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The emergence of XBB.1.16 has gained rapid global prominence. Previous studies have elucidated that the infection of SARS-CoV-2 induces alterations in the mitochondrial integrity of host cells, subsequently influencing the cellular response to infection. In this study, we compared the differences in infectivity and pathogenicity between XBB.1.16 and the parental Omicron sublineages BA.1 and BA.2 and assessed their impact on host mitochondria. Our findings suggest that, in comparison with BA.1 and BA.2, XBB.1.16 exhibits more efficient spike protein cleavage, more efficient mediating syncytia formation, mild mitochondriopathy, and less pathogenicity. Altogether, our investigations suggest that, based on the mutation of key sites, XBB.1.16 exhibited enhanced infectivity but lower pathogenicity. This will help us to further investigate the biological functions of key mutation sites.

This article studies the finite-time stabilization and finite-time H∞control problems for a class of Takagi–Sugeno fuzzy singular systems and proposes a finite-time H∞fuzzy controller to enable the system to cope with external disturbances, and the closed-loop system state converges to the equilibrium point. Before designing the controller, impulse controllability of the Takagi–Sugeno fuzzy singular system is discussed. Then, a finite-time H∞fuzzy controller is designed, and the finite-time stabilization conditions of the Takagi–Sugeno fuzzy singular system are expressed by linear matrix inequality. Finally, the simulation outcomes of a nonlinear singular system demonstrate that the designed controller has a good suppression effect on external disturbances, and the closed-loop system state converges to the equilibrium point in finite-time T and remains at the equilibrium point after T.

In the present study, indoor experiments were carried out to investigate the effects of rainfall on subsequent wind erosion processes on the simulated Gobi surface, with soils and gravels collected from the Alax Gobi in northwestern China. The results showed that the wind erosion rate (WR) ranged from 0.4 to 1931.2 g m−2min−1and that the sediment transportation rate (STR) ranged from 0.00 to 51.47 g m−2s−1under different gravel coverage conditions (0%, 20%, 40% and 60%) when the wind velocity changed from 6 m s−1to 18 m s−1. Both WR and STR increased with increasing wind velocity as a power function and decreased with increasing gravel coverage. The rainfall event had significant inhibitory effects on WR and STR, and the complex effects of soil crust formation and the changing soil surface roughness (SSR) by rainfall event played significant roles in reducing these rates during subsequent wind erosion. In this study, a valuable exploration of the effects of rainfall events on subsequent wind erosion processes in the Gobi area was conducted. The findings are of great significance for a better understanding and effective prediction of dust emissions in this region.

Background:The interaction between the host and Candida albicansis dynamic and intricate. We performed proteomic analysis to explore monocyte-C. albicanshyphae interaction. Materials & methods:Primary human monocytes were stimulated by heat-killed C. albicanshyphae and their proteins were profiled by tandem liquid chromatography with mass spectrometry (LC-MS/MS). Results:Based on the protein database of different species for analysis, we found that stimulation of monocytes by hyphae was accompanied by upregulation of histones and activation of extracellular traps (ETs) formation pathway. Meanwhile, monocyte ETs (MoETs) were evoked by synthesis or alteration of C. albicanscell wall proteins expression during the morphological switch to hyphal. Conclusion:MoETs formation is linked to cell wall proteins of C. albicanshyphae.

This article studies robust stabilization and adaptive H∞control problems for a class of continuous-time nonlinear singular systems by static output feedback. First, under sufficient conditions which the system is impulse controllable, the static output feedback controller is designed, and the stabilization problem of the system is discussed. Second, the H∞and adaptive H∞controllers are designed for the continuous-time nonlinear singular systems with external disturbances. Compared with the existing conclusions, the controller can be designed for more nonlinear singular systems. Finally, an example of a nonlinear singular circuit is given, and the simulation results verify the validity of the proposed controllers.

To control the microstructure and improve the mechanical properties of Mn–Cu alloy additive manufacturing components, this work adopts various scanning strategies (rotations of 0°, 45°, 67°, and 90° between successive layers) to change the heat input distribution and heat dissipation. The results show that the scanning strategies can impact the porosity, cracks, grain size, and grain growth direction of Mn–Cu alloy additive manufacturing parts. By adjusting scanning strategies to change the heat flow direction the columnar-to-equiaxed transition can be achieved. The samples exhibit minimal cracks and pores (porosity of 0.0006 %). Using a scanning rotation angle of 67° during processing, the maximum tensile strength can reach 510 MPa with a 29 % elongation, attributed to effective grain refinement and a high dislocation density. This study demonstrates the feasibility of grain refinement and improved mechanical properties for the Mn–Cu alloys by changing the scanning strategies.

This article discusses the input-output finite-time stability and stabilization problems of a class of nonlinear descriptor systems. Two classes of disturbance inputs which belong to L2and L∞are considered. Under the impulse-free condition of the descriptor systems, the article first studies the input-output finite-time stability with respect to the nonlinear descriptor systems with L2and L∞disturbance inputs. Based on this, the design of the state feedback controllers ensures that the closed-loop descriptor systems are input-output finite-time stabilization. Finally, the results of simulation on a nonlinear descriptor circuit system verify the effectiveness of the controllers in this article.

An all-metal phased array with full polarization reconfigurability is presented in this article. Septum polarizers as phased array elements are first used to achieve left-handed and right-handed circular polarizations (LHCP and RHCP), and arbitrary linear polarizations (LPs) can be further synthesized. Two pairs of metal ridges are loaded into the septum polarizer to reduce the profile and aperture size so that the spacing between the two adjacent array elements can be constrained to about half of the free-space wavelength at the center operating frequency. Phased arrays of $1\times $ 8 and $8\times $ 8 elements covering 25.5–27 GHz are designed to demonstrate the 1-D and 2-D beam scanning performance with different polarizations. For demonstration, the $1\times $ 8 element phased array is implemented. Experimental results show that the array exhibits stable beam scanning performance for both circular polarizations (CPs) and LPs. The synthesized beam scanning range is up to ±55° with a gain-reduction of 4.7 dB for all polarizations. Under beam scanning, the axial ratio (AR) remains below 3.1 dB for the LHCP and RHCP, and the maximum gain variation during polarization reconfiguration is less than 0.8 dB.

Tumor microenvironment responsive drug delivery system presents great potential in tumor-targeted drug delivery. In this study, a poly (ethylene glycol) (PEG) coated biodegradable core-shell microsphere PMAA@DOX-SiO2-PEG with a poly (methylacrylate acid) (PMAA) core and a biodegradable silica layer was prepared. Doxorubicin (DOX) was effectively loaded into the PMAA core and sealed by the silica layer with a drug loading efficiency of 15.3 %. The PEG-modified drug-loaded microspheres present high stability at simulated physiological media with minimized drug leakage (8 %, 56 h), while 80 % drug could be released within 10 h at simulated tumor environment due to the effective carrier degradation. In vitrocell experiments also confirm the good biocompatibility of the blank carrier and the effective tumor inhibition of the drug-loaded microspheres. The study is expected to further promote the development of tumor microenvironment-responsive drug delivery systems.

An efficient molecularly-imprinted electrochemical sensor for the detection of ampicillin was prepared using polypyrrole tetracycline polymer modified with ZrO2nanofibers. The ZrO2nanofibers prepared by electrostatic spinning increased the surface area of the electrode with the binding sites of the electropolymerized membrane. The ampicillin sensor with polypyrrole as the functional monomer was able to specifically bind ampicillin molecules and detect ampicillin in various types of samples. In this study, cyclic voltammetry and differential pulse voltammetry were used to evaluate the electrochemical performance of ZrO2-MIP. Under the optimized conditions, the detection limit of this sensor was 0.397 nM, the detection range was 0.5 ∼ 500 nM, and the R2reached 0.998. It has good selectivity, reproducibility, and stability, and achieves the AMP detection of the milk of the actual samples, which has a good prospect of application.

AbstractFew of existing literatures on the airflow distribution of compartments have studied combined applications of radiant heating and air conditioning in winter. Simulation of airflow distribution in 25 T soft sleeper compartments under different heating and ventilation schemes is provided in this paper. Firstly, reliability of the numerical simulation model has been verified by the experimental data in the literature, and the appropriate turbulence model has been selected. Afterwards, numerical simulations are carried out on airflow distribution in those compartments with four ventilation modes under radiant heating conditions in winter. Research results show that as for thermal comfort, task air supply can provide the smallest temperature difference between head and foot positions as well as the best thermal comfort. As for effectiveness of air supply, the ventilation efficiency of louver side air supply is the highest among others. As for effectiveness of pollutant removal, the ventilation efficiency of task air supply is higher than the other three options. These four heating and ventilation schemes are evaluated comprehensively with fuzzy comprehensive evaluation method. Results reveal that task air supply is the mode with best comprehensive performance indices. It is followed, respectively, by louver side air supply, perforated ceiling air supply and louver top air supply.

Part of the Northern Hemisphere has experienced widespread autumn cooling during the most recent decades despite overall warming, but how this contrasting temperature change has influenced the ecosystem carbon exchange remains unclear. Here, we show that autumn cooling has occurred over about half of the area north of 25° N since 2004, producing a weak cooling trend over the period 2004–2018. Multiple lines of evidence suggest an increasing net CO2release in autumn during 2004–2018. In cooling areas, the increasing autumn CO2release is due to the larger decrease of gross primary productivity (GPP) growth than total ecosystem respiration (TER) growth suppressed by cooling. In the warming areas, TER increased more than GPP because the warming and wetting conditions are more favourable for TER growth than GPP increase. Despite the opposite temperature trends, there has been a systematic increase in ecosystem carbon release across the Northern Hemisphere middle and high latitudes.

Acute Achilles tendon rupture is a severe injury of the lower extremities; however, optimal treatment options are not yet available. This study aimed to investigate the surgical method and clinical effect of the Krackow and tendon-bundle techniques for managing acute Achilles tendon rupture.

The growing antimicrobial resistance (AMR) in Neisseria gonorrhoeaeis a serious global threat to gonococcal therapy. Molecular typing is an ideal tool to reveal the association between specific genotypes and resistance phenotypes that provide effective data for tracking the transmission of resistant clones of N. gonorrhoeae. In our study, we aimed to describe the molecular epidemiology of AMR and the distribution of resistance-associated genotypes in Shenzhen, China, during 2014 to 2018.

In this paper, the problem of sampled-data stabilization for a class of nonlinear differential-algebraic systems is considered by using partial-state and output feedback. First, based on the output feedback domination approach, a systematic design procedure for sampled-data output feedback controller is proposed without using the states of the algebraic subsystem. It is shown that the proposed sampled-data controller can ensure the whole closed-loop nonlinear differential-algebraic system is asymptotically stable by choosing appropriate scaling gains and sampling period. In addition, due to the domination nature of the proposed method, the obtained results can be extended to more general class of nonlinear differential-algebraic systems easily. Finally, simulation examples are provided to illustrate the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]

It is of great significance to quantify sediment load changing with erosion processes for improving the precision of soil loss prediction. Indoor rainfall experiments were conducted in 2 rainfall intensities (90 mm·h−1and 120 mm·h−1), four slope gradients (17.60%, 26.80%, 36.40%, 46.60%) and 2 slope lengths (5 m, 10 m). Erosion processes are divided into five stages. Results show that sediment yield is mainly sourced from rill erosion, contributing from 54.60% to 95.70% and the duration of which is extended by slope gradients. Sediment load and sediment concentration are significantly different along erosion stages, with the highest values in rill development stage (SIV). Surface flow velocities (interrill and rill) demonstrate less significant differences along erosion stages. Rainfall intensity increases sediment load in all stages, with up to 12.0 times higher when changing from 90 to 120 mm·h−1. There is an increasing trend for sediment load and sediment concentration with the rising slope gradient, however, fluctuations existed with the lowest values on 26.80% and 36.40%, respectively, among different treatments. The slope gradient effects are enhanced by rainfall intensity and slope length. Results from this study are important for validating and improving hillslope erosion modelling at each erosion stage.

ABSTRACTThis study investigates the combined effect of the El Niño–Southern Oscillation (ENSO) and stratospheric quasi-biennial oscillation (QBO) on the Madden Julian Oscillation (MJO). The results show that the western Pacific MJO originating from the Indian Ocean during La Niña/QBO easterly years is stronger than that during El Niño years. This relation, however, disappears during La Niña/QBO westerly years. The reason is that ENSO and the QBO have different effects on each MJO event. For an El Niño year, there is only about one MJO event, and the QBO effect is small. During a La Niña/QBO easterly year, there are 1.7 MJO events, while during a La Niña/QBO westerly year, there are only 0.6 MJO events. El Niño can reinforce the MJO over the western Pacific because of the positive moisture advection of the El Niño mean state by MJO easterly wind anomalies. The QBO mainly affects the MJO over the Maritime Continent region by changing the high-cloud-controlled diurnal cycle; and the Maritime Continent barrier effect is enhanced during the QBO westerly phase because of the strong diurnal cycle. During El Niño years, even the MJO over the Maritime Continent is suppressed by the QBO westerly phase; the MJO can be reinforced over the western Pacific. During La Niña/QBO westerly years, the MJO over the Maritime Continent is suppressed because of the strong Maritime Continent diurnal cycle, and it is further suppressed over the western Pacific because of the lack of a reinforcement process.

The magazine Meiyu 眉語 (Eyebrow Talk), published from 1914 to 1916 and edited by Gao Jianhua 高劍華, was China's first literary magazine edited by a woman and targeted at a female audience. It was also the first modern magazine to pay extensive attention to nudity and to physical and romantic intimacy through at times carefully considered juxtapositions of texts and images. In addition, it was the first Chinese magazine to be banned on the basis of obscenity legislation introduced during the early Republic. The committee that banned Meiyu was led by Zhou Shuren 周樹人, who later became known as the author Lu Xun 魯迅, and his disparaging reminiscence about Meiyu caused the magazine to be all but forgotten for nearly a century. In this article, the authors use a wide variety of archival material to reconstruct the complex publishing history of the magazine, as well as the processes and cultural standards involved in its banning. This is followed by a close analysis of aspects of the contents of Meiyu, especially the interaction between texts and images in the representation of nudity, intimacy, and coupledom.

Saline soils are significantly affected by water-salt phase changes, evaporation, and groundwater during seasonal freezing and thawing. For the study of physical and mechanical properties of saline soils, solubility is an important indicator that varies with temperature. However, there have been very limited computational studies on solubility at low temperatures. The model for calculating the solubility of Na2SO4-NaCl-H2O ternary system under low temperature conditions was constructed in this paper, based on the Pitzer and BET models. Improvements were made to the parameters ∅and γin the Pitzer model, while improvements were made to the parameters c, r, and awin the BET model. The solubility changes within the range of 273.15 ​K–373.15 ​K were calculated and validated by combining them with indoor experiments. It was found that both the improved Pitzer model and BET model accurately predicted relative equilibrium solubility data of the Na2SO4-NaCl-H2O ternary system at temperatures ranging from 273.15 ​K to 373.15 ​K. Additionally, compared with the Pitzer model, the BET model had advantages such as easy parameter acquisition and wider application range. The findings from this research hold great significance for understanding the process and patterns of salt analysis during soil freeze-thaw cycles as well as providing a scientific foundation for further comprehension of phase change laws and physical properties related to saline soils.

We present 3 cases of thumb polydactyly treated with a 2-stage “on-top plasty” technique. For all the 3 cases, the ulnar thumbs floated in the first web with a skin pedicle, and the radial thumbs presented hypoplasia of different degree. We designed a 2-stage “on-top plasty” technique. The first operation included transplantation of the ulnar floating thumb and construction of skin tube containing the neurovascular bundle. When followed up after the first operation, there was no vascular compromise, and all union was achieved. At the time of the second operation, the skin tube was opened up, the neurovascular bundle was transposed to the reconstructed thumb, and the first web plasty was performed. At the final follow-up, 3 cases showed acceptable results both cosmetically and functionally.

Abstract This paper investigates the finite-time robust control problem of a class of nonlinear time-delay systems with general form, and proposes some new delay-independent and delay-dependent conditions on the issue. First, by developing an equivalent form, the paper studies finite-time stabilization problem, and presents some delay-dependent stabilization results by constructing suitable Lyapunov functionals. Then, based on the stabilization results, we study the finite-time robust control problem for the systems, and give a robust control design procedure. Finally, the study of two illustrative examples shows that the results obtained of the paper work well in the finite-time stabilization and robust stabilization for the systems. It is shown that, by using the method in the paper, the obtained results do not contain delay terms, which can avoid solving nonlinear mixed matrix inequalities and reduce effectively computational burden. Moreover, different from existing finite-time results, the paper also presents delay-dependent sufficient conditions on the finite-time control problem for the systems. [ABSTRACT FROM AUTHOR]

This paper investigates the finite-time control problems for a class of discrete-time nonlinear singular systems via state undecomposed method. Firstly, the finite-time stabilization problem is discussed for the system under state feedback, and a finite-time stabilization controller is obtained. Then, based on which, the finite-time H ∞ boundedness problem is studied for the system with exogenous disturbances. Finally, an example of population distribution model is presented to illustrate the validity of the proposed controller. Because there is no any constraint for singular matrix E in the paper, controllers can be designed for more discrete-time nonlinear singular systems. [ABSTRACT FROM AUTHOR]

The high sand content of the crude oil produced from some oilfields influences the production efficiency. The fine sand deposits gradually in the three-phase separator during the treatment process of crude oil, which also seriously affects the dewatering treatment. To address the desanding and removal issue in high-sand-content oilfield, the large-size sedimentation tank is applied to enhance the treatment of the desanding process. Therefore, the numerical simulation for the separation process of suspended fine sand from oil and water emulsion in large-size sedimentation tank is implemented. The multiphase flow model of Eulerian and DPM model are chosen to simulate the depositing situation. The full flow field under different operating conditions for desanding is simulated and the applicable emulsion effluent standards under both static and dynamic sedimentation conditions are obtained. Comparing the simulated results to experimental results, a good agreement could be achieved. It was found that, the effluent-recycle process is not recommended if the viscosity-reduction process via heating is adopted to upgrade the desanding efficiency. The time required for desanding was 7~10 hours, and the volume of the large sedimentation tank which meets the current requirement was 3000 m3. The desanding efficiency can reach 90% when the sand size is larger than 80 μm, which provides guidance for whether to add the next level of desanding equipment or not. The formula for calculating the periodic time of cleaning deposited sand at tank bottom is given. It is also suggested that the sedimentation tank should be directly heated to reduce the liquid viscosity and prolong the sedimentation time, which is the optimum design for the whole desanding process.

Drug delivery system has shown multi advantages in cancer treatment, but the complex fabrication process limits their clinical application. This work developed a chitosan-based co-delivery system for doxorubicin and nano selenium. The one-pot co-precipitation process was utilized to form the PEGylated nanoparticles. It was found that the PEGylation might affect the co-precipitation process and result in different nanoparticle sizes and drug release behavior. The PEGylated nanoparticles (Se@DOX/CS-PEG) present a larger diameter (about 230 nm) and higher drug loading capacity (31%). A faster drug release was also observed for PEGylated Se@DOX/CS-PEG nanoparticles and drug release could be completed in 2 h at pH 5.0 while the drug release at pH 7.4 could be limited (<5%, 10 h). In vitro cell experiments confirmed the anti-cancer efficiency and intracellular delivery ability of the co-delivery system. In conclusion, this work presents a novel way to fabricate co-delivery system and may provide more insights into the development of smart drug delivery systems.

A nonlinear controller design method based on quarter-car model of semi-active suspension is proposed for input constraints problem. Taking the system nonlinear characteristics and input constraints into account sufficiently, an auxiliary system is introduced to combine backstepping method to cut down vibration of semi-active suspension. In the design process, we use a Nussbaum function to compensate for the nonlinear term arising from the input constraints. Due to the absence of any linearization method, the control input is limited to a certain range while maintaining the nonlinear characteristics of the system. The simulation results show that the suspension system can move toward stability quickly in the condition of input saturation, and can effectively improve the ride quality of the vehicle.

In this paper, an approach of constructing modified equations of weak $$k+k'$$ k+k′ order ($$k'\ge 1$$ k′≥1 ) apart from the k-th order weakly convergent stochastic symplectic methods, i.e., stochastic symplectic methods with respect to weak convergence and of weak order k, is given using the underlying generating functions of them. This approach is valid for stochastic Hamiltonian systems with additive noises, and those with multiplicative noises but for which the Hamiltonian functions $$H_r(p,q),\,\,r\ge 1$$ Hr(p,q),r≥1 associated to the diffusion parts depend only on por only on q. In such cases, we find that the modified equations of the weakly convergent stochastic symplectic methods are perturbed stochastic Hamiltonian systems of the original systems.

Ag/LaCoO3perovskite catalysts for soot combustion were prepared by the impregnation method. The structure and physicochemical properties of the catalysts were characterized using X-ray diffraction, N2adsorption-desorption, H2temperature-programmed reduction, soot temperature- programmed reduction, and X-ray photoelectron spectroscopy. The catalytic activity of the catalysts for soot oxidation was tested by temperature-programmed oxidation in air and in a NOxatmosphere. Metallic Ag particles were the main Ag species. Part of the Ag migrated from the surface to the lattice of the LaCoO3perovskite, to form La1-xAgxCoO3. This increased the amount of oxygen vacancies in the perovskite structure during thermal treatment. Compared with unmodified LaCoO3, the maximum soot oxidation rate temperature (Tp) decreased by 50–70 °C in air when LaCoO3was partially modified by Ag, depending on the thermal treatment temperature. The Tpof the Ag/LaCoO3catalyst calcined at 400 °C in a NOxatmosphere decreased to about 140 °C, compared with that of LaCoO3. Ag particles and oxygen vacancies in the catalysts contributed to their high catalytic activity for soot oxidation. The stable catalytic activity of the Ag/LaCoO3catalyst calcined at 700 °C in a NOxatmosphere was related to its stable structure.

This technical note studies the control design problem for a class of affine nonlinear descriptor systems with actuator saturation, and presents several new results. A stabilization controller design method is first proposed by state feedback and compensation, and a robust H\infty controller and a robust adaptive H\infty controller are respectively designed for the discussed system when external disturbances and/or parametric perturbations are taken into account. Simulation results on a nonlinear descriptor circuit system illustrate the efficiency of the controllers presented in this technical note. [ABSTRACT FROM PUBLISHER]

This paper presents an underwater lidar time-of-flight ranging system that combines the variable forgivable factor recursive least-squares (VFF-RLS) adaptive filter algorithm and the constant fraction discriminator (CFD) timing technology. The effectiveness of suppressing the backscattering and increasing timing accuracy is experimentally verified in the water basin under the different target distances, especially near the detection limit. The classical RLS is creatively transformed by introducing the VFF, which is highly correlated to the target echo at any distance. The improvement of the signal-to-backscatter ratio always exceeds 18.9 dB. The Monte Carlo simulation proves the applicability of the proposed method in the media of different turbidity. The influences of the selective timing methods on the walk error and time jitter are compared, and the optimum zero point of CFD is achieved by the slope analysis of leading (falling) edge in experimental target pulses.

ABSTRACTBackgroundThis study was conducted to characterize the long-term effect of mobile-based education on Chinese female freshmen and disclose the possible predictors of their willingness to get vaccinated based on the information-motivation-behavioral skills (IMB) model.MethodsWe randomly assigned 509 participants to a 7-day mobile-based educational intervention or control group and collected information about general information, health, and sexual behavior, HPV vaccination intention and action, HPV-related knowledge, cognition, and behavioral skill by an online self-administrated questionnaire at baseline, post-intervention, and at the 1-month and 3-month follow-ups.ResultsThe intervention arm showed an improvement in IMB scores after education. Despite the persistent improvement in knowledge, the improvement in their motivation and behavioral skills decreased at the 1-month and 3-month follow-ups. Participants’ vaccination willingness was elevated after the baseline survey in both the intervention and control groups, while the overall appointment/vaccination rate was only 3.73% 3 months later. The intention to get vaccinated was associated with knowing HPV (adjusted OR: 2.37, 95% CI: 1.44 – 3.89), perceiving more barriers (adjusted OR: 2.16, 95% CI: 1.44 – 3.25), higher subjective norms (adjusted OR: 2.05, 95% CI: 1.26 – 3.32), and having more behavioral skills (adjusted OR: 2.95, 95% CI: 1.79 – 4.87).ConclusionSeven-day mobile-based education was effective to increase IMB model scores among female freshmen. However, the improvement in motivation and behavioral skills was not persistent. Information, perceived barriers, subjective norms, and behavioral skills were discovered to be influencing factors of vaccination intention. Future research with longer, more convenient, and more tailored education to the main influencing factors is warranted.

Rills are frequently observed on slope farmlands and rill erosion significantly contributes to sediment yields. This paper focuses on reviewing the various factors affecting rill erosion processes and the threshold conditions of rill initiation. Six factors, including rainfall, runoff, soil, topography, vegetation and tillage system, are discussed. Rill initiation and network are explored. Runoff erosivity and soil erodibility are recognized as two direct factors affecting rill erosion and other types of factors may have indirect influences on rill erosion through increasing or decreasing the effects of the direct factors. Certain conditions are necessary for rill initiation and the critical conditions are different with different factors. Future studies should be focused on 1) the dynamic changes of rill networks; 2) the combined effect of multiple factors; and 3) the relationships of threshold values with other related factors.

A three-dimensional (3D) nitrogen-doped carbon nanotubes/graphene (NCNTs/G) composite was prepared by pyrolysis of pyridine over a graphene-sheet-supported Ni catalyst. The morphology and structure of the NCNTs/G composite was investigated by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Tangled NCNTs with lengths of several hundred nanometers are sparsely, but tighly, distributed on graphene sheets, forming quasi-aligned NCNT arrays. The N content in the NCNTs/G measured by X-ray photoelectron spectroscopy is about 6.6 at. %. The NCNTs/G shows a higher activity and selectivity to the oxygen reduction reaction in alkaline electrolyte compared with undoped CNTs/G, as demonstrated by cyclic voltammetry, rotating disk electrode, and rotating ring-disk electrode measurements. The results indicate that the 3D NCNTs/G composite has potential application in fuel cells.

Abstract: This paper studies the stabilization and H ∞ control of a class of nonlinear Hamiltonian descriptor systems. Firstly, based on the structural characteristic of the nonlinear Hamiltonian descriptor system, an equivalent nonlinear dissipative Hamiltonian differential-algebraic system is obtained by using restricted system equivalent theory. With the dissipative form, the stabilization problem is then discussed for the nonlinear Hamiltonian descriptor systems, and an H ∞ controller is designed. Finally, simulations on a nonlinear circuit system are given.

Mycoreovirus 1 (MyRV1), a member of the Reoviridae family possessing a genome consisting of 11 dsRNA segments (S1-S11), and the prototype hypovirus (CHV1-EP713) of the Hypoviridae family, which is closely related to the monopartite picorna-like superfamily with a ssRNA genome, infect the chestnut blight fungus and cause virulence attenuation and distinct phenotypic alterations in the host. Here, we present evidence for reproducible induction of intragenic rearrangements of MyRV1 S6 and S10, mediated by the multifunctional protein p29 encoded by CHV1. S6 and S10 underwent an almost full-length ORF duplication (S6L) and an internal deletion of three-fourths of the ORF (S10ss). No significant influence on symptom induction in the fungal host was associated with the S6L rearrangement. In contrast, S10-encoded VP10, while nonessential for MyRV1 replication, was shown to contribute to virulence reduction and reduced growth of aerial mycelia. Furthermore, p29 was found to copurify with MyRV1 genomic RNA and bind to VP9 in vitro and in vivo, suggesting direct interactions of p29 with the MyRV1 replication machinery. This study provides the first example of a viral factor involved in RNA genome rearrangements of a different virus and shows its usefulness as a probe into the mechanism of replication and symptom expression of a heterologous virus.

This research aims to improve erosion control practice in the Loess Plateau, by studying the surface erosion processes, including splash, sheet/interrill and rill erosion in four contrasting soils under high rainfall intensity (120 mm h−1) with three-scale indoor artificial experiments. Four contrasting soils as sandy loam, sandy clay loam, clay loam and loamy clay were collected from different parts of the Loess Plateau. The results showed that sediment load was significantly impacted by soil properties in all three sub-processes. Splash rate (4.0–21.6 g∙m−2∙min−1) was highest in sandy loam from the north part of the Loess Plateau and showed a negative power relation with the mean weight diameter of aggregates after 20 min of rainfall duration. The average sediment load by sheet/interrill erosion (6.94–42.86 g∙m−2∙min−1) was highest in clay loam from middle part of the Loess Plateau, and the stable sediment load after 20 min showed a positive power relation with the silt content in soil. The average sediment load increased dramatically by rill and interrill erosion (21.03–432.16 g∙m−2∙min−1), which was highest in loamy clay from south part of the Loess Plateau. The average sediment load after the occurrence of rill showed a positive power relation with clay content and a negative power relation with soil organic matter content. The impacts of slope gradient on the runoff rate and sediment load also changed with soil properties. The critical factors varied for different processes, which were the aggregate size for splash erosion, the content of silt particles and slope gradient for sheet/interrill erosion, and the content of clay particles, soil organic matter and slope gradient for rill erosion. Based on the results of the experiments, specific erosion control practices were proposed by targeting certain erosion processes in areas with different soil texture and different distribution of slope gradient. The findings from this study should support the improvement of erosion prediction and cropland management in different regions of the Loess Plateau.

We present a design of a linear optical waveguide that utilizes a C-shaped metallic nano-aperture that efficiently transports light while maintaining a spot size of λ/10. The performance of a C-aperture waveguide is superior to both a regular ridge waveguide and other surface plasmon based metal nano-optical waveguides. The energy transport mechanisms are explained by the coupling of an aperture surface resonance and the thickness resonances inside the guide channel. Finite-difference time-domain simulations of gold C-aperture waveguides are performed for a 1.5 μm wavelength incident plane wave. The 1/e decay length in power transmission is predicted to be ∼2.5 μm. The total power throughput is 1.66 for the 2.55 μm long guide, with an intensity 6 times that of the incident wave at a distance 120 nm from the exit plane, having a spot size of 150 nm.

Current understanding of volcanic effects on El Niño–Southern Oscillation in terms of eruption type and initial ocean condition (IOC) remains elusive. We use last‐millennium proxy reconstructions to show how volcanic impacts depend on eruption type and IOC. When the IOC is not a strong El Niño, it is likely that an El Niño will mature in the second winter following 79% (p< 0.01) of Northern Hemispheric eruptions and in the first winter following 81% (p< 0.01) of tropical and 69% of Southern Hemispheric eruptions. For a strong El Niño‐IOC, no significant El Niño will occur in the first winter after any type of eruption. The eruptions need to be large enough to cause these diverse effects. Our last‐millennium simulation confirms the IOC effect, except that a La Niña occurs in the first winter following most tropical eruptions due to overestimated volcanic cooling in the model. Investigation of the volcanic effect on the El Niño–Southern Oscillation is important to understanding the climate variability excited by natural forcing. For the first time, we explore the combined effects of volcanic type and initial ocean condition, which have been found crucial to understanding the El Niño–Southern Oscillation evolution solely. Based on the reconstruction analysis in this work, we have enough confidence to predict an El Niño in the second winter following Northern Hemisphere eruptions and the first winter following tropical eruptions when the initial ocean condition does not involve a strong El Niño. Otherwise a La Niña should be predicted. This reconstruction analysis provides a good reference for the evaluation of models' performance with respect to the volcano‐El Niño–Southern Oscillation relationship. The inconsistence of first‐winter responses after tropical eruptions between the reconstructions and simulation found in this work calls for further investigation and model improvement. Our conclusions here are based on one model, but they may still provide some guidance to the Model Intercomparison Project on the climatic response to Volcanic forcing. The IOC has a strong impact on the volcano‐ENSO relationship only when it involves a strong El NiñoA significant El Niño can be expected in the second/first winter after NH/tropical eruptions when the IOC is not a strong El NiñoIn the CESM simulation the volcanic cooling outweighs the Bjerknes feedback‐induced warming

Eukaryotes employ RNA silencing as an innate defense system against invading viruses. Dicer proteins play the most crucial role in initiating this antiviral pathway as they recognize and process incoming viral nucleic acids into small interfering RNAs. Generally, 2 successive infection stages constitute viral infection in plants. First, the virus multiplies in initially infected cells or organs after viral transmission and then the virus subsequently spreads systemically through the vasculature to distal plant tissues or organs. Thus, antiviral silencing in plants must cope with both local and systemic invasion of viruses. In a recent study using 2 sets of different experiments, we clearly demonstrated the differential requirement for Dicer-like 4 (DCL4) and DCL2 proteins in the inhibition of intracellular and systemic infection by potato virus X in Arabidopsis thaliana. Taken together with the results of other studies, here we further discuss the functional specificity of DCL proteins in the antiviral silencing pathway.

This paper studies the finite-time H ∞ control problem for the nonlinear discrete Hamiltonian descriptor system (NDHDS). Firstly, based on a proper state-feedback controller, a strict dissipative system, which is equivalent to the NDHDS, is obtained. Then, two sufficient conditions are derived for finite-time boundedness and finite-time H ∞ boundedness of the strict dissipative system, and the obtained results are applied to finite-time H ∞ control problem for the NDHDS. Finally, a simulation example is given to illustrate the effectiveness of our results. [ABSTRACT FROM AUTHOR]