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Considering that the perturbation of controller parameters may cause severe performance deterioration in practice, this work is focused on asynchronous resilient H∞control for discrete-time switched systems under average dwell time switching. The multiple non-monotonic Lyapunov function approach is employed to analyze the stability and H∞performance to reduce the conservation level. First, an H∞stability criterion is derived for general switched nonlinear systems, based on which a sufficient condition is further obtained for the resultant closed-loop system under asynchronous average dwell time switching. Then, a synthesis condition for a resilient output-feedback H∞controller is developed using Fensler’s lemma. Finally, the effectiveness and advantages of the proposed controller design method are demonstrated by two simulated examples.

Anaerobic biodegradation of crude oil is one of the main mechanisms for the formation of heavy oil and gas (referred to as crude oil degradation gas). With the Linfanjia area in the Jiyang Depression of the Bohai Bay Basin in eastern China taken as an example, we conducted a biodegradation simulation experiment on the conventional crude oil of well Y141-1 using cultured anaerobic microbial flora. The causes and characteristics of crude oil alteration and natural gas formation were studied by combining oil and gas geochemistry and carbon isotope data. The theoretical analysis and experimental results show that the saturated hydrocarbon content of crude oil is significantly reduced with the progress of anaerobic biodegradation, while the contents of aromatic compounds, resins, and asphaltenes remain relatively high. Crude oil components, such as n-alkanes and isoparaffins, undergo different degrees of biodegradation. The values of pristane (Pr)/phytane (Ph) and ∑C21–/∑C22+are significantly reduced, while the values of Pr/n-C17, Ph/n-C18, the carbon-preference index, the odd-over-even predominance, and 25-norhopane/hopane are relatively high. Biodegradation causes crude oil to continuously thicken to form heavy oil. Moreover, methane and carbon dioxide gas are produced as crude oil is degraded by anaerobic microorganisms; for example, the average production per gram of crude oil reaches 3 mmol of methane during 250 days of biodegradation. Both the carbon isotope values of methane (all less than −45‰) and carbon isotope values of carbon dioxide (all greater than 2‰) tend to become heavier, which are typical characteristics of crude oil degradation gas. Therefore, anaerobic biodegradation of crude oil can not only generate heavy oil but also produce a considerable amount of crude oil degradation gas that is mainly composed of methane. Data provide evidence for the large-scale methanogenic biodegradation of crude oil under anaerobic conditions during the geological period. Crude oil degradation gas and crude oil release gas together form the main sources of shallow gas reservoirs and at least 60% of the crude oil degradation gas in shallow gas reservoirs. The homologous symbiotic relationship and coupling distribution characteristics of heavy oil reservoirs and shallow gas reservoirs can provide a theoretical basis for the efficient joint exploration of both types of reservoirs.

This paper deals with the robust stabilization of continuous-time hybrid stochastic systems with time-varying delay by feedback controls based on discrete-time state observations. By employing the Razumikhin technique, delay-independent criteria to determine controllers and time lags are established just under a weaker condition that the time-varying delay should be a bounded function. Meanwhile, for the nondelay system, we obtain a better bound on the duration τ between two consecutive state observations. The new theory developed in this paper improves the existing results. Numerical examples are provided to demonstrate the effectiveness of our results. [ABSTRACT FROM AUTHOR]

Inter-salt shales are both important organic-rich sediments and shale oil exploration targets. This paper examines the controls on the composition of retained fluids in an inter-salt lacustrine shale oil system based on geochemical analysis of 125 samples with vitrinite reflectances of approximately 0.9% Rofrom a 50 m shale-rich sequence between two evaporites. Core samples were immediately stored at −50 °C to reduce the evaporative loss of hydrocarbons. The sequence is highly heterogeneous and includes siltstone, argillaceous mudstone, calcareous mudstone, dolomitic mudstone, and argillaceous dolomite. Source rock samples with higher TOC contents (>1.0 wt%) and higher genetic potentials (S1 + S2 > 2.0 mg HC/g rock) are typically calcareous mudstone, dolomitic mudstone, and argillaceous dolomite, and contain predominantly type II kerogen. Salinity controlled both bottom water deoxygenation and the development of carbonate minerals, and the increase in aquatic organisms (including prokaryotes and eukaryotes) leads to a positive relationship between OM richness and quality. High TOC (>2.0 wt%) samples contain oil-prone kerogens and have high absolute contents of liquid hydrocarbons (S1-1 > 0.2 mg HC/g rock, S1-2 > 1.0 mg HC/g rock), and high relative contents of liquid hydrocarbons [(S1-1 + S1-2)/(S1-1 + S1-2 + S2-1) > 0.45]. The amount of oil retained in source rock horizons is mainly controlled by the sorptive properties of the solid phase organic matter. Oils (S1) within siltstones are derived from adjacent source intervals; multi-stage temperature pyrolysis shows that they are lighter – and thus more readily produced - than the oils retained within the source intervals. Although the absolute amounts of oil in siltstones are lower than those in the source intervals, a smaller fraction is sorbed on solid phase organic matter, so that there are similar amounts of moveable oil in siltstones and source rocks. Interbedded siltstones, organic-rich calcareous mudstones, dolomitic mudstones, and argillaceous dolomites are all favourable intervals for inter-salt shale oil development.

A good understanding the effects of environmental factors on the spatial variety of soil organic carbon density (SOCD) helps achieve a relatively accurate estimation of the soil organic carbon stock of terrestrial ecosystems. The present study analysed the SOCD of 1033 top soil samples (0–20cm) from the Jinjing catchment located in subtropical China. Spatial variability of SOCD was estimated using a geostatistics method and a geographically weighted regression (GWR) model, and the major environmental factors affecting SOCD were also explored. In the present study, SOCD had a moderate spatial dependence and the best-fitting model was exponential with a nugget-to-sill ratio of 60.72% and a range of 182m. Land use types (woodlands, paddy fields and tea fields) and topography (elevation, slope, topographic wetness index (TWI)) affected the spatial variation of SOCD. Mean SOCD in the paddy fields was higher than in woodland and tea fields (3.50 vs 3.24 and 2.81kgCm-2 respectively; P<0.05). In addition, SOCD was generally higher in the valleys of paddy fields (with low slope and high TWI) and the hills of woodland (with high elevation and increased slope). GWR generated the spatial distribution of SOCD more accurately than ordinary kriging, inverse distance weighted, multiple linear regression model, and linear mixed-effects model. The results of the present study could enhance our understanding of the effects of land use and topography on SOCD, and improve the accuracy in predicting SOCD by GWR in small catchments of complex land use and topography.

The temporal-spatial geographic distribution of archaeological sites and its feature between 10.0–2.8 ka BP (ka BP= thousands of years before 0 BP, where “0 BP” is defined as the year AD 1950) were determined, based on GIS spatial analysis in the Poyang Lake Basin. The relationship between geographic distribution of sites of different periods under subsistence existence of ancient civilizations, climate and environmental change was investigated. The results revealed numerous archaeological sites of the Neolithic Age (10.0–3.6 ka BP). The sites were mainly located in the northern part of the Poyang Lake Basin, a hilly and mountainous area with many river terraces suitable for the development of human civilization. The number of archaeological sites rapidly increased during the Shang and Zhou dynasties (3.6–2.8 ka BP) and spread widely on the floodplains of the middle and lower reaches of Ganjiang River and onto the west, south, and southeast beach areas of the Poyang Lake. Holocene records of climate change suggested that it was possible that climate fluctuations had a great impact on human evolution in the study area. Before 3.6 ka BP, westward and northward expansion of Neolithic cultures in the Poyang Lake watershed occurred under the background of climate amelioration (becoming warmer and wetter). The ancient people lived in the hilly areas with high elevation. The simple mode of a fishing and gathering economy was mostly suited to this area in the early Neolithic Age. The scope of human activities was expanded and cultural diversity developed in the late Neolithic Age. However, with population growth and increasing survival pressure in a dry-cold climatic stage after 3.6 ka BP, this simple living mode had to be abandoned, and various forms of economy, the majority being agriculture, were developed on flood plains of the lower reaches of numerous rivers around Poyang Lake. This promoted flourishing of the Bronze culture of South China.

Nur77, encoded by Nr4a1(alias Nur77), plays roles in cell death, survival, and inflammation. To study the role of Nur77 in liver regeneration, wild-type (WT) and Nur77knockout (KO) mice were subjected to standard two-thirds partial hepatectomy (PH). Nur77mRNA and protein levels were markedly induced at 1 hour after PH in WT livers, coinciding with ERK1/2 activation. Surprisingly, Nur77KO mice exhibited a higher liver-to-body weight ratio than WT mice at 24, 48, and 72 hours after PH. Nur77KO livers exhibited increase in Ki-67–positive hepatocytes at 24 hours, with early induction of cell-cycle genes. Despite accelerated regeneration, Nur77KO livers paradoxically incurred necrosis, hepatocyte apoptosis, elevated serum alanine aminotransferase activity, and Kupffer cell accumulation. Microarray analysis revealed up-regulation of genes modulating inflammation, cell proliferation, and apoptosis but down-regulation (due to Nur77 deficiency) of glucose and lipid homeostasis genes. Levels of proinflammatory cytokines IL-6, IL-12, IL-23, and CCL2 were increased and levels of anti-inflammatory IL-10 were decreased, compared with WT. Activated NF-κB and STAT3 and mRNA levels of target genes Mycand Bcl2l1were elevated in Nur77KO livers. Overall, Nur77 appears essential for regulating early signaling of liver regeneration by modulating cytokine-mediated inflammatory, apoptotic, and energy mobilization processes. The accelerated liver regeneration observed in Nur77KO mice is likely due to a compensatory effect caused by injury.

Background: Dopamine transporter gene (SLC6A3)represents a promising candidate involved in the development of alcoholism. This study aimed to explore the association between the 9‐repeat allele (A9) of a 40‐bp variable number tandem repeat (VNTR) polymorphism in the 3′ un‐translated region (3′ UTR) of the SLC6A3gene and alcoholism.

This study compares the population and repair ability of bone marrow hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) in experimental colitis (EC) rat model after allogeneic stem-cell transplantation (SCT).

Despite the development in the last two decades of new imaging techniques for the detection of pancreatic disease, discrepancies between functional and morphological findings can be remarkable. Pancreatic function tests may aid in the detection of disease at an earlier stage in some patients and can assess the degree of functional damage which is helpful in assessing patients for supplemental therapy. While direct intubation methods are invasive and time consuming, they remain the gold standard against which the other investigations have to be assessed. An indirect test, such as the pancreolaural test, has been shown to be a useful addition to ultrasound for the screening of pancreatic disease. Pancreatic markers and radioisotope methods have failed to live up to early promise, but fecal tests can be used effectively to monitor enzyme replacement. A judicious combination of pancreatic function tests and imaging techniques may be able to rationalize investigation and treatment of pancreatic disease.

Exocrine pancreatic function tests (PFTs) remain of value in the diagnosis and assessment of chronic pancreatic disease. Direct intubation PFTs, using secretin/cholecystokinin or secretin/caerulein as the stimulants, continue to the the 'gold standard', although they are invasive, expensive and time consuming. Tubeless indirect tests, ie, the N-benzoyl-L-tyrosyl-para-aminobe-zoic acid and pancreolauryl tests, have gained increasing acceptance particularly as screening tests. The fecal measurement of chymotrypsin remains a useful screening test for pancreatic insufficiency and fecal fat testing standard for steatorrhea. Radioisotope tests are now outdated. Estimation of pancreatic markers in serum, urine and body fluids are useful when abnormal hut miss mild disease. Combining PFTs with imaging techniques provides a rational approach to early diagnosis and gives a better assessment of the patient with chronic pancreatic disease.