检索结果-南通市图书馆

Seasonal variability in CDOM absorption and fluorescence properties in the Barataria Basin,Louisiana,USA

Journal of Environmental Sciences 2010年第10期22卷 1481-1490页

作者： shatrughan singh Eurico D'Sa Erick Swenson Department of Oceanography and Coastal Sciences Louisiana State University

Absorption and fluorescence properties of chromophoric dissolved organic matter （CDOM） along a 124 km transect in the Barataria Basin, a large estuary located in Louisiana, USA, were investigated during high and low flow periods of the Mississippi River in the spring and winter of 2008-2009. Mean CDOM absorption at 355 nm from the marine to the freshwater end member stations ranged from （3.25 ± 0.56） to （20.76 ± 2.43） m^-1 for the three month high flow period whereas it varied from （1.48 ± 1.08） to （25.45 ± 7.03） m^-1 for the same stations during low flow period. Corresponding salinity values at these stations indicated the influence of river and shelf exchanges in the lower basin and precipitation and runoff in the upper basin. An inverse relationship of CDOM absorbance and fluorescence with salinity observed in the basin could he a useful indicator of salinity. CDOM fluorescence also varied over a large range showing an approximately 8 to 12-fold increase between the marine and freshwater end members for the two flow seasons. Excitation-emission matrix spectral plots indicated the presence of various fluorescence components with highest being the A-peak, lowest the T-peak, and the C and M-peaks showing similar trends along the transect. During low flow season the A/C ratio were well correlated with station locations indicating increased terrestrial influence towards the upper basin. CDOM absorption and fluorescence at 355 nm were highly correlated and independent of CDOM sources suggesting that fluorescence could be used to characterize CDOM in the basin.

关键词： Barataria Basin chromophoric dissolved organic matter CDOM fluorescence excitation-emission matrix

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of photo-biodegradation and biodegradation on the biogeochemical cycling of dissolved organic matter across diverse surface water bodies

引用

Journal of Environmental Sciences 2019年第3期31卷 130-147页

作者： M.S.Sankar Padmanava Dash shatrughan singh YueHan Lu ANDrew E.Mercer Shuo Chen Department of Geosciences Mississippi State University Department of Geological Sciences University of Alabama Academy for Advanced Interdisciplinary Studies Southern University of Science and Technology

The objective of this research was to quantify the temporal variation of dissolved organic matter(DOM) in five distinct waterbodies in watersheds with diverse types of land use and land cover in the presence and absence of sunlight. The water bodies were an agricultural pond, a lake in a forested watershed, a man-made reservoir, an estuary, and a bay. Two sets of samples were prepared by dispensing unfiltered samples into filtered samples in 1:10 ratio(V/V). The first set was exposed to sunlight(10 hr per day for 30 days) for examining the combined effect of photo-biodegradation, while the second set was stored in dark for examining biodegradation alone. Spectroscopic measurements in tandem with multivariate statistics were used to interpret DOM lability and composition. The results suggest that the agricultural pond behaved differently compared to other study locations during degradation experiments due to the presence of higher amount of microbial humic-like and protein-like components derived from microbial/anthropogenic sources. For all samples, a larger decrease in dissolved organic carbon(DOC) concentration(10.12% ±9.81% for photo-biodegradation and 6.65% ± 2.83% for biodegradation) and rapid transformation of DOM components(i.e., terrestrial humic-like components into microbial humic and protein-like components) were observed during photo-biodegradation *** suggest that sunlight facilitated DOM biodegradation, resulting in simpler recalcitrant molecules regardless of original composition. Overall, it was found that combined effects of light and bacteria are more efficient than bacterial effects alone in remineralizing and altering DOM, which highlights the crucial importance of sunlight in transforming aquatic DOM.

关键词： Photo-biodegradation Biodegradation Dissolved organic matter Land use and land cover Half-life EEM-PARAFAC

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Perceived stress and coping capacities among frontline healthcare workers of AIIMS during COVID-19 pandemic:A cross-sectional study

引用

Journal of Acute Disease 2023年第2期12卷 67-72页

作者： Mudita Sharma Digpal singh Chundawat Rohit Richhariya Sunil Kumar Tailor shatrughan Pareek AIIMS BhopalIndia Indian Railway Health Services BikanerRajasthanIndia

Objective:To assess perceived stress and coping capacity of frontline health workers from AIIMS during COVID-19 ***:This cross-sectional study conducted from May to July 2021 enrolled 694 *** online questionnaire based on Google Forms was developed to collect the *** were assessed using the validated Perceived Stress Scale and the Coping Resources Inventory ***:The age of participants were 27(23-52)years *** majority of respondents(73.5%)felt moderately *** the 694 participants,83.0%of the 576 participants had average stress management ***,marital status,and profession were significantly associated with perceived *** addition,marital status and profession were significantly associated with coping ***:The majority of participants have moderate stress levels and average coping *** healthcare workers have to maintain mental and physical *** this requires early screening and stress management for healthcare workers.

关键词： COVID-19 Prevalence Perceived stress Coping capacity Frontline health workers Mental health

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：