Normalmodenanalyse der Struktureigenschaften des asiatischen Sommermonsuns

This thesis is about normal mode analysis on multi-scale characteristics of Asian summer monsoons. In this study a new concept of utilizing generalized normal mode initialization (NMI) is introduced for climatic analysis and diagnosis. For the actual constitution of normal modes (NMs)in this study, a two layer shallow water model was selected. We used the 17 year-atmospheric data to construct the basic state with the summer mean over those 17 years and to define the actual anomalies of the special summers relative to the climatic mean. The highlight in this study about normal mode analysis of Asian Summer Monsoons is that for the first time the following were considered with the instability of the 3-D basic state: 1) the nonlinear dynamic balancing of NMI, 2) the effects of hard orography (not only quasi-linear effects of vorticity and divergence), 3) actual anomalies of special episodes relative to a climatic mean and 4) the normal mode group with a specific range of oscillation frequencies. The NMs and NMI were conducted in two experiment-groups: 1)impacts of SST-anomalies with ENSO on Asian summer monsoons and 2)interannual variability of Meiyu and connections to multi-scale oscillations of Asian summer monsoons and yielded the interesting conclusions on Asian monsoon climate. The important insight from this thesis is that MNs and NMI, which have been used in the numerical weather forecast, were successfully applied in climatic analysis of Asian summer monsoons. Compared with the other methods, NMs and NMI have two advantages: 1) the atmospheric circulation structures in different time scales can be identified with normal mode groups giving distinctive signals, and 2) the impacts of various physical processes on the atmospheric circulation or climate change can be detected from the complement of the actual atmosphere to the model solution

A New Model for Capturing the Spread of Computer Viruses on Complex-Networks

Based on complex network, this paper proposes a novel computer virus propagation model which is motivated by the traditional SEIRQ model. A systematic analysis of this new model shows that the virus-free equilibrium is globally asymptotically stable when its basic reproduction is less than one, and the viral equilibrium is globally attractive when the basic reproduction is greater than one. Some numerical simulations are finally given to illustrate the main results, implying that these results are applicable to depict the dynamics of virus propagation

Cause Analysis on Eastward Movement of Southwest China Vortex and Its Induced Heavy Rainfall in South China

The movement of southwest China vortex (SWV) and its heavy rainfall process in South China had been investigated during June 11–14, 2008. The results show that under the steering of upper-level jet (ULJ) and mid-level westerly trough, SWV moved eastward from southern Sichuan Plateau, across eastern Yunnan-Guizhou Plateau to South China, forming an obvious heavy rain belt. SWV developed in the large storm-relative helicity (SRH) environment, as environmental wind field continuously transferred positive vorticity to it to support its development. The thermodynamic structures of distinctive warm (cold) advections in front (rear) of the SWV movement are also important factors for the SWV evolutions with a southwest low-level jet (LLJ) and vertical wind shear. SWV development was associated with the distributions of negative MPV1 (the barotropic item of moist potential vorticity) and positive MPV2 (the baroclinic item of it). The MPV1 and MPV2 played the dominant role in the formation and the evolution of SWV, respectively. The mesoscale convective systems (MCSs) frequently occurred and persisted in water vapor convergence areas causing the severe heavy rainfall. The areas of high moist helicity divergence and heavy rainfall are consistent, and the moist helicity divergence could be a good indicator for heavy rainfall occurrence

Mesoscale aerosol numerical system developed in NMC, China

National Meteorogical Center(China)AQRM, Meterological Service of CanadaProceeding : International Symposium of Kanazawa University 21st-Century COE Program Vol.2(2004),Schedule: February 29(SUN)-March 3(WED), Venue: 29 FEB, Ishikawa Life-Long Learning Center(Former Prefectural Government Building) / 1-3 MAR Kanazawa Art Hall, Organized by: Kanazawa University 21st-Century COE Program / Ishikawa International Cooperation Research Centre / United Nations University-Institute of Advanced Studies, Supported by: Ishikawa Prefectural Government / City of Kanazawa, Eds : Hayakawa, Kazuichi / Kizu, Ryoichi / Kamata, Naok

Achievements and Challenges in Improving Air Quality in China: Analysis of the Long-Term Trends from 2014 to 2022

Due to the implementation of air pollution control measures in China, air quality has significantly improved, although there are still additional issues to be addressed. This study used the long-term trends of air pollutants to discuss the achievements and challenges in further improving air quality in China. The Kolmogorov-Zurbenko (KZ) filter and multiple-linear regression (MLR) were used to quantify the meteorology-related and emission-related trends of air pollutants from 2014 to 2022 in China. The KZ filter analysis showed that PM2.5 decreased by 7.36 ± 2.92% yr􀀀 1, while daily maximum 8-h ozone (MDA8 O3) showed an increasing trend with 3.71 ± 2.89% yr􀀀 1 in China. The decrease in PM2.5 and increase in MDA8 O3 were primarily attributed to changes in emission, with the relative contribution of 85.8% and 86.0%, respectively. Meteorology variations, including increased ambient temperature, boundary layer height, and reduced relative humidity, also contributed to the reduction of PM2.5 and the enhancement of MDA8 O3. The emission-related trends of PM2.5 and MDA8 O3 exhibited continuous decrease and increase, respectively, from 2014 to 2022, while the variation rates slowed during 2018–2020 compared to that during 2014–2017, highlighting the challenges in further improving air quality, particularly in simultaneously reducing PM2.5 and O3. This study recommends reducing NH3 emissions from the agriculture sector in rural areas and transport emissions in urban areas to further decrease PM2.5 levels. Addressing O3 pollution requires the reduction of O3 precursor gases based on site-specific atmospheric chemistry considerations

Drug repurposing screens identify Tubercidin as a potent antiviral agent against porcine nidovirus infections

The emergence of new coronaviruses poses a significant threat to animal husbandry and human health. Porcine epidemic diarrhea virus (PEDV) is considered a re-emerging porcine enteric coronavirus, which causes fatal watery diarrhea in piglets. Currently, there are no effective drugs to combat PEDV. Drug repurposing screens have emerged as an attractive strategy to accelerate antiviral drug discovery and development. Here, we screened 206 natural products for antiviral activity using live PEDV infection in Vero cells and identified ten candidate antiviral agents. Among them, Tubercidin, a nucleoside analog derived from Streptomyces tubercidicus, showed promising antiviral activity against PEDV infection. Furthermore, we demonstrated that Tubercidin exhibited significant antiviral activity against both classical and variant PEDV. Time of addition assay showed that Tubercidin displayed a significant inhibitory effect on viral post-entry events but not during other periods. Molecular docking analysis indicated that Tubercidin had better docking efficiency and formed hydrophobic interactions with the active pocket of RNA-dependent RNA polymerase (RdRp) of PEDV and other nidoviruses. Additionally, Tubercidin can effectively suppress other porcine nidoviruses, such as SADS-CoV and PRRSV, demonstrating its broad-spectrum antiviral properties. In summary, our findings provide valuable evidence for the antiviral activity of Tubercidin and offer insights into the development of new strategies for the prevention and treatment of coronavirus infections

A Modelling Study for Predicting Life of Downhole Tubes Considering Service Environmental Parameters and Stress

A modelling effort was made to try to predict the life of downhole tubes or casings, synthetically considering the effect of service influencing factors on corrosion rate. Based on the discussed corrosion mechanism and corrosion processes of downhole tubes, a mathematic model was established. For downhole tubes, the influencing factors are environmental parameters and stress, which vary with service duration. Stress and the environmental parameters including water content, partial pressure of H2S and CO2, pH value, total pressure and temperature, were considered to be time-dependent. Based on the model, life-span of an L80 downhole tube in oilfield Halfaya, an oilfield in Iraq, was predicted. The results show that life-span of the L80 downhole tube in Halfaya is 247 months (approximately 20 years) under initial stress of 0.1 yield strength and 641 months (approximately 53 years) under no initial stress, which indicates that an initial stress of 0.1 yield strength will reduce the life-span by more than half

Application progress of two-dimensional correlation spectroscopy in biomass

As a renewable resource, biomass resources have been widely concerned. The internal structure and changes of the graduate students play an important role in the utilization of biomass. Compared with conventional spectroscopy technology, two-dimensional correlation spectroscopy (2D-COS) can provide not only the characteristic information of each functional group, but also the interaction information between each functional group. Therefore, the application of two-dimensional correlation spectroscopy in biomass has attracted increasing attention. First introduced the 2D-COS technology, focusing on the application progress of 2D-COS in the internal structure of graduate student molecules and molecules, biomass energy utilization technology and other aspects. Finally, the existing problems and future prospects are analyzed