An Empirical Research on the Marginal Value of Cash Holdings for the Listed Firms in China

近十年来，国内外财务学界开始更加关注并深入研究企业现金持有（CorporateCashHoldings）的问题。很多财务学者在这方面进行研究时，较为一致地将企业持有的现金定义为现金及其等价物总额，具体来说等于企业的货币资金、银行存款和短期投资之和。 目前，国内外的学者多从验证企业现金持有量的影响因素出发进行研究，但是，从股东角度对上市公司持有现金行为经济后果的研究成果则较少。对于股东来说，上市公司增持1元额外现金，市场价值增加多少（即现金的边际价值MarginalValueofCash问题），哪些因素会影响现金的边际价值，这部分内容属于企业现金持有经济后果的一部份。本文从代理问题、信息不对称...For the past decade, domestic and foreign financial scholars have paid more attention to the enterprise cash holdings behavior; a great number of academic achievements on the listed companies’ behavior of cash holdings have emerged. For the research of the revenues and costs of holding cash, more scholars at home and abroad study on the determinants of corporate cash holding, but studies on econom...学位：管理学硕士院系专业：管理学院企业管理系_企业管理(含财务管理、市场营销、人力资源管理)学号：1762006115134

The Experimental Study on Flow Boiling Heat Transfer of Working Fluid R245fa in Horizontal Tube

设计了管内沸腾换热系数及总传热系数测定试验台架,对R245fa工质在内径6 mm水平光管内的流动沸腾换热特性进行试验研究。测试质流密度为50 ~; 150 kg /(m~2·s),工质蒸发温度为50, 60和70℃。结果表明:; 随着工质含汽率的增加,R245fa的流动沸腾换热系数呈先增大后降低趋势。对于304不锈钢套管式换热器,烟气与R245fa工质进行换热的总传热系数; 约在40 ~ 65 W/(m~2·K) 。A bench - scale facility was designed for testing the flow boiling heat; transfer coefficient and the total heat transfer coefficient. The; boiling heat transfer characteristics of the R245fa refrigerant were; studied in a horizontal smooth tube with 6 mm inner diameter. The; parameters investigated were mass flow rate (50 ~ 150 kg /(m~2·s)),; evaporation temperature (50, 60 and 70 ℃). The results showed that the; flow boiling heat transfer coefficient of R245fa increased with the; increase of rate of vapor content, and decreased slightly with the; further increase of rate of vapor content. The total heat transfer; coefficient of the flue gas and the R245fa is about 40 ~ 65 for the 304; stainless steel heat exchanger.国家国际科技合作专项资助项

应用型本科高校人才培养的特色化研究——以厦门理工学院“亲产业”大学办学实践为例

应用型本科高校人才培养要基于应用型本科高校发展的合理定位,并在人才培养的全过程中力行特色化培养理念,还要有与之相呼应的质量管理机制予以保障应用型本科高校人才培养的特色化发展。厦门理工学院坚持“以生为本,服务产业,培养海西一流亲产业应用型人才“的办学思路,着力优化专业结构布局,使“专业链“紧密亲和“产业链“;实施“教学卓越工程“并采取一系列质量保障措施,培养亲产业应用型人才。这一办学实践是对应用型本科高校人才培养的特色化发展的探索。福建省社科项目“应用型本科人才培养质量研究”(项目编号:2011B241)的研究成果之

高首效富镍正极材料LiNi0.6Co0.2Mn0.2O2的合成及电化学性能研究

采用共沉淀—高温固相烧结的方法合成了富镍正极材料LiNi0.6Co0.2Mn0.2O2（简称NCM622）,通过X射线粉末衍射（XRD）/Rietveld精修法、扫描电子显微镜（SEM）及电化学测试,对不同温度下合成材料的结构、形貌、电化学性能进行表征.结果表明,800℃下NCM622阳离子混排程度最低（1.97%）,首周库仑效率高达92.2%,100周容量保持率为81.4%.国家自然科学基金项目(No.21233004,No.21428303)资

Comparative study of the macrobenthic community in intertidal mangrove and non-mangrove habitats in Tong'an Bay,Fujian Province

底栖动物群落是红树林生态系统多样性研究的重要内容之一。为了解大型底栖动物群落对高有机质含量和富营养的红树林生境的响应,从2006年4月到2007年1月,对福建省同安湾红树林生境和非红树林生境大型底栖动物群落及其时空变化进行了研究。我们在同安湾红树林种植区设置了凤林(fl)和山后亭(XA)两条断面,每条断面在红树林内各设2个取样站(fl1,fl2,XA-A和XA-b),林外各设1个取样站(fl3和XA-C)。底质研究结果显示凤林3个取样站(fl1,fl2和fl3)的有机质含量均超过底质污染评价标准的临界值3.4%,且无论凤林还是山后亭,红树林生境的有机质含量均要高过非红树林生境。共获得大型底栖动物91种,其中在红树林生境内获得77种,高于非红树林生境内获得的67种。红树林生境和非红树林生境的大型底栖动物平均栖息密度分别为4,445.8IndS/M2和1,707.2IndS/M2,平均生物量分别为51.1g/M2和94.6g/M2。独立样本T-检验结果显示,红树林生境和非红树林生境大型底栖动物平均栖息密度和平均生物量均存在显著差异。研究结果指示红树林生境对于寡毛类生存(如在高耐有机污染中能大量繁殖的沼蚓)有积极作用。但由于邻近的非红树林林生境的水淹时间更长,一些具有移动能力的软体动物和甲壳动物能迁移到更适合生存的非红树林生境中去。其他底质因子如盐度和土壤中值粒径等也会影响大型底栖动物群落变化。Research on the biodiversity of mangrove ecosystems should include not only the plants but other components,such as the macrobenthos.In order to understand the response of the macrobenthos to a mangrove habitat with high organics and nutrients,we compared the mangrove and non-mangrove macrobenthic communities,and analyzed their spatial-temporal distributions in these two habitats from April 2006 to January 2007 in Tong'an Bay,Fujian.Six sampling stations were set in Tong'an Bay,four of them(FL1,FL2,XA-A and XA-B) were in the mangrove habitat,the other two(FL3 and XA-C) were in the non-mangrove habitat.An analysis of sediment properties showed that total organic matter(TOM) of the three sampling stations at Fenglin exceeded the critical threshold,namely 3.4%,and TOM in mangrove stations was higher than in the non-mangrove ones.A total of 91 macrobenthic taxa were obtained from the six sampling stations in Tong'an Bay,including 77 and 67 taxa from the mangrove and non-mangrove habitats,respectively.Mean macrobenthic densities in the mangrove and non-mangrove habitats were 4,445.8 inds/m2 and 1,707.2 inds/m2,respectively.Mean biomasses in the mangrove and non-mangrove habitats were 51.1 g/m2 and 94.6 g/m2,respectively.The results of an independent-samples t-test showed that mean density and mean biomass were significantly different in the two habitats.The present study revealed that the mangrove habitat has a positive influence on the Oligochaeta,such as Limnodriloides sp.,that thrives in the high TOM sediments.Because of the shorter inundation period in the mangrove habitat,however,free-living molluscs and crustaceans preferred the non-mangrove habitat.Other sediment properties such as interstitial salinity and median particle diameter also affected the macrobenthic community

前列腺移行带腺体定量分析

目的通过定量分析良性前列腺增生(BPH)患者前列腺和成人正常前列腺移行带腺体各成分含量及相关组织学形态的变化,探讨良性前列腺增生症治疗方案的选择。方法用计算机图像分析系统对经HE染色的40例良性前列腺增生症患者手术切除的前列腺和10例成人正常前列腺移行带组织标本进行形态学定量分析,分别测定腺体、腺腔、上皮的平均面积及上皮细胞高度。结果(1)正常前列腺和BPH前列腺移行带上皮细胞高度分别为(24.87±4.53)μm和(19.06±5.49)μm(P0.05)。结论BPH前列腺组织主要以基质成分增生为主;BPH的治疗应以α受体阻滞剂和手术治疗为主

Reactor model with cross-flow for aromatics catalytic hydrogenation

[中文文摘]提出了一种抗硫中毒的芳烃加氢催化反应器模型,称之为交叉流反应器模型,把反应物料分为两股,其中含有噻吩的乙苯物料采用轴向连续流动方式由反应器进口进入催化剂床层,而氢气由铅直导管直接进入催化剂床层中,然后与乙苯物料混合。在氢气导管出口处形成含硫乙苯浓度低而氢气浓度高的特殊区域,因而硫对催化剂的中毒效应大幅度降低,整体上提高了乙苯加氢饱和反应效率。与传统轴向混合流反应器进行比较,在相同条件下交叉流反应器具有更好的整体加氢反应性能。分别建立了交叉流反应器与传统轴向混合流反应器模型,提出了两种反应器的催化反应转化率方程;利用此转化率方程,对实验数据进行处理,得到动力学参数,模型的计算结果与实验数据相吻合,也验证了在交叉流反应器中,硫的中毒效应明显减弱。[英文摘要]A novel reactor model named cross-flow reactor for aromatics catalytic hydrogenation was proposed.The reactants were divided into two flows:ethylbenzene with thiophene was introduced to the catalyst bed along the axial direction of the columnar reactor,while hydrogen was introduced into catalyst bed through a vertical pipe with openings.Because special areas with high H2 pressure and low H2S pressure were formed near these openings,the poisoning of catalyst by thiophene was substantially decreased,and consequently the reaction of et hylbenzene hydrogenation was improved as compared with the traditional reactor with mixed co-flow. Finally , kinetic models were established for this cross-flow reactor and the traditional reactor1And the conversion equations of these two reactors were given.By using these equations , the experiments data were fitted to obtain kinetics parameters. The calculation results agreed well with the experimental data. It was also demonst rated that sulfur poisoning in cross-flow reactor was weakened.国家重点基础研究发展计划项目(2004CB217805); 福建省“百千万人才工程”支持项目; 福建省自然科学基金项目(U0750016)

类泛素蛋白及其中文命名

泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家

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