660MW超超临界燃煤机组灵活运行的燃煤掺配优化

某燃煤发电厂2×660 MW超超临界机组为了适应电网调峰的需求,探索入炉煤采用"炉前预混+分磨配煤"的方式,实现了精确配煤,在扩大煤种适应性的前提下,确保机组25%~100%负荷的灵活性运行.机组深调负荷过程中炉内稳定燃烧,锅炉升降负荷平稳,在电网负荷波动期间满足机组顶峰能力需求,机组运行效果良好.通过燃煤掺配的优化,在降低燃料成本的同时,实现机组环保、安全、经济和灵活性运行,对推动煤电"三改联动",实现煤电的健康可持续发展具有促进意义.

三种预测模型对中国流行性腮腺炎月度发病率预测的应用与比较

目的建立三种预测模型分析流行性腮腺炎的季节发病情况,为流行性腮腺炎的预测方法提供理论依据。方法收集2004年1月—2018年12月全国流行性腮腺炎月度发病率数据,训练集数据为2004年1月—2017年12月流行性腮腺炎月度发病率,分别建立季节性差分自回归移动平均(seasonal autoregressive integrated moving average,SARIMA)模型、温特线性与季节指数平滑(Winter linear and seasonal exponential smoothing,Holt-Winters)模型和神经网络自回归(neural network autoregressive,NNAR)模型,以2018年1—12月中国流行性腮腺炎月度发病率数据作为测试集,评估三种模型的预测效果。结果2004年1月—2018年12月全国流行性腮腺炎月度发病率最高月份是2012年6月,发病率最低月份是2016年2月,每年有两个发病高峰,大高峰发生在每年的4—7月,小高峰发生在每年的11月至次年1月;SARIMA模型、Holt-Winters模型和NNAR模型预测的平均相对误差的绝对值(mean absolute percentage error,MAPE)分别是18.63%、18.65%和16.31%,均方根误差(root mean square error,RMSE)分别为0.29、0.36和0.39,平均绝对误差(mean absoluteerror,MAE)0.26、0.30和0.30,R^(2)分别为93.43%、83.79%和78.24%。预测效果最好的为SARIMA模型,其次为Holt-Winters模型,NNAR模型的预测效果最差。结论SARIMA模型能很好地预测全国流行性腮腺炎的发病情况,可为今后流行性腮腺炎的预防控制工作提供借鉴方法。

Acupuncture plus naloxone hydrochloride in the treatment of coma after surgery for cerebral hemorrhage: a randomized controlled trial

Objective To observe the efficacy of acupuncture combined with naloxone hydrochloride in the treatment of coma after surgery for cerebral hemorrhage and to explore its possible mechanism of action.Methods Seventy-two patients were divided into a control group and an observation group according to the random number table method,with 36 cases in each group.The control group was treated with intravenous naloxone hydrochloride,and the observation group received additional acupuncture treatment.After 1 month of treatment,the awakening rate,Glasgow coma scale(GCS)score,cerebral edema volume,mean velocity(Vm)of the middle cerebral artery,and cerebrospinal fluid Caspase-3,and macrophage migration inhibitory factor(MIF)levels were compared between the two groups.Results During the study,there were 2 cases of shedding in the control group and 34 remaining valid cases;1 case of shedding in the observation group and 35 remaining valid cases.After treatment,the awakening rate was higher in the observation group than in the control group(P<0.05);the GCS score increased in both groups compared with that before treatment(P<0.05),and was higher in the observation group than in the control group(P<0.05);the volume of cerebral edema decreased in both groups(P<0.05),and was smaller in the observation group than in the control group(P<0.05);the middle cerebral artery Vm increased in both groups(P<0.05),and was higher in the observation group than in the control group(P<0.05);the cerebrospinal fluid Caspase-3 and MIF levels decreased significantly in both groups(P<0.05)and were lower in the observation group than in the control group(P<0.05).Conclusion Acupuncture combined with naloxone hydrochloride for the treatment of coma after surgery for cerebral hemorrhage can promote patients’awakening,improve the degree of coma,reduce the volume of cerebral edema,and enhance cerebral blood flow velocity,producing a better effect than naloxone hydrochloride used alone;it may be related to its reduction of cerebrospinal fluid Caspase-3 and MIF levels.