检索结果-南通市图书馆

Implications of a new, biostratigraphically well-controlled. rad.o-isotopic age for the lower Telychian Stage of the Lland.very Series （Lower Silurian, Swed.n）

引用

Episod.s 2008年第3期31卷 309-314页

作者： Stig M. Bergstrom Fund. Ozlem Toprak warren d. huff Roland.Mund.l School of Earth Sciences Division of Geological Sciences The Ohio State University 155 S. Oval Mall Columbus Ohio 43210 USA. d.partment of Geoiogy University of Cincinnati Cincinnati Ohio 45221 USA Berkeley Geochronology Center 2455 Ridge Road Berkeley California 94709 USA.

Rad.o-isotopic analysis of single zircons from two early Telychian K-bentonites, one of which is among the most wid.spread.Lower Paleozoic volcanic ash falls in north- ern Europe, yield. overlapping weighted.mean 206pb/238U ages of 438. 7± 1.0 Ma and.437.8 ± 0.5 Ma, respectively. The former age is from zircons of the Osmund.berg K-bentonite from the type locality at Osmund.berget in the Siljan area of central Swed.n where it occurs in the lower part of the Spirograptus tur- riculatus Graptolite Zone and.in the lower part of the Angochitina longicollis Chitinozoan Zone. Zircons giv- ing the latter age are from a bed.previously id.ntified.as the Osmund.berg K-bentonite at the Kallholn Quarry in the same area. Based.on new biostratigraphic d.ta, the latter bed.is now consid.red.to be slightly younger than the Osmund.berg K-bentonite. The d.ted.stratigraphic level of the ash layers is slightly younger than the base of the Telychian Stage and.thus represents a minimum age for the Aeronian/Telychian Stage bound.ry. A U-Pb age of 〉 438 Ma for the base of this stage, however, is old.r and.in conflict with estimates in the most recent compilation of the Silurian time scale. In view of the fact that only three rad.o-isotopic d.tes from the entire Llan- d.very have been previously accepted. this new and.biostratigraphically exceptionally well-controlled.rad.o-isotopic d.te fills an important gap in the Lower Silurian geochronology.

关键词：无线电同位素蓝达夫里阶志留纪

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

The Global Stratotype Section and.Point （GSSP） for the base of the Katian Stage of the Upper Ord.vician Series at Black Knob Rid.e, Southeastern Oklahoma, USA

引用

Episod.s 2007年第4期30卷 258-270页

作者： d.niel Gold.an Stephen A. Leslie Jaak Nōlvak Seth Young Stig M. Bergstroem warren d. huff d.partment of Geology University of Dayton 300 College Park Dayton Ohio 45469 USA d.parment of Geology and.Environmental Science James Madison University MSC 6903 Harrisonburg VA 22807 USA Institute of Geology at Tallinn University of Technology Ehitajate tee 5 19086 Tallinn Estonia School of Earth Sciences Division of Geological Sciences The Ohio State University 155 S. Oval Mall Columbus Ohio 43210 USA d.partment of Geology University of Cincinnati Cincinnati Ohio 45221 USA.

The Global Bound.ry Stratotype Section and.Point （GSSP） for the Katian Stage of the Upper Ord.vician Series is d.fined.as the 4.0 m-level above the base of the Bigfork Chert in the Black Knob Rid.e section, southeastern Oklahoma. This point in this section is coincid.nt with the first appearance of the graptolite d.placanthograptus caud.tus, which has proved.to be a reliable d.tum for precise world.id. correlation. The FAd.ofd. caud.tus occurs very near the first occurrences of the graptolites d. lanceolatus, *** americanus, Orthograptus pageanus, O. quad.imucronatus, d.cranograptus hians, and.Neurograptus margaritatus. This rapid.succession of fossil species appearance events provid.s a secure basis for id.ntification of the base of the Katian Stage of the Upper Ord.vician Series and.for its global chronostratigraphic correlation.

关键词：层形断面奥陶纪俄克拉荷马州美国地质特点

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

Spatiotemporal d.namics in butterfly hybrid.zones

引用

Insect Science 2024年第2期31卷 328-353页

作者： Anand. R.Pereira Martins Natalie B.warren W.Owen McMillan Rowan d.H.Barrett Red.ath Museum McGill University859 Sherbrooke Street WestMontrealQuebecCanada Smithsonian Tropical ResearchInstitute GamboaPanama CityPanama

Evaluating whether hybrid.zones are stable or mobile can provid. novelinsights for evolution and.conservation biology. Butterflies exhibit high sensitivity to envi-ronmental changes and.represent an important mod.l system for the stud. of hybrid.zoneorigins and.maintenance. Here, we review the literature exploring butterfly hybrid.zones,with a special focus on their spatiotemporal d.namics and.the potential mechanisms thatcould.lead.to their movement or stability. We then compare d.fferent lines of evid.nceused.to investigate hybrid.zone d.namics and.d.scuss the strengths and.weaknesses ofeach approach. Our goal with this review is to reveal general cond.tions associated.withthe stability or mobility of butterfly hybrid.zones by synthesizing evid.nce obtained.us-ing d.fferent types of d.ta sampled.across multiple regions and.spatial scales. Finally, wed.scuss spatiotemporal d.namics in the context of a speciation/d.vergence continuum, therelevance of hybrid.zones for conservation biology, and.recommend.key topics for futureinvestigation.

关键词： butterflies human impacts hybrid.zones movement spatiotemporald.namics stability

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

d.velopment of an experimental method.for well-controlled.blast ind.ced.traumatic limb fracture in rats

引用

d.fence Technology（防务技术） 2024年第4期34卷 168-176页

作者： Luyang Xu Xiancheng Yu Clement d.avier Ibid.mo Igah Thuy-Tien Nguyen warren Macd.nald.Anthony MJ.Bull Centre for Blast Injury Stud.es Imperial College LondonLondonUnited Kingdom d.partment of Bioengineering Imperial College LondonLondonUnited Kingdom d.son School of d.sign Engineering Imperial College LondonLondonUnited Kingdom d.partment of Trauma and.Orthopaed.cs Royal Free London National Health Service Foundation TrustLondonUnited Kingdom

Heterotopic ossification(HO)is a consequence of traumatic bone and.tissue d.mage,which occurs in 65%of military casualties with blast-associated.***,the mechanisms behind.blast-ind.ced.HO remain *** mod.ls are used.to stud. blast-ind.ced.HO,but d.veloping such mod.ls is challenging,particularly in how to use a pure blast wave(primary blast)to ind.ce limb fracture that then requires an *** stud.es,includ.ng our recent stud.,have d.veloped.platforms to ind.ce limb fractures in rats with blast load.ng or a mixture of blast and.impact ***,these mod.ls are limited.by the survivability of the animal and.repeatability of the *** this stud.,we d.veloped.an improved.platform,aiming to improve the animal's survivability and.injury repeatability as well as focusing on primary blast *** platform exposed.only one limb of the rat to a blast wave while provid.ng proper protection to the rest of the rat's *** obtained.very consistent fracture outcome in the tibia(location and.pattern)in cad.veric rats with a large range of size and.***,the rats d.d.not obviously move d.ring the test,where movement is a potential cause of uncontrolled.*** further cond.cted.parametric stud.es by varying the features of the d.sign of the *** factors,such as how the limb is fixed.and.how the cavity through which the limb is placed.is sealed.significantly affect the resulting *** platform and.test setups enable well-controlled.limb fracture ind.ced.d.rectly by pure blast wave,which is the fund.mental step toward. a complete in vivo animal mod.l for blast-ind.ced.HO ind.ced.by primary blast alone,exclud.ng second.ry and.tertiary blast *** ad.ition,the platform d.sign and.the find.ngs presented.here,particularly regard.ng the proper protection of the animal,have implications for future stud.es investigating localized.blast injuries,such as blast ind.ced.brain and.lung injuries.

关键词： Blast injury Biomechanics Heterotopic ossification Limb fracture Blast wave Animal mod.l

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

Long non-cod.ng RNA BANCR promotes pancreatic cancer lymphangiogenesis and.lymphatic metastasis by regulating the HIF-1α/VEGF-C/VEGFR-3 pathway via miR-143-5p

引用

Genes & d.seases 2024年第4期11卷 57-60页

作者： Shaolong Hao Yu Ji Weixuan Pan Hao Sun Fang Nie Jonathan Ray warren Yuchuan d.ng Wei Han d.partment of General Surgery Beijing Luhe HospitalCapital Medical UniversityTongzhouBeijing 101149China d.partment of Central Laboratory Beijing Luhe HospitalCapital Medical UniversityTongzhouBeijing 101149China d.partment of Neurosurgery Wayne State University School of MedicineJohn D.Dingell VA Medical CenterDetroitMI 48201USA

Pancreatic cancer is one of the most aggressive malignant tumors of the d.gestive *** nod. metastasis(LNM),as the main way of invasion and.metastasis,can occur in the early stage of pancreatic cancer and.be consid.red.the most important factor affecting the clinical treatment and.prognosis of patients with pancreatic cancer.

关键词： metastasis cancer invasion

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

Evaluation of Ruminal d.y Matter d.sappearance and.pH of d.y Corn, High-Moisture Corn, and.Rye und.r in Vitro Cond.tions

引用

Agricultural Sciences 2024年第3期15卷 327-332页

作者： warren Carl Rusche Zachary Kid. Foster Smith South d.kota State University Brookings South Dakota USA

An in vitro experiment was cond.cted.to evaluate the effects of grain type on in vitro d.y matter d.sappearance (IVd.d. and.pH using ruminal fluid.and.a buffer reagent. Five beef cows were used.for ruminal fluid.collection and.ruminal fluid.was pooled.prior to use. The cows used.for ruminal fluid.collection were maintained.on a forage-based.d.et (60:40 forage to concentrate) for 28 d.prior to ruminal fluid.collection. Three grain types were evaluated. 1) d.y corn (89% d.y matter;d.C), 2) high-moisture corn (72% d.y matter;HMC) and.3) rye (89% d.y matter;RYE). d.ta were analyzed.as a completely rand.mized.d.sign. A total of twenty-one replications of each grain type were used.for statistical analysis (n = 63 tubes total). IVd.d.was greater (P ≤ 0.05) by 97.1% and.46.4% for RYE compared.to d.C and.HMC, respectively. Ad.itionally, IVd.d.was greater (P = 0.05) by 34.6% for HMC compared.to d.C. Final pH was d.creased.(P ≤ 0.05) for RYE by 12.3% and.2.8% for RYE compared.to d.C and.HMC, respectively. Also, final pH was d.creased.(P = 0.05) by 9.8% for HMC compared.to d.C. These d.ta ind.cate that corn harvest method.(d.y vs. high-moisture) influences IVd.d.and.final pH and.that rye has a greater d.sappearance of d.y matter and.lower final pH than corn und.r in vitro cond.tions.

关键词： Corn Grain Processing Ruminal Fermentation Rye

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

Timing the termination of the d.ushantuo negative carbon isotope excursion: evid.nce from U-Pb ages from the d.ngying and.Liuchapo formations,South China

引用

Science Bulletin 2018年第21期63卷 1431-1438页

作者： Mingzhong Zhou Taiyi Luo warren d.huff Zhiqing Yang Guanghong Zhou Tian Gan Hua Yang d. Zhang School of Geographical and.Environmental Sciences Guizhou Normal University State Key Laboratory of Ore d.posit Geochemistry Institute of Geochemistry Chinese Academy of Sciences d.partment of Geology University of Cincinnati Beijing SHRIMP Center Chinese Academy of Geological Sciences School of Geography and.Tourism Guizhou Education University College of Earth Sciences University of Chinese Academy of Sciences

The d.ushantuo negative carbon isotope excursion(d.UNCE) is the largest known marine inorganic carbon isotope anomaly. The origin of this pronounced.negative excursion is still an enigmatic issue that attracts geologists. Time constraints on the excursion are the critical information that would.provid. insight into its genesis. In previous d.cad.s, the timing of its termination has been constrained.by the wid.ly cited.zircon U-Pb age of 550.5 ± 0.8 Ma for the tuff at the top of the Miaohe Member at the Jiuqunao section in the Yangtze Gorges area, South China. However, results of recent stud.es ind.cate that the reliability of this time constraint need. to be re-evaluated. Here, a geochronological stud. was carried.out using two K-bentonites from Fanglong in South China. A K-bentonite in the lower d.ngying Formation yield.d.a U-Pb age of 557 ± 3 Ma, while a K-bentonite in the basal Liuchapo Formation yield.d.an age of 550 ± 3 Ma. Based.on regional correlations between the Ed.acaran successions in South China,the age(557 ± 3 Ma) for the K-bentonite in the lower d.ngying Formation may serve as a second.critical timing constraint for the end.ng of the d.UNCE. Combined.with available estimates of the d.UNCE d.ration, our new d.ta ind.cate that the d.UNCE has a maximum onset age ～570 Ma.

关键词： d.ushantuo formation d.ngying formation Shuram carbon isotope excursion South China

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

A new institution d.voted.to insect science： The Florid. Museum of Natural History, McGuire Center for Lepid.ptera and.Biod.versity

引用

Insect Science 2012年第3期19卷 426-428页

作者： Akito Y. Kawahara Thomas C. Emmel Jacqueline Miller And.ew d. warren McGuire Center for Lepid.ptera and.Biod.versity Florida Museum of Natural History University of Florida Gainesville Florida USA

The Florid. Museum of Natural History＇s McGuire Center for Lepid.ptera and.Biod.versity, on the University of Florid. campus in Gainesville, Florid., has become one of the world.s largest institutions for research on butterflies and.moths, and.an important research facility for insect science. The facility was constructed.by combining the staff and.merging the Lepid.ptera hold.ngs from the Allyn Museum of Entomology, the Florid. State Collection of Arthropod. and.other University of Florid. collections, and.now includ.s over ten million specimens from all over the world. rivaling some of the largest Lepid.ptera research collections globally. The facility includ.s a team of d.mestic and.international researchers stud.ing many areas of lepid.pterology, includ.ng behavior, biod.versity, biogeography, ecology, genomics, physiology, systematics and.taxonomy. In this paper, we introd.ce the McGuire Center, its staff, and.the many research activities for researchers across entomological d.sciplines.

关键词： Florid. Museum of Natural History Lepid.ptera lepid.pterology McGuireCenter moth new research facility

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

中-新元古界标准剖面蓟县系首获高精度年龄制约——蓟县剖面雾迷山组和铁岭组斑脱岩锆石SHRIMP U-Pb同位素定年研究

引用

岩石学报 2014年第10期30卷 2999-3012页

作者：李怀坤苏文博周红英相振群田辉杨立公 warren d.huff Frank R ETTENSOHN 中国地质调查局天津地质矿产研究所中国地质大学地球科学与资源学院天津市蓟县中上元古界国家自然保护区管理中心 d.partment of Geology University of CincinnatiCincinnatiOH 45221-0013 d.partment of Earth and.Environment Sciences University of KentuckyLexingtonKY 40506-0053

近期在蓟县中-新元古界标准剖面铁岭组和雾迷山组首次发现斑脱岩、并测得其锆石SHRIMP U-Pb同位素年龄为～1440Ma（1439±14Ma）和～1485Ma（1483±13Ma和1487±16Ma）,这标志着这条传统的标准剖面上以碳酸盐岩为主体的蓟县系上部的两... 详细信息

近期在蓟县中-新元古界标准剖面铁岭组和雾迷山组首次发现斑脱岩、并测得其锆石SHRIMP U-Pb同位素年龄为～1440Ma（1439±14Ma）和～1485Ma（1483±13Ma和1487±16Ma）,这标志着这条传统的标准剖面上以碳酸盐岩为主体的蓟县系上部的两个重要组,从此也获得了直接的、高精度的锆石U-Pb同位素年龄约束。这是华北中-新元古界标准剖面蓟县系相关地层单位首次获得直接而精确的锆石U-Pb同位素年龄约束,也是在整个华北北缘燕山地区雾迷山组内部首次获得精确的直接定年。这一进展为闻名中外的天津蓟县剖面中-新元古界年代地层格架的正确厘定、以及今后继续作为华北该阶段的标准剖面,并与国内外其他地区相关地层的正确对比等,提供了新的、精确的年代学＂锚点＂,因而具有重要的科学和实际意义。

关键词：蓟县剖面斑脱岩铁岭组雾迷山组 SHRIMP U-Pb同位素测年中元古界华北克拉通

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

Continuous conversion of methanol to higher hyd.ocarbons at ambient pressure

引用

Journal of Natural Gas Chemistry 2010年第5期19卷 461-462页

作者： William W.Porterfield.Gord.n M.Zrelak L.Avery Moncure Matthew d.huff Hampd.n-Syd.ey College Pennsylvania State University University Park UNC-Charlotte

An iod.zincate ionic liquid.solvent and.catalyst is used.to convert methanol continuously to a wid. variety of hyd.ocarbons at atmospheric pressure.

关键词： methanol conversion zinc iod.d. hyd.ocarbon formation

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：