三角格上的σ全一问题

主要研究三角格上的σ全一问题.应用图论知识,利用数学归纳法,分别给出了以三角形,菱形(四边形)和正六边形为边界的三角格上的σ全一问题无解的充要条件,并在证明中给出有解情况下详细解的刻画

五苓散抗高血压机理探析

五苓散出自张仲景的《伤寒论》,药物组成有泽泻、茯苓、猪苓、白术、桂枝,具有利水渗湿、温通经脉、温阳化气、宁心安神之功,原方主治口渴烦躁、小便不利、水肿等病症。现代临床以五苓散为主方治疗原发性高血压、肾性高血压、代谢性高血压等已取得较好

连续输出1.60W/473nm直腔蓝光激光器

报道了LD端面泵浦Nd∶YAG晶体,LBO腔内倍频473 nm全固态直腔蓝光激光器.根据谐振腔稳定性理论,利用简单的平-平腔直接测得不同泵浦功率下的热焦距值.通过数值计算分析了不同热焦距下,Nd∶YAG与LBO晶体中的腰斑半径以及LBO中光腰的位置,并在准三能级系统模型和倍频理论的指导下优化激光腔体结构,使激光器实现最佳的模式匹配和倍频效率,得到高效的蓝光激光输出.激光阈值为1.92 W;当泵浦激光功率为20.58 W时,473 nm蓝光的输出功率为1.60 W,光-光转化效率为7.8%

Application of a Resuspension Test Chamber in PM_(2.5) Source Profile Analysis

为解决PM2.5源解析中无组织排放源的采样问题,在前人基础上发展了一套简便高效的再悬浮采集装置,并对进样量、再悬浮时间等关键运行参数进行了优化,总结了无组织排放源采样分析流程.重复测试表明,双切割头的PM2.5捕集量偏差<8%,粒径分布比率变化不超过5%,显示出再悬浮装置良好的采样平行性和稳定性.将该装置应用于陶瓷工业尘、公路扬尘和二次降尘等3类无组织排放尘及生物质燃烧的源排放再悬浮采样分析,获得了各颗粒源的粒径分布谱和PM2.5无机成分谱,以此对各排放源特征进行有效区分.PM2.5平行样中各化学成分浓度偏差<15%.与其他装置相比,本研究介绍的再悬浮装置简便经济,具有较高的采样效率,在无组织尘排放源谱分析中具有较高的实用价值.A resuspension chamber was developed and optimized to obtain PM2.5 fraction from fugitive sources.In accordance,a basic protocol of sampling and analysis was concluded.Replicate tests showed that mass deviation of PM2.5 between two sampling cascade impactors was less than 8% and size distribution ratios varied by no more than 5%,indicating good sampling parallelism and stability.Chemical profiles and size distribution of three kinds of fugitive dusts(paved road dust,secondary dust and ceramic industrial dust) as well as biomass burning emission had been measured based on the above chamber.The relative standard deviations(RSD%) of inorganic elements in duplicate PM2.5 samples were less than 15%.Comparing with other devices,the resuspension chamber described in this study features convenience and efficiency,and has a high practical value in the source sampling of fugitive dust.环保公益性行业科研专项(201009004);国家自然科学基金项目(40971257

基于石墨烯可饱和吸收体的脉冲光纤激光器研究进展

单层石墨烯是一种具有独特电学及光学特性的二维碳材料,尤其是在光学应用方面,它对可见光到近红外波段范围内光波仅有2.3%的线性吸收.由于石墨烯的独特性质,使得它可以作为一种具有超快响应时间以及超宽带工作特性的可饱和吸收体.本综述将展开石墨烯的线性及非线性光学特性分析,并重点阐述基于石墨烯可饱和吸收体的调Q及锁模光纤激光器研究进展,并指出厦门大学光电子技术研究所近几年来在这一方面所取得的成果.国家自然科学基金(61275050);高等学校博士学科点专项科研基金(20120121110034

Characteristics and Sources of PM_(10)-bound PAHs During Haze Period in Winter-Spring of Xiamen

采集了厦门市冬春季(2008-12-04~2009-03-20)湖里工业区和大嶝岛旅游区大气PM10样品,用gC-MS定量了PM10负载的19种多环芳烃(PAHS),并结合采样期间气象资料对灰霾期和非灰霾期多环芳烃的差异特征进行对比分析.结果表明,冬春季采样期内,厦门市大气PM10中PAHS的浓度变化范围为12.93~79.27 ng.M-3,平均42.28 ng.M-3,比2004年冬季增长近3倍.灰霾期间PM10中PAHS总的质量浓度明显高于非灰霾期,并且灰霾期间低分子量组分菲、荧蒽和芘的质量分数显著下降,高分子量组分苯并[b]荧蒽、苯并[k]荧、苯并[A]芘、苝、茚并[1,2,3-Cd]芘、苯并[gHI]苝和晕苯的质量分数相对升高.采用特征化合物比值、主成分分析与多元线性回归对来源与贡献率进行了分析和估算.灰霾期间识别出3类污染源:机动车尾气排放+天然气燃烧、煤燃烧和焦炉排放,其贡献率分别为62.7%、28.1%和9.2%;非灰霾期间同样识别出这3类污染源,其贡献率分别为48.6%、36.9%和14.5%.表明厦门市冬春季灰霾期间PM10中PAHS受本地源排放影响相对较多,非灰霾期间受北方燃煤长距离传输影响更显著.PM10 samples were collected at Huli(industrial zone) and Dadeng Island in Xiamen from December 2008 to March 2009.Nineteen polycyclic aromatic hydrocarbons(PAHs) during haze and non-haze periods were determined by GC/MS.Combined with the meteorological data,the differences of chemical composition and source of PAHs were compared.During sampling periods,the concentrations of PM10-bound PAHs ranged from 12.93 to 79.27 ng·m-3 with the average of 42.28 ng·m-3,which were almost three times higher than those in the winter of 2004.PAHs concentrations were much higher during the haze periods than those in the non-haze periods.Meanwhile,during the haze periods the percentages of lower molecular weight PAHs such as Phe,Fluo and Pyr decreased significantly,on the contrary,individual components of BbF,BkF,BaP,Per,Icdp,BghiP and COR were more abundant.The main sources of PAHs were estimated by the Principal Component Analysis method and the contributions of various pollution sources to PAHs were calculated by the Multiple Linear Regression method.Results showed that the main pollutant sources of PM10-bound PAHs in winter-spring of Xiamen during the haze period were vehicle emission plus natural gas,coal combustion and coke oven,their contribution rates were 62.7%,28.1% and 9.2%,respectively.During non-haze periods,the main pollutant sources identified were the same and the contribution rates were 48.6%,36.9% and 14.5%,respectively.In winter-spring of Xiamen,PM10-bound PAHs were more influenced by local emission sources during the haze periods;coal combustion emissions in north China had a big contribution to PAHs during the non-haze periods.环保公益项目(201009004);厦门市科技计划项目(3502Z20093013

端面泵浦Nd∶YAG连续输出1052nm波长激光器

设计了一个简单紧凑的1052nm波长激光器。首次利用激光二极管(LD)端面泵浦Nd∶YAG晶体,使用镀有高度选择性介质膜的反射镜产生该波段的激光。激光阈值为0.3W,当808nm波长泵浦光功率达到18W时产生了3.5W的1052nm波长激光输出。光-光转换效率为20%,输出激光功率波动不超过3%

The Empirical Research on Public Hospital Financial Management based on? Du Pont Analysis

目的:分析公立医院的财务管理现状,为进一步提高我市公立医院财务精细化管理水平、实现医院财务目标提供基础。方法:基于传统杜邦分析法建立公立医院杜邦分析体系及财务指标关系,选取厦门市A、B、C 3家有代表性的公立医院,应用杜邦分析法对其财务管理能力进行实证分析。结果 A、B、C 3家公立医院的年均净资产收益率分别为6.87%、4.04%、4.36%,超过年均银行1年期存款利率。其中A医院的净资产收益率较B、C医院高,C医院受权益乘数的驱动作用,净资产收益率较B医院平均高出0.32%,但3家医院的净资产收益率整体均下降。进一步分析业务收益率发现,业务收支结余增长幅度低于业务收入增长幅度,其中专用材料支出的大幅度增长导致业务收支结余增加缓慢。结论:公立医院的财务管理能力整体较好,在保持一定资产盈利水平的同时,能调整资金结构和控制财务风险。但还需要适当利用外部资金投入,加强医院成本控制,尤其是专业材料的支出,进一步提升运营水平和业务获利能力。Objective To analyze the status of financial management in public hospital,provide the basis for further improving refined management level and finally realize the goal of public hospital financial management. Methods Du Pont analysis system of public hospital and relationship between financial indicators were established based on traditional Du Pont analysis method. Three public hospitals were purposively chosen,and then an empirical study on financial management ability was conducted by applying Du Pont analysis. Results The annual net assets income rates were 6. 87%,4. 04%,4. 36%,respectively. All of them were larger than one-year deposit rate. Moreover,Hospital A was higher than hospital B and hospital C. Hospital C was 0. 32% higher than that of B hospital under the driving effects of rights multiple. However,all three hospitals' net assets income rate showed a descending tendency. Further analyzing return ratio of business it could be obtained that the increase of business revenue and expenditure surplus was less than that of business revenue. A major reason was that special? material expenditure increased rapidly. Conclusion Three hospitals' financial management ability was generally well,they could adjust the capital structure and control the financial risk while maintaining assets profitability. In spite of that,they still needed to use external funding appropriately,strengthen cost control special material expenditure and further improve capital operating level as well as business profitability.上海交通大学中国医院发展研究院招标课题“建立符合国情的现代医院管理制度系列研究”——公立医院财务制度研究(编号:SJYF2014XD007A);; 中国卫生经济学会中标课题“公立医院改革对公立医院经济运行及现行医院财务会计制度的影响研究”(编号:卫学字(2015)12号

Vegetation carbon stocks and net primary productivity of the mangrove forests in Shenzhen,China

红树林是滨海湿地"蓝碳"的主要类型之一.准确和定位评估不同植物群落的固碳能力,对于红树林保育管理和恢复造林具有指导作用.本研究对深圳福田红树林4种代表性群落(白骨壤群落、秋茄群落、海桑群落、无瓣海桑群落)的各个植被碳库组分(乔木植物生物量碳库、林下灌丛碳库、呼吸根碳库、枯立木碳库、枯倒木碳库和枯枝落叶层碳库等)进行调查,计算各群落的植被碳储量,并通过生长增量-凋落物产量法计算得到各群落的净初级生产力.结果表明:白骨壤群落、秋茄群落、海桑群落和无瓣海桑群落的植被碳储量分别为28.7、127.6、100.1、73.6 t C·hm~(-2),各群落的净初级生产力分别为8.75、7.67、9.60、11.87 t C·hm~(-2)·a~(-1).位于深圳市中心的福田红树林,每年固定大气CO2高达4000 t.本研究结果将为红树林"蓝碳"碳汇功能的评估提供理论指导,并为我国红树林碳汇林建设提供依据.Mangroves are the most important coastal blue carbon sinks. The accurate estimation on the carbon sequestration capacity of plant communities would guide the mangrove conservation,afforestation and management. This study investigated the vegetation carbon stocks of dominant mangrove communities,which were Avicennia marina,Kandelia obovata,Sonneratia caseolaris,and Sonneratia apetala in Futian Nature Mangrove Reserve in Shenzhen,Guangdong Province of China.Vegetation carbon stock consisted of living trees( aboveground and belowground biomass),understory,pneumatophore,standing dead trees,fallen dead trees and litter in these communities. The net primary productivity( NPP) was calculated from the litterfall and incremental growth in the same year of each community. Our results showed that the vegetation carbon stocks for A. marina,K. obovata,S. caseolaris,and S. apetala communities were 28. 7,127. 6,100. 1,and 73. 6t C·hm~(-2),and the NPP were 8.75,7.67,9.60,and 11.8 t C·hm~(-2)·a~(-1),respectively. Therefore,acting as urban forests,Futian mangroves in Shenzhen assimilated about 4000 t CO2·a-1.These results provided guidance for mangrove blue carbon assessment,and theoretical basis for the construction of coastal carbon sequestration forests in China.国家自然科学基金项目(31270581);; 福建省自然科学基金项目(2013J01145);; 深圳城市管理局科研项目(201406)资助~