检索结果-南通市图书馆

Sources of methacrolein and methyl vinyl ketone and their contributions to methylglyoxal and formaldehyde at a receptor site in pearl River Delta

引用

Journal of Environmental Sciences 2019年第5期31卷 1-10页

作者： Zhenhao Ling Zhuoran He Zhe Wang Min Shao Xuemei Wang School of Atmospheric Sciences Sun Yat-sen University Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University Department of Civil and Environmental Engineering Hong Kong Polytechnic University Institute for Environmental and Climate Research Jinan University

Methacrolein(MACR) and methyl vinyl ketone(MVK) are two major intermediate products from the photochemical oxidation of isoprene, the most important biogenic volatile organic compound. In addition, MACR and MVK have primary emissions. Investigating the sources and evolution of MACR and MVK could provide helpful information for the oxidative capacity of the atmosphere. In this study, hourly measurements of isoprene, MACR, and MVK were conducted at a receptor site in the pearl River Delta region(PRD), i.e., the Heshan site(HS), from 22 October to 20 November, 2014. The average mixing ratios of isoprene,MACR and MVK were 151 ± 17, 91 ± 6 and 79 ± 6 pptv, respectively. The daily variations and the ratios of MVK/MACR during daytime and nighttime suggested that other sources besides isoprene photooxidation influenced the MACR and MVK abundances at the *** matrix factorization was utilized to resolve the sources of MACR and MVK. Five sources were identified and quantified, including biogenic emissions, biomass burning,secondary formation, diesel, and gasoline vehicular emissions. Among them, secondary formation made the greatest contribution to observed MACR and MVK with average contributions of ～ 45% and ～ 70%, respectively. Through the yields of secondary products from the oxidation of MACR and MVK by the OH radical and the concentrations of MACR and MVK, it was found that methylglyoxal and formaldehyde were the main oxidation products of MACR and MVK at the HS site. Overall, this study evaluated the roles of primary emissions on ambient levels of MACR and MVK and advanced the understanding of photochemical oxidation of MACR and MVK in the PRD.

关键词： Source apportionment Methacrolein Methyl vinyl ketone pearl River Delta

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

Potential effect of sedimentary iron-phosphorus accumulation on frequent algal bloom in the pearl River Estuary

引用

Science China Earth Sciences 2007年第3期50卷 453-461页

作者： WENG HuanXin SUN XiangWei CHEN JingFeng CHEN JianFang CHEN LiHong CHEN XiangHua QIN YaChao Institute of Environment&Biogeochemistry Zhejiang UniversityHangzhou 310027China Second Institute of Oceanography State Oceanic AdministrationHangzhou 310027China

Based on laboratory culture of harmful alga on iron and phosphorus uptake, and the study of accu-mulation of iron-phosphorus in cores and release of iron and phosphorus from surficial sediments collected in the pearl River Estuary, the reasons of the high frequency of phytoplankton bloom therein are discussed. The results show that Fe starvation can make algal growth rate slow down and the peak of cell number decrease. Fe and P contents in algal cell bear a significant correlation and the molar ratio of P:Fe is ~356:1, suggesting that algal uptake of Fe and P is synergistic. Total Fe and total P in sediments are positively correlated and Fe-P is the main species of inorganic sedimentary P. Through continuous leaching with agitation, 34.26%―80.21% of exchangeable P and 4.04%―22.52% of ex-changeable Fe are released from surficial sediments, implying that the accumulation of Fe-P in sedi-ments is available for providing nutrients (P and essential Fe) for the demand of phytoplankton bloom. These factors might be responsible for a higher frequency of red tides than other marine regions.

关键词： sedimentary Fe-P iron limitation harmful algal bloom pearl River Estuary

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

Source attribution for mercury deposition with an updated atmospheric mercury emission inventory in the pearl River Delta Region, China

引用

Frontiers of Environmental Science & Engineering 2019年第1期13卷 39-52页

作者： Jiajun Liu Long Wang Yun Zhu Che-Jen Lin Carey Jang Shuxiao Wang Jia Xing Bin Yu Hui Xu Yuzhou Pan Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control College of Environment and Energy South ChinaUniversity of Technology Guangzhou Higher Education Mega Center Guangzhou 510006 China Department of Civil and Environmental Engineering Lamar University Beaumont TX 77710 USA US EPA Office of Air Quality Planning & Standards Res Triangle Park NC 27711 USA State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment. Tsinghua University Beijing 100084 China Guangzhou Environmental Monitoring Centre Guangzhou 510030 China

We used CMAQ-Hg to simulate mercury pollution and identify main sources in the pearl River Delta (PR.D) with updated local emission inventory and latest regional and global emissions. The total anthropogenic mercury emissions in the PRD for 2014 were 11,939.6 kg. Power plants and industrial boilers were dominant sectors, responsible for 29.4 and 22.7%. We first compared model predictions and observations and the results showed a good performance. Then five scenarios with power plants (PP), municipal solid waste incineration (MSWI), industrial point sources (IP), natural sources (NAT), and boundary conditions (BCs) zeroed out separately were simulated and compared with the base case. BCs was responsible for over 30% of annual average mercury concentration and total deposition while NAT contributed around 15%. Among the anthropogenic sources, IP (22.9%) was dominant with a contribution over 20.0% and PP (18.9%) and MSWI (11.2%) ranked second and third. Results also showed that power plants were the most important emission sources in the central PRD, where the ultra-low emission for thermal power units need to be strengthened. In the northern and western PRD, cement and metal productions were priorities for mercury control. The fast growth of municipal solid waste incineration were also a key factor in the core areas. In addition, a coordinated regional mercury emission control was important for effectively controlling pollution. In the future, mercury emissions will decrease as control measures are strengthened, more attention should be paid to mercury deposition around the large point sources as high levels of pollution are observed.

关键词： Emission inventory Mercury deposition pearl River Delta (PRD) Source attribution Control strategy

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

Electrospun composites of PHBV/pearl powder for bone repairing

引用

Progress in Natural Science:Materials International 2015年第4期25卷 327-333页

作者： Jingjing Bai Jiamu Dai Guang Li College of Material Science and Engineering Donghua University

Electrospun fi ber has highly structural similarity with natural bone extracelluar matrix(ECM). Many researches about fabricating organic–inorganic composite materials have been carried out in order to mimic the natural composition of bone and enhance the biocompatibility of materials. In this work, pearl powder was added to the poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV) and the composite nano fi ber scaffold was prepared by electrospinning. Mineralization ability of the composite scaffolds can be evaluated by analyzing hydroxyapatite(HA)formation on the surface of nano fi ber scaffolds. The obtained composite nano fi ber scaffolds showed an enhanced mineralization capacity due to incorporation of pearl powder. The HA formed amount of the composite scaffolds was raised as the increase of pearl powder in composite scaffolds. Therefore, the prepared PHBV/pearl composite nano fi ber scaffolds would be a promising candidate as an osteoconductive composite material for bone repairing.

关键词： Hydroxyapatite pearl PHBV Mineralization Composite nano fi bers scaffolds

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Crustal Structure Revealed by a Deep Seismic Sounding Profile of Baijing-Gaoming-Jinwan in the pearl River Delta

引用

Journal of Ocean University of China 2018年第1期17卷 186-194页

作者： ZHANG Xiang YE Xiuwei LV Jinshui SUN Jinlong WANG Xiaona CAS Key Laboratory of Ocean Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China University of Chinese Academy of Sciences Beijing 100049China Guangdong Earthquake Agency China Earthquake AdministrationGuangzhou 510070China

The pearl River Estuary area, located in the middle part of the southern China coastal seismic belt, has long been considered a potential source of strong earthquakes above magnitude 7.0. To scientifically assess the potential strong earthquake risk in this area, a three-dimensional artificial seismic sounding experiment, consisting of a receiving array and seabed seismograph, was performed to reveal the deep crustal structure in this region. We used artificial ship-borne air-gun excitation shots as sources, and fixed and mobile stations as receivers to record seismic data from May to August 2015. This paper presents results along a line from the western side of the pearl River Estuary to the western side of the Baijing-Gaoming-Jinwan profile. A two-dimensional velocity structure was constructed using seismic travel-time tomography. The inversion results show that the Moho depth is 27 km in the coastal area and 30 km in the northwest of the pearl River Estuary area, indicating that the crust thins from land to sea. Two structural discontinuities and multiple low-velocity anomalies appear in the crustal section. Inside both discontinuity zones, a low-velocity layer, with a minimum velocity of 6.05 km s^(-1), exists at a depth of about 15 km, and another, with a minimum velocity of 6.37 km s^(-1), exists at a depth of about 21.5 km between the middle and lower crust. These low velocities suggest that the discontinuities may consist of partly molten material. Earthquakes with magnitudes higher than 5.0 occurred in the low-velocity layer along the profile. The deep Kaiping-Enping fault, rooted in the crust, may be one of the most important channels for deep material upwelling and is related to tectonic movement since the Cretaceous in the pearl River Delta tectonic rift basin.

关键词： pearl River Estuary seismic sounding profile crustal structure Kaiping-Enping fault earthquake potential

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

Intra-population genetic variance for grain iron and zinc contents and agronomic traits in pearl millet

引用

The Crop Journal 2016年第1期4卷 48-54页

作者： Mahalingam Govindaraj Kedar N.Rai Ponnusamy Shanmugasundaram International Crops Research Institute for the Semi-arid Tropics (ICRISAT) Centre for Plant Breeding and Genetics Tamil Nadu Agricultural University

Crop biofortification is a sustainable approach for fighting micronutrient malnutrition in the world. The estimation of variance components in genetically broad-based populations provides information about their genetic architecture, allowing the design of an appropriate biofortification breeding method for cross-pollinated crops such as pearl millet. The objective of this study was to estimate intra-population genetic variance using self(S1) and half-sib(HS) progenies in two populations, AIMP92901 and ICMR312. Field trials were evaluated in two contrasting seasons(2009 rainy and 2010 summer; otherwise called environments) in Alfisols at ICRISAT, Patancheru. Analyses of variance showed highly significant variation for S1 s and HS progenies, reflecting high within-population genetic variation for both micronutrients and other key traits. However, the HS showed narrow ranges and lower genetic variances than the S1 for all of the traits. The micronutrients were highly positively correlated in S1(r = 0.77 to 0.86; P pearl millet shows largely additive variance, so that breeding high-iron hybrids will require incorporation of these micronutrient traits into both parental lines.

关键词： Genetic variance Iron Micronutrient malnutrition pearl millet Zinc

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

Magnetic properties of sediments from the pearl River Delta,South China:Paleoenvironmental implications

引用

Science China Earth Sciences 2008年第1期51卷 56-66页

作者： Rodney GRAPES Department of Earth Sciences Sun Yat-Sen University

Magnetic parameters and their environmental implications of sediments in a core (PD) from the pearl River Delta, South China, indicate that ferrimagnetic minerals with low coercivity, such as magnetite, dominate the magnetic properties although small amounts of Fe-sulphides occur. The fraction of Fe-sulphides increases and becomes the dominant minerals determining the magnetic characteristics in grey-black organic-rich clay horizons, indicating an anoxic, sulphate-reducing swamp environment resulting from a marine regression. In the "Huaban clay" , hard magnetic minerals, such as hematite and goethite, largely control the magnetic properties of the sediments and imply a long period of exposure and weathering. Where magnetite is the main magnetic mineral, its fraction and grain size determine properties such as magnetic susceptibility (κ ) and saturation isothermal remanent magnetization (SIRM). Ratios of SIRM/κ and χarm/SIRM reflect changes in sea level with high SIRM/κ and χarm/SIRM correlating with a smaller magnetic mineral grain size and rising sea level. Based on downcore variations of these environmental magnetic parameters along with sediment characteristics and microfauna, the sedimentary environment of the pearl River Delta area can be divided into two main cycles of transgression and regression during the late Pleistocene and Holocene with more sub-cycles of sea level fluctuation during each transgression.

关键词： the pearl River Delta rock magnetic properties environmental magnetic signatures sedimentary environment sea-level change

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

Offshore Fault Geometrics in the pearl River Estuary,Southeastern China:Evidence from Seismic Reflection Data

引用

Journal of Ocean University of China 2018年第4期17卷 799-810页

作者： CAO Jinghe XIA Shaohong SUN Jinlong ZHAO Fang WAN Kuiyuan XU Huilong CAS Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesCruangzhou 510301China University of Chinese Academy of Sciences Beijing 100049China

The pearl River Estuary(PRE) is located at the onshore-offshore transition zone between South China and South China Sea Basin, and it is of great significant value in discussing tectonic relationships between South China block and South China Sea block and seismic activities along the offshore active faults in PRE. However, the researches on geometric characteristics of offshore faults in this area are extremely lacking. To investigate the offshore fault distribution and their geometric features in the PRE in greater detail, we acquired thirteen seismic reflection profiles in 2015. Combining the analysis of the seismic reflection and free-air gravity anomaly data, this paper revealed the location, continuity, and geometry of the littoral fault zone and other offshore faults in PRE. The littoral fault zone is composed of the major Dangan Islands fault and several parallel, high-angle, normal faults, which mainly trend northeast to northeast-to-east and dip to the southeast with large displacements. The fault zone is divided into three different segments by the northwest-trending faults. Moreover, the basement depth around Dangan Islands is very shallow, while it suddenly increases along the islands westward and southward. These has resulted in the islands and neighboring areas becoming the places where the stress accumulates easily. The seismogenic pattern of this area is closely related to the comprehensive effect of intersecting faults together with the low velocity layer.

关键词： offshore active faults littoral fault zone pearl River Estuary earthquake seismic reflection data

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

Effects of Nitrogen and Phosphorus on the Growth of Levanderina fissa:How It Blooms in pearl River Estuary

引用

Journal of Ocean University of China 2017年第1期16卷 114-120页

作者： WANG Zhaohui GUO Xin QU Linjian LIN Langcong College of Life Science and Technology Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes Jinan UniversityGuangzhou 510632P.R.China

Effects of nitrogen(N) and phosphorus(P) from different sources and at different concentrations on the growth of Levanderina fissa(= Gyrodinium instriatum) were studied in laboratory conditions. The findings might explain the recurrent blooms of this species in pearl River Estuary, China. Results showed that nutrient limitation significantly inhibited the growth of L. fissa. The values of specific growth rate(μmax) and half-saturation nutrient concentration(KS) were 0.37 divisions/d and 8.49 μmol L^(-1) for N, and 0.39 divisions/d and 1.99 μmol L^(-1) for P, respectively. Based on KS values, dissolved inorganic N level in PRE was sufficient to support the high proliferation of L. fissa, while dissolved inorganic P concentration was far lower than the minimum requirement for its effective growth. L. fissa was not able to utilize dissolved organic N(DON) compounds such as urea, amino acids, and uric acid. However, it grew well by using a wide variety of dissolved organic P(DOP) sources like nucleotides, glycerophosphate, and 4-nitrophenylphosphate. The results from this study suggested that the ability in DOP utilization of L. fissa offers this species a competitive advantage in phytoplankton communities. The high level and continuous supply of DIN, enrichment of DOP, together with warm climate and low salinity in the pearl River Estuary provided a suitable nutrient niche for the growth of L. fissa, and resulted in the recurrent blooms in the estuary.

关键词： Levanderina fissa growth nitrogen phosphorus pearl River Estuary Gyrodinium instriatum

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

Comparative Study on the Antioxidant Activity of Peptides from pearl Oyster(Pinctada martensii) Mantle Type V Collagen and Tilapia(Oreochromis niloticus) Scale Type Ⅰ Collagen

引用

Journal of Ocean University of China 2017年第6期16卷 1175-1182页

作者： XIA Guanghua ZHANG Xueying DONG Zhenghua SHEN Xuanri College of Food Science and Technology Hainan University Haikou 570228 P. R. China

In this study, pearl oyster mantle type V collagen(POMC) and tilapia scale type I collagen(TSC) were extracted and hydrolyzed by various proteases in order to obtain peptides. The antioxidant activity of the peptides was investigated by DPPH, hydroxyl radical scavenging experiments and a dynamic digestion model in vitro. The results show that there are significant differences in amino acid composition between POMC and TSC. The collagen peptides obtained from pearl oyster mantle(POMCP) by treating with alkaline protease exhibited higher antioxidant activity than that from tilapia scale(TSCP) treated with papaya protease, and both of them showed greater DPPH and hydroxyl radical scavenging activity than other peptides. After being separated via Sephadex G-25 chromatography, the M1 fraction isolated from POMCP, and the S1 fraction from TSCP with which both had higher molecular weights showed the strongest antioxidant activity than other fractions, and the M1 fraction exhibited stronger antioxidant activity than the S1 fraction in scavenging free-radicals and protecting cells from the oxidation damage. Furthermore, after treating the dynamic digestion system model in vitro, the DPPH and hydroxyl radical scavenging activity of the M1 fraction increased slightly. These results suggest that POMCP exhibits stronger antioxidant activity than TSCP, which means that PMOP may be a good candidate to be a potential natural antioxidant in the food-processing industry.

关键词： tilapia scale pearl oyster mantle collagen peptide antioxidant activity

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

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

在线全文

在线全文

在线全文

在线全文

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

在线全文

在线全文

在线全文

在线全文

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：