石墨电极的超声波检测

用超声波透射制品,测得超声波在制品中的穿透速度,是检测制品质量的无损检测方法之一。为了确定声速与电极炼钢单耗的关系,用振荡频率为６０ｋＨｚ,声速测量相对误差为１．５％的УК－１４П型超声波检测仪对Φ４００、Φ５５０和Φ６１０ｍｍ石墨电极进行分选,然后将合格品和条件废品两个等级电极分别在伏尔加格勒的一家冶炼厂进行炼钢试验。试验表明,测得声速值大的电极,炼钢单耗低;测得声速值最差的电极使用中折断最多。证明用超声波测电极声速是评价电极质量的可靠方法。表２参４石墨电极的超声波检测@李玉丹     

超声波在聚合物浓度检测中的应用

利用超声波检测溶液浓度方法,通过大量实验研究,对不同浓度、不同温度的聚合物溶液进行检测。明确了超声波声速与聚合物溶液浓度存在一定的函数关系。并进一步分析了影响超声波检测聚合物溶液浓度的影响因素。通过超声波频率优选、检测探头长度优化以及温度补偿等试验,提出了超声波检测聚合物溶液浓度的新方法。并在矿场得到了很好的验证。     

沥青混合料的超声波强度检测

根据超声波检测的基本原理对沥青混合料长方体试件进行了强度检测,并对超声波检测的影响因素进行了理论分析.结果表明:超声波的声速与沥青混合料强度之间具有良好的相关性,可以很好地预测沥青混合料的强度.     

炭制品的均质质量与超声波声速检测

分析了炭制品的均质结构及其影响因素，概述了超声波在炭制品中的传播情况及在炭制品均质结构检测中特点。介绍了独联体国家利用超声波声速对石墨电极进行检测的情况。     

RMA预计2006年美国轮胎产量下降

美国休珀（Huber）32程材料公司从2007年1月1日起，将其工业用碳酸钙（包括橡胶级碳酸钙）的售价上调7％-10％。具体调价幅度依购买的批量大小、品种和等级而异。但是，食品级和药用级碳酸钙，不在此次调价范围内。     

聚天冬氨酸复配物及其阻垢缓蚀性能

通过合成丙烯酸-丙烯酸乙酯-衣康酸（AA-AE-IA）三元共聚物阻垢分散剂,开发出一种具有优良阻垢分散和缓蚀性能的新型聚天冬氨酸复配物（PASP＋AA-AE-IA＋PBTCA）,考察了不同条件下聚天冬氨酸复配物对碳酸钙和硫酸钙的阻垢性能。利用扫描电子显微镜对碳酸钙晶型进行了分析,结果表明：聚天冬氨酸复配物可使碳酸钙晶体发生明显的扭曲现象,碳酸钙结晶更加细小分散。     

乳化液浓度超声波在线检测技术的研究

介绍了一种基于超声波技术的乳化液浓度在线检测技术,通过检测超声波的传播速度和乳化液的温度,并利用乳化液浓度、温度和超声波声速三者之间的曲线拟合关系,来实现乳化液浓度的在线连续监测,为实现乳化液的自动配比奠定了坚实的基础。     

应用超声技术测定三聚甲醛在二氯乙烷溶剂中的浓度

<正>1前言 三聚甲醛生产过程中溶于二氯乙烷溶剂中的浓度变化于30％～40％间,此浓度变化对三聚甲醛生产的产量、质量、能源的消耗以及溶剂的周转消耗等技术经济指标都有直接的影响.三聚甲醛浓度的在线检测是其生产工艺及控制的一项难题. 国内外对液体浓度的超声检测已有报道”’.Povey等用声速测定牛奶中的脂肪浓度’“,并.研制了测定悬浮液浓度的超声探头”’.novev’‘’研究了经过固化的油脂中的超声传播特性·Yasunaga”‘、Zacharias”’和 Steele”‘也曾利用超声波测定液体的浓度.但迄今尚未见用超声波方法检测三聚甲醛-二氯乙烷溶液浓度的报道. 本文通过一套由PC286微机控制的超声波测量仪”’,测定了浓度为0％～48％、温度为0～40℃的三聚甲醛和二氯乙烷混合液的超声波声时,计算了超声波声时、温度和浓度间的相互关系,为三聚甲醛浓度的超声在线检测提供了依据.利用三者关系制成的超声波三聚甲醛浓度在线检测仪经在上海溶剂厂生产流程中1年多运行,取得了良好的测量效果,精度优于0.5％.2 测量原理2.1 超声波脉冲回波法 液体中沿X方向传播的超声平面波的波动方程为 护钉2尸一V’护钉拙’（1）超声波在液体中的传播速度 v一④（2） 液体的浓度、温度和压强的变化会引起液体体积弹性模量和密度的变     

聚氯乙烯／弹性体／纳米碳酸钙复合材料性能研究

用熔融共混法制备了聚氯乙烯／弹性体／纳米碳酸钙复合材料，其中弹性体为一种改性的苯乙烯-丁二烯-丙烯腈共聚物Blendex（BLENDEX（r）338）。透射电镜观察显示纳米碳酸钙在聚合物基体中分散良好。性能测试表明，纳米碳酸钙可以提高复合材料的缺口冲击强度、弯曲模量、维卡软化点、储能模量和玻璃化转变温度，但是复合材料的屈服强度、断裂伸长率以及热分解温度降低。     

超声波合成β-烯胺酯

β-烯胺酯（2）是合成生物活性肽和小分子药物的重要中间体，可以从β-酮酸酯与胺（或铵）反应制得。传统的合成方法是在室温或回流条件下进行。本文采用超声波合成技术，以3-氨基-2-丁烯酸乙酯（2a）的合成为模型反应，探讨了超声波法合成2的最佳工艺条件。与传统的合成方法比较，超声波法操作简单，收率高，并显著地缩短了反应时间。     

Possibilities of using the ultrasonic wave transmission method to estimate initial setting time of cement paste

In this paper, the applicability of the ultrasonic wave transmission method to estimate the initial setting time of an arbitrary cement paste is discussed. Ultrasonic pulse velocity measurements were fully automated and measured continuously. The Vicat Needle Test was used in order to determine the initial setting time of cement pastes. Different cement pastes were prepared in order to check the influence of the water/cement ratio, type of cement, curing temperature, cement fineness, and some clinker compositions, on the relationship between the initial setting time and ultrasonic pulse velocity. It was found that the initial setting time of an arbitrary cement paste can be estimated very accurately by the time the first inflection point appears on the ultrasonic pulse velocity curve. Moreover, it can be estimated quite accurately by the time the ultrasonic pulse velocity reaches a fixed value, close to the value of the ultrasonic pulse velocity in water.     

超声波气升式反应器内声压的测定

测定了在空气—水和空气—羧甲基纤维素水溶液体系中 (羧甲基纤维素含量 :2g/L)超声波气升式反应器声压随轴向位置、表观气速、黏度和超声电功率的变化。测定结果表明 ,小气速下声压在气升式反应器内的轴向分布与离开超声探头的距离有关 ,距离越远 ,声压越小 ;与气速的大小有关 ,气速越大 ,声压越小 ;与液体的黏度有关 ,黏度越大 ,声压越小 ;超声电功率越大 ,声压越大。     

Ultrasonic Velocity Technique for Nondestructive Quantification of Elastic Moduli Degradation during Creep in Silicon Nitride

The ultrasonic velocity technique was used for nondestructive quantification of creep damage during interrupted tensile creep tests at 1400°C in an advanced silicon nitride to investigate the possibilities of this technique for creep damage monitoring in ceramic components. The longitudinal and shear wave velocities, Poisson's ratio, and Young's, shear, and bulk moduli linearly decreased with strain. Precise density change measurements indicated a linear relationship with a coefficient of proportionality of 0.69 between the volume fraction of cavities and tensile strain. Cavitation was identified as the main creep mechanism in the studied silicon nitride and the reason for ultrasonic velocity and elastic moduli degradation. The measurement of just the longitudinal wave velocity changes was found to be sufficient for quantification of cavitation during creep. The capability of the ultrasonic velocity technique for simple, sensitive, and reliable nondestructive monitoring of creep damage during intermittent creep was demonstrated in silicon nitride.     

Ultrasonic velocity and attenuation of polymeric solids under oscillatory deformation: Apparatus and preliminary results

A new apparatus has been constructed in which ultrasonic velocity and attenuation coefficients can be measured under oscillatory deformation. Using this apparatus, dynamic ultrasonic parameters were obtained with sufficient accuracy to investigate plastic deformation directly. It is found that this method has potential as a new tool for the study of solid polymers during deformation.     

生漆及其掺杂物质中超声波传播速度的测定

在22℃时,采用脉冲法测定了生漆的超声波传播速度为1550m/s,衰减系数分别为6.3dB/cm。同时测定了桐油、机油和水的超声波速度。并把桐油、机油、水分别按不同的比例与生漆混合,测其超声波传播速度的变化。结果为不同物质按相同比例混入生漆中其声速不同,同一种物质按不同的此例与生漆混合其声速也不相同。     

Experimental Study on the Hydrodynamics and Mass Transfer Characteristics of Ultrasonic Loop Airlift Reactor

The promoting effect of ultrasonic wave on the hydrodynamics and mass transfer characteristics of the loop airlift reactor was studied. The gas holdup, liquid circulation velocity, mixing time and overall volumetric mass transfer coefficient were examined and compared, with and without ultrasonic wave in the reactor. The experimental results show that ultrasound has almost no notable effect on the gas holdup, but has a tendency to decrease gradually the liquid circulation velocity and increase the overall volumetric mass transfer coefficient; and the effect on the mixing time is relatively complex. At low superficial gas velocity, the low powered ultrasound promotes the radial mixing of fluid; with the ultrasonic power increasing, ultrasonic vibration obstructs the axial mixing of fluid. Moreover, the effect of ultrasonic wave on the mixing time gradually decreases with the increase in the superficial gas velocity. Therefore there exists an optimal ultrasonic power for hydrodynamics and mass transfer. Correlations were also proposed for the hydrodynamics and mass transfer characteristics of the reactor.     

超声处理对芳纶Ⅲ性能的影响研究

为了改善芳纶Ⅲ的表面状态,以二甲基乙酰胺(DMAc)为超声介质,对纤维进行超声处理,研究了超声处理速率和超声波功率对纤维性能的影响。结果表明:超声处理后,纤维的强度和模量随着超声波功率的增大而下降;超声波处理速率越慢,处理时间越长,纤维的强度和模量下降越明显,纤维表面沟壑越深,比表面积明显增大;纤维拔出强度随超声波功率和超声处理速率的增大而先增大再减小。     

Correlation between Surface Area Reduction and Ultrasonic Velocity in Sintered Zinc Oxide Powders

Specific surface area and longitudinal wave ultrasonic velocity were measured in zinc oxide (ZnO) powder compacts partially sintered to different pore fractions ( P ). A linear correlation was observed between the reduction in surface area and the increase in ultrasonic velocity at all P up to the onset of pore closure. During the initial stage of sintering, the ultrasonic velocity increased by as much as 300%, with negligible reduction in P , whereas during the intermediate stage, the surface area reduction was accompanied by increasing ultrasonic velocity and decreasing P . During the final stage of sintering, the pores closed and became isolated. The linear relation between the reduction in surface area and the increase in longitudinal wave velocity encompassed the entire range of porosity from completely unsintered to the onset of pore closure, thus spanning the transition from initial- to intermediate-stage sintering. Ultrasonically inferred surface areas were used to evaluate the kinetics of the initial stage of sintering, and the results compared favorably with previously published values.     

Effect of new additives on the ultrasonic attenuation and mechanical properties of styrene–butadiene rubber

The change in attenuation of longitudinal ultrasonic waves has been measured as a function of frequency and temperature for styrene–butadiene-rubber (SBR) mixed with Ismacorr 141 as plasticizer and antioxidant. Analysis of the results showed relaxation processes and the activation energies for these processes were calculated and found to be related to the plasticization of samples. Also the velocity of the ultrasonic longitudinal waves through different samples was measured. The effect of Ismacorr 141 on the physical and mechanical properties of SBR was also studied.     

超声空化对污垢沉积特性影响的数值研究

在超声波防垢过程中，超声波的传播以及空化效果会受到流体及超声波参数的影响，析晶污垢的沉积特性也会随之发生变化。对此，采用FLUENT数值模拟与实验参数相比对的方法研究了不同流体速度、超声波频率下超声空化对CaSO₄析晶污垢剥蚀的影响。结果表明：同频率条件下，增大流速超声空化对污垢的剥蚀效果减弱；同流速条件下，增大超声波频率超声空化对污垢的剥蚀效果减弱。将空化效应引起的剥蚀率代入污垢的沉积过程，得到超声波频率对污垢沉积特性的影响，随着超声波频率的增加，污垢净沉积率增加、污垢热阻变大。