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The Bypass Dual Throat Nozzle (BDTN) is a novel fluidic Thrust Vectoring (TV) nozzle, it switches to TV state by opening the valve in the bypass. To greatly manipulate the BDTN, the dynamic characteristics in the TV starting process should be analyzed. This paper conducts numerical simulations to grasp the variation processes of performances and the flow field evolution of BDTN and Dual Throat Nozzle (DTN). The dynamic responses of TV starting in typical DTN models are investigated at first. Then, the TV starting processes of BDTN in different Nozzle Pressure Ratio (NPR) conditions are simulated, and the valve opening durations (T) are also considered. Before the expected TV direction is achieved in the DTN, the jet is deflected to the opposite direction at the beginning of the dynamic process, which is called the reverse TV phenomenon. However, this phenomenon disappears in the BDTN. The larger injection width of DTN intensifies unsteady oscillations, and the reverse TV phenomenon is strengthened. In the BDTN, T determines the delay degree of performance variations compared to the static results, which is called hysteresis effect. At NPR = 10, the hysteresis affects the final stable performance of BDTN. This study analyses the dynamic characteristics in DTN and BDTN, laying a foundation for further design of nozzles and control strategies.

This paper studies the bicriteria problem of scheduling njobs on a parallel-batching machine to minimize maximum cost and makespan simultaneously. A parallel-batching machine is a machine that can handle up to bjobs in a batch. The jobs in a batch start and complete respectively at the same time and the processing time of a batch is equal to the largest processing time of jobs in the batch. We consider the unbounded case. For the above bicriteria scheduling problem, we present an O(n3)-time algorithm, which improved the best known O(n4)-time algorithm, and the time complexity is the same as the special case in which maximum cost is maximum lateness. Meanwhile, our algorithm can also solve the single-criterion unbounded parallel-batching scheduling problem to minimize maximum cost in O(n3) time, which improved the best known O(n4)-time algorithm.

N4-Acetylcytidine (ac4C) has been found to affect a variety of cellular and biological processes. For a mechanistic understanding of the roles of ac4C in biology and disease, we present an antibody-free, fluorine-assisted metabolic sequencing method to detect RNA ac4C, called “FAM-seq”. We successfully applied FAM-seq to profile ac4C landscapes in human 293T, HeLa, and MDA cell lines in parallel with the reported acRIP-seq method. By comparison with the classic ac4C antibody sequencing method, we found that FAM-seq is a convenient and reliable method for transcriptome-wide mapping of ac4C. Because this method holds promise for detecting nascent RNA ac4C modifications, we further investigated the role of ac4C in regulating chemotherapy drug resistance in chronic myeloid leukemia. The results indicated that drug development or combination therapy could be enhanced by appreciating the key role of ac4C modification in cancer therapy.

Bypass Dual Throat Nozzle (BDTN) is a novel type of fluidic thrust vectoring nozzle. To improve the infrared stealth performance of BDTN, a nozzle based on BDTN is proposed and numerically simulated. Each cross-section along the x-axis of the novel nozzle becomes a trapezoid, which is named “BDTN-TRA.” The main numerical simulation results show that BDTN-TRA can produce a thrust vectoring angle when the upper or lower bypass valve is open. The angle difference between the two conditions mentioned above is usually approximately 1°–2°. Even if the two bypasses are closed, BDTN-TRA can produce a small thrust vectoring angle at around 3°–5°. When the sidewall angle increases from 60° to 90°, the thrust coefficient and thrust vectoring angle under each work condition usually decrease. A larger aspect ratio indicates better performance. As the aspect ratio increases over 7.2, the performance of BDTN-TRA is quite close to that of BDTN with rectangular cross-sections at the same aspect ratio. These features will benefit the control and trimming for future aircraft design, especially for the flying wing layout aircraft. Last but not least, BDTN-TRA has a more extraordinary mixing performance compared with BDTN. The distributions of static temperature and axial velocity along the x-axis of BDTN-TRA with sidewall angle of 60° decrease faster than those of BDTN. When the total temperature of the inlet equals 1600 K, the static temperature difference between BDTN-TRA with sidewall angles of 60° and 90° is over 360 K at twice the length of the nozzle downstream of the nozzle exit, which is the reflection for excellent infrared stealth for the fighter.

In order to effectively remove grease for the detection of sulfonamides, a non-toxic and low-cost hierarchical porous zirconia material was synthesized using the dual template method. The lipid impurities in an animal-derived food matrix can be absorbed by hierarchical zirconia. A ZrO2prepolymer was synthesized by mixing amphiphilic triblock copolymer poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (P123) with tannin extract as the double template and Zr(SO4)2as the metal source. After aging, drying and calcination at high temperature, the prepolymer transforms into a hierarchical porous structure. The synthesized materials were characterized using SEM, XRD, FT-IR, and BET. The results show that the material has an abundant pore structure and hierarchical pore structure. The adsorption conditions were optimized. The hierarchical porous ZrO2synthesized by this method is relatively uniform, and is characterized by large specific surface area as well as high lipid impurity adsorption capacity. Through the optimization experiment of adsorption conditions, we found that hierarchical porous ZrO2can reach the maximum adsorption capacity in 60 min under weak acidic conditions. The samples are used for actual sample testing such as HPLC of sulfadiazine (SD), sulfamethazine (SM2), sulfamethoxydiazine (SMD), sulfamethoxazole (SIZ) and sulfadimethoxine (SDM), and the recovery experiment of sulfonamides in chicken was carried out. The recoveries were 80.9–97.6% and the detection limit was 3.8–17.6 μg L−1. This work provides a new strategy for oil removal using hierarchical porous materials.

A G-quadruplex (G4) is a four-stranded nucleic acid secondary structure maintained by Hoogsteen hydrogen bonds established between four guanines. Experimental studies and bioinformatics predictions support the hypothesis that these structures are involved in different cellular functions associated with both DNA and RNA processes. An increasing number of diseases have been shown to be associated with abnormal G4 regulation. Here, we describe the existence of G4 and then discuss G4-related pathogenic mechanisms in neurodegenerative diseases and the viral life cycle. Furthermore, we focus on the role of G4s in the design of antiviral therapy and neuropharmacology, including G4 ligands, G4-based aptamers, G4-related proteins, and CRISPR-based sequence editing, along with a discussion of limitations and insights into the prospects of this unusual nucleic acid secondary structure in therapeutics. Finally, we highlight progress and challenges in this field and the potential G4-related research fields.

With the development of supersonic/hypersonic vehicles, the influence of non-uniform flow has attracted increasing attention. Non-uniform flow exists everywhere in a scramjet, which is a potent engine for supersonic/hypersonic vehicles. Most flows entering the isolator, combustor, and nozzle exhibit high non-uniformity. Thus, several design methods for generating non-uniform flow have been proposed. However, these design methods cannot simulate flow distortion with high accuracy, especially the non-uniform flow caused by shock wave interaction. Thus, a design method for distortion generators, which can generate non-uniform flow associated with flow deflection angles, is proposed in this study to mimic the shock wave-dominated non-uniform flow with shock wave interaction. Numerical simulation and experiment are adopted to verify the effectiveness and reliability of the proposed method. The Mach number on the outlet and the surface pressure distribution on the upper wall of the distortion generator obtained in the experiment show a good agreement with the target one.

G-Quadruplex (G4) is a noncanonical nucleic acid secondary structure with multiple biofunctions. Identifying G4-related proteins (G4RPs) is important for understanding the roles of G4 in biology. Current methods to identify G4RPs include discovery from specific biological processes or in vitropull-down assays with specific G4 sequences. Here, we report an in vivostrategy used to identify G4RPs with extensive sequence tolerance based on G4 ligand-mediated cross-linking. Applying this method, we identified 114 and 281 G4RPs in SV589 and MM231 cells, respectively. The results successfully overlapped with all the pull-down assay literature. Through the electrophoretic mobility shift assay (EMSA), we identified some new G4-binding proteins. Moreover, enhanced cross-linking and immunoprecipitation (eCLIP) confirmed that one newly identified G4-binding protein, SERBP1, interacts with G4 in the cellular environment. The method we developed provides a new strategy for identifying proteins that interact with nucleic secondary structures in cells and benefit the study of their biological roles.

Cross-linking poly(9-(6-(thiophene-3-yl)hexyl)-9H-carbazole) (PTh-H-Cz) films were synthesized one-step by anodic oxidation of its monomer precursor 9-(6-(thiophene-3-yl)hexyl)-9H-carbazole (Th-H-Cz) in boron trifluoride-ethyl ether (BFEE). The electrochemistry, electronic properties, electrochromic, and thermoelectric properties of the resultant free-standing PTh-H-Cz films were minutely studied. The PTh-H-Cz film-modified electrode exhibited reversible redox activity and good stability, combining the features of polythiophene and polycarbazole. The optical band gaps (Eg) of the polymer was calculated to be 2.52 eV. The HOMO and LUMO energy levels of PTh-H-Cz film were -4.13 and -1.61 eV, respectively. During its doping/dedoping process, the polymer film displayed a reversible color change from yellow green in the neutral state to atrovirens in the oxidation state. Additionally, the electrical conductivity of free-standing PTh-H-Cz films was determined to be only 1.2x10-3 S cm[?]1, but the film showed a very high but unstable Seebeck coefficient in the range of 5000-10000 uV K[?]1 at ambient temperature.

The aerodynamic design of a rigid-flexible coupling profile is the decisive factor for the flow-field quality of a supersonic free jet wind tunnel nozzle, and its mechanic dynamic features are the key for engineering implementation of continuous Mach number regulations. To fulfill the requirements of a free jet inlet/engine compatibility test within a wide simulation envelop, both uniform flow-fields of continuous acceleration and deceleration are necessary. In this paper, the aerodynamic design methods of an expansion wall and machinery implementation plan for the half-flexible single jack nozzle were researched. The profile control in nozzle flexible plate design was studied with a rigid-flexible coupling method. Design and calculations were performed with the help of numerical simulation. The technique of axial free stretching of the flexible plate was used to improve the matching performance between the designed elasticity profile and the theoretical one, and the rigid-flexible coupling structure was calibrated by wind tunnel tests. Results indicate that the flexible plate aerodynamic design method used here is effective and feasible. Via rigid-flexible coupling design, the flexible plate agrees with the rigid body very well, and continuous Mach number changes can be achieved during the tests. The nozzle’s exit flow-field uniformity meets the requirements of China Military Standard (GJB).

A one-equation turbulence model which relies on the turbulent kinetic energy transport equation has been developed to predict the flow properties of the recirculating flows. The turbulent eddy-viscosity coefficient is computed from a recalibrated Bradshaw’s assumption that the constant a1= 0.31 is recalibrated to a function based on a set of direct numerical simulation (DNS) data. The values of dissipation of turbulent kinetic energy consist of the near-wall part and isotropic part, and the isotropic part involves the von Karman length scale as the turbulent length scale. The performance of the new model is evaluated by the results from DNS for fully developed turbulence channel flow with a wide range of Reynolds numbers. However, the computed result of the recirculating flow at the separated bubble of NACA4412 demonstrates that an increase is needed on the turbulent dissipation, and this leads to an advanced tuning on the self-adjusted function. The improved model predicts better results in both the non-equilibrium and equilibrium flows, e.g. channel flows, backward-facing step flow and hump in a channel.

In this article, the flowfield of an overexpanded axisymmetric supersonic impinging jet with exit Mach number 1.754 is studied using particle image velocimetry. In particular, the influence of the impinging height on the detailed flowfield velocity distributions has been investigated. The velocity distribution precisely indicates where the Mach disk and the plate shock are generated. With the increasing impinging height, the plate shock position is found to move away from the impinging wall, until it reaches the maximum of 0.767D for the dimensionless impinging height of Z/D = 2.5. With a further increasing of the impinging height, the plate shock moves back to the impinging wall. Furthermore, the shape, position, as well as size of the stagnation bubble zone can also be deduced from the velocity distribution. According to the time-averaged flowfield result, the velocity coefficient of the radial wall jet is found to be as high as 0.8146, which is critical to the ground erosion problem in the application. It indicated that although the radial velocity appeared to be supersonic in the instantaneous result in Part I [Xu J, Lin C and Sha J. Particle image velocimetry study of the impinging height effect on the overexpanded supersonic impinging free jet of Ma = 1.754. Part I: global coherent structure. Proc IMechE, Part G: J Aerospace Engineering 2012; 226(1): 64–73.], it is high subsonic in the mean result in this part. This disagreement is due to the intrinsic highly unsteady nature of the flow under investigation. The vorticity isopleths demonstrate that the stagnation bubble and the recirculating flow are formed due to the impingement of the nozzle inner shear layer of the main jet.

Cross-linking poly(9-(6-(thiophene-3-yl)hexyl)-9H-carbazole) (PTh-H-Cz) films were synthesized one-step by anodic oxidation of its monomer precursor 9-(6-(thiophene-3-yl)hexyl)-9H-carbazole (Th-H-Cz) in boron trifluoride-ethyl ether (BFEE). The electrochemistry, electronic properties, electrochromic, and thermoelectric properties of the resultant free-standing PTh-H-Cz films were minutely studied. The PTh-H-Cz film-modified electrode exhibited reversible redox activity and good stability, combining the features of polythiophene and polycarbazole. The optical band gaps (Eg) of the polymer was calculated to be 2.52 eV. The HOMO and LUMO energy levels of PTh-H-Cz film were -4.13 and -1.61 eV, respectively. During its doping/dedoping process, the polymer film displayed a reversible color change from yellow green in the neutral state to atrovirens in the oxidation state. Additionally, the electrical conductivity of free-standing PTh-H-Cz films was determined to be only 1.2×10-3S cm−1, but the film showed a very high but unstable Seebeck coefficient in the range of 5000-10000 μV K−1at ambient temperature.