Carborane and cyanine conjugated galactose targeted amphiphilic copolymers for potential near infrared imaging-guided boron neutron capture therapy (BNCT)

Near infrared fluorescent galactose targeted glycopolymer containing m-carborane has been synthesized through ring open and atom transfer radical polymerization, followed by post-functionalization with a cyanine NIR dye. The copolymer could self-assemble into micelles which work as a potential agent for imaging-guided boron neutron capture therapy. The NIR micelles revealed no cytotoxicity for HepG2 cells. An enhanced and fast endocytosis due to the specific interaction between the HepG2 cells and the glycopolymer could be traced by fluorescence microscopy, and the bioimaging makes it possible to trace the nanoparticles and provides information where and when the neutron irradiation should be triggered.     

锂离子电池硅基负极黏结剂研究进展

硅在自然界中储量丰富,其理论比容量高达4 200 mA∙h/g,已成为高能量密度锂离子电池负极材料的研究热点。但是Si作为负极材料也存在许多不足,最大的问题是电池充放电过程中,硅体积膨胀（高达300%）,导致Si基负极材料粉化脱落、电池容量迅速衰减,其循环性能尚难以满足实际需求。通过研究开发硅基负极专用黏结剂材料,可以有效抑制循环过程中硅的体积变化,维持硅负极结构稳定,提升电池循环性能。本文综述了近年来硅基负极黏结剂材料的研究进展,主要从合成高分子聚合物黏结剂、天然高分子聚合物黏结剂、导电高分子聚合物黏结剂三个方面进行详细归纳总结,并介绍了本课题组在硅基负极黏结剂方面的部分研究成果,期望能为将来的硅基负极专用黏结剂的研究和应用提供一些思路。     

Optimization of C/TiCx duplex diffusion barrier coatings for SiCf/Ti composites based on interfacial structure evolution exploration

Introducing a carbon single coating is a popular method used to protect SiC_f/Ti composites from severe interface reactions. However, carbon coatings lose their protective effect on SiC fibres at high temperature, even after a short period time. As such, given the strong demand for high temperature applications in aeronautics and astronautics a more coating which is more effective at high temperatures is desirable. In order to improve the high temperature interfacial stability of SiC_f/Ti composites, a C/TiC_x duplex coating system with different C contents in TiC_x was introduced to explore the protection of fibres at 1200?°C for 1?h. The results show that the C/quasi-stoichiometric TiC coating system protects the SiC fibres most effectively. Based on insights from the evolution of the interface structure, TiC_x has been identified as an interfacial reaction product from the C single coating, exhibiting a gradient in C content and grain size, which is different from a deposited TiC layer with a well-distributed composition and structure. The different coating structure gives rise to different ability to resist C diffusion at high temperatures, in which poor resistance ability appears in TiC_x interfacial reaction layer coming from C single coating due to short-circuit diffusion in C-rich fine-grained TiC layer and fast intracrystalline diffusion trigged by amounts of vacancies in sub-stoichiometric coarse-grained TiC layer. Therefore, C/quasi-stoichiometric TiC duplex coatings with a thick, coarse-grained quasi-stoichiometric TiC layer could effectively inhibit C diffusion by comparison to C single coatings, and is more effective than C/rich-carbon TiC duplex coatings due to the existence of short-circuit diffusion in the latter. As such, C/quasi-stoichiometric TiC duplex coatings appear to be an optimal diffusion barrier for SiC_f/Ti composites at high temperature.     

焊缝表面缺陷激光扫描三维重构测量

为检测工件焊缝表面缺陷，采用点激光位移传感测距法和数据拟合技术进行焊缝表面缺陷检测试验研究. 首先采集缺陷表面轮廓数据点，利用高斯滤波对原始数据降噪处理. 再对处理后的数据点进行Delaunay三角剖分，使散乱点连接并结合其空间坐标重构出缺陷的三维模型. 结果表明，基于点激光位移传感测距技术及焊缝表面缺陷三维重构方法可以准确判断焊缝成形情况.     

Rare earth element cerium substituted Ca–Si–Mg system bioceramics: From mechanism to mechanical and degradation properties

Cerium (Ce)-substituted diopsides (CaMgSi₂O₆) with enhanced mechanical strength and bioactivity were fabricated by precipitation method, followed by annealing at 1000 °C for 4 h. The mineralogical, morphological, in vitro biomineralization, degradation, and mechanical properties were investigated in order to assess the factors and mechanisms affecting the resultant properties. The X-ray diffractometer results showed that the onset of substitutional solid solubility in 0.25 mol Ce would result in new phase formation (cerium dioxide [CeO₂], and magnesium silicate [MgSiO₃]) further causing lattice instability. With increasing Ce dopant levels to 1.00 mol, the initial CaMgSi₂O₆ phase was completely replaced by new phases. The field-emission scanning electron microscopy results indicated that the 0.25 mol Ce had the best biomineralization performance in vitro, while less hydroxyapatite precipitates were found with further increasing Ce dopant levels, suggesting the new phases led to the hindrance of precipitates. The weight loss values indicated that the high dissolution rate of ions in the matrix was observed in the pure sample, while the high readsorption rate of ions in the simulated body fluid (SBF) occurred with increasing Ce dopant levels. The pH value and the inductively coupled plasma-mass spectrometer results suggested that the release of Ca and Mg ions controlled the pH value. The mechanical strength of matrices before SBF immersion was related to the phase transformation, the elastic modulus of CeO₂ and CaMgSi₂O₆, and the release of Mg ions, while the mechanical strength of matrices after SBF immersion was dominated by the structure of matrices.     

Fabrication strategies and application fields of novel 2D Ti3C2Tx (MXene) composite hydrogels: A mini-review

Ti₃C₂T_x (MXene), a new kind of 2D ceramic nanosheets, is receiving more and more attention in the fields of medicine, biology, energy, electronics, etc. However, the preparation and application of MXene in hydrogel is still in its infancy period. Here, we review the latest progress (after 2018) related to MXene hydrogels in time. Aiming at the key issue of the dispersion stability of MXene in hydrogel systems, the preparation strategy, mechanism, advantages and disadvantages of MXene hydrogels are sorted out in detail, and the potential application prospects of MXene composite hydrogel are introduced. Finally, future viewpoints are put forward for the dispersion stability challenges that need solving in the design of MXene hydrogel.     

一种新型10 kV双环网结构

通过比对国内外配电网网架情况,提出一种新的10kV双环网结构,并应用在实际案例中,结果表明该结构在满足负荷、可靠性的要求下,能够有效降低线路半径、节约投资.     

复杂框排架结构体系抗震设计及性能分析

工业厂房内部附楼框架与大柱网主厂房相连不允许设防震缝时,结构抗侧力体系往往复杂且不规则.针对某内嵌多个框架的大柱网厂房,进行了合理的抗侧力构件布置,选择了合适的性能目标,采用两种软件对整体结构进行了设计和性能分析,并单独提取附楼模型与整体模型进行包络设计.分析结果显示通过不断调整支撑布置,结构规则性已调整至较好的水平,结构基本达到预期的抗震性能目标,且具有较好的二道防线.