纳米TiO2光催化技术在室内空气净化方面的应用进展

本文介绍了纳米TiO2光催化材料的空气净化原理及纳米TiO2光催化材料的特点,综述了目前纳米TiO2光催化材料在实际应用中存在的问题和研究现状并指出了发展趋势。     

Gas sensors for CO_2 detection based on RGO–PEI films at room temperature

In this paper,polyethyleneimine(PEI)and reduced graphene oxide(RGO)were selected as sensing materials for carbon dioxide detection.Two kinds of sensors with different sensitive film structures,i.e.,RGO–PEI composite film and RGO–PEI bi-layer film were fabricated by airbrushing the sensitive films on interdigitated electrodes.Response performances of both sensors at room temperature were investigated.Results showed that sensors with bi-layer film exhibited smaller baseline drift and more stable sensing characteristics than the counterparts with composite film.Furthermore,bi-layer film sensors with different quantity of PEI solution deposited were studied.Performances of long-time stability,repeatability,low concentration of detection for carbon dioxide,and measurements of response time and recovery time were investigated.It was found that appropriate weight ratio of RGO and PEI was critical for sensing response.In addition,the sensor with bi-layer film exhibited a better repeatability but had longer response time and recovery time than RGO single-layer sensor,and both of them could detect as low as20 parts per million carbon dioxide gas.Sensing responses of the prepared sensors to carbon dioxide under dry air or nitrogen were compared.The relevant sensing mechanisms were studied as well.     

竹材碎料复合板的结构设计与弯曲性能预测理论

对称结构的竹材碎料复合板静曲强度与弹性模量试验值与试件宽度无相关性。根据这一规律,用拟梁法研究了竹材碎料复合板受横向载荷时的刚度特性和应力分布特性,并推导出竹材碎料复合板静曲强度和弹性模量的理论估计模型;提出了竹材碎料复合板的最佳结构设计准则;对不同支承跨距时试件的破坏形式进行了分析,提出了竹材碎料复合板在实际使用时的失效判据。     

不锈钢拉深制品表面质量改进研究

本文对影响不锈钢拉深制品表面质量的因素进行了研究。Si3N4-SiCw复合陶瓷凹模和工件之间的粘连和摩擦要大大小于传统的模具材料．Si3N4发生化学反应的产物可以降低摩擦。水基润滑剂可以通过边界润滑、极压反应和固体粉剂润滑,以及较强冷却性能的共同作用减小凹模圆角处和工件之间的摩擦。因此采用Si3N4-SiCw复合陶瓷作为凹模并使用水基润滑剂可以提高拉深制品的表面质量和模具的寿命。     

海南部分野生菊科植物类缘关系的RAPD分析

对海南境内的30份野生菊科植物和2份栽培种菊科植物进行了RAPD扩增,构建了这32份材料的指纹图谱,并进一步利用所得数据建立了这些材料的RAPD系统进化树.其中引物S40扩增的指纹图谱特异性最强,能同时将这32份材料明确区分开来,故可作为种质鉴定的重要依据.     

基于对抗迁移的复合材料检测领域命名实体识别

命名实体识别(named entity recognition, NER)可整合复合材料检测领域相关数据精准提取关键实体信息,促进产业信息化,为行业发展提供技术支撑。针对复合材料检测领域专业名词过多及边界混淆等问题,提出了一种基于对抗训练(adversarial training)和BERT(bidirectional encoder representations from transformers)嵌入相结合的领域命名实体识别模型(BERT-AdBC)。首先,复合材料检测领域数据规模较小,BERT嵌入增强了领域迁移能力,通过融合字向量获取充分的语义表示;其次,领域语句繁杂冗长,引入自注意力机制结合双向长短期记忆网络(Bi-LSTM)模型增强了上下文之间语义关系的获取;最后,对抗训练利用分词任务与实体识别任务的共享信息解决了边界混淆问题。实验结果表明,本文所提出的BERT-AdBC模型对复合材料检测领域实体识别的效果要优于传统模型,综合评价指标F₁最高提升6.48%。     

等离子喷涂Ni60A/MoS_2复合润滑涂层摩擦学特性研究

在UMT-2微观磨损试验机上研究了等离子喷涂Ni60A/MoS2复合润滑涂层的摩擦学特性,且对摩擦表面进行了SEM观察和分析.研究结果表明:随着MoS2含量的增加,摩擦因数显现先减小后增大的趋势,并在MoS2的质量分数为40%时达到最小值.随着载荷的增加磨损量明显增大,当载荷由80 N变化到120 N时,载荷对磨损的影响较为显著,120 N时的磨损量大约为80 N时的1.7倍左右,载荷对摩擦因数也有较大的影响,等离子喷涂涂层的主要磨损失效形式为磨粒磨损和粘着磨损.     

CFG桩在山区建筑中的设计应用

位于山区建筑物其填方区地基岩土较差,需要作地基处理,CFG桩能够有效地处理粘性土、粉土、粉细砂、素填土、厚度小于5m的卵石层（卵石含量小于50％）,大大提高承载力,为岩土工程勘察设计、治理提供处理措施和技术参考。     

Fabrication and character ization of electrospun TiO2/CuS micro–nano-scaled composite fibers

A process to fabricate a kind of novel micro–nano scaled TiO2/CuS composite fibers by electrospinning technique and chemical precipitation method was developed in the present study. The microstructures and photoelectronic properties of the fibers were characterize d using SEM, FT-IR, UV–vis and fluorescence spectroscopy. The results revealed that the TiO2 portion in the composite fibers was a mixture rutile and anatase phases while TiO2 and CuS had been fully composite. The fibers had smooth surface with a diameter of 50–300 nm. Comparing with pure TiO2 fiber, the TiO2/CuS micro–nano-scaled composite fibers exhibited a strong absorption in the visible light region and the efficiency of photo-induced charge separation were enhanced. This composite system is of widely potential applications in the areas such as solar cells, supercapacity, photocatalysis, etc.     

环保型有机硅改性/纳米原位复合聚丙烯酸酯粘合剂的制备

采用正交试验法研究无机纳米粉体的修饰工艺,主要包括:分散温度、分散时间和分散助剂的选择及用量,研究了改性纳米粉体用量对丙烯酸酯粘合剂稳定性、皮膜耐水性等性能的影响。研究结果表明:无水乙醇2%(对单体),40Be°硅酸钠溶液5ml,室温分散30min,确定为SiO2粉体表面修饰的工艺。纳米SiO2相对于纳米TiO2对粘合剂性能提升更加明显,也更易分散,且纳米SiO2用量为丙烯酸酯单体的0.6～0.8%时,可得到应用性能较好的纳米原位复合有机硅改性丙烯酸酯乳液。