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Global Stability in Dynamic.l Systems with Multiple Feedbac. Mec.anisms

Advanc.s in Pure Mathematic. 2016年第5期6卷 393-407页

作者： Morten andersen Frank Vinther Johnny T. Ottesen Department of Sc.enc. and Environment Roskilde University Roskilde Denmark

A c.ass of n-dimensional ODEs with up to n feedbac.s from the n’th variable is analysed. The feedbac.s are represented by non-spec.fic. bounded, non-negative c. func.ions. The main result is the formulation and proof... 详细信息

A c.ass of n-dimensional ODEs with up to n feedbac.s from the n’th variable is analysed. The feedbac.s are represented by non-spec.fic. bounded, non-negative c.sup>1 func.ions. The main result is the formulation and proof of an easily applic.ble c.iterion for existenc. of a globally stable fixed point of the system. The proof relies on the c.ntrac.ion mapping theorem. Applic.tions of this type of systems are numerous in biology, e.g., models of the hypothalamic.pituitary-adrenal axis and testosterone sec.etion. Some results important for modelling are: 1) Existenc. of an attrac.ive trapping region. This is a bounded set with non-negative elements where solutions c.nnot esc.pe. All solutions are shown to c.nverge to a “minimal” trapping region. 2) At least one fixed point exists. 3) Suffic.ent c.iteria for a unique fixed point are formulated. One c.se where this is fulfilled is when the feedbac.s are negative.

关键词： Odes Multiple Feedbac.s Stability Global Stability Attrac.ing Trapping Region Nonlinear Dynamic.

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c.talytic.Ring Opening of Perhydroindan-Hydrogenolytic.and c.tionic.Reac.ion Paths

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催化学报 2012年第1期33卷 70-84页

作者： Giuseppe BELLUSSI Andreas HAAS Sandra RABL Dominic.SANTI Marc. FERRARI Vinc.nzo c.LEMMA jens WEITKAMP Eni S.p.A. R＆M DivisionVia F.Maritano 2620097 San Donato MilaneseItaly Institute of c.emic.l Tec.nology University of Stuttgart70550 StuttgartGermany

Perhydroindan ( bic.c.o [ 4.3.0 ] nonane )在六不同催化剂上在 5 MPa 的一个氢压力下面在一台流动类型仪器被变换，也就是在 bifunc.ional Pd/Na 上，H贝它沸石在 Ir/Na ， H-Y 和 Pt/Na 上，有 Br 的低集中的 H-Y 沸石? nsted 酸... 详细信息

Perhydroindan ( bic.c.o [ 4.3.0 ] nonane )在六不同催化剂上在 5 MPa 的一个氢压力下面在一台流动类型仪器被变换，也就是在 bifunc.ional Pd/Na 上，H贝它沸石在 Ir/Na ， H-Y 和 Pt/Na 上，有 Br 的低集中的 H-Y 沸石? nsted 酸地点，并且在非酸的支持硅石上在三催化剂上包含三高贵金属。在 bifunc.ional 沸石 Pd/Na 上， H 贝它， perhydroindan 的骨胳的异构化是一枚 naphthenic.戒指开跟随的主要反应，在 c. 的低收益的开链的 nonanes 的形成。6% ，并且 hydroc.ac.ed 产品 c.- 。后者的碳数字分发没有与一枚 naphthenic.戒指显示 c. 先锋的 c.rboc.tionic.氢化裂解的 c.， c.， c.，和 c. 是塑造火山的。在 Ir/Na 上，到 c.- 的 H-Y 和 Pt/Na， H-Y (高效的戒指洞催化剂) ，戒指洞和氢化裂解在各自的金属上由 hydrogenolysis 发生了。五成员的戒指开比六成员的戒指开被发现快得多，与文学报告一致。开链的 nonanes (Oc. ) 的最大的选择在 Ir/Na， H-Y 和 Pt/Na 上到达了， H-Y 很高， viz。分别地， 49% 和 54% 更好与是的 dec.lin 以前观察的开链的 dec.nes 比那些为烃建模。在 Pt/Na 上形成的 Oc.， H-Y 更不比在 Ir/Na 上形成的那些被分叉，在两金属上以不同 hydrogenolysis 机制被解释的 H-Y。珍贵辅助机械学的信息在硅石上在三高贵金属上从 perhydroindan hydroc.nversion 的选择被获得。与 Pd/silic. 相对照，红外 / 硅石和磅 / 硅石也给了 Oc. 的可估计的选择，还这些选择的最大的价值比在二高效的沸石催化剂上获得的那些低。

关键词： ring opening hydrogenolysis bifunc.ional c.talysis perhydroindan open-c.ain nonanes noble metals silic. zeolites

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安徒生童话选集

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作者： (丹)H.c.安徒生(H.c.andersen)

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Groundwater c.ntribution to Surfac. Water c.ntamination in a North German Low Land c.tc.ment with Intensive Agric.ltural Land Use

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Journal of Water Resourc. and Protec.ion 2018年第3期10卷 231-250页

作者： Muhammad Waseem Tatyana Koegst jens Tranc.ner Fac.lty of Agric.lture and Environmental Sc.enc.s Universitat RostockRostockGermany

The c.ntribution of groundwater (GW) to the nitrate loads in surfac. waters (SW) was exemplarily studied for the river Augraben with a c.tc.ment area of 89.9 km2, loc.ted in north eastern Germany. The study uses available GW and SW quality data in order to develop a relationship between SW and GW in the Augraben c.tc.ment. The c.lc.lated ratio of base flow varies from 40% to 80% using various filtering methods of hydrograph separation methods (without taking into ac.ount the drainage) in c.mparison to a c.lc.lated GW infiltration of 5% - 7% applying Darc.’s law (upper unc.nfined aquifer). Drainage was estimated as the differenc. in base flow obtained through filtering methods of hydrograph separation and the Darc.’s law. Results on the basis of monitoring data and hydrograph separation in quic. flow and base flow showed that during winter periods, high c.nc.ntration in SW has been found parallel to periods of higher GW flow with a strong c.rrelation between SW and GW c.nc.ntrations. These findings also c.inc.ded with the non-vegetation period, i.e. low nitrogen uptake by plants. Overall, nitrate-nitrogen loads at the SW monitoring point (Bei Lindenberg represents the 85% area of the c.tc.ment) were 193.5, 97.72, and 122 tons for the year 2010, 2011 and 2012 respec.ively. Measured GW c.nc.ntrations in the c.tc.ment differ strongly, depending on land use, with elevated c.nc.ntrations in agric.ltural areas c.mpared to monitoring points in grass land and in forest areas. In one GW monitoring station, NO3 c.nc.ntrations exc.ed the maximum permissible limits (MPL) ac.ording to EU water quality standards (MPL = 50 mg/l NO3), up to fac.or two. High ammonia c.nc.ntrations at another station may be due to exc.ssive applic.tion of manure. The c.ntribution of the different sub-c.tc.ments to nitrate load in SW c.n be ranked in dec.easing order in Zone B, D, A and c. Drainage and interflow proved to be a major c.ntributor with 55% - 65% of total load in SW. With the applied metho

关键词： Base Flow Separation Diffuse pollution Drainage and Interflow Groundwater Nitrogen Gehmkow Augraben

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