Kinematic deformation and intensity assessment of the 2021 Maduo M_(S)7.4 earthquake in Qinghai revealed by high-frequency GNSS

Rapid acquisition of the kinematic deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue,disaster assessment,and future seismic risk research.The advancement of GNSS observation and data processing makes it play an important role in this field,especially the high-frequency GNSS.We used the differential positioning method to calculate the 1 HZ GNSS data from 98 sites within 1000 km of the M_(S)7.4 Maduo earthquake epicenter.The kinematic deformation field and the distribution of the seismic intensity by using the peak ground velocity derived from displacement waveforms were obtained.The results show that:1)Horizontal coseismic response deformation levels ranging from 25 mm to 301 mm can be observed within a 1000 km radius from the epicenter.Coseismic response deformation on the east and west sides shows bilateral asymmetry,which markedly differs from the symmetry presented by surface rupture.2)The seismic intensity obtained through high-frequency GNSS and field investigations exhibits good consistency of the scope and orientation in the high seismic intensity area,although the former is generally slightly smaller than the latter.3)There may exist obstacles on the eastern side of the seismogenic fault.The Maduo earthquake induced a certain tectonic stress loading effect on the western Kunlun Pass-Jiangcuo fault(KPJF)and Maqin-Maqu segment,resulting in higher seismic risk in the future.

Dynamic Response of Foundations during Startup of High-Frequency Tunnel Equipment

The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale,multifunctional,and complex orientations.The vibration caused by the high-frequency units during regular operation is supported by the foundation of the units,and the magnitude of vibration and the operating frequency fluctuate in different engineering contexts,leading to variations in the dynamic response of the foundation.The high-frequency units yield significantly diverse outcomes under different startup conditions and times,resulting in failure to meet operational requirements,influencing the normal function of the tunnel,and causing harm to the foundation structure,personnel,and property in severe cases.This article formulates a finite element numerical computation model for solid elements using three-dimensional elastic body theory and integrates field measurements to substantiate and ascertain the crucial parameter configurations of the finite element model.By proposing a comprehensive startup timing function for high-frequency dynamic machines under different startup conditions,simulating the frequency andmagnitude variations during the startup process,and suggesting functions for changes in frequency and magnitude,a simulated startup schedule function for high-frequency machines is created through coupling.Taking into account the selection of the transient dynamic analysis step length,the dynamic response results for the lower dynamic foundation during its fundamental frequency crossing process are obtained.The validation checks if the structural magnitude surpasses the safety threshold during the critical phase of unit startup traversing the structural resonance region.The design recommendations for high-frequency units’dynamic foundations are provided,taking into account the startup process of the machine and ensuring the safe operation of the tunnel.

Review of the Analysis and Suppression for High-frequency Oscillations of the Grid-connected Wind Power Generation System

High-frequency oscillation(HFO)of gridconnected wind power generation systems(WPGS)is one of the most critical issues in recent years that threaten the safe access of WPGS to the grid.Ensuring the WPGS can damp HFO is becoming more and more vital for the development of wind power.The HFO phenomenon of wind turbines under different scenarios usually has different mechanisms.Hence,engineers need to acquire the working mechanisms of the different HFO damping technologies and select the appropriate one to ensure the effective implementation of oscillation damping in practical engineering.This paper introduces the general assumptions of WPGS when analyzing HFO,systematically summarizes the reasons for the occurrence of HFO in different scenarios,deeply analyses the key points and difficulties of HFO damping under different scenarios,and then compares the technical performances of various types of HFO suppression methods to provide adequate references for engineers in the application of technology.Finally,this paper discusses possible future research difficulties in the problem of HFO,as well as the possible future trends in the demand for HFO damping.

Efficient activation of the Co/SBA-15catalyst by high-frequency AC-DBD plasma thermal effects for toluene removal

Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated during the discharge process leads to energy waste and low energy utilization efficiency.In this work,an innovative DBD thermally-conducted catalysis(DBD-TCC)system,integrating high-frequency AC-DBD plasma and its generated thermal effects to activate the Co/SBA-15 catalyst,was employed for toluene removal.Specifically,Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 k V.At12.4 k V,the temperature in the catalyst zone reached 261℃ in the DBD-TCC system,resulting in an increase in toluene degradation efficiency of 17%,CO_(2)selectivity of 21.2%,and energy efficiency of 27%,respectively,compared to the DBD system alone.In contrast,the DBD thermally-unconducted catalysis(DBD-TUC)system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation,highlighting the crucial role of AC-DBD generated heat in the activation of the catalyst.Furthermore,the degradation pathway and mechanism of toluene in the DBD-TCC system were hypothesized.This work is expected to provide an energy-efficient approach for high-frequency AC-DBD plasma removal of VOCs.

Effects of unilateral superimposed high-frequency jet ventilation on porcine hemodynamics and gas exchange during one-lung flooding

BACKGROUND Superimposed high-frequency jet ventilation(SHFJV)is suitable for respiratory motion reduction and essential for effective lung tumor ablation.Fluid filling of the target lung wing one-lung flooding(OLF)is necessary for therapeutic ultrasound applications.However,whether unilateral SHFJV allows adequate hemodynamics and gas exchange is unclear.AIM To compared SHFJV with pressure-controlled ventilation(PCV)during OLF by assessing hemodynamics and gas exchange in different animal positions.METHODS SHFJV or PCV was used alternatingly to ventilate the non-flooded lungs of the 12 anesthetized pigs during OLF.The animal positions were changed from left lateral position to supine position(SP)to right lateral position(RLP)every 30 min.In each position,ventilation was maintained for 15 min in both modalities.Hemodynamic variables and arterial blood gas levels were repeatedly measured.RESULTS Unilateral SHFJV led to lower carbon dioxide removal than PCV without abnormally elevated carbon dioxide levels.SHFJV slightly decreased oxygenation in SP and RLP compared with PCV;the lowest values of PaO_(2) and PaO_(2)/FiO_(2) ratio were found in SP[13.0;interquartile range(IQR):12.6-5.6 and 32.5(IQR:31.5-38.9)kPa].Conversely,during SHFJV,the shunt fraction was higher in all animal positions(highest in the RLP:0.30).CONCLUSION In porcine model,unilateral SHFJV may provide adequate ventilation in different animal positions during OLF.Lower oxygenation and CO_(2) removal rates compared to PCV did not lead to hypoxia or hypercapnia.SHFJV can be safely used for lung tumor ablation to minimize ventilation-induced lung motion.

Therapeutic efficacy of methylprednisolone sodium succinate via diverse administration routes for mid-to high-frequency sudden sensorineural hearing loss

BACKGROUND Sudden sensorineural hearing loss(SSNHL),characterized by a rapid and unexplained loss of hearing,particularly at moderate to high frequencies,presents a significant clinical challenge.The therapeutic use of methylprednisolone sodium succinate(MPSS)via different administration routes,in combination with conventional medications,remains a topic of interest.AIM To compare the therapeutic efficacy of MPSS administered via different routes in combination with conventional drugs for the treatment of mid-to high-frequency SSNHL.METHODS The medical records of 109 patients with mid-to high-frequency SSNHL were analyzed.The patients were divided into three groups based on the route of administration:Group A[intratympanic(IT)injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection],Group B(intravenous injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection),and Group C(single IT injection of MPSS).The intervention effects were compared and analyzed.RESULTS The posttreatment auditory thresholds in Group A(21.23±3.34)were significantly lower than those in Groups B(28.52±3.36)and C(30.23±4.21;P<0.05).Group A also exhibited a significantly greater speech recognition rate(92.23±5.34)than Groups B and C.The disappearance time of tinnitus,time to hearing recovery,and disappearance time of vertigo in Group A were significantly shorter than those in Groups B and C(P<0.05).The total effective rate in Group A(97.56%)was significantly greater than that in Groups B and C(77.14%and 78.79%,χ^(2)=7.898,P=0.019).Moreover,the incidence of adverse reactions in Groups A and C was significantly lower than that in Group B(4.88%,3.03%vs 2.57%,χ^(2)=11.443,P=0.003),and the recurrence rate in Group A was significantly lower than that in Groups B and C(2.44%vs 20.00%vs 21.21%,χ^(2)=7.120,P=0.028).CONCLUSION IT injection of MPSS combined with conventional treatment demonstrates superior efficacy and safety compared to systemic administration via intravenous infusion and a single IT injection of MPSS.This approach effectively improves patients'hearing and reduces the risk of disease recurrence.

GPR图像的数据集构建及其DRDU-Net去噪算法

为了解决生成对抗网络(Generative Adversarial Network,GAN)在生成探地雷达(Ground Penetrating Radar,GPR)图像时存在训练不稳定的问题,提出利用带有梯度惩罚的Wasserstein距离生成对抗网络(WGAN-GP)生成GPR图像,并结合时域有限差分法和实地采集图像提出了一种构建GPR图像数据集的方法.相较于原始GAN与Wasserstein GAN等方法,WGAN-GP具有更好的稳定性,而且生成的GPR图像更接近真实图像.在此基础之上,将密集残差块和U-Net相结合提出了一种适合于GPR图像的密集残差去噪U-Net方法.该方法利用U-Net中编码-解码结构提高了GPR图像的去噪性能;同时,密集残差块的引入加强了GPR图像的特征复用,且使U-Net训练更加稳定.最后,利用仿真实验验证了所提去噪方法的性能,并与三维块匹配(BM3D)和U-Net方法进行了对比.结果表明:所提方法与BM3D以及U-Net去噪方法相比,具有更好的去噪效果.当σ等于20时,在模拟和实测数据上取平均值,其峰值信噪比分别提升了约6.5 dB和2.4 dB;结构相似性分别提升了约0.09和0.04.

基于GPR-LSTM的地震热红外背景场的构建方法

地震监测是一项非常重要且具有挑战性的任务,遥感技术的不断发展加强了在宏观尺度上对地球表面的监测能力。研究表明,地震前通常都会出现地表温度异常升高的现象,因此各种异常提取算法被应用于地震热异常研究中。其中,基于背景场的提取方法由于具有较强的机理解释性而受到广泛应用。然而,以往基于背景场的异常提取方法更多将背景场限定于某一固定阈值,忽略了受外界因素(非震)影响导致的地表温度的小范围正常波动。据此,文中提出了一种基于GPR-LSTM的地震热红外背景场的构建方法。该方法包括两大部分:震期年变基准场的建立、实际LST的残差波动范围计算及背景场的构建。基于MODIS地表温度产品,以2008年四川汶川和新疆于田地震为研究对象,使用所述方法对地震前兆热异常信息进行提取与分析,经过实验得出以下结论:1)地震热异常通常沿青藏高原的断层分布,这不仅证明了文中方法能够减弱地表温度数据中噪声的干扰,同时也证明该方法在热异常信息提取方面的有效性;2)地震年份的构造活动比非地震年份更加活跃,导致地表温度的异常增温更加明显;3)不同地震案例震前的热异常时空特征各不相同。

模袋护坡工程GPR检测机理和应用研究

GPR技术近年来在许多领域得到了广泛应用,但公路工程在道路脱空探测时对于充水型脱空无法检测,且从未在模袋护坡工程检测中应用。鉴于此,通过室内模型试验,研究了模袋含水率对波速和相对介电常数的影响,并分析了电磁波波长在模袋中的变化情况;通过水池模型试验,在不同电导率的水中对电磁波波速、波长、衰减常数和趋肤深度进行了研究分析。结果表明:模袋护坡工程探测时,应尽量选择高频天线,以提高钢筋分辨率,且重点考虑模袋含水率的影响,选取准确的相对介电常数,准确计算钢筋位置。充水型脱空探测时,应重点考虑水中电磁波的衰减,高频段衰减程度取决于水的电导率。当水的电导率不大于0.1 s/m时,高频段天线均可探测到脱空层底部;当水的电导率大于0.1 s/m和小于1 s/m时,高频段天线均识别困难;当电导率达到1 s/m时,高频段的所有频率均无法识别。

基于GPR探测的长江源地区冰川与冻土厚度研究

长江源地区的冰川变化揭示了青藏高原气候变化趋势。冰下地形探测作为冰川发育和运动过程研究的基础,对长江地区水土保持和淡水资源储量研究具有指导意义。长江科学院在长达10 a的江源科考基础上,分别于2022年、2023年采用探地雷达(GPR)技术对长江正源沱沱河发源地格拉丹东主峰的冰川厚度进行精准探测,并对查旦湿地冻土厚度上限进行了探测研究。结合多种冰川和冻土地质模型的GPR波场模拟结果,提高了GPR技术在长江源地区冰川和冻土探测的有效性和精准度。探测结果表明,格拉丹东主峰冰川厚度和查旦湿地冻土厚度上限均有不同程度降低,冰川厚度和冻土厚度上限观测是一个常年积累的结果,后续仍需持续进行观测,积累更多数据,分析变化趋势,以估算探测区域内冰储量,研究气候变化对冰川的影响效果。

脂肪酸受体GPR119在动物脂代谢调控中的作用研究进展

中国是水产养殖大国,而高脂饲料的广泛使用导致了鱼类脂肪代谢异常,这严重制约了水产养殖业的发展,亟待对此问题寻求解决方案。近年来在哺乳动物中的研究表明,脂代谢紊乱诱导的非酒精性脂肪肝病(Non-alcoholic fatty liver disease, NAFLD)是危害动物健康的主要问题之一,而GPR119被认为是治疗NAFLD的新靶点。GPR119在鱼类中的研究相对较少,大部分鱼类GPR119功能相关研究主要聚焦于其在调控鱼类食欲中的作用,而其在调控鱼类脂肪代谢中的作用尚不清楚。本文总结了动物中GPR119基因的结构功能及其对脂肪代谢调控机制的研究现状,旨在为研究GPR119在鱼类脂肪代谢中的作用提供新思路,为探索缓解鱼类脂代谢紊乱的新型策略提供理论参考。

基于GPRS无线通讯技术的自动化灌溉系统设计

针对传统的大水漫灌等灌溉方式灌水不均、容易造成农作物病害或涝死、浪费水资源和人工成本较高的问题,基于GPRS无线通讯技术对自动化灌溉系统进行了设计。为了获取有效的灌溉数据,同时能够对数据进行统计、分析和预测,设计了自动灌溉数据信息的预处理方法,并采用多元线性回归预测模型对灌溉数据进行预测。为了验证该自动化灌溉系统的性能,对其进行了数据采集试验和灌溉预测试验,结果表明:系统对灌溉数据监测和预测的准确率均较高。

GPR信号去噪的变分模态分解

为了进一步提高探地雷达(ground penetrating radar,GPR)数据的信噪比,压制由随机扰动引起的随机绕射能量,将二维变分模态分解(two-dimensional variational mode decomposition,2D-VMD)引入二维GPR数据的噪声压制处理中。首先,对GPR数据进行2D-VMD处理,并分析各阶本征模态函数(intrinsic mode function,IMF)分量及其对应的频率-波数域谱来确定雷达剖面中的各回波类型。然后,计算IMF分量与原始数据的互相关系数来确定信号模态和噪声模态,并对信号模态进行重构得到降噪后的数据。理论数据和实测数据测试表明,相比于传统的1D-VMD法,2D-VMD滤波后的含噪正演记录峰值信噪比由6.44 dB增加到7.72 dB;经2D-VMD降噪处理后的雷达剖面在保留有效信号的基础上,可以有效压制随机扰动带来的噪声,并且得到的雷达剖面同相轴连续性更好。

GPR绕射波与反射波分离的变分模态分解方法研究

针对传统绕射波与反射波分离方法易造成有效信号丢失的问题,本文利用二维变分模态分解(2D-VMD)进行探地雷达(GPR)数据的绕射波与反射波分离。对二维GPR数据进行2D-VMD分解后,可得到包含从低频低波数到高频高波数的各阶模态分量及各阶模态分量的F-K谱。通过分析绕射波与反射波在频率-波数域的差异,分别重构绕射波与反射波对应的模态分量,得到分离后的绕射波与反射波数据。数值模拟与实测数据处理结果表明,相比于传统方法,该方法可以有效分离绕射波与反射波,并且不损失任何有效信号。

Radio-frequency measurements of energetic-electron-driven emissions using high-frequency magnetic probe on XuanLong-50 spherical torus

A high-frequency magnetic probe is designed and developed on the XuanL ong-50(EXL-50)spherical torus to measure high-frequency magnetic field fluctuation.The magnetic loop,radio filters,radio-frequency limiter,and data acquisition system of the probe are comprehensively examined.The fluctuation data from the EXL-50 plasma are analyzed in the time–frequency domain using fast Fourier transforms.Moreover,distinct high-frequency instabilities are detected using this diagnostic system.In particular,significant frequency chirping is observed,which is consistent with the bumpon-tail drive instability predicted using the Berk–Breizman model.

基于数据预处理和计算机VMD-LSTM-GPR的储能系统离子电池剩余寿命预测

离子电池剩余寿命影响储能系统运行能力,准确预测电池寿命,有助于判断系统的实时运行状态,为获得较为可靠的预测结果,提出基于数据预处理和计算机VMD-LSTM-GPR的储能系统离子电池剩余寿命预测方法。针对储能系统离子电池剩余寿命预测的相关理论问题进行研究,并联合储能数据预处理标准与计算机VMDLSTM-GPR模型,计算锂离子电池的容量退化能力,从而评估剩余电池寿命,实现基于数据预处理和计算机VMD-LSTM-GPR的储能系统离子电池剩余寿命预测。

基于GPR的巷道围岩空区探测及支护设计

为确保地下矿山掘进巷道围岩稳定性,发现前方不良地质体,采用地质雷达对掘进巷道围岩及底板进行空区探测,并对巷道围岩进行不同地应力作用下的稳定性分析,对不同长度锚杆加固后的锚杆轴力进行对比。结果表明:雷达探测的两个区域均出现不同深度的振幅较强反射区;1.5 m锚杆支护作用下围岩最大位移量分别减少39.3%和10.0%,X-有效应力分别增加42.8%和37.5%;1.5 m和1.8 m锚杆支护时轴力变化基本相同。根据同相轴的连续性对异常区进行判断,异常信号为充填不密实区及空洞,采用锚杆锚网喷浆支护。研究成果可以为类似矿山巷道围岩稳定性及支护提供借鉴意义。

GPR37L1对奶牛乳腺上皮细胞乳成分合成相关基因表达的影响

运用分子生物学技术构建GPR37L1表达和干扰载体,以奶牛乳腺上皮细胞为试验模型,通过瞬时转染技术构建载体转染乳腺上皮细胞,探究GPR37L1对乳成分合成相关基因表达的影响。结果表明,GPR37L1表达和干扰载体构建成功,GPR37L1过表达或干扰可提高或降低乳脂合成相关基因及β-酪蛋白表达,揭示GPR37L1可正向调节乳成分合成。

Tuning magneto-dielectric properties of Co_(2)Z ferrites via Gd doping for high-frequency applications

Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,and 0.20)materials are successfully prepared by using solid-state method at 925℃for 4 h with 2.5-wt%Bi_(2)O_(3)sintering aids.The content of Gd^(3+)ion can affect micromorphology,grain size,bulk density,and magneto-dielectric properties of the ferrite.With Gd^(3+)ion content increasing,saturation magnetization(Ms)first increases and then decreases.The maximum value of Ms is 44.86 emu/g at x=0.15.Additionally,sites occupied by Gd^(3+)ions can change magnetic anisotropy constant of the ferrite.Magnetocrystalline anisotropy constant(K_1)is derived from initial magnetization curve,and found to be related to spin-orbit coupling and intersublattice interactions between metal ions.The real part of magnetic permeability(μ′)and real part of dielectric permittivity(ε′)are measured in a frequency range of 10 MHz-1 GHz.When x=0.15,material has excellent magneto-dielectric properties(μ′≈12.2 andε′≈17.61),low magnetic loss(tanδμ≈0.03 at 500 MHz),and dielectric loss(tanδε≈0.04 at 500 MHz).The results show that Gd-doped Co_(2)Z ferrite has broad application prospects in multilayer filters and high-frequency antennas.

GPR120在慢性气道炎症疾病中作用的研究进展

慢性气道炎症疾病(包括慢性阻塞性肺疾病和哮喘等)的发病率不断增加,但当前对此类疾病的治疗和控制手段有限,需要寻找潜在的治疗靶点。目前研究发现G蛋白偶联受体120(G protein-coupled receptor 120,GPR120),又称游离脂肪酸受体4(free fatty acid receptor,FFA4)或ω-3脂肪酸受体1,具有抑制炎症、降低气道阻力、舒张支气管、调节天然免疫的功能,这与气道炎性疾病的发生发展密切相关。本文重点对GPR120的结构、分布等生物学特性、传导通路等方面进行综述。一些证据表明,它们在炎症调控中具有重要意义,并探讨基于GPR120在慢性气道炎性疾病中发挥作用的进展过程。