21 research outputs found

    Does participation in poverty alleviation programmes increase subjective well-being? Results from a survey of rural residents in Shanxi, China

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    Government programme interventions that improve rural settlements are expected to foster human development. Although existing studies have shown that rural dwellers can economically benefit from programme participation, relatively little is known about whether their subjective well-being has improved. To shed new insights, in this study, we estimate the impact of participation in China’s targeted poverty alleviation (TPA) programme on subjective well-being using survey data from 542 rural dwellers collected from poverty-stricken areas in China. A second-order confirmatory factor analysis model was applied to obtain a comprehensive measurement of subjective well-being by utilising four commonly used measurement scales. The results show that TPA participants do not manifest significantly different subjective well-being compared to their non-participant counterparts. The subjective well-being of rural dwellers is positively influenced by age, marital status, dependency ratio, and income, but negatively influenced by illness. Rural dwellers’ TPA programme participation is positively associated with gender, illness, and farmland size, but negatively correlated with education, marital status, and dependency ratio

    Deep carbon dioxide flows substantially contributes to soil-atmosphere carbon flux from Robinia pseudoacacia forests

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    Alterations in land use and vegetation cover cause CO2 transfer not only to the soil surface but also across soil profiles. To explore the vertical diffusion characteristics of CO2 in deep soil profiles and their driving factors, we calculated CO2 flux and measured environmental factors in sections situated from 0 to 200 cm in Robinia pseudoacacia forests (Loess Hilly Region, China). The results found that (1) Deep soils (>80 cm) exhibited a stable contribution to the soil-atomosphere CO2 flux, ranging from 21.81% to 24.42%. (2) The total CO2 storage within deep layers accounted for 55.03–79.98% of the total storage in the layer at 0–200 cm. The stable storage of CO2 at deep layers helped suppress the mineralization of organic carbon in deep soil; (3) Soil temperature, moisture, CO2 concentration, aerated porosity, SOC content, bulk density, total porosity, root density, microbial biomass carbon (MBC), pH, and profile depth explained 86.0% and 89.1% of the variance in CO2 flux at shallow and deep layers, respectively. Soil moisture was the key limiting factor for vertical differentiation of CO2 fluxes in deep and shallow layers. The sensitivity of temperature and aerated porosity on CO2 flux increased with soil depth increasing. While the soil microbial biomass carbon had a weaker effect on CO2 flux both in the deep and shallow layers. Root stimulation was more likely to induce CO2 emission in deep layers. However, increase of pH was more conducive to CO2 fixation and flux reduction in deep layers. Our results help to further clarify the mechanisms of carbon emission in deep soil carbon pools, and provide a theoretical basis for scientific evaluation of soil carbon emissions

    Social pensions and risky financial asset holding in China

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    This study explores the impact of social pensions on risky household financial asset holding, taking the Urban and Rural Residents Pension Scheme (URRPS) in China as an example. We combine regression discontinuity with the difference-in-difference approach to analyse the 2015 and 2017 China Household Finance Survey (CHFS) data. The results show that the URRPS has significantly increased the likelihood of holding risky financial assets among Chinese households. Furthermore, the effect is larger for urban households than for rural households. Apart from social pensions, marital and health status, education, risk attitude, household size, asset value, and urban residence also affect the households’ risky financial asset holdings

    Significance of three reservoir profiles for the risk exploration in Ordos Basin

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    The Ordos Basin went through six main stages of geological evolution, developed three sets of soure rocks, two unconformities, several sets of reservoirs and caprocks, and had three typical petroleum systems, i.e. Lower Paleozoic Ordovician gas reservoirs, Upper Paleozoic Carboniferous-Permian gas reservoirs, and Mesozoic Triassic-Jurassic oil reservoirs. Three well-tie profiles of oil and gas reservoirs in the basin are analyzed, which are the Wuzhong-Mizhi profile, Guyuan-Yichuan profile, and Baotou-Chengcheng profile. The size and distribution of the oil and gas reservoirs are controlled by the spatial distribution of soure rocks. Mesozoic oil reservoirs are located inside or near hydrocarbon depressions, where oil and gas had a short secondary migration distance. Paleozoic gas in the basin, after having a large-scale short migration in the range of source rocks, eventually gathered in the effective traps of the Ordovician weathering crust, and in the low permeability effective sand traps inside or near Carboniferous-Permian source rocks. The future risk exploration targets are: (1) for Mesozoic oil exploration, it will extend northward and explore unconventional reservoirs in source rocks; (2) for Upper Paleozoic gas exploration, it will extend southward and explore marine clastic gas reserviors; (3) for Lower Paleozoic gas exploration, it will search for lithologic-structural traps of carbonate weathering crust in the north-central and southeastern Yishan slope and those of carbonate reef flat. Key words: Ordos Basin, reservoir profile, petroleum system, risk exploratio

    Numerical analysis of a compact all-fiber polarization beam splitter based on dual-core photonic crystal fiber with As2S3 thin layer

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    Modern-day optical systems are evolving towards miniaturization and integration, leading to higher performance demands for polarizing beam splitters (PBSs). A simple-structure and high-performance PBS based on dual-core photonic crystal fiber (DC-PCF) with As2S3 layer is proposed. The finite element method (FEM) and classical coupled-mode theory (CMT) are utilized to investigate the performance of this PBS. Simulation results demonstrate that the proposed PBS can achieve a minimum length of 2.65 mm, a minimum extinction ratio of −64 dB, an operating bandwidth of 420 nm, and a minimum insertion loss of 0.03 dB when the optimal parameters include cladding hole diameter of 1.0 μm, central hole diameter of 2.0 μm, lattice spacing of 2.0 μm, and As2S3 ring layer thickness of 50 nm. Moreover, it also possesses a high birefringence of 3.58 × 10−3 and a negative dispersion of −30 ps/km/nm at 1.55 μm. It is believed that the proposed PBS holds great potential to become a critical device in optical multiplexing technologies

    Acute Effects of Air Pollution on Ischemic Heart Disease Hospitalizations: A Population-Based Time-Series Study in Wuhan, China, 2017–2018

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    Evidence of the acute effects of air pollutants on ischemic heart disease (IHD) hospitalizations based on the entire population of a megacity in central China is lacking. All IHD hospitalization records from 2017 to 2018 were obtained from the Wuhan Information Center of Health and Family Planning. Daily air pollutant concentrations and meteorological data were synchronously collected from the Wuhan Environmental Protection Bureau. A time-series study using generalized additive models was conducted to systematically examine the associations between air pollutants and IHD hospitalizations. Stratified analyses by gender, age, season, hypertension, diabetes, and hyperlipidemia were performed. In total, 139,616 IHD hospitalizations were included. Short-term exposure to air pollutants was positively associated with IHD hospitalizations. The age group ≥76 was at higher exposure risk, and the associations appeared to be more evident in cold seasons. PM2.5 and PM10 appeared to have greater effects on males and those without hypertension or diabetes, whereas NO2 and SO2 had greater effects on females and those with hypertension or diabetes. The risk of IHD hospitalization due to air pollutants was greater in people without hyperlipidemia. Our study provides new evidence of the effects of air pollution on the increased incidence of IHD in central China

    Left ventricular-arterial coupling is associated with prolonged mechanical ventilation in severe post-cardiac surgery patients: an observational study

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    Abstract Background Weaning post-cardiac surgery patients from mechanical ventilation (MV) poses a big challenge to these patients. Optimized left ventricular-arterial coupling (VAC) may be crucial for reducing the MV duration of these patients. However, there is no research exploring the relationship between VAC and the duration of MV. We performed this study to investigate the relationship between left ventricular-arterial coupling (VAC) and prolonged mechanical ventilation (MV) in severe post-cardiac surgery patients. Methods This was a single-center retrospective study of 56 severe post-cardiac surgery patients from January 2015 to December 2017 at the Department of Critical Care Medicine of Peking Union Medical College Hospital. Patients were divided into two groups according to the duration of MV (PMV group: prolonged mechanical ventilation group, MV > 6 days; Non-PMV group: non-prolonged mechanical ventilation group, MV ≤ 6 days). Hemodynamics and tissue perfusion data were collected or calculated at admission (T0) and 48 h after admission (T1) to the ICU. Results In terms of hemodynamic and tissue perfusion data, there were no differences between the two groups at admission (T0). Compared with the non-prolonged MV group after 48 h in the ICU (T1), the prolonged MV group had significantly higher values for heart rate (108 ± 13 vs 97 ± 12, P = 0.018), lactate (2.42 ± 1.24 vs.1.46 ± 0.58, P < 0.001), and Ea/Ees (5.93 ± 1.81 vs. 4.05 ± 1.20, P < 0.001). Increased Ea/Ees (odds ratio, 7.305; 95% CI, 1.181–45.168; P = 0.032) and lactate at T1 (odds ratio, 17.796; 95% CI, 1.377–229.988; P = 0.027) were independently associated with prolonged MV. There was a significant relationship between Ea/EesT1 and the duration of MV (r = 0.512, P < 0.01). The area under the receiver operating characteristic (AUC) of the left VAC for predicting prolonged MV was 0.801, and the cutoff value for Ea/Ees was 5.12, with 65.0% sensitivity and 90.0% specificity. Conclusions Left ventricular-arterial coupling was associated with prolonged mechanical ventilation in severe post-cardiac surgery patients. The assessment and optimization of left VAC might be helpful in reducing duration of MV in these patients

    Natural gas accumulation and models in Ordovician carbonates, Ordos Basin, NW China

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    According to sedimentary environment, sources, hydrocarbon accumulation characteristics and gas reservoir types of the Ordovician in the Ordos Basin, the Ordovician carbonate rocks in the basin have good gas accumulation conditions. A large number of geological and geochemical evidence shows a triple source supply. In addition to the Upper Carboniferous – Permian coal measures hydrocarbon source rocks as the main hydrocarbon source rocks, the Middle-Upper Ordovician marine hydrocarbon source rocks and Carboniferous Benxi marlstones have certain ability for hydrocarbon. Analysis of the known gas reservoir reveals that the gas in the gas fields of the central basin belongs to thermal cracking gas which is a mixed gas of coal-derived gas and crude oil cracking gas. Coal-derived gas comes from the coal measures hydrocarbon source rocks of the Carboniferous-Permian undoubtedly. Crude oil cracking gas mainly comes from the high temperature cracking gas in the Jurassic reservoir. Asphalts and hydrocarbon inclusions in the Ordovician reservoirs evidence that the oil of the Jurassic paleo-oil reservoir is mainly from the Middle-Upper Ordovician marine hydrocarbon source rocks. Gas accumulation has evolved from oil reservoir to gas reservoir: oil pool formed in the Jurassic and the oil cracked into gas in the Cretaceous. Controlled by tectonic sedimentary setting, four accumulation models of carbonate gas reservoir have been structured. Among them, weathering crust lithostratigraphic gas reservoir in the central part of the basin and composite lithology gas reservoir of structure – bedding karst type in the northwest platform marginal zone are the focus of the carbonate gas exploration. Key words: Ordos Basin, Ordovician, carbonate, hydrocarbon source rock, accumulation characteristics, accumulation evolution, gas reservoir mode

    Accumulation conditions and exploration directions of Ordovician lower assemblage natural gas, Ordos Basin, NW China

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    Based on drilling cores, well logging and seismic data, source rocks and reservoirs are evaluated; and the natural gas genesis is identified through the analysis of natural gas isotopes, components and fluid inclusions, to study the gas accumulation conditions of the gypsum salt rock related strata of the Ordovician lower assemblage in Ordos Basin. (1) The natural gas from Ordovician lower assemblage is high thermal evolution dry gas from marine source rock, characterized by relatively light δ13C value of methane and heavy δ13C value of ethane. The natural gas is identified as gas cracking from crude oil according to component analysis. Thermochemical sulfate reduction (TSR) reaction has happened between the hydrocarbon fluid and sulfate as sulfur crystals are found in the cores, hydrogen sulfide is found in the natural gas, and hydrocarbon and hydrogen sulfide fluid inclusions are widespread in secondary minerals. (2) Around the gypsum-salt lows, argillaceous rocks are extensive in the Ordovician lower assemblage, reaching a cumulative thickness of 20–80 m. The effective source rocks include argillaceous rock rich in organic laminae, algal clump and algal dolomite. Analysis shows that the source rocks have a dominant TOC of 0.1%–0.5%, 0.31% on average and 3.24% at maximum. The source rocks have an average TOC of 0.58% after recovered through organic acid salt method, indicating the source rocks have high hydrocarbon supply potential. (3) In the sedimentary period, the palaeo-uplift controlled the distribution of reservoirs. The inherited secondary palaeo-uplift in Wushenqi–Jingbian east of the central palaeo-uplift and the low uplift formed by thick salt rocks near Shenmu–Zizhou area controlled the distribution of penecontemporaneous grain shoal dolomite reservoirs. The salinization sedimentary environment of gypsum salt rock can promote the development of reservoir. There are three types of dolomite reservoirs, the one with intercrystalline pore, with dissolution pore, and with fracture; intercrystalline and dissolution pores are main reservoir spaces. (4) There are two types of cap rocks, namely tight carbonate rock and gypsum-salt rock, constituting two types of source-reservoir-cap assemblages respectively. The general accumulation model is characterized by marine source rock supplying hydrocarbon, beach facies limy dolomite reservoir, small fractures acting as migration pathways, and structural-lithologic traps as accumulation zones. (5) The third and fourth members of Majiagou Formation are major target layers in the lower assemblage. The Wushengqi–Jingbian secondary paleo-uplift area and Shenmu–Zizhou low uplift are dolomite and limestone transition zone, there develops tight limestone to the east of the uplift zone, which is conducive to the formation of gas reservoir sealed by lithology in the updip. Two risk exploration wells drilled recently have encouraging results, indicating that the two uplift zones are important prospects

    Progress in construction of bio-inspired physico-antimicrobial surfaces

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    Bacteria are widely distributed in the natural environment and the surfaces of objects, bringing about much trouble in our lives. Varies nanomaterials have been demonstrated good effect on killing microbe, but the consistency and stability seem to be improved. Recently, antibacterial effect on surfaces of some natural nanostructures was recognized, and more and more evidences were provided as a new type of bactericidal mechanism, the physical sterilization. The dragonfly and cicada wings have been found to possess the most exceptional antibacterial properties because of the specific nanostructure. Inspired by the biofunctions, researchers began to build a series of physico-antimicrobial surfaces on different materials to avoid the abuse of antibiotics and the environmental pollution of organic antibacterial agents. The physico-antimicrobial structure does not rely on chemical components, and a series of physico-antimicrobial models have been established. To deeply understand the physically bactericidal effect, this article reviews a series of natural and biomimetic physical antibacterial surfaces and makes reasonable expectations for the application of such composite materials in constructing physical antibacterial surfaces
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