Significance of Mangrove Pollen in Research of Marine Geology

红树林是热带—亚热带海岸潮间带的一种特有的植被类型和指示植物 .根据沉积物中出现的红树植物花粉种类和数量 ,推测了海滨红树林的演化、海面升降、海岸线变迁 ,追溯了古海流和沉积物来源 ,阐述了红树植物花粉在海洋地质研究中对深入探讨古环境变化和海陆相互作用等方面的重要意义 .Mangrove flora are special vegetation and indicative plants existing in certain areas of tropical and subtropical coasts.According to the variety and quantity of mangrove pollen discoveried in the sediments,this paper inferred the evolution of mangrove flora and changes of sea level and paleo-shoreline.Mangrove pollen also provide evidence for tracing paleo-ocean current and sediments source.In marine geological research,the study on mangrove pollen is also important for exploring paleoenvironment changes and ocean-continent interaction.国家自然科学基金资助项目 ( 4 95 76 2 87) ;; 华东师范大学河口海岸国家重点实验室资助项目 ( 2 0 0 0 0 1) ;; 国家海洋局海底科学 重点实验室资助项目 ( 2 0 0 1-4

脱氧胆酸改性普鲁兰多糖纳米粒子制备与表征

通过酯化反应将脱氧胆酸偶联于普鲁兰多糖骨架形成具有两亲性的普鲁兰多糖衍生物(DP),采用纳米沉淀法制备纳米粒子(DPNs),考察制备条件对纳米粒子性质影响,为进一步将其作为药物载体的研究提供基础。衍生物DP结构通过FT-IR和1 H NMR表征,DPNs经透射电镜、动态光散射仪和zeta电位仪表征检测。获得不同取代度脱氧胆酸改性普鲁兰多糖衍生物,制备得到的纳米粒子呈球形,表面光滑规整,平均粒径100～300nm,zeta电位在-20mV左右。脱氧胆酸改性普鲁兰多糖衍生物通过纳米沉淀法能制备出纳米粒子,颗粒性质受制备条件影响

Mechanism of geniposide in improving free fatty acid metabolism in rats with non-alcoholic fatty liver disease

观察栀子苷改善非酒精性脂肪性肝病的效果,从游离脂肪酸探讨栀子苷调节非酒精性脂肪性肝病的作用机制。健康雄性Wistar大鼠40只,随机分为4组:正常组、模型组、栀子苷组和血脂康组,每组大鼠10只,正常组大鼠给予正常大鼠饲料喂养,其余3组大鼠均采用高脂饲料喂养以诱导非酒精性脂肪性肝病,造模时间为8周,从第5周起至第8周末,栀子苷组和血脂康组分别灌服相应的药物。记录大鼠体重、肝湿重、脂肪质量;用相应方法检测肝组织TG,FFA,FAS,AMPK,ACCase及Malonyl-Co A含量,血清CHO,LDL-C的含量,血清AST,ALT的活性;观察肝脏组织肉眼及病理变化(HE染色法)。结果显示,与正常组相比,模型组大鼠的体重;肝湿重;脂肪重;血清CHO,LDL-C,ALT,AST;肝组织TG,FFA,FAS,ACCase及Malonyl-Co A含量皆显著升高(P<0.01);肝组织AMPK活性显著降低(P<0.01),肝组织肉眼外观及病理切片脂肪变性明显,并出现炎症损伤;与模型组相比,栀子苷组大鼠体重、脂肪质量、肝组织FFA含量、血清ALT,AST活性均显著降低(P<0.01),肝湿重,肝组织TG,FAS,ACCase及Malonyl-Co A含量明显降低(P<0.05),肝组织AMPK活性明显增多(P<0.05),肝脏肉眼外观及病理学表现均有所改善;与模型组相比,血脂康组大鼠的肝湿重、脂肪质量、肝组织TG,FFA和血清LDL-C水平明显降低(P<0.05);与血脂康组相比,栀子苷组大鼠的体重、脂肪质量、肝组织FFA含量均显著降低(P<0.01),其他方面无明显差异。结果表明,栀子苷具有显著的改善高脂饮食诱导的大鼠非酒精性脂肪性肝病的药理效应;其改善大鼠非酒精性脂肪性肝病的游离脂肪酸代谢是通过调节"AMPK-ACCase-Malonyl-Co A-FFA"轴来实现的。To observe the effect of geniposide on non-alcoholic fatty liver disease( NAFLD),and discuss the mechanism of geniposide for NAFLD from the aspect of free fatty acid,forty healthy Wistar male rats were randomly divided into normal group,model group,geniposide and Xuezhikang group. The rats in normal group were fed with normal diets,and the rats in other 3 groups were given with high-fat diet for 8 weeks to induce the NAFLD models. From the week 5 to end of week 8,the rats in geniposide and Xuezhikang group were intervened with corresponding medicines. The body weight,liver wet weight,and fat weight of the rats were recorded.Visual and pathological changes in hepatic tissues were observed with HE staining. The contents of TG,FFA,FAS,AMPK,ACCase and Malonyl-Co A in hepatic tissue,contents of CHO and LDL-C in serum and activities of AST and ALT in serum were detected by using corresponding methods. The results showed that the body weight,liver wet weight,and fat weight of the rats,CHO,LDL-C,ALT and AST levels in serum,TG,FFA,FAS,ACCase and Malonyl-Co A levels in hepatic tissues of the rats in model group were significantly higher than those in normal group( P < 0. 01),while AMPK activity was significantly lower than that of the normal group( P < 0. 01),with obvious visual and pathological steatosis in hepatic tissues,and inflammatory injury occurred in model group. Compared with the model group,body weight of the rat,fat weight,levels of FFA in hepatic tissues,ALT and AST activities in serum,liver wet weight,TG,FAS,ACCase and Malonyl-Co A levels were significantly decreased in geniposide group( P < 0. 01),while the AMPK activity in hepatic tissues was significantly increased( P < 0. 05),with improvement in visual and pathological performance.Compared with the model group,liver wet weight,fat weight,TG and FFA levels in hepatic tissues,and LDL-C level in serum were significantly decreased in Xuezhikang group( P < 0. 05). Compared with Xuezhikang group,the body weight of rat,fat weight and FFA level in hepatic tissues were significantly lower in geniposide group( P < 0. 01),but with no significant difference in other aspects. These findings indicated that geniposide was highly effective in improving the pharmacological effect of NAFLD induced by highfat diet,and the mechanism was achieved through AMPK-ACCase-Malonyl-Co A-FFA axis.国家自然科学基金项目(81274155;81503529);; 福建省自然科学基金项目(2014J01374);; 福建省高等学校新世纪人才计划项目;; 厦门市科技计划项目(3502Z20134020);; 福建省中医药科研项目(WZPW201308

Microwave radiation-assisted synthesis of Pt-CNTs

Carbon nanotube-supported platinum nanoparticles (Pt-CNTs) were synthesized using glycol as a reducer and H2PtCl6 as an oxidant under microwave radiation. The CNTs was first hydroxylated in refluxing concentrated HNO3. Transmission electron microscopy was used to investigate the influence of the hydroxylation time on the amount of supported platinum on the carbon nanotubes and the effect of the amount of platinum on the morphology of Pt-CNTs. Selected area electron diffraction, X-ray diffraction, and UV-visible spectroscopy were employed to characterize the structure of the Pt-CNTs and the results showed that Pt was of polycrystal nanoparticles. Cyclic voltarnmetric study indicated that the CNTs surface was covered by a compact layer of Pt when the loadings of platinum to CNTs was as high as 0.1875 mmol . g(-1). The result, on one hand, showed that cyclic voltammetry could be used to study the surface structure and properties of CNTs supported platinum nanoparticles, and on the other hand, indicated that it was possible to obtain novel electrode materials with good catalytic activity and stability by optimizing the synthesizing method for CNTs supported platinum nanoparticles

机器翻译中句法语义相结合的汉语分析研究

本文在研究了汉语的语法现象的基础上，采用基于规则的方法实现了机器翻译中文分析原型系统RCAS的设计和开发。该系统对已经正确切词的中文单句进行语法和语义相结合的分析，得到准确的中间语言分析结果。 汉语的分析是汉外机器翻译系统实现的基础和关键，目标语言生成所需要的所有信息都来自于源语言分析得到的中间语言结果。汉语是一种缺少形态、高度语义化的语言，汉语的名词、形容词都具有多种语法功能，而且汉语词组和句子的构造规则基本相同，这些都给汉语的分析带来了困难。但汉语的语法分析还有很多潜力可以挖掘，本文利用北京大学《现代汉语语法信息词典》所提供的语法知识，针对汉语中趋向动词的处理、多动词谓词识别、量词的处理...Based on the deep studying of the phenomena of Chinese，the paper studied and implemented a Rule-based Chinese Analysis System――RCAS. The system analyses Chinese simple sentences which have been segmented correctly into the interlingua combining syntax with semantics. Analysis of Chinese is the basis and the heart of Chinese-English machine translation system. All the information that the target l...学位：工学硕士院系专业：计算机与信息工程学院计算机科学系_计算机应用技术学号：19972800

Design and simulation of asymmetric Doherty power amplifier based on ADS

为在高线性的前提下提高WCdMA基站系统中功率放大器的效率,仿真设计了一款工作于2.14 gHz频段不对称功率驱动的dOHErTy功率放大器。基于AdS平台,采用Mrf6S21140H ldMOS晶体管,通过优化载波放大器和峰值放大器的栅极偏置电压改善三阶互调失真(IMd3),同时通过调节输入功率分配比例改善由于峰值放大器对载波放大器牵引不足导致的失配问题,从而改善不对称dOHErTy功率放大器的输出性能。仿真结果表明,当载波放大器的栅极偏置电压为2.84 V,峰值放大器的栅极偏置电压为0.85 V并且输入功率比例为1:2.3,输出功率为44 dbM时其功率附加效率(PAE)为24.21%,IMd3为-44.46 dbC,和传统Ab类平衡功率放大器相比PAE提高了8.58%,IMd3改善了6.98 dbC。A uneven power drive asymmetric Doherty power amplifier was designad,to improve efficiency and linearity at 2.14GHz WCDMA base-station system.This design used ADS simulation platform and MRF6S21140H LDMOS transistor.By optimizing gate bias voltage at carrier and peaking amplifier,the third-order intermodulation distortion was advanced.Meanwhile,it adjusted input power distributions to improved mismatch problem and advanced performance.This problem is caused by insufficient carrier amplifier's impedance which pulled with peaking amplifier.The test result shows that,power-added efficiency is 24.21%,and the third-order intermodulation distortion is-44.46dBc,when the output power is 44dBm,the peaking amplifier gate bias voltage at 0.85V,carrier amplifier gate bias voltage at 2.84V,and using 1:2.3 uneven power drive to asymmetric Doherty power amplifier.The result verifies the asymmetric Doherty power amplifier perform with 8.58% higher power-added efficiency and 6.98dBc better third-order intermodulation distortion than the traditional balanced class-AB amplifier

基于国家标本资源共享平台数据的中国杜鹃花科植物标本采集地理偏差分析

植物标本是植物学家长期从事科研活动的积累和人类自然遗产的永久记录之一,是研究物种的分布及其历史、现状、系统演化的证据。为了分析我国杜鹃花科植物标本地理采集偏差问题,本研究基于国家标本资源共享平台收录的149559份中国杜鹃花科植物标本,在筛选校对后,以县级行政单位为分类单元,分析我国杜鹃花科标本采集现状,并对杜鹃花科植物标本采集质量进行评估,分析了中国杜鹃花科植物物种丰富度的分布格局及影响其分布的气候因子之间的关系。结果显示杜鹃花科植物标本采集较为完整的县级行政区集中分布于长江以南地区以及西南地区,东北、西北及东部地区相对较少;两种评估方法对标本采集完整性的结果具有一定的相关性,但斜率法更具科学性;斜率法结果显示虽某些地区采集数目较多,如横断山区,但仍有部分地区采集不完整,即区域内部分县仍存在未被采集的种类;昼夜温差与年温差比值(Bio3)、年温度变化范围(Bio7)、年平均雨量(Bio12)及最暖季度平均雨量(Bio18)等气候因子与杜鹃花科植物物种丰富度呈现显著的线性相关,其中Bio7与观察物种丰富度、估计物种丰富度、估计与观察物种丰富度的差值等3个物种丰富度呈负相关,Bio3、Bio12及Bio18与3个物种丰富度呈正相关;能量因子对物种丰富度的解释率高于水分因子,并且二者的单独解释率均低于二者共同作用的解释率。以上结果表明,我国各地区采集完整性地理偏差严重,,故我国标本采集工作仍需改进;气温稳定性对杜鹃花科植物物种空间分布格局的影响最为显著,水分与能量共同决定杜鹃花科植物物种丰富度格局

离子液体和果糖双水相体系的研究

&lt;正&gt;双水相萃取技术由于其操作条件温和、生物相溶性高、能耗小、易于工程放大、连续操作等特性而在生物制剂如蛋白质、酶、有机化合物和金属整合物的分离和纯化、预浓缩过程中表现出相当好的性能,并有望用于大规模提取和纯化生物活性物质,因此倍受人们的关注。令人振奋的是,作为新型绿色溶剂的离子液体,也可以形成双水相体系。美国教授Robin D．Rogers等在2003年首先报道了该体系:亲水的离子液体1-丁基-3-甲基咪唑氯盐([C4mim]Cl)和K3PO4可形成双水相,