Further study of the viscoelastic phase separation of cyanate ester modified with poly(ether imide)

In this study, the viscoelastic phase separation process was studied further by time‐resolved light scattering, differential scanning calorimetry, and scanning electron microscopy in the system of poly(ether imide)‐modified bisphenol‐A dicyanate. It was observed that the evolution time of phase structure and relaxation time of diffusion flow of the bisphenol‐A dicyanate were similar with the phase diagram of curing conversion versus content of PEI. The results suggested that the viscoelastic phase separation was affected by the curing conversion of the system at the onset point of phase separation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 517–523, 2006     

受激布里渊散射相位共轭现象的二维数值模拟

 使用P.H.Hu等人[3，4]提出的计算途径，数值解了A.Flusberg等人[2]提出的零级方程。计算了布里渊池内随位置而变化的斯托克斯光强度、泵浦光强度和保真度，得到了布里渊池内几个位置上的斯托克斯光相位和强度的横向分布，并计算了泵浦光入口处的反射率和保真度。     

气密性碳涂覆光纤筛选强度与电阻关系研究

通过实验分析确立了把光纤电阻作为衡量气密性碳涂覆光纤通过２％应变筛选的过渡标准。要拉制２％应变筛选的碳涂覆光纤，其电阻值应小于３０ｋΩ／ｃｍ。     

Bombieri's theorem in short intervals

The well-known Bombieri-A. I. Vinogradov theorem states that (1) $$\sum\limits_{q \leqslant x^{\tfrac{1}{2}} (\log x)^{ - s} } {\mathop {\max }\limits_{(a,q) = 1} \mathop {\max }\limits_{y \leqslant x} } \left| {\psi (y,q;a) - \frac{y}{{\varphi (q)}}} \right| \ll \frac{x}{{(\log x)^A }},$$ whereA is an arbitrary positive constant,B=B(A)>0, and as usual, $$\psi (x,q;a) = \sum\limits_{\mathop {n \leqslant x}\limits_{n = a(q)} } {\Lambda (n),}$$ Λ being the Von Mangoldt's function. The problem of finding a result analogous to (1) for short intervals was investigated by many authors. Using Heath-Brown's identity and the approximate functional equation for DirichletL-functions, A. Perelli, J. Pintz and S. Salerno in 1985 established the following extension of Bombieri's theorem: Theorem 1. (2) $$\sum\limits_{q \leqslant Q} {\mathop {\max }\limits_{(a,q) = 1} \mathop {\max }\limits_{h \leqslant y} \mathop {\max }\limits_{\frac{x}{2}< \approx \leqslant x} } \left| {\psi (z + h,q;a) - \psi (z,q;a) - \frac{h}{{\varphi (q)}}} \right| \ll \frac{y}{{(\log x)^A }}$$ where A>0 is an arbitrary constant,y=x ^θ $$\frac{7}{{12}}< \theta \leqslant 1, Q = x^{\frac{1}{{40}}} .$$ ,Q=x ^1/40. By improving the basic lemma which A. Perelli, J. Pintz and S. Salerno used as the main tool to prove Theorem 1, we obtain Theorem 2.Under the same condition as in Theorem 1,for Q=x ^1/38.5, (2)still holds.     

同位素稀释-火花源质谱法分析人参样品中微量元素

本文采用同位素稀释-火花源质谱法定量分析了吉林野山参,园参及高丽参中30多种微量元素的含量。测定下限2μg/g,相对标准偏差在5～28％以内。     

烷基季铵盐插层剂的合成及应用

Three novel intercalation agents were synthesized for the first time, which arose from oleic acid diethylenetriamine or triethylenetetramine 3 - chloro - 2 - hydroxypropy trimethylammonium choride (CHPTA) and chloroethanol. Organophilic vermicullites were synthesized from sodium type vermiculite by cation exchange with new intercalation agents. The results of X - ray diffraction study showed that the gallery distance of the organophilic vermiculite was enlarged from 1 nm to 5 nm or more. A new idea of making design for intercalation agent was provided.     

磷脂液相二次离子质谱分析中的分子离子簇

对3种极性头不同的磷脂DMPG、DMPC、DMPE的液相二次离子质谱分析中出现 的分子离子簇现象进行了系统的研究。结果表明，虽然分子离子簇的形成与许多因素有关， 如PH值、离子强度等，但起决定作用的是样品在底物中的浓度，浓度增大有利于分子离子簇 的形成。研究还发现，由不同种类磷脂分子形成的分子离子簇峰明显高于由同种磷脂分子所 形成的分子离子簇峰，指出异种磷脂分子间的簇离子形成能力高于同种磷脂分子。此外还讨 论了磷脂分子在离子源条件下的稳定性、裂解规律及相互作用等。结果表明，本实验所选用 的磷脂分子在LSIMS条件下是稳定的，均能得到较强的分子离子峰，其主要碎片峰是磷酰键断裂而产生的碎片离子峰。     

Synthesis of novel tetracyclic chromenes through carbanion chemistry of 4-methyl coumarins

Various substituents were introduced onto the methyl group in 4-methyl coumarins through lithiation, followed by reactions with a wide range of electrophiles. The presence of an alkoxy group on 6′-phenyl ring was found to be pivotal for the success of this reaction. This procedure provided a convenient synthetic pathway to elaborate the methyl group of 4-methylcoumarins. Application of this methodology was showcased with the synthesis of biologically important novel tetracyclic chromene ring systems (n = 1-3).     

从α－蒎烯直接催化酯化高选择性地合成乙酸正龙脑酯的研究－催化剂与反应机理初探

本文提出了新的硼酸类催化剂体系ＨＢ，用该体系对α－蒎烯与无水乙酸相互作用直接合成乙酸正龙脑酯作了较系统的研究。反应得到两种系列产物－酯化产物和异构化产物，酯化产物主要是乙酸正龙脑酯，葑醇酯和松油酯，异构化产物主要是莰烯、烯和松油烯等，总酯化产率为５０％以上，其中乙酸正龙脑酯为２０％以上，是至今从α－蒎烯直接合成乙酸正龙脑酯的最好结果。通过对产物的￣１ＨＮＭＫ图谱分析及动力学考察，确证反应主产物是正龙脑酯而不是异龙脑酯。文章对Ｈ＿２ＳＯ＿４、ＨＣｌＯ＿４、多聚磷酸（ＰＰＡ）和杂多酸（１２－磷钨酸）等催化剂进行了实验考察、对比和评述，表明了自制的ＨＢ催化剂体系具有高选择性合成乙酸正龙脑酯的显著优点，并对其反应机理作了初步探讨。     

应用大孔吸附树脂从农药废水中回收毕克草

毕克草为一种新型除草剂,通常情况下很难被降解,本文利用物理吸附原理通过自行制备的大孔吸附树脂从农药水中对其进行了回收,回收效果良好,同时也达到了废水处理的目的。优化的最佳实验条件:室温下,pH=1.0以及流速为5BV/h时,对COD为15000mg/L的毕克草废水吸附处理后,其出水可达《污水综合排放标准》(GB89—1996)中的一级排放标准;洗脱再生时,室温下,用95%的乙醇洗脱,流速为2BV/h,(即2倍树脂床体积/h)回收率可达98.4%,纯度达93.7%,总流程一次可处理该废水240mL。