Removal of Boron and Phosphorus from Silicon Using CaO-SiO2-Na2O-Al2O3 Flux

A combination of solvent refining and flux treatment was employed to remove boron and phosphorus from crude silicon to acceptable levels for solar applications. Metallurgical grade silicon (MG-Si) was alloyed with pure copper, and the alloy was subjected to refining by liquid CaO-SiO₂-Na₂O-Al₂O₃ slags at 1773 K (1500 °C). The distribution of B and P between the slags and the alloy was examined under a range of slag compositions, varying in CaO:SiO₂ and SiO₂:Al₂O₃ ratios and the amount of Na₂O. The results showed that both basicity and oxygen potential have a strong influence on the distributions of B and P. With silica affecting both parameters in these slags, a critical $ P_{{{\text{O}}_{2} }} $ could be identified that yields the highest impurity pick-up. The addition of Na₂O to the slag system was found to increase the distributions of boron and phosphorus. A thermodynamic evaluation of the system showed that alloying copper with MG-Si leads to substantial increase of boron distribution coefficient. The highest boron and phosphorus distribution coefficients are 47 and 1.1, respectively. Using these optimum slags to reduce boron and phosphorus in MG-Si to solar grade level, a slag mass about 0.3 times and 17 times mass of alloy would be required, respectively.     

可降解血管支架用Mg-4.0Zn-0.2Mn-0.2Ca微细管的体外降解行为

通过浸泡实验和电化学测试研究了Mg-4.0Zn-0.2Mn-0.2Ca（质量分数）微细管的体外降解行为与腐蚀机理。结果表明,退火处理可以提高微细管的耐腐蚀性。长期浸泡实验表明腐蚀过程相对均匀,退火微细管在Hank''s溶液中的腐蚀速率约为0.30 mm/a。在浸泡初期,退火管材表面生成Mg(OH)₂,形成保护膜,阻碍腐蚀进行。虽然Mg(OH)₂膜上形成的羟基磷灰石（HA）可以进一步降低腐蚀速率,但是镁基体中粗大的第二相会增强电偶腐蚀效应,并且生成的大量氢气,从而破坏HA膜,使腐蚀继续进行。     

Laser pulse heating and phase changes in the irradiated region: Temperature-dependent thermal properties case

Laser heating and phase change processes in the substrate material are formulated using the energy method. Constant and temperature-dependent thermal properties (variable thermal properties) of the substrate material are considered in the simulations for comparison. Temperature rise in the substrate material and mushy zones formed across liquid–solid and liquid–vapor phases are predicted for constant and variable thermal properties cases. Laser pulse intensity resembling the actual laser pulse is accommodated in the analysis. The recession velocity predicted from the present simulation is compared with the results of analytical solution obtained previously for constant properties case. The cavity depth predicted is compared with the experimental results. It is found that the simulation for constant properties results in early evaporation of the surface and deeper cavities as compared to variable thermal properties case. The prediction of cavity depth for variable thermal properties case agrees well with the experimental results.     

用激光多普勒测速计（LDA）分析粘弹性对Metzner和Otto系数的影响

The Metzner and Otto correlation is the single practical method for incorporating non-Newtonian effects in the mixing process. In this article, the Metzner and Otto' s idea, the role of viscoelasticity on the Metzner and Otto coefficient, ks, effects of flow regime on ks and the determination of ks for Rushton turbine impeller have been studied using the direct method of the laser Doppler anemometry (LDA) velocity measurement for the case of viscoelastic liquids. The normalized mean tangential velocity profiles are independent of Rushton turbine impeller speeds. Contrary to literature findings, it is shown that the variation of local shear rate against the impeller speed is better correlated by the power equation, i.e. γ= ks' · Nb' , in the transition region, i. e. ～ 30 < Re <～ 2000. Also, a correlation between improved coefficient, ks', and the elasticity number of viscoelastic liquids is given which is very helpful in designing of the mixing of both viscoelastic and inelastic non-Newtonian fluids t     

Prediction of in-service microstructural degradation of A106 steel using eddy current technique

In-service microstructural degradation of ASTM A106 steel occurs by the spheroidising and coarsening of pearlite. The specimens of the A106 have been exposed at 710 °C for different durations to simulate service conditions. The resultant pearlite coarsening was evaluated by measuring eddy current inductive reactance and resistance; phase angles were measured using these values and compared with results of optical microscopy, image analysis and resistivity measurements. It was observed that the eddy current phase angle has a linear relation with pearlite variations. It can further be used for in-situ eddy current evaluation of microstructural degradation of pipes or steel vessels. A mathematical model has been proposed to assist such field investigations.     

Dormancy in Breast Cancer,the Role of Autophagy,lncRNAs, miRNAs and Exosomes

Breast cancer (BC) is the most frequently diagnosed cancer in women for which numerous diagnostic and therapeutic options have been developed. Namely, the targeted treatment of BC, for the most part, relies on the expression of growth factors and hormone receptors by these cancer cells. Despite this, close to 30% of BC patients may experience relapse due to the presence of minimal residual disease (MRD) consisting of surviving disseminated tumour cells (DTCs) from the primary tumour which can colonise a secondary site. This can lead to either detectable metastasis or DTCs entering a dormant state for a prolonged period where they are undetectable. In the latter, cells can re-emerge from their dormant state due to intrinsic and microenvironmental cues leading to relapse and metastatic outgrowth. Pre- and clinical studies propose that targeting dormant DTCs may inhibit metastasis, but the choice between keeping them dormant or forcing their “awakening” is still controversial. This review will focus on cancer cells’ microenvironmental cues and metabolic and molecular properties, which lead to dormancy, relapse, and metastatic latency in BC. Furthermore, we will focus on the role of autophagy, long non-coding RNAs (lncRNAs), miRNAs, and exosomes in influencing the induction of dormancy and awakening of dormant BC cells. In addition, we have analysed BC treatment from a viewpoint of autophagy, lncRNAs, miRNAs, and exosomes. We propose the targeted modulation of these processes and molecules as modern aspects of precision medicine for BC treatment, improving both novel and traditional BC treatment options. Understanding these pathways and processes may ultimately improve BC patient prognosis, patient survival, and treatment response.     

Green transmission for C-RAN based on SWIPT in 5G: a review

Wireless Networks - C-RAN is a promising new design for the next generation, an important aspect of it in the energy efficiency consideration. Hence, it is considering an innovative candidate to...     

Near-field and Far-field Optical Properties of Silver Nanospheres: Theoretical and Experimental Investigations of the Size,Shape, Dielectric Environment,and Composition Effects

Protection of Metals and Physical Chemistry of Surfaces - Collective oscillation of electrons in the conduction band of noble metal nanoparticles is known as localized surface plasmon resonance...     

A Miniaturized Frequency Reconfigurable Patch Antenna for IoT Applications

Wireless Personal Communications - This work presents a novel frequency reconfigurable patch antenna design for Internet of Things (IoT) applications. The proposed antenna structure has hexagonal...