Search

In the field of rail transit, vehicle intelligent operation and maintenance system uses various big data technologies to realize real-time calculation and analysis of vehicle status data. With status monitoring and fault warning, the system guides the maintenance of key equipments, and effectively improves the work efficiency of vehicle operation and maintenance personnel. However, data flood occurs due to the instability of network communication environment between vehicle and ground system, resulting in performance bottleneck when big data computing framework uses the general configuration. This paper makes an in-depth analysis on the causes of the performance bottleneck, and proposes an optimization method based on the user-defined Kafka partition strategy and the optimization of Spark Streaming processing parameters. Data of different vehicles is written to different Kafka partitions, and the rate at which the Spark Executor reads data from Kafka is controlled. Actual project application results show that this method can effectively solve the problem of performance bottleneck when the processing rate of streaming data cannot keep up with the reading rate in the data flood scenario.

Doping narrow‐gap semiconductors is a well‐established approach for designing efficient thermoelectric materials. Semiconducting half‐Heusler (HH) and full‐Heusler (FH) compounds have garnered significant interest within the thermoelectric field, yet the number of exceptional candidates remains relatively small. It is recently shown that the vacancy‐filling approach is a viable strategy for expanding the Heusler family. Here, a range of near‐semiconducting Heuslers, TiFexCuySb, creating a composition continuum that adheres to the Slater‐Pauling electron counting rule are theoretically designed and experimentally synthesized. The stochastic and incomplete occupation of vacancy sites within these materials imparts continuously changing electrical conductivities, ranging from a good semiconductor with low carrier concentration in the endpoint TiFe0.67Cu0.33Sb to a heavily doped p‐type semiconductor with a stoichiometry of TiFe1.00Cu0.20Sb. The optimal thermoelectric performance is experimentally observed in the intermediate compound TiFe0.80Cu0.28Sb, achieving a peak figure of merit of 0.87 at 923 K. These findings demonstrate that vacancy‐filling Heusler compounds offer substantial opportunities for developing advanced thermoelectric materials. [ABSTRACT FROM AUTHOR]

As a new class of fluorescent carbon materials, graphene quantum dots (GQDs) have attracted tremendous attention due to their outstanding properties and potential applications in biological, optoelectronic, and energy-related fields. Herein, top-down and bottom-up strategies for the fabrication of GQDs, mainly containing oxidative cleavage, the hydrothermal or solvothermal method, the ultrasonic-assisted or microwave-assisted process, electrochemical oxidation, controllable synthesis, and carbonization from small molecules or polymers, are discussed. Different methods are presented in order to study their characteristics and their influence on the final properties of the GQDs. The respective advantages and disadvantages of the methods are introduced. With regard to some important or novel methods, the mechanisms are proposed for reference. Moreover, recent exciting progresses on the applications of GQD, such as sensors, bio-imaging, drug carriers, and solar cells are highlighted. Finally, a brief outlook is given, pointing out the issues still to be settled for further development. We believe that new preparation methods and properties of GQDs will be found, and GQDs will play more important roles in novel devices and various applications.

Yield potential, plant height and flowering time are three classes of traits that determine the productivity of rice. Rice heading greatly depends on the accurate measurement of environment changes, particularly in day length and temperature. We discuss all genes reported to be related to the heading time in this review. The accumulation of florigen, such as Hd3a or RFT1, is the key factor for rice heading. Florigen is found in the rice leaf and then transports into the shoot apical meristem (SAM), where floral initiation occurs. We discuss the formation of florigen activation complex (FAC) with 14-3-3 and FD1 proteins to induce the expression of flowering genes. In addition, two key pathways related to heading date, GI-Hd1-Hd3a and Ghd7-Ehd1-Hd3a/RFT1 are introduced in this review. We summarize proteins with histone modification functions, due to the modification of histone is also significant for heading date. The flowering time also extremely dependent on the environments, including nutrient availability, abiotic and biotic stresses, we argue the phenotypes of rice heading date under different extreme environments, as well. Lastly, we gather genes that are reported having a change in heading time, but their detail molecular regulation is still elusive. Thus, this review introduces heading time systematically, providing knowledge and ideas for researchers to study further the phenotype of heading time. [ABSTRACT FROM AUTHOR]

Nickel (Ni) stress adversely affects plant growth and biomass accumulation, posturing severe menace to crop production and food security. The current study aimed to determine the putative role of sodium nitroprusside (SNP) in mitigating Ni‐induced phytotoxicity and identify the underlying defense mechanisms in maize, which are poorly understood. Our findings showed that SNP significantly augmented plant growth, biomass, and photosynthesis‐related attributes (Fv/Fm, Fm, qP ETR, and ΦPSII) through diminishing Ni uptake and translocation in root and shoot tissues of maize under Ni stress conditions. In parallel, exogenous SNP substantially relieved maize seedlings from Ni‐induced stress by enhancing enzymatic (SOD, CAT, and GPX) and non‐enzymatic (phenol and flavonoids) antioxidant defenses and reducing oxidative stress indicators (MDA and H2O2). The results revealed that SNP treatment increased the content of organic osmolyte glycine betaine and the activity of GST, concomitantly with ATP and ionic exchange capacity (including Ca2+‐ATPase and Mg2+‐ATPase), advocating its sufficiency to promote plant growth and avert Ni‐induced stress in maize plants. The only exception was the production of organic acids (citric, oxalic, malic, and formic acids), which was reduced as SNP treatment relieved maize seedlings from Ni‐induced oxidative damage. The application of SNP also displayed higher expression of defense‐ and detoxifying‐related genes than in control treatments. Together, our data highlighted the mechanism involved in the amelioration of Ni toxicity by SNP; thus, suggesting a potential role of SNP in mitigating the adverse effects of Ni‐contaminated soils to boost growth and yield of crop plants, that is, maize. [ABSTRACT FROM AUTHOR]