论电力设备维修存在的问题及对策探讨

电站设备的维护和管理是电力行业许多工作的重要组成部分。如何选择科学合理的维修方法,提高维修效率和质量是每个人关注的焦点。本文讨论了电力设备维护的问题和对策。</jats:p

A Formulation for Numerically Computing Sound at Moving Observers Based on Frequency-Domain Ffowcs Williams-Hawkings Equation

To circumvent the difficulties in computing sound at moving observers for the prompting Cooperative Autonomous Underwater Vehicles, we propose a frequency-domain formulation for computing sound with Ffowcs Williams-Hawkings equation. The proposed formulation avoids the expensive integration at each moment over the frequency domain when the acoustic pressure is computed at moving observers, because we novelly decompose the far-field asymptotics of the Green's function into time- and frequency-dependent components. The proposed formulation is applicable to computation of sound at moving observers with both rectilinear and non-rectilinear motions in subsonic flows. We validate the proposed formulation by computing sound generated from moving acoustic monopole and dipole in freestream flows. The oscillating and rectilinear motions of a far-field observer along various paths are specially considered. The results demonstrate that the proposed formulation provides reliable predictions for sound received by moving observers

基于核磁共振技术的临床尿毒症的代谢组学研究

采用核磁共振技术与统计学分析方法,结合尿液的生化指标,进行临床尿毒症尿样的代谢组学研究。结果表明,尿毒症患者和健康对照人群尿样的代谢轮廓存在明显差异,通过核磁共振氢谱鉴定出70种代谢物,其中20种具有显著差异。与健康人群相比,尿毒症患者尿液中2-羟基异丁酸、3-羟基丁酸、丙酮、丁酸、谷氨酸、肌氨酸、肌酐、赖氨酸、N,N-二甲基组氨酸、柠檬酸、天冬酰胺、乙醇和乙醇胺的含量明显偏低,而支链氨基酸(包括亮氨酸、缬氨酸、异亮氨酸)、牛磺酸、乳酸、α-葡萄糖和β-葡萄糖的含量明显偏高。这些代谢物涉及氨基酸代谢、能量代谢和脂质代谢中的多条代谢途径,可作为尿毒症代谢影响的潜在的生物标志物,有助于理解尿毒症发病的生化机制。国家自然科学基金项目(Nos.31671920,81272581)资助~

藏茵陈饮片的制备方法

<p><font face="宋体" size="3">发明属医药技术领域，本发明公开了一种藏茵陈饮片的制备方法。该方法包括以下步骤：先将藏茵陈经过紫外照射消毒，同时将黑曲霉依序经过麦芽浸粉斜面培养、种子培养基扩大培养和发酵培养基发酵培养后，将发酵物烘干、粉碎，定量装入胶囊或制成片剂。本发明所采用的方法主要是通过黑曲霉产生的纤维素分解酶、半纤维素分解酶破坏植物药细胞壁结构，从而有利于藏茵陈中有效成分的消化吸收。该方法具有操作简单，成本低廉，资源利用率高的优点，易于进行工业化生产，具有很高的实际应用价值，市场前景广阔。此外，本方法对于其他中药饮片的制备同样具有借鉴意义。</font></p

Measurement of integrated luminosity of data collected at 3.773 GeV by BESIII from 2021 to 2024

We present a measurement of the integrated luminosity e+e- of collision data collected by the BESIII detector at the BEPCII collider at a center-of-mass energy of Ecm = 3.773 GeV. The integrated luminosities of the datasets taken from December 2021 to June 2022, from November 2022 to June 2023, and from October 2023 to February 2024 were determined to be 4.995±0.019 fb-1, 8.157±0.031 fb-1, and 4.191±0.016 fb-1, respectively, by analyzing large angle Bhabha scattering events. The uncertainties are dominated by systematic effects, and the statistical uncertainties are negligible. Our results provide essential input for future analyses and precision measurements

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^