The excessive use of power electronics makes power quality problems in power grids increasingly prominent. The estimation of the harmonic parameters of harmonic sources in the power grid and the division of harmonic responsibilities are of great significance for the evaluation of power quality. At present, methods for estimating harmonic parameters and harmonic responsibilities need to provide the amplitude and phase information of the current and voltage of the point of common coupling (PCC). However, in practical engineering applications, the general power quality monitor only provides the amplitude information of the voltage and current of the measured point and the phase difference information between them. Missing phase information invalidates existing methods. Based on the partial least squares regression method, the present work proposes a method for estimating harmonic parameters in the case of monitoring data without phase. This method only needs to measure the amplitude information of the harmonic voltage and current of the PCC and the phase difference between them, then use the measurable data to estimate the harmonic parameters and the harmonic responsibility of each harmonic source. It provides a new way to effectively solve the problem that the measured data of the project has no phase information. The feasibility and effectiveness of the proposed method are proved by simulation data and measured engineering data.

Binary composite of graphene/poly(ethylene oxide) (PEO) with microwave absorption property is prepared by in situ reduction process. Graphite oxide (GO) is prepared from flake graphite by modified Hummers' method and further dispersed in distilled water to get GO solution. Then, PEO powder is slowly added into GO solution to get GO/PEO solution, and graphene/PEO composites is prepared via a facile and quick reduction process in GO/PEO solution. PEO and graphene/PEO composites are characterized by scanning electron microscopy, atomic force microscopy, thermo gravimetric analysis, and vector network analyzer. The results show that graphene is uniformly dispersed in PEO matrix because GO and PEO can be uniformly dispersed at molecular level due to their water‐solubility and the agglomeration of graphene can be prevented by PEO macromolecular chains during in situ reduction process. Graphene/PEO composite has better thermal stability than PEO, which can be explained by the graphene restoration of sp2 bonded carbon structure. Meanwhile, graphene/PEO composite shows excellent microwave absorption property at low grapheme content. The minimum reflection loss of graphene/PEO composite is up to −20.0 dB when the content of graphene is only 1 wt%. POLYM. COMPOS., 35:461–467, 2014. © 2013 Society of Plastics Engineers

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ObjectivesThis retrospective study aimed to describe our institutional experience with cytoreductive cystectomy (Cx) in patients with pathological T4 (pT4) bladder cancer (BCa) and to investigate the clinicopathologic factors that can predict patient survival outcomes.MethodsWe reviewed the baseline demographics, clinicopathologic features, perioperative complications, and follow-up data of 44 patients who underwent Cx for pT4 BCa at our institution between 2013 and 2021. The Kaplan–Meier curve and the log-rank test were used to analyze progression-free survival (PFS) and overall survival (OS). Univariate and multivariate analyses were performed using the Cox regression model.ResultsThe median age of the patients was 68 years [95% confidence interval (CI) 49–81]. Overall, 21 patients (47.7%) were estimated to have a high age-adjusted Charlson comorbidity index (ACCI) score (>4), and nine patients (20.5%) had pT4b substage BCa. None of the patients died of complications within 30–90 days after surgery. Severe complications occurred in 16% (n = 7) of patients within 30–90 days. During a median follow-up of 51 months, disease progression was detected in 25 patients (56.8%), and 29 patients (65.9%) died of any cause. The median PFS and OS were 15.0 and 21.0 months, respectively. The Kaplan–Meier analysis indicated that patients with high ACCI scores or pT4b BCa had worse PFS (P = 0.003 and P = 0.002, respectively) and OS (P = 0.016 and P = 0.034, respectively) than those with low ACCI scores or pT4a BCa. On multivariate analysis, pT4b substage [hazard ratio (HR), 4.166; 95% CI, 1.549–11.206; P = 0.005] and ACCI score >4 (HR, 2.329; 95% CI, 1.105–4.908; P = 0.026) remained independent risk factors for PFS and OS, respectively.ConclusionOur study revealed that the pT4b substage is associated with a poor prognosis and that the ACCI score is a relevant and practical method to evaluate survival outcomes in patients with pT4 BCa after Cx.