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In the acoustic signal receiving section of underwater vehicle, an effective measure to improve surface acoustic impedance and reduce signal attenuation is to cover acoustic barrier plate of hydrophone array with high impedance material (signal conditioning plate). Compared with traditional full coverage mode, an acoustic grating (periodic installation of regulator plate array) can greatly improve the received signal gain and reduce the weight of the receiving segment. In order to deeply understand the signal enhancement mechanism and optimize the design of acoustic grating, the factors that influence the signal enhancement performance of acoustic grating from the aspects of width, thickness, incident angle and structure width ratio is studied. Simulation results show that the oblique incidence will change the symmetrical distribution of signal ratio (SR), but will not significantly change the acoustic performance of the structure. Wider and thicker regulating plate lead to stronger non-mirror scattering and better signal enhancement performance of structure. In practical application, geometric parameters of acoustic grating should be reasonably designed to meet multiple constraints of real environment to achieve optimal overall performance. In addition, the moderate width ratio can obtain a good overall acoustic performance.

Sound field reproduction is a method that uses multiple secondary sound sources to reproduce a predefined desired sound field in a listening area. The configuration of the secondary sound sources is a key factor affecting the reproduction performances. To optimize the secondary source configuration, this study proposes a new method that combines the Gram-Schmidt orthogonalization method with the group Lasso method, which is called GSO-GL method. Firstly, it selects a certain number of the secondary sources from all the alternative secondary sources using the Gram-Schmidt orthogonalization method. The excitation sources are then further selected from the secondary sources selected in the previous step using the group Lasso method. The sound field simulation from the 2D room model show that the GSO-GL method outperforms the Gram-Schmidt orthogonalization method or the group Lasso method alone, combining the high system stability of the Gram-Schmidt orthogonalization method with the high reproduction accuracy of the group Lasso method.

The purpose of this study was to compare the outcomes of the buccal mucosa and lingual mucosa used in children who received multiple failed hypospadias surgeries.We conducted a retrospective study of 62 children who received buccal or lingual mucosa graft urethroplasty in our hospital between 2012 and 2015. The ages ranged from 3.5-11 y. All cases included multiple failed hypospadias procedures, and the subjects received previous operations 2-3 times. All patients underwent one-stage operations. Thirty-three cases were treated with lingual mucosa grafts. The patient ages ranged from 3.5 to 11 y (median 7.5 y), and they had previous operations 2-3 times (mean 2.8±0.7). Grafts ranged from lengths of 2-6 cm (mean 5.1±0.46 cm) and widths of 0.5-1.5 cm (mean 1.2± 0.16 cm). Our follow-up was 5 to 12 m (mean 8.3±1.2 m). Twenty-nine cases were treated with buccal mucosa grafts. The patient ages ranged from 4 to 9.2 y (median 7.0 y), and they had previous operations 2-3 times (mean 2.5±0.2). Grafts ranged from lengths of 2-5.3 cm (mean 4.9± 0.28 cm) and widths of 0.5-1.5 cm (mean 1.0±0.11 cm). Our follow-up was 5 to 12 m (mean 7.9±0.5 m). The results were tested with SPSS 18.0. The rates of complications were compared by a chi-square test, and pre-operative conditions were compared by t test.For the outcomes of the two groups, there was no significant difference between the groups in terms of age, preoperative surgery time, and the length and width of the grafts (p>0.05). For the lingual mucosa graft group, fistula: 2/33 (6.0%), stricture: 1/33(3.0%), ventral curvature: 2/33(6.0%), complications: 5/33(15.0%), success rate: 28/33(84.8%), Hose score: 14.34±0.95, peak flow: 6.5 ml/s-12.0 ml/s, and mean peak flow: 9.3±0.4 ml/s. For the buccal mucosa graft group, fistula: 2/29(6.8%), stricture: 2/29(6.8%), ventral curvature: 1/29 (3.4%), complication rate: 5/29(17.0%), success rate: 24/29 (83.0%), Hose score: 14.28±1.03, peak flow: 6.5 ml/s-12.0 ml/s, and mean peak flow: 9.2±0.2 ml/s. There were no differences between the two groups for overall success, complication rates, peak flow, and the Hose scores(P>0.05).The lingual mucosal graft and the buccal mucosa graft both achieved good outcomes, and the lingual mucosa graft made up for the shortcomings of the buccal mucosa graft, which provided a reliable way to treat the multiple failed hypospadias surgeries in pre-pubertal boys.

Introducing a third component into organic bulk heterojunction solar cells has become an effective strategy to improve photovoltaic performance. Meanwhile, the rapid development of non-fullerene acceptors (NFAs) has pushed the power conversion efficiency (PCE) of organic solar cells (OSCs) to a higher standard. Herein, a series of fullerene-free ternary solar cells are fabricated based on a wide bandgap acceptor, IDTT-M, together with a wide bandgap donor polymer PM6 and a narrow bandgap NFA Y6. Insights from the morphological and electronic characterizations reveal that IDTT-M has been incorporated into Y6 domains without disrupting its molecular packing and sacrificing its electron mobility and work synergistically with Y6 to regulate the packing pattern of PM6, leading to enhanced hole mobility and suppressed recombination. IDTT-M further functions as an energy-level mediator that increases open-circuit voltage (VOC) in ternary devices. In addition, efficient Förster resonance energy transfer (FRET) between IDTT-M and Y6 provides a non-radiative pathway for facilitating exciton dissociation and charge collection. As a result, the optimized ternary device features a significantly improved PCE up to 16.63% with simultaneously enhanced short-circuit current (JSC), VOC, and fill factor (FF).

Ternary organic solar cells (OSCs) provide a convenient and effective means to further improve the power conversion efficiency (PCE) of binary ones via composition control. However, the role of the third component remains to be explored in specific binary systems. Herein, we report ternary blend solar cells by adding the narrow-band-gap donor PCE10 as the mediator into the PBDB-T:IDTT-T binary blend system. The extended absorption, efficient fluorescence resonance energy transfer, enhanced charge dissociation, and induced tighter molecular packing of the ternary blend films enhance the photovoltaic properties of devices and deliver a champion PCE of 10.73% with an impressively high open-circuit voltage (VOC) of 1.03 V. Good miscibility and similar molecular packing behavior of the components guarantee the desired morphology in the ternary blend films, leading to solar cell devices with over 10% PCEs at a range of compositions. Our results suggest that ternary systems with properly aligned energy levels and overlapping absorption among the components hold great promises to further enhance the performance of corresponding binary ones.

Objective: To evaluate the effect of a new strategy of transperineal anastomotic urethroplasty (TAU) with proximal transection in treating pelvic fracture urethral injury (PFUI) associated with urethrorectal fistula (URF). Patients and Methods: A retrospective review of all patients treated by TAU with proximal transection and fistula repair for PFUI associated with URF was performed between August 2013 and July 2022. Information on demographics, peri‐operative variables, and postoperative follow‐up outcomes was collected. Successful surgery was defined as restoration of a uniform urethral calibre using flexible cystoscopy (third postoperative month) without strictures or leakage, with no further interventions required. Functional outcomes, including erectile function (assessed using the five‐item International Index of Erectile Function) and urinary continence, were assessed. Results: Forty patients diagnosed with PFUI associated with URF and treated by TAU with proximal transection and rectal fistula repair were enrolled. Six patients (15.0%) had a history of failed urethral reconstruction. The mean stenosis length and fistula diameter were 2.9 cm and 1.2 cm, respectively. All patients underwent faecal diversion before urethroplasty. After a median (range) follow‐up of 45 (3–115) months, the final success rate was 90.0% (36/40). Postoperative complications included haematoma in three patients, epididymo‐orchitis in three, wound infection in one, wound bleeding in one, delayed wound healing in three, and wound numbness in three. The overall incidence of postoperative erectile dysfunction reached 75.0%, with a median (range) score of 9 (0–19). Normal continence was achieved in 31 patients (77.5%). Occasional incontinence without the need for urinal pads occurred in eight patients, whereas one patient required urinal pads. Conclusions: Transperineal anastomotic urethroplasty with proximal transection is a precise and effective surgical strategy for treating PFUI associated with URF. This strategy ensures a high success rate and improves surgical efficiency. [ABSTRACT FROM AUTHOR]

l‐2‐Hydroxyglutarate (l‐2‐HG) is a functionally compartmentalized metabolite involved in various physiological processes. However, its subcellular distribution and mitochondrial transport remain unclear owing to technical limitations. In the present study, an ultrasensitive l‐2‐HG biosensor, sfLHGFRH, composed of circularly permuted yellow fluorescent protein and l‐2‐HG‐specific transcriptional regulator, is developed. The ability of sfLHGFRH to be used for analyzing l‐2‐HG metabolism is first determined in human embryonic kidney cells (HEK293FT) and macrophages. Then, the subcellular distribution of l‐2‐HG in HEK293FT cells and the lower abundance of mitochondrial l‐2‐HG are identified by the sfLHGFRH‐supported spatiotemporal l‐2‐HG monitoring. Finally, the role of the l‐glutamate transporter SLC1A1 in mitochondrial l‐2‐HG uptake is elucidated using sfLHGFRH. Based on the design of sfLHGFRH, another highly sensitive biosensor with a low limit of detection, sfLHGFRL, is developed for the point‐of‐care diagnosis of l‐2‐HG‐related diseases. The accumulation of l‐2‐HG in the urine of patients with kidney cancer is determined using the sfLHGFRL biosensor. [ABSTRACT FROM AUTHOR]

Herein, we presented an enantioselective intramolecular Diels–Alder (IMDA) reaction with vinyl branched vinylidene ortho-quinone methide (VQM). The control of site selectivity in the IMDA reaction led to both chiral bridged bicyclo[4.3.1] and [5.3.1] architectures with high isolated yields (up to 85%) and excellent enantioselectivities (up to 97% ee). [ABSTRACT FROM AUTHOR]

Efficient initiation of oblique detonation waves (ODWs) is crucial for optimizing the performance of oblique detonation wave engines. A novel approach is proposed for enhancing ODW initiation through expansion waves in this research. Validation of the expansion wave-reinforced initiation method is conducted via numerical simulations employing multi-species reactive Euler equations and a pressure-dependent reaction mechanism. Results demonstrate a significant reduction in the initiation length of ODWs with the addition of an expansion wave ahead of the wedge, contrasting with the absence of detonation wave initiation on a wedge lacking an expansion wave. A theoretical model, based on expansion wave and shock wave relations, along with constant volume combustion theory, elucidates the underlying mechanism of reinforcement. The model reveals that crossing the expansion wave elevates the fluid's Mach number and locally enlarges the flow deflection angle on the wedge surface, without altering the wedge's structure. Furthermore, post-shock temperature increases and pressure decreases compared to the wedge not encountering an expansion wave. The heightened temperature predominantly triggers ODW initiation, thus reinforcing the process. Theoretical analyses indicate the reinforcement's greater efficacy at lower inflow temperatures and lower inflow Mach numbers, suggesting the expansion wave's suitability for initiation in the early flight stages of an aircraft equipped with oblique detonation wave engines. [ABSTRACT FROM AUTHOR]

Superconducting Radio Frequency technologies are widely employed in particle accelerators to explore the frontiers of science. Pure niobium cavity with 2.8–4 mm thickness is the traditional technology of a compromise between the thermal conduction and mechanic stability. To meet the requirements of the higher stability of accelerators such as ADS linac, high intensity pulse linac, a solution for enhancing the stability of superconducting cavities by the Al–Nb double layer structure is proposed while maintaining enough heat transfer capacity. In this work, a 3.9 GHz single cell Al–Nb elliptical cavity was fabricated to validate this proposal. During the vertical testing, the cavity shows a significant enhancement in the mechanical stability with LFD coefficient reduction by 88% compared to the pure Nb cavity and Q 0 value is kept at the same level. Additionally, the basic parameters of Al–Nb composite material were tested and reported as well. [ABSTRACT FROM AUTHOR]