一种基于二级索引的快速读取野外地震采集大道数单炮方法研究

岩高效勘探技术导致野外采集数据快速增长,如何提高大道数单炮的I/O效率直接影响现场的作业速度。考虑野外作业现场的施工环境及实际需求,通过深入研究单炮SEGY文件存储结构,本文提出了针对大数据单炮构建二级索引方法提升单炮I/O速度。该方法通过二级索引快速定位大数据单炮文件的任一单炮、任一排列及任一道的边界位置,省去顺序寻找单炮或道的时间,从而实现单炮、排列或道数据的快速读取。实际应用表明,该方法大幅提升检索单炮在文件中起始位置的效率,从而提升大道数单炮I/O速度,为全面提升现场质控效率、数据处理效率等业务奠定了基础。

仪器的大道数能力在高精度勘探中的重要性与实现

随着地球物理勘探技术的发展,仪器的道能力已经成为地震数据采集记录系统的一个重要指标。而影响道能力指标的关键因素是采集地震数据的传输方法(或数据传输速率)和地震仪器本身的结构或者说外线地震数据进入仪器主机(中央控制与记录单元)的接入方法。本文阐述了仪器道能力在地球物理勘探中的重要性和实现方法,采用高的数据传输率可以实现大道数的数据采集,而经过科学设计的仪器结构更为道数的扩展提供新的途径,从而可以有效地提高地球物理数据采集的效率,降低采集成本,实现高效、高精度勘探的普及。

大道数采集中串感应成因及防范消除探讨

串感应现象是困扰野外数据采集的一大难题,严重影响地震记录的品质。本文从对当前主流的大道数采集生产中串感应的特点和成因进行分析,介绍了一些在地震采集生产阶段如何防范和消除串感应现象的有效方法。

G3i仪器大道数高效采集的配置与实施

G3i仪器实现大道数远距离同步滑动扫描是本文叙述的主题,与之相应的设备配置及性能指标要求也是重要内容之一。本文还介绍了DSSS模式下的仪器设置及操作中的关键环节,并针对仪器大道数采集管理的稳定性、高速数据传输、记录存储、多震源组同步激发以及QC监控等问题,提出了切实可行的解决方法。

PB级地震勘探数据的质控与管理

现今的地球物理勘探观测精度要求越来越高,采集数据动辄达PB级,如何对PB级的海量数据进行质控与管理成为了新的挑战。本文提出了地震采集实时质量控制(RTQC,Real Time QC)、模块流程化工序、软件实现等方法。该方法在中东某20万道级数字检波器三维项目中成功应用,通过实际验证和基础数据分析证明了该质控与管理方法的实用性,为类似地震勘探项目PB级地震数据的数据管理提供了可借鉴思路。

地震勘探中的实时采集技术

介绍了现行地震数据采集系统实时与非实时采集、采集周期与等待时间等概念,以408UL地震数据采集系统为例,分析了影响实时采集道容量的因素,提出了确定实时采集道容量的原则,为合理配置、合理设计利用现行地震数据采集系统的资源提供参考。

基于428XL系统的现场实时质控软件的开发及应用

428XL是目前使用最为广泛的陆上地震数据采集系统。该系统所提供的实时质控功能在应用于大道数高效采集时存在一定的局限性,不能很好地满足高效采集项目生产的现场需求。针对中东地区某大道数高效采集项目在野外生产中所遇到的428XL质控难题,本文提出了一种新的针对于该系统的实时质控方法,通过外部软件获取生产数据并实时地判别生产炮的好坏,对不合格的炮及时报警提示,从而达到实现野外实时质量监控、实时重放不合格炮的目的。该方法能够有效提高地震勘探队的生产效率,并降低野外发生质量事故的风险。

Scorpion系统在国内西部万道采集项目中的应用

本文主要介绍了Scorpion系统升级到4.1.1.16版本的改进及特点,通过对A单元及电源站APP的升级,解决了系统延迟的问题,并可以方便地判断出问题大线的所在位置。在国内西部的大道数采集试验中,合理地运用Scorpion系统野外单元状态管理和野外采集单元记录参数锁定等技巧,保证了排列的稳定,并通过独立绘图及隔线回放的功能,提高了生产效率,证明了其升级后的优越性。

基于508XT系统的现场实时质控软件的应用

在大道数高效采集中实施野外现场实时质量监控是提高野外生产效率的有效手段.通过现场实时监控,不仅可以及时地发现废炮,避免后续补炮浪费时间,还可以在生产中及时地发现问题,防止发生质量事故.本文介绍了基于508XT的野外实时监控软件的功能应用.

Influence of enlarged section parameters on pressure transients of high-speed train passing through a tunnel

The influence of enlarged section parameters on pressure transients of high-speed train passing through a tunnel was investigated by numerical simulation.The calculation results obtained by the structured and unstructured grid and the experimental results of smooth wall tunnel were verified.Numerical simulation studies were conducted on three tunnel enlarged section parameters,the enlarged section distribution along circumferential direction,the enlarged section area and the enlarged section distribution along tunnel length direction.The calculation results show that the influence of the different enlarged section distributions along tunnel circumferential direction on pressure transients in the tunnel is basically consistent.There is an optimal enlarged section area for the minimum value of the pressure variation amplitude and the average pressure variation in the tunnel.The law of the pressure variation amplitude and the average pressure variation of the enlarged section distribution along tunnel length direction are obtained.

Numerical simulation and disaster prevention for catastrophic fire airflow of main air-intake belt roadway in coal mine—A case study

Coal mine belt fire develops very rapidly and is difficult to control. If not suppressed quickly, a belt fire could easily lead to airflow disorder and undermine the ventilation system. However, belt fire can be prevented effectively by establishing fire airflow control system. In this work, the 5th belt roadway of Kongzhuang coal mine was taken as the object of investigation, where geometrical models of this roadway were established firstly. Then, based on mathematical model of fire smoke flow, the CO volume fraction, smoke density distribution, air temperature and pollutant velocity vector in the roadway before and after taking airflow control measures were simulated by using Fluent software. It can be known from the simulation that with the normal ventilation status in 5th belt roadway, the countercurrent of smoke does not happen when a fire occurs; the roadway's section is almost filled with CO at 10 m downstream from the fire source, and with air velocity getting stable gradually, the CO concentration reaches about 15 %. After taking airflow control measures, the effect range of temperature field which are harmful to the miners decreases from 69 m to 30 m; and the distance of the roadway fully filled with CO is 5 m farther than that before taking measures. Finally, according to the numerical simulation results and the actual condition of the belt roadway, the warning and automatic remote airflow control system with short-circuit method for the 5th belt roadway was designed to guarantee the safety production.

Deformation mechanism and excavation process of large span intersection within deep soft rock roadway

The FLAC3D software was used to simulate and analyze numerically the displacement, stress and plastic zone distribu-tion characteristics of a large span intersection in a deep soft rock roadway after the surrounding rock was excavated. Our simula-tion results show that there are two kinds of dominating factors affecting roadway stability at points of intersection, one is the angle between horizontal stress and axial direction of the roadway and the other are the angles at the points of intersection. These results are based on a study we carried out as follows: first, we analyzed the failure mechanism of a large span intersection and then we built a mechanical model of a rock pillar at one of the points of intersection. At the end of this analysis, we obtained the failure characteristics of the critical parts on the large span intersection. Given these failure characteristics, we proposed a new supporting method, i.e., a Double-Bolt Control Technology (DBCT). By way of numerical simulation, DBCT can effectively control the deformation of the surrounding rock at the points of intersection in roadways.

Wind tunnel study of aerodynamic wind loading on middle pylon of Taizhou Bridge

Segment sectional model tests are carried out to investigate the wind loading on middle pylon of Taizhou Bridge, which has complicated three-dimensional flow due to its feature of double columns. Through the force measuring tests, aerodynamic force coefficients of every segment of the pylon columns have been obtained. It is found that the tested aerodynamic force coefficients are much smaller than those given by codes. The interference effects of aerodynamic force coefficients between columns of pylon are discussed. The results show that the interference effect is the most evident when the yaw angle is about 30 ° from transverse direction. This kind of interference effect can be described as diminutions in transverse aerodynamic force coefficients and magnifications in longitudinal aerodynamic force coefficients of downstream columns.

Capacity Maximization Based Power Loading Analysis for Digital Channelized Satcom Systems

For digital channelized frequency division multiple access based satellite communication(SATCOM) systems,it is a challenging but critical issue to improve the transponder power and spectrum efficiency simultaneously under limited and non-linear high-power amplifier conditions.In this paper,different from the traditional link supportability designs aiming at minimizing the total transponder output power,a maximal sum Shannon capacity optimization objective is firstly raised subject to link supportability constraints.Furthermore,an efficient multilevel optimization(MO) algorithm is proposed to solve the considered optimization problem in the case of single link for each terminal.Moreover,in the case of multiple links for one terminal,an improved MO algorithm involving Golden section and discrete gradient searching procedures is proposed to optimize power allocation over all links.Finally,several numerical results are provided to demonstrate the effectiveness of our proposals.Comparison results show that,by the MO algorithm,not only all links' supportability can be guaranteed but also a larger sum capacity can be achieved with lower complexity.

Manufacturers’channel selections under the influence of the platform with big data analytics

To obtain the platform s big data analytics support,manufacturers in the traditional retail channel must decide whether to use the direct online channel.A retail supply chain model and a direct online supply chain model are built,in which manufacturers design products alone in the retail channel,while the platform and manufacturer complete the product design in the direct online channel.These two models are analyzed using the game theoretical model and numerical simulation.The findings indicate that if the manufacturers design capabilities are not very high and the commission rate is not very low,the manufacturers will choose the direct online channel if the platform s technical efforts are within an interval.When the platform s technical efforts are exogenous,they positively influence the manufacturers decisions;however,in the endogenous case,the platform s effect on the manufacturers is reflected in the interaction of the commission rate and cost efficiency.The manufacturers and the platform should make synthetic effort decisions based on the manufacturer s development capabilities,the intensity of market competition,and the cost efficiency of the platform.

An Assessment of MJO and Tropical Waves Simulated by Different Versions of the GAMIL Model

Simulated outgoing longwave radiation （OLR） outputs by two versions of the grid-point atmospheric general circulation model （GAMIL） were analyzed to assess the influences of improvements in cloud microphysics and convective parameterization schemes on the simulation of the Madden-Julian oscillation （MJO） and other tropical waves. The wavenumber-frequency spectral analysis was applied to isolate dominant modes of convectively coupled equatorial waves, including the M30, Kelvin, equatorial Rossby （ER）, mixed Rossby-gravity （MRG）, and inertio-gravity （1G） waves. The performances of different versions of the GAMIL model （version 1.0 （GAMIL1.0） and version 2.0 （GAMIL2.0）） were evalu- ated by comparing the power spectrum distributions of these waves among GAMIL 1.0, GAMIL2.0, and observational data. GAMIL1.0 shows a weak MJO signal, with the maximum variability occurring separately at wavenumbers 1 and 4 rather than being concentrated on wavenumbers 1-3, suggesting that GAMILI.0 could not effectively capture the intraseasonal variability. However, GAMIL2.0 is able to effectively reproduce both the symmetric and anti-symmetric waves, and the significant spectra of the MJO, Kelvin, and MRG waves are in agreement with observational data, indicating that the ability of GAMIL2.0 to simulate the MJO and other tropical waves is enhanced by improving the cloud microphysics and convective parameterization schemes and implying that such improvements are crucial to further improving this model＇s performance.

Analysis of the Energetic Particles Around the Chili Earthquake of M8.8

Based on the IDP data from the French DEMETER satellite,global distribution is shown,which corresponds to three precipitation zones:the aural precipitation zone,the mid-high latitude precipitation zone and the South Atlantic precipitation zone.Then the Chili earthquake with M8.8 which occurred on February 27,2010 is taken as an example.The IDP fluxes from repeat orbits are compared and the results show that there is a clear enhancement on February 26,2010,just one day ahead of the Chili earthquake.In the south zone with L=2.1～2.7,the flux on February 26 is higher than that on previous days.However in the north zone with L=2.1～2.7,there is no clear change during the day but great enhancement during the night,which is close to the time of the earthquake.At the same time,the flux on February 26 near the equator is far lower than that on previous days.

Particle Size and Shape of On-road Suspended Coarse Dust in the Shijiazhuang City, China

The particle size and shape measured by image analysis is helpful to discuss the human health effects of particulate beside the aerodynamic scale. To explore the size and shape features of particle suspended in the road environment, this research selected 12 bus stations as the sampling sites along the main road in the air polluted city Shijiazhuang, China, where a Car-Free Campaign had been carried out. We hung 2 slides covered with a layer of petroleum jelly to collect suspending particles for 24 hours at each sampling site, and measured the particles size and shape parameters with the Particle Size Analyzer of CIS-50. The results show that the average particle size by the equivalent area diameter is around 10 μm, the size distributions are multi-modal with wide span, demonstrating that coarse dust suspended on road derived from several particle sources. Most of the particles suspended are square or square-like in shape with rugged border. Compared the samples of ordinary days and of the Car-Free day, the size and shape features vary little, inferring the ineffective results for the particle control of the Campaign. There is certain relationship between particle size and shape. The number percent of PMs-E （particulate matter with equivalent area diameter beneath 5 pro） is positively correlative with the number percent of particles of square or square-like shape, and negatively correlative with that of round or round-like shape. This relationship pattern in the road environment is contrary to the situations in the upper atmosphere, inferring different transportation and source emission mechanism influences.

Material transportation and fluid-melt activity in the subduction channel: Numerical modeling

The subduction channel is defined as a planar to wedge-like area of variable size,internal structure and composition,which forms between the upper and lower plates during slab subduction into the mantle.The materials in the channel may experience complex pressure,temperature,stress and strain evolution,as well as strong fluid and melt activity.A certain amount of these materials may subduct to and later exhume from>100 km depth,forming high to ultra-high pressure rocks on the surface as widely discovered in nature.Rock deformation in the channel is strongly assisted by metamorphic fluids activities,which change composition and mechanical properties of rocks and thus affect their subduction and exhumation histories.In this study,we investigate the detailed structure and dynamics of both oceanic and continental subduction channels,by conducting highresolution petrological-thermomechanical numerical simulations taking into account fluid and melt activities.The numerical results demonstrate that subduction channels are composed of a tectonic rock melange formed by crustal rocks detached from the subducting slab and the hydrated mantle rocks scratched from the overriding plate.These rocks may either extrude sub-vertically upward through the mantle wedge to the crust of the upper plate,or exhume along the subduction channel to the surface near the suture zone.Based on our numerical results,we first analyze similarities and differences between oceanic and continental subduction channels.We further compare numerical models with and without fluid and melt activity and demonstrate that this activity results in strong weakening and deformation of overriding lithosphere.Finally,we show that fast convergence of orogens subjected to fluid and melt activity leads to strong deformation of the overriding lithosphere and the topography builds up mainly on the overriding plate.In contrast,slow convergence of such orogens leads to very limited deformation of the overriding lithosphere and the mountain building mainly occurs on the subducting plate.

Statistical characteristics of the equatorial boundary of the nightside auroral particle precipitation

Based on the auroral electron/ion precipitation boundary database observed by the DMSP satellites during 1984–2009, the characteristics of the nightside equatorial boundaries of the electron precipitation（B1E） and the ion precipitation（B1I） in the Northern/Southern Hemispheres（NH/SH） are statistically investigated. The results show： That most of the boundaries are located between magnetic latitude（MLAT） of 60°–70° with the mean MLAT for B1E/B1 I to be 64.30°N/63.22°N and 64.48°S/63.26°S in the NH and SH, respectively, indicating that B1 E and B1 I in both hemispheres are located in conjugated magnetic field lines with B1 E ~1.2° poleward of B1I; that the MLAT of B1 E and B1 I in both hemispheres shift to lower MLAT（from ~70° to ~55°） as geomagnetic activity increases; that MLAT of both B1 E and B1 I and their differences slowly decrease from dusk to midnight with some difference in both hemispheres during different levels of geomagnetic activities; that B1 E and B1 I in both hemisphere decrease linearly with Kp and exponentially with Dst, AE, and SYM-H, respectively, demonstrating that auroral particle precipitation is closely related with geomagnetic activity; that in different magnetic local time（MLT） sectors, the changing rates of the boundaries with Kp are different, and the rates of B1 E are generally larger than that of B1 I, implying that the difference between B1 E and B1 I reduce with increasing geomagnetic activity. Compared with previous studies, the statistical results based on the long-term large database in this paper can well reflect the properties of the equatorial boundaries of auroral precipitation and may be used for physical modeling or space weather forecasting in future.