动力基础四周土体对地基刚度的影响

本文通过一系列现场模型基础强迫振动试验结果,分析了埋置基础四周土体对基础动力反映特性的影响,着重探讨了天然埋置与回填埋置的差异,文中的研究结论将有助于设计中更合理地选择地基刚度系数。     

ICRP Publication 114. Environmental protection: transfer parameters for reference animals and plants

In Publication 103 (ICRP, 2007), the Commission included a section on the protection of the environment, and indicated that it would be further developing its approach to this difficult subject by way of a set of Reference Animals and Plants (RAPs) as the basis for relating exposure to dose, and dose to radiation effects, for different types of animals and plants. Subsequently, a set of 12 RAPs has been described in some detail (ICRP, 2008), particularly with regard to estimation of the doses received by them, at a whole-body level, in relation to internal and external radionuclide concentrations; and what is known about the effects of radiation on such types of animals and plants. A set of dose conversion factors for all of the RAPs has been derived, and the resultant dose rates can be compared with evaluations of the effects of dose rates using derived consideration reference levels (DCRLs). Each DCRL constitutes a band of dose rates for each RAP within which there is likely to be some chance of the occurrence of deleterious effects. Site-specific data on Representative Organisms (i.e. organisms of specific interest for an assessment) can then be compared with such values and used as a basis for decision making. It is intended that the Commission's approach to protection of the environment be applied to all exposure situations. In some situations, the relevant radionuclide concentrations can be measured directly, but this is not always possible or feasible. In such cases, modelling techniques are used to estimate the radionuclide concentrations. This report is an initial step in addressing the needs of such modelling techniques. After briefly reviewing the basic factors relating to the accumulation of radionuclides by different types of biota, in different habitats, and at different stages in the life cycle, this report focuses on the approaches used to model the transfer of radionuclides through the environment. It concludes that equilibrium concentration ratios (CRs) are most commonly used to model such transfers, and that they currently offer the most comprehensive data coverage. The report also reviews the methods used to derive CRs, and describes a means of summarising statistical information from empirical data sets. Emphasis has been placed on using data from field studies, although some data from laboratory experiments have been included for some RAPs. There are, inevitably, many data gaps for each RAP, and other data have been used to help fill these gaps. CRs specific to each RAP were extracted from a larger database, structured in terms of generic wildlife groups. In cases where data were lacking, values from taxonomically-related organisms were used to derive suitable surrogate values. The full set of rules which have been applied for filling gaps in RAP-specific CRs is described. Statistical summaries of the data sets are provided, and CR values for 39 elements and 12 RAP combinations are given. The data coverage, reliance on derived values, and applicability of the CR approach for each of the RAPs is discussed. Finally, some consideration is given to approaches where RAPs and their life stages could be measured for the elements of interest under more rigorously controlled conditions to help fill the current data gaps.     

关于飞行力学理论体系的探讨

从飞行力学的基本定义和理论出发,以实践的观点和发展的观点,对飞行力学的研究对象、研究范畴、研究手段以及理论基础进行了比较深入的探讨,提出了比较完整的现代飞行力学的理论体系框架.     

末段脉冲修正弹攻击区研究

为了确定采用激光半主动制导的末段脉冲修正弹的攻击区域,建立了导引头探测区模型,建立了六自由度有控弹道方程组,并提出了攻击区建模和仿真的方法.利用上述模型对不同条件下的攻击区进行了仿真计算与分析,结果表明增大导引头视场角、脉冲修正能力、启控点高度和发射条件都将影响攻击区的范围.     

轴对称凹腔燃烧室点火影响因素的试验研究

对采用凹腔作为火焰稳定器的亚燃燃烧室进行了点火试验研究.通过考察不同的凹腔结构及其组合方式、煤油喷注方式,分析了凹腔大小、火焰的轴向、周向传播对点火性能的影响.结果表明,点火瞬间的凹腔有效储能大小来源于轴向容积比率;凹腔内的轴向火焰传播是火焰发展的主要机制;在凹腔前方壁面以使喷油能使凹腔内维持合适的燃油浓度分布,是可靠点火的前提.     

Preparation and biodistribution of ^99Tc^m-PIDP as bone imaging agent

A novel zoledronic acid derivative,1-hydroxy-2-(2-propyl-1H-imidazol-1-yl)ethane-1,1-diyldiphosphonic acid (PIDP),was synthesized by three-step reactions from 2-propyl-1H-imidazole.It was labeled with 99Tcm in conditions of 0.1 mg SnCI2.2H2Cl2·2H2O at pH 6.0 and 99TcmO4-in aqueous solution for 20 min at room temperature.The labeling yield and radiochemical purity of 99Tcm-PIDP are both higher than 95%.The biodistribution results show that the bone uptake is up to 8.47%ID/g which is the maximum of bone uptake at 30 min after injection of 99Tcm-PIDP in mice.The pharmacokinetic parameters can be estimated from the exponential equation of C=59.565e-11.307t+ 2.069e-1.211t.The clear bone image of rabbit was obtained at 120 min after injection of 99Tcm-PIDP.The results indicate that 99Tcm-PIDP has highly selective uptake in the skeletal and low uptake,rapid clearance in soft tissues,so it would be a potential novel bone imaging agent.     

羧酸富勒烯C3的合成及其保护辐射损伤效应

通过Bingle环加成反应,利用富勒烯与丙二酸二乙酯催化合成羧酸富勒烯C3,经^1H-NMR,^13C-NMR以及MS-ESI确认其结构和分子量。通过芬顿体系检测了C3清除自由基的能力。利用CCK-8法和Annexin-V／PI染色和流式细胞分析法,分别检测C3对γ射线照射后AHH-1、HIEC细胞存活率,细胞凋亡和细胞周期变化的影响。结果表明,C3具有良好的清除自由基的能力,当芬顿体系中C3终浓度为1000mg／L时,清除效率高达93％左右。对1．12Gyγ射线照射的细胞,C3具有良好的辐射保护作用,表现为照后细胞存活率明显升高,细胞凋亡率显著降低;且对于较高剂量的照射,辐射防护效果较好。说明C3对γ射线照射的细胞具有较好的辐射防护作用,其机理可能主要与其清除自由基的作用有关。     

DHP铜板爆炸硬化实验研究

DHP铜板是制造连铸结晶器的主要材料,表面硬化技术研究对于提高结晶器使用寿命,具有十分重要的应用价值。采用高应变速率下爆炸硬化方法,对厚度为14 mm的DHP铜板进行表面硬化研究。本研究方法打破传统塑性加工硬化和表面化学硬化等方法,是一种高能率硬化方式。通过检测爆炸硬化后DHP铜板表面的硬度、耐磨性及硬化层组织等指标,表现出突出的表面硬化效应,为这一研究成果的工业应用奠定了良好的研究基础。     

新型环形多极柱电磁阀衔铁的结构优化

针对环形多极柱高速电磁阀衔铁设计需要兼顾磁路磁阻、衔铁质量及衔铁运动的阻尼问题,提出了环形极柱电磁阀衔铁不同区域对电磁力贡献大小不同的设想,通过仿真计算结果证实了设想的正确性,并得到了电磁力在衔铁上的分布规律。据此,提出了两种在衔铁上开槽的结构设计。通过对比分析得出,扇形槽方案比梯形槽方案好。然后以电磁阀开启响应时间和关闭响应时间为目标,对扇形槽几何参数和衔铁厚度开展多目标优化。结果表明：优化后,运动件减重21.6%,电磁阀开启响应时间减少11.1%,关闭响应时间减少30.0%,减小衔铁运动油膜阻尼的同时提升了电磁阀整体的动态响应特性。     

The Somma–Vesuvius complex and the Phlaegrean Fields caldera: New chronological data of several eruptions of the Copper–Middle Bronze Age period

Radiocarbon dating of short-lived sample materials is a useful tool applied to date deposits of volcanic eruptions. Several archaeological sites discovered and excavated in Campania witnessed important volcanic eruptions, which occurred in the Copper and Middle Bronze Ages. These eruptions come from the Somma–Vesuvius complex and the Phlaegrean Fields caldera. At least four Plinian eruptions have been identified in the eruptive history of Somma–Vesuvius, interspersed by interplinian events, called protohistoric, which occurred between Avellino and Pompeii. At S. Paolo Belsito a stratigraphic sequence below Avellino and above the first two protohistoric events after Avellino were highlighted; while Nola (Naples) gives new information on the chronology of Avellino. Sites like Caivano and Gricignano D’Aversa, involved by the Agnano 3, Paleoastroni 2 and Agnano Monte Spina eruptions were highlighted and investigated. In this work, we want to clarify the chronology of some eruptions by comparing our results with previous data. Charcoal, bone and seed samples were collected, treated and measured at the CIRCE laboratory in Caserta.