Fine Geological Radar Processing and Interpretation

Geological radar probing technology finds wide application in engineering projects. The high-precision characteristics of geologic radar should be studied in connection with fine processing and interpretation. This article discusses such issues as (1) geologic radar noise source and (2) fine processing and interpretation of radar data. It is focused on how to achieve fine processing and interpretation.

Preparation of Well Dispersed and Ultra-Fine Ce(Zr)O_2 Mixed Oxide by Mechanochemical Processing

Ultra-fine CeO_2-ZrO_2 mixed oxide was successfully synthesized by wet-solid phase mechanochemical processing, Ce_2(CO_3)_3·8H_2O, ZrOCl_2·xH_2O and ammonia were used as reactants. It is found that the crystalline Ce_2(CO_3)_3·8H_2O and ZrOCl_2·xH_2O are changed to amorphous cerium and zirconium hydroxide precursor after milling with ammonia, and Ce_(0.15)Zr_(0.85)O_2 mixed oxide with pure tetragonal phase structure and medium particle size(D_(50))less than 1μm is formed by calcining precursor over 673 K. The XRD patterns indicate that the crystal unite size increases with rising calcining temperature due to crystal growth. However, the particle size and BET surface area of the Ce(Zr)O_2 mixed oxide decreases with rising calcining temperature, which may be attributed to the contract of particles and the vanish of holes inside grains.

Preparation of Strontium Bismuth Tantalum (SBT) Fine Powder by Sol-Gel Process Using Bismuth Subnitrate as Bismuth Source

Strontium bismuth tantalum (SBT) fine power was prepared by Sol-Gel method. Pentaethoxy tantalum, strontium acetate and bismuth subnitrate were used as raw materials, and were dissolved in proper order in ethylene glycol to form transparent sol. The mixed precursor was dried at 80℃ and annealed at 800℃ for 1 h. Crystallized nanometer sized SBT fine powder was obtained and characterized by XRD.

Effect of milling process on the core-shell structures and dielectric properties of fine-grained BaTiO_3-based X7R ceramic materials

Fine-grained BaTiO3-based X7R ceramic materials were prepared and the effects of milling process on the core-shell structures and dielectric properties were investigated using scanning electron microscope, transmission electron microscope, and energy dispersive spectroscopy （EDS）. As the milling time extends, the dielectric constant of the ceramics increases, whereas the temperature coefficient of capacitance at 125℃ drops quickly. The changes in dielectric properties are considered relevant to the microstructure evolution caused by the milling process. Defects on the surface of BaTiO3 particles increase because of the effects of milling process, which will make it easier for additives to diffuse into the interior grains. As the milling time increases, the shell region gets thicker and the core region gets smaller; however, EDS results show that the chemical inhomogeneity between grain core and grain shell becomes weaker.

AGGREGATE STRUCTURE OF FINE POWDER AND COMPACTION PROCESS

Compacting process of fine powder is greatly affected by the aggregate structure of particles. According to the experiment in which several kinds of silicon nitrides in different partical shape and size were compacted in uniaxialorientation, it is found that the volume compacting rate offorming body differs with the pressure. The aggregatestructure of each sample A, B or C was estimated by applying Cooper's equation to the analysis of the compacting process of each sample

Fine analysis on advanced detection of transient electromagnetic method

Fault fracture zones and water-bearing bodies in front of the driving head are the main disasters in mine laneways,thus it is important to perform their advanced detection and prediction in advance in order to provide reliable technical support for the excavation.Based on the electromagnetic induction theory,we analyzed the characteristics of primary and secondary fields with a positive and negative wave form of current,proposed the fine processing of the advanced detection with variation rate of apparent resistivity and introduced in detail the computational formulae and procedures.The result of physical simulation experiments illustrate that the tectonic interface of modules can be judged by first-order rate of apparent resistivity with a boundary error of 5%,and the position of water body determined by the fine analysis method agrees well with the result of borehole drilling.This shows that in terms of distinguishing structure and aqueous anomalies,the first-order rate of apparent resistivity is more sensitive than the secondorder rate of apparent resistivity.However,some remaining problems are suggested for future solutions.

提升埋线工艺精细线路制作的能力

随着电子产品趋向轻、薄、小发展,线路设计日益精细,布局更加复杂,因此,埋线工艺备受关注。在埋线工艺制作过程中,主要难点在于精细线路的制作及基板的双面闪蚀。为提升埋线工艺中精细线路制作能力,进一步展开研究。结果表明,通过选择高解析度和强附着力的干膜,结合最优曝光能量、超粗化层压前处理及线宽补偿技术,采用双面不对称分步闪蚀法,对闪蚀工艺展开研究,解决了埋线工艺中不对称铜厚闪蚀的问题。另外,探索最优工艺条件,最终成功制作了线宽/线距为6/6μm的埋线工艺精细线路。

Liquid Phase Behavior during Elevated Temperature Deformation of the Fine-Grained 5083 Al Alloy

The liquid phase behavior of the fine-grained 5083 AI alloy obtained through thermomechanical process was investigated during the tensile tests in a temperature range of 380-570℃ and strain rate range of 4.17× 10^-4- 1.0× 10^-2 s^-1. The maximum elongation 530% of the fine-grained 5083 AI alloy was obtained at 550℃ and 4.17× 10^-4 s^-1. Fracture analysis by scanning electron microscopy （SEM） indicated that the formation of filament （formed by liquid phase） was greatly affected by the tensile temperature and strain rate. The results also showed that the optimum morphology of formed filament was obtained at 550℃ and a strain rate of 4.17× 10^-4 s^-1. The effect of liquid phase on superplastic deformation of the alloy was further discussed.

Influence of fabricating process on microstructure and properties of spheroidal cast tungsten carbide powder

A super-high temperature furnace was developed to fabricate spheroidal cast tungsten carbide powder with excellent flowability and fine feathery structure in a large scale. Optical microscope and scanning electron microscope were taken to characterize the morphology and microstructure of cast tungsten carbide powder. X-ray diffractometry was used to analyze the phase composition of powders involved. It is found that the carbon potential in the furnace and feeding speed play an important role on the microstructure, morphology and properties of the spheroidal cast tungsten carbide powder. As carbon potential is between 0.3% and 0.9% in the furnace, cast tungsten carbide powder with hardness over 2800(HV0.5), flowability over 7.1 s/50 g and tap density over 10.3 g/cm3 is obtained.

Methods for Improving Volume Stability of Steel Slag as Fine Aggregate

Suitable methods for enhancing the volume stability of steel slag utilized as fine aggregate were determined. The effects of steam treatment at 100 ℃ and autoclave treatment under 2.0 MPa on the soundness of steel slag sand were investigated by means of powder ratio, linear expansion, compressive and flexural strength. DTA, EDX, XRD and ethylene glycol methods were employed to analyze both the treated slags and susceptible expansion grains. Experimental results indicate that powder ratio, content of free lime and rate of linear expansion can express the improvement in volume stability of different treated methods. Steam treatment process cannot ultimately prevent specimens from cracking and decrease of strength, but mortar made from autoclave treated slag keeps integration subjected to hot water of 80℃ until 28 d and its strength do not show significant decrement. The hydration of over-burn free lime and periclase phase are the main cause for the disintegration or crack of untreated and steam treated steel slag＇s specimens. Autoclave treatment process is more effective than steam treatment process on enhancement of volume stability of steel slag.

基于系统因素作用理论的轨道加氢站Fine Kinney风险评估方法

由于液态氢能源燃料具有高能量密度优势,在轨道交通运输中有望得到广泛应用。考虑到液态氢能源在加注或运输环节具有潜在风险性,提出了轨道交通加氢站风险评估模型,在Fine Kinney框架中应用因素相互作用理论,对风险指数进行多层次评估。在案例分析中,对佛山市某加氢站的风险指数进行科学评估,确保加氢站全过程全态势的运行安全。结果表明:氢能不稳定特性与周边较为频繁流动车辆和人员,给轨道交通加氢站带来一定的安全风险,在加氢站运营过程中应高度关注。

Ideas for Accelerating Development of Deep Processing Industry of Agricultural Products--A Case Study of Nanchong City

In order to provide certain references for further deepening the development of processing industry of agricultural products,this paper analyzed and elaborated the basic principles,construction priorities and safeguard measures of the development of deep processing industry of agricultural products in Nanchong City of Sichuan Province. Besides,it made a scientific planning for accelerating the deep processing of agricultural products in Nanchong City in 2018-2020,to ensure the full implementation of fine and deep processing of agricultural products.

STUDY ON THE DIGESTION PROCESS OF ASF-AQ WHEAT STRAW PULP

A study on alkaline sulfite anthraquinone pulping of wheat straw indicated that the addition of formaldehyde could improve fine pulp yield effectively, enhance brightness of unbleached pulp, and decrease kappa number. Finally, the optimum conditions of this process were formed.

Synthesis and Characterization of Ultra-fine Cr_2O_3 from Hydrogen Reduction of K_2CrO_4

As a part of the green process for manufacturing chromium compounds, two steps are involved in the synthesis of ultra-fine Cr2O3 powders： the first is the hydrogen reduction of K2CrO4 into intermediate trivalent （Cr^3＋） or tetravalent （Cr^4＋） chromium compounds; the second is the decomposing of the intermediate into Cr2O3 by heat treating. The intermediate is well characterized by means of SEM, XRD, and XPS. The possible reaction mechanism of the process is analyzed.

基于Fine Kinney和Dematel理论的城市火灾风险评估

基于Fine Kinney和Dematel风险评估理论,运用AHP层次分析法,建立了城市消防灾害风险评估框架。通过对灾害种类相似度、灾害环境暴露度和灾害后果概率进行评估,提出了城市消防灾害风险评估模型与步骤,确定灾害风险评估等级。以哈尔滨市某大型商场建筑为研究对象,对其火灾风险指数和火灾风险等级进行评估。

镍钼矿选矿工艺分析

镍钼矿选矿是有价元素提取的关键过程,会为后续矿产资源开发奠定基础。本案例中的镍钼矿中镍含量为0.52%、钼含量0.74%,呈现出集合产出形态。为实现对矿产资源的良好开发,按照工艺流程脱质后,将CMC作为抑制剂,使用浮选工艺处理,选矿实验得到的镍、钼回收率,分别为81.22%、72.55%,有利于降低后续矿产焙烧投入的成本,提高镍钼矿冶炼效率。

MO捕收剂对煤气化细渣浮选性能的影响

这是一篇矿物加工工程领域的文章。煤气化细渣的综合利用是现阶段的一大发展方向。煤气化细渣孔隙发达且含氧基团丰富,使得煤油等传统捕收剂难以回收其中的残炭。将油酸甲酯和煤油复配得到的药剂MO进行浮选实验,并通过激光粒度仪、红外光谱分析、接触角分析、XPS分峰拟合等手段进行机理探讨。结果表明,当MO药剂用量提高到16 kg/t时,尾矿烧失量降低到7.12%,可燃体回收率超过95.63%。MO药剂引入了极性基团酯基,其可以降低煤油表面的界面张力,增强捕收剂在水中的分散作用,从而增加残炭颗粒与捕收剂液滴的接触面积与碰撞概率,进而提高残炭颗粒的疏水性和可浮性。通过接触角分析不同药剂作用下残炭表面的疏水性,解释其与精矿产率的关系。通过XPS分析说明,MO与残炭表面的含氧官能团作用,能够在残炭的亲水位点形成有效的覆盖层,使得疏水部分朝外,降低了水化作用,增加了接触概率,增加该煤气化细渣的表面疏水性。MO药剂的使用为煤气化固体废弃物的综合利用提供了一种新途径。

以对比学习与时序递推提升摘要泛化性的方法

为了有效缓解基于交叉熵损失函数训练的传统文本摘要模型所面临的推理过程中性能下降、泛化性较低、生成过程中曝光偏差现象严重、生成的摘要与参考摘要文本相似度较低等问题,提出了一种新颖的训练方式,一方面,模型本身以beamsearch的方式生成候选集,以候选摘要的评估分数选取正负样本,在输出的候选集中以“argmax-贪心搜索概率值”和“标签概率值”构建2组对比损失函数;另一方面,设计作用于候选集句内的时序递推函数引导模型在输出每个单独的候选摘要时确保时序准确性,并缓解曝光偏差问题。实验表明,所提方法在CNN/DailyMail和Xsum公共数据集上的泛化性得到提升,Rouge与BertScore在CNN/DailyMail上达到47.54和88.51,在Xsum上达到了48.75和92.61。

纤维再生微粉泡沫混凝土的配合比设计及制备研究

为解决再生微粉应用受限问题,提高资源化利用率,分析研究水灰比、发泡剂、掺合料、外加剂及纤维等因素对现有普通泡沫混凝土的影响规律,提出基于再生微粉的微活性和填充性,采用再生微粉部分取代水泥,通过物理发泡法制备纤维再生微粉泡沫混凝土,阐述新型纤维再生微粉泡沫混凝土配合比设计及制备工艺流程。

微细粒矿物浮选颗粒−气泡碰撞的湍涡作用机理及过程强化

微细矿物分选一直是困扰业界的难题,浮选是分选细粒矿物的主要方法,微细粒矿物质量小、惯性低、动能低,遇气泡易随流线绕流气泡而过,难以摆脱流线与气泡发生接触,与气泡的碰撞概率极低,是导致微细颗粒浮选回收困难的重要原因之一。强湍流流动因能提高颗粒动能以及颗粒−气泡碰撞频次,成为微细粒浮选的必要条件,然而,受制于湍流高频脉动及多尺度涡特征,颗粒、气泡在湍流环境中的运动及矿化过程与层流中差异极大,碰撞机理并不明晰。利用高频粒子图像测速技术(Particle Image Velocimetry,PIV)和高速显微摄像技术测量了各向同性湍流场中流体、颗粒及气泡的微尺度动力学行为,借助小波变换等数学手段,对湍流场的多尺度涡特性进行数学分解,从微观湍流层面解析了湍流小尺度涡运动对颗粒、气泡运动及碰撞过程的影响规律。研究发现:湍流场中微细颗粒运动受制于湍流小尺度涡运动,两者尺度具有相关性,在研究尺度范围内,流场所能够产生的Kolmogorov涡尺度越接近颗粒尺寸,颗粒滑移速度越大,颗粒摆脱流线与气泡发生碰撞的可能性越大;湍涡也会短暂“捕获”气泡且并影响气泡速度及轨迹;与常规碰撞矿化认知不同,大多颗粒在随流场主流宏观运动的过程中,局部跟随微观小尺度涡旋转,气泡在高涡量区内随涡体旋转且自转过程中裹挟颗粒,通过剪切碰撞的方式与颗粒发生矿化。基于此,提出了冲击流、涡流发生器等高涡量小尺度涡场的构涡方法,使浮选流场湍涡运动能有效作用到微细尺度颗粒上,提高微细颗粒−气泡碰撞概率,降低浮选有效回收粒度下限;不同类型纯矿物及实际矿物的浮选试验表明,通过对流场的湍涡调控,切实有效提高了微细矿物颗粒的浮选性能。研究将微细粒矿物浮选的过程强化从“调粒/调泡/调药”扩展到“调涡”,为低品质贫杂难选矿产资源的强化回收提供了新的思路和方法。