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Aims This study aimed to isolate and identify entomopathogenic fungi (EPF) from fungus-infected Ostrinia furnacalis larvae, screen their bio-efficacy against O. furnacalis, and select the most suitable virulent native EPF for biocontrol agent development. Methods and Results The occurrence of EPF isolated from various maize production regions in Xinjiang was investigated. Of 13,864 O. furnacalis cadavers surveyed, 536 were selected, and of 136 fungal specimens collected, 14 species were identified. Four fungal isolates were highly pathogenic to O. furnacalis: Aspergillus sp., Lecanicillium attenuatum, Beauveria bassiana and Penicillium polonicum. The Aspergillus sp. was the most abundant (42.25% distribution frequency). Bioassay results revealed that it was as pathogenic as B. bassiana (positive control), with 96.58% lethality against O. furnacalis (LC50: 1.40 × 104 conidia ml−1, LT50: 3.41 days). Through morphological examination and rDNA-benA and rDNA-CaM homogeneity analyses, the isolate was identified as Aspergillus nomius. Conclusions Four EPF species were highly pathogenic, with A. nomius being the most prevalent in Xinjiang. A. nomius is a potential biocontrol agent. Significance and Impact of Study For sustainable prevention and control of O. furnacalis infestation, identifying biocontrol agents with high virulence against O. furnacalis is crucial. The findings of this study support the development of EPF-based biocontrol approaches.

In this study, B4C–SiC–rGO composites with different SiC contents were prepared by spark plasma sintering at 1800 °C for 5 min under a uniaxial pressure of 50 MPa. The effects of SiC on the microstructures and mechanical properties of the B4C–SiC–rGO composites were investigated. The optimal values for flexural strength (545.25 ± 23 MPa) and fracture toughness (5.72 ± 0.13 MPa·m1/2) were obtained simultaneously when 15 wt.% SiC was added to 5 wt.%–GO reinforced B4C composites (BS15G5). It was found that SiC and rGO inhibited the grain growth of B4C and improved the mechanical properties of the B4C–SiC–rGO composites. The clear and narrow grain boundaries of rGO–B4C and rGO–SiC, as well as the semi-coherent B4C–SiC interface, indicated strong interface compatibility. The twin structures of SiC and B4C observed in the composites improved their fracture toughness. Crack deflection and crack bridging caused by the SiC grains as well as rGO bridging and rGO pull-out were observed on the crack propagation path.

Monolithic B4C, B4C–TiB2, and B4C–TiB2–graphene nanoplatelets (GNPs) were fabricated by hot pressing (HP) at 1900 °C for 1 h under an axial pressure of 30 MPa. The microstructures and mechanical and electrical properties of the B4C composites were investigated. The results show that the GNPs are distributed homogeneously in B4C-based ceramic composites. Compared with monolithic B4C, the TiB2–GNPs-containing B4C composite exhibits an approximately 68 % increase in flexural strength and a 169 % increase in fracture toughness due to the synergistic effects of TiB2 particles and GNPs. The toughening mechanisms mainly include TiB2 crack deflection, crack branching, transgranular fracture and GNPs crack deflection, crack bridging, and GNPs pull-out. Additionally, the electrical conductivity of the B4C composite reinforced with dual fillers is three orders of magnitude higher than that of monolithic B4C due to the establishment of a conductive network. The addition of GNPs can efficiently connect the isolated conductive TiB2 particles in the B4C matrix and provides an additional channel for electron migration.

High-resistance connections (HRC) in permanent magnet synchronous motor (PMSM) drive system is a precursor of uncontrollable overheating or fire. However, the current HRC test environment is typically founded on fixed resistors and lacks the capability to simulate the dynamic characteristics of real-world HRC faults in a manner of stepless regulation. To fill the gap, a flexible HRC injection strategy is proposed in this paper. This signal is stimulated by a high-frequency equivalent circuit regulated by closed-loop hardware feedback mechanism, which is then integrated into a self-developed HRC dynamic test system. Meanwhile, to reduce dependence on online resources, a rapid online diagnosis method for detecting HRC in PMSM is proposed. Based on the two-phase current, the negative-sequence currents are calculated and subjected to Fast Fourier Transform analysis, fulfilling the requirements of low computational burden and real-time performance. Furthermore, the fault indicators derived from the mathematical model of PMSM in abc framework are established to detect the HRC fault, obviating the need for additional voltage sensors. Finally, various experiments are conducted under different loads and rotational speeds. The experimental results show that the proposed simulation system can solve the problems of HRC simulation with quick responses, continuous control, and high robustness in high-power circuits. The results also prove that the proposed diagnosis method can not only effectively detect the location of HRC, but also can precisely calculate the resistance.

Invasive alien species are generally highly fertile and adaptable and can pose a severe threat to the ecological security of invaded localities. Bemisia tabaci (Gennadius) is a rapidly evolving cryptic complex. Among them, Mediterranean (MED) and Middle East–Asia Minor 1 (MEAM1) is the most invasive and widely distributed. To clarify the invasion source, population structure, and genetic differentiation drivers of whitefly populations in Xinjiang, China, we collected B. tabaci from 14 host crops in Xinjiang, China. A total of 453 sequenced cytochrome c oxidase subunit I(COI) fragments were analysed. We used common methods and parameters of genetic analysis, such as phylogenetic analysis, haplotype diversity, and nucleotide diversity, neutrality testing, and mismatch distribution chart analysis to determine the genetic structure and genetic differentiation and explore the origin of the invasion of B. tabaci populations in Xinjiang. The results have shown that global MED and MEAM1 populations are genetically differentiated, and MED has a significant geographical lineage structure at the Xinjiang and global spatial scales. This was the same for the MEAM1 population at the Xinjiang spatial scale. There have been multiple local expansions and founder effects in the MED populations. The MEAM1 population has retained a stable population size with a bottleneck effect. Based on the phylogenetic tree for MED and MEAM1, it has been demonstrated that there have been multiple points and pathways of invasion of B. tabaci and the sources in Xinjiang, China were complex. The sources of MED invasion of MED are likely to be Zhejiang, Hebei, or Shanxi. The source for MEAM1 is complex, and Zhejiang is one of the main invasion sources. This study has shown that host plant differences in open habitats, geographic isolation, and habitat differences were the driving factors for genetic differentiation of B. tabaci populations in Xinjiang, China

Colorado potato beetle (CPB; Leptinotarsa decemlineata) is a destructive quarantine pest that develops broad physiological adaptations to potato plants. During feeding, CPB deposits a copious amount of wet frass onto the surface of leaves and stems that remains in place for long periods. Insect behaviors such as feeding, crawling and oviposition are able to mediate plant defenses. However, the specific role of CPB defecation-associated cues in manipulating plant defenses remains unclear.CPB larval frass significantly suppressed potato polyphenol oxidase activity and enhanced larval growth on treated potato plants. The incorporation of antibiotics into larval frass triggered higher jasmonic acid (JA)-regulated defense responses in potato plants compared with antibiotic-free frass. Four bacterial symbionts belonging to the genera Acinetobacter, Citrobacter, Enterobacter and Pantoea were isolated from larval frass and suppressed plant defenses. After reinoculation of these bacteria into axenic larvae, Acinetobacter and Citrobacter were found to be highly abundant in the frass, whereas Enterobacter and Pantoea were less abundant probably due to the negative effect of potato steroidal glycoalkaloids (SGA) such as α-solanine. Furthermore, direct application of Acinetobacter and Citrobacter to wounded potato plants significantly inhibited the expression of genes associated with the JA-mediated defense signaling pathway and SGA biosynthesis.Our findings demonstrate that CPB exploits frass-associated bacteria as a deceptive strategy of plant defense suppression, adding an interesting dimension to our understanding of how CPB successfully specializes on potato plants. © 2022 Society of Chemical Industry.

Dense tantalum carbide (TaC) ceramics were prepared using TaC nanopowder via spark plasma sintering (SPS). The effects of the sintering temperature and applied pressure on the densification and grain growth behaviour of TaC ceramics were investigated. The results showed that high temperature and pressure promoted sintering densification, while their increase caused an increase in the grain size of TaC ceramics. A highly dense TaC ceramic (∼97.19%) with a fine grain size of 2.67 μm was obtained by sintering at 1800 °C for 10 min under 80 MPa. The Vickers hardness, Young's modulus and fracture toughness were 15.60 GPa, 512.66 GPa and 3.59 MPa·m1/2, respectively. The densification kinetics were investigated using a creep deformation model. Diffusion and grain boundary sliding were proven to be the dominant densification mechanisms based on the stress and grain size exponents combined with the microstructural characteristics. The apparent activation energy of the mechanism controlling densification was 252.94 kJ/mol.

TiB2-BN composite ceramics combine excellent electrical conductivity, thermal shock resistance, high-temperature resistance, corrosion resistance, and easy processing of TiB2 and BN. However, in practical applications, their high-temperature oxidation resistance is poor and the resistivity distribution is uneven and changes substantially with temperature. A TiB2-BN-SiC composite ceramic with stable and controllable resistivity was prepared by introducing SiC into the TiB2-BN composite ceramics. In this work, spark plasma sintering (SPS) technology was used to prepare TiB2-BN-SiC composite ceramics with various TiB2-SiC ratios and sintering temperatures. The samples were tested by XRD, SEM, and thermal and mechanical analysis. The results show that as the volume ratio of TiB2-SiC was increased from 3:1 to 12:1, the resistivity of the sample decreased from 8053.3 to 4923.3 μΩ·cm, the thermal conductivity increased from 24.89 to 34.15 W/(m k), and the thermal expansion rate increased from 7.49 (10−6/K) to 10.81 (10−6/K). As the sintering temperature was increased from 1650 to 1950 °C, the density of the sample increased, the mechanical properties were slightly improved, and the resistivity, thermal expansion rate, and thermal conductivity changed substantially. The volume ratio and sintering temperature are the key factors that control the resistivity and thermal characteristics of TiB2-SiC-BN composite ceramics, and the in situ from liquid phases of FeB and FeO also promotes the sintering of the TiB2-BN-SiC ceramics.

B4C–TiB2 ceramic composites were fabricated by a two-step method. First, B4C–TiB2 composite powders were synthesized from TiC–B powder mixtures at 1400 ℃, then mixed with commercial B4C powders by ball milling and the B4C–TiB2 ceramic composites were prepared by hot pressing at 1950 ℃. This two-step method not only effectively refined TiB2 grains, but also allowed the composition of the composites to be freely designed. The microstructure and mechanical properties of the composites were investigated. The results showed that the B4C–TiB2 ceramic composite with a 10 wt% TiB2 content obtained the ideal comprehensive performance, with a volume density, Vickers hardness, bending strength, and fracture toughness of 2.61 g/cm3, 35.3 GPa, 708 MPa, and 5.82 MPa m1/2, respectively. The advantages of the in-situ reaction process were fully exerted by the two-step method, which made a remarkable contribution to the excellent properties of B4C–TiB2 ceramic composites.

High-performance and fine-grained TiB2–SiC composite ceramics were fabricated via hot pressing with ball-milled TiB2 powder doped with SiC. The final product was densified at a relatively low sintering temperature of 1850 °C and brief soaking time of 30 min. The effects of ball milling on TiB2 powder composition and densification behavior, mechanical properties, and microstructures of the ceramic composites were investigated. TiO2 and B2O3 in the raw material were converted to SiO2 via reactions with SiC and Si3N4, thereby forming liquid phases to promote densification. A longer milling time resulted in a small TiB2 grain size. The relative density, Vickers hardness, flexural strength, and fracture toughness of the fabricated TiB2–SiC composites reached 99.0% ± 0.3%, 24.25 ± 1.10 GPa, 647 ± 30 MPa, and 6.43 ± 0.15 MPa m1/2, respectively. The primary toughening mechanisms in the composites were crack deflection, partial crack branching, and crack bridging.

Background Matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) are involved in the pathological mechanism of osteonecrosis of the femoral head (ONFH). This study aimed to investigate the relationship between serum MMP-9, TIMP-1, and MMP-9/TIMP-1 ratio and disease severity in patients with nontraumatic ONFH. Methods An enzyme-linked immunosorbent assay (ELISA) was used to measure Serum levels of MMP-9 and TIMP-1 in 102 patients with ONFH and 96 healthy individuals and 16 FICAT stage 2 patients undergoing vascularized iliac grafting in the postoperative period (1 week ,1 month, 2 month, and 3 month) Results The serum MMP-9 levels and the MMP-9/TIMP-1 ratio were significantly increased in patients with ONFH compared to normal controls, and TIMP-1 levels did not differ between the two groups. Serum MMP-9 levels and MMP-9/TIMP-1 ratio were positively correlated with FICAT stage and VAS, and negatively correlated with HHS score. Compared with the preoperative period, patients with vascularized iliac grafting had lower VAS scores, higher HHS scores, and significantly lower serum MMP-9/TIMP-1 ratios.ROC curve analysis indicated that decreased serum MMP-9/TIMP-1 ratio could be a decent biomarker with regard to monitoring improved condition in patients with ONFH after vascularized iliac grafting. Conclusions We hypothesize that increased MMP-9 expression and imbalance in the MMP-9/TIMP-1 ratio play a role in the development of ONFH and correlate with the severity of ONFH. measurement of MMP-9 and MMP-9/TIMP-1 can be a useful tool in order to evaluate the bone remodelling processes after vascularized iliac grafting in patients with ONFH.

All-solid-state batteries (ASSBs) have been considered as the next generation of lithium-ion batteries. Physics-based models have the advantage of providing internal electrochemical information. To promote physics-based models in real-time applications, in this study, a series of model reduction methods are applied to obtain a reduced-order model (ROM) for ASSBs. First, analytical solutions of the partial differential equations (PDEs) are derived by the Laplace transform. Then, the Pade approximation method is used to convert the transcendental transfer functions into lower order fractional transfer functions. Next, the concentration distributions in electrodes and electrolytes are approximated by parabolic and cubic functions, respectively. Due to the fast calculation of concentration distributions in real time, the equilibrium potential, overpotentials, and battery voltage can now be directly calculated. Compared with the original PDE-based model, the voltage errors of the proposed ROM are less than 2.6 mV. Compared with the voltage response of experimental data, a good agreement can be observed for the ROM under three large C-rates discharging conditions. The calculation time of ROM per step is within 0.2 ms, which means that it can be integrated into a battery management system. The proposed ROM achieves excellent performance and a better tradeoff between model fidelity and computational complexity.

Under the current background of the national standard requirements for electric vehicle remote management and the companies’ needs for their digital platform services, automobile factories habitually transmit battery data to a cloud in a sparse way for state of health (SOH) estimation. Compared with the dynamic discharge condition of the vehicle, the charging process has been noticed in recent years due to its relatively stable advantages. In this paper, a cloud-based SOH estimation method for lithium-ion batteries using sparse charging data is proposed. A HI feature that can be extracted from the sparse data is derived and only the constant voltage charging process is considered. By using the experimental data deployed on the cloud computing system, the correlation of battery health with the HI is verified and SOH can be efficiently estimated by taking as this feature an input to three data-driven methods. The results show that all methods can achieve a low test error of 2% under 10s sparsity, which is promising to be applied in cloud sparse charging conditions.

Pesticide resistance in pests drives the development of RNA interference (RNAi)-based technology as a novel approach for pest control. To investigate the effects of the positional dependency of double-stranded RNAs (dsRNAs), we newly designed four different 200 bp dsRNAs targeting Colorado potato beetle (CPB) β-Actin gene, termed as dsACT200-1 to dsACT200-4, to compare their insecticidal activity to CPB larvae together with our previously used 200 bp and 700 bp dsRNAs (dsACT200 and dsACT700), respectively (He et al., 2020a). Each of dsRNAs harbors different numbers of expected siRNAs predicted by sequence-based prediction platform, dsACT200 and dsACT200-2 have a relatively higher number of siRNA than other 200 bps dsRNAs. When CPB larvae were fed with in vitro synthesized dsRNA-painted potato leaves, all the tested dsRNAs showed significant effects to protect against CPB larvae. Combined with the survival rate of CPB larvae, β-Actin gene expression level and the surviving CPB larvae weight, various positional dsRNAs from the same allele showed different plant protection activity against CPB larvae and partially correlated with the predicted siRNA numbers and distribution on the target sequence. This study suggests the specific allelic locus for rational dsRNA design triggering RNAi efficiency for target gene silencing is an essential factor in enhancing the insecticidal activity.

In this study, TiN–TiB2–hBN composite ceramics were prepared via reactive hot pressing using TiN and amorphous B powders as raw materials. Different sintering temperatures and composition ratios were studied. The results show that the 70 vol% TiN–17.6 vol% TiB2–12.4 vol% hBN ceramic composites obtained ideal comprehensive properties at 1600 °C. The relative density, Vickers hardness, bending strength, and fracture toughness were 99%, 11 GPa, 521 MPa, and 4.22 MPa·m1/2, respectively. Densification was promoted by the highly active reaction product TiB2, and the structural defects formed in the grains. Meanwhile, the good interfacial bonding between TiN and TiB2 grains and the uniform dispersion of ultrafine hBN in the matrix contributed to the excellent bending strength. Moreover, the toughening mechanism of crack deflection and grain pull-out improved the fracture toughness.

Colorado potato beetle (CPB; Leptinotarsa decemlineata) has been detected in Xinjiang, China, since 1993 and has caused serious damage to potato production during its eastward expansion to new geographic ranges. Symbiotic bacteria often play an essential role for insects to exploit novel food sources and expand into otherwise inaccessible ecological niches. An important yet unresolved question is whether herbivore populations from different geographic ranges have distinct or equal abilities to adapt to plant-induced defenses. We examined whether two geographic CPB populations collected from Urumqi and Ili varied in triggering induced defenses in potato plants, and the results demonstrated that plants damaged by Ili CPB larvae showed higher levels/activities of the defensive protein polyphenol oxidase (PPO) than those damaged by Urumqi CPB larvae. Intriguingly, application of oral secretions (OS) from Ili CPB larvae triggered higher PPO activity in potato compared with the treatments by OS collected from Urumqi larvae. Moreover, higher counts of bacterial colonies were observed in Urumqi CPB larvae by traditional culturing and quantitative PCR. Comparing the gut bacterial composition of CPB individuals by 16S rRNA amplicon sequencing also revealed higher abundance and diversity of gut-associated bacteria in the Urumqi population than that in the Ili population. These results indicate that the gut bacteria of CPB larvae were geographically shaped during the process of invasion, which played an important role in mediating plant–insect interactions and possesses a great potential to drive further invasion.

Magnetization roasting and magnetic separation is an effective method of recovering iron from low-grade ores. The phase transformation mechanism of minerals is an important basis for optimizing technological parameters. In this study, biomass was used as a reducing agent to roast Baotou low-grade limonite in a high-temperature vacuum furnace. The phase transformation law and its influence on magnetic properties were studied via X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. The results show that roasting temperature is related to the magnetism of iron ore. With an increase in temperature, iron content increases gradually, and limonite magnetism also increases, at 700 °C reaching a maximum saturation magnetization of iron concentrate of 43.06 emu/g. It was also found that during vacuum roasting, S elements migrated and accumulated on the surface of limonite and distributed evenly on the surface of mineral particles in the form of FeS, forming ash shells.

Breast cancer remains the most commonly diagnosed cancer in Chinese women. Paclitaxel (PTX) is a chemotherapy medication used to treat breast cancer patients. However, a side effect of paclitaxel is the severe drug resistance. Previous studies demonstrated that dysregulation of microRNAs could regulate sensitivity to paclitaxel in breast cancer. Here, the present study aimed to lucubrate the underlying mechanisms of miR-107 in regulating the sensitivity of breast cancer cells to PTX. The results demonstrated that miR-107 was down-regulated in breast cancer tumor tissues, while TPD52 was significantly up-regulated compared with the non-tumor adjacent tissues. After confirming that TPD52 may be a major target of miR-107 via a dual-luciferase reporter assay, the western blot and RT-qPCR assays further demonstrated that miR-107 may reduce the expression level of TPD52 as well. In addition, miR-107 may prominently enhance PTX induced reduction of cell viability and the promotion of cell apoptosis in breast cancer, and the variation could be reversed by co-transfected with pcDNA3.1-TPD52. Finally, miR-107 could further reduce the decreased expression of TPD52, Wnt1, β-catenin and cyclin D1 that was induced by PTX in both mRNA and protein levels, which were rescued by pcDNA3.1-TPD52 indicating that miR-107 regulated breast cancer cell sensitivity to PTX may be targeting TPD52 through Wnt/β-catenin signaling pathway.

RNA interference (RNAi) has been developed for plant pest control. In this study, hairpin-type double-stranded RNA (dsRNA) targeting the juvenile hormone (JH) acid methyltransferase ( JHAMT) gene ( dsJHAMT) was introduced in potato plants via Agrobacterium-mediated transformation. The results indicated that the transcriptional RNA of dsJHAMT accumulated in the transgenic plants. The transcripts and proteins of the L. decemlineata JHAMT gene were significantly reduced in larvae feeding on dsJHAMT transgenic foliage. The dsJHAMT had a significant negative effect on the growth and development of L. decemlineata, especially resulting in less oviposition. Importantly, in the field trials, transgenic plants are high-efficiently protected from insect damage mainly because surviving insects laid fewer or no eggs. Even full protection from beetle damage can be acquired by continuously lowering insect population size at large scale in the field over the years. Therefore, the transgenic plants expressing dsJHAMT successfully provided an additional option for plant pest control.

In cold regions, the soil freezing always restricts the application of ground source heat pump. The aim of this study is to develop a numerical model to simulate the soil freezing course and investigate the characteristics of soil freezing and associated pipe deformation. Meanwhile, the influence of initial pipes center distance on pipe-soil structure is discussed. It can be found that the ice content and soil compressive stress show asymmetric distributions near the U-pipe. The soil freezing can lead to the pipe deformation and displacement. Smaller initial pipe center distance can lead to more asymmetric and larger soil compressive action on the pipes.

Accurate prediction of the battery remaining useful life (RUL) at different operating conditions is critical for the battery management system to guarantee safe and efficient operation. However, because of the complicated degradation mechanisms inside the battery, it is extremely challenging to predict the battery life by measuring the external variables. Due to the sparse and random segment data in practical applications, the existing methods are difficult to be applied for online prediction. In this paper, a hybrid parallel residual convolutional neural networks (HPR CNN) model for RUL prediction is proposed. By fusing the charging data of voltage, current and temperature curves in multiple cycles, the hidden feature information of different depths is effectively extracted through the residual network. Based on the sparse data corresponding to only 20% charging capacity, combined with a cloud computing system, this method is able to achieve online prediction in various practical applications. By calculating the difference between each cycle as supplementary input data, the method is able to predict the RUL of a battery with high accuracy and reliability. Validated by a public data set and compared with other methods, the proposed method achieves a low test error of 4.15%, which is promising to be applied in the conditions of random charging process.

A novel tooth surface design method of face-hobbed spiral bevel gears is proposed, which utilizes a solid cutter without axis tilting through tool path control combining with optimized cutter blade profile to control tooth contact patterns and realize tooth lengthwise chamfering. Firstly, a gear tooth surface generating plan of tool path controlling actively is developed, the mathematical model of the tool path is built, and the equations are given in detail, the determination method of all control parameters is also described. Next, the tooth surface functions of generating gear and machined gear are established based on a mathematic model of the traditional cradle machine tool. Then, the machine setting is also given in concise equations. Finally, the tooth contact analysis is also conducted for a specific gear pair to validate the validity and the reasonability of the new tooth modification method.