17 research outputs found

    九寨沟林下28种乡土观赏植物种子基本特征

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    为了筛选九寨沟旅游退化地段林下植被恢复的适宜物种,并揭示乡土植物种子基本性状特征,研究了九寨沟28种观赏性乡土植物种子基本特征(长宽、种皮厚度、千粒重、活力、萌发率)以及低温层积提高种子发芽能力的作用。调查研究结果是:1)28种植物种子中4种为小种子(9.9mg)。小种子均出现萌发,与小种子相比,种子休眠普遍存在于中等大小和大的种子中。2)77%的物种种子活力较高(>72%),但仅有7种常规条件下能萌发;窄叶鲜卑花的萌发率最高,达到80%左右,6种植物的萌发率3%~50%。3)低温层积显著提高了蔷薇、毛果铁线莲、宽叶旌节花、假升麻的萌发率(P<0.05),也相对较早地提高了陇东海棠、鲜黄小檗、独活的萌发,但对大多数种子萌发没有促进作用。综合分析表明,九寨沟28种林下或林缘乡土植物中只有窄叶鲜卑花、毛果铁线莲、宽叶旌节花、假升麻、陇东海棠、鲜黄小檗、蔷薇等12种可直播或通过低温层积处理后直播用于旅游干扰退化地段的林下植被恢复中,而其他种类尚需进一步寻求打破休眠的措施和方法

    太湖梅梁湾生物控藻围栏内鲢、鳙比肠长和比肝重的动态变化

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    为了解滤食性鱼类的消化生理指标及其生态适应性,2005年1-10月,调查了太湖梅梁湾生物控藻围栏中鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)在不同生长阶段的比肠长和比肝重指数的动态变化,分析了比肠长和比肝重与温度、体长、体重以及饵料组成的关系。结果表明,鲢、鳙比肠长和比肝重的季节变化都非常明显,比肠长均值分别为9.66和5.73,夏季的比肠长均明显增大。总的来看,鲢的比肠长和季节变化幅度均大于鳙,表明在滤食和消化浮游植物上,鲢具有更强的环境适应能力;鲢、鳙的比肠长与水温显著正相关(鲢P<0.01;鳙P<0.05),而与体长、体重以及饵料组成的相关性不显著;温度导致的摄食强度变化应是鲢、鳙比肠长季节变化的主要原因。鲢、鳙的比肝重均值分别为1.57%和1.91%,鳙的比肝重明显大于鲢,这可能与鳙摄食更多的浮游动物有关;鲢、鳙的比肝重与温度、体长、体重以及饵料组成均有显著的相关性(P<0.05),表明生物个体的形态特征与其所利用的资源环境有非常紧密的联系

    太湖梅梁湾大型控藻围栏对浮游甲壳动物群落结构的影响

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    2005年对太湖梅梁湾大型鲢、鳙控藻围栏内外浮游甲壳动物群落结构的季节变化进行了监测.结果表明:围栏内外的环境因子、浮游植物生物量、浮游甲壳动物种类组成无显著差异.但鲢、鳙放养对浮游甲壳动物的生物量产生了较大的影响,围栏内浮游甲壳动物的总生物量和枝角类的生物量显著低于围栏外.总体上,枝角类各种类的生物量受鲢、鳙放养的影响程度大于桡足类的种类.太湖梅梁湾浮游甲壳动物的季节演替明显,大部分种类只是季节性出现.冬季和春季以溞(Daphnia sp.)和近邻剑水蚤(Cyclops vicnus)等大型种类为主,夏季和秋季以象鼻溞(Bosmina sp.)、角突网纹溞(Ceriodaphnia cornuta)和中华窄腹剑水蚤(Limnoi-thona sinensis)等小型种类为主.典范对应分析表明,透明度、温度和浮游植物的生物量是影响浮游甲壳动物季节变化的主要因素

    太湖梅梁湾大型控藻围栏对浮游甲壳动物群落结构的影响

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    2005年对太湖梅梁湾大型鲢、鳙控藻围栏内外浮游甲壳动物群落结构的季节变化进行了监测.结果表明:围栏内外的环境因子、浮游植物生物量、浮游甲壳动物种类组成无显著差异.但鲢、鳙放养对浮游甲壳动物的生物量产生了较大的影响,围栏内浮游甲壳动物的总生物量和枝角类的生物量显著低于围栏外.总体上,枝角类各种类的生物量受鲢、鳙放养的影响程度大于桡足类的种类.太湖梅梁湾浮游甲壳动物的季节演替明显,大部分种类只是季节性出现.冬季和春季以溞(Daphnia sp.)和近邻剑水蚤(Cyclops vicnus)等大型种类为主,夏季和秋季以象鼻溞(Bosmina sp.)、角突网纹溞(Ceriodaphnia cornuta)和中华窄腹剑水蚤(Limnoi-thona sinensis)等小型种类为主.典范对应分析表明,透明度、温度和浮游植物的生物量是影响浮游甲壳动物季节变化的主要因素

    太湖梅梁湾大型生态控藻围栏内鲢鳙的生长特征

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    富营养化湖泊围栏养殖鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)控制蓝藻水华在生物操纵示范中得到了广泛应用。在2004和2005年,研究了太湖梅梁湾生态修复区内大型生物控藻围栏中鲢鳙的季节生长特征,分析了影响其生长的因素。结果表明,鲢鳙生长受养殖密度的影响很大,鲢在养殖密度低的2004年和养殖密度高的2005年的日均增重分别为6.07 g和4.30 g,鳙则分别为11.29 g和5.09 g。鳙的生长速度比鲢快,但受密度影响的程度比鲢大。从季节变化来看,鲢属于单峰型生长,生长速度和水温显著正相关;而鳙一年中呈现出2个生长高峰期,分别在5~6月和9~10月,夏季爆发的蓝藻水华对鳙的生长速度有所抑制。为使当年投放的鱼苗在年底能达到出售的商品规格,太湖梅梁湾水域围栏养殖鲢鳙的初始鱼苗投放密度应低于12 g/m3

    Kinetic Investigation of Electron TransFer Reaction between trans - [(en)_2(NO_2)Co(O_2CC_5H_5N)]--(2+)/Fe(Ⅱ)

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    合成了新型CO(Ⅲ)配合物TrAnS-[(En)_2(nO_2)CO(O_2CC_5H_5n)](ClO_4)_2,并通过紫外可见光谱、红外光谱、元素分析和X射线单晶衍射分析进行了表征.同时分别以[fE(Cn)_6]--(4-)和[fE(Cn)_5(H_2O)]--(3-)作为还原剂,考察了该配合物被还原的反应动力学行为.结果表明两反应体系分别按外配位界机理和内配位界机理进行电子传递.在25℃,I=0.5MOl·l--(-1),TrAnS-[(En)_2(nO_2)CO(O_2CC_5H_5n)]--(2+)/[fE(Cn)_6]--(4-)反应体系的前驱配合物离子对形成常数Q_(IP)=29MOl--(-1)·l,电子转移速率常数k_(ET)=2.4x10--(-4)S--(-1),电子转移过程的活化焓△H_(ET)--≠和活化熵△S_(ET)--≠分别为1.2x10--2kJ·MOl--(-1)和5.0x10--2J·MOl--(-1)·k--(-1)在40℃,PH=8.0,I=0.1MOl·l--(-1),TrAnS-[(En)_2(nO_2)CO(O_2CC_5H_4n)]--(2+)/[fE(Cn)_5(H_2O)]--(3-)反应体系前驱双核配合物分子内电子转移速率常数为7.0x10--(-5)S--(-1).最后讨论了分子轨道对称性,两金属中心氧化还原电势差等因素对电子转移速率的影响.trans - [(en)2(NO2)Co(O2CC5H5N) ]2+ (C1O4)2, which is First reported, has been synthesized and characterized by elemental analysis, UV - Vis and IR spectra, and X - ray structural analyses.Kinetic behaviours of the Co( III) complex reduced by [Fe(CN)6]4- and [Fe (CN)5 (H2O)]3- have been investigated.The results indicated the electron transFer (ET) reactions Followed the outer- sphere mechanism or the inner- sphere mechanism respectively.At25℃ ,I= 0.50mol L-1, the ion - pair Formation constant Qip and ET rate constant ket of theprecursor complex For trans - [ (en)2 ( NO2 ) Co( O2CC5H5N) ]2+ /[ Fe(CN)6 ]4- are 29mol-1·Land 2.4 × 10-1s-1, the activation enthalpy △H≠er and the activation entropy △S≠er of this ETprocess are 1.2 × 102kJ·mol-1 and 5.0 ×102kJ·mol-1·K-1 respectively.The intramolecular ET rate constant of the precursor binuclear complex For trans - [(en)2(NO2)Co(O2CC5H4N) ] + /[Fe(CN)5(H2O)]3- is 7.0×10-5 at 40℃ , pH=8.0 and I= -0.10mol L-1.Finally the inFluence of the moar orbital symmetry and the redox potentials on ET rate have been discussed.国家自然科学基金资助的项

    Problems Present in the Hatchery Industry of Kuruma Shrimp, Penaeus japonicus in North Area of China

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    在 1998和 1999年日本对虾 (Penaeusjaponicus)生产性育苗试验的基础上 ,结合对北方地区日本对虾育苗业的调查研究和多年来从事对虾养殖生产 ,科研以及经营管理的一些经验 ,提出目前北方地区日本对虾育苗业中存在的问题 :①育苗场基础设施和体制的问题 ;②传统养殖习惯的束缚和盲目性的生产 ;③亲虾和无节幼体的质量 ;④有关育苗技术的问题 ,并对上述问题进行详细的分析和讨论 .The problems present in hatchery industry of kuruma shrimp, Penaeus japonicus in north area of China based on the experiments of P japonicus seedlings conducted from 1998 to 1999,investigations of P japonicus hatchery industry in north area of China and experiences in shrikmp culture,research and cultrual management for years was analyzed and discussed.The problems are present in four parts:① basic installation and organizing system in shrimp hatchery;② trammels of traditional customs in shrimp culture and blindly productions of shrimp;③ quality of parent shrimp and nauplius;④ artificial hatchery techniques of P japonicus福建省自然科学基金资助项目!(B9910 0 0 3

    Antigenicity and Immunogenicity of Influenza M2 e Protein Fused with Intramolecular Adjuvant CRM197

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    流感病毒严重威胁人类健康且流行株不断变化,传统疫苗对流感预防具有局限性。流感病毒M2蛋白胞外区(M2; e)氨基酸序列高度保守,可诱导产生特异性抗体,是通用流感疫苗研究的主要靶标之一。白喉毒素突变体(CRM197)是一种理想的蛋白载体,可增强小分子; 抗原的免疫原性,商业化的肺炎球菌疫苗采用CRM197结合形式提高多糖分子的免疫原性。本实验通过重组蛋白融合的方式,将M2 e与CRM197(aa; 1~535)、CRM197-N190 (aa 1~190)、CRM197-N389(aa; 1~389)的C端或N端进行融合表达,并考察融合蛋白的反应活性以及免疫原性。融合蛋白中的M2; e和CRM197均具有反应活性;超速离心分析和四聚体特异构象单抗反应均表明融合蛋白(CRM197-N190)-M2 e及M2; e-(CRM197-N190)主要以类似M2 e天然构象的四聚体形式存在;融合蛋白可与多株流感M2; e特异性单抗以及CRM197特异性单抗反应,M2; e融合至CRM197N末端形成的重组蛋白的反应活性高于C端融合蛋白;相比融合GST,与CRM197-N190的融合显著增强了M2; e蛋白的免疫原性,为流感通用疫苗研究提供了新思路。New strategies are needed urgently to develop broad-spectrum vaccines; against the influenza virus and to reduce the risk of pandemics.The; conserved M2 eprotein is a potential candidate for development of a; universal vaccine against influenza viruses.In this work,M2 ewas fused; to the N-or C-terminus of CRM197(aa1~535),CRM197-N389(aa1~389)and; CRM197-N190(aa1~190)by gene engineering.Data from SDS-PAGE and western; blotting showed that these fusion proteins formed multimers,and that the; monomer and dimer bands were the most prominent.Moreover,AUC data; demonstrated that the tetramers of some fusion proteins were present in; solutions that might reflect the native conformation of the M2 e; protein.The fusion protein of M2 efused to the N-terminus of; CRM197,CRM197-N389,and CRM197- N190 showed excellent reactivity to the; characterized monoclonal antibodies O19 and L18 as compared with M2; efused to the C-terminus of CRM197,CRM197-N389,and; CRM197-N190.Furthermore,the immunogenicity of these fusion proteins was; evaluated in mice.Results demonstrated that the immunogenicity of M2; ewas enhanced significantly when being fused to CRM197-N190 than to; GST.These findings provide some clues for the development of a M2; e-based,broad-spectrum influenza vaccine.国家自然科学基

    Kinetic investigation of electron transfer reaction between trans- (en)(2)(NO2)Co(O2CC5H5N) (2+)/Fe(II)

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    trans - [(en)(2)(NO2)Co(O2CC5H5N)](2+) (ClO4)(2), which is first reported, has been synthesized and characterized by elemental analysis, UV - Vis and IR spectra, and X - ray structural analyses. Kinetic behaviours of the Co(III) complex reduced by [Fe(CN)(6)](4-) and [Fe(CN)(5)(H2O)](3-) have been investigated. The results indicated the electron transfer (ET) reactions followed the outer-sphere mechanism or the inner-sphere mechanism respectively. At 25 degrees C, I = 0.50mol . L(-1), the ion-pair formation constant Q(ip) and ET rate constant k(et) of the precursor complex for trans - [(en)(2)(NO2)Co(O2CC5H5N)](2+)/[Fe(CN)(6)](4-) are 29mol(-1). L and 2.4 x 10(-1) s(-1), the activation enthalpy Delta H-et(not equal) and the activation entropy Delta S-et(not equal) of this ET process are 1.2 x 10(2)kJ . mol(-1) and 5.0 x 10(2)kJ . mol(-1). K-1 respectively. The intramolecular ET rate constant of the precursor binuclear complex for trans - [(en)(2)(NO2)Co(O2CC5H4N)](+)/[Fe(CN)(5)(H2O)](3-) is 7.0 x 10(-5) s(-1) at 40 degrees C, pH = 8.0 and I = -0.10mol . L(-1). Finally the influence of the molecular orbital symmetry and the redox potentials on ET rate have been discussed
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