Surface modification of hydrophobic NaYF_4:Yb,Er upconversion nanophosphors and their applications for immunoassay

β-NaYF4:Yb,Er upconversion nanophosphor (UCNP) is known as one of the most efficient NIR-to-visible upconversion materials, which shows great potential in bioanalytical chemistry and bioimaging. However, its applications are greatly limited due to its low water dispersibility and thus poor biocompatibility. In this paper, poly(acrylic acid) (PAA)-based ligand exchange strategies are carried out to modify oleic acid-capped hydrophobic β-NaYF4:Yb,Er UCNPs into hydrophilic ones. After efficient surface modific...     

Spectral Characteristics of LiSrBO3：Tb^3＋ Green Phosphor

LiSrBO3:Tb3+ green phosphor was synthesized by means of a solid state reaction and its spectral characteristics were studied. The emission spectrum of LiSrBO3:Tb3+ consists of four major bands at 486, 544, 595 and 620 nm under the excitation of near ultraviolet irradiation, which are originated from the 5D4→7F6, 5D4→7F5, 5D4→7F4 and 5D4→7F3 characteristic transitions of Tb3+, respectively. Monitored at 544 nm, the excitation spectrum of the phosphor extends from 220 nm to 390 nm, with the excitation peaks c...     

对酞内酰胺苯甲酰氯柱前衍生反应HPLC分析痕量多胺

本文提出了一种快速、简便、灵敏检测痕量多胺的新方法。用对酞内酰胺苯甲酰氯同多胺进行柱前衍生反应,以反相高效液相色谱定量测定多胺含量。在4～500 pmol范围内有良好的定量线性关系,腐胺、精脒和精胺的检测限均为0.1 pmol。     

二次冷却对板坯中间裂纹的影响

目前,如何在保证铸坯质量的前提下提高内部质量,特别是防止影响最终产品轧制性能的严重中间裂纹的出现,是转炉一连铸治金工艺路线存在地普遍问题。结合连铸板坯凝固过程的二冷DYNACS冷却模型模拟计算,阐述了二次冷却对铸坯中间裂纹的影响,并在此基础上提出了解决方案。     

超声技术在焦化废水处理中的应用与研究进展

超声技术作为一种新型的氧化方法,能提高难降解有机物的降解率和增强水处理中的可生化性,在焦化废水处理中已经发挥了一定的作用并有广阔的发展前景。介绍了焦化废水的性质及成分以及超声空化降解难生物降解有机废水的机理和主要影响因素对降解焦化废水中污染物的影响及其机理,并综述了超声技术在焦化废水处理中的应用与研究进展。     

基于神经网络的管件开式冷挤压相对伸长量预测

为了预测各参数组合下的无芯棒开式冷挤压厚壁管件的伸长量，拓展开式冷挤压的实验结果，建立了无芯棒开式冷挤压厚壁管件的伸长量预测的神经网络模型，通过实验结果与预测结果的比较，二者吻合良好，为深入研究开式冷挤压工艺，建立开式冷挤压工艺设计专家系统提供了新的思路。     

Effective Factors on Forming Precision in Patternless Casting Manufacturing Technique

The patternless casting manufacturing (PCM) technique, which adopts a new concept of double scanning method, combines the principle of discreteness and deposition with resin-bonded sand technique. This paper is to evaluate the dimensional accuracy of sand mould on PCM. The two important factors-the liquid penetration rule in the space of particles and the shape and dimension of the agglomeration unit body, which influence the process parameters such as scanning speed, layer thickness, liquid flux on dimension accuracy, and surface qualities, were investigated systematically, thus the theoretical basis for these parameters was provided. Experiments on rapid manufacturing of sand mould were carried out, and the results of the free penetration and the constraint penetration well verified the relationship of the two factors and the process parameters.     

汽车防护气袋有效性研究

介绍与汽车防护气袋有效性有关的计算机模型参数，并用以分析气袋设计是否可以根据一些参数来进行调整，以适应更广泛的碰撞情况．     

白洋淀内水体的流动特征研究

研究了风对白洋淀内水体循环流动的影响，研究指出：(1)风应力可看作是水体循环 的主要驱动力. (2)在风应力的作用下，水体表层的流动主方向与风的方向一致，下层水体 的流动方向与表层方向相逆或近似相逆. (3)表层以下水体流动复杂，次表层水平流动有明 显的双涡结构. (4)淀底地形对水体垂向流动影响很大，垂向速度变化复杂，垂向上有双涡 流动现象. 从动力学角度研究了淀内水体流动的情况.     

二氧化锆及其复相氮化硅陶瓷

分析了二氧化锆的性质及氧空性对二氧化锆相变的影响，讨论了二氧化锆韧化氮化硅陶瓷的影响因素，提出了二氧化锆韧化氮化硅陶瓷时避免氮化锆生成、促进复相氮化硅陶瓷烧结的途径。