Nonlinearity of Subtidal Estuarine Circulation in the Pearl River Estuary, China

The Pearl River Estuary (PRE) is a bell-shaped estuary with a narrow deep channel and wide shoals. This unique topographic feature leads to different dynamics of the subtidal estuarine circulation (SEC) in the PRE compared with a narrow and straight estuary. In this study, the nonlinear dynamics of the SEC in the PRE under mean circumstance are analyzed by using a validated 3D numerical model. Model results show that the nonlinear advections reach leading order in the along-channel momentum balance. Modulated by tide, the nonlinear advections show significant temporal variations as they have much larger values during spring tide than that during neap tide. Unlike straight and narrow estuaries, both tidally and cross-sectionally averaged axial and lateral advections play important roles in driving the SEC in the PRE in which the axial advection dominates the nonlinear effect, but the two nonlinear terms balance each other largely resulting in a reduced nonlinear effect. Despite this, the total nonlinear advection is still comparable with other terms, and it acts as the baroclinic pressure to reinforce the SEC, especially during the ebb tide, suggesting a flood–ebb asymmetry of the nonlinear dynamics in the PRE. In addition, diagnostic analyses of the along-channel vorticity budget show that nonlinear advections also make significant contribution to drive the lateral circulation in the PRE as Coriolis and baroclinic pressure terms, indicating complex dynamics of the circulation in the PRE

Coordinating Multiple Resources for Optimal Postdisaster Operation of Interdependent Electric Power and Natural Gas Distribution Systems

Electric power and natural gas systems are not separated but rather are increasingly connected physically and functionally interdependent due to the continuing development of natural gas-fired generation and gas industry electrification. Such interdependency makes these two systems interact with each other when responding to disasters. The aggravated risk of cascading failures across the two systems has been exposed in recent energy crises, highlighting the significance of preparing these interdependent systems against disasters and helping their impacted services quickly recover. This promotes us to treat power and gas systems as one whole to fully capture their interactive behaviors. In this paper, we focus on the interdependent electric power and natural gas distribution systems (IENDS) and propose a "supply - demand - repair" strategy to comprehensively help the IENDS tide over the emergency periods after disasters by coordinating mobile or stationary emergency resources for various uses. Specifically, 1) on the supply side, the fuel supply issue of different types of generators for emergency use is considered and the fuel delivery process among different fuel facilities is mathematically formulated; 2) on the demand side, a zonewise method is proposed for integrated dispatch of power and gas demand responses; and 3) in the repair process, a varying efficiency related to the repair units at work is introduced to accurately model repairs. The proposed strategy is formulated into a mixed-integer second-order cone programming model to obtain a globally optimal decision of deploying all of those resources in a coordinated and organized manner. A series of case studies based on test systems are conducted to validate the effectiveness of the proposed strategy.Comment: 31 pages, 9 figures, submitted to Applied Energ

Prevalence of hyperglycemia among adults with newly diagnosed HIV/AIDS in China

BACKGROUND: The prevalence of hyperglycemia among HIV-infected persons who are not receiving antiretroviral therapy is unknown. We conducted a cross-sectional survey to estimate the prevalence of hyperglycemia among Chinese adults with newly diagnosed HIV/AIDS. METHODS: Two thousand and six newly diagnosed HIV/AIDS patients from 10 provinces and municipalities in China were selected during 2009 to 2010. After an overnight fast, serum samples were collected to measure glucose concentrations. Demographics and medical histories were recorded. Factors associated with the presence of diabetes were analysed by logistic regression. RESULTS: Among the 2006 patients, 75.67% were male. Median age was 40 years (range: 18–86 years). 19.99% had hyperglycemia, 9.47% had impaired fasting glucose (IFG) and 10.52% had diabetes. The prevalences of hyperglycemia, of IFG and of diabetes were 21.54%, 10.28% and 11.27% among men and 15.16%, 6.97% and 8.20% among women, respectively. The prevalence of diabetes increased with increasing age (7.00%, 13.36% and 21.21% among patients who were 18–40, 40–60, and ≥60 years of age respectively) and with decreasing CD4 count (6.74%, 8.45%, 9.69%, and 12.66% among patients with CD4 count of ≥350, 200–350, 50–200, and < 50/mm(3) respectively). The prevalence of diabetes was higher among ethnic minority patients than among the Han patients (14.37% versus 9.24%). The logistic analysis showed that older age, lower CD4 count and minority ethnicity were significantly associated with an increased risk of diabetes. CONCLUSIONS: Hyperglycemia is highly prevalent among Chinese adults with newly diagnosed HIV/AIDS. Older age, lower CD4 count and minority ethnicity are associated with increased risk of diabetes. All newly diagnosed HIV/AIDS individuals should be routinely evaluated for hyperglycemia

Electrochemistry of myoglobin on graphene–SnO2 nanocomposite modified electrode and its electrocatalysis

AbstractIn this paper direct electrochemistry and electrocatalysis of myoglobin (Mb) immobilized on a graphene (GR)–SnO2 nanocomposite modified carbon ionic liquid electrode was reported. GR–SnO2 nanocomposite was synthesized by a simple solution method and further characterized by TEM and SEM, which exhibited large surface area beneficial for Mb immobilization. Spectroscopic results indicated Mb retained its native structure without denaturation after mixed with nanocomposite. Electrochemical investigation showed that a pair of well-defined redox peaks appeared on cyclic voltammogram, indicating that direct electron transfer of Mb with the underlying electrode was realized. The results could be attributed to the presence of GR–SnO2 nanocomposite that could enhance the electron transfer between the protein and the electrode. The Mb modified electrode exhibited good stability and catalytic activity to the electroreduction of NaNO2 in the concentration range from 0.2 to 350.0μmolL−1 with wider dynamic range and lower detection limit. Therefore the fabricated electrode has the potential application in the third-generation electrochemical biosensor

COVID-19 infection: the China and Italy perspectives.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the COVID-19 pandemic. Since its first report in December 2019, despite great efforts made in almost every country worldwide, this disease continues to spread globally, especially in most parts of Europe, Iran, and the United States. Here, we update the recent understanding in clinical characteristics, diagnosis strategies, as well as clinical management of COVID-19 in China as compared to Italy, with the purpose to integrate the China experience with the global efforts to outline references for prevention, basic research, treatment as well as final control of the disease. Being the first two countries we feel appropriate to evaluate the evolution of the disease as well as the early result of the treatment, in order to offer a different baseline to other countries. It is also interesting to compare two countries, with a very significant difference in population, where the morbidity and mortality has been so different, and unrelated to the size of the country