Fabrication of aligned microwire arrays of perylene bisimide by micromolding in capillary

In this work, we synthesized a novel perylene tetracarboxylic acid diimides derivative (APBI-G) which shows a strong self-assembling tendency to the semiconducting nano/microwires based on the augmented intermolecular hydrogen bonding interaction. We demonstrate the spinning of continuous thread of APBI-G from the liquid–liquid interface and also the fabrication of patterned nano/microwire arrays using MIMIC (micromolding in capillaries) method. MIMIC-fabricated APBI-G nano/microwires showed the excellent uniaxial orientation, large birefringence, and reproducible electrical conductivity (1.93 ± 0.47 × 10^?6 S cm^?1).     

嗜酸氧化亚铁硫杆菌（ATCC 23270）浸出黄铜矿过程中的EPS、Cu2+和Fe3+的相互作用机制（英文）

采用超声-离心方法提取嗜酸氧化亚铁硫杆菌(ATCC 23270)胞外多聚物(EPS)、EPS中的Cu2+、Fe3+离子,研究生物浸出黄铜矿过程中Cu2+、Fe3+和EPS的相互作用机制。结果表明:与Fe3+离子相比,Cu2+离子可刺激细菌产生更多的EPS;当Cu2+离子浓度从0.01mol/L增加到0.04mol/L时,EPS中Fe3+/Cu2+质量比从4:1降低到2:1;从1%黄铜矿的无铁9K介质中提取的EPS中铜铁含量是从含0.04mol/LCu2+离子的9K介质中提取的量的2倍。在生物浸出黄铜矿过程中,黄铜矿表面结合黄铁钾钒的EPS层减弱了Cu2+、Fe3+离子的迁移,逐渐成为离子扩散壁垒。     

环形加热炉液压系统的改造

简述了广州钢铁股份有限公司无缝钢管分厂环形加热炉液压系统改造前存在的问题。介绍了改造后所采用的具有自动卸压装置和按国家现行标准设计制造的密封式液压系统的构成、传动原理和优点。生产实践表明，该密封式液压系统运行状况良好，调整和维护监控方便，设备故障率下降了80％，能满足生产需要。     

冰箱围板的折弯机设计简

研究了某型号冰箱围板折弯机成形的过程。通过工艺分析,确定围板一次完成折弯成形工序。同时,介绍了该折弯机的结构及动作过程,并分析了其设计要点。经大批量生产证明,此折弯机满足生产使用要求。     

热镀锌电磁封流技术的研究综述

热镀锌是镀锌板生产过程中必不可少的步骤,而热镀锌电磁封流技术相对于传统热镀锌技术具有带钢表面无划伤、沉没辊和稳定辊不被腐蚀、维修频率低和工作效率高的优势,具有重要的工程应用价值。首先,介绍了热镀锌电磁封流技术的特点和意义。其次,分别介绍了电磁泵热镀锌电磁封流技术、CVGL热镀锌电磁封流技术、直流磁场热镀锌电磁封流锌技术和永磁感应密封热镀锌电磁封流技术的工作原理、研究现状、技术组成及其优缺点。再次,分析了热镀锌电磁封流锌工作过程中,温度场、流场、固体结构力学场和电磁场之间复杂耦合的特点,并且依据热镀锌电磁封流过程的技术特点,指出了热镀锌电磁封流过程中带钢振动的抑振技术、锌液不稳定流动抑制技术、温度稳定性控制技术、张力控制等关键技术。最后,提出了电磁装置结构参数优化、带钢振动抑制技术和基于大数据的过程控制技术是提高热镀锌电磁封流锌工作过程的关键技术。     

Enclosed atmospheric corrosion in ship spaces

Abstract

The process of enclosed atmospheric corrosion within ship spaces is investigated. It is proposed that corrosion rates are influenced mainly by three parameters; time of wetness, salt deposition and temperature. Assuming atmospheric corrosion to be primarily cathodically controlled, it is shown that, as a first approximation, the rate of atmospheric corrosion is linearly proportional to both temperature and salt deposition. This is shown to be consistent with available experimental data. An equation is presented for the prediction of corrosion rates within ship spaces exposed to an enclosed atmosphere, such as cargo holds and ballast tanks, on a per voyage basis. The influencing parameters identified in this study, and the proposed model, provide a starting point for future probabilistic modelling of one component of ship corrosion, namely, enclosed atmospheric corrosion.     

Fortschrittliche Korrosionsprüfung von Rohren aus ferromagnetischem Material mit dem Wirbelstrom-Fernfeldverfahren

Modern corrosion inspection for ferromagnetic tube material with remote field eddy current technique Heat exchangers are used in nearly all fields of energy supply, chemistry, petrochemistry and shipping. Unexpected failures of heat exchanger tubing cause inadmissible mixture or discharge of the enclosed media. The aim of modem corrosion inspection is therefore avoiding production disturbances by early detection Of damages. Currently used electromagnetic techniques for inspection of heat exchanger tubing of ferromagnetic materials are presented. The remote field eddy current technique shows advantages compared to the flux leakage technique and the magnetic biased eddy current technique.     

高铬铸铁-铸钢双金属复合锤头的研制

介绍了采用镶铸复合铸造工艺生产破碎用高铬铸铁-铸钢双金属复合锤头的材质选取,组织性能及生产工艺.锤端采用高铬铸铁,化学成分如下C25%;Cr18%,锤柄采用碳钢材质,锤端与锤柄间采用冶金结合和机械结合双重结合工艺.所生产的锤头锤端硬度高(HRC＞56),锤柄韧性好,两者结合良好,使用安全可靠,与高猛钢锤头相比,使用寿命提高4倍左右.     

Inkjet Printing of Amphotericin B onto Biodegradable Microneedles Using Piezoelectric Inkjet Printing

The delivery of amphotericin B, a pharmacologic agent with activity against a broad spectrum of fungi as well as against parasitic protozoa, has been complicated by the fact that amphotericin B exhibits poor solubility in aqueous solutions at physiologic pH levels. In this study, piezoelectric inkjet printing was used to modify the surfaces of Gantrez 169 BF microneedles (Ashland, Covington, KY). These amphotericin B-loaded microneedles demonstrated activity against Candida parapsilosis in a radial diffusion assay. The results of this study suggest that a combination of visible light dynamic mask microstereolithography, micromolding, and piezoelectric inkjet printing may be used to prepare amphotericin B-loaded microneedles with antifungal properties. It is envisioned that microneedles containing amphotericin B may be used for transdermal delivery of pharmacologic agents for the treatment of cutaneous fungal infections as well as cutaneous leishmaniasis.     

Effects of ion irradiation on fatigue of Fe-12Cr-20Mn stainless steel for fusion reactor applications

To minimize waste disposal problems associated with the residual radioactivity of the first wall material of a fusion reactor, fast induced radioactive decay (FIRD) alloys based on the Fe-Cr-Mn system are being investigated. The objective of this research was to evaluate the effects of irradiation on cyclic strain localization and fatigue crack initiation in a FIRD Fe-12Cr-20Mn alloy and to compare the response to commercially available 316 stainless steel. The alloys were irradiated with 200 keV Fe ions to a dose of 1 x 10 ions/cm² and 15.5 keV He ions to a dose of 7 x 10¹⁵ ions/cm² to simulate the irradiation-induced defect structure and helium concentration that would be produced in a fusion reactor. Irradiated specimens were fatigued in a cantilever beam fatigue testing machine with the deflection set to produce a fully reversed total strain amplitude of 0.25% on the surface of the specimen. Acetate replicas were obtained during the fatigue tests to provide a record of surface fatigue damage. Transmission electron microscopy (TEM) analyses were performed to characterize the microstructural changes resulting from the irradiations and interactions between fatigue-induced glide dislocations and the irradiation-induced defects. Results indicate that the irradiated Fe-Cr-Mn alloy exhibits fatigue properties similar to 316 stainless steel. Glide dislocations produced by fatigue cycling annihilate irradiation-induced defects. The defect annihilation causes the formation of cleared channels in which the cyclic plastic strain is localized. Subsurface slip bands penetrate the irradiated regions through the cleared channels and serve as fatigue crack initiation sites.     

Comparative Assessment of Zinc and Cadmium Electroplates by the Weight of Retained Corrosion Products and the Total Weight

The correlation between the corrosion weight losses, the weight of retained corrosion products, and the total weight–change of steel specimen, which has a plain or superficially converted zinc or cadmium electroplate 24 m thick, is studied. The specimens measuring 50 × 70 × 2 and 100 × 150 × 2 mm were exposed for 1 to 5 years in the open and semienclosed atmosphere in coastal and continental test stations and for up to 20 years in the enclosed atmosphere on coasts. The retained product weight and the total specimen weight gain (or loss) vary linearly with the corrosion metal weight loss (K= a+ bX) both in low- and high-corrosive atmospheres. Cadmium coatings retain a lower amount of products than zinc ones, while superficially converted ones retain lower amount than plain ones. The largest amount of products is retained in enclosed atmosphere. In semienclosed and open atmospheres, the amounts are smaller by factors of approximately 1.5 and 2–4, respectively. Knowing the coefficients of a corresponding linear equation and the weight of retained products of zinc or cadmium corrosion on specimens (in a certain time), one can calculate the corrosion rate of a coating in each atmosphere. For a predicted corrosion of 50 g/m², the estimation error will not exceed ±20–30%.     

Three-dimensionally periodic conductive nanostructures: network versus cermet topologies for metallic PBG

Highly periodic three-dimensional metallic mesh composites with silica have been prepared by micromolding synthetic opals using melts of metals and semimetals. These metallic photonic crystals show photonic and electronic properties, which strongly depend on their geometry. Network topology, created in a form of interconnected spherical cages of 200–400 nm diameter, shows a reflectivity peak in the infrared (IR) spectral range, due to a metallic photonic band gap (MPBG), reminiscent of plasmon edge of bulk metal, which is significantly shifted to longer wavelengths. On the other hand, a discontinuous topology of separated clusters in a matrix (so called cermet topology) obtained by three distinct techniques involved controlling the pressure and temperature of the melt during the infiltration process), do not show any MPBG. In the visible spectral range, bright sharp colors of Bragg scattering are observed from both topologies, which are more intense than in conventional, dielectric gem opals in agreement with computer modeling of light reflection from cermet metallo-dielectric photonic crystals.This metallic PBG structures can be used as novel type IR reflectors, color mirrors and conductive electrodes having properties controlled by the topology of 3-D superstructure.     

The U.S. Superalloys Industry — Status and Outlook

It has been proposed, only half in jest, that aircraft and other aerospace production, as well as computer hard and software production, are also modern benchmarks of technological development. The United States is by far the free world’s major producer of civilian (business), commercial, and military aircraft. It is interesting that about two-thirds of current U.S. produced airliners are sold to foreign airlines, with a significant number of those units being bought by East Asian and Middle Eastern companies.¹ In recent years the United States has also made its latest fighters available to select foreign buyers.¹ Historically, the commercial and military aircraft business has been highly cyclic, and should remain so.² The principal use of superalloys is in the aircraft/aerospace industry (see Table I).³ The other significant use of superalloys is in the power generation industry. As one might expect, since the highly cyclic aircraft industry accounts for most of the superalloy sales, the volume of superalloy shipments is also highly cyclic (see Figure 1). In the 1976 downturn, superalloy shipments were estimated at 45 million pounds. They climbed to a peak of over 80 million pounds in 1979 and 1980, then dropped to lower levels in 1982. The consequences of the highly cyclic demand for superalloys, hedge buying and production overcapacity are considered, along with the internationalization of superalloy production, feedstock insecurities, and the effect of advanced materials to the current industry.     

灰铸铁件加工面麻点状小孔缺陷的分析及防止

采用金相方法对HT300铸件加工面麻点状小孔缺陷的形貌、分布特征和产生原因进行了分析。认为:麻点是由许多尺寸在0.3mm以下的小孔组成,多产生在凝固过程中冷速较慢的厚壁部位,主要分布在石墨密集区域,特别是在石墨封闭或半封闭区域;铸件w(C)和w(Si)量偏高,凝固过程中局部冷速过慢,切削用量偏大都有可能引起这种缺陷。提出了预防这种缺陷的四条措施。     

Effect of irradiation by nitrogen and helium ions on the structure and electrical resistance of nanocrystalline V-N coatings

The results of studies of the radiation damage of V-N coatings irradiated by nitrogen and helium ions with energies of 40 and 20 keV, respectively, are presented. The coatings have been obtained using a technique of ion-stimulated deposition and represented a nanocrystalline composite with grain sizes of 20–50 nm, intergrain junctions of which contained voids with sizes of 3–6 nm. It has been shown that during irradiation, the electrical resistivity of such objects increases. No visible structure changes are observed up to doses of 7–8 × 10¹⁶ ion/cm². A further increase in the dose leads to changes in the void structure and to a transformation of the closed porosity to an open one. It has been shown that the system of arising channels creates conditions for evolving the accumulating helium and preserving the integrity of the coating.     

Accelerated corrosion of MoO3-deposited copper

The accelerated oxidation kinetics of MoO₃-deposited copper were studied in the temperature range of 480–700 °C in air. The accelerated oxidation followed the parabolic-rate law, indicating that the process was diffusion-controlled. Oxygen diffusion along liquid channels in the oxide scale was inferred to be the rate-limiting step in the overall mechanism. The rate constant increased from 9.2 × 10⁻⁶ to 3.8 × 10⁻⁵ kg² m⁻⁴ s⁻¹ with increasing the deposit mass from 0.3 to 0.9 kg m⁻² at 700 °C.     

The corrosion of Fe3Al alloy in liquid zinc

A systematic study of the isothermal corrosion testing and microscopic examination of Fe₃Al alloy in liquid zinc containing small amounts of aluminum (less than 0.2 wt.%) at 450 °C was carried out in this work. The results showed the corrosion of Fe₃Al alloy in molten zinc was controlled by the dissolution mechanism. The alloy exhibited a regular corrosion layer, constituted of small metallic particles (diameter: 2-5 μm) separated by channels filled with liquid zinc, which represented a porosity of about 29%. The XRD result of the corrosion layer formed at the interface confirmed the presence of Zn and FeZn_6.67. The corrosion rate of Fe₃Al alloy in molten zinc was calculated to be approximately 1.5 × 10⁻⁷ g cm⁻² s⁻¹. Three steps could occur in the whole process: the superficial dissolution of metallic Cr in the corrosion layer, the new phase formation of FeZn_6.67 and the diffusion of the dissolved species in the channels of the corrosion layer.     

Some Observations on the Growth Mechanism of Hard Anodic Oxide Coatings on Aluminium

In general, Keller, Hunter and Robinson's theory will explain the reactions taking place during the anodic oxidation of aluminium and many of the properties of the coatings. However, there are instances where observations do not agree with this theory. For example, when aluminium is anodized under special conditions very thick oxide coatings (150 to 250 μ) of high hardness (HV=500-620 kg/mm² Vickers) are obtained: these show structural features which cannot be explained by the classical model. In these thick hard coatings, it is possible to distinguish between primary oxidation nuclei and secondary oxidation zones, which appear to be in agreement with Franck's theory on the initial oxidation reaction. The structure consists of irregularly formed pore channels which are frequently bent or otherwise distorted. The distribution of the pore openings on the surface of the coatings is similarly irregular. The bundles of similar pore channels which may grow into each other yield a fibrous structure and form blocks which may differ in size, shape and orientation. Under polarized light, the cross-section of these coatings show a differential laminar layer structure which lies parallel to the metal surface. It is possible that the film growth reactions suggested by Murphy and Michelson play an important part in the formation of the laminar structure of the coating however.     

高光注塑模具加热管道布局优化设计

高光注塑成型技术可除塑件表面熔痕、流线、银线等缺陷,应用领域广泛。模具温度是影响高光注塑件质量的关键因素,而模具内部管路分布又直接影响模具成型面温度分布。以102 cm液晶电视机前壳的高光注塑模具为例,分析了影响其型腔表面温度分布的因素,以模具型腔表面的温度均匀性为目标函数,将CAD软件、有限元软件和优化设计软件iSIGHT有效集成,实现了加热/冷却管道的布局参数的优化设计。结果表明,优化后模具型腔表面的温度分布的均匀性显著提高,将优化结果应用于实际生产中,获得了高品质的高光塑件。     

High-temperature alloys for long-term service in chemical process industry applications

HAYNES® alloys No. 230 und No. 556 are new high-temperature alloys for the chemical industry. 230^TM alloy is used in nitric acid production, while 556^TM is employed in waste incineration and complex aggressive process environments. Performance properties are discussed.