Catalytic Cracking and Heat Sink Capacity of Aviation Kerosene Under Supercritical Conditions

Catalytic cracking of China no. 3 aviation kerosene using a zeolite catalyst was investigated under supercritical conditions. A three-stage heating/cracking system was specially designed to be capable of heating 0.8 kg kerosene to a temperature of 1050 K and pressure of 7.0 MPa with maximum mass flow rate of 80 g/s. Sonic nozzles of different diameters were used to calibrate and monitor the mass flow rate of the cracked fuel mixture. With proper experiment arrangements, the mass flow rate per unit throat area of the cracked fuel mixture was found to well correlate with the extent of fuel conversion. The gaseous products obtained from fuel cracking under different conditions were also analyzed using gas chromatography. Composition analysis showed that the average molecular weight of the resulting gaseous products and the fuel mass conversion percentage were a strong function of the fuel temperature and were only slightly affected by the fuel pressure. The fuel conversion was also shown to depend on the fuel residence time in the reactor, as expected. Furthermore, the heat sink levels due to sensible heating and endothermic cracking were determined and compared at varying test conditions. It was found that at a fuel temperature of similar to 1050 K, the total heat sink reached similar to 3.4 MJ/kg, in which chemical heat sink accounted for similar to 1.5 MJ/kg

Performance of supersonic model combustors with distributed injection of supercritical kerosene

Supersonic model combustors with two-staged injections of supercritical kerosene were experimentally investigated in both Mach 2.5 and 3.0 facilities with the stagnation temperatures of approximately 1750K. Supercritical kerosene at temperatures of approximately 760K and various pressures was prepared using a two-staged heater developed in Ref. 1 and injected at equivalence ratios of 0.98 to 1.46. Two pairs of integrated injector/flameholder cavity models in tandem were used to facilitate the fuel-air mixing and stabilize the combustion. Combustor performances with different fuel injection locations, injector numbers, combinations of injection stages, and combustor entry Mach numbers were investigated systematically and discussed based on the measured static pressure distributions and the specific thrust increments due to combustion. With two-staged fuel injections the overall performance of the combustors was shown to be improved and fuel injections at equivalence ratio higher than unity could be reached without combustor-inlet interaction. Reducing the number of injectors while increased its diameter was very effective to increase the pressure rise in the combustor with single-stage injections but had little effect on the combustor performance with two-staged fuel injections. Increasing the entry Mach number resulted in lower combustion levels, in particular, with fuel injections at locations close to the combustor exit but was balanced with two-staged fuel injections

Thermal cracking of aviation kerosene for scramjet applications

Thermal cracking of China No.3 aviation kerosene was studied experimentally and analytically under supercritical conditions relevant to regenerative cooling system for Mach-6 scramjet applications. A two-stage heated tube system with cracked products collection/analysis was used and it can achieve a fuel temperature range of 700-1100 K, a pressure range of 3.5-4.5 MPa and a residence time of approximately 0.5-1.3 s. Compositions of the cracked gaseous products and mass flow rate of the kerosene flow at varied temperatures and pressures were obtained experimentally. A one-step lumped model was developed with the cracked mixtures grouped into three categories: unreacted kerosene, gaseous products and residuals including liquid products and carbon deposits. Based on the model, fuel conversion on the mass basis, the reaction rate and the residence time were estimated as functions of temperature. Meanwhile, a sonic nozzle was used for the control of the mass flow rate of the cracked kerosene, and correlation of the mass flow rate gives a good agreement with the measurements

Heat Transfer of Aviation Kerosene at Supercritical Conditions

The heat transfer characteristics of China no. 3 kerosene were investigated experimentally and analytically under conditions relevant to a regenerative cooling system for scramjet applications. A test facility developed for the present study can handle kerosene in a temperature range of 300-1000 K, a pressure range of 2.6-5 MPa, and a mass How rate range of 10-100 g/s. In addition, the test section was uniquely designed such that both the wall temperature and the bulk fuel temperature were measured at the same location along the flowpath. The measured temperature distributions were then used to analytically deduce the local heat transfer characteristics. A 10-component kerosene surrogate was proposed and employed to calculate the fuel thermodynamic and transport properties that were required in the heat transfer analysis. Results revealed drastic changes in the fuel flow properties and heat transfer characteristics when kerosene approached its critical state. Convective heat transfer enhancement was also found as kerosene became supercritical. The heat transfer correlation in the relatively low-fuel-temperature region yielded a similar result to other commonly used jet fuels, such as JP-7 and JP-8, at compressed liquid states. In the high-fuel-temperature region, near and beyond the critical temperature, heat transfer enhancement was observed; hence, the associated correlation showed a more significant Reynolds number dependency

关于理财目标与公司治理结构的思考

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四部分：管理会计创新及相关模式6文章根据委托代理理论原理分析了公司治理结构与公司理财目标的关系，寻求探索所有者与经营者理财目标的交合点，建立所有者与经营者财务目标动态平衡模型，并试图通过重新定位所有者与总经理、总会计师的关系，以总会计师为载体，完善现代非对称信息环境中的企业激励与约束机制，协调企业经营者与所有者理财目标，从而提高企业资源配置效率

Expression and significance of p-catenin inhibitor Chibby in Nasopharyngeal Carcinoma

第一作者简介及通讯: 蔡成福, 男, 福建人, 医学硕士, 副主任医师, 主要研究方向为头颈肿瘤的临床工作 E-ma il:d yy- [email protected] 通讯作者. 赵德安(E- mail:[email protected])[中文文摘]目的研究β-catenin拮抗因子Chibby在鼻咽癌组织中的表达情况,并探讨其与鼻咽癌临床病理因素的相关性。方法分别采用Real time PCR及免疫组织化学(SABC法)检测45例鼻咽癌及癌旁正常鼻咽黏膜组织中Chibby mRNA及蛋白的表达情况,统计Chibby的表达与鼻咽癌患者临床病理因素的关系。结果 Chibby mRNA在癌旁正常鼻咽黏膜及鼻咽癌组织中平均相对表达量分别为0.0835±0.0056和0.0776±0.0059,Chibby蛋白在癌旁正常鼻咽黏膜及鼻咽癌组织中的阳性表达率分别为91.1%(41/45)和42.2%(19/45)。鼻咽癌组织中Chibby的表达与T分期及临床分期有相关性,与性别、年龄、颈淋巴结转移及病理分型无明显相关性。结论与癌旁正常鼻咽黏膜组织相比,鼻咽癌组织中Chibby mRNA及蛋白的表达均降低,Chibby的表达与肿瘤T分期及临床分期相关,与性别、年龄、颈淋巴结转移及病理分型无明显相关性,Chibby可能参与了鼻咽癌的发生过程,有望成为鼻咽癌基因治疗新的作用靶点。[英文文摘]OBJ ECTIVE TO investigate the expression of Chibby a new β-catenin inhibitor in nasopharyngeal careinoma , and to explore the relationship between Chibby and clinicopathological features of nasopharyngeal carcinoma . METHODS Real time PCR and SABC im munohistochemical staining were used to detect the expression of Chibby mR N A and protein in nasopharyngeal carcinoma tissues and nasopharyngeal normal tissues of 45 cases , respectively .The re!ationships between Chibby expression and cIinicopathological features the gender, age , T stages .Iymph node metastasis , clinical stages and pathological grade were analyzed by statistics . RULTS The expressions of Chibby mRNA were 0 .0835士0 .0056 and0.0776 士0.0059 in nasopharyngeal normal tissues and nasopharyngeal carcinoma tissues, respectively.The positive expressive rates of chibby protein were 91.1 % (41/45 ) and 42 .2 % (19/45 ) in nasopharyngeal norma l tissues and nasopharyngeal carcinoma tissues,respectively.There were eminent relation between the lower expression of Chibby in nasopharyngeal careinoma and T stages and clinical stges , but no relation with the sex , age , metastasis of lymph and pathological grades .CONCLUSION Compare with normal nasopharyngea l tissues, the expressions of Chibby mRNA and prote in were reduced in nasopharyngeal carcinoma tissues.The Iower expressive levels of Chibby were associated with the T stages and clinica l stages of carcinoma , but no relation with the sex , age , metastasis of Iymph and pathological grades.Chibby may be involved in the pathogenesis of nasopharyngeal carcinoma ,and be expected to become a new target of gene t herapy of it

中国物理海洋学研究70年：发展历程、学术成就概览

本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军

铕在包头含稀土高炉渣中的富集规律

利用含稀土氧化物的合成炉渣进行了高炉生铁脱硫反应,对包头含稀土高炉渣中铕的分布及富集规律做了实验研究

Flow rate analyses and calibrations of kerosene cracking for supersonic combustion

Measurements of kerosene conversion due to thermal cracking and mass flow rate through a sonic nozzle have been made under supercritical conditions. Based on the temperature dependency of mole fraction of gaseous products from kerosene cracking, a one-step cracking model has been proposed to correlate the kerosene conversion and the mass flow rate through a sonic nozzle. In this model, the cracked kerosene was described as a three-component ideal gas mixture (IGM) of unreacted kerosene, gaseous products after cooled to room temperature and residuals. The composition of unreacted kerosene and gaseous products were determined by a gas chromatography, while the approximate chemical formula of the residuals was derived from the average molecular weight of cracked kerosene mixture at high temperature. The mass flow rate of cracked kerosene was then calculated from ideal gas law for the three-component mixture. Agreement was obtained when comparing the calculated mass flow rate with the measurements. Kerosene residence time and the rate constant of conversion inside a heater were also discussed based on this global cracking model

城市生活垃圾焚烧体系化学热力学平衡分析

采用化学热力学平衡分析方法，分析城市生活垃圾焚烧体系污染物的排放特性。主要计算了聚氯乙烯(PVC)及典型城市垃圾焚烧过程氯元素的化学平衡组成及其浓度，同时研究了脱氯剂对PVC及垃圾中氯转化的影响。计算结果表明，PVC热态反应的主要产物是HCl气体，在加入脱氯剂后温度低于600℃时，脱氯剂对HCl的脱除作用很明显；城市生活垃圾热解和燃烧过程中在温度超过600℃，垃圾中的有机氯和无机氯都将转化为HCl气体，而此时脱氯剂失去效果。由计算结果得到控制HCl生成，消除二噁英污染物的生成反应工艺条件