Flux of Atmospheric Mercury of Mangrove Leaves under Mercury Stess and Impacts of Mercury Stress on Mangrove Ecophysiology

红树植物对汞具有较高的富集能力，其叶片和大气之间有着频繁的汞交换。为认识红树植物叶片富集和释放气态汞的规律和生物学机制，对秋茄（Kandeliaobovata）、白骨壤（Avicenniamarina）和桐花树（Agicerascorniculatum）三种红树植物幼苗进行急性（14h）高浓度（100ppm）的Hg2+胁迫实验，测定三种植物叶片与大气之间气态汞交换通量的昼间变化，同时对秋茄、白骨壤、桐花树的光合作用指标和各部位汞含量进行测定。此外，对代表性非泌盐植物秋茄和代表性泌盐植物白骨壤进行了不同浓度（1ppm、5ppm、10ppm、50ppm、100ppm）的5d汞胁迫实验，测定叶片汞交...Mangrove species showed high accumulation abilities of Hg, and there was a frequent exchange of mercury between mangrove leaves and atmosphere. In order to study the biology mechanisms and variation law of enrichment and release of atmospheric Hg of mangrove species, designing the experiments of Hg2+ stress on three mangrove species that was Kandelia obovata , Avicennia marina and Agiceras co...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：2172008115269

On the Covering Law Model in the Practice of Historical Explanation

一九四二年著名科学哲学家亨普尔在《哲学》杂志上发表“普遍规律在历史中的作用”一文，文章认为普遍规律在历史学中与在自然科学中所起的作用一样重要，即历史学的解释方法与自然科学的解释方法并没有什么不同。这种观点与当时普遍流行的相对主义观点背道而驰，引发了历史哲学界有关历史解释的唇枪舌战。这种现象使得历史解释成为二十世纪历史哲学界众说纷纭的一个学术论题，对整个历史哲学中历史解释的研究和发展都是举足轻重的。 十九世纪末二十世纪初，在整个历史哲学的发展过程中以康德、黑格尔、马克思和汤因比为主要代表的思辨的历史哲学日渐衰微，而分析批判的历史哲学趋向昌盛，杰出代表有李凯尔特、柯林武德和克罗齐等。同时大批有关...Carl Gustav Hempel’s famous article “The Function of General Law in History” was published on Journal of Philosophy in 1942, in which he argued that the general law played the same part in history as well as in the natural science. This viewpoint is so different from that of the relativism popular at that time that it initiated a fierce dispute on Explanation of History in the western philosophy b...学位：哲学硕士院系专业：人文学院_外国哲学学号：1042011115221

OPNET Simulation Method for Underwater Acoustic Networks Based on Chirp Spread Spectrum

针对OPNET软件在水声网络协议仿真中不支持信道结构改变和自定义调制方式的局限,以啁啾扩频的水声网络ALHOA协议仿真为例,提出了一种适合在OPNET上实现更真实水声通信协议仿真的方法。物理层调制方式采用自定义的π/4-DM-DQPSK制式,利用MATLAB将生成的调制曲线导入OPNET中配合OPNET其他管道的配置。在2种具有结构差异的Bellhop信道中验证对ALHOA协议的仿真效果,结果表明信道结构的变化能灵敏地影响ALHOA协议的仿真。此方法对利用OPNET软件灵活开展水声网络协议仿真具有较好的参考价值。Underwater acoustic(UWA) network protocol simulation on OPNET software could not follow the changing of channel structure and did not support custom modulation. In view of the limitations mentioned, a more realistic method of UWA protocol simulation on OPNET was introduced. UWA network ALHOA protocol simulation was token as an example. The physical layer modulation customized was called π/4-DM-DQPSK which was based on Chirp Spread Spectrum. In Matlab, the system would generate a modulation curve which would then be imported into OPNET to adjust the configuration of other pipelines. The simulation results of ALHOA protocol was verified in two Bellhop channels with different structures, which showed changing structure had a sensitive impact on ALHOA protocol. The method introduced has reference value on simulating UWA network protocol flexibly in OPNET.国家自然科学基金项目(61571377;61471308

Application of Chirp Signal in Underwater Acoustic Supervision System for Illegal Throwing Sand Behavior Detection

为找到一种高效便捷的方法判断疏浚船舶是否存在违规抛泥行为,研究了基于啁啾信号探测抛泥行为的方法。设计了3种实现方案:分段FFT(Fast; Fourier Transformation)快速相关、FRFT (Fractional Fourier; Transform)变换、去斜脉冲压缩。结合五缘湾实验及仿真结果验证了3种方案的可行性,同时发现:FRFT变换抗多径和抗噪性能最佳,而去斜脉冲压; 缩算法效果最差。通过分析:当多径影响较为严重时,建议使用FRFT算法进行检测;当多径影响较小而对数据实时性处理要求较高的时,建议使用分段FFT快; 速相关算法进行检测。To find an efficient and convenient method to determine whether a; dredging is illegal is a very meaningful research content. A method of; detection of throwing sand behavior based on Chirp signal was studied; and three implementation schemes (subsection FFT fast correlation), FRFT; and DeChirp were designed. The feasibility of the three schemes was; verified by Wu Yuan Bay experiment and the simulation results.; Anti-multipath and anti-noise performance of FRFT transform is the best.; The performance of dechirp is the worst. Through the analysis, it comes; out the conclusion: when the multipath effect is serious,FRFT algorithm; for detection is recommended; When the multipath effect is small and the; requirement of the data real-time processing is strict,subsection FFT; fast correlation algorithms for detection is recommended.国家自然科学基

美国国会议员访台现象研究(1997～2008)

台湾地区是美国国会议员访问最频繁的地区之一。本文分析了从1997年到2008年的美国国会议员访台记录分布及其决定因素,获得了如下主要发现:第一,美国国会议员访台频次变动受台湾岛内政治变动和美国国会选举周期影响,但以前者更为重要;第二,《与台湾关系法》赋予美国国会及其议员干预台湾问题的"权力",是造成美国国会议员、特别是外交事务、军事、情报等委员会成员频繁访台的根本原因;第三,意识形态、选区利益、经贸关系等对美国国会议员访台也产生了一定的影响

Impacts of mercury stress on Avicennia marina seedlings eco-physiology

为了解红树植物的重金属抗性机制,对白骨壤(AVICEnnIA MArInA)幼苗进行不同浓度Hg2+(1、5、10、50、100 Mg.l-1)的胁迫实验,测定并分析了Hg2+胁迫对白骨壤幼苗叶片的光合作用和抗氧化酶活性的影响。结果表明:叶片净光合速率随着胁迫时间的延长而降低,高浓度(≥50 Mg.l-1)Hg2+胁迫下叶片的净光合速率低于中低浓度胁迫,且高浓度胁迫的叶片净光合速率在48 H后快速下降;叶片净光合速率与胞间二氧化碳浓度呈极显著负相关,叶绿素含量随Hg2+浓度的增加而降低。气孔导度在不同浓度胁迫下反应不同,低浓度Hg2+对白骨壤幼苗光合的影响可能是气孔因素,中高浓度Hg2+对白骨壤幼苗光合作用的抑制主要是非气孔因素。低浓度Hg2+胁迫,白骨壤幼苗叶片SOd、POd活性升高,表现了一定的抗逆性,而高浓度表现为抑制作用,基本在100 Mg.l-1Hg2+胁迫下活性达到最低值。说明Hg2+可以抑制白骨壤叶片的光合活性,高浓度Hg2+胁迫削弱了白骨壤的活性氧清除能力,植物极易受到伤害。In order to understand the heavy metals resistance mechanism of mangrove,a stress experiment with the seedlings of mangrove species Avicennia marina from Fujian Province was conducted to study the impacts of different concentration(1,5,10,50,and 100 mg·L-1) mercury(Hg2+) on the seedlings leaf photosynthesis and antioxydase activities.With the increase of added Hg2+ concentration and exposure time,the seedlings leaf net photosynthetic rate(Pn) and chlorophyll content decreased.Under the stress of high concentration Hg2+(≥50 mg·L-1),the decrement of Pn was higher than that under the stress of low concentration Hg2+,and the Pn decreased rapidly after 48 h.There was a significantly negative correlation between Pn and extracellular carbon dioxide concentration(Ci).The chlorophyll content decreased with increasing Hg2+ concentration.The stomatal conductance(Gs) had different responses to the stress of different Hg2+ concentration.At low Hg2+ concentration,stomatal factors could limit the photosynthesis;while at high Hg2+ concentration,non-stomatal factors could be the main causes inhibiting photosynthesis.Low Hg2+ concentration promoted the activities of superoxide dismutase and peroxidase,while high Hg2+ concentration inhibited the activities of the two enzymes,being the lowest under the stress of 100 mg Hg2+·L-1.All the results implied that Hg2+ could inhibit the leaf photosynthesis of A.marina,and high concentration Hg2+ impaired the active oxygen elimination capability of A.marina,making the plants easily to be damaged.国家自然科学基金项目(40676064)资

Preliminary Study on the Distribution and Impact Factors of Methylmercury in Surficial Sediments from Main Mangrove Wetlands of China

通过对海南、广东、广西、福建的8个主要红树林地区沉积物中甲基汞以及环境因子的研究,分析了红树林生态系统中甲基汞的分布及其汞的甲基化作用.结果表明:1沉积物中总汞和甲基汞的含量分布并不一致.中国主要红树林区海南(三亚、东寨港)、广东(特呈岛、雷州、高桥、福田)、广西(大冠沙)、福建(浮宫)表层沉积物中甲基汞含量分别为(0.24±0.04)、(0.58±0.27)、(0.52±0.23)、(1.56±0.49)、(0.50±0.25)、(1.21±0.36)、(1.86±1.04)和(0.47±0.16)ng.g-1.甲基汞含量有很明显的地域区别,其含量顺序为大冠沙>雷州>福田>东寨港>特呈岛>高桥>浮宫>三亚.工业和养殖业输入的汞和有机质显著增加了沉积物中甲基汞水平.对比世界其他河口湿地,我国红树林湿地沉积物中的甲基汞污染较为严重.2红树林沉积物的甲基化比率介于0.11%~7.13%.甲基化比率顺序由大到小为大冠沙>特呈岛>雷州>福田>高桥>东寨港>三亚>浮宫.甲基化比率与砂粒显著正相关(P三亚>高桥>东寨>福田>大冠沙.各环境因子对微生物数量的影响无显著差异.沉积物中Srb的含量介于1.73x104~4.92x106Cfu/g,福田>浮宫>东寨港>三亚>高桥>大冠沙.高有机废水是导致沉积物中Srb含量增高的主要原因.沉积物类型对Srb在沉积物表层的分布也有较大影响.甲基汞和环境因子之间并没有明显的相关性,外源输入是我国红树林湿地沉积物中的甲基汞污染的主要原因.Total mercury(THg),methylmercury(MeHg) and environmental factors were determined to study distributions of MeHg and Hg methylation in the sediments from 8 main mangrove areas of China.The results showed that it was not consistent for distributions of THg and MeHg in sediments.Concentrations of MeHg in sediments from Sanya,Dongzhaigang(Hainan Province),Techengdao,Leizhou,Gaoqiao,Futian(Guangdong Province),Daguansha(Guangxi Autonomous Region),Fugong(Fujian Province) were(0.24 ± 0.04),(0.58 ± 0.27),(0.52 ± 0.23),(1.56 ± 0.49),(0.50 ± 0.25),(1.21 ± 0.36),(1.86 ± 1.04),(0.47 ± 0.16) ng.g-1 respectively.There were regional difference in MeHg contents which decreased in the order of Daguansha > Leizhou > Futian > Dongzhaigang > Techengdao > Gaoqiao > Fugong > Sanya.Input of Hg and organic matter from industry and aquiculture may lead to high level of MeHg.Compared with sediments from other estuaries of the world,serious pollution of MeHg was found in mangrove sediments of China.② % MeHg in mangrove sediments ranged from 0.11% to 7.13%,which decreased in the order of Daguansha > Techengdao > Leizhou > Futian > Gaoqiao > Dongzhaigang > Sanya > Fugong.There was significantly positive correlation between % MeHg and sandy fraction(p Sanya > Gaoqiao > Dongzhaigang > Futian > Daguansha.Sulfate-reducing bacterium(SRB) ranged from 1.73 × 104 to 4.92 × 106 CFU/g,SRB decreased in the order of Futian > Fugong > Dongzhaigang > Sanya > Gaoqiao > Daguansha.Wastewater with high organic matters leads to high SRB.The types of surface sediments also had a great impact on the amount of SRB.There was no significant correlation among MeHg and environmental factors,which indicated that exogenous input is the main cause of MeHg pollution in mangrove sediments.国家自然科学基金项目(40676064;30530150);中国科学院地球化学研究所环境地球化学国家重点实验室项

四种石蜡包埋组织DNA提取方法的比较

背景:由于在甲醛固定石蜡包埋组织的制作及保存过程中对DNA造成的损害,影响了后续的聚合酶链反应等研究。选择一种简便有效且经济实用的石蜡包埋组织DNA提取方法成为研究者们关注和亟待解决的问题。目的:比较甲醛固定石蜡包埋组织中4种提取DNA的方法对DNA质量的影响,探讨一种操作简便、污染少、经济实用的石蜡包埋组织中提取DNA的方法。方法:取手术切除的普通甲醛固定石蜡包埋的非小细胞肺癌组织标本20例,分别以二甲苯脱蜡-酚氯仿法、改良TES水浴脱蜡-酚氯仿法、试剂盒法和改良TES水浴脱蜡-试剂盒抽提DNA法提取其DNA,然后进行电泳分析、紫外分光光度计测定A260/A280比值及PCR扩增。结果与结论:改良TES水浴脱蜡-酚氯仿法和改良TES水浴脱蜡-试剂盒抽提DNA法可获得较大的DNA片段,且两种方法与试剂盒法所提取DNA的A260/A280值相比较,均有显著性意义(P0.1),以改良TES水浴脱蜡-酚氯仿法所得DNA为模板,扩增的目的条带亮度与阳性对照相当。结果证实改良TES水浴脱蜡-酚氯仿法简便有效,所用试剂价格低廉,是一种经济实用的石蜡包埋组织DNA提取方法

X射线双星系统的探测

搜寻X射线双星并建立大规模样本是解决众多科学问题(如\"银河系中有多少黑洞X射线双星?黑洞和中子星之间有无质量间隙?球状星团中有无黑洞?\"等)的基础.爱因斯坦探针卫星拥有更灵敏的探测能力,将在运行的几年之中,预计可以发现一批新的中子星和黑洞X射线双星,研究其空间和动力学质量分布成为解决上述问题的关键.国家重点研发计划(编号:2016YFA040080X);;国家自然科学基金(编号:1133305);;中国科学院战略性先导科技专项(编号:XDA15052100,XDB23040000)资助项

Structural Characteristics and Sources of the Surface Sediments in Xiamen Coast

为研究厦门近海海域表层沉积物的结构特征、组成及来源,于2010年7月采集厦门湾表层沉积物,综合粒径分析、X射线衍射、扫描电镜等方法对沉积物进行表征。粒径分析的结果表明,沉积物的主体粒径在80μM附近,且有明显的次粒级峰,并以粗颗粒的主体粒级峰占有优势。研究的沉积物类型主要有三种,砂质粉砂、粉砂质砂和砂-粉砂,其中砂质粉砂是分布最广泛的沉积物类型区域沉积物,其含量达90%以上;而粘土含量以背景点鸡屿岛为最高,达到11.97%。X射线衍射分析表明,沉积物中优势轻矿物为石英、高岭石,部分区域含有石墨及一些零星分布的伊利石、海绿石和斜绿泥石。这些矿物组成显示了厦门湾海域表层沉积物具有较好的亲陆性,同时,其组成也受到了涨潮流的较大影响。沉积物形貌形态的研究发现,厦门湾沉积物组分较为复杂,其中含有多种藻类及其碎片(主要为硅藻)、矿物颗粒(高岭石)及未知名碎片;形状主要有孔状结构、层叠状结构、长条片状和不规则的六边形块状等。In order to study the structural characteristic,composition and source of the sediment in Xiamen coastal waters,the surface sediment in Xiamen Bay was collected in July,2010,and the samples were comprehensively analyzed by particle size analysis,X-ray diffraction,scanning electron microscopy and other methods.The results of the particle size analysis showed that the main diameter of the sediment was near 80 μm,with a pronounced secondary pea.There are three main types of sea sediments(sandy silt,silty sand,and sand-silt) and sandy silt is the most widely distributed type,which the content of the silt-sand at all study areas was nearly 90%,while the clay content was highest at the background point and reached to 11.97%.The X-ray diffraction analysis showed that the dominant light minerals in sediments were Quartz,Kaolinite;some areas contained Graphite.Illite,Glauconite and Clinochlore also had been found in some areas accidentally.The mineral composition showed the surface sediments had a good pro-land,meanwhile,it was affected by the flood current.While,the morphology study found that the composition of the sediments at the study areas were complex,containing a variety of algae and debris(mainly diatoms),minerals(kaolinite) and unknown debris.Cavernous structure,stack-like structure,long flake and irregular hexagon were the main shapes in these sediments.国家自然科学基金(41005082);近海海洋环境科学国家重点实验室青年访问学者基金(MELRS1017