15 research outputs found

    Characteristics of transuranic nuclides incinerated in a small modular chloride fast reactor

    No full text
    BackgroundLiquid molten salt reactors that use chloride salts as fuel are characterized by the high solubility of heavy metals and a hard energy spectrum, hence are ideal for transmuting transuranic nuclides (TRU). A small modular reactor exhibits the characteristics of a modular design and construction, which is one of the future development directions for nuclear energy.PurposeThis study aims to investigate the TRU incineration characteristics of a small modular chloride fast reactor (sm-MCFR) that can be refueled online and applied to the disposal of TRU in nuclear waste produced by pressurized-water reactors.MethodsFirstly, a 50-MW sm-MCFR scheme was proposed, and its neutron properties, as well as the performance of TRU incineration, were explored using the Monca program TMCBurnup (TRITON MODEC Coupled Burnup Code), a combination of the SCALE 6.1 (Standardized Computer Analyses for Licensing Evaluation) and the high-precision point burn-up program MODEC (Molten Salt Reactor Specific DEpletion Code). Then, the analysis of critical parameters, burn-up evolution, and the transmutation efficiency of both TRU mixed with Depleted Uranium (DU) and TRU combined with 232Th were investigated, using a straightforward post-processing approach.ResultsThe findings of this study indicate that using TRU as fission fuel in the sm-MCFR requires the online addition of TRU. When the heavy metal balance is maintained, the effective multiplication factor (keff) is less than 1. Conversely, when the balance is not maintained, keff > 1, allowing continuous operation. When operating at full power for 40 years, the core's residual TRU content will be significantly higher than the initial fuel load, with 657 kg remaining for the TRU+Th mix and 725 kg for the TRU+DU mix. Notably, the sm-MCFR demonstrates efficient transmutation when TRU is added online without maintaining the heavy metal balance. Over 40 years at full power, the transmutation rates will be 41% for TRU+DU and 49% for TRU+Th, effectively reducing the production of long-lived small-actinide elements.ConclusionsThe sm-MCFR can effectively incinerate TRU and provide a feasible scheme for minimizing spent fuel

    Design and Implementation of a Real-Time Multi-Beam Sonar System Based on FPGA and DSP

    No full text
    Aiming at addressing the contradiction between the high-speed real-time positioning and multi-channel signal processing in multi-beam sonar systems, in this work we present a real-time multi-beam sonar system based on a Field Programmable Gate Array (FPGA) and Digital Signal Processing (DSP) from two perspectives, i.e., hardware implementation and software optimization. In terms of hardware, an efficient high-voltage pulse transmitting module and a multi-channel data acquisition module with time versus gain (TVG) compensation with characteristics such as low noise and high phase amplitude consistency, are proposed. In terms of algorithms, we study three beamforming methods, namely delay-and-sum (D&S), direct-method (DM) and Chirp Zeta Transform (CZT). We compare the computational efficiency of DM and CZT in the digital domain. In terms of software, according to the transmission bandwidth of the Gigabit Ethernet and a serial rapid IO (SRIO) interface, the data transmission paths of the acquired data and the beam pattern between the FPGA, the DSP, and a personal computer (PC) are planned. A master-slave multi-core pipelined signal processing architecture is designed based on DSP, which enhances the data throughput of the signal processor by seven times as compared with that of the single-core operation. The experimental results reveal that the sound source level of the transmitting module is around 190.25 dB, the transmitting beam width is 64° × 64°, the background noise of the acquisition module is less than 4 μVrms, the amplitude consistency error of each channel is less than −6.55 dB, and the phase consistency error is less than 0.2°. It is noteworthy that the beam number of the sonar system is 90 × 90, the scanning angle interval is 0.33°, the working distance ranges from 5 m to 40 m, and the maximum distance resolution is 0.384 m. In the positioning experiment performed in this work; the 3-D real-time position of the baffle placed in the detection sector is realized. Please note that the maximum deviation of azimuth is 2°, the maximum deviation of elevation is 2.3°, and the maximum distance deviation is 0.379 m

    Comparative Genomics of Three <i>Aspergillus</i> Strains Reveals Insights into Endophytic Lifestyle and Endophyte-Induced Plant Growth Promotion

    No full text
    Aspergillus includes both plant pathogenic and beneficial fungi. Although endophytes beneficial to plants have high potential for plant growth promotion and improving stress tolerance, studies on endophytic lifestyles and endophyte-plant interactions are still limited. Here, three endophytes belonging to Aspergillus, AS31, AS33, and AS42, were isolated. They could successfully colonize rice roots and significantly improved rice growth. The genomes of strains AS31, AS33, and AS42 were sequenced and compared with other Aspergillus species covering both pathogens and endophytes. The genomes of AS31, AS33, and AS42 were 36.8, 34.8, and 35.3 Mb, respectively. The endophytic genomes had more genes encoding carbohydrate-active enzymes (CAZymes) and small secreted proteins (SSPs) and secondary metabolism gene clusters involved in indole metabolism than the pathogens. In addition, these endophytes were able to improve Pi (phosphorus) accumulation and transport in rice by inducing the expression of Pi transport genes in rice. Specifically, inoculation with endophytes significantly increased Pi contents in roots at the early stage, while the Pi contents in inoculated shoots were significantly increased at the late stage. Our results not only provide important insights into endophyte-plant interactions but also provide strain and genome resources, paving the way for the agricultural application of Aspergillus endophytes

    Pharmacokinetics and Tissue Distribution of a Novel Bis-Chelated Gold(I) Diphosphine Compound, Bis(2,3-bis(tert-butylmethylphosphino)Quinoxaline)Aurate(I), in Rats

    No full text
    GC20, a novel soluble bis-chelated gold(I)&minus;diphosphine compound, has been reported as a promising anticancer candidate. Assessing the pharmacokinetic properties of GC20 is critical for its medicinal evaluation. First, a sensitive and specific liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed and well validated to determine GC20 in rat plasma and rat tissue homogenate after one step protein precipitation. Chromatographic separation was achieved on an Angilent ZORBAX-C18 column (3.5 &mu;m, 2.1 &times; 50 mm) with gradient elution and mass spectrometry was performed on a triple quadrupole in positive ion mode using an electrospray ionization source. This method was then applied to investigate the pharmacokinetics and tissue distribution of GC20 in rats after intravenous administration. The results showed that the plasma exposure of GC20 in vivo increased with increasing doses after a single dose. However, after multiple doses, a significant accumulation and a saturation at elimination were observed for GC20 in rats. Moreover, after intravenous administration, GC20 was widely distributed in various tissues, with the highest levels in the lung, spleen, liver, and pancreas, followed by the kidney and heart, while the lowest level was found in the brain. This is the first report on the pharmacokinetic properties of GC20

    Targeted delivery of microRNA 146b mimic to hepatocytes by lactosylated PDMAEMA nanoparticles for the treatment of NAFLD

    No full text
    <p>Non-alcoholic fatty liver disease (NAFLD) is one of the most common chronic liver diseases worldwide, and precision therapeutic will be a benefit for the NAFLD regression. In this study, we observed low microRNA 146 b (miR-146 b) expression in NAFLD mice model induced by methionine–choline-deficient diet (MCD) compared with control group. Furthermore, miR-146b<sup>−/−</sup> mice induced MCD exhibited severe liver steatosis and hepatitis. A bio-distribution study showed that novel Lactosylated PDMAEMA nanoparticles effectively targeted hepatocytes Lac-PDMAEMA. We coupled miR-146b mimic with Lac-PDMAEMA and then were administrated to NAFLD mice model, which could obviously alleviate the hepatic steatosis. Lac-PDMAEMA effectively delivered miR-146b mimic to hepatocytes with a ∼8-fold upregulation of miR-146b mimic targeting MyD88 and IRAK1, and in turn suppressed the expression of PPARγ. Meanwhile, TNF-α and IL-6 mRNA levels were decreased after administration of Lac-PDMAEMA/miR-146b mimic. So, we made a conclusion that targeted delivering miR-146b mimic to the hepatocytes by, coupling Lac-PDMAEMA nanoparticles could effectively alleviate the hepatic steatosis in NAFLD mice, which maybe bring a new and effective way to intervene and therapy the NAFLD.</p

    Efficient Deep-Blue Electrofluorescence with an External Quantum Efficiency Beyond 10%

    No full text
    Summary: The design of blue fluorescent materials combining both deep-blue emission (CIEy<0.06) and high-efficiency climbing over the typically limited exciton production efficiency of 25% is a challenge for organic light-emitting diodes (OLEDs). In this work, we have synthesized two blue luminogens, trans-9,10-bis(2-butoxyphenyl)anthracene (BBPA) and trans-9,10-bis (2,4-dimethoxyphenyl)anthracene with high photoluminescence quantum yields (PLQYs) of 89.5% and 87.0%, respectively. Intriguingly, we have proposed a strategy to avoid aggregation-caused quenching, which can effectively reduce the undesirable excimeric emission by introducing two host matrices with twisted molecular structure, 9,10-di(naphth-2-yl) anthracene and 10,10′-bis-(4-fluorophenyl)-3,3′-dimethyl-9,9′-bianthracene (MBAn-(4)-F), in the BBPA emission layer. The device containing the EML of BBPA-doped MBAn-(4)-F exhibited a high external quantum efficiency of 10.27% for deep-blue emission with the Commission International de L'Eclairage CIE coordinates of (0.15, 0.05) via the steric effect. Importantly, this represents an advance in deep-blue-emitting fluorescent OLED architectures and materials that meet the requirements of high-definition display. : Materials Science; Polymers; Optical Materials Subject Areas: Materials Science, Polymers, Optical Material
    corecore