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111.
卢俊立 《贵州民族学院学报》2007,(5):169-171
歌唱中的大多数问题,都可以在呼吸中找到原因。因此,对歌唱呼吸的关注和锻炼,应该也必须贯穿歌唱者学习和工作的全部过程。文章对于歌唱呼吸对抗力的训练与运用分别进行了分析,指出呼吸可以最大限度地改善声带机能,对抗力的训练在一定程度上就是呼吸与声带搭配能力的训练,声带张力与呼吸的对抗力可以说是同时获得锻炼的。 相似文献
112.
卢文芸 《贵州民族学院学报》2007,(4):176-179
分析了当前生物化学教学中存在的问题;研究和探索了生物化学及其实验教学改革的思路和措施. 相似文献
113.
由于人口老龄化和较高的工资替代率 ,城镇职工养老总额与职工工资总额的比例逐渐上升 ,因此 ,必须对我国的养老制度进行重构 :提高职工本人缴费数额 ,从现有的国有资产存量中“割一块”注入已退休职工和跨体制职工的养老金个人帐户。而改制成功必须具备三个条件 ,一是大力发展非银行金融机构确保养老金基金保值增值 ;二是发展补充养老保险与个人储蓄养老保险 ;三是要加强法制建设 ,确保养老金制度的有法可依 相似文献
114.
Lu Jiahuan Lin Weiwei Wang Qiushi 《Voluntas: International Journal of Voluntary and Nonprofit Organizations》2019,30(3):593-609
VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - This article explores how and to what extent revenue diversification and concentration strategies affect financial... 相似文献
115.
Yunquan Song Yanji Zhu Xiuli Wang Lu Lin 《Journal of Statistical Computation and Simulation》2019,89(17):3196-3212
Nonresponse is a very common phenomenon in survey sampling. Nonignorable nonresponse – that is, a response mechanism that depends on the values of the variable having nonresponse – is the most difficult type of nonresponse to handle. This article develops a robust estimation approach to estimating equations (EEs) by incorporating the modelling of nonignorably missing data, the generalized method of moments (GMM) method and the imputation of EEs via the observed data rather than the imputed missing values when some responses are subject to nonignorably missingness. Based on a particular semiparametric logistic model for nonignorable missing response, this paper proposes the modified EEs to calculate the conditional expectation under nonignorably missing data. We can apply the GMM to infer the parameters. The advantage of our method is that it replaces the non-parametric kernel-smoothing with a parametric sampling importance resampling (SIR) procedure to avoid nonparametric kernel-smoothing problems with high dimensional covariates. The proposed method is shown to be more robust than some current approaches by the simulations. 相似文献
116.
The traditional estimation of higher order co-moments of non-normal random variables by the sample analog of the expectation faces a curse of dimensionality, as the number of parameters increases steeply when the dimension increases. Imposing a factor structure on the process solves this problem; however, it leads to the challenging task of selecting an appropriate factor model. This paper contributes by proposing a test that exploits the following feature: when the factor model is correctly specified, the higher order co-moments of the unexplained return variation are sparse. It recommends a general to specific approach for selecting the factor model by choosing the most parsimonious specification for which the sparsity assumption is satisfied. This approach uses a Wald or Gumbel test statistic for testing the joint statistical significance of the co-moments that are zero when the factor model is correctly specified. The asymptotic distribution of the test is derived. An extensive simulation study confirms the good finite sample properties of the approach. This paper illustrates the practical usefulness of factor selection on daily returns of random subsets of S&P 100 constituents. 相似文献
117.
Lighting plays an important role in daily life: It helps people perform daily activities independently and safely, and also benefits their health. This study assesses the research evidence of lighting’s impacts on older adults in four domains: (a) performance of activities of daily living and instrumental activities of daily living; (b) circadian rhythm; (c) fall prevention and postural stability; and (d) sleep quality. A comprehensive review of lighting studies on older adults’ visual and nonvisual performance was conducted using a modified PRISMA systematic review process. For the first domain, some older adults had difficulty in using the toilet, preparing meals, and doing laundry under lower illuminance. For the second domain, brighter and bluish lighting improved older adults’ circadian rhythm. For the third domain, low-intensity LED lighting affixed on door frames can help older adults maintain postural stability and prevent falling during nighttime movement. Finally, some studies concluded that receiving outdoor daylight during exercise was beneficial to older adults’ sleep quality. This study provides several methodological, theoretical, and collaborative suggestions for developing a more conclusive evidence base for lighting standards and strategies for older adults. 相似文献
118.
Shiyu Lu 《Journal of social service research》2019,45(2):241-253
Community-based elder care has become a dominant model in the world. However, the role of community-level factors in helping or hindering the individuals concerned in obtaining the needed care has not received much attention. This research aims to investigate how community-level factors, including neighborhood disadvantage, residential instability, and social service environment affect the need for instrumental, medical, and emotional services of Chinese senior residents. Employing the hierarchical multiple regression analysis, the results show that instrumental activities of daily living impairment contributed significantly to the need for instrumental, medical and emotional services. Living alone was found to be associated with the need for medical and emotional services. Objective socioeconomic status was only significantly related to the need for medical care. The type of urban community was positively associated with the need for instrumental services and was negatively related to the need for medical care. Residential instability was positively associated with of the need for instrumental services and medical care. Social service environments had heterogeneous effects on the need for social services. However, neighborhood disadvantage had no significant impact on the need for social services. Implications for future research and policy reform were also discussed. 相似文献
119.
Lilia Abadia Rosa Cabecinhas Isabel Macedo Luís Cunha 《Identities: Global Studies in Culture and Power》2018,25(3):339-357
This article provides an exploratory analysis of the life narratives of migrants in the Portuguese-speaking world. By interweaving the life experiences of eight participants in three thematic clusters – ‘shared past’, language and sense of community – we propose a critique of the deep-seated idea of the Lusophone space as a community constructed by the harmonious conviviality of different countries and people. Drawing on contributions from cultural studies, social psychology, anthropology and sociology, we first aim to give voice to the human subjects who embark on migrations and then to understand how the engendered process of identity construction is framed by their social world, simultaneously reframing it. Thus, we aim at shedding light on the ways in which aspects of the political discourses on Lusophony are used (and are instrumental) to the migrants’ identity narrative (re)construction. 相似文献
120.
Rafaela Ganga José Pedro Silva Rui Gomes Henrique Vaz João Teixeira Lopes Sílvia Silva Luísa Cerdeira Belmiro Cabrito Dulce Magalhães Maria de Lurdes Machado‐Taylor Paulo Peixoto Tomás Patrocínio Rui Brites 《International migration (Geneva, Switzerland)》2016,54(6):43-55
In the economic and social aftermath of the 2008 crisis there has been an important and growing new wave of highly qualified Portuguese emigration comprising scientists. No or very few public policies have been designed to reverse this phenomenon, risking the consequences of brain drain. International literature argues that professional reasons are central to scientists’ decision to migrate, even after the 2008 crisis. Spending some time in a foreign country to study, research, or teach, is perceived as a common step in an individual academic trajectory and an advantage for a successful professional career in academia. It is also encouraged by European Union policies. Twelve individual portraits of Portuguese scientists living in central Europe reveal how important other factors are to the migration decision‐making process. These factors include the economic crisis, student mobility programmes, and the current Portuguese scientific system revision. 相似文献