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Several previous researches had found artery stiffness associated skeletal muscle mass, but not considering muscle strength and physical performance, which also were compositions of sarcopenia. This study aims to reveal the relationship of artery stiffness and sarcopenia using the Asian Working Group for Sarcopenia criteria. Study was performed on 1002 Chinese community dwelling participants aged ≥65 years from November 2016 to March 2017. Body composition, muscle strength, physical performance, and brachial-ankle pulse wave velocity (baPWV) considering as artery stiffness index were measured. In multiple regression analysis, baPWV was associated with handgrip (β=−0.13, P=0.04) and Relative skeletal muscle mass index (ASM/Ht2) (β=−0.02, P<0.01), but not with 4-meter velocity (P=0.21). Multiple logistic regression analysis showed that 1-SD (3.50m/s) increased in baPWV was still associated with a 11% (CI, 4%–20%; P<0.01) higher odds of being sarcopenia. In the gender subgroup analysis, the relationship of baPWV and sarcopenia remain significant in men (OR, 1.23; 95% CI, 1.07–1.42, P<0.01), but not in women (P=0.07). High brachial-ankle pulse wave velocity is associated with sarcopenia in Chinese community-dwelling elderly, with gender differences.

The mitigation of air pollution in megacities remains a great challenge because of the complex sources and formation mechanisms of aerosol particles. The 2014 Asia-Pacific Economic Cooperation (APEC) summit in Beijing serves as a unique experiment to study the impacts of emission controls on aerosol composition, size distributions, and oxidation properties. Herein, a high-resolution time-of-flight aerosol mass spectrometer was deployed in urban Beijing for real-time measurements of size-resolved non-refractory submicron aerosol (NR-PM1) species from 14 October to 12 November 2014, along with a range of collocated measurements. The average (±σ) PM1 was 41.6 (±38.9) μg m−3 during APEC, which was decreased by 53 % compared with that before APEC. The aerosol composition showed substantial changes owing to emission controls during APEC. Secondary inorganic aerosol (SIA: sulfate + nitrate + ammonium) showed significant reductions of 62–69 %, whereas organics presented much smaller decreases (35 %). The results from the positive matrix factorization of organic aerosol (OA) indicated that highly oxidized secondary organic aerosol (SOA) showed decreases similar to those of SIA during APEC. However, primary organic aerosol (POA) from cooking, traffic, and biomass-burning sources were comparable to those before APEC, indicating the presence of strong local source emissions. The oxidation properties showed corresponding changes in response to OA composition. The average oxygen-to-carbon level during APEC was 0.36 (±0.10), which is lower than the 0.43 (±0.13) measured before APEC, demonstrating a decrease in the OA oxidation degree. The changes in size distributions of primary and secondary species varied during APEC. SIA and SOA showed significant reductions in large accumulation modes with peak diameters shifting from ~ 650 to 400 nm during APEC, whereas those of POA remained relatively unchanged. The changes in aerosol composition, size distributions, and oxidation degrees during the aging processes were further illustrated in a case study of a severe haze episode. Our results elucidated a complex response of aerosol chemistry to emission controls, which has significant implications that emission controls over regional scales can substantially reduce secondary particulates. However, stricter emission controls for local source emissions are needed for further mitigating air pollution in the megacity of Beijing.

The megacity of Beijing has experienced frequent severe fine particle pollution during the last decade. Although the sources and formation mechanisms of aerosol particles have been extensively investigated on the basis of ground measurements, real-time characterization of aerosol particle composition and sources above the urban canopy in Beijing is rare. In this study, we conducted real-time measurements of non-refractory submicron aerosol (NR-PM1) composition at 260 m at the Beijing 325 m meteorological tower (BMT) from 10 October to 12 November 2014, by using an aerosol chemical speciation monitor (ACSM) along with synchronous measurements of size-resolved NR-PM1 composition near ground level using a high-resolution time-of-flight aerosol mass spectrometer (HR–ToF–AMS). The NR-PM1 composition above the urban canopy was dominated by organics (46 %), followed by nitrate (27 %) and sulfate (13 %). The high contribution of nitrate and high NO3− / SO42− mass ratios illustrates an important role of nitrate in particulate matter (PM) pollution during the study period. The organic aerosol (OA) was mainly composed of secondary OA (SOA), accounting for 61 % on an average. Different from that measured at the ground site, primary OA (POA) correlated moderately with SOA, likely suggesting a high contribution from regional transport above the urban canopy. The Asia–Pacific Economic Cooperation (APEC) summit with strict emission controls provides a unique opportunity to study the impacts of emission controls on aerosol chemistry. All aerosol species were shown to have significant decreases of 40–80 % during APEC from those measured before APEC, suggesting that emission controls over regional scales substantially reduced PM levels. However, the bulk aerosol composition was relatively similar before and during APEC as a result of synergetic controls of aerosol precursors. In addition to emission controls, the routine circulations of mountain–valley breezes were also found to play an important role in alleviating PM levels and achieving the \"APEC blue\" effect. The evolution of vertical differences between 260 m and the ground level was also investigated. Our results show complex vertical differences during the formation and evolution of severe haze episodes that are closely related to aerosol sources and boundary-layer dynamics.

The changes in breakup time of the Antarctic polar vortex in the years 1980–2004 are examined using the output of chemistry climate model (CCM) calculations, data from the National Centers for Environmental Prediction/the National Center for Atmospheric Research (NCEP/NCAR) Reanalysis, and data from the European Center for Medium‐Range Weather Forecasts Reanalysis (ERA40). The CCM used in this study is from the Center for Climate System Research/National Institute for Environmental Studies (CCSR/NIES). The CCM calculations are performed with the two ensemble members for REF1 scenario of the chemistry climate model validation (CCMVal) and the one ensemble member for the REF2 scenario. CCM simulates the development of the ozone hole from 1982 to 2000, as observed with a total ozone mapping spectrometer (TOMS), although the year‐to‐year variation is different from the observation owing to the internal variability of CCM and the ozone decreasing trends of CCM ozone in the two ensemble members of REF1 are underestimated. The trends in temperature and zonal mean zonal wind are analyzed and compared with the observations. There is consistency among the trends in zonal mean temperature, zonal mean zonal wind, and total ozone, but they differ among the ensemble members and observations. The diabatic heating rates and Eliassen‐Palm flux fields are investigated in order to explain the differences. A delay trend in the breakup time of the Antarctic polar vortex is obtained for the period of 1980–1999 in the NCEP/NCAR and ERA40 data. A similar trend is also obtained from the CCM simulations, with statistical significance in one ensemble member of REF1 and REF2. Because the trends of the observations in the EP flux from the troposphere and its deposition in the lower stratosphere are consistent with an advanced breakup date of the polar vortex and because the trends of the CCM simulations are very small, it is likely that the Antarctic ozone depletion had some effect on the delay during the period 1980–1999. From 2000 to 2004, the NCEP/NCAR data show a large variation in breakup time, which makes the delay trend much less important. It is likely that the large variation in wave flux masked the effects of the ozone loss during that period. The two ensemble members of the REF1 simulation do not show such a dramatic change in the trend for the period 2000–2004, whereas REF2 shows a change in the trend for that period.

Return times to 1980 values of ozone and the halogen concentrations in the future atmosphere were examined using the outputs of the Center for Climate System Research/National Institute for Environmental Studies chemistry‐climate model (CCM). The CCM calculation for the future atmosphere was performed for the period of 1975–2100 under a future scenario of time‐varying halogens, greenhouse gases, and sea surface temperatures for chemistry‐climate model validation (CCMVal‐REF2 scenario). A sensitivity test of a no‐climate‐change run for the future atmosphere was also performed, in which the concentrations of CO2, CH4, and N2O were fixed at those for 1975, and the sea surface temperature was fixed at that for the 1970–1979 mean, while the halogen concentrations were changed following the REF2 scenario. A comparison of the return time to 1980 values in these two runs was made. The return times of the halogen concentrations and column ozone in the extratropics for the REF2 run are earlier than those for the no‐climate‐change run, influenced by an enhancement of the meridional circulation and stratospheric cooling in the atmosphere. In the tropics, the column ozone of the REF2 run shows a second decrease after 2050, influenced by a stronger upward motion in the future atmosphere than in the present atmosphere. Trends in the zonal mean ozone concentration, zonal mean temperature, zonal mean zonal wind, Eliassen‐Palm (EP) flux, EP flux divergence, vertical component of the residual mean meridional circulation, and chemical forcing to the ozone concentration are examined in the periods of 2000–2050 and 2051–2100. These trends in the dynamical and chemical factors explain the earlier return times of halogens and ozone in the extratropics of the REF2 run than in the no‐climate‐change run. In the no‐climate‐change run, a better correlation between the return time of column ozone to the 1980 level and that of the lower stratospheric halogen concentration is calculated for the Southern Hemisphere corresponding to the facts that the ozone concentrations in the Southern Hemisphere lower stratosphere are more controlled by chlorine and bromine chemistries than those in the Northern Hemisphere.

The results from a three‐dimensional chemistry climate model (CCM) of the Center for Climate System Research/National Institute for Environmental Studies (CCSR/NIES) were analyzed for 1980–2000 to detect variations due to the 11 year solar cycle. Multiple regression analysis, including the constant, linear trend, solar, quasi‐biennial oscillation, volcanic, and sea surface temperature (SST) terms, was applied for ozone and temperature of the CCM for the REF1 scenario of CCM Validation. Using observed SST as a lower boundary condition, the results suggest that the contribution of solar cycle forcing in the CCSR/NIES CCM is about 1% in ozone volume mixing ratio and 0.2 K in temperature per 100 units of 10.7 cm solar microwave flux in the tropical lower stratosphere for the period 1980–2000. A change in ozone transport may be the main factor for the solar signal of ozone concentration in the lower stratosphere. Another sensitivity experiment excluding solar cycle forcing shows a small solar response in the lower stratosphere, suggesting that the interannual variability of the SST could contribute to the solar term in the lower stratosphere through troposphere‐stratosphere processes and/or have an effect as an artifact of interference due to the insufficient period for analysis.

Abstract There is an increasing interest in applying methanol to diesel engines so as to achieve fuel diversity and reduce engine emissions. Dual-fuel application is the most promising method, but its combustion characteristics have been less extensively studied. In this paper, with the measured cylinder pressures of the engine operated on pure diesel and on dual fuel (methanol—diesel), the engine combustion characteristics are investigated. The increase in methanol mass fraction lowers the polytropic index of compression and the temperatures at BDC and TDC, as well as the oxygen concentration in the mixture. This prolongs the ignition delay under the same engine load and speed condition by comparison with diesel operation. The combustion heat release rate changes from dual-peak mode to single-peak mode. The centre of the heat release rate curve moves near to TDC under high load conditions, which indicates a better fuel economy. The high methanol mass fraction will realize a simultaneous reduction in both smoke and NO x under all the operating conditions. Meanwhile, the NO x smoke trade-off curve disappears in combustion of the dual fuel, but CO and HC increase.

In this paper, a method for diagnosing defects inside insulated tubular busbars based on LDA optimized multi-scale texture features is proposed to help to guarantee stable operation of the tubular busbars and the whole power grid. Firstly, multi-scale PRPD spectrum space was built with the UHF discharge signals of different defects by image pyramid theory. Then first-order, second-order and higher-order texture statistics were extracted from each image in the multi-scale PRPD spectrum space to form multi-scale texture features and LDA algorithm was used to optimize the features. The method was used to make texture features contain more information about partial discharge and help to improve the accuracy of diagnosis. Experiments were conducted on a 40.5kV insulated tubular busbar and CART classification trees were established as a classifier to identify the types of defects. The results of experiments show that this method can identify the defects of insulated tubular busbars accurately.

Abstract Dimethyl ether (DME) is one of the promising fuels for a compression ignition engine. However, pure DME cannot be used on internal combustion engines directly owing to its low viscosity and poor lubricity. Experimental investigation of the performance of a DME engine with two different kinds of vegetable oil is carried out. Results prove that a certain proportion of rapeseed oil or castor oil dissolves well in DME fuel at the engine's normal operating condition. The lubricity of DME fuel can be improved by adding a proportion of vegetable oil to it, and the plunger surface of the fuel pump has no large wear scars. Also the plunger surface of the fuel pump with DME-rapeseed oil is a little smoother than that with DME-castor oil. The power outputs of a DME engine with these two kinds of vegetable oil are comparable with that of a diesel engine and even exceed that of a diesel engine at low speeds and loads. However, the power output of the engine with DME-castor oil is a little lower than that with DME-rapeseed oil. Smokeless combustion can be realized in a DME engine with these two kinds of vegetable oil, and NO x emission is about 40 per cent of that of a diesel engine. The peak pressure of a DME engine with these two kinds of vegetable oil is lower than that of a diesel engine, which indicates lower noise and ballistic load. Furthermore, the peak cylinder pressure for DME-castor oil operation is a little lower than that for DME-rapeseed oil operation. Experiments prove not only that the drawback of low viscosity and poor lubricity of DME fuel can be overcome but also that high efficiency and clean and low-noise combustion can be realized with the addition of vegetable oil to a DME engine.

The relationship between the output signal to jamming and noise ratio (SJNR) of frequency diverse array (FDA) and the correlation coefficient between the jamming and signal steering vector are deduced. The influence of the change of signal and jamming position on the output SINR is obtained. When jamming is located in mainlobe, the improper frequency interval will sharply reduce the output SINR and form a null. The detection ability of the FDA radar will also drop sharply and the null will change periodically with the selection of frequency interval. Both the theories and simulations verified this periodic null and demonstrated the necessity for selecting FDA's optimal frequency interval.