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The combination of Al nanoparticles (ANPs) as fuel and H2O2 as oxidizer is a potential green space propellant. In this research, reactive force field molecular dynamics (ReaxFF-MD) simulations were used to study the influence of water addition on the combustion of Al/H2O2. The MD results showed that as the percentage of H2O increased from 0 to 30%, the number of Al-O bonds on the ANPs decreased, the number of Al-H bonds increased, and the adiabatic flame temperature of the system decreased from 4612 K to 4380 K. Since the Al-O bond is more stable, as the simulation proceeds, the number of Al-O bonds will be significantly higher than that of Al-H and Al-OH bonds, and the Al oxides (Al[O]x) will be transformed from low to high coordination. Subsequently, the combustion mechanism of the Al/H2O2/H2O system was elaborated from an atomic perspective. Both H2O2 and H2O were adsorbed and chemically activated on the surface of ANPs, resulting in molecular decomposition into free radicals, which were then captured by ANPs. H2 molecules could be released from the ANPs, while O2 could not be released through this pathway. Finally, it was found that the coverage of the oxide layer reduced the rate of H2O2 consumption and H2 production significantly, simultaneously preventing the deformation of the Al clusters’ morphology.

Laser processing platform for micro crystal resonator (MCR) frequency modulation is an important piece of equipment to apply laser etching technology to the MCR frequency modulation process. The positioning accuracy of the laser processing platform has an important influence on frequency modulation characteristics. In order to improve the precision and efficiency of the laser processing platform for MCR frequency modulation, the error model of the laser processing platform for MCR frequency modulation is established based on the multi-body system theory. According to the Monte Carlo simulation method, the influence of laser processing platform error for MCR on frequency modulation characteristics is analyzed. Considering the requirements of the MCR frequency modulation process, the laser processing platform for MCR frequency modulation is built, and the frequency deviation and frequency modulation performance are verified to meet the engineering requirements.

The adjustment of the natural frequency of a micro crystal resonator (MCR) is the key requirement in its manufacturing, which determines the actual performance of the product. Laser processing is a new method for MCR frequency modulation, and its process parameters directly affect the frequency modulation effect. Aiming at the laser processing equipment for MCR frequency modulation, the structure of the laser processing control system for MCR frequency modulation is designed by analyzing the requirements of a laser processing control system. The working flow of the laser processing control system for MCR frequency modulation is studied, the motion control method of the laser processing platform for MCR frequency modulation is proposed, and the laser processing control system for MCR frequency modulation is designed. By analyzing the laser characteristics for MCR frequency modulation, an orthogonal experiment is carried out to optimize the laser processing parameters for MCR frequency modulation.

The combination of Al nanoparticles (ANPs) as fuel and H[sub.2]O[sub.2] as oxidizer is a potential green space propellant. In this research, reactive force field molecular dynamics (ReaxFF-MD) simulations were used to study the influence of water addition on the combustion of Al/H[sub.2]O[sub.2]. The MD results showed that as the percentage of H[sub.2]O increased from 0 to 30%, the number of Al-O bonds on the ANPs decreased, the number of Al-H bonds increased, and the adiabatic flame temperature of the system decreased from 4612 K to 4380 K. Since the Al-O bond is more stable, as the simulation proceeds, the number of Al-O bonds will be significantly higher than that of Al-H and Al-OH bonds, and the Al oxides (Al[O][sub.x]) will be transformed from low to high coordination. Subsequently, the combustion mechanism of the Al/H[sub.2]O[sub.2]/H[sub.2]O system was elaborated from an atomic perspective. Both H[sub.2]O[sub.2] and H[sub.2]O were adsorbed and chemically activated on the surface of ANPs, resulting in molecular decomposition into free radicals, which were then captured by ANPs. H[sub.2] molecules could be released from the ANPs, while O[sub.2] could not be released through this pathway. Finally, it was found that the coverage of the oxide layer reduced the rate of H[sub.2]O[sub.2] consumption and H[sub.2] production significantly, simultaneously preventing the deformation of the Al clusters’ morphology.

The combination of Al nanoparticles (ANPs) as fuel and H O as oxidizer is a potential green space propellant. In this research, reactive force field molecular dynamics (ReaxFF-MD) simulations were used to study the influence of water addition on the combustion of Al/H O . The MD results showed that as the percentage of H O increased from 0 to 30%, the number of Al-O bonds on the ANPs decreased, the number of Al-H bonds increased, and the adiabatic flame temperature of the system decreased from 4612 K to 4380 K. Since the Al-O bond is more stable, as the simulation proceeds, the number of Al-O bonds will be significantly higher than that of Al-H and Al-OH bonds, and the Al oxides (Al[O] ) will be transformed from low to high coordination. Subsequently, the combustion mechanism of the Al/H O /H O system was elaborated from an atomic perspective. Both H O and H O were adsorbed and chemically activated on the surface of ANPs, resulting in molecular decomposition into free radicals, which were then captured by ANPs. H molecules could be released from the ANPs, while O could not be released through this pathway. Finally, it was found that the coverage of the oxide layer reduced the rate of H O consumption and H production significantly, simultaneously preventing the deformation of the Al clusters' morphology.

Design of power distribution networks (PDNs) in high speed digital circuit has become a more challenging task in view of decreasing supply voltages and increasing transient currents. The parasitic inductance of a PDN is the most crucial parameter that limits high frequency performance. In this paper, a specific PDN on printed circuit board (PCB), with multiple supply voltages, is diagnosed and optimized. A simple method is developed to extract the parasitic inductances of the PDN by examining the Y parameters. An equivalent lumped circuit model is built to interpret the input impedance curve of the PDN. Based on this model, a simpler circuit model is presented. Predictions based on the simple circuit model are in agreement with the field simulated performance of the whole structure and with measured results. The performance of the PDN can be improved by optimizing segmentation and distribution of power planes along with strategic placement of decoupling capacitors. It is crucial for PDN design to decrease the parasitic inductance between power/ground pads on PCB and their junction points to PDN power/ground pairs.

A fully differential transimpedance amplifier （TLA） with integrated differential photodetector in standard CMOS technologies has been realized for optical receivers in optical communications and optical interconnects. And a novel, fully differential photodetector aiming to convert the incident light into a pair of fully differential photo-generated currents and ensure the differential symmetry on circuit configuration and model has also been proposed for the differential TIA to achieve the fully differential characteristic. Theoretical analysis and simulation results both indicate that the fully differential TIA reaches a higher bandwidth than a conventional one and at the same time a doubled sensitivity. Based on this new TIA, a monolithic, fully differential optoelectronic integrated receiver was designed and implemented in a Chartered 3.3 V, 0.35 μm standard CMOS process. It demonstrates 98.75 dB~t transimpedance gain, and 0.334 μA equivalent input integrated referred noise current from 1 Hz up to -3 dB frequency. The power dissipation from a single 3.3 V supply is 100 mW for the TIA-LIA （limiting amplifier）-combination plus 138 mW for the 50 Ω output buffer. At 850 nm wavelength, the optical receiver achieves a 1.1 CHz 3 dB bandwidth, and can handle bitrates up to 1.6 Gbit/s for -12.2 dBm peak-peak optical power and 231-1 PRBS （pseudorandom bit sequency） input signal.

Innovations relating to the consumption of hard prey are implicated in ecological shifts in marine ecosystems as early as the mid-Paleozoic. Lungfishes represent the first and longest-ranging lineage of durophagous vertebrates, but how and when the various feeding specializations of this group arose remain unclear. Two exceptionally preserved fossils of the Early Devonian lobe-finned fish Youngolepis reveal the origin of the specialized lungfish feeding mechanism. Youngolepis has a radically restructured palate, reorienting jaw muscles for optimal force transition, coupled with radiating entopterygoid tooth rows like those of lungfish toothplates. This triturating surface occurs in conjunction with marginal dentition and blunt coronoid fangs, suggesting a role in crushing rather than piercing prey. Bayesian tip-dating analyses incorporating these morphological data indicate that the complete suite of lungfish feeding specializations may have arisen in as little as 7 million years, representing one of the most striking episodes of innovation during the initial evolutionary radiations of bony fishes. It is unclear how Lungfishes evolved durophagy, the consumption of hard prey, despite being the longest lineage of vertebrates with this feeding mechanism. Here, the authors describe exceptionally preserved fossils of Youngolepis from the Early Devonian, showing early adaptations to durophagy.

Both aquatic and terrestrial biodiversity information can be detected in riverine water environmental DNA (eDNA). However, the effectiveness of using riverine water eDNA to simultaneously monitor the riverine and terrestrial biodiversity information remains unidentified. Here, we proposed that the monitoring effectiveness could be approximated by the transportation effectiveness of land-to-river and upstream-to-downstream biodiversity information flows and described by three new indicators. Subsequently, we conducted a case study in a watershed on the Qinghai–Tibet Plateau. The results demonstrated that there was higher monitoring effectiveness on summer or autumn rainy days than in other seasons and weather conditions. The monitoring of the bacterial biodiversity information was more efficient than the monitoring of the eukaryotic biodiversity information. On summer rainy days, 43–76% of species information in riparian sites could be detected in adjacent riverine water eDNA samples, 92–99% of species information in riverine sites could be detected in a 1-km downstream eDNA sample, and half of dead bioinformation (the bioinformation labeling the biological material that lacked life activity and fertility) could be monitored 4–6 km downstream for eukaryotes and 13–19 km downstream for bacteria. The current study provided reference method and data for future monitoring projects design and for future monitoring results evaluation.

Toxoplasma gondii is a worldwide food-borne parasite that can infect almost all warm-blooded animals, including humans. To date, there are no effective drugs to prevent or eradicate T. gondii infection. Recent studies have shown that probiotics could influence the relationship between the microbiota and parasites in the host. Koumiss has been used to treat many diseases based on its probiotic diversity. Therefore, we explored the effect of koumiss on T. gondii infection via its effect on the host intestinal microbiota. BALB/c mice were infected with T. gondii and treated with PBS, koumiss and mares’ milk. Brain cysts were counted, and long-term changes in the microbiota and the effect of koumiss on gut microbiota were investigated with high-throughput sequencing technology. The results suggested that koumiss treatment significantly decreased the cyst counts in the brain ( P  < 0.05). Moreover, T. gondii infection changed the microbiota composition, and koumiss treatment increased the relative abundance of Lachnospiraceae and Akkermansia muciniphila , which were associated with preventing T. gondii infection. Moreover, koumiss could inhibit or ameliorate T. gondii infection by increasing the abundance of certain bacteria that control unique metabolic pathways. The study not only established a close interaction among the host, intracellular pathogens and intestinal microbiota but also provided a novel focus for drug development to prevent and eradicate T. gondii infection.