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• The effects of the equivalence ratio, ϕ , on duct-vented hythane–air deflagration were studied. • Reverse flow due to the secondary explosion in the relief duct was observed in all test. • Secondary explosion creates a pressure peak both in the vented vessel and the relief duct. • The maximum overpressure in the vessel and outside the duct first increased and thereafter decreased with ϕ. • Shock wave due to the supersonic flame propagation outside the duct was visualized in some tests. In this study, experiments on the duct-vented deflagrations of hydrogen–methane–air mixtures were performed in a cylindrical vessel connected with a relief duct, at an initial pressure of 101 kPa and an initial temperature of 290 K, to investigate the effects of equivalence ratio (ϕ), in the range of 0.6–1.8, on flame evolution and pressure buildup within and outside the venting configuration. Experimental results reveal that secondary explosion in the relief duct occurred and a pressure peak with amplitude higher than the overpressure in the vented chamber formed, which resulted in the gases in the relief duct flowing reversely to the vented chamber (reverse flow). The secondary explosion in the relief duct reduced the venting efficiency in the vented chamber and created a pressure peak there, which dominated the pressure–time histories in the vented cylindrical vessel for ϕ ranging from 0.8 to 1.4. Acoustic oscillations of the overpressure in the cylindrical vessel could be easily distinguished for ϕ ≤ 1.0, and the pressure peak owing to acoustic enhanced combustion was dominant at ϕ = 0.6. The maximum overpressure in the cylindrical vessel first increased and thereafter decreased as ϕ was increased from 0.6 to 1.5 and was independent of ϕ for richer mixtures. A shock wave was visualized in the tests with ϕ in a range of 1.0–1.2 when the combustible cloud outside the venting configuration was ignited, which resulted in a pressure spike in the external pressure–time histories. The maximum overpressure outside the relief duct first increased and thereafter decreased as ϕ was increased. [ABSTRACT FROM AUTHOR]

We present a novel collagen-based hydrophobic aerogel for oil/water separation. The key feature of our approach is based on all-biomass materials, combined with effective crosslinking of collagen and dialdehyde carboxymethyl cellulose (DCMC) and hydrophobic coating by naturally derived waxes. The results show that the collagen with small amount of DCMC (∼0.25 wt%) under freezing and subsequent lyophilization can result in a spongy-like aerogel substrate with hierarchical structure and great reversible compressibility. The waxes coating not only maintains the interconnected porous structure, but also confers the micro/nano-scale wrinkling patterns on the resulting WC-Col aerogel surfaces. The hydrophobicity and lipophilicity of WC-Col aerogel is thus significantly improved as evidenced by a high contact angle of 144.4° and selective adsorption of oils from water. The repeated adsorption-squeezing tests demonstrate its reasonably good adsorption capacities and recyclability for varied oily liquids. Our study provides an ingenious approach to exploitation of biomass in pollutants removal. [Display omitted] • First study on fabricating of collagen-based superhydrophobic all-biomass aerogel. • Cross-linking by minute DCMC can enhance the compressibility of aerogels markedly. • Superhydrophobic conversion of amphiphilic surfaces is achieved by waxes coating. • The aerogel shows high oil absorption capacity and reasonably good recyclability. [ABSTRACT FROM AUTHOR]

The development of hydrogels as wound dressings has gained considerable attention due to their promising ability to promote wound healing. However, in many cases of clinical relevance, repeated bacterial infection, which might obstruct wound healing, usually occurs due to the lack of antibacterial properties of these hydrogels. In this study, we fabricated a new class of self-healing hydrogel with enhanced antibacterial properties based on dodecyl quaternary ammonium salt (Q12)-modified carboxymethyl chitosan (Q12-CMC), aldehyde group- modified sodium alginate (ASA), Fe3+ via Schiff bases and coordination bonds (QAF hydrogels). The dynamic Schiff bases and coordination interactions conferred excellent self-healing abilities to the hydrogels, while the incorporation of dodecyl quaternary ammonium salt gave the hydrogels superior antibacterial properties. Additionally, the hydrogels displayed ideal hemocompatibility and cytocompatibility, crucial for wound healing. Our full-thickness skin wound studies demonstrated that QAF hydrogels could result in rapid wound healing with reduced inflammatory response, increased collagen disposition and improved vascularization. We anticipate that the proposed hydrogels, possessing both antibacterial and self-healing properties, will emerge as a highly desirable material for skin wound repair. [ABSTRACT FROM AUTHOR]

Current‐mode multi‐scroll chaos generator is introduced. It uses second generation current controlled current conveyor (CCCII) and produces current output chaotic signals. PSPICE simulations show that current‐mode multi‐scroll chaos generator can generate more scroll chaotic attractors with high frequency and low voltage. [ABSTRACT FROM AUTHOR]

Abstract: Acid-base bifunctional mesoporous catalysts Al-KIT-6-NH2 containing different aluminum content have been synthesized through post synthetic grafting method. The materials were characterized by X-ray diffraction (XRD), scanning electron micrographs (SEM), transmission electron micrographs (TEM), Fourier-transform infrared spectroscopy (FTIR), IR spectra of pyridine adsorption, NH3-TPD and TG analysis. The characterization results indicated that the pore structure of KIT-6 was well kept after the addition of aluminum and grafting of aminopropyl groups. The acid amount of Al-KIT-6 increased with enhancing aluminum content. Catalytic results showed that weak acid and weak base favor the Knoevenagel reaction, while catalysts with strong acid and weak base exhibited worse catalytic behavior. [Copyright &y& Elsevier]

In this paper, we study the perturbed biharmonic equations [ABSTRACT FROM AUTHOR]

Highlights: [•] The MVCO could provide six or eight different phase sinusoidal signals. [•] The frequency tuning range of the six-phase MVCO is from 788.5MHz to 2.506GHz. [•] The frequency tuning range of the eight-phase MVCO is from 558.9MHz to 1.512GHz. [Copyright &y& Elsevier]

Abstract: In this paper, a novel four-dimensional smooth system is presented. What particularly interests us is that the novel multi-wing chaotic system has only one equilibrium point at the origin. Furthermore, the strange phenomenon that different chaotic attractors such as the two-wing, three-wing chaotic attractors and four-wing hyperchaotic attractor could be generated by changing a single system parameter makes this system unique. By applying either analytical or numerical methods, basic properties of the system such as phase portraits, Poincaré mapping, bifurcation diagram and Lyapunov exponents are investigated to observe chaotic motions. The physical existences of the multi-wing chaotic attractors are verified by an electronic circuit. [Copyright &y& Elsevier]

A scheme to measure multiple Jones–Mueller matrices over a fibre system is proposed based on the concept of system estimation. The method modulates the input state of polarization (SOP) of each piece of testing fibre by using a rotatable coiled fibre wave plate, rather than measuring the input SOP with an in-line polarization state analyser as conventional methods do. The Jones–Mueller matrix can be expressed as a set of quadratic equations and estimated with least square optimization. A scheme to determine the retardance of the rotating fibre wave plate instantly is proposed for calibrating the environmental sensitivity of the rotating fibre wave plate. Moreover, the measurement uncertainty of the scheme is simulated and the Mueller matrices of two pieces of fibre are measured experimentally. [ABSTRACT FROM AUTHOR]

In this paper, we study the following semilinear elliptic system [ABSTRACT FROM AUTHOR]

In this paper, a new active device, current differencing cascaded transconductance amplifier (CDCTA), has been presented. The proposed CDCTA simplifies the design of the current-mode filter circuit considerably, especially the design of high-order filter. Moreover, a current-mode nth-order filter based on the CDCTA is proposed in the paper. The proposed circuit, which adopts only an active component and n grounded capacitors, contains minimal active component and passive one. It enjoys the simple configuration and is suitable for integrated circuit (IC) fabrication. PSpice simulations for current-mode third-order filter based on this structure have also been conducted, and the results are in good agreement with the theoretical analysis. The influences of the CDCTA non-idealities are also discussed. [ABSTRACT FROM AUTHOR]

• Ignitability of the stratified gasoline vapor depends on both ignition position and t ig. • Ignition position affects only the initial expansion of the flame for a certain t ig. • P max is nearly independent of ignition position for a certain t ig. • The relationship between P max and t ig varies with ignition position. Stratified vapor–air mixtures are formed owing to evaporation after a leakage of gasoline in confined spaces. In this study, the effects of ignition position and ignition delay (t ig), defined as the time interval between ignition and the moment of fuel spill, on the ignitability and flame behavior of the stratified vapor above a 0.8-mm-thick gasoline layer were experimentally investigated in a horizontal duct. Experimental results revealed that the ignitability of the stratified gasoline vapor depended on both ignition position and t ig. The closer the ignition source was to the oil surface, the earlier the local stratified gasoline vapor became ignitable and thereafter lost flammability. A two-zone flame structure, including a blue premixed flame and a following yellow diffusion flame, was observed, and the blue flame propagated along only a certain layer of the gasoline vapor. The depth of the leading blue flame first increased and thereafter decreased with an increase in t ig. The heat release owing to the yellow diffusion flame played an important role in the maximum explosion overpressure (P max), which closely related to both ignition position and t ig. For a certain t ig , P max was nearly independent of ignition position. The relationship between P max and t ig varied with ignition position. The highest value of P max was obtained when ignition source was around the center of the duct, and the lowest value of 66 kPa appeared when ignition source was close to the duct roof. [ABSTRACT FROM AUTHOR]

Due to its nontoxicity and eco-friendliness, waterborne polyurethane (WPU) has attracted increasing attention for use in various industrial applications. To ensure dispersal or dissolution in water, the molecular structures of most WPUs contains ionic groups. Dried WPU films, however, are generally hydrophilic and have a limited application range. To confer high hydrophobicity and antifouling properties to WPU, the incorporation of a fluorocarbon chain into WPU is an efficient approach. Herein, we present a facile and effective approach for synthesizing a novel WPU with a fluorinated side group, a key aspect of which is the preparation of dihydroxy-terminated 1,1,2,2-tetrahydroperfluorodecyl methacrylate (FDMA(OH) 2) by a thiol-ene "click" reaction. A chain extender rich in fluorinated side groups is then adapted specifically to an OCN-terminated WPU prepolymer to obtain fluorinated waterborne polyurethane (FWPU). Our results show that fluorine units are present on the surface of FWPU films. The introduction of FDMA side groups slightly decreases the storage and thermal stability of FWPU but does not affect its usability and significantly increases its hydrophobicity. The result of a repelling test demonstrates that the introduction of FDMA side groups endows the WPU films with excellent waterproofing and antifouling properties. This new method provides a facile and effective way to fabricate of FWPU for its practical application in waterproof and antifouling coatings. [Display omitted] • A novel fluorinated diol was synthesized via thiol-ene click reaction. • The fluorinated waterborne polyurethane coating shows reasonably good water-resistance and antifouling. • This new method provides a facile and effective way to fabricate high-performance fluorinated waterborne polyurethane. [ABSTRACT FROM AUTHOR]

Upgrading furfural (FAL) to cyclopentanone (CPO) is of great importance for the synthesis of high-value chemicals and biomass utilization. The hydrogenative ring-rearrangement of FAL is catalyzed by metal-acid bifunctional catalysts. The Lewis acidity is a key factor in promoting the rearrangement of furan rings and achieving a high selectivity to CPO. In this work, highly dispersed Pd nanoparticles were successfully encapsulated into the cavities of a Zr based MOF, UiO-66-NO2, by impregnation using a double-solvent method (DSM) followed by H2 reduction. The obtained Pd/UiO-66-NO2 catalyst showed a significantly better catalytic performance in the aforementioned reaction than the Pd/UiO-66 catalyst due to the higher Lewis acidity of the support. Moreover, by using a thermal treatment. The Lewis acidity can be further increased through the creating of missing-linker defects. The resulting defective Pd/UiO-66-NO2 exhibited the highest CPO selectivity and FAL conversion of 96.6% and 98.9%, respectively. In addition, the catalyst was able to maintain a high activity and stability after four consecutive runs. The current study not only provides an efficient catalytic reaction system for the hydrogenative ring-rearrangement of furfural to cyclopentanone but also emphasizes the importance of defect sites. [ABSTRACT FROM AUTHOR]

Abstract: This paper explores the importance of differential output growth across regions within a country in reducing the country's total carbon dioxide emissions from the combustion of fossil fuels. It proposes a framework that decomposes changes in emissions into sources attributable to 1) national growth rate of gross domestic product (GDP), 2) differential GDP growth across regions, 3) changes in energy intensity, and 4) changes in CO2 emission coefficient of energy. Data for China (1995–2009) and the United States (1990–2009) are analyzed. Uneven growth across regions reduced carbon dioxide emissions in both countries. [Copyright &y& Elsevier]

A five-term three-dimensional (3D) autonomous chaotic system with an exponential nonlinear term is reported in this paper. Basic dynamical behaviours of the chaotic system are further investigated. Then a new synchronization phenomenon, complete switched modified function projective synchronization (CSMFPS), for this novel five-term chaotic system with uncertain parameters and disturbances is investigated. This paper extends previous work, where CSMFPS of chaotic systems means that all the state variables of the drive system synchronize with different state variables of the response system. As the synchronization scheme has many combined forms, it is a promising type of synchronization and can provide greater security in secure communication. Based on Lyapunov stability theory, a robust adaptive controller is contrived to acquire CSMFPS, parameter identification and suppress disturbances simultaneously. Finally, the Lorenz system and the new five-term chaotic system are taken as examples and the corresponding numerical simulations are presented to verify the effectiveness and feasibility of the proposed control scheme. [ABSTRACT FROM AUTHOR]

In this paper, we consider the p-Laplacian equations in [ABSTRACT FROM AUTHOR]

In this paper, we are concerned with the existence of multi-bump solutions for a nonlinear Schrödinger equations with electromagnetic fields. We prove under some suitable conditions that for any positive integer m, there exists ε(m) > 0 such that, for 0 < ε < ε(m), the problem has an m-bump complex-valued solution. As a result, when ε → 0, the equation has more and more multi-bump complex-valued solutions. [ABSTRACT FROM PUBLISHER]

Abstract: This letter presents a single CDTA (Current Differencing Transconductance Amplifier)-based current-mode quadrature oscillator (QO). The proposed circuit structure is very simple, which only consists of one CDTA, one resistor and two capacitors, and it is easy for monolithic integration. The oscillation frequency of the QO can be electronically controlled by the bias current of the CDTA. Moreover, the oscillator can provide two quadrature current outputs. PSPICE simulation results are provided to verify all the theoretical analysis. [Copyright &y& Elsevier]

Abstract: Acid–base bifunctional mesoporous catalysts Al-SBA-15-NH2 containing high content of Al and organic amine functional groups have been synthesized through the “pH-adjusting” method. The materials were characterized by X-ray diffraction (XRD), scanning electron micrographs (SEM), transmission electron micrographs (TEM), Fourier-transform infrared spectroscopy (FTIR), IR spectra of pyridine adsorption, NH3-TPD and elemental analysis. Catalytic results showed that 6-Al-SBA-15-NH2 (Si/Al=6mol%) was more active than 10-Al-SBA-15-NH2 (Si/Al=10mol%) in one-pot deacetalization–Knoevenagel and deacetalization–nitroaldol (Henry) reactions. [Copyright &y& Elsevier]

Abstract: We investigated the influence of palygorskite on the conformation and thermal stability of type I collagen. Fluorescence spectroscopy and Fourier transform infrared spectroscopy (FTIR) studies demonstrated that the interaction between collagen and purified palygorskite (PAL) led to the contraction and aggregation of collagen molecules, but did not destroy the triple helix backbone of collagen. Due to the structure of collagen and PAL, the interaction mainly involved hydrogen bonding and electrostatic forces. Atomic force microscopy (AFM) observations clearly displayed the nanorod morphology of PAL, and further revealed the fibril aggregation of collagen in the presence of PAL. Differential scanning calorimetry (DSC) measurements indicated that the PAL-collagen nanocomposites improved the thermal stability in comparison with pure collagen. The present study showed that PAL could modify collagen as a reinforcing agent and preserve the triple helix structure of collagen. [Copyright &y& Elsevier]

Astilbin (AST), isoastilbin (ISO), and engeletin (ENG) are the main flavonoids in Rhizoma Smilacis Glabrae (RSG) and have many biological activities. In this study, the adsorption kinetics of AST, ISO, and ENG on HPD-300 resin was investigated and their adsorption processes conformed to a pseudo-second-order kinetics equation. The fitting curves of the intraparticle diffusion model showed three linear stages and did not pass through the origin, meaning the adsorption process of the three flavonoids was controlled by boundary layer diffusion and intraparticle diffusion. Their adsorption isotherms were also constructed and could be well-fitted by the Langmuir equation. A low temperature was favorable for their adsorption. The relative adsorption capacity of ENG was significantly higher than those of the other two compounds, indicating that the substitution pattern on ring B has an important impact on the adsorption of flavonoids with resin. The separation process was optimized by dynamic adsorption/desorption experiments. After separation, the purities of AST, ISO, and ENG increased from 5.55%, 1.22%, and 0.45% to 27.46%, 6.14%, and 2.27%, respectively, and all the recoveries exceeded 75%. After that, the three compounds were further separated by preparative HPLC and silica gel chromatography. In the final product, the purities of AST, ISO, and ENG could reach above 98%. [ABSTRACT FROM AUTHOR]

We study the limiting behavior of maximal partial sums for arrays of rowwise ρ-mixing random variables and obtain some new results that improve the corresponding theorem of Zhu [M.H. Zhu, Strong laws of large numbers for arrays of rowwise ρ-mixing random variables, Discrete Dyn. Nat. Soc., 2007, Article ID 74296, 6 pp., 2007]. [ABSTRACT FROM AUTHOR]

This paper empirically identifies socio-economic, physical, and geographic factors of the demand for open space in the state of North Carolina in the United States. Estimated coefficients suggest that spatial dependency exists in open space demand and that open space is a normal good. The paper provides the first empirical investigation of how open space demand is affected by local weather conditions. It is found that the demand has a statistically significant substitution relationship with nice weather. We discuss the socio-economic rationale for the estimated demand models within the regional context of North Carolina and point to some relevant policy implications. Resumen. Este artículo identifica empíricamente los factores socioeconómicos, físicos y geográficos de la demanda de espacios al aire libre en el estado de Carolina del Norte en los Estados Unidos. Los coeficientes estimados sugieren que existe una dependencia espacial en la demanda de espacios al aire libre y que los espacios al aire libre son un bien normal. El artículo ofrece la primera investigación empírica sobre como se ve afectada la demanda de espacios al aire libre por las condiciones meteorológicas locales. Se ha encontrado que la demanda tiene una relación de substitución estadísticamente significativa con una meteorología benigna. Discutimos el fundamento socioeconómico de los modelos de demanda estimados dentro del contexto regional de Carolina del Norte e indicamos varias implicaciones relevantes para la formulación de políticas. [ABSTRACT FROM AUTHOR]

Abstract: A new low complexity ultra-wideband 3.1–10.6GHz low noise amplifier (LNA), designed in a chartered 0.18μm RFCMOS technology, is presented in this paper. The ultra-wideband LNA only consists of two simple amplifiers with an inter-stage inductor connected. The first stage utilizing a resistive current reuse and dual inductive degeneration techniques is used to attain a wideband input matching and low noise figure. A common source amplifier with inductive peaking technique as the second stage achieves high flat gain and wide the −3dB bandwidth of the overall amplifier simultaneously. The implemented ultra-wideband LNA presents a maximum power gain of 15.6dB, a high reverse isolation of −45dB and a good input/output return losses are better than −10dB in the frequency range of 3.1–10.6GHz. An excellent noise figure (NF) of 2.8–4.7dB was obtained in the required band with a power dissipation of 14.1mW under a supply voltage of 1.5V. An input-referred third-order intercept point (IIP3) is −7.1dBm at 6GHz. The chip area including testing pads is only 0.8mm×0.9mm. [Copyright &y& Elsevier]

Abstract: In this paper, we study the existence of positive solutions to the following semilinear elliptic equation with a Sobolev–Hardy term where is a bounded domain with smooth boundary in , , , is the corresponding critical exponent and where is the first eigenvalue of in . When , we prove that problem (0.1) has at least one positive solution by using the mountain-pass lemma and a global compactness result. The case is quite different and we deal with this case by using the method in Jannelli (1999) to prove the existence result. Moreover, we obtain the nonexistence result of (0.1) in a star shaped domain. Our main results extend a recent result of Castorina et al. (2009) where and . [Copyright &y& Elsevier]

Abstract: TiO2 nanopowders could be prepared by thermal processing of the precursor of titanium hydroxide, urea and Na2SiO3. The powders were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The results show that Na2SiO3 has an important effect on the average crystallite size and dispersity of TiO2 nanopowders, and other phases (Na2SO4 and SiO2) will be introduced. However, Na2SO4 has distinctive intercalation ability and catalytic activity; SiO2 coating layers can effectively inhibit the agglomeration of TiO2 nanopowders. TiO2 (anatase) powders with well dispersity can be prepared at ∼600°C for 2h with addition of 2–6 wt.% Na2SiO3, and the average crystallite size is 15.5–22.1nm. The surface of the sample mainly consists of Ti, O, C, Si, Na and S six species elements. [Copyright &y& Elsevier]

Many recent reports have discussed specific effects of anions on the properties of lipid membranes and possible roles of such effects within biochemistry. One key parameter in both theoretical and experimental treatments of membrane–salt interactions is the net affinity, that is, the free energy of interaction. This parameter has been analyzed theoretically and by modeling of experimental data but not directly measured even for simple salt–membrane systems. To provide such information, we have studied the interaction of unilamellar liposomes of dimyristoyl phosphatidylcholine (DMPC) and eight sodium salts by dialysis equilibrium measurements. This method provides model free thermodynamic data and allows investigations in the dilute concentration range where solution nonideality and perturbation of membrane structure is limited. The transfer free energy of DMPC from water to salt solutions, Δμ2,trans, was found to scale proportionally to the salt concentration, m3, in the 0–50 mmolal range, and we suggest that the slope, Δμ2,trans/outm3, represents an experimental salt–membrane interaction potential. The values of Δμ2,trans/outm3for sodium salts of monovalent anions ranged from .2 kJ (mol·molal)−1for F–to −16.9 kJ (mol·molal)−1for SCN–, thus confirming a distinct membrane specificity among the anions. For Na2SO4, the interaction was strongly unfavorable with Δμ2,trans/outm3= .6 kJ (mol·molal)−1. The dialysis data were supplemented with calorimetric measurements and analyzed with respect to a two-domain model. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a low-voltage low-power transmitter front-end using current mode approach for 2.4GHz wireless communication applications, which is fabricated in a chartered 0.18μm CMOS technology. The direct up-conversion is implemented with a current mode mixer employing a novel input driver stage, which can significantly improve the linearity and consume a small amount of DC current. The driver amplifier utilizes a transimpedance amplifier as the first stage and employs an inter-stage capacitive cross-coupling technique, which enhances the power conversion gain as well as high linearity. The measured results show that at 2.4GHz, the transmitter front-end provides 15.5dB of power conversion gain, output P−1dB of 3dBm, and the output-referred third-order intercept point (OIP3) of 13.8dBm, while drawing only 6mA from the transmitter front-end under a supply voltage of 1.2V. The chip area including the testing pads is only 0.9mm×1.1mm. [Copyright &y& Elsevier]

Abstract: This paper proposes a new current-mode current-controlled single input multiple output (SIMO) type universal filter. The proposed circuit employs two current-controlled current conveyors (CCCIIs), one MO-CCCA (current-controlled current amplifier with multi-outputs) and two grounded capacitors. The filter can simultaneously realize lowpass, bandpass, highpass, bandstop and allpass filter outputs, and offers an independent electronic control of the natural angular frequency () and quality factor (Q) by means of adjusting the bias currents of the CCCIIs. The parameter sensitivities are small. Moreover, a high Q-value filter can be easily obtained by adjusting the ratio of two bias currents of MO-CCCA. PSPICE simulation results are given to demonstrate the advantages of the proposed circuit. [ABSTRACT FROM AUTHOR]

A new circuit topology using a current-mode low-pass filter for sinusoids has been presented. The technique is relatively simple, in the proposed circuit, only three identical current-mode low-pass filters are connected to each other to realize the small signal path. No external passive components are required except for three capacitors. When compared with LC oscillators, the die area of this work, without inductors, is much smaller. When compared with voltage-mode ring oscillators, the supply voltage of this work is much lower. As a particular example, a 2.4 GHz, 1.2-V power supply, 5-mW sinusoidal oscillator is demonstrated. The oscillation frequency is tuned by the value of that three capacitors, over ∼900 MHz, and the tuning range is 37.5%. The phase noise results in −94 and −120 dBc/Hz at 1 and 10 MHz from the carrier, respectively. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we consider the class of equations where , and . In various range of the parameters involved, we obtain both results of existence and nonexistence of positive solutions by combining the Mountain Pass Lemma and the Pohozaev-type identity. [Copyright &y& Elsevier]

Biomarkers play an important role in disease diagnosis and prognosis, which demand reliable, sensitive, rapid, and economic detection platform to conduct simultaneous multiple-biomarkers analysis in serum or body liquid. Here, we developed a universal biosensing platform through integrating the advantages of unique nanostructure and biochemistry properties of graphene oxide quantum dots and high throughput and low cost of microfluidic chip for reliable and simultaneous detection of multiple cancer antigen and antibody biomarkers. The performance of the proposed biosensing platform is validated through the representative cancer biomarkers including carcino-embryonic antigen (CEA), carbohydrate antigen 125 (CA125), α-fetoprotein (AFP), carbohydrate antigen 199 (CA199) and carbohydrate antigen 153 (CA153). It has a large linear quantification detection regime of 5–6 orders of magnitude and an ultralow detection limit of 1 pg/mL or 0.01 U/mL. Moreover, the proposed biosensing chip is capable of conducting 5–20 kinds of biomarkers from at least 60 persons simultaneously in 40 min with only 2 μL serum of each patient, which essentially reduces the detection cost and time to at least 1/60 of current popular methods. Clinical breast cancer and healthy samples detection results indicated its promising perspective in practical applications including cancer early diagnosis, prognosis, and disease pathogenesis study. [Display omitted] • An ultrasensitive, multiple biomarkers simultaneous detection biochip was reported. • Microfluidic integrated with QDs to realize the high-performance biosensing platform. • The biochip has an ultralow LOD (1 pg/mL), a broad dynamic range and high-throughput. • Healthy and cancerous serums were diagnosed by the biochip successfully. [ABSTRACT FROM AUTHOR]

Decades of research into cryogels have resulted in the development of many types of cryogels for various applications. Collagen and gelatin possess nontoxicity, intrinsic gel-forming ability and physicochemical properties, and excellent biocompatibility and biodegradability, making them very desirable candidates for the fabrication of cryogels. Collagen-based cryogels (CBCs) and gelatin-based cryogels (GBCs) have been successfully applied as three-dimensional substrates for cell culture and have shown promise for biomedical use. A key point in the development of CBCs and GBCs is the quantitative and precise characterization of their properties and their correlation with preparation process and parameters, enabling these cryogels to be tuned to match engineering requirements. Great efforts have been devoted to fabricating these types of cryogels and exploring their potential biomedical application. However, to the best of our knowledge, no comprehensive overviews focused on CBCs and GBCs have been reported currently. In this review, we attempt to provide insight into the recent advances on such kinds of cryogels, including their fabrication methods and structural properties, as well as potential biomedical applications. [ABSTRACT FROM AUTHOR]

Abstract: By using output distance functions, this paper decomposes energy productivity change into several components: effects of the changes in the ratios of non-energy inputs to energy, energy supply composition, and output composition; technical efficiency change; technological change. We apply this method to decompose energy productivity change in 23 OECD countries between 1980 and 1990. Results show that technological change is the most important source; increase in capital–energy ratio and the growing importance within total energy supply of electricity also contribute to it. [Copyright &y& Elsevier]

The diffraction properties of volume holographic gratings are studied when the gratings are illuminated by an ultrashort pulsed beam with different polarization states. The developed coupled wave theory of Kogelnik is used. Considering the dispersion effect of the grating media, solutions for the diffracted and transmitted intensities, diffraction efficiencies and the bandwidths of the gratings are given in transmission volume holographic gratings and reflection volume holographic gratings. The bandwidths of the gratings are reduced by the dispersion effect of the grating media. They also have different influences on the diffraction of an ultrashort pulsed beam with different polarization states. For different values of the ratio of the spectral bandwidth of the input pulse to that of the grating, the changes of the spectral and temporal distributions of the diffracted intensities, as well as the diffraction efficiencies of the gratings are shown. [ABSTRACT FROM AUTHOR]

[Display omitted] • The modification has been carried out to the burner structure. • The industrial test and numerical simulation of the burner are carried out. • The excess air coefficient and flue gas recirculation rate was optimized. • The flue gas recirculation rate can be as high as 40 %. • The NO x emission index of the burner is lower than 30 mg/Nm3. A new low NO x burner for gas boiler is designed. A hollow tube is embedded in the burner axial center line, which is combined with the flared flame stabilizer to draw back the internal flue gas from inside the boiler, and a flue gas recirculation tube is installed outside the boiler to draw back the flue gas from the end of the boiler. The effectiveness of the burner is evaluated by industry experiments and extensive computational fluid dynamics (CFD) simulations. The research results show that the excess air ratio and external flue gas recirculation (e-FGR) rate significantly alter the temperature distribution and NO x emission of the boiler. The temperature and NO x emission do not vary monotonically with the excess air ratios, but decrease monotonically with the e-FGR rates. To achieve the low NO emission, the optimum excess air coefficient α should be 1.15 due to the better temperature uniformity, and the value of e-FGR rate should be in the range of 28%–40%. In addition, the maximum concentration of NO does not appear on the flame surface, but in the downstream region of the flame. [ABSTRACT FROM AUTHOR]

Cellular phenotypic and functional heterogeneities have advanced cancer evolution and treatment resistance. Although exosome‐bound proteins reflect cellular functions, single‐cell exosomes are rarely profiled owing to the lack of effective platforms. Herein, the authors developed an integrated microfluidic platform consisting of a single‐cell trapping chip and a spatially coded antibody barcode chip for the multiplexed outline of exosome secretion by single cells. Using this platform, five phenotypic exosomes of over 1 000 single cells are simultaneously profiled, in addition to inflammatory factor secretion from the same single cell. Also, a robust analysis workflow for single‐cell secretion profiling is proposed to explore the intercellular heterogeneity, which integrated unsupervised clustering and linear clustering. When applied to the tumor cell lines of epithelial‐origin and normal epithelial cell lines, the strategy identifies functionally heterogeneous subpopulations with unique secretion patterns. Notably, special functional cell subsets for unique phenotypic exosomes (HSP70+, EPCAM+) are found within ovarian tumor cells. The strategy proposed offers a new analysis approach for cellular differential exosome secretion at single‐cell resolution using inflammatory factors, ultimately reinforcing the understanding of cell‐to‐cell heterogeneity and tumor landscape, and providing a valuable universal platform for single‐cell biomarker exploration in biological and clinical research. [ABSTRACT FROM AUTHOR]

The analog circuit design of the memristive neural network (MNN), which can automatically perform the online learning algorithm, is an open question. In this article, a memristive self-learning neuron circuit for implementing the online least mean square (LMS) algorithm is designed. Extending on the designed neuron circuit, the circuit implementation of the monolayer and multilayer neural network is proposed. The proposed neural network can automatically converge the output to the set target according to the input. The application-level validations of the circuits are done using pattern recognition and license plate detection. The performances of the designed MNN circuits and the effect of memristive variation are analyzed through PSPICE simulations. The learning accuracy of the proposed circuit for license plate detection can reach 93%. Circuit simulation results reveal that the proposed MNN circuits can accelerate the training speed and have the tolerance to the variations of the memristor. [ABSTRACT FROM AUTHOR]

To identify early doxorubicin-induced cardiotoxicity by applying 7.0 T cardiac magnetic resonance (CMR) combined with creatine kinase isoenzymes (CKMB) from rat models, using pathological results as a reference standard. The 48 male rats included in the study were divided into a doxorubicin (DOX) group (n = 32) and a control group (n = 16). Each group was further divided into four subgroups according to the interval weeks between the first administration and CMR examination. DOX group and the controls were injected with DOX (2.5 mg/kg) or physiological saline (2.5 mg/kg) through vena caudalis weekly. The rats in first subgroup received 4 weekly injections and were sacrificed after CMR examination at week 4. Rats in the second, third and fourth DOX or control subgroups underwent 6 weekly injections and were sacrificed after CMR examination at weeks 6, 8 and 10, respectively. The conventional cardiac function parameters, myocardial strain, standardized myocardial T2 value, late gadolinium enhancement, CKMB and pathological results of each rat were analyzed. The LV mass index was reduced and CKMB was increased in the first subgroup (week 4), global circumference strain was decreased and normalized myocardial T2 relaxation time was prolonged in the second subgroup (week 6). At these early point of time, LVEF remained unaffected. Myocardial fibrosis was observed in the third and fourth subgroups (in week 8 and 10, respectively) and the collagen volume fraction was significantly negatively correlated with the LVEF and myocardial strain. CMR can be used to identify doxorubicin-induced cardiotoxicity at early stage, with the LV mass index, global circumference strain, normalized myocardial T2 relaxation time as the early markers. CKMB can indicate the optimal timing for CMR examination of chemotherapy recipients to improve medical efficiency. Myocardial fibrosis persists in the advanced stage of doxorubicin-induced cardiotoxicity which comprises the main cause of LV dysfunction. • LV mass index, T2 mapping, LVGCS and serum biomarker changed in DOX-induced cardiotoxicity at early stage. • CKMB can indicate the optimal timing for CMR examination of chemotherapy recipients to improve medical efficiency. • Myocardial fibrosis persists in the advanced stage of DOX-induced cardiotoxicity which caused LV dysfunction. [ABSTRACT FROM AUTHOR]

A novel sub‐harmonic upconversion mixer using Chartered 0.18 μm radio‐frequency (RF) CMOS technology for 2.4 GHz wireless application is introduced. Using the sub‐harmonic technique, the required local oscillator (LO) frequency can be reduced a half, which simplifies the design of the LO. Moreover, the sub‐harmonic technique can effectively reduce the influence of LO leakage. The measured results demonstrate that the novel upconversion mixer can provide about 14.4 dB conversion gain, whereas the power consumption is only 1.65 mW with a 1 V supply voltage, and the input‐referred third‐order intercept point (IIP3) of the mixer is about 4 dBm. The chip area including test pads is only 0.7 × 0.72 mm2. [ABSTRACT FROM AUTHOR]

Reducing CO 2 emissions is a global effort to improve industrial cost efficiency, enhance product compatibility, and fight climate change. For leather-making industry, the optimization of tanning process is crucial to fulfill the goal of low-carbon manufacturing. Artificial intelligence (AI) is an emerging technology for its ability to reduce errors, increase efficiency, and help realizing precise optimization of manufacturing processes. Herein, an AI-assisted method was first proposed to optimize chrome tanning process for energy-saving and carbon reduction. By comparing the performance of four machine learning (ML) algorithms, i.e., multiple linear regression (MLR), polynomial regression (PR), support vector regression (SVR), and backpropagation-artificial neural network (BP-ANN), it was found that machine learning models are superior in identifying the optimization of process parameters (pH and time) which lead to maintain key product quality indexes in the penetration procedure and binding procedure. Out of the four ML models, the BP-ANN algorithm and SVR algorithm are proven to have good predictive ability. Thus, we systematically optimized the chrome tanning process for energy saving, with key product quality as the constraints. The optimal process parameters, namely pickling pH of 2.86, penetration time of 90 min, pH after basifying of 4.08, and binding time of 90 min, were generated by solving the optimization models of the chrome tanning process via the genetic algorithm (GA) with powerful global optimization capability. Finally, it was validated that the optimized process was highly reliable by evaluating the wet blue product performances, such as the evenness of chrome distribution, thermal stability, surface reactivity, morphology, as well as physical and mechanical properties. Notably, compared to conventional chrome tanning, the optimized process will save 8353.33 kgce of energy and reduce 87295.6 kgCO 2 of CO 2 emission in an average tannery with an annual production capacity of 300,000 standard sheets of upper cowhide leather. This approach can precisely optimize conventional leather-making process, providing a fesible way to achieve energy-saving and low-carbon leather production. [Display omitted] • The AI-assisted optimization approach for the tanning process was first proposed. • Mathematical models in chrome tanning procedure were developed and evaluated. • The optimization model of tanning process was systematically constructed. • The optimal process parameters were generated by GA and validated via lab testing. • The optimal tanning process can achieve energy saving and carbon reduction. [ABSTRACT FROM AUTHOR]

Owing to its convenient, sustainable and green process, photocatalysis has become a feasible technique for solving environmental pollution issues. So far, significant achievements have been realized in photocatalytic pollutant elimination. Nevertheless, photocatalytic processes require a continuous external light illumination to drive photoredox reactions, seriously prohibiting their applications in darkness. In this context, exploring a photocatalyst with reliable photocatalytic activity in dark condition is therefore highly meaningful and an ultimate target of photocatalysis technique. Recently, long afterglow phosphor has aroused great attention due to its "light battery" role for driving catalytic reactions in dark conditions. To be specific, long-afterglow phosphor or long-afterglow phosphor/semiconductor composite can be used as a photocatalyst to simultaneously promote the photoredox processes and store extra photoexcited charges in the trapping states upon light irradiation. When the light illumination terminates, a gradual release of the charges from trapping states occurs in long-afterglow phosphor, which can continuously spur photoredox reactions under the dark environment and even maintains the photocatalysis around the clock. In this work, we comprehensively reviewed the recent advances of long afterglow phosphor based round-the-clock photocatalysts in environmental pollutant elimination. Meanwhile, the inherent mechanism of long afterglow photocatalysis was discussed in depth. More importantly, the relationship between the improved long afterglow photocatalytic capability and the engineering of long afterglow system is correlated systematically. Finally, the ongoing challenges and future prospects for the mass production and commercial utilization of round-the-clock photocatalysts are analyzed and outlooked. [ABSTRACT FROM AUTHOR]

The effects of different pretreatment methods on the microstructure and electrochemical properties of porous carbon materials are investigated by using mature loofah as carbon material source. Compared with the samples without pretreatment, the porous carbon material produced under the condition of sulfuric acid pretreatment has the largest specific surface area and the richest pore structure. The structure can quickly transform the long-chain polysulfide into the short-chain polysulfide, thus effectively fixing the polysulfide and blocking the shuttle effect. At 2C, the initial specific capacity of the battery is 772.8 mAh/g. And after 300 cycles, the capacity retention rate is 87.7 %. It has good rate performance. Therefore, the physical and electrochemical properties of biomass materials are significantly improved by the proper pretreatment process. The research shows that the low cost biomass carbon material has significant advantages as the cathode material of lithium sulfur battery through the simple and reasonable pretreatment. [ABSTRACT FROM AUTHOR]

This research employs the fuzzy‐set qualitative comparative analysis (fsQCA) method to investigate the configurations of multiple factors influencing scientific concept learning, including augmented reality (AR) technology, the concept map (CM) strategy and individual differences (eg, prior knowledge, experience and attitudes). A quasi‐experiment was conducted with 194 seventh‐grade students divided into four groups: AR and CM (N = 52), AR and non‐CM (N = 51), non‐AR and CM (N = 40), non‐AR and non‐CM (N = 51). These students participated in a science lesson on ‘The structure of peach blossom’. This study represents students' science learning outcomes by measuring their academic performance and cognitive load. The fsQCA results reveal that: (1) factors influencing students' academic performance and cognitive load are interdependent, and a single factor cannot constitute a necessary condition for learning outcomes; (2) multiple pathways can lead to the same learning outcome, challenging the notion of a singular best path derived from traditional analysis methods; (3) the configurations of good and poor learning outcomes exhibit asymmetry. For example, high prior knowledge exists in both configurations leading to good and poor learning outcomes, depending on how other conditions are combined. Practitioner notes What is already known about this topic Augmented reality proves to be a useful technological tool for improving science learning. The concept map can guide students to describe the relationships between concepts and make a connection between new knowledge and existing knowledge structures. Individual differences have been emphasized as essential external factors in controlling the effectiveness of learning. What this paper adds This study innovatively employed the fsQCA analysis method to reveal the complex phenomenon of the scientific concept learning process at a fine‐grained level. This study discussed how individual differences interact with AR and concept map strategy to influence scientific concept learning. Implications for practice and/or policy No single factor present or absent is necessary for learning outcomes, but the combinations of AR and concept map strategy always obtain satisfactory learning outcomes. There are multiple pathways to achieving good learning outcomes rather than a single optimal solution. The implementation of educational interventions should fully consider students' individual differences, such as prior knowledge, experience and attitudes. What is already known about this topic Augmented reality proves to be a useful technological tool for improving science learning. The concept map can guide students to describe the relationships between concepts and make a connection between new knowledge and existing knowledge structures. Individual differences have been emphasized as essential external factors in controlling the effectiveness of learning. What this paper adds This study innovatively employed the fsQCA analysis method to reveal the complex phenomenon of the scientific concept learning process at a fine‐grained level. This study discussed how individual differences interact with AR and concept map strategy to influence scientific concept learning. Implications for practice and/or policy No single factor present or absent is necessary for learning outcomes, but the combinations of AR and concept map strategy always obtain satisfactory learning outcomes. There are multiple pathways to achieving good learning outcomes rather than a single optimal solution. The implementation of educational interventions should fully consider students' individual differences, such as prior knowledge, experience and attitudes. [ABSTRACT FROM AUTHOR]

On the basis of the chaotic system proposed by Wang et al. in 2023, this paper constructs a 5D fractional-order memristive hyperchaotic system (FOMHS) with multiple coexisting attractors through coupling of magnetic control memristors and dimension expansion. Firstly, the divergence, Kaplan–Yorke dimension, and equilibrium stability of the chaotic model are studied. Subsequently, we explore the construction of the 5D FOMHS, introducing the definitions of the Caputo differential operator and the Riemann–Liouville integral operator and employing the Adomian resolving approach to decompose the linears, the nonlinears, and the constants of the system. The complex dynamic characteristics of the system are analyzed by phase diagrams, Lyapunov exponent spectra, time-domain diagrams, etc. Finally, the hardware circuit of the proposed 5D FOMHS is performed by FPGA, and its randomness is verified using the NIST tool. [ABSTRACT FROM AUTHOR]

We elucidated the factors, evolution, and compensation of antimicrobial resistance (AMR) in Mycobacterium tuberculosis (MTB) isolates under dual pressure from the intra-host environment and anti-tuberculosis (anti-TB) drugs. This retrospective case-control study included 337 patients with pulmonary tuberculosis from 15 clinics in Tianjin, China, with phenotypic drug susceptibility testing results available for at least two time points between January 1, 2009 and December 31, 2016. Patients in the case group exhibited acquired AMR to isoniazid (INH) or rifampicin (RIF), while those in the control group lacked acquired AMR. The whole-genome sequencing (WGS) was conducted on 149 serial longitudinal MTB isolates from 46 patients who acquired or reversed phenotypic INH/RIF-resistance during treatment. The genetic basis, associated factors, and intra-host evolution of acquired phenotypic INH/RIF-resistance were elucidated using a combined analysis. Anti-TB interruption duration of ≥30 days showed association with acquired phenotypic INH/RIF resistance (aOR = 2·2, 95% CI, 1·0–5·1) and new rpoB mutations (p = 0·024). The MTB evolution was 1·2 (95% CI, 1·02–1·38) single nucleotide polymorphisms per genome per year under dual pressure from the intra-host environment and anti-TB drugs. AMR-associated mutations occurred before phenotypic AMR appearance in cases with acquired phenotypic INH (10 of 16) and RIF (9 of 22) resistances. Compensatory evolution may promote the fixation of INH/RIF-resistance mutations and affect phenotypic AMR. The TB treatment should be adjusted based on gene sequencing results, especially in persistent culture positivity during treatment, which highlights the clinical importance of WGS in identifying reinfection and AMR acquisition before phenotypic drug susceptibility testing. [ABSTRACT FROM AUTHOR]

A Pd/UiO-66 catalyst was synthesized with well-dispersed Pd nanoparticles. The obtained catalyst was tested in the hydrogenation of furfural to tetrahydrofurfuryl alcohol in various solvents, Water was found to be the most suitable solvent. Pd/UiO-66 exhibited much higher activity than Pd/SiO 2 and Pd/γ-Al 2 O 3 , completely converting furfural to tetrahydrofurfuryl alcohol with 100% selectivity under mild conditions. The hydrogenation of C O moiety in tetrahydrofurfural was rate-determining step. Static adsorption measurement indicated that the adsorption of furfural on UiO-66 was significantly stronger than that on SiO 2 or γ-Al 2 O 3 , suggesting that the adsorption play an important role in the gas-liquid-solid furfural hydrogenation reaction. Unlabelled Image • A Pd/UiO-66 catalyst was prepared with average Pd particle size of 2–3 nm. • 100% selectivity to tetrahydrofurfuryl alcohol was achieved by Pd/UiO-66. • Hydrogenation of C O moiety in tetrahydrofurfural was the rate-determining step. [ABSTRACT FROM AUTHOR]

Large-eddy simulations were conducted to study the film cooling characteristics of a serrated trenched-hole cooling geometry on a scaled turbine guide vane. The simulations were carried out under a blowing ratio of M = 2.0. The serrated trench was placed on the suction and pressure side, respectively. The results show that the mainflow environment above the suction side differs from that above the pressure side. Therefore the adiabatic film cooling effectiveness changes correspondingly. Within the range of x/d = 3 to x/d = 25, the are-averaged adiabatic film cooling effectiveness on the pressure side is about 21% higher than that on the suction side. By presenting the vortex structure and unstable statistic results of the trenched-hole region and downstream flow field, the present study analyses in detail the characteristics of the coolant flow patterns and the coolant-mainflow interaction at both the suction and pressure side. Results show that the cooling jet penetration is suppressed on the suction side, while the intense mainflow entrainment results in dramatic destruction of the cooling film protection. Unlike the situation at the suction side, although coolant penetration is more substantial on the pressure side, film cooling shows good performance due to the unstable concave flow. [ABSTRACT FROM AUTHOR]

Background: Non-invasive modalities for assessing axillary lymph node (ALN) are needed in clinical practice. Purpose: To investigate the suspicious ALN on unenhanced T2-weighted (T2W) imaging and intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI) for predicting ALN metastases (ALNM) in patients with T1–T2 stage breast cancer and clinically negative ALN. Material and Methods: Two radiologists identified the most suspicious ALN or the largest ALN in negative axilla by T2W imaging features, including short axis (Size-S), long axis (Size-L)/S ratio, fatty hilum, margin, and signal intensity on T2W imaging. The IVIM parameters of these selected ALNs were also obtained. The Mann–Whitney U test or t-test was used to compare the metastatic and non-metastatic ALN groups. Finally, logistic regression analysis with T2W imaging and IVIM features for predicting ALNM was conducted. Results: This study included 49 patients with metastatic ALNs and 50 patients with non-metastatic ALNs. Using the above conventional features on T2W imaging, the sensitivity and specificity in predicting ALNM were not high. Compared with non-metastatic ALNs, metastatic ALNs had lower pseudo-diffusion coefficient (D*) (P = 0.043). Logistic regression analysis showed that the most useful features for predicting ALNM were signal intensity and D*. The sensitivity and specificity predicting ALNM that satisfied abnormal signal intensity and lower D* were 73.5% and 84%, respectively. Conclusions: The abnormal signal intensity on T2W imaging and one IVIM feature (D*) were significantly associated with ALNM, with sensitivity of 73.5% and specificity of 84%. [ABSTRACT FROM AUTHOR]