在线自适应波长选择方法及其在汽油调和过程中的应用

近红外光谱分析技术作为一种非侵入性的分析手段在工业上得到了广泛应用。然而,大多数近红外模型的波长选择方法是离线建立的,无法有效跟踪过程特性的变化。提出了一种新的在线自适应波长选择方法——在线自适应区间高斯过程回归波长选择方法（adaptive interval Gaussian process regression, AIGPR）,并用于汽油调和过程中的近红外模型的建立。该方法可以根据待测样本的特性对波长结构进行调整。为了降低在线应用的计算成本,该方法分为离线和在线两个部分,离线部分将光谱分割成若干个波长区间,并在每个波长区间上建立局部模型,为在线应用做准备;在线部分中根据划分规则将采样得到待测样本光谱进行分割并代入相应的局部模型中计算波长区间重要性指标,获得最优波长区间。在汽油辛烷值的光谱数据上证明了该方法的有效性。与重要变量投影法和改进的相关系数法相比,该方法具有更好的性能。     

Mathematical Properties of the Moments of Truncated Dynamic Magnetic Resonance Spectra and Their Potential Application

The moments of truncated dynamic magnetic resonance spectra, M_n(L), are expanded in terms of power series of the integration range −L to +L. The expansion consists of three contributions: 1) an L-independent term that, for the first three moments (n=1 to 3), is independent of the motion and equals the corresponding moment, M_n, of the rigid powder spectrum; 2) a limited number of (positive) terms, diverging as L^k (k<n, odd), reflecting the broadening effect due to motion; these terms vanish for the first three moments and become nonzero, with motion-dependent coefficients, only from the fourth moment on; and 3) an infinite series of converging (negative) terms, in powers of 1/L^k (k is odd), reflecting the reduction of the moments due to the truncation of the spectra; these terms are motion dependent for all moments. The convergence properties of this series are discussed and expressions for the lower (truncated) moments in the slow and fast motion limits of a secular Hamiltonian are derived. For the slow motion limit, it is shown how the L-dependence of the moments can be used to estimate the magnetic and dynamic parameters. The procedure is demonstrated using computer-simulated spectra. In the fast motion regime, closed expressions are obtained in a similar form to those of the relaxation equations. The effect of natural line width and strong-collision dynamics on the various moments as well as that of nonsecular terms in the Hamiltonian are also briefly discussed.     

分析化学实验教学的现状与改进

文章针对分析化学的实验性科学特点及实验教学的现状,研究探索了分析化学实验教学改革的新思路。通过端正学生的学习态度,提高学生对分析化学实验教学课程的认识;优化教学内容结构,以激发学生的实验兴趣,培养学生的创新能力;改革分析化学的实验教学方法,科学评定和考核实验成绩,调动学生的学习积极性,切实提高学生实验操作技能。     

Hormonal Regulatory Patterns of LaKNOXs and LaBEL1 Transcription Factors Reveal Their Potential Role in Stem Bulblet Formation in LA Hybrid Lily

In lily reproduction, the mechanism of formation of bulbs has been a hot topic. However, studies on stem bulblet formation are limited. Stem bulblets, formed in the leaf axils of under- and above-ground stems, provide lilies with a strong capacity for self-propagation. First, we showed that above-ground stem bulblets can be induced by spraying 100 mg/L 6-BA on the LA hybrid lily ‘Aladdin’, with reduced endogenous IAA and GA₄ and a higher relative content of cytokinins. Then, expression patterns of three potential genes (two KNOTTED1-like homeobox (KNOX) and one partial BEL1-like homeobox (BELL)), during stem bulblet formation from our previous study, were determined by RT-qPCR, presenting a down-up trend in KNOXs and a rising tendency in BELL. The partial BELL gene was cloned by RACE from L. ‘Aladdin’ and denoted LaBEL1. Physical interactions of LaKNOX1-LaBEL1 and LaKNOX1-LaKNOX2 were confirmed by yeast two-hybrid and bimolecular fluorescence complementation assays. Furthermore, hormonal regulatory patterns of single LaKNOX1, LaKNOX2, LaBEL1, and their heterodimers, were revealed in transgenic Arabidopsis, suggesting that the massive mRNA accumulations of LaKNOX1, LaKNOX2 and LaBEL1 genes during stem bulblet formation could cause the dramatic relative increase of cytokinins and the decline of GAs and IAA. Taken together, a putative model was proposed that LaKNOX1 interacts with LaKNOX2 and LaBEL1 to regulate multiple phytohormones simultaneously for an appropriate hormonal homeostasis, which suggests their potential role in stem bulblet formation in L. ‘Aladdin’.     

表面活性剂在分析化学中应用的研究进展

表面活性剂在分析化学中起增敏、增溶、增稳、增敏、乳化、分离富集以及提高抗干扰性和选择性等作用,已成为分析化学法中一种理想的增敏、增溶、增稳试剂。基于表面活性剂在分析化学法中的广泛应用,侧重综述其在光度分析、色谱分析、极谱分析中的应用研究进展。     

药学专业分析化学实验课改革探讨

通过对分析化学实验教学现状分析,从分析化学实验课的实验内容、教学方式、考核方法等方面进行了改革。以此帮助学生激发学习兴趣,掌握操作技能,学会并掌握与专业有关的实验方法和岗位职业能力。     

分析化学实验教学改革与实践

分析化学实验是高校的重要课程之一,本文通过对目前分析化学实验教学的现状,以提高分析化学实验教学效果为目的,分别对实验内容、教学模式、教学理念和考核制度进行了探讨,以调动学生学习的主动性,培养学生的动手能力和创新能力,从而提高分析化学实验教学的质量。     

脱硫建筑石膏三相分析方法研究及应用

从脱硫建筑石膏各相所具有的水化和脱水特性角度,利用卤素水分测定仪,提出一种用于脱硫建筑石膏相组成分析的简单而有效的方法.就残余二水石膏及无水石膏含量对脱硫建筑石膏性能的影响进行试验研究,对相组成在煅烧设备及煅烧工艺改进方面的应用进行探讨,从而肯定了相分析的重要性及有效性.     

液相化学发光及其在分析化学中的应用

综述了常用发光体系在分析化学中的应用，简单介绍了化学发光的基本原理、产生的主常见体系的发光机理等。     

分析化学课程教学改革探讨与实践

结合分析化学课程特点,在分析化学教学中开展教学改革,在课程讲授方法、科研渗透教学过程等方面进行探索与实践,提高课程教学质量,以满足人才培养的要求。     

谈分析化学实验课程建设

分析化学实验主要涉及到化学分析、传统仪器分析等内容,与社会需求基本相符;但未涉及到生化分析等内容,与社会需求和学科发展不匹配。从教学内容、教学过程、教学管理方面进行分析化学实验的课程建设是必要的。教学内容要体现分析化学的生龙活虎、立体多维;教学过程实现互助学习,体现个性化培养;教学管理实现实验室开放和开放实验。提高教学质量,实现能力、素质的培养。