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Response of Microcystis aeruginosa FACHB-905 to different nutrient ratios and changes in phosphorus chemistry

Journal of Oceanology and Limnology 2018年第4期36卷 1040-1052页

作者：彭国涛 steven W.WILHeLM 林思劼王祥荣 College of environmental Science and engineering State Key Laboratory of Pollution Control and Resource Reuse Tongji University Department of environmental Science and engineering Fudan University Department of Microbiology University of Tennessee

Cyanobacterial blooms are a global problem, with their occurrence tightly tied to nutrient loading. We cultured Microcystis aeruginosa FACHB-905 in growth medium with either inorganic(orthophosphate) or organic(β-glycerophosphate or polyphosphate) phosphorus and at different N:P ratios with 50:1, 30:1, 16:1, 4:1 and 1:4, serving as the phosphorus source. Fluorescence parameters were measured to determine the response of cellular responses to nutrient stress. Scanning electron microscopy(SeM) and estimates of antioxidant activity were employed to examine potential mechanisms of physical change. The results demonstrate that inorganic phosphorus was more bioavailable to M. aeruginosa relative to organic phosphorus in culture. The highest cell concentration(2.21×10~6 cells/mL), chlorophyll-a(0.39 pg/cell) and phycocyanin(1.57 pg/cell) quotas and high levels of chlorophyll fluorescence parameters( reTR, e_k, α, φ_(PSⅡ) and F_v/F_m) were obtained when phosphorus was supplied as K_2 HPO_4 at a N:P ratio of 16–30. Organic sources of phosphorus(β-glycerophosphate and polyphosphate) were bioavailable to M. aeruginosa. In addition, too concentrated orthophosphate(N:P=1:4) resulted in the oxidative stress and lipid peroxidation of cell membrane(identified by the antioxidant system activity), and the photosynthetic activity declined consequently. This study has demonstrated the effects of different phosphorus chemistries and N:P ratios on the cyanobacterial growth, photosynthetic activity and cell physiology, which could be an effective tool for predicting cyanobacterial dominance or N-deficiency in natural lakes(due to the superior ability of cyanobacteria for dissolved N and fix atmospheric N in some cases).

关键词：蓝藻植物学湖泊生态系统

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Male competition strategies change when information concerning female receptivity is available

Male competition strategies change when information concerni...

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第七届全国野生动物生态与资源保护学术研讨会

作者： steven e.Brauth Department of Psychology University of Maryland

Males compete for access to resources or females or to influence female mate choice in many animal *** competitive activities are accompanied by high energy expenditure and increased risk of predator *** therefore hyp... 详细信息

关键词： male competitive strategy female choice vocal competition Xenopus laevis

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Metalorganic chemical vapor deposition of InN quantum dots and nanostructures

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Light(Science & Applications) 2021年第8期10卷 1409-1420页

作者： Caroline e.Reilly Stacia Keller Shuji Nakamura steven P.DenBaars Materials University of CaliforniaSanta BarbaraCA 93106USA electrical and Computer engineering University of CaliforniaSanta BarbaraCA 93106USA

Using one material system from the near infrared into the ultraviolet is an attractive goal,and may be achieved with(ln,AI,Ga)***Ⅲ-N material system,famous for enabling blue and white solid-state lighting,has been pushing towards longer wavelengths in more recent *** a bandgap of about 0.7 eV,InN can emit light in the near infrared,potentially overlapping with the part of the electromagnetic spectrum currently dominated byⅢ-As andⅢ-P *** has been the case in these otherⅢ-V material systems,nanostructures such as quantum dots and quantum dashes provide additional benefits towards optoelectronic *** the case of InN,these nanostructures have been in the development stage for some time,with more recent developments allowing for InN quantum dots and dashes to be incorporated into larger device *** review will detail the current state of metalorganic chemical vapor deposition of InN nanostructures,focusing on how precursor choices,crystallographic orientation,and other growth parameters affect the *** optical properties of InN nanostructures will also be assessed,with an eye towards the fabrication of optoelectronic devices such as light-emitting diodes,laser diodes,and photodetectors.

关键词： optoelectronic quantum chemical

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Uncertainty analysis of hydrological modeling in a tropicalarea using different algorithms

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Frontiers of earth Science 2018年第4期12卷 661-671页

作者： Ammar RAFIeI eMAM Martin KAPPAS steven FASSNACHT Nguyen Hoang Khanh LINH Department of Cartography GIS and Remote SensingUniversity of Goettingen37077GoettingenGermany Colorado State University Fort CollinsCO 80523-1476USA Faculty of Land Resources and Agricultural environment (FLRAe) Flue University of Agriculture and Forestry (F1UAF)Hue UniversityHue City 0084Vietnam

Hydrological modeling outputs are subject to uncertainty resulting from different sources of errors (e.g., error in input data, model structure, and model parameters), making quantification of uncertainty in hydrological modeling imperative and meant to improve reliability of modeling results. The uncertainty analysis must solve difficulties in calibration of hydrological models, which further increase in areas with data scarcity. The purpose of this study is to apply four uncertainty analysis algorithms to a semi-distributed hydrological model, quantifying different source of uncertainties (especially parameter uncertainty) and evaluate their performance. In this study, the Soil and Water Assessment Tools (SWAT) eco-hydrological model was implemented for the watershed in the center of Vietnam. The sensitivity of parameters was analyzed, and the model was calibrated. The uncertainty analysis for the hydrological model was conducted based on four algorithms: Generalized Likelihood Uncertainty estimation (GLUe), Sequential Uncertainty Fitting (SUFI), Parameter Solution method (ParaSol) and Particle Swarm Optimization (PSO). The performance of the algorithms was compared using P-factor and Rfactor, coefficient of determination (R2), the Nash Sutcliffe coefficient of efficiency (NSe) and Percent Bias (PBIAS). The results showed the high performance of SUFI and PSO with P-factor>0.83, R-factor 0.91, NSe>0.89, and 0.18ence, we would suggest to use SUFI-2 initially to set the parameter ranges, and further use PSO for final analysis. Indeed, the uncertainty analysis must be accounted when the outcomes of the model use for policy or management decisions.

关键词： SWAT-CUP GLUe SUFI2 ParaSol PSO Vietnam

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The first discovery of eucommia fruit fossil in China

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Chinese Science Bulletin 1999年第16期44卷 1506-1508页

作者： Baoyin Geng steven R. Manchester Anming Lu Chinese Acad Sci Inst Bot Ctr Studies Systemat & Evolut Bot Beijing 100093 Peoples R China Univ Florida Florida Museum Nat Hist Gainesville FL 32611 USA

A fruit of eucommia has been recovered from the eocene of Fushun, Liaoning Province. This represents the only confirmed occurrence of fruits of this genus in the paleobotanical record of China. Although eucommia is endemic to central China today, the genus was more widespread in the Northern Hemisphere during the Tertiary. The fossil speci-

关键词： eucommia fruit fossil eocene first discovery.

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DeSIGNING eFFeCTIVe INSTRUCTION / 4th ed.

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2004年

作者： GARY R. MORRISON steven M. ROSS JeRROLD e. KeMP.

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Meteorology 7th ed.

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丛书名： Brooks/Cole earth sciences and geography series

2003年

作者： Ackerman, steven A

Includes index.

ISBN: (纸本)053437199X

Includes index.

关键词： Meteorology.

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Targeting duplex DNA with the reversible reactivity of quinone methides

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Signal Transduction and Targeted Therapy 2016年第1期1卷 101-105页

作者： Chengyun Huang Yang Liu steven e Rokita Department of Chemistry and Biochemistry University of MarylandCollege ParkMDUSA Chengdu Integrated Testing Center of Rocks and Ores ChengduSichuanChina National Institutes for Food and Drug Control BeijingChina Department of Chemistry Johns Hopkins UniversityBaltimoreMDUSA.

DNA alkylation and crosslinking remains a common and effective strategy for anticancer chemotherapy despite its infamous lack of *** a reactive group to a sequence-directing component has the potential to enhance target selectivity but may suffer from premature degradation or the need for an external signal for ***,quinone methide conjugates may be employed if they form covalent but reversible adducts with their sequence directing *** resulting self-adducts transfer their quinone methide to a chosen target without an external signal and avoid off-target reactions by alternative intramolecular *** transfer is shown to depend on the nature of the quinone methide and the sequencedirecting ligand in applications involving alkylation of duplex DNA through a triplex recognition *** required an electron-rich derivative that enhanced the stability of the transient quinone methide intermediate and a polypyrimidine strand of DNA to associate with its cognate polypurine/polypyrimidine *** quinone methide conjugates with peptide nucleic acids were capable of quinone methide transfer from their initial precursor but not from their corresponding *** active peptide nucleic acid derivatives were highly selective for their complementary target.

关键词： reversible alkylation reactivity

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Shoot and root traits in drought tolerant maize(Zea mays L.) hybrids

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Journal of Integrative Agriculture 2018年第5期17卷 1093-1105页

作者： ZHAO Jin XUe Qing-wu Kirk e Jessup HOU Xiao-bo HAO Bao-zhen Thomas H Marek XU Wen-wei steven R evett Susan A O'Shaughnessy David K Brauer Texas A&M AgriLife Research and extension Center at Amarillo TX 79106 USA Department of Soil Water and Environmental Sciences University of Arizona AZ 85721 USA School of Science and Technology Xinxiang University Xinxiang 453003 P.R.China Texas A&M AgriLife Research and extension Center at Lubbock TX 79403 USA USDA-ARS Conservation and Production Research Laboratory TX 79012 USA

This study aimed to investigate the differences in shoot and root traits, and water use and water use efficiency（WUe） in drought tolerant（DT） maize（Zea mays L.） hybrids under full and deficit irrigated conditions. A two-year greenhouse study was conducted with four hybrids（one conventional hybrid, 33D53AM, two commercial DT hybrids, P1151 AM, N75H, and an experimental hybrid, exp HB） grown under two water regimes（I（100） and I（50）, referring to 100 and 50% of evapotranspiration requirements）. Under water stress, the hybids P1151 AM, N75, and exp HB showed more drought tolerance and had either greater shoot dry weight or less dry weight reduction than the conventional hybrid（33 D53 AM）. However, these three hybrids responded to water stress using different mechanisms. Compared with the conventional hybrid, the two commercial DT hybrids（P1151 AM and N75H） had a smaller leaf area, shoot dry weight, and root system per plant. As a result, these hybrids used less water but had a higher WUe compared with the conventional hybrid. In contrast, the experimental hybrid（expHB） produced more shoot biomass by silking stage at both irrigation levels than all other hybrids, but it had relatively lower WUe. The hybrids demonstrated different drought response mechanisms that may require different irrigation management strategies. More investigation and validation are needed under field conditions and in different soil types.

关键词： drought tolerant hybrid rooting characteristics water use water use efficiency

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A CONSeRVATIVe VIeW OF RADIAL KeRATOTOMY

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眼科学报 1991年第3期7卷 130-139页

作者： steven Olkowski Walter J.Stark John D.Gottsch Gerri Goodman Daniel Goodman A.e.Maumenee Ivan esente The Wilmer Ophthalmological Institute The Johns Hopkins University School of MedicineBaltimoreMaryland 21205U.S.A.

It has been known for almost a century that radial keratotomy(RK)will flatten the cornea and reduce *** the introduction of radial keratotomy(RK)in the United States by Bores in 1978,there have been many published studies documenting the effects of this *** *** radial keratotomy today are not only quantitative but also qualitative in *** know this technique can flatten the cornea,but how reliably can the results be predicted?

关键词： RK A CONSeRVATIVe VIeW OF RADIAL KeRATOTOMY

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