mTOR、p-4EBP1的表达水平。结果与空白组比较,模型组癌组织与癌旁组织中AKT1、mTOR、p-4EBP1的表达均上调,差异有显著性(P<0.05),且AKT、mTOR、p-4EBP1的表达水平均为癌组织>癌旁组织>正常肠黏膜组织。与模型组比较,健脾化瘀解毒法能在一定程度上抑制结肠癌癌组织及癌旁组织中AKT、mTOR、p-4EBP1的表达水平,差异有统计学意义(P<0.05);健脾益气法、化瘀解毒法均能下调癌组织与癌旁组织中AKT、mTOR、p-4EBP1蛋白,但其降低水平不如健脾化瘀解毒法。结论健脾化瘀解毒法能够降低AKT、mTOR、p-4EBP1蛋白的表达,健脾益气法与化瘀解毒法协同增效,以获得最佳疗效。

具p-双调和算子的非局部椭圆方程Navier边值问题的广义解

利用变分方法和相应的临界点定理研究一类具有p-双调和算子的非局部椭圆方程Navier边值问题,在非线性项满足超线性条件时,得到了两个非平凡广义解的存在性定理.

多场景下基于AHP-EWM的人体健康状态评估模型研究

为解决人体健康评估方法个性化监测不足的问题以及在满足不同场景下健康状态精细化评估的需求,需要一种基于多场景的人体健康状态评估方法来实现长期自动化监测。提出一种基于层次分析法(AHP)和熵权法(EWM)组合的多场景人体健康状态评估模型。首先采集人体在运动、休息、工作/学习和娱乐等4种不同场景下的健康监测指标数据,构建相应的评估指标体系。然后分别根据评估指标计算出AHP和EWM权重,再采用量子粒子群优化(QPSO)算法对AHP和EWM中的主客观权重进行分配,以确保评价指标占比的客观性。最后通过模糊综合评价法对人体健康状态进行评估和量化,并利用实际监测数据对方法的可靠性和稳定性进行验证。实验结果表明,在4种场景下所提方法的综合得分分别为63.78、59.83、58.71和59.21,表明在不同场景下该模型都具有较好的准确性和稳定性。根据评估结果,对测试者的身体状态评价结果进行分析,并给出一些健康建议。所提模型可全面了解人体在不同场景下的健康状况,并为人们提供科学的健康指导,从而为健康管理和疾病预防提供科学依据。

A Review on Sources,Extractions and Analysis Methods of a Sustainable Biomaterial:Tannins

Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses.

An extended multiple-support response spectrum method incorporating fluid-structure interaction for seismic analysis of deep-water bridges

The effects of ground motion spatial variability(GMSV)or fluid-structure interaction(FSI)on the seismic responses of deep-water bridges have been extensively examined.However,there are few studies on the seismic performance of bridges considering GMSV and FSI effects simultaneously.In this study,the original multiple-support response spectrum(MSRS)method is extended to consider FSI effect for seismic analysis of deep-water bridges.The solution of hydrodynamic pressure on a pier is obtained using the radiation wave theory,and the FSI-MSRS formulation is derived according to the random vibration theory.The influence of FSI effect on the related coefficients is analyzed.A five-span steel-concrete continuous beam bridge is adopted to conduct the numerical simulations.Different load conditions are designed to investigate the variation of the bridge responses when considering the GMSV and FSI effects.The results indicate that the incoherence effect and wave passage effect decrease the bridge responses with a maximum percentage of 86%,while the FSI effect increases the responses with a maximum percentage of 26%.The GMSV and FSI effects should be included in the seismic design of deep-water bridges.

新型GFRP-钢屈曲约束支撑设计与受力性能分析

为发展轻质、耐腐蚀的屈曲约束支撑,以玻璃纤维(GFRP)拉挤型材和缠绕工艺构造支撑约束构件,H型钢为内芯,提出一种新型GFRP-钢屈曲约束支撑.通过理论分析与数值模拟,探究了支撑内芯的屈曲模态发展规律;结合GFRP的各向异性和层合板结构特性,建立了GFRP约束构件的设计参数计算公式;分析了支撑间厚比、翼缘和腹板宽厚比及纤维角度对GFRP约束构件与内芯相互作用特征的影响规律,并给出了合理取值;通过算例分析,验证了该设计方法的可靠性.结果表明:H型钢内芯依次发生翼缘局部屈曲、绕弱轴整体屈曲、腹板局部屈曲和绕强轴整体屈曲,且整体屈曲模态较低,而局部屈曲模态较高;间厚比和宽厚比均会影响内芯的屈曲模态发展,进而改变约束构件的受力状态,间厚比宜为0.125 0~0.50,宽厚比宜小于6.29;GFRP约束构件主应力方向接近45°,为充分发挥纤维纵向承载能力,纤维宜按45°相互垂直交叉布置.

地铁齿轮的C-P-S-N曲线研究及其可靠性分析

在对齿轮进行寿命设计与可靠性分析时,了解齿轮的强度和寿命分布极为重要。为此,以弯曲疲劳、接触疲劳实验数据为基础,对某地铁齿轮的C-P-S-N曲线进行了研究,对其可靠性进行了分析。首先,针对P-S-N曲线的失真,提出了一种利用拟合材料参数的修正方法,分别计算了齿轮不同置信度下的接触和弯曲C-P-S-N曲线;然后,以置信度为95%的C-P-S-N曲线为基准,得出了郑州某地铁齿轮箱在不同工况下的疲劳寿命分布参数,并分析了其寿命离散度规律;最后,运用顺序可靠度理论,对齿轮多工况下的综合可靠度进行了评判。研究结果表明:与其他方法相比,采用拟合材料参数的方法得到的疲劳强度差异最大为0.48%,与采用其他方法所得结果具有相同的参考性;随着置信度的增加,齿轮疲劳强度的离散度也随之增加;弯曲疲劳强度的变异系数约为0.096,接触疲劳强度的变异系数约为0.062,且接触疲劳寿命的可靠度小于弯曲疲劳寿命,即小齿轮更容易发生接触疲劳破坏;当地铁运行里程达到1.36×10^(7)km时,不发生接触疲劳破坏的概率约为0.989。

亚油酸诱导植物乳杆菌p-8产生共轭亚油酸的蛋白组和类组蛋白乙酰化分析

研究亚油酸(linoleic acid,LA)诱导下植物乳杆菌(Lactobacillus plantarum)p-8的蛋白组和类组蛋白乙酰化水平差异,探究共轭亚油酸(conjugated linoleic acid,CLA)产生的机制。结果表明,LA的最佳诱导质量浓度为1 mg/mL,在此质量浓度条件下,蛋白质组学分析发现,烯酰-酰基载体蛋白还原酶、酰基载体蛋白等脂肪酸合成的关键蛋白因子下调,脂肪酸合成下调,乙酰基转移酶水平上调。Western blot结合体外添加NaAc实验表明,乙酰辅酶A含量增加导致类组蛋白乙酰化水平提升。实时聚合酶链式反应检测显示,添加LA和NaAc使CLA相关酶、转录调控因子和Sigma因子的mRNA表达升高,CLA含量也提高。相关性分析得出,乙酰辅酶A与LA水合酶转录水平和CLA含量之间呈显著正相关,揭示乙酰辅酶A和乙酰基转移酶含量上调导致类组蛋白乙酰化加强而上调CLA合成。结果为分子改良或科学调控乳酸菌以提高CLA转化率奠定了基础。