Synthesis of high-quality semiconductor nanoparticles in a composite hot-matrix

Semiconductor nanocrystals are of a great interest for many practical applications which motivates the search of low cost and environmental-friendly methods for their manufacturing. Here we report the synthesis of CdSe and CdS nanoparticles utilizing composite matrix of liquid paraffin as a non-coordinating solvent and stearic acid as a coordinating ligand. The nanoparticle growth kinetics is compared to that of the classical synthesis in trioctylphosphine oxide matrix. It is found that the nucleation and crystal growth are remarkably affected by the coordinating ligand. The CdSe and CdS nanocrystals can be isolated and purified from the matrix which makes it possible their large-scale synthesis for applications.     

分子极化效应与烷烃、醇的空腔表面积

烷烃以及醇在水中形成的空腔表面积CSA可由下式计算:CSA=122.984+8.65736SBL-103.862ΔMPEI。其中SBL是分子中所有化学键长度的总和, ΔMPEI是含有相同碳原子数目的(烷烃或者醇)支链异构体分子极化效应指数MPEI支与直链异构体分子极化效应指数MPEI直的差值。     

Gallium-containing zeolites: characterization of catalytic role of gallium species in converting light paraffins to aromatics

The structures and the chemical nature of gallium species in gallium-containing zeolite catalysts prepared by hydrothermal synthesis and post-synthesis treatments are discussed based on the results of X-ray absorption spectroscopy (XAS), including X-ray absorption near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS), and nuclear magnetic resonance (NMR) investigations. The in-situ analysis of properties of gallium active sites during oxidation/reduction cycles has been found to be further helpful on the understanding of the catalytic role of gallium species in the aromatization of alkanes.     

The effect of zinc stearate on thermal degradation of paraffin wax

In this research, the effects of zinc stearate addition on paraffin wax degradation were investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG). The apparent activation energies of wax decomposition in nitrogen and air atmospheres were determined as 76 and 37 kJ mol⁻¹, respectively applying Kissinger method to TG data. The degradation rate constants of paraffin containing zinc stearate (0.1–0.5%) were found to be almost two times greater than that of paraffin only in air atmosphere. However, zinc stearate did not affect the rate constants in nitrogen significantly.     

内扩散行为对F-T合成反应过程影响的研究

选用Co/ZrO2催化剂,通过改变催化剂颗粒径,在积分固定床反应器上研究了内扩散行为对F-T合成反应过程的影响。以表观活化能、烯/烷比的变化等为依据,考察了内扩散行为对F-T合成反应历程、催化剂活性及产物选择性的影响。催化剂颗粒径不同,内扩散限制程度会发生相应变化。实验结果表明,不同程度的内扩散限制条件下,F-T合成反应历程会有较大差异。当反应开始后,颗粒内孔从"干"到"湿",不同粒径的催化剂颗粒上气态烯/烷比变化均呈"U"型趋势。在固定床反应器上,增加空速通常会有CH4选择性升高、气态烯/烷比略有增加的现象,这是由于内扩散限制未完全消除的缘故。     

蓄热调温石蜡相变微胶囊的制备及性能

采用界面聚合法,以甲苯2,4-二异氰酸酯和哌嗪为反应单体、30号相变石蜡为芯材,制得了一种智能纺织品用蓄热调温相变微胶囊。通过红外光谱、扫描电镜、差示扫描量热仪对微胶囊的化学组成、形貌和蓄热性能进行了表征,测试了其耐热和耐溶剂性。结果表明:所得微胶囊主要为球形,表面光滑,平均粒径为10.6μm,对w=0.40的NaOH溶液、w=0.60的H2SO4溶液、无水乙醇、丙酮稳定,能被甲苯、二甲基甲酰胺、乙醚破坏。相变潜热为118 J/g,石蜡在微胶囊中的质量分数为84%。     

延长Rb原子退相干时间镀膜材料的可行性研究

实验测量了镀石蜡Rb池和石英玻璃Rb池中Rb原子自旋态寿命. 研究表明,镀石蜡Rb池的Rb原子自旋态寿命在温度T=50℃约为7　ms,而在同样温度的石英玻璃池中,Rb原子自旋态寿命仅为20 μs. 这为基于自旋的量子存储实验提供了很好的借鉴. 同时讨论了其他候选的材料来隔绝碱金属原子和容器壁的非弹性碰撞相互作用. 根据实验结果,我们认为H原子布于笼状结构内部的C₆₀H₆₀以及BN材料有较大的实用前景.     

二乙基二硫代氨基甲酸铜电化学传感器的研究

研制了二乙基二硫代氨基酸铜电位型传感器，并考察了电极性能，该修饰电极对Ｃｕ＾２＋具有类能斯特响应。电极已应用于试样分析。     

基于石蜡庚烷溶液的低成本纸基微流控分析装置的制备及其应用

介绍了一种新型的使用石蜡庚烷溶液制备纸基微流控分析装置的工艺,操作更加简单迅速,成本更加低廉。使用混合样品溶液进行测试,证明该装置可以完成对蛋白质、葡萄糖和pH值的同时检测,并可以用于定量分析。纸基微流控分析装置对样品检测的精度范围分别为:牛血清蛋白2.0×10-5~1.00×10-4mol/L,葡萄糖0.02~0.1 mol/L。并对加热处理过程中微流控通道壁的扩散现象进行了初步研究,发现加热前后通道壁厚度的变化呈线性规律。     

Extracellular matrix alterations in low‐grade lung adenocarcinoma compared with normal lung tissue by imaging mass spectrometry

Lung adenocarcinoma (LUAD) is the second most common cancer, affecting both men and women. Fibrosis is a hallmark of LUAD occurring throughout progression with excess production of extracellular matrix (ECM) components that lead to metastatic cell processes. Understanding the ECM cues that drive LUAD progression has been limited due to a lack of tools that can access and report on ECM components within the complex tumor microenvironment. Here, we test whether low‐grade LUAD can be distinguished from normal lung tissue using a novel ECM imaging mass spectrometry (ECM IMS) approach. ECM IMS analysis of a tissue microarray with 20 low‐grade LUAD tissues and 20 normal lung samples from 10 patients revealed 25 peptides that could discriminate between normal and low‐grade LUAD using area under the receiver‐operating curve (AUC) ≥0.7, P value ≤.001. Principal component analysis demonstrated that 62.4% of the variance could be explained by sample origin from normal or low‐grade tumor tissue. Additional work performed on a wedge resection with moderately differentiated LUAD demonstrated that the ECM IMS analytical approach could distinguish LUAD spectral features from spectral features of normal adjacent lung tissue. Conventional liquid chromatography with tandem mass spectrometry (LC‐MS/MS) proteomics demonstrated that specific sites of hydroxylation of proline (HYP) were a main collagen post translational modification that was readily detected in LUAD. A distinct peptide from collagen 3A1 modified by HYP was increased 3.5 fold in low‐grade LUAD compared with normal lung tissue (AUC 0.914, P value <.001). This suggests that regulation of collagen proline hydroxylation could be an important process during early LUAD fibrotic deposition. ECM IMS is a useful tool that may be used to define fibrotic deposition in low‐grade LUAD.