A Validated Approach to Discovering Implication Knowledge from Empirical Data with Applications in Chemometrics

Implication knowledge is useful for drawing conclusions or confirming hypotheses based on some observed data. The challenge here is where/how to derive such knowledge. Traditional knowledge acquisition methodologies or tools have limited power in that they rely on human knowledge engineers' judgements and are applicable only under controlled situations. It would be desirable as well as imperative if we can demonstrate any automatic means of mining such implication knowledge directly from empirical data-this is because in practical applications,data samples are usually available and most importantly the automatically induced implications are less subjective and mathematically sound. As a response to this challenge, our work has developed and validated a new method of automatically discovering implication knowledge by statistically inducing the implication relationships among the data attributes in empirically-obtained sample data.     

Synthesis and Luminescence of a Novel Conjugated Europium Complex with 6-Aniline Carbonyl 2-Pyridine Carboxylic Acid

A novel organic ligand, 6-aniline carbonyl 2-pyridine carboxylic acid (HAP), and the corresponding europium complex, tris(6-aniline carbonyl 2-pyridine carboxylato) europium (III) (Eu-AP) have been designed and synthesized. The results showed that Eu-AP was a conjugated complex, emitting strong red luminescence. The lifetimes of ⁵D₀ of Eu³⁺ in the complex were examined using time-resolved spectroscopic analysis, and the lifetime value was 0.55 ± 0.01 ms for solid Eu(AP)₃. Thermogravimetric analysis showed that the europium complex had good thermal stability.     

Regioselectivity for condensation reactions of quinonoid models of tryptophan tryptophylquinone: a density functional theory study

The model compounds of tryptophan tryptophylquinone (TTQ), o-benzoquinone (OBQ), 3-methyl-6,7-dihydro-1H-6,7-indoledione (MIQ), and 3-methyl-4-(3-methyl-1H-2-indolyl)-6,7-dihydro-1H-6,7-indoledione (IIQ), all of which are characteristic of o-quinone groups, have been studied with density functional theory. The dihedral angle of the two indole rings (chi) of IIQ is calculated to be 49.6 degrees for the global minimum. Another local minimum, 0.74 kcal/mol higher in energy, with a chi value of 123.5 degrees is also fully optimized. The transition state connecting the two minima, with a chi value of 97.9 degrees, has been located and the rotation barrier is 1.71 kcal/mol. A scan of the potential energy surface along this dihedral angle showed that the difference of the total energy was within 1.0 kcal/mol at a range of the dihedral angle from 30 degrees to 75 degrees. Hence, IIQ is flexible for the rotation of inter-indole rings. The origin of regioselectivity for the condensation reactions of the models MIQ and IIQ with NH(3) has been elucidated. It is shown that the energy difference between the two different types of carbinolamine intermediates (Delta E) and their corresponding transition structures (Delta E(++)) should be responsible for the regioselectivity. To assess the effect of the fused ring on regioselectivity of the condensation reaction, a series of models were designed. A good linear correlation has been found between the energy difference of the two different carbinolamine intermediates (Delta E) and that of the corresponding transition states (Delta E(++)), suggesting that the factors that stabilize the carbinolamine intermediate also favor the stability of the corresponding transition structure. The pair, 6-amino-6-hydroxy-8-methyl-6H-quinolin-5-one and 5-amino-5-hydroxy-8-methyl-5H-quinolin-6-one (7/8), deviates from the correlation and represents some anomalous behavior, which may be due to their structural particularity. It also has been shown that the tricyclic models, which consist of OBQ and two fused heterocyclic rings, represent more regioselectivity in contrast to the bicyclic systems. Moreover, the fused electron-donating pyrrole and the fused electron-withdrawing pyridine or pyrimidine show a somewhat synergistic effect on each other via the medial OBQ molecule. The barrier of the condensation reaction for pyrrolo[2,3-f]quinoline-4,5-dione is calculated to be ca. 22 kcal/mol. This is lower than that for MIQ (ca. 33 kcal/mol) and IIQ (ca. 32 kcal/mol) by as much as 10.0 kcal/mol, explaining reasonably the larger catalytic effect of pyrroloquinolinequinone (PQQ) relative to TTQ.     

Enhanced p-Type ZnO Films through Nitrogen and Argentum Codoping Grown by Ultrasonic Spray Pyrolysis

The N-Ag codoped ZnO films are deposited on quartz glass substrates by ultrasonic spray pyrolysis technology. The results indicate that the p-type conductivity in ZnO films is greatly enhanced by the double acceptor codoping of N and Ag compared with that of Ag- and N-monodoped ZnO films, and the NAg codoped low-resistivity p-type ZnO films with the resistivity of 1.05 Ω·cm, relatively high carrier concentration of 5.43×10^17 cm^-3, and Hall mobility of 10.09 cm^2 V^-1s^-1 are obtained under optimized conditions. This achievement confirms that p- type ZnO with acceptable properties for optoelectronic applications could be realized by simultaneous codoping with two potential acceptors.     

Cellulose acetate-directed growth of bamboo-raft-like single-crystalline selenium superstructures: high-yield synthesis, characterization, and formation mechanism

High-yield synthesis of bamboo-raft-like single-crystalline selenium superstructures has been realized for the first time via a facile solvothermal approach by reducing SeO2 with ethylene alcohol in the presence of cellulose acetate. The formation of a raftlike superstructure with various forms is strongly dependent on the temperature, amount of cellulose acetate, reaction time, and even preheating treatment. The suitable amount of cellulose acetate is essential for the formation of elegant and uniform raft Se. The morphology, microstructure, optical properties, and chemical compositions of bamboo-raft-like selenium were characterized using various techniques (X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM), high-resolution (HR) TEM, X-ray photoelectron spectroscopy, UV-vis spectroscopy, FTIR spectroscopy, and Raman spectroscopy). A possible growth mechanism has been proposed. Such special superstructures could provide a useful precursor for potential applications.     

双亲水嵌段共聚物存在下特殊形貌的BaC2O4晶体合成

近年来 ,无机新型材料已经广泛应用于各个技术领域 ,而对于所合成材料的大小和形貌的调控已经成为该材料能够应用于催化、药物、电子、陶瓷、染料和化妆品等领域的一个关键因素[1 ] .利用水溶性有机添加剂作为晶体生长的诱导剂来控制无机晶体的形貌和晶型已有很多报道 .例如 :多种生物分子[2～ 5] 和普通合成的大分子添加剂[6] 对 Ca CO3 晶体在成核、晶化和生长过程中的晶型和形貌有着明显的控制作用 .近年来 ,双亲水嵌段共聚物的功能型高分子 (DHBC) [7]已经发展成为能够有效控制无机晶化过程的新型晶体生长的调控剂 .这类高分子通常是…     

基于最优化线性波数光谱仪的谱域光学相干层析成像系统

相比传统光谱仪,基于线性波数光谱仪的谱域光学相干层析(OCT)无需对非线性波数干涉光谱数据进行重采样和插值,可大大减少数据计算量并提高成像灵敏度.通过模拟计算干涉光谱信号和点扩散函数,以点扩散函数半峰全宽值的倒数作为评价准则,可以优化包括色散棱镜材料的折射率、顶角角度以及衍射光栅和色散棱镜之间旋转角角度的线性波数光谱仪的结构参数.根据优化结果,实验中选用F2玻璃等边色散棱镜,以光栅-棱镜间旋转角角度为21.8°搭建了最优化线性波数光谱仪,并引入谱域OCT成像系统.实验测得成像系统的轴向分辨率达到8.52μm,灵敏度达到91 dB,6 dB成像深度达到1.2 mm.结合具有通用并行计算能力的图形处理卡,在无需重采样和插值的情况下可实时处理和显示人手指指甲皮肤接缝处的横断面OCT图像,验证了基于最优化线性波数光谱仪的谱域OCT系统的成像性能.     

压电免疫传感器用于B因子的测定

B因子是一种不耐热的球蛋白,它参与机体的防御,在炎症过程、细胞和组织损伤中均起重要作用.B因子的检测方法常用的有单扩散法、火箭电泳法和溶血法,前者灵敏度不高,重复性差;后两者操作较复杂^[1,2].