从高放废液中去除超铀元素的TRPO流程热实验

阐述了从高放废液中去除超铀元素的ＴＲＰＯ流程热实验。热实验是用真实动力堆的 高放液进行的，取得了很好的效果。超铀元素镅、镎、钚和铀的去污系数分别大于 ３ ０００，４ ０００， ９５０和 ７ ０００。 ＴＲＰＯ流程在去除超铀元素的同时，还能去除对放射性废物长期危害起决定作用 的９９Ｔｃ。实验结果表明ＴＲＰＯ流程具有去污效率高，反萃效果好，锕系组分之间交叉污染小和试 剂成本低等诸多优点。ＴＲＰＯ流程是一个有效的从高放废液中去除超铀元素的流程。     

Sorption of Cesium by Potassium Titanium Hexacyanoferrate

ＳｏｒｐｔｉｏｎｏｆＣｅｓｉｕｍｂｙＰｏｔａｓｓｉｕｍＴｉｔａｎｉｕｍＨｅｘａｃｙａｎｏｆｅｒｒａｔｅＸｕＳｈｉｐｉｎｇ（徐世平）；ＳｏｎｇＣｈｏｎｇｌｉ（宋崇立）；ＪｉａｎｇＣｈａｎｇｙｉｎ（姜长印）（ＩｎｓｔｉｔｕｔｅｏｆＮｕｃｌｅａｒＥｎｅｒｇ...     

萃取液闪法测定高放废液及其处理工艺中的~（90）Sr

研究了三烷基氧膦萃取液闪法从大量盐份和强放射性下分析９０Ｓｒ活度的情况。在１ｍｏｌ／ＬＨＮＯ３介质中，体积分数φ为３０％的ＴＲＰＯ煤油有机相通过萃取除去Ｕ，Ｎｐ，Ｐｕ，Ａｍ，Ｃｍ，Ｔｃ，稀土等干挠元素，萃余水相放置２周以上让９０Ｓｒ子体９０Ｙ生长，然后用新的３０％ＴＲＰＯ煤油萃取９０Ｙ，取此有机相０．４ｍＬ加入到１０ｍＬ闪烁液中在液闪分析仪上测定９０Ｙ活度，９０Ｓｒ的活度根据９０Ｙ活度计算得到。本方法放化回收率大于９８％，精密度为２％，结果令人满意。     

海洋沉积物岩心放射性核素的γ谱测定

用HPGeγ谱仪测定了海洋沉积物岩心的天然放射性核素^40K、^210Pb、^226rA、^228tH、^238U和人工放射性核素^137Cs,进行了不同体积样品的效率刻度,对所用直径75mm、高度5－45mm柱形样品几何条件,14种能量的γ射线,用2次多项式拟合效率随样品高度变化的相关系数R^2好于0．98,用内插的不同样品高度的效率值,进行了46．5－1460．5keV能区5－45mm高度样品的效率刻度,测量了一些沉积物岩心并就其中的一个柱样中^40K、^210Pb、^226Ra、^228Ra、^228Th、^238U和^137Cs的深度分布及其所揭示的海洋学意义进行了分析、讨论。     

地理信息系统(GIS)在土壤侵蚀研究中的应用

地理信息系统强大的空间数据处理能力 ,使其在众多领域和部门中得到了广泛应用 .本文在概述地理信息系统的建立与应用的基础上 ,对其在国内外土壤侵蚀研究中的应用进行了简要的回顾 .在概述1 37Cs示踪技术研究土壤侵蚀的同时 ,展望其与地理信息系统结合在土壤侵蚀研究中的应用方法及前景     

Characteristics of 137Cs deposition in steppe area

Soil wind erosion in the semiarid steppe area was studied using the 137Cs tracing technique. Comparisons of 137Cs deposition characteristics between different soil profiles indicated that slight aeolian activities occurred on sandy grasslands and semi-fixed dunes with erosion/deposition rates of less than 0.108 cm/a, whereas they were intense on semi-shifting dunes with erosion/deposition rates of higher than 1.35 cm/a.     

土壤侵蚀137Cs法研究进展

同位素1 37Cs示踪技术具有简单、快速、准确的优点 ,它已广泛应用于土壤侵蚀的研究中 .本文先简单概述了现代土壤侵蚀速率的研究方法 ,然后着重综述了1 37Cs法在土壤侵蚀研究中的应用及其研究进展 (主要集中在1 37Cs的空间分布、土壤侵蚀速率计算模型、土壤侵蚀量估算模型等方面 ) ,最后提出未来1 37Cs法在土壤侵蚀研究中的发展趋势     

Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using 137Cs technique

The worldwide fallout of caesium-137 (137Cs) associated with the nuclear weapon tests during the 1950s and 1960s has provided a valuable man-made tracer for studies of soil erosion and sediment delivery. But relatively few researchers have used it to estimate wind erosion. In this note, the 137Cs technique is introduced into the studies of wind erosion and its modern processes in the Qinghai-Tibetan Plateau. Two 137Cs reference inventories of 982.11 and 2 376.04 Bq·m-2 were established preminarily, distributed in the south and middle-north parts of the studied area respectively. By analyzing the patterns of 137Cs depth profiles from sampling sites, the aeolian processes of erosion and deposition in nearly 40 years have been revealed, i.e. the shrub coppice dunes (S1) and semi-fixed dunefields (S3) experienced the alternation of erosion and deposition, while the grasslands (S4, S6 and S7) and dry farmlands (S5) suffered erosion only. By using 137Cs model, the average wind erosion rates for shrub coppice dune (S1), semi-fixed dune fields (S3), dry farmlands (S5) and grasslands (S4, S6 and S7) were estimated to be 84.14, 69.43, 30.68 and 21.84 t·ha-1·a-1 respectively, averaging 47.59 t·ha-1·a-1 for the whole plateau, which can be regarded as of the medium erosion standard. These results derived from 137Cs for the first time have significant implications for the further research of wind erosion and desertification control in the Qinghai-Tibetan Plateau.     

水稻氮素分配指数的试验研究与动态模拟

提出养分分配指数即某一时刻地上部各器官的吸氮量与地上部总吸氮量的比例的概念来描述水稻氮素的分配．在扬州大学实验农场进行了不同品种与不同氮肥用量对水稻氮素分配影响的试验，结果表明，水稻氮素分配指数表现出一致的规律性变化．根据分配指数的变化特点，构建了叶片、茎鞘、穗部氮素分配指数随水稻生理发育时间变化的动态关系模型，从而较简明地反映水稻植株各器官氮分配指数的连续变化，提高了模拟的可用性．将品种特征参数和施氮水平作为调节因子引入模型，提高了模型的适应能力．对叶片和穗氮素分配指数模拟的相对误差分别为7．2％和6．3％，模拟效果良好．     

贵州遵义埃洛石对Sr、Co、Cs的吸附性能实验研究

对贵州遵义埃洛石吸附Sr、Co、Cs的性能进行了实验研究,结果表明:(1)埃洛石对Sr2 、Cs2 、Co2 的吸附能力随着pH值增大而增大;(2)埃洛石对Sr2 、Cs2 、Co2 的吸附随着液固比的增大,吸附率逐渐增大,单位质量吸附量明显减小;(3)埃洛石对Sr2 、Cs2 、Co2 的吸附过程中,当吸附剂量相同时,其单位质量吸附量随初始浓度的升高而增加,吸附率则随初始浓度的升高而减小;(4)埃洛石对Sr2 、Cs2 、Co2 的吸附主要靠断键产生的可变负电荷和分子吸附。     

Estimation of wind erosion rates by using ~(137)Cs tracing technique:A case study in Tariat-Xilin Gol transect, Mongolian Plateau

Wind erosion is one of the major environmental problems in semi-arid and arid regions. Here we es- tablished the Tariat-Xilin Gol transect from northwest to southeast across the Mongolian Plateau, and selected seven sampling sites along the transect. We then estimated the soil wind erosion rates by using the ~(137)Cs tracing technique and examined their spatial dynamics. Our results showed that the ~(137)Cs inventories of sampling sites ranged from 265.63±44.91 to 1279.54±166.53 Bq·m~(-2), and the wind erosion rates varied from 64.58 to 419.63 t·km~(-2)·a~(-1) accordingly. In the Mongolia section of the transect (from Tariat to Sainshand), the wind erosion rate increased gradually with vegetation type and climatic regimes; the wind erosion process was controlled by physical factors such as annual precipitation and vegetation coverage, etc., and the impact of human activities was negligible. While in the China section of the transect (Inner Mongolia), the wind erosion rates of Xilin Hot and Zhengxiangbai Banner were thrice as much as those of Bayannur of Mongolia, although these three sites were all dominated by typical steppe. Besides the physical factors, higher population density and livestock carrying level should be responsible for the higher wind erosion rates in these two regions of Inner Mongolia.     

同位素稀释质谱-γ能谱法测定天然铀燃料元件燃耗

天然铀燃料元件燃耗低,裂变产物少,燃耗测定难度大.本文选取137 Cs为燃耗监测核素,采用高效液相色谱法(HPLC)分离燃料元件溶液中的铀,同位素稀释-热电离质谱法(ID-TIMS)测定燃料元件中铀浓度,基于高灵敏度γ能谱法测定裂变产物137 Cs.介绍了铀与裂变产物高效液相色谱分离、铀质谱测定、稀释剂与样品比例优化、137 Cs点源制备、数据修正计算等过程,给出了3根天然铀燃料棒所取样品的燃耗测定值.     

BSP树消隐算法的改进研究

BSP树算法是在三维景物空间中实现消隐的一种常见算法.BSP树消隐算法中的遍历算法通常是采用递归来实现,在实时虚拟环境具体实现时会导致很大的系统开销.本文在分析BSP树消隐算法中的BSP树的构造和遍历方法的基础上,以一种基于顺序存储结构的非递归算法来代替通常的递归算法,有效的提高了BSP树的遍历速度,提高了三维景物空间的消隐的生成速度,降低了场景中的景物表面多边形的存储空间,有利于实时虚拟环境中三维景物的快速生成.     

人参煎剂对实验红鲫经137Cs辐射后肝肾组织HSP70表达量的影响

目的 研究137Cs辐射对实验红鲫肝肾组织HSP70表达的影响,并探讨人参煎剂对实验红鲫的辐射防护效应。方法 将实验红鲫随机分为8组,即空白对照组、人参对照组、4.1Gy辐照组、4.1Gy人参预防组、4.1Gy人参治疗组、8.2Gy辐照组、8.2Gy人参预防组及8.2Gy人参治疗组。分别以137Cs辐照处理,或辐照处理前以人参煎剂浸浴7 d做预防处理,或辐照处理后以人参煎剂浸浴7 d做治疗处理,然后分别采集实验红鲫肝脏和肾脏组织,利用Western blot方法检测各组HSP70表达量。结果 与空白对照组相比,经4.1Gy或8.2Gy辐照处理后的HSP70蛋白表达量均增加;与辐照组相比,经人参煎剂预防或治疗处理后的HSP70表达量均下降;单独的人参煎剂处理,对HSP70蛋白表达量无明显影响;比较人参煎剂做预防与治疗处理,发现两者之间的HSP70蛋白表达量差异不明显。结论 137Cs辐射能够引起实验红鲫肝脏和肾脏的HSP70表达量升高,再经人参煎剂预防或治疗处理后的HSP70表达量均下降。     

Distribution characteristics of ^137Cs in wind-eroded soil profile and its use in estimating wind erosion modulus

~~Distribution characteristics of ~(137)Cs in wind-eroded soil profile and its use in estimating wind erosion modulus1.Tamura, T, Jacobs, D. G, Structural implications in cesium sorp-tion, Health Physics, 1960, 6(2): 391-398. 2.Rogowshi, A. S., Tamura, T, Movement of 137Cs by runoff, erosion and infiltration on the alluvial captina silt loam, Health Physics, 1965, 11(12): 1333-3340. 3.Owens, P. N., Walling, D. E., He, Q. P., The behaviour of bomb-derived caesium-137 fallout in …     

矿物材料对核素Sr、Cs的吸附及其固化材料的性能研究

在分析若干矿物材料的基本物性基础上,对其吸附放射性核素锶、铯的性能进行了研究.沸石、钠化改性凹凸棒石粘土矿物对锶、铯具有优良的吸附性能.矿物对锶、铯的吸附以化学吸附为主,物理吸附不是决定的因素.由热活化高岭土、新疆沸石、改性凹凸棒粘土为基质材料构成的富铝碱矿渣粘土矿物胶凝材料具有高强、较低孔隙率、较少的有害孔、抗硫酸盐侵蚀和耐辐照性能好的特点.以此材料为基材的模拟放射性废物固化体Sr2 、Cs 的浸出率较低.     

Soil Erosion Spatial Distribution Character of Sloping Field in the Sichuan Hilly Basin： Taking a Cultivated Slope in Neijiang as Example

0IntroductionNeijiang City locates in the south of The SichuanHilly Basin.The Sichuan Hilly Basin is underlainby horizontally bedded Mesozoic mudstones,siltstonesand sandstones.Purple soils developed on these rapidlyweathering rocks are widely distributed across the basin.According to second state soil erosion surveys based onremote sensing,the soil erosion rates in local area aretypicallyinthe range of3000-5000t·km-2·a-1[1,2].Inthe Sichuan Hilly Basin,one sloping field may is com-pose…     

Numerical study and prediction of nuclear contaminant transport from Fukushima Daiichi nuclear power plant in the North Pacific Ocean

On March 11,2011,a large earthquake and subsequent tsunami near the east coast of Japan destroyed the Fukushima Daiichi nuclear power plant(FD-NPP),causing a massive release of nuclear contaminants.In this paper,a Pacific basin-wide physical dispersion model is developed and used to investigate the transport of nuclear contaminants.The Pacific circulation model,based on the Regional Ocean Modeling System(ROMS),is forced with air-sea flux climatology derived from COADS(the Comprehensive Ocean-Atmosphere Data Set).It is shown that ocean current dominates nuclear contaminant transport.Following the Kuroshio Extension and North Pacific Current,nuclear contaminants at the surface will move eastward in the Pacific as far as 140°W,thereafter dividing into two branches.For the south branch,nuclear contaminants will be transported westward by the equatorial current,and can reach the Philippines after 10 years’ time.In contrast,the north branch will arrive at the American west coast and then migrate to the Bering Sea.At 200 m water depth,part of the nuclear materials will move southwestward along with deep ocean circulation,which could potentially reach the east coast of Taiwan.The other part will move to the west coast of America and separate into two branches.One will move northward along the west coast of Alaska,while the other will travel southward to the Hawaiian Islands.The transport of radiation contaminants below 500 m is slow,and will primarily remain in the central Pacific.The physical dispersion model results show that high concentrations of the radioactive isotope cesium-137(137 Cs) will move eastward and reach the central Pacific and west coast of North America in two and eight years,respectively.The sea areas influenced by the nuclear contaminants continue to expand,while peak concentrations decrease in the North Pacific.     

Sediment source identification by using ^137Cs and ^210pb radionuclides in a small catchment of the Hilly Sichuan Basin, China

The Hilly Sichuan Basin is one of the most populous agricultural regions in the Upper Yangtze River Basin and has an area of about 105000 km2. Cropland ratios and population densities vary between 0.3 and 0.7 and be-tween 400 and 800 people/km2, respectively, in the Si-chuan basin. The basin is considered as one of the most severely eroded regions in the Upper Yangtze River Basin as well in China. Soil erosion rates were reported mostly to be greater than 5000 t·km-2·a-1 by the first st…     

Estimation of wind erosion rates by using 137Cs tracing technique: A case study in Tariat-Xilin Gol transect, Mongolian Plateau

Wind erosion is one of the major environmental problems in semi-arid and arid regions. Here we established the Tariat-Xilin Gol transect from northwest to southeast across the Mongolian Plateau, and selected seven sampling sites along the transect. We then estimated the soil wind erosion rates by using the 137Cs tracing technique and examined their spatial dynamics. Our results showed that the 137Cs inventories of sampling sites ranged from 265.63=44.91 to 1279.54=166.53 Bq. m-2, and the wind erosion rates varied from 64.58 to 419.63 t. km-2. a-~ accordingly. In the Mongolia section of the transect （from Tariat to Sainshand）, the wind erosion rate increased gradually with vegetation type and climatic regimes; the wind erosion process was controlled by physical factors such as annual precipitation and vegetation coverage, etc., and the impact of human activities was negligible. While in the China section of the transect （Inner Mongolia）, the wind erosion rates of Xilin Hot and Zhengxiangbai Banner were thrice as much as those of Bayannur of Mongolia, although these three sites were all dominated by typical steppe. Besides the physical factors, higher population density and livestock carrying level should be responsible for the higher wind erosion rates in these two regions of Inner Mongolia.