SOME NEWER CONCEPTS OF ETHYLENE ALPHA-OLEFIN COPOLYMERIZATION ON HETEROGENEOUS ZIEGLER-NATTA CATALYSTS

Unsteady diffusion kinetic, recently advanced by this laboratory, is applied to the examination of some polymerization and molecular chain structure problems. Hitherto deemed "anomalous" phenomena, such as the faster rate of copolymerization of ethylene/alpha-olefin than the homopolymerization of ethylene and the enrichment in the incorporation of a higher alpha-olefin in its copolymerization with ethylene by a lower alpha-olefin, are reasonably explained by unsteady diffusion of monomers. Molecular chain structure of copolymers, such as compositional heterogeneity and its dependence on comonomer incorporation originates from the difference in diffusion coefficients of the monomers. A copolymer composition equation taking into consideration the unsteady diffusion was developed. In cases where simulated curves were compared with experimental curves, good agreements were found.

AN ALL-SOLID-STATE LITHIUM POLYANILINE RECHARGEABLE CELL

The performance of an all-solid-state cell having a lithium negative electrode, a modified polyethylene oxide (PEO)-epoxy resin (ER) electrolyte, and a polyaniline (PAn) positive electrode has been studied using cyclic voltammetry, charge/discharge cycling, and polarization curves at various temperatures. The redox reaction of the PAn electrode at the PAn/modifed PEO-ER interface exhibits good reversibility. At 50-80-degrees-C, the Li/PEO-ER-LiClO4/PAn cell shows more than 40 charge/discharge cycles, 90% charge/discharge efficiency, and 54 W h kg-1 discharge energy density (on PAn weight basis) at 50-mu-A between 2 and 4 V. The polarization performance of the battery improves steadily with increase in temperature.

碳-13核磁共振定量测定萄葡糖及果糖的含量

本文利用~(13)C-NMR方法测量由葡萄糖通过葡萄糖异构酶的作用,在不同的条件下,在转化为果糖的过程中葡萄糖和果糖的相对含量。同时~(13)C-NMR技术也是直接测定各种构型糖含量的有效方法。实验结果表明,Gd-DPTA弛予试剂能够使自旋-晶格弛豫时间(T1)缩短。同时对NOE效应的消除也作了描述。本法测定的相对误差低于±0.5％。

STUDY ON THE COMPLEXATION OF ACENAPHTHENE AND FLUORANTHENE WITH CYCLODEXTRINS BY MEANS OF TIME-RESOLVED FLUORESCENCE TECHNIQUE

The complexation of acenaphthene and fluoranthene with beta-cyclodextrin (CD) in aqueous solutions in the presence and absence of ethanol was investigated by means of the time-resolved fluorescence technique. The appearance of a longer lifetime component and the increase of its fraction relative to that of the shorter lifetime component with increasing CD concentration demonstrate the formation of inclusion complex between the guest molecule and CD. The formation constants for complexation were derived from the pre-exponential factor A(i) of fluorescence decay curves. The presence of ethanol in the reaction systems enhanced the inclusion to a large extent.

藉时间分辨荧光技术研究二氢苊、荧蒽与环糊精的络合过程

用时间分辨荧光技术研究二氢苊、荧蒽与β-环糊精的络合过程以及乙醇分子对络合过程的影响,观察到它们在环糊精水溶液中有长寿命组份存在.证明这些分子与环糊精分子发生了络合作用,并根据荧光衰减曲线的指前因子计算出了它们的络合平衡常数.

Effect of stocking density on growth, settlement and survival of clam larvae, Meretrix meretrix

To determine the optimal larval density for hatchery culture of the clam Meretrix meretrix, experiments with stocking densities of 5, 10, 20, 40 and 60 larvae ml(-1) were designed, which included the developmental stages from D-veliger to 8 days postsettlement. Shell length, settlement time and survival rate of the larvae were recorded. Results showed that, at each sampling time, larvae reared at the highest density had the smallest mean size, whereas larvae reared at the lowest density had the largest mean size. Statistical differences in mean shell length at different stocking densities appeared from day 2, and greater differences occurred with increased culture time. Specific growth rate (SGR) in the rapid growing stage (day 0-3) was negatively correlated with density; however, no correlation was found between SGR and density in the slow growing stage (days 3-7). Settlement time was prolonged and shell length of settled larvae decreased as density increased. However, larval survival rate (74.8-79.1%) was independent of stocking density. Results showed that a high stocking density, in the designated range, is feasible for larval culture of the clam M. meretrix. However, for large-scale culture, in the interest of costs and safety, a stocking density of 10-20 larvae ml(-1) is recommended. (c) 2006 Elsevier B.V. All rights reserved.

Settling abalone veliger larvae in a free-swimming microalgal culture

In the current abalone hatchery in China, insufficient diatoms on vertically placed corrugated pvc plates at later stage often could not support the growth of postlarvae up to the stage that they can feed on live macroalgae. As a result, stripping the spats (35 mm) off by anaesthetization and switching the diet from live diatoms to artificial powdered diet in combination has to be performed in most of the abalone farms. This manipulation normally leads to more than 50% mortality. Here we report the direct use of the unicellular green alga Platymonas helgolandica Kylin var. tsingtaoensis as a potential alga to be used to settle the veliger larvae of the Pacific abalone Haliotis discus hannai and to feed the postlarvae. Settlement rate of 2-day-old veliger larvae in mono culture of P helgolandica could be as high as 92% ( +/- 4.2%) on day 10 in small scale trials, higher than that in the selected benthic diatom strain (53.6% +/- 12.7%) when settled in the water in which bacteria propagation was controlled by treatment of 2 ppm of benzylpenicillinum calcium and streptomycin sulfate. Postlarvae fed solely on P. helgolandica or the selected benthic diatom Navicula-2005-A grew at rates of 40.1 ( +/- 1.9) and 45.8 (+/- 13.4) mu m day(-1), respectively, when raised at 22 degrees C until day 50 postfertilization. P. helgolandica was shown to have distinct diurnal settling rhythm characterized with a peak of settled cells in the middle of the night for cell division and a peak of free-swimming cells in the middle of the day. High density of attached P. helgolandica cells on the inner surface of the culture facility in the night fits the nocturnal feeding behavior of the abalone spats. Judged by the promising larvae settling rate, growth and survival rates of the postlarvae fed with this alga, the free-swimming micro-green alga P. helgolandica constitutes a potential species for settling the veliger larvae and for supporting the growth of postlarvae as well. (c) 2006 Published by Elsevier B.V.

Genetic analysis of the gametophytes of Undaria pinnatifida (Phaeophyceae) with ISSR method

Inter-simple sequence repeat (ISSR) analysis was used to assess eleven pairs of Undaria pinnatifida (Harv.) Suringar male and female gametophytes. After screening fifty primers, 18 ISSR primers were selected for final analysis. A total of 104 loci were obtained, of which 77 were polymorphic, among the gametophytes studied. Genetic relationships were analyzed with simple matching (S), Jaccard's (J) and Dice's (D) distance coefficients. Little genetic variations were found among the selected Undaria gametophytes, for instance, the genetic distances ranging from 0.010 to 0.125 with Dice coefficients. UPGMA dendrograms showed that 11 pairs of Undaria gametophytes were distributed into five groups. Most Undaria strains cultivated in China exhibited closely genetic relationships with the strains from Japan. However, gametophytes from Qingdao appeared as distinct clades from other Undaria strains with all three distance coefficients used. Mantel test showed that the three distance measurements generated congruent clustering patterns on the same data. Our results demonstrated the feasibility of applying ISSR markers for genetic analysis of Undaria gametophytes. (c) 2006 Elsevier B.V. All rights reserved.

Pharmacological and immunocytochemical investigation of the role of catecholamines on larval metamorphosis by beta-adrenergic-like receptor in the bivalve Meretrix meretrix

Catecholamines regulate several physiological processes in mollusks. Many pharmacological experiments have been conducted to determine the effects of adrenergic agonist and antagonist of catecholamine receptors on Meretrix meretrix metamorphosis. Results showed that adrenaline (AD) and noradrenaline (NA) had substantial effects (p < 0.05) on larval metamorphosis at concentrations ranging from 10 mu M to 100 mu M. 10 mu M beta-adrenergic receptor (AR) agonist isoproterenol showed the same inducement effect as that of NA and AD on metamorphosis, whereas the alpha-AR agonist phenylephrine had no significant effect at concentrations between 0.1 mu M and 100 mu M concentrations (p > 0.05). Furthermore, I mu M beta-AR antagonist propanolol, but not alpha-AR antagonist prazosin, depressed the larval metamorphosis induced by NA or AD. By immunocytochemistry, two cell bodies of beta-adrenergic-like receptor, C/A1, C/A2, were observed in the cerebral/apical ganglion of competent larvae. In addition, there were other immunoreactive dots near C/A1 and C/A2. The results of pharmacology and immunocytochemistry suggests that beta-adrenergic-like receptor located in the larval CNS, might play a considerable role in the larval metamorphosis of M meretrix by AD or NA. (c) 2006 Elsevier B.V. All rights reserved.

鼠尾藻的生理生态和繁殖生物学研究

鼠尾藻 [Sargassum thunbergii (Mert.) O’Kunte] 是北太平洋西部特有的一种暖温性大型经济褐藻，在我国沿海地区北起辽东半岛南至雷州半岛的硇州岛，都有广泛分布。鼠尾藻在食品和医药领域的应用开发在我国有悠久历史。近年来，随着水产动物养殖业迅速发展，其应用领域得到了进一步拓展，发现鼠尾藻是海参、鲍鱼等水产动物的优质天然饵料。 受海参和鲍鱼产业发展影响，鼠尾藻的市场需求量成倍增加。目前鼠尾藻的供应全部依赖自然资源。掠夺式的采收方式导致鼠尾藻的野生资源遭到了很大破坏，种群规模和数量不断减小，生态环境也发生了变化。近年来鼠尾藻供需矛盾已经非常突出，如何保护和有效利用该海藻资源已经成为海藻科研和产业界的一个重要话题。 以往对鼠尾藻的生态学和人工育苗技术方面的比较深入的研究工作很少，许多基础科学问题研究不够，人工繁殖技术没有很好地掌握，已经不能满足产业发展需求并限制了鼠尾藻应用价值的发挥。为此，有必要系统性研究鼠尾藻原生态环境、野生状态下生长发育的年际交替规律、鼠尾藻有性生殖过程、人工育苗方法途径、鼠尾藻吸收无机营养能力、以及在调控藻际菌群能力等基础科学技术问题，带动鼠尾藻饵料规模的良性健康扩大，并进一步推动海参和鲍鱼等水产业的发展。 本文以青岛汇泉角的鼠尾藻为基本实验材料，通过野外实地周年观察并结合实验室工作，对上述问题初步进行了初步探索，主要获得如下结果： （1）在青岛地区海滨岩石地带，全年都可观察到鼠尾藻藻体，藻体的形态大小和生理发育状况随季节变化表现出很大的差别性。夏季藻体黄褐色，初生分枝伸展，有次生分枝、生殖枝和气囊的发育，而冬季的藻体黑褐色，初生分枝粗短，没有次生分枝、生殖枝和气囊的发育。6月鼠尾藻出现有性生殖器官生殖托，到7月生殖托发育成熟，7月藻体最长，平均在50厘米左右，11月可观察到有性生殖和假根产生的幼苗。假根营养繁殖再生苗是鼠尾藻种群新苗源的主体，在维持种群自然繁衍和发展中起主导作用。 （2）有性生殖过程是鼠尾藻个体发育的大事件，精卵结合产生幼苗的潜力巨大，是开展未来规模化人工育苗的希望依托。鼠尾藻初生分枝长度和外形株间差异较大，每株鼠尾藻平均大约有20个初生分枝，约一半初生分枝可发育成熟，充分发育的初生分枝可产生30－50个次生分枝，每个次生分枝上又有大约20－30个生殖枝，每个生殖枝上生殖托数量一般为1－3个，雌托长度大多在3－5mm，雄托长度在10－15mm。生殖托的成熟度由基部向顶端递减。一个雌托排卵量平均为400多粒。以此计算，每株雌性鼠尾藻在生殖季节可产生200多万个卵。 卵从生殖窝孔排出后粘附于雌托表面，雄托排精时间稍晚于雌托挂卵时间，精子游动到卵周围与之结合完成受精过程。受精卵大约在受精后1小时分裂为两个大小相近的细胞，2小时后再进行第二次分裂，其中一个细胞横裂为两个细胞：一个细胞较大，另一个细胞较小，另一个细胞的分裂面与第一次分裂垂直，等分为两个细胞，随后细胞不断分裂。在受精后48小时左右，胚苗一端产生出假根。胚苗从雌托脱落的第一周内，尽管细胞数量增加较快，但新细胞体积减小，使得胚苗的体积增加不多。从第二周开始幼苗的体积出现明显的增加。此时，无机营养盐的有效补充对鼠尾藻幼苗培养长大是十分必要的。下海后的管理是保障幼苗成活的关键，此时常常发生脱苗现象。 （3）鼠尾藻对无机氮、磷都有较强的吸收能力，鼠尾藻从海水中吸收无机氮和无机磷的能力分别为75.1mg/kg/day和36.2mg/kg/day，鼠尾藻对氮、磷吸收的质量浓度比例接近5：1。 （4）鼠尾藻具有调节藻际微生物种群的能力，鼠尾藻对弧菌和总异养菌菌群都有一定程度的抑制作用，研究发现鼠尾藻抑制弧菌的能力存在种的差异，其中对鳗弧菌65#显示的抑制作用最强，鼠尾藻的抑菌能力的强弱还与其生理状态的好坏有显著关系。 通过上述研究结果，我们认为：鼠尾藻通过有性生殖过程培育种苗在理论上具有可行性，发展潜力很大。而解决幼苗后期培养中的脱苗问题、提高苗的成活率是下一步需要研究攻克的关键技术；假根营养繁殖再生苗源是维持该藻自然种群的主要方式，也是目前开展人工养殖获得健壮苗种的重要途径，连根采收方式对鼠尾藻野生资源破坏严重；建议野生鼠尾藻在7月底到8月初（水温27℃左右）采收（此时藻体生物量接近最大、并完成生殖过程），采用剪切方式保留假根和幼小的初生枝收获，该方式还可以应用到收获人工筏式养殖的鼠尾藻中，这对保证假根的完整性，大量获得下一个栽培季节的健壮新苗有实际意义；建议进一步开发鼠尾藻吸收富营养化物质、净化养殖环境水质的能力，以及对弧菌和总异养菌的抑制能力，建立海参、鲍鱼和鼠尾藻生态互补、环境友好的养殖模式，控制病害发生，提高水产品产量和质量。

A new three-phase culture method for Manila clam, Ruditapes philippinarum, farming in northern China

Studies on reproduction, hatchery management, and culture of Manila clams Ruditapes philippinarum were carried out in an attempt to optimize their culture conditions and techniques. Results from these studies led to the development of a three-phase culture method for Manila clam farming in northern China. The key components of the new method were: 1) early spawning and over-wintering indoors (greenhouse); 2) optimized larval culture conditions and techniques; 3) juvenile rearing in shallow, fertilized nursery ponds; 4) optimized stocking size and density and substrate for mudflat grow out. Broodstock were maturated indoors for a month from early April to early May. Primarily because of higher water temperatures in the greenhouse the clams spawned more than one month earlier than in the natural environment. From May to July, juveniles were reared for 1-2 months indoors to a size of 2.0-3.0 mm in shell length before being moved to outdoor, pre-disinfected, nursery ponds. Juveniles were then reared in the nursery ponds for one month to about 1.0 cm before being transferred to the mudflat for grow out. Juvenile clams in nursery ponds grew considerably faster than in the natural environment probably because of higher temperatures and more abundant natural food. During grow out, the clams were reared for 4-7 months until they reached a market size (3.0-3.3 cm). Juveniles produced after August were over-wintered in the greenhouse in which the water temperature was about 3 degrees C higher than that of the outdoor environment. Juveniles grew at an average rate of > 20 mu m day(-1), while in the natural environment no growth was observed during winter because of low temperatures. Juveniles in the greenhouse grew to 2-3 mm by the following March before being moved into outdoor nursery ponds. The three-phase culture method not only shortened the production period from spawn to market size from 24-36 months to about 10-14 months, but also prolonged the spawning season from 2 to 7 months, resulting in increased production of seed and market-size clams. Compared with the traditional method, the new method could increase the yield of market-size clams by 10-11 times, and increase the profit per ha mudflat by as much as 124 times and the profit per kg market-size clams produced by 13 times. (c) 2006 Elsevier B.V. All rights reserved.

青藏高原祁连山东段高寒小嵩草草甸植物种群物候学研究(简报)

通过对青藏高原祁连山东段高寒小嵩草草甸主要植物种群物候特性的观测研究,采用聚类分析和主分量排序法将小嵩草草甸26种植物种群划分为不同的物候类群.利用相关系数排序法指出了影响不同物候期的主要生态因子依次是温度、降水量和日照时数.研究结果对物候资料积累、分析以及放牧管理具有指导意义.

三种高寒草甸植被分布及与湍流交换通量关系的比较

对海北定位站分布的金露梅灌丛草甸、矮嵩草草甸、藏嵩草沼泽化草甸3种高寒植被类型群落结构、感热(H)和潜热(LE)通量比较观测表明,3种植被类型年地上净初级生产力表现出矮嵩草草甸(318.600 g/m~2)＞藏嵩草沼泽化草甸(258.341 g/m~2)＞金露梅灌丛草甸(217.6 g/m~2).植物种类组成有矮嵩草草甸(54种)＞金露梅灌丛草甸(47种)＞沼泽草甸(24种).3种植被类型区近地表大气能量交换过程中,LE和H的月际变化明显,而且随植被类型的不同月际变化差异显著.3种不同植被类型在年内均表现出H+L E＞0,表明在青海海北高寒草甸地区,太阳辐射强烈,近地层湍流输送明显,地表为-热源.3类型高寒草甸植被的年地上净生产量基本与波文比(β)呈现正效应,与LE+H呈现明显的反效应.植物种类组成基本与LE+H有反效应,与β呈明显的正效应.

唐古特大黄染色体的核型分析

目的对蓼科（Polygonaceae）植物唐古特大黄（Rheum tanguticum Maxim、ex Balf．）染色体核型进行研究。方法采用常规压片方法，并结合显微摄影对染色体进行检测分析。结果唐古特大黄体细胞染色体数目为2n=22；核型公式为K（2n）=22=20m＋2sm，核型为“1A”型。结论唐古特大黄染色体的核型属于较原始的类型。