检索结果-南通市图书馆

Contribution of subducted Pacific slab to Late Cretaceous mafic magmatism in Qingdao region,china:A petrological record

在线全文

学校读者我要写书评

暂无评论

Contribution of subducted Pacific slab to Late Cretaceous ma...

中国科学院地质与地球物理研究所2008学术年会

作者： jin zhang,Hong-fu zhang,~* ji-feng Ying,Yan-jie Tang and Li-feng niu State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,chinese Academy of sciences,PO Box 9825,beijing 100029,china

The occurrence of the Pishikou mafic dike in the Qingdao region,china provides important constraints on the origin of Late Cretaceous(86-78 Ma) mafic magmatism on the eastern North china *** Pishikou mafic dike is distributed in the Cretaceous Laoshan granitoid body,Qingdao region and contains peridotitic and granulitic xenoliths, xenocrysts,and *** from the Pishikou mafic dike are basanites and have low SiO(12.5 wt%) contents,and high MgO(>8 wt%),total alkalis (NaO + KO>4.8 wt%,NaO/KO>1),TiO(>2.5 wt%),CaO(>9 wt,%) and PO (>1 wt%).In trace element abundances,they are highly enriched in large ion lithophile elements(LILEs) and light rare-earth elements(LREEs)(ΣREE = 3.9-403.ppm,(La/ Yb) = 3.-42) without high field strength element(HFSE) *** rocks have radiogenic Sr and Pb,and less radiogenic Nd isotopic compositions[(Sr/Sr);>0.7059,εNd≈2.7-3.8(Pb/Pb)≈18.0±0.1].The diagnostic elemental ratios,such as Nb/La, Nb/U,and Nb/Th,are compatible with those of mid-oceanic ridge basalts(MORBs) and oceanic island basalts(OIBs).Therefore,the Pishikou mafic dike has a geochemical feature completely different from those of the Early Cretaceous mafic dikes from the Qingdao region,but similar to those of back-arc basalts from the Japan *** geochemical feature suggests that the Pishikou mafic dike was derived from an asthenosphere source, but contaminated by materials from the subducted Pacific *** discovery of this mafic dike thus provides a petrological evidence for the contribution of subducted Pacific slab to the Late Cretaceous magmatism in the Qingdao region of the eastern North china craton.

关键词： asthenospheric source contribution of subducted Pacific slab Late Cretaceous mafic dike Qingdao

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

西藏扎日南木措流域水环境特征及其影响因素

环境科学 2024年第8期45卷 4529-4539页

作者：李志龙张惠芳刘长兵陈旭索娜卓嘎德吉央宗周云桥牛学锐董慧科王小萍兰州大学资源环境学院兰州730000 西藏自治区生态环境监测中心拉萨850000 中国科学院青藏高原研究所青藏高原地球系统与资源环境全国重点实验室北京100101

扎日南木措位于藏西北高寒草原带,为西藏第三大湖,生态环境脆弱,长期以来其流域水环境的研究资料缺乏,为探究其流域地表水环境特征及影响因素,于2021年8月~2022年6月丰、枯、平水期对流域湖泊和入湖河流水环境进行调查,结合数理统计以... 详细信息

扎日南木措位于藏西北高寒草原带,为西藏第三大湖,生态环境脆弱,长期以来其流域水环境的研究资料缺乏,为探究其流域地表水环境特征及影响因素,于2021年8月~2022年6月丰、枯、平水期对流域湖泊和入湖河流水环境进行调查,结合数理统计以及水化学分析、相关分析和主成分分析等方法,对流域水化学特征进行了评价,分析了水质时空差异特征,并对水质影响因素进行了探讨.结果表明:①扎日南木措流域水体呈碱性,湖水离子组成以Na^(+)、SO_(4)^(2-)和Cl^(-)为主,河流以Ca^(2+)、HCO_(3.~-和SO_(4)^(2-)为主.②硫酸盐、砷、氯化物和总磷为主要超标污染物,流域水质存在明显时空差异.时间上,硫酸盐、砷和总磷超标均表现为:丰水期>枯水期>平水期,氯化物的水期差异不明显;空间上,河流水质优于湖泊,湖泊中砷、总磷、TDS、硫酸盐、氯化物、K^(+)和Na^(+)的浓度较河流高1~2个数量级,水质超标现象基本集中于湖区,而湖内水质空间差异小.③流域水化学过程主要受蒸发-浓缩和岩石风化下的自然过程控制,各类元素经地表径流进入湖泊后,在蒸发浓缩作用下不断富集最后产生超标.④水质时间差异主要是丰水期更多的元素淋失和更强烈的蒸发作用导致;而空间差异则主要是流动水体和封闭水体的水动力条件差异导致.

关键词：扎日南木措水化学特征时空差异影响因素主成分分析

Bilateral Ureteral Fibroepithelial Polyps:a Case Report

在线全文

学校读者我要写书评

暂无评论

chinese Medical sciences Journal 2012年第2期27卷 125-126页

作者： ji-rui niu Shi Rong Zhi-gang ji Hua Fan jing-min Zhou Zhen-yu zhang Departments of Urology Peking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China

DRIMARY benign ureteral tumors are rare and they arise from the mesodermal tissue of the ureteral wall. Less than 200 cases have been docu- mented in published reports.1 Bilateral ureteralfibroepithelial polyps are extremely rare and commonly occur in the proximal ureter, causing complete ureteral obstruction. Pyeloplasty is an effective treatment for im- proving renal function. Here we report a case with se- quential bilateral ureteral fibroepithelial polyps causing obstructive hydronephrosis.

关键词： ureteral polyps fibroepithelial polyps

2016—2022年珠三角地区PM_(2.5)中多环芳烃污染特征及健康风险

在线全文

学校读者我要写书评

暂无评论

环境卫生学杂志 2024年第5期14卷 431-437,447页

作者：牛计伟李晓恒季佳佳刘宁张振裴迎新施小明中国疾病预防控制中心北京100050 广东省疾病预防控制中心广州410030 深圳市疾病预防控制中心中国疾病预防控制中心

目的评价多环芳烃暴露的人群健康风险,了解珠三角地区大气PM_(2.5)及其中16种多环芳烃的污染特征和来源。方法2016—2022年在广东省珠三角地区的广州、深圳、佛山及珠海市选10个区设置10个监测点,每月10—16日采集环境空气样品,测定PM_(... 详细信息

目的评价多环芳烃暴露的人群健康风险,了解珠三角地区大气PM_(2.5)及其中16种多环芳烃的污染特征和来源。方法2016—2022年在广东省珠三角地区的广州、深圳、佛山及珠海市选10个区设置10个监测点,每月10—16日采集环境空气样品,测定PM_(2.5)及其中16种多环芳烃含量,分析多环芳烃污染来源,使用BaP毒性当量法评价多环芳烃呼吸暴露途径的人群健康风险。结果2016—2022年珠三角地区PM_(2.5)逐年平均浓度(x±s)分别为(57.45±29.66)、(51.26±3..69)、(43.86±3.0}7)、(40.53.24.70)、(29.26±3..27)、(3..57±24.91)、(3..17±21.06)μg/m^(3.,呈下降趋势(Z=-29.83.P1),PM_(2.5)中多环芳烃平均浓度(x±s)分别为(6.23.6.29)、(5.17±6.95)、(4.00±4.46)、(3.3.±3.93.、(2.52±2.92)、(3.05±4.3.)、(2.65±2.60)ng/m^(3.,浓度虽然降低近60%,但下降趋势无统计学意义,多环芳烃16种成分除萘(NAP)外均呈下降趋势(P2018—2022年PM_(2.5)中多环芳烃致癌效应健康风险CR值M(P_(25),P_(75))为5.3.×10^(-7)(2.54×10^(-7),1.21×10^(-6)),自第69百分位数开始大于1×10^(-6),第99百分位数为9.19×10^(-6),均小于1×10^(-4)。结论珠三角地区四城市大气PM_(2.5)污染整体呈不断改善趋势,四城市中临海的深圳和珠海市优于佛山和广州市,PM_(2.5)与多环芳烃成分含量呈显著正相关,逐月变化趋势基本一致。多环芳烃污染主要是本地源排放所致,存在石化燃料燃烧、机动车尾气排放、石油挥发和有机物质燃烧等多重来源,不同城市多环芳烃污染构成和来源并不完全一致,且高温燃煤对多环芳烃浓度变化有重要影响。珠三角地区大气PM_(2.5)中多环芳烃具有潜在致癌风险,宜引起关注。

关键词：空气污染细颗粒物多环芳烃污染特征健康风险评估

北非地区Ghadames盆地早古生代岩相古地理演化特征

在线全文

学校读者我要写书评

暂无评论

古地理学报 2024年第1期26卷 45-57页

作者：张忠民李依霖郑乃熙曹喆吕雪雁李宗峰孙润明夏昌盛李磊牛博宿宇驰张浩飞冯志强季汉成鲍志东中国石油化工股份有限公司石油勘探开发研究院油气资源与工程全国重点实验室中国石油大学(北京) 中国石油大学(北京)地球科学学院东北石油大学非常规油气研究院

北非地区Ghadames盆地已成为中国海外油气勘探与项目投资的重点盆地之一,对其早古生代沉积体系及岩相古地理特征的准确认识是进一步勘探的基础,也是建立盆地早期构造与沉积演化过程的关键。以Gha dames盆地早古生界为研究目标,利用岩心... 详细信息

北非地区Ghadames盆地已成为中国海外油气勘探与项目投资的重点盆地之一,对其早古生代沉积体系及岩相古地理特征的准确认识是进一步勘探的基础,也是建立盆地早期构造与沉积演化过程的关键。以Gha dames盆地早古生界为研究目标,利用岩心、地震与测井等资料综合分析,开展古地貌恢复,对沉积体系、岩相古地理演化特征进行探讨。结果表明,Ghadames盆地早古生代共发育4种沉积体系:冲积扇、辫状河、辫状河三角洲和浅海。早中寒武世,阿瓦隆地体向波罗的板块漂移,原特提斯洋初步扩张,形成活动大陆边缘,盆地以陆相沉积为主;奥陶纪,盆地经加里东运动初步形成台内隆坳格局,Ghadames盆地西部和北部大范围剥蚀,冰川大规模出现,发育冰碛岩;早中志留世,古特提斯洋持续扩张,海平面不断上升,盆地北部发生大规模海侵,以浅海沉积环境为主,广泛发育放射性页岩与泥岩,是区域内重要的烃源岩与盖层;泥盆纪,海西运动使区域整体抬升,盆内海域范围减小,以陆相沉积为主。在此基础上,建立Ghadames盆地早古生代特提斯洋演化背景下的海陆过渡沉积模式,可为研究区下一步勘探工作提供参考依据。

关键词：沉积体系岩相古地理沉积模式早古生代 Ghadames盆地北非地区

Pulse electrochemical synaptic transistor for supersensitive and ultrafast biosensors

在线全文

学校读者我要写书评

暂无评论

InfoMat 2023年第11期5卷 25-39页

作者： jianlong ji Zhenxing Wang Fan zhang Bin Wang Yan {3. Xiaoning jiang Zeng-ying Qiao Tian-ling Ren Wendong zhang Shengbo Sang Zhengdong Cheng Qijun Sun College of Electronics Information and Optical Engineering Taiyuan University of TechnologyTaiyuanthe People’s Republic of China beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijingthe People’s Republic of China Department of Mechanical and Aerospace Engineering North Carolina State UniversityRaleighNorth CarolinaUSA D Artificial Intelligence Biomedical Research Institute Taiyuanthe People’s Republic of China CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology(NCNST)Beijingthe People’s Republic of China Institute of Microelectronics Tsinghua UniversityBeijingthe People’s Republic of China College of Chemical and Biological Engineering Zhejiang UniversityHangzhouthe People’s Republic of China

High sensitivity and fast response are the figures of merit for benchmarking commercial *** to the advantages of intrinsic signal amplification,bionic ability,and mechanical flexibility,electrochemical transistors(ECTs)have recently gained increasing popularity in constructing various *** the current work,we have proposed a pulse-driven synaptic ECT for supersensitive and ultrafast *** pulsing the presynaptic input(drain bias,VD)and setting the modulation potential(gate bias)near transconductance intersection(VG,i),the synaptic ECT-based pH sensor can achieve a record high sensitivity up to 124 mV pH^(-1)(almost twice the Nernstian limit,59.2 mV pH^(-1))and an ultrafast response time as low as 8.75 ms(7169 times faster than the potentiostatic sensors,62.73.s).The proposed synaptic sensing strategy can effectively eliminate the transconductance fluctuation issue during the calibration process of the pH sensor and significantly reduce power ***,the most sensitive working point at VG,i has been elaborately figured out through a series of detailed mathematical derivations,which is of great significance to provide higher sensitivity with quasi-nonfluctuating amplification *** proposed electrochemical synaptic transistor paired with an optimized operating gate offers a new paradigm for standardizing and commercializing high-performance biosensors.

关键词： fast response pH sensor pulse electrochemical transistor supersensitive synaptic transistor

Development of an innovative one-step nested PCR strategy for virus detection using the LNA technique

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

Science china(Life sciences) 2019年第3期62卷 428-430页

作者： ji Wang Li Zhao Zhihua Sun Guixia Li Peihua niu DANDi Li Lianjun Wang Yi zhang Zhishan Feng Xuejun Ma National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention Hebei Medical university beijing Chaoyang Maternal & Child Health Hospital Children's Hospital of Hebei Province Dongcheng Center for Disease Control and Prevention Beijing

Dear Editor,Polymerase chain reaction(PCR)is a molecular diagnostic technique that has been widely used for diagnosing viral *** PCR(N-PCR)is a variation on the standard PCR technique that involves two amplification steps,yielding greater sensitivity and *** there are two main disadvantages:the protocol is more complex than conventional PCR,and the risk of cross-contamination is relatively ***-step nested PCR(OSN-PCR)enables conventional N-PCR to be performed as a closed reaction in a single tube that contains both outer and inner *** strategy makes OSN-PCR more rapid than N-PCR,lowers the probability of cross-contamination,and requires a smaller amount of reagents.

关键词： Dear Editor PCR strategy LNA technique

Three-dimensional bioprinting collagen/silk fibroin scaffold combined with neural stem cells promotes nerve regeneration after spinal cord injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第5期15卷 959-968页

作者： ji-Peng jiang Xiao-Yin Liu Fei Zhao Xiang Zhu Xiao-Yin Li Xue-Gang niu Zi-Tong Yao Chen Dai Hui-You Xu Ke Ma Xu-Yi Chen Sai {3. Department of Thoracic Surgery General Hospital of People’s Liberation Army (PLA)BeijingChina Tianjin Key Laboratory of Neurotrauma Repair Institute of Traumatic Brain Injury and NeuroscienceCenter for Neurology and Neurosurgery of Chinese People’s Armed Police Force (PAP) Medical CenterTianjinChina Tianjin Medical university TianjinChina Department of Neurology Luoyang First Hospital of Traditional Chinese MedicineLuoyangHenan ProvinceChina Department of Neurosurgery Fourth Central Hospital of TianjinTianjinChina

Many studies have shown that bio-scaffolds have important value for promoting axonal regeneration of injured spinal ***,cell transplantation and bio-scaffold implantation are considered to be effective methods for neural *** study was designed to fabricate a type of three-dimensional collagen/silk fibroin scaffold (3.-CF) with cavities that simulate the anatomy of normal spinal *** scaffold allows cell growth in vitro and in *** observe the effects of combined transplantation of neural stem cells (NSCs) and 3.-CF on the repair of spinal cord *** Sprague-Dawley rats were divided into four groups: sham (only laminectomy was performed),spinal cord injury (transection injury of T10 spinal cord without any transplantation),3.-CF (3. scaffold was transplanted into the local injured cavity),and 3.-CF + NSCs (3. scaffold co-cultured with NSCs was transplanted into the local injured ***,imaging,hematoxylin-eosin staining,argentaffin staining,immunofluorescence staining,and western blot assay were *** from the sham group,neurological scores were significantly higher in the 3.-CF + NSCs group compared with other ***,latency of the 3.-CF + NSCs group was significantly reduced,while the amplitude was significantly increased in motor evoked potential *** results of magnetic resonance imaging and diffusion tensor imaging showed that both spinal cord continuity and the filling of injury cavity were the best in the 3.-CF + NSCs ***,regenerative axons were abundant and glial scarring was reduced in the 3.-CF + NSCs group compared with other *** results confirm that implantation of 3.-CF combined with NSCs can promote the repair of injured spinal *** study was approved by the Institutional Animal Care and Use Committee of People’s Armed Police Force Medical Center in 2017 (approval No.2017-0007.2).

关键词： 3. bioprinting collagen diffusion tensor imaging functional recovery magnetic resonance imaging nerve regeneration neural regeneration neural stem cell scaffold silk fibroin spinal cord injury

Defining honeybee subspecies in an evolutionary context warrants strategized conservation

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2023年第3期44卷 483-493页

作者： Lifei Qiu jiangxing Dong Xingan Li Sajad HParey Ken Tan Michael Orr Aquib Majeed Xue zhang Shiqi Luo Xuguo Zhou Chaodong Zhu Ting ji Qingsheng {3. Shanlin Liu Xin Zhou Department of Entomology College of Plant ProtectionChina Agricultural UniversityBeijing 100193China Key Laboratory for Bee Genetics and Breeding Jilin Provincial Institute of Apicultural SciencesJilinJilin 132108China Department of Zoology School of Biosciences and BiotechnologyBaba Ghulam Shah Badshah UniversityRajouri(Jammu and Kashmir)185234India CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesXishuangbannaYunnan 650000China Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China Department of Entomology University of KentuckyLexingtonKY 40546USA Yangzhou university YangzhouJiangsu 225009China

Despite the urgent need for conservation consideration,strategic action plans for the preservation of the Asian honeybee,Apis cerana Fabricius,1793.remain *** the convergent and divergent adaptations of this widespread insect have led to confusing phenotypical traits and inconsistent infraspecific *** subspecies boundaries pose a significant challenge to honeybee conservation efforts,as it is difficult to effectively prioritize conservation targets without a clear understanding of subspecies ***,we investigated genome variations in 3.2 worker bees representing almost all populations of mainland *** to understand how evolution has shaped its population ***-genome single nucleotide polymorphisms(SNPs)based on nuclear sequences revealed eight putative subspecies,with all seven peripheral subspecies exhibiting mutually exclusive monophyly and distinct genetic divergence from the widespread central *** results demonstrated that most classic morphological traits,including body size,were related to the climatic variables of the local habitats and did not reflect the true evolutionary history of the ***,such morphological traits were not suitable for subspecific ***,wing vein characters showed relative independence to the environment and supported the subspecies boundaries inferred from nuclear *** phylogeny further indicated that the present subspecies structure was a result of multiple waves of population divergence from a common *** on our findings,we propose that criteria for subspecies delineation should be based on evolutionary independence,trait distinction,and geographic *** formally defined and described eight subspecies of mainland *** of the evolutionary history and subspecies boundaries enables a customized conservation strategy for both widespread and endemic honeybee conservation units,guiding colony introduction and

关键词： Apis cerana Integrative taxonomy Species concept Pollinator insect Centrifugal diversification Morphology Genomics