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Photocatalytic degradation of the dye sulforhodamine-b: A comparative study of different light sources

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Journal of Environmental Sciences 2007年第1期19卷 97-102页

作者： FANG Yan-fen HUANG Ying-ping LIU De-fu HUANG Yang GUO Wei DAVID johnson Center for Ecologic and Environmental Science Three Gorges University Yichang 443000 China Department of Chemistry and Environment Sciences Ferrum College VA 24088 USA

The photocatalytic degradation of dye pollutant sulforhodamine-b （SRb） in aqueous titanium dioxide （TiO2） dispersions was examined under three lighting regimes： UV light （330 nm〈λ〈 380 nm）, sunlight, and visible light （λ〉450 nm）, all investigated at pH=2.5. Total organic carbon （TOC） and chemical oxygen demand （CODer） assays show that the degradation rate of SRb is much higher when irradiated with UV and sunlight compared with visible light. The temporal concentration changes of SRb illustrated a first-order reaction and the rate constant, k, is 0.197 min^-1, 0.152 min^-1, 0.027 min^-1, respectively, under the three lighting conditions. The final mineralized products were amine compounds identified by infrared spectrophotometry. When irradiated with visible light, the photocatalytic degradation rate could be improved by lowering the H2O2 concentration and inhibited by increasing the H2O2 concentration, but results contrary to the above were obtained when UV light was used for irradiation.

关键词： TiO2 photocatalytic degradation sulforhodamine-b (SRb)

Intraspecific variation in precipitation responses of a widespread C_(4) grass depends on site water limitation

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Journal of Plant Ecology 2017年第2期10卷 310-321页

作者： Michael J.Aspinwall Philip A.Fay Christine V.Hawkes David b.Lowry Albina Khasanova Jason bonnette briana K.Whitaker Nicholas johnson Thomas E.Juenger Hawkesbury Institute for the Environment Western Sydney UniversityHawkesbury CampusLocked Bag 1797PenrithNew South Wales 2751Australia USDA-ARS Grassland Soil and Water Research Laboratory 808 East Blackland RdTempleTX 76502USA Department of Integrative biology University of Texas at Austin1 University StationAustinTX 78712USA Department of Plant biology Michigan State University612 Wilson RoadEast LansingMI 48824USA

Aims Variation in precipitation strongly influences plant growth,species distributions and genetic *** variation in pheno-typic plasticity,the ability of a genotype to alter its growth,morphol-ogy or physiology in response to the environment,could influence species responses to changing precipitation and climate *** this,the patterns and mechanisms of intraspecific varia-tion in plasticity to variable precipitation,and the degree to which genotype responses to precipitation are influenced by variation in edaphic conditions,remain poorly ***,we determined whether genotypes of a widespread C_(4) grass(Panicum virgatum L.,switchgrass)varied in aboveground productivity in response to changes in precipitation,and if site edaphic conditions modified genotype aboveground productivity responses to *** also determined if genotype productivity responses to precipitation are related to plasticity in underlying growth and phenological *** Nine *** genotypes originating from an aridity gradient were grown under four treatments spanning the 10th to the 90th percentiles of annual precipitation at two sites in central Texas:one site with deep,fine-textured soils and another site with shallow,coarse-textured *** measured volumetric soil water content(VWC),aboveground net primary productivity(ANPP),tiller pro-duction(tiller number),average tiller mass,canopy height,leaf area index(LAi)and flowering time on all plants at both sites and examined genotype responses to changes in *** Findings Across precipitation treatments,VWC was 39%lower and more variable at the site with shallow,coarse-textured soils compared to the site with deep,fine-textured *** averaged across genotypes and precipita-tion treatments was also 103%higher at the site with deep,fine-textured soils relative to the site with shallow,coarse-textured soils,indicating substantial differences in site water limitation.W

关键词： climate change Panicum virgatum phenology phenotypic plasticity precipitation

Correlates of subjectively and objectively measured physical activity in young adolescents

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Journal of Sport and Health Science 2015年第3期4卷 222-227页

作者： Kelly Kavanaugh Justin b. Moore Leisha johnson Hibbett Andrew T. Kaczynski Office of Practice and Community Engagement University of South Carolina Columbia SC 29208 USA Department of Health Promotion Education and Behavior University of South Carolina Columbia SC 29208 USA Coastal Community Action Newport NC 28570 USA

background： Many studies examining individual-level correlates in youth utilize self-report rather than objective measures of physical activity （PA）. This utilization of self-report may result in associations that are not present when examining objectively measured PA. The present study investigates the relationship between hypothesized correlates of PA with objectively and subjectively measured PA. Methods： Participating children （n 232, 101 males, mean age - 12.3 years） provided a minimum of four monitored days of PA （via accelerometer） and completed a survey assessing moderate-to-vigorous physical activity （MVPA）, sport competence, appearance, enjoyment, and self-efficacy. Height and weight were measured and body mass index （bMI） was calculated. Results： Hierarchical regression models controlling for sex, race, and bMI Z-score showed that only sex and bMI Z-score were significant correlates of objective MVPA while only sex was a significant correlate of objective total PA. However, in a separate model examining the relationship with subjective MVPA, enjoyment of PA and self-efficacy for PA were the only significant correlates of self-reported PA. Conclusion： Measuring MVPA via self-report versus accelerometry produces considerably different results in a sample of young adolescents. Future studies should use caution when selecting outcome measures if the intent is to identify modifiable correlates of MVPA in youth.

关键词： Accelerometry Enjoyment Self-efficacy Youth

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The living world

The living world

Laxtons building price book 2005

1000年

作者： George b. johnson

来源：畅想之星图书光盘版（南... 评论

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Vegetation fractional coverage change in a typical oasis region in Tarim River Watershed based on remote sensing

2005年

作者： V.b. johnson & Partners.

来源：畅想之星图书光盘版（南... 评论

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Journal of Arid Land 2013年第1期5卷 89-101页

作者： Fei ZHANG Tashpolat TIYIP JianLi DING Mamat SAWUT Verner Carl johnson NigaraTASHPOLAT DongWei GUI College of Resources and Environment Science Xinjiang University Urumqi 830046 China Key Laboratory of Oasis Ecology Xinjiang University Urumqi 830046 China Department of Physical and Environmental Sciences Colorado Mesa University Grand Junction Colorado 81501 USA Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Cele National Station of Observation & Research for Desert-Grassland Ecosystem in Xinjiang Cele 848300 China

Vegetation fractional coverage （VFC） is an important index to describe and evaluate the ecological system. The vegetation index is widely used to monitor vegetation coverage in the field of remote sensing （RS）. In this paper, the author conducted a case study of the delta oasis of Weigan and Kuqa rivers, which is a typical saline area in the Tarim River Watershed. The current study was based on the TM/ETM＋ images of 1989, 2001, and 2006, and supported by Geographic Information System （GIS） spatial analysis, vegetation index, and dimidiate pixel model. In addition, VbSl （vegetation, bare soil and shadow indices） suitable for TM/ETM＋ irrlages, constructed with FCD （forest canopy density） model principle and put forward by ITTO （International Tropical Timber Organization）, was used, and it was applied to estimate the VFC. The estimation accuracy was later prow^n to be up to 83.52%. Further, the study analyzed and appraised the changes in vegetation patterns and revealed a pattern of spatial change in the vegetation coverage of the study area by producing the map of VFC levels in the delta oasis. Forest, grassland, and farmland were the three main land-use types with high and extremely-high coverage, and they played an important role in maintaining the vegetation. The forest area determined the changes of the coverage area, whereas the other two land types affected the directions of change. Therefore, planting trees, protecting grasslands, reclaiming farmlands, and controlling unused lands should be included in a long-term program because of their importance in keeping regional vegetation coverage. Finally, the dynamic variation of VFC in the study area was evaluated according to the quantity and spatial distribution rendered by plant cover diigital images to deeply analyze the reason behind the variation.

关键词： vegetation fractional coverage (VFC) VbSI (vegetation, bare soil and shadow indices) dimidiate pixel model delta oasis of Weigan and Kuqa rivers

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影响羊羔肉品质的因素

草食家畜 1987年第1期 56-56页

作者： b.johnson 雒友直

一、胴体大小据有关调查,消费者一般喜欢从较大胴体上切下的分割肉,因他们较喜欢较大的连骨肉和肉片;另一方面又喜欢从较小胴体(20千克以下)切下的腿肉。研究人员认为肉品业应将目标放在生产20千克以上的胴体上,同时改进切割技术,保证... 详细信息

一、胴体大小据有关调查,消费者一般喜欢从较大胴体上切下的分割肉,因他们较喜欢较大的连骨肉和肉片;另一方面又喜欢从较小胴体(20千克以下)切下的腿肉。研究人员认为肉品业应将目标放在生产20千克以上的胴体上,同时改进切割技术,保证适当的腿肉大小。

关键词：母羔公羔羔羊绵羊

Development and optimization of thermal contrast amplification lateral flow immunoassays for ultrasensitive HIV p24 protein detection

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Microsystems & Nanoengineering 2020年第1期6卷 683-693页

作者： Li Zhan Timothy Granade Yilin Liu Xierong Wei Ae Youngpairoj Vickie Sullivan Jeff johnson John bischof Department of Mechanical Engineering University of MinnesotaMinneapolisMNUSA Centers for Disease Control and Prevention AtlantaGAUSA Department of biomedical Engineering University of MinnesotaMinneapolisMNUSA

Detection of human immunodeficiency virus(HIV)p24 protein at a single pg/ml concentration in point-of-care(POC)settings is important because it can facilitate acute HIV infection diagnosis with a detection sensitivity approaching that of laboratory-based ***,the limit of detection(LOD)of lateral flow immunoassays(LFAs),the most prominent POC diagnostic platform,falls short of that of laboratory protein detection methods such as enzyme-linked immunosorbent assay(ELISA).Here,we report the development and optimization of a thermal contrast amplification(TCA)LFA that will allow ultrasensitive detection of 8 pg/ml p24 protein spiked into human serum at POC,approaching the LOD of a laboratory *** achieve this aim,we pursued several innovations as follows:(a)defining a new quantitative figure of merit for LFA design based on the specific to nonspecific binding ratio(bR);(b)using different sizes and shapes of gold nanoparticles(GNPs)in the systematic optimization of TCA LFA designs;and(c)exploring new laser wavelengths and power regimes for TCA LFA ***,we optimized the blocking buffer for the membrane and running buffer by quantitatively measuring the bR using a TCA *** TCA reader interprets the thermal signal(i.e.,temperature)of GNPs within the membrane when irradiated by a laser at the plasmon resonance wavelength of the *** process results in higher detection and quantitation of GNPs than in traditional visual detection(i.e.,color intensity).Further,we investigated the effect of laser power(30,100,200 mW),GNP size and shape(30 and 100 nm gold spheres,150 nm gold-silica shells),and laser wavelength(532,800 nm).Applying these innovations to a new TCA LFA design,we demonstrated that 100nm spheres with a 100 mW 532 nm laser provided the best performance(i.e.,LOD=8pg/ml).This LOD is significantly better than that of the current colorimetric LFA and is in the range of the laboratory-based p24 *** summary,this TCA LFA for p24 prote

关键词： optimization approaching flow

DISTRIbUTION OF DISSOLVED AND PARTICULATE TRACE METALS IN ANOXIC SEAWATER, SAANICH INLET, b . C. CANADA

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Chinese Journal of Oceanology and Limnology 1992年第1期10卷 75-83页

作者：詹滨秋 C.S.Wong K.W.johnson Institute of Oceanology Academia Sinica Qingdao 266071 Institute of Ocean Sciences Canada

This paper discusses the spatial and seasonal distribution character of dissolved and paniculate trace metals in the anoxic seawater of Saanich Inlet, b.C., Canada. The study showed that concentration of dissolved and paniculate trace metals in anoxic seawater is closely related to (1) the concentration of H2S and the depth of the O2-H2S interface, (2) the exchange of seawater in Saanich Inlet with outside seawater, (3) biotic action, and (4) the flushing event. The study was based in part on the ratio between trace metals and nutrients. There was a steep change in the concentration of dissolved trace metals at the O2-H2S interface. The concentration of dissolved trace metals in the H2S-controlled zone was dependent on the H2S there. The suspended matter in Saanich Inlet comes from the Hero Strait seawater, phytoplankton production and resuspension of flushed-up sediments. The concentration of particulate trace metals was rather low in Saanich Inlet and tended to increase with depth. The total

关键词： distribution trace metal seawater