低碳微合金化含硼冷镦钢的冲击性能

通过对不同B含量的低碳硼钢和Nb、V微合金化低碳硼钢的冲击实验,研究了B含量及Nb、V微合金化对低碳硼钢冲击性能的影响. 结果表明:0.0006%～0.0015%的B将提高热处理状态钢的冲击韧性,B质量分数超过0.003%将降低钢的冲击韧性. Nb、V复合微合金化同时加入适量Al可显著提高热处理状态低碳硼钢的冲击韧性. Ti质量分数超过0.03%对低碳硼钢和微合金硼钢的冲击性能不利.     

单壁氮化硼纳米管储氢的理论研究

采用蒙特卡罗方法模拟常温、中等压强下单壁氮化硼纳米管的储氢,重点研究了单壁氮化硼纳米管的管径、管长和手性以及压强对其物理吸附储氢的影响.与单壁碳纳米管的物理吸附储氢相比较,氮化硼纳米管的储氢性能明显优于碳纳米管.计算结果显示,在常温、中等压强下单壁氮化硼纳米管的物理吸附储氢量(质量百分数)可以达到美国能源部提出的商业标准.     

基于硼氮共掺杂荧光碳点定量分析吡罗昔康

以邻苯二胺、谷氨酸及硼酸为前驱体,通过简单的一步水热法成功制备水溶性极好的硼氮共掺杂荧光碳点(B,N-CDs)。该B,N-CDs粒径约为20 nm,在吡罗昔康(PRX)的存在下,由于B,N-CDs和PRX之间存在强烈的电子或能量转移导致发生了强烈的荧光淬灭效应。据此,应用荧光碳点B,N-CDs作为荧光探针成功构建了高选择性、高灵敏性的PRX检测荧光传感器。实验数据显示,该传感器具有响应速度快、线性范围宽和检测限低等优点。检测PRX的线性范围为2×10~(-5)～1.5×10~(-4) mol/L,LOD为5.7×10~(-8) mol/L。该传感器用于实际样品检测得到了较好的回收率(94.3%～103.3%),充分说明B,N-CDs在药物检测领域具有很好的潜在应用价值。     

电子束蒸发制备碳化硼球面涂层的表面氧化研究

利用电子束蒸发技术沉积制备了碳化硼微球涂层,将微球涂层依次经退火和稀硫酸腐蚀处理后得到碳化硼空心微球,并借助XRD和SEM对碳化硼微球涂层的表面氧化问题进行了研究.XRD结果显示当衬底温度在120℃附近时,碳化硼涂层部分被晶化;对退火前后和酸腐蚀后的微球涂层进行SEM分析,结果表明,退火前的涂层表面部分被氧化成B2O3,退火后B2O3覆盖在涂层表面,酸腐蚀可以去掉B2O3,得到表面光洁的碳化硼空心微球.     

氟硼荧染料修饰衍生研究进展

氟硼荧光（BODIPY）染料是近些年来新兴起来的,与传统染料相比大多都具有优异光化学物理性能的一类荧光化合物。尤其是长波近红外的BODIPY荧光染料,更适合于活体细胞成像进而研究生命过程的发生和变化。然而其吸收和发射波长都处于小于600nm的可见区域。因此,研究BODIPY荧光染料的合成方法以及通过对其进行修饰衍生实现吸收发射光谱红移尤为必要。笔者总结了目前常见的BODIPY荧光染料分子的合成方法及其修饰衍生方法,并对这些方法优缺点进行了比较。     

Pseudo-<Emphasis Type="Italic">in-situ</Emphasis> stir casting: a new method for production of aluminum matrix composites with bimodal-sized B<Subscript>4</Subscript>C reinforcement

A new method was applied to produce an Al-0.5wt%Ti-0.3wt%Zr/5vol%B₄C composite via stir casting with the aim of characterizing the microstructure of the resulting composite. For the production of the composite, large B₄C particles (larger than 75 μm) with no pre-heating were added to the stirred melt. Reflected-light microscopy, X-ray diffraction, scanning electron microscopy, field-emission scanning electron microscopy, laser particle size analysis, and image analysis using the Clemex software were performed on the cast samples for microstructural analysis and phase detection. The results revealed that as a consequence of thermal shock, B₄C particle breakage occurred in the melt. The mechanism proposed for this phenomenon is that the exerted thermal shock in combination with the low thermal shock resistance of B₄C and large size of the added B₄C particles were the three key parameters responsible for B₄C particle breakage. This breakage introduced small particles with sizes less than 10 μm and with no contamination on their surfaces into the melt. The mean particle distance measured via image analysis was approximately 60 μm. The coefficient of variation index, which was used as a measure of particle distribution homogeneity, showed some variations, indicating a relatively homogeneous distribution.