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High-energy ultrasonic controlling Al-KBF4-K2ZrF6 reaction system was used to prepare ZrB2/AA6016 nanoparticle-reinforced aluminum matrix composites (PRAMC). Microstructural observations revealed that acoustic fluidic cavitation promoted the collapse and dispersion of nano-clusters. The plateau of the hardening curve indicates that ultrasonic treatment can improve the plasticity and toughness of the composite. Under 250 °C-70MPa, the apparent stress exponents of the matrix alloy, 3wt% ZrB2/AA6016 and 3wt% ultrasonic-assisted ZrB2/AA6016 composites are 7.34, 9.37, 12.62, respectively. The apparent activation energies are 165.20kJ/mol, 178.83kJ/mol and 215.33kJ/mol, respectively. According to the linear correlation coefficient, the true stress index of the composite material is determined to be 5, which indicates that the creep mechanism of the composite material is the dislocation climbing mechanism. Creep fracture analysis showed that the nano-ZrB2 particles can effectively hinder the propagation of cracks, and ultrasonic treatment can effectively alleviate the stress concentration defects caused by nano-clusters. [ABSTRACT FROM AUTHOR]

Riboswitches are functional RNA elements that regulate gene expression by directly detecting metabolites. Twenty years have passed since it was first discovered, researches on riboswitches are becoming increasingly standardized and refined, which could significantly promote people's cognition of RNA function as well. Here, we focus on some representative orphan riboswitches, enumerate the structural and functional transformation and artificial design of riboswitches including the coupling with ribozymes, hoping to attain a comprehensive understanding of riboswitch research. [ABSTRACT FROM AUTHOR]

The heat pipe cooled reactor (HPR) has a multi-purpose application prospect due to its significant advantages such as simple system, compact structure, high inherent safety, etc. It is one of the best chooses for the power supply of new strategic weapons. However, the heat pipe reactor technology is still in its infancy, and the technical feasibility remains to be verified. This paper proposes a dual-mode heat pipe reactor concept design that combines dynamic thermoelectric conversion and static thermoelectric conversion, an integrated experimental device of “Core matrix-heat pipe-Stirling-thermoelectric power generation” was established, which utilized red copper matrix and heating rod to simulate the reactor core, utilized bending high-temperature potassium heat pipes to cool the core and transform the energy, utilized Stirling generators and bismuth telluride thermoelectric modules to realize dynamic and static thermoelectric conversion processes. Before the construction and experiment of the prototype, the pre-experiment of each important module was carried out. This research completed the development and test of bending high-temperature potassium heat pipes, the test of static thermoelectric conversion module and the test of dynamic thermoelectric conversion module. K-type thermocouple was used for experimental temperature measurement, and the error was less than 3 ℃. The relative uncertainty of temperature caused by thermocouple was within 3.0%. Voltmeter and ammeter with uncertainty of ±0.1 V and ±0.1 A were used to measure voltage and current, and the relative uncertainty of heat transfer power caused by instrument was within 2.5%. The results show that the developed bending high-temperature potassium heat pipe meets the design requirements. When the heating power is 878 W, the axial wall temperature difference of the heat pipe is less than 60 K, and the length of the non-condensable gas section is less than 5 cm. When the input power is 4.2 kW and the inlet cooling water temperature is 20 ℃, the hot side temperature of thermoelectric modules is 310 ℃. The power generation of 30 thermoelectric chips in 5 groups is 102.6 W, the thermoelectric conversion efficiency is 2.44%. When the heating power is 3.3 kW, the generation power of Stirling module is 429 W and the thermoelectric conversion efficiency is 13.1%. After the improvement, when the input power is 3 047.2 W, the average temperature of the evaporation section of the heat pipe is 627 ℃, the average temperature of Stirling hot end is 475.3 ℃, the temperature difference from heat pipe evaporation section to condensation section is 74 ℃, the temperature difference from heat pipe condensation section to Stirling hot end is 76 ℃, the generating power of a single Stirling energy conversion device is 673 W, and the overall thermoelectric conversion efficiency is 22.1%.

Xylose, the major component of lignocellulosic biomass, cannot be naturally or efficiently utilized by most microorganisms. Xylose (co)utilization is considered a cornerstone of efficient lignocellulose-based biomanufacturing. We evolved a rapidly xylose-utilizing strain, Cev2-18-5, which showed the highest reported specific growth rate (0.357 h21) on xylose among plasmid-free Corynebacterium glutamicum strains. A genetically clear chassis strain, CGS15, was correspondingly reconstructed with an efficient glucose-xylose coutilization performance based on comparative genomic analysis and mutation reconstruction. With the introduction of a succinateproducing plasmid, the resulting strain, CGS15-SA1, can efficiently produce 97.1 g/L of succinate with an average productivity of 8.09 g/L/h by simultaneously utilizing glucose and xylose from corn stalk hydrolysate. We further revealed a novel xylose regulatory mechanism mediated by the endogenous transcription factor IpsA with global regulatory effects on C. glutamicum. A synergistic effect on carbon metabolism and energy supply, motivated by three genomic mutations (Psod(C131T)-xylAB, Ptuf(D21)-araE, and ipsAC331T), was found to endow C. glutamicum with the efficient xylose utilization and rapid growth phenotype. Overall, this work not only provides promising C. glutamicum chassis strains for a lignocellulosic biorefinery but also enriches the understanding of the xylose regulatory mechanism. [ABSTRACT FROM AUTHOR]

To improve the conical pick cutting performance by per cutting to the free surface. The cutting performance of rock and rock plate breaking are investigated by theoretical and experimental methods. Analyzed the fracture position of the rock plate with constrained one side by the pick to study the effect of rock properties and the rock plate structural parameters on cutting force. The results indicated that the rock plate fracture is mainly from the constrained side and center of the rock plate. The cutting force of the conical pick is significantly affected by the rock plate structural parameters and the constraint sides of the rock plate number. The cutting force increases obviously with the increase of plate thickness, cutting point depth, and the rock uniaxial compressive strength. However, the influence of rock plate constrains sides number is opposite. It provides a basis for improving the cutting performance of pick and predicting the rock plate fracture. [ABSTRACT FROM AUTHOR]

In the era of mobile Internet, a large number of APP users pay more attention to product experience and express their usage and suggestions through comments. Research on online comment data has become a hot topic, and user feedback from comments is conducive to APP evolution and upgrading. But comment mining for APP is in the ascendant. In this paper, a large number of user comment data are collected from 9 APP stores to screen the demand attributes and emotional tendencies contained in the comments. The KANO model is used for modeling and analysis, and the attributes are mapped to attractive quality, one-dimensional quality, must-be quality and other cate-gories. According to the KANO category of the APP attribute, a reasonable and effective update evolution strategy is proposed: the APP developers should give priority to meeting the requirements of one-dimensional quality and must-be quality, and gradually realize the requirements of attractive quality. Finally, this paper proves the robustness and portability of the method.

The article introduces a renewable alternative to traditional epoxy resin thermosets, focusing on recyclability. Topics discussed include the synthesis strategy, material properties, recyclability via methanolysis, and the potential for application in closed-loop recycling systems, emphasizing the importance of integrating thermosets into the circular and bio-based economy.

Phytophthora capsici causes significant losses to vegetable production worldwide. Pyrimorph, a new carboxylic acid amide fungicide, has been registered to control P. capsici in China. A mutation (Q1077K) in cellulose synthase 3 has been reported to confer resistance to pyrimorph. In this study, we measured the competition between pyrimorph-resistant and pyrimorph-sensitive isolates of P. capsici. Mixed zoospore suspensions of resistant (R) and sensitive (S) isolates at five ratios (1R:9S, 3R:7S, 5R:5S, 7R:3S, and 9R:1S) were applied to carrot agar in vitro test (with five successive transfers) and to the soil surface around pepper plants in planta test (with 10 successive disease cycles). The proportion of resistant isolates was measured by a conventional assay in which single zoospore isolates recovered after transfers or disease cycles were grown on agar medium with a discriminatory concentration of pyrimorph. The results were then compared with those of a real-time polymerase chain reaction (PCR)-based method developed here, the results were similar. Both assays showed that the competitive ability of the resistant isolates was similar to or less than that of the sensitive isolates. The real-time PCR assay developed will be useful for high-throughput analysis and monitoring the development of pyrimorph resistance in field populations of P. capsici. [ABSTRACT FROM AUTHOR]