非标准色传感器引起的颜色误差分析

本文推导了两种非标准色传感器在测色时引入的误差公式,并对其进行分析。最后通过计算8个样品的颜色对分析结果给于验证。     

Automated derivatization for on-line solid-phase extraction-gas chromatography; phenolic compounds

An automated system for derivaatization was coupled on-line with solid-phase extraction-gas-chromatography (SPE-GC). The system was optimized for the determination of phenol and chlorinated phenols in aqueous samples. The test analytes were acetylated with acetic anhydride; proper buffering of the sample was a critical factor. Next, the phenol acetates were enriched on a SPE cartridge and transferred to a GC; two appraoaches were studied. In the first approach, the derivatives were enriched on disposable C18 cartridges (ASPEC type) and desorbed with methylacetate. Aan aliquot of the final eluate was injected on-line the GC by means of a loop-type interface. In the second approach, trace enrichment was performed on 10 × 2 mm i.d. LC-type precolumn packed with polystyrenedivinylbenzene copolymer (PLRP-S) this precolumn was dried with a mitrogen purge and the phenol acetates were desorbed with ethyl acetate which was injectedon-line into the retention gap of the GC under partially concurrent solvent evaporation (PCSE) conditions. The Derivatization-SPE-GC system which was based on the loop-type interface has the advantage of simplicity and easy operation, the main drawback is the impossibility to determine phenol acetates which elute prior to trichlorophenol acetates. With the derivatization-SPE-GC approach using PCSE-based desorption, even the most volatile analyte of the test series, phenol acetate, can be determined successfully. The entire procedure, including the derivatization step, was fully automated and integrated in one set-up. The precision data for the integrated on-line derivatization-SP-FID system were fully satisfactory, with RSD values of 1–12 % at the 1 μg/1 level. When a sample volume of 2.2 ml was analyzed, The detection limits for the chlorinated phenol acetates were in the 0.1–0.3 μg/1 range.     

Experimental investigation of the aquatic propulsion caused by localised flexural wave propagation in immersed wedges and plates

This paper describes the results of the experimental verification of the idea of wave-like aquatic propulsion of autonomous and man-inhabited vessels first published about 10 years ago by one of the present authors (V.V.K.). The idea is based on employing the unique type of localised flexural elastic waves propagating along edges of wedge-like structures immersed in water (wedge elastic waves). Such wedge-like structures supporting localised elastic waves can be attached like fish fins to a body of a small ship or a submarine and used for their propulsion. The proposed principle of employing localised flexural waves as a source of aquatic propulsion has been biologically inspired by the specific swimming mode used in nature by stingrays. To verify the idea experimentally, the first working prototype of a small catamaran using the above-mentioned wave-like propulsion via the attached rubber keel has been build and tested in Loughborough University. The tests have been carried out in two phases, in a water tank and then in open water. The test results have shown that the catamaran was propelled very efficiently and could achieve the speed of 36 cm/s, i.e., about one vehicle length per second, thus demonstrating that the idea of wave-like propulsion of small man-inhabited craft is viable. The reported proof of the viability of this idea may open new opportunities for marine craft propulsion, which can have far reaching implications.     

Photon interaction studies using 241Am γ-rays

We have carried out some photon interaction measurements using 59.54 keV γ-rays from a ²⁴¹Am source. These include γ attenuation studies as well as photoelectric absorption studies in various samples. The attenuation studies have been made using leaf and wood samples, samples like sand, sugar etc., which contain particles of varying sizes as well as pellets and aqueous solutions of rare earth compounds. In the case of the leaf and wood samples, we have used the γ-ray attenuation technique for the determination of the water content in fresh and dried samples. The variation of the attenuation coefficient with particle size has been investigated for sand and sugar samples. The attenuation studies as well as the photoelectric studies in the case of rare earth elements have been carried out on samples containing such elements whose K-absorption edge energies lie below and close to the γ-energy used. Suitable compounds of the rare earth elements have been chosen as mixture absorbers in these investigations. A narrow beam good geometry set-up was used for the attenuation measurements. A well-shielded scattering geometry was used for the photoelectric measurements. The mixture rule was invoked to extract the values of the mass attenuation coefficients for the elements from those of the corresponding compounds. The results are consistent with theoretical values derived from the XCOM package.     

Small random perturbations of finite- and infinite-dimensional dynamical systems: Unpredictability of exit times

We apply previous results on the pathwise exponential loss of memory of the initial condition for stochastic differential equations with small diffusion to the problem of the asymptotic distribution of the first exit times from an attracted domain. We show under general hypotheses that the suitably rescaled exit time converges in the zero-noise limit to an exponential random variable. Then we extend the results to an infinite-dimensional case obtained by adding a small random perturbation to a nonlinear heat equation.     

Simultaneous separation and identification of hashish constituents by coupled liquid chromatography-mass spectrometry (HPLC-MS)

Summary This paper reports the use of liquid chromatography for the separation and determination of the major cannabinoids extracted from hashish samples. The direct coupling to the mass spectrometer enables the selective identification both of neutral and acidic cannabinoids. The developed method does not require any preliminary derivatization and should, therefore, be of interest in forensic analysis for simple and unequivocal determination of hashish constituents.Part of this work was presented at the 2nd Italian-Spanish Joint Meeting of Medicinal Chemistry, 30 August–3 September 1995, Ferrara, Italy.     

环境水样及食品中亚硝酸根的分析进展

评述了自1997年至2002年国内外环境水样及食品中亚硝酸根(NO2^-)的分析进展。包括分子光谱法、电化学分析法和色谱分析法，引用文献96篇。     

环境样品中痕量邻苯二甲酸酯的分离与测定

本文研究了以小粒径（１０－４０μ）硅胶柱色谱分离富集、反相高效相色谱分析测定大气颗粒物、土主植物样品中痕量邻苯二甲酸酯的方法，方法操作简单，回收率高，空白值低，利用该方法分析了部分环境样品中邻苯二甲酯酯含量。     

环孢霉素A与小分子化合物的超分子识别作用

环孢霉素A(Cyclosporin A)是一种20世纪80年代引入临床的新的十一环多肽抗生素.因其毒性小,有较高的选择性,在临床上将其用于脏器移植中抗排异反应的首选免疫抑制剂.