225 research outputs found
Research on Groundwater Discharge into Jiulongjiang Estuary
本论文依托国家自然科学基金项目“近岸海域的海底地下水排泄及其海洋生态环境效应研究(40672166)”,通过运用天然存在的镭同位素(224Ra,226Ra)示踪技术,对九龙江河口区的地下水输入通量进行评价,并对其输送的营养盐数量进行评估。 相对只有河水端元和海水端元保守混合的水体而言,九龙江河口区水体显然存在Ra的过量,推测有经由其它途径输入的Ra。通过识别九龙江河口区224Ra和226Ra的源汇项,认为它们的源项主要有:SGD输入的镭,河流输入的镭,河流悬浮颗粒解吸的镭,沉积物扩散的镭,沉积物再悬浮解吸的镭,径流和涨潮输入的镭;汇项主要有:放射性衰变损失的镭,径流和退潮输出的镭。 通过构...This paper, supported by the project of submarine groundwater discharge and its eco-environmental effects in the coastal area(40672166), which belongs to the National Natural Science Foundation of China, calculates flux of SGD in Jiulongjiang estuary via using naturally-occurring radium isotopes(224Ra,226Ra) tracer technique and estimates flux of nutrients, which lead to the discussion of their po...学位:理学硕士院系专业:海洋与环境学院海洋学系_海洋地质学号:2242006115232
Research and Implementation of the Content-Based MP3 Music Retrieval
基于内容的音乐检索就是把音乐本身的内涵,如节奏、旋律、和弦、伴奏音型、音色等,作为查询条件,对一个由不同格式的音频媒体(如MIDI、MP3或其它格式的波形音乐)所构成的音乐数据库实施查询检索以获取数据库中满足查询条件或包含相同或相似音乐片段的音乐资源。这些表征不同音乐内涵的查询条件可以通过哼唱或借助现有的乐谱输入工具输入到检索系统中以实施检索。本论文对基于内容的MP3音乐检索技术进行了研究,并实现了一个灵活的具有多种查询音乐输入方式的MP3音乐检索原型系统。 目前,大部分基于内容的音乐检索系统所检索的对象都是MIDI音乐,对MP3音乐检索的研究相对来说比较少,并且查询音乐的输入方式也大都比较...Content-based music retrieval uses the content of music itself as query, such as rhythm, melody, chord, accompaniment, timbre etc., to get the music resource which meets the query condition or contains same or similar music clip in a music database. The audio media in the music database may be of different formats, such as MIDI, MP3 and other wave audio. These queries can be inputted into the retr...学位:工学硕士院系专业:信息科学与技术学院计算机科学系_计算机应用技术学号:2005130234
InCl3 Catalyzed One-Pot Synthesis of Highly Substituted Pyrroles from Propargylic Alcohols, 1,3-Dicarbonyl Compounds and Primary Amines and Synthesis of 2'-Deoxy-β-L-thymidine and C24H30 as Precursor to C24, C24H12 Fullerene
一、InCl3催化的炔丙醇、1,3-二羰基化合物和伯胺一锅法合成多取代吡咯 吡咯广泛存在于各种天然产物和各种生物活性物质中,并已应用于制药领域的合成。即使在非天然的有机小分子中,吡咯也作为一个重要的结构单元出现在各种有机合成的中间体之中。因此,吡咯环的合成一直是有机化学家感兴趣的课题。我们成功发展了一种快速有效的三氯化铟催化的炔丙醇、1,3-二羰基化合物和伯胺一锅法合成多取代吡咯的新方法。该方法经连续的取代/胺化/成环过程,中间体无需分离,一锅法即可得到五取代吡咯环产物。反应条件温和,适用于多种类型取代基的吡咯环合成,反应所用金属催化剂便宜易得,对环境友好,可作为多种吡咯合成方法的又一重要补...1. InCl3 Catalyzed One-Pot Synthesis of Highly Substituted Pyrroles from Propargylic Alcohols, 1,3-Dicarbonyl Compounds and Primary Amines Pyrrole was widely found in various natural products and many bioactive materials, and had been applied to the synthesis of the pharmaceutical area. Pyrrole, as an important structure unit, was shown in many organic synthesis intermediates even in non-natura...学位:理学硕士院系专业:化学化工学院化学系_有机化学学号:2052006115193
中小企业融资瓶颈问题探讨
市场经济环境下,我国的各个中小企业都得到了快速发展,但融资问题仍是中小企业发展的瓶颈问题,因此本文就在分析我国中小企业融资现状的基础上,进一步探讨产生瓶颈问题的原因,并最终提出解决这些问题的策略
A Comparative Study on Postgraduate Training Models in Hong Kong,Macao and Taiwan
通过文献资料法、比较分析法、逻辑分析法对港澳台体育硕士专业学位研究生的学位类型、招生、专业设置、培养目标、课程、毕业要求、师资模式、教育实践进行比较。研究表明:港澳台体育硕士专业学位研究生的教育选拔机制灵活;培养方式多样且务实,注重教育国际化;质量保障客观高效,学术管理严格;注重跨学科人才的引进培养。大陆体育硕士专业学位研究生培养经过多年的培育和发展,逐渐走向成熟,但仍可以从港澳台应用型体育硕士人才培养中进行借鉴和学习,其目的是更好地优化大陆高校体育硕士专业学位研究生的培养模式,为提高我国体育学科硕士研究生的培养质量提供参考依据。The comparative study shows: the selection mechanism is more flexible; cultivating model is diverse and pragmatic;paying attention to the Education Internationalization; the objective of efficient quality guarantee; academic management strictly; laying emphasis on introduction and cultivation of multidisciplinary talents. After years of cultivation and development,it gradually becomes more mature for Chinese mainland Physical Education professional master degree. But we shall learn from each other in the above aspects from the talents Cultivation of Hong Kong,Macao and Taiwan of Physical Education Professional master,aiming at the cultivation of the Chinese mainland college Physical Education Professional master of Degree Postgraduates with new inspiration,in order to improve our country cultivation of the Postgraduates quality of physical education disciplinary and provided a reference.国家社会科学基金资助青年项目子课题(12CTY023
SSR Polymorphism of Alligator sinesis and Conservation Strategy of Genetic Diversity
作者简介: 黄 磊( 1978- ) , 硕士研究生, 研究方向: 动物分子遗传
通讯作者。E-mail:wangyqnj@ jlonline. com[中文文摘]扬子鳄 (Alligatorsinensis)是中国特有的珍稀保护动物 ,为保护这一濒危物种 ,我国于 80年代初在安徽宣州先后建立了扬子鳄繁殖研究中心和国家级扬子鳄自然保护区 ,现饲养种群存鳄数量已达 10 0 0 0余头。为了揭示扬子鳄种群的遗传结构 ,共采集了 3 9个个体的样品 ,其中包括 6件剥制标本 ,按代系不同 ,分为野生群、F1代饲养群及F2 代饲养群 ,用微卫星DNA分子标记对其进行研究。分析结果显示 :扬子鳄种群在微卫星水平表现出很低的遗传多样性 ,平均等位基因数A =2 3 8,平均有效等位基因数Ne=1 60 ,平均观察杂合度Ho=0 3 74,平均期望杂合度He=0 3 50 ,平均多态信息含量PIC =0 3 2 7,3个群体间A、Ne、Ho、He、PIC及各微卫星位点等位基因频率分布无显著差异 ,但F2 代饲养群在Ami μ 6和Ami μ 2 2 2两个位点表现出极显著的遗传不平衡。扬子鳄种群遗传多样性水平低下的主要原因是近几十年来种群数量大幅减少造成 ,现阶段应将全部现存的扬子鳄作为一个整体加以保护 ,在建立新的繁殖群体时 ,应考虑保存物种遗传多样性所必需的有效种群大小 ,在种群的遗传管理上应注重低频等位基因的发现和保持.[英文文摘]Chinese alligator, Alligator sinesis , is a critically endangered endemic species under legislative protection. Results of recent investigations revealed that the number of the alligator was continuously declining in the past 50 years and less than 150 individuals were surviving in the wild until 2000. In order to prevent the extinguishing of this species, the Reproductive Research Center of Alligator sinesis and the National Nature Reserve of Alligator sinesis were set up in early 1980 s in Xuanzhou, Anhui Province. After 20 years of breeding efforts, the number of captive individuals has been brought up to more than 10, 000 in total. In order to reveal the genetic structure of Chinese alligator population, total of 39 individuals including 7 wild individuals outside of the research center were sampled to construct wild, F1 and F2 groups according to their generations, and 10 micorsatellite loci selected from 25 primer pairs originally designed for Alligator mississippiensis were employed for investigating the genetic diversity of Alligator sinesis .The results indicated that, contrasting with Alligator mississippiensis and some other endangered species, Chinese alligator had an extremely low genetic diversity level with A= 2.38, Ne= 1.60, Ho= 0.374, He= 0.350 and PIC= 0.327. There were no significant differences of A, Ne , Ho , He , PIC and each SSR locus alleles frequency distribution among 3 groups. However, Hardy Weinberg equilibrium analysis revealed that F2 captive group showed a remarkable genetic disequilibrium at loci Ami μ 6 and Ami μ 6 222 . The reason accounting for the current genetic status of Chinese alligator is dramatically shrink of the population in past decades. Due to the lack of significant difference between wild group and captive group, all survived Chinese alligator should be treated as one ESU in the next conservation practice. More attention regarding the effective population size and low frequency alleles should be emphasized in genetic management of captive alligators and establishing new separate propagation.教育部骨干教师资助计划项目(编号:GG18021002403 1740);教育部留学回国人员启动基金资
Research progress on the objectification, quantitation and standardization of tongue manifestation in traditional Chinese medicine
舌诊是中医诊断学的重要组成部分,舌象在中医临床治疗中具有重要的诊断意义与辨证价值。传统中医舌象易受主客观因素影响,难以客观化、定量化、标准化,严; 重制约舌象临床应用及发展。随着医学、计算机等现代技术的迅猛发展,中医舌象客观量化研究取得了长足进步,并被应用于基础及临床研究。文章对近几年中医舌; 象采集分析系统、舌象定量化研究、现代仪器应用与舌象基础研究进行概述,为舌象应用于临床治疗提供客观、科学的思路与方法。Tongue diagnosis is an important part of traditional Chinese medicine; (TCM), and the tongue manifestation is also important in the diagnosis; and syndrome differentiation in TCM clinical treatment. However, due to; the lack of objective, quantitative and standardized valuation, with it; being susceptible to subjective and objective factors, the application; and development of traditional tongue diagnosis is limited for a long; period. Recently, with the rapid development of medical and other modern; technology, the objectification, quantitation and standardization of TCM; tongue manifestation have been received great progress, including the; progress in basic and clinical researches. Recent researches on the; tongue image acquisition and analysis system, the quantitation of tongue; manifestation, the application of modern instruments and the basic; research in tongue manifestation were reviewed to provide certain; objective and scientific ideas and methods for TCM tongue manifestation.教育部新世纪优秀人才支持计划; 中国博士后科学基金面上项
The application of microsatellite DNA markers in conservation genetics of endangered animals
通讯作者Author for correspondence. E-mail : wangyq @xmu. edu. cn[中文摘要]微卫星DNA广泛分布于真核生物基因组中 ,具有多态性高、共显性遗传、选择中性、易于操作等特点 ,是一种极具应用价值的分子遗传标记 ,近年来在濒危动物保护遗传学研究中得到越来越多的应用。微卫星DNA高度多态性提供的高分辨率遗传信息 ,使其不仅适合个体水平的亲子鉴定与交配系统研究 ,而且也已成为种群遗传结构与多样性分析的有效分子标记。微卫星分析所需的DNA量极少 ,用非损伤性方法获取的极少量样品或陈旧样品就能用于有效分析 ,方便了濒危动物野外调查工作的开展 ,并且可以利用年代久远的馆藏历史标本揭示种群的重要历史进程。另外 ,某些微卫星DNA大小在近缘物种间可相互区分 ,这使得部分物种的DNA分子鉴别将更为简便。但微卫星分子标记的座位筛选和特异引物开发耗时费力 ,一定程度上限制了其广泛应用。针对不同的研究目的选择合适的分子标记方法将有助于更好的揭示问题本质.[英文摘要]Microsatellite DNA is widely dispersed in eukaryotic genomes with the characters of high polymorphism , high abundance , codominance , selective neutrality , and easy manipulation. Therefore , it has been increasingly applied to studies of conservation genetics of endangered animals in recent years. The polymorphism of microsatellite DNA is so high that it can provide excellent resolution not only for kinship and mating system studies at the individual level , but also for genetic structure research at the population level . The DNA template needed for microsatellite analysis is very low and has no special demands , so that small samples obtained
with noninvasive method and from old specimen can be analyzed effectively. Therefore , the approach not only makes investigation of endangered animals surviving in the wild more convenient and exact , but also can make use of the rare specimens preserved in museums to reveal important evolutionary history for some species. Fur2
thermore , some microsatellite fragments′sizes can be discriminated among related species , which makes it possible to identify species more conveniently with only fragment analysis. However , application of microsatellite DNA markers also has its own shortcomings , and appropriate molecular makers should be adopted for a given
issue according to different research purposes.教育部留学回国人员启动基金;教育部高等学校骨干教师资助计划项目 (GG 180 2 10 0 2 40 3 1740
开放式基金,大众理财的首选
开放式基金是投资基金一个主要品种,指发行总额不固定,基金单位总数随时增减,投资者可按基金报价在国家规定的营业场所申购或者赎回基金单位的投资基金。由于开放式基金的某些特点,所以它广受投资者的欢迎。本文将着重向投资者介绍开放式基金的理财特点以及如何投资于开放式基金
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