Distribution of radioactivity in wheat plants grown in the presence of strontium-90

Thatcher wheat grown in soil to which Sr(90) had been added showed that accumulation of radioactivity in the kernels was about one-tenth the accumulation in leaves and stems. Experimental milling of the kernels gave brans with the largest amounts and flours with the least amounts of activity, the Sr(90) concentrations being related practically linearly to the weights of total ash in the various milling products.     

Maximum permissible body burden of strontium-90

The permissible body burden of Sr(99) is discussed with respect to the mode of intake. It appears that the maximum permissible load may depend on the type of exposure, acute or chronic, the acute being the more serious.     

Life shortening and tumor production by strontium-90

A linear relationship between dose of internal radiation and two effects, which implies no threshold, is shown to be a possible interpretation of data given by Finkel in "Mice, men and fallout" (1). This interpretation is at variance with that offered by Finkel, which was that the dose-effect relationship is nonlinear and indicates a threshold.     

交换钙对锶-89在小麦和大豆中积累的影响

运用同位素示踪技术研究了交换钙对~(89)Sr在小麦及其连作作物大豆中积累的影响。结果表明,交换钙将抑制~(89)Sr由土壤向小麦和大豆植株的输运和积累。~(89)Sr在该两种作物中的滞留浓度C_i与交换钙量x呈线性负相关:麦根(?)_1=124.2-10.1x,麦秸(?)_2=99.3-3.8x,麦壳(?)_3=40.1-6.0x,麦粒(?)_4=12.3-1.5x;大豆根(?)_1=333.0-53.5x,豆秸(?)_2=230.2-36.5x,豆壳(?)_3=240.5-42.3x,豆叶(?)_4=309.2-48.9x,豆籽(?)_5=11.8-1.6x。     

小麦耕层土壤微生物分布情况的研究

为提高土壤肥力、改善土壤生态环境,并为提高小麦产量提供理论依据,文章分别对山西省、河南省、黑龙江省、天津市西青区、天津市武清区、宁夏回族自治区的小麦地耕层土壤微生物的类群、数量及分布进行测定并比较。结果表明,随着耕层深度的增加,土壤微生物数量先增加后减少,在第2层或第5层出现最大菌落数量,并且发现麦田土壤微生物含量与小麦产量和土壤的理化性质有着密切的联系。     

黄淮麦区部分小麦种质资源中矮秆基因的分布

选用254份黄淮麦区小麦品种(系),利用BFMR1,DFMR2和微卫星xgwm261标记检测了矮秆基因Rht-B1b,Rht-D1b和Rht8的分布.结果表明,在254份材料中,含有Rht-B1b,Rht-D1b和Rht8基因的材料分别有84,171和178份,平均株高分别为80.7,78.5和80.7 cm.只含有Rht-B1b,Rht-D1b和Rht8基因的材料分别有15,36和31份,平均株高分别为83.8,80.1和86.2 cm.只含Rht-B1b和Rht-D1b基因有16份,平均株高为73.7cm,Rht-B1b和Rht-D1b基因具有累加效应,两个基因同时存在时株高降低幅度会更大.只含Rht-B1b和Rht8基因的有94份,只含Rht-D1b和Rht8基因的有28份,同时含有Rht-B1b,Rht-D1b和Rht8基因的有25份,同时不含这3个矮秆基因的有9份,说明黄淮麦区小麦品种(系)中绝大部分品种均含有不同种类的矮秆基因.微卫星WMS 261及基于PCR的2个STS标记可以分别用于对品种(系)中Rht8,Rht-B1b和Rht-D1b基因型的鉴定以及育种世代该基因型的筛选.     

Orphan strontium-87 in abyssal peridotites: daddy was a granite

The (87)Sr/(86)Sr ratios in some bulk abyssal and alpine peridotites are too high to be binary mixtures of depleted mantle and seawater components. The apparent excess, or "orphan," (87)Sr appears to be separated from its radioactive parent. Such observations were widely held to be analytical artifacts. Study of several occurrences of orphan (87)Sr shows that the orphan component in abyssal peridotite is located in the alteration products of olivine and enstatite in the peridotite. The orphan (87)Sr is most likely introduced by infiltration of low-temperature (<200 degrees C) seawater bearing suspended detrital particulates. These particulates include grains of detrital clay that are partly derived from continental (that is, granitic) sources and thus are highly radiogenic. Orphan (87)Sr and other radiogenic isotopes may provide a tracer for low-temperature seawater penetrating into the oceanic crust.     

Chondrites: initial strontium-87/strontium-86 ratios and the early history of the solar system

A sodium-poor, calcium-rich inclusion in the carbonaceous chondrite Allende had a (87)Sr/(86)Sr ratio at the time of its formation of 0.69880, as low a value as that found in any other meteorite. The higher (87)Sr/(86)Sr ratios found in ordinary chondrites indicate that their formation or isotopic equilibration occurred tens of millions of years later.     

Stratospheric fallout of strontium-89 and barium-140

A series of nuclear test explosions which occurred in the fall of 1958 caused a very large increase of Sr(89) and Ba(140) in the stratosphere. The Ba(140)/Sr(89) ratio in the stratosphere, and hence in the troposphere, has decreased steadily since then with a half-life of approximately 17 days.     

产量相关优异等位变异在小麦骨干亲本阿夫及其衍生后代中的分布

[目的]利用已报道的穗粒数和千粒重位点,通过分析上述位点优异等位变异在骨干亲本阿夫及其在河南育成衍生后代中的分布,从分子水平解析骨干亲本阿夫在小麦育种中发挥的作用。[方法]对骨干亲本阿夫及其在河南育成的18份衍生后代的26个SSR位点使用ABI3730进行基因型扫描分析。[结果]26个SSR标记分布在小麦13条染色体上,其中主要等位变异频率平均值为0.557,频率的变异范围为0.211~0.889;标记所对应的等位变异呈现了从2到9的数量变化;多态性信息指数平均值为0.512,范围为0.194~0.830。NJ聚类分析结果显示,19份材料聚成3组。对优异等位变异的分析表明,阿夫子四代豫30691-1-3携带与穗粒数关联的优异等位变异最多(8个),阿夫子一代开封10号携带与千粒重关联的优异等位变异最多(8个)。[结论]阿夫及其在河南选育的衍生后代覆盖了全部26个产量相关优异等位变异,这也一定程度上从分子角度揭示了这些后代能够成为河南省育成品种的原因。     

澄城县小麦地土壤全氮含量空间分布的ArcGIS模拟

采用试验分析与地统计学方法对陕西省澄城县91个样区小麦土壤全氮含量进行了空间结构分析.结果表明:样点原始全氮值不符合正态分布,经Cox-box变换后符合正态分布;普通克里格插值法半变异函数符合圆型模型,函数块金值为3.79×10-3,偏基台值为4.15×10-3,变程为4 856m;澄城县调查样区96.7%的小麦地土壤全氮含量处于不同的缺乏状态.     

铅在小麦籽粒中的分布及与其他8种元素的关系

运用环境扫描电镜结合X射线电子探针显微分析技术,对不同基因型小麦籽粒皮层、糊粉层、盾片、胚芽、胚轴、胚根、内胚乳7个部位的铅相对含量进行测定。结果表明：铅在小麦籽粒不同部位的含量存在明显差异,由大到小的依次为：糊粉层、胚轴、胚根、盾片、胚芽、皮层、内胚乳。不同基因型小麦籽粒对铅的富集量存在遗传差异,这种差异体现在同一部位和不同部位之间铅相对含量的差异上;不同基因型小麦籽粒皮层、糊粉层、盾片、胚芽、胚轴、胚根和内胚乳铅相对含量之间均呈现极显著的线性关系。通过比较不同基因型小麦籽粒各部位铅相对含量与其他元素的关系,发现各个部位的铅与铝、镉、镁、钾、磷、钙、硒和硫相对含量之间均存在着极显著的线性关系。     

钙对锶－89在马铃薯与水稻中积累的影响

采用同位素示踪技术研究了钙对￣（８９）Ｓｒ在马铃薯和水稻中积累的影响。结果表明钙对￣（８９）Ｓｒ在作物植株内的分布和积累具有明显的影响和抑制作用。马铃薯和水稻各部位中￣（８９）Ｓｒ的浓度与钙的引人量呈线性负相关，在同一处理条件下，不同部位中￣（８９）Ｓｒ浓度具有显著的差异，马铃薯：地上部＞＞块茎．水稻：稻草＞＞稻壳＞＞糙米。     

Strontium-90 in Ecuador

Samples of bone and soil collected in 1958 show highest values for Sr90 in the tropical region on the east side of the Andes. Lowest values are found in the high central valley, where samples used in estimating world-wide distribution of fallout were collected. If the major fallout deposition occurs in the interior of the South American continent, such estimates for these latitudes may be low by as much as a factor of ten. Although there has apparently been greater Sr90 deposition in regions of greater rainfall, analysis of data from 16 locations fails to show a significant correlation between rainfall and fallout.     

不同品系对小麦白粉病的抗性鉴定

通过田间自然发病和人工接种鉴定，对2000年华北北部203份材料中选育出来的抗病性、丰产性好的48份材料再次进行成株期和苗期抗白粉病鉴定，鉴定结果：成株期免疫材料有24份，高抗材料9份，中抗材料6份。苗期无免疫材料，高抗材料31份，中抗材料10份。     

90Sr-90Y敷贴治疗皮肤毛细血管瘤和神经性皮炎的疗效观察

目的:了解放射性核素敷贴器(90S r-90Y敷贴器)治疗毛细血管瘤、神经性皮炎的效果。方法:对157例毛细血管瘤患者、65例局限性神经性皮炎患者,采用90S r9-0Y敷贴器进行β射线外照射治疗。剂量安排:一次大剂量法5~15G y,酌情间隔4~8周进行下一次治疗。结果:毛细血管瘤治愈95例(60.5%),显效44例(28.0%),有效18例(11.5%),无效0例,总显效率100.0%。局限性神经性皮炎治愈14例(21.5%),显效32例(49.2%),有效19例(29.2%),无效0例,总显效率100.0%。结论:对毛细血管瘤和局限性神经性皮炎,放射性核素敷贴器治疗具有疗效确切的特点,是治疗此两病的有效方法之一。