封装技术对自光数码管光衰的影响

引起白光数码管衰减的因素有多种,主要分析了封装技术对白光数码管光衰的影响。通过对传统技术制备的蓝、白光数码管光衰的测试,认为光在荧光粉层间的各向同性散射作用和环氧树脂对短波长光辐射的吸收是白光数码管衰减加剧的原因之一。针对传统技术的缺陷,提出一种新的封装技术,通过对新制备数码管的测试和分析,得出新技术制备的白光数码管比传统白光数码管更优越,更有市场价值。     

Direct injection analysis of fatty and resin acids in papermaking process waters by HPLC/MS

A novel HPLC-atmospheric pressure chemical ionization/MS (HPLC-APCI/MS) method was developed for the rapid analysis of selected fatty and resin acids typically present in papermaking process waters. A mixture of palmitic, stearic, oleic, linolenic, and dehydroabietic acids was separated by a commercial HPLC column (a modified stationary C(18) phase) using gradient elution with methanol/0.15% formic acid (pH 2.5) as a mobile phase. The internal standard (myristic acid) method was used to calculate the correlation coefficients and in the quantitation of the results. In the thorough quality parameters measurement, a mixture of these model acids in aqueous media as well as in six different paper machine process waters was quantitatively determined. The measured quality parameters, such as selectivity, linearity, precision, and accuracy, clearly indicated that, compared with traditional gas chromatographic techniques, the simple method developed provided a faster chromatographic analysis with almost real-time monitoring of these acids.     

Resin and fatty-acid analysis by solid-phase extraction coupled to atmospheric pressure chemical ionization–mass spectrometry

Abstract

DNA biosensors are realised immobilising a DNA structure on a suitable transducer to obtain selective information. In this paper we show how the determination of low-molecular weight compounds with affinity for DNA was measured by their effect on the oxidation signal of the guanine peak of calf thymus DNA immobilised on the electrode sensor and investigated by chronopotentiometric analysis. The DNA biosensor is able to detect known intercalating and groove binding compounds. Applicability to river water samples was demostrated.

Moreover, a piezoelectric sensor coupled to a short oligonucleotide can be used as detector of the hybridisation reaction. We show as a model the detection of a specific mutation in apolipoprotein E (ApoE) gene.

Biotinylated 23-mer probes were immobilised on the streptavidin coated gold surface of a quartz crystal; the protein was covalently bound to the thiol/dextran modified gold surface. The device was able to distinguish different synthetic oligonucleotides. The hybridisation reaction was also performed using real samples of DNA extracted from human blood and amplified by Polymerase chain reaction PCR. The extension of such procedure to samples of environmental interest is discussed.     

CURING AND RHEOLOGICAL BEHAVIOR OF VINYL ESTER RESINS PREPARED IN THE PRESENCE OF TERTIARY AMINES

Vinyl ester resins V₁, V₂ & V₃ of acid value (～6 mg KOH g^?1 solid) were synthesized using bisphenol-A epoxy and acrylic acid in the presence of triethyl-, tripropyl- and tributyl-, amines in 210, 270 and 340 minutes, respectively. The synthesized resins were characterized by FTIR spectroscopy and a new peak at 2360 cm^?1 was observed which is due to attachment of amines to resin structure by hydrogen bond. The curing behavior of synthesized resin containing 40% styrene (w/w) and 2% benzoyl peroxide was studied using DSC technique and found to be affected by presence of amines. Activation energy and frequency factor for the curing reaction increases from 14 Kcal mol^?1 to 23 Kcal mol^?1. Rheological behavior of resins containing 40% styrene was studied using a Haake Rotovisco RV20 viscometer, and viscosity was found to increase with shear rate up to 200 sec^?1. The average values of activation energy at constant shear stress (6-15 Pa) were 12.94, 13.20, 13.70 Kcal mol^?1 for V₁, V₂ and V₃, respectively. The activation energy at constant shear rate decreases with an increase in the shear rate.     

Dynamic adsorption of diarrhetic shellfish poisoning (DSP) toxins in passive sampling relates to pore size distribution of aromatic adsorbent

Solid-phase adsorption toxin tracking (SPATT) technology was developed as an effective passive sampling method for dissolved diarrhetic shellfish poisoning (DSP) toxins in seawater. HP20 and SP700 resins have been reported as preferred adsorption substrates for lipophilic algal toxins and are recommended for use in SPATT testing. However, information on the mechanism of passive adsorption by these polymeric resins is still limited. Described herein is a study on the adsorption of OA and DTX1 toxins extracted from Prorocentrum lima algae by HP20 and SP700 resins. The pore size distribution of the adsorbents was characterized by a nitrogen adsorption method to determine the relationship between adsorption and resin porosity. The Freundlich equation constant showed that the difference in adsorption capacity for OA and DTX1 toxins was not determined by specific surface area, but by the pore size distribution in particular, with micropores playing an especially important role. Additionally, it was found that differences in affinity between OA and DTX1 for aromatic resins were as a result of polarity discrepancies due to DTX1 having an additional methyl moiety.     

固相络合萃取脱除柴油中碱性氮化物的工艺及模型研究

应用自行合成的分离材料对固相络合萃取脱除柴油中碱性氮化合物进行了研究。测定了不同条件下柴油在合成树脂柱中的穿透曲线和洗脱曲线,实验测得动态吸附容量达到了7.85mg/gwetresin,碱性氮的脱除率达到了91%。表明本法具有树脂吸附容量大,碱性氮或收率高的特点;同时利用二阶动力学推动力模型描述固定床动态过程,考察了轴向返混对穿透曲线的影响,模型计算值与实验数据符合较好。     

NIR Clusteroluminescence of Non-conjugated Phenolic Resins Enabled by Through-Space Interactions

Clusteroluminescence (CL) and through-space interactions (TSIs) of non-conjugated molecules have drawn more attention due to their unique photophysical behaviors that are different from largely conjugated luminogens. However, achieving red and even near-infrared (NIR) emission from such systems is still challenging due to the intrinsic drawbacks of non-conjugated molecules and the lack of theories for structure–property relationships. In this work, six phenolic resins are designed and synthesized based on two molecule-engineering strategies: increasing the number of TSIs units and introducing electron-donating/-withdrawing groups. All phenolic resins are verified as luminogens with CL property (CLgens), and the first example of CLgens with NIR emission (maximum emission wavelength ≥680 nm) and high absolute quantum yield (47 %) is reported. Experiments and theoretical analysis reveal that two TSIs types, through-space locally excited state and through-space charge transfer state, play essential roles in achieving CL from these non-conjugated polymers, which could be manipulated via changing structural conformation and electron density or altering electron transition behaviors. This work not only provides an approach to manipulate TSIs and CL of non-conjugated polymers but also endows commercially available phenolic resins with high practical value as luminescence materials.