747 research outputs found

    Adsorption of Selemiun and Cr(VI) and rapid detection of Cr(VI) in aqueous solution using composite materials based on fuctionalizing bentonite

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    随着工业化程度的不断提高,环境中重金属污染日益严重。由于重金属不可生物降解的特性,在水体中富集就造成水域环境污染;通过食物链在人体中富集,则危及人类身体健康。硒是人体必需的微量元素,适量硒具有增强机体免疫功能,抗氧化和防癌作用。但是,摄人过高或过低的硒元素均会对人体健康造成危害,反而具有致突变和癌变作用。水体中的硒元素污染主要由于人类对矿物的过度开采以及一些工业生产部门的废水乱排造成的。水域中重金属铬污染主要来源于铬矿的采选矿、造纸、印刷、冶炼电镀、染料、机器制造、制药等工业部门排出的废水。其中,六价铬因其强氧化性和对皮肤的高渗透性,比三价铬毒害性大100倍。因此,包括美国、日本、欧盟等许多国...With the increasing improvement of the level of industrialization, contamination accidents regarding heavy metals are becoming more and more serious. Because of the non-biodegradable property of heavy metals, they will cause environmental pollution if they accumulate enough in the water. Moreover, heavy metals will also enrich in human body through food chain, and even endanger people’s health. Se...学位:理学博士院系专业:化学化工学院_分析化学学号:2052006015321

    Design and Implementation of the 360°Panoramic Tourism Resources Display System based on GIS

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    旅游资源数据库构建是旅游数字规划、数字化管理以及各种旅游信息系统开发的重要数据基础。本文针对旅游资源数字化技术基础薄弱、共享程度差的现状,首先研究基于GoogleMaps兴趣点获取为主要方式,以Qmini移动GIS终端现场采集作为补充手段,快速进行旅游资源空间位置及其属性信息采集的方法。采用360°全景软硬件技术,对典型旅游景区进行拍摄、合成及场景制作与建库。为了方便存储管理并提高数据的开放共享程度,基于OracleMapBuilder工具导入矢量数据、栅格数据、属性数据,实现旅游资源遥感数据、矢量数据、属性数据的一体化管理。同时基于OracleMap融合中间件开发具有地图视图、360°全景展...The construction of tourist resources database is the important data base of digital planning, digital management and various tourism information system development. This paper is based on the situation of weak and poor sharing of tourism resources digital technology. First, we study based on the Google Maps to grab points of interest as the main way, to capture a Qmini Mobile GIS terminal site as...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201323229

    The Role and Mechanism of RARα in the Development of Colorectal Cancer

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    结肠癌在世界范围内的发病率和死亡率均位列第三位。由于其发病隐匿,早期诊断困难,大多数结肠癌患者确诊时已处于晚期。因此,急需寻求结肠癌诊断和治疗的分子靶点。研究表明,视黄酸受体α(RARα)在白血病、乳腺癌、肺癌等多种癌症的发生发展中发挥了重要的作用,而RARα参与结肠癌发生发展的作用和分子机制尚不清楚。本论文以结肠癌为研究对象,阐明RARα在结肠癌发生发展中的作用及其分子机制,为寻找新的药物靶点和安全高效的治疗方法提供科学依据。 本论文研究发现,RARα在结肠癌组织中的表达明显高于癌旁相对正常组织,在结肠癌细胞株中的表达明显高于正常结肠上皮细胞,且RARα在胞浆胞核中均有表达。RARα的表达...Colorectal cancer (CRC) is the third most common cancer and the third leading cause of cancer-related morbidity and mortality around the world. Due to difficulty in early diagnosis, the majority of patients are not diagnosed until the late stage. So, it is urgent to find molecular targets in the diagnosis and treatment of CRC. Previous studies have shown that retinoic acid receptor α (RARα) plays ...学位:理学博士院系专业:生命科学学院_生物化学与分子生物学学号:2162014015421

    Construction of Drug-Induced Toxicity related Profile Database

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    药物不良反应(AdverseDrugReactions,ADRs)是临床医学和公共卫生领域的重大难题之一。它不仅影响临床药物治疗效果,而且对病患的健康造成不同程度的危害甚至是死亡;它同时也是新药研发失败和药物退市的主要因素之一。 由于缺乏足够的基础信息支持,目前对药物不良反应分子机制研究存在较大的局限性。本课题针对ADR发生的几种机制,收集了蛋白质-ADR、基因调控-ADR和遗传变异-ADR三个层次的关系数据。我们在上一代药物诱导毒性相关蛋白质数据库(Drug-InducedToxicityProtein)DITOP的基础上,广泛地从PubMed文献中提取报道的蛋白引起的药物不良反应关系信息...Adverse drug reaction (ADR) is a severe medical and social problem that needs to be solved immediately. Every year, it leads to not only substantial pains to patients but also a number of new drug discovery failures. One of the key factors that slows down ADR mechanism study and assessment is the shortness of sufficient supporting information for ADRs. Therefore, in this study, we collect...学位:理学硕士院系专业:生命科学学院_生物化学与分子生物学学号:2162014115253

    The Research on Personalized Service System of Five Star Hotels Based on Big Data ——Taking Sheraton Xiamen Hotel for an Example

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    随着社会经济的发展及经济全球化,服务经济时代已经到来,酒店业作为主 导性的服务行业,一方面面临着前所未有的激烈竞争,另一方面也面临客户需求 的日益多元化,经营转型,推出差异化的产品和服务,开辟新增需求来开拓市场, 成为摆在星级酒店面前的重要课题。同时,大数据环境的成熟,也为酒店提供了 打造以个性化为基础的差异化服务的技术条件。 全文第一章对研究背景和意义进行了概括、总结,简要回顾了个性化服务、 大数据的概念和基本特征,论述个性化服务和大数据的关系。并对国内外研究的 现状进行了介绍和评述。第二章使用PEST模型对酒店业的宏观环境进行深入剖 析,论述酒店业目前面临的机遇和调整。提出...With the rapid development of market economy,the improvement of new technique and high techonology make the consumers' choice more diverse and their demand more personalized.Facing the diversity of the consumers' demand and the division of market, the hotel need the think from the consumers' perspective and enhance their satisfaction during the service.On the other hand, it is necessary to bui...学位:旅游管理硕士院系专业:管理学院_旅游管理硕士学号:1782012115114

    The water and nutrition relationships between mistletoe and its host mangrove species

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    本文研究了瘤果槲寄生Viscumovalifolium和红树植物海桑Sonneratiacaseolaris的寄生系统。槲寄生属Viscum是桑寄生科常绿灌木或亚灌木,属于半寄生植物。试验地点为海南清澜港红树林自然保护区,样地内海水平均盐度为17.2ppt。自然条件下测定植物叶片的叶绿素荧光和光合气体交换速率,并于控制环境下测定光响应曲线和CO2响应曲线。同时测定叶绿素含量、叶片渗透势、木质部和叶片的元素(Na、Cl、K、Ca、Mg、N、P)含量等。 1. 与以往的研究结果不同,此处的槲寄生叶片蒸腾速率(Tr)全天低于寄主,但是两者均具有非常高的叶片氮含量。所以 (1) 验证假设:当氮供应...Mistletoes are xylem-tapping hemi-parasites. They obtain heterotrophic carbon coupled with water and mineral nutrients via haustoria which connect to the internal tissues of their hosts, however, they are capable of photosynthesis because they contain chlorophyll. Xylem-tapping mistletoes generally have higher transpiration rate (E), lower CO2 assimilation rate (A) and lower water-use efficiency (...学位:理学硕士院系专业:生命科学学院生物学系_生态学学号:2172006115227

    Behind Corporate Philanthropy:Is Giving for Getting?

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    本文以2003-2012年在沪深交易所A股上市的企业为样本,研究企业的慈善捐赠行为是否有利于企业获得银行贷款,是否有利于企业获取商业信用。研究结果发现:(1)企业的慈善意识在逐渐加强,这不仅表现在参与慈善捐赠的企业越来越多,也表现在企业的慈善捐赠数额在逐渐增加。(2)慈善捐赠与企业银行借款、慈善捐赠与商业信用都存在显著的正相关关系,有捐赠行为的企业比无捐赠行为的企业获得更多的银行借款、更长的借款期限以及更好的商业信用条件,捐赠越多的企业,能获得越多的银行贷款、及更长的贷款期限,同时捐赠的越多,企业越能获得良好的商业信用条件。(3)企业的政治关系对慈善捐赠的银行借款效应和商业信用效应都有减弱作用...This article empirical tests whether corporate philanthropy lead to obtaining bank loans or whether philanthropic activities help an enterprise to gain access to the credit market in Shanghai and Shenzhen A-share listed companies, using 2003- 2012 data as a sample. The result shows that: Firstly, enterprises awareness of corporate philanthropy is gradually strengthened, not only in the growing n...学位:经济学硕士院系专业:王亚南经济研究院_金融学(含保险学)学号:2772011115266

    Accounting Treatment for Enterprises’ Tradable Emission Permit

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    排污权交易的主要思想是通过以排污许可证的形式建立合法的污染物排放权利,并容许这种权利像商品一样可以在市场上自由买卖。其一般做法是:政府机构评估出一定区域内满足环境容量的污染物最大排放量,并将最大允许排放量分成若干规定的排放份额,每份排放份额为一份排污权。政府在排污权一级市场上,采取一定方式,如拍卖、奖励等,将排污权出让给排污者。排污者取得排污权后,可根据使用情况,在二级市场上进行排污权买入或卖出。 随着我国排污权交易改革的逐步推进,排污权交易制度将成为我国环境保护、防治污染的重要手段。排污权交易制度实施后,对于企业来说,污染物的排污不再是一个政府行政许可的问题,而是一个有选择的环境决策问题。...Emission permit transaction mainly refers to legalizing the permit to discharge pollutants by means of delivering permit and the legalized permit can be traded freely in the market. Generally speaking, the related government organs will make an assessment about the largest amount of pollutants discharge within the boundaries of environmental accommodation ability of certain area and divide it into...学位:管理学硕士院系专业:管理学院会计系_会计学学号:1752007115105
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