Synthesis and fluorescence of europium-doped barium fluoride cubic nanocolumns

Europium-doped barium fluoride cubic nanocolumns were synthesized from the quaternary water in oil reverse microemulsions In this process, the aqueous cores of water/cetyl trimethyl ammonium bromide (CTAB)/n-butanol/n-octane reverse microemulsions were used as microreactors for the precipitation of europium doped barium fluoride. XRD analysis shows that under the dopant concentration of 0.06% (molar fraction), the products are single phase. The result products are cubic column-like with about 30 similar to 50 nm edge length of cross section, and about 200 nm of length obtained from the transmission electron microscopy (TEM), and atomic force microscopy (AFM). Under the 0.06 % (molar fraction) of dopant concentration I the fluorescence of Eu2+ and Eu3+ under the 589 of excitation wavelength is observed.

A two-dimensional molybdenum (V) phosphate with covalently bonded transition metal coordination complexes: hydrothermal synthesis and structure characterization of Na-2[{Mn(phen)(2)(H2O)}{Mn(phen)(2)}(3){Mn (Mo12O24)-O-V (HPO4)(6)(PO4)(2)(OH)(6)}] center dot 4H(2)O (phen=1,10-phenanthroline)

An organic-inorganic hybrid molybdenum phosphate, Na-2[{Mn(phen)(2)(H2O)} {Mn(phen)(2)}(3){(MnMo12O24)-O-v (HPO4)(6)(PO4)(2) (OH)(6)}] . 4H(2)O (phen=1,10-phenanthroline), involving molybdenum present in V oxidation state and covalently bonded transition metal coordination complexes, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Deep brown-red crystals are formed in the triclinic system, space group P (1) over bar, a=16.581(l)Angstrom, b=18.354(1)Angstrom, c=24.485(2)Angstrom, alpha=80.589(l)degrees, beta=71.279(1)degrees, gamma=67.084(1)degrees, V=6493.8(8)Angstrom(3), Z=2, lambda(MoKalpha)=0.71073Angstrom (R(F)=0.0686 for 29,053 reflections). Data were collected on a Bruker Smart Apex CCD diffractometer at 293 K in the range of 1.76 < theta < 28.06degrees using omega-2theta scans technique. The structure of the title compound may be considered to be based on {Mo6O12(HPO4)(3)(PO4)(OH)(3)} units bonded together with {Mn(phen)(2)} subunits into a two-dimensional network. Two types of tunnels are observed in the solid of the title compound.

Tremolite-reinforced nylon 66 composites: Mechanical and rheological properties

The reinforcement effect of an acicular inorganic filler, tremolite, on nylon 66 was studied. The mechanical properties of tremolite-filled nylon 66 composites and the effect of the filler particle size on them were obtained. The dynamic mechanical properties and rheological properties of the composites were measured. Two treatments, silane and unsaturated polyester, were used to improve the interface between tremolite and the nylon matrix. The morphologies of the composites were investigated using SEM. (C) 1998 John Wiley & Sons, Inc.

Rapid analysis of steroidal saponin mixture using electrospray ionization mass spectrometry combined with sequential tandem mass spectrometry

Using electrospray ionization mass spectrometry (MS) combined with sequential tandem MS(ESI-MSn), two major steroidal saponins extracted from Tribulus terrestris were studied, and considerable useful structural information was obtained. The structure of the proposed known steroidal saponin was verified, and the structure of the unknown saponin was investigated using MSn experiments. Some special fragment ions were also observed, and the corresponding fragmentation mechanisms were investigated which are characteristic for steroidal saponins and can give some information on the linkage position of some sugar groups in saponins. This methodology has been established as a powerful tool for the rapid, comparative analysis of mixtures such as crude plant extracts. (C) 1998 John Wiley & Sons, Ltd.

FORMATION OF [C60C5H5] ADDUCT CATIONS AND THEORETICAL-STUDY OF THE ISOMERS

We study here the reactions between C-60 and planar C5H5+ cations that lead to the formation of [C60C5H5](+) adduct cations in the chemical ionization source of the mass spectrometer. The structures, stabilities and charge locations of some possible isomers of [C60C5H5](+): sigma-adduct, pi-complex, [1,4]- and [1,2]-addition cations, are studied by AM1 semiempirical molecular orbital calculations. We find that the most stable is the sigma-addition cation. Another interesting and stable structure is the pi-complex cation which is bonded by the electrostatic interaction at the inter-ring distance of 1.589 Angstrom with the C-5v symmetry. The C5H5+ cyclopentadienium cation seems to be an ''inverted umbrella'' sitting on a five-membered ring of the C-60 cage.

尼龙-1010非等温结晶动力学

尼龙-1010是我国独创的工程塑料品种,已被较广泛地应用于精密机械零件、仪表制造、家用电器、航空等方面。有关尼龙-1010的基础研究大多在我国学者中间进行,由于在实际加工生产过程中,如通常的融熔纺丝、注射、模压等工艺均是在非等温条件下进行,有关它的非等温结晶动力学尚未见报道,本文用几种理论方法对尼龙-1010的非等温结晶动力学过程进行研究。

SYNTHESIS AND CHARACTERIZATION OF BINUCLEAR ORGANOLANTHANIDE COMPLEXES INVOLVING CYCLOPENTADIENYL AND N-PROPYLOXIDE LIGANDS - X-RAY CRYSTAL-STRUCTURE OF [(C5H5)2YB(MU-OCH2CH2CH3)]2

By the reaction of Cp3Ln (Cp = C5H5; Ln = Dy, Ho, Yb) with equimolar n-propyl alcohol in THF (tetrahydrofuran) at room temperature three new binuclear organolanthanide complexes, [CP2Ln(mu-OCH2CH2CH3)]2 (Ln = Dy, Ho, Yb), have been synthesized, as shown by X-ray single-crystal structure analysis for the complex [Cp2Yb(mu-OCH2CH2CH3)]2. All the complexes were characterized by elemental analysis, IR and MS spectra. The Yb2O2 unit is planar, and the ytterbium atom is coordinated by two Cp ring centroids and two oxygen atoms of two n-propyloxide ligands to form a distorted tetrahedral geometry. The average Yb-C (Cp) bond distance is 2.589(17) angstrom. The average Yb-O distance is 2.199(5) angstrom. The Yb-Yb separation [3.521(1) angstrom] indicates that no metal-metal interaction is present.

STUDY ON ELECTRODE PROCESS OF MYOGLOBIN AT A POLYMERIZED AZURE A FILM ELECTRODE

The electrochemically polymerized azure A film electrode was firstly reported in this paper. A quasi-reversible electrode processes of myoglobin with the formal heterogeneous electron transfer rate constant (k(sh)) of 1.73 x 10(-4) cm.s-1 at the polymerized azure A modified electrode have been achieved using in-situ UV-visible spectroelectrochemistry. The adsorption of myoglobin on the polymerized azure A film electrode surface was confirmed by XPS. With simultaneously studying of cyclic voltammetry and in-situ cyclic voltabsorptometry, the attribution of the voltammetry responses of myoglobin at the film electrode has been studied. The mechanism for the heterogeneous electron transfer of myoglobin at the polymerized azure A film modified electrode has been proposed as well.

肌红蛋白在聚天青A薄膜修饰电极上电极过程的研究

本文采用电聚合方法成功地制备了聚天青A(AZA)薄膜修饰电极。利用现场光透薄层光谱电化学方法研究了肌红蛋白于聚AZA薄膜修饰铂网光透电极上的准可逆异相电子传递过程,给出了电极反应的热力学参数[标准式电位E~0′=0.055V(vs·NHE),电子反应数n=1.1]和动力学参数(异相电子传递速率常数k_(sh)=1.73×10~(-4)cm·s~(-1),电子传递系数α=0.68).X光电子能谱表面分析表明肌红蛋白于修饰电极表面存在吸附。用现场循环电位吸收和循环伏安法解析了肌红蛋白于膜电极上的伏安响应,提出了肌红蛋白于聚AZA薄膜修饰电极上的异相电子传递过程机理。

电沉积多晶CuInSe_2薄膜的光电化学——Ⅰ.CuInSe_2薄膜的电沉积

研究了含Cu~(2+),In~(3+),HSeO_2~+等离子的酸性电解液中CuInSe_2的电沉积过程.对电沉积条件进行了优化选择,对电沉积机理进行了探讨.对钛基底上的沉积膜的物性和结构分析表明,沉积膜的结晶性良好,颗粒均匀而连续,为多晶黄铜矿型结构.在多硫氧化还原电对液中,用这种沉积膜制成的光电化学电池具有明显的光响应.

不同脱乙酰度壳聚糖Mark-Houwink方程的订定

通过多步脱乙酰基反应和溶液超声波降解制备了脱乙酰度D.D在49—100％(wt),重均分子量在1.94—25.1×10~5的系列壳聚糖样品,在0.1mol/L CH_3COONa+0.2mol/L CH_3COOH溶剂中和30℃下,用光散射法首次订定出了不同D.D壳聚糖的M-H方程常数K和α值,结果如下:D.D(wt％) K×10~3(ml·g~(-)1) α69 0.104 1.1284 1.424 0.9691 6.589 0.88100 16.800 0.81导致K和α值差别的主要原因是由于壳聚糖大分子链上的胺基(—NH_2)被酸质子化后,失去了形成分子内氢键的能力,减弱了内旋转受阻程度,同时,质子化后形成的阳离子聚电解质分子链链段间以及链段与溶剂之间的相互作用增强,有效电荷密度的增加使得聚电解质溶液粘度增大。

Isolation, properties and spatial site analysis of gamma subunits of B-phycoerythrin and R-phycoerythrin

Polysiphonia urceolata R-phycoerythrin and Porphyridium cruentum B-phycoerythrin were degraded with proteinaseK, and then the nearly native gamma subunits were isolated from the reaction mixture. The process of degradation of phycoerythrin with proteinaseK showed that the gamma subunit is located in the central cavity of (alpha beta)(6) hexamer of phycoerythrin. Comparative analysis of the spectra of the native phycoerythrin, the phycoerythrin at pH 12 and the isolated gamma subunit showed that the absorption peaks of phycoerythrobilins on alpha or beta subunit are at 535 nm (or 545 nm) and 565 nm, the fluorescence emission maximum at 580 nm; the absorption peak of phycoerythrobilins on the isolated gamma subunit is at 589 nm, the fluorescence emission peak at 620 nm which overlaps the absorption maximum of C-phycocyanin and perhaps contributes to the energy transfer with high efficiency between phycoerythrin and phycocyanin in phycobilisome; the absorption maximum of phycourobilin on the isolated gamma subunit is at 498 nm, which is the same as that in native phycoerythrin, and the fluorescence emission maximum at 575 nm.

皱纹盘鲍的遗传育种与养殖技术研究

优良的种质是产业发展的重要保证，品种更新和养殖技术的发展已经给世界农业带来了令人瞩目的成就，然而我国水产生物的育种工作刚处于起步阶段，而育种技术的研究则更是滞后。借鉴陆生生物中发展起来的相对成熟的研究方法，可以帮助加快海洋生物遗传育种相关研究的进度。本研究以我国北方海区重要的海洋经济动物－皱纹盘鲍为研究对象，从表型遗传、数量性状遗传等2个方面开展了皱纹盘鲍的遗传育种研究，同时从幼鲍培育密度与分选效应等方面研究了皱纹盘鲍的中间培育技术。 主要结果如下： 1. 皱纹盘鲍的贝壳颜色遗传、食物对贝壳颜色表现型的影响，贝壳颜色与生长速度间的关系 将贝壳颜色为橘红色（O表型）的突变型皱纹盘鲍与贝壳颜色为绿色（G表型）的野生型皱纹盘鲍进行了连续2代的交配实验。结果表明：皱纹盘鲍橘红色的贝壳颜色相对于绿色的贝壳颜色为隐性性状，皱纹盘鲍的贝壳颜色表型受单位点、2个等位基因遗传控制，其中基因型为oo的个体，贝壳颜色的表现型为橘红色（O表型），而基因型为GG或Go的个体，贝壳颜色的表现型为野生型（G表型）。 为探讨食物类型对不同基因型皱纹盘鲍贝壳颜色表现型的影响，对不同贝壳颜色表型的个体投喂不同种类的食物，结果表明，除遗传因素外，皱纹盘鲍的贝壳颜色表现型显著地受食物类型的调控。其中oo基因型的个体，在摄食底栖硅藻（Navicula sp.）和红藻时，贝壳颜色的表型为橘红色；而在摄食褐藻、绿藻和以海带粉为唯一海藻源的人工配合饵料时，贝壳颜色的表型为黄色。GG和Go基因型的个体，在摄食底栖硅藻、红藻时，贝壳颜色的表型为褐红色；在摄食褐藻、绿藻和以海带粉为唯一海藻源的人工配合饵料时，贝壳颜色的表型为绿色。该结果表明，相同基因型的皱纹盘鲍在摄食不同类型的食物时，贝壳表现型不同，即不同类型的食物可以导致2种基因型皱纹盘鲍的贝壳颜色表现型在一定范围内发生转换：oo基因型的个体，贝壳的颜色可以表现为橘红色或者黄色，不会出现野生型皱纹盘鲍的褐红色或绿色；而GG与Go基因型的个体，相应的贝壳颜色表型只能是褐红色或者绿色，不会出现oo基因型可能表现的橘红色或黄色。特定基因型的皱纹盘鲍，在摄食特定类型的食物时贝壳的相应部位可表现出特定的颜色。皱纹盘鲍的这种“食物－贝壳颜色”的相关性可作为一种形态标记，用于标识皱纹盘鲍的个体和群体，该标记技术可用于皱纹盘鲍的养殖技术和遗传学研究。 此外，选用了贝壳颜色遗传学实验中建立的贝壳颜色发生分离的家系为实验材料，以壳长为指标，分析比较了来自相同家系的O表型与G表型个体之间的生长速度。结果表明，在幼鲍发育至412天止的3-5个统计时段内，没有在同一家系来源的2种贝壳颜色表型个体之间检验到生长速度的显著差异。 2. 皱纹盘鲍不同选育群体及杂交群体的贝壳形态参数分析 在皱纹盘鲍的7个群体中（包括已经对生长速度为指标进行了多代人工选育的群体4个、野生群体之间直接杂交繁育的杂交F1群体3个），测量了4-6龄成体样本的壳长（L）、壳宽（W）、壳高（H）和壳重（Sw），并计算了L/（L+W+H）、W/（L+W+H）、H/（L+W+H）和Sw/（L×W×H）等4个壳形态学参数。用方差分析方法（MANOVA、ANOVA）统计并比较了这些壳形态参数在皱纹盘鲍群体间的遗传变异。结果表明，4个壳形态参数在不同群体间变异系数分别为0.34、0.74、2.62和6.54，其中，H/（L+W+H）与Sw/（L×W×H）在各供试群体间均具有较高的多态性且差异达显著水平，表明这2个参数在不同群体间存在较高的遗传变异。由于在活体情况下无法测量壳重（Sw）性状，建议以参数H/（L+W+H）为指标对皱纹盘鲍贝壳形态（如壳型）等进行人工选择。 3. 皱纹盘鲍成体阶段生长性状的遗传参数估计 采用巢式设计，分析了成体阶段不同发育期皱纹盘鲍的壳长与生长速率的遗传力、不同发育期的壳长性状之间的遗传相关、以及不同发育期的生长速率之间的遗传相关，结果表明：（1）壳长遗传力在受精后第70 、130、320、320、380、490与550天的雄性组分估计值分别为0.161 ± 0.075、0.312 ± 0.131、0.326 ± 0.331、0.135 ± 0.228、0.153 ± 0.185和0.180 ± 0.106；雌亲组分估计分别为0.312 ± 0.172、0.699 ± 0.168、0.695 ± 0.168、0.977 ± 0.407、0.427 ± 0.195和0.449 ± 0.027。（2）生长速率遗传力在受精后第320~380天、490 ~ 550天，雄、雌组分估计值分别为0.080 ± 0.120（雄）、 0.210 ± 0.191（雌）以及0.299 ± 0.146（雄）、0.306± 0.148（雌）。雌亲组分的壳长遗传力和生长速率遗传力估计值较大且均达显著水平，表明皱纹盘鲍在成体阶段依然受母性效应的影响。成体阶段生长性状遗传力水平的估计对制定科学的皱纹盘鲍育种方案有指导意义。（3）雄亲组分估计的不同发育期（第390 ~ 550天）壳长间遗传相关为0.597 ~ 1.000，雌亲组分估计为0.589 ~ 1.177。由雄亲、雌亲组分估计，受精后第320~380天与第490 ~ 550天两个发育阶段生长速率间遗传相关均接近于0。雌亲组分估计不同发育期壳长间遗传相关均达显著水平（t0.05, d.f.=13 = 4.33 ~ 11.69，P<0.01），表明壳长性状早期选择有效，即在皱纹盘鲍早期阶段依据壳长性状对个体进行择优或去劣可在后期阶段获得壳长较大的个体。由于使用的雄亲数目少（8个父系半同胞），实验中以雄亲组分估计的遗传参数误差较大。 4. 皱纹盘鲍选育系间的群体杂交 进行了皱纹盘鲍4个人工选育系之间的完全双列杂交实验，以群体交配的方式共建立了16个组合；此外，以大连“98”选群与汕头“S”选群为亲本，以群体交配的方式建立了4个交配组合。对不同方向的杂交组合进行了中亲杂种优势、超亲杂种优势以及配合力等方面的评价。 （1）测量了4个选育群体（R、97、S和J）及其各杂交组合在受精后第9、20和30天时的壳长，统计分析了不同选育系间壳长性状的差异、评价了不同方向杂交组合的中亲与超亲杂种优势、以及配合力。结果如下： 选育系群体内交配繁育的4个组合，在受精后第9、20和30天的壳长均有显著差异，其中，97  97组合在早期发育各阶段均为最小，分别为0.462 ± 0.023mm、0.698 ± 0.057mm和1.476 ± 0.234mm；S  S组合的3次测量值均为最大，分别为0.522 ± 0.023mm、0.824 ± 0.084mm和1.798 ± 0.229mm。 两个方向杂交组合与选育系亲本群体内交配组合的平均值和高亲值比较，得到如下结果：（A）受精后第9天壳长表现正向中亲杂种优势的组合有6个、表现负向中亲杂种优势的组合6个，其中J  97组合的中亲优势率最高，为9.05%；R  S组合最低，为-6.61%。正向高亲杂种优势组合有4个、负向高亲杂种优势组合有8个，其中S  J组合的高亲优势率最高，为5.77%；R  S组合最低，为-7.96%。（B）受精后第20天壳长表现正向中亲杂种优势的组合有7个、表现负向中亲杂种优势的组合5个，其中J  97组合的中亲优势率最高，为12.60%；J  R组合最低，为-8.72%。正向高亲杂种优势组合有3个、负向高亲杂种优势组合有11个，其中J  97组合的高亲优势率最高，为12.20%；J  R组合最低，为-12.67%。（C）受精后第30天壳长表现正向中亲杂种优势的组合有7个、负向中亲杂种优势的组合5个，其中97  S组合的中亲优势率最高，为24.08%；S  97组合最低，为-12.69%。正向高亲杂种优势组合有6个、负向高亲杂种优势组合有6个，其中97  S组合的高亲优势率最高，为15.95%；S  J组合最低，为-19.44%。上述结果表明，皱纹盘鲍不同选育系之间的交配组合，杂种优势率差异很大，因此，通过组配实验，将杂种优势率高的交配组合选择出来应用于生产，可望显著提高目标性状的产量。 对早期发育阶段各生长期壳长性状，亲本一般配合力（GCA）、各杂交组合间特殊配合力（SCA）以及正反交（REC）效应值进行方差分析，结果表明：各亲本GCA差异显著，说明各选育群体存在显著的遗传差异，其中汕头选群“S”在测量的各个生长期均为正值且显著大于其它各亲本；特殊配合力（SCA）以及正反交（REC）效应值较大在各杂交组合间存在显著差异，说明在早期生长发育阶段非加性遗传效应（显性和上位效应）占主导地位。综合各个生长期亲本GCA和杂交组特殊配合力（SCA）以及正反交（REC）效应值，杂交组合97×S在早期生长阶段不仅有较高SCA值而且两个亲本也具有较大的GCA值，表明选育系97和S较适宜作为杂交亲本使用。 （2）大连“98”选群与汕头“S”选群进行2×2因子设计的群体杂交实验，比较了各交配组合早期存活相关性状如受精率、孵化率、变态率以及壳长性状，评价了两个方向杂交组合平均以及不同方向杂交组合的中亲杂种优势率。结果表明早期发育阶段各组合间的受精率无显著差异，而孵化率、变态率等两个杂交方向平均的中亲杂种优势率为5.49%与12.53%，高于壳长性状的优势率（0.936-1.534%）。方差分析结果表明不同方向的杂交组合在早期发育阶段存活相关性状以及壳长性状存在显著差异。孵化率、变态率性状，S×98的中亲杂种优势率分别为13.21%与21.10%，均高于98×S的-3.84%与3.85%；而第10和25d壳长性状，S×98的中亲杂种优势率为1.14%与-2.52%，低于98×S的1.93%与4.41%。 为进一步评价“98”选群与“S”选群不同交配组合在不同温度条件下的生长，进行了基因型与环境的互作研究。从“98”选群与“S”选群的4个交配组合中分别取5月龄幼鲍100头，各组合随机分成3组，每组1个重复，分别于12°C、16°C和 22°C温度条件下进行培育，比较各交配组合基因型与温度对幼鲍生长的影响。不同温度条件下，各组合壳长生长的方差分析结果表明，基因型和温度都能够对幼鲍生长以及最终壳长产生极显著的影响（P < 0. 01），它们的交互作用也达到显著水平（P < 0.05）。杂交子代的幼鲍壳长在12°C、16°C和 22°C温度条件下均表现出杂种优势，双向杂交的中亲杂种优势率分别为5.32%、5.55%和0.03%，表明低温条件（12°C），比高温条件（22°C）下有更强的杂种优势。汕头“S”选群的早期孵化率、变态率、生长性状以及低温条件下幼鲍生长性状的单亲杂种优势率分别为16.64%、42.49%、3.42~5.79%和5.73~9.15%，单亲杂种优势率较大，表明可通过杂交手段，显著地改良汕头“S”选群在早期发育阶段的生长速度、存活率以及幼鲍期的生长性状。本研究的结果支持了Lerner（1954）杂种优势的基因与环境互作学说。 5. 皱纹盘鲍幼鲍的中间培育技术研究 （1）对南方越冬方式的评价 目前，每年的11月前后，将6-7月龄幼鲍运往南方的闽东、闽中、闽南沿海越冬，翌年4月至6月再运回到北方（大连、山东半岛）的养殖模式已经普遍应用于皱纹盘鲍的实际生产，为评价南方越冬的幼鲍培育方式，本研究分别以不同幼鲍材料在闽东三都海湾进行了越冬培育实验。 选择生产上壳长分别为18.37 ± 1.28 mm、15.89 ± 1.10 mm、14.55 ± 1.10 mm与10.59 ± 0.84 mm的幼鲍进行了为期6.5个月的越冬培育，实验结束时，存活率分别为95.56 ± 2.21%、90.55 ± 1.96%、83.97 ± 1.63%与63.30 ± 2.79%。回归分析表明，供试幼鲍在实验起始时的壳长与越冬阶段的存活率成正相关（P = 0.018 < 0.05）。该结果表明，提高幼鲍的规格可显著提高皱纹盘鲍的越冬成活率，因此对于实际生产而言，采取适当措施提高皱纹盘鲍越冬苗种的规格将大幅增加生产的收益，而采用生长速率快的品种、品系或提早采苗均可实现该目标。综合各规格组幼鲍，幼鲍在南方开放性水域进行越冬培育的平均存活率较高，可达到91.38±0.01%，从幼鲍南方越冬的存活曲线可以看出，幼鲍的死亡主要集中在从大连运至福建某地后的15天内，出现死亡高峰的原因可能是由于运输过程的胁迫。此外，2月及4月中下旬水温出现显著降低或回升时也有较明显的死亡出现。该部分结果，对皱纹盘鲍幼鲍的养成管理有指导意义，可以通过合理安排越冬时间、避开死亡的敏感期等措施减少苗种越冬阶段的死亡量。 以中国大连野生群体繁育的子一代为亲本（10♀，10♂），以群体交配的方式繁育F2代个体为实验材料，分别于南方海区以及北方室内升温水方式下进行生长、存活比较，结果表明南方越冬培育方式下，幼鲍壳长的日增长率为81.37-108.89 µm•day-1，与北方室内升温培育条件相比，壳长生长提高了1.08 ~ 1.68倍；而存活率无显著差异。皱纹盘鲍幼鲍南方越冬方式的优势主要体现在鲍鱼幼鲍的生长速度加快，同时节约养殖场的能耗 （2）幼鲍培育过程中的养殖密度与分选效应评价 以3种规格皱纹盘鲍幼鲍为材料比较幼鲍在4个培育密度以及分选或混养条件下壳长的平均日生长及特定生长率。在南方越冬培育方式下实验进行106天，多因素方差分析结果表明实验初始幼鲍的壳长以及培育密度对壳长的生长有显著影响，而且密度效应在不同幼鲍起始规格组中有不同表现；分选没有能够提高不同规格组的生长。本研究的结果对皱纹盘鲍幼鲍的越冬培育有一定的指导作用。

Fast microzooplankton grazing on fast-growing, low-biomass phytoplankton: a case study in spring in Chesapeake Bay, Delaware Inland Bays and Delaware Bay

Dilution experiments were performed to examine the growth and grazing mortality rates of picophytoplankton (< 2 mu m), nanophytoplankton (2-20 mu m), and microphytoplankton (> 20 mu m) at stations in the Chesapeake Bay (CB), the Delaware Inland Bays (DIB) and the Delaware Bay (DB), in early spring 2005. At station CB microphytoplankton, including chain-forming diatoms were dominant, and the microzooplankton assemblage was mainly composed of the tintinnid Tintinnopsis beroidea. At station DIB, the dominant species were microphytoplanktonic dinoflagellates, while the microzooplankton community was mainly composed of copepod nauplii and the oligotrich ciliate Strombidium sp. At station DB, nanophytoplankton were dominant components, and Strombidium and Tintinnopsis beroidea were the co-dominant microzooplankton. The growth rate and grazing mortality rate were 0.13-3.43 and 0.09-1.92 d(-1) for the different size fractionated phytoplankton. The microzooplankton ingested 73, 171, and 49% of standing stocks, and 95, 70, and 48% of potential primary productivity for total phytoplankton at station CB, DIB, and DB respectively. The carbon flux for total phytoplankton consumed by microzooplankton was 1224.11, 100.76, and 85.85 mu g C 1(-1) d(-1) at station CB, DIB, and DB, respectively. According to the grazing mortality rate, carbon consumption rate and carbon flux turn over rates, microzooplankton in study area mostly preferred to graze on picophytoplankton, which was faster growing but was lowest biomass component of the phytoplankton. The faster grazing on Fast-Growing-Low-Biomass (FGLB) phenomenon in coastal regions is explained as a resource partitioning strategy. This quite likely argues that although microzooplankton grazes strongly on phytoplankton in these regions, these microzooplankton grazers are passive.

藏药秦艽、麻花艽中落干酸和龙胆苦甙的HPLC法含量测定

应用反相高效液相色谱法同时测定藏药秦艽、麻花艽中落干酸、龙胆苦甙含量.并比较了加热回流提取及超声提取两种方法对分析结果的影响.还测定了两种藏药全草及根、茎、叶、花等不同部位两种成分的含量.