Predicting microseismic,acoustic emission and electromagnetic radiation data using neural networks

Microseism,acoustic emission and electromagnetic radiation(M-A-E)data are usually used for predicting rockburst hazards.However,it is a great challenge to realize the prediction of M-A-E data.In this study,with the aid of a deep learning algorithm,a new method for the prediction of M-A-E data is proposed.In this method,an M-A-E data prediction model is built based on a variety of neural networks after analyzing numerous M-A-E data,and then the M-A-E data can be predicted.The predicted results are highly correlated with the real data collected in the field.Through field verification,the deep learning-based prediction method of M-A-E data provides quantitative prediction data for rockburst monitoring.

South China Sea Typhoon Hagibis enhanced Xinfengjiang Reservoir seismicity

There was an evident increase in the number of earthquakes in the Xinfengjiang Reservoir from June to July 2014 after the landing of Typhoon Hagibis.To understand the spatial and temporal evolution of this microseismicity,we built a high-precision earthquake catalog for 2014 and relocated 2275 events using recently developed methods for event picking and catalog construction.Seismicity occurred in the southeastern part of the reservoir,with the preferred fault plane orientation aligned along the Heyuan Fault.The total seismic energy peaked when the typhoon passed through the reservoir,and seismicity correlated with typhoon energy.In contrast,a limited seismic response was observed during the later Typhoon Rammasun.Combining data regarding the water level in the Xinfengjiang Reservoir and seismicity frequency changes in the Taiwan region during these two typhoon events,we suggest that typhoon activity may increase microseism energy by impacting fault stability around the Xinfengjiang Reservoir.Whether a fault can be activated also depends on how close the stress accumulation is to its failure point.

智慧城市多模式数据融合模型

随着云计算和大数据等技术的发展及城市发展的迫切需求,智慧城市已成为近年来国内外研究的热点之一。随着城市中摄像头、监测传感器等采集设备数量的增加,城市数据种类也越来越多。所获取的城市数据具有多源、异构、时变、高维等多模式特性。如何让这些多模式的城市数据关联起来,实现它们的互通互联,挖掘出更丰富多样的信息,从而能更好地指导智慧城市的构建,是本领域的难点。本文提出了一个城市多模式数据融合模型,即多模式互联生长(MICROS)模型,并从3个层面对该模型进行了描述。首先,针对多模式数据的特点,重点描述了多模式数据多源、异构、时变、高维等特点。其次,针对多模式数据的特点,自底向上构建实现针对多模式数据的融合过程的3层基础模型,分别是服务信息描述模型、元数据模型和数据互联模型。最后,在这3层模型的基础上,本文提出了一个适用于智慧城市建设的多模式数据融合模型。

纳米脱钙骨基质的制备及其性能检测

[目的]通过MICROS超细粉碎机制备同种异体纳米脱钙骨基质(DBM),观察纳米DBM结构特征,研究DBM纳米化工艺及其作为骨移植替代物的生物相容性。[方法]采用改良Urist法制备同种异体脱钙骨基质,液氮冷冻球磨机将块状DBM预粉碎,使用MICROS超细粉碎机进一步研磨粉碎制备纳米DBM。电镜扫描观察其结构,按照我国卫生部《生物材料和医疗器材生物学评价的技术要求》中的标准,对纳米DBM进行急性毒性实验、热原实验、溶血实验等检测。[结果]制备颗粒直径在50～200纳米的脱钙骨基质,生物相容性检测无毒性,无热源性,不引起溶血反应,纳米DBM具有良好的生物相容性。[结论]纳米DBM可在低温或控制温度条件下制备,是一种无毒、无刺激,不含热源、不引起免疫排斥反应的生物材料,具有良好生物相容性。

纳米六味地黄液的制备与性能

用MICROS超细粉碎机制备纳米六味地黄液,对其显微结构、稳定性和体外溶出度进行了表征,研究了服用六味地黄液的小鼠血清中的SOD对邻苯三酚自氧化速率的抑制率.结果表明,六味地黄药材纳米粉碎后,细胞壁、细胞膜大部分被破碎,有效成分可直接溶出.纳米化使六味地黄液的稳定性得到改善.六味地黄细粉的指标成分-丹皮酚的溶出与时间呈线性关系,而纳米六味地黄中丹皮酚的溶出与时间之间没有线性关系.服用纳米六味地黄液45min后,六味地黄的累积溶出度比细粉的溶出度高.服用纳米六味地黄组的老龄小鼠血清的SOD活性显著高于细粉组(提高67%),即六味地黄纳米化使抗衰老的药效得到提高.

纳米脱钙骨基质促进骨愈合

背景:纳米脱钙骨基质具有较大的表面积/体积比,纳米颗粒团聚后在表面自然形成不规则的纳米沟槽,可促进成骨细胞在其表面黏附生长及基质分泌。目的:评价纳米脱钙骨基质作为骨移植替代物的植骨融合能力。方法:以改良Urist法制备人同种异体脱钙骨基质,使用液氮冷冻球磨机及MICROS超细粉碎机制备纳米脱钙骨基质。咬除家兔L2-4双侧小关节及双侧椎板和横突表面皮质骨,随机分为3组,分别在腰椎椎板及横突间植入纳米脱钙骨基质、脱钙骨基质及自体骨,术后4,8,12周通过影像学、组织学观察植骨融合效果。结果与结论:①X射线与CT表现:术后12周,纳米脱钙骨基质组椎板、附件形态已接近正常节段,新生骨与椎板间隙完全消失,新生骨与植骨床骨质密度均匀一致;脱钙骨基质组植骨区域椎板表面有少量新生骨块影,在新生骨与椎板表面尚有一定间隙;自体骨组椎板与植骨融合界面愈合良好,植骨区有新生骨块影,融合骨块质地均匀。②组织学表现:术后12周,纳米脱钙骨基质被新生骨替代,与椎板间形成骨性连接,新生骨内可见大量骨细胞,与自体骨组效果相似;脱钙骨基质组植骨区达到骨性愈合,新生骨内可见板层样骨,也有类骨物质。表明纳米脱钙骨基质具有良好的成骨诱导能力,是自体骨移植的良好替代物。

ABX MICROS 60-OT型血细胞分析仪的性能评价

目的 评价ABXMICROS 60 -OT(以下简称ABX -60 )血细胞分析仪的分析性能 ,推广临床应用。 方法 用EDTA -K2静脉抗凝血标本连续测定和每天随机插入常规标本测定及稀释法分别测定ABX -60的精密度 ,携带污染率和线性性能 ,并与COULTERJT -IR结果进行比较。 结果 ABX -60的批内和批间精密度的变异系数均 <5 ,病人标本测定携带污染率均≤ 0 4% ,对白细胞、红细胞、血红蛋白、血小板测定结果与COULTERJT -IR比较有良好的相关性。 结论 ABX -60是一种较为理想的中档血细胞分析仪 ,适合中心型单位使用。

一种简便血球仪比对试验介绍

用临床新鲜抗凝全血标本对几台器进行了比对试验，结果报告如下。 1材料与方法 1．1仪器Sysmex xs-800i五分类血球仪、ABX MICROS 60三分类血球仪、MEK-6318K三分类血球仪各一台。

伤亡事故统计分析信息管理系统的开发

利用Visual Basic语言和Microsoft Access数据库相结合的技术,建立伤亡事故统计分析信息管理系统,对企业历年来发生的伤亡事故进行统计分析从而预防事故的发生。

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.

Preparation of microsized silver crystals with different morphologies by a wet-chemical method

A wet-chemical method was presented for preparation of spherical, flowerlike, hexagonal, and triangular microsized silver crystals. Well-defined particles were prepared by mixing of iron（II） sulfate heptahydrate solution with silver nitrate solution at the presence of different modifiers with high-speed stirring at 8-20℃. It is found that the diameters of resulting products are 0.6-6.0 um and the morphologies of the silver microcrystals are greatly affected by the introduced modifiers. It is concluded that the microsized silver crystals with different morphologies can be synthesized by introducing appropriate modifiers at appropriate experimental parameters. Scanning electron microscopy and X-ray diffraction were used to characterize the resulting products.

Anomalous tremor before 2008 Ms8.0 Wenchuan earthquake: a review

In this paper we give a review of several previously published papers on anomalous tremors observed before the 2008 Ms8.0 Weuchuan earthquake. Based on the observed time and frequency shifts between coastal and inland stations, we discussed some methods to distinguish different kinds of microseisms, and speculated that a pre-earthquake typhoon might have caused a ＂mainland-originated microseism＂ which in turn trig- gered the earthquake.

Cumulative damage effect on debris slopes under frequent microseisms

Debris slopes are widely distributed across the Three Gorges Reservoir area in China,and seasonal fluctuations of the water level in the area tend to cause high-frequency microseisms that subsequently induce landslides on such debris slopes.In this study,a cumulative damage model of debris slope with varying slope characteristics under the effects of frequent microseisms was established,based on the accurate definition of slope damage variables.The cumulative damage behaviour and the mechanisms of slope instability and sliding under frequent microseisms were thus systematically investigated through a series of shaking table tests and discrete element numerical simulations,and the influences of related parameters such as bedrock,dry density and stone content were discussed.The results showed that the instability mode of a debris slope can be divided into a vibration-compaction stage,a crack generation stage,a crack development stage,and an instability stage.Under the action of frequent microseisms,debris slope undergoes the last three stages cyclically,which causes the accumulation to slide out in layers under the synergistic action of tension and shear,causing the slope to become destabilised.There are two sliding surfaces as well as the parallel tensile surfaces in the final instability of the debris slope.In the process of instability,the development trend of the damage accumulation curve remains similar for debris slopes with different parameters.However,the initial vibration compaction effect in the bedrock-free model is stronger than that in the bedrock model,with the overall cumulative damage degree in the former being lower than that of the latter.The damage degree of the debris slope with high dry density also develops more slowly than that of the debris slope with low dry density.The damage development rate of the debris slope does not always decrease with the increase of stone content.The damage degree growth rate of the debris slope with the optimal stone content is the lowest,and the increase or decrease of the stone content makes the debris slope instability happen earlier.The numerical simulation study also further reveals that the damage in the debris slope mainly develops in the form of crack formation and penetration,in which,shear failure occurs more frequently in the debris slope.

Pressure induced by the interaction of water waves with nearly equal frequencies and nearly opposite directions

We present second-order expressions for the free-surface elevation, velocity potential and pressure resulting from the interaction of surface waves in water of arbitrary depth. When the surface waves have nearly equal frequencies and nearly opposite directions, a second-order pressure can be felt all the way to the sea bottom. There are at least two areas of applications： reflective structures and microseisms. Microseisms generated by water waves in the ocean are small vibrations of the ground resulting from pressure oscillations associated with the coupling of ocean surface gravity waves and the sea floor. They are recorded on land-based seismic stations throughout the world and they are divided into primary and secondary types, as a function of spectral content. Secondary microseisms are generated by the interaction of surface waves with nearly equal frequencies and nearly opposite directions. The efficiency of microseism generation thus depends in part on ocean wave frequency and direction. Based on the second-order expressions for the dynamic pressure, a simple theoretical analysis that quantifies the degree of nearness in amplitude, frequency, and incidence angle, which must be reached to observe the phenomenon, is presented.

A Preliminary Study on the Phenomenon of Microseismic Fluctuations before Impending Strong Earthquake

Based on repeated comparison studies of broadband digital seismic records before the Wenchuan MS8. 0,Yushu MS7. 1 and Qingchuan MS5. 4 earthquakes,the possible microseismic fluctuations before impending earthquakes were preliminarily identified. In order to verify and test this phenomenon,a real-time tracking technical system was established by using continuous waveform records of more than 200 wide-band digital seismic stations in regional networks such as Gansu,Qinghai,Sichuan,Yunnan and Tibet.Through real-time tracking and dynamic monitoring of 24 earthquakes with M≥5. 0 occurring in the Qinghai-Tibetan block during the period of 2012-2014 and the observations of stations in some non-seismic areas,the reproducibility and objectivity of the impending earthquake phenomenon were verified. The main characteristics of the microseismic fluctuation phenomena immediately preceding the strong earthquakes are as follows:(1)the spectrum range is wider,the dominant frequency is 11-16 Hz,and the spectrum shape is more regular;(2)it appears 6-24 days before the earthquake,averaging about 15 days;(3)it is possible to be recorded by the stations within the epicenter distance of 50 km,and the stations with the epicenter distance of more than 50 km generally cannot record it;(4)this phenomenon is directional,i. e. the direction in which the activity degree,N-value,varies significantly may be related to the location of the seismic source,the seismogenic fault and the distribution of aftershocks of the strong earthquake. The preliminary study shows that the impending-earthquakes microseismic phenomena may be related to the pre-activity,micro-vibration and micro-rupture in the source region in the imminent stage,or the microactivity and micro-rupture associated with the active tectonics.

Preparation of microsized hematite powder from ferrous sulfate via microwave calcination

The preparation of microsized hematite powder from ferrous sulfate using microwave calcination was investigated based on the TG/DTG curves. The decomposition of industrial ferrous sulfate under air atmosphere was divided into three stages, and a ferrous sulfate sample added with 15% Fe_2O_3 could strongly absorb microwave energy. Therefore, preparing hematite powder from ferrous sulfate using microwave calcination was feasible. Hematite was obtained under the following optimized conditions: calcination temperature, 850 °C; microwave power, 650 W; and sample amount, 40 g. The obtained hematite satisfied the first-grade quality requirements. The total ferrum value was more than 58%, and the total sulfur and phosphorus contents were less than 0.5% and 0.2%, respectively. X-ray powder diffraction and scanning electron microscopy were used to characterize the structure and morphology of microsized hematite powder. The particles were non-spherical in shape, and the average particle size distribution was 10.45 μm. This work provides new potential applications for waste ferrous sulfate.

Microseism Variations in Response to Antarctic Seasonal Changes in Sea Ice Extent

The temporal and spatial distributions of Antarctic sea ice play important roles in both the generation mechanisms and the signal characteristics of microseisms. This link paves the way for seismological investigations of Antarctic sea ice. Here we present an overview of the current state of seismological research about microseisms on Antarctic sea ice. We first briefly review satellite remote-sensing observations of Antarctic sea ice over the past 50 years. We then systematically expound upon the generation mechanisms and source distribution of microseisms in relation to seismic noise investigations of sea ice, and the characteristics of Antarctic microseisms and relationship with sea ice variations are further analyzed. We also analyze the continuous data recorded at seismic station BEAR in West Antarctica from 2011 to 2018 and compare the microseism observations with the corresponding satellite remotesensing observations of Antarctic sea ice. Our results show that:(1) the microseisms from the coastal regions of West Antarctica exhibit clear seasonal variations,SFM with maximum intensities every April-May and minimum intensities around every October-November;while DFM intensities peak every February-March,and reach the minimum around every October. Comparatively,the strong seasonal periodicity of Antarctic sea ice in better agreement with the observed DFM;and(2) microseism decay is not synchronous with sea ice expansion since the microseism intensity is also linked to the source location,source intensity(e. g.,ocean storms,ocean wave field),and other factors. Finally, we discuss the effect of Southern Annular Mode on Antarctic sea ice and microseisms,as well as the current limitations and potential of employing seismological investigations to elucidate Antarctic sea ice variations and climate change.

Analysis of microseismic activity in rock mass controlled by fault in deep metal mine

Aiming at evaluating the stability of a rock mass near a fault,a microseismic(MS) monitoring system was established in Hongtoushan copper mine.The distribution of displacement and log(/),the relationship between MS activity and the exploitation process,and the stability of the rock mass controlled by a fault were studied.The results obtained from microseismic data showed that MS events were mainly concentrated al the footwall of the fault.When the distance to the fault exceeded 20 m,the rock mass reached a relatively stable state.MS activity is closely related to the mining process.Under the strong disturbance from blasting,the initiation and propagation of cracks is much faster.MS activity belongs in the category of aftershocks after large scale excavation.The displacement and log(C/) obtained from MS events can reflect the difference in physical and mechanical behavior of different areas within the rock mass,which is useful in judging the integrity and degradation of the rock mass.