Search

Sub-10 nm metal-based nanoparticles have garnered immense interest due to their unique properties and versatile applications. In this study, we created sub-10 nm Ag-based particles with a spark discharge generator and explored the parameters impacting their size distribution and charging properties, including carrier gas flow rates, spark discharge voltage, electrode gap distances, and capacitance. Our findings illuminate that there is a comparable influence of different factors on both self-charged and neutral particles. Among the different factors, carrier gas flow rates emerging as a paramount determinant in particle size. While increasing spark discharge voltage and capacitance within the spark circuit increases particle concentrations, the associated changes in particle size prove to be less straightforward. Significant differences between the concentration of positive and negative self-charged particles manifest when the carrier gas flow rate surpasses 5.0 L min−1, with positive particles ranging from 0.8 to 1.2 nm and negative particles spanning 0.8 to 3.0 nm. Self-charged particles close to 1 nm tend to exhibit positive charges, whereas those larger than 2 nm tend to acquire negative charges, which suggests the growth of negative particles is faster than positive ones in the spark chamber. Nevertheless, these disparities between bipolar particles diminish with the increase of residence time, leading to the observation of similar particle size distributions. Positive particles consistently bear a single charge, while some negative particles exceeding 3 nm exhibit multiple charges, primarily under carrier gas flow rates exceeding 7.5 L min−1. This study provides insights into the control of properties of nano-sized metal particles, which are crucial for their practical utilization. Copyright © 2024 American Association for Aerosol Research [ABSTRACT FROM AUTHOR]

Under a global carbon-neutralizing environment, renewable wood is a viable alternative to non-renewable resources due to its abundance and high specific strength. However, fast-growing wood is hard to be applied extensively due to low mechanical strength and poor dimensional stability and durability. In this study, epoxy-acrylic resin-modified wood was prepared by forming a functional monomer system with three monomers [glycidyl methacrylate (GMA), maleic anhydride (MAN), and polyethylene glycol-200-dimethylacrylic acid (PEGDMA)] and filling into the wood cell cavity. The results showed that in the case of an optimal monomer system of nGMA:nPEGDMA = 20:1 and an optimal MAN dosage of 6%, the conversion rate of monomers reached 98.01%, the cell cavity was evenly filled by the polymer, with the cell wall chemically bonded. Thus, a bonding strength of as high as 1.13 MPa, a bending strength of 112.6 MPa and an impact toughness of 74.85 KJ/m2 were applied to the modified wood, which presented excellent dimensional stability (720 h water absorption: 26%, and volume expansion ratio: 5.04%) and rot resistance (loss rates from white rot and brown rot: 3.05% and 0.67%). Additionally, polymer-modified wood also exhibited excellent wear resistance and heat stability. This study reports a novel approach for building new environmentally friendly wood with high strength and toughness and good structural stability and durability. [ABSTRACT FROM AUTHOR]

Wood is a viable alternative to traditional steel, cement, and concrete as a structural material for building applications, utilizing renewable resources and addressing the challenges of high energy consumption and environmental pollution in the construction industry. However, the vast supply of fast-growing poplar wood has bottlenecks in terms of low strength and dimensional stability, making it difficult to use as a structural material. An environmentally friendly acrylic resin system was designed and cured in this study to fill the poplar cell cavities, resulting in a new type of poplar laminated veneer lumber with improved mechanical strength and dimensional stability. The optimized acrylic resin system had a solid content of 25% and a curing agent content of 10% of the resin solid content. The cured filled poplar veneer gained 81.36% of its weight and had a density of 0.69 g/cm3. The static flexural strength and modulus of elasticity of the further prepared laminated veneer lumber were 123.12 MPa and 12,944.76 MPa, respectively, exceeding the highest flexural strength required for wood structural timber for construction (modulus of elasticity 12,500 MPa and static flexural strength 35 MPa). Its tensile strength, impact toughness, hardness, attrition value, water absorption, water absorption thickness expansion, and water absorption width expansion were 58.81%, 19.50%, 419.18%, 76.83%, 44.38%, 13.90%, and 37.60% higher than untreated laminated veneer lumber, demonstrating improved mechanical strength and dimensional stability, significantly. This method provides a novel approach to encouraging the use of low-value-added poplar wood in high-value-added structural building material applications. [ABSTRACT FROM AUTHOR]

Measurements of sub-3 nm particles are technically challenging and characterized with significant uncertainties. This study selected two types of widely used commercial instruments: an Airmodus® Particle Size Magnifier (PSM) and a TSI® diethylene glycol-based Scanning Mobility Particle Sizer (DEG–SMPS), and examined factors that govern their abilities on measurements of sub-3 nm particles. Monodisperse standard particles used in the experiments include positively and negatively charged tungsten oxide particles and nickel–chromium (Ni/Cr) oxide particles, positive and negative ions produced in a soft X-ray neutralizer, and positively charged organic particles including tetraheptylammonium bromide (THABr), tetrabutylammonium bromide (TBABr), and polyethylene glycol (PEG) particles. Our results show that both PSM and DEG–SMPS are subject to the influence of particle composition. Negatively charged tungsten oxide particles were detected at higher efficiencies than positively charged ones, whereas opposite results were observed for Ni/Cr particles and background ions produced in the soft X-ray neutralizer. In addition, the concentration accuracy of PSM and DEG–SMPS are explored after calibration using Ni/Cr particles. The inverted total concentrations by DEG–SMPS are usually underestimated because of the overestimation of penetration efficiency through different modules, whereas the inverted total concentrations by PSM can be either overestimated or underestimated, when the properties of analyte particles are significantly different from the calibration particles. A better understanding on the effects of particle chemical composition and charging state, and their diffusion losses in the instruments will help to diminish the uncertainties in the measurements. Copyright © 2022 American Association for Aerosol Research. [ABSTRACT FROM AUTHOR]

Ficus altissima , also known as lofty fig, is a monoecious plant from the Moraceae family commonly found in southern China. In this study, we isolated and identified one new isoflavone (1), three new hydroxycoumaronochromones (2a , 2b and 3a) and 12 known compounds from the fruits of F. altissima. Their chemical structures were determined using spectroscopic analysis methods. We also tested all the isolated compounds for their anti-proliferative activities against eight human tumour cell lines (A-549, AGS, K562, K562/ADR, HepG2, HeLa, SPC-A-1 and CNE2) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Our experiments showed that compound 6 exhibited obvious anti-proliferative activity against the K562 cell line with an IC 50 value of 1.55 μM. Additionally, compounds 8 and 9 showed significant anti-proliferative activities against the AGS and K562 cell lines, respectively. Moreover, compound 6 induced apoptosis in K562 cells through the caspase family signalling pathway. [Display omitted] • Four new isoflavones were isolated from the fruits of Ficus altissima. • Compound 6 showed obvious anti-proliferative effect against K562 cell line. • Compounds 8 and 9 showed anti-proliferative effects against AGS and K562 cells. [ABSTRACT FROM AUTHOR]

Micro air vehicles with propellers have been widely used in military and civilian applications due to their high maneuverability and low cost. As the mission scenarios and requirements of rotorcrafts become more complex, proximity effects caused by confined environments, such as the ceiling effect cause significant interference to the performance and stability of rotors. Most researchers have analyzed this phenomenon by considering the ceiling effect in hover conditions. However, few scholars considered the tilt angle between the rotor and the ceiling, which is more likely to occur in real missions, such as the close inspection of bridges or large equipment, flight in narrow indoor environments, and flight near the ceiling for fully actuated multirotors. In this study, a CFD-based study is conducted to evaluate the ceiling effect for small-scale tilted propellers. The aerodynamic analysis was experimentally evaluated through a series of ground tests in a test bench designed for this research. The CFD results were validated by a mesh-independent study and experimental data comparison. The results show that in contrast to the phenomenon of reduced thrust when tilt angles exist between the rotors and ground, the existence of tilt angles between the propeller and the ceiling reduces the thrust-increasing effect of the ceiling when the dimensionless distance is greater than 0.6. When the distance gets smaller, the thrust-increasing effect increases when the tilt angle is greater than 10 ∘. In particular, when the distance is less than 0.3, the existence of tilt angles will increase the thrust-increasing effect of the ceiling. Additionally, a data-driven model has been proposed to predict the thrust with the distance to the ceiling and the angle inclination between the rotor and the ceiling. This model enables future rotorcrafts that require accurate models to operate in narrow environments. [ABSTRACT FROM AUTHOR]

Growing computation requirements in emerging intelligently connected vehicle (ICV) networks has posed a big challenge for vehicles to process computation-intensive tasks on-board, and thus computation partition and offloading plays a critical role. Owing to broadcast nature of wireless channels, confidential messages without proper security protection in ICVs may be easily exposed to malicious users. In this paper, a mobile crowdsourcing (MCS) based mobile crowd computing framework for ICV networks is proposed, where multiple vehicles act as workers to provide computing services for end user (EU). In particular, artificial noise (AN) assisted physical (PHY) layer security approaches are used to enhance the security in offloading links. Ergodic secrecy rates in different offloading phases in time-varying channels are derived. In addition, an incentive-driven mechanism is introduced to encourage workers to share their idle computing resources, and an optimization problem is formulated to minimize the overall price paid for computing tasks, subject to energy consumption and delay constraints. Finally, Monte Carlo simulations verify the analysis on the ergodic secrecy rates. [ABSTRACT FROM AUTHOR]

Metallic glass (MG) shows great potential for a wide range of functional and structural applications. However, it remains a challenge to enhance the ductility of metallic glasses without compromising their strength during development. A composite of bulk metallic glass/graphene (BMG/C (n)) was prepared using the suction casting method in argon atmosphere, with a nominal composition of (Zr 60 Ni 20 Al 20) 100-x (C (n)) x (x = 5,10,15). The results indicate that the graphene well dispersed in the BMG matrix without any other intermetallic compounds present. Mechanical property testing reveals a significant increase in both plasticity and hardness with increasing graphene content, while maintaining high fracture strength of the BMG matrix. [Display omitted] • An effective method for preparing BMG-graphene composite was presented. • A dual-phase structure of the BMG and graphene were designed. • The strength-plasticity synergy in this composite was presented. • The plasticity of this composite has been increased by about 6 times. [ABSTRACT FROM AUTHOR]

This article aims to provide a comprehensive overview on PHY layer security assisted ICV networks. Beginning with a discussion from a general perspective of the ICV network architecture, this work summarizes the major security threats faced by ICV networks. To achieve confidential data transmission with a low latency and a high data rate, several physical layer security schemes are surveyed in this article, which include RRM, cooperative jamming, multi-antenna technologies, and PHY-layer key generation. In addition, the performances of the aforementioned schemes are compared in terms of different aspects, followed by a discussion on some major challenges that need to be tackled in the implementation of ICV networks. [ABSTRACT FROM AUTHOR]

This paper proposes a brain–robot interface (BRI)-based control strategy in combination with the simultaneous localization and mapping (SLAM) to achieve the navigation and control of a mobile robot in uncertain environments. The BRI is based on steady state visually evoked potentials, utilizing the multivariate synchronization index classification algorithm to analyze the human electroencephalograph (EEG) signals in such a manner that human intentions can be recognized and motion commands can be produced for the brain controlled robot. The entire system is semi-autonomous since the navigation of mobile robot is commanded by the BRI, and the low-level motion of the mobile robot is autonomous with a designed kinematic controller. By utilizing vanishing points and door plates as the environmental features, a global metric map of the environment has been built by a sequential SLAM algorithm. The main contribution of this paper is the combination of an artificial potential field (APF) and the brain signals, which builds up the relationship between the strength of EEG signals and the intensity of the potential field. Through the proposed EEG-APF method, motion commands that would plan an obstacle-free trajectory in un-structured environments, can be obtained. The entire system has been tested with eight volunteer subjects, and all subjects are able to successfully fulfill manipulating mobile robot in the experiments. [ABSTRACT FROM AUTHOR]

In device-to-device (D2D) underlaying vehicle-to-vehicle (V2V) communications, radio resource blocks (RBs) are allocated to primary cellular users, which yields sub-optimal rates and a long access latency for secondary D2D-enabled vehicles. This work investigates a joint radio resource and power management (RRPM) problem for secure cellular underlaying V2V communications, where cellular users and vehicles have the same priority, giving vehicles more opportunities to access the RBs. Specifically, we aim to maximize secrecy rates of V2V channels under the condition that eavesdropper has an adaptive receiving detection vector to maximize the received signal-to-interference-plus-noise ratio (SINR) from vehicles. For a single pair of a vehicle and a cellular user, the closed-form optimal power allocation expressions are derived for the interference-limited scenario and the noise-limited scenario, respectively. Moreover, for multiple pairs of vehicles and cellular users, a 3-partite hypergraph based 3-dimensional matching approach is proposed to solve a mixed-integer and non-convex problem, which achieves a near-optimal result with an $O(n^4)$ time complexity. Simulations in different scenarios show that the secrecy rate of the proposed scheme can be improved by 50% if compared to existing schemes. [ABSTRACT FROM AUTHOR]

Geometries and dissociation energies of water molecules on Aln (n = 2-25) clusters were investigated using density functional theory with all electron relativistic spin-polarized calculations under the generalized gradient approximation. An extensive structure search was performed to identify the low-energy conformations of AlnH2O complexes for each size. Optimal adsorption sites were assigned for low-energy isomers of the clusters. Size and site specific dependences were studied for the AlnH2O complexes in stabilities, geometries, adsorption energies, dissociation energies, Al-O bond lengths, and other characteristic quantities. The stabilities and geometries revealed that H atom in H2O is not inclined to bond with Al atoms. The most stable AlnH2O configurations for each size tend to correspond to the most stable bare Aln cluster except of Al6 and Al24 clusters. The HO bond lengths increase generally 0.01 Å with respect to the isolated H2O in all of the adsorption complexes. The dissociation energy of an isolated H2O into HO and H was 5.39 eV, which decreased about two-thirds to the energy range of 0.83-2.12 eV with the help of Aln clusters. In spite of the fluctuations, the dissociation energies of AlnH2O complexes rise with the size increasing as a whole. In addition, we also found that the bare Aln clusters with high vertical ionization potentials usually have high dissociation energies of H2O in the corresponding adsorption models. The energetically preferred spin-multiplicity of all the odd-n AlnH2O complexes is doublet, and it is singlet for all the even-n complexes with exception of Al2H2O which is triplet. [ABSTRACT FROM AUTHOR]

• Sources and general situation of incineration industrial by-products were summarized. • Physicochemical properties of incineration industrial by-products were discussed. • The effects and hydration mechanism of incinerated ash CLSMs were analyzed. • Incineration ash can be used to prepare cementless CLSM. Incineration industrial by-products can be used as supplementary cementitious materials (SCMs) to degrade the cement output, thereby reducing fossil-fuel combustion and contributing to the utilization and management of waste resources. This paper summarizes the state-of-the-art uses of incineration industrial by-products (coal ash, waste incineration ash, and biomass incineration ash), which are used as SCMs in partial cement replacement. It also summarizes alkali-activated by-products as cementitious materials that replace all cement with controlled low-strength material (CLSM). After introducing the general situation and physicochemical characteristics of these pozzolanic incineration ashes, the influences and mechanisms of the by-products on the performance of CLSM are summarized and analyzed. The discussions and analyses in this paper are expected to inspire further research and provide a basis for the sustainable development of CLSMs from incineration industrial by-products as cementitious materials. [ABSTRACT FROM AUTHOR]

Normally, authentication in vehicular ad hoc networks (VANETs) uses public key infrastructure to verify the integrity of messages and the identity of message senders. The issues considered in the authentication schemes include the level of security and computational efficiency in the verification processes. Most existing schemes mainly focus on assuring the security and privacy of VANET information. However, these schemes may not work well in VANET scenarios. For instance, it is difficult for a roadside unit (RSU) to verify each vehicle's signature sequentially when a large number of vehicles emerge in the coverage areas of an RSU. To reduce the computational overhead of RSUs, we propose a proxy-based authentication scheme (PBAS) using distributed computing. In the PBAS, proxy vehicles are used to authenticate multiple messages with a verification function at the same time. In addition, the RSU is able to independently verify the outputs from the verification function of the proxy vehicles. We also design an expedite key negotiation scheme for transmitting sensitive messages. It is shown from the analysis and simulations that an RSU can verify 26 500 signatures per second simultaneously with the help of the proxy vehicles. The time needed to verify 3000 signatures in the PBAS can be reduced by 88% compared with existing batch-based authentication schemes. [ABSTRACT FROM PUBLISHER]

The Geometries, relative stabilities, and electronic properties of the most stable host Ga n +1 and doped Ga n Ti (0, ±1) ( n = 1–10) clusters are studied using density functional theory (DFT) with valence basis set LANL2DZ. We determine the equilibrium geometries of host Ga n +1 and doped Ga n Ti( 0, ±1) ( n = 1–10) clusters by optimizing the bond length and bond angle of various structural isomers. With increasing cluster size, the Ga n Ti (0, ±1) clusters tend to adopt compact structures, and the ground state structures of Ga n Ti ±1 keep the similar geometric structure as the Ga n Ti clusters. When the number of Ga atom is even, the natural population analysis of Ga n Ti − clusters possess high charges transfer. In order to study the stability of cluster, the average binding energies per atom ( E b /atom), fragmentation energies ( E f ), second-order differences of total energies (Δ 2 E ) of host Ga n +1 and doped Ga n Ti (0, ±1) ( n = 1–10) clusters are studied. The calculation results of fragmentation energies of Ga n +1 clusters present a leaping odd–even oscillatory behavior from n = 1 to n = 10. Furthermore, the calculated HOMO–LUMO gaps of Ga n Ti clusters are distinctly higher than those of Ga n +1 clusters, except for Ga 3 Ti clusters. The size dependence of cluster’s vertical electron detachment energies (VDE), adiabatic electron affinities (AEA), and adiabatic ionization potentials (AIP), vertical ionization potentials (VIP) are discussed. [ABSTRACT FROM AUTHOR]

Abstract: This paper is concerned with the global asymptotic stability of a stochastic delay predator–prey system with Beddington–DeAngelis functional response. Sufficient criteria for the global asymptotic stability of the system are established. Some simulation figures are provided to show that our model is more realistic than existing models. [Copyright &y& Elsevier]

Increasing global cement and steel consumption means that a significant amount of greenhouse gases and metallurgical wastes are discharged every year. Using metallurgical waste as supplementary cementitious materials (SCMs) shows promise as a strategy for reducing greenhouse gas emissions by reducing cement production. This strategy also contributes to the utilization and management of waste resources. Controlled low-strength materials (CLSMs) are a type of backfill material consisting of industrial by-products that do not meet specification requirements. The preparation of CLSMs using metallurgical waste slag as the auxiliary cementing material instead of cement itself is a key feature of the sustainable development of the construction industry. Therefore, this paper reviews the recent research progress on the use of metallurgical waste residues (including blast furnace slag, steel slag, red mud, and copper slag) as SCMs to partially replace cement, as well as the use of alkali-activated metallurgical waste residues as cementitious materials to completely replace cement for the production of CLSMs. The general background information, mechanical features, and properties of pozzolanic metallurgical slag are introduced, and the relationship and mechanism of metallurgical slag on the performance and mechanical properties of CLSMs are analyzed. The analysis and observations in this article offer a new resource for SCM development, describe a basis for using metallurgical waste slag as a cementitious material for CLSM preparation, and offer a strategy for reducing the environmental problems associated with the treatment of metallurgical waste. [ABSTRACT FROM AUTHOR]

Abstract: This paper is related to a class of inverse problems for identification of the coefficient in a square porous medium. The unknown coefficient depends on the solution and belongs the class of admissible coefficients. Using continuous dependence of solutions on the coefficient convergence in the corresponding direct problems, the existence of the quasi-solution of the inverse problem is obtained in the appropriate class of admissible coefficients. [Copyright &y& Elsevier]

Abstract: A stochastic delay logistic system with Markov switching and impulsive toxicant input in a polluted environment is proposed and studied. Some sufficient criteria for extinction, non-persistence in the mean and weak persistence of the solutions are established. [Copyright &y& Elsevier]

Abstract: The structure, stability and electronic properties of the different B-site partial substituted derivatives LaNi4.5M0.5 (M=Al, Mn, Fe, Co) have been investigated by means of the density functional theory using the full-potential linearized augmented plane wave (FLAPW) method with the generalized gradient approximation (GGA). The optimized results indicate that all of Al, Mn, Fe, Co atoms prefer to substitute Ni atoms in the 3g sites. Due to the different radius of elements, the cell volume would increase with the doping Ni (3g) atoms. And the sequence of volume is LaNi4.5Al0.5 >LaNi4.5Mn0.5 >LaNi4.5Fe0.5 >LaNi4.5Co0.5 >LaNi5, which is in agreement with the experimental result. The calculated data of formation and cohesive energies indicate that LaNi4.5Mn0.5 has the stablest structure among five alloys. Based on the analysis of the density of states and charge density, the interactions of Mn–Ni, Fe–Ni, Co–Ni atoms are greatly stronger compared to the Ni–Ni interaction, while the interaction of Al–Ni atoms is weakened. Based on the formation energy of hydrogen atom in LaNi4.5M0.5H0.5, the sequence of bounding hydrogen atoms is LaNi4.5Mn0.5 >LaNi4.5Fe0.5 >LaNi4.5Co0.5 >LaNi4.5Al0.5 >LaNi5. [Copyright &y& Elsevier]

Abstract: In this paper, we prove the existence and uniqueness of solutions for systems of fractional differential equations with antiperiodic boundary conditions by applying some standard fixed point principles. [Copyright &y& Elsevier]

Abstract: In this paper, we consider the existence of solutions for first order nonlinear impulsive functional integro-differential equations with integral boundary value conditions. We firstly build a new comparison theorem. Then by utilizing the monotone iterative technique and the method of lower and upper solutions, we obtain the existence of extremal solutions or quasi-solutions. [Copyright &y& Elsevier]

Abstract: In this paper, we study the impulsive integro-differential equationsThe existence of maximal and minimal solutions to the problem is proved by using an upper and lower solutions method together with monotone iterative technique. And two monotone sequences which uniformly converge to the relevant solutions are obtained. An example is included to show the applicability of our results. [Copyright &y& Elsevier]

Abstract: Transparent TiO2 nanotube arrays of micrometer lengths were prepared by anodization of titanium thin film RF sputtered on indium tin oxide (ITO) which was coated on glass substrate. The sputtering process took place at elevated temperature of 500°C. The structures of the films were studied using scanning electron microscopy (SEM) and X-ray diffraction (XRD) while the optical properties of the films were investigated using UV–visible spectroscopy. Two types of electrolytes were used in this work: an aqueous mixture of acetic acid and HF solution and a mixture of NH4F and water dissolved in ethylene glycol. The concentration of NH4F, voltage and the thickness of the sputtered titanium film were varied to study their effect on the formation of TiO2 nanotube arrays. It is demonstrated in this work that the nanoporous layer is formed on top of the ordered array of TiO2 nanotubes. Furthermore, the optical transmittance of TiO2 nanotubes annealed at 450°C is much lower than the non annealed TiO2 nanotubes in the visible wavelength region. [Copyright &y& Elsevier]

The protective effect of early pregnancy against breast cancer can be attributed to the transition from undifferentiated cells in the nulliparous to the differentiated mature cells during pregnancy. Considerable evidence suggests strongly that the n-3 polyunsaturated fatty acid (PUFA) content of adipose breast tissue is inversely associated with an increased risk of breast cancer. Here, we report that there was a decrease in the n-6/n-3 PUFA ratio and a significant increase in concentration of n-3 PUFA docosapentaenoic acid and eicosapentaenoic acid in the pregnant gland. The functional role of n-3 PUFAs on differentiation was supported by the studies in the fat-1 transgenic mouse, which converts endogenous n-6 to n-3 PUFAs. Alternation of the n-6/n-3 ratio in favor of n-3 PUFA, and particularly docosapentaenoic acid, in the mammary gland of fat-1 mouse resulted in development of lobulo-alveolar-like structure and milk protein β-casein expression, mimicking the differentiated state of the pregnant gland. Docosapentaenoic acid and eicosapentaenoic acid activated the Jak2/Stat5 signaling pathway and induced a functional differentiation with production of β-casein. Expression of brain type fatty acid binding protein brain type fatty acid binding protein in virgin transgenic mice also resulted in a reduced ratio of n-6/n-3 PUFA, a robust increase in docosapentaenoic acid accumulation, and mammary differentiation. These data indicate a role of mammary derived growth inhibitor related gene for preferential accumulation of n-3 docosapentaenoic acid and eicosapentaenoic acid in the differentiated gland during pregnancy. Thus, alternation of n-6/n-3 fatty acid compositional ratio in favor of n-3 PUFA, and particularly docosapentaenoic acid and eicosapentaenoic acid, is one of the underlying mechanisms of pregnancy-induced mammary differentiation. [ABSTRACT FROM AUTHOR]

Abstract: A composite photocatalyst, Pd–TiO2−x N x –WO3, was synthesized by the template method and characterized by energy dispersive X-ray microanalysis (EDX), X-ray diffraction (XRD), UV–vis spectrometer, and scanning electron microscope (SEM). The results of EDX analysis reveals that the molecular formula of the composite photocatalyst can be expressed as Pd–TiO1.72N0.28–WO3. The UV–vis absorption spectrum indicates that the absorption edge of the catalyst red-shifts to around 600nm. Under the irradiation with ultraviolet and visible light, the catalyst showed good performance for photocatalytic hydrogen production with a Na2S/Na2SO3 system as the sacrificial agent. [Copyright &y& Elsevier]

A mammary-derived growth inhibitor-related gene (MRG) was previously identified and characterized. MRG induces differentiation of mammary epithelial cells in vitro and its expression is associated with mammary differentiation. To further define the role of MRG on mammary gland differentiation, a MRG transgenic mice model under the control of mouse mammary tumor virus promoter was established and the effect of MRG on mammary gland differentiation was investigated at histological and molecular levels. Expression of endogenous mouse MRG gene was significantly increased from the non-differentiated gland of control virgin mice to the functionally differentiated gland of pregnant control mice. Whole mount analyses demonstrated that ductal development was not affected by MRG transgene expression. While there was no lobuloalveolar structure in control virgin mice, expression of MRG transgene in the mammary gland resulted in the development of lobuloalveolar-like structure, which mimics the gland from early pregnancy. Consistent with the morphological change, expression of MRG also increased milk protein β-casein expression in the gland. To study the mechanism of MRG-induced mammary differentiation, we investigated the Stat5 activation in the glands from the transgenic mouse versus virgin control mouse. While activated Stat5 was expressed at the minimal level in the non-differentiated control virgin gland, a significant Stat5 phosphorylation was observed in the virgin transgenic gland. Our data indicate that MRG is a mediator of the differentiating effects of pregnancy on breast epithelium, and overexpression of MRG in young nulliparous mice can induce differentiation. [ABSTRACT FROM AUTHOR]

Methadone maintenance treatment is effective for managing opioid use disorder, but it can have many adverse effects that result in dose reduction. Patients often report persistent withdrawal symptoms after the dose reduction, which can decrease their adherence to treatment and increase the risk for relapse. Acupuncture has been recognized as an appropriate nonpharmacologic treatment for substance dependence. This multicenter, randomized, sham-controlled trial assessed the efficacy of acupuncture versus sham acupuncture on methadone dose reduction. Visual Abstract. Effect of Acupuncture for Methadone Reduction: Methadone maintenance treatment is effective for managing opioid use disorder, but it can have many adverse effects that result in dose reduction. Patients often report persistent withdrawal symptoms after the dose reduction, which can decrease their adherence to treatment and increase the risk for relapse. Acupuncture has been recognized as an appropriate nonpharmacologic treatment for substance dependence. This multicenter, randomized, sham-controlled trial assessed the efficacy of acupuncture versus sham acupuncture on methadone dose reduction. Background: Methadone maintenance treatment (MMT) is effective for managing opioid use disorder, but adverse effects mean that optimal therapy occurs with the lowest dose that controls opioid craving. Objective: To assess the efficacy of acupuncture versus sham acupuncture on methadone dose reduction. Design: Multicenter, 2-group, randomized, sham-controlled trial. (Chinese Clinical Trial Registry: ChiCTR2200058123) Setting: 6 MMT clinics in China. Participants: Adults aged 65 years or younger with opioid use disorder who attended clinic daily and had been using MMT for at least 6 weeks. Intervention: Acupuncture or sham acupuncture 3 times a week for 8 weeks. Measurements: The 2 primary outcomes were the proportion of participants who achieved a reduction in methadone dose of 20% or more compared with baseline and opioid craving, which was measured by the change from baseline on a 100-mm visual analogue scale (VAS). Results: Of 118 eligible participants, 60 were randomly assigned to acupuncture and 58 were randomly assigned to sham acupuncture (2 did not receive acupuncture). At week 8, more patients reduced their methadone dose 20% or more with acupuncture than with sham acupuncture (37 [62%] vs. 16 [29%]; risk difference, 32% [97.5% CI, 13% to 52%]; P  < 0.001). In addition, acupuncture was more effective in decreasing opioid craving than sham acupuncture with a mean difference of −11.7 mm VAS (CI, −18.7 to −4.8 mm; P  < 0.001). No serious adverse events occurred. There were no notable differences between study groups when participants were asked which type of acupuncture they received. Limitation: Fixed acupuncture protocol limited personalization and only 12 weeks of follow-up after stopping acupuncture. Conclusion: Eight weeks of acupuncture were superior to sham acupuncture in reducing methadone dose and decreasing opioid craving. Primary Funding Source: National Natural Science Foundation of China. [ABSTRACT FROM AUTHOR]

Herein, La 0.7 Ca 0.3− x K x MnO 3 (LCKMO) films with highly oriented growth were prepared on La 0.3 Sr 0.7 Al 0.65 Ta 0.35 O 3 (00 l) substrates by sol–gel spin coating method. Comprehensive analysis of microstructure, surface morphology, ion valence, and electrical transport properties of LCKMO films indicates that the substitution of K+ ions for Ca2+ ions increased the ratio of Mn4+/(Mn3+ + Mn4+), narrowed the one electron bandwidth, and enhanced double exchange mechanism and electron–lattice coupling. Moreover, the doping of K+ ions induced the dense and uniform conical-structured growth of grains on the surface of the films. Results demonstrated that at x = 0.1, LCKMO film exhibited the maximum TCR of 17.84% K−1 at 253.07 K, which was 31.76% higher than that of previously reported La 1− x−y Ca x K y MnO 3 ceramic with the highest TCR. Further theoretical insights into the effects of Ca/K co-doping on electrical transport properties were supplemented. [ABSTRACT FROM AUTHOR]

A butanol-based fast condensation particle counter (Fast CPC, Model 3650, Kanomax Inc., Japan) was characterized in this study with three different types of monodisperse particles, including positively and negatively charged nickel-chromium (Ni/Cr) particles, positively charged tetraheptyl ammonium bromide (THABr) and tetrabutyl ammonium bromide (TBABr) particles, and positively charged polyethylene glycol (PEG) particles. The PEG particles were characterized with varied numbers of charges, whereby the charge number effect on particle activation was investigated. The performance of the Fast CPC was compared with a TSI® 3775 CPC and a TSI® 3776 CPC, respectively, under both factory temperature settings and boosted temperature settings, the latter of which corresponded to the brink of butanol homogeneous nucleation. Our results show that size-resolved Ni/Cr particles were detected by the Fast CPC with comparable detection efficiencies regardless of the charge polarity. When the charge number on a PEG particle increased from 1 to 3, an increasing tendency of the detection efficiency was observed, hinting that multiple charges on a particle will facilitate its activation. Particle activation was affected by the particle chemical composition as well, which is suggested by the higher activation efficiencies of PEG particles than those of Ni/Cr particles. The effects of multiple charges and chemical composition on particle activation were both more significant under factory temperature settings, but became less pronounced under boosted temperature settings. In addition to a quicker response time, the Fast CPC was capable of detecting sub-3 nm particles under boosted temperature settings, with the detection efficiency higher than that of the 3775 CPC but lower than that of the 3776 CPC, and can be used as a good candidate for the measurement of rapidly varying concentrations of small particles. • Fast CPC can detect small particles of rapidly varying concentrations. • Boosted CPC temperature settings is recommended for sub-3 nm particle measurements. • Effects of multiple charges on particle activation are investigated. • Effects of chemical composition on particle activation are investigated. [ABSTRACT FROM AUTHOR]

Scanning mobility particle sizer (SMPS) is widely used for particle number size distribution measurements of submicron particles. In this work, two TSI® SMPSs equipped with a soft X-ray neutralizer and a Kr-85 neutralizer, respectively, were operated in parallel to measure particle number size distributions of ambient air. An independent TSI® ultrafine condensation particle counter (CPC) was used as a reference to measure the total concentration of particles in the ambient air. Our results show that the total particle concentrations measured by the two SMPSs were comparable with each other, while their size-resolved concentration ratios were size-dependent and relative humidity (RH)-dependent. Neutralizer was found to be essential to quickly bring small particles to charge equilibrium in field measurements, as indicated by the comparison of particle number size distributions measured by the Kr-85 SMPS with those inverted from naturally charged particles. The total particle concentrations measured by two SMPSs tend to exceed those by the reference CPC at high RH, hinting that the particle concentrations measured by SMPSs could be overestimated at high RH. This study urges a better understanding of the bipolar charging processes under high RH conditions. • Size-resolved concentration ratios by X-ray &85Kr SMPSs are size- & RH-dependent. • Neutralizers are essential to quickly bring small particles to charge equilibrium. • Particle concentrations observed by X-ray &85Kr SMPSs are overestimated at high RH. • A better understanding of bipolar charging processes under high RH is needed. [ABSTRACT FROM AUTHOR]

Describes the myoepithelium-derived serine proteinase inhibitor (MEPI) from normal mammary gland and discusses its biological relevance in inhibiting human breast cancer progression. Molecular cloning of MEPI complementary DNA; Expression of MEPI in human breast myoepithelial cells; Transfection and selection of MEPI positive clones.

We recently identified, cloned, and characterized a novel human tissue inhibitor of metalloproteinases-4, TIMP-4 (Greene et al., 1996). To determine if TIMP-4 can modulate the in vivo growth of human breast cancers, we transfected a full-length TIMP-4 cDNA into MDA-MB-435 human breast cancer cells and studied the orthotopic growth of TIMP-4-transfected (TIMP4-435) versus control (neo-435) clones in the mammary fat pad of athymic nude mice. TIMP4-435 clones expressed TIMP-4 mRNA and produced anti-metalloproteinase (MMP) activity, while neo-435 clones did not express TIMP-4 mRNA or produce detectable anti-MMP activity. Overexpression of TIMP-4 inhibited the invasion potential of the cells in the in vitro invasion assay. When injected orthotopically into nude mice, TIMP-4 transfectants were significantly inhibited in tumor growth by 4 – 10-fold in primary tumor volumes; and in an axillary lymph node and lung metastasis as compared with controls. These results suggest the therapeutic potential of TIMP-4 in treating cancer malignant progression [ABSTRACT FROM AUTHOR]

Two-Dimensional carbon-based materials as a potential hydrogen storage medium have attracted great attention. In this study, various key aspects such as structure, electronic properties, stability, and hydrogen storage performance of Na-modified Irida-Graphene (IG) were thoroughly investigated using density functional theory (DFT) calculation methods. The calculation results show that the binding energy of Na atoms with the substrate is 1.51 eV, far exceeding the cohesive energy. The AIMD results reflect the good thermal stability of the model. One Na atom can adsorb up to 5H 2 molecules. The IG loaded with eight Na atoms on both sides can adsorb 32H 2 molecules, achieving a hydrogen storage capacity of 7.82 wt % , far exceeding the US DOE target of 5.5 wt %. The calculated Van 't Hoff equation indicates a desorption temperature of 248 K for the model. Moreover, reversible hydrogen storage can be achieved at medium to low pressures, with desorption temperatures ranging from 285 K to 417 K. These results suggest that Na-Modified IG models are candidate materials for reversible hydrogen storage under near-ambient conditions. [Display omitted] • Sodium modification of Irida-Graphene enhances its hydrogen adsorption capacity. • The interaction between IG-Na and H 2 was analyzed using the IGMH method. • The hydrogen storage capacity of IG-Na medium reaches 7.82%. [ABSTRACT FROM AUTHOR]

Electrical mobility and mass of atmospheric ions are of great importance, since both properties jointly determine their charging states. In this work, different carrier gases of bottle N 2 , bottle air, and particle-free lab air were passed through a TSI® soft X-ray aerosol neutralizer to produce both positive and negative ions. The electrical mobilities and mass-to-charge ratios of these ions were measured with a high-resolution half-mini differential mobility analyzer (DMA) coupled to an atmospheric pressure interface time-of-flight (APi-TOF) mass spectrometer. The effects of carrier gas, sample flowrate, and relative humidity (RH) on the ion mobility and mass-to-charge ratio were evaluated. Most detected ions could be traced back to the impurities in the carrier gases, or the compounds used to manufacture the system components. However, severe fragmentation of DMA-classified clusters was observed, especially under high RH conditions, which likely occurred inside the APi-TOF and complicated the identification of the chemical composition of the DMA-classified clusters. The mobility spectra and ion identities were comparable when using bottle N 2 and bottle air as the carrier gas, whereas different features on ion mobility and mass-to-charge ratio were found in the case of particle-free lab air. Residence time of the carrier gas inside the neutralizer as a function of the sample flowrate, when at the order of a few seconds, exerted a weak impact on the ion mobility spectra. The effect of RH on the electrical mobility was contingent on the polarity and chemical composition of ions. The presence of water vapor would grow the acid radical ions and hydronium ions to larger sizes by forming clusters, whereas the positively charged polydimethylsiloxanes in the case of particle-free lab air were marginally impacted. In addition, the concentration of neutral clusters formed through the ion-ion recombination or radiolysis was measured with a particle size magnifier (PSM). Compared with those in the case of bottle gases, the neutral cluster concentrations were significantly larger when particle-free lab air was used as the carrier gas. Higher concentrations of neutral clusters were observed in the high RH experiments, likely because high RH could either enhance the ion-ion recombination or the detection efficiency of PSM. Our work indicates that RH and the impurities in the carrier gas have a significant effect on the measured electrical mobilities and mass spectra for ions generated by a soft X-ray aerosol neutralizer. • Properties of bipolar ions produced in a soft X-ray neutralizer were measured. • Ion species generated from different carrier gases were compared. • Residence time exerted a weak impact on the ion mobility spectra. • Relative humidity induced-shift in ion mobility was contingent on ion properties. • High concentrations of sub-2 nm neutral clusters were formed and observed. [ABSTRACT FROM AUTHOR]

The original version of this article unfortunately contained a mistake. "Southwest Minzu Nationalities" in affiliation 1 should be "Southwest Minzu University". [ABSTRACT FROM AUTHOR]

Organic acids are important contributors to the acidity of atmospheric precipitation, but their existence in the Chinese atmosphere is largely unclear. In this study, twelve atmospheric gaseous organic acids, including C 1 -C 9 alkanoic acids, methacrylic acid, pyruvic acid, and benzoic acid, were observed in the suburb of Wangdu, Hebei Province, a typical rural site in the northern China plain from 16th December, 2018 to 22nd January, 2019, using a Vocus® Proton-Transfer-Reaction time-of-flight mass spectrometer (Vocus PTR-ToF). The quantification of C 2 -C 4 alkanoic acids by the Vocus PTR-ToF was calibrated according to the titration of a NaOH solution by C 2 -C 4 alkanoic acids from home-made permeation sources, and the other organic acids except for formic acid were quantified based on the k cap -sensitivity linearity in the Vocus PTR-ToF, whereas formic acid was not quantified because our instrument setting led to a significant underestimation in its concentration. The average total concentration of eleven gaseous organic acids was 6.96 ± 5.20 ppbv (parts per billion by volume). The average concentration of acetic acid was the highest (3.86 ± 3.00 ppbv), followed by propanoic acid, butyric acid, and methacrylic acid. Domestic straw burning was likely the dominant source of the observed gaseous organic acids according to the good correlations between acetonitrile and organic acids and between particulate K+ and organic acids, and traffic emissions could also have contributed. During episodes with continuously high concentrations of organic acids, short-distance transport dominated in Wangdu according to the backward trajectory analysis. Baoding, Shijiazhuang, and Hengshui areas were the main source areas based on potential source contribution function and concentration weighing track analysis. [Display omitted] [ABSTRACT FROM AUTHOR]

Purpose: The issue of employee engagement has increasingly become a focus of concern in public management practice. Based on the theory of purposeful work behavior, integrative theory of employee engagement and Pratt and Ashforth's typology of work meaningfulness, this study proposes and examines the mediating effects of two types of meaningfulness between transformational leadership and work engagement and the moderating effects of transformational leadership on the relationship between two types of meaningfulness and work engagement. Patients and Methods: By adopting a multilevel cross-sectional design, this study examines assumed mediation and moderation effects. The data collection was conducted anonymously by means of an online survey. A total of 261 local police officers from 32 police stations were recruited in professional training programs as a sample. Results: The analysis reveals that both meaningfulness in work and meaningfulness at work positively mediate the relationship between transformational leadership and work engagement. Transformational leadership moderates the relationship between meaningfulness at work and work engagement rather than the relationship between meaningfulness in work and work engagement. There are no other significant effects of sex, age or length of service. Conclusion: Work meaningfulness transmits and combines the effect of transformational leadership to impact work engagement. These findings not only confirm the critical role of work meaningfulness proposed by the theoretical frameworks of the theory of purposeful work behavior, integrative theory of employee engagement and Pratt and Ashforth's typology of work meaningfulness, but also further extend and clarify the role of and difference in two substructures of work meaningfulness (ie, work meaningfulness in work and at work) in the context of the linkage between transformational leadership and work engagement. [ABSTRACT FROM AUTHOR]

This study investigated the inhibition effect of nanoscale silver–copper particle (20 nm) against Coriolus versicolor and Gloeophyllumtrabeum. Poplar wood samples (Populus L.) were vacuum-impregnated using aqueous nano-AgCu solutions at concentrations of 0.01 %, 0.02 %, 0.03 %, 0.05 %, 0.075 %, and 0.1 %. Alkaline copper quaternary (ACQ, 0.1 %), boric acid (0.2 %) and untreated control group (CK) were employed for comparisons. Decay resistance and leachability were studied. The anti-fungi effects were compared between nano-AgCu, nano-Ag, Ag+ (silver nitrate), Cu2+ (copper nitrate), and a composite of Ag+–Cu2+. Nano-AgCu particle exhibited effective resistance to fungi after 12 weeks of exposure. The threshold retention of the nano-AgCu against C. versicolor and G. trabeum on poplar wood was 0.19 kg m−3 and 0.62 kg m−3, respectively. The silver–copper nanoparticles demonstrated excellent leach resistance, and the inhibition effect was retained after leaching. The nano-AgCu particle provided better antifungal effects than single ions or metal nanoparticles. This study illustrates the potential of using nano-AgCu particle as an efficient wood preservative compared to commercial water-soluble preservatives. [ABSTRACT FROM AUTHOR]

Al17 clusters exhibit apparent changes in curvature, which resemble macroscopic metal tips. Here, we show, using the density functional theory method, how surface charges of Al17q (q = −2 to +3) ions affect the adsorption and dissociation behavior of HCl molecules. Geometries, adsorption energies, vibrational frequencies, Mulliken population analysis and transition states of (Al17HCl)q (q = −2 to +3) adsorption complexes were studied. The results revealed that HCl molecules tend to locate on tip sites of the Al17q (q = −2 to +3) ions. Anionic adsorption complexes are prone to H affinity adsorption, whereas cationic adsorption complexes favor Cl-affinity adsorptions. These adsorption behaviors look quite like macroscopic tip effects. H–Cl bonds of the adsorption complexes weaken with an increase in either positive or negative charge. Dissociation barriers of the H–Cl bonds exhibit binding energies that are 2 orders of magnitude smaller than those of an isolated HCl molecule. Considering adsorption energies and dissociation barriers comprehensively, HCl molecules should dissociate spontaneously for all the models considered. Generally, the more negative charges the clusters carry, the more energy the reaction will release. [ABSTRACT FROM AUTHOR]

The interrelation between grassland vegetation greenness and hydrothermal conditions on the Tibetan Plateau demonstrates a significant correlation. However, understanding the spatial patterns and the degree of this correlation, especially in relation to minimum and maximum air temperatures across various vertical gradient zones of the Plateau, necessitates further examination. Utilizing the normalized difference phenology index (NDPI) and considering four distinct hydrothermal conditions (minimum, maximum, mean temperature, and precipitation) during the growing season, an analysis was conducted on the correlation of NDPI with hydrothermal conditions across plateau elevations from 2000 to 2021. Results indicate that the correlation between vegetation greenness and hydrothermal conditions on the Tibetan Plateau grasslands is spatially varied. There is a pronounced negative correlation of greenness to maximum temperature and precipitation in the northeastern plateau, while areas exhibit stronger positive correlations to mean temperature. Additionally, as elevation increases, the positive correlation and sensitivity of alpine grassland vegetation greenness to minimum temperature significantly intensify, contrary to the effects observed with maximum temperature. The correlations between greenness and mean temperature in relation to elevational changes primarily exhibit a unimodal pattern across the Tibetan Plateau. These findings emphasize that the correlation and sensitivity of grassland vegetation greenness to hydrothermal conditions are both elevation-dependent and spatially distinct. [ABSTRACT FROM AUTHOR]

The activation of large ancient rock landslides caused by reservoir operation is a primary threat to the TGR. Understanding the deformation characteristics and failure mechanisms of these landslides can be helpful for stability assessment and long-term landslide prediction. The primary aim of this study is to research the motion characteristics of ancient rock landslides and their relationships with engineering activities and natural factors. The Tanjiahe landslide, a large reactivated landslide in the TGR region, is used as an example. Long-term professional monitoring data collected since 2006 show that the landslide is experiencing creep deformation. By combining 15 years of meteorological, hydrological and manual GNSS monitoring information, 5 years of displacement measurements from open fractures and deep boreholes, automatic GNSS measurements, and macroscopic inspection results, the deformation mechanisms of landslides are studied in detail. The study shows that landslide deformation is affected by the reservoir water level and that rainfall promotes landslide deformation. Specifically, from November to May, during the high reservoir water level stage and subsequent declining water level stage, the landslide exhibits a very distinct movement pattern with high deformation, lasting nearly 7 months. As the water level rises, the deformation subsides until almost no deformation exists. Landslide displacement continues to increase each year, indicating likely slope instability. However, the deformation rate of the Tanjiahe landslide is gradually decreasing, and the probability of large-scale sliding is low; still, the monitoring system must be strengthened, and additional research must be performed on the corresponding deformation mechanism. [ABSTRACT FROM AUTHOR]

To understand the influence of doping Sr atoms on the structural, magnetic, and electronic properties of the infinite-layer NdSrNiO2, we carried out the screened hybrid density functional study on the Nd9-nSrnNi9O18 (n = 0–2) unit cells. Geometries, substitution energies, magnetic moments, spin densities, atom- and lm-projected partial density of states (PDOS), spin-polarized band structures, and the average Bader charges were studied. It showed that the total magnetic moments of the Nd9Ni9O18 and Nd8SrNi9O18 unit cells are 37.4 and 24.9 emu g−1, respectively. They are decreased to 12.6 and 4.2 emu g−1 for the Nd7Sr2Ni9O18-Dia and Nd7Sr2Ni9O18-Par unit cells. The spin density distributions demonstrated that magnetic disordering of the Ni atoms results in the magnetism decrease. The spin-polarized band structures indicated that the symmetry of the spin-up and spin-down energy bands around the Fermi levels also influence the total magnetic moments. Atom- and lm-projected PDOS as well as the band structures revealed that Ni (d x 2 − y 2 ) is the main orbital intersecting the Fermi level. As a whole, electrons of Sr atoms tend to locate locally and hybridize weakly with the O atoms. They primarily help to build the infinite-layer structures, and influence the electronic structure near the Fermi level indirectly. [ABSTRACT FROM AUTHOR]

The deposition characteristics of weld fume particles in an electrostatic precipitator were investigated by means of numerical simulations. In the calculations, the particle characteristics of the weld fume particles and the effect of ionic wind are considered. The effects of applied voltage, flow velocity, collecting plate spacing, particle concentration, electric field strength, and ionic wind on the collection efficiency of weld fume particles in the ESP are discussed. The velocity distribution of weld fume particles in the Electrostatic precipitator (ESP) was also investigated. The results show that the smaller the collection plate spacing, the higher the collection efficiency of particles. The particle concentration has a small effect on the collection efficiency of weld fume particles. The higher the applied voltage, the more obvious the difference of ESP on the collection efficiency of different particles. [Display omitted] • The characteristics of welding fume particles was considered. • The influencing factors of collection efficiency were explored. • The movement of particles in ESP was investigated. [ABSTRACT FROM AUTHOR]

The modified catalyst exhibited stronger basicity and COS adsorption capacity. The more readily generated HSCO 2 - species on the surface was the key to high hydrolytic activity. [Display omitted] • Pore modifier were employed to improve the pore structure and surface oxygen species. • The preferred catalyst exhibits a COS conversion of 97 % and a H 2 S selectivity of 91 % at 75 ℃. • The presence of oxygen vacancies promoted the adsorption of COS. • The formation of HSCO 2 - species was critical for the reaction of COS hydrolysis. The high activation temperature and poor stability of COS hydrolysis catalysts greatly hinder its application in the field of blast furnace gas desulfurization. Various organic additives were applied to modulate the pore structure of the catalyst. Combined with the loading of K, the catalytic performance, H 2 S selectivity and enhanced mechanism of the modified catalysts were deeply explored. The preferred catalyst exhibited an improved low-temperature activity of 97.2 % and H 2 S selectivity of 91 % at 75 ℃. The COS conversion of the preferred catalyst remained above 95 % after 50 h reaction. The characterization results revealed that the addition of pore modifiers and basic components resulted in a wider pore size distribution and increased specific surface area. More oxygen vacancies and enhanced surface alkalinity were also certified to contribute to the catalysis properties. In-situ DRIFTS results exhibited that the COS adsorption ability was significantly strengthened due to enhanced alkalinity, while more intermediate active species such as HCO 3 – and HSCO 2 - were produced. DFT calculation results indicates that the modified catalyst displays larger adsorption energy of reaction gas molecules·H 2 O molecular promotes the adsorption of COS and H 2 S, while H 2 S inhibits the adsorption of COS. The presence of oxygen vacancies promoted the adsorption of COS and weakened the competitive adsorption of COS and H 2 S. The adsorbed COS reacts with OH– or H species to form the key intermediate HSCO 2 -, which is further hydrogenated and decomposed into H 2 S and CO 2. The lower energy barrier and shorter reaction steps for the formation of HSCO 2 - species are the key incentives for the improved activity of the K-modified catalyst. [ABSTRACT FROM AUTHOR]

The successful establishment of invasive populations is closely linked to environmental factors. It is unclear whether coexisting species in the native area follow the same genetic pattern in the invaded continents under the local climate factors. Two coexisting morphologically similar snails (Pomacea canaliculata and P. maculata), native to tropical and sub-tropical South America, have become invasive species for agriculture production and wetland conservation across five continents over 40 years. We analyzed the correlation between the genetic diversity of the two snails and the climate factors or habitat changes. Based on the 962 sequences from the invaded continents and South America, the nucleotide diversity in the agricultural habitat was low for P. canaliculata, whereas it was high for P. maculata, compared with that in the non-agricultural habitat. The two snails showed a divided population structure among the five continents. The P. canaliculata population in the invaded continents has remained stable, whereas the P. maculata population expanded suddenly. Seven main haplotype networks and two ancestral haplotypes (Pc3, Pm1) were found in the P. canaliculata and P. maculata populations. The haplotypes of the two snails were related to local climate factors. The overall fixation index of P. canaliculata and P. maculata was 0.2657 and 0.3097 between the invaded continents and South America. The population expansion of the two snails fitted the isolation-by-distance model. We discovered nine new sequences from the sampling locations. Overall, the genetic diversity and genetic differentiation of the two invasive snails were closely related to geographic separation, agricultural habitat, and climate factors. [ABSTRACT FROM AUTHOR]

Various transition metals were employed to enhance the catalytic performance and N 2 selectivity of Mn-based catalysts. The modification of Fe and Cu promoted the low-temperature activity, while the Al-modified catalyst displayed the highest N 2 selectivity close to 100 %. The characterization results proved that the content of O β and Mn4+ were increased after adding transition metals. N 2 selectivity experiments revealed that the reduction of NO to N 2 O and the oxidation of NH 3 to N 2 O did not occur. The product of NH 3 oxidation was only N 2. Combined with the results of the in-situ DRIFTS experiments, it was proposed that N 2 O was generated from the decomposition of NHNO and NH 4 NO 3 in the SCR reaction. The poor N 2 selectivity of the unmodified catalyst was related to the existence of inactive N 2 O 2 2- species on the surface, while the high content of active NH 2 - species on the Mn 0.1 Ho 0.005 Ce 0.015 Al 0.01 /TiO 2 catalyst enhanced its catalytic activity and N 2 selectivity. In addition, the results also revealed that only the E-R mechanism existed on the unmodified catalyst, while both the E-R and L-H mechanism were activated after the transition metal modification. The SCR reaction of NH 3 and NO proved to be the source of N 2 O. The activation of the L-H mechanism might play a key role in the improvement of activity and selectivity. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, we focus on the approximate controllability of control systems described by a large class of fractional evolution hemivariational inequalities. Firstly, we introduce the concept of mild solutions and present the existence of mild solutions for this kind of problems. Next, we show the approximate controllability of the corresponding linear control system. Finally, the approximate controllability of the fractional evolution hemivariational inequalities is formulated and proved under some appropriate conditions. An example demonstrates the applicability of our results. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]