新型磺酸盐型Gemini表面活性剂的合成及其与聚合物相互作用

以溴代正烷烃、乙二胺、1,3-丙磺内酯合成了一系列新型磺酸盐型Gemini表面活性剂(SGS-8、SGS-10、SGS-12、SGS-14);采用IR、1H NMR及元素分析等手段对合成产物进行结构表征,并研究了其表面活性,采用等温滴定微量热技术、表面张力法和稳态荧光光谱法研究了SGS-12与聚丙烯酰胺(PAM)的相互作用规律及热力学参数。结果表明,合成的产物纯度较高,具有较低的cmc值和较好的表面活性;SGS-12/PAM混合体系的表面张力曲线和芘探针在体系中微极性的变化表明,二者发生相互作用且形成混合胶束;SGS-12与PAM结合是一个由焓驱动的自发过程,△H和△S均小于0,表明相互作用力以氢键和范德华力为主,合成产物在聚丙烯酰胺分子上的平均结合数为287。     

基于LMS自适应时延估计和FPGA的超声波测风系统研究

利用超声波传感器进行风速测量时,温度对超声波传播有很大影响,时延估计对超声波测风系统的精度起到很大的作用。本超声波测风系统为避免温度对风速测量中的影响,采用了基于时差法的测量原理,为了提高时延估计值的精度,提出了基于最小均方(LMS)自适应时延估计的测量方法,研制了以单片机Atmega128和现场可编程门阵列(FPGA)为核心的硬件系统。仿真和实际测试的结果表明,该超声波测风系统的时延估计值精确度较高,具有很高的应用价值。     

THE ADSORPTION BEHAVIORS OF TOLUENE ON HYPERCROSSLINKED RESINS

1. INTRODUCTION Toluene has been widely used for many industrial purposes. Owing to their toxicity and recalcitrance, the presence of toluene in the natural environment, especially in the groundwater, has been a great concern. The removal of toluene is of…     

THE ADSORPTION BEHAVIORS OF 2,6-DICHLOROPHENOL ONTO HYPERCROSSLINKED RESINS

1. INTRODUCTION Chlorophenolic compounds are very toxic, and many are known or suspected human carcinogens. They have been widely used for many industrial purposes. The removals of chlorophenols are of high industrial and environmental interest [1~2]. The adsorption resin is another adsorbent widely employed for isolation and purification of organic substances, treatment of wastewaters, solid phase extraction, and so on. A variety of materials has been developed and tested, such as Amber…     

间接原子吸收光谱法测定氢溴酸山莨菪碱

研究了原子吸收光谱法间接测定氢溴酸山莨菪碱。在溶液pH为 5 1～ 5 3,当四苯硼钠过量时可完全沉淀氢溴酸山莨菪碱 ;加入过量的氯化钾沉淀滤液中剩余的四苯硼钠 ;干过滤 ,用原子吸收分光光度计在76 6 5nm波长下测定滤液中过量的钾 ,因四苯硼钠与氢溴酸山莨菪碱和氯化钾均按 1∶1的计量关系生成沉淀 ,可以直接计算得到氢溴酸山莨菪碱的含量。对氢溴酸山莨菪碱注射液进行了测定 ,测定结果准确。方法简单快速 ,回收率在 96 %～ 10 3%之间 ,相对标准偏差为 1 4 %。该方法可进一步推广原子吸收光谱法在其他相关药物测定方面的应用。     

两性孪联表面活性剂的合成及溶液性质

用C10～C16脂肪醇与2-氯-2-氧-1,3,2-二氧磷杂环戊烷低温反应生成环状磷酸酯的中间产物,再用N,N-二甲基十二胺在亲核溶剂中65℃下开环反应合成了4种含N 和磷酸根阴离子的两性孪联表面活性剂C10-C12、C12-C12、C14-C12和C16-C12,其质量收率分别为32%、54%、18%和28%。产物的结构通过1HNMR和元素组成分析,表明两性离子表面活性剂C、H、O、N的分析值与理论计算值偏差不超过0.3%。四种表面活性剂的临界胶束浓度(cmc)在0.0072~0.0125mmol/L之间,临界胶束浓度时表面张力(γcmc)依次为23.90、25.61、27.68和36.08mN/m。其中,C10-C12、C12-C12和C14-C12有较好的界面活性,加入盐可以使表面活性剂与烷烃间的界面张力下降,但下降程度有限,不能达到超低界面张力(10-3mN/m)。     

Synthesis of 1,4‐Cyclohexanedimethanol, 1,4‐Cyclohexanedicarboxylic Acid and 1,2‐Cyclohexanedicarboxylates from Formaldehyde,Crotonaldehyde and Acrylate/Fumarate

Valuable polyester monomers and plasticizers—1,4‐cyclohexanedimethanol (CHDM), 1,4‐cyclohexanedicarboxylic acid (CHDA), and 1,2‐cyclohexanedicarboxylates—have been prepared by a new strategy. The synthetic processes involve a proline‐catalyzed formal [3+1+2] cycloaddition of formaldehyde, crotonaldehyde, and acrylate (or fumarate). CHDM is produced after a subsequent hydrogenation step over a commercially available Cu/Zn/Al catalyst and a one‐pot hydrogenation/oxidation/hydrolysis process yields CHDA, whereas 1,2‐cyclohexanedicarboxylate is obtained by a Pd/C‐catalyzed tandem decarbonylation/hydrogenation step.     

二茂钛含氟有机酸衍生物的质谱研究

本文研究了二茂钛含氟长链有机酸衍生物(1～3)和具有环状结构的新型二茂钛全氟有机酸(4～7)的电子轰击质谱(EIMS)和负离子化学电离质谱(NICIMS)。在EI谱中出现弱的或不出现M~+,1～7均以CpTiF_2离子为基峰。高质量区的主要特征碎片离子有[M-·cp]~+、[M-R]~+(1～3)和氟重排离子。在低质量区出现一系列二茂钛及茂钛氟重排离子。 1、4～7的NICI(CH_4)质谱中,4、5出现强的M~-离子峰,1出现[M-1]-离子峰,有两个钛的环状结构化合物6和7出现双电荷M~=离子峰,而不出现M~-。     

Accurate discrimination of Gastrodia elata from different geographical origins using high‐performance liquid chromatography fingerprint combined with boosting partial least‐squares discriminant analysis

Gastrodia elata from different geographical origins varies in quality and pharmacological activity. This study focused on the classification and identification of Gastrodia elata from six producing areas using high‐performance liquid chromatography fingerprint combined with boosting partial least‐squares discriminant analysis. Before recognition analysis, a principal component analysis was applied to ascertain the discrimination possibility with high‐performance liquid chromatography fingerprints. And then, boosting partial least‐squares discriminant analysis and conventional partial least‐squares discriminant analysis were applied in this study. Experimental results indicated that the adaptive iteratively reweighted penalized least‐squares algorithm could eliminate the baseline drift of high‐performance liquid chromatography chromatograms effectively. And compared with partial least‐squares discriminant analysis, the total recognition rates using high‐performance liquid chromatography fingerprint combined with boosting partial least‐squares discriminant analysis for the calibration sets and prediction sets were improved from 94 to 100% and 86 to 97%, respectively. In conclusion, high‐performance liquid chromatography combined with boosting partial least‐squares discriminant analysis, which has such advantages as effective, specific, accurate, non‐polluting, has an edge for discrimination of traditional Chinese medicine from different geographical origins. And the proposed methodology is a useful tool to classify and identify Gastrodia elata from different geographical origins.     

Exhaled gas detection by a novel Rh-doped CNT biosensor for prediagnosis of lung cancer: a DFT study

Lung cancer has received considerable attention in recent years due to its high mortality. The difficulty in awareness of such disease can be attributed to its strong insidiousness during the early stage. Therefore, the prognosis of lung cancer becomes significant so as to nip this disease in the bud. In this paper, the Rh-doped CNT-based biosensors were introduced to realise the diagnosis of lung cancer through detecting the exhaled gas of possible patients. The adsorption property and sensing mechanism of Rh-CNT towards two kinds of mainly typical gases of lung cancer, namely, C₆H₆ and C₆H₇N, were analysed based on density functional theory, aiming at evaluating the potential application of such material to be gas sensors. The results indicated that the Rh-CNT not only has good adsorption towards such two gases but also obvious conductivity increase when interacted with any of them, while presents insensitivity upon the common exhaled gas, CO₂. We suggest the Rh-CNT be prepared as biosensors applied in the field of lung cancer pre-diagnosis that can be used in our daily life without pain and complex clinical examination.