自然伽马能谱测井在海相页岩储层评价中的应用研究

为了破解南方海相页岩储层在有机碳含量/泥质含量计算、岩性识别、沉积环境恢复、储层评价等方面的难题,对龙马溪组岩心进行系统采样和测试,对自然伽马能谱测井数据、解释成果等进行深入的分析和研究。通过对龙马溪组岩心的标定,建立页岩铀和有机碳含量的关系,经过验证有机碳含量计算值与实测值基本吻合;利用相对值法,对海相页岩泥质含量进行提取,提高泥质含量计算的准确性;采用钍、铀、钾比值和交会图开展黏土矿物类型划分、岩性识别和沉积环境辨识,龙马溪组地层岩性以泥页岩、粉砂岩为主,黏土矿物以伊蒙混层为主,含伊利石;黑色页岩为海相强还原环境的沉积产物,水动力条件较弱,以低能为主;测井上铀含量高、钍和钾含量低,指示可能为高放射性、裂缝发育的储层;自然伽马能谱测井对页岩储层的划分和评价具有较好的指示性,可为页岩储层评价和沉积环境恢复提供依据。     

核磁共振测井束缚水模型研究

核磁共振(NMR)测井是目前唯一能区分地层中可动流体和束缚流体的测井方法,具有其他测井方法不具备的独特优势。在分析孔隙介质中束缚水存在机理的基础上,给出了目前利用核磁共振测井确定束缚水的模型和方法,分析了各种方法的适用条件。研究结果表明:T2截止值方法(CBVI)是目前广泛使用的确定束缚水体积方法,这种方法在很多情况下是适用的,但不适合于高含水饱和度的粗粒砂岩以及碳酸盐岩储层;T2谱系数法(SBVI)不适合近似束缚水状态的含烃地层;渐变截止值法(TB-VI)适合于任何饱和水的以及水基泥浆冲刷的地层,在纯净、分选好的砂岩和碳酸盐岩地层,该方法计算结果更准确;BVI加权函数法对孔隙几何形状不敏感。     

利用快中子散射截面定量评价砂泥岩储层含气饱和度的方法及应用

陆相砂岩和海相碳酸盐岩等致密气储层非均质性强,气水关系复杂,孔隙度低,定量评价含气性是储层评价必然需求.为建立含气储层饱和度的评价方法,通过研究非弹性散射伽马计数、快中子散射截面与含气饱和度响应关系,利用蒙特卡罗软件建立不同孔隙度和泥质含量等条件下井筒-储层模型,模拟非弹性散射伽马计数分布.结果表明,利用非弹伽马计数可...     

致密砂岩气藏核磁共振测井与常规测井的孔与渗透模型关系

为建立良好的测井物性解释模型,以更准确地评价塔巴庙地区上古生界盒3段致密砂岩气藏产能,对比了14块岩样的核磁孔隙度与其岩心孔隙度,发现它们有线性相关性;对比核磁渗透率与岩心渗透率,也获相同结果.这表明核磁孔渗与常规孔渗线性相关.以此为依据,以核磁共振测井的孔渗为桥梁,以常规测井数据为基础,建立了常规测井的孔、渗计算模型.所建模型既避免了取心位置与常规测井之间深度的不一致性,又不会存在因岩心数据的不连续而带来的岩心孔渗模型计算值应有的误差,所以它更适合于盒3段储层孔渗的评价.     

核磁共振T2谱最优化反演方法

基于模型构制思想将核磁共振T2谱反演问题转化为求目标函数极小值的最优化问题,建立新的易于实现T2谱非负性约束的优化反演模型,然后利用共轭梯度FR算法解决上述反演问题。将该方法应用于无噪声理论回波数据反演、信噪比SNR=25的理论回波数据反演以及岩心NMR实验数据反演,并与真实谱及实验室国外软件反演结果对比表明,无噪声理论回波数据反演的T2谱与构造谱几乎完全符合;信噪比SNR=25时反演的T2谱和构造谱符合得很好;岩心反演的T2谱与实验室国外软件反演的T2谱符合得很好,谱线光滑连续。利用反演结果计算的核磁孔隙度与实验室氦孔隙度绝对误差为0.65%。     

致密油岩心孔隙度核磁共振实验测量的杂质信号处理方法

核磁孔隙度的测定是核磁共振岩心分析的重要内容和基础性工作。通过5块致密油岩心的核磁共振测量发现,核磁孔隙度明显高于质量孔隙度。分析原因主要是致密油岩心洗油难度大、部分含氢物质未能洗去,存在较强的杂质测量信号。为了消除杂质信号对测量核磁孔隙度的影响,提出了谱差值法和差值谱法,给出了两种方法的实验测量和数据处理方法,并通过实验数据分析了两种处理方法的适用性。差值谱法的处理结果表明,5块致密油岩心的核磁孔隙度与质量孔隙度比值的平均值由1.660变为1.196,明显减小了核磁孔隙度的测量误差;采用差值谱法处理致密油岩心的核磁共振实验数据可有效地提高核磁孔隙度的测量精度。     

古陶瓷元素谱产地和年代特征的SRXRF分析方法学研究

用同步辐射X荧光(SRXRF)分析了土壤和岩石标准参考物质、泰兵马俑和江西洪州窑古瓷中的元素谱。实验结果表明用扫描方式分析古陶瓷中的元素谱能提高实验数据的重复性，在古陶瓷元素谱的无损分析中，现有标准参考物质可以用于部分元素含量的的标定和分析质量控制。     

数字测井在地浸采铀中的应用研究

采用数字测井,建立孔隙度模型、渗透率模型和泥质含量模型,由测井直接获得了各分层有效孔隙度、渗透率、泥质含量等资料,对含矿含水层进行了更为详细的岩性划分,为地浸采铀的工艺生产、技术管理提供准确的信息资料.     

U_3Si_2-Al燃料元件γ射线吸收系数标定方法研究

为了更准确标定U_3Si_2-Al燃料元件的γ射线吸收系数,论文设计了不同标样进行了单独定标和联立定标。利用不同标定方法获得的γ射线吸收系数进行燃料元件U_3Si_2、Al质量厚度的测试,并将测试结果分别与化学分析结果进行对比。实验结果表明,以燃料元件作为标样的联立定标法在保证Al测量精确的同时提高了U_3Si_2的测量精度。     

230 MeV超导回旋加速器测磁线圈校准

正磁场测量与垫补系统是230 MeV超导质子回旋加速器主磁铁系统的子系统之一。目前,230 MeV超导质子回旋加速器主磁铁、线圈、配套电源均已完成加工,磁场测量工作即将展开。磁能量法是加速器中常用的磁场测量方法。磁能量法原理简单,但误差来源较丰富,需要对感应线圈探头的面积进行标定。利用回旋加速器研究设计中心临时厂房的标准C型二极铁提供高均匀度磁场,校准时利用NMR测量探头进行磁场标定。通过多次校准,经计算后取平均值可得到感应线圈的面积与厂家所     

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.     

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。     

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.     

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.     

Gamma radiation levels in the ambient environment of the QNPP Base

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.     

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.     

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.