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运用中学生男性性别角色期望调查表和因子分析方法对贵阳市中学生进行男性性别角色期望调查和定性与定量分析,为中学生树立适宜的性别角色观,促进其心理健康发展提供量化依据.分析显示:传统的男性角色并不被现代中学生完全接受,无论是男中学生还是女中学生都在力图探求一种新的男性性别角色模式,且两性中学生对这一新的男性性别角色模式的期望和把握是有一定差异的.  相似文献   
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This paper reports on two-dimensional numerical simulation of cellular detonation wave in a / / mixture with low initial pressure using a detailed chemical reaction model and high order WENO scheme. Before the final equilibrium structure is produced, a fairly regular but still non-equilibrium mode is observed during the early stage of structure formation process. The numerically tracked detonation cells show that the cell size always adapts to the channel height such that the cell ratio is fairly independent of the grid sizes and initial and boundary conditions. During the structural evolution in a detonation cell, even as the simulated detonation wave characteristics suggest the presence of an ordinary detonation, the evolving instantaneous detonation state indicates a mainly underdriven state. As a considerable region of the gas mixture in a cell is observed to be ignited by the incident wave and transverse wave, it is further suggested that these two said waves play an essential role in the detonation propagation.Received: 16 September 2003, Accepted: 14 June 2004, Published online: 20 August 2004[/PUBLISHED]PACS: 47.40.-x, 82.40.Fp, 82.33.Vx, 83.85.PtX.Y. Hu: Correspondence to Current address: Institut für Strömungsmechanik, Technische Universität Dresden, 01062 Dresden, Deutschland  相似文献   
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Forty-eight cuticular hydrocarbons (CHCs) were characterized by gas chromatography-mass spectrometry from the epicuticular surface of the major Afrotropical malaria vector Anopheles gambiae. The hydrocarbons identified were 14 n-alkanes, 16 monomethyl alkanes, 13 dimethyl alkanes, 5 alkenes, with main-chain lengths ranging from C(17) to C(47), and the results are consistent with those from other Culicidae species. Qualitative differences were not observed between laboratory pools of three females and males, between different age-groups (0-16 days) and between single field specimens, whereas quantitative differences in CHC profiles were observed. Differences between sexes were more marked in individuals aged 0-2 days than in older ones. Both sexes undergo strong CHC profile changes with age, and individuals aged 0-2 days differ remarkably from the older ones. The possibility of exploiting these changes for estimating the age of mosquito was explored through multivariate analyses of the relative abundance of the compounds, using either the whole CHC profile or a subset of CHCs. Such a method allows us to assign more than 85% of females and 75% of males to the correct age-group. Although preliminary, these results show that the method is promising, as it has already been shown in Aedes aegypti and An. stephensi. The correct determination of the vector age (particularly in the case of the An. gambiae complex of sibling species) provides valuable information in malaria epidemiology and in evaluation of the effectiveness of vector control strategies. Further efforts will be made to validate this method on single specimens reared in seminatural conditions before being proposed to medical entomologists working in the Afrotropical region.  相似文献   
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Understanding the complex process of information spread in online social networks (OSNs) enables the efficient maximization/minimization of the spread of useful/harmful information. Users assume various roles based on their behaviors while engaging with information in these OSNs. Recent reviews on information spread in OSNs have focused on algorithms and challenges for modeling the local node-to-node cascading paths of viral information. However, they neglected to analyze non-viral information with low reach size that can also spread globally beyond OSN edges (links) via non-neighbors through, for example, pushed information via content recommendation algorithms. Previous reviews have also not fully considered user roles in the spread of information. To address these gaps, we: (i) provide a comprehensive survey of the latest studies on role-aware information spread in OSNs, also addressing the different temporal spreading patterns of viral and non-viral information; (ii) survey modeling approaches that consider structural, non-structural, and hybrid features, and provide a taxonomy of these approaches; (iii) review software platforms for the analysis and visualization of role-aware information spread in OSNs; and (iv) describe how information spread models enable useful applications in OSNs such as detecting influential users. We conclude by highlighting future research directions for studying information spread in OSNs, accounting for dynamic user roles.  相似文献   
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本文对江西省儿童医院近年来收治的 1 2 7例外源性假性性早熟女童的临床检测数据进行 R型分析 ,推导出衡量女童外源性假性早熟病情的综合指标 ,为临床诊治工作提供了一定的理论依据  相似文献   
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针对RBAC应用系统中角色具有多层语义的特点,提出了多维角色访问控制模型.模型中角色用多维角色分量表示,给出了在角色分量上定义角色层次、角色限制和角色权限指派关系的方法,使角色的语义清晰,简化了模型的角色管理和角色的权限分配.  相似文献   
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在铝氟联合中毒的系列研究中 ,发现性发育成熟前头发和血尿高铝的骨软化畸形病人 ,肝、肾铝显著升高的大鼠和鸡的骨铝、脑铝含量在接近或明显甚至显著低于正常对照组时 ,出现了铝骨病和铝危害的其它表现 ;AlCl3 ·6H2 O对童鸡非蓄积危害阈值范围指数 >5 (2 1 40 41 9) ,较低浓度比较高浓度饲铝组病变更为显著 ,铝在一定浓度或剂量范围与反应强度可呈非正相关关系 ;一定浓度以上 ,摄铝与高氟促成铝吸收和蓄积的数倍到 1 0数倍浓度差别的病情差异并不明显。表明人和动物在地壳高铝环境中的长期进化与适应 ,于生长发育旺盛的性成熟前形成并完善了对自然条件下进入内环境高铝的排斥和主动调节保护及自身平衡稳定反应的机制 ,以避免铝危害和减轻铝的危害程度  相似文献   
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讨论了一类三种群的Holling II类功能反应系统,且第二个种群对第一个种群具有性别偏食现象.利用不等式放缩方法得到了种群一致持续生存的条件,并通过构造适当的Liapunov函数得到了系统存在唯一、全局渐近稳定的正周期解的充分条件.  相似文献   
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