169 research outputs found
Characteristics of the Jinwuwei and Its Relationship to the Xingjun System
No full textThis article analyzes the relationship between the Jinwuwei 金吾衛, which was one of the twelve central guards (Shierwei 十二衛), and the system of the army in the field (Xingjun 行軍), through an examination of Tang period tactical manuals, like Taibaiyin-jing 太白陰経, and the statutes concerning the duties of Jinwuwei contained in Tongdian (通典).The research to date argues that since the main duty of the Jinwuwei was to patrol the capital palace, it was more a security police force than an army regiment. This notion is based on Tangliudian 唐六典, by and large an explanation of various Tang institutions. However, according to Tongdian, the majority of the statutes concerning the duties of Jinwuwei was derived from the Xingjun system as described in the Tang tactical manuals.During the Beizhao 北朝 and Sui-Tang periods, whenever an army in the field was organized, a unit called yuhoujun 虞候軍 was usually formed within it to take charge of reconnaissance and sentry duties during military operations, the same duties entrusted to the Jinwuwei. In other words, the main purpose of the Jinwuwei was to guard the Emperor like a yuhoujun unit, whenever he journeyed away from the capital.The author concludes that the Jinwuwei should be considered essentially a yuhoujun unit within the Shierwei, the army in the field (Xingjun) under the direct command of the Emperor.journal articl
Comparison of isolation and quantification methods to measure humic-like substances (HULIS) in atmospheric particles
No full textTemporal variations of the abundance and optical properties of water soluble Humic-Like Substances (HULIS) in PM2.5 at Guangzhou, China
No full textHumic-Like Substances (HULIS) are important macromolecular compounds that are present in PM2.5 and play significant roles in the atmospheric environment. In this study, 48 PM2.5 samples were collected from February 2010 to January 2011 at an urban site in Guangzhou, southern China. The water soluble HULIS fractions in PM2.5 were analyzed to explore the temporal variation of abundance and optical properties and to identify their possible sources. The HULIS concentrations were in the range of 0.4 to 8.2 mu g C m(-3), with a mean of 2.4 mu g C m(-3). HULIS are important components in organic aerosols, accounting for 17 +/- 5% of the organic carbon (OC), and 49 +/- 6 and 68 +/- 5% of water soluble organic carbon (WSOC) as determined with a total organic carbon (TOC) analyzer and UV absorbance at 250 nm, respectively. The special UV absorbance (SUVA) at 254 nm and 280 nm and the E-250/E-365 ratio of HULIS were 3.2 +/- 0.5 L (m mg C)(-1), 2.2 +/- 0.4 L (m mg C)(-1), and 5.9 +/- 0.9, respectively. The HULLS fractions had higher concentrations, slightly higher SUVA values, and lower E-250/E-365 ratios from November to January, indicating the important contribution of aromatic compounds to HULIS in the dry season. The concentrations of HULIS were positively correlated with water soluble K+, secondary organic carbon (SOC), and secondary inorganic ions (NH4+, NO3-, and SO42-). These results suggest that biomass burning and secondary photochemical formation are both sources of HULLS in our study area. In addition, the SUVA(280) of HULIS was strongly correlated with k(+) and SOC, suggesting that HULIS properties were also influenced by their primary source of biomass burning and secondary atmospheric formation. (C) 2016 Elsevier B.V. All rights reserved
Comprehensive characterization of humic-like substances in smoke PM2.5 emitted from the combustion of biomass materials and fossil fuels
No full textHumic-like substances (HULIS) in smoke fine particulate matter (PM2: 5) emitted from the combustion of biomass materials (rice straw, corn straw, and pine branch) and fossil fuels (lignite coal and diesel fuel) were comprehensively studied in this work. The HULIS fractions were first isolated with a one-step solid-phase extraction method, and were then investigated with a series of analytical techniques.elemental analysis, total organic carbon analysis, UV-vis (ultraviolet-visible) spectroscopy, excitationemission matrix (EEM) fluorescence spectroscopy, Fourier transform infrared spectroscopy, and H-1-nuclear magnetic resonance spectroscopy. The results show that HULIS account for 11.2-23.4 and 5.3% of PM2.5 emitted from biomass burning (BB) and coal combustion, respectively. In addition, contributions of HULIS-C to total carbon and water-soluble carbon in smoke PM2.5 emitted from BB are 8.0-21.7 and 56.9-66.1 %, respectively. The corresponding contributions in smoke PM2.5 from coal combustion are 5.2 and 45.5 %, respectively. These results suggest that BB and coal combustion are both important sources of HULIS in atmospheric aerosols. However, HULIS in diesel soot only accounted for similar to 0.8% of the soot particles, suggesting that vehicular exhaust may not be a significant primary source of HULIS. Primary HULIS and atmospheric HULIS display many similar chemical characteristics, as indicated by the instrumental analytical characterization, while some distinct features were also apparent. A high spectral absorbance in the UV-vis spectra, a distinct band at lambda(ex)=lambda(em) approximate to 280/350 nm in EEM spectra, lower H/C and O/C molar ratios, and a high content of [Ar-H] were observed for primary HULIS. These results suggest that primary HULIS contain more aromatic structures, and have a lower content of aliphatic and oxygen-containing groups than atmospheric HULIS. Among the four primary sources of HULIS, HULIS from BB had the highest O/C molar ratios (0.43-0.54) and [H-C-O] content (10-19 %), indicating that HULIS from this source mainly consisted of carbohydrate-and phenolic-like structures. HULIS from coal combustion had a lower O= C molar ratio (0.27) and a higher content of [Ar-H] (31 %), suggesting that aromatic compounds were extremely abundant in HULIS from this source. Moreover, the absorption anstrom exponents of primary HULIS from BB and coal combustion were 6.7-8.2 and 13.6, respectively. The mass absorption efficiencies of primary HULIS from BB and coal combustion at 365 nm (MAE365/ were 0.97-2.09 and 0.63m2 gC 1, respectively. Noticeably higher MAE365 values for primary HULIS from BB than coal combustion indicate that the former has a stronger contribution to the light-absorbing properties of aerosols in the atmospheric environment
Periodontitis connection with systemic comorbidities: evidence from epidemiology and clinical trials
No full textPeriodontitis is a chronic inflammatory condition affecting periodontal tissues, leading to gingival separation and destruction of the periodontal ligament and alveolar bone. Dysbiosis of the oral microbiome leads to microbial accumulation in the form of plaque. This subverts the immune system leading to local destruction and exacerbated inflammation. Daily activities such as tooth-brushing and eating can lead to bacteremia. In the context of periodontitis, dissemination of bacteria and inflammatory mediators increases the burden of systemic inflammation, complexifying noncommunicable diseases when comorbid. Periodontal therapy is relatively safe, minimally invasive, and known to reduce systemic levels of inflammatory markers. We can consider periodontal disease as a manageable risk factor and associate periodontal therapy with a wide range of health benefits. Associations between periodontitis and noncommunicable diseases have been established despite their high prevalence and shared similarities. While we can infer a biological relationship in many cases, more research is needed to establish effective interventions
Comparative study for separation of atmospheric humic-like substance (HULIS) by ENVI-18, HLB, XAD-8 and DEAE sorbents: Elemental composition, FT-IR, H-1 NMR and off-line thermochemolysis with tetramethylammonium hydroxide (TMAH)
No full textFan and Ventilation Rate Monitoring of Cage-Free Layer Houses in California
No full textVentilation rates were continuously monitored in two cage-free layer houses located in California from March 1, 2012 to May 13, 2013. The average number of brown Lohmann laying hens in each house was 33,300. Temperature, relative humidity, static pressure, and running status of 48 ventilation fans were continuously monitored and recorded every minute. Regression models were developed to relate house temperature and ventilation rate to inlet air temperature, and to relate airflow rate to building static pressure (R2 = 0.98). Results showed that the daily mean ventilation rate per hen ranged from 1.91 to 8.72 m3 h-1 hen-1, averaging at 4.49 ±1.53 m3 h-1 hen-1. The standard uncertainty of daily mean ventilation rate was determined to be 3.7%. The 91-cm and 130-cm fans were found to perform at 82% and 63% of the manufacturer rated airflow rates, respectively. The minimum and maximum static pressure was 11.0 and 50.6 Pa, respectively, corresponding to 2 and 16 running tunnel fans. When the house temperature exceeded 30ºC, an evaporative cooling system was activated, which could reduce the inlet air temperature by 6.3ºC and concurrently increased the indoor air humidity ratio by 3.4 g per kg dry air. Cooling pad efficiency was 66%. The sidewall fans and tunnel fans were operated at 65% and 20% of the total time when layers occupied the houses. The new rational formula to calculate dry base ventilation rates was developed based upon the ratio of water vapor volume to moist air volume. The developed models and data collected in this research can be used to calculate the ventilation rates in cage-free layer houses so that it can be possible to assure healthy conditions needed for layers. They can also be used in the design of cage free houses and in the calculations of emissions of air pollutants from these houses.This article is published as Lin, Xingjun, Ruihong Zhang, Shumei Jiang, Hamed M. El-Mashad, and Hongwei Xin. "Fan and Ventilation Rate Monitoring of Cage-Free Layer Houses in California." Transactions of the ASABE 61, no. 6 (2018): 1939-1950. DOI: 10.13031/trans.12831. Posted with permission.</p
The analysis of improving effect of parallel hole cut blasting on the basis of test results
No full textHigh-contrast visualization of upconversion luminescence in mice using time-gating approach
No full textPublished: February 25, 2016Optical imaging through the near-infrared (NIR) window provides deep penetration of light up to several centimeters into biological tissues. Capable of emitting 800 nm luminescence under 980 nm illumination, the recently developed upconversion nanoparticles (UCNPs) suggest a promising optical contrast agent for in vivo bioimaging. However, presently they require high-power lasers to excite when applied to small animals, leading to significant scattering background that limits the detection sensitivity as well as a detrimental thermal effect. In this work, we show that the time-gating approach implementing pulsed illumination from a NIR diode laser and time-delayed imaging synchronized via an optical chopper offers detection sensitivity more than 1 order of magnitude higher than the conventional approach using optical band-pass filters (S/N, 47321/6353 vs 5339/58), when imaging UCNPs injected into Kunming mice. The pulsed laser illumination (70 μs ON in 200 μs period) also reduces the overall thermal accumulation to 35% of that under the continuous-wave mode. Technical details are given on setting up the time-gating unit comprising an optical chopper, a pinhole, and a microscopy eyepiece. Being generally compatible with any camera, this provides a convenient and low cost solution to NIR animal imaging using UCNPs as well as other luminescent probes.Xianlin Zheng, Xingjun Zhu, Yiqing Lu, Jiangbo Zhao, Wei Feng, Guohua Jia, Fan Wang, Fuyou Li, and Dayong Ji
Inhibition of Crystallin Ascorbylation by Nucleophilic Compounds in the hSVCT2 Mouse Model of Lenticular Aging
No full text- …
