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Modern systematics and environmental significance of stable isotopic variations in Wanxiang Cave, Wudu,Gansu, China

Chinese Science Bulletin 2004年第15期49卷 1649-1652页

作者： kathleenr.johnson LvnnInaram ZHANGXinli VVANGSumin PANGFushun LONGLude DepartmentofEarthandPlanetarySciences UniversityofCaliforniaBerkeleyCAUSA TheScientificInformationCenterforResourcesandEnvironment ChineseAcademyofSciencesLanzhou730000China NanjingInstituteofGeographyandLimnology ChineseAcademyofSciencesNanjing210008China WuduAdministrationUnitofWanxiangCave Wudu746000China

This paper presents the stable isotopic compo- sitions from the cave dripwater and actively forming soda straw stalactites collected from Wanxiang Cave, Wudu, Gansu, located on the Qinghai-Tibetan Plateau and Loess Plateau transition zone, China. The δ Odw and δ Ddw of 18 dripwater samples in the cave plot directly on the local MWL, constructed by using GNIP data from 3 sites surrounding the cave regions (Lanzhou, Xi’an, and Chengdu), the nearest site to the cave, suggesting that there is a close relationship be- tween the δ 18Odw of the cave water and the δ 18O of the pre- cipitations. Using the measured δ Odw and δ Omc values 18 18 from the mid-farthest parts from the cave entrance and the carbonate paleotemperature equation, the calculated tem- peratures range from 8.9 to 12.4℃, with the mean value of 10.7℃ and the temperature calculated at 8 locations in the farthest part of the cave is in the range of 10.1—12.4℃, with the mean value of 11.5℃, being consistent with the survey value(10.99℃)in the cave, slightly lower than the mean an- nual temperature (14.4℃) in Wudu. This suggests that mod- ern speleothems are forming under isotopic equilibrium and their isotopic composition accurately reflects the mean an- nual temperature at the surface, indicating that the isotopic composition of the modern speleothems records local tem- perature change with credibility.

关键词：青藏高原黄土高原中国现代分类学稳定同位素变化氢同位素氧同位素岩洞水滴气候变化洞穴堆积物

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Biodiversity and interactions of acidophiles:Key to understanding and optimizing microbial processing of ores and concentrates

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中国有色金属学会会刊：英文版 2008年第6期18卷 1367-1373页

作者： D.B.johnson School of Biological Sciences Bangor University

采矿公司为从低档矿石恢复贱、宝贵的金属，并且为重新调停变得逐渐地知道 microbiological 途径的潜力从操作和放弃的矿地点排干的酸的、充满金属的废水。生物系统出现很多环境并且(有时) 超越常规途径的节俭的优点尽管他们的申请是，... 详细信息

采矿公司为从低档矿石恢复贱、宝贵的金属，并且为重新调停变得逐渐地知道 microbiological 途径的潜力从操作和放弃的矿地点排干的酸的、充满金属的废水。生物系统出现很多环境并且(有时) 超越常规途径的节俭的优点尽管他们的申请是，例如热冶学，别处于每种状况拨出。矿物质用微生物处理为提取黄金，铜，铀和钴被利用了，并且当前的开发正在指向另外的贱金属。最近，我们 biomining 环境，并且微生物怎么与对方一起交往的微生物学的差异的知识和理解有大增加。从模仿了搅动的坦克和堆生物反应器系统的实验室实验的结果证明了微生物引起的协会比氧化矿物质的 acidophiles 的纯文化更柔韧，并且也趋于在 bioleaching 和氧化简历的矿石更有效并且专注。纸论述了性质的简明评论和涉及硫化物矿物质的氧化的微生物引起的协会的相互作用，并且这些怎么可能被改编在 biomining 操作遇见未来挑战。

关键词：嗜酸细胞生物采矿生物多样性微生物加工

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Experimental Modelling of Transverse Oscillations in Aquaculture Netting Parallel to the Flow – Sounds Baffling

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China Ocean Engineering 2015年第3期29卷 391-400页

作者： Andrew johnson Cheslav BALASH National Centre for Maritime Engineering and Hydrodynamics Australian Maritime CollegeUniversity of Tasmania Launceston

Numerous studies have been undertaken to improve the viability, durability and suitability of materials and methods used for aquaculture enclosures. While many of the previous studies considered macro-deformation of nets, there is a paucity of information on netting micro-deformation. When aquaculture pens are towed, industry operators have observed the motion described as ＂baffling＂ – the transverse oscillation of the net planes parallel and near parallel to the flow. The difficulty to observe and assess baffling motion in a controlled experimental environment is to sufficiently reproduce netting boundary conditions and the flow environment experienced at sea. The focus of the present study was to develop and assess experimental methods for visualisation and quantification of these transverse oscillations. Four netrig configurations with varied boundary conditions and model-netting properties were tested in a flume tank. While the Reynolds number was not equivalent to full-scale, usage of the pliable and fine mesh model netting that enabled baffling to develop at low flow velocities was deemed to be of a larger relevance to this initial study. Baffling was observed in the testing frame that constrained the net sheet on the leading edge, similarly to a flag attachment onto a pole. Baffling motion increased the hydrodynamic drag of the net by 35%–58% when compared to the previously developed formula for taut net sheets aligned parallel to the flow. Furthermore, it was found that the drag due to baffling decreased with the increasing velocity over the studied Reynolds numbers（below 200）; and the drag coefficient was non-linear for Reynolds numbers below 120. It is hypothesised that baffling motion is initially propagated by vortex shedding of the netting twine which causes the netting to oscillate; there after the restoring force causes unstable pressure differences on each side of the netting which excites the amplitude of the netting oscillations.

关键词： aquaculture pen baffling model net testing netting drag netting micro-deformation

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Speciation:genomic sequence data and the biogeography of speciation

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National Science Review 2022年第12期9卷 13-14页

作者： Norman A.johnson Department of Biology University of Massachusetts–Amherst

Two papers in this issue show how the use of genomic sequence data can illuminate the biogeography of the speciation ***,I provide a backdrop to these studies,with a brief history of the use of markers and the biogeog... 详细信息

关键词： Speciation:genomic sequence data and the biogeography of speciation

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Min-Max Theory for Cell Complexes

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Algebra Colloquium 2020年第3期27卷 447-454页

作者： Lacey johnson Kevin Knudson Department of Mathematics University of FloridaGainesvilleFL 32611USA

In the study of smooth functions on manifolds,min-max theory provides a mechanism for identifying critical values of a *** introduce a discretized version of this theory associated to a discrete Morse function on a(regular)cell *** applications we prove a discrete version of the mountain pass lemma and give an alternate proof of a discrete Lusternik-Schnirelmann theorem.

关键词： discrete Morse theory min-max theory

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Hippo signaling and epithelial cell plasticity in mammalian liver development, homeostasis, injury and disease

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Science China(Life Sciences) 2019年第12期62卷 1609-1616页

作者： Randy L.johnson Department of Cancer Biology University of Texas MD Anderson Cancer Center

A traditional view of cellular differentiation is unidirectional: progenitor cells adopt specific fates in response to environmental cues resulting in deployment of cell-specific gene expression programs and acquisition of unique differentiated cellular properties such as production of structural and functional proteins that define individual cell types. In both development and in tissue repair stem and progenitor cells are thought to both self-renew to maintain the pool of precursors and to expand to give rise to transient amplifying and differentiated cell types. Recently, however, it has become appreciated that differentiated cell types can be reprogrammed to adopt progenitor and stem cell properties. In the case of epithelial cells in the mammalian liver, hepatocytes and biliary epithelial cells there is a significant degree of plasticity between these lineages that has been implicated in mechanisms of tissue repair and in liver pathologies such as cancer. Recent studies have highlighted the role of Hippo signaling, an emerging growth control and tumor suppressor pathway, in regulating epithelial cell plasticity in the mammalian liver and in this review, the role of cellular plasticity and Hippo signaling in regulating normal and abnormal tissue responses in the mammalian liver will be discussed.

关键词： liver homeostasis plasticity regeneration cancer Hippo pathway

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Breather Dynamics of the Sine-Gordon Equation

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Communications in Theoretical Physics 2013年第6期59卷 664-670页

作者： Stephen johnson Anjan Biswas Stephen johnson and Anjan Biswas Department of Mathematical Sciences Delaware State University Department of Mathematics Faculty of Science King Abdulaziz University

This paper studies the adiabatic dynamics of the breather soliton of the sine-Gordon equation. The integrals of motion are found and then used in soliton perturbation theory to derive the differential equation governing the soliton velocity. Time-dependent functions arise and their properties are studied. These functions are found to be bounded and periodic and affect the soliton velocity. The soliton velocity is numerically plotted against time for different combinations of initial velocities and perturbation terms.

关键词： solitons phonons conservation laws perturbations numerics

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Adsorption kinetics of the herbicide safeners,benoxacor and furilazole,to activated carbon and agricultural soils

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Journal of Environmental Sciences 2020年第3期32卷 23-34页

作者： Saraswati Poudel Acharya Jacob johnson Jennifer Weidhaas Civil and Environmental Engineering University of UtahSalt Lake CityUTUSA Center for Science and Mathematics Education University of Utah155 South 1452 EastSalt Lake CityUT 84112USA

Chloroacetamide herbicides,namely acetochlor and metolachlor,are common herbicides used on corn and soybean *** safeners,namely benoxacor and furilazole,are commonly used in formulations containing chloroacetamide *** reports on adsorption of chloroacetamide herbicides are available,yet little information exists regarding adsorption potential of co-applied ***,the adsorption and desorption characteristics of selected herbicide safeners to granular activated carbon(GAC) and in agricultural soils are ***,soil column studies were performed to understand the leaching behaviour of the herbicide Dual II *** sorption experiments of safeners to three agricultural soils and one GAC showed that adsorption was best fitted by the Freundlich *** Freundlich adsorption constant,Kf,for benoxacor and furilazole sorption onto three agricultural soils ranged from0.1 to 0.27 and 0.1 to 0.13(mg/g) x(mg/L)(1/n),*** Kf for benoxacor and furilazole to GAC was 6.4 and 3.4(mg/g) x(mg/L)(1/n),respectively,suggesting more favorable sorption of benoxacor to GAC than furilazole to *** sorption to soils was reversible as almost 40%-90% of both safeners was desorbed from three *** results were validated in four replicated soil column studies,where S-metolachlor was shown to leach similarly to the safener benoxacor,originating from the herbicide *** leaching of S-metolachlor and benoxacor was influenced by soil ***,these results show that safeners will move through the environment to surface waters similarly to the active ingredients in herbicides,but may be removed during drinking water treatment via GAC.

关键词： Herbicide safener Dual Ⅱ magnum Adsorption Granular activated carbon Soil column transport

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Distinct Modes of Winter Arctic Sea Ice Motion and Their Associations with Surface Wind Variability

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Advances in Atmospheric Sciences 2010年第2期27卷 211-229页

作者：武炳义 Mark A. johnson Chinese Academy of Meteorological Sciences Arctic Region Supercomputing Center University of Alaska Fairbanks Institute of Marine Science University of Alaska Fairbanks

Using monthly mean sea ice velocity data obtained from the International Arctic Buoy Programme （IABP） for the period of 1979–1998 and the monthly mean NCEP/NCAR re-analysis dataset （1960–2002）, we investigated the spatiotemporal evolution of the leading sea ice motion mode （based on a complex correlation matrix constructed of normalized sea ice motion velocity） and their association with sea level pressure （SLP） and the predominant modes of surface wind field variability. The results indicate that the leading winter sea ice motion mode’s spatial evolution is characterized by two alternating and distinct sea ice modes, or their linear combination. One mode （M1） shows a nearly closed cyclonic or anti-cyclonic circulation anomaly in the Arctic Basin and its marginal seas, resembling to a large extent the response of sea ice motion to the Arctic Oscillation （AO）, as many previous studies have revealed. The other mode （M2） displays a coherent cyclonic or anti-cyclonic circulation anomaly with its center close to the Laptev Sea, which has not been identified in previous observational studies. In fact, M1 and M2 respectively reflect the responses of sea ice motion to two predominant modes of winter surface wind variability north of 70 ？ N, which well correspond, with slight differences, to the first two modes of EOF analysis of winter monthly mean SLP north of 70 ？ N. These slight differences in SLP anomalies lead to a difference of M2 from the response of sea ice motion to the dipole anomaly. Although the AO significantly influences sea ice motion, it is not crucial for the existence of M1. The new sea ice motion mode （M2） has the largest variance and clearly differs from the response of winter monthly mean sea ice motion to the dipole anomaly in SLP fields, and corresponding SLP anomalies also show differences compared to the dipole anomaly. This study indicates that in the Arctic Basin and its marginal seas, slight differences in SLP anomaly patterns can force distinctl

关键词： distinct mode Arctic sea ice motion Arctic surface wind forcing

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Comparison of a Spectral Bin and Two Multi-Moment Bulk Microphysics Schemes for Supercell Simulation:Investigation into Key Processes Responsible for Hydrometeor Distributions and Precipitation

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Advances in Atmospheric Sciences 2024年第5期41卷 784-800页

作者： Marcus johnson Ming XUE Youngsun JUNG Center for Analysis and Prediction of Storms University of OklahomaNormanOK 73072USA School of Meteorology University of OklahomaNormanOK 73072USA Office of Science and Technology Integration National Weather ServiceSilver SpringMD 20910USA

There are more uncertainties with ice hydrometeor representations and related processes than liquid hydrometeors within microphysics parameterization(MP)schemes because of their complicated geometries and physical *** supercell simulations are produced using the WRF model coupled with“full”Hebrew University spectral bin MP(HU-SBM),and NSSL and Thompson bulk MP(BMP)***-SBM downdrafts are typically weaker than those of the NSSL and Thompson simulations,accompanied by less rain ***-SBM produces more cloud ice(plates),graupel,and hail than the BMPs,yet precipitates less at the *** limiting mass bins(and subsequently,particle size)of rimed ice in HU-SBM and slower rimed ice fall speeds lead to smaller melting-level net rimed ice fluxes than those of the *** from plates in HU-SBM,together with snow–graupel collisions,leads to a greater snow contribution to rain than those of the *** HU-SBM’s fall speeds using the formulations of the BMPs after aggregating the discrete bin values to mass mixing ratios and total number concentrations increases net rain and rimed ice ***,they are smaller in magnitude than bulk rain,NSSL hail,and Thompson graupel net fluxes near the ***,the melting-layer net rimed ice fluxes are reduced when the fall speeds for the NSSL and Thompson simulations are calculated using HU-SBM fall speed formulations after discretizing the bulk particle size distributions(PSDs)into spectral *** results highlight precipitation sensitivity to storm dynamics,fall speed,hydrometeor evolution governed by process rates,and MP PSD design.

关键词： precipitation spectral bin microphysics bulk microphysics parameterization microphysics processes WRF model supercell storm

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