Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation b...Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation but little study about the relation between serration and mode. Thus, taking axial single-turbine test bench NPU-Turb as object, the effect of Stator with Serrated Trailing-edge (Bionic S) and Rotor with Serrated Leading-edge (Bionic R) on duct acoustic modes of turbine turbulence interac-tion noise were studied in detail using DDES/AA hybrid model validated by acoustic experiment of NPU-Turb. Serval conclusions can be made here. First, for broadband noise, the effect of serrations on duct modes (increased or reduced of PWL<sub>mn</sub>) with the increasing frequency is more prominent. Second, the changing trend of ?PWL<sub>mn</sub> is something like Chinese character “人” with circumferential mode m and alternating with radial mode. Such distribution is more obvious at higher frequency. More theoretical and mechanistic research work needs to be carried out in depth in the future. .展开更多
We describe some recent developments of high-Reynolds-number asymptotic theory for the nonlinear stage of laminar-turbulent transition in nearly parallel flows.The classic weakly nonlinear theory of Landau and Stuart ...We describe some recent developments of high-Reynolds-number asymptotic theory for the nonlinear stage of laminar-turbulent transition in nearly parallel flows.The classic weakly nonlinear theory of Landau and Stuart is briefly revisited with the dual purposes of highlighting its fundamental ideas,which continue to underlie much of current theoretical thinking,as well as its difficulty in dealing with unbounded flows.We show that resolving such a difficulty requires an asymptotic approach based on the high-Reynolds-number assumption,which leads to a nonlinear critical-layer theory.Major recent results are reviewed with emphasis on the non-equilibrium effect.Future directions of investigation are indicated.展开更多
It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispens...It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispensable to meet the demands for high throughput and low latency in next generation mobile communication systems. This paper unveils the fact that interleavers based on permutation polynomials modulo N are contention-free for every window size W, a factor of the intedeaver length N, which, also called maximum contention-free interleavers.展开更多
Background: bladder tumors rank 2nd among urological tumors in sub-Saharan Africa, particularly in Côte d’Ivoire. Objective: to report the results of transurethral resection of the bladder (TURB) for the treatme...Background: bladder tumors rank 2nd among urological tumors in sub-Saharan Africa, particularly in Côte d’Ivoire. Objective: to report the results of transurethral resection of the bladder (TURB) for the treatment of non-muscle-infiltrating bladder tumors (NMIBT) in Bouaké. Patients and methods: we conducted a cross-sectional, descriptive study of transurethral resection of the bladder (TURB) for the treatment of non-muscle-infiltrating bladder tumors (NMIBT) between January 2022 and April 2023. All patients and their families were informed in advance and had signed an informed consent form. All patients with a non-muscle-invasive bladder tumor confirmed by an initial TURB were included, and patients with a bladder tumor infiltrating the bladder muscle were excluded. Diagnosis was based on cystoscopy and anatomopathological examination of resection shavings. Parameters studied were: age, sex, risk factors, reason for consultation, clinical signs, cystoscopy findings, stage, grade, Evolution. Results: 17 patients with a mean age of 53.7 years (22-73 years) underwent trans-ureteral bladder resection to treat a non-muscle-infiltrating bladder tumor (NMIBT). Male gender predominated with 88.23% (n = 15), the majority of patients came from the ME region with 47.05% (n = 8), farmers were the most numerous (52.94%;n = 9). The most frequent reason for consultation was macroscopic hematuria with 64.1% (n = 11), risk factors were dominated by urinary bilharziasis with 70.58% (n = 12), physical examination was normal in 47.05% (n = 8). Hemoglobin (HB) levels were between 7.5 and 8.5 g/dl in 52.94% (n = 9). On cystoscopy, the tumor was budding in 76.45% (n = 13), the localization was trigonal in 52.9% (n = 9) and the base of implantation was sessile in 70.52% (n = 12). On ultrasound, the tumor was 3 cm or larger in 70.52% (n = 12). Therapeutically, 82.35% (n = 14) of patients received a blood transfusion. TURB was complete in the majority of cases 88.23% (n = 15). Squamous cell carcinoma was the most frequent histological type with 76.47% (n = 13). PTa and PT1 grade accounted for 23.52% (n = 4) and 76.47% (n = 13) respectively. High-grade PT1 accounted for 64.70% (n = 11). Follow-up to TURB was straightforward in 94.11% (n = 16). At three months post-TURB, seven patients presented a tumor recurrence, with 41.17% (n = 7) requiring a second TURB. At 6 months, follow-up noted 14 patients free of any clinical or endoscopic signs of bladder tumors. Conclusion: TURB is a safe and effective means of treating non-muscle-invasive bladder tumors.展开更多
文摘Turbine noise would be one of the dominant noise sources especially in future UHBR (Ultra High Bypass-Ratio) aeroengine, but its currently far from being studied enough. Acoustic mode is crucial for duct propagation but little study about the relation between serration and mode. Thus, taking axial single-turbine test bench NPU-Turb as object, the effect of Stator with Serrated Trailing-edge (Bionic S) and Rotor with Serrated Leading-edge (Bionic R) on duct acoustic modes of turbine turbulence interac-tion noise were studied in detail using DDES/AA hybrid model validated by acoustic experiment of NPU-Turb. Serval conclusions can be made here. First, for broadband noise, the effect of serrations on duct modes (increased or reduced of PWL<sub>mn</sub>) with the increasing frequency is more prominent. Second, the changing trend of ?PWL<sub>mn</sub> is something like Chinese character “人” with circumferential mode m and alternating with radial mode. Such distribution is more obvious at higher frequency. More theoretical and mechanistic research work needs to be carried out in depth in the future. .
文摘We describe some recent developments of high-Reynolds-number asymptotic theory for the nonlinear stage of laminar-turbulent transition in nearly parallel flows.The classic weakly nonlinear theory of Landau and Stuart is briefly revisited with the dual purposes of highlighting its fundamental ideas,which continue to underlie much of current theoretical thinking,as well as its difficulty in dealing with unbounded flows.We show that resolving such a difficulty requires an asymptotic approach based on the high-Reynolds-number assumption,which leads to a nonlinear critical-layer theory.Major recent results are reviewed with emphasis on the non-equilibrium effect.Future directions of investigation are indicated.
基金Project (No. 60332030) supported by the National Natural ScienceFoundation of China
文摘It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispensable to meet the demands for high throughput and low latency in next generation mobile communication systems. This paper unveils the fact that interleavers based on permutation polynomials modulo N are contention-free for every window size W, a factor of the intedeaver length N, which, also called maximum contention-free interleavers.
文摘Background: bladder tumors rank 2nd among urological tumors in sub-Saharan Africa, particularly in Côte d’Ivoire. Objective: to report the results of transurethral resection of the bladder (TURB) for the treatment of non-muscle-infiltrating bladder tumors (NMIBT) in Bouaké. Patients and methods: we conducted a cross-sectional, descriptive study of transurethral resection of the bladder (TURB) for the treatment of non-muscle-infiltrating bladder tumors (NMIBT) between January 2022 and April 2023. All patients and their families were informed in advance and had signed an informed consent form. All patients with a non-muscle-invasive bladder tumor confirmed by an initial TURB were included, and patients with a bladder tumor infiltrating the bladder muscle were excluded. Diagnosis was based on cystoscopy and anatomopathological examination of resection shavings. Parameters studied were: age, sex, risk factors, reason for consultation, clinical signs, cystoscopy findings, stage, grade, Evolution. Results: 17 patients with a mean age of 53.7 years (22-73 years) underwent trans-ureteral bladder resection to treat a non-muscle-infiltrating bladder tumor (NMIBT). Male gender predominated with 88.23% (n = 15), the majority of patients came from the ME region with 47.05% (n = 8), farmers were the most numerous (52.94%;n = 9). The most frequent reason for consultation was macroscopic hematuria with 64.1% (n = 11), risk factors were dominated by urinary bilharziasis with 70.58% (n = 12), physical examination was normal in 47.05% (n = 8). Hemoglobin (HB) levels were between 7.5 and 8.5 g/dl in 52.94% (n = 9). On cystoscopy, the tumor was budding in 76.45% (n = 13), the localization was trigonal in 52.9% (n = 9) and the base of implantation was sessile in 70.52% (n = 12). On ultrasound, the tumor was 3 cm or larger in 70.52% (n = 12). Therapeutically, 82.35% (n = 14) of patients received a blood transfusion. TURB was complete in the majority of cases 88.23% (n = 15). Squamous cell carcinoma was the most frequent histological type with 76.47% (n = 13). PTa and PT1 grade accounted for 23.52% (n = 4) and 76.47% (n = 13) respectively. High-grade PT1 accounted for 64.70% (n = 11). Follow-up to TURB was straightforward in 94.11% (n = 16). At three months post-TURB, seven patients presented a tumor recurrence, with 41.17% (n = 7) requiring a second TURB. At 6 months, follow-up noted 14 patients free of any clinical or endoscopic signs of bladder tumors. Conclusion: TURB is a safe and effective means of treating non-muscle-invasive bladder tumors.
