Physical modeling of long-term dynamic characteristics of the subgrade for medium-low-speed maglevs

To investigate the dynamic characteristics and long-term dynamic stability of the new subgrade structure of medium-low-speed(MLS)maglevs,cyclic vibration tests were performed under natural and rainfall conditions,and the dynamic response of the subgrade structure was monitored.The dynamic response attenuation characteristics along the depth direction of the subgrade were compared,and the distribution characteristics of the dynamic stress on the surface of the subgrade along the longitudinal direction of the line were analyzed.The critical dynamic stress and cumulative deformation were used as indicators to evaluate the long-term dynamic stability of the subgrade.Results show that water has a certain effect on the dynamic characteristics of the subgrade,and the dynamic stress and acceleration increase with the water content.With the dowel steel structure set between the rail-bearing beams,stress concentration at the end of the loaded beam can be prevented,and the diffusion distance of the dynamic stress along the longitudinal direction increases.The dynamic stress measured in the subgrade bed range is less than 1/5 of the critical dynamic stress.The postconstruction settlement of the subgrade after similarity ratio conversion is 3.94 mm and 7.72 mm under natural and rainfall conditions,respectively,and both values are less than the 30 mm limit,indicating that the MLS maglev subgrade structure has good long-term dynamic stability.

Dynamics of Bottom Boundary Layers in the Yellow River Subaqueous Delta Based on Long-Term In-Situ Observations

Objective In geo-marine science,the generalized bottom boundary layer（BBL）represents a layer between sediments and seawater.The BBL plays an important role in geological,geobiochemical,geophysical and geotechnical research because it is the connection region of hydrosphere,

Characteristics of dynamic strain and strength of frozen silt under long-term dynamic loading

The dynamic swain and strength of frozen silt under long-term dynamic loading are studied based on creep tests. Three groups of tests are performed (Groups I, II, and III). The initial deviator stresses of Groups I and II are same and the dynamic stress ampli- tude of Group II is twice as that of Group I. The minimum value of dynamic stress in Group IlI is near zero and its dynamic stress amplitude is larger than those of Groups I and II. In tests of all three groups there are similar change trends of accttmulative sWain, but with different values. The accumulative swain curves consist of three stages, namely, the initial stage, the steady stage, and the gradual flow stage. In the tests of Groups I and II, during the initial stage with vibration times less than 50 loops the strain ampli- tude decreased with the increase of vibration times and then basically remained constant, fluctuating in a very small range. For the tests of Group III, during the initial and steady stages the sWain amplitude decreased with the increase of vibration times, and then increased rapidly in the gradual flow stage. The dynamic strength of frozen silt decreases and trends to terminal dynamic strength as the vibration times of loading increase.

Long-term dynamic behavior of monopile supported offshore wind turbines in sand

The complexity of the loads acting on the offshore wind turbines （OWl＇s） structures and the significance of investigation on structure dynamics are explained. Test results obtained from a scaled wind turbine model are also summarized. The model is supported on monopile, subjected to different types of dynamic loading using an innovative out of balance mass system to apply cyclic/dynamic loads. The test results show the natural frequency of the wind turbine structure increases with the number of cycles, but with a reduced rate of increase with the accumulation of soil strain level. The change is found to be dependent on the shear strain level in the soil next to the pile which matches with the expectations from the element tests of the soil. The test results were plotted in a non-dimensional manner in order to be scaled to predict the orototvoe conseouences usin~ element tests of a soil usin~ resonant column aoDararus.

ERROR ESTIMATE FOR INFLUENCE OF MODEL REDUCTION OF NONLINEAR DISSIPATIVE AUTONOMOUS DYNAMICAL SYSTEM ON LONG-TERM BEHAVIOURS

From viewpoint of nonlinear dynamics, the model reduction and its influence on the long-term behaviours of a class of nonlinear dissipative autonomous dynamical system with higher dimension are investigated theoretically under some assumptions. The system is analyzed in the state space with an introduction of a distance definition which can be used to describe the distance between the full system and the reduced system, and the solution of the full system is then projected onto the complete space spanned by the eigenvectors of the linear operator of the governing equations. As a result, the influence of mode series truncation on the long-term behaviours and the error estimate are derived, showing that the error is dependent on the first products of frequencies and damping ratios in the subspace spanned by the eigenvectors with higher modal damping. Furthermore, the fundamental understanding for the topological change of the solution due to the application of different model reduction is interpreted in a mathematically precise way, using the qualitative theory of nonlinear dynamics.

Nonlinear Differential Equation of Macroeconomic Dynamics for Long-Term Forecasting of Economic Development

In this article we derive a general differential equation that describes long-term economic growth in terms of cyclical and trend components. Equation is based on the model of non-linear accelerator of induced investment. A scheme is proposed for obtaining approximate solutions of nonlinear differential equation by splitting solution into the rapidly oscillating business cycles and slowly varying trend using Krylov-Bogoliubov-Mitropolsky averaging. Simplest modes of the economic system are described. Characteristics of the bifurcation point are found and bifurcation phenomenon is interpreted as loss of stability making the economic system available to structural change and accepting innovations. System being in a nonequilibrium state has a dynamics with self-sustained undamped oscillations. The model is verified with economic development of the US during the fifth Kondratieff cycle (1982-2010). Model adequately describes real process of economic growth in both quantitative and qualitative aspects. It is one of major results that the model gives a rough estimation of critical points of system stability loss and falling into a crisis recession. The model is used to forecast the macroeconomic dynamics of the US during the sixth Kondratieff cycle (2018-2050). For this forecast we use fixed production capital functional dependence on a long-term Kondratieff cycle and medium-term Juglar and Kuznets cycles. More accurate estimations of the time of crisis and recession are based on the model of accelerating log-periodic oscillations. The explosive growth of the prices of highly liquid commodities such as gold and oil is taken as real predictors of the global financial crisis. The second wave of crisis is expected to come in June 2011.

Model test and numerical simulation on the dynamic stability of the bedding rock slope under frequent microseisms

Shake table testing was performed to investigate the dynamic stability of a mid-dip bedding rock slope under frequent earthquakes. Then, numerical modelling was established to further study the slope dynamic stability under purely microseisms and the influence of five factors, including seismic amplitude, slope height, slope angle, strata inclination and strata thickness, were considered. The experimental results show that the natural frequency of the slope decreases and damping ratio increases as the earthquake loading times increase. The dynamic strength reduction method is adopted for the stability evaluation of the bedding rock slope in numerical simulation, and the slope stability decreases with the increase of seismic amplitude, increase of slope height, reduction of strata thickness and increase of slope angle. The failure mode of a mid-dip bedding rock slope in the shaking table test is integral slipping along the bedding surface with dipping tensile cracks at the slope rear edge going through the bedding surfaces. In the numerical simulation, the long-term stability of a mid-dip bedding slope is worst under frequent microseisms and the slope is at risk of integral sliding instability, whereas the slope rock mass is more broken than shown in the shaking table test. The research results are of practical significance to better understand the formation mechanism of reservoir landslides and prevent future landslide disasters.

Soil phosphorus dynamic, balance and critical P values in longterm fertilization experiment in Taihu Lake region, China

Phosphorus（P） is an important macronutrient for plant but can also cause potential environmental risk. In this paper, we studied the long-term fertilizer experiment（started 1980） to assess the soil P dynamic, balance, critical P value and the crop yield response in Taihu Lake region, China. To avoid the effect of nitrogen（N） and potassium（K）, only the following treatments were chosen for subsequent discussion, including： C0（control treatment without any fertilizer or organic manure）, CNK treatment（mineral N and K only）, CNPK（balanced fertilization with mineral N, P and K）, MNK（integrated organic manure and mineral N and K）, and MNPK（organic manure plus balanced fertilization）. The results revealed that the response of wheat yield was more sensitive than rice, and no significant differences of crop yield had been detected among MNK, CNPK and MNPK until 2013. Dynamic and balance of soil total P（TP） and Olsen-P showed soil TP pool was enlarged significantly over consistent fertilization. However, the diminishing marginal utility of soil Olsen-P was also found, indicating that high-level P application in the present condition could not increase soil Olsen-P contents anymore. Linear-linear and Mitscherlich models were used to estimate the critical value of Olsen-P for crops. The average critical P value for rice and wheat was 3.40 and 4.08 mg kg^（–1）, respectively. The smaller critical P value than in uplands indicated a stronger ability of P supply for crops in this paddy soil. We concluded that no more mineral P should be applied in rice-wheat system in Taihu Lake region if soil Olsen-P is higher than the critical P value. The agricultural technique and management referring to activate the plant-available P pool are also considerable, such as integrated use of low-P organic manure with mineral N and K.

A preliminary study of 3D difference scheme with energy dynamic equilibrium

In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equations for atmosphere and sea motion, a three dimensional compact upwind scheme (CUWS) is constructed, as the basis of the DS-EDE. The DS-EDE satisfies the following condition of energy dynamic equilibrium (EDE): the total work of external forces on the region boundary is equal to the sum of the total effective variation of the kinetic energy and the energy dissipation in the average flow motion and the effective variation of the potential energy per unit time within the region of interest. It really reflects the basic mechanism of the action of external forces and dissipation in atmosphere and sea movement. Therefore, the DS-EDE developed in this paper is a suitable model for simulating long-term atmosphere and sea movement with forcing and dissipation.

Dynamic Characteristics of a Damaged Nine-story Building during the 2011 off the Pacific Coast Tohoku Earthquake

This paper describes the dynamic characteristics of a damaged nine story building in Sendal during the 2011 Tohoku Earthquake. Dynamic hysteresis characteristic is investigated. The system identification using the extended Kalman filter determined the amplitude dependency of natural frequency and damping factor, which are consistent with damage feature. Occurrence of partial uplifting in the transverse direction is suggested by the induced higher harmonics based on the wavelet analysis. Historical change of the amplitude dependent dynamic characteristics is also discussed based on the long-term monitoring data from microtremor level to strong motion level.

On Simplified Models for Dynamics of Pointlike Objects

Motivation: We study the asymptotic-type dynamics of various real pointlike objects that one models by a variety of differential equations. Their response to an external force one defines solely by the trajectory of a single point. Its velocity eventually stops changing after cessation of the external force. The response of their acceleration to the long-term external force is slow and possibly nonlinear. Objective: Our objective is to present technique for making simplified models for the long-term dynamics of pointlike objects whose motion interacts with the surroundings. In the asymptotic-type long-term dynamics, the time variable t ∈ (tm, +∞) and tm > 0 is large, say ! Method: We apply Taylor series expansion to differential equations to model the acceleration of pointlike object whose response to the long-term external force is not instantaneous and possibly nonlinear. Results: We make simplified models for the long-term dynamics of pointlike objects by Taylor polynomials in time derivatives of the external force. Application: We interpret the relativistic Lorentz-Abraham-Dirac equation as an equation for modeling the long-term dynamics, where t ≥ tm ≫ 0. This interpretation resolves the conceptual and usage controversy surrounding its troublesome application to determine the trajectory of a radiating charged particle, thus contributing to the development of more adequate modeling of physical phenomena.

肺源性心脏病患者24h动态心电图参数与肺功能的相关性及对不良事件的预测价值

目的探究肺源性心脏病(PHD)患者动态心电图参数与肺功能的相关性及对不良事件的预测价值。方法选取PHD患者73例为观察组,并纳入同期健康志愿者42例为对照组,两组均接受24 h动态心电图和肺功能检测;比较入组时两组被检者及观察组患者治疗前、治疗后第7天时24 h动态心电图参数[24 h RR间期标准差(SDNN)、每5 min时段正常RR间期标准差(SDANN)]和肺功能指标[1秒用力呼气容积(FEV1)/用力肺活量(FVC)、FEV1预计百分比(FEVl%)];随访6个月,根据不良事件发生情况将观察组分为预后良好组和预后不良组,比较两组患者临床特征,分析24 h动态心电图参数与肺功能的相关性及其对PHD不良事件的预测价值。结果观察组入院后SDNN、SDANN、FEV1/FVC、FEVl%低于对照组(P<0.05),73例PHD患者在治疗后第7天时的SDNN、SDANN、FEV1/FVC、FEVl%较治疗前升高(P<0.05);随访6个月,73例PHD患者中有32例出现不良事件,预后不良组急性加重期占比、平均病程均高于预后良好组(P<0.05),预后不良组治疗前、治疗后第7天时SDNN、SDANN、FEV1/FVC、FEVl%均低于预后良好组(P<0.05);Pearson相关分析结果显示,治疗前及治疗后第7天时SDNN、SDANN均与治疗前及治疗后第7天时FEV1/FVC、FEVl%呈正相关(P<0.05);ROC分析结果显示,PHD患者发生不良事件的治疗前、治疗后第7天时SDNN、SDANN的cut-off值分别为72 ms、55 ms、92 ms、91ms,AUC范围在0.702~0.813(P<0.05)。结论PHD患者治疗前及治疗后7 d的SDNN、SDANN与肺功能呈正相关,24 h动态心电图参数对PHD不良事件的具有一定的预测价值。

动态心电图及sST2、PAI-1在川崎病伴发冠脉损伤诊断中的研究

目的探讨动态心电图及可溶性人基质裂解素-2(sST2)、纤溶酶原激活物抑制物-1(PAI-1)在川崎病伴发冠脉损伤诊断中的意义。方法研究对象选取2018年1月至2024年1月郑州大学第一附属医院收治的102例川崎病患儿,根据患儿是否伴发冠脉损伤分为两组,其中损伤组40例,未损伤组62例。比较两组患儿的临床病例资料[性别、年龄、身体质量指数(BMI)、发热持续时间、白细胞计数、25-羟维生素D3(25-(OH)D_(3))、血红蛋白、血小板计数、肌酸激酶同工酶(CK-MB)、氨基末端脑利钠肽前体(NT-proBNP)、C反应蛋白(CRP)、sST2、PAI-1]及动态心电图异常率,通过多因素分析川崎病伴发冠脉损伤的影响因素,绘制ROC曲线评价不同指标对川崎病患儿伴发冠脉损伤的诊断价值。结果损伤组患儿的发热持续时间、血小板计数、CRP、CK-MB、NT-proBNP、sST2、PAI-1水平高于未损伤组,25-(OH)D_(3)水平低于未损伤组,差异具有统计学意义(P<0.05)。损伤组患儿的动态心电图异常率为60.00%,未损伤组患儿的动态心电图异常率为16.13%,损伤组高于未损伤组,差异具有统计学意义(P<0.05)。二元Logistic分析结果显示,发热持续时间、25-(OH)D_(3)、血小板计数、CRP、CK-MB、NT-proBNP、sST2、PAI-1、动态心电图异常是川崎病患儿伴发冠脉损伤的影响因素(P<0.05)。以sST2、PAI-1、动态心电图异常及3项指标联合应用作为变量绘制诊断川崎病伴发冠脉损伤的ROC曲线,sST2的AUC为0.789,PAI-1的AUC为0.729,动态心电图异常的AUC为0.719,联合检测的AUC为0.978。结论动态心电图及sST2、PAI-1水平诊断川崎病是否伴发CAL具有较高的诊断价值。

黄芪桂枝五物汤联合沙丁胺醇治疗缓慢性心律失常64例临床疗效及对动态心电图和心脏功能的影响

目的 探讨黄芪桂枝五物汤联合西药治疗缓慢性心律失常疗效及对病人动态心电图和心脏功能的影响。方法 选取2019年6月至2022年6月河北省沧州中西医结合医院收治的128例缓慢性心律失常病人,按随机数字表法分为对照组(64例)和观察组(64例),对照组给予口服沙丁胺醇片治疗,观察组在对照组的基础上给予黄芪桂枝五物汤治疗。比较两组病人治疗前后中医证候积分、动态心电图(最快心率、最慢心率、平均心率、QT间期、QRS间期、心率变异性相关指标)、心功能指标[心排血量(cardiac output,CO)、心脏指数(cardiac index,CI)、左室射血分数(left ventricular ejection fraction,LVEF)],比较两组病人治疗前、治疗1个月、治疗3个月的血压变化情况以及治疗后的临床疗效。结果 与治疗前比较,对照组和观察组治疗后的中医证候积分[(13.52±2.51)分比(19.54±3.47)分,(10.85±2.04)分比(19.23±3.26)分]、QT间期[(0.412±0.003)s比(0.445±0.003)s,(0.408±0.004)s比(0.446±0.004)s]、QRS间期[(0.09±0.05)s比(0.11±0.02)s,(0.07±0.03)s比(0.10±0.04)s]、正常窦性心律R-R间期标准差(SDNN)、全程相邻正常窦性心律R-R间期之差的均方根值(RMSSD)、正常窦性心律R-R间期平均值的标准差(SDANN)、在一定时间内相邻两正常心动周期差值>50 ms的个数所占的百分比(PNN50)均降低(P<0.05),且观察组更低(P<0.05);治疗后对照组和观察组最快心率[(74.56±3.98)次/分比(66.47±2.87)次/分,(83.23±4.68)次/分比(66.23±2.65)次/分]、最慢心率[(45.32±2.68)次/分比(40.23±1.74)次/分,(47.89±3.54)次/分比(40.46±1.89)次/分]、平均心率、CO、CI、LVEF均升高(P<0.05),且观察组更高(P<0.05);经重复测量方差分析,收缩压(SBP)、舒张压(DBP)在组间、时间及交互方面差异无统计学意义(P>0.05);观察组临床疗效(90.63%)高于对照组(76.56%)(P<0.05)。结论 采用黄芪桂枝五物汤联合西药应用于缓慢性心律失常病人,有利于其临床症状和心功能的改善,还可有效提高心率,具有较好的临床疗效。

常规心电图与动态心电图对心肌缺血的诊断价值

目的探究常规心电图与动态心电图检查对心肌缺血的诊断价值。方法选取2020年7月至2022年7月滕州市中心人民医院接诊的90例心肌缺血患者作为研究对象,均进行常规心电图检查、动态心电图检查。比较两种检查方法的24 h心率变异性频率[低频功率(LF)、超低频功率(ULF)、低级频功率(VLF)、高频功率(HF)],以冠状动脉造影检查为金标准,比较两种检查方法的诊断效能(准确度、特异度、灵敏度)。结果动态心电图检查LF、ULF、VLF、HF均高于常规心电图检查,差异有统计学意义(P<0.05)。动态心电图检查的准确度、灵敏度、特异度分别为95.56%、98.11%、91.89%,均高于常规心电图检查的77.78%、84.91%、67.57%,差异有统计学意义(P<0.05)。动态心电图检查的约登指数为0.9,高于常规心电图检查的0.524。结论心肌缺血患者行心电图检查、动态心电图检查均可取得一定的诊断效果,但动态心电图检查的诊断价值更高。

腺苷负荷CT心肌灌注扫描、24h动态心电图联合检查在冠心病心肌缺血诊断中的效能

目的:观察腺苷负荷CT心肌灌注扫描、24h动态心电图联合检查在冠心病心肌缺血诊断中的效能。方法:选取2020年12月至2022年12月该院收治的80例疑似冠心病心肌缺血患者进行前瞻性研究,所有患者均接受24h动态心电图和腺苷负荷CT心肌灌注扫描检查,以核素心肌灌注显像检查诊断结果为金标准,比较腺苷负荷CT心肌灌注扫描、24h动态心电图单项及联合检查诊断冠心病心肌缺血的效能。结果:核素心肌灌注显像检查结果显示,阳性52例,阴性28例。24h动态心电图检查结果显示,阳性46例,阴性34例;腺苷负荷CT心肌灌注扫描检查结果显示,阳性46例,阴性34例;联合检查结果显示,阳性51例,阴性29例。腺苷负荷CT心肌灌注扫描、24h动态心电图联合检查诊断冠心病心肌缺血的灵敏度、特异度、准确度、阳性预测值、阴性预测值均高于二者单项检查,差异有统计学意义(P<0.05)。结论:腺苷负荷CT心肌灌注扫描、24h动态心电图联合检查诊断冠心病心肌缺血的效能高于二者单项检查。

不同年龄患者早期复极综合征的动态心电图特征比较

目的探究不同年龄患者早期复极综合征的动态心电图特征。方法选取2020年1月至2022年1月萍乡市人民医院收治的100例早期复极综合征(ERS)患者为研究对象,根据不同年龄分为A组(<18岁,n=30)、B组(18~45岁,n=38)和C组(>45岁,n=32)。三组患者均行动态心电图检查,并行心率变异性(HRV)分析。比较三组各项参数包括HRV指标、J波出现的导联情况、ST改变程度及参数之间的差异。结果B组和C组的标准差(SDNN)、均值标准差(SDANN)、差值的均方根(rMSSD)和差值>50 ms的百分比(PNN50)、极低频(VLF)、低频(LF)、高频(HF)、LF/HF均低于A组,差异有统计学意义(P<0.05);B组和C组V2~V3高于A组,V4~V5低于A组,B组的Ⅱ、Ⅲ、aVF低于A组,C组的Ⅱ、Ⅲ、aVF高于A组,差异有统计学意义(P<0.05);B组和C组ST段抬高距离高于A组,且Q-T离散度高于A组,差异有统计学意义(P<0.05)。结论不同年龄段ERS患者的动态心电图特征存在一定差异,且监测动态心电图对判断ERS患者的预后及评估病情严重程度有重要意义,从不同角度为ERS的临床监测提供新的理论依据,正确评估疾病的进展及预后,对指导临床治疗具有重要意义。

动态心电图与常规心电图对无症状性冠心病的诊断效果比较

目的比较动态心电图与常规心电图诊断无症状性冠心病的效能。方法选取2020年1月至2023年1月我院收治的疑似冠心病患者100例,均给予常规心电图检查及动态心电图检查。以冠状动脉造影检查结果为依据,比较动态心电图、常规心电图的诊断效能。结果常规心电图与冠状动脉造影检查结果的一致性一般(Kappa值=0.741,P<0.001),动态心电图与冠状动脉造影检查结果的一致性较好(Kappa值=0.923,P<0.001)。动态心电图诊断无症状性冠心病的灵敏度、特异度、准确率均显著高于常规心电图(P<0.05)。结论动态心电图较常规心电图诊断无症状性冠心病具有更高的效能,可降低误诊、漏诊风险。

24小时动态心电图对预激综合征伴心房颤动患者射频消融术后心房颤动复发的预测价值

目的探讨24 h动态心电图对预激综合征(WPW)伴心房颤动患者射频消融术后心房颤动复发的预测价值。方法选取2021年8月至2023年9月在新疆维吾尔自治区喀什地区第一人民医院心电功能科就诊的WPW伴心房颤动射频消融术后6个月心房颤动复发的患者51例(复发组)及51例术后未复发心房颤动患者(未复发组)。比较2组患者术前24 h动态心电图[P波振幅、最大P波时限(P_(max))、P波离散度(Pd)和P波终末电势(Ptf)、PR间期、心率校正后QT间期(QTc)和Tp-Te间期]。采用多因素Logistic回归模型分析WPW伴心房颤动患者射频消融术后心房颤动复发的影响因素,并用受试者工作特征(ROC)曲线分析24 h动态心电图对术后心房颤动复发的预测价值。结果复发组QTc、P波振幅、P_(max)、Pd值高于未复发组,而Ptf则低于未复发组(均P<0.05)。复发组年龄、病程、左心房直径、消融前心房颤动发作频率高于未复发组,左心室射血分数(LVEF)低于未复发组(均P<0.05)。Logistic回归分析结果显示,年龄大、高P_(max)和Pd值及低LVEF均是WPW伴心房颤动患者射频消融术后心房颤动复发的独立危险因素(均P<0.05)。ROC曲线显示,P_(max)、Pd单独预测WPW伴心房颤动患者射频消融术后心房颤动复发的曲线下面积(AUC)为0.809(95%置信区间:0.769~0.838)、0.811(95%置信区间:0.770~0.875),二者联合预测AUC为0.918(95%置信区间:0.878~0.949),联合预测效能较单独预测效能更好(均P<0.05)。结论24 h动态心电图参数与WPW伴心房颤动患者射频消融术后心房颤动复发有关,其中P波电位的P_(max)和Pd值是WPW伴心房颤动患者射频消融术后心房颤动复发的危险因素,且二者联合预测术后心房颤动复发的效能较高。

心肌损伤标志物联合AECC对HHD患者MACE的预测价值研究

目的探讨心肌损伤标志物联合动态心电图(ambulatory electrocardiography,AECC)对高血压性心脏病(hypertensive heart disease,HHD)患者主要不良心脏事件(major adverse cardiac events,MACE)的预测价值。方法回顾性分析2020年1月—2023年12月湖北省天门市第一人民医院收治的88例HHD患者为研究对象。按照患者1年内是否发生MACE分为研究组(发生MACE,n=18)与对照组(未发生MACE,n=70)。比较2组AECC结果、心肌损伤标志物水平。绘制受试者工作特征(receiver operating characteristic,ROC)曲线。结果研究组碎裂型波(fragmented QRS complexes,fQRS)发生率为66.67%,高于对照组的24.29%,差异有统计学意义(P<0.05)。研究组微伏级T波电交替(microvolt T-wave alternans,MTWA)、肌酸激酶同工酶(creatine kinase-MB,CK-MB)、心肌肌钙蛋白I(cardiac troponin I,cTnI)和N端脑钠肽前体(N-terminal pro-B-type natriuretic peptide,NT-proBNP)分别为(62.35±6.25)μV、(14.26±1.07)U/L、(101.25±5.36)ng/mL和(4022.35±151.36)pg/mL,均高于对照组的(47.98±4.06)μV、(10.89±0.79)U/L、(75.36±2.16)ng/mL和(3625.35±121.35)pg/mL,差异有统计学意义(P<0.05)。ROC曲线显示,联合预测的ROC曲线下面积最大,AUC=0.933(95%CI 0.879~0.986)。总体模型质量结果分析显示,联合指标的模型值最大为0.88。结论使用AECC对MTWA波和fQRS波的实时监测分析同时联合对NT-proBNP、CK-MB、cTnI 3种标志物的检测在预测HHD患者MACE方面有较高敏感度和实用效能,能够在临床实践中更真实地评测MACE风险程度,能够为临床实践提供重要的参考指导依据。