943 resultados para Simonides, ca. 556-467 B.C.


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A história da pólis de Esparta como, por vezes, nos foi apresentada tomou uma perspectiva historiográfica dotada de pressupostos Atenocêntricos, os quais acabaram apresentando-a como rústica, dotada de uma economia e uma cultura estática e demasiadamente inclinada às atividades militares. No entanto, através de nossa pesquisa verificamos que as práticas político-culturais dos cidadãos de Esparta eram dinâmicas, para sua época. Seguindo por esse viés, verificamos que as representações de Esparta, sobretudo dos esparciatas e dos seus basileus, variaram de acordo com o grupo social e o contexto histórico em que foram empregadas. Com isso, observamos que embora os cidadãos de Esparta tenham sido, em algumas circunstâncias, criticados pelos pensadores antigos, esta não foi uma tendência hegemônica. Sendo assim, mediante os indícios da documentação literária do período Clássico, notamos que os esparciatas e os seus basileus teriam sido homens dotados de um habitus tradicional, o qual valorizava o aprimoramento físico e mental, assim como a responsabilidade com os deveres sagrados. Através da interação entre os vestígios documentais e dos estudos historiográficos mapeamos parte das representações de Esparta que figuraram os diversos discursos no decorrer da história do Ocidente, no intuito de materializarmos as possíveis motivações político-culturais nas apropriações do habitus espartano. Por conseguinte, recorremos à documentação literária para entendermos como parte dos pensadores clássicos concebeu, por meio de uma memória ancestral, a formação da região da Lacedemônia e da pólis de Esparta, a qual teria se dado concomitantemente com a legitimação político-cultural da identidade étnica dos basileus e dos esparciatas. Por fim, analisamos as práticas rituais em honra ao deus Apolo como um mecanismo empregado pelos segmentos sociais hegemônicos da Lacedemônia para ratificar o seu poder político frente a grupos sociais submetidos.

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A bioassay study was conducted using three organic pesticides to determine their comparative toxicity to fingerlings of Hypophthalmichthys molitrix. There was wide variation in the toxicity of different pesticides with 24 hr LC sub(50) values ranging from 0.000403 to 0.294 mg/l. Endosulfan appeared to be the most toxic, whereas BHC was the least.

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比较了云南高黎贡山地区的贡山独龙江和腾冲大蒿坪白颌大角蟾(Megophryslateralis)两个地理种群的核型、C-带和Ag-NORs结果表明,两个地理种群在核型和带型上都有差异两个地理种群的核型均为2n=26,NF=52染色体形态差异不明显,而次缢痕的位置完全不同,贡山独龙江标本的次缢痕位于No.2的长臂上近着丝点处,腾冲标本的次缢痕位于No.5的短臂上近着丝点的部位在腾冲标本中发现一雄性个体中有一条额外的染色体,可能是B染色体两地标本的C-带差异不太显著,贡山独龙江标本的C-带相对较为显著.贡山独龙江标本的Ag-NORs位于No.2长臂近着丝点处,与次缢痕的部位对应,两条同源染色体上大小有显著差异.腾冲标本的Ag-NORs位于No.5短臂上近着丝点处,与次缢痕的部位对应依据核型和带型的比较,对白颌大角蟾的分类和进化问题进行了讨论。

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银额果蝇昆明群体有丝分裂中期核型中存在B染色体, 出现频率为69.1%在已 研究过的来自各个地区的银额果蝇中, 昆明群体的B染色体频率最高。B染色体 数目为1—6条。该群体内单雌系间的B染色体数目不同, 个体间和细胞间的B染色 体数目也不同。在核型中, B染色体最小, 形态稳定, 点状, C-带和G-带呈阳性 。 图版1图2表1参12

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鲤科是鱼类最大的科,在中国淡水鱼类组成中鲤科鱼类的成分占一半以上.鲤科鱼类的演化过程代表了东亚淡水鱼类的整体演化过程.为探讨东亚鲤科鱼类系统发育关系,共分析了包括18种新测序列在内的54种鲤科鱼类细胞色素b基因的全序列.分析的物种涵盖了鲤科鱼类的12个亚科并对问题较多的(鱼丹)亚科(Danioninae)和雅罗鱼亚科(Leuciscinae)进行了广泛的采样.系统发育树的建立使用了多种方法,包括邻接法、最大简约法和最大似然法.亚口鱼科(Catostomidae)的胭脂鱼(Myxocyprinus asia

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本文首次合成了Lar_xSr_xFe_yCor_yO_3(x、y:0.1、0.3、0.5、0.7、0.9)系列化合物和Lar_xBa_xFe_yCor_yO_3(x、y:0.1、0.3、0.5、0.7、0.9)系列化合物,并对其结构,电性及气敏性质进行了研究。关于ABO_3型稀土过渡金属复合氧化物的结构研究,文献上报道比较混乱,不同的人在进行结构研究中采用不同的结构基元得到了不同的晶型和相应的晶胞参数。本文根据上述化合物的X射线谱图,对其进行指标化,得到了上述两系列化合物为主方晶系结构,晶胞参数计算结果表明:在Y = 0.7时,化合物Lar_xSr_xFe_(0.7)Co_(0.3)O_3的晶胞参数随X值的增大而减小。化合物Lar_xBa_xFe_(0.7)Co_(0.3)O_3的晶胞参数随X值的增大而增大。在X = 0.3时,上述两条系列化合物的晶胞参数均随Y值的增大而增大。对以上两系列化合物所表现出的结构变化规律,我们用起决定作用的离子半径大小进行了解释。针对上述两系列化合物,我们研究了它们的电学性质,研究结果表明,上述两系列化合物,在Y = 0.7时,其室温电阻率均随X在 0 < x < 0.5内增大而减小。在0.5 < x < 1内随X值增大而增大。在X = 0.5时的两个化合物具有最小的室温电阻率。在此方面,其电阻率变化规律与LarxMxBO_3(M:Ca Sr、 Ba、 B:Fe Co)化合物的变化规律相似。在X = 0.3时,上述两系列化合物的室温电阻率均随Y值的增大而增大,上述两系列化合物所表现出的室温电阻率变化规律可以运用C. Zener的双交换模型加以解释,同时,低温电阻率测定表明:上述两系列化合物在温度100-263K内,表现半导体性质。液氮温度下它们不具有超导性。除以上研究之外,我们针对Lar_xSr_xFe_yCor_yO_3 (X = 0.3、 Y:0.1、0.5、 0.9, Y = 0.7, X:0.1、 0.9)系列化合物初步地进行了气敏性研究。结果为:化合物La_(0.7)Sr_(0.3)Fe_yCor_yO_3 (Y:0.1、 0.5、 0.9)都不同程度地对乙醇、石油醚、 乙炔、烟具有气敏性,它们对乙醇的气敏响应时间约为1分钟,而对石油醚、乙炔和烟的气敏响应时间要用5分钟左右,在上述化合物中,La_(0.7)Sr_(0.3)Fe_(0.5)Co_(0.5)O_3化合物表现出最强的对乙醇、石油醚、乙炔的气敏性。对化合物La_(0.7)Sr_(0.3)Fe_(0.5)Co_(0.5)O_3的进一步研究表明,在乙醇气氛下,化合物La_(0.7)Sr_(0.3)Fe_(0.5)Co_(0.5)O_3在工作电流I_(Dn) = 0.20A时具有最佳的气敏数应。工作电流高于或低于此值都将导致其气敏效应的大小顺序为La_(0.7)Sr_(0.3)Fe_(0.5)Co_(0.5)O_3 > La_(0.7)Sr_(0.3)Fe_(0.9)Co_(0.1)O_3 > La_(0.7)Sr_(0.3)Fe_(0.1)Co_(0.9)O_3对化合物Lar_xSr_xFe_(0.7)Co_(0.3)O_3 (X:0.1、 0.9)的气敏性研究表明:它们只对乙醇和烟具有气敏性。对上述两种气氛的气敏响应时间为5分钟。上述两种化合物中,La_(0.1)Sr_(0.9)Fe_(0.7)Co_(0.3)O_3气敏效应最强。

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从新几内亚核桃木的树皮中分离得到的吲哚类喹诺里西定生物碱10-Desbromoarborescidine A,因发现其具有阻滞钙离子通道的活性而倍受关注。10-Desbromoarborescidine A由A、B、C、D四个环组成,只有一个手性中心,是吲哚生物碱中结构较简单的一种,常作为此类生物碱全合成方法的模型化合物。但迄今为止,能高效而简便的实现手性10-Desbromoarborescidine A不对称全合成方法线路不多,大多数以不对称诱导的方式建立其手性中心,手性催化的方式仅有一例金属催化。从逆合成分析可知,Desbromoarborescidine A的全合成可以通过亚胺不对称催化还原进行关键的手性中心构建,而本课题组在之前的研究中通过手性有机小分子催化剂的发展,已将三氯硅烷氢转移还原亚胺发展成了一类简便实用、高效、高对映选择性并具有优良底物适应范围的不对称催化反应,我们希望以这一反应作为关键手段,发展一条Desbromoarborescidine A及其类似物不对称合成新路线。 根据我们设计的新路线,首先成功合成了其关键中间体,然后我们进行了关键的不对称催化尝试。用本实验室已有的高性能有机小分子催化剂虽得到了较好的对应选择性,但是产率很低。同时,为了验证整条线路的可行性,我们也用消旋的中间体进行拉通线路的尝试。但不幸的是,在脱除保护基时遇到了很大困难。尝试换不同的保护基,或改变脱保护基的顺序,都未能成功合成目标产物。究其原因可能是由于吲哚的特殊性造成的,吲哚类亚胺与常规的芳香亚胺有较大的差异,其NH基团无论保护还是不保护,对与其2位相联接的C=N双键均有很大的影响,导致其不对称催化还原难以进行。另外,由于所设计的还原产物含有处在吲哚苄位的胺基,稳定性较差,造成保护基脱除困难。 烯胺C-亚磺酰化反应是本课题组最近发现的一个新反应,之前未见文献报道。本研究对该反应进行了反应条件优化和底物扩展,发现带Cbz,Ac,COt-Bu,CO2Et,Bz等保护基的一系列环状和非环状烯胺在亚磺酸钠、DMAc和MeSiCl3的共同作用下能高效高产率生成β-胺基烯基亚砜类新化合物,为合成多官能团化的烯基亚砜新化合物提供了一条简便实用的途径。 The main constituent of Dracontomelum mangiferum B1, indoloquinolizidine alkaloid 10-Desbromoarborescidine A, has drawn great attention due to its calcium channel blocking activity. Its molecular structure is relatively simple compared with the other alkaloids of the same type, which has only one chiral center, albeit with four cycles A, B, C, and D. This compound is often used as a model target for exploring different strategies for the total synthesis of indole alkaloids. Nevertheless, so far there still lack practical and highly efficient methods for the asymmetric total synthesis of 10-Desbromoarborescidine A. Most of the current available methods rely on stoichiometric asymmetric synthesis for the construction of the chiral center. There is only one example reporting utilization of asymmetric catalysis, but with transition metal complex as the catalyst. Our retrosynthetic analysis shows that catalytic asymmetric reduction of imine could be used as the key step for the construction of the chiral center of Desbromoarborescidine A. Since in the previous studies our group has developed the asymmetric reduction of imines by trichlorosilane into a practical and highly efficient and enantioselective method using newly designed chiral organocatalysts, we hope to apply this method to develop a novel synthetic route for the total synthesis of Desbromoarborescidine A and its analogues in this study. According to the newly designed synthetic route, we first accomplished the synthesis of the key intermediates which was then examined for the critical asymmetric catalysis. The asymmetric reduction using the highly efficient organocatalysts, developed in our lab afforded high ee but poor yield. We tried different reaction conditions to improve the yield, but failed to get any good results. Simultaneously, to vertify the feasibility of the synthetic route we designed, we also tired to go through the route toward the racemic synthesis of Desbromoarborescidine A. But unfortunately, protection and deprotection proved to be big hurdles. All the different protection groups and different sequences of protection and deprotection we tried failed to get us through the designed synthetic sequence and furnish the final product. Most likely, the indole part is the culprit behind the failures.The NH group of the indole, no matter protected or not, may impact the catalytic asymmetric reduction of C-N double bond connected with 2-C. Additionally, the reduction product we designed contains an amino group in the β-position of the indole, which may cause problems due to its instability. C-sulfenylation of enamines is a novel reaction discovered recently by our group, which has not been seen before in the literature. In this study, optimization of the reaction conditions and exploration of the substrate scope were further undertaken for this reaction, which reveal that a series of enamines with N-Cbz, Ac, COt-Bu, CO2Et protection groups could all undergo smooth C-sulfinylations with the comined use of sodium benzene sulphinate, DAMc and MeSiCl3, efficiently furnishing the β-amino vinylsulfoxide products in high yield, affording a practical and highly efficient methods for synthesis of functional vinylsulfoxides.

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大气臭氧的损耗导致了地球表面具有生物学效应的紫外线-B(UV-B)辐射增强。同时,大气成分变化中除了UV-B辐射增强外,氮沉降是一个新近出现而又令人担忧的环境问题,其来源和分布正在迅速扩展到全球范围,并不断向陆地和水生生态系统沉降。本试验在四川省境内的中国科学院茂县生态站内进行,以云山、冷杉、色木槭和红椋子幼苗为模式植物,从生长形态、光合作用、抗氧化能力和矿质营养等方面研究了青藏高原东缘4种树苗对全球变化-增强UV-B辐射和氮供应(氮沉降)的响应。该试验为室外盆栽试验,包括四个处理:(1)大气UV-B辐射+无额外的氮供应(C);(2)大气UV-B辐射+额外的氮供应(N);(3)增强UV-B辐射+无额外的氮供应(UV-B);(4)增强UV-B辐射+额外的氮供应(UV-B+N)。其目的:一方面有助于丰富我国对全球变化及区域响应研究的全面认识,进一步完善在全球气候变化条件下臭氧层削减和氮沉降对陆地生态系统影响的内容;另一方面,在一定程度上有助于我们更好的理解在全球变化下森林更新的早期过程。具体结果如下: 增强的UV-B辐射在生长形态、光合、抗氧化能力、活性氧和矿质营养方面对4种幼苗都有显著的影响。UV-B辐射增强对幼苗的影响不仅与物种有关,而且,还与氮营养水平相关。总体表现为,高的UV-B辐射导致了色木槭和红椋子幼苗叶片的皱缩和卷曲,并降低了色木槭幼苗的叶片数和叶重,在额外的氮供应下,云杉、冷杉和红椋子的叶重也显著地降低了;色木槭和红椋子幼苗叶片的解剖结构受到了增强的UV-B辐射的影响,增强的UV-B辐射显著地降低了色木槭叶片的栅栏组织厚度,提高了红椋子叶片的厚度;增强的UV-B辐射显著地降低了4种幼苗的单株总生物量、植物地下部分的生长、总叶绿素含量 [Chl (a + b)]、净光合速率和最大量子产量(Fv/Fm),提高了4种幼苗叶片的膜脂过氧化(MDA含量),改变了植物体不同器官中的矿质元素含量;增强的UV-B辐射提高了冷杉、色木槭和红椋子叶片中的过氧化氢含量(H2O2)、超氧负离子(O2-)生成速率,在额外的氮供应下,云杉叶片中的活性氧含量也显著地提高了;在无额外的氮供应条件下,增强的UV-B辐射显著地提高了4种幼苗叶片中的UV-B吸收物质、脯氨酸含量和抗氧化酶的活性(SOD、POD、CAT、GR和APX)。在额外的氮供应条件下,UV-B辐射的增强却显著地降低了冷杉叶片中脯氨酸含量和红椋子叶片中UV-B吸收物质含量,但是,在4种幼苗叶片中,5种抗氧化酶的活性对UV-B辐射的增强没有明显的规律性,增强的UV-B辐射显著地提高了云杉叶片中的POD、SOD和GR的活性,提高了冷杉叶片中的POD和GR活性,提高了色木槭叶片中的POD、SOD和CAT活性和红椋子幼苗叶片中的POD和SOD活性。从这些结果可知,植物在遭受高的UV-B辐射导致的过氧化胁迫时,植物体内形成了一定的保护机制,但是,这种保护不能抵抗高的UV-B辐射对植物的伤害。 额外的氮供应在生长形态、光合、抗氧化能力、活性氧和矿质营养方面对4种幼苗都有一定的影响,不同幼苗对额外的氮供应响应不同,并且受到UV-B辐射水平的影响。在当地现有的UV-B辐射水平下,额外的氮供应显著地提高了幼苗的单株总生物量、植物地下部分的生长、Chl (a + b)、净光合速率(红椋子除外)、UV-B吸收物质(冷杉除外)、脯氨酸含量(红椋子除外)和部分抗氧化酶的活性,降低了H2O2的含量、O2-的生成速率和MDA含量(红椋子除外),改变了植物体内部分矿质元素含量,显著地提高了云杉和冷杉叶片中的Fv/Fm。这些指标总体表明,在当地现有大气UV-B辐射水平下,额外的氮供应对植物的生长和发育是有利的。在增强的UV-B辐射水平下,4种幼苗的生长形态和光合大部分指标都没有受到额外氮供应的影响,额外的氮供应提高了红椋子幼苗的单株总生物量和Chl (a + b)含量,提高了冷杉和色木槭叶片中的活性氧含量和MDA含量,却降低了红椋子叶片中的活性氧含量;额外的氮供应也提高了云杉、色木槭和红椋子叶片中UV-B吸收物质和脯氨酸含量,降低了冷杉叶片中UV-B吸收物质和脯氨酸含量;在抗氧化酶活性方面,额外的氮供应降低了云杉、冷杉叶片中5种抗氧化酶的活性和红椋子叶片中POD和GR的活性,提高了色木槭叶片中的POD和SOD的活性;4种幼苗植物体内的矿质元素含量对额外的氮供应没有显著的规律性。从这些结果可知,在高的UV-B辐射下,额外的氮供应提高了云杉、冷杉和色木槭幼苗对高的UV-B辐射的敏感性,然而,额外的氮供应却促进了红椋子幼苗的生长,原因可能是,在高的UV-B辐射下,额外的氮供应增加了红椋子叶片的厚度、叶重和叶片数,降低了叶片中活性氧含量的结果。表明在高的UV-B辐射水平下,额外的氮供应降低了红椋子幼苗对高的UV-B辐射的敏感性。 在全球变化的趋势下,UV-B辐射增强和氮沉降可能同时存在,我们的研究表明,与大气UV-B辐射+无额外的氮供应处理相比,增强UV-B辐射+额外的氮供应处理显著地降低了幼苗的单株总生物量(红椋子除外)、Chl (a + b)、净光合速率、Fv/Fm(冷杉除外)和MDA含量(红椋子除外),提高了活性氧含量 (云杉除外)、UV-B紫外吸收物质含量(冷杉除外)、脯氨酸含量和部分抗氧化酶的活性,改变了植物体不同器官中的矿质元素含量。结果表明,在当地现有条件下,全球变化(UV-B辐射增强和氮沉降)对云杉、冷杉和色木槭幼苗的生长是不利,尽管植物体内一些抗氧化性指标提高了,然而,却对红椋子幼苗的单株总生物量的累积没有显著的影响。 The depletion of the ozone led to the increase of ultraviolet-B (UV-B) with biological effects in the earth’s surface. At the same time, except for enhanced UV-B radiation, nitrogen deposition was an anxious environmental problem at present, rapidly expanding to the global scope and continuously depositing to land and aquatic ecosystem. The experiment was conducted in Maoxian Ecological Station of Chinese Academy of Sciences, Sichuan province, China. Picea asperata, Abies faxoniana, Acer mono Maxim and Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings were selected as model plants to assess the effects of enhanced UV-B radiation and supplemental nitrogen supply on growth, morphological, photosynthesis, antioxidant and mineral nutrient traits of 4 species seedlings in east Qinghai-Tibetan Plateau. The experiment was potted outdoor, including 4 treatments: (1) ambient UV-B without supplemental nitrogen (control, C); (2) ambient UV-B with supplemental nitrogen (N); (3) enhanced UV-B without supplemental nitrogen (UV-B); (4) enhanced UV-B with supplemental nitrogen (UV-B+N). One hand, it was helpful for enriching our country to comprehensive understanding of the researches in the global change and the region response, further perfecting the effects of the depleted ozone layer and nitrogen deposition on land ecosystem under the global change; the other hand, it was favorable for us to better understanding of the early process of forest renews under the global change. The results were as follows: Enhanced UV-B radiation had significant effects on 4 species seedlings in growth, morphological, photosynthesis, antioxidant and mineral nutrient traits of 4 species seedlings. The effects of enhanced UV-B on plants were not only related with species, but also related with nitrogen nutrient level. Generally, the increase of UV-B radiation led to the shrinkage and curl of leaves in Acer mono Maxim and Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings, and reduced the number of leaf and leaf weight of Acer mono Maxim seedlings, under supplemental nitrogen supply, leaf weight of Picea asperata, Abies faxoniana and Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings significantly also reduced; the anatomical features of leaf in Acer mono Maxim and Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings affected by enhanced UV-B radiation, the increase of UV-B radiation markedly reduced the palisade tissue thickness of Acer mono Maxim leaf and enhanced the leaf thickness of Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings; the enhanced UV-B radiation significantly reduced total biomass per plant of 4 species seedlings, the growth of the underground parts, Chl (a + b), net photosynthetic rate and maximum potential quantum yield of photosynthesis (Fv/Fm), and increased the degree of lipid peroxidation (MDA content) and changed the content of mineral elements in different parts of plants; the enhanced UV-B radiation also increased the rate of superoxide radical (O2-) production and hydrogen peroxide (H2O2) content in leaves of Abies faxoniana, Acer mono Maxim, Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings, under supplemental nitrogen supply, the reactive oxygen species in leaves of Picea asperata seedlings also significantly increased by enhanced UV-B radiation; under without supplemental nitrogen supply, enhanced UV-B radiation evidently induced an increase in UV-B absorbing compounds, proline content and the activities of antioxidant enzymes (SOD, POD, CAT, GR and APX) of leaves in 4 species seedlings. Under supplemental nitrogen supply, enhanced UV-B radiation induced a decrease in proline content of leaves in Abies faxoniana seedlings and UV-B absorbing compounds of leaves in Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings, but, there were no obvious rules in the activities of five antioxidant enzymes of 4 species seedling leaves to enhanced UV-B radiation, enhanced UV-B radiation significantly increased the activities of POD, SOD and GR in Picea asperata leaves, the activities of POD and GR in Abies faxoniana leaves and the activities of POD, SOD and CAT in Acer mono Maxim leaves. The results indicated that some protective mechanism was formed when plants were exposed to enhanced UV-B radiation, but the protection could not counteract the harm of high UV-B radiation on plants. Supplemental nitrogen supply had some effects on 4 species seedlings in growth, morphological, photosynthesis, antioxidant and mineral nutrient traits. The response of 4 species seedlings was different to supplemental nitrogen supply, and was affected by UV-B levels. Under local ambient UV-B radiation, supplemental nitrogen supply significantly increased the total biomass per plant, the growth of underground parts, Chl (a + b), net photosynthetic rate (except for Acer mono Maxim seedlings), UV-B absorbing compounds (except for Abies faxoniana seedlings), proline content (except for Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings) and the activities of some antioxidant enzymes, and reduced H2O2 content, the rate of O2- production and MDA content (except for Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings) and changed the content of mineral elemental in different parts; supplemental nitrogen supply also evidently increased Fv/Fm in Picea asperata and Abies faxoniana seedlings. These results indicated that supplemental nitrogen supply was favorable for the growth of plants under local ambient UV-B radiation. Under enhanced UV-B radiation, mostly parameters in growth and morphology of 4 species seedlings were not affected by supplemental nitrogen supply. Supplemental nitrogen supply increased the total biomass per plant and Chl (a + b) of Swida hemsleyi (Schneid. et Wanger.) Sojak seedling, increased the reactive oxygen species and MDA content in Abies faxoniana and Acer mono Maxim leaves, and reduced the reactive oxygen species in Swida hemsleyi (Schneid. et Wanger.) Sojak leaves; supplemental nitrogen supply also increased UV-B absorbing compounds and proline content in Picea asperata, Acer mono Maxim and Swida hemsleyi (Schneid. et Wanger.) Sojak leaves, decreased UV-B absorbing compounds and proline content in Abies faxoniana leaves; in the activities of antioxidant enzymes, supplemental nitrogen supply significantly reduced the activities of antioxidant enzymes in Picea asperata and Abies faxoniana leaves and the activities of POD and GR in Swida hemsleyi (Schneid. et Wanger.) Sojak leaves, and increased the activities of POD and SOD in Acer mono Maxim leaves; the content of mineral elements in 4 species seedlings was no significantly rule to supplemental nitrogen supply. We knew from the results, under enhanced UV-B radiation, supplemental nitrogen supply made Picea asperata, Acer faxoniana and Acer mono Maxim seedlings more sensitivity to enhanced UV-B radiation, however, accelerated the growth of Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings. The reason was probably that supplemental nitrogen supply increased the leaf thickness, leaf weight and leaf number, reduced the reactive oxygen content of leaf in Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings grown under high UV-B radiation. This showed that supplemental nitrogen supply reduced the sensitivity of Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings to high UV-B radiation. Under the tendency of the global change, enhanced UV-B radiation and nitrogen deposition may probably coexist. The results showed, compared with the treatment of ambient UV-B radiation without supplemental nitrogen supply, the treatment of enhanced UV-B radiation with supplemental nitrogen supply significantly reduced the total biomass per plants (except for Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings), Chl (a + b), net photosynthetic rate, Fv/Fm and MDA content (except for Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings), and increased reactive oxygen content (except for Picea asperata seedlings), UV-B absorbing compounds (except for Abies faxoniana seedlings), proline content and part antioxidant enzymes, and changed the content of mineral elements of different parts. The results indicated that the global change (enhanced UV-B and nitrogen deposition) were not favorable for the growth of plants under local ambient UV-B radiation and nitrogen nutrient level,, though increased some antioxidant indexes, however, the treatment of enhanced UV-B with supplement nitrogen supply did not significantly affect on the biomass accumulation of Swida hemsleyi (Schneid. et Wanger.) Sojak seedlings.

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高等植物种子胚乳贮藏蛋白是种子发芽时的主要氮源,也是人类和动物食用植物蛋白的主要来源。大麦种子胚乳贮藏蛋白主要是醇溶蛋白(hordeins),占大麦胚乳总蛋白的50–60%。根据大麦醇溶蛋白的大小和组成特点,大麦醇溶蛋白被划分为三种类型:富硫蛋白亚类(B,γ-hordeins)、贫硫蛋白亚类(C-hordeins)以及高分子量蛋白亚类(D-hordeins)。B组和C组醇溶蛋白是大麦胚乳的两类主要贮藏蛋白,它们分别占大麦总醇溶蛋白成分的70–80%和10–12%。遗传分析表明,大麦B、C、D和γ-组醇溶蛋白分别是由位于大麦第五染色体1H(5)上的Hor2、Hor1、Hor3和Hor5位点编码。Hor2位点编码大量分子量相同但组成不同的B组醇溶蛋白(B-hordein)。B-hordein的种类、数量和分布是影响大麦酿造、食用及饲养品质的重要因素之一。为深入了解B-hordein基因家族的结构和染色体组织,探明Hor2位点基因表达的发育调控机制,最终达到改良禾谷类作物籽粒品质的目的,本研究以青藏高原青稞为材料,采用同源克隆法,分别克隆B-hordein基因和启动子,通过原核生物表达验证B-hordein基因功能,并利用实时定量PCR探索B-hordein基因表达时空关系,取得如下研究结果: 1. 以具有特殊B组醇溶蛋白亚基组成的9份青藏高原青稞为材料,根据GenBank中三个B-hordein基因序列(GenBank No. X03103, X53690和X53691)设计一对引物,通过PCR扩增,获得23个B-hordein基因克隆并对其进行了序列分析。核苷酸序列分析表明,所有克隆均包含完整的开放阅读框。有11个克隆都存在一个框内终止密码子,推测这11个克隆可能是假基因。推测的氨基酸序列分析表明,所有大麦B-hordein具有相似的蛋白质基本结构,均包括一个高度保守的信号肽、中间重复区以及C-端结构域。不同大麦种重复区内重复基元的数目有较大差异。青稞材料Z07–2和Z26的B-hordeins仅具有12个重复基元结构,更接近于野生大麦。这些重复基元数目的差异导致了重复区序列长度和结构的变异。这种现象极可能是由于醇溶谷蛋白基因在进化过程中染色体的不平衡交换或复制滑动所造成的。对所克隆基因和禾本科代表性醇溶谷蛋白基因进行聚类分析,结果表明所有来自栽培大麦的B-hordeins聚类成一个亚家族,来自野生大麦的B-hordeins以及普通小麦的LMW-GS聚类成另外一个亚家族,表明这两个亚家族的成员存在显著差异。此外,我们发现B-hordein基因推测的C-末端序列具有一些有规律的特征:即具有相同C-末端序列的B-hordein基因在系统发生树中聚类为同一个亚组(除BXQ053,BZ09-1,BZ26-5分别单独聚为一类外)。这个特征将有助于我们对所有B组醇溶蛋白基因家族成员进行分类,避免了在SDS-PAGE电泳图谱上仅依靠大小分类的局限性。 2. 根据上述克隆的青稞B-hordein基因的5’端序列设计三条基因特异的反向引物,以青稞Z09和Z26的基因组DNA为模板,采用SON-PCR和TAIL-PCR技术分离克隆出8个B-hordein基因的上游调控序列(命名为Z09P和Z26P)。序列分析表明,推测的TATA box位于–80 bp,CAAT–like box位于–140 bp处。此外,Z09P和Z26P中有六个序列在–300 bp处均存在一个由高度保守的EM基序和类GCN4基序构成的胚乳盒(Endosperm Box,EB),在约–560 bp处存在一个胚乳盒类似结构。而Z09P-2和Z26P-3不存在保守的胚乳盒或其类似结构,预示着这两个启动子所调控的基因表达可能受不同类型反式作用因子的调节,推测该启动子对基因的表达调控具有多样性。 3. 将B-hordein基因的开放阅读框定向克隆到表达载体pET-30a中,将其导入大肠杆菌表达菌株BL21中进行外源基因的诱导表达以验证所克隆基因的功能。结果表明仅含重组子pET-BZ07-2和pET-BZ26-5的BL21细菌有目的表达蛋白产生。在诱导3 h时的蛋白表达量最高;3 mM IPTG诱导的蛋白表达量要高于1 mM IPTG诱导的表达量。这为分离纯化B-hordein蛋白以及进一步研究其对大麦籽粒品质的影响奠定基础。 4. 根据从青稞Z09和Z26中分离克隆的B-hordein基因序列设计一对基因特异的引物,同时,选择大麦α-微管蛋白基因(GenBank no. U40042)为看家基因并设计特异引物,利用实时荧光定量PCR检测了青稞籽粒4个胚乳发育时间段的B-hordein基因表达,荧光定量结果显示:两份材料中B-hordein基因的表达量均随发育过程的进行而逐渐升高。Z09中B-hordein基因在开花后7天开始转录,而Z26开花4天后就有低水平B-hordein的表达,这表明Z26中B-hordein基因可能比Z09表达的较早或者Z09中B-hordein基因表达水平较低以致于不能被检测到。此外,在4个不同的胚乳发育时期中,Z26中B-hordein基因的表达量均高于Z09材料。在开花12天到18天的过程中,Z09和Z26中B-hordein基因的表达水平有一个急剧性的升高。这说明在不同胚乳发育时期,Hor2位点的B-hordein等位基因变异体存在mRNA的差异表达。 Seed endosperm storage proteins in higher plants are the main resources of nitrogen for germinating and plant proteins for human and animals. Barley prolamins (also called hordeins) are the major storage proteins in the endosperm and account for 50–60% of total proteins. Hordeins are classically divided into three groups: sulphur-rich (B, γ-hordeins), sulphur-poor (C-hordeins) and high molecular weight (HMW, D-hordeins) hordeins based on the size and composition. B-hordeins and C-hordeins are two major groups and each respectively account for about 70-80% and 10-12% of the total hordein fraction in barley endosperm. Genetic analysis showed that B-, C-, C-, γ-hordeins are encoded by Hor2, Hor1, Hor3 and Hor5 locus on the chromosome 1H (5). Hor2 locus is rich in alleles that encode numerous heterogeneous B-hordein polypeptides. It is reported that B-hordein species, quantity and distribution are significant factors affecting malting, food and feed quality of barley. To understand comprehensively the structure and organization of B-hordein gene family in hull-less barley and explore the developmental control mechanisms of Hor2 locus gene expression and eventually to better exploitation in crop grain quality improvement, we isolated and cloned B-hordein genes and promotors of hull-less barley from Qinghai-Tibet Plateau by PCR, and testified their expression founction in bacteria expression system and explore their spatial and temporal expression pattern by quantitative real time PCR. Our results are as followed, 1. Twenty-three copies of B-hordein gene were cloned from nine hull-less barley cultivars of Qinghai-Tibet Plateau with special B-hordein subunits and molecularly characterized by PCR, based on three B-hordein genes published previously (GenBank No. X03103, X53690 and X53691). DNA sequences analyses confirmed that the six clones all contained a full-length coding region of the barley B-hordein genes. Eleven clones all contain an in-frame stop codon and they are probably pseudogenes. The analysis of deduced amino acid sequences of the genes shows that they have similar structures including signal peptide domain, central repetitive domain, and C-terminal domain. The number of the repeats was largerly variable and resulted in polypeptides in different sizes or structures among the genes. Twelve such repeated motifs were found in Z07–2 and Z26, and they are close to those of the wild barleys, and it is most probably caused by unequal crossing-over and/or slippage during replication as suggested for the evolution of other prolamins. The relatedness of prolamin genes of barley and wheat was assessed in the phylogenetic tree based on their polypeptides comparison. Our phylogenetic analysis suggested that the predicted B-hordeins of cultivated barley formed a subfamily, while the B-hordeins of wild barleys and the two most similar sequences of LMW-GS of T. aestivum formed another subfamily. This result indicated that the members of the two subfamilys have a distinctive difference. In addition, we found the B-hordeins with identical C-terminal end sequences were clustered into a same subgroup (except BXQ053,BZ09-1 and BZ26-5 as a sole group, respectively), so we believe that B-hordein gene subfamilies possibly can be classified on the basis of the conserved C-terminal end sequences of predicted polypeptide and without the limit of SDS-PAGE protein banding patterns. 2. The specific primers were designed according to the published sequences of barley B-hordein genes from Z09 and Z26. Using total DNA isolated from them as the templates, eight clones (designated Z09Pand Z26P) of upstream sequences of the known B-hordein genes was obtained by TAIL-PCR and SON-PCR. Sequences analysis shows that the putative TATA box was present at position –80 bp and CAAT-like box at position –140 bp. Besides, a putative Endosperm Box including an Endosperm Motif (EM) and a GCN4-Like Motif was found at position –300 bp in six clones, and another Endosperm-like box was found at positon –560 bp. While the Endosperm Box or Endosperm-like box was not found in Z09P-2 and Z26P-3. This may indicate that gene expression drived by the two promtors was probably controlled by different trans-acting factors and the genetic control mechanism of corresponding gene expression may be diverse. 3. The B-hordein genic region coding for the mature peptide was cloned into expression vector pET-30a and transformed into bacterial strain BL21 for identifying gene expression fountion. Protein SDS–PAGE analysis showed that only the transformed lysate with the pET-BZ07-2 and pET-BZ26-5 constructs produced proteins related to B-group hordeins of barley, and the mounts of proteins induced by 3 mM IPTG and 3 h were higher than other conditions. This established a base for isolating and putifying B-hordein and further exploring their effects on barley grain quality. 4. The gene-specific primers of B-hordein genes from Z09 and Z26 were used for the quantification of B-hordein gene expression. The α-tubulin gene from Hordeum vulgare subsp. vulgare (GenBank accession number U40042) was used as a control gene. The result shows the transcription of the B-hordein genes in Z09 was found 7 days after flowering, while the transcription of the B-hordein genes in Z26 was found 4 days after flowering, but at a very low level, and it suggested that the B-hordein genes in Z26 probably expressed earlier than those in Z09, or the B-hordein genes in Z09 expressed at so a lower level than Z26 that it can not detected. In addition, B-hordein genes in Z26 accession showed higher expression levels than those in Z09 in four developing stages. Furthermore, a progressive increase in the expression levels of the B-hordein genes between 12 and 18 days after anthesis was observed in both Z09 and Z26. It implies that the B-hordein allelic variants encoded by Hor2 locus exist the differential expression in mRNA levels of during barley endosperm development.

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依据东北西部沙质荒漠化地区植被的分类与排序,分析了不同演替梯度上植被群落多样性指数与DCA序坐标值的相关关系,利用其探讨群落多样性与沙质荒漠化过程的关系;科尔沁沙地、呼伦贝尔沙地,1)植物群落的生态优势度λ、Renyi的均匀度E1与群落分布的地下水位有显著的相关关系;2)植物群落Hill的多样性指数H0,H1、Hill的均匀度Eh、Hill指数的均匀度E′1与海拔、湿润系数、Thornthwaite指数、降水量、地下水位、放牧干扰等有显著的相关关系;3)植物群落Renyi的多样性指数N0,N1、Heip修正的均匀度Ep、Alatalo修正的均匀度E′h与经度、温暖指数、冷暖指数、Thornthwaite指数、土壤有机质、地下水位、放牧等干扰有显著的相关关系。4)呼伦贝尔沙地的完工-海拉尔沙带,樟子松林、贝加尔针茅羊草草甸草原;科尔沁沙地的油松林、羊草草甸草原、丛生禾草草原具有较高的多样性,各群落类型随着沙质荒漠化过程的逐渐加剧,物种丰富度逐渐降低,其递减趋势分为旱生沙化系列、湿生沙化系列、盐水至水生系列。按各群落类型的物种丰富度递减顺序可分为6个级别,6个级别所含的群落类型分别对应着稳定沙地(A、B),固定沙丘(C),半固定沙丘(D),半流动沙丘(E),流动沙丘(F)。

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A novel supramolecular compound 1,6-hexanediamine trimolybdate ((C6H18N2[Mo3O10], denoted as HDAMo) has been synthesized by a hydrothermal method and its structure has been characterized by elemental analyses, Fourier transform infrared (FT-IR) spectra, single-crystal X-ray diffraction (XRD) technique. This single crystal compound consists of protonated 1,6-hexanediamine (HDA) cations and polyoxometalate [Mo3O10](2-) anions. Its crystal structure belongs to monoclinic system (space group P2(1)/n) with a = 7.7508(14), b = 11.467(2), c = 16.167(3) angstrom, beta = 92.689(3)degrees, V = 143 5.3(5) angstrom(3), Z = 4 and D-ealc = 2.619 g cm(-3). The final statistics based on F-2 are GOF = 0.980, R-1 = 0.0261 and wR(2) = 0.0506 for I > 2 sigma(I). XRD analysis revealed that in the crystal structure of HDAMo, novel infinite [Mo3O10](2-) chains parallel to a axis are made up of distorted MoO6 octahedra connected by corners and edges. The protonated HDA cations occupy channels formed by [Mo(3)O3(10)](2-) Chains and exhibit strong hydrogen bond interactions to terminal and bridging oxo groups of the chains. The [Mo3O10](2-) chains linked through protonated HAD cations formed a one-dimensional network. The HDAMo compound shows novel photochromic properties, i.e., its color changes from white to reddish brown gradually under UV irradiation. XRD, FT-IR, ESR spectra and XPS are used to investigate the photochromic behavior of the compound.

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苯硫酚的巯基是一个较强的亲核基团 [1] ,对 α,β-不饱和双键的 Michael加成反应已有报道 [2~ 4 ] .但是当巯基的邻位存在与其形成氢键的基团时 ,如果按文献条件进行反应 ,或者反应无法进行 [5,6 ] ,或者要使用反应条件苛刻的丁基锂 [6 ] ,或者使用吡啶等毒性较大的反应溶剂 [2~ 9] ,而且产率较低 .本文选择了饱和碳酸氢钠水溶液 /n-四丁基硫酸氢铵的反应条件 ,探讨了该类化合物在此条件下的 Michael加成反应 .以 3个含分子内氢键的苯硫酚 (邻羟基苯硫酚、邻氨基苯硫酚和邻羧基苯硫酚 )为起始物 ,对丙烯酸乙酯和丙烯腈进行了 Michael加成反应 .本方法的特点在于不使用特殊的有机溶剂 ,反应在水相[10~ 12 ] 中进行 ;反应速度快 ,收率高 ,无巯基偶联 [13] 副产物生成 .反应式如 Scheme1所示 .RSH1 a— 1 c+ OONa HCO3,H2 On-Bu4 N HSO4RSOO2 a— 2 cRSH1 a— 1 c+ NC Na HCO3,H2 On-Bu4 N HSO4RSCN3 a— 3 ca. R =OH;b. R =N H2 ;c. R...

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对青海油菜蜂花粉及生物酶解破壁花粉的营养成分进行了分析和比较。结果表明,花粉经酶解破壁后,粗蛋白、粗脂肪、还原糖、核酸、总黄酮、灰份、多数氨基酸、维生素(A、B、C和K)及黄酮类化合物(原青花素、芦丁、槲皮素、异鼠李索)的含量得到了明显提高,而K、Na、CaMg、Fe、Zn、Cu、Cr、Cd、Ni、Mn等矿质元素的含量无明显变化。青海油菜花粉经破壁后更有利于营养成分和活性成分的释放。

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在地球的环境界面上,发生着重要的物理、化学和生物学反应,进行着频繁的物质交换和输送,研究和认识环境界面的地球化学过程对揭示环境演化,评价环境质量,认识成矿机理具有重要意义[万国江,1988]化学风化是元素表生地球化学循环的重要环节,是地表碉石(浮土)-水界面间的物质交换过程,其中大气成份和植物微生物代谢产物作为活化剂。化学风化的研究历史大致分为三个阶段:定性描述阶段、化学风化速度定量测定阶段、化学风化的环境生态效应研究阶段。化学风化的动力学理论经过了扩散作用理论、表面反应理论、表面络合反应理论三个发展阶段。化学同化动力学理论及其生态效应方面的研究存在的主工问题是:矿物溶解速度是由表面反应控制的,土壤具有特殊的表面性质,但目前还没有土壤化学同化动力学的实验数据。溶解铝主要来自土壤活性铝,但土壤铝的溶解机理还不清楚;仅根据化学平衡计算就认为Al~(3+)浓度是由矿物溶解平衡控制的,这很不可靠;因为土壤孔隙水的酸度控制矿物的溶解平衡,而土壤中Al~(3+)的水解制约着土壤孔隙水的酸度。孤立地研究养分的释放和流失是不完深善的,需要建立养分循环的动力学模型。黄壤是贵州分布最广的一种土壤。贵州存在着环境酸化、土壤缺钾和“石山”化等一系列生态环境问题。黔中是一个较强的酸雨区,区内降水pH值位于3.5-4.2之间;黄壤酸度高,缓冲能力弱。黄壤中活性铝浓度高,但国内没有进行黄壤中铝的淋溶和毒性的研究。黄壤是中国最贫钾的土壤之一,但缺钾的原因和发展趋势还不清楚。本文的目的是完善土壤化学风化动力学理论、阐明环境中铝的转化机理、建立钾素循环的动力学模型。同时,预测环境酸化趋势、评价土壤钾素供给状况和铝的毒性,讨论关于贵州环境酸化、土壤缺钾和“石山”化等环境生态问题的对策。作者在红枫湖汇水区采集土壤、土壤孔隙水和河水样品。土壤孔隙水用经改进的离心法提取;用化学浸提法测定土壤中铝的形态;完成了河水、土壤孔隙水的水化学全分析、土壤化学性质的测定、土壤的化学全分析和X射线衍射分析,湖水水化学全分析数据由导师提供。作者完成了土壤淋溶实验的研究,测定了淋溶前土壤样品的化学质和化学组成,测定了淋溶液的pH、Ca~(2+)、Mg~(2+)、K~+、Na~+溶解硅和单体铝。通过土壤、土壤孔隙水、湖水的化学年组成,研究土壤的化学风化动力学;通过土壤、土壤孔隙水中铝的形态分布,研究环境中铝的迁移转化机理;根据河水中钾的含量,研究土壤钾素的地球化学循环;通过土壤淋溶实验研究土壤化学风化、土壤铝淋溶、钾素循环的动力学过程。综合现场取样和淋溶实验两方面的研究成果,获得以下几点认识:1、红枫湖汇水区黄壤的化学风化处于高岭石化阶段,酸沉降增大化学风化速度,土壤化学风化符合硅酸盐矿物溶解的表面反应理论。2、实验证实了Johnson (1981)提出的土壤缓冲机制,同时发现弱酸性和中性土壤在淋溶过程中吸附H~+。3、黄壤中铝的移动性与土壤酸度和有机质含量有关,溶解铝在土壤A-B、B-C面发生沉淀。4、实验证实铝的溶解由三水铝石溶解反应控制,同时发现溶解铝浓度由H~+供给量和盐基离子释放量控制。5、建立钾素循环的动力学模型:EXCH. K=Fw-Fd-Fa利用河水中K~+浓度计算土壤钾素的化学侵蚀速率,可以预测土壤缺钾的趋势。6、实验发现土壤钾素的化学侵蚀过程由离子交换反应控制,钾素侵蚀速率与径流强度、土壤酸度和酸沉降有关。7、酸沉降加剧黄壤酸化和缺钾的趋势,加重黄壤中铝的毒性,需要控制酸沉降通量,使雨水pH值大于4.5。

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A diagnose foliar foi desenvolvida para fornecer informações sobre o estado nutricional das plantas e servir de orientação para o manejo de nutrientes visando produtividades ótimas. As outras aplicaões incluem também, a estimativa regional do estado nutricional. No entanto pouco se sabe ainda sobre a variação espacial do estado nutricional, particularmente no sistema de plantio direto. Em uma lavoura de soja, cultivada no sistema de plantio direto na região Sul do Brasil, avaliou-se a variabilidade espacial dos teores de nutrientes e o estado nutricional, para identificar as limitações à produção da cultura. Amostras de solo e folhas georeferenciadas foram coletadas em um talhão de 13 ha, em grades de amostragem de 40 por 40 m, e em grades menores de 20 por 20 m, 10 por 10 m, e 5 por 5 m. Os teores foliares de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, Mo e Zn foram determinados. Foram utilizados e discutidos dois procedimentos para avaliação do estado nutricional: as faixas de suficiência e os índices DRIS. Avaliouse a produção de grãos na época da colheita. Ajustou-se semivariogramas para todos os teores de nutrientes nas folhas. Os alcances dos semivariogramas indicaram que a grade amostragem de 20 por 20 m foi a mais adequada para representar a variabilidade espacial dos teores de nutrientes nas folhas de soja. Os métodos de avaliação do estado nutricional foram complementares e indicaram que o potássio foi o nutriente mais limitantes à produção de soja. São apresentados os mapas krigados dos teores de macro e micronutrientes e dos índices DRIS.