Change of fuel-to-cladding gap width with the burn-up in FBR MOX fuel irradiated to high burn-up

In order to study the dependence of the gap width change on the burn-up, the fuel-to-cladding gap widths were investigated by ceramography in a large number of FBR MOX fuel pins irradiated to high burn-up. The dependence of gap widths on the burn-up was closely connected with the formations of JOG (joint oxyde-gaine) and rim structure. The gap widths decreased gradually due to the fuel swelling until ∼30 GWd/t, but beyond this burn-up the dependence showed two different tendencies. With the increase of burn-up, the gap widths decreased due to the increase of fuel swelling in the low fuel temperature region where the rim structure was observed, but they increased in the high fuel temperature region where the JOG rich in Cs and Mo formed in the gap.     

Investigation of physico-mechanical properties of ceramic oxide kernels for nuclear applications

In the present work, two different classes of oxide kernels were investigated: unirradiated thoria, urania and (Th,U)O₂ fuel kernels and low-density Al₂O₃ kernels for the incorporation of minor actinides. The physical mechanism of oxide kernel failure under uniaxial compression was investigated. A new method for determining the physico-mechanical properties of kernels has been developed and the parameters P_S and δ, characterising the level of stress required for destruction of the material structure and the brittleness of the investigated materials, respectively, were evaluated and discussed. It was shown that the value of P_S is analogous to traditional characteristics of material such as microhardness Hv. The `quantisation' effect was revealed in the kernel crushing strength and deformation distributions. The physico-mechanical properties of ceramic kernels (average particle size, microstructure, phase state, density, P_S and δ) were investigated and comparative analysis of different kernel types was performed. Additionally, the impact of annealing time on the properties of low-density Al₂O₃ kernels was examined.     

Preliminary results of post-irradiation examinations on LiSoR-2 test section

Liquid-solid reaction under irradiation (LiSoR) experiments are aimed at understanding the effects of liquid lead-bismuth eutectic (LBE) corrosion and embrittlement under irradiation on structural materials, which is one of the key items of the materials R&D for the future accelerator-driven system (ADS). The LiSoR setup is basically a LBE loop with a test section irradiated with 72 MeV protons. The second irradiation was conducted for about 34 h and terminated after a leakage of LBE was detected. Post-irradiation examinations (PIE) are being performed on both the tube and tensile specimen in the test section. Optical microscopy, scanning electron microscopy, transmission electron microscopy and microhardness tests have been completed. The results show that a crack formed in the irradiation zone of the tube. In the material in the irradiation zones of both the tube and the tensile specimen dislocation cell structure is well developed, which indicates heavy deformation due to thermal fatigue. The crack should start at the inner surface and propagate to the outer surface. The fracture surfaces of the crack are dominated by a brittle cleavage fracture mode. However, on the surfaces of the tensile specimen, no microcracks are observed.     

镀锡板镀锡量检测分析仪

为了精确测量镀锡板的镀锡量，提高镀锡板生产和进口的质量，用稀盐酸作电解液，根据电解剥离原理，采用微分电位法，解决了各层界面自动分层难题，研制出镀锡板镀锡量检测分析仪。仪器以Cygnal F005单片机作为智能部件，既可提供本机显示和打印测量结果的功能，又能通过USB接口与上位机配合使用。对双电层电容充电电流引起的测量误差作了修正。仪器小型轻便，操作界面友好。     

基于CAN总线的核医疗设备测控系统设计

介绍了以DSPIC30F6014单片机为核心控制器进行信号检测,并通过执行机构对设备实现控制.系统采用PC总线方式连接新型的CMOS集成温湿度传感器,同时控制CAN总线控制器和总线收发器MCP2551构成的总线通信系统进行数据传输,通过PCI-CAN适配卡将上位机与控制网络连接起来,完成核医疗设备的分布式测控系统设计.详细介绍了系统构成、部分软硬件设计方法等.     

Effect of niobium on thermal stability and impact toughness of Nd-Fe-B magnets with ultra-high intrinsic coercivity

The effects of Nb on the thermal stability and impact toughness of ultra-high intrinsic coercivity of Nd-Fe-B magnets were investigated.The results showed that the addition of Nb could improve the thermal stability,and obviously increased the impact toughness of sintered Nd-Fe-B magnets.The optimum thermal stability of sintered Nd-Fe-B magnets was obtained when the content of Nb was 1.0 at.%.The maximum impact toughness of sintered Nd-Fe-B magnets was obtained when the content of Nb was 1.5 at.%,but the magnetic properties of sintered Nd-Fe-B magnets drastically deteriorated when the content of Nb increased from 1.0 at.% to 1.5 at.%.The microstructure showed that overfull Nb addition made many ultra-fine grains get together,which led to the density of sintered Nd-Fe-B magnets decline and drastically deteriorated the magnetic properties of sintered Nd-Fe-B magnets.     

轿车发动机电控喷射系统用新型传感器的开发

天津大学在国家“８６３”新材料领域的资助下,研制开发新型氧敏薄膜材料,研制出近百个Ａ／Ｆ传感器样件。该样件材料新颖,结构简单,响应速度快,成本低,具有独立知识产权。装在夏利车上,与国外生产进行了排放控制试验比较。试验结果表明,控制能力达到国外生产件水平;响应速度比后者快。     

Postischemic Neuroprotection of Aminoethoxydiphenyl Borate Associates Shortening of Peri-Infarct Depolarizations

Brain stroke is a highly prevalent pathology and a main cause of disability among older adults. If not promptly treated with recanalization therapies, primary and secondary mechanisms of injury contribute to an increase in the lesion, enhancing neurological deficits. Targeting excitotoxicity and oxidative stress are very promising approaches, but only a few compounds have reached the clinic with relatively good positive outcomes. The exploration of novel targets might overcome the lack of clinical translation of previous efficient preclinical neuroprotective treatments. In this study, we examined the neuroprotective properties of 2-aminoethoxydiphenyl borate (2-APB), a molecule that interferes with intracellular calcium dynamics by the antagonization of several channels and receptors. In a permanent model of cerebral ischemia, we showed that 2-APB reduces the extent of the damage and preserves the functionality of the cortical territory, as evaluated by somatosensory evoked potentials (SSEPs). While in this permanent ischemia model, the neuroprotective effect exerted by the antioxidant scavenger cholesteronitrone F2 was associated with a reduction in reactive oxygen species (ROS) and better neuronal survival in the penumbra, 2-APB did not modify the inflammatory response or decrease the content of ROS and was mostly associated with a shortening of peri-infarct depolarizations, which translated into better cerebral blood perfusion in the penumbra. Our study highlights the potential of 2-APB to target spreading depolarization events and their associated inverse hemodynamic changes, which mainly contribute to extension of the area of lesion in cerebrovascular pathologies.     

射频卡智能水表系统的设计

给出了一种基于超低功耗芯片MSP430F149单片机的射频卡智能水表系统的设计方案,其中采用射频卡T5557及其读写基站U2270B作为系统的射频读写模块。重点阐述了系统的硬件构成及软件设计流程,并简单介绍了基于此系统的用水管理系统的设计。该射频卡智能水表可广泛应用于各城市供水系统,并可作进一步推广应用到工业用液体如石油,化工等流量计量计费系统。     

热电机组DCS硬件分层设计和模块化组态方法

基于美国ABB公司生产的Freelance 800FDCS,提出了硬件分层和软件模块化的设计方案。将热电机组中特性相似的设备作为一类单独设计,简化控制逻辑的组态,以便于控制系统的维护和控制逻辑组态的修改。将该设计方案应用于山东某热电机组的DCS,系统投运后从未出现故障,控制效果良好。