一种改进的自适应模糊阈值图象分割方法

自适应模糊阈值图象分割方法的关键和困难在于隶属函数窗宽的自动调整和阈值搜索范围的确定.依靠图象灰度的统计特性初步确定阈值搜索范围，提出了一种改进方法，进而得到隶属函数的窗宽.实验表明这种方法避免了确定图象灰度直方图峰位置的困难，对较低亮度图象分割效果良好.     

红外单站被动定位技术速度更新算法研究

针对红外单站被动定位技术中空中机动目标的运动速度不断变化这一实际情况,提出了一种基于红外相机运动特性的对目标的运动速度进行实时更新的校正算法.该算法克服了大多基于匀速直线运动这一空间模型的红外单站被动定位方案目标速度不变的缺点,客观地反映了空中机动目标的实际运动状况,不仅能对目标的运动速度进行实时准确的更新校正,而且可推演出一种新的红外单站被动定位算法,对推动红外单站被动定位技术的工程实用化进程具有重要的意义.     

ORGANIC CHELATING REAGENT ON REDOX ADSORPTION OF ACTIVATED CARBON FIBER TOWARDS Au^3+

Organic chelating reagent influences upon the redox adsorption of activated carbon fibertowards Au3- were systematically investigated. The experimental results indicated that the presenceof organic chelating reagent on activated carbon fiber strongly affects adsorption capacity ofactivated carbon fiber towards Au3+. The reduction-adsorption amount of Au3+ increased three timesby the presence of 8-quinolinol. Furthermore, The reduction-adsorption amount of Au3+ depended onthe pH value of adsorption and temperature.     

改性凹凸棒的制备及对砷离子的吸附研究

针对日益严重的砷离子污染问题，本文采用灵敏简便的原子荧光分析法，探究了凹凸棒石粘土吸附剂对砷离子的吸附性能，测定了pH、吸附时间、砷离子的初始浓度等因素对凹凸棒石粘土负载铁氧化物对砷离子吸附能力的影响，并通过SEM、EDX、FTIR对所制得的吸附剂进行了表征研究，同时进行了吸附动力学和吸附等温模型的分析。研究结果表明，改性后的凹凸棒对砷离子的吸附性能有了显著提升，在较低浓度时吸附效率可达98%，该吸附符合Langmuir等温吸附模型和准二级动力学方程。     

Chiral separation of amino acids derivatized with fluoresceine-5isothiocyanate by capillary electrophoresis and laser-induced fluorescence detection using mixed selectors of beta-cyclodextrin and sodium taurocholate

Chiral separation of 20 pairs of amino acids derivatized with fluoresceine-5-isothiocyanate (FITC) by capillary electrophoresis and laser-induced fluorescence detection was studied using the mixture of beta-cyclodextrin (beta-CD) and sodium taurocholate (STC) as selector. Resolution was considerably superior to that obtained by using either beta-CD or STC alone. The molar ratio of beta-CD to STC of about 2:3 was found to be critical to achieve maximum separation. At this beta-CD-to-STC ratio, chiral separation occurred at really low total concentration of beta-CD and STC (<0.1 mM). Other impacting factors were investigated including the total concentration of beta-CD and STC, pH, and capillary conditioning procedure between two successive runs. Using a running buffer of 80 mM borate containing 20 mM beta-CD and 30 mM STC at pH 9.3, all of the 20 pairs of FITC-amino acid enantiomers were baseline resolved. The resolutions of the most pairs of the amino acid enantiomers (17 of 20) were higher than 3.0, only three pairs gave a resolution lower than 3.0 but higher than 1.90 (beta-phenylserine, pSer). The highest resolution reached 14.58 (Glu). Two derivatives of beta-CD, 2-hydroxypropyl-beta-CD (HP-beta-CD) and heptakis(2,6-di-O-methyl)-beta-CD (DM-beta-CD) were also explored. HP-beta-CD showed similar cooperative effect with STC, while DM-beta-CD together with STC led to poorer chiral separation.     

交换半环中理想的实根

在交换半环范畴中引进和研究理想的实根,从而将实代数学中有关结果推广到交换半环上。如下结果被建立:在半环中,一个理想的实根恰等于包含该理想的所有实理想的交集,并也恰等于包含该理想的所有实素理想的交集。此外,形式更为一般的理想的实根--广义实根被考虑,并获得相应的结果。     

Rapid determination of catecholamines in urine samples by nonaqueous microchip electrophoresis with LIF detection

A method was developed for the rapid separation of catecholamines by nonaqueous microchip electrophoresis (NAMCE) with LIF detection, A homemade pump‐free negative pressure sampling device was used for rapid bias‐free sampling in NAMCE, the injection time was 0.5 s and the electrophoresis separation conditions were optimized. Under the optimized conditions, the samples were separated completely in <1 min. The average migration times of the epinephrine (E), dopamine (DA), and norepinephrine (NE) were 34.26, 43.81, and 50.07 s, with an RSD of 1.05, 1.26, and 0.89% (n = 7), respectively. The linearity of the method ranged from 0.0125 to 2.0 mg/L for E and 0.025～4.0 mg/L for DA and NE, with correlation coefficients ranging between 0.9978 and 0.9986. The detection limits of E, DA, and NE were 2.5, 5.0, and 5.0 μg/L, respectively. The recoveries of E, DA, and NE in spiked urine samples were between 86 and 103%, with RSDs of 4.5～6.8% (n = 5). The proposed NAMCE with LIF detection combined with a pump‐free negative pressure sampling device is a simple, inexpensive, energy efficient, miniaturized system that can be successfully applied for the determination of catecholamines in urine samples.     

Novel electrochemical biosensor based on functional composite nanofibers for sensitive detection of p53 tumor suppressor gene

A novel electrochemical biosensor based on functional composite nanofibers for sensitive hybridization detection of p53 tumor suppressor using methylene blue (MB) as an electrochemical indicator is developed. The carboxylated multi-walled carbon nanotubes (MWNTs) doped nylon 6 (PA6) composite nanofibers (MWNTs–PA6) was prepared using electrospinning, which served as the nanosized backbone for pyrrole (Py) electropolymerization. The functional composite nanofibers (MWNTs–PA6–PPy) used as supporting scaffolds for ssDNA immobilization can dramatically increase the amount of DNA attachment and the hybridization sensitivity. The biosensor displayed good sensitivity and specificity. The target wild type p53 sequence (wtp53) can be detected as low as 50 fM and the discrimination is up to 57.5% between the wtp53 and the mutant type p53 sequence (mtp53). It holds promise for the early diagnosis of cancer development and monitoring of patient therapy.     

Anisotropic charge carrier transport of optoelectronic functional selenium-containing organic semiconductor materials

Organic semiconductors (OSCs) materials are currently under intense investigation because of their potential applications such as organic field-effect transistors, organic photovoltaic devices, and organic light-emitting diodes. Inspired by the selenization strategy can promote anisotropic charge carrier migration, and selenium-containing compounds have been proved to be promising materials as OSCs both for hole and electron transfer. Herein, we now explore the anisotropic transport properties of the series of selenium-containing compounds. For the compound containing Se Se bond, the Se Se bond will break when attaching an electron, thus those compounds cannot act as n-type OSCs. About the different isomer compounds with conjugated structure, the charge transfer will be affected by the stacking of the conjugated structures. The analysis of chemical structure and charge transfer property indicates that Se-containing materials are promising high-performance OSCs and might be used as p-type, n-type, or ambipolar OSCs. Furthermore, the symmetry of the selenium-containing OSCs will affect the type of OSCs. In addition, there is no direct relationship between the R groups with their performance, whether it or not as p-type OSCs or n-types. This work demonstrates the relationship between the optoelectronic function and structure of selenium-containing OSCs materials and hence paves the way to design and improve optoelectronic function of OSCs materials.