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21.
杜雪梅  吴云  满拥军 《包钢科技》2003,29(6):85-86,98
为了能及时了解放射性工作人员的受照剂量,以便能够更好地保障放射工作人员的健康与安全,采用热释光测量法对包头地区从事放射性工作的工作人员进行了个人剂量监测,并对他们的剂量当量频数分布进行了统计与分析,对工作环境的防护进行了调查对比,就今后的工作提出建议。  相似文献   
22.
The eye movements of young and older adults were tracked as they read sentences varying in syntactic complexity. In Experiment 1, cleft object and object relative clause sentences were more difficult to process than cleft subject and subject relative clause sentences; however, older adults made many more regressions, resulting in increased regression path fixation times and total fixation times, than young adults while processing cleft object and object relative clause sentences. In Experiment 2, older adults experienced more difficulty than young adults while reading cleft and relative clause sentences with temporary syntactic ambiguities created by deleting the that complementizers. Regression analyses indicated that readers with smaller working memories need more regressions and longer fixation times to process cleft object and object relative clause sentences. These results suggest that age-associated declines in working memory do affect syntactic processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
23.
Buffalo milk Cheddar cheese samples of different ages were analysed for compositional attributes (CA), ripening indices (RI) and Instron Textural Profile (ITP). All samples were compositionally alike, except for pH and salt-in-moisture (SM) contents. RI showed significant variations. CA and RI showed highly significant correlations within themselves and with each other, except for moisture with pH, SM with moisture, MNFS, Fat and FDM and Fat with MNFS. The ITPs of cheeses showed significant variations and had highly significant intercorrelations indicating their interdependence. CA (except moisture and MNFS) and RI showed a highly significant correlationship with ITPs. Moisture content showed a highly significant correlationship with all ITPs, except cohesiveness and springiness, where it was significant. MNFS content showed significant correlations only with hardness and brittleness. Stepwise regression analysis revealed that MI was the most predominant factor influencing cheese texture, followed by pH, SM, FDM and TVFA. Knowing Ca and RI, the textural properties of cheeses can be forecast through mathematical equations. Similarly the age of cheese can also be predicted if RI and/or textural properties are known.  相似文献   
24.
考虑初始椭圆度的套管抗载能力分析   总被引:1,自引:1,他引:0  
针对套管的不同初始椭圆度建立了套管、水泥环、地层平面应变力学模型。分析认为,在非均匀地应力作用下,套管内壁的径向变形较大,抗载能力明显降低,破坏主要是由地下非均匀地应力引起的;随着初始椭圆度的增加,在地应力作用下套管各部位产生的应力分布不均程度增大,使得套管抗外载能力减弱。建议在生产和使用过程中应严格将套管椭圆度控制在规定的范围内,从而提高套管的抗载能力。  相似文献   
25.
提出了一种求解任意截面形状脊形光波导的方法,先利用有效折射率的概念解出某种截面形状脊形光波导的等效折射率,再利用转移矩阵的理论求解出波导的模式色散方程。  相似文献   
26.
Much research has examined gender and age effects on compensation, concluding that a wage gap exists favoring men and negative stereotypes against older workers persist. Although the effect of an employee's gender or age has been widely studied, little work has examined the impact of the demographic characteristics of a focal employee's immediate referent groups (e.g., subordinates, peers, or supervisors) on pay. The effect of the gender and age composition of a focal manager's subordinates, peers, and supervisor on the manager's compensation levels was investigated in a sample of 2,178 managers across a wide range of organizations and functional areas. After controlling for a number of human capital variables, results indicated that not only does a wage gap favoring men exist, but also managerial pay is lower when managers' referent groups are largely female, when subordinates are outside the prime age group, and when peers and supervisors are younger. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
27.
提出了一种轴向极化压电圆环和圆片的径厚二维耦合等效电路模型。应用这一模型分析了它们的耦合振动,比较了不同尺寸比例下耦合振动与单一模式振动的异同,发现这种方法比一维等效电路方法能在较宽尺寸范围内更准确的分析压电振子的振动问题。有限元计算和试验测量结果验证了这一模型对压电振子频率计算的准确性。  相似文献   
28.
中国大油田的分布特征与发现前景   总被引:9,自引:7,他引:2  
大油田在石油储量增长和产量构成中占有重要位置.截至2004年底,中国大油田的可采储量占总探明储量的77%,2004年大油田产量占全国石油产量的70%.中国大油田的储集层主要是白垩系和第三系的陆相碎屑岩,圈闭以背斜圈闭和混合圈闭为主,20世纪70年代是中国大油田发现的高峰期.中国的大油田主要分布在富油气凹陷中;凹陷的资源丰度越大,发现大油田所需的时间越短;凹陷的资源量越大,发现的大油田规模也越大.中国目前整体勘探程度比较低,未来在中西部地区和海域都可能有大油田发现.图6表1参10  相似文献   
29.
The main purpose of the study reported here was to investigate the relative importance of complexity of syllable structure and task differences in measuring phonological awareness in low-literacy adults. This study is a replication of a study with children conducted by S. A. Stahl and B. A. Murray (1994). Results indicated that the complexity of syllable structure did indeed better describe the construct of phonological awareness in low-literacy adults. At the same time, the authors also found some differences in the pattern of literacy acquisition for their Spanish adults in comparison with child literacy acquisition in English. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
30.
The authors examined students' understanding of hypotheses as beliefs that can be empirically verified. Thirty second graders and 30 sixth graders considered cases of disagreement about foods and colors that reflected either alternative hypotheses or different preferences. Their task was to decide whether the validity of each expressed belief could be determined and to justify their decision. Younger students considered both hypotheses and preferences as empirically verifiable, whereas older students were better able to recognize in some cases that preferences are legitimately variable. This lack of distinction may reflect limited metaconceptual ability or a deterministic epistemological view, both of which might interfere with the understanding of the hypothesis-testing process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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