Edge-defined, film-fed growth (EFG) technique for the preparation of alpha-Al2O3 : C crystal with highly sensitive thermoluminescence response

In this work, alpha-Al2O3:C, a highly sensitive thermoluminescence dosimetry crystal, was grown by the EFG method in which a graphite heating unit and shield acted as the carbon source during the growth process. The optical, luminescent properties and dosimetric characteristics of the crystal were investigated. The as-grown crystal shows a single glow peak at 536 K, which is associated with Cr3+ ions. After annealing in H-2 at 1673 K for 80 h, the crystal shows a single glow peak at 460 K and a blue emission band at 415 nm. The thermoluminescent response of the annealed crystal shows linear-sublinear-saturation characteristics in the dose range from 5 x 10(-6) to 100 Gy.

Le courant de Lomonosov dans le fond du Golfe de Guinée en mai 1973

A cruise of the R. V. Capricorne in May 1973, in inner part of the gulf of Guinea, allowed the authors to identify the main part of the Atlantic circulation at the longitude of 5 degrees E, between 4 degrees N and 4 degrees S. It gave new data on the termination of the equatorial undercurrent. At the equator, under the westward south equatorial current flows the Atlantic equatorial undercurrent with a maximum eastward velocity of 90 cm/sec at 30 m depth linked to a salinity maximum higher than 36.20 ppt. Below the equatorial undercurrent, about 80-100 m depth, flows a westward current with a velocity as high as 30 cm/sec. At 4 degrees S, the south equatorial countercurrent is well delineated by a high salinity core (more than 36.10 ppt) at 30 m depth with an eastward velocity core of 40 cm/sec. On the contrary, near 3 degrees 30N, a high salinity core (36.10 ppt) flows westwards with a speed of 40 cm/sec at 40 m depth: it is the "return flow" of the undercurrent (Hisard and Moliere 1974). At 4 degrees N the Guinea current carries eastwards surface salinities of 34.50 ppt at 40 cm/sec. Off Cape Lopez (0 degrees 35'S-8 degrees 42'E) the high salinity core of the undercurrent becomes wider near the shore. It is 25m wide offshore, and 70 m wide near the cape. A part of undercurrent water extends northwards, then flows westwards with the subsurface westward circulation in the inner part of the Gulf of Guinea. Another part flows south-southwestwards in a high salinity tongue along the African coast to 4 degrees S. South-west of Cape Lopez, the trades divergence contributes to an upwelling of cold and high salinity water; this water increases at the Cape Lopez front.

Population structure and variance effective size of red snapper (Lutjanus campechanus) in the northern Gulf of Mexico*

We assayed allelic variation at 19 nuclear-encoded microsatellites among 1622 Gulf red snapper (Lutjanus campechanus) sampled from the 1995 and 1997 cohorts at each of three offshore localities in the northern Gulf of Mexico (Gulf). Localities represented western, central, and eastern subregions within the northern Gulf. Number of alleles per microsatellite per sample ranged from four to 23, and gene diversity ranged from 0.170 to 0.917. Tests of conformity to Hardy-Weinberg equilibrium expectations and of genotypic equilibrium between pairs of micro-satellites were generally nonsignificant following Bonferroni correction. Significant genic or genotypic heterogeneity (or both) among samples was detected at four microsatellites and over all microsatellites. Levels of divergence among samples were low (FST ≤0.001). Pairwise exact tests revealed that six of seven “significant” comparisons involved temporal rather than spatial heterogeneity. Contemporaneous or variance effective size (NeV) was estimated from the temporal variance in allele frequencies by using a maximum-likelihood method. Estimates of NeV ranged between 1098 and >75,000 and differed significantly among localities; the NeV estimate for the sample from the northcentral Gulf was >60 times as large as the estimates for the other two localities. The differences in variance effective size could ref lect differences in number of individuals successfully reproducing, differences in patterns and intensity of immigration, or both, and are consistent with the hypothesis, supported by life-history data, that different “demographic stocks” of red snapper are found in the northern Gulf. Estimates of NeV for red snapper in the northern Gulf were at least three orders of magnitude lower than current estimates of census size (N). The ratio of effective to census size (Ne/N) is far below that expected in an ideal population and may reflect high variance in individual reproductive success, high temporal and spatial variance in productivity among subregions or a combination of the two.

木通科植物分类学研究

本文对木通科植物进行全面分类学修订，确认8属35种（包括16亚种）。这8个属是：猫儿屎属(Decaisnea，1种)，串果藤属(Sinofranchetia，1种)，牛藤果属(parvatia，2种)，野木瓜属(Stauntonia，24种)，长萼木通属(Archakebia，1种)，木通属（Akebia，4种），拉氏藤属（Lardizabala，1种）和勃奎拉属（Boquila，1种）。我们建立了1个新属(长萼木通属Archakebia)、4个新种（短蕊八月瓜Stauntonia brachyandra，厚叶八月瓜S．crassifolia，离丝野木瓜S．libera和墨脱八月瓜S．medogensis）和5个新亚种（长萼三叶木通Akebia trifolialassp. longisepala，线叶五风藤Stauntonia angustifolia ssp. linearifolia，三叶五风藤S．a．ssp, trifoliata，海南野木瓜S．chinensis ssp. hainaensis和纸叶八月瓜S．latifolia ssp. chartacea)，重新组合了8个名称(Parvatia brunoniana ssp. elliptica，Stauntonia angustifolia，S． chapaensis，S．coriacea，S．grandiflora，S．latifolia，S．obovatifoliola .ssp. urophylla和S．pterocaulis)和归并了32个类群（种及种下等级）。 我们对1989年系统进行了补充，在拉氏藤族(tribe Lardizabaleae)中建立两个亚族，并对野木瓜属(Stauntonia)提出一个详尽的属下分类系统，包括两个亚属4个组。本修订主要根据作者对近七千余份腊叶标本的研究和野外考察结果撰写而成。在前一部分中，我们全面阐述木通科形态性状特征及其演化意义，并应用于科下种上分类群的划分及其亲缘关系讨论。在此基~础上，我们进一步确认串果藤族(Sinofranchetieae)和猫儿屎族(Decaisneeae)均为木通科植物早期演化的分支，也是系统位置比较孤立的类群;拉氏藤族(Lardizabaleae)与亚洲类群分开的历史很长，其内部分化也很显著;木通族(Akebineae)是木通科植物演化的主干，也是较晚近时期发生的类群，它正处在强烈分化之中，存在有各种演化式样，是木通科植物分类实践的难点。 作者仍然认为木通科植物是毛茛类与木兰类之间联系的扭带，它可能在白垩纪初期就已经在联合古陆上起源，并在古陆分裂之前就发生了东亚及南美两群植物的隔离事件。 我们在本文后一部分（即分类处理）中，描述了每个种（共35种）的性状特征、物候期、生态习性及其与近缘种的关系，并作出种分布图和形态线描图。最后列出所研究标本的索引（中英对照）。

一种改进的高分辨率RFLPs 分析

国家自然科学基金和云南省自然科学基金资助

Species diversification in coastal aquaculture: production potentials of shrimp (Penaeus monodon) with mono and mixed sex tilapia

An experiment of 120 days of culture was conducted in brackishwater earthen ponds having an area of 0.2ha each. The hatchery produced shrimp (Penaeus monodon) post larvae were stocked in the 40m² fine meshed nylon net nursery enclosures were fed with commercial pellet feed. After two weeks of nursing, juveniles were allowed to spread in cultural pond by opening the fence. Fingerlings of three different strain of tilapia were stocked as shrimp and Strain-1 all male (monosex) (T1), shrimp and Strain-2 all male (T2), shrimp and Strain-3 mixed sex population (T3) @ 20.000/ha and 10.000/ha, respectively and shrimp only (monoculture) (T4) @ 20.000/ha. The shrimp and fish were fed with farm made feed consisting of a mixture of fishmeal 29%, MOC 15%, rice bran 30%, soybean meal 16%, wheat flour 9% and vitamin premix 0.1%. The average final weight of shrimp was 24.9±1.13g, 23.41±3.26g and 26.67±1.89g that stocked with tilapia in treatments T1, T2, and T3 respectively. The final average weight of shrimp in monoculture (T4) was 27.41±0.76g, apparently higher but insignificant in treatments. The survival of shrimp was 42.17%, 32.38%, 39.45% and 61.98% in treatments T1 T2, T3 and T4 respectively. The production of shrimp in concurrent culture was 193.67, 154.26 and 210.41kg/ha in T1, T2 and T3, respectively, while in monoculture (T4) was 339.77 kg/ha. The growth and survival of tilapia among the treatments was insignificant. The growth of monosex tilapia ranged 225.29 and 291.31g and survival 62.77 and 72.20% in T1 and T2, respectively, in mixed sex was 193.0g and 83.20% (T3). The production of tilapia monosex strains was 1676.69kg/ha (Strain-2 all male) and 1668.98 kg/ha (Strain-1 all male) while that of Strain-3 mixed sex population was 1622.92 kg/ha.

Milkfish grow-out culture in ponds

Milkfish farming is regarded as the backbone of Philippine aquaculture. In 2001, nearly 50% of the Philippines' aquaculture production was milkfish cultured from brackishwater ponds. It has 3 major culture systems: extensive; semi-intensive and intensive. A brief outline is given of the stocking and feeding procedures, providing also some details as to investment costs and returns.

不同培养基对湖泊氨氧化细菌MPN计数的影响

本文研究了培养时间、培养基类型、硫酸铵浓度对湖泊沉积物与水中氨氧化细菌(AOB)MPN计数的影响。结果表明,MPN值随培养时间的延长而增大,且趋于稳定。对不同样品而言,培养40d后,MSF培养基均给出稳定的MPN值。在3种不同类型的培养基(XZ-AOB、MSF、SW)中,MSF产生的MPN值最大。此外,培养基中的硫酸铵浓度对MPN计数亦有重要影响,与沉积物AOB相比,湖水AOB对硫酸铵浓度更为敏感。

四种底栖螺类饥饿代谢的研究

研究了四种常见优势底栖螺类的饥饿代谢(R,mgO2/ind.d)与温度(T,℃)、体重(Wd,mg dry-wt或Ww,mg wet-wt)的关系,并计算出三者间的复合关系,分别是:铜锈环棱螺,R=0.044Wd0.537e0.061T;长角涵螺,R=0.0004Ww0.9405·e0.0735T;纹沼螺,R=0.004Wd1.072e0.091T;短沟蜷,R=0.023Wd0.777e0.042T。