对-硝基苯甲酸的光解行为探讨

以对-硝基苯甲酸为模型,探索两个取代基处于对位而同时不溶于水但溶于有机溶剂的芳香族硝基类有机物的光解行为,为有效降解此类化合物提供实验方法与理论支持。通过266nm激光光解和254nm紫外光降解两种手段对对-硝基苯甲酸的光解行为进行了研究,考察了不同体系对对-硝基苯甲酸光解行为的影响,并获得了相应的ns级激光光解瞬态吸收光谱及紫外光降解效果,为其降解机理研究奠定了基础。通过实验发现,在激光光解条件下,310nm附近有激发三线态的生成;紫外光难以直接降解对-硝基苯甲酸,但UV/H2O2却可提高其降解效率,经分析,认为H2O2在紫外光作用下产生的.OH起到了关键性作用。     

EB degradation of perfluorooctanoic acid and perfluorooctane sulfonate in aqueous solution

Electron beam (EB) degradation of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) in aqueous solutions was studied.It suggested that PFOA and PFOS degradation followed the pseudo-firstorder kinetics,and degradation rates increased with increasing initial pH.Radical scavengers' experiments indicated that hydrated electron and hydrogen radical were important in the electron beam degradation of PFOA and PFOS,especially hydrated electron.The decomposition efficiencies were 95.7％ for PFOA and 85.9％ for PFOS,by EB irradiation in an anoxic alkaline solution (pH =13).The potential degradation pathways of PFOA and PFOS by electron beam irradiation through defluorination and the removal of CH2 unit were proposed.     

Diagnosis of surface degradation of flame-retardant ethylene propylene diene copolymer by scanning probe microscopy

Most electric cables installed in nuclear power plants use organic polymers for their electrical insulation. Regarding this, degradation of the polymers could lead to fatal accidents. However, no truly reliable diagnostic methods that can detect the degradation of polymer insulation in electric cables have been established. Therefore, development of a reliable diagnostic method is very important. The present research shows that scanning probe microscopy can be a good tool to evaluate microscopic changes induced on the surface of flame-retardant ethylene propylene diene copolymer by its degradation.     

基于退化失效模型的旋转机械寿命预测方法

退化失效模型与传统可靠性预测的根本区别在于,不论在统计推断还是寿命分布拟合过程中,可以充分利用退化数据提供的更多过程和寿命信息,能较准确地进行具有耗损特性的机械产品的寿命预测.针对旋转机械运行过程中强度破损失效模式,本文利用正态随机过程模型描述其退化失效过程,进行了旋转机械的寿命预测方法研究.通过分析加速寿命方程与退化失效模型的关系,考虑到加速寿命试验方法以"应力换时间"的有效性,进行了旋转机械加速寿命试验.通过对试验结果进行最佳线性无偏估计,得到强度退化失效模型的退化轨迹;在解决了退化失效方程奇异性的基础上,进行了旋转机械的寿命预测,得到点估计与区间估计的可靠寿命预测结果.     

基于灰色马尔可夫链的核设备退化趋势预测

核设备的状态退化趋势预测是确定其在役检查以及维修计划的重要依据,但由于核设备样本小、退化数据缺乏、退化轨迹具有波动性,难以采用传统的概率统计模型对其退化趋势进行精确预测。为此,本文提出应用灰色马尔可夫链模型对核设备退化趋势进行预测的方法,该方法充分利用GM（1,1）和马尔可夫链的优点,能够有效提高核设备退化趋势预测的精度。并以屏蔽泵的退化数据为样本,精确预测了屏蔽泵的退化趋势,同时与GM（1,1）模型的预测结果进行了对比。结果表明,灰色马尔可夫链模型的预测精度更高,能够对核设备的退化趋势进行精确预测。     

Quantitative common cause failure modeling for auxiliary feedwater system involving the seismic-induced degradation of flood barriers

Flood barriers are important defenses which will reduce the internal flood-induced failure risk of safety-related equipment in the turbine building. Contrarily, the degradation of flood barriers will increase the risk of internal flood-induced common cause failure (CCF). Two layouts of auxiliary feedwater pumps system are compared to demonstrate the quantitative risk assessment of the possible degradation of flood barriers. The alpha decomposition method has been developed by the authors in order to quantitatively evaluate the CCF parameters based on the causal inference. Occurrence frequency and CCF triggering ability are two important elements which will decide the CCF risk significance of potential common causes. The seismic-induced internal flood combining with the degradation of flood barriers is analyzed. The degradation of flood barriers is treated as a stochastic process and a Markov model is applied to consider the time-dependent states. The failure time of three auxiliary feedwater pumps is calculated based on the water flow rate through flood barriers. CCF triggering abilities of internal floods are calculated which are represented as decomposed alpha factors. This article shows the updating process of CCF parameters according to Bayesian inference and hypothetical databases. It is concluded that the issue of CCF modeling is not only decided by the number of redundant components but also decided by causes and plant-specific design.     

Treatment of Wastewater with High Conductivity by Pulsed Discharge Plasma

A wastewater treatment system was established by means of pulsed dielectric barrier discharge（DBD）. The main advantage of this system is that the wastewater is employed as one of the electrodes for the degradation of rhodamine B, which makes use of the high conductivity and lessenes its negative influence on the discharge process. At the same time, the reactive species like ozone and ultraviolet（UV） light generated by the DBD can be utilized for the treatment of wastewater. The effects of some factors like conductivity, peak pulse voltage, discharge frequency and pH values were investigated. The results show that the combination of these reactive species could enhance the degradation of the dye while the ozone played the most important role in the process. The degradation efficiency was enhanced with the increase of energy supplied. The reduction in the concentration of rhodamine B was much more effective with high solution conductivity;under the highest conductivity condition, the degradation rate could rise to 99%.     

PHEBUS FPT0~FPT2实验堆芯降级过程数值模拟

严重事故下，由于堆芯冷却剂丧失引起的堆芯裸露、过热和熔化过程对后期安全壳完整性、裂变产物行为等具有重要影响。法国辐射防护与核安全研究所主导的PHEBUS-FP研究项目旨在研究轻水堆严重事故下堆芯降级过程以及裂变产物行为。本文使用ATHLET-CD程序对PHEBUS-FP中的FPT0、FPT1和FPT2进行建模计算，主要分析堆芯过热，包壳氧化，堆内材料熔化、迁移及再定位过程。计算结果表明：不同蒸汽流量、不同加热功率将导致不同堆芯降级进程，在趋势上计算值与实验值吻合；模型的限制导致了部分计算值的偏差，本文讨论了包壳氧化与燃料再定位现象中的模型参数。     

Radiation Effects on Microcircuits

Microcircuit response to nuclear radiations has become an increasingly important concern over the past year. This discussion will consider transient radiation effects (TRE); a companion discussion will cover space radiation effects. The interesting effects occur in two areas: displacement effects resulting from fast neutron irradiation, and ionizing effects caused by prompt pulses composed of x-rays and ?-rays. Fast neutron degradation of microcircuit performance is dominated by transistor current gain reduction. Current gain degradation in microcircuit transistor elements follows the same laws as current gain reduction in discrete transistors of similar base region design and geometry.     

Electrical and optical surface degradation of silica due to superficial He implantation

Different oxides will be used in ITER and future fusion reactors for electrical insulation and optical components. The vacuum face of these materials will be subjected not only to neutron and gamma irradiation, but also to particle bombardment, due mainly to ionization of the residual gas and acceleration of the resulting ions by local electric fields. Previous work showed that silica suffers electrical and optical degradation when subjected to He bombardment with energies from 300 keV down to 27 keV. As the He ion energy may extend down to some few keV, or less, further work has been performed to study possible degradation for energies from 21 keV down to 5 keV. The results show that both surface and optical degradation occur at these low energies, more rapidly for the lowest energy (5 keV) ions. They also suggest that the superficial narrow implanted He profile plays an important role in the surface degradation.     

Aseismic evaluation for aging degradation of nuclear power plant components

The commercial operation of light water reactor plants in Japan already has a history of nearly 30 years. Since the beginning of the 1990s, studies have been conducted on aging degradation of nuclear power plants in Japan and abroad and, earlier in 1999, the domestic program of plant life management (PLM) was settled on. The program is based on the results of the PLM Study, which started in 1997. The purpose of the study was to develop the preventive maintenance program with an evaluation of aging degradation for maintaining the functions of plant component equipment. Taking account of the need for proper management of aging degradation, meanwhile, the technical evaluation of aseismic capability of aged plants is also considered to be important. Based on this concept, we evaluated the impact of assumed aging degradation on the aseismic capability of the plant facilities and structures covered by the PLM Study. In the aseismic evaluation, aging degradation modes selected in the PLM Study were divided into two categories—the one is including some degradation modes which impact on the aseismic capability of the facilities and structures should be taken into account, the other is including those whose impact might be ignored. Then the aging degradation modes composing the former one were quantitatively evaluated primarily based on the Technical Guidelines for Aseismic Design of Nuclear Power Plants (JEAG-4601) (NUREG/CR-6241, 1987). The result of the evaluation indicated that no aging degradation mode to be reflected in the maintenance program was extracted from the viewpoint of securing the aseismic capability of the plant components. However, establishment of rational evaluation methods for aging degradation, e.g. aseismic capability evaluation of thinned piping systems, was made a future technical subject.     

Chemo-mechanical coupling behaviour of leached concrete: Part I: Experimental results

This paper deals with concrete behaviour under chemical and mechanical degradations. Experimental investigations are described where the effects of the calcium leaching process of concrete on its mechanical properties are highlighted. The calcium leaching and mechanical tests on cement paste, mortar and concrete samples are presented. Because of the slow kinetics of leaching under deionised water, an accelerated method has been chosen by using an ammonium nitrate solution instead. The specimens are immersed into a 6 mol/l ammonium nitrate solution with a controlled pH disposal. To quantify the leaching evolution, the degradation depth is then measured at certain time intervals by means of a phenolphthalein solution. The experimental results show the chemical degradation of the cement-based material and the important role of aggregate in the calcium leaching process of concrete. Compression tests of concrete samples are also performed. We observe that there is a strong coupling between the calcium leaching and the mechanical behaviour; as leaching grows, a loss of stiffness and of strength are observed and a smoother post-peak behaviour is noted.     

对硝基苯胺的辐照降解研究

采用电子束辐照对硝基苯胺水溶液,研究了对硝基苯胺的辐照降解过程,并对吸收剂量、初始浓度、溶液pH及H202加入等因素对辐照降解效果的影响进行了探讨。结果表明,电子束辐照能够有效地降解对硝基苯胺。初始浓度为100mg／L,吸收剂量为20kGy时,对硝基苯胺的降解率可达95％以上,化学需氧量（Chemical oxygen demand,COD）的去除率可达41％以上。     

Plasma Induced Degradation of Aniline in Aqueous Solution

In this paper,the degradation of aniline by plasma which was generated in a localized zone between an electrolytic solution and an anode was reported.The influence of the initial concentration.temperature,pH and different mediums of aniline on the reaction kinetic was investigated.The results showed that temperature had a remarkable effect on the degradation of aniline,but the concentration had no appreciable effect on the degradation.There is a maximum elimination rate on the degradation of aniline in neutral condition .Iron(II) and other cations had a remarkble catalytic action on it .On the basis of the detailed analysis of the kinetical consideration,it was demonstrated that the oxidative degradation would be a first-order reactioin,Some of the intermediate products of the degradatio process in the solution were detected by HPLC.     

反熔丝FPGA的电离总剂量效应与加固技术

简要叙述了商用FPGA用于空间领域时面临的抗电离总剂量加固总是，对Actel公司反熔丝FPGA的电离总剂量效应进行了较为详细的分析，包括制造了工艺，偏置条件，电泵对总剂量效应的影响，并特别指出，电泵的退化可能会对系统造成较为严重的后果，因此，必须重视加电后的瞬态变化，提出了可以采取的加固措施。     

Influence of gas atmosphere on synergistic control of mercury and dioxin by nonthermal plasma

In this paper, narrow-pulse power discharge is used to study the synergistic control of mercury and dioxins, in which 1,2,4-trichlorobenzene (TCB) was used as a dioxin analog, by using a self- designed experimental system. The competitive effects of NO, SO₂ and HCl on the TCB removal by non-thermal plasma are discussed. The influence of acid gas on TCB degradation is reflected in the competitive effect. NO has the greatest influence on TCB degradation efficiency. The oxidation efficiency of Hg⁰ decreased by about 10% in all three acidic gas atmospheres, and the effect of each gas component on Hg⁰ oxidation is complex. In the flue gas atmosphere of ‘acid gas+Hg⁰ +TCB’, the mechanism of the synergistic control of Hg⁰ and TCB by the non- thermal plasma is different, which has competition and promotion relationship between each other. The contribution of various flue gas components to the results was complicated, but the overall experimental results show that the synergistic control effect of the system can continue to improve. According to the generated product backstepping, ·OH plays an important role in the synergistic control of the degradation of Hg⁰ and TCB. Through this study, we hope to provide basic research data for the collaborative control of flue gas in the incineration industry.     

苯胺类污染物的电子束辐照降解研究

苯胺及其衍生物是一类主要的环境污染物，许多已被我国及欧洲国家列为优先污染物。本工作研究了苯胺、对硝基苯胺和间氯苯胺水溶液的电子束辐照降解过程。三种溶液初始浓度均为0．5mmol／L，其辐照前后稀释五倍的紫外可见吸收光谱表明，苯胺在230nin的吸收峰，对硝基苯胺在380nm的吸收峰，以及间氯苯胺在236nm的吸收峰，均随辐照吸收剂量的增加而逐渐降低。辐照吸收剂量为23kGy时，     

基于SWT与相空间曲变的控制棒驱动机构退化状态跟踪和识别

控制棒驱动机构（CRDM）是保证反应堆正常运行与安全的重要设备。针对其转速低、性能退化特征微弱且易受其他信号源干扰的特点,本文采用小波半软阈值（SWT）与相空间曲变相结合的方法对其退化状态进行了跟踪与识别。通过与基于振动幅值均方根（RMS）方法的对比,表明该方法能够克服传统基于线性信号处理理论对微弱性能退化状态不能很好地跟踪和识别的缺点,可以较好地对强背景噪声下的旋转机械性能退化状态进行跟踪和识别。      

The control and measurement of high power high-gradient acceleration structures

Conditioning an accelerating structure is important, and its performance is limited by breakdown and vacuum degradation, hence the necessity of finding problem in the conditioning. In order to save time, a judging process built in the firmware layer is applied in this paper. The system using the embedded algorithm in the Field Programmable Gate Array(FPGA) locates the position of breakdown and displays the result in the user interface.Also, the system has the functions of automatic conditioning and interlock protection, which are useful during the conditioning process of an S-band accelerating structure.     

修饰性产物SDB-g-MMA与丙烯腈单体的辐射接枝

以共辐照接枝共聚物SDB-g-MMA为基材,利用γ射线在空气中对SDB-g-MMA进行预辐照,然后在场外接枝丙烯腈单体,获得了SDB-g-MMA-AN材料。通过FT-IR分析和接枝率测定,确认了预辐照接枝反应的进行。XRD和SEM分析结果表明,丙烯腈侧链的引入对材料的整体结构有序度具有显著影响。探讨了SDB-g-MMA二次辐照过程中的降解与氧化反应机理,获得了预辐照接枝产物SDB-g-MMA-AN的结构模型。