检索结果-南通市图书馆

Qiu Shi 2016年第3期8卷 104-107页

作者： chen shuguang

Intake of tobacco nitrosamines of smokers in various provinces of China and their cancer risk:A meta-analysis

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

Journal of Environmental Sciences 2024年第7期141卷 249-260页

作者： Xiao Li Zhiwei Ye Jun Wang Pengfei Lin Xiaojin Zhang shuguang Xie Chao chen Research Institute for Environmental Innovation(Suzhou) TsinghuaSuzhouJiangsu 215163China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Shenzhen Key Laboratory of Organic Pollution Prevention and Control State Key Laboratory of Urban Water Resource and EnvironmentHarbin Institute of TechnologyShenzhen 518055China State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Science and EngineeringPeking UniversityBeijing 100871China

Nitrosamines are a class of carcinogens which have been detected widely in food,water,some pharmaceuticals as well as *** objectives of this paper include reviewing the basic information on tobacco consumption and nitrosamine contents,and assessing the health risks of tobacco nitrosamines exposure to Chinese *** searched the publications in English from“Web of Science”and those in Chinese from the“China National Knowledge Infrastructure”in 2022 and collected 151 literatures with valid *** content of main nitrosamines in tobacco,including 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone(NNK),N-nitrosonornicotine(NNN),N-nitrosoanatabine(NAT),N-nitrosoanabasine(NAB),total tobacco-specific nitrosamines(TSNA),and N-nitrosodimethylamine(NDMA)were *** information of daily tobacco consumption of smokers in 30 provinces of China was also ***,the intakes of NNN,NNK,NAT,NAB,TSNAs,and NDMA via tobacco smoke were estimated as 1534ng/day,591 ng/day,685 ng/day,81 ng/day,2543 ng/day,and 484 ng/day by adult smokers in30 provinces,*** cancer risk(CR)values for NNN and NNK inhalation intake were further calculated as 1.44×10^(-5)and 1.95×10^(-4).The CR value for NDMA intake via tobacco smoke(inhalation:1.66×10^(-4))indicates that NDMA is similarly dangerous in tobacco smoke when compared with the *** China,the CR values caused by average nitrosamines intake via various exposures and their order can be estimated as the following:smoke(3.75×10^(-4))>food(1.74×10^(-4))>drinking water(1.38×10^(-5)).Smokers in China averagely suffer 200%of extra cancer risk caused by nitrosamines in tobacco when compared with non-smokers.

关键词： N-nitrosamine Tobacco Cancer risk Tobacco specific nitrosamines(TSNAs) N-nitrosodimethylamine(NDMA)

河套盆地临河坳陷超深层碎屑岩油气勘探突破及富集高产因素

在线全文

学校读者我要写书评

暂无评论

石油勘探与开发 2024年第5期51卷 962-971页

作者：武玺史原鹏陈树光武函蔡军淡伟宁刘喜恒王晓坤张晰蒙张建丽中国石油华北油田公司河北任丘062552

基于钻井、录井、测井、地质实验等基础资料,对河套盆地临河坳陷超深层碎屑岩油气地质特征及富集高产因素开展研究。研究表明:①临河坳陷古近系发育的内陆咸化湖相优质烃源岩具有早熟早排、高产烃率和持续高效生烃特征,为超高压高产油... 详细信息

基于钻井、录井、测井、地质实验等基础资料,对河套盆地临河坳陷超深层碎屑岩油气地质特征及富集高产因素开展研究。研究表明:①临河坳陷古近系发育的内陆咸化湖相优质烃源岩具有早熟早排、高产烃率和持续高效生烃特征,为超高压高产油气藏形成奠定重要资源基础;②弱压实、早充注、弱胶结保孔,叠加超高压保孔扩缝增渗,使得6500 m以深的超深层依然发育孔隙度大于15%、渗透率达226×10^(−3)μm^(2)的中孔中渗型优质储集体,极大拓展了油气勘探空间;③临洼构造临河组砂地比偏低、储盖组合好,且上覆巨厚优质泥岩盖层,具备持续高效生烃增压并形成超高压油气藏的有利条件;④邻近临河组生烃中心、有良好构造背景且构造圈闭发育的地区是最有利勘探方向,主要包括兴隆断裂构造带和纳林湖断裂潜山带超深层领域。临河坳陷超深层油气勘探重大突破,揭示了该地区超深层碎屑岩良好的勘探潜力,同时对其他地区超深层碎屑岩油气勘探具有重要借鉴意义。

关键词：河套盆地临河坳陷超深层临河组河探101井富集因素

The Influence of Anaerobic Bacteria on Human Urinary System

在线全文

学校读者我要写书评

暂无评论

International Journal of Technology Management 2015年第3期 62-64页

作者： Li LIU shuguang chen Weifang University of Science and Technology ShouguangWeifangShandong 262700 China Shouguang City Hospital of traditional Chinese Medicine ShouguangWeifangShandong China

The anaerobic bacteria can cause infections in different parts of the body, including appendicitis, cholecystitis, otitis media, oral infections, endocarditis, endometritis, brain abscess, myocardial necrosis, osteomyelitis, peritonitis, empyema, salpingitis, septic arthritis, liver abscess, sinusitis, intestinal surgery or post-traumatic wound infections, and bacteremia, such as pelvic inflammatory disease. This paper analyzes the experimental method of anaerobic bacteria to human urinary system through the influence of literature.

关键词： anaerobic bacteria the human urinary system influence

A Radial Waveguide Power Divider for Ka Band Phased Array Antennas

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

A Radial Waveguide Power Divider for Ka Band Phased Array An...

Aboveground carbon sequestration of Cunninghamia lanceolata forests:Magnitude and drivers

2002 3rd International Conference on Microwave and Millimeter Wave Technology

作者： shuguang chen Paratek Microwave Inc.USA 6935N Oakland Mills RoadColumbiaMD 21045

ISBN: (纸本)078037486X

＜正＞*** Low-eost,low profile two-dimensional seanning phased array antennas have wide potential appheations in low earth orbit（LEO）,medium earth orbit（MEO）,and geostationary earth orbit（GEO） satellite communieation *** waveguide is one of the cheapest and simplest selections of a power divider for these kinds of phased array antennas.A radial waveguide power divider has already been used in radial line slot array

关键词： power dividers scanning antennas antenna phased arrays waveguide antenna arrays antenna accessories radial waveguide power divider Ka band phased array antennas two-dimensional scanning antenna return loss sidelobe requirements amplitude errors mass production -20 dB

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Forest Ecosystems 2024年第1期11卷 32-41页

作者： chen Wang shuguang Liu Yu Zhu Andrew R.Smith Ying Ning Deming Deng National Engineering Laboratory for Applied Technology of Forestry&Ecology in South China Central South University of Forestry and TechnologyChangsha 410004China Technology Innovation Center for Ecological Conservation and Restoration in Dongting Lake Basin Ministry of Natural ResourcesChangsha 410007China College of Life Science and Technology Central South University of Forestry and TechnologyChangsha 410004China School of Ecology and Environment Hainan UniversityHaikou 570228China School of Natural Sciences Bangor UniversityGwyneddLL572UWUK College of Forestry Central South University of Forestry and TechnologyChangsha 410004China Hunan Prospecting Designing&Research General Institute for Agriculture Forestry&IndustryChangsha 410007China

Understanding the spatial variation,temporal changes,and their underlying driving forces of carbon sequestration in various forests is of great importance for understanding the carbon cycle and carbon management *** carbon density and sequestration in various Cunninghamia lanceolata forests,extensively cultivated for timber production in subtropical China,vary with biodiversity,forest structure,environment,and cultural factors remain poorly explored,presenting a critical knowledge gap for realizing carbon sequestration supply potential through *** on a large-scale database of 449 permanent forest inventory plots,we quantified the spatial-temporal heterogeneity of aboveground carbon densities and carbon accumulation rates in Cunninghamia lanceolate forests in Hunan Province,China,and attributed the contributions of stand structure,environmental,and management factors to the heterogeneity using quantile age-sequence analysis,partial least squares path modeling(PLS-PM),and hot-spot *** results showed lower values of carbon density and sequestration on average,in comparison with other forests in the same climate zone(i.e.,subtropics),with pronounced spatial and temporal ***,quantile regression analysis using carbon accumulation rates along an age sequence showed large differences in carbon sequestration rates among underperformed and outperformed forests(0.50 and 1.80 Mg·ha^(-1)·yr^(-1)).PLS-PM demonstrated that maximum DBH and stand density were the main crucial drivers of aboveground carbon density from young to mature ***,species diversity and geotopographic factors were the significant factors causing the large discrepancy in aboveground carbon density change between low-and high-carbon-bearing *** analysis revealed the importance of culture attributes in shaping the geospatial patterns of carbon *** work highlighted that retaining largesized DBH trees and increasing shade-t

关键词： Carbon density Carbon accumulation rate Forest age Spatial variation Cultural influence

基于图像处理的连续纤维增强复合材料3D打印精度在线优化方法

在线全文

学校读者我要写书评

暂无评论

江苏科技大学学报（自然科学版） 2024年第3期38卷 84-90页

作者：王叶松计良张礼华章中森陈曙光孙梓轩江苏科技大学机械工程学院镇江212100 同济大学航空航天与力学学院上海200092 北京航天新立科技有限公司北京100039

为了改善“独立挤出型”连续纤维增强复合材料3D打印(continuous fiber reinforced composite 3D printing, CFRC 3DP)制件的尺寸精度,提出了基于图像处理技术的在线优化方法,建立了CFRC 3DP尺寸精度的在线反馈优化模型,研究了图像滤波... 详细信息

为了改善“独立挤出型”连续纤维增强复合材料3D打印(continuous fiber reinforced composite 3D printing, CFRC 3DP)制件的尺寸精度,提出了基于图像处理技术的在线优化方法,建立了CFRC 3DP尺寸精度的在线反馈优化模型,研究了图像滤波、边缘检测及边缘几何基元的提取方法,基于CFRC 3DP打印层实际尺寸与理论尺寸的误差对比,求解了打印制件的误差比例系数,修正了电机步进值,实现了CFRC 3DP尺寸精度的在线优化.通过对典型轴套类零件优化前后的打印尺寸研究,并利用假设检验进行了统计学分析,实验结果表明优化前后打印样件的尺寸存在显著性差异,8 mm轴和16 mm轴的直径打印精度分别提升了1.34%和0.76%,且标准差均有所减小,验证了尺寸精度在线优化方法的可行性和有效性.

关键词：独立挤出 CFRC 3DP 图像处理在线优化尺寸精度

Petroleum geological features and hydrocarbon enrichment of Linhe Depression in Hetao Basin, NW China

在线全文

学校读者我要写书评

暂无评论

石油勘探与开发:英文版 2023年第4期50卷 798-811页

作者： ZHANG Ruifeng HE Haiqing ZHU Qingzhong chen shuguang LIU Xiheng DAN Weining HU Yanxu SHI Yulei ZHANG Yufei YU Haijun ZHANG Ximeng PetroChina Huabei Oilfield Company Renqiu 062552China PetroChina Oil&Gas and New Energy Company Beijing 100007China Logging Technology Research Institute of CNPC Logging Company Beijing 100007China No.2 Mud Logging Company CNPC Bohai Drilling Engineering Company LimitedRenqiu 062552China

Based on paleogeomorphology, drilling and seismic data, this paper systematically studies the structural and sedimentary evolution, source rock characteristics, reservoir characteristics and formation mechanism, hydrocarbon accumulation model and enrichment law in the Linhe Depression of the Hetao Basin, NW China. The Hetao Basin mainly experienced three stages of evolution, namely, weak extensional fault depression, strong extensional fault depression and strike-slip transformation, giving rise to four positive structural belts(Jilantai, Shabu, Nalinhu and Xinglong), which are favorable areas for oil and gas accumulation. The two main saline lacustrine source rocks, Lower Cretaceous Guyang Formation and Oligocene Linhe Formation, are characterized by high sulfur content, rich algae, early maturity, early expulsion, and wide oil generation window. The large structural transition belt in the intermountain area around the Hetao Basin controls the formation of large-scale braided river delta deposits, which are characterized by high quartz content(50%-76%), long-term shallow burial and weak compaction, low cement content, and good reservoir properties in delta front sandbody. The burial depth of the effective Paleogene reservoirs is predicted to reach 8000 m. Three hydrocarbon accumulation models, nose-uplift near sag, buried hill surrounding sag, fault nose near source rock, are constructed. The law of hydrocarbon accumulation in the Linhe Depression is finally clarified as follows: near-source around the depression is the foundation, high-quality thick reservoir is the premise, good tectonic setting and trap conditions are the key.

关键词： Hetao Basin Linhe Depression Cretaceous Guyang Formation Paleogene Linhe Formation Jilantai Oilfield Bayan Oilfield hydrocarbon enrichment law

A Catalog of ^(13)CO Clumps from the MWISP in l=10°–20°

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第5期24卷 218-234页

作者： Xiaoyu Luo Sheng Zheng Zhibo Jiang Zhiwei chen Yao Huang shuguang Zeng Xiangyun Zeng Rui Zhang chen Long Guangrong Zhou Jinbo Hu Center for Astronomy and Space Sciences China Three Gorges UniversityYichang 443000China College of Electrical Engineering and New Energy China Three Gorges UniversityYichang 443000China College of Science China Three Gorges UniversityYichang 443000China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China

In this study, we present a catalog of molecular clumps extracted from ^(13)CO(J=1-0) emission data of the Milky Way Imaging Scroll Painting(MWISP) project. The data covers the inner Milky Way within the longitude range10°≤l≤20° and the latitude strip of |b|≤ 5°. 25. The workflow for the extraction of clumps, namely Facet-SS-3DClump, consists of two parts: the identification of clump candidates and their verification. First, Facet-SS-3DClump employs FacetClumps to identify clump candidates. Subsequently, high-confidence clumps are obtained by cross-matching with the clumps detected by other algorithms, such as dendrogram. Second, these high-confidence clumps are used as prior knowledge to train a semi-supervised deep clustering approach, SS-3D-Clump, which is applied to verify clump candidates detected by FacetClumps, providing confidence levels for the molecular clumps. Finally, the catalog comprising 18,757 molecular clumps was obtained using Facet-SS-3D-Clump, and the catalog is 90% complete above 37 K km s^(-1). We observe a significant deviation of the mean Galactic latitude for clumps within |b|≤ 2° from the midplane, with b=-0°.110. We found that 82.3% of the dust clumps correspond to ^(13)CO clumps by matching with Herschel infrared dust clumps. In the future, Facet-SS-3D-Clump will be applied to detect ^(13)CO clumps in the entire MWISP data.

关键词： ISM molecules methods data analysis-stars formation

Novel insights into the dehalogenation mechanism and ecotoxicity assessment of 6:2 Cl-PFESA from density functional theory calculations

在线全文

学校读者我要写书评

暂无评论

Emerging Contaminants 2024年第2期10卷 115-122页

作者： Youxin Xu chenxi Zhang Zhe Wang Bing chen Xiaomin Sun shuguang Wang Huifang Tian Institute of Environmental Biotechnology and Functional Materials School of Environmental Science and EngineeringShandong UniversityQingdaoShandong266237China Shandong Engineering Laboratory for Clean Utilization of Chemical Resources Weifang University of Science and TechnologyWeifang262700China Northern Region Persistent Organic Pollution Control(NRPOP)Laboratory Faculty of Engineering and Applied ScienceMemorial University of NewfoundlandSt.John'sNLA1B 3X5Canada Environment Research Institute Shandong UniversityQingdaoShandong266237China Sino-French Research Institute for Ecology and Environment(ISFREE) Shandong UniversityQingdaoShandong266237China

The electroplating industry is the main source of 6:2 chlorinated polyfluorinated ether sulfonate(6:2 Cl-PFESA)pollution,which presents risks to human health and the *** is therefore crucial to develop effective 6:2 Cl-PFESA degradation *** oxidation is a potential treatment method for 6:2 Cl-PFESA due to its outstanding oxidative degradability following the generation of the sulfate radical(SO_(4)^(•−))and hydroxyl radical(•OH).It has proven difficult to acquire a full understanding of the reaction mechanism and formation of intermediate(IM)products through conventional experimental studies because they are costly and ***,a theoretical analysis method based on density functional theory(DFT)calculations was *** DFT results showed that electron transfer for the degradation of 6:2 Cl-PFESA could be initiated by the protonated sulfate radical(HSO_(4)•,ΔG≠SET=9.16 kcal/mol),rather than SO4•−(ΔG≠SET=41.60 kcal/mol).After desulfonation,the reaction underwent stepwise decarboxylation cycles under the action of•OH,leading to the elimination of the CF_(2) units until there was complete mineralization into HCl,HF,and CO_(2).Furthermore,the IMs and the end products of 6:2 Cl-PFESA were evaluated using ECOSAR and TEST *** low bioaccumulation of the short-chain IMs meant that they could be considered safe in terms of ecotoxicity and health *** research determined the theoretical and mechanistic basis of the effects of persulfate in the treatment of water containing 6:2 Cl-PFESA,and its structural analogues.

关键词： Active free radicals Dehalogenation reaction Degradation mechanisms Theoretical prediction Ecotoxicity assessment