Effects of electric-field treatment on a Ni-base superalloy

The effects of electric-field treatment on the microstructure and deformation behavior of a nickel-base superalloy were summarized.The results show that the electric-field treatment increases the ductility of the superalloy but has no evident influence on its static strength at both room and elevated temperatures,while,the strength increases but elongation changes weekly with the increasing tensile strain rate.It is found that the direction of microcrack propagation can be changed by the presence of the annealing twins during the tensile deformation,and it causes the increasing of the plastic deformation energy and delay of the fracture,which is considered as the reason for the increasing the ductility.

Effects of electric field treatment on microstructures of GH4199 superalloy after long-term aging

The effects of electric field intensity and treatment temperature on the microstructures of GH4199 superalloy after long-term aging were investigated. The results show that the number and size of carbides and TCP(σphase andμphase) phase in the alloy increase with increasing electric field intensity at the same heat treatment temperature and holding time. While the number and size of carbides and TCP phase are weekly influenced by treatment temperature with lower electric field intensity of 2 kV/cm. When the treat temperature is up to 1 093 K, annealing twins appear in the alloy, and the number of twins increases with increasing holding time. Since the electric field can provide the enough energy for the movement of vacancies and atom, it is considered that the nucleus of the twins formed with formation stack faults due to the mismatch of local atom in crystal caused by the vacancies, and the twins will grow with the increase of holding time. Meanwhile, such promoting effects on atom movement of the electric field increase with the increase of the electric field intensity, meantime the carbides and TCP phase grow fast with the increase of electric field intensity.

EFFECT OF SOLUTION TREATMENT IN AN ELECTRIC FIELD ON MECHANICAL PROPERTIES AND MICROSTRUCTURE OF 2091 Al—Li ALLOY

Solution treatment of 20% Al-Li alloy in an electric field has been studied. The results show that it increases the solubility of elements and accelerates the nucleation of T1-phase and promotes the formation of the precipitation free zones(PFZ), and increases the strength and decreases the plasticity of the alloy.

Temperature field analysis of main steam pipe under local post weld heat treatment

In local post weld heat treatment, the temperature difference is the criterion of the process. The temperature field in the main stream pipe under local post weld heat treatment is simulated by finite element method. A close-loop control program is designed to simulate the temperature field of two different pipes. Both the skin effect of induction heating and electro-thermal coupled effect are considered in the heating model. The local heat treatment temperature difference at the inner and outer side of the pipe is analyzed and the different convection conditions are also considered. The simulation results show that in appropriate induction heating process, the temperature difference in the pipe can be controlled within 30 ℃.

Effect of homogenization treatment in electric field on microstructure and properties of 1420 Al-Li alloy

In comparison with the homogenization treatment without an electric field prior to the same solid solution and aging treatment, the homogenization treatment in an electric field increases the hardness and strength of 1420 Al Li alloy, but somewhat decreases the elongation of the alloy. Moreover, the elongation of the alloy increases with the homogenization temperature in an electric field increasing. TEM observation showed that the homogenization treatment in an electric field can accelerate the dissolution of the coarse particles of second phase on the grain boundary as well as make δ′phase precipitated in subsequent aging process finer and more numerous.

Surface Treatment of Polypropylene Films Using Dielectric Barrier Discharge with Magnetic Field

Atmospheric pressure non-thermal plasma is of interest for industrial applications. In this study, polypropylene （PP） films are modified by a dielectric barrier discharge （DBD） with a non-uniform magnetic field in air at atmospheric pressure. The surface properties of the PP films before and after a DBD treatment are studied by using contact angle measurement, atomic force microscopy （AFM） and X-ray photoelectron spectroscopy （XPS）. The effect of treatment time on the surface modification with and without a magnetic field is investigated. It is found that the hydrophilic improvement depends on the treatment time and magnetic field. It is also found that surface roughness and oxygen-containing groups are introduced onto the PP film surface after the DBD treatment. Surface roughness and oxygen-containing polar functional groups of the PP films increase with the magnetic induction density. The functional groups are identified as C-O, C=O and O-C=O by using XPS analysis. It is concluded that the hydrophilic improvement of PP films treated with a magnetic field is due to a greater surface roughness and more oxygen-containing groups.

Field Comparison of the Impact of Different Treatment Durations in the Treatment of Acute Otitis Externa

Background: Acute otitis externa is a common multi-factorial disorder in the dog. Several topical preparations are available on the veterinary market, which are licensed for an either specified duration of treatment or for a discretionary period that is determined by the clinician. Objectives: To compare the efficacy of two topical products, both licensed for the treatment of otitis externa in the dog, but with different treatment durations. Animal Population: One hundred and sixty dogs were enrolled in this multicentre field study from which 157 dogs were analysed in the Per Protocol sample (73 Aurizon?treated animals and 84 Easotic?treated animals). Method: Dogs were randomly assigned to Aurizon?or Easotic?treatment groups. Aurizon?(Vétoquinol SA: marbofloxacin, clotrimazole, dexamethasone) was administered daily in the affected ear(s) for 7 or 14 days, and was compared with a daily administration of Easotic?(Virbac SAS: gentamicin, miconazole, hydrocortisone aceponate) for 5 days. General and localised clinical signs were scored on days 0 (D0), 3 (D3), 7 (D7), 14 (D14) and 21 (D21). Results: Clinical cure rates at the end of treatment were 56.3% and 48.8% (p=0.35) in the Aurizon?and Easotic?groups respectively and 81.2% versus 74.7% one week after completing the course of treatment (p = 0.34). Twenty-one days after initially presenting for the study, cure rates were 84.3% in the Aurizon?group and 73.8% in the Easotic?(p=0.12). A relationship between severity of clinical signs and treatment duration was observed. Conclusion and Clinical Significance: At the end of the trial period, cure rates showed a tendency to be higher in the Aurizon?treated animals. The flexible dosage and the veterinary monitoring permitted treatment duration to be adjusted based upon the severity of otitis externa thus increasing the likelihood of clinical cure.

高海拔严寒地区隧道冻害研究现状及展望

针对高海拔严寒地区隧道冻害问题,结合隧道冻害的相关研究,从冻害类型及原因分析、冻害机制、温度场、处置措施等4个方面的现状进行阐述和分析,对当前研究存在的不足和未来的发展方向进行探讨。主要成果为:1)通过对高海拔严寒地区隧道工程实例进行分析,总结4种冻害类型及4种冻害原因;2)基于含水风化层冻胀理论、整体性围岩冻胀理论、衬砌背后积水冻胀理论、裂隙水冻胀理论等4种冻胀理论,建立多年冻土区以整体性围岩冻胀理论为主、季冻区以裂隙水冻胀理论为主的多理论联合分析的方法;3)温度场研究方法分为现场监测、理论解析、模型试验、数值模拟等4种,其中现场监测是对洞内外温度进行监测,而理论分析、模型试验、数值模拟则是对监测结果进行验证分析;4)冻害处置措施有防排水措施、保温防寒措施、抗冻措施等3种,防冻的关键是将三者相结合进行综合治理;5)指出冻害机制适用性、温度场研究方法现状、处置措施适用性等方面的不足,未来应在高海拔严寒地区建立多种冻胀理论、多种研究方法综合应用的研究体系,并在隧道防排水、保温防寒、抗冻等方面给出处置措施。

INFLUENCE OF HOMOGENIZATION TREATMENT UNDER AN ELECTRIC FIELD ON DUCTILITY OF 2091 Al－Li ALLOY DURING HOT ROLLING

For 2091 Al-Li alloy, the volume fraction of second phase particles is greatly determined by the homogenization temperature and homogenization time under an electric field and the ductility of the alloy is determined by the fraciton of second phase particles. The combined homogenization treatment shortens the homogenization time, reduces the loss ofLi content and increases the ductity of the alloy.

肿瘤治疗电场在肿瘤治疗中的应用和机制研究进展

[背景]肿瘤治疗领域缺乏高效、安全的非侵入式治疗方法.近年来,肿瘤治疗电场(tumor treating fields,TTFields)作为一种新兴的非侵入性物理治疗技术,通过释放中频、低强度的交变电场有效抑制肿瘤生长,引发的副作用较小.[进展]目前TTFields已被广泛应用于各类肿瘤治疗的临床研究中,包括脑胶质瘤、间皮质瘤、非小细胞肺癌、胰腺癌、卵巢癌、肝癌及胃癌等.TTFields通过向生物分子施加生物物理力,扰乱肿瘤细胞的生物学功能从而抑制其生长,但具体分子机制尚不明确.为研究TTFields在肿瘤治疗中的分子机制,研究人员通过设计和搭建不同电极和交变电场发生平台,在体外研究TTFields对肿瘤细胞的作用机制.研究发现TTFields干扰细胞分裂、DNA修复、自噬、细胞迁移和细胞膜通透性等生物学过程,也影响血脑屏障、血管生成和肿瘤免疫等肿瘤微环境.[展望]本文回顾了近年来TTFields在肿瘤治疗中的应用、用于体外研究的电极设计和电场发生平台,及其潜在的抗肿瘤机制.然而,TTFields抑制肿瘤生长的分子机制仍需深入研究,评估其对能够自我更新的非肿瘤细胞和终端分化细胞的影响,以减少可能的副作用.这些研究将有助于提升TTFields的治疗潜力,为更多恶性肿瘤的治疗开辟新的可能性.

EFFECT OF HOMOGENIZATION TREATMENT UNDER AN ELECTRIC FIELD ON T_1 DISTRIBUTION AND MECHANICAL PROPERTIES OF 2091 Al－Li ALLOY

Homogenization treatment under an electric field increases the distributive homogeneity of the T1 precipitation and improves the yield strength of 2091 Al-Li alloy.

一起自然环境暴露感染皮肤炭疽疫情案例分析

本文以2021年山东省济南市报告的1起皮肤炭疽疫情为案例,分析自然环境暴露感染皮肤炭疽疫情的处理方式,总结疫情处置中存在的主要问题和经验,提出今后预防相关疫情的工作建议。

磁场对合金材料服役性能影响的研究进展

随着我国海洋工程、运载火箭、天地往返等重大战略工程的实施,合金作为各种装备的主要材料,在苛刻工况下的服役性能提升尤为迫切,如合金材料在海洋大气、深海、高原严寒等复杂环境中的防腐性能提升,在高温、重载环境中关键部件的长寿命可靠服役,在航空航天、地质钻探环境中的减摩,在高速、高压环境中的力学性能提升等问题,使得实现合金材料高性能、高可靠的研究成为近年来的热点话题。磁场处理区别于传统合金加工方法,为提高合金材料性能提供了新的途径和方法,具有无接触、清洁、降低资源能耗等特点,对合金材料的制备以及加工工艺而言具有极其重要的意义。本文首先从固态和熔融态合金两条路线出发归纳了磁场不同的典型作用机理及其研究进展,梳理分析了磁场处理下凝固过程中的晶体结构以及磁场对固态合金微观组织(包括磁畴、相变和位错)的影响;其次针对磁场对合金性能影响的问题,从力学、摩擦、疲劳性能、耐腐蚀四个方面来阐述,对比分析不同类型、强度、方向的磁场对合金性能的影响效果差异;最后展望了磁场处理合金的未来发展趋势,并提出了亟待解决的问题。

滋养节杆菌S17的分离鉴定及其对黄瓜促生能力研究

为筛选出具有促生效果的生防细菌,本研究从河北、山东等地采集土样,分离筛选具有高产IAA能力的促生菌株,基于形态学特征、生理生化指标及多基因系统发育树分析,对潜在具有促生能力的菌株进行鉴定。同时测定促生菌株对黄瓜种子出芽及在盆栽试验、田间试验中对黄瓜幼苗的促生效果。结果表明:分离并鉴定出1株对黄瓜幼苗具有显著促生效果的细菌,滋养节杆菌ArthrobacterpascensS17。在DF+培养基中滋养节杆菌S17可大量合成IAA,其合成的IAA含量最高为128.54μg/mL。使用滋养节杆菌S17灌根处理,对黄瓜幼苗株高的增长率达到35.99%、对黄瓜幼苗叶面积的增长率达到26.90%,黄瓜幼苗各项生理指标均显著高于对照。滋生节杆菌S17对黄瓜促生效果显著,具有一定的开发应用前景。

超声能场在金属增材制造组织性能调控中的应用

针对金属增材制造构件存在微观组织缺陷、残余应力及各向异性等问题,各种组织性能调控技术应运而生。结合近年来超声能场对增材制造组织性能调控的研究工作,详细分析了超声能场在增材制造过程中的“液-固”双重效应,总结了超声能场对增材制造金属材料的显微组织及其表面粗糙度、显微硬度、残余应力、耐腐蚀等性能的影响。研究表明,超声能场使材料内部组织晶粒显著细化、孔隙率降低、耐腐蚀性能提高;同时使增材制造构件显微硬度升高,应力状态向有利于构件性能的残余压应力转变。

金属氧化物基生物炭复合材料在污水处理领域中的应用现状

生物炭是生物质在缺氧条件下热解产生的一种富含碳固体物质,特点为疏松多孔、比表面积大且表面富含酚羟基、羧基和氨基等多种官能团。同时,生物炭是一种廉价易得、性能优良的吸附材料,因其环境友好、来源广泛,在污水处理领域具有广泛应用。分析了生物炭对水中污染物的吸附机理,重点阐述了TiO_(2)、磁性氧化铁、MnO_(2)以及其他氧化物等金属氧化物基生物炭复合材料在污水处理领域中的应用现状、循环利用以及再生性能,最后展望了金属氧化物基生物炭复合材料的发展前景。

高压静电场处理对青皮扁桃果实采后生理与种仁品质的影响

青皮扁桃采后易褐变腐烂,种仁易出芽,品质易变劣,为了延长青皮扁桃贮藏时间,提升市场价值,该文以“晋扁一号”青皮扁桃为试验试材,采用不同强度的高压静电场对其进行处理,然后将其用0.03 mm厚的打孔聚乙烯袋包装,在(0±1)℃下贮藏,测定青皮扁桃果实的失重率、褐变指数、裂果率、色泽、呼吸强度和乙烯释放量的变化,以及种仁过氧化值、酸价、过氧化氢酶和过氧化物酶活性的变化。结果表明,通过比较100、150、200 kV/m三个电场处理组各指标的数值,发现150 kV/m的电场处理组效果最好,对青皮扁桃的失重率、褐变指数和裂果率有显著的抑制作用,抑制或推迟乙烯释放高峰及呼吸高峰,维持果皮的色泽,抑制种仁过氧化值和酸价的提高以及过氧化氢酶和过氧化物酶活性的下降。因此,高压静电场处理可以有效保持青皮扁桃在贮藏过程中的果实品质,延缓果实衰老。

脉冲磁场对6082铝合金时效组织和性能的影响

采用光学显微镜、扫描电镜、透射电镜和电子万能试验机等研究了脉冲磁场时效工艺对6082铝合金组织和力学性能的影响。结果表明:在6082铝合金时效过程中施加脉冲磁场,能够提高扩散通量及原子振动频率,使合金在时效早期形成更多GP区,这些GP区在后续时效过程中形成β″相,并且由于原子扩散加快,形成β″相的速度远大于常规时效,使得6082铝合金基体中β″相数量增加,β′相尺寸缩小;经175℃脉冲磁场时效180 min后,6082铝合金的力学性能最优,其抗拉强度为348.41 MPa、屈服强度为300 MPa、伸长率为17%,相比常规时效工艺,力学性能更好,且时效时间缩短了62.5%。

电场处理对YG8硬质合金及其刀具性能的影响

为探索一种高效的硬质合金强化处理技术,研究了电场处理对YG8硬质合金显微组织及性能的影响,采用TEM、SEM等对电场处理前后的YG8硬质合金试样及其刀具进行微观组织分析,采用维氏硬度计进行力学性能测试,数控车床进行切削加工实验。结果表明:经电场处理后,YG8硬质合金试样断裂韧性有所增大,其刀具切削性能得到提升,且电场处理刀具的被加工工件表面质量明显得到提高。在脉冲电流作用下,材料会发生电塑性效应,为位错运动提供驱动力,使位错更容易进行增殖和滑移,位错密度增加,从而有利于材料性能的提高。当脉冲电流为15 A/mm^(2)时,断裂韧性达到最大值9.41 MPa·m^(1/2),相比于未使用电场处理的断裂韧性提高了近10%。经电场处理的YG8硬质合金刀具在切削过程中切削温度降低,可有效防止积屑瘤产生,改善切削过程的摩擦状态,保证了切削质量,使得被加工工件表面质量明显提高。

电场预处理对藻菌共生体处理养猪废水的影响机制分析

随着畜禽养殖业规模化集约化的发展,畜禽养殖废水已经成为了农业面源污染的主要来源,但其自身包含大量碳氮磷等营养元素又是重要的农业资源。针对养猪废水高色度浊度、高碳氮磷的特点,引入电场预处理来降低废水的色度、浊度,在促进藻菌共生体生长的同时提高废水中污染物的去除效率。结果表明:电场预处理能使养猪废水中的色度、浊度得到有效降低,铁、铝做阳极时色度、浊度的去除率均能达到90%以上。经电场预处理的废水在藻菌共生体的培养上也有更优的表现,铁、铝做阳极组中藻菌共生体对COD、TN、TP的7 d去除率分别为59.09%、61.78%、68.96%和62.26%、62.26%、83.92%,优于未经电场预处理组的47.82%、59.3%、60.48%。此外,铁、铝做阳极组和未经电场预处理组叶绿素含量分别从7.63、7.32、7.37 mg·L^(-1),增长到24.39、26.08、12.98 mg·L^(-1),是接种时的3.20、3.54、1.70倍,电场预处理明显提高了藻菌共生体中叶绿素的含量。说明电场预处理能有效提升藻菌共生体对污染物的去除效果,并获得更大的生物质资源,同步实现对废水的深度处理和资源利用。