辽宁省辽阳灌区综合效益评价

针对辽阳灌区骨干工程特征、农业灌溉用水条件、自然环境和经济发展状况,将生态-社会-经济系统相耦合构建综合效益评估体系。依据各指标打分结果和灌区运行实际情况计算评价了灌区综合效益,在此基础上识别了灌区效益关键性要素。结果表明:耦合了生态、社会和经济效益的评估体系,有效规避了单一要素存在的片面性;高效节水灌溉项目的实施可大大提升辽阳灌区干渠以下斗、农、支渠的综合水利用系数,为提升灌区用水效率、管理水平、综合效益提供科学指导。

基于特征选择和支持向量机的电网线损异常分类与识别研究

电网线损异常是电力系统中的重要问题,对系统的运行和经济效益具有重要影响。文章旨在基于特征选择和支持向量机方法,进行电网线损异常的分类与识别研究。试验结果表明,提出的方法在电网线损异常的分类与识别中对单一和多元异常识别准确率分别为80.7692%和76.9231%。文章的方法对故障和非故障样本进行有效分类,并成功识别出电网线损隐患,为电力系统运行管理提供了重要支持。

高可用性和可靠性要求下的配电网规划与设备配置研究

文章采用了系统分析和规划方法,结合实地数据和模拟技术。通过对电网关键参数的分析,建立了电网的可靠性模型。提出了一种基于可靠性模型的配电网规划方法,以优化供电能力和设备配置。通过灵活调整电网的拓扑结构和设备布局,以及引入智能监控和故障自愈技术,提高电网的可用性和可靠性。研究表明,电网系统的运行稳定性得到了显著提升。

水利工程监理单位评标优选研究

科学合理的评标优选水利工程监理单位为保证工程建设质量的重要基础,从施工与监理招投标异同的角度阐述监理评标的内容条件、宗旨,在此基础上归纳与分析了监理评标方法;依据水利工程监理评标项目及其特点,选取管理实施方案、业绩与信誉、投标报价、人员配备、公司实力等指标构建监理评标体系,然后将各工程监理单位利用灰色模糊综合评判模型优选,并以工程案例验证了其可行性与可靠性,可为优选水利工程监理和完善监理评标体系提供科学指导。

The characteristics and future projections of fire danger in the areas around mega-city based on meteorological data–a case study of Beijing

It is crucial to investigate the characteristics of fire danger in the areas around Beijing to increase the accuracy of fire danger monitoring,forecasting,and management.Using meteorological data from 17 national meteorological stations in the areas around Beijing from 1981−2021,this study calculated the fire weather index(FWI)and analyzed its spatiotemporal characteristics.It was found that the high and low fire danger periods were in April−May and July−August,with spatial patterns of“decrease in the northwest−increase in the southeast”and a significant increase throughout the areas around Beijing,respectively.Next,the contributions of different meteorological factors were quantified by the multiple regression method.We found that during the high fire danger period,the northern and southern parts were affected by precipitation and minimum relative humidity,respectively.However,most areas were influenced by wind speed during the low fire danger period.Finally,comparing with the FWI characteristics under different SSP scenarios,we found that the FWI decreased during high fire danger period and increased during low fire danger period under different SSP scenarios(i.e.,SSP245,SSP585)for periods of 2021−2050,2071−2100,2021−2100,except for SSP245 in 2071−2100 with an increasing trend both in high and low fire danger periods.This study implies that there is a higher probability of FWI in the low fire danger period,threatening the ecological environment and human health.Therefore,it is necessary to enhance research on fire danger during the low fire danger period to improve the ability to predict summer fire danger.

Assessment of Urban Climate Environment and Configuration of Ventilation Corridor:A Refined Study in Xi'an

Integrating urban spatial landscape(USL) parameters into refined climate environment assessment is important. By taking the central urban area(CUA) of Xi’an, China as an example, this study develops an evaluation method based on Urban Climatic Map(UCMap) technology. We define surface urban heat island intensity(SUHI) and surface ventilation potential coefficient(VPC), which can effectively reflect local urban climate. Based on SUHI and VPC,we analyze the influences of seven typical USL metrics including building height(BH), building density(BD), floor area ratio(FAR), sky view factor(SVF), frontal area index(FAI), surface roughness length(RL), and vegetation cover(VC). Then, we construct a comprehensive evaluation model and create an urban climate zoning map on a 100-m resolution. The climate optimization on the map is performed for configuration of possible ventilation corridors and identification of associated control indicators. The results show that the main factors affecting SUHI in the CUA of Xi’an are VC and BD, which explain 87.9% of the variation in SUHI, while VPC explains 50% of the variation in SUHI. The main factors affecting VPC are BH, FAR, FAI, and RL, all of which contribute to more than 95% of the variation in VPC. The evaluation model constructed by SUHI, VPC, and VC can divide the CUA into climate resource spaces, climate preservation spaces, climate sensitive spaces, and climate restoration spaces. On this basis, a ventilation corridor network of 3 level-1 corridors(each over 500 m wide), 6 level-2 corridors(each over 500 m wide) and 13 level-3 corridors(each over 50 m wide) is established. Meanwhile, the main quantitative control indicators selected from the USL metrics are proved to be capable of ensuring smooth implementation of the planned corridors at different levels.

Clinical features and outcomes of 2019 novel coronavirus-infected patients with high plasma brain natriuretic peptide levels

Background As shown in previous studies,high brain natriuretic peptide(BNP)is one of common abnormal laboratory test results in some critical patients infected with 2019 novel coronavirus(2019-nCoV),while the role of BNP in the prognosis of coronavirus disease 2019(COVID-19)is still unknown.This study aims to investigate the effects of the increased BNP value on the outcomes of 2019-nCoV infected patients.Methods Our study initially included patients diagnosed with COVID-19 in Guangzhou Eighth People’s Hospital from January 20 th,2020 to February 24 th.After screening out the participants based on the exclusion criteria,a total of 34 participants were finally enrolled in our research for retrospective analysis.The primary outcome was severe pneumonia defined according to the international guidelines for community-acquired pneumonia.Clinical characteristics and laboratory data were collected from their medical records.Results The best cut-off value of BNP for predicting severe pneumonia was 97.5 pg/mL with the sensitivity for 80%and the specificity for 91.7%.The median age for high BNP level group(>97.5 pg/mL)was 60.5 years(interquartile range:40-80 years).The ratio of males in those patients was 60.0%.Compared with the normal BNP level group,higher temperature(P=0.09),higher values of aspartate aminotransferase(P=0.02),troponin I(P<0.001),C-reactive protein(P<0.001)and myoglobin(P=0.001)as well as lower levels of hemoglobin(P=0.04)and platelet count(P=0.001)were observed in the high BNP group.Multivariable logistic regression demonstrated that 2019-nCoV infected patients with high BNP were more likely to develop severe pneumonia(OR:17.368,P=0.025)and be admitted to the intensive care unit(OR:27.093,P=0.048).Conclusions The increased level of BNP is associated with the undesirable condition and disease aggravation of patients with COVID-19.BNP is expected to be an independent prognostic predictor of clinical outcomes for patients with COVID-19.

The association between the level of serum conjugated bilirubin and mortality in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention

Background Even with percutaneous coronary intervention(PCI),patients with ST-segment elevation myocardial infarction(STEMI)faced a substantial mortality.We aimed to evaluate the relationship between the level of bilirubin and mortality in patients with STEMI undergoing PCI.Methods Patients with the diagnosis of STEMI and subsequently treated with PCI was enrolled retrospectively in Guangzhou Eighth People's Hospital,from March2013 to October 2019.The primary clinical outcome was in-hospital death,and the secondary clinical outcome was one-year mortality.Results Overall,844 patients were included.The receiver-operation characteristics(ROC)curves analysis showed a higher discriminative ability for conjugated bilirubin(CB=0.805,95%CI:0.703-0.907,P<0.001)in predicting in-hospital death,compared to total bilirubin(TB).Patients were divided into a lower CB group(CB<5.7 umol/L,n=656)and a higher CB group(CB≥5.7 umol/L,n=188).There were 6(0.9%)patients died in the lower CB group,and 17(9.0%)patients died in the higher CB group(P<0.001).In the univariate Logistic regression analysis,CB≥5.7 umol/L were associated with in-hospital death(OR=10.77,P<0.001).After adjusting confounding factors,CB≥5.7 umol/L was independently correlated with in-hospital death(OR=5.13,95%CI:1.67-15.75,P=0.004).During one-year follow-up,there were 69(10.5%)patients died in the lower CB group and40(21.3%)patients died in the higher CB group(log-rank=41.90,P<0.001).The multivariate Cox regression analysis showed that CB≥5.7 umol/L was independently associated with one-year mortality(HR=2.45,95%CI:1.37-4.40,P=0.003).Conclusions CB could be a feasible biomarker in differentiating high-risk STEMI patients treated with PCI.