Narrow Results

The activity and solubility of Si in Mo solid solution were studied by the first-principles calculations and quasi-harmonic approximation. The lattice constants, bulk modulus, and formation enthalpies of Mo-Si intermetallics were investigated, and the thermodynamic properties of Mo were also calculated. The Si activity coefficient ${\gamma }_{\mathrm{\text{Si}}}$ is approximately 10${}^{-16}$ at 100 K, while it increases by about 15 orders of magnitude over the investigated temperature range (100–2000 K). It is clear that Si activity coefficient in Mo solid solution increased rapidly with the increasing temperature, which should be ascribed to the Si–Mo interaction being evidently stronger than Mo–Mo interaction. According to the calculated thermodynamic properties, the solubility curve of Si in Mo solid solution was also predicted. The solubility limit of Si in Mo solid solution is $\sim$5.5 at.%, which agrees well with the other experiment and assessed results.

This paper presents a mathematical theory of behavioral swarms, where the state of interacting entities, which are called active particles, includes in addition to position and velocity, an internal variable, called activity, which has the ability to interact with mechanical variables thus affecting the interaction rules. In turn, the mechanical variables can modify the dynamics of activity variable. This approach is useful for describing the dynamics of living systems with a finite number of interacting entities. This paper provides a general conceptual framework that extends the pioneering work [N. Bellomo, S.-Y. Ha and N. Outada, Towards a mathematical theory of behavioral swarms, ESAIM$:$ Control Theory Var. Calculus 26 (2020) 125, https://doi.org/10.1051/cocv/2020071]. The theory is firstly developed for the constant number of active particles. Then, it is considered for the case of particles tending to infinity. This theory is useful for describing the dynamics of living systems. Therefore, it provides the conceptual basis for developing a mathematical theory of behavioral swarms, which naturally lead to the study of a theory of swarm intelligence. A study of the dynamics of swarms shows how the theory can be applied to real world collective dynamics.

High energy transients make up a diverse and exotic class of objects, from terrestrial lightning to $\gamma$-ray bursts at cosmological distances. In this review, we provide a detailed look at some of the more exciting transients observed over the last few years by Swift and other high energy missions.

In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, “The missing circuit element”. The memristor equations were originally supposed to represent a passive circuit element because, with active circuitry, arbitrary elements can be realized without limitations. Therefore, if the memristor equations do not guarantee that the circuit element can be realized by a passive system, the fundamental physics claims about the memristor as “missing circuit element” loses all its weight. The question of passivity/activity belongs to physics thus we incorporate thermodynamics into the study of this problem. We show that the memristor equations are physically incomplete regarding the problem of passivity/activity. As a consequence, the claim that the present memristor functions describe a passive device lead to unphysical results, such as violating the Second Law of thermodynamics, in infinitely large number of cases. The seminal memristor equations cannot introduce a new physical circuit element without making the model more physical such as providing the Fluctuation–Dissipation Theory of memristors.

The geometries, vibrational frequencies, electronic properties and reactivity of potassium supported on SBA-15 have been theoretically investigated by the density functional theory (DFT) method. The structural model of the potassium supported on SBA-15 was constructed based on our previous work [Wang ZX, Wang DX, Zhao Z, Chen Y, Lan J, A DFT study of the structural units in SBA-15 mesoporous molecular sieve, Comput. Theor. Chem.963, 403, 2011]. This paper is the extension of our previous work. The most favored location of potassium atom was obtained by the calculation of substitution energy. The calculated vibrational frequencies of K/SBA-15 are in good agreement with the experimental results. By analyzing the properties of electronic structure, we found that the O atom of Si-O(2)-K group acts as the Lewis base center and the K atom acts as the Lewis acid center. The reactivity of K/SBA-15 was investigated by calculating the activation of oxygen molecule. The oxygen molecule can be activated by K/SBA-15 with an energy barrier of 103.2 kJ/mol. In the final state, the activated oxygen atoms become new Lewis acid centers, which are predicted to act as the active sites in the catalytic reactions. This study provides a deep insight into the properties of supported potassium catalysts and offers fundamental information for further research.

In a previous article (G. A. Chauvet, 2002), presenting a theoretical approach for integrating physiological functions in nervous tissue, we showed that a specific hierarchical representation, incorporating the novel concepts of non-symmetry and non-locality, and an appropriate formalism (the S-propagator formalism) could provide a good description of a living system in general, and the nervous system in particular. We now show that, in the framework of this theory, in spite of the complexity inherent to nervous tissue and the great number of elementary mechanisms involved, the numerical resolution of the global non-local system allows us to envisage simulations that would otherwise be impossible to realize. Here, the study is limited to one physiological function, i.e., the spatiotemporal variation of membrane potential in neuronal tissue. We demonstrate that the role of the kinetic constants at the molecular level is in agreement with the observed activity of the neuronal network. The method also reveals the critical role of the maximum density of synapses along the dendritic tree in the behavior of the network. This illustrates the great advantage of the theoretical approach in studying separately any other complementary coupled function without having to modify the computational methods used here. The application of this method to the spatiotemporal variation of synaptic efficacy, which is the basis of the learning and memory function, will be treated in a forthcoming paper.

A mathematical model is developed to describe and investigate interstitial branching of axonal networks during nervous system development. The model under consideration describes axonal network growth in which the concentration of axon guidance molecules controls axon's growth and interstitial branching from axon shaft. Numerical simulations show that in the model framework axonal networks branch similarly to real neural networks in vitro.

In this study, efforts are created to develop a quantitative structure–activity relationship (QSAR)-based model, which are used for the prediction of toxicities to reduce testing in animals, time, and money in the early stages of drug development. An efficient machine learning model is developed to predict the toxicity of those drug molecules which binds to the androgen receptor (AR). Toxicity prediction is performed in terms of their activity, activity score, potency, and efficacy by using various physicochemical properties. A multilevel ensemble model is proposed, where its first level is performed ensemble-based classification of activity, and the second level is performed ensemble-based regression of activity score, potency, and efficacy of only those drug molecules which have been found active during the classification level. The AR dataset has 10,273 drug molecules where 461 are active, and 9812 are inactive, and each drug molecule has 1444 features. Therefore, our dataset is highly imbalanced having a very large number of features. Initially, we performed feature selection then the class imbalance problem is resolved. The $k$-fold cross-validation is accomplished to measure the consistency of the model. Finally, our proposed multilevel ensemble model has been validated and compared with some existing models.

The paper investigates differences in entrepreneurial activity, attitudes, aspirations, connectivity and behavior among nascent entrepreneurs across five key nationality groups residing in the United Arab Emirates (UAE). It also seeks to identify key differences between entrepreneurs and non-entrepreneurs' perceptions and attitudes toward entrepreneurship. More than 8000 adult residents were randomly surveyed as part of the GEM UAE studies conducted in 2006, 2007, 2009 and 2011. The findings indicate that the temporary residency status of expatriate workers has not prevented them from becoming entrepreneurs in the UAE. Arab expatriates in particular, have higher entrepreneurship rates compared to other nationality groups. Sharing a common culture and language appears to play a part in increased entrepreneurial activity. Moreover, socioeconomic factors like income and employment have a significant influence in determining entrepreneurship activity in the UAE. Regardless of nationality, entrepreneurs have more in common with each other compared to non-entrepreneurs in regards to their attitudes, connectivity and activities related to entrepreneurship, suggesting some homogenizing force that exists within the entrepreneurial population of the UAE.

Selaginella willdenowii, a commonly used greenhouse fern, was often used as a biowaste to synthesize zinc oxide nanoparticles (ZnO NPs) in an eco-friendly and cost-effective way. UV–Visible spectra studies were carried out to confirm the synthesis of S. willdenowii-mediated ZnO NPs (SW-ZnO NPs), and a peak at 367nm with a sharp band gap of 3.415eV was observed. The X-ray diffraction analysis indicated that the crystalline size of the synthesized SW-ZnO NPs was 11.971nm. The phytochemicals present in the extracts and the compounds involved in the reduction of metal to nanoparticles were determined by Fourier Transform Infrared analysis. Scanning electron microscopy was utilized to analyze the surface morphology and size of the obtained SW-ZnO NPs. The examination revealed that they exhibited a hexagonal shape, with an average size falling within the range of 17–23nm. Under ultra-violet light, reactive blue 220 and reactive yellow 145 dyes showed 78.06% and 60.14% degradation, showing potential photocatalytic degradation activity. The synthesized SW-ZnO NPs also exhibited antimicrobial activity against bacterial strains (Escherichia coli and Bacillus subtilis) and fungal cultures (Candida tropicalis and Candida albicans) showed cytotoxic activity against Hep-G2 cell lines. Our results suggest the green synthesized SW-ZnO NPs have potential photocatalytic, antimicrobial and cytotoxic potential.

Water electrolysis is one of the most feasible ways to utilize clean and renewable energy sources in the form of hydrogen energy. However, the anodic oxygen evolution reaction (OER) is a slow kinetic process, so it is of great significance to develop efficient oxygen evolution catalysts (OECs). Many studies have shown that Ce plays an important role in high-performance transition-metal-based OECs. We discuss and summarize possible causes for the improved OER activity and stability with emphasis on the hybrids of cerium and transition metals, including cerium-doped catalysts, ceria-support catalysts and ceria-loaded catalysts. Finally, current challenges for the Ce-containing catalysts are identified, pointing to the future directions for propelling the water electrolysis research.

In the Sun-as-a-star Project, the sun was observed spectroscopically and photometrically for more than 25 years in order to determine variability and luminosity changes. This project detected systematic longterm decrease in the total irradiance as a consequence of the solar magnetic activity cycle (scale of years) and variability on solar activity from a time scale of days-months. The solar magnetic activity cycles could mimic the radial velocity modulation signal of a long-period companion in several spectral lines. This effect is an important limitation for the exoplanet searches programs using the radial velocity technique. The Lomb-Scargle periodogram analysis of the Sun-as-a-star spectroscopic data shows that the photospheric line C I 5380 Å and other 11 lines seems to not show significant influence from the rotational or cromospheric magnetic activity modulation. Thus, our analysis suggest that C I 5380 Å line could be used in programs that require extremely line stability.

Background: The purpose of this study was to determine whether baseline characteristics predict outcomes twelve weeks after open reduction and internal fixation of proximal phalangeal fracture.

Methods: A cohort of patients (n = 48, mean 35 years; SD 11) commencing outpatient rehabilitation within one week of surgery were reviewed. Outcomes of interest were active PIP extension; active total range of motion; pain at rest; comprehensive pain; strength; and hand use (reported difficulty performing specific activities such as turning a door handle, as well as usual activities including housework and recreation) at twelve weeks. Possible predictors included which finger is injured, whether the fracture is intra or extra-articular, whether the dominant or non-dominant hand is injured and/or how much pain is experienced in the first post-operative week. Multiple linear regression was performed to produce a model of the prediction for each outcome of interest at Week 1 (baseline).

Results: Results from multivariate linear regression analyses suggest that pain at rest at baseline was significantly predictive of pain at rest (OR = 1.25, 95% CI = 1.06–1.47), p = 0.01), comprehensive pain (OR = 3.18, 95% CI = 1.47–6.84, p = 0.01), and hand use (OR = 2.38, 95% CI = 1.18–4.80, p = 0.02) twelve weeks after open reduction and internal fixation of proximal phalangeal fracture. The turning point on the receiver-operator characteristic curve of false versus true risk (AUC = 0.94, p = 0.04) indicated that at least a score of 4.5 on the 10 cm visual analogue scale for baseline resting pain was needed for significant likelihood of reduced hand use. Which finger was injured, location of fracture and side of injury were not predictive of any outcomes.

Conclusions: Moderate to high levels of resting pain in the week following surgery for proximal phalangeal fracture is predictive of pain and hand use at twelve weeks. Moderate to high levels of resting pain should be recognised as unusual, and could be targeted in rehabilitation. Further prospective studies are needed to determine whether early identification and targeted intervention to reduce pain improves outcomes at 12 weeks.

In his seminal paper, Chua presented a fundamental physical claim by introducing the memristor, “The missing circuit element”. The memristor equations were originally supposed to represent a passive circuit element because, with active circuitry, arbitrary elements can be realized without limitations. Therefore, if the memristor equations do not guarantee that the circuit element can be realized by a passive system, the fundamental physics claims about the memristor as “missing circuit element” loses all its weight. The question of passivity/activity belongs to physics thus we incorporate thermodynamics into the study of this problem. We show that the memristor equations are physically incomplete regarding the problem of passivity/activity. As a consequence, the claim that the present memristor functions describe a passive device lead to unphysical results, such as violating the Second Law of thermodynamics, in infinitely large number of cases. The seminal memristor equations cannot introduce a new physical circuit element without making the model more physical such as providing the Fluctuation Dissipation Theory of memristors.

High energy transients make up a diverse and exotic class of objects, from terrestrial lightning to γ-ray bursts at cosmological distances. In this review, we provide a detailed look at some of the more exciting transients observed over the last few years by Swift and other high energy missions.

By measuring the slag activity index and angle of repose, the effects of slag powder activity and angle of repose were studied on monomer of grinding aids MY-□, JS, molasses and LS et al. by single factor test method and orthogonal design test, and the industrial grinding test of grinding aids JS and MY-□ were introduced. Analysed the grinding aids composition influences on activity of slag powder and stability of material layer, and with comprehensive consideration of cost and performance reached an optimal solution: MY-□ is 0.02%, JS 0.03%, molasses 0.06%, LS 0.1%. The results show: MY-□ can obviously increase the activity of slag powder 15%, 19% respectively at 7d and 28d. JS can improve the output of slag grinding 10% by vertical mill. The vertical mill grinding aids can significantly improve the activity and output of slag powder.

The thermal analysis and DTA are used to study the effect of metakaolin on the hydration process and mechanism of cement. The result shows that the second exothermal peaks are in advance which means metakaolin can accelerate the hydration speed. DTA and strength result show that metakaolin can increase the strength observably, especial for 28 days strength.

Leaf extract of Clinacanthus nutans(Burm.f.)Lindau and extract of the whole plant of Selaginella uncinata (Desv.) Spring could inhibit the activity of cholinesterase slightly. Leaf extract of Artemisia indica Willd ., Radix Isatidis and Alpinia zerumbet could inhibit the activity of cholinesterase evidently. Leaf extract of Pteris semipinnata L. and Artemisia anomala S.Moore showed no effects on the activity of cholinesterase respectively. Leaf extract of Eupatorium catarium Veldkamp could activate the activity of cholinesterase slightly. Leaf extract of H.chrysoleucum could activate the activity of cholinesterase evidently.

The activities of components in the CaO-MgO-Al₂O₃-SiO₂ refining slags at 1873K were calculated through the coexistence theory. The calculated results of activities of CaO, MgO, Al₂O₃ and SiO₂ were found to be similar to those of experiment tests. The activities of CaO, MgO increase with the increase of basicity and CaO contents, respectively. However, the activities of MgO decrease with the increase content of SiO₂. The activity of Al₂O₃ and SiO₂ is influenced by the basicity, and the activities of Al₂O₃ and SiO₂ decrease with the increase of basicity in wMgO 10% at 1873K. The activity of CaO, MgO, Al₂O₃ and SiO₂ in the CaO-MgO-Al₂O₃-SiO₂ refining slags (T=1873K, wMgO =7%), has big fluctuation, is the range from 0.2 to 0.5, from 0.18 to 0.25, from 0.02 to 0.006, from 2×10^-5 to 2×10^-4, respectively. At wMgO 5%, the activity of components in the CaO-MgO-Al₂O₃-SiO₂ refining slags, has small fluctuation, is 0.1~0.5, 0.13~0.18, 0.005~0.02, 2×10^-5~1×10^-3. The thermodynamic calculation of activities of components in GCr15 refining slag provides theoretical foundation for exploring the relationship between refining slag and inclusions in liquid steel.