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181.
迈克尔·杰克逊(MichaelJackson,歌迷昵称MJ),一个享誉世界的歌王和舞王,一个浑身上下充满神秘的力量,被称为神奇怪物的人,他的突然离世再次引起了人们对他排山倒海般的关注,只是这次变得更加温情、善意,更加乐意将他还原为本真的普通人。比如,人们突然发现,原来天王不仅仅是靠四肢舞蹈,同时还在靠智慧、头脑,甚至专利……  相似文献   
182.
In this study, the under-examined area of privacy perception and protection on Chinese social media is investigated. The prevalence of digital technology shapes the social, political and cultural aspects of the lives of urban young adults. The influential Chinese social media platform WeChat is taken as a case study, and the ease of connection, communication and transaction combined with issues of commercialisation and surveillance are discussed in the framework of the privacy paradox. Protective behaviour and tactics are examined through different perceptions of privacy in the digital age. The findings of this study suggest that users possess certain amount of freedoms on WeChat. However, users’ individual privacy attitudes and behaviour in practice suggest they have a declined sense of their own freedom and right to privacy. A privacy paradox exists when users, while holding a high level of concerns, in reality do little to further the protection of their personal information on WeChat. We argue that once a user has ingrained part of their social engagement within the WeChat system, the incentive for them to remain a part of the system outweighs their requirement to secure their privacy online as their decision-making is largely based on a simple cost-benefit analysis. The power and social capital yielded via WeChat is too valuable to give up as WeChat is widely used not only for private conversations, but also for study or work-related purposes. It further blurs the boundaries between the public, the professional and the private, which is a rather unique case compared with other social media around the world.  相似文献   
183.
Structural equation modeling (SEM) is now a generic modeling framework for many multivariate techniques applied in the social and behavioral sciences. Many statistical models can be considered either as special cases of SEM or as part of the latent variable modeling framework. One popular extension is the use of SEM to conduct linear mixed-effects modeling (LMM) such as cross-sectional multilevel modeling and latent growth modeling. It is well known that LMM can be formulated as structural equation models. However, one main difference between the implementations in SEM and LMM is that maximum likelihood (ML) estimation is usually used in SEM, whereas restricted (or residual) maximum likelihood (REML) estimation is the default method in most LMM packages. This article shows how REML estimation can be implemented in SEM. Two empirical examples on latent growth model and meta-analysis are used to illustrate the procedures implemented in OpenMx. Issues related to implementing REML in SEM are discussed.  相似文献   
184.
The prevalence of social media has provided consumers with many opportunities to post online reviews on a wide range of products on the Internet. In this study, we attempt to investigate the moderating effect of inconsistent reviews (i.e., a mix of positive and negative reviews) on consumers’ purchase decision. We further examine whether the effect will differ from female to male consumers.  相似文献   
185.
Back injury is common in rowers. Asymmetrical lower limb reaction force on the foot stretchers during rowing may compromise trunk biomechanics and lead to back injury. However, such a mechanism remains putative. Therefore, this study examined lower limb reaction force in experienced rowers with and without a history of back injury. Six rowers who suffered from back injury for more than one week in the past year and another 19 rowers who were never injured performed maximal exertion rowing on a fixed-head rowing machine for 30 strokes. Peak force, average and peak loading rate of the lower limb reaction force during the middle 10-stroke were recorded using strain-gauge transducers placed at the foot stretchers. Asymmetries and intra-limb variability were quantified as asymmetry indices and coefficients of variation, respectively. No significant asymmetry was observed in all selected kinetic parameters between the injured and healthy rowers (p = 0.448–0.722, Hedges' g = 0.162–0.310). Subgroup analyses also did not reveal any significant kinetic differences between injured and healthy scullers or sweepers (p = 0.194–0.855, Hedges' g = 0.203–0.518). Rowers with a history of back injury, regardless of the rowing types, did not demonstrate greater lower limb reaction force asymmetry when compared with healthy rowers.  相似文献   
186.
In this work, we demonstrate the use of stereolithographic 3D printing to fabricate millifluidic devices, which are used to engineer particles with multiple compartments. As the 3D design is directly transferred to the actual prototype, this method accommodates 3D millimeter-scaled features that are difficult to achieve by either lithographic-based microfabrication or traditional macrofabrication techniques. We exploit this approach to produce millifluidic networks to deliver multiple fluidic components. By taking advantage of the laminar flow, the fluidic components can form liquid jets with distinct patterns, and each pattern has clear boundaries between the liquid phases. Afterwards, droplets with controlled size are fabricated by spraying the liquid jet in an electric field, and subsequently converted to particles after a solidification step. As a demonstration, we fabricate calcium alginate particles with structures of (1) slice-by-slice multiple lamellae, (2) concentric core-shells, and (3) petals surrounding the particle centers. Furthermore, distinct hybrid particles combining two or more of the above structures are also obtained. These compartmentalized particles impart spatially dependent functionalities and properties. To show their applicability, various ingredients, including fruit juices, drugs, and magnetic nanoparticles are encapsulated in the different compartments as proof-of-concepts for applications, including food, drug delivery, and bioassays. Our 3D printed electro-millifluidic approach represents a convenient and robust method to extend the range of structures of functional particles.  相似文献   
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