Dynamically triggered seismicity on a tectonic scale:A review

Earthquakes triggered by dynamic disturbances have been confirmed by numerous observations and experiments.In the past several decades,earthquake triggering has attracted increasing attention of scholars in relation to exploring the mechanism of earthquake triggering,earthquake prediction,and the desire to use the mechanism of earthquake triggering to reduce,prevent,or trigger earthquakes.Natural earthquakes and large‐scale explosions are the most common sources of dynamic disturbances that trigger earthquakes.In the past several decades,some models have been developed,including static,dynamic,quasi‐static,and other models.Some reviews have been published,but explosiontriggered seismicity was not included.In recent years,some new results on earthquake triggering have emerged.Therefore,this paper presents a new review to reflect the new results and include the content of explosion‐triggered earthquakes for the reference of scholars in this area.Instead of a complete review of the relevant literature,this paper primarily focuses on the main aspects of dynamic earthquake triggering on a tectonic scale and makes some suggestions on issues that need to be resolved in this area in the future.

Trigger转座子衍生蛋白1对肝癌细胞生长的影响

细胞周期失调是肿瘤重要的标志之一,生物信息学分析结果表明,Trigger转座子衍生蛋白1(TIGD1)在临床肝癌组织中高表达且与细胞周期相关,但相关机制未知。为了探究TIGD1调控肝癌细胞生长的具体机制,首先,利用shRNA质粒构建靶向敲低TIGD1的肝癌细胞系Hep3B,并分析TIGD1敲低对肝癌细胞生长的影响,结果表明细胞生长受阻;接着,通过细胞流式技术分析TIGD1敲低对肝癌细胞周期进程的影响,结果显示,TIGD1敲低的Hep3B细胞系的细胞周期进程主要阻滞于G2/M期;然后,通过免疫沉淀(IP)实验验证TIGD1可能发生相互结合的蛋白分子,结果表明,TIGD1可能与Aurora激酶相互作用蛋白1(AURKAIP1)存在相互结合,进一步的Co-IP实验证实了TIGD1和AURKAIP1之间的相互作用。已知AURKAIP1可调控Aurora激酶A(AURKA)的蛋白酶体降解途径,AURKA是一种有丝分裂调控蛋白,与细胞周期进程密切相关。文中进一步探究TIGD1对AURKA蛋白水平的影响,实验结果表明,在TIGD1敲低的情况下,AURKA在Hep3B细胞系中的蛋白水平明显下调,mRNA水平没有明显变化。综上所述,TIGD1可能通过调控AURKA在肝癌细胞中的转录后水平来影响细胞周期进程,从而影响肝癌的发生发展。

Byzantine Robust Federated Learning Scheme Based on Backdoor Triggers

Federated learning is widely used to solve the problem of data decentralization and can provide privacy protectionfor data owners. However, since multiple participants are required in federated learning, this allows attackers tocompromise. Byzantine attacks pose great threats to federated learning. Byzantine attackers upload maliciouslycreated local models to the server to affect the prediction performance and training speed of the global model. Todefend against Byzantine attacks, we propose a Byzantine robust federated learning scheme based on backdoortriggers. In our scheme, backdoor triggers are embedded into benign data samples, and then malicious localmodels can be identified by the server according to its validation dataset. Furthermore, we calculate the adjustmentfactors of local models according to the parameters of their final layers, which are used to defend against datapoisoning-based Byzantine attacks. To further enhance the robustness of our scheme, each localmodel is weightedand aggregated according to the number of times it is identified as malicious. Relevant experimental data showthat our scheme is effective against Byzantine attacks in both independent identically distributed (IID) and nonindependentidentically distributed (non-IID) scenarios.

Stress triggering effect on the 2022 Honghe M_(S)5.0 earthquake with historical strong earthquakes

The 2022 Honghe M_(S)5.0 seismic event is intriguing due to its occurrence in the south of the Red River Fault,an area historically lacking seismic activities greater than M_(S)5.0.To elucidate the seismogenic mechanism and scrutinize stress-triggered interactions,we calculated co-seismic and post-seismic Coulomb stress alterations induced by nine historical seismic events(M≥6.0).The analysis reveals that these substantial seismic events provoked co-seismic stress augmentations of 1.409 bar and postseismic stress increments of 0.159 bar.Noteworthy seismic events,such as the 1833 Songming,1877Shiping,1913 Eshan,and 1970 Tonghai earthquakes,catalyzed the occurrence of the Honghe earthquake.Areas of heightened future seismic risk include the southern region of the Red River Fault and the eastern segments of the Shiping-Jianshui and Qujiang faults.Additionally,we assessed the correlation between the spatial distribution of aftershocks and the Coulomb stress shift triggered by the mainshock,taking into account the influence of calculation parameter settings.

Characteristics and triggering mechanisms of early negative Indian Ocean Dipole

Negative Indian Ocean Dipole(nIOD)can exert great impacts on global climate and can also strongly influence the climate in China.Early nIOD is a major type of nIOD,which can induce more pronounced climate anomalies in summer than La Niña-related nIOD.However,the characteristics and triggering mechanisms of early nIOD are unclear.Our results based on reanalysis datasets indicate that the early nIOD and La Niña-related nIOD are the two major types of nIOD,and the former accounts for over one third of all the nIOD events in the past six decades.These two types of nIODs are similar in their intensities,but are different in their spatial patterns and seasonal cycles.The early nIOD,which develops in spring and peaks in summer,is one season earlier than the La Niña-related nIOD.The spatial pattern of the wind anomaly associated with early nIOD exhibits a winter monsoon-like pattern,with strong westerly anomalies in the equatorial Indian Ocean and eastly anomalies in the northern Indian Ocean.Opposite to the triggering mechanism of early positve IOD,the early nIOD is induced by delayed Indian summer monsoon onset.The results of this study are helpful for improving the prediction skill of IOD and its climate impacts.

A study of pulsed high voltage driven hollow-cathode electron beam sources through synchronous optical trigger

In this study,a pulsed,high voltage driven hollow-cathode electron beam sources through an optical trigger is designed with characteristics of simple structure,low cost,and easy triggering.To validate the new design,the characteristics of hollow-cathode discharge and electron beam characterization under pulsed high voltage drive are studied experimentally and discussed by discharge characteristics and analyses of waveform details,respectively.The validation experiments indicate that the pulsed high voltage supply significantly improves the frequency and stability of the discharge,which provides a new solution for the realization of a high-frequency,high-energy electron beam source.The peak current amplitude in the high-energy electron beam increases from 6.2 A to 79.6 A,which indicates the pulsed power mode significantly improves the electron beam performance.Besides,increasing the capacitance significantly affects the highcurrent,lower-energy electron beam more than the high-energy electron beam.

Mechanisms to explain soil liquefaction triggering,development,and persistence during an earthquake

Mechanisms have been proposed to explain the triggering,development,and persistence of soil liquefaction.The mechanism explaining the horizontal failure plane(triggering)and its depth below the phreatic surface is governed by the flux properties and effective stress at that plane.At the failure plane,the pore water pressure was higher than the effective stress,and the volume change was the highest.The pore water pressure is a function of the soil profile features(particularly the phreatic zone width)and bedrock motion(horizontal acceleration).The volume change at the failure plane is a function of the intrinsic permeability of the soil and bedrock displacement.The failure plane was predicted to occur during the oscillation with the highest amplitude,disregarding further bedrock motion,which was consistent with low seismic energy densities.Two mechanisms were proposed to explain the persistence of soil liquefaction.The first is the existence of low-permeability layers in the depth range in which the failure planes are predicted to occur.The other allows for the persistence and development of soil liquefaction;it is consistent with homogeneous soils and requires water inflow from bedrock water springs.The latter explains many of the features of soil liquefaction observed during earthquakes,namely,surficial effects,“instant”liquefaction,and the occurrence of short-and long-term changes in the level of the phreatic surfaces.This model(hypothesis),the relationship between the flux characteristics and loss of soil shear strength,provides self-consistent constraints on the depth below the phreatic surfaces where the failure planes are observed(expected to occur).It requires further experimental and observational evidence.Similar reasoning can be used to explain other saturated soil phenomena.

Resilient Event-Triggered Model Predictive Control for Adaptive Cruise Control Under Sensor Attacks

Dear Editor,This letter addresses the resilient model predictive control(MPC)problems for adaptive cruise control(ACC)systems under sensor attacks.In the light of vulnerabilities of ACC systems to sensor attacks,an intrusion detection mechanism is proposed at the controller side to distinguish abnormal data.Then,the robust control gains are derived to design the terminal region constraint for MPC.

A review of tidal triggering of global earthquakes

Earthquake prediction remains a challenging and difficult task for scientists all over the world.The tidal triggering of earthquakes is being proven by an increasing number of investigations,most of which have shown that earthquakes are positively correlated with tides,and thus,tides provide a potential tool for earthquake prediction,especially for imminent earthquakes.In this study,publications concerning the tidal triggering of earthquakes were compiled and analyzed with regard to global earthquakes,which were classified into three main types:tectonic,volcanic,and slow earthquakes.The results reveal a high correlation between tectonic earthquakes and tides(mainly for semidiurnal and diurnal tides;14-day tides) before and after the occurrence of significant earthquakes.For volcanic earthquakes,observations of volcanoes on the seafloor and land indicate that volcanic earthquakes in near-shore volcanic areas and mid-ocean ridges have a strong correlation with tidal forces,mostly those with semidiurnal and diurnal periods.For slow earthquakes,the periodicity of the tremor duration is highly correlated with semidiurnal and diurnal tides.In conclusion,the tidal triggering of these three types of earthquakes makes a positive contribution to earthquake preparation and understanding the triggering mechanism,and thus,the prediction of these types of earthquakes should be investigated.However,there are still several inadequacies on this topic that need to be resolved to gain a definitiveanswer regarding the tidal triggering of all earthquakes.The main inadequacies are discussed in this paper from our point of view.

Description of the Factors Associated with Trigger Finger in Patients Treated at Petroleos Mexicanos “Pemex”

Background: The trigger finger, also known as stenosing tenosynovitis of the flexor tendon, is a common cause of hand disability;This can result in significant limitations in certain daily living activities. It is possible to treat this condition with conservative or surgical methods. Methods: This is a retrospective, observational, cross-sectional and descriptive study. The source population consisted of all patients with a diagnosis of trigger finger who had been treated in the department of plastic and reconstructive surgery of our institution between 2020 and 2023. The primary objective of this study is to determine the prevalence and characterize the clinical and surgical characteristics of the population affected by trigger finger in our hospital. Results: The total population was 237 patients, of which 165 were women (70%) and 72 men (30%). The most affected hand was the right hand, with a total of 158 patients (67%). In the right hand, the middle finger was the most affected (45%). Of the 237 patients, 80 of them had obesity (34%), 86 had type 2 diabetes mellitus (36%), 95 had systemic arterial hypertension (40%). Open technique was performed in 190 (80%) patients, while percutaneous technique was performed in 47 (20%) of them. Conclusion: The female sex was twice as frequent, and the middle finger and thumb were the most affected. Most of the patients received surgical treatment with open approach and percutaneous approach in 20% of them.

Tidal triggering of seismicity in the region of Palu, Central Sulawesi, Indonesia

This paper investigates the correlation between tidal stress and earthquakes for periods ranging from hours to months in the limited zone of the Palu region(Central Sulawesi,Indonesia).Through Schuster and binomial tests,we examined the relation between the seismicity(time density of seismic events)and tidal potential arising from the Moon and Sun,using all tidal components simultaneously and focusing on the estimation of specific terms.The results show significant correlations between the seismicity and tidal potential for S2(0.5 d)and O1(1.075 d)tidal components in the case of solely isolated earthquake events,particularly for shallow earthquakes.Meanwhile,there is a strong relationship between aftershocks and tidal components larger than the Mf period(13.661 d).Finally,the analysis of the temporal variation of the earthquake-tide relation reveals an optimal correlation for about six years before the 2018 great Palu earthquake.The correlation becomes insignificant afterwards.

News event prediction by trigger evolution graph and event segment

Event prediction aims to predict the most possible following event given a chain of closely related context events.Previous methods based on event pairs or the entire event chain may ignore much structural and semantic information.Current datasets for event prediction,naturally,can be used for supervised learning.Event chains are either from document-level procedural action flow,or from news sequences under the same column.This paper leverages graph structure knowledge of event triggers and event segment information for event prediction with general news corpus,and adopts the standard multiple choice narrative cloze task evaluation.The topic model is utilized to extract event chains from the news corpus to deal with training data bottleneck.Based on trigger-guided structural relations in the event chains,we construct trigger evolution graph,and trigger representations are learned through graph convolutional neural network and the novel neighbor selection strategy.Then there are features of two levels for each event,namely,text level semantic feature and trigger level structural feature.We design the attention mechanism to learn the features of event segments derived in term of event major subjects,and integrate relevance between event segments and the candidate event.The most possible next event is picked by the relevance.Experimental results on the real-world news corpus verify the effectiveness of the proposed model.

Enhancement of holding voltage by a modified low-voltage trigger silicon-controlled rectifier structure for electrostatic discharge protection

A novel structure of low-voltage trigger silicon-controlled rectifiers(LVTSCRs) with low trigger voltage and high holding voltage is proposed for electrostatic discharge(ESD) protection. The proposed ESD protection device possesses an ESD implant and a floating structure. This improvement enhances the current discharge capability of the gate-grounded NMOS and weakens the current gain of the silicon-controlled rectifier current path. According to the simulation results, the proposed device retains a low trigger voltage characteristic of LVTSCRs and simultaneously increases the holding voltage to 5.53 V, providing an effective way to meet the ESD protection requirement of the 5 V CMOS process.

Triggering,clicking,locking and crepitus of the finger:A comprehensive overview

Triggering,locking,clicking,and crepitus of the fingers are common symptoms patients present with.Even though crepitus and triggering can occur as part of the same underlying diagnosis,it is important to differentiate between them,as they usually indicate different possible diagnoses.The differential diagnoses that should be considered include trigger finger,metacarpophalangeal joint(MCPJ)arthritis,fractures or dislocations,extensor digitorum communis subluxation or dislocation,locked MCPJ,avascular necrosis of the metacarpal head,and Dupuytren’s disease.A thorough clinical examination with appropriate special investigations can permit the clinician to make the correct diagnosis.Appropriate management of a confirmed diagnosis is successful in providing symptomatic improvement.

特高压混合直流工程快速旁路保护用兆伏级SF_6间隙等离子体喷射触发特性及工程设计

在江苏白鹤滩±800 kV特高压混合直流工程中,受端交流侧三相接地故障穿越失败时,会在±400 kV柔直母线上产生高幅值过电压,严重威胁柔直阀组安全,而基于等离子体喷射的超快速旁路开关1 ms内将柔直母线快速接地保护柔直阀组是一种全新的解决方案。DC 400 kV触发间隙需满足高耐压(>1.2 MV)、低工作系数(<5%)、短延时(<1 ms)、大通流等严苛要求,而如何实现高气压、长间隙的可靠触发导通,并提出工程化设计方案是关键难题。为此搭建了增强型等离子体喷射触发间隙导通研究平台,重点研究触发电压、气压、间隙长度以及工作系数等关键影响因素对SF_(6)触发间隙导通特性的影响规律。结果表明,提升触发电压可显著提升触发导通概率、降低触发延时,但存在一定的饱和现象;在固定的工作电压下,随气压或间隙长度的增加,工作系数显著减小,导致触发延时骤增且导通概率急剧减小;在相同工作系数下,高气压短间隙的触发导通性能更强。据此提出满足特高压混合直流工程400 kV柔直母线快速接地用DC 400 kV间隙开关,间隙采用复合外套单间隙结构,轮转型触发腔设计实现多次触发。研制了触发间隙试验样机(间隙距离为10 cm、压强为0.5 MPa的SF_(6)),其雷电耐压>1250kV,临界可触发电压<50 kV,导通时延<0.5 ms。该研究结果为特高压混合直流输电系统中柔直阀组快速保护用兆伏级SF_6触发间隙工程应用提供了理论支持和工程初步设计方案。

基于网侧资源协调的自储能柔性互联配电系统日前-日内优化

为优化储能型智能软开关(E-SOP)、传统网侧调控设备的运行策略,提升高渗透率光伏配电网运行水平,提出了基于网侧资源协调的自储能柔性互联配电系统日前-日内优化模型。首先,提出了“源网荷储”下多种网侧资源协调利用的多时间尺度优化控制架构;其次,在日前阶段构建计及有载调压变压器、无功补偿装置、联络开关、E-SOP和柔性负荷的长时间有功-无功联合优化模型,在日内阶段建立多目标滚动优化模型,并采用线性化方法将模型转换为混合整数线性规划模型;然后,基于KL散度构建源荷不确定性模糊集,给出日前两阶段分布鲁棒优化模型转化过程和基于列与约束生成算法的求解方法;最后,算例仿真验证所提方法的有效性。

2023年甘肃积石山6.2级地震中川乡液化流滑灾害调查及诱因初析

2023年12月18日甘肃省临夏州积石山县发生了6.2级地震,地震导致青海省民和县中川乡金田村和草滩村发生特殊的流滑灾害,其规模之大、灾害之重在国内外实不多见。通过实地考察,得出了地震土壤液化是此次流滑灾害诱因的结论,且此次灾害是近70 a以来首次具有现场实证性质的液化流滑型地震灾害。调查分析结果表明:流滑区上游滑源区地下土壤液化触发了流滑,中游流通区特殊的水文地质条件加剧了流滑的发展;土壤液化潜在多区、多源特性,即中游流通区存在疑似液化区;流滑区地震动强度较大,初步估计地震动峰值加速度值为0.4(±0.1)g。调查分析结果可为认识此次液化流滑灾害提供科学依据。

基于Scott Triggers评分的分级干预在神经外科患者术中压力性损伤预防中的应用研究

目的:探讨基于Scott Triggers评分的分级干预在神经外科患者术中压力性损伤预防中的应用效果。方法:选取2021年3月—2023年2月我院神经外科收治的102例患者为研究对象,随机分为对照组和观察组,对照组采取手术室常规护理,观察组在常规护理基础上采取基于Scott Triggers评分的分级干预。比较两组患者术中压力性损伤发生率。结果:两组患者年龄、体质指数(Body Mass Index,BMI)、手术时间、麻醉分级比较差异无统计学意义(P>0.05),观察组术中压力性损伤发生率(3.9%)明显低于对照组术中压力性损伤发生率(19.6%),差异有统计学意义(P=0.028)。结论:基于Scott Triggers评分的分级干预可有效预防神经外科患者术中压力性损伤的发生。

锦屏一级水电站库区中小地震震源机制解与局部应力场特征

利用四川及邻区数字地震台网2013—2018年的波形资料,基于CAP和HASH方法反演得到锦屏一级水电站(以下简称锦屏水库)库区及周边M_(L)≥2.5地震的震源机制解,根据DRSSI方法计算得到库区局部应力场信息,结合该区域的地质资料,从震源机制参数和局部应力场变化等方面讨论了水库加卸载对该区域地震活动的影响.取得的主要认识如下:(1)库区地震活动类型以走滑型为主,不同加卸载阶段震源机制类型存在一定差异,库区蓄水前期震源机制类型呈现多样性,蓄水后期与区域背景场趋于一致;(2)库区应力场最大主应力方向以NNW-SSE向为主,分时段结果显示,蓄水后期局部应力场最大主应力方向由NNW向逐渐发生偏转至NW向;(3)库区周边的地质构造和岩性条件有利于库水的渗透,蓄水后重力载荷和流体渗透的共同作用导致岩体断层面库仑应力的变化,从而呈现出库区蓄水前后中小地震活跃程度的显著差异特征.

针灸肌筋膜触发点作用机制研究进展

肌筋膜触发点(myofascial trigger points,MTrPs)为骨骼肌绷紧带中的过敏结节,可引发压痛、特征性转移痛、运动功能障碍和自主神经现象。近年来,基于MTrPs特殊的病理生理机制,采用针灸治疗非器质性神经肌纤维的疼痛综合征取得了满意的效果。针刺干预MTrPs对于组织修复、恢复功能活动具有重要的指导价值,为临床治疗肌筋膜疼痛综合征(myofascial pain syndrome,MPS)提供了有效手段。但针刺MTrPs作用机制尚未完全阐明,今后还需从多层次、多角度、多领域深入探究,以期为临床针灸施治提供有力的理论依据。