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Background: In research to improve the quality of transgenic crops, it is often necessary to introduce multiple functionally related genes into recipient plants simultaneously to improve crop genetic traits effectively. Compared with unidirectional promoters, bidirectional promoters simultaneously regulate the expression of multiple genes and improve the efficiency of biotechnology. Therefore, in this study, bidirectional gene pairs were systematically analyzed in Gossypium hirsutum TM-1, and the structure, function and evolutionary relationships of the bidirectional genes were analyzed. The endogenous bidirectional promoters of cotton were mined, and their specific regulatory elements and biological functions were explored to provide useful promoter resources and a theoretical basis for cultivating new cotton germplasms with excellent fiber quality. Results: Using an improved search model, a total of 1,383 bidirectional transcript pairs were identified in the Gossypium hirsutum TM-1 genome, and their gene structure and functional annotations were systematically analyzed. Thirty bidirectional intergenic sequences were randomly screened for promoter activity analysis via a transient expression system, and 25 intergenic sequences were found to have bidirectional promoter activity. Comparative analysis of the bidirectional gene profiles of the four cotton subspecies revealed that these subspecies presented abundant bidirectional gene pairs with high homology and that the bidirectional genes in the cotton subspecies were more similar in terms of their molecular functions, cellular components and biological processes. In addition, parallel analysis of bidirectional genes in dicotyledons and monocotyledons revealed that abundant bidirectional gene pairs exist in different species. Although the total number of orthologous bidirectional genes was similar, there was a significant difference in the number of orthologous bidirectional gene pairs between dicotyledons and monocotyledons. This evolutionary analysis of the function and structure of homologous bidirectional gene pairs in different varieties and different subspecies of the same species revealed potential pathways by which these gene pairs originated, which may be necessary for the evolution of a new species. Conclusion: In this study, many bidirectional gene pairs in Gossypium hirsutum TM-1 were identified using computer programming, and systematic analysis was conducted to explore their functions and evolutionary relationships. In addition, the promoter activity of the bidirectional intergenic sequences was verified. The combination of computer programming screening, experimental validation and other methods is expected to provide preferred bidirectional promoters for transgenic breeding work via multigene cotransformation methods, and this information is valuable for genetic engineering research and applications. [ABSTRACT FROM AUTHOR]

Landslide dam failure and induced morphological changes are dependent on the material composition. A bimodal material composition is observed in landslide dams and riverbeds, but its influence on dam failure and morphological changes is poorly understood. In this study, we experimentally investigate landslide dam failure and its effect on local morphology by varying both dam and bed material composition. The results show that the peak discharge and final breach size increase, while the upstream residual water level decreases with increasing fine material (sand) content in the dam material. The effect of the bed material is limited and the whole dam failure process is rather controlled by the dam material. However, erosion surface slope and final erosion depth vary with changes in both dam and bed material. Sediments are deposited unevenly on the erodible bed, resulting in the formation of sandbars after dam failure. Similar topographies are observed with different erodible beds, while the deposition area and the anisotropy of deposition depth increase with increasing sand content in the dam material. The influence of bimodal material on dam failure and morphological changes is related to the incipient motion and transport of sediments, leading to the formation of armour layer and non-uniform bedform after dam failure. A dam failure pattern is proposed by considering the variation of the erosion surface slope caused by the change in erosion rate and the occurrence of deposition during dam failure. This study improves the understanding of landslide dam failure and induced morphological changes, and further aids the hazard management. [ABSTRACT FROM AUTHOR]

In this paper, we study a stochastic predator–prey model with Beddington–DeAngelis functional response and time-periodic coefficients. By analyzing the stability of the solution on the boundary and some stochastic estimates, the threshold conditions for the time-average persistence in probability and extinction of each population are established. Furthermore, the existence of a unique periodic measure of the model is also presented under the condition of the time-average persistence in probability of the model. Several numerical simulations are given to verify the effectiveness of the theoretical results and to illustrate the effects of the white noises on the persistence and periodic measure of the model. [ABSTRACT FROM AUTHOR]

Searching for superhard materials with excellent properties has been a key challenge in materials science over the past decades. In this study, based on high throughput and density functional theory (DFT), we identified 24 new stable carbon allotropes from 50 initially identified candidates through structural optimization by removing repetitive structures and mechanically, molecularly dynamic, and thermally unstable structures. In addition, we built a crystal convolution residual neural network (CCRNN) to predict the elastic properties and mechanical hardness of the carbon allotropes and used chemical formulas as inputs to the model. The model used nearly 9979 target compounds, monomers, and 143 element-based features such as covalent radius, electronegativity, volume, and magnetic moment. To accurately predict carbon allotropes, we added lattice constants (a , b , c) and lattice angles (alpha,beta,gamma) as inputs after the feature descriptors. Random forest (RF) and gradient-boosted decision tree (GBDT) regression algorithms were constructed, and the r of the CCRNN model was 0.978 and 0.955 for the bulk and shear moduli, respectively, and the best model (CCRNN) was chosen to predict the bulk and shear moduli of the stabilized carbon allotropes obtained from high-throughput calculations. Density functional theory validated the machine learning results. This study not only revealed 7 new superhard carbon allotropes, but also proposed a new deep learning model, and these newly discovered superhard carbon allotropes had wide-ranging potential applications in the fields of industry, electronics, aerospace, geology, and biomedicine. Our research has provided an important theoretical and experimental basis for the development of new superhard materials and applications and was significant in advancing the field of materials science and engineering. [Display omitted] • Identified 24 stable carbon allotropes from 50 candidates by high flux and DFT. • Prediction of elastic property and hardness using chemical formulas and features. • Lattice constants and lattice angles accurately predict bulk and shear moduli. • CCRNN obtains a high r value and performs best compared to other models. • The study revealed 7 new superhard carbon allotropes. [ABSTRACT FROM AUTHOR]

Homopolar inductor machine (HIM) has caught much attention in the field of flywheel energy storage system (FESS) due to its merits of robust rotor, brushless exciting, and high reliability. Compared with permanent magnet HIM (PM-HIM), the HIM with field winding (FW-HIM) can effectively eliminate the idling loss caused by the no-load magnetic field by cutting off the excitation current, while the charge/discharge efficiency of the HIM would be decreased due to the copper loss of field winding. To address this contradiction, a novel PM-HIM with a mechanical flux modulator (MFM-HIM) is proposed to achieve low idling loss and high charge/discharge efficiency. First, the special structure and operation principle of the MFM-HIM are investigated. Afterwards, the characteristic of the equivalent magnetic circuit of the MFM-HIM is analyzed and the key structure parameters of it are derived and optimized. Moreover, the electromagnetic performance indexes of the MFM-HIM, including back electromotive force, flux weakening ability, losses, etc. are fully analyzed. Finally, a prototype of the MFM-HIM is designed, manufactured, and tested. Experiment results confirm those obtained by simulations. Results show that the proposed MFM-HIM inherits the merits of high charge/discharge efficiency of PM-HIM and almost no idling electromagnetic loss of FW-HIM. The MFM-HIM could be a promising candidate for the application of FESS. [ABSTRACT FROM AUTHOR]

Permanent magnet (PM) machines have attracted much attention in the field of flywheel energy storage system (FESS) due to their merits of high power density and high efficiency. However, the flux generated by the PMs would cause large stator core loss during the idling state of FESS, which would reduce the energy conversion ratio and limit the application of FESS in long-term energy storage occasions. Addressing this issue, a novel dual-rotor single-stator coreless PM machine (DSSCPMM) with dual-flywheel is proposed in this article. The stator of the DSSCPMM is made of ceramic material, which can effectively eliminate the stator core loss. The rotor of the DSSCPMM contains inner and outer rotors, which are used as the flywheels and can be helpful to improve the energy storage density. First, the structure and operation principle of the proposed DSSCPMM are illustrated. Then, the influences of the key structure parameters and arrangement of PMs, winding configurations, and magnetization method on the electromagnetic performance of the proposed DSSCPMM are investigated. Finally, the optimized structure of the DSSCPMM is obtained and the efficiency is calculated. The result shows that the proposed DSSCPMM is a promising candidate for the application of FESS. [ABSTRACT FROM AUTHOR]

Cotton is an important natural fiber crop and economic crop worldwide. The quality of cotton fiber directly determines the quality of cotton textiles. Identifying cotton fiber development-related genes and exploring their biological functions will not only help to better understand the elongation and development mechanisms of cotton fibers but also provide a theoretical basis for the cultivation of new cotton varieties with excellent fiber quality. In this study, RNA sequencing technology was used to construct transcriptome databases for different nonfiber tissues (root, leaf, anther and stigma) and fiber developmental stages (7 days post-anthesis (DPA), 14 DPA, and 26 DPA) of upland cotton Coker 312. The sizes of the seven transcriptome databases constructed ranged from 4.43 to 5.20 Gb, corresponding to approximately twice the genome size of Gossypium hirsutum (2.5 Gb). Among the obtained clean reads, 83.32% to 88.22% could be compared to the upland cotton TM-1 reference genome. By analyzing the differential gene expression profiles of the transcriptome libraries of fiber and nonfiber tissues, we obtained 1205, 1135 and 937 genes with significantly upregulated expression at 7 DPA, 14 DPA and 26 DPA, respectively, and 124, 179 and 213 genes with significantly downregulated expression. Subsequently, Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analyses were performed, which revealed that these genes were mainly involved in catalytic activity, carbohydrate metabolism, the cell membrane and organelles, signal transduction and other functions and metabolic pathways. Through gene annotation analysis, many transcription factors and genes related to fiber development were screened. Thirty-six genes were randomly selected from the significantly upregulated genes in fiber, and expression profile analysis was performed using qRT-PCR. The results were highly consistent with the gene expression profile analyzed by RNA-seq, and all of the genes were specifically or predominantly expressed in fiber. Therefore, our RNA sequencing-based comparative transcriptome analysis will lay a foundation for future research to provide new genetic resources for the genetic engineering of improved cotton fiber quality and for cultivating new transgenic cotton germplasms for fiber quality improvement. [ABSTRACT FROM AUTHOR]

Homopolar inductor machine (HIM) has been applied in the field of flywheel energy storage system (FESS) due to its merits of simple structure, high reliability, and low idling losses. However, the HIM features unipolar air-gap flux density, which makes its power density lower than that of the electrical machine with bipolar air-gap flux density. Addressing this issue, a novel outer rotor homopolar inductor machine (OR-HIM) is proposed in this article. First, the special structure and operation principle of the OR-HIM are illustrated. Then, the unit motors of the OR-HIM are obtained and investigated based on the magnetic equivalent circuit method to facilitate the design. Moreover, the performance indexes, including power density, output characteristics, losses, and rotor stress of the OR-HIM, are fully analyzed. Finally, a 13-kW prototype is designed, manufactured, and tested. The back electromotive force, load voltage, output torque, and efficiency are measured and compared with those obtained by the finite element analysis. The results indicate that the proposed OR-HIM is a promising candidate for the application of FESS. [ABSTRACT FROM AUTHOR]

The homopolar inductor machine (HIM) has attracted recent interest in the field of flywheel energy storage system due to its merits of robust rotor and low idling losses. In some situations, the analytical methods of a conventional wound-field synchronous machine (WSM) can be used to analyze the HIM, but the clear explanation about why these can be done and the relationship between HIM and WSM were not given in the literature. To address these issues, this paper studies the HIM based on the basic theoretical model and equations. First, the structure and magnetic circuit characteristics of HIM are introduced. Second, the mathematical model of HIM is derived and then decomposed, which indicates that the HIM can be seen as a WSM with large end leakage inductance when rotor tooth width $ {\theta _t} \leq \pi /p$ , or a combination of WSM and synchronous reluctance machine (SynRM) when ${\theta _t} > \pi /p$. Third, the performance indexes of HIM and corresponding equivalent machines, including air gap flux density, back electromotive force, and inductance parameters, are analyzed and fully compared. Finally, an HIM is prototyped and tested on an experimental platform. The simulation and experiment results show that it is reasonable to regard the HIM as a WSM or a combination of WSM and SynRM. The conclusion gives a transparent explanation about the relationship between HIM and WSM, which helps to simplify the analysis of the HIM. [ABSTRACT FROM AUTHOR]

Homopolar inductor machine (HIM) has a wide range of applications in the field of flywheel energy storage system and ship propulsion due to its merits of simple structure, brushless exciting, and low idling losses. However, the three-dimensional finite element method (3-D FEM) is mainly used to investigate the electromagnetic performance indexes of HIM due to its intrinsic 3-D flux density distribution, which is time-consuming. To facilitate the analysis of HIM, an analytical method (AM) is necessary, especially in the initial design stage. Hence, this article presents an AM for analyzing the electromagnetic performance of HIM. First, the structure and operation principle of HIM are illustrated. Second, the magnetic equivalent circuit of HIM is built considering the saturation of stator and rotor core. Third, the air-gap permeance function is obtained considering the affection of stator and rotor slots. Finally, the magnetomotive force, air-gap flux density, back electromotive force, inductances and electromagnetic torque of HIM are calculated, then validated by 3-D FEM and corresponding experiments. The results indicate that the proposed AM can provide reasonable results to estimate the electromagnetic performance of HIM, which would be helpful for the analysis of HIM. [ABSTRACT FROM AUTHOR]

The article offers information on the Tenofovir disoproxil fumarate (TDF), a nucleotide reverse transcriptase inhibitor can be used to treat human immunodeficiency virus (HIV) infection In adults; and mentions the tenofovir disoproxil was hydrolyzed to generate an equivalent of monoester.

The compensated pulsed alternators (CPAs) have good applications in high-energy lasers, electromagnetic rail guns, and other electromagnetic launch devices. Among various electrical machine topologies, homopolar inductor alternators (HIAs) have attracted interest as CPAs due to their merits of simple and reliable structure, brushless excitation, and high-speed operation. However, the length of the conventional HIA is difficult to expand because it is limited by the rotor diameter, and the rotor diameter is restricted by the maximum speed of rotor tip, which results in low-energy storage capacity of a single machine. Besides, HIA suffers from the relatively low-power density due to its unipolar air-gap flux density (UAFD). To solve these problems, two novel HIAs with multistage stator cores (HIA-MSCs) are proposed in this paper. One is HIA with UAFD (HIA-UAFD) and the other is HIA with unipolar and bipolar air-gap flux density (HIA-UBAFD). First, the structure and operation principle of HIA-MSCs are illustrated. Then, the key parameters of HIA-MSCs are derived, and the corresponding models are built. Finally, the electromagnetic performances of HIA-MSCs are investigated by 3-D finite-element analysis method. Compared with HIA-UAFD, HIA-UBAFD has relatively higher discharge current and output power, which indicates that HIA-UBAFD is a better candidate for the pulsed alternator. [ABSTRACT FROM AUTHOR]

Homopolar inductor machines (HIMs) are promising candidates of the pulsed alternator for the application of high power pulsed supplies. However, a single HIM can hardly serve as both a pulsed alternator and a motor, because the voltage and frequency of the pulsed alternator are usually much higher than those of the motor. Thus, a prime motor is needed to drag the pulsed alternator, which makes the pulsed alternator system rather complex. To simplify the structure of the system, this paper proposes a novel four-stator-core HIM (FSCHIM) consisting of an alternator and a motor. First, both the configuration and operation principle of the FSCHIM are introduced. Second, the sizing equations of the FSCHIM are deduced to obtain its primary size parameters. Third, the armature reaction is investigated and the influences of main structure parameters on key output indices are studied by using finite-element analysis (FEA). Finally, the optimized scheme is validated by three-dimensional FEA and experimental results on the subelectrical machines. The results demonstrate that the FSCHIM can serve as a combination of the motor and the pulsed alternator, which enjoys the merits of high-voltage and high-frequency discharge performance with a lower voltage and lower frequency driving system. [ABSTRACT FROM AUTHOR]

Abstract This paper presents a process for the fabrication of subwavelength bilayer metal wire grid polarizers and describes the performance characterization of polarizers that were produced using the proposed method. These polarizers have a period of 278 nm and were fabricated on flexible plastic substrates using nanoimprint lithography followed by an aluminum deposition process. Transmission efficiency in excess of 0.55 and an extinction ratio of more than 32 dB were achieved in the visible range when the aluminum layer thickness of the polarizer was 70 nm. When a polarization analyzer with a six-channel sensor prototype was tested, an average error of 0.2002°was obtained, with a maximum error of 1.105°and a standard deviation of 0.7255°. The proposed fabrication method will be suitable for many applications in optics, including the manufacture of compound eye structures. [ABSTRACT FROM AUTHOR]

The homopolar inductor machine (HIM) is of particular interest in the field of flywheel energy storage system, where it has the potential to significantly reduce self-discharge associated with magnetic losses. However, the conventional HIM suffers from low power and torque density due to its unipolar air-gap flux density. Besides, the air-gap flux density of HIM is limited by the cross section of rotor, and the rotor diameter is limited by the maximum tip speed of the rotor. Thus, the maximum effective length and diameter of rotor should be within a certain range, which constrains the output power and stored energy of the HIM. To solve these problems, a novel multi-unit out-rotor HIM (MO-HIM) with bipolar air-gap flux density is proposed in this paper. First, the structure and operating principle of MO-HIM is illustrated. Then, the characteristics of the proposed machine are analyzed, indicating that MO-HIM can be regarded as a superposition of multiple unit machines. Finally, to verify the superior performances of the proposed MO-HIM, it is compared with a unipolar out-rotor HIM with multi-segment stator cores in terms of air-gap flux density, back electromotive force, and output torque. Results show that the proposed MO-HIM has larger fundamental air-gap flux density, higher power, and torque density. [ABSTRACT FROM AUTHOR]

This paper presents a global positioning method based on a polarized light compass system. A main limitation of polarization positioning is the environment such as weak and locally destroyed polarization environments, and the solution to the positioning problem is given in this paper which is polarization image de-noising and segmentation. Therefore, the pulse coupled neural network is employed for enhancing positioning performance. The prominent advantages of the present positioning technique are as follows: (i) compared to the existing position method based on polarized light, better sun tracking accuracy can be achieved and (ii) the robustness and accuracy of positioning under weak and locally destroyed polarization environments, such as cloudy or building shielding, are improved significantly. Finally, some field experiments are given to demonstrate the effectiveness and applicability of the proposed global positioning technique. The experiments have shown that our proposed method outperforms the conventional polarization positioning method, the real time longitude and latitude with accuracy up to 0.0461° and 0.0911°, respectively. [ABSTRACT FROM AUTHOR]

Here, a simple and low-cost fabrication strategy to efficiently construct well-ordered micron and submicron gratings on polymeric substrates by oxygen plasma treatment is reported. The Polydimethylsiloxane (PDMS) substrate is prepared on the polyethylene (PET) by spin-coating method, then the curved PDMS-PET substrates are processed in oxygen plasma. After appropriate surface treatment time in plasma the curved substrates are flattened, and well-ordered wrinkling shape gratings are obtained, due to the mechanical buckling instability. It is also demonstrated that changing the curvature radius of PDMS-PET substrates and the time of plasma treatment, the period of the wrinkling patterns and the amplitude of grating also change accordingly. It is found the period of the wrinkling patterns increased with the radius of curvature; while the amplitude decreased with that. It also shows good optical performance in transmittance diffraction testing experiments. Thus the well-ordered grating approach may further develop portable and economical applications and offer a valuable method to fabricate other optical micro strain gauges devices. [ABSTRACT FROM AUTHOR]

Pulsed alternators have the merits of high energy and power densities, which are applied to a wide range of applications, such as the electromagnetic launch, the pulsed laser, and the pulsed high magnetic field. A new type of high-speed and high-frequency pulsed alternator integrating an alternator and a motor, is proposed in this paper. A solid rotor which is made of high-strength alloy steel with high yield strength is used in the pulsed alternator, so it can work at a high tip speed. This machine consists of two alternators and a motor which share one rotor and one field winding. According to different voltage levels and operation frequencies, the motor and the alternators with different stack lengths and pole-pairs are designed, respectively. Therefore, it has the abilities of being driven by low-frequency current and discharging high-frequency pulses. In this paper, the basic structure and fundamental of the pulsed alternator are introduced, the specific parameters of the prototype are given, and the performances are verified by the simulation. The results show that the machine proposed in this paper is suitable for the applications that require high-frequency pulsed discharge. [ABSTRACT FROM PUBLISHER]

Homopolar inductor alternator (HIA) has been widely used as a high-speed pulsed alternator in the electromagnetic launch field due to its merits of high-speed operation, power density, and reliability. To achieve the above-mentioned merits, a high-strength and high-stiffness solid rotor is usually adopted in the HIA. However, the solid rotor would be subject to high eddy current loss. Some works have been done to analyze the rotor eddy current of the HIA, while the research on analytic calculation and reduction of rotor eddy current loss is relatively few. In this paper, an analytic calculation method is established to calculate no-load rotor eddy current loss for HIA, which is validated by the finite-element analysis and corresponding experiments. Besides, to minimize the rotor eddy current loss, a simple method, by slitting the rotor tooth, is proposed. Moreover, the influence of circumferential and axial slits on the rotor eddy current loss and air friction loss is comparatively studied. Finally, the influence of the width, depth, and number of slits on the eddy current loss is investigated. It is shown that the circumferential slits have better performance than that of axial slits to reduce the eddy current loss. [ABSTRACT FROM PUBLISHER]

A mixed competition–predation model is proposed where the switches between competition and predation are seasonal-dependent. The threshold values are derived above which the populations are stochastically permanent, and below which a population becomes extinct for the prey–predator interactions or the weak competitions. [ABSTRACT FROM AUTHOR]

Lack of knowledge on the destiny of organic micropollutants (OMPs) in the Tibetan Plateau region of China prevents the public from being aware of the need for protecting these unique aquatic ecosystems that are precious water resources and source areas of the Yellow River. To address this knowledge gap, this study systematically investigated the multi-residue analysis, distribution, and potential risks of six types of OMPs, namely, neonicotinoid pesticides (NEOs), fungicides, organophosphate esters (OPEs), organophosphorus pesticides (OPPs), psychoactive substances (PSs), and antidepressants (ADs), in surface waters of major cities in Qinghai. A total of 31 compounds, consisting of 8 NEOs, 1 fungicide, 12 OPEs, 2 OPPs, 5 PSs, and 3 ADs, were detected in >50% of the sites, showing their ubiquitous nature in the study area. Results showed that the total OMP concentration in surface water was 28.3–908 ng/L, and OPEs were the dominant composition (48.6%–97.4%). The risk quotient values of the detected diazinon and dursban regularly exceeded 1 for aquatic organisms at all sampling sites, indicating moderate–high chronic ecological risk. The joint probability curves showed that dursban and NEOs have higher risk levels than other OMPs. Although the results of the non-carcinogenic total hazard quotient of the OMPs in the surface water was less than 1 in all age groups and the carcinogenic risk was lower than the negligible risk level, the potential risks to children and infants were considerably greater and should not be underestimated. In addition to pollutant concentration and exposure duration, ingestion rate and body weight (BW) are also important factors affecting health risk, with BW having a negative effect. To the best of the authors' knowledge, this report is the first to describe OMP pollution in Qinghai, and the results provide new insight into the ecological security of the water resources of the Tibetan Plateau. [Display omitted] • The occurrence of 67 organic micropollutants of surface water in Qinghai was first determined. • Organophosphate esters were dominant organic micropollutants, followed by neonicotinoid pesticides. • The environmental risks of organic micropollutants were assessed based on the risk quotient values and joint probability curves. • Diazinon and dursban had moderate to high chronic ecological risk at all sites. • The priority substances lists provide significant references on pollutant control. [ABSTRACT FROM AUTHOR]

Development of efficient non-precious metal catalysts for water electrolysis is imperative in the area of energy conversion. Herein, transition-metal oxide catalyst of Cu x O@NiO-MoO 2 nanorods with three-dimensional core–shell nanostructures was constructed by a facile route. The Cu x O@NiO-MoO 2 NRs supplies a high electrochemical active area, thus exposing more active centers in full contact with the electrolyte. The fast charge transfer between the nanorods and nanoparticles and the synergistic effect among the bimetals enable the catalyst to show superior catalytic performance. Cu x O@NiO-MoO 2 NRs requires the overpotentials of 65 mV for hydrogen evolution reaction (HER) at 10 mA cm−2 and 321 mV for oxygen evolution reaction (OER) at 50 mA cm−2. Meanwhile, the catalyst also shows satisfactory performance at the high current densities of 100 and 200 mA cm−2 for HER, requiring overpotentials of only 152 and 192 mV, respectively. Moreover, the Cu x O@NiO-MoO 2 NRs needs a voltage of 1.54 V to achieve 10 mA cm−2 as a water electrolyzer. This study provides a promising route for preparing bifunctional catalysts via the rational design of interfaces and nanostructure arrays. [Display omitted] • The Cu x O@NiO-MoO 2 NRs with 3D core–shell nanostructure is prepared by a facile three-step method. • The core–shell structure of the catalyst enables the active shell layer to be sufficiently exposed to the electrolyte. • The shell layer NiO-MoO 2 nanoparticles achieve higher electrochemical active area and expose more catalytic sites. • The synergistic effect between Ni and Mo bimetallic sites significantly enhances the catalytic activity. [ABSTRACT FROM AUTHOR]

The magnetic field effect on the interband optical conductivity of black phosphorene (BP) is considered in the investigation of the absorptance of BP-based multilayer dielectric structures using the transfer matrix method. The BP interband optical conductivity is anisotropic and shows multi-peaks in the presence of the magnetic field because of the splitting of energy levels. The peak position of the absorptance is tuned via the magnetic field strength. In the energy region (0.5 eV - 1.7 eV), the maximum absorptance in the armchair direction is larger than that in the zigzag (ZZ) direction which depends on the angle of incidence and the dielectric structure. But the increased rate of the maximum absorptance in the presence of a magnetic field in the ZZ direction is quite obvious and increased about 10 times. An increased number of BP/Si layers makes the optical absorption in both directions much stronger. • The optical transition channels are tuned by the magnetic field. • The absorptance in the AC direction is larger than that in the ZZ direction. • The modulation of the magnetic field is very obvious along the ZZ direction. • Stronger absorptance is achieved in multilayer structures with BP inserted. [ABSTRACT FROM AUTHOR]

The traditional processing model of the temperature error for a gyroscope is serial, meaning that de-noising and temperature drift compensation are implemented in a two-step procedure. Hence, the result of the latter depends on the performance of the former; in particular, negative de-noising produces a negative compensation result. To reduce this dependence, we propose a parallel processing algorithm of the temperature error based on variational mode decomposition (VMD) and an augmented nonlinear differentiator (AND). An application to a micro-electro-mechanical system gyroscope is described to demonstrate the effectiveness and applicability of the proposed algorithm. Its major advantages are (i) a combination of VMD, extreme learning machines, and AND is proposed, and an adaptive accelerometer factor determination method for AND is given based on the VMD, both of which improve the effectiveness of the de-noising process; (ii) temperature drift and noise in the temperature error can be extracted and processed synchronously, thereby reducing the dependency of drift compensation on the de-noising result and making the temperature error process more efficient. [ABSTRACT FROM AUTHOR]

Two large successive co-site landslide dams blocked the Jinsha River in the Sichuan Province of China in 2018. A quantitative risk analysis was carried out to quantify potential human and economic losses resulting from the failure of these dams, especially the interaction between the co-site landslide dams, and to further investigate the influence of digging a diversion channel on risk mitigation. Flood routing for three scenarios (i.e. after the first dam formation, when the second landslide mass was added, and with a diversion channel after failures) were simulated using HEC-RAS. The human and economic losses were evaluated using a human risk assessment model together with empirical formulations. The results show that the risk of breaching floods had increased significantly after the second co-site landslide dam formation on the pre-existing loose deposits of the first dam. This amplification effect of outburst floods was so great that the peak outflow resulting from the breaching of the second landslide dams was more important, leading to greater economic losses than those resulting from the breaching of the first dam. However, the expected loss of life caused by the breach of the two landslide dams appeared small because of the sufficient time lag provided by the long distance between the residential area and the dam site. The simulations also outline the importance of the diversion channel in decreasing the peak outflow rate and hence downstream risks. A parametric analysis shows that a deep channel with a moderate longitudinal gradient can significantly decrease the peak outflow discharge at the dam site. Flood intensity and risks to downstream towns did not change because of the relatively small attenuation rate of the peak outflow rate. However, a shorter height of the residual dam can be obtained by optimizing the diversion channel, and the amplification effects of such co-site dam can be significantly reduced in the future. • The human and economic risks caused by the two co-site Baige landslide dams are quantitatively assessed. • The reasons why an amplification effect of flood intensity and downstream risks occurred are systematically investigated. • An optimal diversion channel is obtained based on parametric analysis of the peak outflow rate during dam breach. • The influence of the diversion channel in flood intensity, risks in downstream and risk mitigation is discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • The 3D CuO@CoNiS NRs core–shell heterostructure catalyst is fabricated via surface oxidation and electrodeposition method. • The 3D nanorod arrays promote the charge/mass transfer and provide more nucleation sites. • The secondary formation of CoNiS nanosheets offer a larger electrochemical active surface area and expose more active centers. • CuO@CoNiS NRs shows outstanding catalytic performance and long-term durability. The development of high-efficiency electrocatalysts is one of the important ways to mass-produce hydrogen but still confronts many challenges. Herein, a 3D core–shell heterostructure catalyst is rationally designed by interfacial assembled of CoNiS nanosheets on CuO nanorods (CuO@CoNiS NRs). The 3D core–shell heterostructure significantly increases the electrochemical surface area, enabling more active centers to be exposed and facilitating the charge transfer, thus boosting catalytic activity. The catalyst requires low overpotential for HER (96 mV) and OER (246 mV) to achieve 10 mA cm−2 in 1 M KOH. It is capable of attaining 200 mA cm−2 with only 206 mV for HER and achieving 100 mA cm−2 with 314 mV for OER. Meanwhile, CuO@CoNiS NRs as a water electrolyzer to generate 10 mA cm−2 requires a low voltage of 1.52 V. This work provides an effective strategy for developing efficient non-noble metal catalysts by reasonable construction of nanostructure and heterogeneous interface. [ABSTRACT FROM AUTHOR]

• Breaching process of landslide dams is controlled by material composition and internal structures. • Four longitudinal evolution patterns are derived to describe the erosion process. • Peak discharge and residual dam parameters for homogeneous dams are sensitive to median diameters. • Breaching and residual dam parameters for inverse grading structure dams are within the values for dams formed by top and bottom layer material. • Employing top layer materials to characterize inverse grading structure dams lead to significant errors in breach parameters analysis. Landslide dams are composed of wide-graded materials characterized by nonuniform structures that govern breaching mechanisms. However, investigations of the failure characteristics of single-structure dams with different material compositions and inverse grading structure dams remain insufficient. In this study, a series of flume experiments are conducted to investigate the influences of noncohesive dam materials and inverse grading structures on the breaching mechanisms, hydraulic characteristics and residual dam parameters during and after landslide dam failures. The results indicate that the dam breach process is controlled by the material composition and dam structure. A coarse-grained dam remains stable with seepage, a medium-grained dam fails by headcutting and backwards erosion, and a fine-grained dam fails due to layered erosion. An inverse grading dam with coarse-grained overburden features backwards erosion or a combination of sliding and backwards erosion, while a dam with medium-grained overburden fails by headcutting and backwards erosion. The maximum erosion rate occurs at the accelerated breaching stage for single-structure dams and at the initial overtopping or accelerated breaching stage for inverse grading structure dams. Four longitudinal evolution patterns are extracted based on the breach process and erosion characteristics. In addition, the outflow discharge during dam failure can be estimated by measuring the breach width, which is defined as the straight line distance between the ends of the breach crest at the overflow face. Both the peak discharge and residual dam parameters for single-structure dams are sensitive to the median diameter of the material. These parameters of inverse grading structure dams fall within the range of values observed for dams formed by the top layer material and the bottom layer material. The initial overtopping and backwards erosion stages account for 10%–35% and 36%–66% of the total breach duration for single-structure and inverse grading structure dams, respectively. Serious errors in the prediction of breach parameters can occur when top layer materials are considered to characterize the material of inverse grading structure dams. [ABSTRACT FROM AUTHOR]

In recent years, polarized light navigation has been widely used for the application of the autonomous heading measurement of small unmanned combat platforms to satellite navigation rejection. However, current techniques of polarized light navigation yield low accuracy when measuring the heading angle in dynamic environments, and the use of a single source of navigation has some shortcomings as well. In the environment of satellite navigation rejection, a method to measure the heading angle using angle compensation based on three-dimensional image geometric correction is proposed in this paper. A model of polarized light/inertial combination based on the Cubature Kalman Filter (CKF) is established using this, and was verified by outdoor experiments that employed the polarized light/inertial combination heading measurement system. The results showed that the overall stability of the heading angle as calculated by the data fusion algorithm of polarized light and the inertial system based on the CKF followed the trend of the polarized light, which adequately suppressed the angle drift caused by data of the inertial system. Following the application of the CKF filtering algorithm, the root mean square error of the heading angle was 1.0719°, which improved the accuracy of calculating the heading angle of the polarized light/inertial integrated system in non-horizontal road environments. • A method to measure the heading angle using angle compensation was proposed. • A model of polarized light/inertial combination based on the CKF was established. • The root mean square error of the heading angle was 1.0719°. • It improved the accuracy of calculating the heading angle in non-horizontal road environments. [ABSTRACT FROM AUTHOR]

(3R,4R)-2-(4-Chloro-3-(4-(((S)-tetrahydrofuran-3-yl)oxy)benzyl)phenyl)-5-((R)-1,2-dihydroxyet... To a solution of Et SB 3 sb SiH(1.5 g, 11.2 mmol) and BF SB 3 sb -Et SB 2 sb O(15.5 g, 109.2 mmol) in DCM, was added the solution of B 18 b (see above) at 5-10 °C. To a solution of B 6e b (20 g, 91.1 mmol) in DCM (150 mL), was added PCC (26.5 g, 122.6 mmol), and the mixture was stirred at rt for 20 h, then filtered to remove the solid, and the filter cake was washed with DCM (20 mL). Small amounts of water in the tetrahydrofuran (THF) solution of B 13 b and ( I S i )-3-hydroxytetrahydrofuran can lead to the production of degradation products B 15a b and B 15b b (Scheme 1), as previously noted in the literature.[11],[12] Briefly, impurity B 15b b was removed by washing with a sodium bicarbonate solution. (2S,3R,4S,5S,6R)-2-(4-Chloro-3-(4-(((S)-tetrahydronfuran-3-yl)oxy)benzyl)phenyl)-6-(hydroxyme... To a solution of B 16 b (200 g, 546.4 mmol) in THF (600 mL) was slowly added 1.1 eq n-BuLi (240 ml, 2.5 mol/L hexane solution, 600.0 mol) at -75 °C over 40 min. [Extracted from the article]

In this work we study a stochastic predator–prey model with general functional response and time periodic coefficients. The threshold conditions for the persistence and extinction of each population are established. An example and its numerical simulations are given to verify the effectiveness of the theoretical results. • A stochastic predator–prey model with general functional response and time periodic coefficients is considered. • The threshold conditions for the persistence and extinction of each population are established. • We find that white noises have effects on the persistence and extinction of the species. [ABSTRACT FROM AUTHOR]

Brushless structure is beneficial for air-core compensated pulsed alternator (ACPA) because its field current and rotation speed are too large for the slip rings and carbon brushes. To achieve the brushless structure, a cascaded brushless self-excited ACPA (CBSACPA), which consists of an exciter and a generator in cascade, is proposed, in this article. The exciter and generator have a common rotor. A novel squirrel-cage rotor winding (SCRW), which can eliminate the end winding compared with conventional wound rotor winding (WRW), is proposed to simplify the rotor structure and improve the performance. First, the structure of the CBSACPA with the SCRW is introduced. Second, the operation principles of the machine are elaborated. Third, the dynamic mathematical model is presented. Fourth, the operation principles are demonstrated by the finite-element method. In addition, the performance of the SCRW is compared with the WRW as well. Finally, a prototype of CBSACPA is developed and tested to validate the analyses and simulations. In conclusion, this study gives detailed introduction, analyses, and validation about the CBSACPA, which provides a new solution to achieve a brushless structure for the ACPA. [ABSTRACT FROM AUTHOR]

Stacked traits have become an important trend in the current development of genomically modified crops. The bidirectional promoter can not only prevent the co-suppression of multigene expression, but also increase the efficiency of the cultivation of transgenic plants with multigenes. In Gossypium hirsutum, Ghrack1 and Ghuhrf1 are head-to-head gene pairs located on chromosome D09. We cloned the 1429-bp intergenic region between the Ghrack1 and Ghuhrf1 genes from Gossypium hirsutum. The cloned DNA fragment GhZU had the characteristics of a bidirectional promoter, with 38.7% G+C content, three CpG islands and no TATA-box. Using gfp and gus as reporter genes, a series of expression vectors were constructed into young leaves of tobacco. The histochemical GUS (Beta-glucuronidase) assay and GFP (green fluorescence protein) detection results indicated that GhZU could drive the expression of the reporter genes gus and gfp simultaneously in both orientations. Furthermore, we transformed the expression vectors into Arabidopsis and found that GUS was concentrated at vigorous growth sites, such as the leaf tip, the base of the leaves and pod, and the stigma. GFP was also mainly expressed in the epidermis of young leaves. In summary, we determined that the intergenic region GhZU was an orientation-dependent bidirectional promoter, and this is the first report on the bidirectional promoter from Gossypium hirsutum. Our findings in this study are likely to enhance understanding on the regulatory mechanisms of plant bidirectional promoters. [ABSTRACT FROM AUTHOR]

Breaching of a dam depends on the complex interaction between the dam and the backwater lake. Here, we conduct a series of experiments to investigate the failure mechanisms of landslide dams by considering debris composition and geomorphic parameters (dam height and lake volume), discern the failure mode and predict peak outflow rates of landslide dams in the field and in model tests. The failure modes of landslide dams are regulated by soil properties such as the shear strength and seepage. Failures of fine-grained and widely graded dams are induced by overtopping along with seepage instability and headcutting, respectively. Coarse-grained dams remain stable. Geomorphic parameters of dams govern the infilling time and affect the failure modes by the seepage. Seepage significantly reduces the stability of fine-grained dams and changes breach evolution and duration, while its effect on widely graded and coarse-grained dams is weak. Peak outflow rates of fine-grained dams are larger than those of widely graded dams with the same dam height due to larger breach depths and erosion rates. The peak outflow rate and breach duration are more related to the breach depth than the dam height because the influence of soil properties is considered in the former. Peak outflow rates of landslide dams are well predicted by a regression analysis with the lake volume, dam height and soil properties. Our results facilitate the understanding of breach mechanisms of landslide dams and prediction of peak outflow rates based on dam parameters. [ABSTRACT FROM AUTHOR]

Pulsed power technology is widely used in medical treatment, military, and scientific research, such as laser burst and electromagnetic launch. Compensated pulsed alternator (CPA) is a kind of device generating that pulsed power. One of the shortages for the air-core pulsed alternator is the huge excitation loss. In order to solve the problems, a multidisk axial flux CPA (MAFCPA) is proposed, which replaces the excitation windings with permanent magnets, saving the self-excitation process. In addition, multidisks are designed, especially to reduce subtransient reactance when the CPA discharges, which contributes to increasing the discharging current. This paper mainly focuses on researching the feasibility of MAFCPA in aspects of thermal issues, rotor statics, and dynamics problems. First, the topology and principle of MAFCPA are introduced, and the properties of the materials are listed as well. Second, the loss of discharging is calculated and the temperatures of both stator and rotor are solved. Then, the maximum stresses of different materials are obtained. Afterward, the critical speeds are researched in order to avoid resonance. Finally, the conclusion is made that MAFCPA can work safely under a speed of 10000 r/min and supply a pulse of over 50 ms. [ABSTRACT FROM AUTHOR]

An automobile generator has stringent requirements on its weight and volume. As a combination of permanent magnet and electric excitation motor, hybrid excitation machine has the merits of small size, lightweight, and adjustable output voltage, which can meet the requirements of the vehicular generator. In this paper, a novel axial flux stator partition hybrid excitation brushless synchronous generator (ASHG) is proposed. First, the structure and the operating principle of ASHG is illustrated. Afterward, the shape of the magnetic pole is optimized to obtain the air-gap flux density with low harmonic component. Finally, the regulation performance of the magnetic field and output voltage are investigated by using the 3-D finite-element analysis method. The result indicates that the ASHG has a good ability to adjust the terminal voltage. [ABSTRACT FROM AUTHOR]

Nanomedicines while showing a great potential in improving the performance of chemotherapeutics like docetaxel (DTX) are distressed by a high liver deposition and poor tumor penetration, which might not only cause liver toxicity but also moderate therapeutic effect. Herein, we report that cRGD-directed 24 nm disulfide-crosslinked micellar docetaxel (cRGD-MDTX) presents low liver accumulation, high tumor uptake, and deep tumor penetration, leading to the potent suppression of different solid tumors. cRGD-MDTX was optimized with a cRGD density of 4% and DTX loading of 10 wt%. Interestingly, cRGD-MDTX enabled an extraordinary tumor-liver ratio of 2.8/1 with a DTX uptake of 8.3 %ID/g in α v β 3 over-expressing PC3 prostate tumor. The therapeutic studies demonstrated striking antitumor effects of cRGD-MDTX toward PC3 prostate tumor, prostate cancer patient-derived xenografts (PDX), orthotopic A549-Luc lung cancer and orthotopic SKOV3-Luc ovarian tumor models, in which tumor growth was effectually inhibited and 6–8 times better improvement of median survival time over free DTX was observed. This small disulfide-crosslinked micellar drug capable of relegating liver deposition opens a new avenue to nanomedicines for targeted therapy. [Display omitted] • 24 nm disulfide-crosslinked biodegradable micellar docetaxel effectively mitigates liver deposition. • α v β 3 integrin-targeting combined with small size enables high tumor uptake and deep tumor penetration. • cRGD-MDTX induces superior chemotherapy of prostate, lung and ovarian tumors to free DTX. • cRGD-MDTX displays an extraordinary tumor-to-liver ratio of 2.8. [ABSTRACT FROM AUTHOR]

Using the transfer matrix method, the absorption properties of multilayer dielectric structures composed of the molybdenum disulfide (MoS 2), respectively, tungsten disulfide (WS 2) in the visible light range have been investigated theoretically and numerically. The MoS 2 and WS 2 are treated as surface conductivity with infinitesimal thickness. The results show that the absorptance can be modulated by the angle and polarization direction of the incident light, the number of layers and the thickness of the dielectric layers. Under the best selection of these factors, when only a monolayer of MoS 2 or WS 2 covers the surface of silicon, the absorptance can be increased to about 49.7% and 48.9%, respectively. The average value of the absorption of MoS 2 -based structures is greater than that of WS 2 under the same parameters. The investigation would broaden the applications based on MoS 2 /WS 2 optical properties. [ABSTRACT FROM AUTHOR]

The pulsed high-power supplies in this paper employs a homopolar inductor alternator (HIA) as the motor/generator integrated energy storage pulsed alternator. Lumped parameter design equations are developed, which is used to establish the mathematical model of the HIA, and the analytic calculation method of inductance matrix is derived. Prototype flywheel energy storage was built, and the basic structure of HIA is analyzed by using finite-element method (FEM). This paper proposes a simplified equivalent 2-D salient-pole synchronous generator model to simplify the 3-D FEM of HIA and investigates the motor control method of HIA based on the simplified 2-D equivalent model. The experiments were conducted for speed up to 8000 rpm and the six-step inverter drive strategy presented in this paper achieves the motor/generator integrated control on inductor energy storage pulsed alternator (IESPA). Most experimental results were in line with designed value. [ABSTRACT FROM PUBLISHER]

[Display omitted] Since the first introduction of sodium iodide I-131 for use with thyroid patients almost 80 years ago, more than 50 radiopharmaceuticals have reached the markets for a wide range of diseases, especially cancers. The nuclear medicine paradigm also shifts from solely molecular imaging or radionuclide therapy to imaging-guided radionuclide therapy, which is deemed a vital component of precision cancer therapy and an emerging medical modality for personalized medicine. The imaging-guided radionuclide therapy highlights the systematic integration of targeted nuclear diagnostics and radionuclide therapeutics. Regarding this, nuclear imaging serves to "visualize" the lesions and guide the therapeutic strategy, followed by administration of a precise patient specific dose of radiotherapeutics for treatment according to the absorbed dose to different organs and tumors calculated by dosimetry tools, and finally repeated imaging to predict the prognosis. This strategy leads to significantly enhanced therapeutic efficacy, improved patient outcomes, and manageable adverse events. In this review, we provide an overview of imaging-guided targeted radionuclide therapy for different tumors such as advanced prostate cancer and neuroendocrine tumors, with a focus on development of new radioligands and their preclinical and clinical results, and further discuss about challenges and future perspectives. [ABSTRACT FROM AUTHOR]

A typical flywheel energy storage system (FESS) includes an electrical machine, a flywheel, and magnetic bearings, which are independent of each other. Therefore, the structure of FESS is complicated, which leads to the problems of high cost and low integration. This article presents a novel stator PM excitation solid rotor machine (SPE-SRM) for FESS, which integrates an electrical machine, flywheels, and a magnetic bearing. The design method of the SPE-SRM is presented specifically. First, the structure and operation principle of the SPE-SRM are illustrated. Second, the design and optimization of the flywheel-rotor are presented with considering of power, energy storage, and mechanical strength. Third, the magnetic equivalent circuit of the SPE-SRM is established to simplify the design. Besides, the armature reaction and leakage flux factor are investigated. Fourth, the performance indexes, including torque, suspension force, no-load back electromotive force (back-EMF), losses, and temperature rise are fully analyzed by the finite element analysis. Finally, a 22 kW prototype is manufactured and tested. The rationality of the concept and design is validated by experiments. The SPE-SRM has the merits of high integration, robust structure, and low cost, so it has the potential for wide application in FESS. [ABSTRACT FROM AUTHOR]

The Gompertz growth plays an important role in simulating the development of animal, plants and cancer cells. We study a competitive model with the Gompertz growth, which is perturbed by environmental noises. The explicit threshold conditions are obtained for the stochastic permanence and extinction of the populations, which reveal how stochastic noises affect the competitive exclusion and coexistence of two competing populations. [ABSTRACT FROM AUTHOR]

[Display omitted] • The heterostructure electrocatalyst composed of MOF-derived CoNiSe 2 and FeS 2 is synthesized. • This electrocatalyst exhibits superior OER activity and robust durability. • The interfaces of heterostructure is benefit to improved conductivity. • The relationship between catalysis activity and heterostructure are investigated by DFT calculations. Developing effective and low-cost catalysts toward oxygen evolution reaction (OER) is pivotal for hydrogen generation by water electrolysis. The preparation of transition metal based catalysts using the unique structure of metal–organic frameworks is considered a feasible approach. Herein, we have designed and synthesized a heterostructure electrocatalyst composed of FeS 2 and MOF-derived CoNiSe 2. The catalyst exhibits an extraordinary OER activity with a low overpotential of 230 mV to deliver the current density of 10 mA cm−2, a slight Tafel slope of 54 mV dec−1 in 1 M KOH, and robust durability up to 45 h. The result of density functional theory (DFT) calculations reveals that electronic coupling at the heterogeneous interface helps reduce reaction energy barriers and increase electrical conductivity. This work would provide some inspiration for explorations of advanced electrocatalysts with MOF-derived heterostructure. [ABSTRACT FROM AUTHOR]

In this article, we present an adaptive broadband thyristor-controlled impedance matching network (TCIMN) for increasing power utilization from a power amplifier to the loads. Different from the conventional passive impedance matching methods, the proposed one can achieve load impedance matching under a wide frequency range of power amplifiers. First, the operation principle of TCIMN is introduced mathematically. Based on that, the parameter design method is proposed based on the required frequency range. Moreover, the operating range and harmonic analyses are provided to give the TCIMN firing angle operating ranges under different frequencies and alleviate the potential harmonic problem caused by thyristors. To control the proposed TCIMN, the dynamic impedance identification is applied to match the load reactive power adaptively. Finally, the simulation and experimental results of a prototype are given to demonstrate the validity of the proposed TCIMN, analysis, and control method. The results clearly show that the proposed TCIMN can adaptively match the load impedance for the different loads and broadband frequency range. More importantly, the power amplifier power utilization factor is significantly improved without causing harmonic pollutions. [ABSTRACT FROM AUTHOR]

The urban rail transit system has the characteristics of wide voltage fluctuation, intermittent and strong impact load, limited heat dissipation capacity. The high-speed flywheel energy storage system (FESS) is used to provide network voltage stability and regenerative braking energy recovery due to its high power density, unlimited number of charge-discharge cycles, fast response and environmental friendliness. When considering the design of high-speed FESS converter with 3.6 kHz fundamental frequency and 330 kW rated power used in 1500 VDC urban rail transit system, the two-stage topological converter reduces the efficiency and increase the cost and size, meanwhile, the series-connected converters and the multilevel converter increase the difficulties of control and insulation, so the two-level and I-type three-level converters of high-speed FESS are designed and evaluated. Several comparisons are made by detailed experimental data from the perspective of the traction load characteristics of the 1500 VDC urban rail transit system and the technical and economical requirements of the high-speed FESS. It is found that the three-level converter has significant advantages in matching the traction load characteristics for its higher duty cycle capability, as well as improving the technical and economical performances such as efficiency, du/dt value, THD, voltage stability, and reducing the cost by 40% when compared to the two-level converter. While in the future MW class high-speed FESS development, the maximum output power capacity of the three-level FESS is relatively lower than that of the two-level FESS. The theoretical analyses were verified by experiments. [ABSTRACT FROM AUTHOR]

Silica hollow microspheres with moonscape-like rough surface (RS) and macroporous surface (MS) have been controllably synthesized by a water–oil–water three-phase emulsion method, which are used as supports of the heterogeneous catalysts for the catalytic hydrogenation of nitrile-butadiene rubber (NBR). It is found that Pd can be uniformly dispersed on both amino-functionalized RS and MS supports and both the catalysts show high hydrogenation activity with 100% selectivity to C=C bonds. However, the reusability of Pd/N-RS is much better than that of Pd/N-MS, maintaining 92% of activity without any regeneration treatment after five times of recycling experiment. The high activity retention is because the moonscape-like surface of the RS support is favorable for the contact of NBR macromolecules with the active sites, and more importantly, the NBR macromolecules do not need to diffuse into the interior of the catalyst, leading to fast desorption of the hydrogenated NBR from the surface of catalyst and re-exposure of the active sites. [ABSTRACT FROM AUTHOR]

Background: The safety assessment and control of stacked transgenic crops is increasingly important due to continuous crop development and is urgently needed in China. The genetic stability of foreign genes and unintended effects are the primary problems encountered in safety assessment. Omics techniques are useful for addressing these problems. The stacked transgenic maize variety 12–5 × IE034, which has insect-resistant and glyphosate-tolerant traits, was developed via a breeding stack using 12–5 and IE034 as parents. Using 12–5 × IE034, its parents (12–5 and IE034), and different maize varieties as materials, we performed proteomic profiling, molecular characterization and a genetic stability analysis. Results: Our results showed that the copy number of foreign genes in 12–5 × IE034 is identical to that of its parents 12–5 and IE034. Foreign genes can be stably inherited over different generations. Proteomic profiling analysis found no newly expressed proteins in 12–5 × IE034, and the differences in protein expression between 12 and 5 × IE034 and its parents were within the range of variation of conventional maize varieties. The expression levels of key enzymes participating in the shikimic acid pathway which is related to glyphosate tolerance of 12–5 × IE034 were not significantly different from those of its parents or five conventional maize varieties, which indicated that without selective pressure by glyphosate, the introduced EPSPS synthase is not has a pronounced impact on the synthesis of aromatic amino acids in maize. Conclusions: Stacked-trait development via conventional breeding did not have an impact on the genetic stability of T-DNA, and the impact of stacked breeding on the maize proteome was less significant than that of genotypic differences. The results of this study provide a theoretical basis for the development of a safety assessment approach for stacked-trait transgenic crops in China. [ABSTRACT FROM AUTHOR]

In the natural world, insects such as bees and sand ants can navigate with the aid of polarized skylight. Inspired by this, bio-inspired navigation systems based on polarized skylight have attracted considerable attention recently. As an important navigation parameter, attitude information is critical for control and navigation of a vehicle. In this paper, the structural characteristics of full-sky atmospheric polarization mode are studied to calculate the attitude of a vehicle relative to the observation point. The heading angle is obtained by subtraction between two angles. One is the angle between the solar meridian and the geographic north. The other is the angle between the solar meridian and the body coordinate system, which can be obtained from the polarization data detected by the sensor. And the solar position can also gain from the polarization data. Then based on the solar position and the coordinates of solar projection point, the zenith point can be determined. With the coordinates of the zenith point in the body and the reference coordinate system, the pitch angle and roll angle are solved. Simulation and practical experiments are conducted to validate the performance of the attitude calculation method. Experiment results with high accuracy show its feasibility and effectiveness. [ABSTRACT FROM AUTHOR]