Ti2SiC2/Cu纳米复合材料的制备与微观组织

研究了用微米级Ti2SiC2陶瓷与Cu制备纳米复合材料的工艺过程。分别选用钢球和玛瑙球进行球磨，对Ti2SiC2颗粒的细化和在Cu中分散性的影响进行了研究。结果表明，在其它实验参数相同的情况下，用两种不同材质的磨球所获得的混合粉形态有很大差异，用玛瑙磨球可以更好地使Ti2SiC2颗粒细化并均匀分散在Cu基体中，而用钢球则易产生混合粉的团聚。另外，随着球磨时间的延长，Ti2SiC2先后经历了颗粒细化、均匀镶嵌在基体中两个阶段。对球磨后的混合粉在850℃及20MPa的压力下成功地制备了组织成分均匀的大块纳米复合材料，其力学性能与同成分的普通复合材料相比有明显提高。     

聚酯型粉末涂层附着力异常的原因分析

针对热镀锌板表面聚酯型粉末涂层附着力异常的问题,对比了涂层脱落和正常前处理的基材表面形貌、元素组成、清洁度和红外光谱,得出涂层附着力异常的原因为基材表面在喷涂前发生氧化和油污未除净,给出了相应的解决措施。     

Facile Deposition of Silver Nanoparticles on Photonic Cellulose Nanocrystals Films: A Study on Solvent Stability and Post Antibacterial Activity

Cellulose nanocrystals (CNCs) incorporated with silver nanoparticles (AgNPs) photonic films have drawn considerable attention due to their plasmonic chiroptical activity. However, the exploitation of some fundamental properties for practical use such as the affinity analysis of metal nanoparticles attached to the surface of photonic films according to the solvent compatibility and antibacterial activity under physical conditions has yet not been studied. Hence, a facile process of in situ deposition of AgNPs into the chiral structure of CNC films is proposed. CNC photonic films, cross-linked by glutaraldehyde are prepared. This interaction generated the solvents-stable photonic film with a considerable amount of unreacted aldehyde functional groups that facilitates the reduction of Ag salt to AgNPs. The formed AgNPs in the photonic films show excellent stability over immersion in various polar and non-polar solvents. The post-solvent treated photonic films display excellent contact-based antibacterial behavior against gram-negative Escherichia coli.     

无机超细粉体改性锂离子电池隔膜的研究进展

综述了近年来无机超细粉体改性锂离子电池隔膜的研究进展,首先介绍了已在锂电隔膜改性上商业应用的Al₂O₃和AlOOH对传统聚烯烃膜和新型静电纺丝膜的改性方法和改性效果,随后又对常规无机材料TiO₂和SiO₂粉体对锂电隔膜的改性进行了叙述,最后对BN等非常规隔膜改性无机材料进行了简介;总结和讨论了无机材料改性后隔膜的组分、结构和性能对锂离子电池综合性能的影响,并对其无机材料改性锂电池隔膜的未来发展趋势进行了展望。     

混合材对水泥浆体泌水性能的研究

通过调整水泥中钢渣粉、粉煤灰和石灰石粉的含量,检测水泥浆体泌水速率,研究了多种混合材对水泥的泌水性能的影响,结果表明：建立的水泥浆体泌水检测方法可以表征水泥的泌水性能;5%～6%的钢渣粉的加入促进了水泥整体的保水效果,泌水速率和累积泌水率较现行水泥配比和中联水泥的低,但水泥成本上升 2.13元/t和2.89元/t;粉煤灰因其密度低,且多为球状形貌,不利于水泥泌水性能;2%石灰石粉的加入,可降低水泥的泌水率和累积泌水率,其性能曲线与中联水泥的相近,水泥成本降低0.96元/t。     

CHARAC TERIZATION OF TiAl POWDER PRODUCED BY MECHANICAL ALLOYING

The microstructure,alloying reaction and sintering behavior of the powder produced by Mechanical Al-loying(MA)for 8 h from 64 wt.-% Ti powder and 36 wt.-% Al powder were studied by scanning electronmicroscopy,optical microscopy,X-ray diffractometry,differential scanning calorimetry(DSC)and dilatometry.The mechanically alloyed powder partictes are Ti-Al composite particles.Thus,titanium aluminides can formeasily in the powder through diffusion during heat treatment.It is shown that the sintering behavior of this pow-der,different from the behaviors of TiAl alloy powder and mixed powder of 64 wt.-% Ti powder and 36 wt.-%Al powder,changes from expansion at temperatures below 1000℃ to shrinkage at temperatures above 1000℃.Homogeneously alloyed TiAl material with a density over 96% of the theoretical density can be produced fromthe mechanically alloyed powder by compaction-sintering.     

Characterization of ultrafine La x Sr1−x MnO3 powder prepared by spray pyrolysis

The characterization of La _x Sr_1−x MnO₃ powders produced by spray pyrolysis using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observation, specific surface area (Brunauer-Emett-Teller), and particle size distribution measurements shows that the resultant large particles are loose agglomerates consisting of many small particles. However, the sintered tiny particles can form hard agglomerates, and the particle size increases remarkably. The structures of the powders before and after sintering were identified by x-ray diffraction (XRD). The study of the electrical property of the powder shows that the powder is a metallic conductor. In a reducing atmosphere, the powder can be decomposed. When the powder is cofired with yttria-stabilized zirconia 5% (YSZ) powder at 1200 °C for 5 h, no new phase is produced, and the powder remains a single provskite hexagonal-rhombohedral structure.     

超细粉颗粒形貌控制技术的研究

颗粒形貌对颗粒群的许多性质具有重要的影响。本研究以流化床气流磨加工碳化硅磨料微粉为实例，对颗粒形貌控制的基本因素进行理论分析与实验研究，并探讨了超细加工后的整形技术及超细加工前的预处理技术。可获得球形化程度好的等积形颗粒形貌，也可获得较好的多棱形颗粒形貌，这对提高超细粉的工业价值和经济价值，扩大应用领域和范围，具有重要的意义。     

高压粉末制样-X射线荧光光谱法测定海洋沉积物中28种组分

常规粉末压片制样是一种简单、高效的绿色环保制样技术,但是应用于某些沉积物样品制备存在样片表面粗糙和粉末容易脱落的问题。实验采用高于常规的压力进行样品制备,建立了X射线荧光光谱法(XRF)分析海洋沉积物样品中包括硫、氧化钠、氧化镁、三氧化二铝、二氧化硅、五氧化二磷、氧化钾、氧化钙、二氧化钛、氧化锰、三氧化二铁、钴、镍、铜、锌、钒、铬、镓、铌、锆、钇、锶、铷、铅、钡、镧、钕和铪在内的28种主、微量组分的方法。探讨了压力为300 kN和1 600 kN时的制样效果,并尝试引入BP神经网络模型利用其非线性拟合能力校正主量组分的基体效应。结果表明,采用1 600 kN压力制备的样片,表面致密、光滑、不龟裂和不掉粉,制样重复性和测试精密度也有较大提高。以55个有证标准物质中17种组分的数据集为训练样本,建立了海洋沉积物样品中主、微量组分的遗传算法-BP神经网络预测模型。按照实验方法对各组分含量相对较低的实际样品连续测试12次,计算得方法的检出限在 0.63～634 μg/g之间;精密度试验结果表明,各组分测定值的相对标准偏差(RSD, n=7)为0.16%～25.1%。方法用于海洋沉积物实际样品分析,其分析结果与国标法的测定结果吻合,能够满足海洋沉积物样品中多种组分准确分析的要求。     

高技术产品用无源元件与中国钽工业发展

世界高技术产品市场总体看呈增长趋势，预计2020年销售额将比2000年翻一番。以高技术产品为主要应用领域的电阻、电容、电感等无源元件，也将随着高技术产业的发展呈现出良好的市场前景，但是钽电容器市场近几年表现出骤涨急落的发展态势。由于钽电容器产能过剩，且面临着被替代的威协，因此价格将无法返回到2000年以前的水平，并呈现整体持续走低的趋势。中国的钽工业发展应注重提高企业自身的综合竞争力，加强企业间的沟通、交流与合作，维护我国钽工业的整体利益，增强环保意识，做好国外转移到我国的初级产品和低端产品生产的环保工作。