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Search Results: 1 - 10 of 79467 matches for " 谭玉阳 "
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基于初至旅行时差的微地震速度模型反演
,何川,张洪亮
石油地球物理勘探 , 2015,
Abstract: ?为精确定位微地震震源,需已知压裂井和监测井所在工区准确的地层速度模型。常规速度建模方法需用射孔记录中p波和s波初至旅行时信息校正地层速度,这要求已知准确的射孔起始时间。然而受施工条件等因素影响,实际监测过程中射孔的起始时间很难准确测量。因此,本文基于levenberg-marquardt反演算法,提出一种利用初至波旅行时差信息替代旅行时进行速度模型反演的方法,该方法可在射孔起始时间未知的情况下反演出地层速度模型。利用该方法分别对模型数据和实际资料进行试处理,从处理结果可以看出:虽然受观测系统布设位置及初至拾取精度等因素影响,反演出的速度模型存在一定误差,但利用该模型可将射孔位置定位到其真实位置附近,表明该速度模型可用于微地震震源定位。
一种基于流媒体的实时调度控制算法qfec
波?,夏斌?,
软件学报 , 2009,
Abstract: internet视频业务的普及和用户越来越高的服务需求推动了实时流媒体业务的迅速发展,流媒体业务的服务质量(qos)成为业界研究的热点.由于网络的复杂性,流媒体的实时调度控制算法是解决流媒体qos的关键.结合fec编码技术和kalman数字滤波技术,提出一种基于qos的改进fec调度传输控制算法——qfec.该算法根据接收方的状态合理调度流媒体业务,并结合kalman滤波器原理完成传输速率控制.通过算法状态分析,以及实验数据和性能分析表明,该调度算法能够维持视频数据良好的连续传输,降低视频流的丢包率,显著改善流媒体业务的qos.
微地震观测系统及震源定位目标函数研究
Study of Recording System and Objective Function for Microseismic Source Location

李罗兰,何川,
- , 2017, DOI: 10.13209/j.0479-8023.2016.091
Abstract: 摘要 通过模型试验, 分别讨论地面、井下观测系统以及二者的组合对于定位结果的影响。试验结果表明, 联合采用地面与井下观测系统能够有效提高震源定位精度。在采用井下观测系统的基础上, 对比几种常用目标函数的应用效果, 并在更有效的走时残差计算方法基础上, 提出一种新的目标函数。模型数据及实际资料的处理结果表明, 提出的目标函数在水平方向以及垂向上均具有较好的收敛性, 其震源定位结果也更准确、可靠。
Abstract Through synthetic data tests, the influence on source location results of surface and downhole recording systems are discussed, as well as the combination of both. The results indicate that joint use of surface and downhole recording systems can significantly improve the location accuracy. With the downhole recording system, the location results obtained by adopting different objective functions in source location algorithm are compared. Moreover, a new objective function is also proposed. The effectiveness of the new objective function is tested on synthetic and real data sets. The results demonstrate that this objective function shows better convergency in both horizontal and vertical directions, and it can produce more reliable location results.
基于Occam反演算法的微地震速度模型反演
Velocity Model Inversion for Microseismic Monitoring Based on Occam Inversion Algorithm

赵忠,,张洪亮,何川
- , 2015,
Abstract: 摘要 为了能够对微地震震源进行精确定位, 需要已知压裂井和监测井所在工区内准确的地层速度模型。针对这一问题, 在采用Occam反演算法的基础上, 提出一种利用初至波的走时差信息代替旅行时进行速度模型反演的方法。利用该方法, 可以在无须已知射孔起始时间的情况下反演得到地层速度模型。通过模型数据的处理以及对结果的分析, 表明虽然受到初至到时拾取误差的影响, 采用上述方法反演得到的速度模型会存在一定的误差, 但利用该模型可以将射孔位置定位到其真实位置附近, 表明该速度模型可用于进行微地震震源定位。
Abstract In order to accurately locate the microseism sources, a thorough knowledge of the velocity model between the treatment well and monitoring well is essential. A new method is developed to invert the velocity model based on Occam inversion algorithm. Instead of the travel times, this method adopts the moveouts of the first arrivals to invert the velocity models, so it can overcome the limitation of conventional approaches when the perforation origin times are unavailable or measured inaccurately. The feasibility of this method is examined on synthetic datasets. The results demonstrate that although the velocity models obtained using this method show some discrepancies, which are caused by the picking errors, they can locate the perforation shots back to their expected positions, so the inverted velocity models can be used to locate the microseism sources.
1-氨基-3-硝基-5-(5-氨基-3-硝基-1,2,4-三唑-1-基)-1,2,4-三唑的合成及性能
易潜洪,黄明,碧生,贺云,屈延,
含能材料 , 2015, DOI: 10.11943/j.issn.1006-9941.2015.11.011
Abstract: 以5-氨基-3-硝基-1,2,4-三唑(ANTA)和1-氨基-3,5-二硝基-1,2,4-三唑(ADNT)为原料,设计、合成了一种新型C—N互联三唑化合物1-氨基-3-硝基-5-(5-氨基-3-硝基-1,2,4-三唑-1-基)-1,2,4-三唑(DANBT),采用IR、NMR、MS对其结构进行了表征,用差示扫描量热法研究了DANBT的热性能,确定了其熔点为221.8℃,分解峰温为291.8℃,热稳定性优于ADNT和ANTA。采用Kamlet-Jacobs方程预测DANBT的爆速与爆压分别为8.69km·s-1,33.91GPa。
基于波形互相关的微地震事件自动识别及初至拾取
Automatic Microseismic Event Detection and Arrival Picking Based on Waveform Cross-Correlation

魏梦祎,,毛中华,冯刚,胡天跃,何川
- , 2018, DOI: 10.13209/j.0479-8023.2017.079
Abstract: 摘要 根据具有相似震源位置及破裂机理的微地震事件通常在地震记录上表现出相似波形特征的原理, 提出一种基于波形互相关的微地震事件自动识别及初至拾取方法。首先, 通过计算道间互相关函数, 对微地震记录进行时差校正; 然后, 通过计算道间相似系数的方法识别连续地震记录中的微地震事件。在完成事件识别的同时, 对时差校正后的多道记录进行叠加, 并采用STA/LTA方法对叠加道进行初至拾取, 结合各道间的时差信息即可获得各道微地震事件的初至到时。为了检验所提方法的可行性和有效性, 分别对模型数据和实际资料进行处理,结果表明利用所提方法可以在有效地识别微地震事件的同时, 得到较为准确的初至拾取结果。
Abstract Generally, a cluster of seismic events which share similar source locations and focal mechanisms will show similar waveforms on the record. Based on this assumption, a method have been developed for microseismic event detection and arrival picking based on waveform cross-correlation. This method achieves moveout correction for the seismic records based on cross-correlation functions, then calculates a multi-channel semblance coefficient to identify the microseismic events. Meanwhile, the seismic records after moveout correction are superposed. The STA/LTA method is adopt to pick the arrivals for the stacked traces, the arrival times of the microseismic events are then automatically obtained. The performance of the method is evaluated using both synthetic and real datasets. Analysis of the results demonstrates that the proposed method can not only detect the microseismic events, but also obtain relatively accurate arrival picks at the same time.
西北地区四种蜜源蜂蜜的农药残留风险暴露评估

- , 2018, DOI: 10.13982/j.mfst.1673-9078.2018.11.040
Abstract: 采集近两年西北地区油菜蜜、葵花蜜、洋槐蜜和枸杞蜜样品,对其中的五种农药(啶虫脒、吡虫啉、噻虫嗪、多菌灵和克螨特)进行残留检测。针对儿童,孕龄女性及老人三类敏感人群,用风险商值进行蜂蜜膳食暴露风险评估。结果表明,五种农药残留的检出率在5.22%~29.57%之间,参照欧盟限定的农药残留最大限量标准,13.91%的啶虫脒含量超标,吡虫啉超标率为7.83%。不同蜜源蜂蜜的农药残留检出率从25%~100%,枸杞蜜农药检出率最高。对不同蜜源植物蜂蜜的农药残留含量进行方差分析,发现多菌灵,啶虫脒和吡虫啉残留水平都存在显著差异,这可能跟蜜粉源植物中农药的污染程度密切相关。三类人群的风险商值均低于1%,说明残留风险较低,可以接受。在不同人群中,10岁以下儿童的膳食暴露风险最高。
Samples of rape honey, sunflower honey, acacia honey and medlar honey were collected in the past two years. Residues of the five pesticides (acetamiprid, imidacloprid, thiamethoxam, carbendazim, and propargite) were detected. The risk assessment of dietary honey exposure to children, gestational age Female and old man was conducted using the risk quotient RQ%. The results showed that the detection rate of the five pesticides was between 5.22% and 29.57%. With reference to the European Union's limit of pesticide residue, 13.91% of acetamiprid content was exceeded, and the over-standard rate of imidacloprid was 7.83%. The detection rate of pesticide residues in different sources of honey ranged from 25% to 100%, and the detection rate of medlar honey was the highest. ANOVA analysis of pesticide residues in honey from different honey plants revealed significant differences in the residual levels of carbendazim, acetamiprid and imidacloprid, which may be closely related to the degree of pesticide contamination in the pollen source plants. The risk quotients (RQ%) of the three groups were all less than 1%, indicating that the residual risk is low and acceptable. In different populations, children under 10 years of age have the highest dietary exposure risk.
网络安全评估技术综述
Survey on Technology of Network Security Assessment
 [PDF]

赵孟,
Computer Science and Application (CSA) , 2015, DOI: 10.12677/CSA.2015.51003
Abstract:
互联网和信息技术的快速发展,使网络深深的融入到人们的生活中。然而,丰富的互联网服务应用也带来了更多的网络安全问题,网络安全评估技术是当前处理网络安全问题的一种策略。在阐述网络安全评估技术的基本概念、研究意义的基础上,给出了网络安全评估的体系结构,主要从基于数学模型的方法、基于知识推理的方法和基于模式识别的方法三方面分析其研究现状,讨论现有的技术的优势和不足,并探讨了未来的发展方向。
With the rapid development of Internet and information technology, the network has been deeply integrated into our lives. However, the rich services and applications of the Internet bring more security problems. Technology of network security assessment is a strategy to deal with the prob-lems of network security at present. The basic concepts and research significance are shed light on. This paper described the architecture of network security assessment, and analyzed the research status mainly focusing on the method based on mathematical model, the method based on know-ledge reasoning and the method based on pattern recognition. Then the advantages and disad-vantages were pointed out respectively. Finally, some future research directions were given at the end.
基于染色体易位的动态进化算法
,宁可,陈琳
计算机应用 , 2015,
Abstract: ?针对采用二进制编码的进化算法在函数优化过程中会因为维度之间的相互干扰,导致部分低阶模式出现无法进行有效重组的现象,提出一种新的结合细胞学研究成果的进化算法——染色体易位的动态进化算法(ctdea)。算法通过构建基因矩阵来模拟有机染色体在细胞内的结构化过程,并在基因矩阵的基础上对出现同质化的染色体短列实施模块化的易位操作,以此来维护种群的多样性;同时通过个体适应度划分种群的方式来维护精英个体,确保个体间的竞争压力,提升算法的寻优速度。实验结果表明,该进化算法与已有的遗传算法(ga)和分布估计算法相比较,在维护种群多样性方面有较大改进,能够将种群的多样性保持在0.25左右;且在寻优的精度、稳定性以及速度上也有明显的改进和提高。
气相分子吸收光谱法测定硫化物校准曲线的研究
Determination of Sulfide Calibration Curve by Using Gas-Phase Molecular Absorption Spectrometry
 [PDF]

湛玲, 吕保
Water pollution and treatment (WPT) , 2016, DOI: 10.12677/WPT.2016.44019
Abstract:
本文主要阐述了气相分子吸收光谱法测定硫化物时对其校准曲线斜率、截距参考值的分析。通过收集实验室近三年采用气相分子吸收光谱法测定硫化物时制作校准曲线的一系列原始数据,并用数理统计方法对校准曲线及其有关指标进行了详细讨论,得出气相分子吸收光谱法测定硫化物校准曲线的斜率参考值范围为:0.0961 ± 0.0013,截距参考值范围:?0.0018 ± 0.0030。此结果对实验室分析人员判定硫化物项目校准曲线制作是否合格具有一定的参考价值。
This paper mainly analyzed the reference value of the slope rate and intercept from the sulfide’s calibration curve by using gas-phase molecular absorption spectrometry. The calibration curve and its related indexes were discussed in detail by using mathematical statistics method through nearly three-year original data in laboratories. Results showed that the reference range of slope of the gas-phase molecular absorption spectrometry calibration curve is 0.0961 ± 0.0013, and that of intercept is ?0.0018 ± 0.0030. These results provide reference for determining eligibility criteria of sulfide calibration curve.
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