Investigation of the symmetry properties and level density parameters of some superdeformed light even–even nuclei

In this study we have investigated the symmetry properties and R_4/2 energy ratio of energy bands for superdeformed light even–even nuclei from Z = 10 to 30 by the use of a simple and valid analytical relation obtained in terms of a K-quantum number, which is the projection of the total angular momentum on the axis of symmetry of a nucleus. Moreover, the nuclear level density parameters of the nuclei of interest have been calculated by considering different excitation bands of the observed nuclear spectra. The method used assumes equidistant spacing of the collective coupled state bands of the nuclei considered. The values of the calculated nuclear level density parameters and R_4/2 energy ratio have been compared with those of the experimental and compiled values and are in quite good agreement with the experimental and compiled results.     

Associations and Predictors of Posttraumatic Stress Levels According to Person-Related, Disability-Related, and Trauma-Related Variables Among Individuals With Spinal Cord Injuries.

Objective: To examine the associations and predictors of posttraumatic stress among individuals with spinal cord injuries (SCI) in the framework of a Person x Disability x Traumatic Event model. Design: An exploratory study involving analyses of variance, correlations, and a hierarchical multiple regression of a cross-sectional sample. Participants: Three hundred twelve individuals with SCI using a veteran or a civilian SCI clinic. Main Outcome Measures: Purdue Posttraumatic Stress Disorder--Revised scale (PPTSD-R). Results: Four out of all the examined variables had significant regression coefficients: spiritual-religious coping, pain level, severity of SCI, and number of traumatic events. Severity of SCI was a significant predictor, but data suggested that severity of SCI had a curvilinear association with both total posttraumatic stress levels and hyperarousal scores. Conclusion: Treatment of an individual's pain may reduce posttraumatic stress symptoms. Clinicians also can evaluate for previous trauma unrelated to the onset of the SCI and can intervene with the goal of reducing the impact of previous trauma on the individual's present emotional state and reactions to SCI. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Radioactivity levels in soil of salt field area,Kelambakkam,Tamilnadu,India

Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ~(232)Th,~(238)U and ~(40)K are ranged from 27.88 to 45.27 Bq/kg, from BDL to 13.30 Bq/kg,and from 135.54 to 381.28 Bq/kg,respectively.The measured activity concentrations for these radionuclides were compared with world average activity of soil.The average activity concentration of ~(232)Th in the present study is 1.19 times higher than world median value while the activity of ~(238)U and ~(40)K is found to be lower. The absorbed dose rates due to these radionuclides were calculated.The average absorbed gamma dose rate due to the presence of ~(232)Th,~(238)U and ~(40)K in soil samples is 36.99 nGy·h~(-1).These results indicate no radiological anomaly. The data presented in this study will serve as a base line survey for primordial radionuclides concentration in the study area.     

Estrogen-induced changes in place and response learning in young adult female rats.

Many findings suggest that changes in circulating estrogen levels influence cognition, in some cases impairing performance and in others enhancing performance. One interpretation of these mixed effects is that estrogen biases the strategy used to solve a task. To test this idea, young adult female rats, ovariectomized for 21 days, were trained after acute hormone or control treatment in 2 very similar tasks with different cognitive requirements. One task required place learning and the other response learning. Rats given two 10-μg injections of estradiol 48 and 24 hr before training learned the place task significantly faster than did rats without estradiol. Conversely, rats without estradiol performed better on the response task than did rats with replacement. These data suggest that the cognitive actions of estrogen may be task-specific by modulating the relative contribution of different learning and memory systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

型钢混凝土框架结构量化性能指标的理论分析

结构的层间变形由框架梁、柱和节点共同引起,通过分析三种构件产生的层间转角大小,得到钢筋混凝土框架结构的层间屈服位移角计算公式,对比表明,公式计算结果和试验数据吻合较好.采用相同的假设和方法,分析提出型钢混凝土(SRC)框架结构的层间屈服位移角表达公式,并按照各个性能水平极限状态之间的关系,提出具有一定概率保证的SRC框架结构的量化性能指标,为此种结构体系基于性能的抗震设计提供理论基础.     

UHV MOA设定30kA级标称放电电流的必要性

为提高变电站过电压保护及避雷器运行的可靠性,从标称放电电流如何影响1000kV避雷器的保护特性、运行特性,以及特高压变电站的雷电侵入波保护可靠性等方面出发,对1000kV变电站雷电侵入波及通过避雷器雷电流进行了EMTP仿真分析,并按1000kV变电站雷电侵入波平均无故障时间>1500a的要求,根据IEC60071-2、IEC60099-5的基本原则,讨论和分析了1000kV特高压交流系统用无间隙金属氧化物避雷器(MOA)标准,认为设定30kA标称放电电流等级是必要和可行的。     

固态继电器PCB稳态电磁辐射的仿真分析及优化

基于固态继电器印刷线路板(PCB)体积小、布线紧密和电磁辐射发射较强,采用Ansofi软件建立了含有控制电路、主回路的固态继电器PCB上连线的仿真模型.计算了处于稳态下的固态继电器PCB的电磁辐射发射电平,得到该电平与PCB布线方式、环路面积的对应关系.通过PCB布线方式、环路面积优化,降低了PCB电磁辐射发射电平,提高了电磁兼容性.     

高职英语听力分层次教学初探

针对高职院校学生的特点，依据素质教育的要求，在承认学生个体差异的基础上进行听力分层次教学，从而达到根据学生特点调整教学内容，改进教学方法，实行因材施教和大面积提高外语听力教学质量的目的。     

筑坝粗粒料单线法湿化变形模型比较

粗粒土的湿化变形是一种普遍现象,对土石坝长期安全运行至关重要。针对已有多种经验公式拟合精度未知问题,对搜集的试验数据进行验证研究。结果表明：(1)各向等压湿化体变与围压用幂函数拟合效果较好;(2)湿化轴向应变与应力水平用指数函数拟合效果较好,指数函数参数与围压呈良好的线性关系;(3)湿化体变采用双线性模型,形式简单且拟合精度较幂线型及六参数型高;(4)湿化剪应变与应力水平呈良好的双曲线关系,与围压相关性较弱。最后,分析了湿化应变与不同应力水平的相关程度,建立了基于改进相对湿化应力水平的湿化应变经验公式。