Preliminary Study on Thermochemical Curing of Polycarbosilane Fibers

［中文文摘］以异丙醇锆(ZIP)为交联剂、聚碳硅烷(PCS)为先驱体,在Ar气氛的保护下通过干法纺丝、热化学交联工艺使PCS从热塑性转变热固性结构。研究了该工艺对PCS纤维质量变化、Si-H反应程度、溶解性及氧含量等性能的影响。实验结果表明:在不熔化过程中,PCS结构中的Si-H键与ZIP反应,在PCS分子间形成Si-O-Zr交联结构,随着交联温度和保温时间的升高,Si-H反应程度和纤维失重率相应提高;在测试范围内最大Si-H反应程度为73.06%,失重率2.678%,氧含量低于2.0%。［英文文摘］Polycarbosilane from dry spinning to SiC fiber through thermochemical curing,which is catalysed by zirconium iso-propoxide(ZIP) under Ar gas stream,is transformed from thermoplastic to thermoset structure.The effects of curing temperature and holding time on cured PCS fibers are mainly studied in this paper.The experimental result shows that Si-H bonds in polycarbosilane are crosslinked by ZIP during the curing process which is made up of Si-O-Zr structure in PCS molecule.And the reaction degree of Si-H bonds and mass loss of fibers are increased accordingly with thetemperature and holding time rising.The maxium reaction degree of Si -H bonds is 73.06%, mass loss 2.678%,and oxygen content no more than 2.0%, respectively.总装备部预研基金资助(51412020404QT870

基于ERP系统的预算管理研究

由厦门大学会计发展研究中心提供的第五届会计与财务问题国际研讨会——当代管理会计新发展论文集中的第二部分：战略管理会计与平衡记分卡6尽管预算管理在国内外管理实践中受到日益关注，但传统预算管理并未能满足管理者的期望，随着经营环境的变化不断暴露其固有的缺陷。笔者对预算管理应用现状进行了分析，认为预算管理未与ERP系统融合是导致这一现象的重要原因之一，提出将预算管理与ERP系统集成应用，利用ERP系统数据快速处理、信息快速传输、信息共享、企业信息全面集成等特点，以解决预算管理实践环节由于技术原因而引发的效率底、成本高、效果差等问题。本文聚焦于三个关键问题：从技术上，将信息技术与预算管理结合，实现预算实时信息传递与反馈、动态调整与控制；从预算体系的构建上，与信息技术的要求相适应，设计多维预算体系；从预算管理流程上，实现模型化的多循环编制流程

环境与会计教育改革

由厦门大学会计发展研究中心提供的第四届会计与财务问题国际研讨会——会计教育改革与发展论文集中的第一部分：会计教育一般07会计教育的目标服务于会计实践的需求，而会计实务随经济环境的发展变化不断更新和演化，又对会计教育提出了更高的要求。因而会计教育要不断改革以适应经济发展的需求，尤其是在国际化和知识经济环境下，传统的会计教育模式已远远满足不了经济发展的需求。因此，如何改革会计教育体制，培养出适应于国际化和知识经济发展需求的现代会计人才，已成为各国会计界所不断探讨和实践的一个新课题。本文拟从国际化和知识经济环境下会计人员应具备的素质出发，结合我国目前会计教育的现状，提出改革我国会计教育的一些建设性的设想

Research Development of Curing Treatment of Polycarbosilane to Prepare Continuous SiC Fibre

［中文文摘］综述了先驱体转化法制备SiC纤维过程中聚碳硅烷(PCS)的各种不熔化处理方式及其发展状况。通过不熔化方式对终烧产物SiC纤维性能的比较,讨论了各种不熔化方式的优缺点及其对SiC纤维中氧含量的影响,并指出了制备高性能SiC纤维不熔化技术研究的国内外差距及发展趋势。［英文文摘］Different curing treatment methods of polycarbosilane fibres in the process of fabricating SiC ceramic fibres by preceramic polymer pyrolysis usually containing polymer synthesis, spinning, curing and pyrolysis, are reviewed in this paper. Current development situation of these manners is thoroughly presented. By comparing the element composition and mechanical properties of SiC fibre from different cross-linking manners, some advantages and drawbacks of these methods, and their effects on the oxygen content in SiCfibre are also discussed. Moreover , the developmental trend of cross　linking technique to fabricate excellent heat2resistant SiC fibres is proposed

Research Development of Nearly Stoichiometric SiC Fibers Derived from Polycarbosilane

[中文文摘]综述了聚碳硅烷制备近化学计量比SiC纤维的研究进展,总结了H2在PCS纤维裂解过程中的作用机理,比较了纯H2气氛、分阶段不同气氛、全过程H2/Ar混合气氛条件下得到的SiC纤维的组成和性能变化规律。纯H2气氛800℃以上保温4h,可得到近化学计量比SiC纤维;分阶段气氛下,气氛转换温度为800℃,烧结至1300℃保温1h,可得到近化学计量比SiC纤维;混合气氛下,氢气浓度为60%左右,烧结至1300℃保温1h,可得到近化学计量比SiC纤维。在这些气氛条件下得到的近化学计量比SiC纤维,烧结后的高温力学性能均优于非化学计量比SiC纤维。［英文文摘］Nearly stoichiometric SiC fibers prepared from polycarbosilane in three kinds of atmosphere are studied,namely first in H_2 atmosphere,then in Ar atmosphere and H_2/Ar mixed atmosphere. In pure H_2,when temperature T≥800℃ and holding time t≥4h,the stoichiometric SiC fibers could be got.In the second case,when PCS is pyrolided in H_2 from 25℃ to 800℃, in Ar 800～1300℃ and holded for 1h at 1300℃, stoichiometric SiC fibers could be got.In H_2/Ar, when H_2 concentration is 60% and holded for 1h at 1300℃,stoichiometric SiCfibers could be 2 got. In H / Ar , when H concentration is 60 % and holded for 1h at 1300℃,stoichiometric SiC fibers can be got. The　stoichiometric SiC fibers show great mechanical property in high temperature

Catalytic Properties of Ultrafine SiO_2 Supported Amphiphilic Phosphine-Rh Complex Catalysts

作者简介: 彭庆蓉( 1973- ) , 女, 四川达州市, 讲师, 博士。 通讯联系人：袁友珠[中文文摘]针对均相催化反应后催化剂与产物分离困难和高碳烯烃在水-有机两相中反应速率较低的问题,采用水-有机两亲膦铑络合物负载到超细SiO2载体上催化1-己烯氢甲酰化反应,并与超细SiO2制备负载水相催化剂比较,超细SiO2负载型两亲铑膦络合物催化剂表现出较高的1-己烯氢甲酰化反应活性和选择性,且含水质量分数范围较宽,反应后产物与催化剂容易分离。两亲膦铑络合物超细SiO2负载液相催化剂可避免超细SiO2负载水相催化剂循环使用时水分被提取到有机相的缺点,同时获得较高的氢甲酰化反应活性和选择性。[英文文摘]Because of the lower activity of higher olefins in aqueous/organic biphasic catalysis system and the catalyst separation of homogeneous catalysts,ultrafine SiO2 nanoparticles were used as supports to immobilize amphiphilic phosphine-complex to obtain supported catalysts for hydroformylation of 1-hexene. Compared to the supported aqueous-phase catalysts (SAPC) on ultrafine SiO2 support,the ultrafine SiO2-supported catalyst with amphiphilic phosphine-complex presented a higher hydroformylation performance over a relatively wider range of support hydration. Since the water was distilled to organic phase for more times recycled catalysts, the draw backs of ultrafine SiO2 supported water- soluble phosphine-Rh complexes catalyst could be avoided by using supported liquid- phase catalyst prepared by using amphiphilic phosphine- Rh complexes, obtaining higher activity and selectivity of hydroformylation.国家自然科学基金(20023001

A STUDY ON NANO-HYDROXYAPATITE-CHITOSAN SCAFFOLD FOR BONE TISSUE ENGINEERING

作者单位: 1 中国医学科学院中国协和医科大学生物医学工程研究所天津市生物医学材料重点实验室( 天津, 300192 ) ; 2 厦门大学生物医学工 程研究中心厦门大学医学院厦门市生物医学工程技术研究中心 通讯作者: 张其清, 教授, 博士导师, 研究方向: 组织引导再生, E-mail: zhangqiq@ xmu . edu. cn[中文文摘]目的以一种简单、有效的方法制备多孔的纳米羟基磷灰石(nano hydroxyapatite,nano-HA)-壳聚糖(chitosan,CS)复合支架,并评价其理化性能及与细胞相容性。方法采用原位复合-冷冻干燥方法,制备多孔nano-HA-CS支架。通过扫描电镜、透射电镜、X线衍射和傅立叶红外光谱分析支架的微观形貌及材料的组成。分离初生Wistar大鼠的成骨细胞,取传代培养第3代细胞分别与nano-HA-CS支架和纯CS支架共培养2、4、6、8h,各时间点各取4个样品,测定细胞在支架上的黏附率,并通过组织化学染色、扫描电镜观察细胞形态。结果nano-HA-CS复合支架具有多孔结构,孔径为100~500μm,大多数孔径为400~500μm。具有很高的孔隙率,随CS和HA含量的增加,孔隙率明显降低,密度升高。扫描电镜和透射电镜观察显示合成的HA晶体,晶粒大小为纳米级,在支架孔壁上均匀、连续分布如“铺路石”样。X线衍射和红外光谱分析表明合成的HA是含CO32-弱结晶纳米晶体。细胞相容性实验显示,成骨细胞在支架上黏附、增殖,并分泌纤维状细胞外基质;在复合支架上的黏附率明显高于纯CS支架。结论采用原位复合与冷冻干燥法结合制备的nano-HA-CS复合支架具有良好的理化性质和细胞相容性,有望应用于组织工程骨的构建。[英文文摘] Objective To fabricate a nano-hydroxyapatite-chitosan (nano-HA-CS) scaffold with high porosity by a simple and effective technique and to evaluate the physical and chemical properties and the cytocompatibility of the composite scaffold. Methods The three-dimensional nano-HA-CS scaffolds with high porosity were prepared by the in situ hybridization-freeze-drying method. The microscopic morphology and components of the composite scaffolds were analyzed by the scanning electron microscopy (SEM), the transmission electron microscopy(TEM), the X-ray diffraction(XRD)examination, and the Fourier transformed infrared spectroscopy(FTIR). The calvarial osteoblasts were isolated from the neonatal Wistar rats. The serial subcultured cells (3rd passage) were respectively seeded onto the nano-HA-CS scaffold and the CS scaffold, and then were co-cultured for 2, 4, 6 and 8 hours. At each time point, four specimens from each matrix were taken to determine the cell-adhesion rate. The cell morphology was observed by the histological staining and SEM. Results The macroporous nano-HA-CS scaffolds had a feature of high porosity with a pore diameter from 100 to 500 μm (mostly 400-500 μm). The scaffolds had a high interval porosity; however, the interval porosity was obviously decreased and the scaffold density was increased with an increase in the contents of CS and HA. The SEM and TEM results showed that the nano-sized HA was synthesized and was distributed on the pore walls homogeneously and continuously. The XRD and FTIR results showed that the HA crystals were carbonate-substituded and not well-crystallized. The cytocompatibility test showed that the seeded osteoblasts could adhere the scaffolds, proliferating and producing the extracellular matrix on the scaffolds. The adherence rate for the nano-HA-CS scaffolds was obviously higher than that for the pure CS scaffolds. Conclusion The nano-HA-CS scaffolds fabricated by the in situ hybridization-freeze-drying method have a good physical and chemical properties and a good cytocompatibility; therefore, this kind of scaffolds may be successfully used in the bone tissue engineering.天津市科技攻关项目资助项目(05YFGZGX03800

Observation on Aggregation and Resting on Spider Web Behavior of Crane Fly Limonia(Euglochina) sp.from Nanjing Subtropical Rainforest of China

通讯作者: [email protected][中文文摘]在南靖和溪亚热带雨林中分布有数种大蚊,美刺亮大蚊(Lim onia(Euglochina)sp.)是雨林中唯一观察到在圆蛛科蜘蛛网上栖息的大蚊.因此我们对美刺亮大蚊和圆蛛科蜘蛛在蜘蛛网上的同现行为进行了观察研究.借助扫描电镜技术,在比较了其他大蚊、蜘蛛等节肢动物前跗节超微结构的基础上,对美刺亮大蚊栖息于蜘蛛网行为学的形态学机制进行了初步解析.文中也对美刺亮大蚊的聚集行为与雨林温湿度的关系进行了记录.[英文文摘]There are several species of crane flies in Nanjing subtropical rainforest,whereas,the Limonia(Euglochina) sp.is the only one we observed resting on the spider web(primary thread favor).So,observation on co-occurrence behavior of Limonia(Euglochina) sp.with the Araneidae spiders in the same orb-web was conducted.Ultrastructure of the pretarsus of several species of crane flies and one spider species of Araneidae were scanned by SEM technology,in addition,the mechanism of hanging on the orb-web thread by Limonia (Euglochina )sp.was discu ssed in this paper by comparing the tarsal externalmorpho logy of Limonia (Euglochina )sp.with the others. We also recorded the aggregation regulation of Limonia (Euglochina )sp.in the working field in the rainforest.国家基础科学人才培养基金(J0630649);厦门大学第一届大学生创新实验项目资

Mechanism and kinetics of cellobiose hydrogenation catalyzed by Ru/CNT

联系人及第一作者: 谭雪松( 1985- ),男, 硕士, 助理研究员。[中文文摘]引言化石资源的日益枯竭,使得人们对从可再生生物质资源合成化学品和燃料的研究给予了广泛关注[1-2]。木质纤维素是地球上分布最广、产量最多的生物质资源之一。纤维素由葡萄糖通过β-1,4糖苷键连接而成,其分子的刚性结构和高度结晶性使其成为最难转化的多糖[3]。目前通过高温气化或热解转化纤维素为合成气等燃料的工艺过程已经建立[4]。但在温和条件下通过平台分子继而生成油品或化学品的过程还有待开发。山梨醇是纤维素转化中有价值的平台分子之一,可以在较温和条件下通过水汽重整和费托合成等方法合成烷烃燃油和化学品[5-6]。因而,对纤维素催化加氢制备山梨醇的研究将有助于纤维素的有效利用。Fukuoka等[7]报道了在水相体系下,铂/氧化铝催化剂催化纤维素加氢制备山梨醇的反应,在190℃反应24h,山梨醇的收率为25%。Liu等[8]利用高温水形成的独特酸性质,以钌/活性炭为催化剂,245℃反应得到山梨醇,收率为30%。Deng等[9]利用碳纳米管优异的氢吸脱附与溢流性质,以Ru/CNT为催化剂,在185℃反应24h,山梨醇收率达到36%。虽然在催化纤维素加氢制山梨醇的研究方面已取得一定成果,但山梨醇收率不高(<40%),高效催化体系 依旧缺乏, 开展相关基础研究仍十分必要。纤维二 糖是纤维素的次级结构单元, 由两个葡萄糖通过 β-1,4糖苷键连接而成。由于纤维二糖结构与纤维 素类似, 且易于溶解, 故可用于研究纤维素转化的 模型分子[ 10-11] 。 本研究考察了以Ru/ CNT 为催化剂, 水相条 件下催化纤维二糖加氢制备山梨醇的反应。推导了 纤维二糖转化反应机理, 建立了纤维二糖催化加氢 反应的动力学模型, 可为纤维素的催化加氢研究提 供指导。[英文文摘]The production of chemicals or fuels from renewable biomass resources especially cellulose has attracted much attention because of the worldwide demand for less dependence on fossil resources.However,the direct utilization of cellulose is still a challenge because of its robust crystalline structure.Herein,the hydrogenation of cellobiose,a typical cellulose,over carbon nanotube supported ruthenium catalyst (Ru/CNT) was reported.The mechanism of cellobiose conversion was proposed and the kinetic equation was obtained. Based on the kinetic experiments carried out in the range 120- 185℃ under 5. 0 MPa H2 , the reaction rate constants and activation energies of each reaction step in cellobiose hydrogenation were obtained with MATLAB, in which the activation energy for hydroly sis and hydrogenolysis of cellobio se was est imated as 147.1 kJ·mol- 1 and 71.2 kJ·mol- 1, respectively. The obtained kinetic model and some general rules on the catalyt ic hydrog enation of cellobio se may provide impo rtant data for eff icient ut ilization of cellulose.国家自然科学基金项目(20625310, 20773099,20873110