丁卡因在玻碳电极上的伏安行为及测定

对丁卡因在玻碳电极上的伏安行为进行了研究,发现在0.1mol/L高氯酸溶液中,于1.04V(vs.Ag/AgCl)左右产生一个与丁卡因呈良好线性关系的阳极氧化伏安峰,大多数金属离子和20多种有机生化物质不干扰测定.方法用于注射针剂和加标尿样中丁卡因的测定,结果满意,对电极反应也进行了初步探讨.

Effect of physical aging on phenolphthalein polyethersulfone/poly(phenylene sulfide) blend .1. Mechanical properties

The effect of physical aging at 210 degrees C on the mechanical properties of phenolphthalein polyether sulfone (PES-C) and a PES-C/poly(phenylene sulfide) (PPS) blend, with 5% content of PPS, were studied using DMA, tensile experiments, an instrumented impact tester, and SEM observations. The blend shows good mechanical properties in comparison with the corresponding PES-C. The mechanical properties of both materials exhibit characteristics of physical aging, with only the aging rate of the blend relatively slower, which should be attributed to the constraint effect of PPS particles and the good interfacial adhesion. The morphology of the PPS phase in the blend did not change with aging time. The principal role of PPS particles is to induce crazes, which dissipate energy, under applied loading; thus, the blend shows good toughness. On the other hand, the multiple crazing mechanism depends on the molecular mobility or structural state of the matrix. (C) 1996 John Wiley & Sons, Inc.

GENERAL ALPHA-N INDEX AND ITS APPLICATION .1. GENERAL ALPHA-N INDEX AND ITS APPLICATION IN THE EXTRACTION OF Y, CE, U, AND TH BY NEUTRAL PHOSPHORUS EXTRACTANCTS

The general a(N) index is established for molecules containing heteroatoms, rings, and multiple bonds. The general a(N) index is able to describe molecules with minute differences in structure and can also reveal the properties of molecules. This theory is successfully applied to the case of neutral phosphorus extractants. Both the molecular polarity and steric effect are characterized by the general a(N) index. The relationships between these properties and the distribution ratios for extracting Y, Ce, U, and Th are also shown by the general a(N) index.

广义α_N指数及其应用——Ⅰ.广义α_N指数及其在中性磷萃取剂萃取Y、Ce、U和Th性能方面的应用

首先引进一般有机化合物的广义a_N指数,该指数能分辨有微小结构差别的有机化合物分子。在此基础上,计算了某些中性磷萃取剂的广义a_N指数。并将其与萃取性能进行相关分析,得到了满意的结果。

Molecular cloning and characterisation of prophenoloxidase (ProPO) cDNA from Fenneropenaeus chinensis and its transcription injected by Vibrio anguillarum

The prophenoloxidase(ProPO) gene was cloned from haemocytes of Chinese shrimp Fenneropenaeus chinensis by Rapid Amplification Complementary DNA Ends (RACE) method. The full-length cDNA of prophenoloxidase gene consists of 3040 bp with a 2061 bp Open Reading Frame (ORF), encoding 686 amino acids. Phylogenetic analysis revealed that it belongs to insect-type invertebrate prophenoloxidase gene family. To understand ProPO reaction for pathogeny's challenge in shrimp, the expressions of ProPO in different tissues were studied by real-time PCR after challenged by Vibrio anguillarum. The results showed that the expression level of ProPO gene in haemocytes was highest among three studied tissues including haemocytes, lymphoid organ and hepatopancreas. The time-course change of ProPO mRNA levels in challenge experiment showed that ProPO mRNA transcripts had the biggest change extent in lymphoid organ.

Characteristics of low-frequency components of the near-bottom current in the Chinese Pioneer Area

Two deep-sea moorings were deployed respectively in the east area and the west area of Chinese Pioneer Area (CPA) in the tropic east Pacific to monitor the regional deep-sea dynamics below 600 meters above bottom (mab) from July 1997 to Oct. 1999. Results of statistics, spectral estimate and correlation analysis of the low-passed velocity data show that time scales of low-frequency components of the near-bottom currents are 25similar to120 days, in which 51-day period dominates the lower band of the frequency domain. Topographic features have obvious effect on low-frequency currents below 50 mab; modulations of the bottom-intensified sheared mean flow to the low-frequency currents are the dynamic mechanism of the frequency shift that occurs in both the east-area and the west-area.

Chromosomal mapping of major ribosomal rRNA genes in the hard clam (Mercenaria mercenaria) using fluorescence in situ hybridization

Karyotype and chromosomal location of the major ribosomal RNA genes were studied in the hard clam (Mercenaria mercenaria Linnaeus) using fluorescence in situ hybridization (FISH). Metaphase chromosomes were obtained from early embryos. Internal transcribed spacers (ITS) between major RNA genes were amplified and used as FISH probes. The probes were labeled with digoxigenin-11-dUTP by polymerase chain reaction and detected with fluorescein-labeled anti-digoxigenin antibodies. FISH with the ITS probes produced two to four signals per nucleus or metaphase. M. mercenaria had a haploid number of 19 chromosomes with a karyotype of seven metacentric, four metacentric or submetacentric, seven submetacentric, and one submetacentric or subtelocentric chromosomes (7M + 4M/SM + 7SM + 1SM/ST). Two ITS loci were observed: one located near the centromere on the long arm of Chromosome 10 and the other at the telomere of the short arm of Chromosome 12. FISH signals on Chromosome 10 are strong and consistent, while signals on Chromosome 12 are variable. This study provides the first karyotype and chromosomal assignment of the major RNA genes in M. mercenaria. Similar studies in a wide range of species are needed to understand the role of chromosomal changes in bivalve evolution.

小麦体细胞无性系HMW-GS变异及其变异体的研究

关于小麦体细胞无性系变异前人已做了大量的研究,观察到了形态学、细胞学和生化特性变异.对醇溶蛋白和谷蛋白变异的分析,获得了基因突变的证据,但不知突变基因的位点.本研究的目的在于分析体细胞无性系的高分子量谷蛋白亚基(high-molecular-weightglutenin subunits,HMW-GS)的变化,获取特定基因(Glu-l)突变的证据,并研究HMW-GS变异体农艺性状和产量性状的表现.

Application of 2-(11H-benzo[a] carbazol-11-yl) Ethyl Carbonochloridate as a Pro-column Derivatization Reagent of Amino Acid by High Performance Liquid Chromatography with Fluorescence Detection

On a reversed phase Hypersil BDS C-18 (200 mm x 4. 6 mm, 5 mu m) column, 20 amino acids, which were derivatized using 2-(11H-benzo [a] carbazol-11-yl) ethyl carbonochloridate (BCEC-Cl) as pre-column derivatization reagent, were separated in conjunction with a gradient elution. Optimum derivatization was obtained by reacting of amino acids with BCEC-Cl at room temperature for 5 min in the presence of sodium borate catalyst in acetonitrile solvent. The fluorescence excitation and emission wavelengths were 279 nm and 380 nm respectively. The identification of amino acid derivatives from hydrolyzed bovine serum albumin and bee pollen was carried out by post-column mass spectrometry with electrospray ion source in positive ion mode. Linear correlation coefficients of the amino acid derivatives were > 0.9990, and detection limits (at signal to noise of 3:1) were 1.49 - 19.74 fmol for the labeled amino acids.

供应链中物流及信息流管理

供应链管理使企业在变化的市场环境中有效地与其它企业合作 ,取得集体竞争优势。本文首先讨论了后勤学与供应链管理的定义和之间的关系。本文认为供应链管理的核心是物流与信息流的控制。物流控制决策主要包括操作层次的库存补充和运输路径规划 ,以及战略层次的设施地点规划。信息流管理跨越部门与企业的界限将相关的应用集成起来。动态联盟协调各企业内部的生产经营活动 ,战略性地决定物流与信息流的构形。

自治水下机器人研究开发的现状和趋势

简要回顾了自治水下机器人ＡＵＶｓ研究的历史，概述了ＡＵＶｓ研究开发的现状和未来发展趋势

贵阳市表层土壤中铅的环境地球化学基线研究

以土壤环境地球化学研究为主线，以贵州省贵阳市8 064 km2 为研究区域，将土壤重金属污染元素铅的空间分布规律与环境地球化学机理研究相结合，建立区域土壤环境地球化学基线，选用合适的判别指标判识自然作用过程与人类活动过程对土壤环境的影响。得到以下结论：贵阳市表层土壤中铅的基线值为14.8 mg·kg-1，样品中铅元素含量大于70.1mg·kg-1 的样品可能遭受人为污染的影响。地质累积指数分析结果显示贵阳市18%的表层土壤未受铅的污染，47%的表层土壤在无污染到中度污染之间，28%的中度污染，6%的表层土壤介于中度污染到强污染之间，1%的强污染。污染程度指数分析则显示贵阳市49.9%的表层土壤未受到铅的污染，铅的污染程度最大为8.11，总污染程度略大于0，即受到轻微污染。