中国-欧亚经济联盟FTA的经贸效应模拟分析--基于GTAP模型及偏效应分解

缔结FFA是丝绸之路经济带与欧亚经济联盟对接建设的预选方案。文章利用GTAP模型模拟分析了中国-欧亚经济联盟缔结自由贸易协定（FTA）对双边产生的经济贸易效应，并进一步运用偏效应分解法分析各类效应的特征及引致原因。研究发现：中国-欧亚经济联盟若缔结FTA，那么非关税壁垒削减比关税减让更能显著提高双方的经济福利和实际收入；不同区域在FTA下的行业产出水平会因为贸易创造效应而出现差异化调整；中国行业产出主要受双边关税壁垒影响，而欧亚经济联盟和中亚三国则视具体产业而呈现差异化特征；中亚三国加入欧亚经济联盟后，中国与欧亚经济联盟会出现“多赢”局面。此外，FTA框架下的中国、欧亚经济联盟及中亚三国之间的经济福利具有较强契合性，且福利提升呈现典型的帕累托改善特征，但中国产能过剩的部门产出将面临负面冲击。国家社会科学基金一般项目“中国与中亚区域贸易投资便利化推进战略研究”（项目编号：13BGJ024）;新疆高等学校人文社会科学重点研究基地兵团屯垦经济研究中心基金资助项目“丝绸之路经济带建设背景下新疆国际大通道建设研究”（项目编号：XJEDU020214C04）;石河子大学高层次人才科研启动项目“中国与中亚FTA的贸易经济效应模拟测度与政策研究--基于GTAP模型的一般均衡分析”（项目编号：RCSX201401）

The Effect of Chinese OFDI on Energy Import in Central Asia under the Background of "the Belt and Road"

通过运用分位数引力模型研究了中国对中亚区域对外直接投资的能源进口贸易效应及影响因素。结果发现,中国与中亚区域国家的对外直接投资与能源进口之间存在显著的替代效应;人均收入水平对能源进口贸易的促进作用呈"U"型特征,能源进口产品从初级产品规模扩张向高附加值产品提质转变;地理距离对能源进口的负面影响随着条件分位点的提高呈现下降趋势,贸易投资便利化将弱化距离成本的影响。This paper uses quantile gravity model method to investigate the factor of import trade effect and influence on out- ward foreign direct investment and import of energy from China to Central Asian countries. The empirical results show that there is a significant substitutional effect between outward foreign direct investment and import of energy amongst China and Central Asian countries ; the stimulative effect of per capita income level on import of energy present a ＂U＂ shape ; the trade and investment facilitation of ＂the Belt and Road＂ will weaken the influence on cost of distance.国家社会科学基金一般项目(13BGJ024)；新疆维吾尔自治区普通高等学校人文社会科学重点研究基地兵团屯垦经济研究中心基金项目(XJEDU020214C04)；石河子大学高层次人才科研启动项目(RCSX201401)

凤眼莲对福建龙湖重金属的监测及其评价

通过测定龙湖不同区域的水生植物凤眼莲结果表明,凤眼莲对水体的zn、MO、Pb、Cu等都有较大的吸收富集能力。其根部富集能力略大于其茎叶部位。通过测定表明,龙湖在重金属污染方面基本上处于未污染状态至轻污染状态

Impacts of mangrove vegetation on macro-benthic faunal communities

大型底栖动物是红树林生态系统的重要组成部分,从红树林大型底栖动物种类、红树林与其周边生境大型底栖动物群落的比较,以及生境变化对动物群落的影响等方面阐述了红树林植被与大型底栖动物群落的关系。从物种数量上看,软体动物和甲壳类动物构成了红树林大型底栖动物的主要部分。影响大型底栖动物分布的环境因素包括海水盐度、潮位和土壤特性等,但在小范围区域,林内动物的分布更多地与红树林植被特性和潮位有关。因此,由于红树林植被破坏或者恢复引起的生境变化,将导致大型底栖动物群落和常见物种种群的变化,尤其对底上动物影响明显;随着人工恢复红树林的发育,林内底栖动物的多样性相应增加,优势种也发生变化。相比位于相同潮位的无植被滩涂,红树林可促进潮间带生物多样性。Mangrove ecosystems,found on marine coasts of the sub-tropics and tropics,have high biological productivity and rich faunal diversity.Mangrove ecosystems provide organic matter and nutrients critical to marine benthic fauna,primarily through litter-fall which is a major component of the detrital food chain.The macro benthic fauna,in turn,provide an important link between mangrove detritus at the base of the mangrove food web and consumers at higher trophic levels.Benthic fauna also may modify the physical and vegetation structure of mangrove ecosystems.Thus,the community of macro benthic fauna needs to be considered in mangrove restoration if holistic ecosystem restoration is to be achieved.This overview examines the current knowledge of macro benthic fauna in mangroves,and the effects of mangrove vegetation on the faunal community in China.In mangroves,mollusks and crustaceans are the major components of the benthic fauna,and this is a common phenomenon all over the world.In China,the mollusks are represented by more species in most studies;this is similar to that in east coast of the Americas,but different from those in other geographic regions.Dominant fauna varies with mangrove regions,but some species such as Cerithidea cingulata,Littoraia elanostoma,sesarmid crabs and fiddler crabs are common,and some of them are dominant.The community structure of macro benthos seems to be influenced by environmental conditions such as hydroperiod,salinity and sediment texture,but the small-scale distribution pattern of benthic fauna mainly depends on the factors with respect to tidal regime and mangrove vegetation.This is due,in part,to the effects mangrove vegetation has on the chemical characteristics of sediment like the organic matter content,total N and pH.Perhaps more important is the role that mangroves play in providing a solid substrate for gastropods and shade that ameliorates the harsh conditions caused by high temperatures and high evaporation rates.These factors are responsible for making levels of secondary biological productivity and faunal diversity in mangroves comparable to those in seagrass meadows and salt marshes.Recent studies carried out in Jiulongjiang Estuary,showed that the total number of animal species within mangrove forests was greater than that of adjacent non-vegetated tidal flats with similar hydrological,topographical and edaphic conditions,indicating that mangrove vegetation promotes intertidal biodiversity.Studies in Jiulongjiang Estuary also demonstrated that mangrove areas with different vegetation ages or species can support different macro benthic assemblages,and the natural/mature mangroves generally support higher faunal biodiversity than the young or disturbed forest.Studies on mangrove rehabilitation and deforestation have further shown that Uca crabs are more abundant in open areas,while gastropods and sesarmid crabs are likely to prefer closed canopy,suggesting that some of these well represented families of macro benthic fauna(e.g.Phascolosoma esculenta,Metaplax elegans,Uca arcuata,Sesarma plicata and L.elanostoma in Jiulongjiang Estuary) could be valuable indicators of ecological change as part of a long term mangrove monitoring.Despite these advances in knowledge of macro benthic fauna communities in mangroves,our understanding is still limited compared to other components of the mangrove ecosystem.Much of the earlier research has focused on the community structure or the biology of individual species,and continued research on inter-specific interactions and the inter-relationship between habitat and the biota is needed.Studies on the relationship between mangrove rehabilitation and macro benthic fauna also are limited and are important for coastal management.福建省自然科学基金项目(2011J05111); 国家自然科学基金项目(41076049;41276077); 海洋公益性行业科研专项项目(201205008

延长氯吡格雷联合拜阿司匹林治疗冠心病合并糖尿病PCI术后的效果及安全性

目的:研究延长氯吡格雷+拜阿司匹林运用于冠心病合并糖尿病经皮冠状动脉介入术(PCI)后的价值。方法:选择厦门大学附属心血管病医院2014年7月-2016年6月纳入的78例冠心病合并糖尿病PCI术患者,按照随机数字表法分为研究组与对照组,各39例。研究组采取延长氯吡格雷+拜阿司匹林治疗,对照组采取常规治疗,对比两组治疗结果。结果:研究组心力衰竭、心绞痛再发、非致死性心肌梗死及心源性死亡的发生率均低于对照组(P0.05)。研究组不良反应发生率为5.13%,与对照组的10.26%对比,差异无统计学意义(P>0.05)。结论:冠心病合并糖尿病患者PCI术后采用延长氯吡格雷+拜阿司匹林治疗效果明显,可有效减少PCI术后心血管不良事件产生,并不会增加出血现象,避免不良反应发生,安全性高,为预后提供保障

利用加设钢支撑改变单跨框架结构体系的抗震加固效果研究

单跨框架结构大量存在于中小学建筑中,中小学建筑已提高到乙类设防,根据抗震鉴定标准GB50023-2009,框架结构不宜为单跨框架;乙类设防时,不应为单跨框架。单跨框架是一种抗震严重不利体系,缺乏冗余约束,易发生整体倒塌。若从构件加固层次提高建筑的抗震性能,不但造价高、施工复杂,而且效果也不明显。加设支撑是一种改变建筑结构体系的方法,本文结合工程实例,讨论了加设钢支撑后原结构性能变化以及加固过程中应该注意的问题。研究表明,利用支撑改变结构受力体系,可以明显改善结构性能,提高抗震能力

Feeding ecology of sesarmid crabs in mangroves

相手蟹科物种是红树林湿地的主要底栖动物类群,在生态系统中起着重要的作用。我国大陆地区目前已记录的相手蟹科物种数量为12种,低于其它红树林地区(国内常用的采样方法会造成螃蟹物种数量和密度的低估),其中褶痕相手蟹(SESArMA PlICATA)、无齿相手蟹(S.dEAAnI)和双齿相手蟹(S.bIdEnS)等是常见种。红树植物叶片是相手蟹科动物的主要食物来源,相手蟹科动物通过地表摄食和洞穴贮存的形为消耗了大量的红树植物凋落叶,使这些凋落叶的有机质和营养元素得以保留在生态系统内,在凋落叶的周转和物质归还方面起到重要的作用。它们同时也摄食红树植物的繁殖体并且对不同物种的繁殖体具有摄食偏好,这可能对一些红树物种的植被更新能力和红树植被群落结构产生影响。相手蟹科动物对不同物种和不同状态的红树叶片也存在摄食偏好,通常对腐烂的叶片摄食偏好较强;螃蟹的摄食偏好与叶片的营养成份、粗纤维和单宁含量以及C/n比等性质有关;但在恶劣的野外环境下,螃蟹则会表现出随机性摄食。目前关于相手蟹科动物生态学作用的认识仍不充分,例如它们的种群大小和对凋落物的转化作用等,有待于进一步研究。Sesarmid crabs,common macro invertebrates in mangrove ecosystems,influence the structure and function of mangrove habitats through their burrowing activities and processing of leaf litter.A total of 12 sesarmid species have been recorded in mainland China,which may be an underestimate since more sesarmid species have been reported in Hong Kong and other tropical mangrove regions.( The reason for this underestimation could be due to the method commonly used to locate the crabs within mainland China.The most common method used is to place plot frame on the soil surface and simply dig to about 20—30 cm,and sift through the soil to locate crabs which could allow sesarmid crabs to escape deeper into the soil during the digging.) The most common sesarmid species in China are Sesarma plicata,S.deaani and S.bidens,while Neosarmatium meinerti is widely recorded in tropical areas of Australia and Kenya.Mangrove plant tissues,mainly leaves,are the main food source of sesarmid crabs,but crabs also feed on sediment detritus and faunal tissue to supplement the nutrient limited mangrove leaves.Some dietary specializations among different mangrove crabs have been recognized.Some crabs feed on only live leaves obtained by climbing into trees,while some species feed only on dead leaves on the mangrove floor.Crabs also have frequently been observed burying fallen mangrove leaves,to enhance leaf nutrition quality,prevent leaf litter from being removed by tidal flushing and avoid competition and predation when food or time available for collectingfood is limited,and predator abundance is high.The feeding preference of sesarmid crabs for mangrove leaves with different conditions or from different mangrove species also has been reported from the laboratory and the field research.For example,sesarmid crabs in China prefer leaves of Kandelia candel over those of Bruguiera gymnorrhiza and Aegiceras corniculatum.Leaf characteristics such as C /N ratio,tannin,water and crude fiber contents determine the feeding preferences.Generally,sesarmid crabs prefer decomposed leaves,ascribed to the decreased tannin content and C /N ratio,and increases in water during leaf decomposition.It also has been suggested that crabs need to consume more decomposed leaves to obtain adequate C and N since they have lower C and N assimilation rates from those leaves.Feeding preferences have been more often demonstrated in laboratory studies while some field studies have revealed a lack of selective feeding of different mangrove species.This is probably due to the environmental stresses in field like predation,limited feeding time,and limited food availability.The ability of sesarmid crabs to remove leaf litter has been studied frequently in the past decades,and crabs have been shown to consume a large proportion of annual leaf fall production,far in excess of the local production in some mangrove forests.The ability of crabs to remove litter seems to be stronger in tropical areas than in subtropical or warm temperate areas.In subtropical areas like China,removal of leaf litter is affected by temperature and showed significant seasonal variation.Not only sesarmid crabs but some snails( e.g.Terebralia palustris) and ocypodoid /grapsid crabs( e.g.Helograpsus haswellianus and Ucides cordatus) also have been reported to consume mangrove leaves.Direct grazing of leaf litter by crabs accounts for a small proportion of leaf litter removed from mangrove floor in China,while the stocking of leaves in crab burrows for later consumption is the key way by which leaf litter is retained in the ecosystem,preventing tidal export.Through shredding and grazing of leaf litter,crabs also initiate and enhance the breakdown of mangrove detritus and recycling of nutrients.Sesarmid crabs also have been found to graze mangrove propagules and seeds,thus play a critical role in determining seedling recruitment and vegetation regeneration.It also has been suggested that the predation preference on some non-dominant mangrove species regulates their distribution with the vegetation community.The feeding ecology of sesarmid crabs and its involvement of in mangrove restoration,their retention of C and nutrients in mangrove soils and predation of seeds /propagulse are worthy further studies.国家自然科学基金项目(41206108;41076049); 福建省自然科学基金项目(2011J05111); 海洋公益性行业科研专项项目(201205008

靶向HIV-1细胞受体基因CCR5的人工miRNA的构建与鉴定

趋化因子CCR5是HIV-1入侵机体细胞的主要辅助受体之一,通过抑制CCR5的表达可以在一定程度上阻断HIV-1的复制进程.miRNA介导的RNA干扰相比经典的siRNA在应用中具有更多的特点.本研究的目的是构建可特异有效靶向CCR5的人工miRNA元件.本研究以CCR5基因序列为模板设计了14个miRNA靶序列,以天然miR-30a为基础骨架通过靶序列区替换构建人工miRNA元件.通过将miRNA表达质粒与携带靶序列区的报告质粒的共转染抑制实验检测不同miRNA的抑制效率,结果显示miCCR-13A具有较好的抑制效率和特异性.进一步将miCCR-13A表达载体转染CCR5阳性的HIV-1受体细胞株TZM-b1,RT-PCR检测显示miCCR-13A可在细胞中获得有效表达,同时应用免疫流式细胞术检测显示在miCCR-13A转染细胞相比对照细胞的CCR5蛋白的检测活性明显降低.进一步的研究显示miCCR-13A在细胞中不会影响细胞活性和干扰素效应相关基因osa1和stat1 mRNA水平,具有良好的特异性.本研究获得的可特异靶向CCR5的人工miRNA元件可为进一步的抗HIV-1研究提供重要基础

杆状病毒对不同哺乳动物细胞基因转移及表达效率的研究

研究已证实杆状病毒可进入某些哺乳动物细胞 ,这提示了可将重组杆状病毒作为一种对哺乳动物细胞的新型基因转移载体。利用已构建的重组杆状病毒BacV CMV EGFPA ,以含病毒的Sf9细胞培养上清同时孵育多种哺乳动物细胞 ,利用流式细胞术检测报告基因在不同细胞株中的转移效率及表达效率。共使用了 2 0种哺乳动物细胞株 ,其中有 12种人类组织细胞 ,7种小鼠组织细胞 ,1种猴组织细胞。实验结果显示携带CMV启动子的重组杆状病毒可有效进入多数哺乳动物细胞 ,其中对人、猴来源细胞的基因转移效率显著高于对鼠源细胞 ,对贴壁细胞的基因转移效率显著高于对悬浮细胞。同时 ,通过脂质体LipofectAMINE将携带有CMV启动子和EGFP基因的哺乳动物细胞表达质粒pCDNA3 1 EGFP分别转染部分特别是被认为杆状病毒进入能力较低的细胞株 ,结果显示CMV启动子在这些细胞中均可有效引导EGFP基因的表达 ,因此认为携带了CMV启动子的重组杆状病毒对不同哺乳动物细胞基因转移效率能基本反映出杆状病毒对不同种哺乳动物细胞的进入能力。通过综合比较携带CMV启动子的杆状病毒对不同种属及组织来源细胞的基因转移及表达效率 ,可看出杆状病毒对灵长类动物贴壁细胞的基因转移及表达效果是较好的 ,而对小鼠来源的细胞及悬浮培养细胞却并不十分

ERK干扰质粒的构建及对胃癌细胞株BGC823 DcR3表达的影响

目的探讨胃癌发展的分子机制,通过构建ERK1/2shRNA真核表达载体,体外研究其对人胃癌细胞株BGC823ERK1/2蛋白及DcR3表达水平的影响。方法应用PRNAT-U6.1/Neo载体构建ERK1/2基因shRNA重组质粒,经脂质体法导入BGC823细胞中,分别设置对照组、干扰组和U0126抑制剂组。Westernblot法检测转染后BGC823细胞及抑制剂使用后ERK1/2蛋白的表达变化,荧光显微镜检测质粒自带GFP基因的表达情况确认转染效率,ELISA法检测各组细胞上清中DcR3分泌蛋白的表达特点。结果成功构建ERK1/2基因shRNA重组质粒。证明了ERK1/2蛋白的表达与DcR3的分泌水平在BGC823细胞株中呈正相关。结论 ERK1/2干扰质粒明显降低BGC823细胞的ERK1/2蛋白表达水平,ERK信号通路对DcR3的分泌具有重要调控作用,为其下游调控机制的研究奠定了基础