Locating Malleable Bulk Metallic Glasses in Zr-Ti-Cu-Al Alloys with Calorimetric Glass Transition Temperature as an Indicator

We defined the plastic deformability under constrained loading conditions as malleability for bulk metallic glass (BMG) materials. Quaternary Zr-Ti-Cu-Al alloys in the Zr-rich composition range are selected to investigate the compositional dependence of malleability assessed by bending testing and glass transition temperature (Tg ). As indicated, increasing the Al or Cu concentration in the alloys leads to the rise of T g . The Zr(61)Ti2Cu(25)Al(12) (ZT1) and Zr(61.6)Ti(4.4)Cu(24)Al(10) (ZT3) alloys exhibit an optimal combination of lower T g and higher glass-forming ability. The malleable BMGs such as ZT1 manifests two characters during deformation, the stable propagation of a single shear band indicated by large shear offsets and easy proliferation of shear bands. With increasing the T g of BMG, the yield strength σy,Young’s modulus and shear modulus simultaneously increase as well, while the Poisson s ratio decreases. The σy of ZT1 BMG is about 1680 MPa in compression and 1600 MPa in tension. In tensile loading, no any visible plasticity appears even when the strain rate increases up to the order of magnitude of 10(-1)s(-1). In consistent with the T g , malleability of Zr-Ti-Cu-Al BMGs manifests significant compositional dependence. The malleable BMG is associated with lower Tg , as well as lower shear modulus or higher Poisson s ratio, which can be understood on the basis of the correlation of Tg with shear energy barrier in metallic glass. Thus, the calorimetric Tg can be used as an indicator to screen malleable BMG-forming composition, with advantage of experimental accessibility.     

Magnetoacoustic imaging of magnetic iron oxide nanoparticles embedded in biological tissues with microsecond magnetic stimulation

We present an experimental study on magnetoacoustic imaging of superparamagnetic iron oxide (SPIO) nanoparticles embedded in biological tissues. In experiments, a large-current-carrying coil is used to deliver microsecond pulsed magnetic stimulation to samples. The ultrasound signals induced by magnetic forces on SPIO nanoparticles are measured by a rotating transducer. The distribution of nanoparticles is reconstructed by a back-projection imaging algorithm. The results demonstrated the feasibility to obtain cross-sectional image of magnetic nanoparticle targets with faithful dimensional and positional information, which suggests a promising tool for tomographic reconstruction of magnetic nanoparticle-labeled diseased tissues (e.g., cancerous tumor) in molecular or clinic imaging.     

刚果(金)某氧化铜钴矿絮凝沉降试验研究

对刚果(金)某氧化铜钴矿进行絮凝沉降试验研究。结果表明,原矿在磨矿粒度-0.150mm占80%、矿浆浓度10%～12%、絮凝剂用量5～10g/t,絮凝剂浓度0.05%～0.1%的条件下,沉降速度最高可达25m/h,底流浓度可达54%以上。对于磨矿粒度-0.150mm占80%、酸矿比132kg/t、初始矿浆浓度25%、常温浸出时间4h的浸出矿浆,在矿浆浓度6%、絮凝剂用量20g/t,絮凝剂浓度0.1%的条件下,沉降速度最高可达22m/h,底流浓度可达47%以上。     

The minimum squared euclidean distance of multi-h phase codes

The minimum squared Euclidean distance(MSED) of binary multi-h phase codes is presented. The signal segregation degree(SSD) has been put forward to determine MSED of multi-h phase codes. In order to maximize MSED, SSD should be as large as possible. The necessary and sufficient conditions of maximizing SSD are derived. Finally, SSD and the exact formulae for MSED of binary 2-h phase codes are also presented.     

Liquid phase separation and microstructure characterization in a designed Al-based amorphous matrix composite with spherical crystalline particles

The solidification process of the immiscible alloys exhibit a unique opportunity in designing the composites with the spherical crystalline particles dispersed in the amorphous metal matrix. The typical Al–Pb immiscible alloy and the additional elements Ni, Y and Co were selected, and the Al_82.87Pb_2.5Ni_4.88Y_7.8Co_1.95 multicomponent immiscible alloy has been designed. The ribbon samples of the multicomponent alloy were prepared by using the melt spinning technique. The ribbons were characterized by the scanning electron microscopy (SEM). The phase constitution and transformation were studied by the X-ray diffraction (XRD) and the differential scanning calorimeter (DSC). It was revealed in the as-quenched ribbons the Al-based metallic glass matrix is embedded by the spherical crystalline Pb-rich particles. The microstructure evolution, the glass formation and the thermal stability of the as-prepared composite have been discussed in detail. A method has been developed based on the mechanism of the liquid–liquid phase transformation in the miscibility gap of the multicomponent immiscible alloy to produce the spherical crystalline particles in the amorphous matrix.     

An approach for obtaining the structural diversity of multi-walled carbon nanotubes on Ni/Al catalyst with low Ni content

A mass of multi-walled carbon nanotubes were fabricated on Ni/Al catalyst with low Ni content (2.5 wt.%) by chemical vapor deposition in the temperature range of 773–923 K and characterized with respect to their structure. The tubular and the bamboo-shaped structure occurred in the 773–873 K and 873–923 K temperature ranges, respectively. In order to figure out the reasons for the observed structural instabilities, the effects of reduction and reaction temperature on the catalyst particle sizes and the carbon nanotube dimensions (lengths and diameters) were investigated in detail using statistical measurements based on transmission electron microscope observations. The reduction and reaction temperatures have strong influences on the catalyst particle sizes and the carbon nanotube diameters. The influence of reaction temperatures on the carbon nanotube length is feeble. Furthermore, mechanisms of the structure formation are discussed as well as open questions are addressed.     

New fluoranthene-based cyanine dye for dye-sensitized solar cells

In this paper, a new fluoranthene-based unsymmetrical organic cyanine dye I and the corresponding cyanine dye II containing ethynyl unit for the purpose of comparison were designed and synthesized as sensitizers for the application in dye-sensitized solar cells (DSSCs). The absorption spectra, electrochemical and photovoltaic properties of I and II were extensively investigated. The DSSCs based on the fluoranthene dye I showed the better photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 67%, a short-circuit photocurrent density (J_sc) of 7.83 mA cm^?2, an open-circuit photovoltage (V_oc) of 0.476 V, and a fill factor (ff) of 0.63, corresponding to an overall conversion efficiency of 2.34% under simulated AM 1.5G solar light condition. Also, the effects of chenodeoxycholic acid (CDCA) in a solution as a co-adsorbate on the photovoltaic performance of DSSCs based on cyanine dyes were also investigated. The presence of CDCA for 0.5 h, increases both the photovoltage and photocurrent of the DSSC incorporating I, in which the photovoltage and photocurrent increase 9.3% and 20%, respectively. The above photovoltaic results indicate that coadsorption of appropriate amount CDCA is effective to improve solar cell performance.     

Composition and annealing effects in solution-processable functionalized graphene oxide/P3HT based solar cells

Characterization of a solution-processable functionalized graphene oxide (SPFGraphene oxide) was investigated by FT-IR spectroscopy and the result of elemental analysis showed that the isocyanate treatment results in the functionalization groups in SPFGraphene oxide. Doping SPFGraphene oxide to P3HT based solar cells induces absorbing spectra more strongly and a great quenching of the photoluminescence of the P3HT. With an increase in the SPFGraphene oxide content, the overall performances of the hybrid devices increases first, reaching the peak efficiency for the 10 wt% SPFGraphene oxide content, and then decreases. After annealing at 160 °C for different time durations, the device containing 10 wt% of SPFGraphene oxide for 10 min shows the best performance with a power conversion efficiency of 1.046%, an open-circuit voltage of 0.73 V, a short-circuit current density of 3.98 mA cm^?2 and a fill factor of 0.36 under simulated AM1.5G conditions at 100 mW cm^?2; The similar content one for 20 min shows η value of 1.013%, which is lower than the former one to a small extent for longer annealing duration. The graphene has the potential to act as the next-generation material in the photovoltaic devices and other applications for ease of preparation, low price, large surface area, high conductivity and excellent transparency.     

宝钢不锈钢冷轧厂光平整液废水处理系统

介绍了一套完全崭新的工艺用于热镀锌机组排放的光整液及碳钢连退机组排放的平整液废水处理系统。该工艺采用均质调节池—pH中和罐—溶气气浮—冷却塔—EGSB—MBR装置。该工艺流程很好地解决了钢铁行业冷轧厂的光平整液废水处理这一大难题。     

水处理剂用量对缓蚀阻垢性能的影响

冷却水长期循环使用后,会出现腐蚀、结垢、微生物滋生等问题,影响系统的正常运行。通过对循环冷却水系统进行合理的水质处理,同时采用腐蚀在线监测技术对系统的腐蚀状况进行监测,保证了循环水系统安全、稳定运行。