A compact coplanar waveguide (CPW)-fed triple-band monopole antenna with high-band isolation for various wireless applications is presented. The proposed antenna is composed of a CPW-fed structure ...and a hexagon-shaped patch on which a hexagon-shaped slot is etched for covering the wireless local area network (WLAN) band (2.4/5.2/5.8 GHz), and occupies a very compact size of 26 × 25 mm2. By introducing a half-hexagon-shaped stub, additional bands can be realised covering the worldwide interoperability for microwave access (WIMAX) band (2.5/3.5/5.5 GHz). The proposed antenna has been fabricated and measured; results show a higher isolation between adjacent bands, good radiation pattern characteristics and stable gains in the operating bands. The simple feeding structure, compact size and uniplanar design make it easy to be integrated within portable devices for wireless communication.
High biodiversity increases ecosystem functions; however, belowground facilitation remains poorly understood in this context. Here, we explore mechanisms that operate via ‘giving–receiving feedbacks’ ...for belowground facilitation. These include direct effects via root exudates, signals, and root trait plasticity, and indirect biotic facilitation via the effects of root exudates on soil biota and feedback from biota to plants. We then highlight that these two- or three-way mechanisms must affect biodiversity–ecosystem function relationships via specific combinations of matching traits. To tango requires a powerful affinity and harmony between well-matched partners, and such matches link belowground facilitation to the effect of biodiversity on function. Such matching underpins applications in intercropping, forestry, and pasture systems, in which diversity contributes to greater productivity and sustainability.
Belowground facilitation is a vital mechanism underlying ecosystem function in diverse plant communities.A bottleneck to linking theory to application is that interspecific belowground facilitation processes are incompletely understood.Here, we explore direct and indirect facilitation, which requires matching specific belowground responses between the facilitated species and the facilitator.Understanding and integrating the processes of interspecific facilitation helps to design sustainable diverse plant communities with compatible ecosystem functions.
•Young adults are sensitive to the reducibility of uncertainty during belief updating.•Updating processes are quasi-optimal and valence-dependent.•Neural responses in frontoparietal regions show ...valence-dependent recruitments.•Valence asymmetry at behavioral and neural levels is correlated.
Selective use of new information is crucial for adaptive decision-making. Combining a gamble bidding task with assessing cortical responses using functional near-infrared spectroscopy (fNIRS), we investigated potential effects of information valence on behavioral and neural processes of belief and value updating during uncertainty reduction in young adults. By modeling changes in the participants’ expressed subjective values using a Bayesian model, we dissociated processes of (i) updating beliefs about statistical properties of the gamble, (ii) updating values of a gamble based on new information about its winning probabilities, as well as (iii) expectancy violation. The results showed that participants used new information to update their beliefs and values about the gambles in a quasi-optimal manner, as reflected in the selective updating only in situations with reducible uncertainty. Furthermore, their updating was valence-dependent: information indicating an increase in winning probability was underweighted, whereas information about a decrease in winning probability was updated in good agreement with predictions of the Bayesian decision theory. Results of model-based and moderation analyses showed that this valence-dependent asymmetry was associated with a distinct contribution of expectancy violation, besides belief updating, to value updating after experiencing new positive information regarding winning probabilities. In line with the behavioral results, we replicated previous findings showing involvements of frontoparietal brain regions in the different components of updating. Furthermore, this study provided novel results suggesting a valence-dependent recruitment of brain regions. Individuals with stronger oxyhemoglobin responses during value updating was more in line with predictions of the Bayesian model while integrating new information that indicates an increase in winning probability. Taken together, this study provides first results showing expectancy violation as a contributing factor to sub-optimal valence-dependent updating during uncertainty reduction and suggests limitations of normative Bayesian decision theory.
Summary
As a lattice Boltzmann method, He‐Chen‐Zhang model is widely used in two‐phase simulations. However, the pressure boundary conditions applied in He‐Chen‐Zhang model have hardly been discussed ...in detail before. In this article, a pressure boundary condition for single‐phase flows is extended to He‐Chen‐Zhang model for simulating two‐phase flows in porous media or in channel. Several cases are conducted for validation. Qualitatively, the displacement of two‐phase flows in porous media or in channel is reproduced; the manipulations of droplet in T‐junction, duct, or needle are simulated. These numerical results match well with the basic physical reality. Quantitatively, we tested the displacement of two‐phase fluids in a channel under specified pressure gradient, and it is found that the velocity profile on the crosssection coincides with the analytical solution exactly. Moreover, for stable displacement of two‐phase flows in a channel, the numerical linear relation between the apparent contact angle and the velocity of contact line coincides well with the theoretical result reported before. The present pressure boundary condition proves to be a reliable method to deal with the problems of two‐phase flows, which are driven by pressure difference.
A pressure boundary condition for single‐phase flows is incorporated into He‐Chen‐Zhang model for simulating two‐phase flows in porous media or in channel. Several cases are conducted for validation. The present pressure boundary condition proves to be a reliable method to deal with the problems of two‐phase flows which are driven by pressure difference.
Light management holds great promise of realizing high‐performance perovskite solar cells by improving the sunlight absorption with lower recombination current and thus higher power conversion ...efficiency (PCE). Here, a convenient and scalable light trapping scheme is demonstrated by incorporating bioinspired moth‐eye nanostructures into the metal back electrode via soft imprinting technique to enhance the light harvesting in organic–inorganic lead halide perovskite solar cells. Compared to the flat reference cell with a methylammonium lead halide perovskite (CH3NH3PbI3−xClx) absorber, 14.3% of short‐circuit current improvement is achieved for the patterned devices with moth‐eye nanostructures, yielding an increased PCE up to 16.31% without sacrificing the open‐circuit voltage and fill factor. The experimental and theoretical characterizations verify that the cell performance enhancement is mainly ascribed by the broadband polarization‐insensitive light scattering and surface plasmonic effects due to the patterned metal back electrode. It is noteworthy that this light trapping strategy is fully compatible with solution‐processed perovskite solar cells and opens up many opportunities toward the future photovoltaic applications.
A convenient and scalable light trapping scheme is demonstrated to enhance the light harvesting in organic–inorganic lead halide perovskite solar cells, which is realized by incorporating bioinspired moth‐eye nanostructures into the metal back electrode via soft imprinting technique. The efficiency is enhanced to 16.3% due to self‐enhanced absorption by broadband polarization‐insensitive light scattering and surface plasmonic effect.
In this study, we report a hollow microsphere assembled by ultrathin SnS nanosheets prepared by a template method. Hollow ferroferric oxide (Fe
3
O
4
) spheres with abundant pores on the shell are ...used as templates, and SnS nanosheets can grow on the surface of the Fe
3
O
4
shell. The key factor to obtain the unique structure of SnS sphere is the utilization of Fe
3
O
4
template. When employed as the anode for lithium-ion battery, the SnS exhibits the better electrochemical performance than that of the bulk SnS electrode. With morphology observation and electrochemical impedance spectroscopy analysis, SnS/V-SnS electrodes are proved to possess several advantages, i.e., high specific surface area facilitates electrochemical reactions due to more active sites, shortened Li
+
diffusion distance, and sufficient void space to sustain the volume change, which all contribute to its improved electrochemical performance.
Symmetric waterbomb origami Chen, Yan; Feng, Huijuan; Ma, Jiayao ...
Proceedings of the Royal Society. A, Mathematical, physical, and engineering sciences,
06/2016, Volume:
472, Issue:
2190
Journal Article
Peer reviewed
Open access
The traditional waterbomb origami, produced from a pattern consisting of a series of vertices where six creases meet, is one of the most widely used origami patterns. From a rigid origami viewpoint, ...it generally has multiple degrees of freedom, but when the pattern is folded symmetrically, the mobility reduces to one. This paper presents a thorough kinematic investigation on symmetric folding of the waterbomb pattern. It has been found that the pattern can have two folding paths under certain circumstance. Moreover, the pattern can be used to fold thick panels. Not only do the additional constraints imposed to fold the thick panels lead to single degree of freedom folding, but the folding process is also kinematically equivalent to the origami of zero-thickness sheets. The findings pave the way for the pattern being readily used to fold deployable structures ranging from flat roofs to large solar panels.
Photographs of the removal process of motor oil (dyed with Sudan Red I) from water using the rGA.
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To address oil spillage and organic contaminant problems, the preparation of ...efficient sorbent materials is of great importance for global environment and water source protection. Despite extensive studies, sorbents with both high efficiency and recyclability are still desired, particularly with the outstanding sorption performance for different temperature environmental conditions. Herein, we report a robust reduced graphene aerogel (rGA) as an efficient and recyclable sorbent for oils and organic solvents, which shows highly efficient absorption of various oils and organic solvents (up to 19–26 times of its own weight) and excellent recyclability (>5 times) by heat treatment. Moreover, the absorption ability of rGA can be maintained over a wide temperature range of −40°C to 240°C, which can be attributed to the inherent excellent thermal stability of graphene and goodheat dispersal of three dimensional network structure. Based on these excellent properties, the rGA is considered to be an ideal material can be employed for separation and absorption of waste oil and organic contaminants from the water surface at various temperatures.
Graphene oxide (GO) has been extensively explored in nanomedicine for its excellent physiochemical, electrical, and optical properties. Here, polyethylene glycol (PEG) and polyethylenimine (PEI) are ...covalently conjugated to GO via amide bonds, obtaining a physiologically stable dual‐polymer‐functionalized nano‐GO conjugate (NGO‐PEG‐PEI) with ultra‐small size. Compared with free PEI and the GO‐PEI conjugate without PEGylation, NGO‐PEG‐PEI shows superior gene transfection efficiency without serum interference, as well as reduced cytotoxicity. Utilizing the NIR optical absorbance of NGO, the cellular uptake of NGO‐PEG‐PEI is shown to be enhanced under a low power NIR laser irradiation, owing to the mild photothermal heating that increases the cell membrane permeability without significantly damaging cells. As the results, remarkably enhanced plasmid DNA transfection efficiencies induced by the NIR laser are achieved using NGO‐PEG‐PEI as the light‐responsive gene carrier. More importantly, it is shown that our NGO‐PEG‐PEI is able to deliver small interfering RNA (siRNA) into cells under the control of NIR light, resulting in obvious down‐regulation of the target gene, Polo‐like kinase 1 (Plk1), in the presence of laser irradiation. This study is the first to use photothermally enhanced intracellular trafficking of nanocarriers for light‐controllable gene delivery. This work also encourages further explorations of functionalized nano‐GO as a photocontrollable nanovector for combined photothermal and gene therapies.
PEG and PEI dual‐functionalized ultra‐small graphene oxide (NGO‐PEG‐PEI) with excellent physiologial stability against salts and serum is explored as a gene delivery carrier, which exhibits superior gene transfection efficiency even in the presence of serum, as well as an exciting photothermally controlled gene therapy potential under mild NIR laser irradiation.
Prealloyed Ti-6Al-4V powders were prepared by electrode induction melting gas atomization （EIGA） and plasma rotating electrode process （PREP） in this work. A comparative study of EIGA and PREP ...powders for hot isostatic pressing （HIPing） compaction was conducted. Characterization of important technological parameters such as particle size distribution, powder surface morphology and flowability was carried out. Microstructure and mechanical properties of Ti- 6Al-4V powder compacts HIPed from EIGA and PREP powders were also investigated. The results showed that the EIGA powder has a finer average particle size and higher tap density, while the PREP powder has better flowability and less pores. Micropores can be observed in heat-treated EIGA powder compacts by X-ray tomography and the porosity was found to be about 0.02%. There are no micropores （≥4 μm） to be detected in heat-treated PREP powder compacts. Transgranular fracture mode as well as micropores contributes to the scatter in fatigue property of heat-treated PREP powder compacts. The respective advantages and disadvantages of both EIGA and PREP powders for producing Ti-based complex parts through HIPing were also discussed.
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