947 resultados para 315.24
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龙虱科是水生鞘翅目中的第一大科,种类十分丰富,与人类生活息息相关。本文基于大量的文献及中国水甲虫调查期间采集的龙虱科标本的观察,对中国的龙虱科进行了系统的分类学研究,以期为龙虱科生态及系统发育研究提供基础性资料。 在查阅大量文献的基础上,编制了我国龙虱科昆虫名录,共计40属315种;在名录中列出了所有物种的原始发表文献、异名及详细的分布信息。采用国际上多数分类学家认可的10亚科分类系统,编制了我国龙虱科昆虫的分亚科检索表。 检查龙虱科标本1058头,鉴定出24属共90种。对全部种类进行了详细的形态描述,绘制了鉴别特征图;报告了5个新种(其中3种已经发表),分别为拟二叉端毛龙虱、长叶宽缘龙虱、韦氏微龙虱、西双版纳微龙虱和彦宾三叉龙虱;25个省新记录种。全文包含鉴别特征图27版212幅,照片9版共81张。 对我国龙虱科昆虫进行了区系分析,得出了属、种的区系分布特点:1. 在属级阶元上,东洋界中华南区在属级分类单元的数量最为丰富,共有28属,占总属数的70%;古北界中华北区在属级分类单元的数量最多,有20属,占总属数的50%;2. 在种级阶元上,我国龙虱科昆虫以东洋成分占主导,明显高于古北界,但古北东洋界共同种比例亦很高,说明我国龙虱科东洋与古北昆虫有相互渗透的趋向。3. 龙虱科昆虫在全国各大区的分布共有47种分布型,华南区、华中区及东北区物种最丰富,明显高于其它各区,这三个区分布的种类分别为144种,97种,89种。
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近十年,植物群体遗传学的研究飞速发展,然而与海拔相关的植物群体遗传结构和遗传变异研究却相对较少。到目前为止,还不清楚遗传变异与海拔之间是否有一个通用的格局。在山区,各种生态因子,如温度、降水、降雪、紫外线辐射强度以及土壤成分都随海拔梯度急剧变化,造成了即使在一个小的空间区域,植被类型变化显著,这种高山环境的异质性和复杂性为我们研究植物群体遗传结构和分化提供了方便。沙棘(Hippophea)属于胡颓子科(Elaeagnaceae)为多年生落叶灌木或乔木,雌雄异株,天然种群分布极为广泛。中国沙棘(H. rhamnoides subsp. sinensis)是沙棘属植物中分布较广的一个亚种,种内形态变异非常丰富,加之其具有独特的繁育系统和广泛的生态地理分布,是研究沙棘属植物遗传变异和系统分化的理想材料。本文从1,800 m 到3,400 m 分5 个海拔梯度进行取样,用RAPD 和cpSSR 分子标记研究了卧龙自然保护区中国沙棘天然群体的遗传结构和遗传变异。5 个取样群体依次标记为A、B、C、D 和E,它们分别代表分布在海拔1,800,2,200,2,600,3,000 和3,400 m 的5 个天然群体。RAPD实验用11 条寡核苷酸引物,扩增得到151 个重复性好的位点,其中143 个多态位点,多态率达94.7%。在5 个沙棘群体中,总遗传多样性值(HT)为0.289,B群体内的遗传多样性值为0.315,这完全符合沙棘这种多年生、远交的木本植物具有高遗传变异的特性。5 个群体内遗传多样性随海拔升高呈低-高-低变异趋势,在2,200 m海拔处的B群体遗传多样性达最大值0.315,3,400 m海拔处的E群体则表现最小仅0.098。5 个群体间的遗传分化值GST=0.406,也即是说有40.6%的遗传变异存在于群体间,1,800 m海拔处的A群体与其它群体的明显分离是造成群体间遗传分化大的原因。UPGMA聚类图和PCoA散点图进一步确证了5 个群体间的关系和所有个体间的关系。最后,经过Mantel检测,遗传距离与海拔表现了明显的相关性(r = 0.646, P = 0.011)。cpSSR 实验中,经过对24 对cpSSR 通用引物筛选,11 对引物能扩增出特异性条带,只有2 对引物(ccmp2 和ARCP4)呈现多态性。4 个等位基因共组合出4 种单倍型,单倍型Ⅰ出现在A 群体的所有个体和B 群体的8 个个体中,C、D、E 三个群体均不含有,而单倍型Ⅱ出现在C、D、E 三个群体的所有个体及B 群体的18 个个体中,A 群体不含有。另外两种单倍型Ⅲ和Ⅳ为稀有类型,仅B 群体中的4 个个体拥有。这种单倍型分布模式和TFPGA 群体聚类图揭示了,C、D、E 群体可能来源于同一祖先种,而A 群体却是由另一祖先种发展起来的,B 群体则兼具了这两种起源种的信息,这可能是因为在历史上的某一时期,在中国沙棘群体高山分化的过程中,B 群体处某个或者某些个体发生了基因突变,具备了适应高海拔环境的能力,产生了高海拔沙棘群体的祖先种。 In recent ten years, studies about population genetics of plants developed rapidly,whereas their genetic structure and genetic variation along altitudinal gradients have beenstudied relatively little. So far, it is uncleared whether there is a common pattern betweengenetic variation and altitudinal gradients. In the mountain environments, importantecological factors, e.g., temperature, rainfall, snowfall, ultraviolet radiation and soil substratesetc., change rapidly with altitudes, which cause the vegetation distribution varying typically,even on a small spatial scale. The mountain environments, which are heterogeneous andcomplex, facilitate and offer a good opportunity to characterize population genetic structureand population differentiation.The species of the genus Hippophae L. (Elaeagnaceae) are perennial deciduous shrubs ortrees, which are dioecious, wind-pollinated pioneer plants. The natural genus has a widedistribution extending from Northern Europe through Central Europe and Central Asia toChina. According to the latest taxonomy, the genus Hippophae is divided into six species and12 subspecies. The subspecies H. rhamnoides ssp. sinensis shows significant morphologicalvariations, large geographic range and dominantly outcrossing mating system. Thesecharacteristics of the subspecies are favourable to elucidate genetic variation and systemevolution. To estimate genetic variation and genetic structure of H. rhamnoides ssp. sinensisat different altitudes, we surveyed five natural populations in the Wolong Natural Reserve at altitudes ranging from 1,800 to 3,400 m above sea level (a.s.l.) using random amplifiedpolymorphic DNA markers (RAPDs) and cpSSR molecular methods. The five populations A,B, C, D, and E correspond to the altitudes 1,800, 2,200, 2,600, 3,000 and 3,400 m,respectively.Based on 11 decamer primers, a total of 151 reproducible DNA loci were yielded, ofwhich 143 were polymorphic and the percentage of polymorphic loci equaled 94.7%. Amongthe five populations investigated, the total gene diversity (HT) and gene diversity within population B equaled 0.289 and 0.315, respectively, which are modest for a subspecies of H.rhamnoides, which is an outcrossing, long-lived, woody plant. The amount of geneticvariation within populations varied from 0.098 within population E (3,400 m a.s.l.) to 0.315within population B (2,200 m a.s.l.). The coefficient of gene differentiation (GST) amongpopulations equaled 0.406 and revealed that 40.6% of the genetic variance existed amongpopulations and 59.4% within populations. The population A (1,800 m a.s.l.) differed greatlyfrom the other four populations, which contributes to high genetic differentiation. A UPGMAcluster analysis and principal coordinate analyses based on Nei's genetic distances furthercorroborated the relationships among the five populations and all the sampling individuals,respectively. Mantel tests detected a significant correlation between genetic distances andaltitudinal gradients (r = 0.646, P = 0.011).Eleven of the original 24 cpSSR primer pairs tested produced good PCR products, onlytwo (ccmp2 and ARCP4) of which were polymorphic. Four total length variants (alleles) werecombined resulting in 4 haplotypes. The haplotype was present in all individuals of Ⅰpopulation A and 8 individuals of populations B, the other three populations (C, D and Epopulations) did not share. The haplotype was present in all individuals of populations C, D Ⅱand E and 18 individuals of populations B, population A did not share. The other twohaplotypes and were rare haplotypes, which were only shared in 4 individuals of Ⅲ Ⅳpopulation B. The distribution of haplotypes and TFPGA population clustering map showedthat the populations C, D and E might be origined from one ancestor seed and population Amight be from another, whereas population B owned information of the two ancestor seeds. Itwas because that gene mutation within some individual or seed in the location of population Bwas likely to happen in the history of H. rhamnoides, which was the original ancestor of thehigh-altitude populations.
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报道了利用兰州重离子加速器国家实验室ECR源引出的高电荷态离子207Pbq+(24≤q≤36)入射到Si(110)表面产生的电子发射的实验测量结果.结果表明,高电荷态离子与固体表面相互作用产生的电子发射产额Y与入射离子的电荷态q、入射角度ψ和入射能量E都有很强的关联.首次发现,电子发射产额Y与入射角度ψ间有接近1/tanψ的关系.理论分析认为,这些过程与基于经典过垒模型的势能电子发射过程密切相关.
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The electron emission induced by highly charged ions Pb-207(q+) (24 <= q <= 36) interacting with Si(110) surface is reported. The result shows that the electron emission yield Y has a strong dependence on the projectile charge state q, incidence angle psi and impact energy E. In fitting the experimental data we found a nearly 1/tan psi dependence of Y. Theoretical analysis shows that these processes are closely related to the process of potential electron emission based on the classical over-the-barrier model.
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应用景观生态学思想,依据层次分析模式建立了公路生态环境风险评价体系,在专家思想库的基础之上,为突出各评价指标的空间属性,规定其权重值由评价指标影响空间范围的大小来确定.其中环境因子的影响范围,即所占面积,利用GIS对相关图件解读获得,灾害因子影响路段的长度则在施工设计和路线勘测阶段实测而得.使用该评价体系对31 5国道新疆依吞布拉克且末段的生态环境风险性进行评价,结果表明,该路域生态环境风险指数ERA介于1 . 5 5~3 . 2 3之间.由于ERA包含的生态环境脆弱性指数∑xiwi和灾害系数∑yiwj存在空间异质性,故据其最终对路域内的8个景观生态单元,用4个风险级别进行了评价,较真实地反映了该路段生态环境风险特征.
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Analyses of the isothermal and nonisothermal melt kinetics for syndiotactic polystyrene have been performed with differential scanning calorimetry, and several kinetic analyses have been used to describe the crystallization process. The regime II-->III transition, at a crystallization temperature of 239degrees, is found. The values of the nucleation parameter K-g for regimes II and III are estimated. The lateral-surface free energy, sigma = 3.24 erg cm(-2), the fold-surface free energy, sigma(e) = 52.3 +/- 4.2 erg cm(-2), and the average work of chain folding, q = 4.49 +/- 0.38 kcal/mol, are determined with the (040) plane assumed to be the growth plane. The observed crystallization characteristics of syndiotactic polystyrene are compared with those of isotactic polystyrene. The activation energies of isothermal and nonisothermal melt crystallization are determined to be DeltaE = -830.7 kJ/mol and DeltaE = -315.9 kJ/mol, respectively.
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综述了茂金属与非茂金属催化剂引发丁二烯聚合的研究进展。茂钒催化剂在丁二烯聚合中有较高的催化活性,聚合物顺- 1,4-结构摩尔分数约为 80%, 1,2-结构摩尔分数约为 20%。
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By [2 + 2] Schiff base condensation of 5 - bromo - 2 - methoxylbenzene - 1,3 - dicarboxaldehyde with diethylenetriamine, a new hexaaza 24 - membered macrocyclic ligand was obtained,which formed a macrocyclic binuclear copper(I) complex in the presence of [Cu . (CH3CN)(4)]ClO4. When the copper(I) complex was oxidized in air or oxygen, a new macrocyclic binuclear copper( II) complex was obtained. The copper( II.) complex was characterized by several methods and its oxidized products was characterized by H-1 NMR. The results show that during oxidation, a methoxyl group in the ligand ring broke; and the phenoxy - and water - bridged Cu(II) complex formed. In oxidation of monooxygenase such as ligninase, oxidative demethylation also happened. Therefore this work mimicked this process for the first time by using macrocyclic complex. The quantity of absorbed oxygen and the absorption rate of oxygen were determined.
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A pollen record of core PC-1 from the northern Okinawa Trough, East China Sea (ECS), provides information on vegetation and climate changes since 24 cal. kaBP. A total of 103 samples were palynologically analyzed at 8 cm intervals with a time resolution of 230 a. Four pollen zones are recognized: zone I (812-715 cm, 24.2-21.1 cal. kaBP), zone II (715-451 cm, 21.1-15.2 cal. kaBP), zone III (451-251 cm, 15.2-10.8 cal. kaBP), zone IV (251-0 cm, 10.8-0.3 cal. kaBP), corresponding to Late MIS 3, Last Glacial Maximum (LGM), deglaciation and Holocene, respectively. The LGM is characterized by the dominance of herbs, mainly Artemisia, and high pollen influx, implying an open vegetation on the exposed continental shelf and a cool and dry climate. The deglaciation is a climate warming stage with Pinus percentage increased and Artemisia percentage decreased and a rapid sea-level rise. The Holocene is characterized by predominance of tree pollen with rapid increase in Castanea-Castanopsis indicating the development of mixed evergreen and deciduous broad-leaved forest and a warm, humid climate. Low pollen influx during the Holocene probably implies submergence of the continental shelf and retreat of the pollen source area. The vegetation indicated by pollen assemblage found in this upper zone is consistent with the present vegetation found in Kyushu, Japan. Originating from the humid mountain area of North Luzon of the Philippines, Tasmania and New Zealand, Phyllocladus with sporadic occurrence throughout PC-1 core probably suggests the influence of Palaeo-Kuroshio Current or intense summer monsoon. The observed changes in Pinus and Herbs percentage indicate fluctuations of the sea level, and high Pinus percentage corresponds to high sea level. Spectrum analysis of the pollen percentage record reveals many millennial-scale periodicities, such as periodicities of 6.8, 3.85 2.2, 1.6 ka.
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在基础饲料中分别添加0.04%低聚木糖、0.13%酵母细胞壁、0.08%胆汁酸和同量组合添加,形成5个处理组。采用随机区组试验设计,将体重151.3±15.2 g 的健康大菱鲆鱼165尾平均分配到5个处理组(A~E)中(每组3重复),经72天试验,进行了生长、水质、消化、免疫等试验和测定,结果如下: 组合组的生长效果和饲料利用率最好,酵母细胞壁或低聚木糖单独添加,表现出优良的促生长和饲料利用率;单独添加胆汁酸也有良好效果。4试验组(组合组、酵母细胞壁组、低聚木糖组、胆汁酸组)与对照组比较,增重率分别提高15.4%、13.9%、12.4%(p<0.05)和7.4%(P>0.05),饲料系数分别降低6.9%、6.2%、5.4%(p<0.05)和3.8%(P>0.05)。 不同添加剂及组合对试验鱼所处水环境因子变化仅有小幅影响,统计差异不显著(p>0.05)。4试验组比对照组的水体氨氮含量分别提高4.0%、3.2%、3.0%和0.8%(P>0.05),COD含量分别提高2.8%、-2.2%、-3.4%和0.8%(P>0.05)。根据试验结果,建议水环境因子(氨氮、磷酸盐、COD等)作为水产动物营养与饲料研究的主要衡量指标之一。 3种添加剂组合后达到提高生长大菱鲆非特异性免疫功能的最优效果,对补体C3和C4、细胞吞噬活力和SOD的提高作用尤为显著;酵母细胞壁单独添加对补体C3和细胞吞噬活力的作用更加显著;低聚木糖单独添加对补体C4和细胞吞噬活力的作用显著;单独添加胆汁酸提高免疫力的作用相对较弱。 4试验组比对照组的蛋白质消化酶活力在胃和前肠,分别提高20%和24%、17%和19%、16%和15%(p<0.05)、11%和3%(P>0.05);脂肪消化酶活力在前肠和中肠,分别提高22%和19%、19%和17%(p<0.05)、7%和12%(p>0.05)、19%和18%(p<0.05)。 4试验组比对照组的蛋白质消化率分别提高了3.6%、2.9%、3.7%(p<0.05)和1.5%(p>0.05);粪蛋白质排出量减少12.7%、7.1%、13.4%和2.4%(p>0.05)。说明,3种添加剂显著提高了生长大菱鲆蛋白质消化率,使粪蛋白质排出量不同程度降低,显示了试验使用添加剂的无公害效应。 权衡不同添加剂及其组合对大菱鲆生长期生长性能、饲料利用率、水生态因子、消化酶活力、非特异性免疫、蛋白质消化与粪蛋白质排出的综合影响,本研究从生态与环保角度得出:3种添加剂组合的效果最好,酵母细胞壁或低聚木糖单独添加表现出优良效果;单独添加胆汁酸也有良好作用。
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以新鲜尿和粪作气味源,在行为选择箱中观察根田鼠的行为识别模式,结果表明:雌鼠对陌生同性尿、粪气味源行为识别的差异不显著,雄鼠对陌生同性尿、粪气味源的行为识别在多个指标上存在显著差异;根田鼠对陌生异性尿、粪的行为响应模式无明显差异;除嗅舔时间外,雌、雄鼠对粪气味的行为识别在其他指标上不存在明显差异;比较雌、雄鼠对尿刺激的行为识别发现,雄鼠对尿刺激的访问频次和反标记显著大于雌鼠,雌性嗅舔时间显著大于雄性,其他方面二者之间并无显著差异.因此,雌、雄性根田鼠对粪气味的行为识别模式不存在性别差异;对尿气味的行为识别模式存在性别差异.
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A continuous long (224m) and high-resolution core TY2 was recovered from paleo-maar-lake Tianyang, tropical South China. Based on the diatom records of the upper 130-m core, this paper focuses on exploring climate change and the lake evolution history in tropical South China during the past 240ka. The most typical and unique characteristics of the diatom assemblages is that, Aulacoseira granulata was dominant or absolutely dominant species (80-90%) during most parts of the 130-m core, while Cyclotella stelligera var. tenuis and Fragilaria construens var. venter were subdominant species in only limited parts of the lower and upper core, respectively. Time scale is always the biggest problem for the study of TY2 core, so although diatom is seldom used for establishing time scale, here we attempt this by correlating the diatom-reconstructed temperature sequence with the time scale of ODP core 806B from Equatorial Western Pacific. Verified by the few most reliable ages from TY2 core and the parallel core TYl, a rather reasonable and reliable time scale was established. 01S 7/6 falls at the depth of 100m (ca. 194kaBP), OIS 6/5 at 75m (ca. 132kaBP), OIS 5/4 at 46m (ca. 75kaBP), OIS 4-3 at 35m (ca. 60kaBP). Qualitative and quantitative environmental reconstructions are made on the basis of diatom assemblage ecotype and EDDI dataset. Correlation of diatom-reconstructed temperature and moisture changes of Core TY2 with pollen-reconstructed temperature and rainfall sequence of Core TYl proves that the results are quite consistent in most periods. Thus the reconstruction results from diatom are quite reliable, and probably have a much higher resolution than pollen results. Combined with lithological and magnetic susceptibility variations, the diatom analysis reveals that, the general climate in tropical South China during the past 240ka was warm and wet. On the time scale of glacial-interglacial, warm and wet, cool and dry are not always synchronous. It was relatively warm-wet during the penultimate interglacial, cool-dry during the penultimate glacial, warm-dry during the last interglacial, and cooler-drier during the last glacial. In contrast, on the time scale of subglacial-subinterglacial scales, warm and dry, cool and wet corresponds very obviously, showing very clear 21-23 ka precession cycle. Analysis also shows that, the water of Tianyang paleo-maar-lake was generally warm, turbulent, turbid, meso-trophic, slightly alkaline, low conductivity and fresh during the past 240 kaBP, with small variations in some parts. Tianyang paleolake experienced shallow to semi-deep lake in OIS7d, open shallow lake in OIS7c-OIS5b, shallow coastal lake in OIS5a-OIS4c, swamp in OIS4b, and then completely dried up in OIS3c. The lake evolution was mainly controlled by temperature and precipitation changes in tropical China. While temperature and precipitation changes were probably controlled by the migrations of monsoon rainband and the evaporation rate, which was in turn controlled by the evolution of East Asian monsoon. Therefore, when the summer monsoon was strongest the climate was warm-dry, when stronger the climate was warm-wet; when the winter monsoon was strongest the climate was cool-dry, stronger cool-wet. This mechanism caused the warm-dry sub interglacial and cool-wet subglacial climate in the tropical South China.
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采用原子吸收光谱(AAS)、X射线衍射(XRD)、偏光显微镜(OH)和分析型透射电镜(TEM)等技术手段,对贵州产70kN和日本进口120kN、210kN三类瓷绝缘子的化学组成,矿物成分特征和产品性能的关系进行了研究。结果表明,三类产品的主化学成分为siO2、Al2O3。矿物相有刚玉、英来石、石英和长石。产品除含有偏光显微镜可分辨的晶体外,在电镜下还见有微米级以下的显微矿物。不同等级的产品,不但结晶相含量不同,晶体大小、分布状态各有特征。指出贵州产70kN产品应控制K20含量,并用部分工业氧化铝替代铝矾土,通过调整工艺提高结晶相的含量。