Selection Rules in Weak Interaction and Conservation of Fermion Quantum Number

Traditionally, in weak interaction, I3, Y and four flavour quantum numbers are not conserved but several empirical selection rules work well. Recently, it was found that, in weak interaction, there are three levels of conservation of additive quantum numbers, and fermion quantum number F is conserved in all kinds of interactions. It is known that weak interaction has three types: fermionic, pure hadronic and pure leptonic, corresponding to the first and the second level of conservation of additive quantum numbers respectively. It is demonstrated in this paper that the selection rules in all types of weak interaction can be interpreted by conservation of F, and the formula of relation between Q/e, F and F0 is more general than Gell-Mann-Nishijima formula. Description of weak interaction becomes simpler, If only we take Q, F0 and F, based on the conserved physical quantities.

Accelerating the construction of natural gas system engineering in green smart cities

Natural gas is a high-quality,high-efficiency,clean and low-carbon energy.The CO2 produced by its combustion accounts for only 55%of the combustion of coal and 80%of the combustion of petroleum.Natural gas combustion is almost free of sulfur,dust and other harmful substances,thus natural gas can form a benign complement with lowemission and renewable energy,such as electricity,which is an appropriate choice for urban clean energy supply(Ma,2017).A green smart city is composed of subsystems of organization(people),business/govemment affairs,transportation,communication,water and clean energy,among which a clean energy supply subsystem should be green,low carbon,safe,efficient,smart and friendly(Liu and Wang,2017).Natural gas can be used in residences,commerce,public utilities,distributed energy,and other fields in smart cities.

Smart oilfield development and transition of petroleum-based cities

Petroleum-based cities, whose economy and development mainly rely on natural petroleum exploitation, are facing severe economic, social, and environmental problems at present (Tan et al., 2016). The industrial structure of these cities is a relatively traditional industrial pattern, which is a petroleum-based and petroleum-intensive economy with comparatively low technology and efficiency levels (Dong et al., 2007). These cities have undertaken enormous stress of slow development in the rapidly developing society for which their situations must be changed.

Differences in clinical characteristics between younger and older patients with COVID-19 and their relationship with the length of hospital stay

Background:The coronavirus disease 2019(COVID-19)pandemic is currently threatening the health of individuals worldwide.We compared the clinical characteristics between younger patients(aged<60 years)and older patients(aged≥60 years)with COVID-19,detected the risk factors associated with a prolonged hospital stay,and examined the treatments commonly used with a particular focus on antiviral therapies.Methods:This retrospective study was conducted at the West Campus,Union Hospital affiliated to Tongji Medical College of Huazhong University of Science and Technology(Wuhan,China).The sample consisted of 123 patients admitted to the hospital between 9th February,2020,and 3rd March,2020.The data related to the demographics,laboratory findings,and treatment were analyzed to identify discrepancies between younger and older patients and those with and without primary diseases.The risk factors that contribute to a prolonged hospital stay were subsequently identified.Results:Patients aged≥60 years required longer hospital stay than younger patients(P=0.001).The percentage of lymphocytes was significantly lower in older patients and those with primary diseases(P=0.016 and P=0.042,respectively).The findings revealed that the risk factors that contributed to the length of hospital stay were age,the number of days of illness before hospitalization,white blood cell(WBC)count and albumin levels at admission,a neutrophil fraction at discharge,and antibiotic treatment.Analysis using a model that consisted of the above five risk factors for predicting prolonged hospital stay(>14 days)yielded an area under the ROC(AuROC)curve of 0.716.Antiviral and antibiotic treatments were administered to 97.6%and 39.0%of patients,respectively.The antiviral drugs most commonly administered were traditional Chinese medicine(83.7%)and arbidol(75.6%).Conclusions:In this study,older patients and those with primary diseases were at a higher risk of worse clinical manifestations.The physicians who treat the patients should pay close attention to the risk factors that contribute to the length of hospital stay,which could be used for predicting prolonged hospital stay.Traditional Chinese medicine and arbidol were the most frequently used antiviral drugs.Nevertheless,the extent to which these medications can effectively treat COVID-19 warrants further investigation.