A novel hyperbranched polyester acrylate used for microfabrications

A novel hyperbranched polyester acrylate (HPEA) was synthesized based upon ethylenediamine tetraacetic acid as a “core” molecule, 5‐hydroxyisophthalic acid as an AB₂ monomer, and 2‐hydroxyethyl acrylate as an endcapping reagent. The obtained oligomer has an unsaturation concentration of 4.10 mmol_C?C g^?1 measured by nuclear magnetic resonance and a wide molecular weight distribution of 1.64 measured by gel permeation chromatography. The two‐photon absorption (TPA) photopolymerization of HPEA under the exposure of a Ti : sapphire femtosecond laser with a wavelength of 800 nm was investigated through laser exposure dose‐dependant spatial resolutions of its resins. The TPA photopolymerization thresholds at the range 1.6–4.3 × 10⁷ mJ cm^?2, and exposure dose windows at the range 3.4–4.3 for three formulations were determined. A spatial resolution of 0.85 μm was obtained through the TPA photopolymerization of the formulation containing 1 wt% photoinitiator and 0.3 wt% photoinhibitor. A diffraction grating and real three‐dimensional coupled gear wheel created by TPA photopolymerization were described to demonstrate the unique capability of HPEA in microfabrications. Copyright © 2004 John Wiley & Sons, Ltd.     

Structure of the blue forms of bisphthalocyanines of rare-earth elements

Using electron spectroscopy, X-ray photoelectron spectroscopy, and ESR spectroscopy, the blue forms of bisphthalocyanines of rare-earth elements were found to have structures of sandwich-type complexes with isoelectronic phthalocyanine ligands linked with tetravalent metal ions, [Pc^2–Ln⁴⁺Pc^2–]⁰. A comparative spectral and electrochemical study of the blue and green forms oftert-butyl-substituted bisphthalocyanines was carried out for almost the whole series of rare-earth metals. Lutetium octa(perfluoro-tert-butyl)- and perchlorobisphthalocyanines were synthesized for the first time.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 425–430, March, 1995.This study was financially supported by the Russian Foundation for Basic Research (grant No. 94-03-08903).     

双（1,2—丙二胺）合铜的TCNQ盐的合成与光谱研究

合成了导电性ＴＣＮＱ盐Ｃｕ（ｐｎ）２（ＴＣＮＱ）ｎ（ｎ＝２和３，ｐｎ＝１，２－丙二胺，ＴＣＮＱ＝７，７，８，８－四氰基对苯二醌二甲烷）。红外光谱、电子光谱和Ｘ－光电子能谱研究表明ＴＣＮＱ盐中存在ＴＣＮＱ°和ＴＣＮＱ－，ＴＣＮＱ°与ＴＣＮＱ－之间发生了部分电子转移，致使铜呈混合价态。它们的粉末室温电导率为１．１×１０－５～２．４×１０－６ｏｈｍ－１ｃｍ－１。     

纳米氧化铝负载双硫腙分离富集-原子吸收法测定地质样品中的金、铂、钯的研究

金、铂、钯在地质样品中的含量甚微,国内外常采用ICP-AES,ICP-MS和ETAAS直接测定。FAAS法由于仪器便宜、操作方便,也广泛应用于预富集后的痕量贵金属的分析。目前,在测定贵金属的分析方法中,常采用固相萃取法富集分离样品,主要的固相萃取剂有:无机吸附剂,交联树脂[1],螯合树脂[     

Direct and simultaneous voltammetric analysis of heavy metals in tap water samples at Assiut city: an approach to improve the analysis time for nickel and cobalt determination at mercury film electrode

Tap water samples (Assiut city, lie in the middle north of upper Egypt, approx. 370 km from Cairo, January-March, 2002) were taken from the eight sampling sites of different locations at Assiut city. The samples are analyzed to determine the total content of cadmium, copper, lead and zinc by differential pulse anodic stripping voltammetry (DPASV) while nickel and cobalt are determined by a new simple differential pulse adsorptive stripping voltammetry (DPAdSV), using dimethylglyoxime (DMG) as the complexing agent. This method uses sodium sulfite as the supporting electrolyte, which facilitates the removal of oxygen interference without the traditional necessity of purging with inert gas. The effect of various parameters was studied using DPASV (for Cd, Pb, Cu and Zn) and AdSV (for Ni and Co) methods. Subsequently, under the so found experimental conditions, the stability of calibration curves and the detection limits (μg/l) have been determined. The data achieved (for all metals utility) are comparable to those measured by the graphite furnace atomic absorption spectrophotometric (GF-AAS) method. The effects of the interferences between these metal ions have been investigated. Moreover, the effect of storage was discussed and the obtained results were compared favorably with standard official methods. Statistical analysis of the database exhibits applicability and the accuracy of the techniques. The results obtained from the two techniques (Voltammetry and GF-AAS) are in very good agreements in the most tap water samples.     

Ni-B和Ni-Ce-B超细非晶态合金的退火晶化及其催化性能

 采用XAFS,XRD和DTA方法研究了Ni－B和Ni－Ce－B超细非晶态合金在退火过程中的结构变化及其结构与催化性能的关系．活性结果表明,在退火温度为623K时,Ni－B和Ni－Ce－B样品的苯加氢催化反应转化率最高,分别为63％和81％,0．3％Ce的掺入提高了Ni－Ce－B的催化活性．DTA结果表明,Ni－B超细非晶态合金在598和653K有两个晶化峰,而Ni－Ce－B样品有548,603,696和801K四个晶化峰．XAFS和XRD结果进一步说明,在573K退火时,Ni－B样品晶化生成晶态Ni3B和纳米晶Ni,此时Ni－Ce－B仅有少量晶态Ni3B生成．在673K退火时,Ni－B样品中的Ni3B开始分解生成晶态Ni,同时纳米晶Ni聚集并形成大颗粒晶态Ni,而Ni－Ce－B样品晶化生成晶态Ni3B和纳米晶Ni．在773K和更高的温度退火处理后,Ni－B样品中Ni的局域环境结构与金属Ni箔基本一致,但Ni－Ce－B样品晶化生成的Ni晶格有较大畸变,同时Ni3B并未分解．说明0．3％的Ce对提高Ni－Ce－B样品的稳定性有显著作用．本文首次报道了Ni－B和Ni－Ce－B超细非晶态合金中苯加氢催化活性中心为纳米晶Ni和类似于金属Ni的Ni－B非晶态合金．     

Tetrakis(thiadiazolo)porphyrazines. 3. Acid-base Properties and Stability of Tetrakis-3,4-(1,2,5-thiadiazolo)porphyrazine in Sulfuric Acid Solutions

AM1 calculations gave the proton affinities of different types of donor sites in tetrakis-3,4-(1,2,5-thiadiazolo)porphyrazine, H₂{[SN₂)₄PA}, and protonation of the meso-nitrogen atoms was found to be favored. A spectrometric study showed that the basicity of the meso-nitrogen atoms of the porphyrazine macrocycle is strongly diminished and these atoms in CF₃CO₂H are involved in an incomplete acid-base interaction (ABI) to give acid solvates, while a complete ABI (protonation) is found only in the presence of sulfuric acid. The basicity constants of the meso-nitrogen atoms were determined spectrophotometrically in CF₃CO₂H-H₂SO₄. The kinetics of decomposition of the macrocyclic chromophore in concentrated sulfuric acid was studied and a possible mechanism for this process was proposed.__________Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 278–287, February, 2005.     

无火焰原子吸收测定血清中的铝

用无火焰原子吸收法测定血清中的铝,样品用高纯水十倍稀释后,用标准加入法进行测定,不需使用基体改进剂和氘灯扣除背景。方法简单、准确、灵敏度高。用含铝20ng/ml的一份十倍稀释血清样,重复测十次,变异系数5%左右。     

Determination of copper in medicinal plants used as dietary supplements by atomic absorption spectrometry with direct flame solid analysis

An alternative device for the direct solid analysis (DSA) for copper determination by flame atomic absorption spectrometry (FAAS) is proposed. Copper was directly determined in commercial medicinal plants used as dietary supplements. The determination of copper in solid samples by DSA–FAAS was made by using a conventional air–acetylene flame. Between 0.05 and 1.5 mg of each test, sample was weighed directly into a small polyethylene vial connected to the device used for solid introduction into the flame. Test samples were introduced into the flame as a dry aerosol using a T-quartz cell set between the burner and the optical path. The T-quartz cell has a slit in the superior part by which the solid aerosol passes to the flame. A transient signal, evaluated as integrated absorbance, is produced and it is totally integrated in 2 s. Background signals always presented absorbance values less than 0.1. It was found a characteristic mass of 0.8 ng Cu and absolute limit of detection of 1.2 ng (3 s), or 1.2 μg g⁻¹ if a sample mass of 1 mg was used. Optimized conditions for air flow rate, flame stoichiometry, and so on were established as well. No excessive grinding of the samples was needed and samples with particle of size less than 80 μm were used throughout. No statistical difference between the results from the proposed system and those obtained by sample digestion and determination by conventional FAAS was observed. With the proposed procedure, more than 50 test samples can be analyzed in 1 h and it can be easily adapted to conventional spectrometers for FAAS.     

血清必需元素测定中样品预处理方法的探讨

对血清必需元素测定的样品预处理方法进行了研究，用火焰原子吸收法测定了经不同处理的血清样品中的锌，铜，铁，钙，镁含量，结果显示，预处理方法不同，其测定结果有较大差异，变异系数，镁为７．９４％，锌，铜，铁，钙在１５．１９％～５３．５３％之间，并对各样品作了精密度和准确度实验。