Combined effects of ultrasonic vibration and FeCoNiCrCu coating on interfacial microstructure and mechanical properties of Al/Mg bimetal by compound casting

In this work,a new treatment method combining ultrasonic vibration with FeCoNiCrCu high entropy alloy(HEA)coating was used to prepared Al/Mg bimetal through the lost foam compound casting.The effects of composite treatment involving ultrasonic vibration and HEA coating on interfacial microstructure and mechanical properties of Al/Mg bimetal were studied.Results demonstrate that the interface thickness of the Al/Mg bimetal with composite treatment significantly decreases to only 26.99%of the thickness observed in the untreated Al/Mg bimetal.The HEA coating hinders the diffusion between Al and Mg,resulting the significant reduction in Al/Mg intermetallic compounds in the interface.The Al/Mg bimetal interface with composite treatment is composed of Al_(3)Mg_(2)and Mg_(2)Si/AlxFeCoNiCrCu+FeCoNiCrCu/δ-Mg+Al_(12)Mg_(17)eutectic structures.The interface resulting from the composite treatment has a lower hardness than that without treatment.The acoustic cavitation and acoustic streaming effects generated by ultrasonic vibration promote the diffusion of Al elements within the HEA coating,resulting in a significant improvement in the metallurgical bonding quality on the Mg side.The fracture position shifts from the Mg side of the Al/Mg bimetal only with HEA coating to the Al side with composite treatment.The shear strength of the Al/Mg bimetal increases from 32.16 MPa without treatment to 63.44 MPa with ultrasonic vibration and HEA coating,increasing by 97.26%.

Oncological safety of use of ultrasonic activated shears in gastric cancer surgery: Long-term results of randomized controlled trial

Objective： Ultrasonically activated shears （UAS） have been applied in open gastric surgeries with no or little evidence. It was previously reported about the surgical outcome and effectiveness of UAS based on a randomized controlled trial of 256 patients with gastric cancer. We aimed to clarify the long-term oncological safety of the use of UAS in the aspect of overall survival and recurrence.Methods： Gastric cancer patients who underwent gastrectomy with D2 lymph node dissection were enrolled and randomly assigned to either the conventional surgery group （n=125） or the UAS group （n=128）. Survival, recurrence and long-term postoperative complications were compared between the two groups. The median follow-up period was 56 months.Results： Gastric cancer-related death was higher in patients of the UAS group compared with the conventional group （P=0.019）. Overall survival rates stratified by stage were not significantly different between the two groups （P=0.170）. Disease-free survival rates stratified by stage and recurrence-free survival rates of gastric cancer were similar between the conventional group and the UAS group （P=0.313 and 0.199, respectively）. The postoperative complication rate was not significantly different between the groups （P=1.000）. Conclusions： It is suggested that the use of UAS in gastrectomy for gastric cancer showed oncologically acceptable safety compared with conventional electric instruments even in long-term period.

Relationship of ultrasonic shear wave velocity with oncogene and tumor suppressor gene expression in primary liver cancer lesions as well as angiogenesis factor contents

Objective:To discuss the relationship of ultrasonic shear wave velocity (SWV) with oncogene and tumor suppressor gene expression in primary liver cancer lesions as well as angiogenesis factor contents.Methods:100 patients with primary liver cancer who underwent surgical treatment in our hospital between March 2014 and September 2016 were collected as observation group, and 50 healthy subjects who received physical examination in our hospital during the same period were collected as normal control group. The ultrasonic SWV levels of two groups of subjects were measured before the operation, and the observation groups were further divided into high SWV group and low SWV group, 50 cases in each group. Intraoperative tumor tissue samples were kept and fluorescence quantitative PCR was used to determine the mRNA expression of oncogenes and tumor suppressor genes. Enzyme-linked immunosorbent assay was used to determine serum contents of angiogenesis factors in observation group before operation.Results:Hepatic ultrasonic SWV level in observation group was significantly higher than that in normal control group;proto-oncogene CK, Ki67, Gly-3, Survivin and Pokemon mRNA expression in tumor tissue of high SWV group were higher than those of low SWV group while tumor suppressor genes Tg737, p16, p27, PTEN and runx3 mRNA expression were lower than those of low SWV group;serum angiogenesis factors VEGF, MMP-9 and IGF-1R contents were higher than those in low SWV group. Conclusion: The hepatic ultrasonic SWV level increases in patients with primary liver cancer, and the SWV level is directly correlated with oncogene and tumor suppressor gene expression as well as angiogenesis factor contents.

Application of Piezoelectric Materials in a Novel Linear Ultrasonic Motor based on Shear-induced Vibration Mode

A novel linear ultrasonic motor based on d15 effect of piezoelectric materials was presented. The design idea aimed at the direct utilization of the shear-induced vibration modes of piezoelectric material. Firstly, the inherent electromechanical coupling mechanism of piezoelectric material was investigated, and shear vibration modes of a piezoelectric shear block was specially designed. A driving point’s elliptical trajectory induced by shear vibration modes was discussed. Then a dynamic model for the piezoelectric shear stator was established with finite element（FE） method to conduct the parametric optimal design. Finally, a prototype based on d15 converse piezoelectric effect is manufactured, and the modal experiment of piezoelectric stator was conducted with laser doppler vibrometer. The experimental results show that the calculated shear-induced vibration modes can be excited completely, and the new linear ultrasonic motor reaches a speed 118 mm/s at noload, and maximal thrust 12.8 N.

Microstructure and mechanical properties of Mg-to-Al dissimilar welded joints with an Ag interlayer using ultrasonic spot welding

Lightweight ZEK100-0 Mg alloy and A16022-T43 Al alloy with an Ag interlayer were joined via ultrasonic spot welding(USW),focusing on the microstructural change and tensile lap shear strength of the welded joints in relation to welding energy.Mg/Al interface was superseded by Mg/Ag and Al/Ag interfaces,and unfavorable Mg门A-intermetallic compound was eliminated.Ag foil was observed to be intact in the nugget center,while it was broken or dissolved at the nugget edge at high welding energy levels.The diffusion layer at the Mg/Ag interface consisted of two distinctive sub-layers:Mg3Ag intermetallic compound adjoining Ag foil,and Mg3Ag-l-Mg eutectic structure adjacent to Mg.Only a thin diffusion layer consisting mainly of Ag3Al occurred al lhe Al/Ag interface.The tensile lap shear strength first increased,reached its peak value,and then decreased with increasing welding energy.The shear strength achieved in the present study was〜31%higher than that of the joint without interlayer.Interfacial failure occurred at all energy levels,with Ag foil particles or fragments being stuck on both Mg and Al sides due to its intense interaction with Mg and Al via accelerated diffusion during USW.The results obtained pave the way for the challenging dissimilar welding between Mg and Al alloys.

Effect of Ultrasonic Vibration on Deformation in Micro-blanking Process with Copper Foil

Effect of ultrasonic vibration on deformation in micro-blanking was investigated with copper foils of different grain sizes using a developed device. It is found that maximum shearing strength is decreased by ultrasonic vibration, and this effect becomes bigger for coarse grain than that for fine grain, which can be attributed to acoustic softening effect considering the absorbed acoustic energy. Surface roughness R_a of smooth zone decreases for the polishing effect of vibration at the lateral contact surface. When ultrasonic vibration is applied, the sheared deformation area becomes relatively narrow, and it leads to the reduction of radius of rollover. The analysis of cross section in sheared deformation area shows that the crack initiation is inhabited for the existence of acoustic softening, and the proportion of smooth zone is increased. Also, angle of crack propagation becomes smaller because of periodic strain, and the angle of facture surface is decreased. As a result, the quality of micro-sheet parts is improved by applying ultrasonic vibration.

Effect of ultrasonic power and bonding force on the bonding strength of copper ball bonds

Copper wire, serving as a cost-saving alternative to gold wire, has been used in many high-end thermosonic ball bonding applications. In this paper, the bond shear force, bond shear strength, and the ball bond diameter are adopted to evaluate the bonding quality. It is concluded that the ef/~cient ultrasonic power is needed to soften the ball to form the copper bonds with high bonding strength. However, excessive ultrasonic power would serve as a fatigue loading to weaken the bonding. Excessive or less bonding force would cause cratering in the silicon.

光甘草定烟酰胺纳米乳的制剂评价与透皮吸收

为提高光甘草定和烟酰胺的透皮吸收性能,利用两种高能乳化法制备了纳米乳(HPH-NE和HSSU-NE),对其形态、粒径、Zeta电位、稳定性和皮肤渗透性能进行了评价与考察.结果表明:两种纳米乳颗粒均为规则球形,未见聚集现象,平均粒径分别为51.60 nm和42.98 nm,Zeta电位分别为-50.44 mV和-68.50 mV,并且在离心、4℃和20℃以及加速试验条件下均具有较好的稳定性,两种方法制成的纳米乳相对普通乳液具有更好的皮肤渗透性能,光甘草定的平均渗透速率提高3~5倍,烟酰胺的平均渗透率提高1.6~2.6倍,为光甘草定的纳米制剂以及化妆品应用研究奠定了坚实基础.

实时剪切波超声弹性成像在儿童疾病检查中的研究进展

实时剪切波超声弹性成像(SWE)作为超声医学领域的一种新的检查方法,通过声辐射力脉冲在组织不同深度上连续聚焦,反映组织绝对软硬度,已广泛应用于成人疾病检查中。目前SWE亦逐步应用于儿童相关疾病诊断,如脂肪肝、婴幼儿梗阻性黄疸、先天性胆总管囊肿、白血病弥漫性肝浸润等肝脏常见疾病,还应用于慢性肾病、新生儿缺氧缺血性脑病、先天性肌性斜颈及脑性瘫痪等其他儿科疾病中。

超声空化-流体剪切协同强化油团聚分选煤气化细渣

煤气化细渣(CGFS)具有较高的利用价值,但残炭回收率低极大地制约了其资源化利用。油团聚分选法在CGFS分选过程中具有明显优势,但炭灰共生结构严重限制了油团聚分选效率。为突破油团聚法分离富集残炭技术的瓶颈问题,考察了超声时间、超声功率、流体剪切时间及其交互作用对油团聚分选效果的影响,并结合BET、粒度分布、FT-IR、XPS以及SEM-EDS等分析手段,揭示了超声空化-流体剪切(UC-FS)协同预处理对油团聚分选效果的强化机理。结果表明:当超声功率为270 W、超声处理时间29 min、流体剪切时间23 min时,能分选得到灰分为9.55%的精矿、灰分为91.51%的尾矿,可燃体回收率可提高至90.54%。超声空化作用使原本致密的炭灰结构逐渐松散,与流体剪切的冲刷作用协同促进CGFS的孔隙结构的发展,使炭灰颗粒解离度增加,从而降低了精矿灰分。UC-FS协同预处理能够有效增加残炭表面C—C、C=C以及C—H等疏水基团的比例,使其接触角由110.34°增加到121.16°,扩大了炭和灰颗粒表面疏水性差异,提高了油团聚分选的效果。UC-FS协同预处理使炭灰颗粒高效分离的强化作用主要归因于超声空化气泡与细粒微球耦合产生的微磨料效应。可为实现CGFS分质资源化利用提供理论基础和技术指导。

基于COMSOL的剪切速率对超声波流量测量影响分析

为了分析影响超声波流量测量结果的因素,提高超声波流量测量的准确性,需要研究聚合物溶液剪切速率对于流体流态和超声波流量计接收声压的影响,利用多物理场有限元软件COMSOL建立超声波流量计三维模型进行仿真,通过流体域的背景流速曲线和超声波接收器波形图来分析剪切速率的影响。结果表明,在其他条件不变的情况下,随着剪切速率的增大流体流态趋向于湍流,超声波流量计接收器声压最大值与最小值相差1%,其对超声波流量计测量结果影响较小可忽略。

多模态超声在乳腺非肿块型病变鉴别诊断中的应用价值探析

目的 探析多模态超声在乳腺非肿块型病变鉴别诊断中的应用价值。方法 选择2022年3月—2023年3月本院收治的94例乳腺非肿块型病变患者为研究对象,对其进行常规超声、超声血流成像、超声弹性成像检查,以病理检查结果作为金标准,分析多模态超声(三者联合)在乳腺非肿块型病变鉴别诊断中的应用价值。结果 94例乳腺非肿块型病变患者经病理检查,其中41例确诊为乳腺癌,53例确诊为良性乳腺病变。常规超声、超声血流成像、超声弹性成像及多模态超声鉴别诊断乳腺非肿块型病变与病理检查的一致性kappa值分别为0.411、0.617、0.742、0.913。多模态超声检查鉴别诊断乳腺非肿块型病变的灵敏度为95.12%(39/41)、特异度为96.23%(51/53)、准确度为95.74%(90/94)、阳性预测值为95.12%(39/41)、阴性预测值为96.23%(51/53),高于单独的常规超声、超声血流成像、超声弹性成像的鉴别诊断结果,差异显著,具有统计学意义(P<0.05)。结论 多模态超声在乳腺非肿块型病变鉴别诊断中的应用价值较高,与病理结果的一致性较高,可提升诊断准确性。

超声剪切波弹性成像技术检测糖尿病患者不同功能状态下腓肠肌硬度及其临床意义

目的:应用超声剪切波弹性成像(SWE)技术检测2型糖尿病患者不同功能状态下腓肠肌的硬度,为临床早期发现骨骼肌损害提供客观化评价依据。方法:选取70例2型糖尿病患者作为糖尿病组,以70名健康体检者作为对照组。应用SWE技术分别测量2组研究对象腓肠肌在踝关节自然位松弛状态、踝关节跖屈位等张收缩状态和直立位等长收缩状态下的杨氏模量(E)值,并采用体质量指数(BMI)对E值进行标准化(E_(BMI)=E/BMI),比较2组研究对象腓肠肌不同状态下被动硬度和主动硬度的差异,采用Person相关性分析糖尿病患者E值与患者年龄、病程、糖化血红蛋白(HbA1c)水平和糖基化终产物(AGEs)水平的相关性。结果:2组研究对象腓肠肌在踝关节自然位被动硬度E值和E_(BMI)值比较差异无统计学意义(P>0.05);踝关节跖屈位主动硬度E值比较差异无统计学意义(P>0.05),糖尿病组患者E_(BMI)值组低于对照组(P<0.01);糖尿病组患者直立位主动硬度E值和E_(BMI)值均低于对照组(P<0.01)。糖尿病组患者腓肠肌主动硬度E值与患者病程、HbA1c水平和AGE水平呈负相关关系(r=-0.645,P<0.05;r=-0.741,P<0.05;r=-0.675,P<0.05),与患者年龄无相关性(r=-0.116,P>0.05)。结论:2型糖尿病患者存在腓肠肌主动硬度减低,被动硬度早期可能不受影响;采用超声SWE技术在直立位等长收缩状态下检测腓肠肌主动硬度有助于发现2型糖尿病患者亚临床阶段肌肉收缩功能减退。

超声波辅助复合蛋白酶对冬菜扣肉品质的影响研究

以冬菜扣肉为研究对象,为缩短传统冬菜扣肉加工过程的蒸制时间,减少经济能耗,确定冬菜扣肉的工业化生产,采用超声波和蛋白酶对冬菜扣肉的鲜肉进行预处理,以剪切力和感官评分为测定指标,利用响应面实验优化出超声波辅助复合蛋白酶的最佳工艺条件.结果表明:在复合蛋白酶(木瓜蛋白酶和菠萝蛋白酶)比例为2∶1,添加量为420 U/mL,嫩化温度为38℃,嫩化时间为33 min时嫩化效果最佳,冬菜扣肉的剪切力最小,感官评分最高.

二维超声剪切波弹性成像技术肝脏硬度测量在非酒精性脂肪性肝病疾病严重程度预测中的应用价值

目的 研究二维超声剪切波弹性成像技术(2D-SWE)肝脏硬度测量在非酒精性脂肪性肝病(NAFLD)疾病严重程度预测中的应用价值。方法 研究方法为回顾性分析,观察对象为2019年9月至2023年10月皖南医学院附属宣城市医院(宣城市人民医院)收治入院的122例NAFLD患者,设为研究组,并选取同一时期入院的122例健康体检者,设为对照组。两组研究对象均接受2D-SWE检查,比较肝硬度值。同时,参考脂肪性病变程度将研究组122例患者分为轻度组(n=63)与中重度组(n=59)。比较两组患者体重指数、生化指标[总胆红素、空腹血糖、高密度脂蛋白(HDL)、糖化血红蛋白(HbA1c)、甘油三酯、总胆固醇、低密度脂蛋白(LDL)],分析研究组2D-SWE硬度值与体重指数、生化指标的相关性,并分析2D-SWE硬度值对NAFLD严重程度的预测价值。结果 研究组患者的肝硬度值为(12.08±3.04) kPa,高于对照组[(6.98±2.93) kPa],差异有统计学意义(P<0.05)。中重度组肝硬度值为(12.28±3.07) kPa,高于轻度组[(8.39±2.76) kPa],轻度组、中重度组肝硬度值均高于对照组[(6.98±2.93) kPa],差异均有统计学意义(P<0.05)。中重度组患者的体重指数、空腹血糖、HbA1c、甘油三酯、总胆固醇、LDL水平分别为(31.12±4.34) kg/m^(2)、(6.24±0.76)μmol/L、(6.18±0.53) mmol/L、(3.16±0.58) mmol/L、(0.79±0.14) mmol/L、(3.26±0.75) mmol/L,均高于轻度组[(27.48±2.19) kg/m^(2)、(5.36±0.58)μmol/L、(5.27±0.36) mmol/L、(2.08±0.47) mmol/L、(0.61±0.13)mmol/L、(2.77±0.89) mmol/L],差异均有统计学意义(P<0.05)。经Pearson分析,研究组患者肝硬度与体重指数、空腹血糖、HbA1c、甘油三酯、总胆固醇、LDL均呈正相关(r=0.270、0.219、0.215、0.234、0.233、0.264,均P<0.05)。NAFLD程度预测中肝硬度值的受试者工作特征(ROC)曲线下面积为0.908,标准差0.025,P<0.01,95%置信区间(CI)为0.857~0.959。结论 NAFLD检查中2D-SWE肝脏硬度测量效果显著,肝脏硬度值与NAFLD密切相关,且可辅助预测患者疾病严重程度。

基于超声剪切波弹性成像与红热外成像技术探讨浮针治疗子宫腺肌病痛经的研究

目的基于超声剪切波弹性成像与红热外成像技术探讨浮针治疗子宫腺肌病痛经的效果。方法选取2021年1月至2022年12月广州中医药大学第一附属医院收治的84例子宫腺肌病痛经患者作为研究对象,按照随机数字表法分为对照组和观察组,每组42例。对照组予以常规药物治疗,观察组在此基础上予以浮针治疗。比较两组患者临床疗效、视觉模拟评分法(VAS)评分、COX痛经症状量表(CMSS)评分、弹性特征量测值及红外线热成像分布图。结果观察组患者总有效率(95.24%)高于对照组(78.57%),差异有统计学意义(P<0.05)。治疗前,两组患者VAS评分比较,差异无统计学意义(P>0.05);治疗第1个月经周期,观察组VAS评分低于对照组,差异有统计学意义(P<0.05)。治疗前,两组患者痛经症状持续时间、严重程度评分比较,差异无统计学意义(P>0.05);治疗第1个月经周期,观察组痛经症状持续时间、严重程度评分均低于对照组,差异有统计学意义(P<0.05)。治疗后,观察组标准偏差、应变均值、均等性、对比度低于对照组,观察组复杂度、蓝色区域所占百分比、峰度、偏度、杂乱性、相关性、一致性高于对照组,差异有统计学意义(P<0.05)。红外线热成像分布图显示,观察组高温区及分布减少程度优于对照组。结论浮针可以有效缓解子宫腺肌病痛经时间及严重程度,减轻患者疼痛,临床疗效及安全性较高。

单轴压缩下不同饱和度红砂岩横波特征研究

为了研究饱和度对岩石超声波横波传播规律影响,以红砂岩为研究对象,开展不同饱和度下入射频率分别为50、100、200 kHz的超声波横波传播实验,分析饱和度及入射频率对横波声学参数变化规律。结果表明:干燥至饱和状态,横波波速随饱和度增大呈非线性下降趋势,幅值衰减系数随饱和度增大呈非线性递增趋势,均满足三次函数关系,属于高度相关;整体分析发现横波波速受饱和度变化影响大于幅值衰减系数,幅值衰减系数拟合参数能较好反映岩样物理量的变化;基于敏感性及决定系数的综合考虑,建议今后采用100 kHz作为含水砂岩超声波横波测试优势频率。研究成果可为不同饱和度下岩石超声波测试技术发展提供参考。

Effect of Room Temperature Ultrasonic Vibration Compression on the Microstructure Evolution and Mechanical Properties of AZ91 Alloy

To investigate the potential of direct ultrasonic vibration on improving the performance of magnesium alloys,this study first employed the ultrasonic vibration compression(UVC)on the solid solution treated AZ91 alloy,and explored its microstructure evolution and mechanical properties under UVC.Within only two seconds,the UVC alloys showed large deformation strains of 34.8–54.4%,and sudden increase of sample temperature to 243℃.Microstructure characterizations proved that UVC promoted the formation of abundant shear bands,fine grains,and the bimodal distribution of Mg17Al12 precipitates consisting of submicron particles located within the shear bands and nano-sized ones within the matrix.Owing to the unique microstructure,the micro-hardness(and nano-hardness)value of UVC alloy was increased by 37.7%(35%)when compared with the solution-treated alloy.Moreover,the nano-modulus of the developed AZ91 alloy was also significantly increased to 62 GPa by statistical nanoindentation tests,which could be ascribed to increased Mg_(17)Al_(12) precipitates and decreased c/a value to some extent.In general,this work provides a new insight into the design and preparation of high-performance magnesium alloys by UVC at room temperature.

高温镁合金板材超声振动辅助剪切工艺参数优化与质量预测

目的为实现镁合金板材超声振动辅助剪切过程的工艺参数优化和质量预测,提出了一种多目标优化及决策方法,建立了多目标质量预测模型。方法综合考虑经济成本及断面质量等因素,确定了最大剪切力、塌角宽度和毛刺高度为剪切质量的评价指标。依据正交实验结果建立了剪切质量关于各工艺参数的数学响应模型并进行分析,采用改进的多目标灰狼优化(MOGWO)算法进行寻优,利用基于熵权-TOPSIS法对优化后的非支配解进行综合评价,获得了最优工艺参数解。最后基于多输入多输出最小二乘支持向量回归机(MLSSVR),以3个工艺参数为输入、3个评价指标为输出建立了剪切质量预测模型。结果在此范围内,最大剪切力和塌角宽度主要受剪刃间隙和超声振幅的影响,随剪刃间隙的增大而增大,随超声振幅的增大而减小;而毛刺高度则主要受板材温度的影响。在此基础上,根据剪切质量的数学响应模型确定最佳工艺参数为:板材温度为250℃、剪刃间隙为8%板厚、超声振幅为10μm。MLSSVR质量模型精度达95%以上,并且能综合考虑各工艺参数与各评价指标之间的影响,具有较高的预测精度和泛化能力。结论超声振动辅助剪切(UVS)可有效提高板材剪切断面质量,所提方法对于寻求最佳板材剪切工艺参数具有一定的参考价值。

基于PSO-SVM的点焊接头拉剪强度分类分析

点焊是汽车零部件的主要连接方式之一,点焊接头的拉剪强度是评价点焊质量的重要因素,论文在制备大量点焊试样的基础上,对各试样的焊点进行超声信号检测,并运用信号处理获得时域、频域和小波包特征值,随后对点焊试样在拉剪试验中的失效形式进行分析,建立点焊接头拉剪强度的分级标准.根据试验数据设计了BP(back-propagation)神经网络和基于粒子群优化支持向量机(particle swarm optimization support vector machine,PSO-SVM)的神经网络分类器,最后将试样的超声信号特征值作为输入参数,比较两种神经网络模型对点焊试样拉剪强度分类的准确率.试验结果表明,结合9个超声信号特征值的PSO-SVM神经网络具有最高的点焊强度分类准确率.