Simulation and Optimization of CNTs Cold Cathode Emission Grid Structure.

Carbon nanotubes (CNTs) show significant advantages in the development of cold cathode X-ray tubes due to their excellent field emission performance; however, there are still some problems, such as short lifetime and the low emission current of large-area CNTs. In this paper, a front-grid carbon nanotube array model was established, and the electric field intensity near the tip of the CNTs' electric field enhancement factor was analytically calculated. A simulation model of a CNT three-dimensional field emission electron gun was established by using computer simulation technology (CST).

Nanocone-Shaped Carbon Nanotubes Field-Emitter Array Fabricated by Laser Ablation.

The nanocone-shaped carbon nanotubes field-emitter array (NCNA) is a near-ideal field-emitter array that combines the advantages of geometry and material. In contrast to previous methods of field-emitter array, laser ablation is a low-cost and clean method that does not require any photolithography or wet chemistry. However, nanocone shapes are hard to achieve through laser ablation due to the micrometer-scale focusing spot.

Stable Field Emission from Vertically Oriented SiC Nanoarrays.

Silicon carbide (SiC) nanostructure is a type of promising field emitter due to high breakdown field strength, high thermal conductivity, low electron affinity, and high electron mobility. However, the fabrication of the SiC nanotips array is difficult due to its chemical inertness. Here we report a simple, industry-familiar reactive ion etching to fabricate well-aligned, vertically orientated SiC nanoarrays on 4H-SiC wafers.

Determinants of Beijing Residents' Intentions to Take Protective Behaviors against Smog: An Application of the Health Belief Model.

Severe smog, a form of air pollution, has become a threat to public health in Beijing, China. To examine Beijing residents' protective behavioral intentions against smog, we proposed a conceptual model, which applies the health belief model (HBM) and specifies the roles of three distal predictors: exposure to news, discussion, and worry. The proposed model was tested in the context of protective behavioral intentions (i.

The Association Among Social Support, Self-Efficacy, Use of Mobile Apps, and Physical Activity: Structural Equation Models With Mediating Effects.

Background: Physical inactivity is a risk factor for chronic noncommunicable diseases. Insufficient physical activity has become an important public health problem worldwide. As mobile apps have rapidly developed, physical activity apps have the potential to improve the level of physical activity among populations.

When Health Information Meets Social Media: Exploring Virality on Sina Weibo.

This study explored the impacts social media bring about on health communication. The impacts involved four factors: authority, privacy, evidence, and incentive appeals. They were adopted to predict virality of health messages on Sina Weibo in terms of retweeting, endorsing, and replying.

Micropunching lithography for generating micro- and submicron-patterns on polymer substrates.

Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 1977(1). They offer the advantages of low weight, easy tailoring of properties and a wide spectrum of applications(2,3). Due to sensitivity of conducting polymers to environmental conditions (e.

Fibroblast/fibrocyte: surface interaction dictates tissue reactions to micropillar implants.

Micropillar technology has shown great promise for medical implants or sensors in recent years. To study the influence of surface topography on cellular responses, polydimethylsiloxane (PDMS) micropillar arrays with pillar spacing (20-70 μm) and height (14-25 μm) have been fabricated. The influence of micropillar arrays on cellular behavior was tested both in vitro and in vivo.