裂变核全套中子数据评价

裂变核全套中子评价数据对反应堆设计和安全运行、乏燃料少锕系核素嬗变率、嬗变系统及高燃耗反应堆设计提供重要的基础数据。文章对核数据分类、现行主要全套评价数据库及全套核数据评价方法进行阐述,并对234U(n,f)和237Np(n,2n)反应截面的实验数据进行评价。完成的裂变核全套中子数据整体满足用户需求,比原评价结果有较明显改进。     

天然汞的全套中子数据理论计算和评价

在10~(-5)eV～20MeV的中子能量范围内给出了天然汞的全套中子核数据。评价的内容包括总的、弹性、去弹、总非弹、30条分立能级、连续非弹、(n,2n)、(n,3n)、(n,n′p)、(n,n′a)、(n,p)、(n,d)、(n,t)、(n,a)和(n,r)截面;次级中子角分布;双微分中子发射截面(DDX);γ射线产生数据和共振参数等。评价是根据仔细分析和选择的有效实验数据和理论计算而进行的。理论计算程序(UNF-92)对中重核的核反应计算起了重要的作用。评价数据以ENDF/B-6格式编入中国评价核数据库存[MAT=1800],并提供核工程有关部门使用。     

天然汞的全套中子数据理论计算和评价(英文)

在10~(-5)eV～20MeV的中子能量范围内给出了天然汞的全套中子核数据。评价的内容包括总的、弹性、去弹、总非弹、30条分立能级、连续非弹、(n,2n)、(n,3n)、(n,n~1p)、(n,n~1α)、(n,p)、(n,d)、(n,t)、(n,α)和(n,γ)截面;次级中子角分布;双微分中子发射截面(DDX);γ射线产生数据和共振参数等。评价是根据仔细分析和选择的有效实验数据和理论计算而进行的。理论计算程序(UNF-92)对中重核的核反应计算起了重要的作用。评价数据以ENDF/B-6格式编入中国评价核数据库存[MAT=1800],并提供核工程有关部门使用。     

快堆伪裂变产物截面和角分布的计算

为满足我国示范快堆研究的需要并解决以往伪裂变产物截面数据偏小的问题,需重新研制一种制作伪裂变产物数据的方法,为制作多个裂变核的伪裂变产物全套中子数据提供基础。本文用浓度加权求和的方法计算伪裂变产物截面、微分截面和双微分截面。在挑选核素的过程中提出贡献法,即利用裂变率加权产额和吸收截面(反应道MT=27)得到产物核对反应堆的贡献值,从而量化了挑选核素的过程,提高了计算的准确性。最后以CENDL_NP库为主要数据来源,TENDL库数据为补充,制作出了一套~(235) U的伪裂变产物截面数据,通过与以往计算结果比较证明了上述方法的优越性和实用性。     

天然铌的全套中子数据理论计算和评价(英文)

对于天然铌的全套中子核数据评价是依据测量到1989年的实验数据。同时,理论计算采用了MUP2和AUJP程序。该工作是为了建立中国评价核数据库第二版(CENDL-2),同时取代了第一版(CENDL-1)。对铌的中子产生数据是在10~(-5)eV到20MeV中子能量范围内给出。截面部分包括了总的、弹性、去弹、总非弹、13条分立能级、连续非弹、(n,2n)、(n,3n)、(n,n′α) (n,αn′)、(n,n′p) (n,pn′)、(n,n′d) (n,dn′)、(n,p)、(n,d)、(n,t)、(n,α)和俘获截面。对于MT=251、252和253特殊数据及角分布和次级中子能谱也同时给出。     

天热铌的全套中子数据理论计算和评价

对于天然铌的全套中子核数据评价是依据测量到1989年的实验数据。同时,理论计算采用了MUP2和AUJP程序。该工作是为了建立中国评价核数据库第二版(CENDL-2),同时取代了第一版(CENDL-1)。对铌的中子产生数据是在10~(-5)eV到20MeV中子能量范围内给出的。截面部分包括了总的、弹性、去弹、总非弹、13条分立能级、连续非弹、(n,2n)、(n,3n)、(n,n′α) (n,αn′)、(n,n′p) (n,pn′)、(n,n′d) (n,dn′)、(n,p)、(n,d)、(n,t)、(n,α)和俘获截面。对于MT=251、252和253特殊数据及角分布和次级中子能谱也同时给出。     

天然镍中子核数据编评

工作是在中国核数据评价库第1版(CENDL-1)的基础上(由马功佳评价的MAT=1280),为中国核数据评价库第2版(CENDL-2)而做的。天然镍的中子核数据编评是根据收集到1989年的实验数据并使用MUP2程序进行理论计算来完成的。在10~(-5)eV～20MeV能量范围内,以ENDF/B-4库格式给出了中子产生数据(MAT=2280)。其中截面包括了总截面、弹性散射截面、去弹性散射截面、非弹性散射截面、21条分立能级激发曲线、连续非弹性散射截面、(n,2n),(n,3n),(n,n′α) (n,αn′),(n,n′p) (n,pn′),(n,p),(n,d),(n,t),(n,~3He),(n,α)和俘获截面。同时也包括了特殊数据μ,ζ和γ。并且给出角分布和次级中子能谱。     

天然镍中子核数据编评(英文)

工作是在中国核数据评价库第1版(CENDL-1)的基础上(由马功桂评价的MAT=1280),为中国核数据评价库第2版(CENDL-2)而做的。天然镍的中子核数据编评是根据收集到1989年的实验数据并使用MUP2程序进行理论计算来完成。在10~(-5)eV～20MeV能量范围内,以ENDF/B-4库格式给出了中子产生数据(MAT=2280)。其中截面包括了总截面、弹性散射截面、去弹性散射截面、非弹性散射截面、21条分立能级激发曲线、连续非弹性散射截面、(n,2n),(n,3n),(n,n′α) (n,αn′),(n,n′p) (n,pn′),(n,p),(n,d),(n,t),(n,~3He),(n,α)和俘获截面。同时也包括了特殊数据μ,ζ和γ。并且给出角分布和次级中子能谱。     

基于快堆嬗变的伪裂变产物截面制作

从ENDF/B-VII库提取数据,通过NJOY程序对快堆中生成的裂变产物核素进行模块加工,利用Matlab进行编程对NJOY程序计算得到的数据进行再次加工处理,得到235U核素快堆嬗变的多群伪裂变产物截面数据,然后用MCNP程序对设计的快堆进行计算得到中子能谱图,并用中子能谱对MCNP程序生成的多群截面进行并群。把生成的数据与NJOY程序生成的数据进行对比验证表明,经过处理的截面数据可以用于快堆的燃耗计算。     

天然镍全套中子核数据的评价(英文)

评价了天然镍在10~(-5)eV～20MeV能区的全套中子数据。数据包括全截面、弹性、去弹、总非弹、33条分立能级和连续态的非弹及(n,2n),(n,3n),(n,n′α) (n,αn′),(n,n′p) (n,pn′),(n,p),(n,d),(n,t),(n,α),(n,γ)和(n,2p)反应截面,还包括有关反应的次级中子角分布、双微分截面(DDCS),γ产生数据和共振参数。评价依据直到1996年测量的实验数据和用UNF程序的理论计算。评价数据以ENDF/B-6格式给出并纳入中国评价核数据库第三版(CENDL-3)。     

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.     

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。     

Investigations on landmine detection by BF3 detector

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.     

Web Services interface of SSRF archive data analysis system

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.     

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%。     

Assessment of radioactivity levels in some oil samples from the western desert, Egypt

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.     

Preparation and properties of 117m Sn(IV)-TTHMP in in-vitro and in small animals

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.     

The role of AGFA high-energy CR in the calibration and quality control of multileaf collimators （MLC）

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.