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1.
辐射PVDF/PEA共混物的熔融与结晶行为研究   总被引:4,自引:0,他引:4  
PVDF/PEA共混物熔融后在冰水中淬火或自然冷却,制得两种没结晶度的试样,经电子束辐照后,用示差热分析等方法研究它们熔融与结晶行为。结果表明,自然冷却试样的熔点Tm和结晶温度TC随辐照剂量的增加而降低,而熔融热焓ΔHf,结晶度XC和结晶热焓ΔHC随辐照剂量的增加先增加后降低。  相似文献   

2.
研究了在多官能团单体-三烯丙基异腈脲酸酯存在下,PP/LDPE共混物的辐射效应,并用SEM,DSC和动态力学性能对其形态结构和相容性进行了表征。结果表明;通过添加三烯丙基异腈脲酸酯,用辐射可以强化PP/LDPE共混物的相间结合力,改善共混物的相容性,从而提高共混物的力学性能。  相似文献   

3.
DHDECMP-TBP/煤油体系从1.0mol/L HNO3-UO2(NO3)2介质中萃取U(Ⅵ),除了存在TBP和DHDECMP的单独萃取反应外,还存在着DHDECMP-TBP的协同萃取反应。形成的萃合物分别为UO2(NO3)2.2TBP、UO2(NO3)2.2DHECMP和UO2(NO3)2.DHDECMP.TBP。实验测定了TBP/煤油、DHDECMP/煤油和DHDECMP-TBP/煤国同萃  相似文献   

4.
高能Ar离子辐照聚酯薄膜潜径迹蚀刻   总被引:1,自引:0,他引:1  
孙友梅  李长林 《核技术》1998,21(1):27-30
通过900MeVAr离子辐照聚酯(PET)薄膜潜径迹蚀刻过程的研究,给出了表征PET聚合物材料特性的径迹可蚀刻性的能损阈值(dE/dX)c并通过不同方法讨论了PET膜的径迹蚀刻速度和体蚀刻速度。  相似文献   

5.
研究了HDPE并用组分和γ辐射对NR/BR共混物力学性质的影响,发现适当的HDPE组分可以该共混物改性,γ辐射可以使其产生交联结构。  相似文献   

6.
MOSFET模拟特性的电离辐射响应   总被引:2,自引:1,他引:1  
任迪远  余学锋 《核技术》1994,17(9):525-530
通过研究60Coγ射线对MOSFET的线性特性和输出特性的影响,定性地描述了氧化物电荷积累和Si/SiO2界面态增加分别与P-MOSFET和N-MOSFET的迁移率μ退化、跨导gm下降以及输出特性曲线漂移等的依赖关系。试验结果表明,对于P-MOSFET,电离辐照感生氧化物电荷积累和界面态密度增加都将导致器件模拟特性的退化;对于N-MOSFET,这种退化主要由辐射感生Si/SiO2界面态密度增加所支配。  相似文献   

7.
李桂芝  郁伟中 《核技术》1998,21(2):68-73
用正电子湮没技术研究了甲基丙烯酸甲酯-甲基丙烯酸共聚物(P(MMA-MAA)/梯形聚苯基硅倍半氧烷(PPSQ)原位共混体系的自由体积孔穴尺寸及浓度与其组成的关系,具有两种不同配比的该共混物的正电子寿命温度谱表明,该共混物有两种结构转变,即:Tβ,Tg,因含5%PPSQ的共混试样C5中的自由体积分数较大,其TβTg均小于含1%,PPSQ的共混试样C1。研究了热历史对P(MMA-MAA)/梯形PPSQ  相似文献   

8.
^60Coγ辐射制备PEO/PVA水凝胶的研究   总被引:1,自引:0,他引:1  
利用辐射法由PEO/PVA混合液制备了PEO/PVA水凝胶,研究了辐照剂量和混合液浓度及配比对凝胶剪切模量和溶胀率的影响。结果表明,增加辐照剂量,各种配比的凝胶的剪切模量均有不同程度的提高,但同时凝胶的溶胀率下降,提高混合液的浓主也可能加凝胶的剪切模量和降低凝胶的溶胀率。在相同的辐照剂量和相同的混合液浓度下,PVA比例高,所得复合凝胶的剪切模量越高,而溶胀率就越小,因此,通过在PEO中加入PVA的  相似文献   

9.
DHDECMP-TBP-煤油协同萃取Am(Ⅲ)和Gd(Ⅲ)机理的研究   总被引:4,自引:2,他引:4  
研究了TBP-煤油,DHDECMP-煤油,DHDECMP-TBP-煤油从0.05mol/L NHO3-5.0mol/LNaNO3,介质中萃取Am^3+,Gd^3+的机理,其萃合物分别为;Am(NO3)3.3TBP,Gd(NO3)3.3TBP,Am(NO3)3.3CMP,Gd(NO3)3,3CMP,Am9NO303.3CMP.TBP和Gd(NO3)3.2CMP.TBP,并测得了各反应的平衡常数K和热  相似文献   

10.
用正电子湮没技术研究了甲基丙烯酸甲酯-甲基丙烯酸共聚物(P(MMA-MAA))/梯形聚苯基硅倍半氧烷(PPSQ)原位共混体系的自由体积孔穴尺寸及浓度与其组成的关系。具有两种不同配比的该共混物的正电子寿命温度谱表明:该共混物有两种结构转变,即:Tb、Tg,因含5%PPSQ的共混试样C5中的自由体积分数较大,其Tp、T均小于含1%PPSQ的共混试样.C1。研究了热历史对P(MMA-MAA)/梯形PPSQ共混物结构的影响。还发现正电子平均寿命与自由体积分数有着类似的随温度变化的规律  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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。  相似文献   

15.
Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.  相似文献   

16.
Accelerator database stores various static parameters and real-time data of accelerator. SSRF (Shanghai Synchrotron Radiation Facility) adopts relational database to save the data. We developed a data retrieval system based on XML Web Services for accessing the archive data. It includes a bottom layer interface and an interface applicable for accelerator physics. Client samples exemplifying how to consume the interface are given. The users can browse, retrieve and plot data by the client samples. Also, we give a method to test its stability. The test result and performance are described.  相似文献   

17.
Distributions of natural gamma-emitting radionuclides were determined in 93 oil samples collected from some petroleum fields in the western desert of Egypt. The radioisotope activities in the area under investigation lay in the range of (21 ± 4) to (38 ± 13) Bq?L-1 for 226Ra, (9 ± 2) to (15 ± 5) Bq?L-1 for 232Th, and (154 ± 28) to (303 ± 54) Bq?L-1 for 40K. The mean values were 27, 12, and 201 Bq?L-1, respectively. Among oils, variations in radionuclide ac- tivities could be on account of differences in TDS, HCO3, and Ba, with high or low pH. In this environment, oil prop- erties differently affected the mobilization of natural radionuclides. The range of 226Ra variation had been compared with available data from other countries. The calculated absorbed dose rate ranged from 22.33 to 32.66 nGy?h-1 in lo- cation (B) and (E) respectively, which was less than the accepted value.  相似文献   

18.
In this work,TTHMP was synthesized and labelled with 117m Sn.The preparation conditions,stability and lipophilicity of 117m Sn(IV)-TTHMP were investigated.Biodistribution of the complex in rabbits and mice was studied.It was found that the quantity of TTHMP and pH value of the prepararion solution had vital effects on the labeling yield of 117m Sn(IV)-TTHMP.It was also found that 117m Sn(IV)-TTHMP was hydrophilic and stable at room temperature and 37℃ in open air 117m Sn(IV)-TTHMP showed unexpectedly high bone uptake and bone-to-blood ratio in the animals.This made it potentially useful as an reagent for skeletal scintigraphy and radiotherapy of bone tumors.  相似文献   

19.
Linear accelerators equipped with multileaf collimators (MLC) are becoming more common and are widely used in the intensity-modulated radiotherapy (IMRT). There is an imperative need to ensure the commissioning specification of the linear accelerators for the sake of quality assurance (QA) and quality control (QC). This paper is aimed to investigate the role of AGFA high-energy CR (Computed Radiography) in calibrating dynamic multileaf collimators and evaluating the accuracy of the leaf position. The result shows that AGFA high-energy CR can easily and conveniently be used to calibrate MLC and verify its position. Hence, the application of AGFA high-energy CR is proved to be an accurate and time-saving method for routine MLC QC, especially when MLC calibration adjustments are required.  相似文献   

20.
Monitoring results of gamma dose rate level in 1992~2004 in the ambient environment of the Qinshan Nuclear Power Plants(QNPP)Base,the northeast of Zhejiang Province,are reported in this paper.It is shown that the gamma dose rate of five monitoring sites of 2.5 km to QNPP Base is 84~113 nGy/h,with an average of 96 nGy/h in the 13 years.The average value is close to the background level of 93 nGy/h prior to operation of the QNPP Base,and is lower than the monitoring result of 101 nGy/h at the reference site in Hangzhou City.Within 50 km from the QNPP Base,the cumulative dose rate of the thermoluminescent dosimeter(TLD)is 90 nGy/h,which is lower than the back- ground level of 111 nGy/h.  相似文献   

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