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Aimed at the lack of effective stability evaluation methods for the current steam power system, an operation stability assessment method suitable for single parameter is proposed. This method is a composite method, which first applied the midpoint and regression based empirical mode decomposition (MREMD) and singular value decomposition (SVD) to decompose the time series of operation parameters and extract their hidden trend terms. Then, the components are selected for reconstruction according to the optimal algorithm parameter permutation entropy (OAPPE) of each component. Finally, the auto-regressive integrated moving average (ARIMA ) model commonly used in the non-stationary time series analysis is utilized to predict the trend and the disturbance of parameters, and their distribution characteristics are also extracted in this process, based on which, the probability of instability (PI) of operation parameters at each point on the predicted trend are calculated, and their stabilities are quantitatively evaluated. The actual case proves that this method can effectively assess the operation stability of a single parameter of the steam power system, which has a certain theoretical innovation and engineering application value.

In response to the problems of boiler low water level and pump cavitation caused by the leakage of feedwater unloading pipeline in the process of boiler load raising of the conventional steam power system, the relational model of water-lift, mass flow, revs of booster pump, and each impeller of the feedwater pump are identified by using a differential evolution algorithm based on residual correction. The relational model of mass flow and resistance of feedwater pipelines and valves, the calculational model of working fluid parameters in feedwater system, and the performance degradation model of feedwater unloading control valve are established by using be mechanism modeling method. On this basis, the process of boiler load raising is simulated, and the main parameters of feedwater system are obtained at different feedwater unloading flow rates. It is found that the performance degradation of the control valve of the feedwater unloading pipeline is one of the main causes for boiler water low level and pump cavitation in the process of boiler load raising. In order to further clarify the degradation rule of the performance reliability of the feedwater system with the working time, a simulation method integrating the mathematical model and Monte Carlo random sampling is adopted to the performance reliability simulation of a certain type of marine water supply system in the process of boiler load raising. Thus the whole performance reliability changes of this boiler and the performance reliability life of this feedwater unloading control valve are obtained. The research results reveal the mechanism and degeneration rule of a unique fault of the steam power system, which has certain theoretical and engineering application value.

Abstract: Mesoporous magnetite (Fe3O4) was successfully synthesized on a large scale by direct pyrolysis of ferric nitrate-EG (EG=ethylene glycol) gel in a one-end closed horizontal tube furnace in the air without using any template, additions, and carrier gas. The as-synthesized mesoporous Fe3O4 were characterized by powder X-ray diffraction (XRD), infrared spectra (IR), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), Brunauer–Emmett–Teller (BET), Barrett–Joyner–Halenda (BJH), and thermal gravimetric analysis (TGA). Results from TEM showed that the as-obtained Fe3O4 has mesoporous structure formed by the loose agglomeration of nanoparticles with diameter of about 6nm, which was also confirmed by small-angle XRD and nitrogen adsorption analysis. Furthermore, vibrating sample magnetometer (VSM) measurements indicated that the saturated magnetization of the as-obtained mesoporous Fe3O4 was ferromagnetic with the saturation magnetization (Ms) and coercivity (Hc) of 46emu/g and 136Oe, respectively. In addition, a possible growth mechanism of mesoporous Fe3O4 was also discussed. [ABSTRACT FROM AUTHOR]

Abstract: We present a facile one-step approach to large-scale production of single-crystal magnetite Fe3O4 nanosheets (NSs) employing a solid-state thermal decomposition route without the assistance of any template, carrier gas, and other additions. Single-crystal Fe3O4 NSs with average edge length in the range of 80–100nm and thickness of about 30nm were synthesized on a large scale via direct pyrolysis of inorganic–organic hybrid EDTA ferric sodium salt in a one-end closed and horizontal quartz tube furnace in the air. A series of techniques, including XRD, IR, TEM, HRTEM, and TGA, were used to characterize the final products. The HRTEM image obtained from a typical individual nanosheet displays a highly symmetrical lattice, which reveals the single-crystalline nature of the obtained Fe3O4 NSs. Furthermore, a possible formation mechanism from EDTA ferric sodium salt to Fe3O4 was also discussed. All the obtained Fe3O4 NSs are ferromagnetic at room temperature. This method is simple and facile and could synthesize other metal oxides under such experimental conditions. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance: Pelvic inflammatory disease (PID) is a frequently occurring gynecological disorder mainly caused by the inflammation of a woman's upper genital tract. Generally, antibiotics are used for treating PID, but prolonged use poses potential risks of gut bacterial imbalance, bacterial resistance, super bacteria production, and associated adverse reactions. Traditional Chinese medicine (TCM) has shown unique advantages in various ailments and has received widespread clinical research attention. Fuke Qianjin (FUKE) capsule is an approved National Medical Products Administration (NMPA License No. Z20020024) Chinese herbal prescription that has been widely used individually or in combination with other Western medicines for the treatment of various gynecological inflammatory diseases, including chronic cervicitis, endometritis, and chronic PID. Aim: This clinical trial was designed to assess the safety and efficacy of FUKE capsule in mild-to-moderate symptomatic PID patients. Materials and methods: This phase 2, randomized, double-blind, positive controlled clinical trial was conducted in mild-to-moderate symptomatic PID patients at a single center in Pakistan from 21 September 2021 to 11 March 2022. Eligible female participants were randomly assigned to a test and a control group with a ratio of 1:1. The test group subjects received two metronidazole (METRO) tablets and one doxycycline hyclate (DOXY) simulant at a time, twice daily for 14 days, and two Fuke Qianjin (FUKE) capsules, three times a day after a meal for 28 days. Subjects in the control group received two METRO tablets and one DOXY tablet at a time, twice daily for 14 days, and two FUKE simulant capsules, three times a day after meal for 28 days. The primary efficacy outcome was an improvement in pelvic pain symptoms assessed through a visual analog scale (VAS). The secondary outcomes were the improvement in secondary efficacy symptoms like local physical signs, clinical assessment of leucorrhea and cervical secretions through laboratory examination, and improvement in the maximum area of pelvic effusion assessed through gynecological ultrasound after the treatment. The safety outcomes were assessed through vital signs, laboratory tests, electrocardiogram findings, and adverse events/serious adverse events. Results: A total of 198 subjects with active PID were randomly assigned to a test group (n = 99) and a control group (n = 99). The baseline characteristics of the subjects in the two groups were similar. In the intention-to-treat analysis, the primary efficacy was 84.9% for the test group and 71.6% for the control group, with a statistically significant difference ( p = 0.0370; 95% CI -0.2568 to -0.0088). The secondary clinical efficacy was 88.4% for the test group and 82.7% for the control group, with no significant difference ( p = 0.2977; 95% CI -0.1632 to 0.0501). The improvement in local physical signs was 95.8% for the test group and 76.9% for the control group, with no significant difference ( p = 0.0542; 95% CI -0.3697 to -0.0085). The inter-group non-inferiority comparison showed that the upper limit of the 95% CI was less than 0.15 and thus met the non-inferiority requirements of the test group to the control group. The results of clinical signs of leucorrhea and cervical secretions showed that there was no difference in the rate of improvement between the test and control groups, indicating that FUKE was non-inferior to DOXY. A total of 14 adverse events in eight subjects were observed in the trial, with an incidence rate of 4.7%. Four subjects in each group experienced seven adverse events with 4.5% and 4.8% incidence rates of adverse reactions in the test and control groups, with no statistically significant differences ( p = 0.2001). No serious adverse events occurred in the trial. Conclusion: The results of this trial indicate that the test drug (Fuke Qianjin capsule) is non-inferior to the control drug (doxycycline hyclate tablet) in treating mild-to-moderate PID patients with comparable efficacy, safety, and tolerability to the control drug. Clinical Trial Registration: www.clinicaltrials.gov, identifier NCT04723069., Competing Interests: Authors LY, HY, CZ, YZ, MZ, CM, and RL were employed by Zhuzhou Qianjin Pharmaceutical Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Shah, Khan, Fatima, Yao, Yuan, Ullah, Ainuddin, Zeng, Zheng, Sahar, Anwar, Zhu, Ma, Kumari, Wang and Liu.)