442 research outputs found
A Novel Bilateral Energy Trading Mechanism for Electricity Markets with Numerous Prosumers
With the rapid development of distributed energy resources, increasing number
of residential and commercial users have been switched from pure electricity
consumers to prosumers that can both consume and produce energy. To properly
manage these emerging prosumers, a peer-to-peer electricity market has been
explored and extensively studied. In such an electricity market, each prosumer
trades energy directly with other prosumers, posing a serious challenge to the
scalability of the market. Therefore, a bilateral energy trading mechanism with
good scalability is proposed for electricity markets with numerous prosumers in
this paper. First, the multi-bilateral economic dispatch problem that maximizes
the social welfare is formulated, taking into account product differentiation
and network constraints. Then, an energy trading mechanism is devised to
improve the scalability from two aspects: (i) an accelerated distributed
clearing algorithm with less exchanged information and faster convergence rate.
(ii) a novel selection strategy to reduce the amount of computation and
communication per prosumer. Finally, the convergence proof of the proposed
accelerated algorithm is given, and the proposed selection strategy is
illustrated through a Monte Carlo simulation experiment
Psychosocial determinants of depression in the community of the elderly with cardiovascular disease
The co-morbidity of cardiovascular disease (CVD) and depression is quite frequent in old people, and some potential biological and behavioural mechanisms linking them have been reported. Yet the impact of psychosocial factors on depression in the elderly with CVD remains unclear. This study aimed to analyze the psychosocial determinants of depression in the elderly with CVD. Using the Geriatric Mental Status-Automated Geriatric Examination for Computer Assisted Taxonomy, a community-based household survey was performed in 2,199 elderly people from the Anhui cohort third-wave survey from 2007 to 2009 and an extended study in Hubei from 2010 to 2011. Multiple logistic regression analyses were employed to assess the influence of psychosocial factors on depression. Among them, the prevalence of depression was 4.77%. Three factors were associated with depression in elderly in the community: self-assessed physical health status, anything else severely upsetting and unpleasantness with relatives, friends, or neighbors. In particular, associations of psychosocial factors with depression were more evident in individuals with CVD. This study confirms several psychosocial determinants of depression and the impact of CVD on the associations among the elderly, which provides some clues for interventional strategies of late-life depression
Neurochemical characterization of pERK-expressing spinal neurons in histamine-induced itch
Date of Acceptance: 08/07/2015 Acknowledgements This work was supported by grants from the Ministry of Science and Technology of China (2012CB966904, 2011CB51005), National Natural Science Foundation of China (31271182, 81200692, 91232724, 81200933, 81101026), Shanghai Natural Science Foundation (12ZR1434300), Key Specialty Construction Project of Pudong Health Bureau of Shanghai (PWZz2013-17), Shenzhen Key Laboratory for Molecular Biology of Neural Development (ZDSY20120617112838879), Fundamental Research Funds for the Central Universities (1500219072) and Sino-UK Higher Education Research Partnership for PhD Studies.Peer reviewedPublisher PD
High efficiency solar power generation with improved discontinuous pulse width modulation (DPWM) overmodulation algorithms
The efficiency of a photovoltaic (PV) system strongly depends on the transformation process from solar energy to electricity, where maximum power point tracking (MPPT) is widely regarded as a promising technology to harvest solar energy in the first step. Furthermore, inverters are an essential part of solar power generation systems. Their performance dictates the power yield, system costs and reliable operation. This paper proposes a novel control technology combining discontinuous pulse width modulation (DPWM) and overmodulation technology to better utilize direct current (DC) electrical power and to reduce the switching losses in the electronic power devices in conversion. In order to optimize the performance of the PV inverter, the overmodulation region is refined from conventional two-level space vector pulse width modulation (SVPWM) control technology. Then, the turn-on and turn-off times of the switching devices in different modulation areas are deduced analytically. A new DPWM algorithm is proposed to achieve the full region control. An experimental platform based on a digital signal processing (DSP) controller is developed for validation purposes, after maximum power is achieved via a DC/DC converter under MPPT operation. Experimental results on a PV system show that the DPWM control algorithm lowers the harmonic distortion of the output voltage and current, as well as the switching losses. Moreover, better utilization of the DC-link voltage also improves the PV inverter performance. The developed algorithm may also be applied to other applications utilizing grid-tie power inverters
A van der Waals pn heterojunction with organic/inorganic semiconductors
van der Waals (vdW) heterojunctions formed by two-dimensional (2D) materials
have attracted tremendous attention due to their excellent electrical/optical
properties and device applications. However, current 2D heterojunctions are
largely limited to atomic crystals, and hybrid organic/inorganic structures are
rarely explored. Here, we fabricate hybrid 2D heterostructures with p-type
dioctylbenzothienobenzothiophene (C8-BTBT) and n-type MoS2. We find that
few-layer C8-BTBT molecular crystals can be grown on monolayer MoS2 by vdW
epitaxy, with pristine interface and controllable thickness down to monolayer.
The operation of the C8-BTBT/MoS2 vertical heterojunction devices is highly
tunable by bias and gate voltages between three different regimes: interfacial
recombination, tunneling and blocking. The pn junction shows diode-like
behavior with rectifying ratio up to 105 at the room temperature. Our devices
also exhibit photovoltaic responses with power conversion efficiency of 0.31%
and photoresponsivity of 22mA/W. With wide material combinations, such hybrid
2D structures will offer possibilities for opto-electronic devices that are not
possible from individual constituents.Comment: 16 pages, 4 figure
Preparation of Antibacterial Color-Coated Steel Sheets
A simple method to fabricate antibacterial color-coated steel sheet was presented. The Ag-loaded TiO2 was well dispersed in steel coil coating coupled with some special additives, such as plasticizer, wetting dispersant, and flow agent, and finally became the part of coil coating without any negative influence on the properties of final products. The best process parameters were obtained by substantive trial experiments. Ag-loaded TiO2 with the addition of 2% (w/w) in steel coil coating not only improved antibacterial efficiency of the antibacterial color-coated sheet by reaching 99.99%, but also greatly increased the degradation percentage of methyl orange to 88% without decreasing physical properties. The antibacterial color-coated sheets are expected to be used as antimicrobial products in the construction industry considering its low cost and high effectiveness in inhibiting the growth of bacteria
xCoT: Cross-lingual Instruction Tuning for Cross-lingual Chain-of-Thought Reasoning
Chain-of-thought (CoT) has emerged as a powerful technique to elicit
reasoning in large language models and improve a variety of downstream tasks.
CoT mainly demonstrates excellent performance in English, but its usage in
low-resource languages is constrained due to poor language generalization. To
bridge the gap among different languages, we propose a cross-lingual
instruction fine-tuning framework (xCOT) to transfer knowledge from
high-resource languages to low-resource languages. Specifically, the
multilingual instruction training data (xCOT-INSTRUCT) is created to encourage
the semantic alignment of multiple languages. We introduce cross-lingual
in-context few-shot learning (xICL)) to accelerate multilingual agreement in
instruction tuning, where some fragments of source languages in examples are
randomly substituted by their counterpart translations of target languages.
During multilingual instruction tuning, we adopt the randomly online CoT
strategy to enhance the multilingual reasoning ability of the large language
model by first translating the query to another language and then answering in
English. To further facilitate the language transfer, we leverage the
high-resource CoT to supervise the training of low-resource languages with
cross-lingual distillation. Experimental results on previous benchmarks
demonstrate the superior performance of xCoT in reducing the gap among
different languages, highlighting its potential to reduce the cross-lingual
gap.Comment: 11 page
1-[4-(Difluoromethoxy)phenyl]-N-(2,3-dimethylphenyl)-1H-1,2,4-triazole-3-carboxamide
In the molecule of the title compound, C18H16F2N4O2, the 1,2,4-triazole ring forms dihedral angles of 3.6 (2) and 14.9 (6)° with the 4-difluoromethoxy-substituted benzene ring and the 2,3-dimethyl-substituted benzene ring, respectively. The OCHF2 group is twisted away from the plane of the benzene ring, as shown by the C—O—C—C torsion angle of 145.8 (2)°. The conformation is stabilized by an intermolecular N—H⋯N hydrogen bond. In the crystal, short C—H⋯O interactions lead to chains of molecules
Meat molecular detection: sensitivity of polymerase chain reaction-restriction fragment length polymorphism in species differentiation of meat from animal origin
Three restriction enzymes were used in Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) using the mitochondrial cytochrome b region to establish a differential diagnosis which detect and discriminate between three meat species: pork, cow and
chicken. DNA was extracted from samples containing meat of a single animal such as raw pork (Sus scrofa domesticus), chicken (Gallus gallus) and cow (Bos taurus) as well as mixed samples of two species of animals in different ratios. The amplified 359 base pairs (bp) portion of the
mitochondrial cyt b gene from pure or mixed samples in different ratios was cut using three different restriction enzymes resulting in species specific restriction fragment length polymorphism (RFLP). This technique proved to be extremely reliable in detecting the presence of low levels of target DNA obtained from a 0.25 mg component in a particular mixed meat sample. This revealed the cyt b region as highly conserved and consequently a good molecular
marker for diagnostic studies. Thus, this technique can be applied to food authentication for the identification of different species of animals in food products
Evaluation on efficiency of pyroligneous acid from palm kernel shell as antifungal and solid pineapple biomass as antibacterial and Plant Growth Promoter
Generation of huge volumes of lignocellulosic biomass from agricultural sector is of concern due to its direct effects on the depletion of overall environmental quality. Conversion of biomass into solid biofuel through pyrolysis reaction has become one of the solutions to manage the abundance of biomass. Pyroligneous acid (PA) produced from the condensation of smoke generated during biomass carbonization process has the potential to be applied in various applications based on the diverse active chemical compounds present. In this study, PA obtained from palm kernel shell (PKS) was evaluated for antifungal activity and solid pineapple biomass (PB) was evaluated for antibacterial and plant growth promoter activities. Higher antifungal activity was determined for crude PA from PKS (PA-PKS) and dichloromethane-extract (DPA-PKS) with 0% coverage area when evaluated using rubber wood blocks against mold and blue sapstain after for 4 weeks of observation. This antifungal activity can be attributed to the presence of phenols and its major derivatives as suggested from the GC-MS and FTIR analysis. Concentrated PA from PB displayed good antibacterial capabilities with almost similar growth inhibition for Escherichia coli (13±1 to 20±1 mm) and Corynebacterium agropyri (20±1 mm). PA-PB also showed good potential as PGP where the addition of 2% (v/v) of PA-PB into the fertilizer for okra plant resulted in highest number of leaves and fruits while 4% (v/v) PA-PB managed to give highest plant height, longest root, heaviest fruits and biggest leaf diameter. Thus, thi
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