氢气在碳纳米管基材料上的吸附-脱附特性

利用高压容积法测定多壁碳纳米管(MWCNTs)及钾盐修饰的相应体系(K+-MWCNTs)的储氢容量,并用程序升温脱附(TPD)方法表征研究氢气在MWCNTs基材料上的吸附-脱附特性.结果表明,在经纯化MWC-NTs上,室温、9.0MPa实验条件下氢的储量可达1.51%(质量分数);K+盐对MWCNTs的修饰对增加其储氢容量并无促进效应,但相应化学吸附氢物种的脱附温度有所升高;K+的修饰也改变了MWCNTs表面原有的疏水性质.在低于723K的温度下,H2/MWCNTs体系的脱附产物几乎全为氢气;773K以上高温脱附产物不仅含H2,也含有CH4、C2H4、C2H2等C1/C2烃混合物;H2/K+-MWCNTs储氢试样的脱附产物除占主体量的H2及少量C1/C2烃混合物外,还含水汽,其量与吸附质H2源水汽含量密切相关.H2在碳纳米管基材料上吸附兼具非解离(即分子态)和解离(即原子态)两种形式

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

东方肉穗草异鼠李素诱导HepG2细胞凋亡研究

目的研究东方肉穗草中的主要抗癌活性成分之一异鼠李素诱导HepG2细胞凋亡的机理。方法采用MTT法检测异鼠李素对肝癌HepG2细胞的抑制作用,DAPI染色法对细胞凋亡进行形态学检测。结果实验结果显示异鼠李素对肝癌HepG2细胞的增殖有明显抑制作用,呈浓度依赖性效应。异鼠李素处理48h的IC50为60μmol/L。荧光显微形态学检测显示异鼠李素处理HepG2细胞后出现细胞凋亡的特征性变化。结论研究表明东方肉穗草异鼠李素可以诱导肝癌HepG2细胞凋亡

甲烷在流态化催化剂床裂解生长多壁碳纳米管

在常压、823～873K、流化床反应条件下,用自行研制的Ni0.5Mg0.5O催化剂,催化甲烷分解生长碳纳 米管(CNTs),考察催化剂床层由固定床过渡到流化床状态的条件及其对制管过程的影响。结果表明,在 Φ32mm管式反应器及相应供热工况条件下,其流化床操作条件以管壁温度控制在约853K、原料气CH4线速 v为18～22cm/s、空速GHSV为3×104～6×104mL(STP) CH4/(h·g)为宜;反应1.0h,最高产率达 10g CNTs/g,这相当于固定床将制管反应时间延长至4～5h的产率水平。所得CNTs产物经TEM、SEM、 TPH、XRD和LRS等测试技术表征。结果表明,其为多壁碳纳米管(MWCNTs),外管径在10～50nm范围;纯 化后的CNTs产物含碳量≥99.5%,石墨状碳含量≥90%

H_2在K~0-MWCNTs上储存和吸附/脱附特性研究

利用高压容积法辅以卸压升温脱附排水法,测定金属K修饰多壁碳纳米管对H2的吸附储存容量.结果表明,在室温(25℃),7.25MPa实验条件下,x%K0-MWCNTs(x%=30%～35%,质量百分数)对H2的吸附储存容量可达3.80wt%(质量百分数),是相同条件下单纯MWCNTs氢吸附储量的2.5倍;室温下卸至常压的脱附氢量为3.36wt%(占总吸附氢量的～88%),后续升温至673K的脱附氢量为0.41wt%(占总吸附氢量的～11%).利用LRS和H2-TPD-GC/MS等谱学方法对H2/K0-MWCNTs吸附体系的表征研究表明,H2在K0-MWCNTs上吸附存在非解离(即分子态)和解离(即原子态)两种吸附态;在≤723K温度下,H2/K0-MWCNTs体系的脱附产物几乎全为H2气;723K以上高温脱附产物不仅含H2,也含有CH4,C2H4和C2H2等C1/C2-烃

Study of storage and adsorption/desorption characteristics of H-2 on MWCNTs modified by metal potassium

Storage capacity of H-2 in a kind of potassium-modified multiwalled carbon nanotubes, K-0-MWCNTs, was measured by using high-pressure volumetric method combined with desorption water-displacement method. It was experimentally shown that appropriate incorporation of a certain amount of metallic potassium into the MWCNTs could significantly increase the storage capacity of hydrogen. Under conditions of 7.25 MPa and ambient temperature, H-2 uptake of 3.8 wt% could be achieved by the x%K-0-MWCNTs (x%=30%-35%, mass percentage), which was 2.5 times as high as that by the KO-free MWCNTs under the same conditions. It was also indicated that adsorption of 99% of the H2 was reversible, and that 88% of the stored hydrogen (equalling storage capacities of 3.36 wt%) could be desorbed while the pressure was relieved to atmospheric pressure and similar to 11% of the stored hydrogen (equalling storage capacities of 0.41 wt%) was desorbed in the following process of elevating temperature from room temperature to 673 K. The Raman-spectroscopic and TPD-MS/GC investigations of the H-2/K-0-MWCNTs adsorption systems showed that adsorption of H-2 on the MWCNTs could occur in associative and dissociative forms, with the observed v(s)(C-H) for CH2, v(C-H) for CH and v(H-H) for H-2 (a) at 2856, 3228 and 3946 cm(-1), respectively, and that H-2 Was the predominant products desorbed at temperatures lower than 723 K, whereas in addition to H-2, light hydrocarbons such as CH4, C2H4, C2H2, etc. were also involved in the products desorbed at temperatures higher than 723 K