Study on removing calcium carbonate plug from near wellbore by high-power ultrasonic treatment

In this paper, the effects of ultrasonic wave on the removal of inorganic scaling and plugging in cores and the influence of the key wave field parameters, process parameters and core physical parameters on the plugging removal efficiency are systematically studied. The main dynamic mechanism of ultrasonic plugging removal is also systematically analyzed. Results show that the transducer frequency, transducer power, ultrasonic treatment time and initial permeability of core have great influence on the effect of ultrasonic scale removal. When the cumulative treatment time of ultrasonic wave exceeds 60 min, the recovery rate of core permeability tends to be stable. Best effect can be achieved when processing for 80–120 min cumulatively; the plugging removal effect is improved with the increase of ultrasonic transducer power and ultrasonic frequency, but the effect of plugging removal is not obvious with the further increasing of them. In addition, it is proved that the effect of removing calcium carbonate plug from near wellbore by hydrochloric acid solution is slightly better than that by ultrasonic treatment alone. Finally, the micro dynamic mechanism of removing inorganic scale plug by high-power ultrasonic treatment is discussed in view of ultrasonic inorganic scale body crushing, ultrasonic cavitation, ultrasonic friction, ultrasonic peristaltic transport operation and ultrasonic fracture-making and permeability-increasing effect.     

超声-硝酸联合法提取褐煤腐植酸工艺

实验考察了超声、硝酸预处理、酸化程度、碱液浓度、反应温度、液固比、反应时间等对腐植酸提取率的影响,并通过正交设计选择最佳预氧化条件和褐煤腐植酸的最佳提取条件.结果表明;超声硝酸联合氧化法提取腐植酸的最佳条件为：超声频率80kHz,氧化温度50℃,硝酸液固比（mL/g）为5∶1,氧化时间90min,硝酸浓度1.5mol/L.     

Spatiotemporal measurement using L-band ESR-CT system for water sonolysis in the presence of 1-Hydroxy-2,2,5,5-tetramethyl-3-imidazoline-3-oxide

When using ESR to measure the radicals generated by ultrasound, it is necessary to extract a solution and place it in the ESR system. To avoid this process, we incorporated an ultrasonic reaction cell in an L-band ESR-CT system, producing a system that allows the detection of the concentration of radicals during ultrasonic irradiation. This system was used to measure the time and space dependences of OH radicals generated by ultrasonic irradiation. When a 10 ml aqueous solution of 1-hydroxy-2,2,5,5-tetramethyl-3-imidazoline-3-oxide (HTIO) was irradiated with ultrasound, it was found that the generation of radicals was clearly shown in a CT image after a period of 10 min. It was also found that continued irradiation resulted in an increased concentration of radicals. In addition to this system, an X-band ESR system was also used to measure the concentration of OH radicals generated, and the results of both systems were then compared. Both results are very similar, showing that the proposed system, which was realized by incorporating an ultrasonic irradiation cell in the L-band ESR-CT system, operated properly. Because this system allows the measurement of sonochemical reactions in an opaque cell or an opaque solution such as blood and industrial wastewater, it is a very useful measurement system for achieving the applying of sonochemistry to the medical engineering field.     

聚丙烯酰胺水溶液的超声研究

浓的聚丙烯酰胺水溶液的切变粘滞系数是如此之大,以致按经典声吸收理论超声振动在其中根本不能传播。但我们用11.4兆赫兹的超声做实验,却发现它的吸收系数具有同水一样的数量级。本文从这类溶液分子结构的特点出发,对实验与理论之间的严重分歧做了定性讨论。对丙烯酰胺水溶液超声吸收随浓度的变化关系也做了测量。比较这两种水溶液超声吸收的实验结果,可以认为聚丙烯酰胺溶液中过量的超声吸收来自于大分子本身的特性行为。对这两种溶液的超声传播速度和密度也做了测量,并由所测数据计算了溶液绝热压缩系数的浓度曲线。结果表明,溶质分子中某些原子基因不管是处在聚合物状态还是处在小分子物质中,它们在水溶液中均表现出完全同样的水化作用。 关键词：     

Effect of ultrasound power on HCl leaching kinetics of impurity removal of aphanitic graphite

This study aimed to investigate the effect of ultrasonic power and temperature on the impurity removal rate during conventional and ultrasonic-assisted leaching of aphanitic graphite. The results showed that the ash removal rate increased gradually (∼50 %) with the increase in ultrasonic power and temperature but deteriorated at high power and temperature. The unreacted shrinkage core model was found to fit the experimental results better than other models. The Arrhenius equation was used to calculate the finger front factor and activation energy under different ultrasonic power conditions. The ultrasonic leaching process was significantly influenced by temperature, and the enhancement of the leaching reaction rate constant by ultrasound was mainly reflected in the increase of the pre-exponential factor A. Ultrasound treatment improved the efficiency of impurity mineral removal by destroying the inert layer formed on the graphite surface, promoting particle fragmentation, and generating oxidation radicals. The poor reactivity of hydrochloric acid with quartz and some silicate minerals is a bottleneck limiting the further improvement of impurity removal efficiency in ultrasound-assisted aphanitic graphite. Finally, the study suggests that introducing fluoride salts may be a promising method for deep impurity removal in the ultrasound-assisted hydrochloric acid leaching process of aphanitic graphite.     

Investigation on damage of DNA molecules under irradiation of low frequency ultrasound in the presence of hematoporphyrin-gallium (HP-Ga) complex

The interaction of deoxyribonucleic acid (DNA) and hematoporphyrin–gallium (HP–Ga) complex and the damage of DNA under ultrasonic irradiation in the presence of HP–Ga complex were studied by means of UV–vis spectrum, fluorescence spectrum and gelatin electrophoresis. In addition, some influence factors such as ultrasonic irradiation time, HP–Ga complex concentration, ionic strength and solution acidity on the damage of DNA were also considered. Under a certain condition, the damage degree of DNA was enhanced with increasing ultrasonic irradiation time, HP–Ga complex concentration and ionic strength. Whether the pH value was too high or too low, it would be disadvantage to the damage of DNA. Perhaps, these results would be significant for driving sonodynamic treatment (SDT) to the clinic application in the future.     

Simple quantification of ultrasonic intensity using aqueous solution of phenolphthalein

Aqueous phenolphthalein solution under sonication was investigated for use as a chemical dosimeter. The fading time of aqueous phenolphthalein solution under sonication depended on the concentration of phenolphthalein and the pH values of solutions. The fading time was correlated to the ultrasonic intensity in a reaction vessel that is estimated on the basis of decomposition of porphyrin. The relation between the fading time and the ultrasonic intensity for different frequencies is expressed by a single curve. From these results, it is indicated that aqueous solutions of phenolphthalein is useful for simple quantification of ultrasonic intensity for practical use, and one can regard it as one of the ultrasonic intensity indicators.     

Ultrasonic study of nitric acid

I.IntroductionBymeansofu1trasonicwavesthedynamicspecificpropertiesofmolecu1esinmediacouldbeapprehended.Fromthe195ostol96osacousticiansstudiedmo1ecu1aracousticandthermodynamicspecificpropertiesof1iquidsandmixtureswithgreate.th.siasm['-'],andkeptonbringto1ighttheirreportsofrc1evantstudiesinthe1astten-oddyearsl'-'l.overrecentyearstheauthorhasbeenengagedinthemeasurementandstudyofsoundve-locityofsevera1chemica1so1utionsinassociationwithu1trasonicmeasurementstudyofthecon-centrationofsolutionsproduce…     

盐酸掺杂聚苯胺薄膜的隐身性能

将本征态聚苯胺的N-甲基吡咯烷酮溶液浇铸在玻璃基板上,烘干脱去基板后得到自支持本征态聚苯胺薄膜,用HCl气体对薄膜进行掺杂,通过控制掺杂时间来控制掺杂浓度.红外反射率测试结果表明:在大气窗口内,掺杂浓度较低时,薄膜的红外反射率随着掺杂浓度的提高而增加;到达一定掺杂浓度后,反射率会随着掺杂浓度的提高有所降低,最终趋于稳定...     

超声法制备碳量子点发光性能的影响因素分析

超声法制备碳量子点过程简单,成本低廉,不易产生二次污染,应用前景广泛。为优化超声法制备碳量子点的各工艺参数,制备了关键工艺参数不同的碳量子点样品,测试其发射与激发光谱,分析了量子点浓度,溶剂种类,辅助剂种类、浓度,超声功率、时间等参数对碳量子点发光性能影响。结果表明超声法制备的碳量子点具有激发光波长依赖性,发射峰位置随激发波长的变化而发生明显改变;碳量子点浓度增加,发光强度由于非辐射能量传递和团聚作用,先增大后减小;由于溶剂效应,碳量子点在乙醇中比在水中发光强度更强,波长更短,且浓度越大时波峰移动越明显;相比盐酸,以NaOH为辅助剂制备的碳量子点表面钝化程度高,发光强度强;增加辅助剂NaOH浓度可提高量子点表面钝化程度,增大发光强度;同等时间下增加超声功率或同等功率下适量增加超声时间,可制备更多的碳量子点样品,但超声时间过长,碳量子点容易发生团聚猝灭现象。以上影响因素分析为超声法制备碳量子点的工艺参数优化提供了理论基础,有利于碳量子点大规模低成本的生产应用。     

Sonolytic degradation of acetic acid in aqueous solutions

In this work, ultrasonic degradation of acetic acid, which is one of the most resistant carboxylic acids to oxidize, was investigated. The effects of parameters such as ultrasonic power, initial concentration, addition of NaCl or several oxides were studied on the degradation of acetic acid. Acetic acid was sonicated indirectly using an ultrasonic bath with 40 kHz. It was observed that degradation degree increased with decreasing power and initial concentration and with increasing NaCl concentration. Initial degradation degree was enhanced with addition of zeolite and SiO(2).     

HG-AFS测定高纯碲中痕量硒干扰的消除

用HNO₃+HCl分解样品,采用Fe3+-柠檬酸混合溶液作抑制剂,研究了下氢化物发生-原子荧光光谱法测定痕量硒时的干扰及其机理,探讨了NO-₃和NO-₂残留的影响,并用正交试验设计结合单因素试验研究了不同浓度Fe3+盐、盐酸、柠檬酸、硼氢化钾等条件下Se的回收率。该方法的检出限为0.15 μg·L-1,样品中Se含量为27.01 μg·L-1的相对标准偏差在3.1%～4.2%之间(n=11),加标回收率为96.1%～102.3%。用于实际样品的测定,结果满意。     

电化学沉积金属铜的分形枝晶生长控制与性能

 以CuSO_{4/sub>为前驱体,HCl为添加剂,采用电化学沉积方法,在室温条件下制得了μm级、面心立方结构分形铜的枝状晶体,研究了铜离子浓度、硫酸浓度、电流密度、沉积时间、氯离子浓度等实验参数对分形枝状铜晶体尺寸、结构的影响。结果表明：硫酸的浓度对铜沉积物结构无明显影响;随着Cu^{2+/sup>浓度的不断增大,铜沉积物的分形效果越来越明显;增大电流密度（0.4～1.6 A·cm-2/sup>）,铜沉积物由致密向多分枝的开放型转变;延长沉积时间（大于等于5 min）,可获得含大量次级分枝铜的晶体;适当增加盐酸用量（0.05～0.20 mol/L）,铜沉积物枝晶尺寸显著减小。最后讨论了分形枝晶铜在碱性条件下氧化甲醇的电化学性能。}}     

Dependence of the threshold voltage in indium-phosphide pore formation on the electrolyte composition

Results of the experimental determination of the threshold voltage of pore formation for n-InP (100) crystals with a charge-carrier density of 2.3 × 10¹⁸ cm^?3 are presented. The threshold voltage of pore formation is shown to be a function of the electrolyte composition, in particular, of the acid concentration in the electrolyte solution. A 5% solution of hydrochloric acid is the most suitable etchant for obtaining high-quality porous indium phosphide films. It is possible to obtain a nanoporous layer that consists of pores 40 nm in diameter spaced by 5–10 nm. The porosity in this case is 45%.     

Kinetics of hydrazinium nitrate decomposition in nitric acid solutions under the effect of power ultrasound

The effect of ultrasound (f = 20 kHz) on the decomposition of hydrazinium nitrate was investigated in a nitric acid medium. The kinetics of N2H5+ decomposition and initial HN3 formation increase in a linear manner with the HNO3 concentration (from 1 to 6 M) and with the ultrasonic intensity (from 0.5 to 3.1 W cm-2). Both rates were equal to that of HNO2 formation in the absence of N2H5+, indicating that the N2H5+ decomposition mechanism is the same as observed without ultrasound between HNO2 and N2H5+. The variation of the steady-state HN3 concentration with the HNO3 concentration and the ultrasonic intensity suggests the existence of a nonexplosive HN3 thermal decomposition mechanism in the cavitation bubble under the effect of ultrasound. It was also observed at ultrasonic intensities exceeding 3.5 W cm-2 that the decomposition of HN3 led to the accumulation of NH4+ in solution.     

超声波在不同浓度NaCl溶液中传播速度的研究

利用超声波声速测定仪测定出超声波在不同浓度NaCl溶液中的传播速度.实验给出,超声波在NaCl溶液中的传播速度与溶液浓度呈线性关系.溶液温度对超声波波速也有影响,并从理论作了分析研究,给出了合理的解释.     

Pyridine–pyrazole compound as inhibitor for steel in 1 M HCl

The influence of 3,5-dimethyl-1H-pyrazole (P1), pyridine (P2) and 2-(3-methyl-1H-pyrazol-5-yl) pyridine (P3) on the corrosion inhibition of steel in molar hydrochloric acid solution is studied using weight-loss, potentiodynamic and EIS measurements. Results obtained shows that P3 is the best inhibitor and its inhibition efficiency increases with the increase of concentration to attain 89% since 10⁻³ M. Potentiodynamic polarisation studies clearly reveal that it acts essentially as a cathodic inhibitor. The inhibitor studied reduces the corrosion rates. E (%) values obtained from various methods used are in good agreement. Adsorption of P3 on steel surface has an S-shaped adsorption isotherm.     

基体溶液改进-原子荧光法测定食品中的汞

探讨改进基体溶液双道原子荧光光谱法测定食品样品中的汞。样品消解后用6mol/L盐酸、硫脲+抗坏血酸(50g/L)作为基体溶液进行仪器测定。本方法检出限0.051μg/g,最低检出质量浓度0.10μg/L,相对标准偏差为7.45%、6.76%,回收率为88.6%—113.2%。方法具稳定性好、灵敏度高、检出限低等优点。     

原子吸收法测定牦牛奶粉中的营养元素

通过改变灰化温度,灰化时间及盐酸浓度三因素设计正交试验,对样品牦牛奶粉及市售奶粉进行干法消化。用火焰原子吸收光谱法对样品中的Ca, Mg, Fe, Cu, Zn, Mn, K和Na等八种元素进行测定。实验表明,最佳消化条件为：灰化温度510 ℃,灰化时间4 h,盐酸体积比为1∶5。在最佳实验条件下,对牦牛奶粉各元素的含量做了回收实验,回收率范围在95.2%～107.3%,相对标准偏差0.38%～3.86%(n=6)。实验结果表明：牦牛奶粉营养元素含量丰富, 是营养价值极高的食品。     

TOPO－TBP萃淋树脂在盐酸、硝酸溶液中萃取铀、钍平衡常数的测定

本文测定了在盐酸、硝酸溶液中，ＴＯＰＯ－ＴＢＰ萃淋树脂萃取铀、钍的平衡常数，结果表明，在相同酸性溶液中，ＴＯＰＯ－ＴＢＰ萃淋树脂萃取铀、钍平衡常数与液－液体系基本一致。