901 resultados para Research progress


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本学位论文报道了西藏产三种藏族传统植物药材的化学成分研究。论文由四章组成,前三章是实验部分,分别报道了尼泊尔黄堇(Corydalis hendersonii Hemsl.)、藏波罗花(Incarvillea younghusbandii Sprague)和全缘叶绿绒蒿(Meconopsis interifolia Franch.)的化学成分研究结果。从这三种青藏高原药用植物中共分离鉴定出33 个化合物,其中1 个是新化合物。第四章概述了罂粟科紫堇属植物的化学和药理研究进展。 第一章为尼泊尔黄堇的化学成分研究。通过正、反相硅胶柱色谱等分离方法从药用植物尼泊尔黄堇的地上部分共分离纯化得到12 个化合物。运用MS、1H-NMR、13C-NMR、DEPT、HMBC、NOESY 等现代波谱学方法将它们的结构鉴定为:刺罂粟碱(1) , 普托品(2) , 新那亭(3) , 斯可任(4) , tetrahydrothalifendine (5) ,9-methyl-decumbenine C (6),tetrahydroberberrubine (7),隐品碱(8),α-别隐品碱(9),6,7-methylenedioxy-1(2H)-oxoisoquinolinone (10),6-丙酮基-5,6 -二氢血根碱(11)和β-谷甾醇(12)。其中化合物6 为新化合物,为首次发现的分子骨架上C-9 位连有甲基的苯肽异喹啉类型生物碱。另外,除化合物1 和2 外,其它9 个生物碱(3~11)均为首次从该种植物中分离得到。同时,我们还对对尼泊尔黄堇中的总生物碱进行了串联质谱分析。 第二章为藏波罗花的化学成分研究。从该药用植物的地上部分共分离得到16个化合物,通过理化常数和波谱数据鉴定为:异佛手柑内酯(1),6-甲氧基当归素(2),欧前胡素(3),花椒毒内酯(4),珊瑚菜素(5),水合氧化前胡素(6),rivulobirin A (7),齐墩果酸甲酯(8),咖啡酸甲酯(9),银桦酸(10),(D)-boschniakinic acid (11),对羟基苯甲酸(12) , tert-O-β-D-glucopyranosyl-(R)-heraclenol (13) , 5-methoxy-8-O-β-D-glucopyranosyloxypsoralen (14),前胡苷V(15)和苯乙醇-O-β-D-吡喃葡萄糖-(1→2)-O-β-D-吡喃葡萄糖苷(16)。所有以上化合物均为首次从该种植物中分离得到。另外我们还首次对藏波罗花挥发油的化学成分进行了气相色谱-质谱(GC-MS)联用分析,共鉴定出39 个挥发性成分。 第三章为全缘叶绿绒蒿化学成分的分离鉴定。从传统藏药材全缘叶绿绒蒿地上部分共分离纯化出8 个化合物。通过理化常数和波谱数据将他们的结构分别鉴定为:去甲血根碱(1),β-谷甾醇(2),3-羟基-齐墩果烷-12(13)-烯-30-酸(3),6-丙酮基-5,6-二氢血根碱(4),木犀草素(5),胡萝卜苷(6),quercetin 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (7)和普托品(8)。其中化合物1,4 和7 为首次从该种药用植物中分离得到。 第四章为综述,总结和归纳了近年来罂粟科紫堇属植物的化学和药理研究进展。 This dissertation consists of four parts. The first, second and third parts report the studies on the chemical constituents from the medicinal plants of Corydalis hendersonii, Incarvillea younghusbandii and Meconopsis interifolia. The forth part reviews the progress of the studies on Corydalis species. The first chapter is about the isolations and identifications of alkalids from the aerial parts of C. hendersonii which is a traditional Tibetan medicine to treat febrifuge, high blood pressure and hepatitis. A new isoquinoline alkaloid, 9-methyl-decumbenine C (6), together with ten known alkaloids, stylopine (1), protopine (2), canadine (3), scoulerine (4), tetrahydrothalifendine (5), tetrahydroberberrubine (7), cryptopine (8), α-allocryptopine (9), 6,7-methylenedioxy-1(2H)-isoquinolinone (10) and 6-acetonyl-5,6-dihydrosanguinarine (11), and β-sitosterol (12) were isolated. Their structures were elucidated by spectroscopic methods. Furthermore, the total alkaloids were analyzed by ESI-MSn. The second chapter is about the isolations and identifications of chemical constituents from the aerial parts of I. younghusbandii. Sixteen compounds were isolated and purified by normal and reversed phase silica gel column chromatography. By spectral analysis, there structures were identified as isobergapten (1), sphondin (2), imperatorin (3), xanthotoxin (4), phellopterin (5), heraclenol (6), rivulobirin A (7), methyl oleanolate (8), methyl caffeate (9), grevillic acid (10), (D)-boschniakinic acid (11), 4-hydroxybenzoic acid (12), tert-O-β-D-glucopyranosyl-(R)-heraclenol (13), 5-methoxy-8-O-β-D-glucopyranosyloxypsoralen (14), decuroside Ⅴ(15), and phenylethyl-O-β-Dglucopyranosyl-(1→2)-β-D-glucopyranoside (16). All of these compounds were isolated from this plant for the first time.By the way, the chemical components of the essential oil from I. younghusbandii were analyzed by GC-MS for the first time. The third chapter is about the the isolations and identifications of the chemical constituents of M. interifolia. Eight compounds were isolated and identified as norsanguinarine (1), β-sitosterol (2), 3-hydroxyolean-12(13)-en-30-oic acid (3), 6-acetonyl-5,6-dihydrosanguinarine (4), luteolin (5), daucosterol (6), quercetin 3-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranoside (7) and protopine (8). The compounds 1, 4 and 7 were isolated from this herb for the first time. The last chapter is a review of the research progress of the studies on Corydalis species, which includes the chemical constituents in this genus and their pharmacology.

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We introduce and summary our research progress on the effective masses of K meson in dense nuclear matter.

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坡面是土壤侵蚀最基本的地貌单元 ,定量研究坡面侵蚀能为研究土壤侵蚀规律、确定坡面重点侵蚀部位、建立土壤侵蚀预报模型提供科学依据。总结了溅蚀、片蚀、细沟侵蚀、浅沟侵蚀的定量研究进展 ,简述了土壤侵蚀模型的研究进展 ,对目前的其它研究方法进行了评述

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植物根系除支撑和固定其地上部这一力学功能外的一个重要功能就是从土壤中吸收水分和养分以满足植物地上部生长所需.表征植物根吸水能力的一个重要的水力学参数是水力导度(用单位时间单位面积的水流速率来表示),可在细胞(细胞水力导度)、单根和整株根系水平上来表达,其中单根导度可分为径向导度和轴向导度,仅径向导度反映了单根吸收水分的能力,而轴向导度则反映了植物根系输导水分的能力,但在整株根系水平上则以通过整个根系的水流通量与根木质部和根表土壤间的水势差之比来表示,既包括径向导度也包括轴向导度.近年来,对植物根系吸水或根水力导度研究已取得了许多重要进展,这对阐明根系吸水机理和地上地下部关系起到了重要作用.下面做一简要综述.1 根系吸收水分的主要部位根系吸水的部位一般认为在距根尖10~100mm的区域内,这种看法是基于解剖上的证据.从根表面到根中心,依次为根表皮、下表皮、皮层、内皮层、中柱,其中根表皮是有最高吸收活性的根区,但一般仅可存活几天,而内皮层将皮层和中柱分开形成了根内侧的一个界面,老根一般有周皮或栓质化的内皮层,有很强的不透水性(即阻力很大).但Sanderson[1]对大麦的研究发现,虽然老根区内重度栓化的内皮层已...

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介绍了国内外土壤侵蚀预报模型的主要研究成果。所介绍的国外土壤侵蚀预报模型除众所周知的USL E/ RUSL E,WEPP,L ISEM和 EUROSEM外 ,还有浅沟侵蚀预报模型 (EGEM)和切沟侵蚀预报模型。国内的侵蚀预报模型主要有在 GIS支持下的陡坡地包括浅沟侵蚀的坡面侵蚀预报模型、有一定物理成因的坡面侵蚀预报模型和流域预报模型。在总结和评价国内外土壤侵蚀预报模型的基础上 ,提出了中国今后土壤侵蚀预报模型研究的设想。

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The research progress of the effect of predation risk on animals’behavior and their decision was introduced in the paper. In recent decade , a lots of researches dealt with effects of predation on prey foraging behavior (including when to feed , where to feed , what to eat , how to consume) , habitat selection and defensive behavior in the various types of ecological systems. The results showed that animals had the ability to assess and control their risk of being pred in ecological time and they could incorporate this information with their making of decision during the lifetime. Some researches suggested that the decision reflected apparent trade-offs between the risk of predation and the benefits to be gained from enaging in a given activity. It was stressed that predation risk was an important and necessary trade-off factor for animals’decision making. In addition , the effect of indirect predation at community level was one of the forces of shaping community structure and become an important way for studing mechanism of community organization. At the population level , it also may be significant advers effecting on population distribution , density and reproduction.

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本文综述了移动机器人的导航、定位及多传感器融合技术,介绍了导航技术的应用现状,并阐述了导航技术的发展趋势。

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对故障诊断和容错技术的发展过程进行了简要概述,以旋翼飞行机器人为研究对象,在分析了旋翼飞行机器人故障诊断与容错控制特点的基础上,介绍了当前国内外在该领域的研究进展和主要方法.最后,总结了该领域待解决的难点问题,并指出了该研究领域的发展趋势.

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根据心理物理学、神经生理学、认知神经学等学科在视觉认知领域的部分研究成果,结合机器视觉、图像处理领域在图像增强方面已经提出的一些方法,提出了结合先验知识的多窗口结构下的分块中值滤波方法,在每一个窗口内单独进行处理与分析,突出了视觉处理目的,减少了运算量, 节省数据存储空间,达到了令人满意的滤波效果,能够在原始图像比较复杂的情况下,较好地对其进行预处理,可以改善、提高后期图像处理过程,如图像分割、图像分析的正确性和有效性。

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水下滑翔机器人是一种新型的水下机器人,可以作为水下监测平台用于大范围、长时间的大尺度海洋环境监测作业。文中调查了水下滑翔机器人的国内外发展现状,分析了其可能的应用领域。详细介绍了中国科学院沈阳自动化研究所开发的水下滑翔机器人系统,包括载体外形优化设计、载体结构设计和控制系统设计。分析了水下滑翔机器人定常滑翔运动和空间螺旋会转运动的运动性能。

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The cognition and memory functions of the Basal Ganglia have been the focus of contemporary cognitive neuroscience researches. This study, from neuroanatomical and neurophysiological point of view, thoroughly surveyed the recent relevant research progress, carefully examined the evidences of the neurological basis for the Basal Ganglia possessing or participating cognition or memory functions. Moreover, it reviewed recent achievements on the cognitive functions of the basal ganglia based on researches on rodent animals, primate animals and human beings. Then it presented a series of experiments conducted, by neuropsychological and cognitive psychological methods, on neurological patients with focal lesions to the basal ganglia or combining with bilateral hippocampus or thalamus impaired to explore what the role of the basal ganglia play in human explicit and implicit memory. It was found that the lesions to the basal ganglia partially handicapped explicit verbal memory and completely impaired perceptual priming. It was also found that right cerebral cortex dysplasia but basal ganglia spared had no effects on priming tasks performances. The results suggested that the basal ganglia contain or accommodate higher cognitive functions and further suggested that priming be irrelevant to right cerebral cortex. It was posited that the basal ganglia, on the basis of interaction with prefrontal or temporal cortices, mediate movement function as well as cognition and memory functions.

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Mesenchymal stem cells (MSCs) reside within the bone marrow cavity and serve as a reservoir for the continuous renovation of various mesenchymal tissues. Recent efforts suggest that MSCs modulate the immune reactions in vitro and escape the immune surveillance in vivo. We provide herein a discussion of the issues including the current research progress on the in vitro interactions of MSCs with multiple subsets of immune cells (dendritic cells, T cells, B cells and natural killer cells), in vivo transplantation outcomes, the possible underlying mechanisms, future research directions as well as potential clinical implications.

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This paper provides a quantitative and qualitative analysis of the profile of the entrepreneur who decides to start business through a labor society in the context of the Autonomous Community of Andalucia. Thus, first the Social Economy is presented as an important alternative to creating and promoting employment, which seeks to combine economic and social objectives in the development of activities. Subsequently, focusing on labor companies, updated its importance in the regional economy for later data and through the analysis of two samples are available, set the attributes or most significant characteristics of these entrepreneurs.

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In attempting to understand the distributions of both introduced species and the native species on which they impact, there is a growing trend to integrate studies of behaviour with more traditional life history/ecological approaches. The question of what mechanisms drive the displacement of the freshwater amphipod Gammarus duebeni by the often introduced G pulex is presented as a case study Patterns of displacement are well documented throughout Europe, but the speed and direction of displacement between these species can be varied. From early studies proposing interspecific competition as causal in these patterns, I review research progress to date. I show there has been no evidence for interspecific competition operating, other than the field patterns themselves, a somewhat tautological argument. Rather, the increased recognition of behavioural attributes with respect to the cannibalistic and predatory nature of these species gave rise to a series of studies unravelling the processes driving field patterns. Both species engage in 'intraguild predation' (IGP), with moulting females particularly vulnerable to predation by congeneric males. G pulex is more able both to engage in and avoid this interaction with G duebeni. However, several factors mediate the strength and asymmetry of this IGP, some biotic (e.g. parasitism) and others abiotic (e.g. water chemistry). Further, a number of alternative hypotheses that may account for the displacement (hybridization; parasite transmission) have been tested and rejected. While interspecific competition has been modelled mathematically and found to be a weak interaction relative to IGP, mechanisms of competition between these Gammarus species remain largely untested empirically. Since IGP may be finely balanced in some circumstances, I conclude that the challenge to detect interspecific competition remains and we require assessment of its role, if any, in the interaction between these species. Appreciation of behavioural attributes and their mediation should allow us to more fully understand, and perhaps predict, species introductions and resultant distributions.