一种数据驱动的VSP多次波压制方法

V SP资料用于提供地下结构的高分辨率信息,但其成像质量通常受到多次波的干扰,影响了地下真实反射界面的识别。本文介绍一种数据驱动的V SP多次波压制方法,该方法基于反馈迭代原理,综合利用地面和井中地震数据,资料中的多次波进行预测并基于最小能量准则实现自适应相减;同时,利用V SP资料中直达波,可以预测出下行波场,进而提取上行波记录。简单模型结果表明,该方法可以有效实现V SP资料多次波压制及上下行波场分离,且无需地下模型先验信息。     

几种简单实用的多次波去除方法及其应用

多次波衰减是地震资料处理中的老问题,多次波的存在严重影响地震剖面成像的真实性和可靠性,干扰地震资料的解释,所以,在叠前应对多次波加以有效的消除,提高资料的品质和精度.而目前,多次波理论方面的研究及成果相当多,但对于实际生产有时却无能为力.因此,本文意在从原理和可操作性上,介绍几种在实际生产中既简单实用又省时有效的多次波去除方法及其应用效果,主要介绍了数据一致性预测反褶积、Radon变换、利用速度扫描工具及内切除等四种多次波去除方法及其应用效果.以提高资料的处理质量和效率.     

埕岛东坡干扰波分析及去噪技术研究

地震资料"高信噪比、高分辨率、高保真度"三高要求中,信噪比是基础,提高信噪比是地震资料处理的首要任务。本文在分析埕岛东坡干扰波的基础上,综合评述了常用的几种去噪技术,包括区域F-X域相干噪音衰减面波技术、区域异常噪音衰减技术、线性噪音衰减技术、多次波压制技术等。地震资料的去噪问题需要根据噪音的具体特征,采用合理、有针对性的去噪方法和技术。     

浅析SRME多次波压制技术的研究与应用

海上地震勘探中一直存在着不同类型的多次波,但与自由界面有关的多次波占其主要成分,由于多次波的存在严重影响了后续地震资料处理的精度,降低了地震资料的可靠性和真实性,并影响最终的地震资料解释结果。本文首先介绍了SRME多次波压制技术的基本原理,对实际工区的地震资料进行了处理,结果表明,该方法可以有效去除与自由界面有关的多次波,提高了资料的信噪比,为后续的地震资料处理和解释提供更好的数据。     

基于τ-p域多次波压制技术的研究与应用

地震勘探中一直存在着不同类型的多次波,由于多次波的存在严重影响了速度分析、动校正、叠加等地震资料处理的精度,使得地震偏移成像缺乏可靠性和真实性,并最终影响地震资料解释。本文首先介绍了τ-p变换的基本原理,对实际工区的地震资料进行了处理,结果表明,该方法可以有效去除多次波,并且明显提高了地震资料的信噪比,可为后面的地震资料处理和解释提供更好的数据。     

塔里木盆地巴楚区块多次波识别与压制

在地震资料处理过程中,多次波的存在,它会降低地震剖面的信噪比,使目的层反射波的振幅、相位产生畸变,影响地震成像的精度。本文以塔里木巴楚区块资料为例,介绍在地震数据处理中几种识别多次波和压制多次的方法,针对实际资料,选择预测反褶积加radon变换压制多次波,取得明显效果,改善了成像效果。     

多次波衰减技术在复杂地区的应用研究

海拉尔盆地呼和湖凹陷南部地区地质构造较为复杂,并且发现有多次波影响目的层段反射的现象,合理有效的对多次波进行衰减,是保证目的层段真实成像的必要手段,本文以海拉尔盆地呼和湖凹陷南部资料为实例,分析复杂地区多次波成因以及类型,根据其干扰特征,运用适当的方法对多次波进行衰减。     

辽河西缘多次波认识及压制方法

在辽河西缘的地震勘探采集过程中,多次波发育较为明显,对有效信号的提取造成了不利影响,针对辽河西缘地震勘探中多次波进行总结分析,主要介绍了该地区多次波的主要特点以及去噪方法,对该地区地震多次波的认识和理解有一定的帮助。     

多次波压制技术在玛围地区的应用

玛围地区全程多次波十分发育。为了能较好地压制多次波,突出有效波,本文根据该地区的实际情况,总结了多次波压制方法的特点,在大量试验工作的基础上,采用了多种方法、分层次全面地对多次波进行压制。主要采用了F-K域滤波法、内切除和近道能量衰减法压制多次波三种技术,取得了较好的效果。     

陆上二维地震资料多次波压制方法

多次波一直以来是地震资料处理的难点,不存在某种方法能压制所有地区不同类型的多次波,在实际生产中不仅要根据其特点,而且还需考虑原始地震资料的品质来选择合适的多次波压制方法。本文以塔里木盆地不同品质的地震资料为例,分析该地区多次波发育的特征,在充分认识其特征的基础上选取最佳的多次波压制方法。根据地震资料品质的不同采取不同的组合方法压制多次波,对于覆盖次数较高的地震资料采用拉东变换结合内切除的方法;对于信噪比偏低的地震资料采用拉东变换结合τ-p域预测反褶积的方法,在实际生产实践中取得了较为理想的效果。     

Determination of chlorophyll in ground rapeseed using a modified near infrared reflectance spectrophotometer

A rapid and accurate method has been developed for the analysis of chlorophyll in ground rapeseed using a modified near infrared filter instrument. Ground rapeseed was scanned with a Cary 17 spectrophotometer, and optimal wavelengths for chlorophyll prediction (674, 696 nm) were selected from the visible wavelength region by multiple linear regression analysis. Six Dickey-john Instalab 600’s were modified to analyze chlorophyll in ground rapeseed by replacing two standard near infrared filters with two filters having central wavelengths of 674 and 696 nm. Calibration equations incorporating data from three wavelengths (674, 696 and 2100 nm) had an average multiple correlation coefficient (R) of 0.980 and standard error of estimate (SEE) of 3.1 ppm. Instrument prediction of chlorophyll agreed well with reference solvent extraction analyses (standard error of prediction, SEP=3.0 ppm). A universal calibration equation developed for the determination of chlorophyll in ground rapeseed was tested with several modified instruments and performed well.     

A new manufacturable filter design approach for spectral reflectance estimation

Selection of the best possible filter set among a set of available filters is the obvious method of increasing dimension of camera signals for spectral reflectance reconstruction. There are also methods that are focusing on the filter design regardless of noticing to the constructability of the designed filters. This study shows that direct optimization of physical variables of filter manufacturing technique is more reliable than indirect approach of designing and then physical manufacturing of the designed filters. Direct optimization of the transmission‐controlling primaries in filter manufacturing process would guarantee having the designed filters in reality. Combination of some solvent dyes was used as the spectral transmission matching system for filter manufacturing. As a conventional technique, filters were designed and best possible dye concentrations that match the desired filters were calculated. As an alternative approach, filters were also designed using direct optimization of dyes concentrations. The results showed that direct optimization of dye concentrations exhibits better performance in comparison with the conventional technique. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 316–326, 2017     

改性纤维球过滤器的应用性研究

介绍了过滤器的结构和亲水憎油改性纤维球滤料 ,根据来水水质情况可以采用压紧式或非压紧式纤维球过滤器的结构。在大庆油田进行现场应用性试验 ,结果表明 ,改性纤维球过滤器具有滤速高、处理量大的特点 ,适用于聚驱油田含油污水深度处理 ,出水达到低渗透层注水水质标准     

Innovation in ceramic foam filters manufacturing process

Ceramic filters have singular properties such as high permeability and specific surface area associated to low density. Some examples of their use can be found in liquid metal deep filtration, water treatment, air purification, and others. These particular properties are dependent on the filters' manufacturing process. One of the most used techniques to produce filters is the replication method, which provides a tridimensional network of struts and interconnected pores. However, a common issue of all ceramic filters produced by this technique is their low mechanical strength due to the hollow struts and microcracking generated during the thermal decomposition of the sponge. Intending to address this limitation and produce filters with higher mechanical strength, this paper analyzed a modified process route for manufacturing filters. Samples of preheated Al₂O₃ filters were vacuum infiltrated with ceramic suspensions (Al₂O₃ and SiO₂) of different solids concentrations (15-40 wt%), particle size distribution (nano to micrometric size) at distinct processing times (1-5 minutes). The data analysis indicated that the best balance among mechanical strength, mass, and strut thickness was achieved by infiltration with SiO₂ colloidal suspension (40 wt%) per 1 minute. SEM analysis confirmed that the struts were filled and microcracks were sealed with colloidal particles.     

Towards a new generation of environmentally-friendly ceramic foam filters: contribution of graphene nanoadditives in calcium aluminate-rich coatings

In this contribution, the widely used non-ecological production process of ceramic foam filters was modified into an environmentally friendly procedure, in which no hazardous materials are involved. Firstly, a large number of carbon-bonded ceramic foam filters were prepared by this approach. In the next step, a thin coating consisting of graphene-doped, carbon-bonded calcium aluminate was applied over these filters. Reference samples as well as coated samples were analyzed in detail with a focus on the phase composition, microstructural analysis, and mechanical as well as thermal properties. The results confirmed that the application of the developed coating improved the cold crushing strength of the ceramic foam filters. In addition, by application of graphene nanoadditives, it is also possible to vary the surface microroughness which will subsequently enable improved efficiency of inclusions elimination from metal melts during the filtration process.     

塑料在汽车滤清器中的应用

针对汽车滤清器用金属材料特别是黑色金属材料存在密度大、易腐蚀、不耐磨、加工工艺要求高等缺点,采用改性聚丙烯、增强尼龙66、(丙烯腈／丁二烯／苯乙烯)共聚物(ABS)、聚甲醛等改性塑料和工程塑料制备了滤清器中的叶片环、扩散锥、汽油滤清器外壳、空气滤清器外壳、旋流管、中心管等部件,既提高了生产效率,又降低了成本,经济效益显著。     

On the Extension of Mass Transfer j-Factor Correlation to the Collection Efficiency of Fibrous Filters

Filtration of submicrometer aerosols in fibrous beds was considered as a mass transfer process. Earlier experimental data on the single-fiber collection efficiency of aerosols collected in fibrous filters were used to calculate j-factors for mass transfer. A correlation for j-factors as a function of the modified Reynold's number in the bed was developed. Comparison of the j-factors based on both experimental data and various correlations for mass transfer in packed beds indicated that aerosol filtration in the submicrometer regime possesses strong similarities to mass transfer in packed beds. Also, the experimental j-factors obtained from aerosol filtration were obtained over a larger range of void fractions of the fibrous filters (from 0.6 to 0.992) than mass transfer data and hence provide a more complete set of data to develop a comprehensive correlation.     

Characterization of functionalized multiwalled carbon nanotubes and application as an effective filter for heavy metal removal from aqueous solutions☆

Filtration efficiency of Ni(II) from aqueous solution using pristine and modified MWCNTs filters was investigated as a function of Ni(II) ion concentration, pH, and filter mass. MWCNTs were synthesized by CVD method and modified using two complementary treatments, purification (using a mixture of hydrochloric acid and hydrogen peroxide) and functionalization (using nitric acid). The effect and mechanism of each treatment on the structural integrity of pristine MWCNTs has been studied. Morphology of the pristine and modified filters was investigated by Raman Spectrometry (RS), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared (FTIR) spectrometry and Thermogravimetric analysis. It was found from Raman spec-tra that the ratio of the intensity of D-band to that of G-band decreased by purification process, and increased by functionalization process. The adsorption mechanism of Ni(II) onto the surface functional groups of modified MWCNTs was confirmed by FTIR spectrum. The filtration results showed that the removal efficiency of Ni(II) is strongly dependent on pH and could reach 85%at pH=8. Also, modified MWCNT filters can be reused through many cycles of regeneration with high performance. Functionalized MWCNTs filters may be a promising adsor-bent candidate for heavy metal removal from wastewater.     

Three-dimensional void space structure of activated carbon packed beds

The three-dimensional void space structure generated by piling active carbon grains has a large impact on the filter operation, through the modification of the transport properties inside the bed. To gain insight into the relation between morphology and transport properties, the three-dimensional void space structure of activated carbon packed beds was studied by X-ray microtomography coupled with image analysis. Image analysis algorithms allowing the determination of the total void fraction, the void size distribution and the radial void fraction profiles were developed. This methodology was used to characterize the void space structure of two filters with the same length but different diameters, 15 and 28 mm. Commercial granular activated carbon with average particle size close to 1 mm was used. The comparison of the void size distributions indicated that void sizes are almost normally distributed around only one maximum for the large filter, while the distribution has a more complex shape in the small filter. The radial void fraction profiles showed an increase of the void fraction from the center of the filter to the wall accompanied with an oscillatory behaviour at the small scale. Power spectrum of radial profiles of the large filter shows a characteristic length matching well with the carbon particle size, indicating that the carbon grains are uniformly packed in the bed. In the small filter, power spectrum suggests an uneven packing of grains. For both filters, the total void fraction measured by image analysis was very close to the value determined ‘physically’ knowing the carbon mass, bulk density and filter dimension.     

Analysis of Size Dependence of Ceramic Fiber and Whisker Strength

The strengths of ceramic fibers and whiskers have been observed to increase with decreasing fiber diameter and length. Typically, both surface flaws and volume flaws exist in ceramic fibers and whiskers, which makes it impossible to characterize the strength dependence of both the diameter and the length with a single-modal Weibull distribution function. Our data also show that the single-modal Weibull distribution is inadequate to characterize the strength of fibers with varying diameters even in the case of a constant fiber length. In addition, experimental data also show that, for sapphire whiskers whose surface flaws were removed by chemical polishing, the whisker strength has a much stronger size dependence on diameter than predicted by the single-modal Weibull function, which indicates that factors other than those characterized by the Weibull function also play a role in the strength of sapphire whiskers. In this paper, the factors affecting the strengths of ceramic fibers and whiskers are analyzed in terms of Weibull statistics, fracture mechanics, and flaw size density variation with varying fiber diameters. A three-parameter modified Weibull distribution, which combines the above strength-affecting factors, is proposed to characterize both the diameter and the length dependence for ceramic fibers and whiskers with or without surface flaws. Characterization of the strength data of sapphire whiskers and Nicalon SiC fibers with varying diameters shows the validity of the modified Weibull distribution function.