PVD法304不锈钢基体表面（Ti，Cr）N和Ti／TiN涂层的磨损腐蚀行为

当坚硬的氮化物涂层应用在腐蚀性的环境下,磨损现象与腐蚀相伴发生;因此把耐腐蚀性和耐磨损性看成是两个独立的方面,它们的特性就不能代表真实降解过程,这两种现象之间的关联就变得极其重要了。通过实验室设备所做的耐磨损实验,很容易得到其电化学特性,在氯化钠溶液中,对TiN涂层（底层有钛和没有钛）和（Ti,Cr）N涂层做了不同的磨损实验。对实验结果进行了比较,并根据PVD过程的膜层织构和残余应力对不同的行为进行了解释。（Ti,Cr）N有着最佳本征耐腐蚀性的涂层,但在磨损腐蚀过程中的耐蚀层却很薄．很有可能是因为残余应力大于在TiN中的的残余应力．使得基体表面的涂层更脆且不易粘接。TiN/Ti样品在磨损腐蚀下表现最好,这主要是由于钛基体加强了涂层的连接性。由此可见,钛基层是减少TiN层残余应力的有效手段。     

1Cr13不锈钢部分滑移区和滑移区的高温微动磨损特性

采用Deltalab—Nene7型电液伺服式高温微动磨损试验机,研究了核反应堆蒸汽发生器管支撑部件材料1Cr13不锈钢从室温到400℃的微动磨损行为。通过动力学特性分析,结合显微观测．结果发现：1Cr13不锈钢的高温微动行为与微动区域特性密切相关。在滑移区内,随着温度的升高,摩擦系数与磨损降低。微动磨损机理为氧化与剥层：高温氧化效应以及氧化膜的形成随温度的升高而加剧。在微动工况下．氧化膜萌生裂纹,裂纹扩展折向表面,直至氧化膜剥落,形成磨屑。然而。在部分滑移区内,温度对微动行为影响很小。     

TiAlZr合金及其热喷涂Ni-Cr合金涂层高温微动磨损的研究

对TiAlZr合金及其热喷涂Ni—Cr合金涂层的高温微动磨损性能进行了对比研究。不同温度下的微动磨损实验结果表明：在滑移区,温度对微动磨损的影响十分显著,TiAlZr合金抗微动磨损能力随着温度上升而急剧下降,热喷涂Ni-Cr合金涂层抗高温微动磨损能力随着温度上升而增强。在400℃时,由于氧化膜快速生成的原因．热喷涂Ni-Cr合金涂层具有优异的抗高温微动磨损特性。     

D2钢电子束表面改性抗微动磨损性能研究

利用强流脉冲电子束（HCPEB）技术对D2钢进行了表面改性处理。结果表明，电子束聂击试样近表层组织结构发生了很大变化，且亚表层显微硬度明显增加。微动磨损结果显示，电子束处理可以改善D2钢抗微动磨损性能，预涂覆TiN和Cr层效果更明显。磨痕SEM分析表明，涂覆Cr层的样品微动磨损主要机制是粘着和氧化，而TiN涂层及电子束直接处理试样主要磨损机制则是表面疲劳微裂纹的扩展和断裂产生的剥落颗粒，在摩擦面造成磨粒磨损，同时也伴随轻微的粘着和氧化，其磨损机制相对比较复杂。     

预处理和溅射工艺参数对锆合金表面TiN涂层膜/基结合强度的影响

为获得高结合强度锆合金表面涂层的制备技术，采用磁控溅射法制备了TiN涂层、划痕法测试了膜/基结合强度，研究了基体预处理表面粗糙度、溅射功率、基体加热温度和基体偏压对锆合金表面TiN涂层膜/基结合强度的影响。实验制备的TiN涂层厚度在5～15 μm范围内、基体预处理表面粗糙度在（0.20±0.03） μm范围内时，溅射功率为500 W及基体加热至300 ℃时涂层均有较好的结合强度。基体偏压为-100 V时涂层在所讨论的4种基体偏压中具有最好的结合强度。结果表明，溅射工艺参数对涂层膜/基结合强度有显著影响，其中影响显著性从大到小依次为基体加热温度、基体偏压、溅射功率、基体预处理表面粗糙度。     

Al-Si共晶合金与1Cr18Ni9Ti不锈钢的相容性研究

用粉末冶金法制备了Al-Si共晶合金与1Cr18Ni9Ti不锈钢反应堆扩散偶。采用电子显微镜（SEM）、能谱分析仪（EDS）、X射线衍射仪（XRD）D究了扩散偶在560℃和650℃时的相容性及扩散层形成机理。结果表明，扩散温度对两种材料之间的相容性有显著影响；650℃时，Al-Si共晶合金与1Cr18Ni9Ti之间通过浸润和扩散反应形成了比较明显的扩散层。XRD谱也表明，扩散层中存在Fe2Al5化合物；560℃时Al-Si共晶合金与1Cr18Ni9Ti之间仅发生固相反应，形成的扩散层很薄，二者相容性较好。     

1Cr17Ni4不锈钢等离子体喷涂金属涂层的摩擦磨损特性研究

研究了1Cr17Ni4马氏体型不锈钢表面等离子体喷涂FeCrA1Y、NiCrAlY2O3和NiCrAlY金属涂层的组织结构和小位移滑动的摩擦磨损特性。采用拉伸方法进一步分析了各涂层的结合强度、结果表明,在该等离子体喷涂工艺下,3种涂层摩擦系数相当,均明显低于ICr17Ni4不锈钢基材的值;Ni基涂层耐磨性能有所提高,其中NiCrAlY金属涂耐磨性能最好．但FeCrAlY涂层耐磨性能不及基体材料。3种涂层的磨损机制主要为磨粒在磨损中的塑性变形机制和疲劳磨损机制。     

多束动态混合注入技术制备TiN厚膜的工艺、结构及性能研究

在多束动态混合(MBMI)-注入系统上利用MBMI技术制备TiN膜，XRD分析表明，N入射角度α(o)、氮钛原子到达比RN/Ti、N2分压PN2对膜生长的择优取向及相结构有影响；性能研究结果表明，高的入射离子能量Ei、基体温度Ts以及合适的RN/Ti对TiN膜的显微硬度HK和膜 -基结合力都有正面影响。     

TiN颗粒增韧Si3N4复合材料磨损行为研究

加入TiN可改善Si3N4陶瓷的脆性，但对复合材料的耐磨性能有何影响尚不清楚，本文TiN颗粒增韧Si3N4复合材料在干摩擦条件下的磨粒磨损行为进行了研究，结果表明：磨损率随载荷和磨粒粒径的增大而增加，但磨损速度对磨损率的影响甚小，在相同的试验条件下，复合材料的磨损率高于Si3N4。Si3N4的磨损主要是磨粒对试样表面的微观犁削，其磨损极低；而30％TiN复合材料磨损表现为磨粒犁削TiN颗粒周围的Si3N4基体后，造成TiN颗粒落，随后TiN颗粒又作为磨粒对试样扩生更大的磨损。     

高速钢镀氮化碳超硬涂层及其应用研究

本文采用DC反应磁控溅射和电弧离子镀相结合的方法在高速钢上沉积氮化碳—氮化钛复合膜，经X射线衍射分析，复合膜中存在α—C3N4和β—C3N4的硬质相。复合膜的显微硬度HL=50．5—54．1GPa，它与高速钢基体的附着力，用划痕试验测得临界载荷L0=40——80N。多种刀具试用证实，该涂层具有很高的耐磨性，与末涂层和镀TiN的刀具相比，大幅度提高了刀具的耐用度。     

Identification of radiation treatment of wheat （Triticum aestivum. L）and rice （Oryza sativa. L） samples using thermoluminescence of contaminating minerals

Food irradiation is gaining popularity worldwide and this technology is important to improve quality and reduce the post harvest losses of food. Because of the rapid commercialization of irradiated foods throughout the world, compliance of different regulations relating to use of technology in different countries and demand of consumers for clear labelling of irradiated foods, there is need for the development of analytical methods to detect radiation treatment of food. Among several methods studied so far, thermoluminescence （TL） is an important method that can be used to find out the irradiation history of food that contain even a very minute amount of dust particles. In this study, the irradiated and unirradiated wheat and rice samples were analyzed using the TL method. The samples were purchased from the local market of Peshawar and irradiated to radiation doses of 0.5 and 1.0 kGy using Co-60 gamma irradiator at the Nuclear Institute for Food and Agriculture （NIFA）, Peshawar. The mineral contaminants were isolated by jet water, ultrasonic treatment, and density gradient. TL glow curves of the isolated minerals from irradiated and unirradiated samples were recorded between the temperature ranges of 50-500℃ using a TL reader. Generally, the glow curves for irradiated samples showed much higher TL intensities （TL1） than the unirradiated samples. The results were normalized by rerradiation of mineral samples to gamma-ray dose of 1.0 kGy followed by determination of the second glow curves （TL2）. The ratio of the area of first glow curve to that of second glow curve （TL1/TL2） was calculated for selected temperature intervals and compared with the recommended values for unirradiated and irradiated samples. Finally, the shapes of the glow curves for irradiated and unirradiated samples were also analyzed. On the basis of these results （comparison of TL-intensities, TL1/TL2 ratios and shapes of the glow curves）, all the irradiated and unirradiated samples of wheat and rice were unequivocally identified.     

有效探测面积大于1000 cm2的正比计数器测量系统性能测试

为对自制的活性面积高达1 000 cm²的大面积源进行表面发射率定值,同时作为现有2πα、2πβ表面发射率标准装置能力的扩充,研制了一套内置式大面积2π多丝正比计数器测量系统,并利用活性区直径为8 mm的²⁴¹Am点源及活性区面积为10 cm×15 cm的大面积²⁴¹Am和⁹⁰Sr-⁹⁰Y源对其进行计量学性能测试。结果表明：计数器内计数响应均匀性优于±0.4%,有效探测面积达1 400 cm²;所得²⁴¹Am源高压坪曲线的坪长为1 400 V,坪斜为0.27%/100 V,坪区内计数变化为0.87%;⁹⁰Sr-⁹⁰Y源高压坪曲线的坪长为300 V,坪斜为0.75%/100 V,坪区内计数变化为0.80%;10次测量重复性好于0.4%,8 h内短期稳定性好于0.3%,1 a内长期稳定性好于0.8%。     

Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET, XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn （11）. When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K 〉 673 K 〉 873 K 〉 573 K 〉 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2 catalyst. It also showed that the photocatalytic degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.     

Current status of radiation therapy for prostate cancer

Radiotherapy for the treatment of prostate cancer has been extensively explored in the past. Along with the comprehensive understanding of the biology of prostate cancer and rapid advances in terms of technology, the out- come of treatment for the patients with prostate cancer has improved. The authors review radiotherapy as the primary treatment for the disease, with particular emphasis on the technological advances from both the radiobiological and radiophysics aspects. Nonconventional fractionated irradiation like hyper- or hypo-fractionation has been imple- mented in the clinic, the final results still need to be confirmed in the future. Technological advances like IMRT, IGRT, in the last two decades have significantly improved the delivery of external radiotherapy to the prostate. This has re- sulted in an overall increase in the total dose that can be safely delivered to the prostate, which has led to modest im- provements in the biochemical outcome. However, establishing the standard therapy for prostate cancer remains con- troversial. It is hoped that the next decades will bring continued advances in the development of biologicals that will further improve current clinical outcomes.     

The control system for SSRF injection and extraction

This paper introduces the injection and extraction control system design for SSRF,which is a distributed control system aimed at stability and reliability of the pulse power supplies,PPS(Personnel Protection System)and MPS(Machine Protection System).The hardware environment is mainly based on PLC(Programmable Logic Con- troller),and ARM(Advanced RISC Machine)is also applied for studying stability of the power supplies.WinCC and EPICS(Experimental Physics and Industrial Control System)have been selected as the platforms of SCADA(Super- visory Control and Data Acquisition).For unifying the interfacing to the control computer,all front-end equipments are connected via Industrial Ethemet.     

Interaction between uranium and humic acid (Ⅰ): Adsorption behaviors of U(Ⅵ) in soil humic acids

The adsorption behaviors of uranium on three soil humic acids (HAs), which were extracted from soils of different depths at the same site, were investigated under various experimental conditions. The adsorption results showed that U(Ⅵ) in solutions can be adsorbed by the three soil HAs, with the order of FHA (HA from 5 m depth of soil) ＞SHA (HA from the surface) ＞THA (HA from 10 m depth of soil) for adsorption efficiency in each desirable condition, and the adsorption reached equilibrium in about 240 min. Although the maximum adsorption efficiency was adsorption could be described with Langmiur isotherm or Freundlich isotherm equation. The L/S (liquid/solid, mL/g)ratio and pH were important factors influencing the adsorption in our adsorption system besides uranium concentration. The adsorption efficiency decreased with the increase of the L/S ratio and pH at the pH range of 2.0-3.0 for SHA and THA or 2.5 - 6.0 for FHA. However, no significant difference in adsorption of U(Ⅵ) was observed at the experimental temperature. All the results implied that humic substances have different characteristics in samples even collected at the same site.     

水平管内含空气蒸汽强制对流冷凝换热模型研究

为研究含空气蒸汽在水平管内强制对流冷凝换热特性,基于对传热传质过程的分析,建立了管内为环状流与波状流条件下的流动冷凝换热模型。从潜热、显热和液膜3个环节对整个换热过程进行建模,最终得到计算局部冷凝换热系数的理论关系式。模型预测结果与实验数据的对比表明,二者相对偏差在±20%以内,验证了该换热模型的准确性与适用性。通过进一步的研究发现：从换热管入口至出口,随着冷凝的进行,管内换热主要热阻由液膜热阻向气液界面的凝结热阻转变;主流气体对流换热过程基本可忽略。     

The preclinical pharmacological study of dopamine transporter imaging agent 18F-FP-β-CIT

The paper is to study pharmacologic characteristics of 18F-FP-β-CIT (18F-N-(3-fluoropropyl)-2β- carbomethoxy-3β- (4-iodophenyl)nortropane) as an imaging agent for dopamine transporter. The radiochemical purity of 18F-FP-β-CIT in aqueous solution was over 95% after standing at room temperature for 4h. Biodistribution displayed rapid uptake in rat brain (1.375 %ID/organ at 5min and 0.100 %ID/organ at 180 min) and the striatal uptake was 1.444,0.731, 0.397, 0.230 and 0.146 %ID/g at 5, 30, 60, 120 and 180 min, respectively. The values of striatum/cerebellum,striatum/frontal cortex and striatum / hippocampus in rat's brain at 30 min were 3.38, 2.17 and 2.40 respectively. The uptake in striatum can be blocked by β-CFT, suggesting that 18F-FP-β-CIT binds to DAT peculiarly. The compound was rapidly cleared from monkey's blood. The striatal uptake was bilaterally decreased in the left-sided lesioned PD rats, compared with normal control. Brain PET imaging studies in normal monkey showed that 18F-FP-β-CIT was concentrated in striatum. The test of undue toxicity showed that the dose received by mice was 1250 times as by human, which indicates that 18F-FP-β-CIT is very safe. So 18F-FP-β-CIT is a promising PET imaging agent for DAT with safety and validity.     

Information for authors

<正>1.NUCLEAR SCIENCE AND TECHNIQUES(NST),a bimonthly journal,is devoted to all aspects of nuclear science and technology,theoretical or experimental.Its special interest lies in the subjects of synchrotron radiation science and technology;low energy accelerators,radiation technology and applications;radiochemistry,radiopharmaceuticals and nuclear medicine;nuclear electronics and instrumen-     

PLASMA SCIENCE AND TECHNOLOGY AUTHOR INDEX TO VOLUME 16(2014)

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