336 research outputs found
Laser frequency offset locking via tripod-type electromagnetically induced transparency
We have demonstrated the laser frequency offset locking via the Rb
tripod-type double dark resonances electromagnetically induced transparency
(EIT) system. The influence of coupling fields power and detuning on the
tripod-type EIT profile is detailed studied. In a wide coupling fields detuning
range, the narrower EIT dip has an ultranarrow linewidth of 590 KHz, which is
about one order narrower than the natural linewidth of Rb. Without the
additional frequency stabilization of the coupling lasers, we achieve the
relative frequency fluctuation of 60 KHz in a long time of ~2000s, which is
narrower than the short-time linewidth of each individual laser
Enhancement of nitrate removal at the sediment-water interface by carbon addition plus vertical mixing
Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Chemosphere 136 (2015): 305-310, doi:10.1016/j.chemosphere.2014.12.010.Wetlands and ponds are frequently used to remove nitrate from effluents or runoffs. However, the efficiency of this approach is limited. Based on the assumption that introducing vertical mixing to water column plus carbon addition would benefit the diffusion across the sediment–water interface, we conducted simulation experiments to identify a method for enhancing nitrate removal. The results suggested that the sediment-water interface has a great potential for nitrate removal, and the potential can be activated after several days of acclimation. Adding additional carbon plus mixing significantly increases the nitrate removal capacity, and the removal of total nitrogen (TN) and nitrate-nitrogen (NO3--N) is well fitted to a first-order reaction model. Adding Hydrilla verticillata debris as a carbon source increased nitrate removal, whereas adding Eichhornia crassipe decreased it. Adding ethanol plus mixing greatly improved the removal performance, with the removal rate of NO3--N and TN reaching 15.0-16.5 g m-2 d-1. The feasibility of this enhancement method was further confirmed with a wetland microcosm, and the NO3--N removal rate maintained at 10.0-12.0 g m-2 d-1 at a hydraulic loading rate of 0.5 m d-1.The present work was supported by the State Oceanic Administration of China (Demonstration project of coastal wetland restoration, north coast of Hangzhou Wan bay), the National Science Foundation of China under Grant No. 51378306 and 41471393, and Science and Technology Planning Project of Zhejiang Province No.2014F50003
A Cross-Sectional Study of Risk Factors for Irritable Bowel Syndrome in Children 8–13 Years of Age in Suzhou, China
To determine the prevalence and risk factors of IBS in children 8–13 years of age in Suzhou city, a cross-sectional study was conducted on children in grades 1 through 6 in public elementary schools in three districts of Suzhou. A multistage stratified random-sampling survey was conducted in a primary investigation using standardized questionnaires. Rome II criteria were used to confirm IBS and their risk factors were analyzed. Of 8,000 questionnaires 7,472 responded satisfactorily for a response rate of 93.4%. IBS was diagnosed in 10.81%. A decrease in the prevalence of IBS was significantly associated with advancing age and grade in school (trend test, P<0.05). The prevalence of IBS in females was higher but not significantly different than males. The significant risk factors for IBS included young age (OR = 0.94), food allergy (OR = 1.53), gastroenteritis during childhood (OR = 1.29), eating fried food (OR = 1.62), anxiety (OR = 1.49), psychological insults in early childhood (OR = 1.47), and parental history of constipation (OR = 1.81; all P<0.05). IBS prevalence of 10.81% in study population warrants preventive measures such as encouraging dietary changes, preventing gastroenteritis and childhood psychological insults
Synthesis, characterization and application of defective metal-organic frameworks: current status and perspectives
Landslide research in China
On 9 April 2000, a 91 Mm3 rock avalanche occurred in Linzhi Prefecture, Tibet. The event was accompanied by a deafening noise, with the rock mass travelling from a maximum elevation of 5132 m and coming to a rest at an elevation of 2163 m. It formed a landslide dam in the Yigong Zangbo River of some 55 m height, impounding a reservoir of some 2 Gm3 for a period of 62 days after which it emptied in less than 12 h. This event was a forewarning of a period of frequent geological disasters in China during the start of the 21st century. The ensuing Wenchuan earthquake (surface-wave magnitude Ms 8.0; May 2008), Zhouqu debris flow (August 2010) and Ludian earthquake (Ms 6.7; August 2014) led to the Chinese Government renewing its campaign against geological disasters and it has since invested heavily in scientific research to guide efforts to mitigate the impact of such natural disasters. This thematic set on Landslide Research in China was initiated to highlight this research. This paper provides a brief review of three of the featured subjects and accompanies the five papers published in the thematic set.
Large earthquakes severely affect the geological environment and also result in the potential for secondary disasters in the days, months and years that follow. There is continued debate on how quickly landscapes recover following a high-magnitude disturbance. Lin et al. (2006, 2009) studied the ChiChi earthquake of 1999 and found that 5 years after the earthquake the area experienced a relatively high number of landslides (including debris flows) followed by a trend of gradual decline. Hovius et al. (2011) concluded that it took c. 6 years for the landslide signal to return to pre-1999 levels. Other examples of long-term landscape recovery have been discussed by, for example, Nakamura et al. (2000) for the 1923 Ms 7.9 Kanto earthquake in Japan, and by Huang (2011) for the 2008 Ms 8.0 Wenchuan earthquake, China. The Wenchuan earthquake took place on 12 May 2008 in Sichuan Province, resulting in some 200 000 landslide events (Xu et al. 2013), and in the following years the province frequently experienced further landslide activity. According to the first author's statistics, the province experienced 668, 934, 2161, 1997 and 3147 geohazard events between 2008 and 2012. The enhanced landslide and debris-flow activity after the 2008 Wenchuan earthquake was highlighted in the Special Issue of Engineering Geology ‘The long-term geologic hazards in areas struck by large-magnitude earthquakes’ (2014, Volume 182, Part B)
Transparent Power-Generating Windows Based on Solar-Thermal-Electric Conversion
Zhang Q, Huang A, Ai X, et al. Transparent Power-Generating Windows Based on Solar-Thermal-Electric Conversion. Advanced Energy Materials . 2021: 2101213.Integrating transparent solar-harvesting systems into windows can provide renewable on-site energy supply without altering building aesthetics or imposing further design constraints. Transparent photovoltaics have shown great potential, but the increased transparency comes at the expense of reduced power-conversion efficiency. Here, a new technology that overcomes this limitation by combining solar-thermal-electric conversion with a material's wavelength-selective absorption is presented. A wavelength-selective film consisting of Cs0.33WO3 and resin facilitates high visible-light transmittance (up to 88%) and outstanding ultraviolet and infrared absorbance, thereby converting absorbed light into heat without sacrificing transparency. A prototype that couples the film with thermoelectric power generation produces an extraordinary output voltage of approximate to 4 V within an area of 0.01 m(2) exposed to sunshine. Further optimization design and experimental verification demonstrate high conversion efficiency comparable to state-of-the-art transparent photovoltaics, enriching the library of on-site energy-saving and transparent power generation
Relationship between TIM3 Expression on Peripheral T Lymphocytes and Post-Stroke Depression
Background: T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) is a regulatory molecule expressed on a variety of cell types, including CD3+ T cells. Few studies have been conducted to look into the correlation between TIM3 expression on peripheral T lymphocytes and post-stroke depression (PSD).Objective: To investigate the relationship between TIM3 expressions on peripheral T lymphocytes in PSD patients.Methods: Acute stroke patients without depression (NPSD) (n=65), PSD patients (n=23), and body mass index (BMI), age, and education-matched healthy controls (HC) (n=59) were enrolled. Using flow cytometry, TIM3 expression was examined in the peripheral CD3+ CD4+ and CD3+ CD8+ T lymphocytes. Evaluation of the depressive severity in PSD patients was assessed using a 17-item Hamilton Depression Rating Scale (HAM-D-17). We used enzyme-linked immunosorbent assay (ELISA) to determine the serum concentrations of IL-1β, IL-6, IL-10, and IL-18. We further assessed the relationships between TIM3 expression, serum cytokine levels, and the HAM-D-17 scores.Results: CD3+ CD4+ T cells reduced significantly in PSD patients compared with the NPSD patients and HC. Both NPSD patients and PSD patients had a significant increase in TIM3 expression in their peripheral CD3+ CD4+ T lymphocytes, compared with HC. In PSD patients, a higher frequency of peripheral CD3+ CD8+ T lymphocytes showed significant expression of TIM3 compared to NPSD patients and HC. High TIM3 level on peripheral CD3+ CD8+ T lymphocytes was positively associated with the HAM-D score.Conclusion: Patients with PSD exhibit immune dysfunction. TIM3 might contribute to the development and severity of PSD, making it a potential therapeutic target
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