塔里木河下游地下水位对柽柳叶绿素荧光特性的影响

选取塔里木河下游3处地下水埋深>6m的监测井位作为研究点,结合典型生态监测断面的地下水位监测数据,分析不同地下水埋深处柽柳的叶绿素荧光特性和光系统的光合活性.结果表明:随着地下水埋深加大和干旱胁迫加剧,柽柳叶片的实际光化学效率、电子传输速率和光化学猝灭等参数普遍下降;非光化学猝灭和调节性能量耗散量子产量等参数显著升高,而最大光量子产量总体处于相对适宜状态.干旱胁迫下柽柳的PSII光合活性随地下水埋深增大而下降,捕获光能的过剩程度加剧,发生光抑制的几率增大,其自身良好的抗旱性和自我调节机制,使光系统II尚未发生显著光损伤

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

Determination of Number of Motion Axes in NC Grinding of Rotary Cutter

【中文文摘】根据回转面刀槽螺旋面的成形原理 ,阐释了回转面刀具数控磨削成形的过程实质上就是控制每一瞬时砂轮几何体与工件几何体在空间的相对位姿和相对运动趋势的过程 ;分析了砂轮平动型和砂轮摆动型CNC工具磨床的运动形式 ,讨论了机床联动轴数的确定原则并给出了计算实例 【英文文摘】According to the forming principle of rotary helical flute surface, it is explained that the shaping process of rotary cutters by NC grinding is virtually the process to control the relative position and attitude and the relative motion direction in the space between the grinding wheel body and workpiece body at the every moment. The motion modalities of CNC tool grinders with moving grinding wheel and swing grinding wheel were analyzed. The principle of determining the number of motion axes was discussed, and a calculating example was presented

Au(111)/咪唑基离子液体界面结构研究:阳离子侧链长度的影响

本文结合电化学方法与原子力显微镜力曲线技术,研究了两种烷基侧链长度不同的离子液体BMITFSA和OMITFSA在Au(111)电极表面附近的层状结构的数目和耐受力对电位的依赖性,探究了烷基侧链长度变化对界面层状结构的影响.研究表明,不同烷基侧链长度的离子液体体系力-电位曲线形状基本相似.在零电荷电位(the potential of zero charge,PZC)附近时,力值最小,因为此时电极表面荷电量较小,层状结构不稳定;电位偏离PZC的过程中,第一层层状结构力值呈现先增大后减小的趋势.受到烷基侧链所处的不同位置影响,在PZC电位以负,短侧链离子液体的层状结构稳定性较好,而PZC电位以正,长侧链离子液体的稳定性较好.国家自然科学基金项目(No.21673193);;福建省自然科学基金项目(No.2016J01075)资

舌鳞癌微血管密度与预后的关系

【目的】研究舌鳞状细胞癌(简称舌鳞癌, 下同)组织中新生微血管的密度(MVD)与舌鳞癌患者预后的关系。【方 法】用免疫组织化学S-P 法对75 例舌鳞癌标本进行染色, 依据Weidner 法进行肿瘤微血管密度计数, 并与舌鳞癌的病理分级、 颈淋巴结转移与否及患者生存期作比较。【结果】不同分化程度舌鳞癌组织中新生血管密度不同(P <0.01), 低分化者 M VD 高于高分化者;G1 , G2 , G3 期MVD 分别为24±10, 31 ±11 和48 ±12 ;颈淋巴结转移组MVD 为36 ±11 , 无颈淋巴结转移 组MVD 为27±9(t =2.383, P <0.01);五年生存组MVD 为26 ±9, 五年内死亡组MVD 为34±10(t =2.042, P <0.01)。 【结论】肿瘤微血管密度与舌鳞癌生物学行为相关, 可以作为舌鳞癌患者预后的指标

缺氧诱导因子1 alpha在急性心肌缺血中的表达规律

【目的】研究心肌缺血状态下HIF-1α的表达规律及其在死亡之后48h的动态变化。【方法】建立SD大鼠急性心肌缺血模型。随机将大鼠分为正常对照组、假手术组、急性心肌缺血试验组和窒息组。用免疫组化、RT-PCR和Western blot检测心肌缺血及死亡后HIF-1α的表达规律。【结果】术后30min缺血心肌中开始出现HIF-1α mRNA表达上调，4～6h达高峰，至术后48h仍维持此高水平；蛋白质的表达相对滞后，于术后2h开始被检测到，之后表达进行性上升，至12h达高峰后维持在高水平；其它各组HIF-1α检测均为阴性。大鼠术后48h处死，死亡后48h内均可检测到HIF-1α mRNA和蛋白质的表达，但表达呈进行性下降趋势；其他各组均未检测到HIF-1α表达。【结论】HIF-1α可作为一个早期心肌缺血的敏感的辅助诊断指标，并用于急性心肌缺血缺氧性死亡和其他原因（例如窒息）缺氧造成的死亡的鉴别

岩石破坏声发射平静期及其分形特征研究

通过岩石加载的室内试验方法,测试不同岩石破裂全过程的力学特征及其声发射特性,得到岩石破坏全过程力学特性——岩石的全应力-应变曲线、声发射事件累积数、声发射事件率等相关曲线及参数,给出声发射事件数、事件率与应力水平、时间之间的关系。着重讨论一次性加载过程中塑性变形阶段明显的岩石在加载接近峰值强度时单位时间内的应力增长速度减小,也即这一阶段出现明显的"耗时"现象;并且在此阶段监测到的声发射事件率出现明显下降,出现声发射相对平静阶段;而对于塑性变形阶段不明显的岩石来说,这一阶段则基本不存在明显的"耗时"现象,声发射的监测中也没有发现声发射相对平静期现象。另外,还运用分形理论,研究分析处于不同加载应力比的岩样在各个阶段的声发射分形维数,特别是研究声发射平静期维数变化情况。指出在加载初期分形维数处于较低值,且分形维数随加载应力增加而逐步增加;在加载到峰值应力的40%左右时,分形维数开始下降;在加载接近到峰值应力时,即处于声发射平静期阶段时分形维数逐步降到最低,且此时预示着岩石的破坏。此外,结合室内试验,还对现场岩体失稳破坏声发射监测中的一些实际问题进行总结和分析,为更好地应用声发射手段进行岩体稳定性现场监测预报提供理论依据、方法和手段

巨噬细胞ABCA1对Ox-LDL诱导的炎症因子的调节及其意义

【目的】研究在氧化低密度脂蛋白(Ox-LDL)诱导作用下,ATP结合盒转运子A1(ABCA1)对巨噬细胞中细胞间黏附分子-1(ICAM-1)、单核细胞化学趋向蛋白-1(MCP-1)mRNA和蛋白质及白介素-1β(IL-1β)蛋白质表达的影响,在细胞水平证实ABCA1对动脉粥样硬化的影响。【方法】用氟波酯(PMA)刺激THP-1细胞使之转变为巨噬细胞,Ox-LDL(30μg/mL)刺激3、6、12、24h后,以荧光定量RT-PCR和Western蛋白印迹法及酶联免疫吸附法(ELISA)检测ABCA1、ICAM-1、MCP-1及IL-1β mRNA和蛋白质表达量;用反义寡核苷酸(100nmol/L)抑制ABCA1的表达,观察Ox-LDL刺激下上述指标的改变。【结果】给予Ox-LDL刺激后,巨噬细胞ABCA1、ICAM-1、MCP-1的mRNA和蛋白及IL-1β蛋白质表达均增高;给予反义寡核苷酸转染后Ox-LDL刺激3、6h,上述指标的mRNA表达降低(P<0.01),12、24h蛋白质表达降低(P<0.01)。【结论】在巨噬细胞,ABCA1可增加Ox-LDL诱导的炎症因子表达,参与动脉粥样硬化的发生

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

Discussion of Innovative Path on Cost Accounting in Modern Hospital

降低医疗成本、提高服务质量,是公立医院经营永恒的目标。成本核算是实现医院经营目标的重要手段。笔者阐述了医院成本核算的复杂性与特殊性,包括医疗服务的自身特点、国家政策和社会环境使医院成本核算基础差,不易比较和控制等特点。当前医院管理面临诸多挑战,加强医院成本核算具有重大意义。本研究就医院成本核算在医院管理中的应用做了初步探讨,并提出改进方法。The goals of hospital operation are decreasing medical cost and increasing quality of medical services.Cost accounting is an important method to achieve these goals.Including factors like the specific features of medical services,state policies and social environment lead to the fact that hospital cost have a weak basis and hard to compare and control,we illustrate the complexity and particularity of cost accounting.Facing a number of challenges,strengthening cost accounting is of great weight.We offer a preliminary account of the application of cost accounting in hospital management.福建省省属公益类科研院所基本科研专项项目(2014R1036-3