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The quantitative evaluation of multi-process collaborative operation is of great significance for the improvement of production planning and scheduling in steelmaking-continuous casting sections (SCCSs). However, this evaluation is difficult since it relies on an in-depth understanding of the operating mechanism of SCCSs, and few existing methods can be used to conduct the evaluation, due to the lack of full-scale consideration of the multiple factors related to the production operation. In this study, three quantitative models were developed, and the multiprocess collaborative operation level was evaluated through the laminar-flow operation degree, the process matching degree, and the scheduling strategy availability degree. Based on the evaluation models for the laminar-flow operation and process matching levels, this study investigated the production status of two steelmaking plants, plants A and B, based on actual production data. The average laminar-flow operation (process matching) degrees of SCCSs were obtained as 0.638 (0.610) and 1.000 (0.759) for plants A and B, respectively, for the period of April to July 2019. Then, a scheduling strategy based on the optimization of the furnace-caster coordinating mode was suggested for plant A. Simulation experiments showed higher availability than the greedy-based and manual strategies. After the proposed scheduling strategy was applied, the average process matching degree of the SCCS of plant A increased by 4.6% for the period of September to November 2019. The multi-process collaborative operation level was improved with fewer adjustments and interruptions in casting.

Intelligent iron/steel manufacturing has been drawing increasing attention in recent years. Slagging is of importance for clean steel production in the ladle furnace (LF) refining process. In this ...

Objective To explore the morbidity of chronic obstructive pulmonary disease (COPD) related complications and mortality of the COPD patients, and analyze the risk factors for complications. Methods 1829 COPD patients were collected from Department of Respiratory and Critical Care Medicine Center of the Second Affiliated Hospital of Army Medical University and Department of Respiratory of the People's Hospital of Fengdu County from January 2018 to December 2018. Then, the morbidity and mortality of the complication were observed, meanwhile, the risk factors were analyzed by multifactor logistic regression. Results 89.2%(1631/1829) of COPD patients complicated with other diseases, the mortality rate was 2.5%(46/1829). The complications main included respiratory and cardiovascular system diseases, the mortality rates were 68.8% and 34.4%, respectively. Then, the data indicated that the disease with the highest mortality rate was nervous system diseases, which was 9.3%, especially pulmonary encephalopathy, the mortality rate was 21.7%. Furthermore, logistic regression analysis showed that age over 80 years, smoking long than 20 years, smoking more than 700 cigarettes per year, drinking, C-reactive protein (CRP) more than 50 mg/L, hyperglycemia and hypoproteinemia were the risk factors of COPD with complications (OR=3.488, 4.085, 4.086, 2.464, 2.208, 2.066, 11.804). Conclusion The incidence of COPD complications is relatively high, and the mortality also increase obviously. Therefore, more attention should be payed to the treatment and prevention for complications of COPD. DOI: 10.11855/j.issn.0577-7402.2020.08.08

Desulphurization is essential in the steelmaking process for high-quality steel production, and sulphide capacity has proven to be an effective index to evaluate the desulphurization ability of mol...

Common burden tests have different statistical performance in genetic association studies of rare variants. Here, we compare the statistical performance of burden tests, such as CMC, WST, SUM and extension methods, using the computer-simulated datasets of rare variants with different parameters of sample sizes, linkage disequilibrium (LD), and different numbers of mixed non-associated variants. The simulation results showed that the type I error for all methods is near 0.05. When the rare variants had the same direction of effect, the higher LD and the less non-associated variants, the higher the power of these method, except the data adaptive SUM test. When the direction was different, the power was significantly reduced for all methods. The methods that consider the direction yielded larger statistical power than those methods without considering the effect direction, except the strong LD condition. And the larger the sample size, the larger the power. The statistical performance of burden tests is affected by a variety of factors, including the sample size, effect direction of variants, non-associated variants, and LD. Therefore, when choosing the method and setting the collection unit and weight, the prior biological information of genetic variation should be integrated to improve study efficiency.

In this study, we analyze spring precipitation from 92 meteorological stations spanning between 1961 and 2012 to understand temporal–spatial variability and change of spring precipitation over Southwest China. Various analysis methods are used for different purposes, including empirical orthogonal function (EOF) analysis and rotated EOF (REOF) for analyzing spatial structure change of precipitation anomaly, and the Mann–Kendall testing method to determine whether there were abrupt changes during the analyzed time span. We find that the first spatial mode of the precipitation has a domain uniform structure; the second is dominated by a spatial dipole; and the third contains five variability centers. The 2000s is the decade with the largest amount of precipitation while the 1990s is the decade with the smallest amount of precipitation. The year-to-year difference of that region is large: the amount of the largest precipitation year doubles that of the smallest precipitation year. We also find that spring precipitation in Southwest China experienced a few abrupt changes: a sudden increase at 1966, a sudden decrease at 1979, and a sudden increase at 1995. We speculate that the spring precipitation will increase gradually in the next two decades.